WO2018047866A1

WO2018047866A1 - Control device for rotary electric machine

Info

Publication number: WO2018047866A1
Application number: PCT/JP2017/032126
Authority: WO
Inventors: 拓人鈴木
Original assignee: 株式会社デンソー
Priority date: 2016-09-12
Filing date: 2017-09-06
Publication date: 2018-03-15

Abstract

A control device (24) applied to a vehicle wherein an engine is automatically stopped when a prescribed automatic stopping condition is satisfied, and the engine is automatically restarted when a prescribed restarting condition subsequently is satisfied, said control device controlling a rotary electric machine (21) which has a power generation function based on the rotational force of the engine, and to which excitation current is supplied from a transistor chopper excitation circuit (23) wherein a first pair of opposing arms in a bridge circuit are configured from power transistors (Spa, Snb), and a second pair of arms are configured from diodes (Dna, Dpb). During automatic stopping of the engine the control device (24) executes a first grounding control wherein, among the first pair of arms, the power transistor (Snb) connected to the earth-side of the rotary electric machine is turned on, and the power transistor (Spa) connected to the output terminal side of the rotary electric machine is turned off.

Description

Control device for rotating electrical machine

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2016-177956 filed on September 12, 2016 and Japanese Application No. 2017-160310 filed on August 23, 2017, the contents of which are described herein. Is used.

The present disclosure relates to a control device that controls a rotating electrical machine having a power generation function.

Conventionally, this type of control device includes a transistor chopper type excitation circuit that supplies an excitation current of a vehicle generator, and regenerates a current that excites a rotor in a battery (see Patent Document 1). In the one described in Patent Document 1, in the excitation circuit, the power transistor connected to the ground side is turned on on condition that the key switch of the engine is off and the rotational speed of the engine is 200 rpm or less. The power transistor connected to the output terminal side is turned off. As a result, when the engine after running of the vehicle is in a non-operating state, the exciting winding of the rotor is prevented from being floated in potential, and the corrosion of the rotor due to leakage current is suppressed. Can do.

Japanese Patent No. 4442582

By the way, there is a vehicle that automatically stops the engine when a predetermined automatic stop condition is satisfied, and then automatically restarts the engine when a predetermined restart condition is satisfied. In such a vehicle, the generator stops while the engine is automatically stopped, and leakage current flows through the stopped rotor, which may cause corrosion of the rotor. The thing of patent document 1 does not consider that a rotor corrodes during an engine automatic stop, and still leaves the room for improvement.

Note that this situation is not limited to generators but is also common in rotating electrical machines having a power generation function.

The present disclosure has been made to solve the above-described problems, and has as its main object to provide a control device for a rotating electrical machine that can prevent the rotor from corroding during an automatic engine stop.

The first means for solving the above problems is as follows.
This is applied to a vehicle that automatically stops the engine when a predetermined automatic stop condition is satisfied, and then automatically restarts the engine when a predetermined restart condition is satisfied. An excitation current is supplied from a transistor chopper type excitation circuit in which arms are configured by power transistors and a second pair of arms are configured by diodes, and the rotating electrical machine having a power generation function based on the rotational force of the engine is controlled. A control device,
During the automatic stop of the engine, among the first pair of arms, the power transistor connected to the ground side of the rotating electrical machine is turned on, and the power connected to the output terminal side of the rotating electrical machine First ground control is performed to turn off the transistor.

According to the above configuration, in the vehicle, the engine is automatically stopped when a predetermined automatic stop condition is satisfied, and the engine is automatically restarted when a predetermined restart condition is satisfied thereafter. A rotating electrical machine having a power generation function is supplied with an excitation current from a transistor chopper type excitation circuit and generates power based on the rotational force of the engine.

Here, during the automatic engine stop, the power transistor connected to the grounding side of the rotating electrical machine is turned on and the power transistor connected to the output terminal side of the rotating electrical machine is turned off. The first ground control is executed. For this reason, even if the rotating electrical machine stops during the automatic stop of the engine, it is possible to prevent the rotor in the stopped state from being floated in terms of potential. Therefore, even if a leak current occurs, it can be passed to the ground via the power transistor on the ground side, and corrosion of the rotor during the automatic engine stop can be suppressed.

The automatic engine stop includes idling stop for stopping engine idling, engine stop during deceleration for stopping the engine when the vehicle decelerates, engine stop during coasting for stopping the engine during vehicle coasting, and the like. Further, during the automatic stop of the engine, the automatic stop includes from the time when the combustion of fuel in the engine is stopped to the time after the engine stops.

In the second means, the rotating electrical machine has a power running function for applying a rotational force to the engine in a state where an excitation current is supplied from the excitation circuit, and the first grounding is performed during the automatic stop of the engine. Before the control is executed, the first pair of arms is provided with a first diagnosis unit that turns on both the power transistors and diagnoses whether the excitation current flows.

According to the above configuration, the rotating electrical machine has a power running function for applying a rotational force to the engine in a state where an excitation current is supplied from the excitation circuit. For this reason, when the engine is restarted, a rotational force can be applied to the engine by the rotating electrical machine. However, when the power transistor of the excitation circuit is out of order, the excitation current cannot be supplied to the rotating electrical machine when the engine is restarted, and the rotational power cannot be applied to the engine by the rotating electrical machine.

In this regard, according to the above configuration, before the first ground control is executed during the automatic engine stop, both the power transistors are turned on in the first pair of arms to diagnose whether the excitation current flows. The first diagnosis is executed. For this reason, it is possible to execute the first grounding control after diagnosing whether or not the rotating electrical machine can apply the rotational force to the engine.

In the third means, each of the diodes constituting the second pair of arms utilizes a body diode of a power transistor, and during the automatic stop of the engine, of the second pair of arms, Second grounding control is performed to turn on the power transistor connected to the ground side of the rotating electrical machine and turn off the power transistor connected to the output terminal side of the rotating electrical machine.

According to the above configuration, each of the diodes constituting the second pair of arms uses a power transistor body diode. During the automatic engine stop, the power transistors in the second pair of arms are controlled, and the second grounding control is executed in the same manner as the first grounding control. For this reason, even if the rotating electrical machine stops during the automatic stop of the engine, it is possible to prevent the rotor in the stopped state from being floated in terms of potential.

In a fourth means, the rotating electrical machine has a power running function for applying a rotational force to the engine in a state where an excitation current is supplied from the excitation circuit, and the second grounding is performed during the automatic stop of the engine. Before the control is executed, a second diagnosis unit is provided that executes a second diagnosis for turning on both the power transistors in the second pair of arms and diagnosing whether the excitation current flows.

According to the above configuration, the power transistors in the second pair of arms are controlled, and the second diagnosis is executed in the same manner as the first diagnosis. For this reason, it is possible to execute the second grounding control after diagnosing whether or not the rotating electrical machine can apply the rotational force to the engine.

In the fifth means, each of the diodes constituting the second pair of arms uses a body diode of a power transistor, and before the first diagnosis is executed during the automatic stop of the engine, A second diagnostic unit for performing a second diagnostic for diagnosing whether or not the excitation current flows by turning on both of the power transistors in the second pair of arms; and An off control unit is provided that performs off control for turning off both the power transistors in the second pair of arms after both of the power transistors are turned on in the pair of arms.

According to the above configuration, the second diagnosis is executed before the first diagnosis is executed while the engine is automatically stopped. For this reason, it is possible to diagnose whether or not the rotating electric machine can apply the rotational force to the engine by flowing an exciting current through the second pair of arms.

Then, after both power transistors are turned on in the second pair of arms, off control is performed to turn off both power transistors in the second pair of arms. For this reason, it is possible to shift to the first diagnosis while avoiding a short circuit between the second pair of arms and the first pair of arms. Then, by executing the first diagnosis, it is diagnosed whether or not the rotating electric machine can apply the rotational force to the engine when the engine is restarted by flowing an exciting current through the first pair of arms. be able to.

In the sixth means, when the off control unit turns off both of the power transistors in the second pair of arms in the off control, the rotation of the second pair of arms is rotated. After the power transistor connected to the output terminal side of the electric machine is turned off, the power transistor connected to the ground side of the rotating electric machine is turned off.

According to the above configuration, when both power transistors in the second pair of arms are turned off in the off control, the power connected to the output terminal side of the rotating electrical machine in the second pair of arms. After the transistor is turned off, the power transistor connected to the ground side of the rotating electrical machine is turned off. For this reason, when the power transistor connected to the output terminal side of the rotating electrical machine is turned off, the same state as the state in which the second ground control is executed can be formed. Therefore, it is possible to shift to the first diagnosis after suppressing the rotor in the stopped state from floating in potential.

In the seventh means, the vehicle includes a starter that applies a rotational force to the engine when the engine is started, and when the first diagnosis unit diagnoses that the excitation current does not flow, When the engine is restarted, a rotational force is applied to the engine by the starter.

According to the above configuration, since the vehicle includes the starter that applies the rotational force to the engine when the engine is started, the rotational force can be applied to the engine by the starter when the engine is restarted. Therefore, when it is diagnosed that the exciting current does not flow in the first diagnosis, a rotational force is applied to the engine by the starter at the time of automatic restart. Therefore, the failure of the excitation circuit is diagnosed, and when the excitation circuit is broken, the engine can be restarted by the starter.

According to an eighth means, the vehicle includes a starter that applies a rotational force to the engine when the engine is started, and the first diagnosis unit or the second diagnosis unit diagnoses that the excitation current does not flow. In this case, a rotational force is applied to the engine by the starter during the automatic restart.

According to the above configuration, the failure of the excitation circuit is diagnosed in the first diagnosis and the second diagnosis, and the engine is restarted by the starter when it is diagnosed that the excitation current does not flow in the first diagnosis or the second diagnosis. Can do.

In the ninth means, the first ground contact control is executed on the condition that the rotational speed of the engine is lower than a predetermined rotational speed.

When the first grounding control is executed, the power transistor connected to the ground side of the rotating electrical machine is turned on in the first pair of arms, so that a closed circuit for flowing an exciting current is formed in the exciting circuit. The For this reason, when the rotational speed of the engine is high, electric power is generated in the rotating electrical machine, and an excessive braking torque may act on the engine.

In this respect, according to the above-described configuration, the first ground contact control is executed on the condition that the rotational speed of the engine is lower than the predetermined rotational speed. Therefore, during the automatic stop of the engine, the first grounding control is executed when the rotational speed of the engine is lower than the predetermined rotational speed, and the first grounding control is performed when the rotational speed of the engine is higher than the predetermined rotational speed. Not executed. Therefore, when the first ground contact control is executed, it is possible to suppress an excessive braking torque from acting on the engine.

In the tenth means, the second grounding control is executed on the condition that the rotational speed of the engine is lower than a predetermined rotational speed.

According to the above configuration, it is possible to suppress an excessive braking torque from acting on the engine when executing the second ground contact control.

When the voltage supplied to the excitation circuit is 48V, the leakage current flowing through the rotor is larger than when the voltage supplied to the excitation circuit is 12V, and the rotor is more easily corroded.

In this regard, in the eleventh means, a voltage of 48 V is supplied to the excitation circuit on the premise of any one of the first to tenth means. Therefore, corrosion of the rotor can be suppressed with respect to a configuration in which corrosion of the rotor easily proceeds.

Specifically, as in the twelfth means, a configuration in which the excitation current is supplied from the excitation circuit to the rotor winding of the rotating electrical machine can be adopted.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing
FIG. 1 is an electric circuit diagram showing an electrical configuration of a vehicle. FIG. 2 is an electric circuit diagram showing an electrical configuration of the rotating electrical machine unit, FIG. 3 is a flowchart showing procedures of diagnosis and ground control, FIG. 4 is an electric circuit diagram showing a modification example of the electrical configuration of the rotating electrical machine unit, FIG. 5 is an electric circuit diagram showing a modification of the electrical configuration of the vehicle.

Hereinafter, an embodiment embodied in a vehicle that travels by assisting (assisting) driving force by a rotating electrical machine using an engine (internal combustion engine) as a driving source will be described with reference to the drawings.

As shown in FIG. 1, the vehicle 10 includes an engine 42, a starter 13, a lead storage battery 11, a lithium ion storage battery 12,

electric loads

14 and 15, a rotating electrical machine unit 16, and the like.

The engine 42 is a gasoline engine, a diesel engine, or the like, and generates driving force by burning fuel. The starter 13 (starting device) applies an initial rotational force to the output shaft (crankshaft) of the engine 42 when the engine 42 is started.

The power supply system of the vehicle 10 is a dual power supply system having a lead storage battery 11 and a lithium ion storage battery 12 as a power storage unit. Each

storage battery

11, 12 can supply power to the starter 13, various

electric loads

14, 15, and the rotating electrical machine unit 16. Further, each of the

storage batteries

11 and 12 can be charged by the rotating electrical machine unit 16. In this system, a lead storage battery 11 and a lithium ion storage battery 12 are connected in parallel to the rotating electrical machine unit 16 and the

electrical loads

14 and 15, respectively.

The lead storage battery 11 is a well-known general-purpose storage battery. The lithium ion storage battery 12 is a high-density storage battery that has less power loss during charging / discharging and higher output density and energy density than the lead storage battery 11. The lithium ion storage battery 12 is desirably a storage battery having higher energy efficiency during charging / discharging than the lead storage battery 11. The lithium ion storage battery 12 is configured as an assembled battery having a plurality of single cells. These

storage batteries

11 and 12 have the same rated voltage, for example, 12V.

The lithium ion storage battery 12 is housed in a housing case and configured as a battery unit U integrated with a substrate. The battery unit U has two output terminals P1 and P2, among which the lead storage battery 11, the starter 13 and the electric load 14 are connected to the output terminal P1, and the electric load 15 and the rotating electrical machine unit are connected to the output terminal P2. 16 is connected.

The electric loads 14 and 15 have different requirements for the voltage of power supplied from the

storage batteries

11 and 12. Specifically, the electric load 14 includes a constant voltage required load that is required to be stable so that the voltage of the supplied power is constant or at least varies within a predetermined range. On the other hand, the electric load 15 is a general electric load other than the constant voltage required load.

Specific examples of the electric load 14 that is a constant voltage required load include various ECUs such as a navigation device, an audio device, a meter device, and an engine ECU. In this case, by suppressing the voltage fluctuation of the supplied power, it is possible to suppress the occurrence of unnecessary reset and the like in each of the above devices, and ensure stable operation. The electric load 14 may include a travel system actuator such as an electric steering device or a brake device. Specific examples of the electric load 15 include a seat heater, a heater for a defroster for a rear window, a headlight, a wiper for a front window, and a blower fan for an air conditioner.

The rotating electrical machine unit 16 includes a rotating electrical machine 21, an inverter 22, a field circuit 23, and a rotating electrical machine ECU 24 that controls the operation of the rotating electrical machine 21. The rotating electrical machine unit 16 is a generator with a motor function, and is configured as an electromechanically integrated ISG (Integrated / Starter / Generator). Details of the rotating electrical machine unit 16 will be described later.

The battery unit U is provided with an electrical path L1 that connects the output terminals P1 and P2 and an electrical path L2 that connects the point N1 on the electrical path L1 and the lithium ion storage battery 12 as an in-unit electrical path. Among these, the switch 31 is provided in the electrical path L1, and the switch 32 is provided in the electrical path L2.

The battery unit U is provided with a bypass path L3 that bypasses the switch 31. The bypass path L3 is provided so as to connect the output terminal P3 and the point N1 on the electrical path L1. The output terminal P3 is connected to the lead storage battery 11 via the fuse 35. By this bypass path L3, the lead storage battery 11, the electric load 15, and the rotating electrical machine unit 16 can be connected without using the switch 31. In the bypass path L3, for example, a bypass switch 36 composed of a normally closed mechanical relay is provided. By turning on (closing) the bypass switch 36, the lead storage battery 11, the electrical load 15, and the rotating electrical machine unit 16 are electrically connected even when the switch 31 is turned off (opened).

The battery unit U includes a battery ECU 37 that controls on / off (opening / closing) of the

switches

31 and 32. The battery ECU 37 is constituted by a microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like. The battery ECU 37 controls on / off of the

switches

31 and 32 based on the traveling state of the vehicle 10 and the storage states of the

storage batteries

11 and 12. Thereby, charging / discharging is implemented using the lead storage battery 11 and the lithium ion storage battery 12 selectively. For example, the battery ECU 37 calculates the charging rate SOC (State Of Charge) of the lithium ion storage battery 12, and sets the charging amount and discharging amount to the lithium ion storage battery 12 so that the charging rate SOC is maintained within a predetermined use range. Control.

The rotating electrical machine ECU 24 of the rotating electrical machine unit 16 and the battery ECU 37 of the battery unit U are connected to an engine ECU 40 as a host controller that manages the

ECUs

24 and 37 in an integrated manner. The engine ECU 40 is composed of a microcomputer including a CPU, ROM, RAM, input / output interface, and the like, and controls the operation of the engine 42 based on the engine operating state and the vehicle traveling state each time. The

ECUs

24, 37, and 40 are connected by a communication line 41 that constructs a communication network such as CAN and can communicate with each other, and bidirectional communication is performed at a predetermined cycle. Thereby, the various data memorize | stored in each ECU24,37,40 are mutually shared.

The engine ECU 40 automatically stops the engine 42 when a predetermined automatic stop condition is satisfied, and automatically restarts the engine 42 when a predetermined restart condition is satisfied thereafter. In order to automatically stop the engine 42, the combustion of fuel in the engine 42 is stopped. Specifically, fuel injection and ignition are stopped for a gasoline engine, and fuel injection is stopped for a diesel engine. In the automatic stop, the period from when the combustion of the fuel in the engine 42 is stopped until the time when the rotation of the engine 42 is stopped (a state where the rotation of the engine 42 is stopped) is included in the automatic stop of the engine 42.

As the automatic stop condition, the operation amount of the accelerator operation member of the vehicle 10 is 0 (smaller than the predetermined operation amount), the operation amount of the brake operation member is not 0 (larger than the predetermined operation amount), and the vehicle 10 At least one of the speeds is lower than a predetermined speed. That is, the automatic stop of the engine 42 includes idling stop for stopping idling of the engine 42, engine stop during deceleration for stopping the engine 42 when the vehicle 10 is decelerated, and coasting engine for stopping the engine 42 when coasting the vehicle 10. Including stoppages. As the automatic restart condition, the operation amount of the accelerator operation member of the vehicle 10 is not 0 (larger than the predetermined operation amount), the operation amount of the brake operation member is 0 (smaller than the predetermined operation amount), and the vehicle The speed of 10 includes at least one of higher than the predetermined speed.

Next, the electrical configuration of the rotating electrical machine unit 16 will be described with reference to FIG. The rotating electrical machine 21 is a three-phase AC motor and includes U-phase, V-phase, and W-

phase windings

25U, 25V, and 25W as three-phase armature windings, and a field winding 26 as a rotor winding. ing. The rotating electrical machine unit 16 includes a power generation function that generates power (regenerative power generation) by rotating the engine output shaft and the axle, and a power running function that applies rotational force to the engine output shaft. Specifically, the rotating shaft of the rotating electrical machine 21 is connected to an engine output shaft (not shown) via a belt so that driving force can be transmitted. Electricity is generated by rotating the rotating shaft of the rotating electrical machine 21 with the rotation of the engine output shaft through the belt, and power is generated by rotating the engine output shaft with the rotating shaft of the rotating electrical machine 21.

The inverter 22 converts the AC voltage output from each phase winding 25U, 25V, 25W into a DC voltage and outputs it to the battery unit U. The inverter 22 converts the DC voltage input from the battery unit U into an AC voltage and outputs the AC voltage to the

phase windings

25U, 25V, and 25W. The inverter 22 is a bridge circuit having the same number of upper and lower arms as the number of phases of the phase winding, and constitutes a three-phase full-wave rectifier circuit. The inverter 22 adjusts the power supplied to the armature winding of the rotating electrical machine 21 in a state where the field current (excitation current) is supplied from the field circuit 23 to the field winding 26, thereby rotating the rotating electrical machine. The drive circuit which drives 21 is comprised.

The inverter 22 includes an upper arm switch Sp and a lower arm switch Sn for each phase. In the present embodiment, voltage controlled semiconductor switching elements are used as the switches Sp and Sn (power transistors), specifically, N-channel MOSFETs are used. An upper arm diode Dp is connected in antiparallel to the upper arm switch Sp, and a lower arm diode Dn is connected in antiparallel to the lower arm switch Sn. In the present embodiment, the body diodes of the switches Sp and Sn are used as the diodes Dp and Dn. The diodes Dp and Dn are not limited to body diodes, and may be diodes that are separate parts from the switches Sp and Sn, for example. An intermediate connection point of the series connection body of the switches Sp and Sn in each phase is connected to one end of each phase winding 25U, 25V, and 25W.

The field circuit 23 is a bidirectional switch, and a DC voltage can be applied to the field winding 26. In the present embodiment, the field circuit 23 (transistor chopper-type excitation circuit) constitutes an H-bridge rectifier circuit in which four switches Spa, Sna, Spb, and Snb are combined. Since the basic configuration of each switch Spa, Sna, Spb, Snb (power transistor) is the same as each switch of the inverter 22, the description thereof is omitted here. In the present embodiment, by adjusting the DC voltage applied to the field winding 26 by switching control of each switch Spa, Sna, Spb, Snb, the direction and current amount of the field current flowing through the field winding 26 are adjusted. Control. The power transistors of the first pair of arms facing each other are configured by the switches Spa and Snb, and the diodes of the second pair of arms are configured by the diodes Dna and Dpb.

The switches Sp, Sn, Spa, Sna, Spb, Snb constituting the inverter 22 and the field circuit 23 are independently switched on / off via the driver 27. In the present system, a current detection unit 29A for detecting each phase current iu, iv, iw and a current detection unit 29B for detecting the field current if are provided. As the

current detection units

29A and 29B, for example, those including a current transformer and a resistor are used.

The rotating electrical machine ECU 24 (control device for the rotating electrical machine) is constituted by a microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like. The rotating electrical machine ECU 24 controls the generated voltage (output voltage to the battery unit U) of the rotating electrical machine unit 16 by adjusting the field current flowing through the field winding 26. Further, the rotary electric machine ECU 24 assists the driving force of the engine 42 by controlling the inverter 22 to drive the rotary electric machine 21 after the vehicle 10 starts traveling. The rotating electrical machine 21 can give an initial rotation to the output shaft when starting the engine, and also has a function as an engine starting device.

Incidentally, the rotating electrical machine 21 is stopped during the automatic stop of the engine 42, and a leak current flows through the stopped rotor, so that the rotor may be corroded. Specifically, when the engine 42 of the vehicle 10 is in a stopped state, the switches Spa, Sna, Spb, and Snb are turned off. At this time, the rotor field winding 26 is in a state of floating in potential. In cold districts and the like, the rotating electrical machine 21 may be covered with water containing a snow melting agent. In such a case, a leakage current may occur between the exposed connection terminal P4 (P6) of the upper arm switch Spa (Spb) and the exposed connection terminal P5 (P7). As a result, the rotor potential becomes the same as the potential of the output terminal P2 of the battery unit U, a current flows between the rotor and the armature core (stator core) that is the ground potential, and a very narrow air gap is present. There is a risk of rusting (corrosion).

In contrast, in the present embodiment, the rotating electrical machine ECU 24 (first diagnosis unit, second diagnosis unit, off control unit) performs the following first diagnosis, first ground control, 2 Diagnosis and off control (second grounding control) are executed. Specifically, the rotating electrical machine ECU 24 executes the diagnosis and the grounding control in the order of the second diagnosis, the off control (second grounding control), the first diagnosis, and the first grounding control.

FIG. 3 is a flowchart showing a procedure for the diagnosis and grounding control. This series of processing is executed by the rotating electrical machine ECU 24 when the engine 42 shifts from the operating state to automatic stop. Whether or not the engine 42 is automatically stopped is determined based on the fact that the fuel injection or ignition of the engine 42 is stopped, the automatic stop condition is satisfied, or the like. Further, the condition for executing this series of processing is that the rotational speed of the engine 42 is lower than a predetermined rotational speed (for example, 200 rpm). That is, even if the engine 42 is being automatically stopped, if the rotational speed of the engine 42 is higher than the predetermined rotational speed, this series of processing is not executed. The rotational speed of the engine 42 can be calculated based on the detection value of the crank angle sensor or the like.

First, as a second diagnosis, in the second pair of arms, both switches Spb and Sna are turned on to diagnose whether or not a field current flows in the field winding 26 (S11). Specifically, it is determined whether or not the field current flows through the field winding 26 based on the detection value of the current detection unit 29B that detects the field current if.

Subsequently, after both switches Spb and Sna are turned on in the second pair of arms in the second diagnosis, both switches Spb and Sna are turned off in the second pair of arms as an off control. (S12). Specifically, in the second pair of arms, the switch Spb connected to the output terminal side of the rotating electrical machine 21 is turned off, and then the switch Sna connected to the ground side of the rotating electrical machine 21 is turned off. That is, when the switch Spb connected to the output terminal side of the rotating electrical machine 21 is turned off, the switch Sna connected to the ground side of the rotating electrical machine 21 is turned on. The control that forms this state corresponds to the second ground control.

Subsequently, as a first diagnosis, both switches Spa and Snb are turned on in the first pair of arms to diagnose whether or not a field current flows through the field winding 26 (S13). Specifically, it is determined whether or not the field current flows through the field winding 26 based on the detection value of the current detection unit 29B that detects the field current if.

Subsequently, as the first ground control, the switch Spa connected to the output terminal side of the rotating electrical machine 21 in the first pair of arms is turned off (S14). At this time, among the first pair of arms, the switch Snb connected to the ground side of the rotating electrical machine 21 is turned on. Thereafter, this series of processing ends (END).

In addition, the process of S11 corresponds to the process as a 2nd diagnostic part, the process of S12 corresponds to the process as an OFF control part, and the process of S13 corresponds to the process as a 1st diagnostic part.

Then, when it is diagnosed that the field current does not flow through the field winding 26 in the first diagnosis or the second diagnosis, the engine ECU 40 applies a rotational force to the engine 42 by the starter 13 during the automatic restart. Give.

The embodiment described above has the following advantages.

During the automatic stop of the engine 42, the switch Snb connected to the ground side of the rotating electrical machine 21 is turned on and the switch Spa connected to the output terminal side of the rotating electrical machine 21 is turned off. The first ground control for setting the state is executed. For this reason, even if the rotary electric machine 21 stops during the automatic stop of the engine 42, it is possible to prevent the rotor in the stopped state from being in a potential floating state. Therefore, even if a leak current occurs, it can flow to the ground via the switch Snb on the ground side, and the rotor can be prevented from corroding during the automatic stop of the engine 42.

When the switches Spa, Sna, Spb, Snb of the field circuit 23 are out of order, the field current cannot be supplied to the rotating electrical machine 21 when the engine 42 is restarted. Rotational force cannot be applied to In this regard, before the first grounding control is executed during the automatic stop of the engine 42, both switches Spa and Snb are turned on in the first pair of arms to diagnose whether or not the field current flows. One diagnosis is performed. For this reason, it is possible to execute the first grounding control after diagnosing whether or not the rotating electrical machine 21 can apply the rotational force to the engine 42.

· The second diagnosis is executed before the first diagnosis is executed while the engine 42 is automatically stopped. For this reason, it is possible to diagnose whether or not the rotating electric machine 21 can apply a rotational force to the engine 42 by causing a field current to flow through the second pair of arms. Then, after both switches Spb and Sna are turned on in the second pair of arms, an off control is performed to turn off both switches Spb and Sna in the second pair of arms. For this reason, it is possible to shift to the first diagnosis while avoiding a short circuit between the second pair of arms and the first pair of arms.

In the off control, when both switches Spb and Sna are turned off in the second pair of arms, the switch Spb connected to the output terminal side of the rotating electrical machine 21 in the second pair of arms is After being turned off, the switch Sna connected to the ground side of the rotating electrical machine 21 is turned off. For this reason, when the switch Spb connected to the output terminal side of the rotating electrical machine 21 is turned off, the switch Spb is turned off and the switch Sna is turned on (the state in which the second ground control is executed). it can. Therefore, it is possible to shift to the first diagnosis after suppressing the rotor in the stopped state from floating in potential.

A failure of the field circuit 23 is diagnosed in the first diagnosis and the second diagnosis, and the engine 42 is restarted by the starter 13 when it is diagnosed that the field current does not flow in the first diagnosis or the second diagnosis. Can do.

When the first grounding control or the second grounding control is executed, the switch Snb or the switch Sna connected to the ground side of the rotating electrical machine 21 is turned on in the first pair of arms. In the circuit 23, a closed circuit for flowing a field current is formed. For this reason, when the rotational speed of the engine 42 is high, electric power is generated in the rotating electrical machine 21, and excessive braking torque may act on the engine 42. In this regard, the first grounding control and the second grounding control are executed on the condition that the rotational speed of the engine 42 is lower than the predetermined rotational speed. Accordingly, it is possible to suppress an excessive braking torque from acting on the engine 42 when the first ground contact control is executed.

It should be noted that the above embodiment can be modified as follows.

It can be excluded from the conditions for executing the first grounding control and the second grounding control that the rotational speed of the engine 42 is lower than the predetermined rotational speed. In this case, it is desirable to disconnect the connection between the output shaft of the engine 42 and the axle of the vehicle 10 when executing the first ground control and the second ground control. Moreover, since the engine 42 stops rapidly, the time until it can be restarted can be shortened.

When the field current does not flow in the first diagnosis or the second diagnosis, the automatic stop of the engine 42 can be interrupted. According to such a configuration, when there is a possibility that the engine 42 cannot be automatically restarted by the rotating electrical machine unit 16, the engine 42 can be prevented from being automatically stopped.

In the off control, when both the switches Spb and Sna are turned off in the second pair of arms, both the switches Spb and Sna can be turned off simultaneously in the second pair of arms.

In FIG. 3, the second diagnosis of S11 can be omitted, and the first diagnosis of S13 can be omitted. The rotating electrical machine ECU 24 (control device) turns on a switch Sna (power transistor) connected to the ground side of the rotating electrical machine 21 among the second pair of arms while the engine 42 is automatically stopped. Only the second ground control for turning off the switch Spb (power transistor) connected to the output terminal side of the electric machine 21 can be executed.

· A vehicle 10 that does not include the starter 13 may be employed.

· Instead of the rotating electrical machine unit 16 having a power running function, a generator unit 116 may be employed as shown in FIG. In this case, the diode rectifier circuit 122 of FIG. 4 can be used instead of the inverter 22 of FIG. 1, and the switches Spb and Sna of the second pair of arms can be omitted in the field circuit 23. Even with such a configuration, the rotating electrical machine ECU 24 can execute the first diagnosis and the first ground control.

As shown in FIG. 5, the rated voltage of the lithium ion storage battery 12 may be 48V, the rotating electrical machine 21 may be driven by a voltage of 48V, and the vehicle 10 may include a bidirectional DCDC converter 50. According to such a configuration, a voltage of 48 V is supplied from the lithium ion storage battery 12 to the field circuit 23 (the rotating electrical machine unit 16). Further, the voltage supplied from the battery unit U to the lead storage battery 11 is stepped down by the DCDC converter 50, and the voltage supplied from the lead storage battery 11 to the battery unit U is boosted by the DCDC converter 50.

Here, when the voltage supplied to the field circuit 23 is 48V, the leakage current flowing through the rotor is larger than when the voltage supplied to the field circuit 23 is 12V, and the rotor is corroded. Is easier to proceed. In addition, the rotating electrical machine unit 16 uses a voltage of 48 V to apply a negative torque so that the rotational speed of the engine 42 quickly passes through a resonance region (for example, 200 to 400 rpm), or reset the piston stop position of the engine 42. There is a case where control is performed to stop at a position suitable for starting. When these controls are performed, a current flows through the field winding 26 until immediately before the engine 42 stops, so that electric charges easily remain in the field winding 26 when the engine 42 stops. Then, when the connection terminal P5 (P7) and the armature core at the ground potential are short-circuited with water or the like containing a snow melting agent in a state where electric charges remain in the field winding 26, the space between the rotor and the armature core is reduced. Leakage current flows through the rotor and corrosion of the rotor easily proceeds. In this regard, by performing each control of the above embodiment on the above configuration, the rotor corrosion can be suppressed as compared with the configuration in which the rotor corrosion easily proceeds.

The engine ECU 40 can instruct the rotating electrical machine ECU 24 to execute the first diagnosis, the first grounding control, the second diagnosis, and the off control (second grounding control). That is, the engine ECU 40 can constitute a first diagnosis unit, a second diagnosis unit, and an off control unit, that is, a control device for a rotating electrical machine.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

This is applied to a vehicle (10) that automatically stops the engine (42) when a predetermined automatic stop condition is satisfied, and then automatically restarts the engine when a predetermined restart condition is satisfied. An excitation current is supplied from a transistor chopper type excitation circuit (23) in which a first pair of arms is configured with power transistors (Spa, Snb) and a second pair of arms is configured with diodes (Dna, Dpb). A control device (24, 40) for controlling the rotating electrical machine (21) having a power generation function based on the rotational force of the engine,
During the automatic stop of the engine, among the first pair of arms, the power transistor (Snb) connected to the ground side of the rotating electrical machine is turned on and connected to the output terminal side of the rotating electrical machine. A control device for a rotating electrical machine that performs first grounding control for turning off the power transistor (Spa).
The rotating electrical machine has a power running function for applying a rotational force to the engine in a state where an excitation current is supplied from the excitation circuit,
Before the first grounding control is executed during the automatic stop of the engine, both the power transistors are turned on in the first pair of arms to diagnose whether the excitation current flows. The control device for a rotating electrical machine according to claim 1, further comprising a first diagnosis unit (24, 40) for executing diagnosis.
The diodes constituting the second pair of arms use body diodes of power transistors (Sna, Spb), respectively.
During the automatic stop of the engine, of the second pair of arms, the power transistor (Sna) connected to the ground side of the rotating electrical machine is turned on and connected to the output terminal side of the rotating electrical machine. The control device for a rotating electrical machine according to claim 1 or 2, wherein second grounding control for turning off the power transistor (Spb) is executed.
The rotating electrical machine has a power running function for applying a rotational force to the engine in a state where an excitation current is supplied from the excitation circuit,
Before the second grounding control is executed during the automatic stop of the engine, both the power transistors are turned on in the second pair of arms to diagnose whether the excitation current flows. The control apparatus for a rotating electrical machine according to claim 3, further comprising a second diagnosis unit (24, 40) for executing diagnosis.
The diodes constituting the second pair of arms use body diodes of power transistors (Sna, Spb), respectively.
Before the first diagnosis is executed during the automatic stop of the engine, a second diagnosis for diagnosing whether the excitation current flows by turning both the power transistors on in the second pair of arms. A second diagnostic unit for executing
After both the power transistors are turned on in the second pair of arms by the second diagnostic unit, off control is performed to turn off both the power transistors in the second pair of arms. The control apparatus for a rotating electrical machine according to claim 2, further comprising an off control unit (24, 40).
In the off control, when the off control unit turns off both of the power transistors in the second pair of arms, the off control unit is connected to the output terminal side of the rotating electrical machine in the second pair of arms. The control device for a rotating electrical machine according to claim 5, wherein the power transistor (Sna) connected to the ground side of the rotating electrical machine is turned off after the connected power transistor (Spb) is turned off.
The vehicle includes a starter (13) that applies a rotational force to the engine when the engine is started.
The control device for a rotating electrical machine according to claim 2, wherein when the first diagnosis unit diagnoses that the exciting current does not flow, the starter applies a rotational force to the engine during the automatic restart.
The vehicle includes a starter (13) that applies a rotational force to the engine when the engine is started.
The rotational force is applied to the engine by the starter at the time of the automatic restart when the first diagnostic unit or the second diagnostic unit diagnoses that the excitation current does not flow. Rotating electrical machine control device.
The control device for a rotating electrical machine according to any one of claims 1 to 8, wherein the first ground contact control is executed on the condition that a rotational speed of the engine is lower than a predetermined rotational speed.
5. The control device for a rotating electrical machine according to claim 3, wherein the second grounding control is executed on the condition that the rotational speed of the engine is lower than a predetermined rotational speed.
11. The rotating electrical machine control device according to claim 1, wherein a voltage of 48 V is supplied to the excitation circuit.
12. The rotating electrical machine control device according to claim 1, wherein the exciting current is supplied from the exciting circuit to a rotor winding of the rotating electrical machine.