JP4655431B2 - Generator motor device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular generator motor apparatus.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, it has been known to perform various functions such as engine starting, power generation, on-vehicle equipment driving at idle stop, regenerative braking, torque assist, and the like with one vehicle generator motor, and in particular, this vehicle generator motor In general, a synchronous machine with a simple structure and high efficiency is generally used.
[0003]
As a synchronous machine used for a vehicular generator motor, a magnet field type, a field winding type, a combined use of a magnet field and a field winding, etc. are known, and the magnet field type has the simplest structure However, in order to prevent demagnetization at high speed, it is necessary to reduce the generated voltage by supplying a phase shift current (demagnetization current) to the armature. In contrast, the field winding type and combined type can solve the above demagnetization problem by reducing the field current at high speed, but extra power consumption increases due to field current conduction, There is a drawback that the efficiency is lower than that of the magnet field type when the magnet is not demagnetized.
[0004]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicular generator motor apparatus that can respond to various demands with a single vehicular rotating electrical machine while suppressing a decrease in efficiency. Yes.
[0005]
[Means for Solving the Problems]
The generator motor device for a vehicle according to claim 1 is disposed between an AC generator motor having a field winding and receiving power from an engine, and between the AC generator motor and a battery to perform orthogonal bidirectional power conversion. An inverter, switching means for controlling a field current flowing through the field winding, and a stator current for driving the inverter at a predetermined duty and passing a predetermined armature current through the armature winding of the AC generator motor Control means;
Periodically short-circuiting the armature winding by driving the inverter at a predetermined short duty at a predetermined low speed, the boost to charge the battery of the power generation current before Ki交 flow generator motor by opening A vehicular generator-motor apparatus comprising control means having a boost power generation mode,
The control means stores a combination of the armature current and the field current at which the apparatus efficiency is substantially the highest in the power generation output (or power generation current) and the rotation speed of the AC generator motor required in the boost power generation mode. In the boost power generation mode, the armature current and the field current are set to the stored combination.
[0006]
It should be noted that the above description “generated current (generated output)” means “generated current or generated output”.
[0007]
That is, according to the present invention, the engine speed is low speed, and the operation of periodically short-circuiting the armature winding of the vehicle generator motor that is a field winding type synchronous machine by switching of the inverter (in this specification, In the operation of charging the battery by performing an inverter short-circuit operation (hereinafter also referred to as a low-speed power generation mode or a boost power generation mode), the combination of the armature current and the field current in which the operation efficiency is maximized is stored in advance. In addition, since the step-up power generation mode is executed by setting the armature current and the field current, the fuel efficiency can be improved with the device efficiency at the low speed rotation of the engine as the highest level.
[0008]
Preferably, the inverter feedback-controls the armature current to its target value (the value of the selected armature current) by controlling the duty (short-circuit duty) during the short-circuit operation period.
[0009]
Further explanation will be given.
[0010]
Generally, a generator motor that is a synchronous machine has an advantage that functions of a starter for engine start and an alternator for power generation can be realized by a single rotating electric machine. Since a large output torque is required for starting the engine, it is necessary to increase the field flux of the synchronous machine. If the field flux is large, the generated voltage becomes excessive during high-speed rotation. Therefore, it is preferable to suppress the generated voltage during high-speed rotation by using a generator motor as a field winding type synchronous machine. In order to start the engine with this field winding type generator-motor, it is effective to maximize the field current and secure the engine starting torque to reduce the size and weight of the generator-motor. Even in the case of power generation during low-speed rotation such as when the vehicle is stopped, the field current is set to be large.
[0011]
However, the fact that a large armature current can flow in the engine starting speed range means that the back electromotive voltage of the armature coil is set to be small (the number of turns of the armature coil is set to be relatively small). As a result, this means that a sufficient generated voltage necessary for battery charging cannot be secured in the low-speed rotation region (low-speed power generation mode) immediately above the engine start rotation zone. In other words, as is well known, it is necessary for the generator motor to generate a considerably higher voltage when charging the battery than when discharging the battery. For this reason, in this low-speed power generation mode, the armature winding is periodically short-circuited by turning on the switching element of the inverter, the generated energy is stored in the generator motor as magnetic energy, and then the armature winding short-circuit is released. Thus, it is preferable to generate a high-voltage generated voltage at both ends of the armature winding so that the battery can be charged. At this time, if the short-circuit duty (armature winding short-circuit period) is small, the magnetic energy storage is not sufficient, so that the amount of generated voltage rise and the battery chargeable period are shortened, and conversely the short-circuit duty (armature winding short-circuit period) ) Is large, the magnetic energy storage is sufficient, so that the amount of increase in the generated voltage and the battery chargeable period are thereby extended. That is, since the short-circuit duty is related to the battery charging capacity, the generated voltage in the low-speed power generation mode can be controlled by both the armature current (short-circuit duty) of the inverter and the field current.
[0012]
Here, the present inventor has noticed that if the field current is increased too much, the power loss due to the field current increases, so that it is not advantageous in terms of device efficiency. That is, the field current and the armature current for obtaining a necessary generated voltage at a certain low speed have a suitable range in terms of device efficiency. Therefore, it can be stored in advance in the control device as data or equivalent. By incorporating this control as a circuit and selectively executing it in the low-speed power generation mode, the low-speed power generation mode can be executed with high efficiency that can be realized, and fuel efficiency can be improved. In other words, the battery can be charged in the low-speed power generation mode while suppressing the field current and reducing the DC power loss.
[0013]
In this configuration, in particular, the low-speed power generation mode has a fixed rotational speed (for example, idle rotational speed) to some extent, and an average generated current (power generation output) value (for example, average vehicle electric load device consumption) It is preferable to store an armature current and a field current that can obtain a substantially maximum device efficiency in terms of power value. This is because, for example, the period during which the engine is operated at the idling engine speed in the low-speed power generation mode is sometimes long, the overall efficiency is improved by obtaining the maximum device efficiency in this engine speed region.
[0014]
According to a second aspect of the present invention, in the vehicular generator / motor apparatus according to the first aspect, the control means further includes an electric quantity related to the armature current and an electric quantity related to the field current in the boost power generation mode. And the power generation output (or power generation current) and device efficiency are stored in advance, and the device efficiency in the boost power generation mode is substantially highest based on the required power generation output (or power generation current) and the storage. A combination of the armature current and the field current is selected.
[0015]
Furthermore, the present inventor has noticed that the relationship among the armature current, the field current, and the maximum device efficiency fluctuates when the required generated current (generated output) changes in the low-speed power generation mode. For example, when the armature current (short-circuit duty) is reduced, the battery chargeable period is shortened, but this is sufficient when the generated current (generated output) is small. Therefore, in this configuration, the relationship among the armature current, the field current, and the maximum device efficiency is stored in advance for each generated current (generated output), and this stored content is determined according to the required generated current (generated output). Select the armature and field current values that will always give the highest device efficiency. Thereby, the apparatus efficiency can be further improved.
[0016]
In this configuration, it is particularly preferable to store an armature current and a field current that can obtain the maximum device efficiency at a fixed rotational speed, for example, an idle rotational speed, to some extent as the low-speed power generation mode. This is because, for example, the operation period at the idling speed is long in the low-speed power generation mode, so that the overall efficiency is improved by obtaining the maximum device efficiency in this speed range.
[0017]
At this time, the maximum values of the armature current and the field current may be restricted due to the temperature rise of the control circuit or the generator motor. Naturally, the combination of the armature current and the field current actually used should be selected within the limits of these other limiting conditions.
[0018]
Structure of claim 3, wherein further the generator-motor apparatus for a vehicle according to claim 1, further comprising a rotational speed detecting means for detecting a rotational speed of the front Ki交 flow generator motor,
The control means stores in advance the relationship between the amount of electricity related to the armature current, the amount of electricity related to the field current, the device efficiency, and the rotational speed in the boost power generation mode, and the detected rotational speed and the storage Based on the above, the combination of the armature current and the field current at which the device efficiency in the boost power generation mode is substantially highest is selected.
[0019]
The inventor further noticed that the relationship among the armature current, the field current, and the maximum device efficiency fluctuates when the rotational speed is changed in the low-speed power generation mode. For example, when the rotational speed increases in the low-speed power generation mode, the armature current or field current necessary for obtaining the necessary generated current (generated output) decreases. Therefore, in this configuration, the relationship between the armature current, the field current, and the maximum device efficiency is stored in advance for each rotation speed, and the armature that always has the maximum device efficiency from this stored content according to the current rotation speed. Select values for current and field current. Thereby, the apparatus efficiency can be further improved.
[0020]
In this configuration, in particular, the armature current and the field current at which the highest device efficiency can be obtained with the average generated current (generated output) value in the low-speed power generation mode (for example, the average power consumption value of the on-vehicle electric load device) Is preferably stored.
[0021]
According to a fourth aspect of the present invention, in the vehicular generator motor apparatus according to the third aspect, the control means further includes an electric quantity relating to the armature current, an electric quantity relating to the field current, and a power generation output (in the boost power generation mode). The relationship between the power generation current), the device efficiency, and the rotational speed is stored in advance, and the device efficiency in the boost power generation mode based on the detected rotational speed, the required power generation output (power generation current), and the storage. Is selected from the combination of the armature current and the field current that is substantially the highest.
[0022]
That is, in this configuration, in the low-speed power generation mode, the relationship between the armature current, the field current, and the maximum device efficiency is stored in advance for each rotation speed and generation current (power generation output), and the current rotation speed and generation current are stored. The values of the armature current and the field current, which are always the highest device efficiency, are selected from the stored contents according to (power generation output). Thereby, the apparatus efficiency can be further improved.
[0039]
According to a fifth aspect of the present invention, in the vehicular generator / motor apparatus according to any one of the first to fourth aspects, the control means further includes an engine start mode in which the AC generator motor is electrically driven to start the engine. Since the field current and the armature current are set to the maximum levels at least in the initial stage, a large engine starting torque can be obtained with a small vehicular generator motor when starting the engine.
[0043]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the invention are illustrated by the following examples.
[0044]
(overall structure)
FIG. 1 is a block diagram showing a vehicle drive system equipped with the vehicular generator motor apparatus of this embodiment.
[0045]
DESCRIPTION OF SYMBOLS 1 is an engine, 2 is a generator motor for vehicles, 3 is an inverter, 4 is a battery, 5 is a rotation sensor, 6 is a controller, 7 is an electromagnetic clutch, 8 is a belt, 9 is an air conditioner compressor (vehicle equipment), 10 is a battery 4 is a field current control switch that intermittently controls the field current supplied from 4 to the field winding of the generator motor 2. An in-vehicle device (not shown) is further connected to the belt 8, but the illustration is omitted.
[0046]
The engine 1 is connected to a belt 8 through a pulley in which an electromagnetic clutch 7 is built, and the belt 8 is connected to a pulley of the generator motor 2 and an air conditioner compressor 9.
[0047]
The generator motor 2 is composed of a field winding type three-phase synchronous machine, and is connected to the battery 4 through the inverter 3 so as to be able to exchange orthogonal bidirectional power.
[0048]
The inverter 3 has six arms (a U-phase upper arm, a U-phase lower arm, a V-phase upper arm, a V-phase upper arm, a W-phase upper arm, and a W-phase) composed of a switching element and a flywheel diode connected in reverse parallel thereto. This is a well-known three-phase inverter having an upper arm), and its illustration is omitted.
[0049]
The controller 6 intermittently controls the switching elements of the inverter 3 based on the rotation angle of the generator motor 2 obtained from the rotation sensor 5. Further, the controller 6 controls the inverter 3 based on the rotation speed of the generator motor 2 obtained from the output signal of the rotation sensor 5, the state of charge of the battery 4, information from an engine ECU (not shown), etc. The size and phase are controlled, the duty of the field current control switch 10 is adjusted, the field current supplied to the field winding of the generator motor 2 is controlled, and the contact / separation of the electromagnetic clutch 7 is controlled.
[0050]
Since the above-described apparatus configuration itself is already well known, further detailed description is omitted.
[0051]
(Operation control)
The operation control of this apparatus performed by the controller 6 will be specifically described below with reference to the flowcharts shown in FIG.
[0052]
First, the controller 6 and the like are initialized when the IG switch is turned on, and then input data such as the rotational speed and battery voltage of the generator motor 2 is read and communicated with the engine ECU to detect the engine operating state (S100).
[0053]
Next, an operation mode in which the generator motor 2 should operate is determined based on the read data (S102). In this embodiment, the generator motor 2 has four engine start modes, step-up power generation modes, normal power generation modes, and in-vehicle device drive modes described below. Of course, a torque assist mode and a regenerative braking mode may be added.
[0054]
Next, it is determined whether or not the engine start mode has been selected (S104). If it is not the engine start mode, the process skips the next step S106 and jumps to step S108.
[0055]
If it is the engine start mode, the process proceeds to step S106, the electromagnetic clutch 7 is engaged, the initial value of the field current If is the maximum value of the field current (the duty of the field current control switch is 100%), and the maximum value of the armature current Ia. The generator motor 2 is electrically driven to start the engine at (the duty value corresponding to the current value limited by the duty of the switching element of the inverter 3 or the maximum current of the switching element), and the battery capacity increases as the engine speed increases. From the viewpoint of saving and improving efficiency, the armature current Ia and the field current If may be gradually decreased. When the rotational speed of the generator motor 2 reaches a predetermined value N1 that can be increased by itself, the armature current Ia for electric operation is set to 0 (the switching element of the inverter 3) while maintaining the field current If at the final value of the engine start mode. Of the generator motor 2 is stopped and the process proceeds to the next step S108.
[0056]
In step S108, it is determined whether or not the boost power generation mode is selected. If the boost power generation mode is not selected, the process skips to next step S110 and jumps to step S112.
[0057]
If it is the step-up power generation mode, the process proceeds to step S110, and the step-up power generation mode is performed. Here, the boost power generation mode will be described in more detail. In this boosting power generation mode, all the switching elements of the upper arm of the inverter 3 are turned off and all the switching elements of the lower arm are turned on every predetermined cycle, and the three-phase armature winding of the generator motor 2 is turned on for a predetermined short-circuit period. Only short circuit. At this time, since all the switching elements of the upper arm are turned off, the battery is not short-circuited. Conversely, it goes without saying that all the switching elements of the upper arm may be turned on and all the switching elements of the lower arm may be turned off. Moreover, you may short-circuit either the upper or lower arm of two phases instead of all three phases. A large current flows through the armature winding that is short-circuited by the generated voltage generated by the armature that rotates during this short-circuit period, and magnetic energy is accumulated in the armature winding inductance. When this short-circuit period ends, the short circuit of the switching element of the inverter 3 is eliminated, and as a result, a charging current flows to the battery through the flywheel diode of the inverter due to a large generated voltage generated at both ends of the armature winding. A value obtained by multiplying the predetermined period by the denominator and the short-circuit period by 100% is the short-circuit duty, and an increase of the short-circuit duty to a predetermined value contributes to an increase in charging current.
[0058]
Furthermore, in this embodiment, the built-in nonvolatile memory of the controller 6 includes the rotation speed, the generated current (generated output), the armature current Ia (or the short-circuit duty Ds) and the field current If that provide the highest device efficiency. The relationship with the pair is stored as a map.
[0059]
Therefore, the current rotational speed and the required power generation current (power generation output) are substituted into this map, and a pair of the armature current Ia and the field current If that obtains the highest device efficiency is read out. The required generation current (generation output) here is a value obtained from a current sensor (not shown), or a suitable battery charging current value calculated from the difference between the battery voltage and its target voltage. You may obtain | require by calculating the value which added the current consumption value of the present vehicle-mounted electrical equipment. Then, the short-circuit duty Ds is adjusted so that the obtained armature current Ia is obtained, the inverter 3 is periodically short-circuited with this short-circuit duty Ds, and the field current If value obtained by determining the duty of the field current control switch The field current control switch is controlled as a value corresponding to.
[0060]
In step S112, it is determined whether or not the normal power generation mode is selected. If the normal power generation mode is not selected, the process skips to the next step S114 and jumps to step S116.
[0061]
If it is the normal power generation mode, the process proceeds to step S114, where the field current control switch 10 is intermittently controlled based on the comparison result between the battery voltage and the target voltage, and the normal power generation control for converging the battery voltage to the target voltage is performed. Proceed to step 116.
[0062]
In step 116, it is determined whether or not the in-vehicle device drive mode is selected. If the in-vehicle device drive mode is not selected, the process bypasses the next step S118 and returns to step S100.
[0063]
If it is the in-vehicle device drive mode, the process proceeds to step S118 and the in-vehicle device drive mode is executed. Here, the in-vehicle device drive mode will be described in more detail. In this in-vehicle device drive mode, normal motor control is performed in which the switching element of the inverter 3 is controlled to form a pseudo three-phase AC voltage waveform and applied to the three-phase armature winding of the generator motor 2.
[0064]
Furthermore, in this embodiment, the built-in nonvolatile memory of the controller 6 stores the relationship between the rotational speed and the pair of the armature current Ia and the field current If that obtains the highest device efficiency as a map.
[0065]
Therefore, the current rotational speed is substituted into this map, and a pair of the armature current Ia and the field current If that obtains the highest device efficiency is read out. Then, the inverter 3 is cyclically operated while adjusting the duty so as to obtain the obtained armature current Ia, and the field current control switch 10 duty is determined as a value corresponding to the value of the field current If obtained. The current control switch 10 is controlled.
[0066]
According to the control described above, the above-described maximum device efficiency can be realized in the low-speed power generation mode and the in-vehicle device drive mode without incurring the complexity of the device configuration.
[0067]
(Modification)
Of the map used in the above embodiment, either or both of the rotational speed and the generated current (generated output) or the electric current (electric output) may be omitted. When both are omitted, the low-speed power generation mode or the in-vehicle device drive mode can be operated with a pair of armature current and field current that provides the highest device efficiency at a specific rotation speed and armature current. .
[0068]
Further, the duty of the field current control switch 10 may be stored instead of storing the field current If.
[0069]
(Modification)
In the in-vehicle device drive mode, when the power steering pump is activated by the driver's steering wheel operation while the armature current / field current pair that maximizes the device efficiency is selected, the load on the generator motor suddenly increases. growing. Therefore, in this case, the necessary output can be obtained (or the output is maximized) and the field current from the operation with the combination of the armature current and the field current that temporarily maximizes the efficiency. By changing to operation in combination with current, it is possible to achieve both improvement in device efficiency and response to heavy load drive without increasing the size of the generator motor.
[0070]
This specific control will be described with reference to FIG. 3. In step 120, it is checked whether or not the electric output is insufficient. If it is insufficient, the electric output is increased as necessary only in step S122. That's fine. Normally, in the in-vehicle device drive mode, the in-vehicle device drive rotation speed is determined in advance, and therefore, it may be determined whether the rotation speed is lower than the predetermined rotation speed. In the case of a decrease, the armature current or field current may be increased to increase the electric output so as to maintain the predetermined rotation speed. Of course, in this case as well, the armature current and the field with the least damage of the device efficiency are minimized based on the map between the armature current, the field current and the device efficiency stored in advance at the predetermined rotational speed. It is preferable to select a combination with a magnetic current.
[0071]
In addition, when it demonstrates further, when a certain vehicle equipment is turned on, the load concerning a generator motor will increase rapidly. Since the inductance of the field coil is large, it takes time to increase the electric output by increasing the field current. In addition, immediately after the certain vehicle-mounted device is turned on, the rotational speed of the certain vehicle-mounted device needs to be accelerated from 0 to a predetermined preferable value. After reaching the value, it is necessary to make it larger than the electric power required to maintain this preferred rotational value. Therefore, when it is detected that a certain in-vehicle device is turned on (when a shortage of electric output is detected), first, the above-mentioned acceleration is improved by performing the maximum electric output operation capable of outputting the generator motor, and then the appropriate rotation What is necessary is just to adjust an armature current and a field current so that it may become the electric output which can ensure a number. In step 120, whether or not the electric output is insufficient is determined by the number of revolutions, and an electric machine for obtaining the output of the required generator motor by adding the expected load power value of the on-vehicle device that is turned on. The determination may be made based on whether the combination of the child current and the field current deviates from the maximum efficiency. In addition, the armature current and the field current are feedback-controlled to maintain a suitable rotational speed, and the armature current, the field current, and the calculated electric output when the rotational speed converges to the suitable rotational speed are calculated. Substituting into the map of armature current, field current, electric power output, and device efficiency stored in advance, and selecting the pair of armature current and field current that provides the best device efficiency at this time, Further, the armature current and the field current may be adjusted respectively.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a vehicle drive system equipped with an example of a vehicular generator motor apparatus of the present invention.
FIG. 2 is a flowchart showing a control operation of the apparatus of FIG.
FIG. 3 is a flowchart showing a control operation of the apparatus of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine 2 Generator motor 3 for vehicles Inverter 4 Battery 5 Rotation sensor (rotation number detection means)
6 Controller (control means)
7 Electromagnetic clutch 8 Belt 9 Air conditioner compressor (on-vehicle equipment)
10 Field current control switch (switching means)

Claims (5)

An AC generator motor that has a field winding and receives power from the engine;
An inverter arranged between the AC generator motor and the battery to perform orthogonal bidirectional power conversion;
Switching means for controlling a field current flowing in the field winding;
Stator current control means for driving the inverter with a predetermined duty to pass a predetermined armature current through the armature winding of the AC generator motor;
Periodically short-circuiting the armature winding by driving the inverter at a predetermined short duty at a predetermined low speed, the boost to charge the battery of the power generation current before Ki交 flow generator motor by opening Control means having a boost power generation mode;
A vehicular generator motor apparatus comprising:
The control means includes
Storing the combination of the armature current and the field current at which the apparatus efficiency is substantially the highest in the power generation output (or power generation current) and rotation speed of the AC generator motor required in the boost power generation mode;
The vehicular generator-motor apparatus, wherein the armature current and the field current are set to the stored combination in the boost power generation mode. The vehicular generator motor apparatus according to claim 1,
The control means includes
A relationship between the amount of electricity related to the armature current, the amount of electricity related to the field current, the generated output (or generated current), and the device efficiency in the boost power generation mode is stored in advance, and the required generated output (or generated current) is stored. ) And the memory, a combination of the armature current and the field current at which the device efficiency in the boost power generation mode is substantially maximized is selected. The vehicular generator motor apparatus according to claim 1,
It has a rotation speed detecting means for detecting a rotational speed of the front Ki交 flow generator motor,
The control means includes
The relationship between the amount of electricity related to the armature current and the amount of electricity related to the field current, the device efficiency, and the rotational speed in the boost power generation mode is stored in advance, and based on the detected rotational speed and the storage A generator motor apparatus for a vehicle, wherein a combination of the armature current and the field current at which the apparatus efficiency in the step-up power generation mode is substantially highest is selected. In the vehicular generator motor device according to claim 3,
The control means includes
A relationship between the amount of electricity related to the armature current, the amount of electricity related to the field current, the power generation output (power generation current), the device efficiency, and the rotational speed in the boost power generation mode is stored in advance, and the detected rotational speed A vehicle, wherein a combination of the armature current and the field current at which the device efficiency in the boost power generation mode is substantially highest is selected based on a required power generation output (power generation current) and the memory. Generator motor equipment. In the vehicular generator motor device according to any one of claims 1 to 4 ,
The vehicle generator motor apparatus is characterized in that the control means sets the field current and armature current to a maximum level at least at an initial stage of an engine start mode in which the AC generator motor is electrically driven to start the engine. .

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