Motor generator control system and hybrid vehicle

Abstract

Provided are an electric generator control system and a hybrid vehicle capable of suppressing the amount of battery charge generated by regenerative braking when the battery is fully charged or nearly fully charged. The electric generator control system (1) comprises: a second electric generator (MG2); a drive current control unit (3) that performs feedback control based on the drive current (Iu, Iv) of the second electric generator so that the drive torque (Tq) of the second electric generator becomes a target torque (Tq*); a current coordinate converter (12) that calculates a d-axis current value (Id) and a q-axis current value (Iq) based on the drive current and outputs them to the drive current control unit; and a strong excitation control instruction unit (21) that performs current consumption control when strong excitation control is performed during regeneration, in which the d-axis current value (Ida) and the q-axis current value (Iqa) are changed so that the drive torque is smaller than the target torque, and feedback control is performed.

Description

Technical Field

[0001] The invention relates to a motor generator control system and a hybrid vehicle. Background Art

[0002] In recent years, as a specific countermeasure to global climate change, initiatives to achieve a low-carbon society or a decarbonized society have been very active. In terms of vehicles, there is also a strong demand to reduce carbon dioxide emissions, and the electrification of drive sources is developing rapidly. Specifically, the development of vehicles such as electric vehicles (Electrical Vehicles) or hybrid electric vehicles (Hybrid Electrical Vehicles) that have an electric motor as a drive source for the vehicle and a secondary battery that can supply power to the electric motor is being promoted.

[0003] Patent document 1 records the following technology: under the condition that surplus power is generated in the charging power for charging the battery, weak excitation control or strong excitation control is performed to maintain the torque of the AC motor while increasing the armature current of the AC motor, thereby consuming the surplus power that cannot be charged into the battery in the AC motor, thereby preventing deterioration of the storage device due to overcharging.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-213253 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, there is room for further improvement in the method of consuming excess power generated by regeneration.

[0009] The present invention provides a motor generator control system and a hybrid vehicle capable of suppressing the amount of charge of a battery caused by regenerative braking when the battery is in a fully charged or nearly fully charged state.

[0010] Solutions to Solve Problems

[0011] The present invention is a motor generator control system, wherein:

[0012] The electric generator control system comprises:

[0013] a motor generator that is powered by the electric power from the battery and that charges the battery by regenerating the driving force input from the drive wheels;

[0014] a drive current control unit that performs feedback control based on the drive current of the motor generator so that the drive force of the motor generator during power running or during regeneration becomes a target drive force;

[0015] a current coordinate control unit that calculates a d-axis current value and a q-axis current value based on the drive current of the motor generator and outputs the calculated values ​​to the drive current control unit; and

[0016] a strong excitation control unit for performing strong excitation control for increasing the excitation intensity compared to the excitation intensity that can obtain the maximum efficiency on the constant driving force line of the motor generator;

[0017] When the strong field control is performed during the regeneration, current consumption control is executed in which the d-axis current value and the q-axis current value are changed so that the driving force becomes smaller than the target driving force, and the feedback control is performed.

[0018] Furthermore, the present invention is a hybrid vehicle, wherein:

[0019] The hybrid vehicle comprises:

[0020] internal combustion engine;

[0021] Storage battery;

[0022] a first motor generator that generates electricity using power from the internal combustion engine;

[0023] a second motor generator driven by electric power from the electric storage device or the first motor generator; and

[0024] The motor generator control system,

[0025] The motor generator of the motor generator control system is the second motor generator,

[0026] When the second motor generator is regenerating,

[0027] The first motor generator is used as a motor to perform power operation by using the regenerative power of the second motor generator.

[0028] executing the current consumption control on the second motor generator,

[0029] During the power operation of the first motor generator,

[0030] The load of the first motor generator is the internal combustion engine,

[0031] For the first motor generator,

[0032] The d-axis current value and the q-axis current value of the first motor generator are changed so that the driving force is smaller than the target driving force, and feedback control is performed based on the driving current of the first motor generator so that the driving force of the first motor generator during power running becomes the target driving force.

[0033] Effects of the Invention

[0034] According to the present invention, when the battery is fully charged or nearly fully charged, the amount of charge to the battery due to regenerative braking can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a block diagram showing the internal structure of a series-type HEV (hybrid electric vehicle).

[0036] Figure 2 yes Figure 1 Circuit diagram of an HEV.

[0037] Figure 3 This is an explanatory diagram showing the flow of energy when the first motor generator is driven as a motor by the regenerative electric power generated by the second motor generator during braking of the hybrid vehicle.

[0038] Figure 4 1 is a diagram showing restrictions on the operating point of the motor generator due to current and voltage in the dq-axis current vector space.

[0039] Figure 5 It is a diagram showing the transition of the operating point of the motor generator before and after the strong field control is performed.

[0040] Figure 6 This is a block diagram showing a configuration example of a motor generator control system according to one embodiment of the present invention.

[0041] Figure 7 It is shown Figure 6 Flowchart of an operation example of resolver phase corrector 18 shown in FIG.

[0042] Figure 8 1 is a diagram showing a d-axis current value Ida and a q-axis current value Iqa when the efficiency optimum control is performed at the operating point Ia.

[0043] Fig. 9 This shows that when strong excitation control (current consumption control) is used, Figure 8 Graph showing the d-axis current value Idb and the q-axis current value Iqb at the operating point Ib where the efficiency optimal control is shifted with the error angle α.

[0044] Fig.10The diagram shows a d-axis current value Idb2 and a q-axis current value Iqb2 at an operating point Ib2 that transitions due to feedback control during strong field control (current consumption control).

[0045] Fig.11 It is shown Figure 8 Graph showing d-axis current value Ida and q-axis current value Iqa in efficiency optimal control, and d-axis current value Idb2 and q-axis current value Iqb2 in strong field control (current consumption control).

[0046] Fig.12 : is a graph showing the relationship between the error angle α and the regenerative torque.

[0047] Fig.13 This is a diagram showing an example of the flow of energy in the strong field control (current consumption control).

[0048] Description of reference numerals:

[0049] 1 Motor generator control system

[0050] 3. Drive current control unit

[0051] 8. Resolver

[0052] 18 Resolver phase corrector (resolver phase change unit)

[0053] 21 Strong excitation control command unit (strong excitation control unit)

[0054] ENG Engine (Internal Combustion Engine)

[0055] BATh High voltage battery (storage device)

[0056] W Drive wheel

[0057] MG1 First motor generator

[0058] MG2 Second motor generator

[0059] Iu driving current

[0060] Iv driving current

[0061] Tq driving torque (driving force)

[0062] Tq* Target torque (target driving force)

[0063] HEV Hybrid Electric Vehicle

[0064] Id d-axis current value

[0065] Iq q-axis current value. DETAILED DESCRIPTION

[0066] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0067] HEV (Hybrid Electrical Vehicle) has an electric generator and an engine, and runs by the driving force of the electric generator and / or the engine according to the driving state of the vehicle. HEV is roughly divided into two types: series type and parallel type. Series type HEV runs by the power of the electric generator. The engine is mainly used for power generation, and the power generated by another electric generator through the power of the engine is charged into the battery or supplied to the electric generator. On the other hand, the parallel type HEV runs by the driving force of either or both of the electric generator and the engine.

[0068] (structure)

[0069] Figure 1 is a block diagram showing the internal structure of a series HEV. Figure 1 As shown, the series HEV (hereinafter referred to as "hybrid vehicle") includes an engine ENG, a first motor generator MG1, a second motor generator MG2, a high-voltage battery BATh, a converter CONV, a low-voltage battery BAT1, a VCU (Voltage Control Unit: voltage control unit) 101, a first inverter INV1, a second inverter INV2, an electric servo brake ESB and a controller 103. In addition, Figure 1 The thick solid lines in the figure represent mechanical connections, the double dashed lines represent power wiring, and the thin solid lines represent control signals.

[0070] The engine ENG drives the first motor generator MG1 as a generator. In addition, the engine ENG also acts as a load for the first motor generator MG1 that operates as a motor when the hybrid vehicle is braked. The first motor generator MG1 is driven by the power of the engine ENG and generates electricity. The second motor generator MG2 operates as a motor by power supply from at least one of the high-voltage battery and the first motor generator MG1, and generates power for the hybrid vehicle to travel. The torque generated by the second motor generator MG2 is transmitted to the drive wheel W via the speed reducer D. In addition, the second motor generator MG2 operates as a generator when the hybrid vehicle is braked.

[0071] The high-voltage battery BATh has a plurality of storage cells connected in series, and supplies a high voltage of, for example, 100 to 200 V. The storage cells are, for example, lithium-ion batteries and nickel-metal hydride batteries. The converter CONV steps down the DC output voltage of the high-voltage battery BATh in a DC state. The low-voltage battery BAT1 stores the voltage stepped down by the converter CONV, and supplies, for example, a constant voltage of 12 V to the electrical components 107 included in the auxiliary machine 105.

[0072] The VCU101 steps up the input voltage of the second motor generator MG2 when the second motor generator MG2 operates as a motor. In addition, the VCU101 steps down the output voltage of the second motor generator MG2 when the second motor generator MG2 operates as a generator during the braking of the hybrid vehicle. Furthermore, the VCU101 steps down the power generated by the first motor generator MG1 through the drive of the engine ENG and converted into direct current. The power stepped down by the VCU101 is supplied to the electric air-conditioning compressor 109 included in the auxiliary machine 105 or is supplied to the high-voltage battery BATh.

[0073] Figure 2 1 is a circuit diagram showing the relationship among the high-voltage battery BATh, the VCU 101, the first inverter INV1, the second inverter INV2, the first motor generator MG1, and the second motor generator MG2. Figure 2 As shown, VCU101 uses the V1 voltage output by the high-voltage battery BATh as the input voltage to switch the two switch elements on and off, thereby boosting the output side V2 voltage to a voltage higher than the V1 voltage. In addition, when the two switch elements of VCU101 are not switched on and off, the V2 voltage is equal to the V1 voltage.

[0074] The first inverter INV1 converts the AC voltage generated by the first motor generator MG1 driven by the engine ENG into a DC voltage. In addition, the first inverter INV1 converts the DC voltage generated by the second motor generator MG2 and converted by the second inverter INV2 into an AC voltage when the hybrid vehicle is braked, and supplies a three-phase current to the first motor generator MG1. The second inverter INV2 converts the DC voltage into an AC voltage, and supplies a three-phase current to the second motor generator MG2. In addition, the second inverter INV2 converts the AC voltage generated by the second motor generator MG2 when the hybrid vehicle is braked into a DC voltage.

[0075] return Figure 1 The electric servo brake ESB brakes the hybrid vehicle by means of hydraulic pressure controlled in response to the operation of the brake pedal by the driver of the hybrid vehicle.

[0076] The controller unit 103 controls the first inverter INV1, the second inverter INV2, the VCU 101, the engine ENG, the electric servo brake ESB, and the auxiliary machine 105. The details of the controller unit 103 will be described later.

[0077] (effect)

[0078] In the present embodiment, when the hybrid vehicle is braked, regenerative braking is used to operate the second motor generator MG2 as a generator. However, when the high-voltage battery BATh is fully charged and the regenerative power generated by the second motor generator MG2 cannot be charged into the high-voltage battery BATh, the first motor generator MG1 is driven as a motor by the regenerative power, and the load of the first motor generator MG1 is the engine ENG. Figure 3 It is an explanatory diagram showing the flow of energy when the first motor generator MG1 is driven as a motor by the regenerative electric power generated by the second motor generator MG2 during braking of the hybrid vehicle.

[0079] In this embodiment, if Figure 3 As shown, during the regeneration of the second motor generator MG2, strong excitation control is performed, thereby driving the second motor generator MG2 at a non-efficient operating point. In the second motor generator MG2 that has undergone strong excitation control, the output efficiency is reduced, and the heat generated mainly due to copper loss increases. In this embodiment, the efficiency is further reduced compared to the general strong excitation control. Hereinafter, the strong excitation control of this embodiment is referred to as current consumption control.

[0080] Here, general strong field control will be described first.

[0081] The operating points of the motor generators represented by the second motor generator MG2 on the dq axis coordinates when the strong field control is performed and the V2 voltage applied to the motor generators are described.

[0082] The range of the motor generator's operating point is limited by the maximum current Imax that can be supplied to the motor generator and the voltage applied to the motor generator. The amplitude of the motor generator's current (Id, Iq) is limited by the maximum current Imax, so it is necessary to satisfy equation (1).

[0083] Id 2 +Iq 2 ≤Imax 2 …(1)

[0084] Furthermore, the induced voltage (Vdo, Vqo) of the motor generator is expressed by equation (2).

[0085]

[0086] Here, Ld and Lq represent dq-axis inductances, ω represents the angular velocity of the motor generator, and ψa represents the interlinkage flux.

[0087] From equation (2), the dq induced voltage (the magnitude of the vector sum of the induced voltage generated in the d-axis armature and the induced voltage generated in the q-axis armature) Vo is expressed by equation (3).

[0088]

[0089] At this time, when Figure 2 When the limit voltage of the V2 voltage shown is set to Vom (Vom is determined by the V2 voltage, and the relationship changes according to the modulation method of the control of VCU101), as shown in equation (4), the dq induced voltage Vo needs to be less than the limit voltage Vom.

[0090] Vo≤Vom…(4)

[0091] That is, according to equations (3) and (4), there are voltage restrictions in the range of the operating point of the motor generator, and therefore equation (5) must be satisfied.

[0092]

[0093] Thus, the current limiting effect on the motor generator operation is expressed by equation (1), which is expressed by Figure 4 The inner area of ​​the constant current circle in the dq axis current vector space shown in FIG. In addition, the voltage restriction on the action of the motor generator is expressed by equation (5), which is expressed by Figure 4 The range of the current that can be supplied to the motor generator is the range that satisfies equations (1) and (5), and this range is given by Figure 4 Indicated by the shaded area.

[0094] On the other hand, the torque T of the motor generator is expressed by equation (6).

[0095] T=Pn{ψaIq+(Ld-Lq)IdIq}…(6)

[0096] Here, Pn represents the number of pole pairs of the motor generator.

[0097] The constant torque curve obtained by transforming the equation (6) is represented by equation (7).

[0098]

[0099] This equation (7) is a hyperbola with Id=ψa / (Lq-Ld) and Iq=0 as asymptotes.

[0100] However, in the control of the operating point of the electric generator without strong excitation control, for example, the following control is performed: maximum torque control to maximize the torque relative to the current (control in which the tangent of the constant torque curve at the operating point is orthogonal to the current vector), and efficiency optimization control to minimize the loss that takes into account not only copper loss but also iron loss (the operating point is often ahead of the maximum torque control phase, that is, the d-axis current is moved in the negative direction). That is, in Figure 5 In the example shown, the motor generator is driven at the operating point indicated by the dotted circle.

[0101] In contrast, in general strong excitation control, such as Figure 5 As shown, the inverter INV is controlled to increase the d-axis current of the motor generator MG to a positive value, and the operating point of the motor generator MG is moved to the target operating point (Id_c, Iq_c). In addition, the V2 voltage used to provide the current vector at the target operating point (Id_c, Iq_c) is the maximum voltage that can be obtained within the range of the constant current circle of the maximum current Imax and the target constant voltage ellipse, and the d-axis current becomes maximum in the positive direction under the condition of constant torque.

[0102] Next, the field strengthening control, that is, the current consumption control according to the present embodiment will be described.

[0103] Figure 6 1 is a block diagram of a motor generator control system 100 for the second motor generator MG2 according to the present embodiment. Figure 6 The motor generator control system 100 shown includes a second motor generator MG2 and a motor control device 2 that performs current control of the second motor generator MG2.

[0104] The second motor generator MG2 is a three-phase AC rotary electric machine having a rotor and a stator, and a rotary transformer 8 for detecting the magnetic pole position, i.e., the rotation angle, of the rotor is assembled on the rotor. The rotary transformer 8 is a well-known rotary transformer composed of a Hall element and a rotary encoder, and outputs a signal representing the detection value of the rotation angle of the magnetic pole from the predetermined reference rotation position of the rotor as a detection signal of the magnetic pole position. In addition, due to an assembly error of the rotary transformer 8, a detection error of the rotary transformer 8, or an abnormality of the rotary transformer, the detection value of the rotation angle obtained from the rotary transformer 8 (hereinafter referred to as the magnetic pole detection angle θ_act) usually generates a magnetic pole position error angle θ_ref relative to the actual magnetic pole position of the rotor (the actual rotation angle of the magnetic pole).

[0105] The motor control device 2 includes a current command generator 9, a current sensor 11u, a current sensor 11v, a current coordinate converter 12, a subtraction processor 13, a subtraction processor 14, a voltage command generator 15, a voltage coordinate converter 16, a PWM (pulse width modulation) inverter 17, a resolver phase corrector 18, a subtraction processor 19, a torque estimation unit 20, and a strong excitation control command unit 21. The motor control device 2 performs operation control of the second motor generator MG2 by vector control using the above-mentioned dq coordinate system. Here, the structure in which the current command generator 9, the subtraction processor 13, the subtraction processor 14, the voltage command generator 15, the voltage coordinate converter 16, and the PWM inverter 17 are combined is an example of the drive current control unit 3 of the present invention.

[0106] The current command generator 9 calculates the d-axis current command value Id* and the q-axis current command value Iq* based on the torque command value Tq_tar, which is the command value for the torque generated by the second motor generator MG2. The d-axis current command value Id* and the q-axis current command value Iq* are the d-axis component and the q-axis component of the command value of the current (drive current) flowing through the stator of the second motor generator MG2.

[0107] The current sensor 11u and the current sensor 11v respectively detect the driving currents Iu and Iv of the U phase and V phase flowing through the stator (armature) of the second motor generator MG2. The stator of the second motor generator MG2 is three-phase, so the current flowing through any one phase is uniquely determined by the current flowing through the other two phases. For example, the current flowing through the W phase is -(Iu+Iv). Therefore, in the present embodiment, the current sensor 11u and the current sensor 11v are provided to detect the currents of two phases (U phase and V phase in the present embodiment).

[0108] The current coordinate converter 12 calculates the d-axis current value Id and the q-axis current value Iq at the command value coordinate d*-q* by performing coordinate conversion on the detection values ​​of the drive currents Iu and Iv detected by the current sensor 11u and the current sensor 11v. The command value coordinate d*-q* represents the dq coordinate used for calculation in the motor control device 2. The motor control device 2 senses the command value coordinate d*-q* based on the magnetic pole rotation angle θ, which is an angle obtained by correcting the magnetic pole detection angle θ_act detected by the resolver 8. The magnetic pole rotation angle θ is a value obtained by adding the resolver zero point correction value θ_ref for efficiency optimal control to the magnetic pole detection angle θ_act. In addition, the motor control device 2 sometimes senses the command value coordinate d*-q* based on the magnetic pole rotation angle θ_act+θ_sf, which is a value obtained by adding the resolver zero point correction value θ_sf for strong excitation to the magnetic pole detection angle θ_act detected by the resolver 8. The zero-point correction value θ_sf of the rotary transformer for strong excitation will be described later. The command value coordinate d*-q* sensed based on the magnetic pole detection angle θ_act before correction is inconsistent with the (i.e. actual) dq coordinate derived from the hardware of the second motor generator MG2, and there is an error corresponding to the magnetic pole position error angle θ_ref between the command value coordinate d*-q* and the dq coordinate. On the other hand, for the corrected magnetic pole rotation angle θ, the command value coordinate d*-q* is consistent with the dq coordinate derived from the hardware of the second motor generator MG2. The coordinate transformation of the current coordinate converter 12 is performed using the magnetic pole rotation angle θ as the angle representing the rotation angle of the magnetic pole of the rotor of the second motor generator MG2.

[0109] Id and Iq obtained by this coordinate transformation mean the detected values ​​of the d-axis current and the q-axis current at the command value coordinates d*-q* (dq coordinates determined with θ as the rotation position of the d-axis) determined by the magnetic pole rotation angle θ.

[0110] return Figure 6 The subtraction processor 13 calculates and outputs the deviation Id_Tar (Id*-Id) between the d-axis current command value Id* output by the current command generator 9 and the d-axis current value Id output by the current coordinate converter 12. The subtraction processor 14 calculates and outputs the deviation Iq_Tar (Iq*-Iq) between the q-axis current command value Iq* output by the current command generator 9 and the q-axis current value Iq output by the current coordinate converter 12.

[0111] The voltage command generator 15 obtains the command values ​​of the applied voltages in the directions of the axes at the command value coordinates d*-q*, i.e., the d-axis voltage command value Vd_tar and the q-axis voltage command value Vq_tar, based on the deviations (Id_tar and Iq_tar) output by the subtraction processors 13 and 14. The voltage command generator 15 obtains the d-axis voltage command value Vd_tar and the q-axis voltage command value Vq_tar by, for example, PI control (feedback control such as proportional-integral control) so that the deviations (Id_tar and Iq_tar) are respectively "0".

[0112] The voltage coordinate converter 16 calculates the command values ​​Vu_tar, Vv_tar and Vw_tar (hereinafter referred to as phase voltage command values ​​Vu_tar, Vv_tar and Vw_tar) of the applied voltage of each phase of the stator of the second motor generator MG2 by performing coordinate conversion on the d-axis voltage command value Vd_tar and the q-axis voltage command value Vq_tar obtained by the voltage command generator 15. The coordinate conversion of the voltage coordinate converter 16 is performed using the same magnetic pole rotation angle θ as the magnetic pole rotation angle used in the coordinate conversion of the current coordinate converter 12.

[0113] The phase voltage command values ​​Vu_tar, Vv_tar, and Vw_tar obtained by this coordinate transformation define the magnitude and phase of the voltage applied to each phase U, V, W of the stator of the second motor generator MG2.

[0114] The PWM inverter 17 controls the actual applied voltage of each phase of the stator of the second motor generator MG2 according to the phase voltage command values ​​Vu_tar, Vv_tar and Vw_tar calculated by the voltage coordinate converter 16. The PWM inverter 17 controls the magnitude (amplitude) and phase of the applied voltage of each phase U, V, W of the stator of the second motor generator MG2 according to the phase voltage command values ​​Vu_tar, Vv_tar and Vw_tar.

[0115] The resolver phase corrector 18 uses the magnetic pole position error angle θ_ref, which represents the error angle between the magnetic pole detection angle and the actual rotation angle of the magnetic pole, as the resolver zero point correction value, and adds it to the magnetic pole detection angle θ_act output by the resolver 8 and outputs it (hereinafter, the magnetic pole position error angle θ_ref is referred to as the resolver zero point correction value θ_ref for efficiency optimal control). The resolver phase corrector 18 stores the resolver zero point correction value θ_ref for efficiency optimal control known in design, and during normal operation, adds the resolver zero point correction value θ_ref for efficiency optimal control to the magnetic pole detection angle θ_act and outputs it. In addition, normal operation refers to operation other than strong excitation control (current consumption control).

[0116] Furthermore, a strong field control command is input to resolver phase corrector 18 from strong field control command unit 21. When the strong field control command is input, resolver phase corrector 18 adds a strong field control resolver zero point correction value θ_sf to the magnetic pole detection angle θ_act detected by resolver 8 and outputs the result.

[0117] The strong field control command unit 21 outputs a strong field control command to the resolver phase corrector 18 when the high voltage battery BATh is fully charged or nearly fully charged.

[0118] The torque estimating unit 20 estimates and outputs the driving torque Tq based on the detection values ​​of the driving currents Iu and Iv detected by the current sensor 11u and the current sensor 11v, the magnetic pole detection angle θ_act output by the resolver 8, and the like.

[0119] The subtraction processor 19 calculates the deviation Tq*-Tq between the target torque Tq* and the drive torque Tq output by the torque estimation unit 20 and outputs it as the torque command value Tq_tar. The target torque Tq* is set by a calculation processing device (not shown) according to the driving state of the vehicle (accelerator operation amount, etc.). The current command generator 9 obtains the d-axis current command value Id* and the q-axis current command value Iq* by PI control (feedback control such as proportional-integral control) for the torque command value Tq_tar set to make the deviation Tq*-Tq "0".

[0120] In the motor generator control system 100 thus configured, the second motor generator MG2 performs power operation by the electric power from the high-voltage battery BATh, and the high-voltage battery BATh is charged by regeneration through the torque input from the drive wheel W. The drive current control unit 3, which is composed of the current command generator 9, the subtraction processor 13, the subtraction processor 14, the voltage command generator 15, the voltage coordinate converter 16, and the PWM inverter 17, performs feedback control based on the drive current Iu and Iv of the second motor generator MG2 so that the drive force during power operation or the drive torque Tq during regeneration of the second motor generator MG2 becomes the target torque Tq*. The current coordinate converter 12 calculates the d-axis current value Id and the q-axis current value Iq based on Iu and Iv of the second motor generator MG2 and outputs them to the drive current control unit 3. Furthermore, when performing strong excitation control (current consumption control), the strong excitation control command unit 21 outputs a strong excitation control command to the resolver phase corrector 18.

[0121] Here, if Figure 7As shown, when a strong excitation control instruction (current consumption control requirement) is input from the strong excitation control instruction unit 21 ("Yes" in S1), the resolver phase corrector 18 adds the resolver zero point correction value θ_sf for strong excitation control to the magnetic pole detection angle θ_act detected by the resolver 8 and outputs it (S2). In other words, the resolver phase corrector 18 replaces the resolver zero point correction value θ_ref for efficiency optimal control used during normal operation with the resolver zero point correction value θ_sf for strong excitation control. The resolver zero point correction value θ_sf for strong excitation control is a value obtained by adding the error angle α to the resolver zero point correction value θ_ref for efficiency optimal control. The error angle α is set to a value that makes the drive torque Tq smaller than the target torque Tq*. In addition, the error angle α satisfies 0°<α<90°. That is, due to the difference between the resolver zero point correction value θ_sf for strong field control and the resolver zero point correction value θ_ref for optimum efficiency control, ie, the error angle α, the drive torque Tq in the strong field control temporarily becomes smaller than the target torque Tq* in the optimum efficiency control.

[0122] Reference Figure 8 and Fig. 9 The effect of the error angle α is further explained. Figure 8 The single-dot chain line in FIG. 1 shows the d-axis current value Ida and the q-axis current value Iqa when the operating point Ia is located on the constant torque curve A in the efficiency optimum control. Figure 8 same, Fig. 9 The dashed line shown in FIG. 1 shows the d-axis current value Ida and the q-axis current value Iqa when the operating point Ia is located on the constant torque curve A in the efficiency optimum control. Fig. 9 As shown, the double-dashed line shows the d-axis current value Idb (Idb = Ida × cosα) and the q-axis current value Iqb (Iqb = Iqa × cosα) that shift due to the error angle α during strong field control. Fig. 9 As shown, during strong excitation control, due to the error angle α, the d-axis current value Ida and the q-axis current value Iqa in the efficiency optimal control migrate to the d-axis current value Idb and the q-axis current value Iqb, and the action point Ia originally located on the constant torque curve A migrates to the action point Ib on the constant torque curve B indicating a torque lower than the constant torque curve A.

[0123] When the target torque Tq* is the operating point Ia, when the resolver phase corrector 18 adds the resolver zero point correction value θ_ref for efficiency optimization control to the magnetic pole detection angle θ_act and outputs it, the d-axis current value and the q-axis current value outputted by the current coordinate converter 12 become Ida and Iqa. In contrast, when the resolver phase corrector 18 adds the resolver zero point correction value θ_sf for strong excitation control to the magnetic pole detection angle θ_act and outputs it, the d-axis current value and the q-axis current value outputted by the current coordinate converter 12 become Idb and Iqb due to the error angle α. As a result, the torque estimation unit 20 detects the drive torque Tq that is smaller than the target torque Tq*.

[0124] As described above, the drive torque Tq output by the torque estimation unit 20 is input to the subtraction processor 19, and the current command generator 9 performs feedback control so that the deviation Tq*-Tq between the target torque Tq* and the drive torque Tq output by the torque estimation unit 20 is "0". Through feedback control, the current command generator 9 sets the d-axis current command value Id* and the q-axis current command value Iq* so that the operating point Ib that migrates from the constant torque curve A to the constant torque curve B due to the error angle α returns to the constant torque curve A. Therefore, if Fig.10 As shown, the current command generator 9 sets Idb2 as the d-axis current command value Id* and sets Iqb2 as the q-axis current command value Iq*.

[0125] Therefore, if Fig.11 As shown, the torque reduction amount (the difference between the constant torque curve B and the constant torque curve A) reduced by the error angle α is adjusted to the original torque (the operating point Ib2 of the constant torque curve A) by feedback control, so that the current is consumed redundantly by the adjustment amount. As a result, the efficiency of the electric generator control system 100 deteriorates, so even if the high-voltage battery BATh is close to fully charged, the charge amount generated by regenerative braking can be suppressed, and the degradation of the high-voltage battery BATh can be prevented. In addition, this strong excitation control (current consumption control) does not require a dedicated mapping and a special control unit, so it can be achieved by the usual strong excitation control and feedback control, so that the complexity of the control can be prevented.

[0126] In addition, in this strong excitation control (current consumption control), the resolver phase corrector 18 only needs to change the value of the rotor rotation angle to a value (θ_act+θ_sf) at which the drive torque Tq is less than the target torque Tq*, so the current consumption can be increased without performing complex control. In other words, the resolver detection angle (phase) of the rotor is offset using the rotation angle amount with a margin reserved in advance as the detection error amount of the resolver 8, thereby reducing the driving efficiency.

[0127] Here, the magnitude of the error angle α will be described. Fig.12 is a diagram showing the relationship between the error angle α and the regenerative torque. As mentioned above, the error angle α is the difference between the zero-point correction value θ_sf of the rotary transformer for strong excitation control and the zero-point correction value θ_ref of the rotary transformer for efficiency optimization control. Therefore, when the error angle α is zero, the magnetic pole rotation angle θ is the value obtained by adding the zero-point correction value θ_ref of the rotary transformer for efficiency optimization control to the magnetic pole detection angle θ_act, so the driving efficiency becomes the highest ( Fig.12 The efficiency is the best), and the regenerative torque takes the maximum value. When the error angle α increases in the + direction or - direction, it may cause the actual torque to deviate from the target torque Tq*, inverter damage caused by the current peak increase, abnormal heating of the rotor magnet, and motor function failure such as demagnetization. Therefore, the strong excitation control (current consumption control) is performed within the range where the difference between the target torque Tq* and the actual torque caused by the error angle α is smaller than the specified torque variation allowable range.

[0128] In addition, by the positive area on the d-axis (refer to Figure 4 and Figure 5 ) by performing the strong excitation control (current consumption control) and the correction of the detection angle of the resolver 8, the drive efficiency can be reliably reduced.

[0129] In addition, the strong excitation control (current consumption control) can also be performed during the power operation of the first motor generator MG1. That is, by performing the strong excitation control (current consumption control) during the power operation of the first motor generator MG1, the conversion efficiency deteriorates, the drive current increases, and a large amount of regenerative current generated by the second motor generator MG2 can be consumed. Fig.13 In the example, strong excitation control (current consumption control) is performed during regeneration of the second motor generator MG2, and strong excitation control (current consumption control) is performed during power operation of the first motor generator MG1. As a result, the regenerative current generated by the second motor generator MG2 is reduced, and the drive current consumed by the first motor generator MG1 is increased, thereby achieving further power consumption of the system as a whole.

[0130] Above, various embodiments have been described with reference to the accompanying drawings, but the present invention is certainly not limited to these examples. Obviously, those skilled in the art can think of various variations or modifications within the scope of the technical solution, and it should be understood that these also belong to the technical scope of the present invention. In addition, the various constituent elements in the above-mentioned embodiments can also be arbitrarily combined within the scope of the main purpose of the invention.

[0131] For example, the hybrid vehicle described above is a series-type HEV, but it may be a parallel-type HEV, or may be a HEV that can switch between the series type and the parallel type.

[0132] In addition, at least the following matters are described in this specification. In addition, although the components corresponding to the above-mentioned embodiments are shown in parentheses, the present invention is not limited to these.

[0133] (1) A motor generator control system (motor generator control system 1), wherein:

[0134] The motor generator control system includes: a motor generator (second motor generator MG2) that performs power operation by electric power from a storage device (high-voltage battery BATh) and charges the storage device by regenerating driving force input from drive wheels (drive wheels W);

[0135] a drive current control unit (drive current control unit 3) that performs feedback control based on the drive current (drive current Iu, Iv) of the motor generator so that the drive force during power operation or the drive force during regeneration (drive torque Tq) of the motor generator becomes a target drive force (target torque Tq*);

[0136] a current coordinate control unit (current coordinate converter 12) that calculates a d-axis current value (d-axis current value Id) and a q-axis current value (q-axis current value Iq) based on the drive current of the motor generator and outputs the calculated values ​​to the drive current control unit; and

[0137] a strong excitation control unit (strong excitation control command unit 21) for performing strong excitation control for increasing the excitation intensity compared to the excitation intensity that can obtain the maximum efficiency on the constant driving force line of the motor generator,

[0138] When the strong excitation control is performed during the regeneration, current consumption control is executed, in which the d-axis current value (Ida) and the q-axis current value (Iqa) are changed to make the driving force smaller than the target driving force (Idb, Iqb), and the feedback control is performed.

[0139] According to (1), when strong excitation control is performed during regeneration, the d-axis current value and the q-axis current value are changed so that the driving force is smaller than the target driving force, and feedback control is performed by the driving current control unit, so that the driving force can be adjusted to the target driving force by feedback control, and on the other hand, the current is consumed excessively by the adjustment amount. As a result, the driving efficiency of the electric generator control system is reduced, and the charge amount of the electric storage device generated by regenerative braking can be suppressed when the electric storage device is in a fully charged or nearly fully charged state, thereby preventing the deterioration of the electric storage device.

[0140] (2) The motor generator control system according to (1), wherein:

[0141] The electric generator control system further comprises:

[0142] a rotary transformer (resolver 8) that detects a rotor rotation angle of the motor generator; and

[0143] a resolver phase changer (resolver phase corrector 18) that changes the value of the rotor rotation angle and outputs the value to the current coordinate control unit,

[0144] In the current consumption control, the resolver phase changer changes the value of the rotor rotation angle (θ_act+θ_ref) to a value (θ_act+θ_sf) at which the driving force is smaller than the target driving force, and outputs the value to the current coordinate control unit.

[0145] According to (2), when strong excitation control is performed during regeneration, it is only necessary to change the resolver zero point correction value by the resolver phase change unit, so that the current consumption can be increased without performing complex control. In other words, the detection angle (phase) of the resolver is shifted with respect to the rotor using the rotation angle amount with a margin reserved in advance as the detection error amount of the resolver, thereby reducing the driving efficiency.

[0146] (3) The motor generator control system according to (2), wherein:

[0147] The current consumption control is performed within a range in which a difference between the target driving force and the actual driving force caused by a difference in the detection angle of the resolver with respect to a reference point of the rotor rotation angle is smaller than a prescribed value.

[0148] According to (3), when the difference between the detection angle of the rotary transformer and the reference point of the rotation angle of the rotor increases, the actual driving force cannot follow the target driving force and the driving force changes. This may cause a motor function failure that hinders driving. Therefore, the value of the detection angle is changed within the range where the difference in driving force is less than a specified value. In this way, the driving efficiency can be reduced within the range that does not cause functional failure.

[0149] (4) The motor generator control system according to (3), wherein:

[0150] The strong field control and the change of the detection angle are performed in the positive region of the d-axis.

[0151] According to (4), the driving efficiency can be reliably reduced by performing strong field control and correcting the detection angle of the resolver in the positive region on the d-axis.

[0152] (5) A hybrid electric vehicle (HEV), wherein:

[0153] The hybrid vehicle comprises:

[0154] Internal combustion engine (ENG);

[0155] Storage battery (high voltage battery BATh);

[0156] a first motor generator (first motor generator MG1) that generates electricity using power from the internal combustion engine;

[0157] a second motor generator (second motor generator MG2) driven by electric power from the battery or the first motor generator; and

[0158] The motor generator control system (motor generator control system 1) according to any one of (1) to (4),

[0159] The motor generator of the motor generator control system is the second motor generator,

[0160] When the second motor generator is regenerating,

[0161] The first motor generator is used as a motor to perform power operation by using the regenerative power of the second motor generator.

[0162] executing the current consumption control on the second motor generator,

[0163] During the power operation of the first motor generator,

[0164] The load of the first motor generator is the internal combustion engine,

[0165] For the first motor generator,

[0166] The d-axis current value (Ida) and the q-axis current value (Iqa) of the first electric generator are changed so that the driving force is smaller than the target driving force (Idb, Iqb), and feedback control is performed based on the driving current (Iu, Iv) of the first electric generator so that the driving force (driving torque Tq) during power operation of the first electric generator becomes the target driving force (target torque Tq*).

[0167] According to (5), in combination with the second motor generator, the efficiency is also deteriorated when the first motor generator loads the engine to drive in order to consume power, thereby further reducing the driving efficiency of the entire system.

Claims

1. A motor generator control system, wherein: The electric generator control system comprises: a motor generator that is powered by the electric power from the battery and that charges the battery by regenerating the driving force input from the drive wheels; a drive current control unit that performs feedback control based on the drive current of the motor generator so that the drive force of the motor generator during power running or during regeneration becomes a target drive force; a current coordinate control unit that calculates a d-axis current value and a q-axis current value based on the drive current of the motor generator and outputs the calculated values ​​to the drive current control unit; as well as a strong excitation control unit for performing a strong excitation control for increasing the excitation intensity compared to the excitation intensity that can obtain the maximum efficiency on the constant driving force line of the motor generator; When the strong field control is performed during the regeneration, current consumption control is executed in which the d-axis current value and the q-axis current value are changed so that the driving force becomes smaller than the target driving force, and the feedback control is performed.

2. The motor generator control system according to claim 1, wherein: The electric generator control system further comprises: a rotary transformer that detects a rotor rotation angle of the motor generator; and a resolver phase changer that changes the value of the rotor rotation angle and outputs the value to the current coordinate control unit, In the current consumption control, the resolver phase changer changes the value of the rotor rotation angle to a value at which the driving force is smaller than the target driving force, and outputs the value to the current coordinate control unit.

3. The motor generator control system according to claim 2, wherein: The current consumption control is performed within a range in which a difference between the target driving force and the actual driving force caused by a difference in the detection angle of the resolver with respect to a reference point of the rotor rotation angle is smaller than a prescribed value.

4. The motor generator control system according to claim 3, wherein: The strong field control and the change of the detection angle are performed in the positive region of the d-axis.

5. A hybrid vehicle, wherein: The hybrid vehicle comprises: internal combustion engine; Storage battery; a first motor generator that generates electricity using power from the internal combustion engine; a second motor generator driven by electric power from the electric storage device or the first motor generator; and The electric generator control system according to any one of claims 1 to 4, The motor generator of the motor generator control system is the second motor generator, When the second motor generator is regenerating, The first motor generator is used as a motor to perform power operation by using the regenerative power of the second motor generator. executing the current consumption control on the second motor generator, During the power operation of the first motor generator, The load of the first motor generator is the internal combustion engine, For the first motor generator, The d-axis current value and the q-axis current value of the first motor generator are changed so that the driving force is smaller than the target driving force, and feedback control is performed based on the driving current of the first motor generator so that the driving force of the first motor generator during power running becomes the target driving force.

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