Motor control method and motor controller

Abstract

To provide a motor control method and a motor controller with improved warm-up efficiency.SOLUTION: A motor control method is provided for a motor unit with an open-winding motor and an inverter that converts power and supplies it to the motor. This motor control method warms up the motor and inverter by passing a zero-phase current through the motor so as to increase the power loss in the motor and inverter.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a motor control method and a motor control device. [Background technology]

[0002] Patent Document 1 discloses a motor control device that performs vector control for motor drive control. In this motor control device, when the battery needs to be warmed up, the lower the battery temperature is, the higher the d-axis current flowing through the motor is, thereby increasing the warm-up speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-165526 ​​A Summary of the Invention [Problem to be solved by the invention]

[0004] In the motor control device described in Patent Document 1, when warm-up is required, the d-axis current flows according to the battery temperature, resulting in an imbalance in the amount of current flowing through each phase of the motor. Therefore, when the current value of the phase with the maximum current amount reaches the current limit value of the motor or peripheral devices, no more current can be passed even if the amount of current flowing through other phases is low, and there is a risk of a decrease in warm-up efficiency.

[0005] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a motor control method and a motor control device with improved warm-up efficiency. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a motor control method for a motor unit including an open-winding motor and an inverter that converts electric power and supplies it to the motor, the motor control method warming up the motor and the inverter by passing a zero-phase current through the motor so as to increase the power loss of the motor and the inverter. Effect of the Invention

[0007] According to the present invention, a zero-phase current is passed through the motor so as to increase the power loss of the motor and the inverter, thereby warming up the motor and the inverter. In this way, a zero-phase current that flows in common to each phase of the motor is passed through to increase the zero-phase current during warming up of the motor and the inverter, so that the current flowing through the motor can be maximized within the range of the current limit value. Therefore, the amount of heat generated by the motor and the inverter during warm-up is maximized, improving the warm-up efficiency. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a vehicle equipped with a motor unit to which a motor control method according to an embodiment of the present invention is applied. [Diagram 2] FIG. 2 is a schematic diagram of the motor unit. [Diagram 3] FIG. 3 is a diagram showing a detailed configuration of the current command value calculation unit. [Figure 4] FIG. 4 is a diagram illustrating the first warm-up method. [Diagram 5] FIG. 5 is a diagram showing phase current waveforms before the zero-phase current is superimposed. [Figure 6] FIG. 6 is a diagram showing phase current waveforms after the zero-phase current is superimposed. [Figure 7] FIG. 7 is a diagram showing a method of selecting a warm-up current command generation method. [Figure 8] FIG. 8 is a diagram showing phase current values ​​versus motor angle when the d-axis current flows. [Figure 9] FIG. 9 is a diagram for explaining a method of calculating the warm-up dq-axis current command values. [Figure 10]FIG. 10 is a diagram showing UVW phase current command values. [Figure 11] FIG. 11 is a diagram showing UVW phase current command values. [Figure 12] FIG. 12 is a flowchart illustrating the warm-up control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] [Embodiment] 1 is a schematic diagram of a vehicle 1 equipped with a motor unit 100 to which a motor control method according to an embodiment of the present invention is applied. As shown in FIG 1, the vehicle 1 is composed of the motor unit 100, a reduction gear 101, a differential gear 102, a drive shaft 103, driving wheels 104, a battery 105, a BMS 106, and a VCM 107.

[0011] The vehicle 1 is an electrically powered vehicle such as an electric vehicle or a hybrid vehicle.

[0012] The motor unit 100 is composed of an inverter 19 (FIG. 2), an open-winding type motor 30 (FIG. 2), and an MCU (Motor Control Unit) that controls the operation of the inverter 19 to perform motor control. The motor unit 100 generates torque T by driving the motor 30 to rotate. Note that in this embodiment, the motor unit 100 is mounted on a vehicle 1 that is an electrically powered vehicle such as an electric vehicle or a hybrid vehicle, but is not necessarily limited to this.

[0013] Torque generated in the motor unit 100 is transmitted to driving wheels 104 via a reduction gear 101, a differential gear 102, and a drive shaft 103, thereby causing the vehicle 1 to travel.

[0014] The battery 105 is, for example, a stacked lithium ion battery, and is a high-power battery that supplies driving power to the motor 30 via the inverter 19 of the motor unit 100. The motor 30 is driven and rotated by the power supplied from the battery 105. The battery 105 is provided with a battery temperature sensor 108 that detects the battery temperature.

[0015] The BMS (Battery Management System) 106 is a terminal voltage V dc , calculates the remaining battery capacity (SOC) based on the integration of the charge and discharge current, and manages the charge and discharge current according to the battery temperature acquired by the battery temperature sensor 108. For example, the BMS 106 determines whether or not the motor 30 and the inverter 19 need to be warmed up based on the battery temperature, and calculates the amount of current required for warming up (hereinafter also referred to as the required current amount). The BMS 106 also calculates the inter-terminal voltage (DC voltage) V of the battery 105. dc If warm-up is required, a warm-up request and information such as a command for the required amount of current are output to the motor unit 100 via the CAN communication line.

[0016] A VCM (Vehicle Control Module) 107 receives information from an accelerator pedal sensor, a brake pedal sensor, an e-PKB (electric parking brake) switch, a shift position signal, and the like, and determines a torque T (required torque) to be output by the motor 30 based on this information. The VCM 107 also calculates the torque T (required torque) to be output by the motor 30 as a torque command value T * and outputs it to the motor unit 100.

[0017] 2 is a schematic diagram of the motor unit 100. The motor unit 100 is composed of a motor control device 10 including an inverter 19, and an open-winding type motor 30. When the motor unit 100 is mounted on a vehicle 1, the motor 30 is used as an electric motor that is a drive source for the electric vehicle, or as a generator in a power generation system mounted on the electric vehicle. The motor unit 100 (motor control device 10 and motor 30) can also be mounted on systems other than automobiles.

[0018] The object of control of the motor control device (hereinafter also simply referred to as the control device) 10 is the motor 30, and the control device 10 is programmed to control the motor 30 at a predetermined control period. The motor 30 does not have stator windings (hereinafter simply referred to as windings) 31 of each phase connected, and the windings 31 of each phase are electrically independent from each other. In other words, the motor 30 does not have a so-called neutral point. In this embodiment, the motor 30 is a three-phase AC synchronous motor, and the windings 31 are independent for each of the UVW phases. The motor 30 rotates the rotor by supplying power from the above-mentioned battery 105 to the windings 31 of each phase.

[0019] The control device 10 includes a current command value calculation unit 11, a current control unit 12, a decoupling control unit 13, a second voltage command value calculation unit 14, a final voltage command value calculation unit 15, a disturbance compensation unit 16, a coordinate conversion unit 17, a PWM conversion unit 18, and an inverter 19. Among these, the current command value calculation unit 11, the current control unit 12, the decoupling control unit 13, the second voltage command value calculation unit 14, the final voltage command value calculation unit 15, the disturbance compensation unit 16, the coordinate conversion unit 17, and the PWM conversion unit 18 configure an MCU, which is a controller that controls the operation of the inverter 19 to perform motor control.

[0020] The current command value calculation unit 11 calculates the torque command value T * , a parameter representing the rotation speed of the motor 30, and an electrical angle θ of the motor 30. re , and the DC voltage V of the battery 105 dc Based on this, the d-axis current command value i d * , q-axis current command value iq * , and the zero-phase current command value i z * Calculate the torque command value T * is the DC voltage V of the battery 105 from VCM107. dc are obtained from the BMS 106. re is input from a pulse counter 24, which will be described later.

[0021] The parameter representing the rotation speed of the motor 30 is, for example, the electrical angular velocity ω re , mechanical angular velocity ω rm , or the number of revolutions N m In this embodiment, the current command value calculation unit 11 uses the mechanical angular velocity ω rm Mechanical angular velocity ω rm is input from the angular velocity calculation unit 25 described later.

[0022] d-axis current command value i d * and q-axis current command value i q * (Hereinafter, the dq-axis current command value i d * ,i q * The torque command value T * The d-axis and q-axis current command values ​​i d * ,i q * are drive command values ​​for controlling the drive of the motor 30. The dq axes are the electrical angular velocity ω re It is a Cartesian coordinate system that rotates with

[0023] Zero-phase current command value i z * is the zero-phase current i flowing through the motor 30 z This is the command value for controlling the value of the zero-phase current i, but in principle it is set to 0. zis a current flowing in phase through each winding 31 in a multi-phase unbalanced AC circuit, and is a zero-phase current i z ' and the zero-phase current i flowing from the inverter 19 to the motor 30. z ′′ and the sum of i z ′+i z ''. Zero-phase current i z does not contribute to the driving of the motor 30, and normally, the zero-phase current i z The zero-sequence current i ′ is suppressed (cancelled) z That is, i z =i z ′+i z Since the zero-phase current command value i z * is set to 0. However, in this embodiment, as will be described later, the zero-phase current i z ≠0, the zero-phase current i z and the motor 30 is supplied with a zero-phase current i z The warm-up control is carried out by passing the current through the exhaust gas. The details of the warm-up control will be described later.

[0024] In this embodiment, the current command value calculation unit 11 calculates the torque command value T * , mechanical angular velocity ω rm and DC voltage V dc The current command value calculation unit 11 has a current command value map in which the torque command value T * , mechanical angular velocity ω rm and DC voltage V dc The dq-axis current command value i d * ,i q * and the zero-phase current command value i z * Calculate the following.

[0025] The detailed configuration of the current command value calculation unit 11 will be described later.

[0026] The current control unit 12 calculates the dq-axis current command value i d * ,i q * and the actual d-axis current i d and q-axis current i q (Hereafter, dq axis current i d ,i q Based on this, the first d-axis voltage command value v d1 * and the first q-axis voltage command value v q1 * (Hereinafter, the first dq-axis voltage command value v d1 * ,v q1 * The first dq-axis voltage command v d1 * ,v q1 * is the dq axis current command value i d * ,i q * The dq-axis current i d ,i q The first dq-axis voltage command value v d1 * ,v q1 * are voltage command values ​​for the dq axes determined by feedback control. The current control unit 12 calculates the dq axis current command value i d * ,i q * and the actual dq axis current i d ,i q The first dq-axis voltage command value v d1 * ,v q1 * This calculates the dq axis current i d ,i q is the dq-axis current command value i with a given responsiveness that can be considered to have no steady-state error. d * ,i q * Follow.

[0027] In addition, the current control unit 12 determines the zero-phase current command value i z * and the actual zero-sequence current i z Based on this, the first zero-phase voltage command value v z1 * Calculate the zero-phase current command value i z * When is 0, the first zero-phase voltage command value v z1 * is the zero-phase current i that flows in common to each phase when the motor 30 is driven. z The zero-sequence current i that suppresses (cancels) z The zero-phase current command value i z * When is not 0, the first zero-phase voltage command value v z1 * is the zero-phase current command value i z * The zero-phase current i corresponding to z The zero-phase current i z The first zero-phase voltage command value v z1 * is a voltage command value for the zero-phase sequence determined by feedback control. The current control unit 12 calculates the zero-phase current command value i z * and the actual zero-sequence current i z The first zero-phase voltage command value v z1 * This calculates the zero-phase current i z is the zero-phase current command value i with a given response that can be considered to have no steady-state error. z * Follow.

[0028] The decoupling control unit 13 controls the electric angular velocity ω re and electrical angle θ re and the dq axis current command value i d * ,i q * , zero-phase current command value i z* Based on this, the d-axis decoupling voltage v d-dcpl , q-axis decoupling voltage v q-dcpl , and the zero-sequence decoupling voltage v z-dcpl (Hereinafter, the dq axis and zero-phase decoupling voltage v q-dcpl ,v q-dcpl ,v z-dcpl The dq axis and zero-phase decoupling voltage v q-dcpl ,v q-dcpl ,v z-dcpl is a command value for a voltage that cancels out the voltage (interference voltage) generated by the interference between the d-axis, q-axis, and zero-phase. re The electrical angle θ re ' is used.

[0029] The second voltage command value calculation unit 14 calculates the first dq-axis voltage command value v d1 * ,v q1 * and the first zero-phase voltage command value v z1 * , the dq axis and zero-phase decoupling voltage v q-dcpl ,v q-dcpl ,v z-dcpl By adding d2 * , the second q-axis voltage command value v q2 * and the second zero-phase voltage command value v z2 * (The following is the second dq axis and the zero-phase voltage command value v d2 * ,v q2 * ,v z2 * (called "square root of the square root of the

[0030] The final voltage command value calculation unit 15 calculates the second dq-axis and zero-phase voltage command value v d2 * ,v q2 * ,v z2 * By applying disturbance compensation to the final d-axis voltage command value vd * , the final q-axis voltage command value v q * and the final zero-phase voltage command value v z * (In the following, the final dq axis and zero-phase voltage command value v d * ,v q * ,v z * In this embodiment, the final voltage command value calculation unit 15 calculates the second dq-axis and zero-phase voltage command value v d2 * ,v q2 * ,v z2 * The d-axis disturbance estimate v d-dist , q-axis disturbance estimate v q-dist and the zero-sequence disturbance estimate v z-dist By adding these, the final dq axis and zero-phase voltage command value v d * ,v q * ,v z * Calculate the following.

[0031] The disturbance compensation unit 16 calculates the electrical angular velocity ω re , electrical angle θ re , the final dq axis and zero-phase voltage command value v d * ,v q * ,v z * , dq-axis current i d ,i q , and zero-phase current i z The disturbance compensation unit 16 estimates the disturbance acting on the motor 30 for the d-axis and the zero-phase, respectively, based on the above. The disturbance compensation unit 16 outputs the estimation result as a d-axis disturbance estimated value v d-dist , q-axis disturbance estimate v q-dist , and the zero-sequence disturbance estimate v z-dist The output is as follows:

[0032] The coordinate conversion unit 17 converts the dqz coordinate system, which includes the zero-phase component in the dq axis, into a three-phase AC coordinate system of the UVW axes, to obtain the final dq axis and zero-phase voltage command value v d * ,v q * ,v z * The voltage command value v of each UVW phase u * ,v v * ,v w * Specifically, the coordinate conversion unit 17 converts the final dq-axis and zero-phase voltage command value v d * ,v q * ,v z * The voltage command value of each UVW phase (hereinafter, the three-phase voltage command value v u * ,v v * ,v w * In this embodiment, the coordinate conversion unit 17 converts the electric angle θ re The electrical angle θ re ' is used.

[0033]

number

[0034] The PWM conversion unit 18 converts the three-phase voltage command value v u * ,v v * ,v w * Based on this, a PWM (Pulse Width Modulation) signal D, which is a drive signal for the switching element of the inverter 19, is generated. uru * ,D url * ,D vru * ,D vrl * ,D wru *,D wrl * ,D ulu * ,D ull * ,D vlu * ,D vll * ,D wlu * ,D wll * Specifically, the PWM conversion unit 18 calculates the three-phase voltage command value v u * ,v v * ,v w * and DC voltage V dc A duty command value (or comparison value) is generated based on this, and the above PWM signal is generated by comparing and matching the duty command value with the carrier wave.

[0035] The inverter 19 drives a switching element based on the PWM signal input from the PWM conversion unit 18 to convert the DC voltage V dc AC voltage V u ,v v ,v w and supplies it to the motor 30. The switching element is, for example, an insulated gate bipolar transistor (IGBT).

[0036] As described above, the motor 30 is an open winding type, and in this embodiment, the inverter 19 is composed of a first inverter 19R connected to one end of the winding 31 of each phase, and a second inverter 19L connected to the other end of the winding 31 of each phase. uru * ,D url * ,D vru * ,D vrl * ,D wru * ,D wrl * is a drive signal for the switching element of the first inverter 19R, and D ulu* ,D ull * ,D vlu * ,D vll * ,D wlu * ,D wll * is a drive signal for the switching element of the second inverter 19L.

[0037] A current flows through the windings 31 of each phase due to the balance between the voltage that the first inverter 19R is trying to apply and the voltage that the second inverter 19L is trying to apply in the opposite direction. At this time, a zero-phase current (zero-axis current) i z In the control device 10, the zero-phase current i z '', the zero-phase current i z (i.e., i z ′+i z '') is the zero-phase current command value i z * The control is made to match the

[0038] The control device 10 includes a current sensor 20, an A / D converter 21, a coordinate conversion unit 22, a magnetic pole position detector 23, a pulse counter 24, an angular velocity calculation unit 25, and a look-ahead compensation unit 26 in order to acquire parameters used in the above-mentioned units.

[0039] The current sensor 20 detects the three-phase AC current i supplied from the inverter 19 to the motor 30. u ,i v ,i w The detected three-phase AC current i u ,i v ,i w is converted into a digital signal by the A / D converter 21. The A / D converter 21 converts the digitized three-phase AC current i us ,i vs ,i ws is output to the coordinate conversion unit 22.

[0040] The coordinate conversion unit 22 converts the three-phase AC current i us ,i vs ,i ws and electrical angle θ re Based on this, the dq axis current i d ,i q and zero-phase current i z Specifically, the coordinate conversion unit 22 calculates the dq-axis current i d ,i q and zero-phase current i z Calculate the following.

[0041]

number

[0042] As can be seen from equation (2), the zero-phase current i z is the three-phase AC current i u ,i v ,i w In general, the zero-phase current i z is the number of phases of the motor 30 (windings 31) n w Then, the number of phases is n w It appears as harmonics of odd multiples (1x, 3x, 5x, …) of the three-phase AC current i u ,i v ,i w is the fundamental wave, the zero-phase current i generated in the motor 30 is z is the third harmonic component (1n w The main components are the 1st harmonic (order harmonics).

[0043] The magnetic pole position detector 23 outputs pulses of phases A, B, and Z corresponding to the position (angle) of the rotor of the motor 30. The pulse counter 24 uses the pulses output by the magnetic pole position detector 23 to calculate the electrical angle θ of the motor 30. re Calculate the following.

[0044] The angular velocity calculation unit 25 calculates the electrical angle θ re Based on the electrical angular velocity ω re , and mechanical angular velocity ω rmThe angular velocity calculation unit 25 calculates the electrical angle θ re By calculating the time rate of change of the electrical angular velocity ω re The angular velocity calculation unit 25 calculates the electrical angular velocity ω re The mechanical angular velocity ω rm Calculate the following.

[0045] The look-ahead compensation unit 26 calculates the electrical angle θ re By performing look-ahead compensation processing on the re Specifically, the look-ahead compensation unit 26 calculates the electrical angle θ re The dead time and electrical angular velocity ω re The electrical angle after look-ahead compensation, θ re Calculate '.

[0046] Fig. 3 is a block diagram showing a detailed configuration of the current command value calculation unit 11. As shown in Fig. 3, the current command value calculation unit 11 includes a current command generation unit 111, a warm-up current command generation method determination unit 112, a warm-up dq-axis current command generation unit 113, a warm-up zero-phase current command generation unit 114, and a final current command generation unit 115.

[0047] The current command generator 111 receives a torque command value T * , the mechanical angular velocity ω of the motor 30 rm and the DC voltage V of the battery 105 dc The current command generator 111 receives the torque command value T * , mechanical angular velocity ω rm and DC voltage V dc Based on this, the motor 30 generates a torque command value T * The first d-axis current command value i d_T * , the first q-axis current command value i q_T * and the first zero-phase current command value i z_T * (Hereinafter, the first dq axis and zero-phase current command value i d_T * ,i q_T * ,i z_T* The current command generator 111 calculates the torque command value T * , mechanical angular velocity ω rm and DC voltage V dc The current command value generating unit 111 has a current command value map in which the torque command value T * , mechanical angular velocity ω rm and DC voltage V dc The first dq-axis and zero-phase current command value i d_T * ,i q_T * ,i z_T * During normal operation other than during warm-up, the first dq-axis and zero-phase current command value i d_T * ,i q_T * ,i z_T * is the final current command value. In addition, the zero-phase current i z does not contribute to the torque T of the motor 30, the first zero-phase current command value i z_T * is usually 0. The current command generator 111 generates the first dq-axis and zero-phase current command value i d_T * ,i q_T * ,i z_T * to the warm-up dq-axis current command generating section 113 and the final current command generating section 115.

[0048] The warm-up current command generation method determination unit 112 receives the torque command value T * and the mechanical angular velocity ω of the motor 30 rm The warm-up current command generation method determination unit 112 receives the torque command value T * and mechanical angular velocity ω rm Based on this, a warm-up current command generation method for warming up the motor 30 and the inverter 19 is selected.

[0049] In this embodiment, two types of warm-up methods are used. d and q-axis current i q The first warm-up method increases the zero-phase current i z and a second warm-up method in which the first warm-up is performed by passing the

[0050] In the first warm-up method, the operating point in the dq-axis coordinates consisting of the d-axis component and the q-axis component of the current supplied to the motor 30 is moved to another operating point on the equal torque line, thereby increasing the power loss of the motor 30 and the inverter 19. For example, if the operating point on the dq-axis coordinates is point A on the normal current command line in FIG. 4 where the power loss of the motor 30 and the inverter 19 is the smallest, the dq-axis current i is adjusted so as to move the operating point to operating point B on the equal torque line and where the amount of current (required amount of current) required for warm-up flows through the motor 30. d ,i q This controls the dq axis current i d ,i q is the i at operating point A d1 ,i q1 from i at operating point B d2 ,i q2 , the power loss of the motor 30 and the inverter 19 increases, and the motor 30 and the inverter 19 are warmed up.

[0051] The second warm-up method is to supply a zero-phase current i to the motor 30 so as to increase the power loss of the motor 30 and the inverter 19. z That is, the zero-phase current i z With respect to the phase current of the motor 30 in the absence of z By superimposing the zero-phase current i shown in FIG. 5 on the U-phase, V-phase, and W-phase of the motor 30, the power loss of the motor 30 and the inverter 19 is increased. For example, assume that currents having waveforms as shown in FIG. 5 flow through the U-phase, V-phase, and W-phase of the motor 30. z When these are superimposed, the currents flowing through the U, V, and W phases have the waveforms shown in Fig. 6. In Fig. 6, the effective values ​​of the currents flowing through the U, V, and W phases are the zero-phase current i zThis increases the power loss of the motor 30 and the inverter 19, and the motor 30 and the inverter 19 are warmed up. In addition, when the torque T of the motor 30 is zero, such as when the vehicle 1 is stopped, almost no current flows through the U-phase, V-phase, and W-phase of the motor 30, so that the zero-phase current i z By passing the zero-phase current i, the power loss of the motor 30 and the inverter 19 increases in a state where the torque T is not generated. This warms up the motor 30 and the inverter 19. z is passed as a direct current.

[0052] 7 shows a method for selecting a warm-up current command generation method. The warm-up current command generation method determination unit 112 selects a warm-up current command generation method as follows.

[0053] First, the mechanical angular velocity ω of the motor 30 rm The absolute value of ω is a given value (threshold value). th If it is greater than the above, the warm-up current command generation method determination unit 112 selects the first warm-up method, sets the first warm-up flag to ON, and sets the second warm-up flag to OFF. For example, when the vehicle 1 is traveling at a normal speed, the rotation speed of the motor 30 (mechanical angular velocity ω rm When the zero-phase current i of the DC current is relatively large, the phase current of the motor 30 is close to or has reached the current limit value (hereinafter, simply referred to as the current limit value) imposed by the motor 30 and peripheral devices such as the inverter 19. z When these are superimposed, the current amounts of the phases become unbalanced, and efficient heat generation cannot be achieved. rm ) is relatively large, the zero-phase current i z is the rotation speed of the motor 30 (mechanical angular velocity ω rm Therefore, the mechanical angular velocity ω rm The absolute value of the threshold ω th If it is greater, the warm-up current command generation method determining unit 112 selects the first warm-up method.

[0054] Next, the mechanical angular velocity ω of the motor 30 rmThe absolute value of ω th The torque command value T * The absolute value of T th1 If the mechanical angular velocity ω of the motor 30 is greater than ω, the warm-up current command generation method determination unit 112 selects the first warm-up method and the second warm-up method to be used in combination, and sets both the first warm-up flag and the second warm-up flag to ON. rm is the threshold ω th Even if the torque required by the motor 30 is relatively large, the zero-phase current i z When the current of the motor 30 is superimposed on the zero-phase current i, the current amount of each phase becomes unbalanced, and efficient heat generation cannot be performed. On the other hand, when the current amount of the motor 30 has a certain margin up to the current limit value, the zero-phase current i z By superimposing the first and second warm-up methods, the power loss of the motor 30 and the inverter 19 can be further increased. Therefore, in this case, the first warm-up method is mainly performed while the second warm-up method is used auxiliary to maximize the heat generation of the motor 30 and the inverter 19. That is, the mechanical angular velocity ω rm The absolute value of the threshold ω th Below, and the torque command value T * The absolute value of the first threshold T th1 If it is greater than the above, the warm-up current command generation method determination unit 112 selects the combined use of the first and second warm-up methods. When the first and second warm-up methods are combined, the first warm-up method is controlled to have a larger contribution rate to warm-up than the second warm-up method.

[0055] Next, the mechanical angular velocity ω of the motor 30 rm The absolute value of ω th The torque command value T * The absolute value of T th2 If the difference is smaller than , the warm-up current command generation method determination unit 112 selects the second warm-up method, sets the first warm-up flag to OFF, and sets the second warm-up flag to ON. As described above, when the vehicle 1 is stopped, the torque T of the motor 30 is 0, so that almost no current flows through the U-phase, V-phase, and W-phase of the motor 30. Therefore, the zero-phase current i zBy passing the zero-phase current i up to the current limit value, it is possible to maximize the power loss of the motor 30 and the inverter 19 in a state where the torque T is not generated. Also, for example, when the vehicle 1 is creeping, and the torque T of the motor 30 is low, the phase current of the motor 30 has a margin up to the current limit value. Even in such a case, the zero-phase current i z By passing the current, it is possible to increase the power loss of the motor 30 and the inverter 19. Therefore, the mechanical angular velocity ω rm The absolute value of ω th Below, and the torque command value T * The absolute value of the second threshold T th2 If it is smaller, the warm-up current command generation method determining unit 112 selects the second warm-up method.

[0056] In addition, the mechanical angular velocity ω of the motor 30 rm The absolute value of ω th The torque command value T * The absolute value of the second threshold T th2 or more and the first threshold T th1 In the following cases, the warm-up current command generation method determining unit 112 holds the previous values, i.e., determines whether the first warm-up flag and the second warm-up flag are on or off so as to continue the previously selected warm-up method.

[0057] Incidentally, as a warm-up method when the motor torque T is 0 or low, there is also a method of passing a current in the d-axis direction where no torque T is generated. However, passing a current in the d-axis direction causes an imbalance in the amount of current passing through each phase of the motor. For this reason, when the current value of the phase with the maximum current reaches the current limit value of the motor or peripheral devices, no more current can be passed even if the amount of current passing through other phases is low, and there is a risk of a decrease in warm-up efficiency. Figure 8 shows the torque command value T *1 shows an example of phase current values ​​with respect to the motor angle when the d-axis current is caused to flow when the motor angle is 0°, but for example, when the motor angle is 0°, the amount of current in the U phase has reached the current limit value. Therefore, even if the V phase and W phase have not reached their current limit values, no more current can be allowed to flow. In contrast, in this embodiment, when warming up is performed while the vehicle 1 is stopped and at low torque, the zero-phase current i z is passed through, and the zero-phase current i z In the second warm-up method, the power loss of the motor 30 and the inverter 19 is increased by increasing the current limit value. This allows current to flow through all phases of the motor 30 up to the current limit value. In other words, the current flowing through the motor 30 can be maximized within the range of the current limit value, and the heat generation of the motor 30 and the inverter 19 can be maximized. This improves the warm-up efficiency.

[0058] The warm-up current command generation method determination unit 112 outputs information on the first warm-up flag to the warm-up dq-axis current command generation unit 113 and the warm-up zero-phase current command generation unit 114, and outputs information on the second warm-up flag to the warm-up zero-phase current command generation unit 114.

[0059] In this embodiment, the warm-up current command generation method determination unit 112 determines the torque command value T * However, the present invention is not limited to this, and the warm-up method may be selected based on a parameter correlated with the torque T. For example, the torque command value T * Alternatively, it may be replaced with an estimated torque value or a norm value of a current command value.

[0060] The warm-up dq-axis current command generating unit 113 receives a first d-axis current command value i d_T * and the first q-axis current command value i q_T * (Hereinafter, the first dq-axis current command value i d_T * ,i q_T *The warm-up dq-axis current command generating unit 113 receives the first warm-up flag information and the required current amount (amount of current required during warm-up) command from the BMS 106. When the first warm-up flag is on, the warm-up dq-axis current command generating unit 113 generates the first dq-axis current command value i d_T * ,i q_T * Based on the required current command, the warm-up d-axis current command value i d_heat * and warm-up q-axis current command value i q_heat * (Hereinafter, the warm-up dq-axis current command value i d_heat * ,i q_heat * Specifically, as shown in FIG. 9, the dq-axis current is calculated based on the first dq-axis current command value i d_T * ,i q_T * On the equal torque line passing through the operating point O1 on the dq-axis coordinates, the dq-axis current at the operating point O2 that is the required current amount is calculated, and this is called the warm-up dq-axis current command value i d_heat * ,i q_heat * The warm-up dq-axis current command generating unit 113 generates the warm-up dq-axis current command value i d_heat * ,i q_heat * to the warm-up zero-phase current command generator 114 and the final current command generator 115. On the other hand, when the first warm-up flag is off, the warm-up dq-axis current command generator 113 outputs the first dq-axis current command value i d_T * ,i q_T * The warm-up dq-axis current command value i d_heat * ,i q_heat * and outputs the result to the warm-up zero-phase current command generating section 114 and the final current command generating section 115.

[0061] The warm-up zero-phase current command generating unit 114 receives the warm-up dq-axis current command value i d_heat * ,i q_heat *, information on the first warm-up flag and the second warm-up flag, and the electrical angle θ of the motor 30 re The warm-up zero-phase current command generating unit 114 receives a warm-up dq-axis current command value i d_heat * ,i q_heat * , electrical angle θ re , and based on the required current command, the warm-up zero-phase current command value i z_heat * Specifically, the warm-up zero-phase current command value i z_heat * In the following process, i INV is the current limit value (allowable current amount), i z_heat_map is a zero-phase current value corresponding to the required current amount calculated by looking up a map based on the required current amount.

[0062] First, from the following equation (3), the warm-up dq-axis current command value i d_heat * ,i q_heat * The U-phase current command value i u * , V-phase current command value i v * , W-phase current command value i w * (Hereinafter, UVW phase current command value i u * ,i v * ,i w * (called the "value").

number

[0063] As shown in (4) and (5) below, the UVW phase current command value i u * ,i v * ,i w * The maximum phase current, which is the phase current in the phase with the largest phase current, is i heat_maxThe minimum phase current, which is the phase current in the phase with the smallest phase current, is i heat_min For example, FIG. 10 and FIG. 11 show a case where the electrical angle θ re UVW phase current command value i u * ,i v * ,i w * However, in FIG. 10 and FIG. 11, the U-phase current command value i u * is the maximum phase current i heat_max , W-phase current command value i w * The phase current minimum value is i heat_min It becomes.

number

number

[0064] Next, when the first warm-up flag is off and the second warm-up flag is on, the warm-up zero-phase current command value i z_heat * Calculate.

[0065] First, the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min Absolute value of i heat_max |?|i heat_min In the case of |, the allowable current value i INV and the minimum phase current value i heat_min The difference between the absolute value of (i INV -|i heat_min |) is the allowable current value i INV and maximum phase current i heat_max The difference between the absolute value of (i INV -|i heat_max In other words, the same or more current can flow to the negative side as to the positive side. Therefore, in this case, the warm-up zero-phase current command value i z_heat * For example, as shown in Fig. 10, the maximum phase current iheat_max The U-phase current command value i u * Therefore, the minimum phase current value is set to i heat_min The W-phase current command value i w * The allowable current value i INV If there is a margin, the zero-phase current i z The warm-up zero-phase current command value i z_heat * This allows more current to flow, improving warm-up efficiency.

[0066] However, the zero-phase current value i according to the required current amount z_heat_map and the minimum value of the phase current i heat_min The absolute value of the difference between the allowable current value i of the motor 30 INV When it exceeds |i z_heat_map -i heat_min |>i INV In this case, the zero-phase current value i according to the required current amount is z_heat_map If current flows as is, the allowable current value i INV Therefore, the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min The absolute value of i is greater than or equal to the required current. z_heat_map and the minimum value of the phase current i heat_min The absolute value of the difference between these is the motor's allowable current value i INV When it exceeds |i heat_max |?|i heat_min |and|i z_heat_map -i heat_min |>i INV When the phase current is the allowable current value i INV In order not to exceed the value of z_heat * Calculate.

number

[0067] On the other hand, the zero-phase current value i according to the required current amount z_heat_map and the minimum value of the phase current i heat_minThe absolute value of the difference between the allowable current value i of the motor 30 INV When |i z_heat_map -i heat_min |?i INV In this case, the zero-phase current value i according to the required current amount is z_heat_map The warm-up zero-phase current command value i z_heat * Therefore, the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min The absolute value of i is greater than or equal to the required current. z_heat_map and the minimum value of the phase current i heat_min The absolute value of the difference between these is the motor's allowable current value i INV When (II)|i heat_max |?|i heat_min |and|i z_heat_map -i heat_min |?i INV In this case, the warm-up zero-phase current command value i z_heat * Calculate.

number

[0068] Next, the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min is smaller than the absolute value of |i heat_max |<|i heat_min In the case of |, the allowable current value i INV and the minimum phase current value i heat_min The difference between the absolute value of (i INV -|i heat_min |) is the allowable current value i INV and maximum phase current i heat_max The difference between the absolute value of (i INV -|i heat_max In other words, a current greater than that of the negative side can flow toward the positive side. Therefore, in this case, the warm-up zero-phase current command value i z_heat * For example, as shown in Fig. 11, the maximum phase current i heat_max The U-phase current command value iu * The phase current minimum value is i heat_min The W-phase current command value i w * than the allowable current value i INV If there is a margin, the zero-phase current i z The warm-up zero-phase current command value i z_heat * This allows more current to flow, improving warm-up efficiency.

[0069] However, the zero-phase current value i according to the required current amount z_heat_map and the maximum value of the phase current i heat_max The absolute value of the difference between the allowable current value i of the motor 30 INV When it exceeds |i z_heat_map -i heat_max |>i INV In this case, the zero-phase current value i according to the required current amount is z_heat_map If current flows as is, the allowable current value i INV Therefore, the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min The absolute value of i is smaller than the zero-phase current value i z_heat_map and the maximum value of the phase current i heat_max The absolute value of the difference between these is the motor's allowable current value i INV When it exceeds |i heat_max |<|i heat_min |and|i z_heat_map -i heat_max |>i INV When the phase current is the allowable current value i INV In order not to exceed the value of z_heat * Calculate.

number

[0070] On the other hand, the zero-phase current value i according to the required current amount z_heat_map and the maximum value of the phase current i heat_maxThe absolute value of the difference between the allowable current value i of the motor 30 INV When |i z_heat_map -i heat_max |?i INV In this case, the zero-phase current value i according to the required current amount is z_heat_map The warm-up zero-phase current command value i z_heat * Therefore, the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min The absolute value of i is smaller than the zero-phase current value i z_heat_map and the maximum value of the phase current i heat_max The absolute value of the difference between these is the motor's allowable current value i INV When (IV)|i heat_max |<|i heat_min |and|i z_heat_map -i heat_max |?i INV In this case, the warm-up zero-phase current command value i z_heat * Calculate.

number

[0071] In this way, when the first warm-up flag is off and the second warm-up flag is on, (I)|i heat_max |?|i heat_min |and|i z_heat_map -i heat_min |>i INV In the case of |i heat_max |?|i heat_min |and|i z_heat_map -i heat_min |?i INV In the case of |i heat_max |<|i heat_min |and|i z_heat_map -i heat_max |>i INV In the case of |i heat_max |<|i heat_min |and|i z_heat_map -i heat_max |?i INVIn this case, the warm-up zero-phase current command value i z_heat * Calculate.

[0072] On the other hand, when both the first warm-up flag and the second warm-up flag are on, the warm-up zero-phase current command value i z_heat * Calculate.

number

[0073] In addition, when the first warm-up flag is on and the second warm-up flag is off, the warm-up zero-phase current command value i z_heat * is calculated as 0.

[0074] The warm-up zero-phase current command generating unit 114 calculates the warm-up zero-phase current command value i z_heat * to the final current command generating unit 115.

[0075] The final current command generating unit 115 includes a first dq axis and zero-phase current command value i d_T * ,i q_T * ,i z_T * , warm-up dq axis current command value i d_heat * ,i q_heat * , and the warm-up zero-phase current command value i z_heat * When the BMS 106 determines that the motor 30 and the inverter 19 need to be warmed up, a warm-up request is input. When there is a warm-up request, the final current command generating unit 115 generates the warm-up dq-axis current command value i d_heat * ,i q_heat * , and the warm-up zero-phase current command value i z_heat * The final dq-axis current command value i d * ,i q *and the zero-phase current command value i z * On the other hand, when there is no warm-up request, the first dq axis and zero-phase current command value i d_T * ,i q_T * ,i z_T * The final dq-axis current command value i d * ,i q * and the zero-phase current command value i z * The output is as follows:

[0076] The torque equation for an open-winding motor is expressed by the following equation (11), where the zero-phase current i z There is no torque change due to

number

[0077] As described above, in this embodiment, warm-up control is performed using the second warm-up method, which warms up the motor 30 and the inverter 19 by passing a zero-phase current that flows commonly to each phase of the motor 30 through the motor 30 so as to increase the power loss of the motor 30 and the inverter 19. This makes it possible to maximize the current flowing through the motor within the range of the current limit value, and maximize the amount of heat generated by the motor 30 and the inverter 19 during warm-up. Therefore, the warm-up efficiency is improved.

[0078] 12 is a flowchart relating to the warm-up control. The following process is repeatedly executed at a predetermined cycle by the controller (MCU) in the control device 10.

[0079] When the vehicle system of the vehicle 1 is started, the warm-up control is started. In step S10, the control device 10 calculates the torque command value T * , the DC voltage V of the battery 105 dc Get the.

[0080] In step S11, the control device 10 calculates the mechanical angular velocity ω rm Calculate the following.

[0081] In step S12, the control device 10 calculates the torque command value T * , mechanical angular velocity ω rm and DC voltage V dc Based on this, the motor 30 generates a torque command value T * The first dq-axis and zero-phase current command value i d_T * ,i q_T * ,i z_T * Usually, the first zero-phase current command value i z_T * will be 0.

[0082] In step S13, the control device 10 determines whether or not there is a warm-up request. That is, it determines whether or not a warm-up request has been input to the motor unit 100 (control device 10) from the BMS 106. If there is no warm-up request, the control device 10 executes the process of step S14.

[0083] In step S14, the control device 10 sets both the first warm-up flag and the second warm-up flag to OFF, and sets the first dq-axis and zero-phase current command value i d_T * ,i q_T * ,i z_T * The dq-axis current command value i d * ,i q * and the zero-phase current command value i z * In step S14, the dq-axis current command value i d * ,i q * and the zero-phase current command value i z * After setting, the control device 10 executes the process of step S25.

[0084] On the other hand, if there is a warm-up request, the control device 10 executes the process of step S15. Note that, if there is a warm-up request, the control device 10 also acquires the required current amount from the BMS 106. In step S15, the control device 10 acquires the mechanical angular velocity ω rm is the threshold ω th It is judged whether the threshold value ω th For example, the zero-phase current i z is the rotation speed of the motor 30 (mechanical angular velocity ω rm ) and can be set in advance through experiments, etc. rm is the threshold ω th If it is greater, the control device 10 executes the process of step S16.

[0085] In step S16, the control device 10 sets the first warm-up flag to ON and the second warm-up flag to OFF, and calculates the first dq-axis current command value i d_T * ,i q_T * Based on the required current command, the warm-up dq axis current command value i d_heat * ,i q_heat * That is, the dq-axis current that is the required current amount is calculated on the equal torque line that passes through the operating point on the dq-axis coordinate system, and this is called the warm-up dq-axis current command value i d_heat * ,i q_heat * That is, the warm-up dq-axis current command value i d_heat * ,i q_heat * At the same time, the control device 10 calculates the warm-up zero-phase current command value i z_heat * Set to 0.

[0086] Warm-up dq axis current command value i d_heat * ,i q_heat * Calculate the warm-up zero-phase current command value i z_heat *When the control device 10 sets the value to 0, the control device 10 executes the process of step S24.

[0087] On the other hand, mechanical angular velocity ω rm is the threshold ω th In the following cases, the control device 10 executes the process of step S17. In step S17, the control device 10 * The absolute value of the first threshold T th1 It is determined whether the first threshold T th1 is set to a value of the torque T at the boundary where the warm-up efficiency is higher when the warm-up control is performed using the first warm-up method than when the warm-up control is performed using the second warm-up method. * The absolute value of the first threshold T th1 If it is greater than , the control device 10 executes the process of step S18.

[0088] In step S18, the control device 10 sets both the first warm-up flag and the second warm-up flag to ON, and sets the first dq-axis current command value i d_T * ,i q_T * Based on the required current command, the warm-up dq axis current command value i d_heat * ,i q_heat * In addition, the warm-up dq-axis current command value i d_heat * ,i q_heat * , electrical angle θ re , and based on the required current command, the warm-up zero-phase current command value i z_heat * Calculate the warm-up dq axis current command value i d_heat * ,i q_heat * The calculation method of is the same as in step S16. z_heat * Specifically, the warm-up dq-axis current command value i d_heat * ,i q_heat * and warm-up zero-phase current command value iz_heat * After calculating, the control device 10 executes the process of step S24.

[0089] In step S17, the torque command value T * The absolute value of the first threshold T th1 In the following cases, the control device 10 determines in step S19 that the torque command value T * The absolute value of the second threshold T th2 It is determined whether the second threshold T th2 is set to a value of torque T that occurs during creep driving, for example. * The absolute value of the second threshold T th2 If it is smaller than , the control device 10 executes the process of step S20.

[0090] In step S20, the control device 10 sets the first warm-up flag to OFF and the second warm-up flag to ON, and calculates the first dq-axis current command value i d_T * ,i q_T * The warm-up dq-axis current command value i d_heat * ,i q_heat * The warm-up dq-axis current command value i d_heat * ,i q_heat * , electrical angle θ re , and based on the required current command, the warm-up zero-phase current command value i z_heat * Specifically, the warm-up zero-phase current command value i z_heat * Calculate the warm-up dq axis current command value i d_heat * ,i q_heat * and warm-up zero-phase current command value i z_heat * After calculating, the control device 10 executes the process of step S24.

[0091] In step S19, the torque command value T* The absolute value of the second threshold T th2 In the above cases, in step S21, the control device 10 determines whether or not the first warm-up flag was set to ON in the previous control cycle.

[0092] If the first warm-up flag was set to on in the previous value, the control device 10 determines in step S22 whether the second warm-up flag was set to on in the previous control cycle. If both the first warm-up flag and the second warm-up flag are set to on in steps S21 and S22, the control device 10 executes the process of step S18. On the other hand, if the first warm-up flag is set to on and the second warm-up flag is set to off in steps S21 and S22, the control device 10 executes the process of step S16.

[0093] On the other hand, if the first warm-up flag was set to off in the previous value in step S21, the control device 10 determines in step S23 whether the second warm-up flag was set to on in the previous control cycle. If the first warm-up flag is set to off and the second warm-up flag is set to on in steps S21 and S23, the control device 10 executes the process of step S20. On the other hand, if both the first warm-up flag and the second warm-up flag are set to off in steps S21 and S23, the control device 10 executes the process of step S14.

[0094] In steps S16, S18, and S20, the warm-up dq-axis current command value i d_heat * ,i q_heat * and warm-up zero-phase current command value i z_heat * After calculating the warm-up dq-axis current command value i d_heat * ,i q_heat * and warm-up zero-phase current command value i z_heat * The dq-axis current command value id * ,i q * and the zero-phase current command value i z * Set as.

[0095] In steps S14 and S24, the dq-axis current command value i d * ,i q * and the zero-phase current command value i z * After setting, the control device 10 executes the process of step S25.

[0096] In step S25, the control device 10 calculates the dq-axis current command value i d * ,i q * and the zero-phase current command value i z * and the actual dq axis current i d ,i q and zero-phase current i z Based on this, the first dq-axis voltage command value v d1 * ,v q1 * and the first zero-phase voltage command value v z1 * Calculate the following.

[0097] In step S26, the control device 10 calculates the electrical angular velocity ω re and electrical angle θ re and the dq axis current command value i d * ,i q * , zero-phase current command value i z * Based on this, the dq axis and zero-sequence decoupling voltage v q-dcpl ,v q-dcpl ,v z-dcpl Calculate the following.

[0098] In step S27, the control device 10 calculates the first dq-axis voltage command value v d1 * ,v q1* and the first zero-phase voltage command value v z1 * , the dq axis and zero-phase decoupling voltage v d-dcpl ,v q-dcpl ,v z-dcpl By adding d2 * ,v q2 * ,v z2 * Calculate the following.

[0099] In step S28, the control device 10 calculates the d-axis disturbance estimate v d-dist , q-axis disturbance estimate v q-dist , and the zero-sequence disturbance estimate v z-dist Calculate the following.

[0100] In step S29, the control device 10 calculates the second dq-axis and zero-phase voltage command value v d2 * ,v q2 * ,v z2 * The d-axis disturbance estimate v d-dist , q-axis disturbance estimate v q-dist , and the zero-sequence disturbance estimate v z-dist By adding these, the final dq axis and zero-phase voltage command value v d * ,v q * ,v z * Calculate the following.

[0101] In step S30, the control device 10 calculates the final dq-axis and zero-phase voltage command value v d * ,v q * ,v z * The voltage command value v of each UVW phase u * ,v v * ,v w * Convert to.

[0102] In step S31, the control device 10 calculates the voltage command value v u * ,v v * ,v w * The PWM signal based on the mechanical angular velocity ω is generated and input to the inverter 19, thereby executing PWM control. In this way, the motor 30 is driven. Also, when there is a warm-up request, the warm-up control is executed according to the following. rm is the threshold ω th If it is greater than ω, the warm-up is performed according to the first warm-up method. rm is the threshold ω th The torque T of the motor 30 is equal to or less than the first threshold T th1 If the mechanical angular velocity ω is greater than ω, the first warm-up method and the second warm-up method are used in combination to perform warm-up. rm is the threshold ω th The torque T of the motor 30 is equal to or less than the second threshold T th2 If the mechanical angular velocity ω is smaller than ω, the warm-up is performed according to the second warm-up method. rm is the threshold ω th The torque T of the motor 30 is equal to or less than the second threshold T th2 or more and the first threshold T th1 In the following cases, warm-up is performed using the same warm-up method as in the previous warm-up control.

[0103] According to the motor control method of the present embodiment described above, the following effects can be obtained.

[0104] According to the motor control method of the present embodiment, a zero-phase current i is supplied to the motor 30 so as to increase the power loss of the motor 30 and the inverter 19. z In this manner, the zero-phase current i that flows in common to each phase of the motor 30 during the warm-up of the motor 30 and the inverter 19 is passed through the motor 30. z is passed through, and the zero-phase current i z Therefore, the amount of heat generated by the motor 30 and the inverter 19 during warm-up is maximized, and the warm-up efficiency is improved.

[0105] According to the motor control method of the present embodiment, the operating point in the dq axis coordinate system is moved to another operating point on the constant torque line to increase the power loss of the motor 30 and the inverter 19, and the zero-phase current i z In this way, a warm-up method according to the operating state of the motor 30 can be selected, and the warm-up efficiency is further improved.

[0106] According to the motor control method of the present embodiment, when the vehicle 1 equipped with the motor 30 is stopped, a zero-phase current i is supplied to the motor 30 so as to increase the power loss of the motor 30 and the inverter 19. z In this manner, the zero-phase current i that flows in common to each phase of the motor 30 while the vehicle 1 is stopped is passed through the motor 30 and the inverter 19. z By using the second warm-up method of passing current through all phases of the motor 30, it is possible to pass current up to the current limit value through all phases of the motor 30. In other words, it is possible to maximize the current flowing through the motor 30 within the range of the current limit value, and to maximize the amount of heat generated by the motor 30 and the inverter 19. Therefore, the warm-up efficiency is further improved.

[0107] According to the motor control method of the present embodiment, the motor 30 and the inverter 19 are warmed up using one or both of the first and second warm-up methods based on the torque T of the motor 30 or a parameter correlated to the torque T. This makes it possible to select a more efficient warm-up method according to the torque T of the motor 30. Therefore, the warm-up efficiency is further improved.

[0108] According to the motor control method of the present embodiment, the torque T of the motor 30 is equal to or lower than the second threshold T th2 If the torque is less than the predetermined first torque, the zero-phase current i zIn other words, when the torque T of the motor 30 is low and the phase current of the motor 30 has a margin up to the current limit value, the zero-phase current i z This increases the power loss of the motor 30 and the inverter 19. This further improves the warm-up efficiency.

[0109] According to the motor control method of the present embodiment, the torque T of the motor 30 is equal to or lower than the second threshold T th2 When the torque is equal to or less than the first predetermined torque, the maximum phase current value i heat_max The absolute value of the phase current minimum value i heat_min When the absolute value of i is greater than or equal to the zero-phase current i, the phase current of each phase is offset to the negative side. z In addition, the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min When the absolute value of i is smaller than , the zero-phase current i z That is, the allowable current value i INV (Limit current value) to offset the zero-phase current i z This allows a larger current to flow through the motor 30, improving the warm-up efficiency.

[0110] According to the motor control method of the present embodiment, the torque T of the motor 30 is equal to or lower than the first threshold T th1 If the torque is greater than the predetermined second torque, the motor 30 and the inverter 19 are warmed up using both the first and second warm-up methods. z By superimposing the currents of the phases of the motor 30, the amount of current in each phase is prevented from becoming unbalanced, and the allowable current value i INV If there is a certain margin up to the limit current value, the phase current is the zero-phase current i z By superimposing these, it is possible to further increase the power loss of the motor 30 and the inverter 19. Therefore, it is possible to further improve the warm-up efficiency.

[0111] According to the motor control method of the present embodiment, the torque T of the motor 30 is equal to or lower than the first threshold T th1 When the motor 30 and the inverter 19 are warmed up using both the first and second warm-up methods, the first warm-up method contributes more to the warm-up than the second warm-up method. In this manner, the first warm-up method moves the operating point in the dq axis coordinate to another operating point on the iso-torque line, and the second warm-up method supplies the zero-phase current i z When using both the first warm-up method and the second warm-up method, the first warm-up method is primarily performed while the second warm-up method is used as an auxiliary, thereby maximizing the amount of heat generated by the motor 30 and the inverter 19. This can further improve the warm-up efficiency.

[0112] According to the motor control method of the present embodiment, the torque T of the motor 30 is equal to or lower than the second threshold T th2 (predetermined first torque) or less, and the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min If the absolute value of is greater than or equal to the required current, the zero-phase current value i z_heat_map and the minimum value of the phase current i heat_min The absolute value of the difference between these is the motor's allowable current value i INV When the command value of the zero-phase current exceeds i z * Calculate the zero-phase current value i according to the required current amount using the above formula (6). z_heat_map and the minimum value of the phase current i heat_min The absolute value of the difference between the allowable current value i of the motor 30 INV In the following cases, the zero-phase current command value i z * is calculated by the above-mentioned formula (7). In addition, when the torque T of the motor 30 is equal to or smaller than the second threshold T th2 (predetermined first torque) or less, and the maximum phase current i heat_max The absolute value of the phase current minimum value i heat_min If the absolute value of i is smaller than the required current, the zero-phase current value i z_heat_map The maximum phase current i heat_max The absolute value of the sum of these is the allowable current value i of the motor 30. INVWhen it exceeds the zero-phase current command value i z * is calculated using the above formula (8), and the zero-phase current value i z_heat_map The maximum phase current i heat_max The absolute value of the sum of these is the allowable current value i of the motor 30. INV In the following cases, the zero-phase current command value i z * is calculated using the above formula (9). In addition, the calculated zero-phase current command value i z * Based on this, the zero-phase current i z This causes the phase current of the motor 30 to increase to the allowable current value i INV Therefore, a larger current can be passed while controlling the current so as not to exceed 100%, and the warm-up efficiency is improved.

[0113] According to the motor control method of the present embodiment, the torque T of the motor 30 is equal to or lower than the first threshold T th1 If it is greater than (predetermined second torque), the zero-phase current command value i z * is calculated using the above equation (9), and the calculated zero-phase current command value i z * Based on the zero-phase current i z This causes the phase current of the motor 30 to increase to the allowable current value i INV Therefore, a larger current can be passed while controlling the current so as not to exceed 100%, and the warm-up efficiency is improved.

[0114] As in this embodiment, it is preferable to perform warm-up using one or both of the first and second warm-up methods based on the torque T of the motor 30 or a parameter correlated to the torque T, but this is not necessarily limited to this. If the first warm-up method is used so as to improve the warm-up efficiency, the conditions for using the first warm-up method may be set arbitrarily.

[0115] In addition, when the first warm-up method is used as in this embodiment, the command value i of the zero-phase current is calculated based on the equations (6) to (10). z *It is preferable to calculate, but not necessarily limited to, the command value i of the zero-phase current if the first warm-up method is used to improve the warm-up efficiency. z * The calculation method may be set arbitrarily.

[0116] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments. [Explanation of symbols]

[0117] 1: vehicle, 10: control device, 11: current command value calculation unit, 111: current command generation unit, 112: warm-up current command generation method determination unit, 113: warm-up dq axis current command generation unit, 114: warm-up zero-phase current command generation unit, 115: final current command generation unit, 12: current control unit, 13: non-interference control unit, 14: second voltage command value calculation unit, 15: final voltage command value calculation unit, 16: disturbance compensation unit, 17: coordinate conversion unit, 18: PWM conversion unit, 19: inverter, 30: motor, 100: motor unit

Claims

1. A motor control method for a motor unit including an open winding type motor and an inverter that converts electric power and supplies it to the motor, comprising: warming up the motor and the inverter by passing a zero-phase current through the motor so as to increase the power loss of the motor and the inverter; Motor control methods.

2. 2. A motor control method according to claim 1, comprising: a first warm-up method for warming up the motor and the inverter by moving an operating point in a dq-axis coordinate system consisting of a d-axis component and a q-axis component of a current supplied to the motor to another operating point on an equal torque line and increasing power losses in the motor and the inverter; and a second warm-up method for warming up the motor and the inverter by passing a zero-phase current through the motor so as to increase the power loss of the motor and the inverter. Motor control methods.

3. 3. A motor control method according to claim 2, comprising: the motor is a motor for a vehicle, When the vehicle is stopped, the motor and the inverter are warmed up by the second warm-up method. Motor control methods.

4. 3. A motor control method according to claim 2, comprising: When the motor and the inverter are warmed up by the second warm-up method, the zero-phase current passed through the motor is a direct current. Motor control methods.

5. 3. A motor control method according to claim 2, comprising: warming up the motor and the inverter using one or both of the first warm-up method and the second warm-up method based on a torque of the motor or a parameter correlated to the torque; Motor control methods.

6. 6. A motor control method according to claim 5, comprising: When the torque of the motor is equal to or lower than a predetermined first torque, the motor and the inverter are warmed up by the second warm-up method. Motor control methods.

7. 7. A motor control method according to claim 6, comprising the steps of: When the torque of the motor is equal to or less than a predetermined first torque, if the absolute value of a phase current maximum value, which is a phase current in a phase having the largest phase current among the phases of the motor, is equal to or greater than the absolute value of a phase current minimum value, which is a phase current in a phase having the smallest phase current, the zero-phase current is caused to flow so that the phase current of each phase is offset to the negative side, and if the absolute value of the phase current maximum value is smaller than the absolute value of the phase current minimum value, the zero-phase current is caused to flow so that the phase current of each phase is offset to the positive side. Motor control methods.

8. A motor control method according to any one of claims 5 to 7, comprising the steps of: When the torque of the motor is greater than a predetermined second torque, the motor and the inverter are warmed up using both the first warm-up method and the second warm-up method. Motor control methods.

9. 9. A motor control method according to claim 8, comprising the steps of: When the torque of the motor is greater than a predetermined second torque, when the motor and the inverter are warmed up using both the first warm-up method and the second warm-up method, the first warm-up method has a larger contribution to warm-up than the second warm-up method. Motor control methods.

10. 9. A motor control method according to claim 8, comprising the steps of: Calculating a zero-phase current value according to a required current amount such that the current flowing through the motor is a current amount necessary for warming up the motor and the inverter; The command value of the zero-phase current to be passed through the motor is i ｚ ＊ A maximum phase current value, which is a phase current in a phase having the largest phase current among the phases of the motor, is i ｈｅａｔ＿ｍａｘ , the minimum phase current value, which is the phase current in the phase with the smallest phase current, is i ｈｅａｔ＿ｍｉｎ , the allowable current value of the motor is i ＩＮＶ , the zero-phase current value according to the required current amount is i ｚ＿ｈｅａｔ＿ｍａｐ In this case, The torque of the motor is equal to or smaller than a predetermined first torque, and the phase current maximum value i ｈｅａｔ＿ｍａｘ The absolute value of the phase current minimum value i ｈｅａｔ＿ｍｉｎ If the absolute value of is greater than or equal to The zero-phase current value i according to the required current amount ｚ＿ｈｅａｔ＿ｍａｐ and the minimum value i of the phase current ｈｅａｔ＿ｍｉｎ The absolute value of the difference between the allowable current value i ＩＮＶ When the command value of the zero-phase current exceeds i ｚ ＊ is calculated by the following formula (1), and the calculated command value i ｚ ＊ A zero-phase current is passed through the motor based on the [0010] The zero-phase current value i according to the required current amount ｚ＿ｈｅａｔ＿ｍａｐ and the minimum value i of the phase current ｈｅａｔ＿ｍｉｎ The absolute value of the difference between the allowable current value i ＩＮＶ In the following cases, the zero-phase current command value i ｚ ＊ is calculated by the following formula (2), and the calculated command value i ｚ ＊ A zero-phase current is passed through the motor based on the [0025] When the torque of the motor is equal to or less than the first torque, the maximum phase current i ｈｅａｔ＿ｍａｘ The absolute value of the phase current minimum value i ｈｅａｔ＿ｍｉｎ If it is smaller than the absolute value of The zero-phase current value i according to the required current amount ｚ＿ｈｅａｔ＿ｍａｐ The maximum value of the phase current i ｈｅａｔ＿ｍａｘ The absolute value of the sum of the above is the allowable current value i ＩＮＶ When the command value i of the zero-phase current is exceeded, ｚ ＊ is calculated by the following equation (3), and the calculated command value of the zero-phase current is set as i ｚ ＊ A zero-phase current is passed through the motor based on the [0030] The zero-phase current value i according to the required current amount ｚ＿ｈｅａｔ＿ｍａｐ The maximum value of the phase current i ｈｅａｔ＿ｍａｘ The absolute value of the sum of the above is the allowable current value i ＩＮＶ In the following cases, the zero-phase current command value i ｚ ＊ is calculated by the following equation (4), and the calculated command value of the zero-phase current is set as i ｚ ＊ A zero-phase current is passed through the motor based on the [0045] Motor control methods.

11. 11. A motor control method according to claim 10, comprising the steps of: When the torque of the motor is greater than a predetermined second torque, the command value i of the zero-phase current is ｚ ＊ is calculated by the following equation (5), and the calculated command value i ｚ ＊ A zero-phase current is passed through the motor based on the [0050] Motor control methods.

12. A motor control device for controlling an open winding type motor, an inverter that converts electric power and supplies it to the motor; A controller for controlling the operation of the inverter; Equipped with The controller warms up the motor and the inverter by passing a zero-phase current through the motor to increase losses in the motor and the inverter. Motor control device.

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