JP7440396B2 - Motor control equipment and vehicles - Google Patents

Description

The present invention relates to motor control technology. In particular, it relates to control technology for switched reluctance motors (SR motors).

Regarding SR motors that do not require permanent magnets or windings in the rotor, a control technique is known that can change motor characteristics depending on usage conditions. For example, in Patent Document 1, "When switching the energized phase from one phase to the other phase, an energization timing output unit that provides an overlapping section in which both the one phase and the other phase are energized. and a current control unit that gradually changes the current flowing through at least one of the one phase and the other phase in at least a part of the overlap section (Summary excerpt). A motor control device is disclosed.

Japanese Patent Application Publication No. 2020-10576

The technology disclosed in Patent Document 1 performs rectangular wave energization control that controls the current flowing through the coils of each phase of the SR motor based on a rectangular wave, so although the torque characteristics are good, problems remain in terms of noise. . For example, if an SR motor is used as the prime mover of an electric vehicle or the like to make it quieter, the driving noise of the motor is suppressed, making it more difficult for surrounding pedestrians to perceive the motor. In order to solve this problem, parts that emit running noise may be separately attached, but this complicates the structure and increases cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control technology that can adjust the running sound of an SR motor used as a prime mover without adding any new parts.

The present invention is a motor control device that controls the drive of a multi-phase SR motor by switching energization of coils corresponding to each phase of the motor, the current controlling the current flowing through the coils of each phase. a control unit, a vehicle speed acquisition unit that acquires the vehicle speed of a vehicle in which the SR motor is mounted, an energization angle corresponding to each of the coils of each phase, and an energization start phase and an energization end phase for each of the coils of each phase. a map storage unit that stores an advance angle representing an angle at which the energization angle is changed from a predetermined value according to a change in inductance of each phase to an advance side; a waveform determining unit that determines a current waveform to be passed through the coils of each phase to either a first waveform or a second waveform different from the first waveform, based on the acquired vehicle speed, the map storage unit , a first waveform lead angle map, a first waveform energization angle map, and a second waveform lead angle map are stored, and the second waveform is such that the driving sound when driving the SR motor with the second waveform is , the first waveform is smaller than the drive sound when driving the SR motor.

According to the present invention, it is possible to adjust the running sound of an SR motor used as a prime mover without adding any new parts.

(a) to (c) are explanatory diagrams for explaining an overview of the first embodiment. (a) is an explanatory diagram for explaining a vehicle control system to which the motor control device of the first embodiment is applied, and (b) is an SR motor of the first embodiment. FIG. 1 is a configuration diagram of a motor control device according to a first embodiment. It is a block diagram of a current control part and a map storage part of a first embodiment. It is a flow chart of current control processing of a first embodiment. FIG. 3 is a configuration diagram of a motor control device according to a second embodiment. It is a flow chart of current control processing of a second embodiment. (a) and (b) are explanatory diagrams for explaining current drive waveforms of modified examples of the embodiment of the present invention.

<<First embodiment>>
Embodiments of the present invention will be described below with reference to the drawings. This embodiment will be described using a three-phase SR motor as an example. However, the number of phases of the SR motor is not limited to this.

The motor control device according to the present embodiment has two methods: rectangular wave energization control that produces loud drive noise and can achieve high torque, and sine wave energization control that produces lower drive noise and lower torque than rectangular wave energization control, depending on the situation. Use them accordingly. For example, when the SR motor to be controlled is used as the prime mover of a vehicle, sine wave energization control is performed when the vehicle is in low speed mode, and square wave energization control is performed during high speed mode, where the vehicle speed is faster than low speed mode. conduct.

Specifically, the drive current for driving the motor is switched between a rectangular wave current shown in FIG. 1(a) and a sine wave current shown in FIG. 1(b) depending on conditions. Note that a square wave current is a drive current in which the current command value changes in a rectangular wave shape depending on the rotational position of the rotor (rotor electrical angle), and a sine wave current is a drive current in which the current command value changes in a sine wave shape depending on the rotor electrical angle. This is a drive current that changes in a waveform. Note that a rectangular wave is a waveform that rises instantaneously, maintains the maximum value for a predetermined period, and then falls instantaneously.

In controlling the SR motor, as shown in FIG. 1(c), the range in which energization control using a sine wave current can be used is limited depending on the speed and torque of the SR motor. If the torque and speed are within this range, switching is possible. In this embodiment, by switching from sine wave energization control, which is used in areas where low vibration and low operating noise are required, to square wave energization control, the torque characteristics in high rotation and high load areas are improved, as shown in this figure. This makes it possible to handle high load areas.

[Vehicle control system]
Hereinafter, in this embodiment, a case where an SR motor is used as a prime mover of an electric vehicle (vehicle) will be described as an example. First, a vehicle control system 100 to which the motor control device of this embodiment is applied will be described using FIG. 2.

The vehicle control system 100 controls the driving force of the SR motor according to the amount of operation and operation state of the operator for operating the vehicle. The controller is, for example, an object that the driver operates to give the vehicle various behaviors, such as an accelerator pedal to adjust the speed of the vehicle, or a range of vehicle conditions such as drive, reverse, neutral, and parking. Includes shift lever for These operators are provided with, for example, a sensor that outputs an electrical output value in conjunction with the operation amount and operation state of the operator. The output value of each sensor is input to the motor control device. Hereinafter, in this embodiment, an output value from a sensor attached to an accelerator pedal is used as an operator.

As shown in FIG. 2A, the vehicle control system 100 includes a motor control device 200, an SR motor 120, a resolver 121, and an accelerator operation detection section 112.

Accelerator operation detection section 112 detects an accelerator signal and outputs it to motor control device 200. The accelerator signal is an output value from a throttle position sensor. The throttle position sensor is a sensor that is provided on the accelerator pedal 111 and detects a rotation angle that changes depending on the amount of depression of the accelerator pedal (accelerator opening degree). The throttle position sensor is, for example, a potentiometer, and is provided on the rotation axis of the accelerator pedal 111, and its resistance value changes depending on the rotation angle of the accelerator pedal 111. The output value from the throttle position sensor is proportional to the accelerator opening. The accelerator operation detection unit 112 applies a voltage to the throttle position sensor and detects the resistance value. Then, the accelerator operation detection unit 112 performs AD conversion on the detected resistance value and outputs it to the motor control device 200 .

The SR motor 120 is a multi-phase drive motor that drives the rear wheels 115 via the rear gear 114. For example, as shown in FIG. 2(b), the SR motor 120 includes a stator 122 having a plurality of excitation coils, and a rotor 123 rotatably disposed within the stator 122. The rotor 123 includes four salient pole parts. Each salient pole portion is formed to protrude radially outward from the rotating shaft 124. The stator 122 is provided concentrically with the rotating shaft 124 of the rotor 123 so as to cover the periphery of the rotor 123, and includes six salient poles. Each salient pole is formed to protrude radially inward toward the rotating shaft 124 of the rotor 123.

A conducting wire is wound around each of the six salient poles of the stator 122 to form an excitation coil. Among the six salient poles, opposing salient poles are paired to form excitation coils Lu, Lv, and Lw. The rotational position of the rotor 123 is detected by the resolver 121.

The resolver 121 is a rotation angle sensor that detects the position (rotor rotation angle) of the rotor 123 of the SR motor 120. The detection result is output to the motor control device 200 as a rotation angle signal.

The motor control device 200 controls the drive (rotation drive) of the SR motor 120. In this embodiment, the motor control device 200 controls the drive of the SR motor 120 based on the accelerator signal obtained from the accelerator operation detection section 112 and the rotation angle signal obtained from the resolver 121. Specifically, motor control device 200 calculates the maximum current command value, which is the maximum value of the target value of the current flowing through SR motor 120, based on the accelerator signal. Then, the motor control device 200 performs feedback control so that the current value flowing through the SR motor 120 becomes a current command value determined by the maximum current command value and the rotor rotation angle according to the rotation angle signal.

Furthermore, the motor control device 200 drives the SR motor 120 by switching energization to each excitation coil Lu, Lv, and Lw. Here, the motor control device 200 obtains the rotor rotation angle based on the detection result of the resolver 121, and controls the pair of excitation coils Lu, Lv, and Lw to be selectively and sequentially energized accordingly. . As a result, the salient poles of the rotor 123 repeat rotation while being magnetically attracted to the salient poles of the stator 122, generating rotational torque in the rotor 123 and generating rotational driving force in the SR motor 120.

In addition, the vehicle control system 100 may include a shift position sensor and the like. The shift lever is provided with a shift position sensor that detects the range switching position of the shift lever. The shift position sensor detects in which range the shift lever is located, for example, using a switch provided in each range. The shift position sensor detects the position of the shift lever and outputs the detected value to the motor control device 200. The shift position sensor outputs different resistance values to the motor control device 200 depending on the range of the shift lever.

[Motor control device]
Next, the configuration of the motor control device 200 will be explained. As shown in FIG. 3, the motor control device 200 includes a drive circuit 210 and a drive circuit control device 240.

The drive circuit 210 switches the power input from the battery 113 to the SR motor 120 and supplies it to the excitation coils Lu, Lv, and Lw of each phase. Switching is performed according to a gate signal from drive circuit control device 240.

The drive circuit control device 240 controls energization and switching of the excitation coils Lu, Lv, and Lw of each phase of the stator 122. In this embodiment, the drive circuit control device 240 generates a gate signal and outputs it to the drive circuit 210.

[Drive circuit]
The drive circuit 210 performs a switching operation based on a gate signal (drive signal) output from the drive circuit control device 240, and changes the power supply voltage of the battery 113 to three-phase (U-phase, V-phase, W-phase) alternating current. The voltage is supplied to the exciting coils Lu, Lv, and Lw as an energization signal.

Drive circuit 210 is connected to battery 113, for example. The drive circuit 210 includes a capacitor 211, switching elements 221-226, and diodes 231-236. The switching elements 221 to 226 are, for example, n-type channel FETs. For example, the switching elements 221 to 226 may be any of IGBTs (Insulated gate bipolar transistors), FETs (Field Effective Transistors), and BJTs (Bipolar junction transistors). It may also consist of only one.

The capacitor 211 has one end connected to the positive electrode of the battery 113 and the other end connected to the negative electrode of the battery 113. The capacitor 211 is a smoothing capacitor, and stabilizes the power supply against voltage fluctuations of the battery 113.

The switching element 221 has a drain connected to the positive electrode of the battery 113 and a source connected to the cathode of the diode 231. The anode of diode 231 is connected to the negative electrode of battery 113. The diode 232 has a cathode connected to the positive electrode of the battery 113 and an anode connected to the drain of the switching element 222 . The source of switching element 222 is connected to the negative electrode of battery 113.

The switching element 223 has a drain connected to the positive electrode of the battery 113 and a source connected to the cathode of the diode 233. The anode of diode 233 is connected to the negative electrode of battery 113. The diode 234 has a cathode connected to the positive electrode of the battery 113 and an anode connected to the drain of the switching element 224. A source of switching element 224 is connected to the negative electrode of battery 113.

The switching element 225 has a drain connected to the positive electrode of the battery 113 and a source connected to the cathode of the diode 235. The anode of diode 235 is connected to the negative electrode of battery 113. The diode 236 has a cathode connected to the positive electrode of the battery 113 and an anode connected to the drain of the switching element 226. A source of switching element 226 is connected to the negative electrode of battery 113.

That is, the capacitor 211, the switching element 221 and diode 231 connected in series, the switching element 222 and diode 232 connected in series, and the switching element 223 and diode 233 connected in series. Switching element 224 and diode 234, switching element 225 and diode 235 connected in series, and switching element 226 and diode 236 connected in series are each connected in parallel to battery 113.

Further, one end of the excitation coil Lu of the SR motor 120 is connected to the connection point between the switching element 221 and the diode 231, and the other end of the excitation coil Lu is connected to the connection point between the switching element 222 and the diode 232. Ru. One end of the excitation coil Lv of the SR motor 120 is connected to the connection point between the switching element 223 and the diode 233, and the other end of the excitation coil Lw is connected to the connection point between the switching element 224 and the diode 234. One end of the excitation coil Lw of the SR motor 120 is connected to the connection point between the switching element 225 and the diode 235, and the other end of the excitation coil Lw is connected to the connection point between the switching element 226 and the diode 236.

The switching elements 221 and 222 and the diodes 231 and 232 constitute an H-bridge circuit, and magnetism can be generated in the exciting coil Lu by turning the switching elements 221 and 222 on and off. The switching elements 223 and 224 and the diodes 233 and 234 constitute an H-bridge circuit, and magnetism can be generated in the exciting coil Lv by turning the switching elements 223 and 224 on and off. The switching elements 225, 226 and the diodes 235, 236 constitute an H-bridge circuit, and magnetism can be generated in the exciting coil Lw by turning the switching elements 225, 226 on and off.

As described above, the drive circuit 210 is composed of three H-bridge circuits. Gate signals output from the drive circuit control device 240 are input to the gates of the switching elements 221 to 226, and the switching elements 221 to 226 are turned on and off according to the input control signals. As a result, current from the battery 113 is applied to each of the excitation coils Lu, Lv, and Lw of the SR motor 120. Note that when the switching elements 221 to 226 are turned off, the diodes 231 to 236 prevent the current from flowing back through the excitation coils Lu, Lv, and Lw.

The current sensor 212 detects the current flowing through each of the excitation coils Lu, Lv, and Lw of the SR motor 120 and outputs the detected current to the drive circuit control device 240. In response to this, the drive circuit control device 240 outputs a gate signal to the drive circuit 210, controls the switching elements 221 to 226, and controls the rotation direction and rotation of the rotor 123 depending on the timing of energizing the excitation coils Lu, Lv, and Lw, respectively. Control speed and torque.

[Drive circuit control device]
The drive circuit control device 240 controls the drive of the SR motor 120 by switching the energization of the excitation coils Lu, Lv, and Lw corresponding to each phase of the multiphase SR motor 120. In this embodiment, a rectangular wave current (first waveform current) in which the current command value changes in a rectangular waveform (first waveform shape) according to the rotor electrical angle, and a sine wave current command value in accordance with the rotor electrical angle. The drive current waveform that drives the drive circuit 210 is switched between a sine wave current (second waveform current) that changes depending on the shape (second waveform shape). Note that driving using a sine wave current produces lower driving noise than driving using a rectangular wave current.

When the current used for driving is a square wave current, the drive circuit control device 240 outputs a square wave drive signal to the drive circuit 210 to energize the excitation coils Lu, Lv, Lw with the square wave energization signal, The rotor 123 of the SR motor 120 is driven. Further, when the current used for driving is a sine wave current, the drive circuit control device 240 outputs a sine wave drive signal to the drive circuit 210 to control the excitation coils Lu, Lv, Lw by the sine wave energization signal. Electricity is applied to drive the rotor 123 of the SR motor 120.

The drive circuit control device 240 in this embodiment will be described below. As shown in FIG. 3, the drive circuit control device 240 includes a current command value generation section 241, a current detection section 242, a position detection section 243, a rotational speed detection section 244, a current control section 245, and a PWM (Pulse Width Modulation) output section 246, advance angle/energization angle setting section 247, energization timing output section 248, gate drive section 249, map storage section 250, and vehicle speed acquisition section 256.

The current command value generation unit 241 generates the maximum target value (hereinafter referred to as "maximum current command value") of the current flowing through the excitation coils Lu, Lv, and Lw of each phase of the SR motor 120 from the required load. Specifically, the accelerator signal output from the accelerator operation detection unit 112 is acquired, and the maximum current command value is generated according to the value of the accelerator signal. Then, the current command value generation section 241 outputs the generated maximum current command value to the current control section 245 and the advance angle/energization angle setting section 247.

For example, the current command value generation unit 241 includes a table in which the operation amount of the accelerator pedal 111 is associated with the maximum current command value, and the current command value generation unit 241 has a table in which the operation amount of the accelerator pedal 111 is associated with the maximum current command value. The maximum current command value is generated by reading the corresponding maximum current command value from the table. Further, the current command value generation section 241 may experimentally determine the maximum current command value from the operation amount of the accelerator pedal 111 indicated by the accelerator signal output from the accelerator operation detection section 112.

Note that when the shift position sensor is provided and a shift signal is input, the current command value generation unit 241 determines that the shift position of the shift lever is in the reverse range based on the shift signal, and is in the reverse traveling position. If it is determined that the rotation direction of the SR motor 120 is reverse rotation. The current command value generation unit 241 may output a rotation direction command signal indicating that the rotation direction of the SR motor 120 is reverse rotation to the current control unit 245.

The current detection unit 242 detects the current value flowing through each of the excitation coils Lu, Lv, and Lw of the SR motor 120 output from the current sensor 212, and outputs the detected current value to the current control unit 245. For example, the current detection unit 242 detects the phase current flowing through the SR motor 120 based on the detection signal of each phase current (winding current) output from each current sensor 212, and calculates the detected value of this phase current. is output to the current control section 245.

Position detection section 243 detects the rotor electrical angle based on the rotation angle signal output by resolver 121 and outputs it to rotation speed detection section 244 , current control section 245 , and energization timing output section 248 .

The rotational speed detection section 244 calculates the rotational speed of the rotor 123 (rotor rotational speed) and outputs it to the advance angle/energization angle setting section 247 and the vehicle speed acquisition section 256. The rotation speed detection section 244 detects the amount of change per unit time in the rotor electrical angle output by the position detection section 243, and calculates the rotor rotation speed from the detected amount of change.

The current control unit 245 performs energization control to control the current flowing through the excitation coils Lu, Lv, and Lw of each phase of the SR motor 120 based on a predetermined waveform (drive current waveform). The current control unit 245 detects the maximum current command value output from the current command value generation unit 241, the rotor electrical angle detected by the position detection unit 243, the rotor rotation speed output from the rotation speed detection unit 244, and current detection. A current difference value is calculated using the current detection values of each exciting coil Lu, Lv, and Lw detected by the unit 242. The calculated current difference value is output to the PWM output section 246. The current difference value calculated here is the deviation between the current command value and the current detection value determined by the maximum current command value, the drive current waveform, and the rotor electrical angle.

In addition, the current control unit 245 of this embodiment switches the drive current waveform between a rectangular wave and a sine wave according to the vehicle speed acquired by a vehicle speed acquisition unit 256, which will be described later, and energizes with the current of either waveform. Take control. To achieve this, the current control section 245 of this embodiment includes a waveform determining section 255, a rectangular wave control section 245a, and a sine wave control section 245b, as shown in FIG.

The waveform determination unit 255 determines whether the drive current waveform of the SR motor 120 is a rectangular wave or a sine wave based on the vehicle speed of the vehicle in which the SR motor 120 is mounted. That is, the waveform determining unit 255 determines whether the current to be passed through the excitation coils Lu, Lv, and Lw of each phase is a rectangular wave current or a sine wave current. The determination result is output to the rectangular wave control section 245a, the sine wave control section 245b, and the advance angle/energization angle setting section 247.

Hereinafter, the drive mode in which the motor control device 200 drives the SR motor 120 with a rectangular wave current will be referred to as a rectangular wave drive mode, and the drive mode in which the SR motor 120 is driven with a sine wave current will be referred to as a sine wave drive mode. Therefore, the waveform determination unit 255 determines whether the drive mode of the SR motor 120 is the rectangular wave drive mode or the sine wave drive mode, depending on the output from the vehicle speed acquisition unit 256, which will be described later. Specifically, when the vehicle speed acquired by the vehicle speed acquisition unit 256 is less than a predetermined vehicle speed threshold, the sine wave drive mode is determined, and when the vehicle speed is equal to or higher than the vehicle speed threshold, the rectangular wave drive mode is determined. Details of the determination method will be described later.

When the waveform determining unit 255 determines the rectangular wave drive mode, the rectangular wave control unit 245a performs the above-described current control based on a rectangular wave current whose current command value changes in a rectangular wave shape according to the rotor electrical angle.

When the waveform determining unit 255 determines the sine wave drive mode, the sine wave control unit 245b performs the above-described current control based on a sine wave current whose current command value changes in a sine wave shape according to the rotor electrical angle.

The PWM output unit 246 determines the duty ratios of the switching elements 221 to 226 so that the current difference value decreases. The PWM output section 246 outputs the calculated duty ratio to the gate drive section 249. Note that the PWM output unit 246 may calculate the above-described duty ratio based on the current difference value using known PI (Proportional Integral) control or PID (Proportional Integral Derivative) control.

The advance angle/energization angle setting section 247 uses the current command value output from the current command value generation section 241, the rotation speed output from the rotation speed detection section 244, and the drive current waveform determined by the waveform determination section 255. Accordingly, the lead angle and the energization angle are output to the energization timing output section 248. The lead angle and the energization angle are acquired from the map storage unit 250.

The energization timing output unit 248 determines each phase of each phase of the SR motor 120 based on the rotor electrical angle output from the position detection unit 243 and the advance angle and energization angle output from the advance angle/energization angle setting unit 247. The energization timing for energizing each of the excitation coils Lu, Lv, and Lw is determined. Then, the energization timing output section 248 outputs the determined energization timing to the gate drive section 249.

The gate drive section 249 turns on or off the switching elements 221 to 226 included in the drive circuit 210 based on the timing signal output from the energization timing output section 248 and the duty ratio output from the PWM output section 246. A control signal (PWM signal) is output to the gates of the switching elements 221 to 226.

The map storage unit 250 stores a rectangular wave advance angle map 251, a rectangular wave conduction angle map 252, and a sine wave advance angle map 253.

The rectangular wave advance angle map 251 is a map in which advance angle values used in the rectangular wave drive mode are associated with each combination of maximum current command value and rotor rotational speed. Here, the advance angle refers to the energization start phase and energization end phase for each of the excitation coils Lu, Lv, and Lw of each phase of the SR motor 120 at a predetermined position according to the inductance change of each phase (for example, the inductance increase start phase and Represents the angle at which the energization angle is changed from the decrease start phase, etc. to the advance side.

The rectangular wave conduction angle map 252 is a map in which values of the conduction angle used in the rectangular wave drive mode are associated with each combination of maximum current command value and rotor rotational speed. The energization angle is associated with each of the excitation coils Lu, Lv, and Lw of each phase of the SR motor 120.

Like the rectangular wave advance angle map 251, the sine wave advance angle map 253 is a map in which advance angle values used in the sine wave drive mode are associated with each combination of maximum current command value and rotor rotational speed.

Note that the advance angle tends to increase as the maximum current command value and rotor rotational speed increase. The rectangular wave advance angle map 251 and the sine wave advance angle map 253 are set, for example, based on the results of simulation. The rectangular wave advance angle map 251 and the sine wave advance angle map 253 may be set based not only on simulation results but also on measurement results obtained by measuring an actual machine. Furthermore, the rectangular wave conduction angle map 252 is set based on the results of simulation. The rectangular wave conduction angle map 252 may be set based not only on simulation results but also on measurement results obtained by measuring an actual device.

Further, the lead angle/energization angle setting unit 247 refers to the map storage unit 250 according to the drive mode notified from the waveform determining unit 255, extracts the lead angle and the conduction angle from the corresponding map, and outputs the energization timing. 248. That is, upon receiving the notification of the rectangular wave drive mode, it refers to the rectangular wave advance angle map 251 and the rectangular wave energization angle map 252 and outputs the advance angle and the energization angle to the energization timing output section 248. On the other hand, upon receiving notification of the sine wave drive mode, it refers to the sine wave advance angle map 253 and outputs only the advance angle.

The vehicle speed acquisition section 256 acquires the vehicle speed of the vehicle in which the SR motor 120 of this embodiment is mounted, and outputs it to the waveform determination section 255. What the vehicle speed acquisition unit 256 acquires may be an index value corresponding to the vehicle speed. Hereinafter, both will be collectively referred to as vehicle speed. In this embodiment, for example, the rotor rotation speed detected by the rotation speed detection unit 244 is used as the vehicle speed. In addition, the vehicle speed acquisition unit 256 may acquire a signal indicating the vehicle speed from the vehicle, or may calculate the vehicle speed from the accelerator signal.

[Current control processing]
The flow of current control processing by the current control unit 245, including the waveform determination processing by the waveform determination unit 255 described above, will be described. FIG. 5 is a processing flow of current control processing of this embodiment. This process is performed every predetermined current control period.

The current control unit 245 acquires the detected current value I_u ^* , the rotor electrical angle θ ^* , the latest maximum current command value Imax ^* , and the latest vehicle speed v ^* (step S1101).

Next, the waveform determining unit 255 determines whether the latest vehicle speed v ^* is low (step S1102). Here, the waveform determining unit 255 compares the acquired vehicle speed v ^* with a predetermined vehicle speed threshold. Then, if the vehicle speed v ^* is less than the comparison threshold, it is determined that the vehicle speed is low.

If the vehicle speed is determined to be low, the waveform determining unit 255 determines the drive mode to be a sine wave drive mode, and notifies the sine wave control unit 245b (step S1103). At this time, the waveform determining section 255 also outputs a signal indicating that the sine wave drive mode has been determined to the advance angle/energization angle setting section 247.

The sine wave control unit 245b performs sine wave energization control processing (step S1104), and ends the processing. Specifically, as the sine wave energization control process, the sine wave control unit 245b first calculates the current command value Iu_ref of the sine wave current, which is determined by the maximum current command value Imax ^* and the rotor electrical angle θ ^* . Then, the difference between the current command value Iu_ref and the current detected value I_u ^* is calculated as a current difference value.

Note that, upon receiving a signal indicating that the sine wave drive mode has been determined, the advance angle/energization angle setting unit 247 sets the maximum current command value received from the current command value generation unit 241 and the maximum current command value received from the rotation speed detection unit 244. The advance angle associated with the rotor rotational speed is acquired from the sine wave advance angle map 253 and output to the energization timing output section 248.

On the other hand, if it is determined in step S1102 that the vehicle speed is not low, the waveform determination unit 255 determines the drive mode to be a rectangular wave drive mode, and notifies the rectangular wave control unit 245a (step S1105). At this time, the waveform determining section 255 also outputs a signal indicating that the rectangular wave drive mode has been determined to the advance angle/energization angle setting section 247.

The rectangular wave control unit 245a performs rectangular wave energization control processing (step S1106), and ends the processing. Specifically, as the rectangular wave energization control process, the rectangular wave control unit 245a first calculates the maximum current command value Imax ^* as the current command value Iu_ref of the rectangular wave current. Then, the difference between the current command value Iu_ref and the current detected value I_u ^* is calculated as a current difference value.

Note that, upon receiving a signal indicating that the rectangular wave drive mode has been determined, the advance angle/energization angle setting unit 247 sets the maximum current command value received from the current command value generation unit 241 and the maximum current command value received from the rotation speed detection unit 244. The energization angle and advance angle associated with the rotor rotational speed are acquired from the rectangular wave advance angle map 251 and the rectangular wave energization angle map 252, respectively, and output to the energization timing output unit 248.

As described above, the motor control device 200 of the present embodiment controls the SR motor 120 by switching the energization of the coils (for example, excitation coils Lu, Lv, Lw) corresponding to each phase of the multiphase SR motor 120. The motor control device 200 controls the driving of the motor, and includes a current control unit 245 that controls the current flowing through the coils of each phase based on a predetermined waveform. The current control unit 245 includes a waveform determining unit 255 that determines the predetermined waveform to be either a first waveform or a second waveform with a lower drive sound than the first waveform. The waveform determination unit 255 determines a predetermined waveform based on the vehicle speed of the vehicle in which the SR motor 120 is mounted.

For example, if the vehicle speed is low, the waveform determination unit 255 of this embodiment sets the predetermined waveform to be a sine wave. Thereby, the motor control device 200 drives the SR motor 120 in a sine wave drive mode that performs energization control using a low noise sine wave current. On the other hand, if the vehicle speed is not low, the waveform determination unit 255 sets the predetermined waveform to a rectangular wave. As a result, the motor control device 200 drives the SR motor 120 in the rectangular wave drive mode in which high torque is obtained although vibrations and noise are increased.

Generally, vehicles travel at low speeds in cities, residential areas, etc., and at high speeds on highways, etc. According to the present embodiment, the above-described method is used to perform energization control using a rectangular wave current when driving at high speeds where high torque is required, and to reduce noise using a sine wave current when driving at low speeds. be able to. Therefore, according to the present embodiment, the SR motor 120 used as a prime mover can be automatically adjusted to the optimal running sound as needed without adding any new parts.

<<Second embodiment>>
Next, a second embodiment of the present invention will be described. Similar to the motor control device of the first embodiment, the motor control device of this embodiment drives the SR motor 120 in the sine wave drive mode when the vehicle equipped with the SR motor 120 is running at low speed, and when the vehicle is running at high speed. is driven in square wave mode. However, the motor control device of this embodiment drives the SR motor 120 in the rectangular wave drive mode if a person is detected around the vehicle even when the vehicle is running at low speed.

The vehicle control system 100 of this embodiment has basically the same configuration as the first embodiment. However, the vehicle control system 100 of this embodiment includes a surroundings detection sensor 116 to detect whether or not there are people around the vehicle (see FIG. 6). The present embodiment will be described below, focusing on the differences from the first embodiment.

The surroundings detection sensor 116 monitors the surroundings of the vehicle and determines the presence or absence of a person based on the surroundings detection signal at predetermined time intervals. and. If it is determined that a person exists within a predetermined area around the vehicle, a person detection signal is output to the drive circuit control device 240. The detection section of the surroundings detection sensor 116 is realized by a camera, a laser sensor, or the like. Note that the range in which the presence of a person is detected may be limited to the traveling direction of the vehicle.

FIG. 6 shows the configuration of the motor control device 201 of this embodiment. As shown in this figure, the motor control device 201 of this embodiment includes a drive circuit 210 and a drive circuit control device 240a, similar to the first embodiment. The drive circuit 210 is the same as the drive circuit 210 of the first embodiment.

The drive circuit control device 240a of the present embodiment has the same configuration as the drive circuit control device 240 of the first embodiment, and further includes a person detection section 257.

The person detection section 257 receives a person detection signal from the surrounding detection sensor 116 and outputs it to the waveform determination section 255 of the current control section 245 . Note that the timing at which the human detection unit 257 receives the human detection signal may be synchronized with the current control cycle or may be asynchronous.

The waveform determination unit 255 of this embodiment determines whether the mode is a rectangular wave drive mode or a sine wave drive mode based on whether or not a human detection signal is received in addition to the vehicle speed. Specifically, the waveform determination unit 255 makes the determination based on whether or not a person detection signal has been received from the person detection unit 257 within a predetermined time. That is, if the waveform determining unit 255 receives a person detection signal within a predetermined time, it determines that a person has been detected, and otherwise determines that a person has not been detected. When a person is detected, the waveform determination unit 255 determines the rectangular wave drive mode, and when no person is detected, the waveform determination unit 255 determines the sine wave drive mode.

[Current control processing]
The flow of current control processing by the current control unit 245, including the waveform determination processing by the waveform determination unit 255 described above, will be described. FIG. 5 is a processing flow of current control processing of this embodiment. This process is performed every predetermined current control period.

The current control unit 245 acquires the detected current value I_u ^* , the rotor electrical angle θ ^* , the latest maximum current command value Imax ^* , and the latest vehicle speed v ^* (step S1101).

Next, the waveform determining unit 255 determines whether the latest vehicle speed v ^* is low using the same method as in the first embodiment (step S1102).

If it is determined that the vehicle speed is low, the waveform determining unit 255 determines whether a person is detected (step S2101).

If it is determined that it is not detected, the waveform determining unit 255 determines the drive mode to be a sine wave drive mode, and notifies the sine wave control unit 245b (step S1103). The following processing is the same as in the first embodiment, so it will be omitted.

On the other hand, if it is determined in step S1102 that the vehicle speed is not low, the waveform and if it is determined in step S2101 that a person is detected, the waveform determination unit 255 determines the drive mode to be a rectangular wave drive mode, and The wave control unit 245a is notified (step S1105). The following processing is the same as in the first embodiment, so it will be omitted.

As described above, similarly to the first embodiment, if the vehicle speed is low, the waveform determination unit 255 of this embodiment sets the predetermined waveform to the second waveform (sine wave). However, even if the vehicle speed is low, the waveform determination unit 255 of the present embodiment determines the predetermined waveform when it receives a person detection signal that is output when it detects that there is a person around the vehicle. is determined to be the first waveform (rectangular wave).

In this manner, the waveform determination unit 255 of this embodiment determines the waveform of the drive current that controls the drive circuit 210 based on the vehicle speed of the vehicle in which the SR motor 120 is mounted, as in the first embodiment. Therefore, according to the motor control device 201 of this embodiment, the same effects as in the first embodiment can be obtained. Further, the motor control device 201 of this embodiment drives the SR motor 120 in the rectangular wave drive mode if a person is detected around the vehicle even if the vehicle equipped with the SR motor 120 is moving at a low speed. In other words, even when driving at low speeds that do not require much torque, if there are people around, the motor control device 201 activates the SR in a rectangular wave drive mode with loud drive noise in order to make people aware of the presence of the vehicle. The motor 120 is driven. As a result, it is possible to improve the problem that motor-driven vehicles generate low running noise and are difficult for people to recognize.

Further, according to the present embodiment, when a person is detected in the surrounding area, the driving mode is changed to generate a running sound. That is, according to the present embodiment, the driving noise can be increased without separately attaching a component that generates running noise. As a result, it is possible to automatically adjust the running sound to the optimum level as needed without complicating the structure or increasing costs, and it is possible to notify the surroundings of the presence of the vehicle. Therefore, according to this embodiment, safety can be improved without any additional configuration.

<Modified example>
In the embodiment described above, the presence or absence of a person is determined by the surrounding detection sensor 116 and a person detection signal is output to the person detection unit 257, but the present invention is not limited thereto. For example, the surrounding detection information acquired by the surrounding detection sensor 116 may be directly transmitted to the person detection unit 257 at predetermined time intervals. In this case, the person detection unit 257 analyzes the surrounding detection information and determines whether there is a person or not.

<Modified example>
In each of the embodiments described above, two types of drive current waveforms are used to drive the SR motor 120: a sine wave with low torque but with small drive noise, and a rectangular wave with high torque but with large drive noise. The case was explained using an example. However, the drive current waveform used to drive the SR motor 120 is not limited to this. Two types of waveforms (a first waveform and a second waveform) capable of generating different torques may be used. That is, it is sufficient to use the first waveform and the second waveform, which changes more slowly than the first waveform and has a lower drive sound.

Another example of such a combination of two types of current waveforms will be shown. For example, as shown in FIG. 8(a), the first waveform may be a rectangular wave, and the second waveform may be a trapezoidal wave. A trapezoidal wave is a rectangular wave with slopes in its rising and falling regions. That is, the trapezoidal wave has a waveform shape that rises more slowly than the rectangular wave, maintains the maximum value for a predetermined period, and then falls more gently. Alternatively, as shown in FIG. 8(b), the first waveform may be a trapezoidal wave, and the second waveform may be a sine wave.

<Modified example>
Note that in each of the embodiments described above, the vehicle speed acquisition unit 256 estimates the vehicle speed from the rotational speed of the SR motor 120, but the present invention is not limited to this. The vehicle speed may be estimated using an acceleration sensor, GPS data, or the like. Furthermore, if data from a vehicle-mounted camera can be used, the vehicle speed may be estimated from the photographed data.

<Modified example>
Note that in the above embodiment, parameters for the sine wave current and the rectangular wave current are prepared in advance, but the method is not limited to this method. For example, only the parameters of the sine wave current may be held, and if necessary, this sine wave current may be shaped to generate a rectangular wave current. This reduces the number of parameters to be held and reduces the burden on memory.

Furthermore, in each of the embodiments described above, in the case of energization control using a sine wave current, the energization angle is not adjusted. However, it is not limited to this. For example, the energization angle may also be adjusted in the sine wave energization control. This makes it possible to further reduce noise.

In the embodiments described above, the diodes 231 to 236 may be replaced with switching elements such as IGBTs, FETs, and BJTs.

Moreover, each part of the motor control devices 200 and 201 may be realized by hardware, may be realized by software, or may be realized by a combination of hardware and software. When implemented as software, motor control device 200 includes a CPU, a memory, and a storage device. Then, the CPU loads programs stored in advance in the storage device into the memory and executes them, thereby realizing each function. The program may be stored on a computer readable medium or on a storage device connected to a network. Note that the term "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs. Further, the program may be realized using a programmable logic device such as an FPGA (Field Programmable Gate Array). Note that the map storage unit 250 is constructed in a storage device.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and includes designs within the scope of the gist of the present invention.

100: Vehicle control system, 111: Accelerator pedal, 112: Accelerator operation detection section, 113: Battery, 114: Rear gear, 115: Rear wheel, 116: Surroundings detection sensor, 120: SR motor, 121: Resolver, 122: Stator, 123: rotor, 124: rotating shaft,
200: Motor control device, 201: Motor control device, 210: Drive circuit, 211: Capacitor, 212: Current sensor, 221: Switching element, 222: Switching element, 223: Switching element, 224: Switching element, 225: Switching element , 226: switching element, 231: diode, 232: diode, 233: diode, 234: diode, 235: diode, 236: diode,
240: Drive circuit control device, 240a: Drive circuit control device, 241: Current command value generation section, 242: Current detection section, 243: Position detection section, 244: Rotation speed detection section, 245: Current control section, 245a: Rectangle wave control section, 245b: sine wave control section, 246: PWM output section, 247: energization angle setting section, 248: energization timing output section, 249: gate drive section, 250: map storage section, 251: rectangular wave advance angle map , 252: Rectangular wave conduction angle map, 253: Sine wave advance angle map, 255: Waveform determination unit, 256: Vehicle speed acquisition unit, 257: Person detection unit

Claims (7)

A motor control device that controls driving of the SR motor by switching energization of coils corresponding to each phase of the multi-phase SR motor,
a current control unit that controls the current flowing through the coils of each phase;
a vehicle speed acquisition unit that acquires the vehicle speed of a vehicle in which the SR motor is mounted;
Changing the energization angle corresponding to each of the coils of each phase and the energization start phase and energization end phase for each of the coils of each phase from a predetermined value corresponding to a change in inductance of each phase to an advanced angle side. a map storage unit that stores advance angles representing angles ;
The current control unit determines a current waveform to be passed through the coils of each phase to either a first waveform or a second waveform different from the first waveform, based on the vehicle speed acquired by the vehicle speed acquisition unit. Equipped with a waveform determining section,
The map storage unit stores a first waveform advance angle map, a first waveform energization angle map, and a second waveform advance angle map,
The second waveform is a waveform in which a driving sound when driving the SR motor with the second waveform is smaller than a driving sound when driving the SR motor with the first waveform.
A motor control device characterized by: The motor control device according to claim 1,
The motor control device according to claim 1, wherein the waveform determining unit determines the current waveform to be the first waveform when the vehicle speed is equal to or higher than a predetermined threshold. The motor control device according to claim 1,
The motor control device according to claim 1, wherein the waveform determining unit determines the current waveform to be the second waveform when the vehicle speed is less than a predetermined threshold. The motor control device according to claim 1,
Further comprising a person detection unit that outputs a person detection signal to the current control unit when there are people around the vehicle,
The motor control device according to claim 1, wherein the waveform determining unit further determines the current waveform to be the first waveform when the current control unit has received the human detection signal. The motor control device according to claim 1,
further comprising a rotation speed detection unit that detects the rotation speed of the SR motor,
The motor control device, wherein the vehicle speed is calculated based on the rotational speed. The motor control device according to claim 1,
The first waveform and the second waveform are:
A combination of a rectangular wave with a waveform shape that rises instantaneously, maintains the maximum value for a predetermined period, and then instantly falls, and a sine wave with a sine wave shape;
a combination of the rectangular wave and a trapezoidal wave having a waveform shape that rises more slowly than the rectangular wave, maintains the maximum value for a predetermined period, and then falls slowly;
A motor control device characterized in that the motor control device is a combination of the trapezoidal wave and the sine wave. polyphase SR motor,
A vehicle comprising: the motor control device according to any one of claims 1 to 6, which controls driving of the multiphase SR motor.