JP7038530B2 - Device condition detectors, power systems and automobiles - Google Patents

Description

The present invention relates to a device state detection device, a power supply system, and an automobile, and in particular, a device state detection device for detecting the state of a power storage device mounted on a vehicle, a power supply system including the device state detection device and the power storage device, and the like. Regarding automobiles equipped with a power supply system.

Conventionally, in a moving body (vehicle) such as an automobile, as seen in a normal gasoline vehicle, for example, the electric power supplied from the alternator during traveling except during braking is charged to a power storage device such as a lead battery to almost charge the power storage device. It was kept fully charged. In recent years, vehicles having an idling stop system (ISS) function (ISS vehicles) have become widespread in order to reduce exhaust gas and improve fuel efficiency.

In ISS vehicles, the engine is stopped when the vehicle is stopped, and the power supply to the discharge load such as the air conditioner and car stereo during that period is covered by the power storage device, and the power is stored when the engine is restarted (idling stop start) after idling stop. The power stored in the device drives the starter (starter motor) to start the engine.

For this reason, in ISS vehicles, the discharge depth (DOD) of the power storage device tends to be larger and the state of charge (SOC) tends to be lower than in ordinary gasoline vehicles and ordinary diesel vehicles. This point also applies to μHEV (gasoline vehicle or diesel vehicle having ISS function, equipped with a power storage device capable of receiving regenerative power supplied from the alternator during braking and discharging to the discharge load), which has been gradually increasing recently. It is the same.

Since the terminal voltage of the power storage device depends on the SOC of the power storage device, if the SOC drops while the engine is stopped, a sufficient voltage for restarting the engine cannot be obtained. Conventionally, in order to keep the power storage device in a state where the engine can be restarted, the SOC and terminal voltage of the power storage device are monitored, and if the power storage device has the power required to start the engine, idling stop is permitted, while the engine is used. When there is no power required for starting, idling stop is prohibited and the alternator is activated as necessary to charge the power storage device. Such a judgment is generally made on the vehicle side (ECU), but the power supply system (device state detection device) detects the state of the power storage device which is the basis of the judgment.

Regarding the device state detecting device for detecting the device state of the in-vehicle power storage device, for example, Patent Documents 1 and 2 describe the relationship between the SOC of the lead battery and the open circuit voltage (OCV) as a linear expression. A technique for calculating SOC using the above is disclosed. Further, for example, Patent Document 3 discloses a technique for estimating SOC by measuring the internal resistance of a lead battery. Further, for example, Patent Documents 4 to 6 disclose techniques for calculating SOC from OCV during charge / discharge suspension and calculating internal resistance and deterioration degree (SOH) from voltage and current at engine start.

Further, in relation to the present invention, for example, Patent Document 7 discloses a parameter estimation device that estimates the parameters of an equivalent circuit model of a power storage device, and Patent Document 8, for example, discloses an equivalent circuit model of a power storage device. The technology of the device state detection device with improved parameter accuracy is disclosed.

Japanese Unexamined Patent Publication No. 4-264371 Japanese Unexamined Patent Publication No. 2009-241633 Japanese Patent No. 368628 Japanese Patent No. 5162971 Japanese Patent No. 3188100 Japanese Patent No. 5163739 Japanese Unexamined Patent Publication No. 2015-206758 Japanese Unexamined Patent Publication No. 2017-3349

By the way, it is generally known that in a power storage device, the amount of electricity that can be discharged differs depending on the magnitude of the discharge current. For example, in the case of a lead battery having a time rate of 12 [V] / 30 [Ah] (5HR), a current of 6 [A] is taken out over 5 hours from the fully charged state until the voltage reaches the discharge end voltage. However, if the discharge current is 10 [A], which is larger, only a shorter time than the proportional calculation value of 3 hours can be taken out, and conversely, if the discharge current is smaller, 3 [A], it is proportional. It can be taken out for a time longer than the calculated value of 10 hours. Therefore, the terminal voltage of the power storage device changes every moment depending on the magnitude of the discharge current.

Since the characteristics of such a power storage device also depend on SOC, SOH, and temperature, even if the terminal voltage of the current power storage device and the expected increase current value of the electrical component are known, the power storage device when the electrical component is used. It is difficult to accurately estimate the terminal voltage of the power storage device only by a simple proportional calculation, and if the terminal voltage of the power storage device becomes lower than expected, there is a possibility that the use of electrical components and the like may be hindered.

In view of the above cases, it is an object of the present invention to provide a device state detection device, a power supply system, and an automobile capable of accurately estimating the terminal voltage of a power storage device.

In order to solve the above problems, the first aspect of the present invention is a device state detection device for detecting the state of a power storage device mounted on a vehicle, which is a current measuring means for measuring a current flowing through the device. The SOC calculation means for calculating the charge state (SOC) of the device, the current measured by at least the current measuring means, which is a model simulating the equivalent circuit of the device, and the SOC calculated by the SOC calculation means are excluded. A model execution means for executing a device model for calculating a terminal voltage estimated value Ve of the device as a raw variable is provided, and the model execution means has an increase / decrease expected current value Ic or an increase / decrease expected power value W of the device. It is characterized in that the terminal voltage estimated value Ve'of the device when given as an exogenous variable of the device model is calculated.

In the first aspect, the device model includes, as endogenous variables, the open circuit voltage Vocv of the device, the voltage drop Vd due to the DC internal resistance of the device, and the voltage drop Vp due to the polarization of the device, and the terminal voltage estimate Ve =. It may be a model simulating the equivalent circuit at the time of discharging of the device for calculating as {Vocv- (Vd + Vp)}. Such an equivalent circuit has a linear DC resistance component, a non-linear DC resistance component having a current dependence, a parallel connection of a resistance component and a capacitance component having a current dependence, and an open circuit voltage Vocv of the device. These may be included and configured by being connected in series. Further, the voltage drop Vd and Vp may be variables having the current measured by the current measuring means as a parameter. Further, the model executing means replaces the current measured by the current measuring means as an exogenous variable with the measured current value I to the measured current value I, and the expected increase / decrease current value Ic or the expected increase / decrease power. The terminal voltage estimated value Ve'when the value (I + Ic) obtained by adding the expected increase / decrease current value Ic calculated from the value W may be calculated.

Further, in the first aspect, in order to calculate the terminal voltage estimated value Ve'with high accuracy, the voltage measuring means for measuring the voltage of the device, the voltage value V measured by the voltage measuring means, and the model executing means. Further provided with a voltage difference calculation means for calculating the voltage difference Dv from the calculated terminal voltage estimated value Ve, the device model further includes the voltage difference Dv calculated by the voltage difference calculation means as an exogenous variable or an endogenous variable. Of the drop voltages Vd and Vp, at least the drop voltage Vd includes a parameter depending on the voltage difference Dv, and the model executing means has the same voltage value V measured by the voltage measuring means and the terminal voltage estimated value Ve. The parameter depending on the voltage difference Dv may be corrected so as to be. Further, a temperature measuring means for measuring the temperature of the device is further provided, and the current flowing through the device measured by the current measuring means and the voltage of the device measured by the voltage measuring means are based on the temperature measured by the temperature measuring means. The temperature may be corrected to the current value and the voltage value at a predetermined reference temperature.

Further, in the first aspect, the SOH calculation means for calculating the deterioration degree (SOH) of the device may be provided, and the SOC calculation means may correct the SOC with the SOH calculated by the SOH calculation means. Alternatively, the SOH calculation means for calculating the degree of deterioration (SOH) of the device and the temperature measuring means for measuring the temperature of the device are further provided, and the device model is the SOH calculated by the SOH calculation means as an exogenous variable and the temperature measurement. It also has the temperature of the device measured by the means, and at least the open circuit voltage Vocv and the drop voltage Vd of the open circuit voltage Vocv and the drop voltage Vd are variables depending on the SOC, the temperature, and the SOH. good.

Furthermore, it is equipped with a determination means for determining whether or not the electrical components mounted on the vehicle can be used, and the determination means is calculated when the rated current value of the electrical components is set to the expected increase / decrease current value Ic or from the rated power value of the electrical components. The availability of electrical components is determined by comparing the terminal voltage estimated value Ve'calculated by the model execution means when the current value is expected to increase or decrease with the preset threshold value. May be good. At this time, the determination means may determine whether or not the vehicle can stop and start idling.

According to the present invention, the model execution means calculates the terminal voltage estimated value V'e of the power storage device when the expected increase / decrease current value Ic or the expected power increase / decrease power value W of the power storage device is given as an exogenous variable of the device model. Therefore, it is possible to obtain the effect that the terminal voltage estimated value V'e of the power storage device when the expected increase / decrease current value Ic or the expected power increase / decrease power value W of the power storage device can be calculated accurately. can.

It is a block circuit diagram of the power supply system of 1st Embodiment to which this invention is applied. It is an equivalent circuit diagram at the time of discharge of the lead battery which constitutes the power supply system of 1st Embodiment. It is explanatory drawing of the battery model which simulated the equivalent circuit at the time of discharge of the lead battery which constitutes the power source system of 1st Embodiment. It is explanatory drawing which shows typically the relationship between the current flowing through the capacitor which constitutes a polarization part, and the capacitance. It is a functional block diagram of the control part which constitutes the power supply system of 1st Embodiment. It is a flowchart of the electrical component useability determination processing routine executed by the CPU of the MPU of the control unit constituting the power supply system of 1st Embodiment. It is explanatory drawing of the battery model which simulated the equivalent circuit at the time of discharge of the lead battery which constitutes the power source system of 2nd Embodiment to which this invention is applied. It is a functional block diagram of the control part which constitutes the power supply system of 2nd Embodiment. It is a flowchart of the electrical component availability determination processing routine executed by the CPU of the MPU of the control unit constituting the power supply system of the second embodiment. It is a functional block diagram of the control part which constitutes the power-source system of 3rd Embodiment to which this invention is applied. It is a flowchart of the electrical component availability determination processing routine executed by the CPU of the MPU of the control unit constituting the power supply system of the third embodiment. It is explanatory drawing of the modification of the battery model which simulated the equivalent circuit at the time of discharge of the lead battery which constitutes the power source system of 2nd Embodiment.

1. 1. First Embodiment Hereinafter, a first embodiment in which the present invention is applied to a 14V system power supply system that can be mounted on an ISS vehicle will be described with reference to the drawings.

1-1. Configuration As shown in FIG. 1, the power supply system 10 of the present embodiment includes a lead battery 1 and a battery state detecting device 8. In the power supply system 10, the battery state detecting device 8 is arranged on the battery lid of the lead battery 1 and integrated with the lead battery 1, and is mounted in, for example, the engine room of an ISS vehicle. Not limited.

1-1-1. Lead battery 1
The lead-acid battery 1 has a monoblock battery in which six cell chambers are defined by a partition wall that partitions the inside. A temperature sensor 6 such as a thermistor that detects the temperature of the lead battery 1 is fixed to the side surface of the monoblock battery.

Each cell chamber of the lead battery 1 contains a set of electrode plates (electrode groups) in which a plurality of positive electrode plates and negative electrode plates are laminated via a separator, and dilute sulfuric acid, which is an aqueous electrolyte, is injected. Has been done. Lead dioxide can be used as the positive electrode active material of the lead battery 1, and spongy lead can be used as the negative electrode active material.

Each cell chamber is sealed with a lid that integrally covers the opening of the monoblock battery chamber, and the electrode plates housed in each cell chamber are connected in series by a conductive connecting member. A positive electrode external terminal and a negative electrode external terminal, which are output terminals, are erected on the monoblock battery case. The nominal voltage of the lead battery 1 of the present embodiment is 12 [V] (nominal voltage of each cell: 2 [V]).

In the state where the lead battery 1 is mounted on the ISS vehicle, the positive electrode external terminal is connected to the central terminal of the ignition switch (IGN) of the ISS vehicle, and the negative electrode external terminal is connected to the GND (same potential as the chassis) of the ISS vehicle. Will be done.

1-1-2. Battery status detector 8
The battery state detection device 8 includes a current detection circuit 2 that detects the current flowing through the lead battery 1, a voltage detection circuit 3 that detects the terminal voltage (total voltage) of the lead battery 1, and a temperature detection circuit that detects the temperature of the lead battery 1. It has 4 and a control unit 7. The operating power of the battery state detecting device 8 is supplied from the lead battery 1.

(1) Current detection circuit 2
The current detection circuit 2 is connected to a current sensor 5 such as a Hall element or a shunt resistor, and has a differential amplifier circuit. The output side of the current detection circuit 2 is connected to the input side of an A / D converter (not shown) provided in the control unit 7 via an input port (not shown) of the control unit 7.

(2) Voltage detection circuit 3
The voltage detection circuit 3 is configured to have a differential amplifier circuit. The input side of the voltage detection circuit 3 is connected to the positive electrode external terminal and the negative electrode external terminal of the lead battery 1, respectively, and the output side is the same as the current detection circuit 2 via an input port (not shown) of the control unit 7. It is connected to the input side of an A / D converter (not shown) provided in the control unit 7.

(3) Temperature detection circuit 4
The temperature detection circuit 4 is connected to the temperature sensor 6 described above, and has a differential amplifier circuit. Similar to the current detection circuit 2, the output side of the temperature detection circuit 4 is also connected to the input side of an A / D converter (not shown) provided in the control unit 7 via an input port (not shown) of the control unit 7. ing.

(4) Control unit 7
The control unit 7 includes the above-mentioned input port and A / D converter (three), a microprocessing unit (hereinafter referred to as MPU), non-volatile memory such as EEPROM and flash memory, and a control unit of an ISS vehicle (hereinafter referred to as ECU). It is configured to have a communication IC for communicating with.).

As will be described later, the MPU functions as a CPU that detects the battery state of the lead-acid battery 1 and calculates an estimated terminal voltage when the lead-acid battery 1 is discharged, a ROM that stores a basic control program and program data, and a work area of the CPU. It also consists of a RAM that temporarily stores various data and an internal bus that connects them.

The internal bus is connected to the external bus. The output side of the above-mentioned A / D converter, the non-volatile memory, and the communication IC are connected to the external bus. The communication IC is connected to the communication line 9 via an I / O (not shown). The communication line 9 is under CAN (Controller Area Network) management by the ECU. CAN is standardized by ISO11898, ISO11519, etc., and is composed of two wires. Even if one of the wires is broken, the other can communicate with the ECU and the control unit 7.

1-2. Features In a word, the features of the power supply system 10 (battery state detection device 8) of the present embodiment are that the lead-acid battery 1 is given the expected increase current value or increase / decrease expected power value of the lead battery 1 using the battery model. The point is to calculate the terminal voltage estimate of, but the details are as follows.

1-2-1. Equivalent circuit (1) Structure of the equivalent circuit FIG. 2 shows an example of the equivalent circuit at the time of discharging the lead battery 1 shown in FIG. Generally, the equivalent circuit of a power storage device is composed of a pure voltage element and other internal impedance elements. Strictly speaking, there is also an inductor element, but it is negligible. The equivalent circuit 11 includes a linear DC resistance component, a non-linear DC resistance component having a current dependence, a parallel connection of a resistance component having a current dependence and a capacitance component, and an open circuit voltage of the lead battery 1. , These are connected in series.

Specifically, in the equivalent circuit 11, the open circuit voltage Vocv of the lead battery 1 is shown as a pure voltage element, and the DC internal resistance portion 12 and the polarization portion 13 are shown as internal impedance elements. The DC internal resistance unit 12 is composed of a resistance Rd1 representing a linear DC resistance component and a resistance Rd2 representing a nonlinear DC resistance component. The linear DC resistance component may be the resistance of the electrode, and the nonlinear DC resistance component may be the liquid resistance. On the other hand, the polarization portion 13 is composed of a parallel circuit of the resistance Rp and the capacitor Cp. The resistance Rp simulates the polarization resistance component of the lead battery 1, and the capacitor Cp simulates the polarization capacitance component.

(2) Terminal voltage of the equivalent circuit The open circuit voltage of the lead battery 1 at time t is Vocv (t), and the DC of the lead battery 1 when the (discharge) current I (t) is flowing through the equivalent circuit 11 at time t. Assuming that the voltage drop due to the internal resistance is Vd (t) and the voltage drop due to the polarization of the lead battery 1 is Vp (t), the terminal voltage V (t) of the lead battery 1 at time t can be expressed by the equation (1). ..

As shown in the equation (2), the voltage drop Vd (t) due to the DC internal resistance is the sum of the voltage drop Vd1 (t) due to the resistance Rd1 at time t and the voltage drop Vd2 (t) due to the resistance Rd2 at time t. Can be expressed as.

Time t is an integer of 0 or more and represents the elapsed time from time 0. Any time can be set for time 0, but in this embodiment, since the reference SOC (SOC (0)) of the lead battery 1 is calculated when the charging / discharging of the lead battery 1 is suspended, this reference SOC is calculated. The time when the measurement is performed is set to time 0.

The polarization portion 12 shown in FIG. 2 is a one-stage parallel circuit composed of a resistor Rp and a capacitor Cp, but may be a multi-stage parallel circuit as in Patent Document 8 mentioned in the background technology column. In the present embodiment, the equivalent circuit 11 is shown to have as simple a structure as possible so that the battery model described below will be briefly described and the present invention will be easy to understand.

1-2-2. Battery model (1) Structure of battery model (1-1) Endogenous variable Ve (t)
FIG. 3 shows an example of a battery model simulating the equivalent circuit 11 shown in FIG. Generally, a model has an extrinsic variable for assigning a value from the outside that is not determined in the model, and an endogenous variable whose value is determined in the model, and is between exogenous variables, exogenous variables, and endogenous. Variables and endogenous variables are connected by arrows indicating a causal relationship. In FIG. 3, the endogenous variables are shown by nodes, and the exogenous variables are shown by boxes with rounded corners.

The battery model 15 shown in FIG. 3 corresponds to (simulates) the open circuit voltage Vocv (t) of the lead battery 1 shown in FIG. 2, and has an endogenous variable Vocv (t) and a voltage drop due to the DC internal resistance of the lead battery 1. The endogenous variable Vd (t) corresponds to Vd (t), the endogenous variable Vp (t) corresponds to the voltage drop voltage Vp (t) due to the polarization of the lead battery 1, and the terminal voltage V (t) of the lead battery 1. It has an endogenous variable Ve (t) corresponding to. The endogenous variable Ve (t) represents the estimated end voltage of the lead battery 1 at time t. Therefore, in the battery model 15, the endogenous variable Ve (t) can be calculated by the equation (3) in the same manner as the equation (1) described above.

(1-2) Endogenous variable Vocv (t)
The endogenous variable Vocv (t) [open circuit voltage of lead-acid battery 1 at time t] is based on the exogenous variable SOC (t) [charge state of lead-acid battery 1 at time t], and the patents mentioned in the background technology column. As disclosed in Documents 1 and 2, the relationship between the state of charge (SOC) and the open circuit voltage can be calculated by referring to a predetermined table or mathematical formula.

The exogenous variable SOC (t) can be calculated, for example, by the equation (4). In the formula (4), s is the full charge capacity of the lead battery 1, ∫I (t-1) dt is the integrated value of the current flowing through the lead battery 1 from time 0 to time (t-1), and SOC. (0) represents the reference SOC measured at the time of charge / discharge suspension of the lead battery 1 as described later.

(1-3) Endogenous variable Vd (t)
The endogenous variable Vd (t) [voltage dropped by the DC internal resistance of the lead battery 1 when the current I (t) is flowing at time t] is as described above (see equation (2)) at time t. It is the sum of the voltage drop Vd1 (t) due to the resistance Rd1 and the voltage drop Vd2 (t) due to the resistance Rd2 at time t.

The voltage drop Vd1 (t) due to the resistance Rd1 at time t can be calculated by the equation (5). In FIG. 3 and equation (5), the endogenous variable R ₀ is the resistance value of the resistance Rd 1, and the exogenous variable I (t) is the current flowing through the lead battery 1 at time t. As shown in FIG. 3, the exogenous variable I (t) [current flowing through the lead battery 1 at time t] is a value after being corrected to a reference temperature value (for example, a room temperature value) by the exogenous variable T (t). Is. The exogenous variable T (t) represents the temperature of the lead battery 1 at time t. The endogenous variable R ₀ can be obtained by referring to a table or mathematical formula in which the relationship between the exogenous variable SOC (t), the exogenous variable SOH, and the exogenous variable T (t) and the resistance value is predetermined. ..

The resistance Rd2 is calculated using a value obtained from the Butler-Volmer equation with the value of the exogenous variable I (t) [current flowing through the lead battery 1 at time t] as a variable. Briefly, as shown in equations (6) to (9), the resistance value R (I) of the resistor Rd2 is calculated using the coefficient V ₀ , the coefficient I ₀ , and the coefficient α. For these coefficients, refer to the exogenous variable SOC (t) [charge state of the lead battery 1 at time t], the exogenous variable SOH and the exogenous variable T (t), and the tables and formulas provided for each of these coefficients. Is set. In FIG. 3, the coefficients V ₀ , I ₀ , α and the constant y described later, which are set in this way, are represented as the endogenous variables V ₀ , I ₀ , α, and y, respectively. The coefficient V ₀ is used to align the dimensions of the resistance value R (I) of the resistance Rd2 and the current I (t), and the coefficient I ₀ is used to standardize the current I (t). α is used to identify the Butler-Volmer equation.

F shown in equation (6) is expressed as a solution of equation (7), that is, a solution of Butler-Volmer equation, where x is its argument (I (t) / I ₀ ). Here, the Butler-Volmer equation can be solved by finding x that satisfies the equation (8) given the constant y and the coefficient α. The constant y has the same relationship as the above-mentioned coefficient, the exogenous variable SOC (t) [charge state of the lead battery 1 at time t], the exogenous variable SOH, and the exogenous variable T (t) and the constant y. It is set by referring to the table or formula that represents it.

x can be obtained by Newton's method. That is, in the equation (9), the value of x at which the value of f (x) becomes 0 (actually, a sufficiently small value, for example, f (x) ≦ ^10-6 ) is obtained by Newton's method. The x of the formula (8) and the formula (9) is different from the x of the formula (7), and the x of the formula (7) is set to y in the formula (8) and the formula (9), and the x of the formula (7) is set. F is x in the equations (8) and (9).

The voltage drop Vd2 (t) due to the resistance Rd2 at time t can be calculated by the equation (10). Therefore, the endogenous variable Vd (t) [the voltage drop due to the DC internal resistance of the lead battery 1 when the current I (t) is flowing at time t] is expressed by the above equation (2) and the equation (5). It is obtained by the equation (11) obtained by substituting the calculated voltage drop Vd1 (t) due to the resistance Rd1 and the voltage drop Vd2 (t) due to the resistance Rd2 calculated by the equation (10).

(1-4) Endogenous variable Vp (t)
As shown in FIG. 2, at least one of the resistance value of the resistor Rp and the capacitance value of the capacitor Cp constituting the polarization portion 13 can be set according to the current I (t) flowing through the equivalent circuit 11.

As shown in FIG. 2, when the current flowing through the resistor Rp is the current I ₁ (t) and the current flowing through the capacitor Cp is the current I ₂ (t), (I (t) = I ₁ (t) + I ₂ ( t)), the resistance value of the resistor Rp may be set according to, for example, the value of the current I ₁ (t). In this case, the resistance value of the resistance Rp is represented by a function that takes the value of the current I ₁ (t) as an argument. Further, the resistance value of the resistance Rp may be set according to the total value of the current I ₁ (t) and the current I ₂ (t), that is, the value of the current I (t). In this case, the resistance value of the resistance Rp is represented by a function that takes the value of the current I (t) as an argument.

On the other hand, the capacitance value of the capacitor Cp may be set according to the value of the current I ₂ (t). In this case, the capacitance value of the capacitor Cp is represented by a function that takes the value of the current I ₂ (t) as an argument. Further, the capacitance value of the capacitor Cp may be set according to the value of the current I (t). In this case, the capacitance value of the capacitor Cp is represented by a function that takes the value of the current I (t) as an argument.

Only the resistance value of the resistor Rp may be set according to the current as described above, or only the capacitance value of the capacitor Cp may be set as described above. When only the resistance value of the resistance Rp is set according to the current, the capacitance value of the capacitor Cp can be a predetermined value. When only the capacitance value of the capacitor Cp is set according to the current, the resistance value of the resistor Rp can be a predetermined value. Further, both the resistance value of the resistor Rp and the capacitance value of the capacitor Cp may be set according to the current as described above. Alternatively, both may be set so that the product of the resistance value of the resistance Rp and the capacitance value of the capacitor Cp becomes a predetermined time constant τ.

For example, when setting the resistance value of the resistance Rp, the resistance value can be set by using the value obtained from the Butler-Volmer equation with the value of the current I (t) as a variable. Specifically, as shown in the equation (12), the resistance value of the resistance Rp can be set by using the coefficients V ₀ , I ₀ , and α described above.

The right side of the equation (12) is the same as the right side of the above equation (6). Therefore, the resistance value of the resistance Rp can be calculated by obtaining F (I (t) / I ₀ ) in the equation by solving the Butler-Volmer equation as described above.

When setting the capacitance value of the capacitor Cp, for example, a spline function, a piecewise linear function, and a linear but positive function with respect to the value of the current I (t) with the value of the current I (t) as a variable. , And functions such as the Gaussian function can be used to set the capacitance value. FIG. 4 shows the behavior of the capacitance value of the capacitor Cp represented by the Gaussian function as an example. In this example, the capacitance value becomes maximum when the value I of the current I (t) is near 0, and then the value of the capacitance value decreases as the value I of the current I (t) decreases or increases.

The endogenous variable Vp (t) [voltage drop Vp (t) due to polarization of the lead battery 1 when the current I (t) is flowing at time t] can be calculated by, for example, the equation (13). In the equation (13), Rp indicates the resistance value of the resistance Rp, and Cp indicates the capacitance value of the capacitor Cp.

(1-5) Main points of the battery model The structure of the battery model 15 has been described above, but the important point in this embodiment is that the endogenous variable Vd (t) [current I (t) flows at time t. The drop voltage due to the DC internal resistance of the lead battery 1 at the time] and the endogenous variable Vp (t) [the drop voltage due to the polarization of the lead battery 1 when the current I (t) is flowing at time t] are outside as parameters. The raw variable I (t) [current flowing through the lead battery 1 at time t] is included. This point will be described below.

(2) Terminal voltage estimated value Ve'(t)
A current I (t) flows through the equivalent circuit 11 shown in FIG. 2 at time t. The terminal voltage estimated value Ve (t) of the lead battery 1 at this time can be obtained by the equation (3). However, the endogenous variable Ve (t) [estimated terminal voltage of the lead battery 1 when the current I (t) is flowing at time t] shown in FIG. 3 constitutes a part of the battery model 15. In the embodiment, the endogenous variable Ve (t) itself when the current I (t) is flowing is not calculated. In the present embodiment, as shown in FIG. 3, when the expected increase current value Ic of the lead battery 1 is given as the exogenous variable, the exogenous variable I (t) [current flowing through the lead battery 1 at time t]. Is the value of the endogenous variable Ve (t) shown in the equation (3) when I'(t) = {I (t) + Ic} instead of the value of the current I (t), that is, the time. The value of the terminal voltage estimated value Ve'(t) of the lead battery 1 assuming that the current I'(t) is flowing at t is calculated.

For that purpose, the value of the exogenous variable I (t) included as a parameter in the equations (11) and (13) is set as I'(t) = {I (t) + Ic}, and the endogenous variable Vd'(t) [Drop voltage due to DC internal resistance when current I'(t) is flowing in lead battery 1 at time t] and endogenous variable Vp'(t) [Current I'in lead battery 1 at time t The voltage drop due to polarization when (t) is assumed to be flowing] is calculated. That is, the value of the endogenous variable Ve'(t) is calculated by moving the value of the exogenous variable I (t) of the battery model 15 according to the expected increase current value Ic of the lead battery 1 as the exogenous variable. The endogenous variable Ve'(t) can be calculated by the equation (14).

1-2-3. Functional block diagram The calculation of the terminal voltage estimated value Ve'(t) of the lead battery 1 as described above is put into practical use of the power supply system 10 (battery state detection device 8) only when the battery model 15 is executed in real time. .. FIG. 5 shows a functional block diagram of the control unit 7 for that purpose. Note that FIG. 5 shows a functional block diagram after the time t, and the functional block portion before the time t is omitted.

The device information storage unit 21 stores the SOC (t) and SOH values of the lead battery 1 that have been calculated before the time t. The device information storage unit 21 outputs the SOC (t) and SOH values of the lead battery 1 to the parameter setting unit 31 and the Vocv (t) calculation unit 32 constituting the model execution unit 30. The SOC (0) shown in the equation (4) is calculated by the reference SOC calculation unit (not shown), and the integration of the current flowing from the time 0 to the time (t-1) and the calculation of the SOC (t) are performed. It is performed by the SOC calculation unit (not shown). Further, the SOH of the lead battery 1 is calculated by the SOH calculation unit (not shown) when the engine is started. The functions of these arithmetic units will be described later (see 1-3-1).

When the current calculation unit 23 receives the power request command (Pw_Dmd) from the ECU via the communication line 9, the rated current value of the electrical component to be used (the ECU is known, the CPU is unknown) is set to the above-mentioned expected increase current value Ic. Assuming that, the value of the current I'(t) obtained by adding the value of the current I (t) and the rated current value Ic is calculated and output to the model execution unit 30 (parameter setting unit 31).

The rated current value of each electrical component to be used is stored in advance in the ROM of the ECU, and is expanded in the RAM of the ECU. When the lead battery 1 is discharged, the ECU issues a power request command to the control unit 7 via the communication line 9 as needed. The power request command includes the rated current value of the electrical component to be used as attribute information. For example, when the rated current value of the electrical component to be used is 3.0 [A], Pw_Dmd (3.0) is transmitted as a power request command.

The model execution unit 30 executes the battery model 15 described above and determines the value of the terminal voltage estimated value Ve'(t) of the lead battery 1 when the current I'(t) is assumed to be flowing at the time (t). Output to unit 24. The model execution unit 30 includes a parameter setting unit 31, a Vocv (t) calculation unit 32, a Vd (t) calculation unit 33, a Vp (t) calculation unit 34, and a terminal voltage calculation unit 35.

The parameter setting unit 31 has a resistance value R ₀ , a coefficient V ₀ , and I of the above-mentioned resistance Rd 1 from the values of the SOC (t), SOH, and the temperature T (t) of the lead battery 1 received from the device information storage unit 21. ₀ , α, and a constant y are set, and these set values and the value of the current I'(t) calculated by the current calculation unit 23 are output to the Vd (t) calculation unit 33, and the resistance value R of the resistance Rd1 is output. The set value excluding ₀ and the value of the current I'(t) calculated by the current calculation unit 23 are output to the Vp (t) calculation unit 34.

The Vocv (t) calculation unit 32 receives the SOC (t) and SOH received from the parameter setting unit 31, and the open circuit voltage Vocv (t) of the lead battery 1 at time t from the values of the temperature T (t) of the lead battery 1. ) Is calculated and output to the terminal voltage calculation unit 35. When the Vd (t) calculation unit 33 assumes that the current I'(t) is flowing through the lead battery 1 at time t based on the set value received from the parameter setting unit 31 and the value of the current I'(t). The value of the drop voltage Vd'(t) due to the DC internal resistance of the above is calculated and output to the terminal voltage calculation unit 35, and the Vp (t) calculation unit 34 receives the set value and the current I'(from the parameter setting unit 31. Based on the value of t), the value of the drop voltage Vp'(t) due to polarization when the current I'(t) is assumed to be flowing in the lead battery 1 at time t is calculated and output to the terminal voltage calculation unit 35. do.

The terminal voltage calculation unit 35 has a value of the open circuit voltage Vocv (t) received from the Vocv (t) calculation unit 32 and a value of the voltage drop Vd'(t) due to the DC internal resistance received from the Vd (t) calculation unit 33. And the terminal voltage estimated value Ve'(t) of the lead battery 1 is calculated by the equation (14) from the value of the voltage drop Vp'(t) due to the polarization received from the Vp (t) calculation unit 34, and output to the determination unit 24. do.

The determination unit 24 determines the terminal voltage estimated value Ve'(t) of the lead battery 1 and the minimum voltage value Vmin (for example, 8.0 [V]) predetermined as the minimum voltage at which the electrical component to be used can operate. By comparison, when the terminal voltage estimated value Ve'(t) is larger than the minimum voltage value Vmin, it is determined that the electrical component to be used can be used, and when the terminal voltage estimated value Ve'(t) is equal to or less than the minimum voltage value Vmin. Judge that the electrical equipment to be used cannot be used.

The device information storage unit 21, the current calculation unit 23, the parameter setting unit 31, the calculation units 32 to 35 and the determination unit 24, and the reference SOC calculation unit, the SOC calculation unit, and the SOH calculation unit discarded in FIG. 3 are included. It is realized by the MPU (ROM, CPU, RAM) of the control unit 7 shown in FIG.

1-3. Operation Next, the operation of the power supply system 10 of the present embodiment will be described mainly by the CPU (hereinafter, simply referred to as CPU) of the MPU of the control unit 7 of the battery-like detection device 8.

1-3-1. General operation (1) Reference SOC
At the start of parking of the ISS vehicle after traveling, the ECU issues a sleep command (command to set the energy saving mode) to the CPU. The CPU that receives the sleep command stops the detection of the battery status (temperature, voltage, current, etc.) of the lead battery 1 and outputs the status information (described later) of the lead battery 1 that was output to the ECU at predetermined time intervals. Is stopped, and only the timing process for determining whether or not a certain period of time (for example, 6 hours when the polarization state of the negative electrode of the lead battery 1 is considered to be eliminated) has elapsed from the time when the sleep command is received is performed. In this state, the lead battery 1 is in a charge / discharge hibernation state.

When the CPU determines that a certain time has elapsed from the time when the sleep command is received, it shifts to the operation mode (away) and detects the open circuit voltage of the lead battery 1 and the temperature at that time. Next, the detected open circuit voltage of the lead battery 1 is temperature-corrected to the open circuit voltage at the reference temperature, and the program data is stored in advance in the ROM of the MPU (hereinafter, simply referred to as ROM) and the RAM of the MPU (hereinafter, simply RAM). Refer to the table or formula showing the relationship between the open circuit voltage and the SOC developed in ()), that is, the value of the reference SOC of the lead battery 1, that is, the SOC (0) shown in the second term on the right side of the formula (4). The value of is calculated and the value is saved in the RAM (the function of the reference SOC calculation unit described above). Then, the CPU notifies the ECU of the open circuit voltage and the reference SOC at the reference temperature, and enters the energy saving mode.

Such processing is repeated at regular time intervals as described above. If the above-mentioned fixed time does not elapse, the polarization state of the lead battery 1 is not eliminated and the reference SOC becomes inaccurate. Therefore, the detection of the open circuit voltage in such a state and the calculation of the reference SOC by the CPU Is not performed, and the most recently acquired standard SOC is treated as the standard SOC.

(2) Status Information During charging / discharging of the lead battery 1, the CPU detects the battery status of the lead battery 1 every predetermined time (2 [ms] for voltage and current, 10 [ms] for temperature). That is, the A / D converter connected to the current detection circuit 2 and the A / D converter connected to the voltage detection circuit 3 have 2 [ms] each of the charge / discharge current flowing through the lead battery 1 and the terminal voltage of the lead battery 1. Each sample is sampled and output to the RAM, and the A / D converter connected to the temperature detection circuit 4 samples every 10 [ms] and outputs the sample to the RAM. Therefore, in the present embodiment, since the charge / discharge current flowing through the lead battery 1 and the terminal voltage of the lead battery 1 are sampled every 2 [ms], the interval of 1 time is 2 [ms].

The CPU calculates the value of SOC (t) shown in the equation (4) by integrating the current value every 1 time (2 [ms]) and stores it in the RAM (device information storage unit 21 shown in FIG. 5). (Function of SOC calculation unit described above). Further, the CPU considers the value of the temperature most recently stored in the RAM as the value of the temperature T (t) at the time t, and the lead battery 1 stored in the RAM according to the value of the temperature T (t). The values of the flowing current and the terminal voltage of the lead battery 1 are temperature-corrected to the current value and the terminal voltage value at the reference temperature, respectively.

Subsequently, the CPU uses the most recently calculated temperature-corrected terminal voltage value and SOC (t) value as the state information of the lead battery 1 every predetermined time (for example, 2 [ms]) in the communication IC and the communication line. Notify the ECU via 9.

(3) SOH
The CPU calculates (updates) the SOH value when the engine of the ISS vehicle is started (including when the engine is restarted after idling stop) and stores it in the RAM. For example, as disclosed in Patent Document 6 (see claims 5 and 7) mentioned in the background technology column, the open circuit voltage calculated from the remaining capacity of the lead battery 1 is OCV _Q , and the lead battery 1 at the time of starting the engine. The internal resistance RQ of the lead battery 1 and the lead battery 1 obtained by the formula RQ = {r (OCV _{Q −Vst} ) / Vst _} , where Vst is the minimum voltage of The SOH is calculated by referring to a table or map whose relationship with the SOH is predetermined, and stored in the RAM (device information storage unit 21 shown in FIG. 5) (the function of the SOH calculation unit described above). The resistance r of the ISS vehicle can be obtained by the formula r = (Vst / Ist), where Ist is the maximum current flowing through the lead battery 1 when the engine is started.

1-3-2. Characteristic Operation Next, with reference to FIG. 6, a routine for determining the availability of electrical components for determining the availability of electrical components to be used will be described.

In the electrical component availability determination processing routine, first, in step 102 (hereinafter, abbreviated as “S”) 102, it is determined whether or not the lead battery 1 is in the discharged state. Such a determination can be made by referring to the temperature-corrected voltage value (for example, V (t-1)) stored in the RAM before the time t. Alternatively or in conjunction with this, the temperature-corrected current value stored in the RAM before the time t may be referred to for judgment.

If a negative determination is made, another process is performed (S104), and the electrical component availability determination process routine is terminated. For this separate processing, for example, the above 1-3-1. The calculation of the reference SOC described in (1) is included. On the other hand, in the case of affirmative determination, it is determined whether or not the power supply command (Pw_Dmd) has been received (S106). If the judgment in S106 is negative, the process returns to S102, and if the judgment is positive, the process proceeds to S110.

In S110, the resistance value R ₀ of the resistance Rd1, the coefficient V ₀ , I ₀ , α, and the constant y (hereinafter, these are collectively referred to) with reference to the look-up table from the values of SOC (t), SOH, and temperature T (t). And set the parameter.). Then, by referring to the attribute information of the power supply command (Pw_Dmd), the expected increase current value Ic (rated current value of the electrical equipment to be used) is acquired, and the current I (t) value (after temperature correction) is obtained. The value of the current I'(t) to which the expected increase current value Ic is added is calculated (S118).

Next, the CPU has an open circuit voltage Vocv (t) of the lead battery 1 at time t, and a voltage drop voltage Vd due to the DC internal resistance when the current I'(t) is flowing through the lead battery 1 at time t. '(T) and the voltage drop due to polarization Vp'(t) are calculated (S120), and the terminal voltage of the lead battery 1 is estimated when the current I'(t) is flowing at time t according to the equation (14). The value Ve'(t) is calculated (S122).

Subsequently, it is determined whether or not the terminal voltage estimated value Ve'(t) is larger than the predetermined minimum voltage value Vmin (S124), and if it is affirmative, it is determined that the electrical component to be used can be used. Then, the process proceeds to (S126) S130, and if a negative determination is made, it is determined that the electrical component to be used is unusable, and the process proceeds to (S128) S130. In S130, the determination result in S126 or S128 is notified to the ECU via the communication IC and the communication line 9, and the process returns to S102 (returning the answer to the power request command). Upon receiving this notification, the ECU operates the alternator as necessary.

In this embodiment, the reason why the equivalent circuit at the time of discharging the lead battery 1 is shown in FIG. 2 and the example of the battery model is shown in FIG. 5 is that the power request command (Pw_Dmd) shown in FIG. 5 discharges the lead battery 1. This is because it is sometimes output from the ECU to the control unit 7. In addition, when the lead battery 1 is charged, the alternator is operated according to the instruction of the ECU, and the electric power from the alternator is supplied to the electrical components.

2. 2. Second Embodiment Next, a second embodiment in which the present invention is applied to a 14V system power supply system that can be mounted on an ISS vehicle will be described. In this embodiment, the resistance Rd1 has a resistance Rd1 so that the voltage difference between the value of the terminal voltage V (t) of the lead battery 1 at time t and the estimated terminal voltage Ve (t) of the lead battery 1 at time t becomes 0. The resistance value R ₀ is corrected. In the embodiments after this embodiment, the same components and steps as those in the first embodiment described above are designated by the same reference numerals, the description thereof will be omitted, and only different parts will be described below.

2-1. Battery model As shown in FIG. 7, in the battery model 16 of the present embodiment, the endogenous variable Ve (t) [current (I) at time t is different from that of the battery model 15 of the first embodiment (see FIG. 3). An arrow indicating a causal relationship is attached from the terminal voltage estimated value of the lead battery 1 when flowing] toward the exogenous variable Dv (t). In the battery model 16 of the present embodiment, the value of the endogenous variable Ve (t) is calculated. The exogenous variable Dv (t) is the voltage difference between the exogenous variable V (t) [the terminal voltage of the lead battery 1 at the time t after temperature correction to the reference temperature value] and the endogenous variable Ve (t). show.

Therefore, in FIG. 7, an arrow is attached from the exogenous variable V (t) to the exogenous variable Dv (t). Further, since the exogenous variable V (t) is temperature-corrected to the value at the reference temperature, the exogenous variable V (t) [time t] is changed from the exogenous variable T (t) [the temperature of the lead battery 1 at time t]. The terminal voltage of the lead battery 1 in the above] is indicated by an arrow. Further, in order to correct the value of the resistance value _R0 of the resistance Rd1 according to the value of the exogenous variable Dv (t), an arrow is attached from the exogenous variable Dv (t) toward the endogenous variable _R0 . ..

2-2. Functional block diagram FIG. 8 is a functional block diagram of the control unit 7 for executing the battery model 16 shown in FIG. 7. In FIG. 8, the terminal voltage V (t) of the lead battery 1 and the voltage difference calculation unit 25 at the time t after temperature correction are added to the reference temperature value with respect to the functional block diagram (see FIG. 5) of the first embodiment. ing.

Unlike the first embodiment, the terminal voltage calculation unit 35 calculates the terminal voltage estimated value Ve (t) value of the lead battery 1 when the current (I) is flowing at time t by the equation (3). The value is output to the voltage difference calculation unit 25. The voltage difference calculation unit 25 calculates the voltage difference Dv (t) between the value of the terminal voltage V (t) of the lead battery 1 and the terminal voltage estimated value Ve (t), and sets the value of the voltage difference Dv (t) as a parameter. Output to the setting unit 31.

The parameter setting unit 31 corrects the value of the resistance value R ₀ by referring to a table or mathematical formula in which the relationship between the voltage difference Dv (t) and the correction value of the resistance value R ₀ of the resistance Rd 1 is predetermined (after correction). The resistance value of is R _1. ), and is output to the Vd (t) calculation unit 33. When the Vd (t) calculation unit 33 uses the resistance value R1 instead of the resistance value _R0 shown in the equation (5) and assumes that the current I'(t) is flowing through the lead battery ₁ at time t. The value of the voltage drop Vd1 due to the resistance Rd1 is obtained, and the value of the voltage drop Vd'(t) due to the DC internal resistance is calculated.

2-3. Electrical Equipment Usability Determination Processing Routine FIG. 9 shows a flowchart of the electrical equipment availability determination processing routine executed by the CPU in accordance with FIG. The electrical component availability determination processing routine of the present embodiment differs from the electrical component availability determination processing routine of the first embodiment between S110 and S122.

That is, after setting the parameters in S110 in the same manner as in the electrical component availability determination processing routine of the first embodiment, the open circuit voltage Vocv (t) of the lead battery 1 is set in S112, and the current I (t) is applied to the lead battery 1 at time t. ) Is flowing, the drop voltage Vd (t) due to the DC internal resistance, the value of the drop voltage Vp (t) due to polarization, and the terminal voltage estimated value Ve (t) are calculated, and the voltage difference Dv (t) is calculated in S114. Calculate the value. Next, in S116, the resistance value R ₀ is corrected to the resistance value R ₁ with reference to a look-up table in which the relationship between the voltage difference Dv (t) and the correction value of the resistance value R ₀ of the resistance Rd 1 is predetermined.

Subsequently, the current value I'(t) is calculated in S118, and the voltage drop Vd'(t) due to the DC internal resistance when the current I'(t) is assumed to be flowing in the lead battery 1 at time t in S121. ) And the voltage drop Vp'(t) due to polarization are calculated, and the process proceeds to S122. Although the value of the open circuit voltage Vocv (t) is also calculated in S120 of the electrical component availability determination processing routine of the first embodiment, the value of the open circuit voltage Vocv (t) is calculated in S121 in this embodiment. The reason for not doing so is that the value of the open circuit voltage Vocv (t) has already been calculated in S112.

3. 3. Third Embodiment Next, a third embodiment in which the present invention is applied to a 14V system power supply system that can be mounted on an ISS vehicle will be described. This embodiment shows a modified example of the determination content in the determination unit 24 of the functional block diagram.

3-1. Battery model The battery model in this embodiment is the same as the battery model 15 shown in the first embodiment (see FIG. 3).

3-2. Functional block diagram FIG. 10 is another functional block diagram of the control unit 7 for executing the battery model 15 shown in FIG. An electrical component information storage unit 26 is added to the functional block diagram (see FIG. 5) of the first embodiment. The electrical component information storage unit 26 corresponds to the MPU (RAM) and the non-volatile memory of the control unit 7 (see FIG. 1).

In the ROM of the ECU, the default value for specifying each target electrical component, the rated current value of each target electrical component, and the power supply priority of each target electrical component when the lead battery 1 is discharged (hereinafter, these are stored). (Generally referred to as electrical component information)) is stored in advance, and the electrical component information is expanded in the RAM of the ECU. Initially, when the power supply system 10 is mounted on the ISS vehicle, the ECU transmits electrical component information to the control unit 7 via the communication line 9 in response to a request from the control unit 7 (CPU). The control unit 7 stores the received electrical component information in the electrical component information storage unit 26 (nonvolatile memory).

Further, the ECU notifies the control unit 7 of the information (Acc_Info) each time the use of each electric component to be used is started or stopped. Therefore, in addition to the above-mentioned electrical component information, information regarding the usage status of each electrical component to be used (hereinafter referred to as usage status information) is stored (expanded) in the electrical component information storage unit 26 (RAM).

Unlike the first embodiment described above, the attribute information of the power supply command (Pw_Dmd) uses a default value for specifying the electrical component to be used. For example, if the power window is assigned a default value of 7, the power supply command will be Pw_Dmd (7). Further, for example, default values 3 and 4 are assigned to the starter (starter motor) and the engine pump, respectively, and when issuing a power supply command for both at the same time, it becomes Pw_Dmd (3,4).

Upon receiving the power request command (Pw_Dmd), the current calculation unit 23 refers to the rated current value of the electrical component to be used stored in the electrical component information storage unit 26 based on the attribute information of the power request command (electrical device to be used). If there are multiple products, calculate the total rated current value of the electrical equipment to be used), consider the rated current value as the expected increase current value Ic, and consider the above-mentioned I'(t) = {I (t) + Ic}. Calculate the value of. Further, the current calculation unit 23 refers to the rated current value of the electrical component in use among the other electrical components to be used stored in the electrical component information storage unit 26 according to the request of the determination unit 24, and reduces the rated current value. The value of I'(t) = {I (t) + Ic-Im} is also calculated by regarding it as the expected current value Im.

The determination unit 24 makes a determination for the power request command with reference to the electrical component information stored in the electrical component information storage unit 26 (RAM), but at that time, the determination unit 24 also makes a determination with reference to the usage state information. Hereinafter, the functions of the current calculation unit 23 and the determination unit 24 will be described in detail with reference to FIG.

3-3. Electrical Equipment Usability Determination Processing Routine FIG. 11 shows a flowchart of the electrical equipment availability determination processing routine executed by the CPU in accordance with FIG. 10.

When the affirmative judgment is made in S106, the CPU reads out the values of the SOC (t) and SOH expanded in the RAM and the temperature T (t) and sets the parameters as described above (S110). Next, the rated current value of the electrical component to be used is read out with reference to the RAM based on the attribute information of the power request command (S115), and the value of the current I'(t) is calculated (S118).

Next, the open circuit voltage Vocv (t), the voltage drop Vd'(t) due to the DC internal resistance when the current I'(t) is flowing in the lead battery 1, and the voltage drop Vp'(t) due to polarization. The value of is calculated (S120).

Next, the terminal voltage estimated value Ve'(t) of the lead battery 1 when the current I'(t) is flowing is calculated from the value calculated in S120 (S122), and the terminal calculated in the next S124. It is determined whether or not the value of the estimated voltage value Ve'(t) is larger than the predetermined minimum voltage value Vmin (S124). If this judgment is affirmative, the process proceeds to S146, and if it is negative, the electrical component information and usage status information expanded in the RAM are referred to, and the priority is given to the electrical component to be used specified in the attribute information of the power request command. It is determined whether or not an electrical component having a low priority) is being used (S132).

If a negative judgment is made in S132, it is determined that the electrical equipment to be used specified in the attribute information of the power request command cannot be used, and the process proceeds to (S134) S148. If a positive judgment is made in S132, the electrical equipment in use is determined. The current consumption value Im of the electrical component with the lowest priority is read from the RAM (S136), the use of the electrical component with the lowest priority is stopped, and the electrical component to be used specified by the attribute information of the power request command is used. The value of the current I'(t) [I'(t) = {I (t) + Ic-Im}] when the product is used is calculated (S138).

Subsequently, the drop voltage Vd'(t) due to the DC internal resistance and the drop voltage Vp'(t) due to polarization when the current I'(t) calculated in S138 is flowing in the lead battery 1 are calculated. (S140), then the terminal voltage estimated value Ve'(t) of the lead battery 1 is calculated (S142). Next, it is determined whether or not the terminal voltage estimated value Ve'(t) of the lead battery 1 is larger than the minimum voltage value Vmim (S144).

In S144, when the affirmative judgment is made, it is determined that the electrical component to be used specified in the attribute information of the power request command can be used, but it is necessary to stop the use of the electrical component having a lower priority (S146). ) Proceed to S148, and if a negative judgment is made, the next lower priority electrical component is returned to S132 in order to make the same judgment as above. In the latter case, the same judgment is made for the next lowest priority electrical component on the assumption that the use of the lowest priority electrical component will be stopped. Subsequently, the determination results in S134 and S146 are notified to the ECU (S148), and the process returns to S102. Upon receiving this notification, the ECU determines to stop the continuous use of some of the electrical components in use and to operate the alternator according to the vehicle conditions.

4. Action and effect, etc. Next, the action and effect of the power supply system 10 (battery state detection device 8) of the above embodiment will be described.

4-1. Action Effect The control unit 7 of the power supply system 10 (battery state detection device 8) of the above embodiment determines the terminal voltage estimated value Ve (t) of the lead battery 1 when the current I (t) is flowing through the lead battery 1. , [(Open circuit voltage of lead battery 1 Vocv (t))-{(Drop voltage Vd (t) due to DC internal resistance) + (Drop voltage Vp (t) due to polarization)}] Run the model. Both the voltage drop Vd (t) due to the DC internal resistance and the voltage drop Vp (t) due to polarization include the current I (t) as a parameter and have a current dependence. The control unit 7 changes the current I (t) included as a parameter in the drop voltage Vd (t) and the drop voltage Vp (t) to the current I (t) instead of the current I (t), and the expected current value Ic. As the current I'(t) to which (Im) is added, the drop voltage Vd'(t) and the drop voltage Vp'(t) when the current I'(t) flows through the lead battery 1 are calculated. .. Then, the terminal voltage estimated value Ve'(t) of the lead battery 1 assuming that the current I'(t) is flowing through the lead battery 1 is set to Ve'(t) = {Vocv (t)-(Vd). It is calculated by the formula'(t) + Vp'(t)}. Therefore, according to the power supply system 10 (battery state detecting device 8) of the above embodiment, when the expected increase / decrease current value Ic is given, the voltage drops. Since the terminal voltage estimated value Ve'(t) of the lead battery 1 is calculated by changing the value of the current I (t) included as a parameter in the voltage Vd (t) and the drop voltage Vp (t), the lead battery 1 It is possible to accurately calculate the terminal voltage estimated value V'e of the lead battery 1 when the expected increase / decrease current value Ic is known.

Further, the control unit 7 of the power supply system 10 (battery state detection device 8) of the above embodiment regards the rated current value of the electrical component to be used as the expected increase / decrease current value Ic, and determines the terminal voltage of the lead battery 1 V'e. (T) is calculated (see S122 in FIG. 6), and the calculated terminal voltage estimated value V'e (t) is compared with the lowest voltage value Vmim in which the target electrical component can operate (S124). It is determined whether or not the product can be used (S126, S128). According to the power supply system 10 (battery state detection device 8) of the above embodiment, since the terminal voltage estimated value V'e of the lead battery 1 can be calculated accurately as described above, whether or not the electrical component to be used can be used is determined. It can be determined accurately. Therefore, for example, it is possible to accurately determine whether or not the engine can be restarted before, after, or during the idling stop of the ISS vehicle or μHEV.

Further, the control unit 7 of the power supply system 10 (battery state detection device 8) of the second embodiment has a terminal voltage V (t) and a current I obtained by temperature-correcting the actually measured terminal voltage of the lead battery 1 at a reference temperature. The voltage difference Dv (t) from the terminal voltage estimated value Ve (t) of the lead battery 1 when (t) is flowing is calculated so that the value of this voltage difference Dv (t) becomes 0 (lead). A current I'(t) is flowing after correcting the resistance value _R0 of the resistance Rd1 (so that the value of the terminal voltage V (t) of the battery 1 and the estimated terminal voltage Ve (t) are equal to each other). The terminal voltage estimated value Ve'(t) of the lead battery 1 is calculated. Therefore, according to the power supply system 10 (battery state detecting device 8) of the second embodiment, the terminal voltage estimated value V'e of the lead battery 1 when the expected increase / decrease current value Ic of the lead battery 1 is known. It can be calculated with high accuracy.

Further, in the control unit 7 of the power supply system 10 (battery state detection device 8) of the third embodiment, the electrical component information and the usage status information are expanded in the RAM (electrical component information storage unit 26), and the attributes are attributed from the ECU. Whether or not the electric component to be used can be used on condition that the use of the low-priority electric component in use is stopped when the power request command (Pw_Dmd) including the default value of the electric component to be used is received as information. Is determined, and the result is notified to the ECU. Therefore, according to the power supply system 10 (battery state detection device 8) of the third embodiment, the ECU stops using the low-priority electrical components in use or operates the alternator according to the determination result of the control unit 7. It is possible to make an appropriate decision as to whether or not to let it. Furthermore, since multiple default values can be included in the attribute information of the power request command, it can be used one by one for each electrical component to be used when it is necessary to operate multiple electrical components at the same time, for example, when starting an engine. There is no need to inquire the control unit 7 (issue a power request command) as to whether or not it is.

4-2. Modifications In the above embodiment, the lead battery 1 is exemplified as the power storage device, but the present invention is not limited thereto. For example, instead of the lead battery 1, a nickel hydrogen battery, a nickel zinc battery, a lithium ion battery, a lithium ion capacitor, or the like may be used.

Further, in the above embodiment, an example of calculating the value of the terminal voltage estimated value Ve'(t) of the lead battery 1 when the expected increase / decrease current value Ic (Im) of the lead battery 1 is given as the exogenous variable is shown. However, the present invention is not limited to this. The value of the terminal voltage estimated value Ve'(t) of the lead battery 1 when the expected increase / decrease power value W of the lead battery 1 of the lead battery 1 is given as an exogenous variable may be calculated.

In such an embodiment, the expected increase / decrease current value Ic of the lead battery 1 may be calculated from the expected increase / decrease power value W of the exogenous variable. For example, in the battery model 15 of FIG. 3, the expected increase / decrease power value W of the exogenous variable may be calculated. An arrow indicating a causal relationship is added toward the expected increase / decrease current value Ic of the exogenous variable. To obtain the expected increase / decrease current value Ic of the lead battery 1 from the expected increase / decrease power value W of the exogenous variable, for example, it is obtained by dividing the expected increase / decrease power value W by the nominal voltage value (12 [V]) of the lead battery 1. The current value obtained may be the expected increase / decrease current value Ic, or the current value obtained by dividing the expected increase / decrease power value W by the measured voltage value V (t) may be the expected increase / decrease current value Ic. Such an operation is performed, for example, by the current calculation unit 23 shown in FIG. 5, and is executed by the CPU, for example, in S118 of FIG.

Further, in the third embodiment, as the electrical component information, the default value for specifying each electrical component to be used, the rated current value of each electrical component to be used, and the electrical component to be used when the lead battery 1 is discharged are used. Although the power supply priority is illustrated, the rated power value of each electric component to be used may be used instead of the rated current value of each electric component to be used. In such an embodiment, the current value obtained by dividing the rated power value of each electric component to be used by, for example, the nominal voltage value (12 [V]) of the lead battery 1, is non-volatile as the rated current value of the electric component to be used. It may be stored in the sex memory.

Further, in the above embodiment, an example of setting parameters by referring to a look-up table from the values of SOC (t), SOH, and temperature T (t) has been shown, but the present invention is not limited thereto. .. For example, the parameter may be set from the value of SOC (t), or the parameter may be set from the corrected SOC (t) by correcting the SOC (t) with SOH or temperature.

Further, in the above embodiment, the equivalent circuit at the time of discharging the lead battery 1 and its battery model are exemplified, but the present invention is not limited to this, and corresponds to the equivalent circuit including the charging time and the hibernation time of the lead battery 1. The battery model may be used. In that case, the above-mentioned equation (1) may be changed to V (t) = {Vocv (t) + Vd (t) + Vp (t)}, and the code may be changed according to the state of the lead battery 1.

Further, in the above embodiment, in order to facilitate understanding of the invention, the number of parameters and endogenous variables for calculating the drop voltage Vd (t) due to the DC internal resistance and the drop voltage Vp (t) due to polarization can be set as much as possible. Although a small number of examples have been shown, the present invention is not limited to this, and the parameters and endogenous variables are such that the terminal voltage estimated value Ve (t) of the lead battery 1 is the terminal voltage V (t) of the lead battery 1. Anything that can accurately simulate a wide range (battery state) to some extent. Further, if the currents I (t) and SOC are included, other exogenous variables may be included in order to improve the accuracy of the battery model, for example.

Further, in the second embodiment, an example in which Dv (t) is used as an exogenous variable is shown, but it may be set as an endogenous variable as in the battery model 17 shown in FIG. Further, in the second embodiment, in order to facilitate understanding of the invention, the resistance value _R0 of the resistance Rd1 among the resistances Rd1 and Rd2 constituting the DC internal resistance is corrected (the voltage drop Vd (t) due to the resistance Rd1 is corrected. An example of correction) is shown, but instead of or in combination with this, the parameter for determining the resistance value of the resistance Rd2 is corrected (correction of the voltage drop Vd (t) due to the resistance Rd2), or the resistance Vp (t) is corrected. The parameters that determine the resistance value and the capacitance value of the capacitor Cp (t) may be corrected (correcting the voltage drop Vp (t) due to polarization).

Furthermore, in the third embodiment, an example in which the minimum voltage value Vmin (threshold value) is uniformly set for the electrical component to be used is shown, but the present invention is not limited to this and is used for each electrical component to be used. It may be set to. For example, among the electrical components, the electrical components directly related to the engine start may be set separately from the other electrical components, and when multiple electrical components to be used are used at the same time, those electrical components may be set separately. Of these, the one with the largest operable minimum voltage may be set to the minimum voltage value Vmin.

Further, in the above embodiment, specific numerical values such as a sampling rate of each circuit constituting the power supply system 10 (battery state detection device 8) are exemplified, but the present invention is not limited thereto. The 14V power supply system 10 is exemplified in the above embodiment, but the present invention is not limited to this, and for example, a power supply system (battery state detection device) other than the 14V power supply system such as a 42V power supply system can be used. Is also applicable.

The present invention provides a device state detection device, a power supply system, and an automobile that can accurately estimate the terminal voltage of a power storage device, and thus contributes to the manufacture and sale of the device state detection device, the power supply system, and the automobile. Has the availability of.

1 Lead-acid battery (power storage device)
2 Current detection circuit (part of current measuring means)
3 Voltage detection circuit (part of voltage measuring means)
4 Temperature detection circuit (part of temperature measuring means)
5 Current sensor (part of current measuring means)
6 Temperature sensor (part of temperature measuring means)
7 Control unit (part of current measuring means, part of voltage measuring means, part of temperature measuring means, SOC calculation means, SOH calculation means, model execution means, determination means, voltage difference calculation means)
8 Battery status detection device (device status detection device)
10 Power supply system 15-17 Battery model (device model)
24 Judgment unit 25 Voltage difference calculation unit 30 Model execution unit

Claims (11)

In the device status detection device that detects the status of the power storage device mounted on the vehicle,
A current measuring means for measuring the current flowing through the power storage device,
An SOC calculation means for calculating the charge state (SOC) of the power storage device, and
It is a model simulating the equivalent circuit of the power storage device, and at least the current measured by the current measuring means and the SOC calculated by the SOC calculation means are used as exogenous variables to calculate the terminal voltage estimated value Ve of the power storage device. Model execution means to execute the device model for
Equipped with
The model executing means calculates the terminal voltage estimated value Ve'of the power storage device when the expected increase / decrease current value Ic or the expected power increase / decrease power value W of the power storage device is given as an exogenous variable of the device model. There,
The current measured by the current measuring means as the exogenous variable is replaced with the measured current value I to the measured current value I from the expected increase / decrease current value Ic or the expected increase / decrease power value W. A device state detection device, characterized in that the terminal voltage estimated value Ve'is calculated when the calculated value (I + Ic) is added to the expected increase / decrease current value Ic. In the device status detection device that detects the status of the power storage device mounted on the vehicle,
A current measuring means for measuring the current flowing through the power storage device,
An SOC calculation means for calculating the charge state (SOC) of the power storage device, and
It is a model simulating the equivalent circuit of the power storage device, and at least the current measured by the current measuring means and the SOC calculated by the SOC calculation means are used as exogenous variables to calculate the terminal voltage estimated value Ve of the power storage device. Model execution means to execute the device model for
A determination means for determining whether or not the electrical components mounted on the vehicle can be used, and
Equipped with
The model executing means calculates the terminal voltage estimated value Ve'of the power storage device when the expected increase / decrease current value Ic or the expected power increase / decrease power value W of the power storage device is given as an exogenous variable of the device model.
The determination means executes the model when the rated current value of the electrical component is the expected increase / decrease current value Ic or when the current value calculated from the rated power value of the electrical component is the expected increase / decrease current value Ic. A device state detection device characterized in that it determines whether or not the electrical component can be used by comparing the terminal voltage estimated value Ve'calculated by the means with a preset threshold value. The device model includes, as endogenous variables, the open circuit voltage Vov of the power storage device, the drop voltage Vd due to the DC internal resistance of the power storage device, and the drop voltage Vp due to the polarization of the power storage device, and obtains the terminal voltage estimated value Ve. The device state detection device according to claim 1 or 2, wherein the model is a model simulating an equivalent circuit at the time of discharging of the power storage device for calculation as Ve = {Vocv- (Vd + Vp)}. The equivalent circuit has a linear DC resistance component, a non-linear DC resistance component having a current dependence, a parallel connection of a resistance component having a current dependence and a capacitance component, and an open circuit voltage Vocv of the power storage device. The device state detection device according to any one of claims 1 to 3, wherein the device state detection device includes, and is configured by connecting these in series. The device state detection device according to claim 3, wherein the voltage drops Vd and Vp are variables having a current measured by the current measuring means as a parameter. Further provided with an SOH calculation means for calculating the degree of deterioration (SOH) of the power storage device,
The device state detection device according to any one of claims 1 to 5, wherein the SOC calculation means corrects the SOC with the SOH calculated by the SOH calculation means. In the device status detection device that detects the status of the power storage device mounted on the vehicle,
A current measuring means for measuring the current flowing through the power storage device,
An SOC calculation means for calculating the charge state (SOC) of the power storage device, and
It is a model simulating the equivalent circuit of the power storage device, and at least the current measured by the current measuring means and the SOC calculated by the SOC calculation means are used as exogenous variables to calculate the terminal voltage estimated value Ve of the power storage device. Model execution means to execute the device model for
A voltage measuring means for measuring the voltage of the power storage device and
A voltage difference calculating means for calculating the voltage difference Dv between the voltage value V measured by the voltage measuring means and the terminal voltage estimated value Ve calculated by the model executing means, and
Equipped with
The device model includes, as endogenous variables, the open circuit voltage Vov of the power storage device, the drop voltage Vd due to the DC internal resistance of the power storage device, and the drop voltage Vp due to the polarization of the power storage device, and obtains the terminal voltage estimated value Ve. It is a model simulating the equivalent circuit at the time of discharging of the power storage device for calculating as Ve = {Vocv- (Vd + Vp)}.
The device model further has a voltage difference Dv calculated by the voltage difference calculation means as an exogenous variable or an endogenous variable, and at least the voltage drop Vd of the voltage drops Vd and Vp depends on the voltage difference Dv. Including parameters
The model executing means calculates the terminal voltage estimated value Ve'of the power storage device when the expected increase / decrease current value Ic or the expected power increase / decrease power value W of the power storage device is given as an exogenous variable of the device model. There,
A device state detecting device comprising correcting a parameter depending on the voltage difference Dv so that the voltage value V measured by the voltage measuring means and the terminal voltage estimated value Ve become equal to each other. Further provided with a temperature measuring means for measuring the temperature of the power storage device,
The current flowing through the power storage device measured by the current measuring means and the voltage of the power storage device measured by the voltage measuring means are at a predetermined reference temperature based on the temperature measured by the temperature measuring means. The device state detection device according to claim 7, wherein the temperature is corrected to a current value and a voltage value. The device state detecting device according to claim 2, wherein the determination means determines whether or not the vehicle can stop and start idling. With a power storage device
The device state detection device according to any one of claims 1 to 9 .
Power system with. An automobile provided with the power supply system according to claim 10.

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