JP2016032324A - Control system for rotating electrical machine mounted in vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control system for a rotating electrical machine mounted in a vehicle, capable of preferential SOC management of one power storage means over SOC management of the other power storage means.SOLUTION: A control system 100 for a rotating electrical machine mounted in an EV vehicle or an HV vehicle comprises: a rotating electrical machine 10 that includes first and second winding groups 11, 12; first and second power conversion means 20, 30; first and second secondary batteries 41, 43; and a control unit 50. The control unit 50 controls the first and second power conversion means 20, 30 on the basis of a vehicle requested torque and an SOC of the first secondary battery, thereby controlling torques generated by the respective first and second winding groups 11, 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control system for a rotating electrical machine mounted on a vehicle, and more particularly to a control system for a rotating electrical machine mounted on a vehicle including two types of power storage means.

  The popularization of electric vehicles (EV vehicles) that run by rotating electrical machines (motor generators) and hybrid vehicles (HV vehicles) that run by using both rotating electrical machines and gasoline engines has begun. These EV vehicles and HV vehicles are equipped with power storage means such as a secondary battery and an electric double layer capacitor, and the vehicle can be driven by driving the rotating electrical machine with the electric energy stored in the power storage means. .

  A general EV vehicle or HV vehicle includes two types of power storage means such as a lithium ion battery that outputs a high voltage and a lead storage battery that outputs a low voltage. Patent Document 1 describes a configuration in which two types of power storage means are connected to a rotating electrical machine via separate power conversion units (inverters / converters).

JP 2002-27717 A

  Power storage means such as secondary batteries and electric double layer capacitors have a safe range of charge (SOC) that can be charged above its upper limit or discharged to below its lower limit. The power storage means deteriorates. Therefore, when these power storage means are mounted on a vehicle, it is necessary to manage so that the SOC is used within a predetermined range.

  The extent to which the SOC management should be strictly performed depends on the type of power storage means. For example, when a power storage device such as a lithium ion battery is mounted on a vehicle, the power storage device is not expected to be replaced regularly, and is never replaced between the time of vehicle manufacture and the end of life. Therefore, it is necessary to strictly manage the SOC so that the power storage device is not deteriorated as much as possible. On the other hand, since lead storage batteries are usually replaced every few years, it is not necessary to manage the SOC so strictly. For this reason, even in the configuration described in Patent Document 1, it is desirable to perform the SOC management of one power storage unit over the SOC management of the other power storage unit depending on the type of power storage unit mounted.

  The present invention has been made to solve such a problem, and is capable of performing SOC management of one power storage means in preference to SOC management of the other power storage means, and is installed in a vehicle. An object of the present invention is to provide a control system.

  In order to solve the above problems, a control system for a rotating electrical machine mounted on a vehicle according to the present invention includes a rotating electrical machine having first and second winding groups, and a first and second winding group. First and second power conversion means connected to each other, first and second power storage means connected to the first and second power conversion means, respectively, vehicle demand torque and first power storage means And control means for controlling the torque generated by each of the first and second winding groups by controlling the first and second power conversion means based on the charge amount.

  Preferably, when the charge amount of the first power storage unit exceeds a predetermined upper limit value, the control unit first and second winding groups so as to discharge the first power storage unit to the maximum extent. The torque generated by each of the first and second windings is controlled so that when the charge amount of the first heat storage means is below a predetermined lower limit, the first power storage means is charged to the maximum extent. The torque generated by each line group is controlled.

  The first power storage means may be any of a lithium ion battery, a nickel metal hydride battery, and a capacitor, and the second power storage means may be a lead storage battery.

  According to the control system for a rotating electrical machine mounted on a vehicle according to the present invention, the SOC management of one power storage means can be performed with priority over the SOC management of the other power storage means.

It is a figure which shows the structure of the control system of the rotary electric machine mounted in the vehicle which concerns on embodiment of this invention. It is a flowchart which shows the detail of the torque control of the rotary electric machine performed by the control unit in the control system of the rotary electric machine mounted in the vehicle which concerns on embodiment of this invention. It is a figure which shows SOC of a 1st secondary battery. (A) is a torque characteristic diagram of the first winding group, and (b) is a torque characteristic diagram of the second winding group. (A) is a torque characteristic diagram of the first winding group, and (b) is a torque characteristic diagram of the second winding group.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment.
FIG. 1 shows the configuration of a control system 100 for a rotating electrical machine mounted on a vehicle according to an embodiment of the present invention.
The rotating electrical machine 10 is a six-phase motor generator that is mechanically coupled to an axle (not shown) of an EV vehicle or an HV vehicle, and operates as an electric motor when the vehicle is powered, and operates as a generator when the vehicle is regenerated. The rotating electrical machine 10 includes a first winding group 11 including Y-connected windings 11a to 11c, and a second winding group 12 including Y-connected windings 12a to 12c. have. The first winding group 11 is connected to a three-phase first power conversion unit 20, and the second winding group 12 is connected to a three-phase second power conversion unit 30.

  The first power conversion unit 20 includes a first arm 21 including switching elements 21a and 21b and freewheeling diodes 21c and 21d, and a second arm including switching elements 22a and 22b and freewheeling diodes 22c and 22d. 22 and a third arm 23 composed of switching elements 23a and 23b and free-wheeling diodes 23c and 23d. The connection point P1 of the first arm 21 is connected to the winding 11a, the connection point P2 of the second arm 22 is connected to the winding 11b, and the connection point P3 of the third arm 23 is the winding. 11c. In this embodiment, each switching element is composed of a bipolar transistor.

  The second power conversion unit 30 has the same configuration as the first power conversion unit 20, and includes a first arm 31 including switching elements 31a and 31b and freewheeling diodes 31c and 31d, It has the 2nd arm 32 comprised from switching element 32a, 32b and free-wheeling diode 32c, 32d, and the 3rd arm 33 comprised from switching element 33a, 33b and free-wheeling diode 33c, 33d. The connection point Q1 of the first arm 31 is connected to the winding 12a, the connection point Q2 of the second arm 32 is connected to the winding 12b, and the connection point Q3 of the third arm 33 is the winding. 12c.

  The positive line 24 of the first power conversion unit 20 is connected to the positive electrode of the first secondary battery 41 via the current sensor 40. The negative line 25 of the first power conversion unit 20 is connected to the positive line 24 of the first power conversion unit 20. The negative electrode of the 1 secondary battery 41 is connected. A smoothing capacitor 42 is connected between the plus line 24 and the minus line 25 in parallel with the first secondary battery 41.

  The positive electrode of the second secondary battery 43 is connected to the plus line 34 of the second power conversion unit 30, and the second secondary battery 43 is connected to the minus line 35 of the second power conversion unit 30. The negative electrode is connected. A smoothing capacitor 44 is connected between the plus line 34 and the minus line 35 in parallel with the second secondary battery 43.

  In this embodiment, the first secondary battery 41 is a lithium-on battery that needs to strictly manage the SOC as described above, and the second secondary battery 43 manages the SOC so strictly. Lead-acid battery that is not necessary.

  A PWM signal is input from the control unit 50 described below to the base terminals of the switching elements of the first and second power conversion units 20 and 30. By performing the switching operation of each element in accordance with the PWM signal, the first and second power conversion units 20 and 30 can convert the DC power output from the first and second secondary batteries 41 and 43 into three-phase. It operates as an inverter that converts AC power to be supplied to the rotating electrical machine 10 or a converter that converts three-phase AC power generated by the rotating electrical machine 10 to DC power and supplies it to the secondary batteries 41 and 43.

  The control unit 50 is configured by a microcomputer, and the required torque of the rotating electrical machine 10 is input from the vehicle ECU 60 that controls the traveling of the vehicle. Here, the required torque is a torque that is desired to be output to the rotating electrical machine 10 that operates as an electric motor during powering of the vehicle, and is a torque that is applied to the rotating electrical machine 10 that operates as a generator during regeneration of the vehicle. In addition, the control unit 50 estimates the SOC of the first secondary battery 41 by integrating the input / output current of the first secondary battery 41 detected by the current sensor 40.

  Based on the required torque of the rotating electrical machine 10 input from the vehicle ECU 60 and the SOC of the first secondary battery 41 estimated from the detection value of the current sensor 40, the control unit 50 performs first and second electric power. By controlling the conversion units 20 and 30, the torque of the first and second winding groups 11 and 12 of the rotating electrical machine 10 is controlled. More specifically, when the SOC of the first secondary battery 41 exceeds a predetermined upper limit value, the control unit 50 controls the rotating electrical machine 10 to discharge the first secondary battery 41 to the maximum extent. When the torques of the first and second winding groups 11 and 12 are controlled and the SOC of the first secondary battery 41 is below a predetermined lower limit value, the first secondary battery 41 is maximized. The torques of the first and second winding groups 11 and 12 of the rotating electrical machine 10 are controlled so as to be charged. By performing such control, the SOC management of the first secondary battery 41 can be performed with priority over the SOC management of the second secondary battery.

  Hereinafter, details of torque control of the rotating electrical machine 10 performed by the control unit 50 in the control system for the rotating electrical machine mounted on the vehicle according to this embodiment will be described with reference to the flowchart of FIG. This flowchart is repeatedly executed at a predetermined cycle.

  In step S <b> 101 of FIG. 2, the control unit 50 acquires the required torque Tref from the vehicle ECU 60. The required torque Tref takes a positive value when operating the rotating electrical machine 10 as an electric motor during powering of the vehicle, and takes a negative value when operating the rotating electrical machine 10 as a generator during regeneration of the vehicle.

  In the next step S102, the control unit 50 sets the torque Tref1 of the first winding group 11 and the torque Tref2 of the second winding group 12 of the rotating electrical machine 10 so that the relationship of Tref1 + Tref2 = Tref is satisfied. Each of them is provisionally determined according to

Tref1 = Tref × k
Tref2 = Tref−Tref1

  However, in the above equation, k is a constant having a value less than 1, for example, k = 0.5.

  In subsequent step S <b> 103, the control unit 50 estimates the SOC of the first secondary battery 41 from the integrated value of the current detected by the current sensor 40. In step S104, the control unit 50 checks whether the SOC of the first secondary battery 41 is in the “high SOC state”. Specifically, as shown in FIG. 3, when the SOC of the first secondary battery 41 exceeds a predetermined upper limit value TH, it is determined that the state is in a high SOC state.

  If it is determined in step S104 that the first secondary battery 41 is in the high SOC state, the control unit 50 discharges the first secondary battery 41 to the maximum extent in steps S105 to S107. An attempt is made to determine the torque of the first and second winding groups 11 and 12 so as to reduce the SOC.

  Specifically, in step S105, the control unit 50 calculates a torque (torque margin ΔT) that can be increased in the first winding group 11 according to the following equation.

    ΔT = Tmax1-Tref1

  However, in the above equation, Tmax1 is an upper limit value of the torque of the first winding group 11 at a given rotational speed of the rotating electrical machine 10 (see FIG. 4A).

  FIG. 4A is a torque characteristic diagram of the first winding group 11. In this figure, the horizontal axis represents the rotational speed of the rotating electrical machine 10, and the vertical axis represents the torque of the first winding group 11. When the torque is positive, it means that the first secondary battery 41 is discharged. When the torque is negative, the first secondary battery 41 is charged. Means. As can be seen from this figure, the torque margin ΔT indicates how much room is left to increase the torque Tref1 of the first winding group 11 at a given number of rotations of the rotating electrical machine 10. Takes the value of

  If the torque Tref1 of the first winding group 11 can be increased by ΔT to the upper limit value Tmax1, the first secondary battery 41 can be discharged to the maximum. However, in order to maintain the relationship of Tref1 + Tref2 = Tref at that time, it is necessary to decrease the torque of the second winding group 12 by ΔT to Tref2−ΔT. However, as shown in the torque characteristic diagram of the second winding group 12 in FIG. 4B, the torque of the second winding group 12 can be reduced only to the lower limit value Tmin2. Therefore, when Tref2-ΔT> Tmin2, the torque of the second winding group 12 is set to Tref2-ΔT, and when Tref2-ΔT <Tmin2, the torque of the second winding group 12 is set to the lower limit. Set to the value Tmin2. As a matter of course, the torque of the second winding group 12 should not exceed the upper limit value Tmax2. Therefore, the control unit 50 determines the torque Tref2 'of the second winding group 12 according to the following equation in step S106.

Tmp = max (Tmin2, Tref2-ΔT)
Tref2 ′ = min (Tmax2, Tmp)

  However, in the above formula, Tmp is an intermediate variable. When the torque Tref2 'of the second winding group 12 is determined in step S106, the control unit 50 determines the torque Tref1' of the first winding group 11 according to the following formula in step S107.

    Tref1 '= Tref-Tref2'

  In step S108, the control unit 50 controls the torque of the first winding group 11 to be Tref1 ′ by adjusting the duty ratio of the PWM signal input to the first power conversion unit 20, By adjusting the duty ratio of the PWM signal input to the second power conversion unit 30, the torque of the second winding group 12 is controlled to be Tref2 ′. At this time, for example, when power is generated by the rotating electrical machine 10 during regeneration, and Tref1 ′> 0 and Tref2 ′ <0, the power discharged from the first secondary battery 41 and the power generated by the rotating electrical machine 10 are generated. The second secondary battery 43 is charged with the electric power.

  As described above, when it is determined in step S104 that the first secondary battery 41 is in the high SOC state, the first secondary battery 41 is replaced with Tmin1 <Tref1 ′ <Tmax1, Tmin2 <Tref2 ′ <Tmax2. As long as the conditions are satisfied, the SOC can be reduced by discharging as much as possible.

  On the other hand, if it is determined in step S104 that the first secondary battery 41 is not in the high SOC state, the control unit 50 determines that the SOC of the first secondary battery 41 is “low SOC state” in step S109. ”Is checked. Specifically, as shown in FIG. 3, when the SOC of the first secondary battery 41 is below a predetermined lower limit value TL, it is determined that the state is in the low SOC state.

  When it is determined in step S109 that the first secondary battery 41 is in the low SOC state, the control unit 50 charges the first secondary battery 41 to the maximum in steps S110 to S112. An attempt is made to determine the torque of the first and second winding groups 11 and 12 so as to increase the SOC.

  Specifically, in step S110, the control unit 50 calculates a torque (torque margin ΔT) that can be reduced in the first winding group 11 according to the following equation.

    ΔT = Tmin1-Tref1

  However, in the above equation, Tmin1 is a lower limit value of the torque of the first winding group 11 at a given rotational speed of the rotating electrical machine 10. As can be seen from FIG. 5A, the torque margin ΔT in this case is how much the torque Tref <b> 1 of the first winding group 11 can be reduced at a given rotational speed of the rotating electrical machine 10. It takes a negative value.

  If the torque Tref1 of the first winding group 11 can be reduced by ΔT to the lower limit value Tmin1, the first secondary battery 41 can be charged to the maximum. However, in this case, in order to maintain the relationship of Tref1 + Tref2 = Tref, it is necessary to increase the torque of the second winding group 12 by | ΔT | to Tref2−ΔT (note that ΔT is negative) ). However, as shown in FIG. 5B, the torque of the second winding group 12 can be increased only to the upper limit value Tmax2. Therefore, when Tref2-ΔT <Tmax2, the torque of the second winding group 12 is set to Tref2-ΔT, and when Tref2-ΔT> Tmax2, the torque of the second winding group 12 is set to the upper limit. Set to the value Tmax2. As a matter of course, the torque of the second winding group 12 should not be lower than the lower limit value Tmin2. Therefore, the control unit 50 determines the torque Tref2 'of the second winding group 12 according to the following equation in step S111.

Tmp = min (Tmax2, Tref2-ΔT)
Tref2 ′ = max (Tmin2, Tmp)

  However, in the above formula, Tmp is an intermediate variable. When the torque Tref2 'of the second winding group 12 is determined in step S111, the control unit 50 determines the torque Tref1' of the first winding group 11 according to the following formula in step S112.

    Tref1 '= Tref-Tref2'

  In step S113, the control unit 50 adjusts the duty ratio of the PWM signal input to the first power conversion unit 20 to control the torque of the first winding group 11 to be Tref1 ′. By adjusting the duty ratio of the PWM signal input to the second power conversion unit 30, the torque of the second winding group 12 is controlled to be Tref2 ′. At this time, for example, when power is consumed in the rotating electrical machine 10 during power running and Tref1 ′ <0, Tref2 ′> 0, a part of the power discharged from the second secondary battery 43 is part of the rotating electrical machine. 10 and the rest is charged to the first secondary battery 41.

  As described above, when it is determined in step S109 that the first secondary battery 41 is in the low SOC state, the first secondary battery 41 is replaced with Tmin1 <Tref1 ′ <Tmax1, Tmin2 <Tref2 ′ <Tmax2. As long as the condition is satisfied, the SOC can be increased by charging as much as possible.

  If it is determined in step S109 that the first secondary battery 41 is not in the low SOC state, the first secondary battery 41 is neither in the high SOC state nor in the low SOC state, and FIG. It is between the upper limit value TH and the lower limit value TL. Therefore, in step S114, the control unit 50 uses the torques Tref1 ′ and Tref2 ′ of the first and second winding groups 11 and 12 using the torques Tref1 and Tref2 temporarily determined in step S102 as follows. decide.

Tref1 ′ = Tref1
Tref2 ′ = Tref2

  In step S115, the control unit 50 controls the torque of the first winding group 11 to be Tref1 ′ by adjusting the duty ratio of the PWM signal input to the first power conversion unit 20, and By adjusting the duty ratio of the PWM signal input to the second power conversion unit 30, the torque of the second winding group 12 is controlled to be Tref2 ′.

  As described above, in the control system 100 for a rotating electrical machine mounted on a vehicle according to this embodiment, the control unit 50 detects the required torque Tref of the rotating electrical machine 10 input from the vehicle ECU 60 and the current sensor 40. The first and second winding groups of the rotating electrical machine 10 are controlled by controlling the first and second power conversion units 20 and 30 based on the SOC of the first secondary battery 41 estimated from the value. 11 and 12 are controlled. More specifically, when the SOC of the first secondary battery 41 exceeds a predetermined upper limit value TH, the control unit 50 controls the first and second so as to discharge the first secondary battery 41 to the maximum extent. The torque of the second winding group 11 and 12 is controlled, and when the SOC of the first secondary battery 41 is below a predetermined lower limit TL, the first secondary battery 41 is charged to the maximum extent. Thus, the torque of the first and second winding groups 11 and 12 is controlled. Thereby, the SOC management of the first secondary battery 41 can be performed with priority over the SOC management of the second secondary battery 43.

Other embodiments.
In said embodiment, the rotary electric machine 10 should just be what can operate | move with alternating current power, and types, such as an induction type and a synchronous type, are not ask | required. Moreover, the rotary electric machine 10 may not be a six-phase type, for example, may be a four-phase type or an eight-phase type. Further, the neutral points of the first and second winding groups 11 and 12 may be shared, or the first and second winding groups 11 and 12 may be connected to a Δ type instead of the Y type. Also good.

  Further, the switching elements of the first and second power conversion units 20 and 30 may not be bipolar transistors, and may be MOSFETs, IGBTs, electromagnetic relays, or the like, for example. Particularly in the case of a MOSFET, a parasitic diode of the MOSFET can be used as a free-wheeling diode.

  The first secondary battery 41 may not be a lithium ion battery, but may be a nickel metal hydride battery or the like that also needs to strictly manage the SOC. Further, instead of the secondary battery, for example, an electric double layer capacitor or the like may be used.

  DESCRIPTION OF SYMBOLS 10 Rotating electrical machine, 11 1st winding group, 12 2nd winding group, 20 1st power conversion unit (1st power conversion means), 30 2nd power conversion unit (2nd power conversion means) ), 41 First secondary battery (first power storage means), 43 Second secondary battery (second power storage means), 50 Control unit (control means).

Claims (3)

A control system for a rotating electrical machine mounted on a vehicle,
A rotating electric machine having first and second winding groups;
First and second power conversion means respectively connected to the first and second winding groups;
First and second power storage means respectively connected to the first and second power conversion means;
The torque generated by each of the first and second winding groups is controlled by controlling the first and second power conversion means based on the required torque of the vehicle and the charge amount of the first power storage means. A control system for a rotating electrical machine mounted on a vehicle, comprising a control means. The control means includes
Torque generated by each of the first and second winding groups so as to discharge the first power storage means to the maximum when the charge amount of the first power storage means exceeds a predetermined upper limit value. Control
When the charge amount of the first heat storage means is below a predetermined lower limit value, it is generated by each of the first and second winding groups so as to charge the first power storage means to the maximum extent. The control system of the rotary electric machine mounted in the vehicle of Claim 1 which controls a torque.   The rotating electrical machine mounted on a vehicle according to claim 1 or 2, wherein the first power storage means is any one of a lithium ion battery, a nickel metal hydride battery, and a capacitor, and the second power storage means is a lead storage battery. Control system.

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