JP2003319507A - Hybrid system, hybrid system controlling method and computer readable recording medium in which program is recorded for to control the hybrid system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid system capable of charging with a simple and low-cost capacitor provided at the input side of an inverter that drives a driving motor on cranking a hybrid car. <P>SOLUTION: In a hybrid system 100, when cranking the hybrid car, a starter 23 starts the engine 22, which rotates the motor 21, which then generates electric power. A controller 30 receives an output voltage V1 of a DC power source 10 and a voltage V2 between both terminals of a capacitor 12 with voltage sensors 11, 13 respectively, and, when a difference between the voltage V1 and the voltage V2 is larger than prescribed, controls the inverter 14 in such a way as to charge the capacitor 12 with the electric power generated by the driving motor 21. When the difference between the voltage V1 and the voltage V2 becomes smaller than prescribed, the controller 30 turns on a system relay 20. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid system mounted on a hybrid vehicle, a control method for the hybrid system, and a computer-readable recording medium having a program for causing a computer to execute control of the hybrid system. Is.

[0002]

2. Description of the Related Art Recently, a hybrid vehicle has attracted a great deal of attention as an environment-friendly vehicle. And, some hybrid vehicles have been put to practical use.

This hybrid vehicle is a vehicle that uses, as a power source, a DC power supply, an inverter, and a motor driven by the inverter in addition to the conventional engine. That is, the power source is obtained by driving the engine, and the DC voltage from the DC power source is converted into AC by the inverter, and the motor is rotated by the converted AC to obtain the power source.

Such a hybrid vehicle is equipped with a motor drive device 110 shown in FIG. Referring to FIG. 6, motor drive device 110 includes DC power supply 111, system relays 112 and 114, resistor 113, capacitor 115, inverter 116, and drive motor 117.
With.

The DC power supply 111 is a system relay 112.
And a DC voltage is supplied to the capacitor 115 via the resistor 113 or the system relay 114. The capacitor 115 smoothes the DC voltage from the DC power supply 111,
Inverter 1 using the smoothed DC voltage as input voltage
Supply to 16.

The inverter 116 switches the DC voltage supplied from the capacitor 115 based on a signal from a controller (not shown) to convert it into an AC voltage, and generates a predetermined torque by the converted AC voltage. The drive motor 117 is driven as described above.

In a hybrid vehicle, when starting,
The drive motor 117 is driven by the motor drive device 110, and the predetermined torque generated by the drive motor 117 is transmitted to the drive wheels. In this case, if the charged amount of the capacitor 115 is small, when the system relay 114 is turned on at the time of starting, the difference between the DC voltage V1 output from the DC power supply 111 and the voltage V2 across the capacitor 115 is large. Inrush current may flow through the capacitor 115, which may shorten the contact life of the system relay 114.

Therefore, in order to solve such a problem, the DC power supply 111 is started when the hybrid vehicle is started.
In order to prevent the inrush current from the capacitor to the capacitor 115,
With the system relay 114 turned off, the system relay 112 is turned on and a DC voltage is supplied from the DC power supply 111 to the capacitor 115 via the resistor 113 so that the capacitor 1
15 is charged, and when the difference between the DC voltage V1 from the DC power source 111 and the voltage V2 across the capacitor 115 becomes small, the system relay 112 is turned off and the system relay 114 is turned on to turn off the capacitor from the DC power source 111. 11
Supplying a DC voltage to 5 is performed.

[0009]

However, in the conventional method shown in FIG. 6, the DC power supply 111 is connected to the capacitor 115.
In order to prevent the inrush current to the system relay 11
2 and the resistor 113 are additionally required, and it is difficult to reduce the number of parts and reduce the cost of the hybrid vehicle.

A method of precharging a capacitor supplying an input voltage to an inverter without using the system relay 112 and the resistor 113 shown in FIG. 6 is disclosed in Japanese Patent Laid-Open No. 5-3366.
No. 11 publication. JP-A-5-336611
The publication discloses an electric system 200 shown in FIG. Referring to FIG. 7, an electric system 200 includes a main battery 210, a main switch 220, a fuse 230, a capacitor 240, an inverter 250, an AC motor 260 for driving a wheel, an auxiliary switch 270, and a DC- D
C converter 280, auxiliary battery 290, DC load 3
00 and.

In the electric system 200, the DC power supply 210 supplies a DC voltage to the capacitor 240 via the fuse 230 when the main switch 220 is turned on, and the capacitor 240 smoothes the DC voltage to invert the inverter 2.
Supply 50. Inverter 250 switches a DC voltage to convert it into an AC voltage, and drives AC motor 260 with the converted AC voltage.

In the electric system 200, the electric system including the auxiliary switch 270, the DC-DC converter 280, the auxiliary battery 290 and the DC load 300 has a capacitor 240, an inverter 250 and an AC motor 2.
It is connected in parallel with the electric system consisting of 60. Then, the DC-DC converter 280 uses the auxiliary switch 27.
When 0 is turned on, the auxiliary battery 290 is charged based on the DC voltage from the DC power supply 210. In addition, the DC-DC converter 280 charges the auxiliary battery 290 and then, based on the DC voltage from the auxiliary battery 290, the capacitor 240.
To charge. That is, the DC-DC converter 280
Is a circuit for charging the auxiliary battery 290 and a capacitor 24.
0 charging circuit. The auxiliary battery 290 supplies a DC voltage to the DC load 300.

When the electric vehicle is started, in the electric system 200, the auxiliary switch 270 is turned on.
Then, the DC-DC converter 280 is connected to the DC power supply 21.
A DC voltage from 0 is used to charge the auxiliary battery 290.
When the charging of the auxiliary battery 290 is completed, the auxiliary switch 27
When 0 is turned off, the DC-DC converter 280 charges the capacitor 240 using the DC voltage from the auxiliary battery 290.

After that, when the charging of the capacitor 240 is completed, the main switch 220 is turned on, and the capacitor 240 is turned on.
Supplies the DC voltage from the DC power supply 210 to the inverter 250 by smoothing the DC voltage. Then, the inverter 250 converts the DC voltage into the AC voltage to convert the AC motor 2
Drive 60.

Therefore, in the electric system 200, an inverter using the DC-DC converter 280 and the auxiliary battery 290, which are an electric system different from the electric system including the DC power source 210 for driving the AC electric motor 260, the capacitor 240 and the inverter 250. The capacitor 240 provided on the input side of 250 is charged.

Then, in the conventional electric system disclosed in Japanese Unexamined Patent Publication No. 5-336611, in order to charge the capacitor provided on the input side of the inverter that drives the AC motor at the time of starting the electric vehicle, the boosting function is used. There is a need for a DC-DC converter that has both a step-down function and a step-down function. As a result, an expensive DC-DC converter must be used, and there is a problem that a low-cost electric system cannot be realized.

Therefore, the present invention has been made to solve such a problem, and an object thereof is to simplify a capacitor provided on the input side of an inverter for driving a drive motor during cranking of a hybrid vehicle, and ,
It is to provide a hybrid system that can be charged with a low-cost configuration.

Another object of the present invention is to simplify a capacitor provided on the input side of an inverter that drives a drive motor during cranking of a hybrid vehicle, and
It is an object to provide a control method for a hybrid system that can be charged with a low-cost configuration.

Another object of the present invention is to control a hybrid system in which a capacitor provided on the input side of an inverter for driving a drive motor during cranking of a hybrid vehicle can be charged with a simple and low-cost structure. It is to provide a computer-readable recording medium in which a program for causing a computer to execute is recorded.

[0020]

According to the present invention, a hybrid system is a hybrid system mounted on a hybrid vehicle, in which a starting motor for starting an engine and a motor connected to the engine. A generator, an inverter that drives the motor generator, and a capacitor that supplies an input voltage to the inverter, and the capacitor is charged by the electric power generated by the motor generator when the starting motor starts the engine during cranking of the hybrid vehicle. To be done.

[0021] Preferably, the hybrid system further comprises a first power supply for supplying a voltage to the starting motor and a second power supply for supplying a voltage to the motor generator, and the motor generator is provided with the first power supply during cranking. Rotate using the voltage from.

More preferably, the hybrid system further comprises a system relay controlling the supply of voltage from the second power supply to the capacitor, the system relay being turned on when the capacitor reaches a predetermined precharge state.

Further, preferably, the hybrid system includes a first voltage sensor for detecting a first voltage output from the second power source and a second voltage sensor for detecting a second voltage across the capacitor. And a control circuit for switching the system relay from off to on when the difference between the first voltage and the second voltage is smaller than a predetermined value.

Further, preferably, the predetermined value is determined based on the resistance value from the second power source to the capacitor.

Further, preferably, the first power source is the second power source.
The voltage is lower than that of the power supply. According to the present invention, the control method is a control method during cranking of a hybrid vehicle, the first step of starting the engine by the starting motor and the second step of rotating the motor generator by the started engine. And a third step of charging a capacitor that supplies an input voltage to an inverter that drives the motor generator using electric power generated by the rotation of the motor generator.

Preferably, the motor generator is rotated by the voltage applied to the starting motor.

More preferably, the control method comprises a fourth step of detecting whether or not the capacitor has reached a predetermined precharge state, and a voltage supply from the DC power supply to the capacitor when the precharge state is reached. And a fifth step of switching a system relay that controls the switch from off to on.

Further, preferably, by detecting whether or not the difference between the first voltage output from the DC power supply and the second voltage across the capacitor is smaller than a predetermined value, the capacitor is set to a predetermined It detects whether or not the charge state is reached.

According to the present invention, the computer-readable recording medium in which the program for causing the computer to execute the control at the time of cranking the hybrid vehicle is recorded is the first step of starting the engine by the starting motor, Using the second step of rotating the motor generator by the started engine and the electric power generated by the rotation of the motor generator,
It is a computer-readable recording medium recording a program for causing a computer to execute a third step of charging a capacitor that supplies an input voltage to an inverter that drives a motor generator.

Preferably, the motor generator is rotated by the voltage applied to the starting motor.

More preferably, the computer-readable recording medium in which a program to be executed by a computer is recorded has a fourth step of detecting whether or not a capacitor has reached a predetermined precharge state, and a precharge state. And the fifth step of switching the system relay controlling the supply of the voltage from the DC power source to the capacitor from OFF to ON is further executed by the computer.

Further, it is preferable that the capacitor can detect a predetermined voltage by detecting whether the difference between the first voltage output from the DC power supply and the second voltage across the capacitor is smaller than a predetermined value. It detects whether or not the charge state is reached.

Therefore, according to the present invention, until the difference between the voltage output from the DC power source and the voltage across the capacitor provided on the input side of the inverter for driving the motor generator becomes smaller than a predetermined value. During cranking of a hybrid vehicle, the starter starts the engine to rotate the motor generator to cause the motor generator to generate electric power, and the AC voltage generated by the motor generator is used to charge the capacitor. Generation of an inrush current from the DC power supply to the capacitor can be prevented without separately providing a DC converter or a system relay and a resistor.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference characters and description thereof will not be repeated.

Referring to FIG. 1, a hybrid system 100 according to an embodiment of the present invention includes DC power supplies 10 and 2.
5, voltage sensors 11 and 13, a capacitor 12,
The inverter 14, system relays 20 and 24, a drive motor 21, an engine 22, a starter 23, a current sensor 26, and a controller 30 are provided. The drive motor 21 is also referred to as “motor generator”.

The DC power supplies 10 and 25 are nickel-hydrogen or lithium-ion secondary batteries. DC power supply 10
Outputs a DC voltage of 36V, for example. The DC power supply 25 outputs a DC voltage of 12V, for example. The DC power supplies 10 and 25 may output DC voltages other than these voltage values, but the DC power supply 25 is the DC power supply 1
A DC voltage lower than 0 is output.

The voltage sensor 11 detects the DC voltage V1 output from the DC power supply 10, and outputs the detected DC voltage V1 to the control device 30. When the system relay 20 is turned on, the capacitor 12 receives the DC voltage from the DC power supply 10, smoothes the received DC voltage, and supplies the smoothed DC voltage to the inverter 14. The voltage sensor 13 detects the voltage V2 across the capacitor 12 and detects the detected voltage V2.
Is output to the control device 30.

The inverter 14 has a U-phase arm 15 and a V-phase arm 15.
It comprises a phase arm 16 and a W phase arm 17. The U-phase arm 15, the V-phase arm 16, and the W-phase arm 17 are provided in parallel between the power supply line and the ground.

The U-phase arm 15 includes NPNs connected in series.
It is composed of transistors Q3 and Q4, and the V-phase arm 16 is
It consists of NPN transistors Q5 and Q6 connected in series, and the W-phase arm 17 consists of NPN transistors Q7 and Q8 connected in series. Further, diodes D3 to D8 for flowing a current from the emitter side to the collector side are respectively connected between the collector and the emitter of each NPN transistor Q3 to Q8.

The midpoint of each phase arm is connected to each phase end of each phase coil of the drive motor 21. That is, the drive motor 21 is a three-phase permanent magnet motor, and U, V,
One end of three W-phase coils is commonly connected to the midpoint, and the other ends of the U-phase coils are NPN transistors Q3 and Q.
4, the other end of the V-phase coil is connected to the intermediate point of the NPN transistors Q5 and Q6, and the other end of the W-phase coil is connected to the intermediate point of the NPN transistors Q7 and Q8.

The current sensor 26 detects the motor current MCRT flowing through each phase of the drive motor 21 and outputs the detected motor current MCRT to the control device 30.

The control device 30 uses the voltage V2 detected by the voltage sensor 13, the motor current MCRT detected by the current sensor 26, and the torque command value TR, based on the torque command value TR, by a method to be described later to make a NPN transistor Q3 of the inverter 14. The switching of Q8 to Q8 controls the drive of the drive motor 21. Further, the control device 30 controls the capacitor 12 during cranking of the hybrid vehicle.
Of the DC voltage is controlled, and the supply of the DC voltage to the inverter 14 is controlled based on the voltage V1 detected by the voltage sensor 11 and the voltage V2 detected by the voltage sensor 13.

The system relay 20 includes a voltage sensor 11
When the difference between the voltage V1 detected by the voltage sensor V1 and the voltage V2 detected by the voltage sensor 13 is smaller than a predetermined value, the signal RS from the control device 30 turns on the DC power supply 1
The DC voltage output from 0 is supplied to the capacitor 12. The drive motor 21 is connected to the engine 22 via the input / output shaft.
When the hybrid vehicle is cranked, the engine 21 is started to generate electric power, and the generated electric power charges the capacitor 12 via the inverter 14. Further, the drive motor 21 generates a predetermined torque when driven by the inverter 14, and transmits the generated torque to drive wheels (not shown). Engine 2
When the starter 23 is activated by the starter 23, the drive motor 2 rotates the drive motor 21 via the input / output shaft. The starter 23 (also referred to as “starting motor”) is connected to the engine 22 via an input / output shaft.
When the system relay 24 is turned on, the engine 22 is started by the DC voltage from the DC power supply 25.
It should be noted that the engine 22 and the starter 23 may be connected by any of a pinion gear type and a belt type, and generally by any method.

The system relay 24 is turned on in response to turning on of an ignition key (not shown), and the DC power source 2
The DC voltage from 5 is supplied to the starter 23. The DC power supply 25 outputs a DC voltage.

FIG. 2 is a functional block diagram of the control device 30. Referring to FIG. 2, control device 30 includes a torque control unit 31 and a charge control unit 32. Torque control unit 31
Is the torque command value TR, the output voltage V1 of the DC power supply 10,
Based on the motor current MCRT, the motor speed MRN and the inverter input voltage V2, a PWM (Pulse Width Moth) for turning on / off the NPN transistors Q3 to Q8 of the inverter 14 by a method described later.
generation) signal and the generated PWM
The signal is output to the inverter 14.

The charge control unit 32 outputs a signal KR indicating that the hybrid vehicle has been cranked when the ignition key is turned on, to an ECU (Ele) provided outside.
It receives the voltage from the voltage sensor 11 and calculates the difference between the voltage V1 from the voltage sensor 11 and the voltage V2 from the voltage sensor 13 according to the received signal KR. Then, the charging control unit 32 converts the AC voltage generated by the drive motor 21 into a DC voltage when the calculated difference is larger than a predetermined value.
The PWC signal for controlling the switching of the NPN transistors Q4, Q6, Q8 is generated and output to the inverter 14.

In this case, the charge control unit 32 turns on the NPN transistors Q4 and Q8 of the inverter 14 when the V phase of the drive motor 21 is generated, and the NPN of the inverter 14 when the U phase of the drive motor 21 is generated. When the transistors Q6 and Q8 are turned on and power is generated in the W phase of the drive motor 21, NPN transistors Q4 and Q6 of the inverter 14 are generated.
Generate a PWC signal to turn on. That is, the charging control unit 32 controls the inverter 14 so as to convert the AC voltage generated by the drive motor 21 into a DC voltage when the drive motor 21 generates power.

The charging control unit 32 also generates a signal RS for turning on the system relay 20 when the calculated difference is smaller than a predetermined value, and outputs the signal RS to the system relay 20.

Referring to FIG. 3, torque control unit 31 includes a motor control phase voltage calculation unit 40 and an inverter PWM signal conversion unit 42.

The motor control phase voltage calculator 40 receives the input voltage V2 to the inverter 14 from the voltage sensor 13, and receives the motor current MCRT flowing in each phase of the drive motor 21.
Is received from the current sensor 26, and the torque command value TR is received from the external ECU. Then, the motor control phase voltage calculation unit 40 calculates the voltage applied to the coils of each phase of the drive motor 21 based on these input signals, and the calculated result is the inverter PWM signal conversion unit 42. Supply to. The inverter PWM signal conversion unit 42, based on the calculation result received from the motor control phase voltage calculation unit 40,
Actually, each NPN transistor Q3 to Q of the inverter 14
A PWM signal for turning on / off 8 is generated, and the generated PWM signal is used for each NPN transistor Q of the inverter 14.
Supply to 3 to Q8.

As a result, each NPN transistor Q3 ...
Q8 is switching-controlled and controls the current flowing through each phase of the drive motor 21 so that the drive motor 21 outputs the commanded motor torque. In this way, the motor drive current is controlled and the motor torque corresponding to the torque command value is output.

In this way, the torque control unit 31 of the control device 30 controls the inverter 14 so that the drive motor 21 generates the torque designated by the torque command value input from the external ECU. As a result, the drive motor 21 generates the torque designated by the torque command value.

The operation of the hybrid system 100 during cranking of a hybrid vehicle will be described with reference to FIG. When the operation during cranking starts, the ignition key IG is turned on (step S1) and the torque command value TR is set to "0" (step S2). Then, when the system relay 24 is turned on in response to the ignition key IG being turned on in step S1 and a DC voltage is supplied from the DC power supply 25, the starter 23 is turned on (step S).
3).

Then, the starter 23 is started (step S4) and the engine 22 is started. The charging control unit 32 included in the control device 30 receives a signal KR indicating that the hybrid vehicle has been cranked from the external ECU in response to the ignition key IG being turned on, and the voltage sensor 11 according to the signal KR. From the voltage V1 from the voltage sensor 13 and the voltage V2 from the voltage sensor 13 are calculated, and the calculated difference (the absolute value of the difference between the voltage V1 and the voltage V2 | V1-V
Say 2 | ) Is smaller than a predetermined value α (step S5). When the calculated difference is smaller than the predetermined value α, the DC power supply 1 is turned on even if the system relay 20 is turned on.
Since no rush current flows from 0 to the capacitor 12, the charging control unit 32 generates the signal RS for turning on the system relay 20 and outputs the signal RS to the system relay 20. Then, the system relay 20 is turned on according to the signal RS from the charging control unit 32 (step S6).

Then, the DC power supply 10 supplies the DC voltage to the capacitor 12, and the capacitor 12 smoothes the DC voltage from the DC power supply 10 and supplies it to the inverter 14. On the other hand, the torque control unit 31 of the control device 30 controls the drive motor 21 based on the torque command value TR, the output voltage V1 of the DC power supply 10, the motor current MCRT, the motor rotation speed MRN, and the inverter input voltage V2 as described above. The NPN transistors Q3 to Q8 of the inverter 14 are arranged to generate the torque designated by the torque command value TR.
A PWM signal for switching control is generated and output to the inverter 14.

As a result, the inverter 14 converts the DC voltage supplied from the capacitor 12 into an AC voltage and drives the drive motor 21. Then, it is determined whether or not the drive motor 21 / engine 22 is started (step S
7) When the drive motor 21 / engine 22 is started, the sequence for starting the drive motor 21 / engine 22 ends (step S8). On the other hand, when it is determined in step S7 that the drive motor 21 / engine 22 is not started, the torque that the drive motor 21 should generate is increased by ΔT (step S9), and then step S7 is repeated.

In step S5, the voltage V1 and the voltage V
When it is determined that the difference from 2 is not smaller than the predetermined value α, it is determined whether the drive motor 21 / engine 22 is started (step S10), and the drive motor 21 / engine 22 is started. When judged, step S
Return to 5. On the other hand, in step S10, the drive motor 2
1 / When it is determined that the engine 22 has not been started, the starter operation is continued (step S11). Only when it is determined in step S5 that the difference between the voltage V1 and the voltage V2 is smaller than the predetermined value α, the system relay 20 is turned on and the drive motor 21 is activated. Therefore, when it is determined in step S5 that the difference between the voltage V1 and the voltage V2 is not smaller than the predetermined value α, the system relay 20 is not turned on.
At 0, it is normally determined that the drive motor 21 / engine 22 is not started, and the starter operation is continued.

In this case, when the starter 23 starts the engine 22, the engine 22 rotates the drive motor 21 and the drive motor 21 generates electricity. On the other hand, the charging control unit 32
Is an NPN transistor Q of the inverter 14 for converting the AC voltage generated by the drive motor 21 into a DC voltage.
A PWC signal for controlling switching of 4, Q6 and Q8 is generated and output to the inverter 14. And NP
The N transistors Q4, Q6, Q8 are switching-controlled by the PWC signal, and when power is generated in the V phase of the drive motor 21, the NPN transistors Q4, Q8 are turned on,
When power is generated in the U phase of the drive motor 21, the NPN transistors Q6 and Q8 are turned on, and when power is generated in the W phase of the drive motor 21, the NPN transistors Q4 and Q6 are turned on. As a result, the inverter 14 converts the AC voltage generated by the drive motor 21 into a DC voltage, and charges the capacitor 12 with the converted DC voltage.

After the starter operation is continued, step S
Returning to 5, it is repeatedly determined whether the difference between the voltage V1 output from the DC power supply 10 and the voltage V2 across the capacitor 12 is smaller than a predetermined value. Then, according to the determination result, the above-described operations of steps S6 to S9 or steps S10 and S11 are repeatedly performed.

The predetermined value α is determined according to the resistance value from the DC power supply 10 to the capacitor 12. The rush current from the DC power supply 10 to the capacitor 12 is
This is because it depends on the resistance value from the capacitor to the capacitor 12.

Thus, when the hybrid vehicle is started, in the hybrid system 100, the difference between the voltage V1 output from the DC power supply 10 and the voltage V2 across the capacitor 12 provided on the input side of the inverter 14 is predetermined. It is determined whether or not the value is smaller than the value α, and only when the difference between the voltage V1 and the voltage V2 is smaller than the predetermined value α, the system relay 20 is turned on and the drive motor 21 is driven by the inverter 14. On the other hand, when the difference between the voltage V1 and the voltage V2 is not smaller than the predetermined value α, the drive motor 21
Is rotated by the engine 22 to generate electric power, and the generated electric power charges the capacitor 12. When the difference between the voltage V1 and the voltage V2 becomes smaller than the predetermined value α, the system relay 20 is turned on and the drive motor 21 is driven to generate torque.

Therefore, in the hybrid system 100 according to the present invention, the system relay 20 is turned on only when the difference between the voltage V1 output from the DC power supply 10 and the voltage V2 across the capacitor 12 is smaller than the predetermined value α. Therefore, the generation of the inrush current from the DC power supply 10 to the capacitor 12 can be prevented without separately providing a DC-DC converter or a system relay and a resistor for preventing the generation of the inrush current as in the conventional case.

The charging control unit 32 described above is specifically composed of the block diagram shown in FIG. With reference to FIG. 5, the charging control unit 32 includes a CPU (Central Process).
ing Unit) 321 and RAM (Random)
Access Memory 322 and ROM (Re
It includes an ad only memory) 323 and a bus BS.

The ROM 323 stores a program for controlling the operation of the hybrid system 100 during cranking of the hybrid vehicle described with reference to FIG. The RAM 322 is a work memory when the CPU 321 performs arithmetic processing. CPU 321 is R
The program stored in the OM 323 is read via the bus BS, and the voltage V1 from the voltage sensor 11 and the voltage V2 from the voltage sensor 13 are read according to the read program.
Is calculated to determine | V1−V2 | <α. Then, when determining that | V1−V2 | <α is not established, the CPU 321 generates the above-described PWC signal and outputs it to the inverter 14. Also, the CPU 321 determines that | V1-
When it is determined that V2 | <α is established, the system relay 2
A signal RS for turning on 0 is generated and output to the system relay 20.

As described above, the charging control unit 32 is
21, the ROM 323, the ROM 323, and the bus BS, the ROM 323 is a recording medium readable by a computer (CPU 321) that stores a program for causing the computer (CPU 321) to control the hybrid system 100.

As described above, the operation of the hybrid vehicle at the time of cranking has been described. In the present invention, "cranking" means a period from when the ignition key is turned on to when the engine is completely detonated. The meaning of "cranking" is described in more detail in Japanese Patent Application Laid-Open No. 60-173367 previously filed by the present applicant.

According to the present invention, in the hybrid system, when the hybrid vehicle is cranked, the difference between the voltage of the capacitor provided on the input side of the inverter for driving the drive motor and the voltage output from the DC power source is a predetermined value. If it is larger than the above value, the drive motor generates power by starting the engine, the capacitor is charged by the generated power, and the system relay is activated when the difference between the voltage of the capacitor and the voltage output from the DC power supply becomes smaller than a predetermined value. Since the charging control unit that controls to drive the drive motor so as to generate a predetermined torque by turning on is provided, it is not necessary to separately provide an expensive DC-DC converter or a system relay and a resistor as in the conventional case. It is possible to prevent generation of inrush current from the power supply to the capacitor.

The embodiments disclosed this time are to 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 embodiments but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a hybrid system according to the present invention.

FIG. 2 is a functional block diagram of the control device shown in FIG.

FIG. 3 is a functional block diagram for explaining the function of the torque control unit shown in FIG.

FIG. 4 is a flowchart for explaining the operation of the hybrid system during cranking of a hybrid vehicle.

5 is a block diagram of a charge control unit shown in FIG.

FIG. 6 is a conventional motor drive device.

FIG. 7 is a conventional electric system mounted on an electric vehicle.

[Explanation of symbols]

10,25,111 DC power supply, 11,13 Voltage sensor, 12,240 Capacitor, 14,116,250
Inverter, 20, 24, 112, 114 system relay, 21, 117 drive motor, 22 engine, 2
3 starter, 26 current sensor, 30 controller,
31 torque control unit, 32 charge control unit, 40 motor control phase voltage calculation unit, 42 inverter PWM signal conversion unit, 100 hybrid system, 110 motor drive device, 113 resistance, 200 electrical system, 21
0 main battery, 220 main switch, 230 fuse,
260 AC motor, 270 auxiliary switch, 280
DC-DC converter, 290 auxiliary battery, 300 DC load, 321 CPU, 322 RAM, 323 R
OM, BS bus.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02D 45/00 376 F02D 45/00 376B H02M 7/48 H02M 7/48 LF term (reference) 3G084 AA00 BA28 CA01 DA00 EA11 EB08 FA03 5H007 BB06 CA01 CB02 CB05 CC01 CC07 CC09 DA06 DC05 GA03 5H115 PA08 PC06 PG04 PI16 PI21 PO06 PO09 PU08 PU24 PV09 QE01 QN03 QN09 RB22 RE01 SE04 TI05

Claims (14)

[Claims] 1. A hybrid system mounted on a hybrid vehicle, comprising a starting motor for starting an engine, a motor generator connected to the engine, an inverter for driving the motor generator, and an input voltage to the inverter. And a capacitor that supplies the electric power generated by the motor generator when the starting motor starts the engine during cranking of the hybrid vehicle. 2. A first power source for applying a voltage to the starting motor, and a second power source for applying a voltage to the motor generator, wherein the motor generator is configured to perform the first power source during the cranking. The hybrid system according to claim 1, wherein the hybrid system is rotated by utilizing a voltage from. 3. A system relay controlling the supply of voltage from the second power supply to the capacitor, wherein the system relay is turned on when the capacitor reaches a predetermined precharge state. The hybrid system according to 2. 4. A first voltage sensor for detecting a first voltage output from the second power source, a second voltage sensor for detecting a second voltage across the capacitor, and the first voltage sensor. 4. The hybrid system according to claim 3, further comprising: a control circuit that switches the system relay from off to on when a difference between the second voltage and the second voltage is smaller than a predetermined value. 5. The hybrid system according to claim 4, wherein the predetermined value is determined based on a resistance value from the second power supply to the capacitor. 6. The hybrid system according to claim 2, wherein the first power supply has a lower voltage than the second power supply. 7. A control method for cranking a hybrid vehicle, comprising: a first step of starting an engine by a starting motor; a second step of rotating a motor generator by the started engine; A third method for charging a capacitor that supplies an input voltage to an inverter that drives the motor generator, using electric power generated by rotating the motor generator.
And a control method. 8. The control method according to claim 7, wherein the motor generator is rotated by a voltage applied to the starting motor. 9. A fourth step of detecting whether or not the capacitor has reached a predetermined precharge state, and controlling the supply of a voltage from a DC power supply to the capacitor when the precharge state is reached. The control method according to claim 8, further comprising a fifth step of switching the system relay from off to on. 10. The capacitor determines whether the difference between the first voltage output from the DC power supply and the second voltage across the capacitor is smaller than a predetermined value. The control method according to claim 9, further comprising detecting whether or not a precharge state is reached. 11. A computer-readable recording medium in which a program for causing a computer to execute control during cranking of a hybrid vehicle is recorded, the first step of starting an engine by a starting motor, and the starting. A second step of rotating the motor generator by the stored engine, and a third step of charging a capacitor that supplies an input voltage to an inverter that drives the motor generator, using electric power generated by the rotation of the motor generator.
And a computer-readable recording medium recording a program for causing a computer to execute the steps of. 12. The motor generator is rotated by a voltage applied to the starting motor.
1. A computer-readable recording medium in which the program to be executed by the computer according to 1 is recorded. 13. A fourth step of detecting whether or not the capacitor has reached a predetermined precharge state, and controlling the supply of voltage from a DC power supply to the capacitor when the precharge state is reached. The computer-readable recording medium which recorded the program for making a computer perform the 5th step which switches a system relay from OFF to ON further. 14. The capacitor is configured to detect the predetermined voltage by detecting whether a difference between a first voltage output from the DC power supply and a second voltage across the capacitor is smaller than a predetermined value. A computer-readable recording medium having recorded thereon a program to be executed by a computer according to claim 13, which detects whether or not a precharge state has been reached.