JP2004274978A - Controlling device for three-phase ac generator motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform conduction control for three-phase rectification simply and to charge a battery efficiently without being affected by the change of revolutions or a load, when the battery is charged by an output generated when a three-phase AC generator motor is driven as a generator. <P>SOLUTION: This controlling device for a three-phase AC generator motor serves as an AC inverter circuit when driven as a three-phase AC motor using a battery. MOS-FETs are used as controlling elements of each phase in a control circuit that functions as a three-phase rectifier circuit when the battery is charged by the output generated when driven as a three-phase AC generator. In this case, means are employed that makes the generator perform synchronous rectification using only the MOS-FETs at the negative potential side of each phase in the control circuit, and that makes conduction timing advance and delay by the gate control of the MOS-FETs at the negative potential side of each phase in the control circuit. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
[Industrial applications]
The present invention relates to a control functioning as a three-phase rectifier circuit that also serves as a three-phase inverter circuit when driven as a three-phase AC motor using a battery and that charges a battery with a generated output when driven as a three-phase AC generator. The present invention relates to a control device for a three-phase alternating-current power generator for controlling power supply to a circuit.
[0002]
[Prior art]
In general, a three-phase AC generator is mounted on a vehicle, and when the engine is started, the battery is used as a power source and driven as a three-phase AC motor via a three-phase inverter circuit. When driven, the battery is charged via the three-phase rectifier circuit.
[0003]
Recently, a control circuit that functions as a three-phase inverter circuit for driving such a three-phase AC generator as a motor and a three-phase rectifier for driving the three-phase AC generator as a generator are shown in FIG. As shown in FIG. 1, the control elements of the U, V, and W phases are controlled to be energized by using MOSFETs 1-6. In the figure, M / G is a three-phase AC generator of a permanent magnet type or the like, Batt is a battery, and D is a parasitic diode of a MOS-FET.
[0004]
Conventionally, in such a control circuit of a three-phase AC generator, when the three-phase AC generator M / G is driven as a generator to charge the battery Batt with the generated voltage, the battery Batt is controlled under the control of a controller (not shown). As shown in FIG. 2, the energization control is performed by turning on and off the gates of the MOSFETs 1 to 6 on both the positive potential side and the negative potential side in each phase.
[0005]
[Problems to be solved by the invention]
The problems to be solved are a three-phase inverter circuit when driving a three-phase AC generator as a motor using a battery and a three-phase rectification when driving a three-phase AC generator as a generator to charge a battery. In the control circuit that also serves as a circuit, a MOS-FET is used as a control element for each phase, and when functioning as a three-phase rectifier circuit during battery charging, the MOS-FET on the positive potential side and the negative potential side in each phase is used. Performing the energization control by turning on and off the gates of the FETs 1 to 6 complicates the control.
[0006]
Also, when charging the battery with the generated voltage of the three-phase AC generator, if the rotation speed or load of the three-phase AC generator fluctuates, the generated voltage fluctuates, and the charging voltage of the battery fluctuates. Problem.
[0007]
[Means for Solving the Problems]
The present invention also functions as a three-phase inverter circuit when driven as a three-phase AC motor using a battery, and functions as a three-phase rectifier circuit when the battery is charged with a power output when driven as a three-phase AC generator. A control device for a three-phase AC generator using a MOS-FET as a control element for each phase in a control circuit that performs three-phase rectification and simplifies energization control for the three-phase AC generator MOS-FET on the negative potential side of each phase in its control circuit when driving as a three-phase AC generator so that the battery can be charged efficiently without being affected by fluctuations in load and load. Means for performing synchronous rectification by using only the gate and controlling the gate of the MOS-FET on the negative potential side of each phase in the control circuit to advance or retard the energization timing. It has to take the means.
[0009]
【Example】
The control device of the three-phase AC generator motor according to the present invention has the configuration shown in FIG. 3 and drives the three-phase AC generator motor M / G as a generator to charge the battery Batt with the generated voltage. Under the control of a controller (not shown), three-phase rectification is performed by turning on / off each gate of only the MOS-FET 2, MOS-FET 4, and MOS-FET 6 on the negative potential side of each of the U, V, and W phases in the control circuit 1. Power supply control can be performed.
[0008]
FIG. 4 shows a three-phase rectified waveform (a) corresponding to the on / off state of each of the MOS-FETs 2, 4, and 6 on the negative potential side in each phase, between the drain D and the source S in each of the MOS-FETs 2, 4, and 6. The voltage waveform (b) and the induced voltage waveform of each phase with the U phase as the neutral point are shown. Note that the gates of the MOS-FETs 1, 3, and 5 on the positive potential side in each phase are kept off.
[0009]
FIG. 5 shows a three-phase rectified waveform (a) when all the MOSFETs 1 to 6 on the positive potential side and the negative potential side in each phase are turned off and three-phase rectification is performed by each parasitic diode D; The voltage waveform (b) between the drain D and the source S in each of the MOSFETs 2, 4, and 6 and the induced voltage waveform of each phase with the U phase as a neutral point are shown. FIG. 6 shows an equivalent circuit of the control circuit 1 at that time.
[0010]
As described above, when the battery Batt is charged with the voltage generated by the three-phase AC generator M / G, the MOS • FET2, the MOS • FET4, and the MOS • FET4 on the negative potential side of each of the U, V, and W phases in the control circuit 1. By performing the synchronous rectification using only the FET 6, the rectification loss can be reduced, and the charging efficiency of the battery Batt can be effectively increased. In addition, the control is simpler than in the case where the ON / OFF control of the gates of the MOSFETs 1 to 6 is performed on both the positive potential side and the negative potential side in each phase as in the related art.
[0011]
When the battery Batt is charged by the generated voltage of the three-phase AC generator M / G, the gates of the positive-side MOS-FETs 1, 3, and 5 of each phase in the control circuit 1 are kept off. Therefore, it is possible to prevent the three-phase AC generator motor M / G from malfunctioning as an electric motor.
[0012]
The present invention relates to such a control device for a three-phase AC generator, particularly when the battery Batt is charged with the generated voltage by driving the three-phase AC generator M / G as a generator. Under the control of the controller, the timing of the energizing timing 7 is controlled by turning on / off each gate of only the MOS-FET 2, MOS-FET 4, and MOS-FET 6 on the negative potential side of each phase of U, V, W in the control circuit 1. The angle and the retard are performed.
[0013]
In this case, if the generated voltage is excessively increased due to a change in the rotation speed or load of the three-phase AC generator M / G, the generated voltage is reduced by utilizing the demagnetization effect by advancing the energization timing, and the generated voltage is reduced. If the battery voltage is too low, the power generation voltage is increased by utilizing the magnetizing action by delaying the energization timing, so that the charging voltage of the battery Batt is always constant.
[0014]
FIG. 7 shows the timing of the energization control by turning ON / OFF the gates of only the MOS-FET2, MOS-FET4 and MOS-FET6 on the negative potential side of each phase of U, V, W in the control circuit 1 by 60 electrical degrees. In this case, the three-phase rectified waveform at that time (a), the voltage waveform between the drain D and source S in each of the MOSFETs 2, 4, and 6 (b), and the induction of each phase with the U phase as a neutral point The respective voltage waveforms are shown. Note that the gates of the MOS-FETs 1, 3, and 5 on the positive potential side in each phase are kept off.
[0015]
In this case, from the characteristics of the three-phase rectified waveform (a), the charging voltage of the battery Batt decreases to a predetermined value.
[0016]
FIG. 8 shows that the timing of the energization control by turning on and off only the gates of the MOS-FET 2, MOS-FET 4, and MOS-FET 6 on the negative potential side of each phase of U, V, and W in the control circuit 1 is delayed by 60 electrical degrees. In this case, the three-phase rectified waveform at that time (a), the voltage waveform between the drain D and source S in each of the MOSFETs 2, 4, and 6 (b), and the induction of each phase with the U phase as a neutral point The respective voltage waveforms are shown.
[0017]
In this case, the charging voltage of the battery Batt rises to a predetermined level due to the characteristics of the three-phase rectified waveform (a).
[0018]
FIG. 9 shows the characteristics of the control voltage with respect to the load current using the rotation speed as a parameter when the energization timing is controlled according to the present invention so that the charging voltage of the battery Batt becomes a constant 14 V.
[0019]
FIG. 10 shows the distribution characteristics of the charging efficiency of the battery Batt with respect to the load current and the rotation speed when the energization timing is controlled according to the present invention. Here, A is the distribution area of the charging efficiency of 85 to 90%, B is the distribution area of the charging efficiency of 80 to 85%, C is the distribution area of the charging efficiency of 70 to 80%, D is 60 to 70%. %, The distribution area of the charging efficiency of 50 to 60%, the distribution area of the charging efficiency of 40 to 50%, and the distribution area of the charging efficiency of 30 to 40%. Is shown.
[0020]
In the present invention, the energization timing is controlled so as to be in the distribution area of the charging efficiency shown by A and B in FIG.
[0021]
【The invention's effect】
As described above, the present invention also functions as a three-phase inverter circuit when driven as a three-phase AC motor using a battery, and is used to charge a battery by a power generation output when driven as a three-phase AC generator. In a control device for a three-phase AC generator using a MOS-FET as a control element for each phase in a control circuit functioning as a rectifier circuit, when driving as a three-phase AC generator, energizing control for three-phase rectification Battery charging can be performed efficiently without being affected by fluctuations in the rotational speed or load of the three-phase AC generator, reducing battery loss and damaging the unit due to overvoltage load. This has the advantage that prevention can be effectively achieved. In addition, there is an advantage that a battery charging voltage from a low rotation can be ensured when driven as a three-phase AC generator.
[Brief description of the drawings]
FIG. 1 shows a three-phase inverter circuit for driving a three-phase AC generator as a motor using a battery as a power source and a three-phase rectifier circuit for charging a battery by driving the three-phase AC generator as a generator. FIG. 3 is a diagram showing a control circuit using a MOS-FET as a control element for each phase.
FIG. 2 shows that the control circuit shown in FIG. 1 controls ON / OFF of a gate of a MOSFET on both the positive potential side and the negative potential side in each phase according to the output voltage of the three-phase AC generator during battery charging. It is a timing chart at the time.
FIG. 3 is a circuit diagram showing the control circuit shown in FIG. 1. According to the present invention, the energization control for three-phase rectification can be performed by turning on / off each gate of only the MOS-FET on the negative potential side of each phase. FIG. 9 is a diagram showing a current flow at the time.
FIG. 4 is a circuit diagram of the control circuit shown in FIG. 1 in which the gates of only the MOS-FETs on the negative potential side of each phase are turned on and off according to the present invention; The three-phase rectified waveform (a) according to ON / OFF, the voltage waveform (b) between the drain D and the source S in each MOS • FET, and the induced voltage waveform (c) of each phase with the U phase as a neutral point are shown. FIG.
FIG. 5 is a diagram illustrating the control circuit shown in FIG. 1 in which all the MOSFETs on the positive potential side and the negative potential side in each phase are turned off, and three-phase rectification is performed by each parasitic diode D; It is a figure which shows the three-phase rectification waveform (a), the voltage waveform (b) between drain-source in each MOS-FET, and the induced voltage waveform of each phase which made U phase a neutral point.
FIG. 6 is a circuit diagram showing the control circuit shown in FIG. 1 in which all the MOSFETs on the positive potential side and the negative potential side in each phase are turned off and three-phase rectification is performed by each parasitic diode D; FIG. 9 is a diagram showing an equivalent circuit at the time.
FIG. 7 shows a three-phase rectified waveform obtained by advancing the timing of energization control by turning on and off the gate of only the MOS-FET on the negative potential side of each phase in the control circuit shown in FIG. 1 by an electrical angle of 60 ° ( 3A is a diagram showing a drain-source voltage waveform (b) in each MOS • FET, and FIG. 4B is a diagram showing an induced voltage waveform in each phase with the U phase as a neutral point.
FIG. 8 is a three-phase rectified waveform when the timing of energization control by turning on and off only the gate of only the MOS-FET on the negative potential side of each phase in the control circuit shown in FIG. a), a voltage waveform (b) between the drain and the source in each MOS • FET, and an induced voltage waveform of each phase with the U phase as a neutral point.
FIG. 9 is a diagram showing a characteristic of a control voltage with respect to a load current using a rotation speed as a parameter when energization timing is controlled according to the present invention so that a charging voltage of a battery is a constant 14V.
FIG. 10 is a diagram showing a distribution characteristic of a battery charging efficiency with respect to a load current and a rotation speed when the energization timing is controlled according to the present invention.
[Explanation of symbols]
1 Control circuit M / G Three-phase AC generator motor Batt Battery D Parasitic diode

Claims (1)

In a control circuit that also functions as a three-phase inverter circuit when driven as a three-phase AC motor using a battery, and that functions as a three-phase rectifier circuit when the battery is charged by the power output when driven as a three-phase AC generator In a control device for a three-phase AC generator using a MOSFET for each phase control element, when driving as a three-phase AC generator, only the negative potential side MOSFET for each phase in the control circuit is used. Means for performing synchronous rectification by using the control circuit, and means for advancing and retarding the energization timing by controlling the gate of the MOS-FET on the negative potential side of each phase in the control circuit. Control device for three-phase AC generator motive.

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