JP2016208620A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To elongate a life of an electric motor while securing the traveling performance of a vehicle as much as possible by adjusting timing for performing an output limit of the electric motor.SOLUTION: When a control device sets an upper limit value Vmax with respect to a voltage command value V on the basis of a history of the voltage command value V and atmospheric pressure P so that the voltage command value V is controlled within a voltage range of the upper limit value Vmax, the control device calculates a value of a function A=∫f(V,P)dt with the voltage command value V, the atmospheric pressure P, and an application time t at which a voltage based on the voltage command value V is applied as parameters, updates an accumulation value A=A+Aof the function A by adding the value of the function A to a previous accumulation value A, and when the accumulation value Aexceeds a threshold Ath, lowers and resets a value of the upper limit value Vmax with respect to the voltage command value V.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control device, and more particularly to a control device that controls an electric motor and an electric device mounted on a vehicle.

  In recent years, low-pollution vehicles such as hybrid vehicles, fuel cell vehicles, and electric vehicles have been developed as part of measures against environmental problems. These vehicles travel by the driving force from the electric motor. In such a vehicle, an electric device such as an inverter circuit that supplies electric power to the electric motor is mounted, and the electric motor is driven with a high voltage.

  Naturally, it is assumed that a vehicle equipped with such an electric motor travels at a high altitude. In high altitudes, it is generally known that atmospheric pressure is low. Under such circumstances, the dielectric constant of air increases. When the dielectric constant of air rises, there is a problem that the amount of partial discharge into the insulator increases in electric devices and electric motors. When the partial discharge amount is increased, the insulating performance of the insulator is deteriorated, and further, the durability life of the insulator is also deteriorated.

  Therefore, there has been proposed a vehicle equipped with a control device that sets a voltage to be supplied to an electric motor and an electric device according to the atmospheric pressure detected by the vehicle and controls the electric motor based on the set voltage (for example, a patent). Reference 1).

  Moreover, although not described in Patent Document 1, even when the temperature of the electric motor is high, the insulating performance of the insulator deteriorates and the durability life deteriorates.

Japanese Patent No. 4639916

  As described in Patent Document 1, when the voltage is changed according to the atmospheric pressure, the output of the electric motor is always limited in a region where the atmospheric pressure is low, such as a high altitude, and the traveling performance of the vehicle is always reduced. There was a problem that it was.

  The present invention has been made to solve such a problem, and even in a region where the atmospheric pressure is low, such as a high altitude, by adjusting the timing for limiting the output of the motor, the driving performance of the vehicle can be ensured as much as possible. However, an object of the present invention is to provide a control device capable of extending the life of an electric motor.

The present invention is a control device for an electric motor mounted on a vehicle, wherein the vehicle is an electric device for supplying electric power to the electric motor, and an atmospheric pressure sensor for detecting an atmospheric pressure P around the vehicle. The control device provides a voltage command value V for controlling an applied voltage applied to the electric motor and the electric device according to an output required by the electric motor when the vehicle travels. A voltage command value calculation unit to be calculated, a storage unit for storing a history of the voltage command value V and the atmospheric pressure P, and a voltage at which the voltage command value V calculated by the voltage command value calculation unit is an upper limit value Vmax An upper limit value setting unit that sets an upper limit value Vmax for the voltage command value V based on a history of the voltage command value V and the atmospheric pressure P stored in the storage unit so as to be controlled within a range; , Voltage command value V and previous Calculating a value of the function A = ∫f (V, P) dt for the application time of the applied voltage and the atmospheric pressure P t as a parameter, the value of the function A, the accumulated value A _n-1 previously calculated by adding, and a cumulative value calculating unit that updates the accumulated value a _{n =} a + a _n-1 of the function a, the upper limit value setting unit, the accumulated value a _n calculated by the accumulated value calculating section Is a control device that lowers and resets the upper limit value Vmax with respect to the voltage command value V when the threshold value Ath exceeds the threshold value Ath.

In the present invention, the upper limit value setting section, when the accumulated value A _n calculated by the accumulated value calculating section exceeds the threshold value Ath, decreases the value of the upper limit value Vmax for the voltage command value V Since resetting is performed, the output of the electric motor is not limited until the accumulated value reaches the threshold value Ath, and thus the maximum performance of the electric motor can be ensured during that period. Further, when said accumulated value A _n has exceeded the threshold value Ath, the order to re-set by reducing the value of the upper limit value Vmax for the voltage command value V, suppressing an increase in internal partial discharge of the electric motor, the electric motor Insulation and reliability of the electric motor can be ensured because deterioration of the insulating property of the electric motor can be prevented and dielectric breakdown of the electric motor can be suppressed. As a result, even when the atmospheric pressure is low, such as at high altitudes, it is possible to extend the life of the motor while ensuring the vehicle's running performance as much as possible by appropriately adjusting the timing for limiting the output of the motor. .

It is a block diagram which shows the structure of the vehicle by which the control apparatus which concerns on Embodiment 1 of this invention is mounted. It is explanatory drawing which shows the relationship between atmospheric pressure, a voltage, and the dielectric breakdown of a motor, and a lifetime with a graph. It is a flowchart which shows the flow of a process of the program performed by HV-ECU which comprises the control apparatus which concerns on Embodiment 1 of this invention. Is an explanatory view showing the change of the upper limit value Vmax of the motion and the voltage command value of the accumulated value A _n of the function A calculated by the HV-ECU configuring the control apparatus according to the first embodiment of the present invention graphically. It is a block diagram which shows the structure of the vehicle by which the control apparatus which concerns on Embodiment 2 of this invention is mounted. It is explanatory drawing which shows the relationship between the stator temperature and voltage of an electric motor, and the dielectric breakdown and lifetime of an electric motor with a graph. It is a flowchart which shows the flow of a process of the program performed by HV-ECU which comprises the control apparatus which concerns on Embodiment 2 of this invention. It is an explanatory view showing a change in the upper limit value Vmax of the motion and the voltage command value of the accumulated value A _n of the function A calculated by the HV-ECU configuring the control apparatus according to a second embodiment of the present invention graphically. It is a flowchart which shows the flow of a process of the program performed by HV-ECU which comprises the control apparatus which concerns on Embodiment 3 of this invention. It is an explanatory view showing a change in the upper limit value Vmax of the motion and the voltage command value of the accumulated value A _n of the function A calculated by the HV-ECU configuring the control apparatus according to a third embodiment of the present invention graphically. It is an explanatory view showing a change in the upper limit value Vmax of the motion and the voltage command value of the accumulated value A _n of the function A calculated by the HV-ECU configuring the control apparatus according to the fourth embodiment of the present invention graphically.

  Hereinafter, a control device according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiments, the same or corresponding components in the drawings are denoted by the same reference numerals, and detailed description thereof will not be repeated. The present invention also relates to a control device for mainly controlling a moving body. An example of the moving body is a vehicle on which an electric motor is mounted, and is not particularly limited as long as the vehicle is the vehicle. Specifically, a hybrid vehicle, an electric vehicle, a fuel cell vehicle, etc. are mentioned, for example. In each of the following embodiments, the moving body will be described as a hybrid vehicle.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a vehicle equipped with a control device according to the present embodiment of the present invention. As shown in FIG. 1, the vehicle includes an HV-ECU (Hybrid Vehicle-Electronic Control Unit) 1, a vehicle ECU 2, a DC / DC converter 4, a battery 5, an inverter 6, and a motor 7. It is installed.

  The vehicle ECU 2 controls the output of an engine (not shown) mounted on the vehicle based on various information (for example, accelerator opening, intake air amount, vehicle speed, etc.) detected by various sensors provided on the vehicle. To do. The vehicle ECU 2 is connected so as to be communicable with the HV-ECU 1. An atmospheric pressure sensor 3 is connected to the vehicle ECU 2. The vehicle ECU 2 is realized by the processor executing a program stored in a storage device (not shown) connected to the vehicle ECU 2. Further, the functions of the vehicle ECU 2 may be executed in cooperation with a plurality of processors and a plurality of storage devices.

  The atmospheric pressure sensor 3 detects the atmospheric pressure around the vehicle. The atmospheric pressure sensor 3 transmits a detection signal corresponding to the detected atmospheric pressure to the vehicle ECU 2. The atmospheric pressure sensor 3 may be a well-known technique and will not be described in detail.

  The HV-ECU 1 constitutes a control device according to the present embodiment. The HV-ECU 1 is realized by a processor executing a program stored in a storage device (not shown) connected to the HV-ECU 1. In addition, a plurality of processors and a plurality of storage devices may cooperate to execute the function of the HV-ECU 1. Based on the program, the HV-ECU 1 controls the voltage applied to the motor 7 and the inverter 6 according to the rotational speed of the motor 7 and the output required by the motor 7 when the vehicle travels. The value V is calculated. Further, the program includes a “motor insulation protection routine” to be described later. The HV-ECU 1 determines an upper limit value for the voltage command value in accordance with the “motor insulation protection routine” based on the history of the atmospheric pressure and the voltage command value, and boosts the DC / DC converter 4 to output the upper limit value. A voltage command value V for the DC / DC converter 4 is output within the range of the maximum value so that the boosted voltage output from the DC / DC converter 4 does not exceed the maximum value. The DC / DC converter 4 is controlled.

  The DC / DC converter 4 boosts the DC voltage from the battery 5 in accordance with the voltage command value V received from the HV-ECU 1.

  The battery 5 is composed of a rechargeable secondary battery such as a lithium ion battery or a nickel metal hydride battery.

  The inverter 6 is an electrical device that supplies power to the motor 7. The inverter 6 converts the DC voltage boosted by the DC / DC converter 4 into an AC voltage and supplies the AC voltage to the motor 7. The inverter 6 controls the AC voltage supplied to the motor 7 according to the control signal received from the HV-ECU 1.

  The motor 7 is composed of an electric motor. The motor 7 is driven based on the AC voltage supplied from the inverter 6. The motor 7 is connected to driving wheels (not shown) of the vehicle and generates driving force corresponding to the supplied AC voltage on the driving wheels. As an example of the electric motor that constitutes the motor 7, for example, a three-phase AC synchronous electric motor can be cited. However, the motor 7 is not limited to a three-phase AC synchronous motor, and may be a multiphase AC motor such as a 5-phase or 7-phase, for example. However, in that case, the inverter 6 and the like have a circuit configuration corresponding to the multiphase winding.

  When the vehicle travels, the DC / DC converter 4 outputs a boosted voltage value V1 based on the voltage command value V instructed from the HV-ECU 1 according to the operation state of the vehicle. Thereby, electric power is supplied to the inverter 6 and the motor 7.

  FIG. 2 is a graph showing the relationship between the atmospheric pressure, the boosted voltage value V1, and the insulation and reliability of the motor 7. In FIG. 2, the horizontal axis represents “atmospheric pressure”, and the vertical axis represents “time until dielectric breakdown or life of the motor 7”. FIG. 2 shows a graph in the case where there are three types of boosted voltage values V1 of 500V, 600V and 700V. At this time, as shown in FIG. 2, as the atmospheric pressure becomes smaller and the boosted voltage value V1 becomes larger, the partial discharge amount inside the motor increases and the insulation of the motor 7 deteriorates. It can be seen that dielectric breakdown tends to occur and the life of the motor 7 is shortened.

  Therefore, in the present embodiment, the history of the atmospheric pressure and the voltage command value is stored in the storage device, and the upper limit value of the voltage command value V is adjusted based on the history so that the high altitude and the like Even in a region where the atmospheric pressure is low, the output of the motor 7 is not immediately limited, and the running performance of the motor 7 is ensured until the history of the atmospheric pressure and the voltage command value reaches a certain level. When the history of the atmospheric pressure and the voltage command value reaches the certain level, the output of the motor 7 is limited to suppress the increase in the partial discharge amount inside the motor. As a result, the running performance is ensured until the history of the atmospheric pressure and the voltage command value reaches a certain level, so the running performance is improved by that amount compared to the conventional technology that immediately performed the output restriction, Since the output of the motor 7 is limited after the history of the atmospheric pressure and the voltage command value exceeds a certain level, the insulation of the motor 7 is prevented from deteriorating and the insulation breakdown of the motor 7 is prevented. The life of the motor 7 can be extended compared to the prior art.

  This will be specifically described. In the HV-ECU 1, a function A relating to the history of the atmospheric pressure and the voltage command value is preset as follows. That is, the voltage command value instructed by the HV-ECU 1 is V, the atmospheric pressure detected by the HV-ECU 1 by the atmospheric pressure sensor 3 is P, and the voltage application time to the motor 7 based on the voltage command value V is t. At this time, in the HV-ECU 1, a function A given by the following equation (1) using the voltage command value V, the atmospheric pressure P, and the application time t as parameters is preset. The application time t may be simply the output time of the voltage command value V.

  As can be seen from the equation (1), the function A is defined as a value obtained by integrating the function f (V, P) having the voltage command value V and the atmospheric pressure P as parameters with the application time t.

When the vehicle travels, the HV-ECU 1 sets the initial value of the function A to A ₀ = 0 and calculates the value of the function A using the current voltage command value V, atmospheric pressure P, and application time t. To do. The value of the function A thus obtained is added to the initial value A ₀ to calculate A ₁ (= A + A ₀ ). Next, A ₂ (= A + A ₁ ) is calculated in the same manner. The HV-ECU 1 repeats this calculation at a preset cycle, and reduces the upper limit value Vmax for the voltage command value V when the value of A _n = A + A _n−1 reaches the threshold value Ath. Hereinafter, A ₁ , A ₂ ,..., A _n−1 , _An are referred to as the accumulated value of the function A or simply as the accumulated value. Note that the threshold value Ath is appropriately set in advance and stored in the storage device.

  In the above description, regarding the parameter V of the function A, the voltage command value V instructed from the HV-ECU 1 has been described as the parameter V of the expression (1). However, the present invention is not limited to this, and the DC / DC converter The boosted voltage value V1 output from 4 to the inverter 6 may be used as the parameter V in equation (1). In this case, however, it is necessary to provide a voltage sensor for detecting the boosted voltage value V1 output from the DC / DC converter 4 to the inverter 6. The voltage value detected by the voltage sensor is output to the HV-ECU 1.

Thus, the HV-ECU 1 constituting the control device according to the present embodiment is supplied to the motor 7 and the inverter 6 according to the rotational speed of the motor 7 and the output required by the motor 7 when the vehicle travels. A voltage command value calculation unit (not shown) for calculating a voltage command value V for controlling the applied voltage, a storage device (not shown) for storing a history of the voltage command value V and the atmospheric pressure P, Based on the history of the voltage command value V and the atmospheric pressure P stored in the storage device, the voltage command value V calculated by the voltage command value calculation unit is controlled within the voltage range of the upper limit value Vmax. An upper limit value setting unit (not shown) for setting an upper limit value Vmax with respect to the command value V, a function A of the above formula (1) using the voltage command value V, the atmospheric pressure P, and the application time t of the applied voltage as parameters. Calculate the value and calculate the value of the function A last time The by adding the accumulated value A _n-1, and includes the accumulation value calculating section for updating the accumulated value _{A n = A + A n-} 1 of the function A and a (not shown). Upper limit setting unit, when the accumulated value A _n calculated by the cumulative value calculation unit exceeds the threshold value Ath, resetting decreases the value of the upper limit value Vmax for the voltage command value V.

  Hereinafter, the operation for determining the upper limit value Vmax in the HV-ECU 1 according to the present embodiment will be described with reference to the flowchart of FIG. Here, the routine shown in FIG. 3 is referred to as a “motor insulation protection routine”.

  In the “motor insulation protection routine” in the present embodiment, as shown in FIG. 3, first, in step S10, the HV-ECU 1 reads the voltage command value V output from itself to the DC / DC converter 4, It memorize | stores in a memory | storage device (not shown). At this time, the application time t to the inverter 6 of the boosted voltage value V1 based on the voltage command value V is also read and stored in the storage device.

  Next, in step S11, the HV-ECU 1 detects the atmospheric pressure P based on the atmospheric pressure detection signal received from the atmospheric pressure sensor 3 via the vehicle ECU 2, reads it, and stores it in the storage device. To do.

  Next, in step S12, the HV-ECU 1 uses the voltage command value V, the atmospheric pressure P, and the application time t stored in the storage device (not shown) to calculate the function A of the above equation (1). Calculate the value.

Next, in step S13, the value of the function A obtained this time is added to the accumulated value A _n−1 calculated and stored in the previous routine, and the accumulated value A _n = A + A _n−1 in the current routine is obtained. Calculate and store in the storage device.

Next, in step S14, HV-ECU 1, the accumulated value _{A n} obtained in step S13, determines whether or exceeds the threshold value Ath previously set. If the result of determination is that the accumulated value _{A n} exceeds the threshold value Ath, the process proceeds to step S15. On the other hand, if the cumulative value _An is equal to or smaller than the threshold value Ath as a result of the determination, the process proceeds to step S16.

  In step S15, the HV-ECU 1 changes the upper limit value Vmax of the voltage command value V instructed from the HV-ECU 1 to the DC / DC converter 4 from the first upper limit value Vmax1 to the second upper limit value Vmax2. Change to The second upper limit value Vmax2 is set to a value lower than the first upper limit value. Note that the values of the first upper limit value Vmax1 and the second upper limit value Vmax2 are determined in advance and stored in the storage device.

  On the other hand, in step S16, the HV-ECU 1 keeps the upper limit value of the voltage command value V from the HV-ECU 1 to the DC / DC converter 4 as the first upper limit value Vmax1, and does not change it.

  Thus, HV-ECU 1 according to the present embodiment determines upper limit value Vmax of voltage command value V according to the routine shown in FIG.

  The HV-ECU 1 controls the boosted voltage value output from the DC / DC converter 4 within a voltage range equal to or lower than the upper limit value Vmax determined in step S15 or step S16. That is, when the voltage command value V output from the HV-ECU 1 is equal to or lower than the upper limit value Vmax, the value of the voltage command value V is output as it is. On the other hand, when the voltage command value V exceeds the upper limit value Vmax, the voltage command value V is By replacing with the upper limit value Vmax, the voltage command value V is rounded to the upper limit value Vmax and output. Since the DC / DC converter 4 outputs the boosted voltage value V1 based on the voltage command value V, the boosted voltage value V1 does not exceed the upper limit value Vmax.

4, based on the above arrangement and operation, the upper limit value Vmax of the motion and the voltage command value V of the cumulative value A _n by the function A is calculated by HV-ECU 1 constituting a control apparatus according to this embodiment Shows changes. In FIG. 4, the horizontal axis represents “time”, and the vertical axis represents “cumulative value A _{n of} function A”.

As shown in FIG. 4, the initial upper limit value Vmax is set to Vmax1. When the vehicle is running, the value of the function A represented by the above equation (1) is calculated from the voltage command value V and the detected atmospheric pressure P, and the accumulated value calculated and stored in the previous routine is stored. by adding the values of _{a n-1} to function a, and calculates the current accumulated value _{a n (= a + a n} -1).

At this time, when the voltage command value V in the vehicle is low, or when the vehicle is traveling on a flat ground and the atmospheric pressure P is high, or in both cases, the value of the function A is small and accumulated. value the slope of a _n continue the gradual increase (X1 region in FIG. 4 for example).

Conversely, when the voltage command value V of the vehicle is high, and, when the atmospheric pressure P is low, the vehicle is not traveling on a highland such as a mountain area, the value of the function A is large, the gradient of the cumulative value A _n is The sudden rise continues (for example, the region X2 in FIG. 4).

Thus, the accumulated value A _n is, while it does not reach the threshold value Ath a predetermined, upper limit value Vmax of the voltage command value remains set to Vmax1.

Then, when the accumulated value _{A n} reaches the threshold value Ath predetermined, i.e., at the point of Y1 in FIG. 4, the upper limit value Vmax of the voltage command value V is changed to Vmax2. At this time, Vmax2 <Vmax1 is set.

  Thereafter, the voltage command value V from the HV-ECU 1 is operated within a range of Vmax2 or less.

  In the present embodiment, the HV-ECU 1 controls the upper limit value Vmax as described above, thereby ensuring the insulation and reliability of the motor 7 even in a region where the atmospheric pressure is low, such as a high altitude. Since the traveling performance of the motor 7 can be ensured during the period until the vehicle reaches, the performance of the motor 7 can be maximized even when a steep uphill in high altitude is necessary, and the traveling performance of the vehicle can be improved. It will not be reduced. Further, since the output of the motor 7 is limited when the threshold value Ath is reached, the running performance of the vehicle from that point is lowered, but the deterioration of the insulation of the motor 7 can be prevented. Can be prevented. In this way, in the present embodiment, both the running performance of the vehicle and the insulation / reliability of the motor are achieved.

  In the present embodiment, a detection signal corresponding to the atmospheric pressure detected by the atmospheric pressure sensor 3 is transmitted to the vehicle ECU 2. However, the present invention is not limited to this, and a detection signal is transmitted from the atmospheric pressure sensor 3 to the HV-ECU 1. You may make it do.

  In the present embodiment, the function A is the integration of the application time t of the voltage command value V. However, the function A may be integrated with another physical quantity corresponding to the application time t. Examples of the physical quantity include the number of switching times of the power semiconductor element in the inverter 6.

  In the present embodiment, the atmospheric pressure sensor 3 is connected to the vehicle ECU 2, but may be directly connected to the HV-ECU 1. Alternatively, the atmospheric pressure sensor 3, the HV-ECU 1, the DC / DC converter 4 and the inverter 6 may be integrated, and the atmospheric pressure sensor 3 and the HV-ECU 1 may be connected inside. By disposing the atmospheric pressure sensor 3 inside, there is no wiring for transmitting the detection signal, and the cost is reduced.

As described above, the HV-ECU 1 that is the control device according to the present embodiment controls the applied voltage supplied to the motor 7 and the inverter 6 according to the output required by the motor 7 when the vehicle travels. Voltage command value calculation unit for calculating the voltage command value V for the storage, a storage device for storing the history of the voltage command value V and the atmospheric pressure P, and the voltage command value V calculated by the voltage command value calculation unit is the upper limit An upper limit value setting unit for setting an upper limit value Vmax for the voltage command value V based on the history of the voltage command value V and the atmospheric pressure P stored in the storage device so as to be controlled within the voltage range of Vmax; The value of the function A = Ｖf (V, P) dt using the voltage command value V, the atmospheric pressure P, and the application time t of the applied voltage as parameters is calculated, and the value of the function A is calculated as the previous accumulated value _An. by adding _-1, the cumulative value of the function _a a n = a + and a cumulative value calculating unit that updates the _n-1. The upper limit value setting unit, when the accumulated value A _n calculated by the cumulative value calculation unit exceeds the threshold value Ath, resetting decreases the value of the upper limit value Vmax for the voltage command value V. As a result, even when the vehicle travels in a region with a low atmospheric pressure such as a high altitude, the maximum performance of the motor 7 can be ensured until it reaches a certain level while ensuring the insulation and reliability of the motor 7. Even when a steep uphill in the highland is required, the performance of the motor 7 can be maximized, and the running performance of the vehicle is not deteriorated.

Embodiment 2. FIG.
FIG. 5 is a block diagram showing a configuration of a vehicle equipped with a control device according to the present embodiment of the present invention. The difference between FIG. 1 and FIG. 5 is that in FIG. 5, a motor 7A is provided instead of the motor 7 of FIG. The motor 7A has basically the same configuration and operation as the motor 7. However, the difference between the motor 7 and the motor 7 is that a thermistor is attached to a current-carrying part such as a stator coil of an electric motor that constitutes the motor 7A. It is a point. With this thermistor, it is possible to detect the stator temperature T of the motor 7A. Since other configurations are the same as those in FIG. 1, the same reference numerals are used here, and descriptions thereof are omitted.

  FIG. 6 is a graph showing the relationship between the stator temperature of the motor 7A, the boosted voltage value V1, and the insulation / reliability of the motor 7A. In FIG. 6, the horizontal axis represents “stator temperature”, and the vertical axis represents “time to reach dielectric breakdown or life of the motor 7 </ b> A”. FIG. 6 shows a graph in the case where there are three types of boosted voltage values V1, 500V, 600V and 700V. As shown in FIG. 6, as the stator temperature of the motor 7A increases and as the boosted voltage value V1 increases, the insulation performance inside the motor deteriorates and the motor 7A tends to break down. It can be seen that the lifetime is shortened.

  Therefore, in the present embodiment, voltage upper limit value Vmax is based on the history of voltage command value V from HV-ECU 1, atmospheric pressure P detected by atmospheric pressure sensor 3, and stator temperature T of motor 7A. Control.

  Specifically, the voltage command value instructed from the HV-ECU 1 is V, the atmospheric pressure detected by the atmospheric pressure sensor 3 is P, the application time of the boosted voltage by the voltage command value V is t, and the stator temperature of the motor 7A is When T is set, the HV-ECU 1 presets a function A given by the following equation (2) using the voltage command value V, the atmospheric pressure P, the application time t, and the stator temperature T as parameters. The application time t may be simply the output time of the voltage command value V.

  As can be seen from the equation (2), the function A is a value obtained by integrating the function f (V, P, T) having the voltage command value V, the atmospheric pressure P, and the stator temperature T as parameters, and the application time t. Is defined.

At this time, the initial value is set to A ₀ = 0, and the HV-ECU 1 uses the values of the current voltage command value V, the atmospheric pressure P, the stator temperature T, and the application time t, and the function A of Equation (2) Calculate the value. The value of the function A thus obtained is added to the initial value A ₀ to calculate A ₁ (= A + A ₀ ). Next, A ₂ (= A + A ₁ ) is calculated in the same manner. This calculation is repeated, and when the value of A _n = A + A _n−1 reaches a preset threshold Ath, the upper limit value Vmax of the voltage command value V is decreased. Hereinafter, A ₁ , A ₂ ,..., A _n−1 , _An are referred to as cumulative values as in the first embodiment.

  Hereinafter, the operation of the HV-ECU 1 according to the present embodiment will be described with reference to the flowchart of FIG. Here, the routine shown in FIG. 7 is referred to as a “motor insulation protection routine”.

  In the “motor insulation protection routine” in the present embodiment, as shown in FIG. 7, first, in step S20, HV-ECU 1 outputs voltage command value V output from HV-ECU 1 to DC / DC converter 4. Read and store in a storage device (not shown). At this time, the voltage value application time t based on the voltage command value V is also read and stored in the storage device.

  Next, in step S21, the HV-ECU 1 detects the atmospheric pressure P based on the detection signal received from the atmospheric pressure sensor 3, reads it, and stores it in the storage device.

  Next, in step S22, the HV-ECU 1 detects the stator temperature T based on the detection signal detected by the thermistor received from the motor 7A, reads it, and stores it in the storage device.

  Next, in step S23, the HV-ECU 1 uses the voltage command value V, the atmospheric pressure P, the stator temperature T, and the application time t stored in the storage device (not shown), and the above equation (2). The value of function A is calculated.

Next, in step S24, the value of the function A obtained this time is added to the accumulated value A _n−1 calculated in the previous routine and stored in the storage device, and the accumulated value A _n = A + A _n in the current routine is added. ₋₁ is calculated and stored in the storage device.

Next, in step S25, HV-ECU 1, the accumulated value _{A n} obtained in step S24, determines whether or exceeds the threshold value Ath previously set. If the result of determination is that the accumulated value _{A n} exceeds the threshold value Ath, the process proceeds to step S26. On the other hand, if the cumulative value _An is equal to or smaller than the threshold value Ath as a result of the determination, the process proceeds to step S27.

  In step S26, the HV-ECU 1 sets the upper limit value Vmax of the voltage command value V instructed from the HV-ECU 1 to the DC / DC converter 4, the first upper limit value Vmax1 that is the current upper limit value, and the second upper limit value. Change to Vmax2. The second upper limit value Vmax2 is set to a value lower than the first upper limit value. Note that the values of the first upper limit value Vmax1 and the second upper limit value Vmax2 are determined in advance and stored in the storage device.

  On the other hand, in step S27, the HV-ECU 1 does not change the upper limit value Vmax1 of the voltage command value V instructed from the HV-ECU 1 to the DC / DC converter 4.

  HV-ECU 1 according to the present embodiment determines upper limit value Vmax of voltage command value V as described above.

  Then, the HV-ECU 1 controls the output voltage of the DC / DC converter 4 within a voltage range equal to or lower than the upper limit value Vmax determined in step S26 or step S27. That is, when the voltage command value V output from the HV-ECU 1 exceeds the upper limit value Vmax, the voltage command value V is rounded to the upper limit value Vmax by replacing the voltage command value V with the upper limit value Vmax. To do.

  In consideration of the degree of insulation deterioration with respect to voltage, atmospheric pressure, and stator temperature, the function A is preferably represented by the following equation (3).

  Here, k, α, and β are coefficients set in advance.

  Others are the same as in the first embodiment, and a description thereof is omitted here.

  In the above description, the voltage command value V instructed from the HV-ECU 1 is described as the parameter V in the equations (2) and (3) as the parameter V of the function A. However, the present invention is not limited to this case. The boosted voltage value V1 output from the DC / DC converter 4 to the inverter 6 side may be used as the parameter V. However, in that case, it is necessary to provide a voltage sensor for detecting the boosted voltage value V1 output from the DC / DC converter 4 to the inverter 6 side. The voltage value detected by the voltage sensor is output to the HV-ECU 1.

8, based on the above arrangement and operation, the upper limit value Vmax of the motion and the voltage command value V of the cumulative value A _n of the function A calculated by the HV-ECU 1 constituting a control apparatus according to this embodiment Shows changes. In FIG. 8, the horizontal axis represents “time”, and the vertical axis represents “cumulative value A _{n of} function A”.

As shown in FIG. 8, the initial upper limit value Vmax is set to Vmax1. At this time, when the voltage command value V in the vehicle is low, when the vehicle is traveling on a flat ground and the atmospheric pressure P is high, or when the stator temperature T is low, or at least one of these If the value of the function a is small, the slope of the cumulative value a _n continue the gradual increase (e.g. X1 region of Figure 8).

Conversely, when the voltage command value V of the vehicle is high, and, when the atmospheric pressure P is low, the vehicle is not traveling on a highland such as a mountain area, the value of the function A is large, the gradient of the cumulative value A _n is The sudden rise continues (for example, the region X2 in FIG. 8).

  Others are the same as those of the first embodiment, and are omitted.

In the present embodiment, by taking into account also the stator temperature T even when the same voltage and the same pressure, with respect to the first embodiment, it is possible to moderate the gradient of the cumulative value A _n, the upper limit value Vmax The time to decrease can be made longer.

  In the present embodiment, as described above, the maximum performance of the motor 7A can be ensured for a longer time while ensuring the insulation and reliability of the motor 7A by taking into account the insulation deterioration of the stator temperature T. .

  As described above, in the present embodiment, the same effect as in the first embodiment can be obtained. Further, in this embodiment, the motor 7A detects the stator temperature T of the motor 7A. The function A is a function A = ∫f (V, P, T) dt having the stator temperature T as a parameter, and the upper limit value provided in the HV-ECU 1. The setting unit sets the upper limit value Vmax for the voltage command value V based on the history of the voltage command value V, the atmospheric pressure P, and the stator temperature T stored in the storage device. Thus, by taking into account the insulation deterioration of the motor 7A due to the stator temperature T, the maximum performance of the motor 7A can be secured for a longer time while further ensuring the insulation and reliability of the motor 7A.

  Furthermore, when the function A is set as shown in the above equation (3) and is a function that takes into account the degree of deterioration of insulation with respect to voltage, atmospheric pressure, and stator temperature, the voltage command value for the insulation of the motor The timing for changing the upper limit value Vmax of V can be accurately determined, and the maximum performance of the electric motor can be ensured for a longer time while ensuring the insulation and reliability of the motor.

Embodiment 3 FIG.
The present embodiment is a modification of the above-described second embodiment.
The present embodiment is the same as the second embodiment in that the value of the function A is calculated using the above formula (2) or (3), but the difference from the second embodiment is that The embodiment is characterized in that the function A is calculated only when the voltage command value V is equal to or higher than the threshold value Vth and the atmospheric pressure P detected by the atmospheric pressure sensor 3 is equal to or lower than the threshold value Pth.

  Hereinafter, the operation of the HV-ECU 1 according to the present embodiment will be described with reference to the flowchart of FIG. Here, the routine shown in FIG. 9 is referred to as a “motor insulation protection routine”.

  In the “motor insulation protection routine” in the present embodiment, as shown in FIG. 9, first, in step S30, HV-ECU 1 uses voltage command value V output from HV-ECU 1 to DC / DC converter 4. Read and store in a storage device (not shown). At this time, the application time t of the boosted voltage value V1 based on the voltage command value V is also read and stored in the storage device. The application time t may be simply the output time of the voltage command value V.

  Next, in step S31, the HV-ECU 1 detects the atmospheric pressure P based on the detection signal received from the atmospheric pressure sensor 3, reads it, and stores it in the storage device.

  Next, in step S32, the HV-ECU 1 detects the stator temperature T based on the detection signal detected by the thermistor received from the motor 7A, reads it, and stores it in the storage device.

  Next, in step S33, the HV-ECU 1 compares the voltage command value V stored in the storage device with a preset threshold value Vth. Further, the HV-ECU 1 compares the atmospheric pressure P stored in the storage device with a preset threshold value Pth. As a result of the comparison, if the voltage command value V> the threshold value Vth and the atmospheric pressure P <the threshold value Pth, the process proceeds to step S34.

  On the other hand, if the comparison result of step S33 shows that the voltage command value V> the threshold value Vth and the atmospheric pressure P <the threshold value Pth, the process proceeds to step S38, and the upper limit value Vmax for the voltage command value V is not changed. , "Motor dielectric breakdown routine" is exited.

  In step S34, the HV-ECU 1 uses the voltage command value V, the atmospheric pressure P, the stator temperature T, and the application time t stored in the storage device (not shown), and the above equation (2) or ( The value of function A in 3) is calculated.

Next, in step S35, the value of the function A obtained this time is added to the accumulated value A _n−1 calculated and stored in the previous routine, and the accumulated value A _n = A + A _n−1 in the current routine is obtained. Calculate and store in the storage device.

Next, in step S36, HV-ECU 1, the accumulated value _{A n} obtained in step S35 it is determined whether it exceeds a threshold value Ath previously set. If the result of determination is that the accumulated value _{A n} exceeds the threshold value Ath, the process proceeds to step S37. On the other hand, when the cumulative value _An is equal to or smaller than the threshold value Ath as a result of the determination, the process proceeds to step S38.

  In step S37, the HV-ECU 1 changes the upper limit value Vmax of the voltage command value V instructed from the HV-ECU 1 to the DC / DC converter 4 from the first upper limit value Vmax1 that is the current upper limit value. Change to Vmax2. The second upper limit value Vmax2 is set to a value lower than the first upper limit value. Note that the values of the first upper limit value Vmax1 and the second upper limit value Vmax2 are determined in advance and stored in the storage device.

  On the other hand, in step S38, the HV-ECU 1 does not change the upper limit value Vmax1 of the voltage command value V instructed from the HV-ECU 1 to the DC / DC converter 4.

  HV-ECU 1 according to the present embodiment determines upper limit value Vmax of voltage command value V as described above.

  The HV-ECU 1 controls the output voltage of the DC / DC converter 4 within a voltage range equal to or lower than the upper limit value Vmax determined in step S37 or step S38. That is, when the voltage command value V output from the HV-ECU 1 exceeds the upper limit value Vmax, the voltage command value V is rounded to the upper limit value Vmax by replacing the voltage command value V with the upper limit value Vmax. To do.

  Others are the same as those of the second embodiment and are omitted.

10, based on the configuration and flowchart as described above, the upper limit value Vmax of the motion and the voltage command value V of the cumulative value A _n of the function A calculated by the HV-ECU 1 constituting a control apparatus according to this embodiment Shows changes. In FIG. 10, the horizontal axis represents “time” and the vertical axis represents “cumulative value A _{n of} function A”.

As shown in FIG. 10, the initial upper limit value Vmax is set to Vmax1. At this time, if the voltage command value V in the vehicle is lower than the threshold value Vth, or if the vehicle is traveling on a flat ground and the atmospheric pressure P is higher than the threshold value Pth, or both, the cumulative value _An Is not calculated, and does not change from the previous cumulative value A _n−1 and remains the value of A _n−1 , so A _n = A _n−1 (for example, the region X3 in FIG. 10).

Conversely, when the voltage command value V in the vehicle is higher than the threshold value Vth, and when the vehicle is traveling in a highland such as a mountainous area and the atmospheric pressure P is lower than the threshold value Pth, the above formula (2) or the above formula the value of the function a shown in (3) is calculated, (X4 region of, for example, FIG. 10) the value of the function a is added to the accumulated value a _n-1 of the previous accumulated value a _n is continuing to rise.

  Others are the same as those of the second embodiment, and the description thereof is omitted.

In the present embodiment, as the voltage command value V increases, as the atmospheric pressure P decreases, the influence on the motor insulation deterioration increases. Therefore, a region where the influence on the insulation deterioration is large (voltage command value V> Vth, by updating the accumulated value _{a n} atmospheric pressure P <Pth) only, since the region accumulated value _{a n} is not changed is present, with respect to the first and second embodiments, the upper limit value Vmax for the voltage command value V It is possible to further increase the time until the decrease. As a result, the maximum performance of the motor can be ensured for a longer time while ensuring the insulation and reliability of the motor.

  In addition, in order to apply the control device of the present embodiment to an automobile electric motor, considering the altitude movement range of the automobile and the required life of the automobile, the threshold value Vth is set in the range of 300 to 500V, It is preferable to set the threshold value Pth in the range of 50 to 70 kPa.

  Further, the detected atmospheric pressure P and threshold value Pth may be physical quantities corresponding to the atmospheric pressure instead of the atmospheric pressure. However, the threshold value Pth for the atmospheric pressure P at that time is set to a value corresponding to the range of the atmospheric pressure of 50 to 70 kPa.

As described above, according to the present embodiment, the same effects as those of the first and second embodiments can be obtained. Further, according to the present embodiment, the cumulative value calculation provided in the HV-ECU 1 can be calculated. part is, the voltage command value V greater than the threshold value Vth, and atmospheric pressure P only when the threshold value Pth smaller, and updates the accumulated value a _n of the function a, otherwise, the accumulated value a of the function a _n is not updated and is kept at the previous value. As the voltage command value V increases, the influence of the motor on the insulation deterioration increases as the atmospheric pressure P decreases. Therefore, the region having a large influence on the insulation deterioration (voltage command value V> V1, atmospheric pressure P <P1 ) by considering only, since the accumulated value a _n does not change (no unnecessary addition) region exists, it is possible to further increase the time before lowering the upper limit value Vmax, motor insulation resistance and The maximum performance of the motor can be secured for a longer time while ensuring reliability.

Embodiment 4 FIG.
In the above first to third embodiments, the upper limit value Vmax for the voltage command value V is two types, Vmax1 and Vmax2, but in this embodiment, the upper limit value Vmax for the voltage command value V is set to three or more types. has a characteristic according to the value of the accumulated value a _n of the function a, a point going stepwise lowering the value of the upper limit value Vmax.

  Since the operation of the program executed by the HV-ECU 1 that is the control device according to the present embodiment is the same as that of the second or third embodiment, the description thereof is omitted here. However, in the present embodiment, the processing in step S25 in FIG. 7 or step S36 in FIG. 9 is slightly different. The difference will be described below.

Figure 11 shows the change in the upper limit value Vmax for the motion and the voltage command value V of the cumulative value A _n of the function A calculated by the HV-ECU 1 constituting a control device according to the present embodiment. In FIG. 11, the horizontal axis represents “time” and the vertical axis represents “cumulative value A _{n of} function A”.

  As shown in FIG. 11, in the present embodiment, HV-ECU 1 has a plurality of types of upper limit values Vmax. In the example of FIG. 11, the upper limit value Vmax has three types of settings: a first upper limit value Vmax1, which is an initial value, a second upper limit value, Vmax2, and a third upper limit value, Vmax3. These are set so as to satisfy the magnitude relationship of the upper limit value Vmax3 <the upper limit value Vmax2 <the upper limit value Vmax1. The types of upper limit values are not limited to three types, and may be four or more types.

As shown in FIG. 11, in this embodiment, the first threshold value HV-ECU 1 is the accumulated value _{A n} calculated in function A of the above formula (2) or formula (3) is predetermined Ath1 Is reached (Y1 point in FIG. 11), the upper limit value Vmax of the voltage command value V is changed from the first upper limit value Vmax1 to the second upper limit value Vmax2. Thereafter, the voltage command value V from the HV-ECU 1 is operated within a range of Vmax2 or less.

Further, when the vehicle travels and the accumulated value _An reaches the second threshold value Ath2 (Y2 point in FIG. 11), the HV-ECU 1 sets the upper limit value Vmax of the voltage command value V to the second upper limit value. The Vmax2 is changed to the third upper limit value Vmax3. Thereafter, the voltage command value V from the HV-ECU 1 is operated within a range of Vmax3 or less. Thus, in the present embodiment, as shown below, for each threshold value Athn, the value of the upper limit value Vmaxn + 1 is stored in the storage device in association with the threshold value Athn. Is reached, the upper limit value Vmax is changed to Vmaxn + 1.

<Value of threshold Ath><Upper limit value Vmax>
Cumulative value _An is less than or equal to threshold value Ath1 → set to Vmax1 (initial value)
Accumulated value _{A n} reaches the threshold Ath1 → Vmax2 to change the accumulated value _{A n} is changed to threshold Ath2 reach → Vmax3
・ ・
・ ・
・ ・
Change accumulation value _{A n} reaches the threshold Athn-1 → Vmaxn changes accumulated value _{A n} is, reaches the threshold Athn → Vmaxn + 1

  Other operations are the same as those in the second to third embodiments, and a description thereof will be omitted here. In the above description, the case where the present embodiment is applied to the second to third embodiments is described as an example. However, the present embodiment is not limited to this case, and the present embodiment is also applied to the first embodiment. Needless to say, it is applicable.

  In the present embodiment, as described above, a plurality of upper limit values Vmax with respect to voltage command value V are provided, and the upper limit value Vmax is decreased step by step. 3, the lowering of the upper limit value Vmax of the voltage command value can be suppressed as much as possible while ensuring the insulation and reliability of the motor, and the maximum performance reduction of the motor can be suppressed as much as possible.

  In order to apply the control device according to the present embodiment to an electric motor for an automobile, considering the altitude movement range of the automobile and the required life of the automobile, each type of set value of the upper limit value max is set to 300V. It is preferable to set in the range of ~ 700V.

As described above, in the present embodiment, the same effects as in the first to third embodiments can be obtained, and in the present embodiment, the upper limit value setting unit provided in the HV-ECU 1 is has stepwise a plurality of threshold value Ath, the accumulated value a _n calculated by the cumulative value calculation unit, depending on whether more than one threshold Ath, the value of the upper limit value Vmax for the voltage command value V Was gradually reduced. In this way, by having a plurality of upper limit values Vmax, it is possible to suppress the lowering of the upper limit value Vmax, which is the maximum value of the voltage command value V, as much as possible while ensuring the insulation and reliability of the motor, and to maximize the motor performance. The reduction can be suppressed as much as possible.

  The first to fourth embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the first to fourth embodiments but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

  1 HV-ECU, 2 vehicle ECU, 3 atmospheric pressure sensor, 4 DC / DC converter, 5 battery, 6 inverter, 7, 7A motor.

Claims (5)

A control device for an electric motor mounted on a vehicle,
The vehicle is
An electrical device for supplying power to the motor;
An atmospheric pressure sensor for detecting the atmospheric pressure P around the vehicle,
The controller is
A voltage command value for calculating a voltage command value V for controlling an applied voltage applied to the electric motor and the electric device according to a rotation speed of the electric motor and an output required by the electric motor when the vehicle travels A calculation unit;
A storage unit for storing a history of the voltage command value V and the atmospheric pressure P;
History of the voltage command value V and the atmospheric pressure P stored in the storage unit so that the voltage command value V calculated by the voltage command value calculation unit is controlled within a voltage range of an upper limit value Vmax. An upper limit value setting unit for setting an upper limit value Vmax for the voltage command value V,
The function A = ∫f (V, P) dt is calculated using the voltage command value V, the atmospheric pressure P, and the applied voltage application time t as parameters, and the value of the function A was calculated last time. by adding to the accumulated value _{a n-1,} and an accumulated value calculating section for updating the accumulated value _{a n = a + a n-} 1 of the function a,
The upper limit setting unit, when the accumulated value A _n calculated by the accumulated value calculating section exceeds the threshold value Ath, resetting decreases the value of the upper limit value Vmax for the voltage command value V,
Control device. The electric motor includes a temperature sensor for detecting a stator temperature T of the electric motor,
The function A is a function A = ∫f (V, P, T) dt with the stator temperature T as a parameter,
The storage unit stores a history of the voltage command value V, the atmospheric pressure P, and the stator temperature T,
The upper limit value setting unit sets an upper limit value Vmax for the voltage command value V based on the history of the voltage command value V, the atmospheric pressure P, and the stator temperature T stored in the storage unit.
The control device according to claim 1. The accumulated value calculating section, the voltage command value V is greater than the threshold value Vth, and the atmospheric pressure P only when the threshold value Pth smaller, and updates the accumulated value A _n of the function A, otherwise the control device according to claim 1 or 2, while the previous value without updating the accumulated value a _n of the function a. The upper limit setting portion has a value stepwise plurality of the threshold Ath, the accumulated value A _n calculated by the cumulative value calculation unit, depending on whether more than one threshold value Ath, The control device according to any one of claims 1 to 3, wherein a value of an upper limit value Vmax with respect to the voltage command value V is decreased stepwise. The function A is

Where k, α, β are preset coefficients,
The control device according to any one of claims 2 to 4.

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