JP5678880B2 - Motor drive system and control method thereof - Google Patents

Description

  The present invention relates to a motor drive system, a motor drive system control method, and a traveling apparatus.

  As this type of technology, Patent Document 1 discloses switching of phases used for driving a motor when one of the motors has five phases.

International Publication No. 2011/089656

  Hereinafter, the motor control system of Patent Document 1 will be described in detail with reference to the drawings.

  For example, in a traveling device that travels while performing inversion control, an inverted state is maintained by driving a motor that rotates wheels. For this reason, when the electric component regarding a motor fails and the function stops, an inverted state cannot be maintained but a traveling apparatus may be in an unstable state and may fall down. For this reason, it is strongly required that the drive of the motor be continued even when one of the electrical components related to the motor fails. For this reason, in the motor drive system of the above-mentioned Patent Document 1, for example, the motor winding is configured as a five-phase star connection, and a five-phase motor is driven by vector control. By adopting a mechanism that switches the phase of the motor to be used from 5 phases to 3 phases, the windings are made redundant, and the system is duplicated.

  FIG. 1 is a configuration diagram of a motor drive circuit 100 according to the present embodiment. The motor drive circuit 100 includes a five-phase inverter 10 to which a DC voltage is supplied from a power source, a five-phase motor 20, and a power relay 30.

  The five-phase inverter 10 includes a five-phase (a, b, c, d, e) arm circuit. The arm circuit of each phase is configured using switching elements Q1 to Q10. For example, the a-phase arm circuit is composed of switching elements Q1 and Q2, the b-phase arm circuit is composed of switching elements Q3 and Q4, the c-phase arm circuit is composed of switching elements Q5 and Q6, and the d-phase arm circuit is switching. The e-phase arm circuit is composed of switching elements Q9 and Q10. On / off of the switching elements Q1 to Q10 is controlled by switching control signals S1 to S10 from the control unit 40 described later.

  The five-phase inverter 10 performs bidirectional power conversion from DC power to AC power by on / off control (switching control) of the switching elements Q1 to Q10 in response to the switching control signals S1 to S10 from the control unit 40. .

  As the switching element, a power MOS (Metal Oxide Semiconductor) transistor, an IGBT (Insulated Gate Bipolar Transistor), a power bipolar transistor, or the like can be used.

  The 5-phase motor 20 is a brushless motor including a rotor (not shown) and 5-phase coil windings (La, Lb, Lc, Ld, Le) provided on the stator. For example, one end of the coil winding La is connected to one end of the coil winding Lc, and the other end of the coil winding La is connected to the a-phase arm of the five-phase inverter 10. The 5-phase motor 20 is a permanent magnet motor having a permanent magnet attached to the rotor.

  The power relay 30 includes a plurality of contacts (P1, P2, P3) for controlling power supply to each phase of the five-phase motor 20. These contact points (P1, P2, P3) are arranged at the other ends of the coil windings La to Le and inserted between the star-connected coils. The power relay 30 controls power supply to each phase of the five-phase motor 20 by opening or closing the contacts P1, P2, and P3 according to a control signal from the control unit 40. That is, the power relay 30 is configured to be able to cut off the power supplied to one or two phases of the coil winding L of the five-phase motor 20. For example, one end of the contact P1 is connected to one end of the coil winding La and one end of the coil winding Lc. The other end of the contact P1 is connected to one end of the contact P2 and one end of the contact P3.

  FIG. 2 is a configuration diagram of the motor drive system according to the present embodiment. The motor drive system 101 includes a control unit 40, a pre-driver 50, and the motor drive circuit 100 shown in FIG.

  The control unit 40 outputs the switching control signals S1 to S10 of the five-phase inverter 10 to the switching elements Q1 to Q10 of the five-phase inverter 10 of the motor drive circuit 100. The control unit 40 includes a microcomputer, a RAM (Random Access Memory) (not shown), a ROM (Read Only Memory), and the like, and is input from an upper electronic control unit (ECU) according to a predetermined program process. Switching control signals S1 to S10 of the five-phase inverter 10 are generated so that the five-phase motor 20 operates according to the motor command.

  The control unit 40 includes a current controller 41, a dq axis / 2 phase coordinate conversion unit 42, a 2 phase / 5 phase coordinate conversion unit 43, a PWM generator 44, a 5 phase / 2 phase coordinate conversion unit 45, A two-phase / dq-axis coordinate conversion unit 46.

  In FIG. 2, id * and iq * indicate a d-axis current command and a q-axis current command, respectively. vd * and vq * indicate a d-axis voltage command and a q-axis voltage command, respectively. vα * and vβ * indicate an α-axis voltage command and a β-axis voltage command, respectively. va ** to ve ** indicate motor voltage commands for each phase of the five-phase motor 20. Ga to Ge indicate PWM signals. S1 to S10 indicate inverter gate signals (switching control signals) of the five-phase inverter 10. “ia” to “ie” indicate motor currents of the respective phases of the five-phase motor 20. iα and iβ represent an α-axis current and a β-axis current, respectively. id and iq indicate a d-axis current and a q-axis current, respectively.

  Here, the equivalent circuit equations of the five-phase motor 20 shown in FIG. 1 are shown in the following equations (1) to (3). Equation (1) represents a circuit equation, Equation (2) represents an induced voltage equation, and Equation (3) represents a torque equation. Further, va, vb, vc, vd, and ve indicate armature voltages of the a, b, c, d, and e phases, respectively. ia, ib, ic, id, and ee respectively indicate armature currents of the a, b, c, d, and e phases. ea, eb, ec, ed, and ee indicate induced voltages of the a, b, c, d, and e phases, respectively. R represents motor winding resistance, L represents motor winding self-inductance, and p represents a differential operator. ωre represents the electrical angular velocity of the motor, and θre represents the electrical angle of the motor. Φfa is the maximum number of armature winding interlinkage magnetic fluxes of the motor, Te is the motor torque, and P is the number of pole pairs of the motor.

  Returning again to FIG. 2, the description will be continued. The current controller 41 performs current control according to the deviation from the calculated d-axis and q-axis currents id and iq after the d-axis and q-axis current commands id * and iq * are given. The current controller 41 receives the d-axis and q-axis current commands id * and iq *, and according to the deviation from the calculated d-axis and q-axis current id and iq, the d-axis and q-axis voltage commands. vd * and vq * are output. The d-axis and q-axis current commands id * and iq * are output from a motor driver (not shown). That is, a motor driver (not shown) generates d-axis and q-axis current commands id * and iq * in accordance with wheel speed commands and the like.

  The dq axis / two-phase coordinate conversion unit 42 converts the d-axis and q-axis voltage commands vd * and vq * into two-phase fixed coordinates using the well-known dq coordinate conversion formula (4) below. To do. As a result, the dq axis / 2-phase coordinate conversion unit 42 outputs the α-axis and β-axis voltage commands vα * and vβ *.

  The two-phase / 5-phase coordinate conversion unit 43 converts the voltage commands vα * and vβ * of the two-phase fixed coordinates from the two-phase fixed coordinates to the five-phase fixed coordinates using the following conversion formula (5). To do. Accordingly, the two-phase / 5-phase coordinate conversion unit 43 outputs motor voltage commands va ** to ve ** for each phase of the five-phase motor 20.

  The PWM generator 44 generates PWM signals Ga to Ge based on the motor voltage commands va ** to ve ** for each phase.

  The 5-phase / 2-phase coordinate conversion unit 45 converts the 5-phase fixed coordinates to 2-phase fixed coordinates using the following conversion formula (6) in the same manner as described above. As a result, the 5-phase / 2-phase coordinate conversion unit 45 outputs the α-axis and β-axis currents iα and iβ.

  The two-phase / dq-axis coordinate conversion unit 46 converts the α-axis and β-axis currents iα and iβ into d-axis and q-axis currents id and iq. In this way, feedback control for power control is performed by feeding back the currents ia to ie detected from the respective phases of the five-phase motor 20. Therefore, by performing the above-described conversion, even the five-phase motor 20 can be controlled by applying a normal vector control theory.

  The pre-driver 50 generates switching control signals S1 to S10 for the five-phase inverter 10 based on the PWM signals Ga to Ge. The pre-driver 50 is a circuit that quickly charges and discharges the gate capacitance with respect to the logic level PWM signal output from the control unit 40. In order to switch the power MOS-FET as the switching element Q at high speed, it is necessary to charge / discharge the input capacitance of the MOS-FET gate at high speed. For this reason, the pre-driver 50 is provided between the control unit 40 and the five-phase inverter 10. In addition, in a MOS-FET adopting a three-phase or five-phase upper / lower bridge configuration, in order to perform switching when the upper arm MOS-FET is an N-channel, a voltage required to add the gate on voltage to the output voltage is required. Become. For this reason, a charge pump system or a booth trap method is used for the operation of the upper arm.

  3, 4, and 5 exemplify values after axis conversion when the d-axis voltage command vd * is 0 and the q-axis voltage command vq * is 1. FIG. 3 is a diagram illustrating a change in the dq-axis voltage command value. FIG. 4 is a diagram illustrating a change in the α-β-axis voltage command value. FIG. 5 is a diagram showing changes in the five-phase voltage command value.

  Next, the phase switching operation by the motor drive system 101 when one phase of the five-phase motor 20 fails will be described. The control unit 40 includes failure detection means for detecting a failure of the switching elements Q1 to Q10, and generates a control signal for the power relay 30 according to the detected content. That is, the failure detection means detects a failure from the switching elements Q1 to Q10 constituting each phase of the five-phase inverter 10 to the five-phase motor 20. The control unit 40 uses the power relay 30 as the disconnecting unit to cut off the power supply for the phase in which the failure is detected by the failure detecting unit.

  For example, when any of the switching elements Q1 to Q10 of the five-phase inverter 10 fails in the short mode, the control unit 40 uses the power relay 30 to disconnect the failed phase. For example, the connection between each winding coil L of the five-phase motor 20 and each contact P of the power relay 30 is configured as shown in FIG. 1, and the response is made according to the switching elements Q1 to Q10 that detect the failure. The contacts P1 to P3 to be opened are opened.

  FIG. 6 shows a combination of a failed phase and a phase used for driving in the configuration shown in FIG. For example, when the b-phase fails, the contact P2 of the power relay 30 is opened. As a result, the power supply to the winding coils Lb and Le of the five-phase motor 20 is cut off, and the control unit 40 uses the c, d, and a phases of the remaining four phases. Continue driving. Here, the combinations of the three phases used for driving among the remaining plurality of phases when a certain phase breaks down are determined such that the phase intervals are substantially the same. This combination is determined based on the failed phase and the configuration of the power relay 30.

  When the switching elements Q1 to Q10 fail, and the failure occurs in the short mode, the return current may become a brake. In order to avoid this, among the winding coils of the five-phase motor 20, it is necessary to open the winding coil corresponding to the failure location. For example, the configuration of the power relay 30 shown in FIG. 1 can be adopted as a configuration in which the winding coil corresponding to the failure location is opened and the phase used for driving the motor is switched to a desired phase. As a result, the number of the contacts P of the power relay 30 can be three, and switching of phases used for continuing motor driving can be realized with a minimum configuration.

  In addition, what is necessary is just to employ | adopt a well-known method about the failure detection method of the location (electrical parts, such as CPU and an inverter) related to the drive of the motor by the motor drive system 101. FIG. For example, the failure of the switching elements Q1 to Q10 can be detected by the following method.

  A failure detection method for switching elements Q1 to Q10 will be described with reference to FIGS. For example, as shown in FIG. 7, shunt resistors 60 and 70 are provided for the motor drive circuit 100 shown in FIG. That is, a shunt resistor 60 (Rdc) is connected in series between the power source and the five-phase inverter 10. A shunt resistor 70 is provided between the five-phase motor 20 and the power relay 30. The resistors Rs1 to Rs5 of the shunt resistor 70 are connected in series to the winding coils La to Le of the five-phase motor 20.

  FIG. 8 shows changes in the current value detected by the shunt resistor 60 (Rdc). When any one of the switching elements Q1 to Q10 fails in the short mode, the current value detected by the shunt resistor 60 (Rdc) exceeds a predetermined threshold (current limit). Therefore, the motor drive system 101 determines that one of the switching elements Q1 to Q10 has failed when the current value detected by the shunt resistor 60 (Rdc) exceeds a predetermined threshold value.

  FIG. 9 shows changes in the current value detected by the resistor (Rs1) in the shunt resistor 70. For example, when the switching element Q1 fails in the open mode, the current value detected by the resistance (Rs1) of the shunt resistor 70 exceeds a predetermined threshold (current limit). Therefore, the motor drive system 101 determines that the switching element Q1 has failed when the current value detected by the resistance (Rs1) of the shunt resistor 70 exceeds a predetermined threshold value.

  As described above, even if one of the phases of the five-phase motor 20 fails, the motor drive system 101 can continue driving using the remaining three phases. Here, the configuration of the power relay 30 is not limited to the configuration illustrated in FIGS. 1 and 2, and may be configured to include a power relay for each phase of the five-phase motor 20. That is, regarding the failed switching element Q, only one contact connected to the corresponding winding coil may be opened.

  Here, a configuration in which a power relay is provided for each phase of the five-phase motor 20 and a motor driving method when any one of the phases of the five-phase inverter 10 fails will be described.

  FIG. 10 is an equivalent circuit diagram of the five-phase motor 20. For example, when either of the switching elements Q3 or Q4 of the five-phase inverter 10 fails, the b-phase armature voltage vb of the five-phase motor 20 cannot be output. For this reason, the motor drive system 101 continues to drive the five-phase motor 20 using, for example, three phases a, c, and d among the remaining four phases. In this case, the transformation matrix is expressed using the following equation (7).

  A case where a configuration including a power relay is adopted for each phase of the five-phase motor 20 and two phases of the phases of the five-phase inverter 10 fail will be described. The motor drive system 101 uses one phase, one phase having a phase difference of 144 ° with respect to the failed phase, and the remaining three phases even when two phases fail. The motor drive can be continued. FIG. 11 shows combinations of two failed phases and other phases used for driving. For example, when two phases of the a phase and the c phase fail, the motor driving is continued using the b, d, and e phases.

  The motor drive system 101 of Patent Document 1 has been described above. However, in the motor drive system 101 of Patent Document 1 described above, when the motor is driven by energizing three phases, the phase difference between adjacent phases is not constant in terms of electrical angle. Pulsation). Hereinafter, the generation mechanism of this torque ripple will be described in detail.

  FIG. 12 shows an equivalent circuit diagram of the five-phase motor 20 at the normal time, and FIG. 13 shows an equivalent circuit diagram of the five-phase motor 20 at the time of the b-phase failure.

  The armature current of each phase in the normal state of FIG. 12 is represented by the following formula (8), and the following formula (8) is shown in a graph form in FIG. Here, I is the maximum value of each phase current. θ is the electrical angle of the motor. Further, the armature current of each phase at the time of the b-phase failure in FIG. 13 is expressed by the following formula (9), and the following formula (9) is shown in a graph form in FIG. When the b-phase failure occurs, as shown in FIG. 6, the control unit 40 opens the contact p <b> 2 of the power relay 30 to perform, for example, three-phase driving of a-phase, c-phase, and d-phase.

  When the armature current of each phase at the normal time shown by the above equation (8) is converted into five phases / 2 phases, the following equation (10) is obtained. Further, when the armature current of each phase at the time of the b-phase failure expressed by the above equation (9) is converted into five phases / 2 phases, the following equation (11) is obtained. iα is an α-axis current in a normal state. iβ is a β-axis current at normal time. iα ′ is an α-axis current at the time of b-phase failure. iβ ′ is the β-axis current at the time of the b-phase failure.

  When the two-phase current of the above formula (10) is dq converted, it becomes a direct current and no torque pulsation occurs. FIG. 16 shows the d-axis current and the q-axis current in the normal state. This is the same as the theory of normal vector control. On the other hand, when the two-phase current of the above formula (11) is dq converted, the following formula (12) is obtained. id ′ is a d-axis current at the time of b-phase failure. iq ′ is a q-axis current at the time of b-phase failure. FIG. 17 shows the d-axis current and the q-axis current when the b-phase fault occurs.

  When only the pulsation component is extracted from the above equation (12), the following equation (13) is obtained. Since iq ′ is proportional to the actual motor output torque in the following equation (13), it can be said that a torque ripple indicated by iq ′ in the following equation (13) is generated at the time of b-phase failure.

  An object of the present invention is to provide a technique for improving torque ripple at the time of failure.

According to the first aspect of the present invention, a motor in which coils of five or more phases are connected by star connection and one end of each coil are connected, and DC power is converted into AC power to each coil of the motor. Using the inverter to be supplied and a plurality of contacts arranged between the coils connected to the other end of each coil and star-connected, the power supplied to at least one of the coils is supplied. A power relay configured to be able to be shut off; and a control unit that controls driving of the motor by generating a control signal of the inverter, wherein the control unit has one or more phases of the motor. When a failure occurs, the contact of the power relay corresponding to the failed phase is opened, and among the remaining phases, three or more phases having substantially the same interval are driven. More than phase So as to cancel the pulsating component of the torque generated by driving the controls the current value in each phase of the three or more phases, the motor drive system is provided. According to the above configuration, the pulsation component of the torque generated by driving the three phases is canceled.
Preferably, the control unit cancels the pulsating component to a current value in each phase of the three or more phases so as to cancel the pulsating component of the torque generated by driving the three or more phases. Add a counteracting ingredient.
Preferably, the control unit adds the cancellation component to a current value in each phase of the three or more phases so as to cancel a pulsation component of torque generated by driving the three or more phases. The cancellation component is added to the current value in each phase of the three or more phases so that the maximum value of the current value in each of the three or more phases becomes the smallest.
According to the second aspect of the present invention, a motor in which coils of five or more phases are connected by star connection and one end side of each coil are connected, and DC power is converted into AC power to each coil of the motor. Using the inverter to be supplied and a plurality of contacts arranged between the coils connected to the other end of each coil and star-connected, the power supplied to at least one of the coils is supplied. A motor drive system control method comprising: a power relay configured to be cut off; and a control unit that controls driving of the motor by generating a control signal of the inverter, wherein the motor When one or more of the phases fail, the contact of the power relay corresponding to the failed phase is opened, and among the remaining phases, three or more phases having substantially the same interval are driven, So as to cancel the pulsating component of the torque generated by driving the phase or phases to control the current value in each phase of the three or more phases, the control method of the motor drive system is provided.
Preferably, a canceling component for canceling the pulsating component is added to the current value in each phase of the three or more phases so as to cancel the pulsating component of torque generated by driving the three or more phases. .
Preferably, when the canceling component is added to the current value in each phase of the three or more phases so as to cancel the pulsating component of torque generated by driving the three or more phases, the three or more phases The cancellation component is added to the current value in each phase of the three or more phases so that the maximum value of the current value in each phase becomes the smallest.
According to a third aspect of the present invention, a traveling device for driving a wheel to perform an inverted control, a motor having five or more phases connected by star connection, and one end of each coil are connected, Using an inverter that converts direct current power to alternating current power and supplies it to each coil of the motor, and a plurality of contacts that are arranged between the other ends of each coil and are star-connected, A power relay configured to be able to cut off power supplied to at least one of the coils, and a control unit that controls driving of the motor by generating a control signal of the inverter; And when the one or more phases of the motor have failed, the control unit opens the contact of the power relay corresponding to the failed phase, and among the remaining phases, three or more phases having substantially the same interval The phase of The traveling device is configured to control a current value in each phase of the three or more phases so as to cancel a pulsation component of torque generated by driving the three or more phases. Is provided.
Preferably, the control unit cancels the pulsating component to a current value in each phase of the three or more phases so as to cancel the pulsating component of the torque generated by driving the three or more phases. Add a counteracting ingredient.
Preferably, the control unit adds the cancellation component to a current value in each phase of the three or more phases so as to cancel a pulsation component of torque generated by driving the three or more phases. The cancellation component is added to the current value in each phase of the three or more phases so that the maximum value of the current value in each of the three or more phases becomes the smallest.

  According to the present invention, the pulsation component of the torque generated by driving the three phases is canceled.

FIG. 1 is a circuit diagram of a motor drive circuit. FIG. 2 is a block diagram of the motor drive system. FIG. 3 is a graph of the d-axis voltage command and the q-axis voltage command. FIG. 4 is a graph of the α-axis voltage command and the β-axis voltage command. FIG. 5 is a graph of motor voltage commands for each phase of a five-phase motor. FIG. 6 is a diagram illustrating a relationship between a failed phase and a power relay to be opened. FIG. 7 is a circuit diagram for detecting a failure phase. FIG. 8 is a graph of the current value when a failure of any switching element is detected. FIG. 9 is a graph of the current value when a failure of each switching element is detected. FIG. 10 is an equivalent circuit diagram of a five-phase motor. FIG. 11 is a diagram showing combinations of two failed phases and other phases used for driving. FIG. 12 is an equivalent circuit diagram of a five-phase motor in a normal state. FIG. 13 is an equivalent circuit diagram of a five-phase motor when a b-phase failure occurs. FIG. 14 is a graph of the armature current of each phase at normal times. FIG. 15 is a graph of the armature current of each phase at the time of b-phase failure. FIG. 16 is a graph showing the d-axis current and the q-axis current in a normal state. FIG. 17 is a graph showing the d-axis current and the q-axis current when the b-phase failure occurs. FIG. 18 is a graph of the d-axis current and the q-axis current obtained by adding the compensation values. FIG. 19 is a block diagram of the motor drive system of this embodiment.

  Hereinafter, a technique for improving torque ripple generated at the time of b-phase failure will be described in detail.

  First, when the pulsation component of the above equation (13) is converted by dq / 2 phase, the following equation (14) is obtained. iα ′ is a pulsating component of the α-axis current at the time of the b-phase failure. iβ ′ is a pulsating component of the β-axis current at the time of the b-phase failure.

  Accordingly, the canceling component as a component that cancels the pulsating component of the α-axis and β-axis currents at the time of the b-phase failure expressed by the above formula (14) is changed to the a-phase, c-phase, and d-phase that are driven at the time of the b-phase failure. If distributed, the pulsation component is canceled as a result, and the torque ripple of the motor is improved.

  As a method of distributing the canceling component, at least three types shown by the following formulas (15) to (17) are listed as candidates in the case of a b-phase failure. Here, ia ′ is an a-phase armature current when torque ripple is improved. ic ′ is a c-phase armature current when torque ripple is improved. id ′ is a d-phase armature current when torque ripple is improved.

  Regardless of which distribution method of the above formulas (15) to (17) is adopted, the torque ripple is improved. However, in any phase, as the maximum current value increases, the efficiency of the motor cannot be expected. Comparing the above formulas (15) to (17), if the above formula (17) is adopted, the largest maximum current value among the maximum current value of ia ′, the maximum current value of ic ′, and the maximum current value of id ′. It can be seen that the value can be suppressed. FIG. 18 shows the d-axis current and the q-axis current when the motor is driven by the armature current of each phase expressed by the above equation (17). As can be seen from FIG. 18, the q-axis current proportional to the motor output torque is constant at all electrical angles.

  Next, a motor drive circuit 100 for implementing the above-described trip ripple improvement technique will be described with reference to FIG. In the following description, differences from the motor drive circuit 100 of Patent Document 1 shown in FIG. 2 will be mainly described, and overlapping descriptions will be omitted as appropriate. Further, in principle, the same reference numerals are assigned to the constituent elements corresponding to the constituent elements of Patent Document 1.

  As shown in FIG. 19, the control unit 40 of the motor drive system 101 controls the current value in each of the three phases so as to cancel the pulsation component of the torque generated by driving the three phases. That is, the control unit 40 adds a canceling component for canceling the pulsating component to the current value in each phase of the three phases so as to cancel the pulsating component of the torque generated by driving the three phases. Specifically, the control unit 40 further includes a failure phase information generation unit 47, a compensation value generator 48, a compensation value table 49, and an addition circuit 80.

  The fault phase information generation unit 47 detects the fault phase by measuring the potential difference between both ends of each resistor Rs of the shunt resistor 70 shown in FIG. 7, for example, and the fault phase information as information for specifying the fault phase Is generated. The failure phase information generation unit 47 outputs the generated failure phase information to the 2-phase / 5-phase coordinate conversion unit 43 and the compensation value generator 48. Further, as described above, the control unit 40 appropriately opens each contact of the power relay 30 based on the failure phase information generated by the failure phase information generation unit 47.

  The two-phase / 5-phase coordinate conversion unit 43 stops outputting the motor voltage commands va ** to ve ** corresponding to the failure phase based on the failure phase information input from the failure phase information generation unit 47.

  The compensation value table 49 stores the relationship between the failure phase and compensation values (Va ′ to Ve ′) as cancellation components in a table format. For example, when the failure phase is the b phase, the compensation value Va ′ corresponds to the second term on the right side of the first equation of the above equation (17) and is represented by the following equation (18). In the following formula (18), Z is the impedance of the motor, R is the winding resistance of the motor, L is the winding self-inductance of the motor, ω is the electrical angular velocity of the motor, and θ is the electrical angle of the motor. Similarly, the compensation value Vc ′ corresponds to the second term on the right side of the second equation of the above equation (17) and is represented by the following equation (19). Similarly, the compensation value Vd ′ corresponds to the second term on the right side of the second equation of the equation (17) and is represented by the following equation (20).

  The case where the failure phase is the b phase in the relationship between the failure phase in the compensation value table 49 and the compensation values (Va ′ to Ve ′) as cancellation components has been described above. The same applies to the case of the phase or the c phase, the case of the d phase or the e phase.

  The compensation value generator 48 acquires the compensation values (Va ′ to Ve ′) corresponding to the failure phase from the compensation value table 49 based on the failure phase information input from the failure phase information generation unit 47, and acquires the compensation value. The compensation values (Va ′ to Ve ′) are output to the adder circuit 80.

  The adder circuit 80 adds the compensation value (output from the compensation value generator 48) to the motor voltage commands va ** to ve ** of each phase of the 5-phase motor 20 output from the 2-phase / 5-phase coordinate conversion unit 43. Add Va 'to Ve'). That is, the adding circuit 80 adds the a-phase compensation value Va ′ to the a-phase motor voltage command va **, adds the b-phase compensation value Vb ′ to the b-phase motor voltage command vb **, and adds the c-phase motor voltage command vc. C-phase compensation value Vc 'is added to **, d-phase compensation value Vd' is added to d-phase motor voltage command vd **, and e-phase compensation value Ve 'is added to e-phase motor voltage command ve **. .

  With the above configuration, for example, when the b-phase fails and the a-phase c-phase d-phase drive is performed, the a-phase armature current is corrected to be ia ′ which is the left side of the first expression of the above expression (17). As a result, torque ripple is improved in a feed-forward manner.

  The motor drive system 101 described above is applied to a traveling device that travels while performing inversion control, for example, as in the above-mentioned Patent Document 1.

20 5-phase motor 30 Power relay 40 Control unit 47 Fault phase information generation unit 48 Compensation value generator 49 Compensation value table 80 Addition circuit 100 Motor drive circuit 101 Motor drive system

Claims (3)

A motor in which coils of five or more phases are connected by star connection;
An inverter connected to one end side of each coil, and converts DC power to AC power and supplies it to each coil of the motor;
The power supplied to at least one of the coils can be cut off by using a plurality of contacts that are arranged on the other end side of each coil and inserted between each star-connected coil. A power relay configured in
A control unit that controls driving of the motor by generating a control signal of the inverter;
With
When one or more phases of the motor fail, the control unit opens the contact point of the power relay corresponding to the failed phase, and among the remaining phases, three or more phases having substantially the same interval are provided. Shall be driven,
The control unit controls a current value in each phase of the three or more phases so as to cancel a pulsation component of torque generated by driving the three or more phases ,
The controller cancels the pulsating component to a current value in each phase of the three or more phases so as to cancel the pulsating component of the torque generated by driving the three or more phases. Add ingredients,
The control unit adds the canceling component to the current value in each phase of the three or more phases so as to cancel the pulsating component of the torque generated by driving the three or more phases. Adding the cancellation component to the current value in each phase of the three or more phases so that the maximum value of the current value in each phase of the phase more than one phase is minimized.
Motor drive system. A motor in which coils of five or more phases are connected by star connection;
An inverter connected to one end side of each coil, and converts DC power to AC power and supplies it to each coil of the motor;
The power supplied to at least one of the coils can be cut off by using a plurality of contacts that are arranged on the other end side of each coil and inserted between each star-connected coil. A power relay configured in
A control unit that controls driving of the motor by generating a control signal of the inverter;
A method for controlling a motor drive system comprising:
When one or more phases of the motor fails, the contact of the power relay corresponding to the failed phase is opened, and among the remaining phases, three or more phases having substantially the same interval are driven.
Controlling the current value in each phase of the three or more phases so as to cancel the pulsation component of the torque generated by driving the three or more phases ;
In order to cancel the pulsating component of the torque generated by driving the three or more phases, a canceling component for canceling the pulsating component is added to the current value in each phase of the three or more phases,
When adding the canceling component to the current value in each phase of the three or more phases so as to cancel the pulsating component of the torque generated by driving the three or more phases, the phase of the three or more phases Adding the cancellation component to the current value in each phase of the three or more phases so that the maximum value of the current value in each phase is minimized;
Control method of motor drive system. A traveling device that drives a wheel to perform an inverted control,
A motor in which coils of five or more phases are connected by star connection;
An inverter connected to one end side of each coil, and converts DC power to AC power and supplies it to each coil of the motor;
The power supplied to at least one of the coils can be cut off by using a plurality of contacts that are arranged on the other end side of each coil and inserted between each star-connected coil. A power relay configured in
A control unit that controls driving of the motor by generating a control signal of the inverter;
With
When one or more phases of the motor fail, the control unit opens the contact point of the power relay corresponding to the failed phase, and among the remaining phases, three or more phases having substantially the same interval are provided. Shall be driven,
The control unit controls a current value in each phase of the three or more phases so as to cancel a pulsation component of torque generated by driving the three or more phases ,
The controller cancels the pulsating component to a current value in each phase of the three or more phases so as to cancel the pulsating component of the torque generated by driving the three or more phases. Add ingredients,
The control unit adds the canceling component to the current value in each phase of the three or more phases so as to cancel the pulsating component of the torque generated by driving the three or more phases. Adding the cancellation component to the current value in each phase of the three or more phases so that the maximum value of the current value in each phase of the phase more than one phase is minimized.
Traveling device.

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