JP6462213B2 - Electric vehicle braking system and electric vehicle braking method - Google Patents

Description

  The present invention relates to a motor regeneration control device and a motor regeneration control method.

  A switched reluctance motor (hereinafter referred to as an SR motor) has a salient pole (protruding pole) structure for both a stator and a rotor. The SR motor winds around each of the plurality of salient poles of the stator to form an excitation coil, and selectively energizes each excitation coil to magnetically attract the salient pole of the rotor to the salient pole of the stator. Drive and brake the rotation of the rotor. For this reason, SR motors do not require the provision of permanent magnets or windings on the rotor, have a simple and inexpensive motor structure, and are mechanically robust, capable of high rotation, and can be used in high temperature environments. ing. For this reason, the SR motor is used for various purposes, and is used as a prime mover in an electric vehicle such as an electric cart, for example.

  In an electric vehicle using an SR motor as a drive source, there is a method of obtaining a regenerative brake by turning off the accelerator to operate the SR motor as a generator and recovering energy at the time of braking (for example, patents) Reference 1).

JP 2008-245495 A

  As described above, there is a conventional method for obtaining a regenerative brake by performing regenerative control according to the operation amount of the accelerator. However, because the brake operation is a mechanical brake process, the regenerative control of the SR motor cannot be performed unlike the regenerative brake. Since energy cannot be generated by regenerative control, the battery cannot be charged to improve energy efficiency.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a motor regeneration control device and a motor regeneration control method capable of obtaining regenerative energy using a regenerative brake according to an operation amount of a brake. It is to be.

According to one aspect of the present invention, a hydraulic brake force necessary for decelerating the electric vehicle and a regenerative brake force corresponding to the operation amount are obtained from an operation amount of a brake pedal of the electric vehicle, and the regenerative brake force is obtained from the hydraulic brake force. A required torque unit for calculating a result obtained by subtracting the braking force, a rotational speed detecting unit for obtaining a rotational speed of an SR motor for driving a wheel in the electric vehicle, and an operation amount of the brake pedal acquired from the required torque unit. Excitation having an excitation current command map in which a brake torque command shown, a rotation speed of the SR motor obtained by the rotation speed detection unit, and a current command value serving as a target value of the current output to the SR motor are stored A current command map unit and a current command value corresponding to the brake torque command and the rotation speed are selected from the excitation current command map. And exciting current command setting unit comprising a current determining unit, by controlling the current flowing in the SR motor based on a current command value selected by the exciting current determining unit, PWM control to generate a braking torque to said SR motor And a hydraulic control device that controls the hydraulic pressure of the hydraulic brake of the wheel of the electric vehicle based on the result calculated by the required torque unit.

Another embodiment of the present invention is an electric vehicle braking system described above, when the brake is applied the electric vehicle, with respect to the rear wheels or the front wheels, regeneration by the hydraulic braking force and the braking torque to the SR motor The brake force is applied in combination, and the applied hydraulic brake force and regenerative brake force are set to increase as the amount of operation of the brake pedal increases .

Further, according to one aspect of the present invention, a hydraulic brake force necessary for decelerating the electric vehicle and a regenerative brake force corresponding to the operation amount are obtained from an operation amount of a brake pedal of the electric vehicle. The process of transmitting the result of subtracting the regenerative braking force to the hydraulic control device of the electric vehicle, the process of obtaining the rotational speed of the SR motor for driving the wheels in the electric vehicle, and the brake pedal acquired from the required torque unit An excitation current command map in which a brake torque command indicating the operation amount of the motor, a rotational speed of the SR motor obtained by the rotational speed detection unit, and a current command value serving as a target value of the current output to the SR motor are stored. An excitation current command map unit having a current command value corresponding to the brake torque command and the rotation speed is selected from the excitation current command map By the exciting current determining unit that controls a process of calculating a current command value of a current flowing to the SR motor in the regeneration control, the current flowing to the SR motor based on a current command value selected by the exciting current determining unit Thus, the SR motor has a process of generating a braking torque, and the hydraulic control device controls a hydraulic pressure of a hydraulic brake of a wheel of the electric vehicle based on the result from the required torque unit. This is an electric vehicle braking method.

  According to the present invention, the brake torque of the motor can be controlled in accordance with the operation amount of the brake pedal.

It is a figure which shows the structural example of the motor regeneration control apparatus 1 in 1st Embodiment. It is a block diagram of motor regeneration control device 1 in a 1st embodiment. It is a figure explaining the example of distribution of the braking force and regenerative braking force of front and rear wheels. It is a figure which shows an exciting current command map. It is a figure which shows a regeneration advance angle map and a regeneration energization angle map. It is a wave form diagram which shows the relationship between the rotational speed of SR motor 5 at the time of regeneration control at the time of low rotation, a torque characteristic, and a current waveform. It is a wave form diagram which shows the relationship between the rotational speed of SR motor 5 at the time of regeneration control at the time of high rotation, a torque characteristic, and a current waveform. It is a flowchart which shows the process of the motor regeneration control apparatus 1 in 1st Embodiment. It is a figure which shows the structural example of 1 A of motor regeneration control apparatuses in 2nd Embodiment. It is a block diagram of motor regeneration control device 1A in a 2nd embodiment.

(First embodiment)
Hereinafter, the motor regeneration control device 1 in the first embodiment will be described with reference to the drawings.
FIG. 1 is a configuration diagram of an electric vehicle system to which the motor regeneration control device 1 according to the first embodiment is applied.
The electric vehicle system includes a brake pedal 2, a brake operation detection unit 3 that detects an operation amount (depression force amount) of the brake pedal 2, a hydraulic control device 4 that distributes hydraulic pressure to the brakes of the front and rear wheels, and a distributed hydraulic pressure. A hydraulic brake 10 for the front wheel 8 that generates braking force, a hydraulic brake 11 for the rear wheel 7, an SR motor 5, a rotation angle sensor 6 provided in the SR motor 5, and a battery 9 are provided.

  The brake operation detection unit 3 detects an operation amount of an input device that selects a braking force of a brake operated by the driver, for example, the brake pedal 2. The brake operation detection unit 3 outputs a brake signal corresponding to the operation amount of the brake pedal to the motor regeneration control device 1. For example, the brake operation detection unit 3 includes a variable resistor, connects the brake pedal 2 and the knob of the variable resistor with a rigid member, and is divided by a variable resistor that changes according to the operation amount of the brake pedal 2. The pressed voltage is detected, and the detected voltage is output to the motor regeneration control device 1 as a brake signal. Moreover, the brake operation detection part 3 may have a pressure sensor etc. which detect the depression amount of the brake pedal 2, and may output the detection result to the motor regeneration control apparatus 1 as a brake signal.

  The SR motor 5 drives the rear wheel 7 via the rear gear 5A. Details of the SR motor 5 will be described later.

  The hydraulic brake 10 for the front wheel 8 and the hydraulic brake 11 for the rear wheel 7 can easily dissipate heat generated during braking, and a disc brake may be used to prevent a reduction in braking performance. At that time, the brake caliper is preferably an opposed piston type. A drum brake may be used when the vehicle weight is light.

  The motor regeneration control device 1 acquires a brake signal from the brake operation detection unit 3. The motor regeneration control device 1 receives the output signal of the rotation angle sensor 6 that detects the rotation speed of the rear wheel 7. The motor regeneration control device 1 controls the driving of the SR motor 5 based on the brake signal and the output signal of the rotation angle sensor 6. Further, the motor regeneration control device 1 outputs a pressure reduction signal indicating that the hydraulic pressure of the hydraulic brake 11 of the rear wheel 7 is reduced to the hydraulic pressure control device 4.

  The hydraulic control device 4 distributes hydraulic pressure to the front and rear wheel brakes. Further, when receiving the pressure reduction signal from the motor regeneration control device 1, the hydraulic pressure control device 4 reduces the hydraulic pressure of the hydraulic brake 11 of the rear wheel 7 based on the pressure reduction signal.

Next, the motor regeneration control device 1 for the SR motor 5 in the first embodiment will be described. FIG. 2 is a block diagram of the motor regeneration control device 1 according to the first embodiment.
As shown in FIG. 2, the motor regeneration control device 1 according to the first embodiment includes a drive circuit 12 and a control device 13.

  The SR motor 5 is provided so as to surround the rotor 31 with four salient pole portions, the stator 32 having six salient pole portions toward the inner rotor, and the rotation angle of the rotor 31. A rotation angle sensor 6 for detection. The six salient pole portions of the stator 32 are respectively wound to form an exciting coil, and coils Lu, Lv, and Lw having pairs of opposing salient pole portions are formed. By selectively energizing the coils Lu, Lv, and Lw, the salient pole part of the stator 32 magnetically attracts the salient pole part of the rotor 31 and causes the rotor 31 to generate drive torque and braking torque.

The drive circuit 12 is connected to the battery 9 and includes a capacitor 51, n-channel FETs (Field Effective Transistors) 52 to 57 as switching elements, and diodes 58 to 63. The capacitor 51 has one end connected to the positive electrode of the battery 9 and the other end connected to the negative electrode.
The FET 52 has a drain connected to the positive electrode of the battery 9 and a source connected to the cathode of the diode 58. The anode of the diode 58 is connected to the negative electrode of the battery 9. The diode 59 has a cathode connected to the positive electrode of the battery 9 and an anode connected to the drain of the FET 53. The source of the FET 53 is connected to the negative electrode of the battery 9.

The FET 54 has a drain connected to the positive electrode of the battery 9 and a source connected to the cathode of the diode 60. The anode of the diode 60 is connected to the negative electrode of the battery 9.
The diode 61 has a cathode connected to the positive electrode of the battery 9 and an anode connected to the drain of the FET 55. The source of the FET 55 is connected to the negative electrode of the battery 9.
The FET 56 has a drain connected to the positive electrode of the battery 9 and a source connected to the cathode of the diode 62. The anode of the diode 62 is connected to the negative electrode of the battery 9.
The diode 63 has a cathode connected to the positive electrode of the battery 9 and an anode connected to the drain of the FET 57. The source of the FET 57 is connected to the negative electrode of the battery 9.

  That is, a capacitor 51, an FET 52 and a diode 58 connected in series, an FET 53 and a diode 59 connected in series, an FET 54 and a diode 60 connected in series, an FET 55 and a diode 61 connected in series, The FET 56 and the diode 62 connected in series and the FET 57 and the diode 63 connected in series are connected in parallel to the battery 9, respectively.

  One end of the coil Lu of the SR motor 5 is connected to the connection point between the FET 52 and the diode 58, and the other end of the coil Lu is connected to the connection point between the FET 53 and the diode 59. One end of the coil Lv of the SR motor 5 is connected to the connection point between the FET 54 and the diode 60, and the other end of the coil Lv is connected to the connection point between the FET 55 and the diode 61. One end of the coil Lw of the SR motor 5 is connected to the connection point between the FET 56 and the diode 62, and the other end of the coil Lw is connected to the connection point between the FET 57 and the diode 63.

As described above, the drive circuit 12 is configured by an H-bridge circuit, and a control signal input from the control device 13 is input to the gates of the FETs 52 to 57, and the FETs 52 to 57 are turned on in accordance with the input control signals. By switching between “off” and “off”, the coils Lu, Lv, and Lw of the SR motor 5 are energized.
The current sensor 20 detects currents that flow through the coils Lu, Lv, and Lw of the SR motor 5 and outputs them to the control device 13.

  The control device 13 includes a regenerative operation mode determination unit 131, a request torque unit 132, an excitation current command setting unit 133, a PWM control unit 134, a position detection unit 135, a rotation speed detection unit 136, an energization timing determination unit 137, and an advance energization angle. A map unit 138 and a current detection unit 139 are provided.

  The regenerative operation mode determination unit 131 is a detection unit that detects a brake signal output from the brake operation detection unit 3. Further, when the regenerative operation mode determination unit 131 detects a brake signal, the motor regeneration control device 1 performs a regenerative operation of the SR motor 5. When the regenerative operation of the SR motor 5 is performed, the regenerative operation mode determination unit 131 outputs a regenerative signal indicating that the regenerative operation is performed to the required torque unit 132.

The requested torque unit 132 acquires a brake signal from the brake operation detection unit 3 when the regeneration signal is supplied from the regenerative operation mode determination unit 131. When the required torque unit 132 acquires the regeneration signal, the required torque unit 132 refers to a first table stored in advance in a storage unit (not shown), and acquires the hydraulic brake force of the rear wheel 7 corresponding to the operation amount of the brake pedal 2. . The hydraulic brake force is a brake force of the hydraulic brake 11 of the rear wheel 7 necessary for decelerating the electric vehicle.
Further, the requested torque unit 132 refers to a second table stored in advance in a storage unit (not shown) and acquires a regenerative braking force corresponding to the operation amount of the brake pedal 2. The regenerative braking force is a braking force that decelerates the electric vehicle by the regenerative operation of the SR motor 5.
The required torque unit 132 outputs a subtraction brake force calculated by subtracting the regenerative brake force from the hydraulic brake force of the rear wheel 7 to the hydraulic control device 4 as a pressure reduction signal.
Further, the requested torque unit 132 transmits the acquired regenerative braking force to the exciting current command setting unit 133 as a brake torque command.

  FIG. 3 is a diagram for explaining an example of distribution of the braking force and the regenerative braking force of the front and rear wheels. FIG. 3A is a schematic diagram for explaining the relationship between the braking force applied to the front wheel 8 and the operation amount of the brake pedal 2. The vertical axis represents the braking force applied to the front wheel 8, and the horizontal axis represents the brake pedal 2. The operation amount is shown. As shown in FIG. 3A, in the braking force of the front wheel 8, the hydraulic control device 4 increases the hydraulic pressure applied to the hydraulic brake 10 of the front wheel 8 in proportion to the operation amount of the brake pedal 2. Decelerate.

FIG. 3B is a schematic diagram for explaining the relationship between the braking force of the rear wheel 7 and the operation amount of the brake pedal 2, where the vertical axis represents the braking force applied to the rear wheel 7 and the horizontal axis represents the brake pedal 2. The operation amount is shown. As shown in FIG. 3B, in the brake for the rear wheel 7, the hydraulic control device 4 increases the hydraulic pressure applied to the hydraulic brake 11 for the front wheel 8 in proportion to the operation amount of the brake pedal 2. Decelerate.
However, when receiving the pressure reduction signal from the required torque unit 132, the hydraulic control device 4 reduces the hydraulic pressure of the hydraulic brake 11 to reduce the braking force of the rear wheel 7 by the subtraction braking force indicated by the pressure reduction signal. FIG. 3C is a schematic diagram for explaining the relationship between the braking force of the rear wheel 7 and the operation amount of the brake pedal 2, where the vertical axis represents the braking force applied to the rear wheel 7, and the horizontal axis represents the brake pedal 2. The operation amount is shown. As shown in FIG. 3C, the motor regeneration control device 1 uses the SR motor to reduce the braking force (subtracted braking force) that the hydraulic control device 4 has reduced in FIG. Compensate with a regenerative braking force of 5.

The position detection unit 135 detects the rotation angle of the rotor 31 (the rotation position of the rotor 31) from the signal output from the rotation angle sensor 6 provided in the SR motor 5, and the rotation speed detection unit 136 and the PWM control unit And 134.
The rotation speed detection unit 136 detects the amount of change per unit time of the signal indicating the rotation angle of the rotor output from the position detection unit 135, and calculates the rotation speed (number of rotations) of the rotor 31 from the detected change amount. Output to the excitation current command setting unit 133 and the energization timing determination unit 137.

The excitation current command setting unit 133 includes an excitation current determination unit 133B and an excitation current command map unit 133A. The excitation current command map unit 133A has an internal storage unit in which, for example, an excitation current map is stored. FIG. 4 shows a model of the excitation current command map stored in the internal storage unit of the excitation current command setting unit 133. In FIG. 4, the excitation current command map unit 133 </ b> A includes a brake torque command indicating the rotational speed of the SR motor 5 and the amount of operation of the brake pedal 2 when performing the regeneration control of the SR motor 5, and a target of current output to the SR motor 5 An excitation current command map is stored in which excitation current command values that are values are stored.
As shown in FIG. 4, the x-axis direction represents the brake torque command, the y-axis direction represents the rotational speed, and the z-axis direction represents the excitation current command value. In the excitation current command map, it is shown that when the brake torque command value increases and the rotation speed tends to decrease, the excitation current command value changes in an increasing trend. The current value (excitation current command value) in the excitation current command map is calculated from the characteristic value of the SR motor 5 using a simulation, or is determined in advance by an actual measurement value of the SR motor 5.

When the excitation current determination unit 133B acquires a brake torque command indicating the operation amount of the brake pedal 2 from the required torque unit 132, the excitation current command map is read from the excitation current command map unit 133A. Further, the excitation current determination unit 133B acquires the rotation speed of the SR motor 5 from the rotation speed detection unit 136. The excitation current determination unit 133B selects an excitation current command value corresponding to the acquired brake torque command and rotation speed from the read excitation current command map, and outputs the selected excitation current command value to the PWM control unit 134.
In addition, the excitation current determination unit 133B outputs a brake torque command to the energization timing determination unit 137.

  The current detection unit 139 receives the detection result of the current flowing in each of the coils Lu, Lv, Lw of the SR motor 5 output from the current sensor 20, and the PWM control unit 134 converts the current value flowing in the coils Lu, Lv, Lw. Output to. For example, based on the detection signal of each phase current (winding current) output from each current sensor 20, the winding current energized in the SR motor 5 is detected, and the detected value of this winding current is used as the PWM control unit 134. Output to.

  The energization timing determination unit 137 selects an advance angle corresponding to the rotation speed from the rotation speed detection unit 136 and the brake torque command from the excitation current determination unit 133B from the regeneration advance angle map. Also. The energization timing determination unit 137 selects an energization angle according to the rotation speed from the rotation speed detection unit 136 and the brake torque command from the excitation current determination unit 133B from the regenerative energization angle map. The energization timing determination unit 137 outputs the selected advance angle and energization angle to the PWM control unit 134.

FIG. 5A shows a regeneration advance angle map. As shown in FIG. 5A, the x-axis direction indicates the brake torque command, the y-axis direction indicates the rotational speed, and the z-axis direction indicates the advance angle. In the regeneration advance angle map, the energization start phase and the energization end phase for each excitation coil Lu, Lv, Lw of each phase of the SR motor 5 are set to a predetermined phase (for example, an inductance increase start phase and an inductance increase phase). 6 is a map showing a predetermined correspondence relationship between an advance angle for changing from a decrease start phase or the like to an advance side, a brake torque command, and a rotation speed.
FIG.5 (b) is a figure which shows a regeneration energization angle map. As shown in FIG. 5B, the x-axis direction indicates the brake torque command, the y-axis direction indicates the rotational speed, and the z-axis direction indicates the energization angle. The regenerative energization angle map is a map showing a predetermined correspondence relationship between energization angles (for example, values of electric angle of 120 ° or more) for each excitation coil Lu, Lv, Lw of each phase, a brake torque command, and a rotation speed. is there.

  The PWM control unit 134 includes a current control processing unit 140, an energization timing output unit 141, and a PWM output unit 142.

  The current control processing unit 140 performs PWM (Pulse Width Modulation) control of the winding current that is energized in the SR motor 5. The current control processing unit 140 calculates a difference between the excitation current command value supplied from the excitation current command setting unit 133 and the current detection value supplied from the current detection unit 139 (hereinafter referred to as “current difference value”). .

  When performing regenerative control of the SR motor 5, the PWM control unit 134 applies a voltage to the SR motor 5 so that the current difference value decreases. For this purpose, for example, the current control processing unit 140 outputs to the PWM output unit 142 a 100% duty ratio that always turns on the FETs 52, 54, and 56. Further, for example, once the current difference value becomes 0, the current control processing unit 140 calculates a voltage value at which the current difference value becomes 0, and calculates a duty ratio in PWM control from the calculated voltage value. The current control processing unit 140 outputs the calculated duty ratio to the PWM output unit 142. Here, the current control processing unit 140 uses the generally known PI (Proportional Integral) control, PID (Proportional Integral Derivative) control, or the like based on the difference between the input current values. Is calculated.

The energization timing output unit 141 acquires the rotation angle of the rotor 31 input from the position detection unit 135. The energization timing output unit 141 acquires the advance angle and the energization angle from the energization timing determination unit 137. The energization timing output unit 141 outputs control signals for switching on and off the FETs 53, 55, and 57 included in the drive circuit 12 based on the acquired rotation angle, advance angle, and energization angle of the rotor 31. Output to the gate.
The energization timing output unit 141 outputs the acquired advance angle and energization angle to the PWM output unit 142.

  The energization timing output unit 141 turns off the FETs 53, 55, and 57 when detecting that the current flowing through the SR motor 5 has reached the excitation current command value from the signal output from the current control processing unit 140 in the regeneration control. To.

  The PWM output unit 142 outputs the duty ratio calculated by the current control processing unit 140 to the gates of the FETs 52, 54, and 56 in the energization period corresponding to the advance angle and the energization angle supplied from the energization timing output unit 141.

FIG. 6 is a waveform diagram showing the relationship among the rotational speed, torque characteristics, and current waveform of the SR motor 5 during regenerative control in the low rotation region. The vertical direction in FIG. 6A is the winding inductance, the vertical direction in FIG. 6B is the winding voltage, the vertical direction in FIG. 6C is the winding current, and FIGS. ), (C) Each horizontal axis direction indicates the rotation angle of the rotor 31.
FIG. 7 is a waveform diagram showing the relationship among the rotational speed, torque characteristics, and current waveform of the SR motor 5 during regenerative control in the high rotation region. 7A is the winding inductance, the vertical direction of FIG. 6B is the winding voltage, the vertical direction of FIG. 7C is the winding current, and FIGS. ), (C) Each horizontal axis direction indicates the rotation angle of the rotor 31.
As shown in FIG. 6 and FIG. 7, each relationship will be described by dividing it into a low rotation region and a high rotation region according to the rotational speed of the rotor 31 in the SR motor 5. First, the regenerative control in this embodiment will be described first, and then the regenerative control in the low rotation region and the high rotation region will be described. Here, the inductance, winding voltage, and winding current in the coil Lu will be described, but the same applies to the coils Lv and Lw.

In the regenerative control, when the salient pole of the rotor 31 approaches the position facing the salient pole of the stator 32 with respect to the coil Lu, the energization timing output unit 141 of the PWM control unit 134 is connected to, for example, the FET 53 to obtain an electromotive force by regeneration. The FET 52 is turned on, the coil Lu is energized until a current having an excitation current command value that is a predetermined current value flows, and the coil Lu is excited. When the current value flowing through the coil Lu reaches the excitation current command value, the energization timing output unit 141 turns off the FET 53, and the PWM output unit 142 turns on the FET 52 according to the duty ratio input from the PWM duty calculation unit 213. Switch off and on.
Here, a state in which both the FETs 52 and 53 are in an ON state, that is, a state in which the power supplied from the battery 9 is applied to the coil Lu is referred to as a supply mode. A state in which the FET 52 is in the on state and the FET 53 is in the off state, that is, a state in which the electromotive force generated in the coil Lu is returned to the FET 52, the coil Lu, and the diode 59 is referred to as a reflux mode. Further, a state in which both FETs 52 and 53 are in an off state, that is, a state in which the electromotive force generated in the coil Lu is output to the battery 9 is referred to as a regeneration mode.

In the low rotation region, the winding inductance increases as the salient pole of the rotor 31 approaches the coil Lu, and becomes highest at the rotation angle at which the salient pole of the rotor 31 and the salient pole of the coil Lu face each other. It decreases as the pole moves away from the coil Lu. Power generation by regeneration is performed in a region where the inductance of the coil Lu decreases.
In the regenerative control, the PWM control unit 134 applies a voltage to the coil Lu to obtain an electromotive force in the vicinity of the coil Lu and the rotor 31 facing each other in the above-described supply mode (the winding voltage becomes a positive value). As a result, the winding current increases. When the winding current reaches the excitation current command value, the PWM control unit 134 switches to the recirculation mode and the regenerative mode, and outputs the electromotive force generated in the coil Lu to the battery 9 (the winding voltage is a negative value and zero). To change). Further, the PWM control unit 134 keeps the winding current flowing in the coil Lu in the vicinity of the excitation current command value by switching between the reflux mode and the regeneration mode.

  In the regeneration control in the high rotation region, a voltage is applied to the coil Lu in order to obtain an electromotive force in the supply mode in the vicinity where the coil Lu and the rotor 31 face each other as in the low rotation region. However, when the current flowing through the coil Lu reaches the excitation current command value, only the regeneration mode is selected without switching between the reflux mode and the regeneration mode, and the electromotive force generated in the coil Lu is output to the battery 9.

  Next, processing of the motor regeneration control device 1 in the first embodiment will be described with reference to the drawings. FIG. 8 is a flowchart showing processing of the motor regeneration control device 1 according to the first embodiment.

  In step S100, when the regenerative operation mode determination unit 131 detects a brake signal, it performs regenerative control. The regeneration operation mode determination unit 131 transmits a regeneration signal to the required torque unit 132 when performing regeneration control.

  In step S <b> 101, the required torque unit 132 acquires a regeneration signal from the regeneration operation mode determination unit 131. Further, the required torque unit 132 acquires a brake signal from the brake operation detection unit 3. The required torque unit 132 subtracts the regenerative braking force corresponding to the brake signal from the braking force of the rear wheel 7 and outputs a pressure reduction signal obtained as a subtraction result to the hydraulic control device 4. Further, the request torque unit 132 transmits the regenerative brake force to the excitation current command setting unit 133 as a brake torque command.

  In step S102, the rotation speed detection unit 136 detects the amount of change per unit time of the signal indicating the rotation angle of the rotor 31 output from the position detection unit 135, and calculates the rotation speed of the rotor 31 from the detected change amount. To the excitation current determination unit 133B and the energization timing determination unit 137.

  In step S <b> 103, the excitation current determination unit 133 </ b> B acquires a brake torque command from the request torque unit 132. Further, the excitation current determination unit 133B acquires the rotation speed from the rotation speed detection unit 136. The excitation current determination unit 133B reads the excitation current command map from the excitation current command map unit 133A. The excitation current determination unit 133B selects an excitation current command value corresponding to the acquired rotation speed and brake torque command from the excitation current command map, and outputs the selected excitation current command value to the current control processing unit 140. In addition, the excitation current determination unit 133B outputs a brake torque command to the energization timing determination unit 137.

  In step S104, the energization timing determination unit 137 selects an advance angle corresponding to the rotation speed from the rotation speed detection unit 136 and the brake torque command from the excitation current determination unit 133B from the regeneration advance angle map. Also. The energization timing determination unit 137 selects an energization angle according to the rotation speed from the rotation speed detection unit 136 and the brake torque command from the excitation current determination unit 133B from the regenerative energization angle map. The energization timing determination unit 137 outputs the selected advance angle and energization angle to the energization timing output unit 141.

In step S <b> 105, the current control processing unit 140 calculates a current difference value and outputs it to the PWM output unit 142 and the energization timing output unit 141.
Further, the current control processing unit 140 outputs to the PWM output unit 142 a 100% duty ratio that always turns on each of the FETs 52, 54, and 56 until the current difference value becomes zero.
The energization timing output unit 141 turns on each of the FETs 53, 55, and 57 according to the rotation angle of the rotor 31 output from the position detection unit 135, calculates an advance angle and an energization angle from the rotation angle of the rotor 31, and performs PWM Output to the output unit 142.
The PWM output unit 142 turns on the FETs 52, 54, and 56 according to the duty ratio output from the current control processing unit 140 and the advance angle and the energization angle output from the energization timing output unit 141, respectively. The energization states of the coils Lu, Lv, and Lw of the motor 5 are set to the supply mode.

In step S106, the current control processing unit 140 determines whether or not the value of the current flowing through the SR motor 5 has reached the excitation current command value.
When the current value output from the current detection unit 139 does not exceed the excitation current command value (when the current difference value is 0 or more), the current control processing unit 140 proceeds to step S105 described above. On the other hand, when the current value output from the current detection unit 139 exceeds the excitation current command value (when the current difference value is less than 0), the current control processing unit 140 proceeds to step S107.

In step S107, the current control processing unit 140 calculates a duty ratio for turning on each of the FETs 52, 54, and 56 according to the current difference value, and outputs the calculated duty ratio to the PWM output unit 142. Further, the energization timing output unit 141 turns off the FETs 53, 55, and 57, respectively. The PWM output unit 142 switches the FETs 52, 54, and 56 on and off according to the duty ratio output from the current control processing unit 140.
As a result, the energization states of the coils Lu, Lv, and Lw of the SR motor 5 are switched between ON and OFF of the FETs 52, 54, and 56, that is, the recirculation mode and the regenerative mode by the PWM control, and the regenerative control is performed. The

  As described above, according to the present embodiment, the motor regeneration control device 1 obtains the excitation current command value from the brake operation amount and the rotational speed of the SR motor 5 using the excitation current command map. Further, the motor regeneration control device 1 controls the current (winding current) flowing through the SR motor 5 based on the current command value. Thereby, the motor regeneration control apparatus 1 can control the brake torque of the SR motor 5 according to the operation amount of the brake pedal 2, and can obtain regenerative braking force.

  Further, as described above, according to the present embodiment, in the electric vehicle in which the hydraulic brake 10 of the front wheel 8 and the hydraulic brake 11 of the rear wheel 7 are independent and the SR motor 5 that drives the rear wheel 7 is mounted. The motor regeneration control device 1 can improve energy efficiency by applying the hydraulic braking force and the regenerative braking force by the SR motor 5 in combination to the rear wheel 7 or the front wheel 8.

(Second Embodiment)
FIG. 9 is a configuration diagram of an electric vehicle system to which the motor regeneration control device 1A according to the second embodiment is applied. The configuration of the electric vehicle system to which the motor regeneration control device 1A according to the present embodiment is applied is used to rotate the rear wheel 7 as compared with the configuration of the electric vehicle system to which the motor regeneration control device according to the first embodiment is applied. Two SR motors 5 are mounted. Accordingly, two rotation angle sensors 6 and two rear gears 5A are similarly mounted. In addition, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and the description is abbreviate | omitted.

FIG. 10 is a block diagram of a motor regeneration control device 1A according to the second embodiment.
As shown in FIG. 10, the motor regeneration control device 1 </ b> A according to the present embodiment includes two motor regeneration control devices 1 in order to perform regeneration control of the two SR motors 5.
The battery 9 is connected to each of the drive circuits 12. Further, the battery 9 is connected to each of the required torque units 132.
The brake operation detection unit 3 is connected to each of the regenerative operation mode determination unit 131 and outputs a brake signal.
The hydraulic control device 4 is connected to each of the required torque units 132 and receives a pressure reduction signal.
Since the process of the motor regeneration control device 1A is the same as the flowchart of FIG. 8, the description thereof is omitted.

The present invention is not limited to the above-described embodiment described with reference to the drawings, and various modifications can be considered within the technical scope thereof.
In embodiment mentioned above, although the motor regeneration control apparatus 1 acquired the brake signal from the brake operation detection part 3, this invention is not limited to this. For example, the motor regeneration control device 1 may acquire the hydraulic pressure of the hydraulic brake 10 of the front wheel 8 from the hydraulic control device 4 as a brake signal.
Further, the motor regeneration control device 1 may acquire the hydraulic pressure of the hydraulic brake 11 of the rear wheel 7 from the hydraulic control device 4 as a brake signal. At that time, the SR motor 5 is configured to drive the front wheels 8, and when the motor regeneration control device 1 acquires the pressure reduction signal, the hydraulic pressure of the hydraulic brake 10 of the front wheels 8 is reduced based on the pressure reduction signal.

  In the above-described embodiment, the motor regeneration control device 1 acquires an SOC signal indicating the state of charge of the battery 9 from the battery 9, and does not perform regenerative control if the state of charge of the battery 9 is nearly full. May be. At that time, the motor regeneration control device 1 does not transmit a pressure reduction signal to the hydraulic control device 4.

  Moreover, in embodiment mentioned above, the motor regeneration control apparatus 1 performed regeneration control by receiving a brake signal from the brake operation detection part 3, However, This invention is not limited to this. For example, the motor regeneration control device 1 may further detect an accelerator signal indicating the operation amount of the accelerator pedal, and perform the regeneration control based on the brake signal and the accelerator signal. Further, the motor regeneration control device 1 may calculate the excitation current command value according to the brake signal and the accelerator signal, and output the calculated excitation current command value to the PWM control unit 134.

  In the above-described embodiment, the motor regeneration control device 1 controls the winding current so that the difference between the excitation current command value and the current detection value from the current detection unit 139 is eliminated. However, the present invention is not limited to this. The winding current may be controlled based on the current command value. For example, the motor regeneration control device 1 may control the winding current so that the current detection value from the current detection unit 139 becomes a current value slightly offset from the excitation current command value. In addition, when the motor regeneration control device 1 controls the winding current with the current value slightly offset from the excitation current command value or the excitation current command value as the target value, the winding current does not coincide with the target value and gradually approaches. Also good.

  Further, instead of the hydraulic control device 4 of the above-described embodiment, an actuator may be provided to perform hydraulic control of the hydraulic brakes 10 and 11. Also, a brake actuator without hydraulic pressure that directly presses the brake pad may be used.

DESCRIPTION OF SYMBOLS 1, 1A ... Motor regeneration control device 2 ... Brake pedal 3 ... Brake operation detection part 4 ... Hydraulic control device 5 ... Switched reluctance motor 6 ... Rotation angle sensor 7 ... Rear wheel 8 ... Front wheel 9 ... Battery 10, 11 ... Hydraulic brake DESCRIPTION OF SYMBOLS 12 ... Drive circuit 13 ... Control apparatus 31 ... Rotor 32 ... Stator 52 ... Capacitor 52, 53, 54, 55, 56, 57 ... FET 58, 59, 60, 61, 62, 63 ... Diode 131 ... Regenerative operation mode discrimination | determination part DESCRIPTION OF SYMBOLS 132 ... Request torque part 133 ... Excitation current command setting part 134 ... PWM control part 135 ... Position detection part 136 ... Rotational speed detection part 137 ... Energization timing determination part 138 ... Advance angle conduction angle map part 139 ... Current detection part 140 ... Current Control processing unit 141... Energization timing output unit 142... PWM output unit

Claims (3)

Obtaining the hydraulic brake force required to decelerate the electric vehicle and the regenerative brake force according to the operation amount from the operation amount of the brake pedal of the electric vehicle, and subtracting the regenerative brake force from the hydraulic brake force A required torque part to be calculated;
A rotational speed detection unit for obtaining a rotational speed of an SR motor for driving wheels in the electric vehicle;
The brake torque command indicating the operation amount of the brake pedal acquired from the required torque unit, the rotation speed of the SR motor obtained by the rotation speed detection unit, and the current that is the target value of the current output to the SR motor An excitation current command map unit having an excitation current command map in which a command value is stored, and an excitation current determination unit that selects a current command value corresponding to the brake torque command and the rotation speed from the excitation current command map An exciting current command setting unit comprising:
A PWM control unit that generates a braking torque in the SR motor by controlling a current flowing in the SR motor based on a current command value selected by the excitation current determination unit ;
A hydraulic control device that controls the hydraulic pressure of the hydraulic brake of the wheel of the electric vehicle based on the result calculated by the required torque unit;
An electric vehicle braking system comprising:   When the brake of the electric vehicle is applied, the hydraulic brake force is applied to the rear wheel or the front wheel in combination with the hydraulic brake force and the regenerative brake force by the braking torque to the SR motor, and the applied hydraulic brake force 2. The electric vehicle braking system according to claim 1, wherein the regenerative braking force is set to increase as the amount of operation of the brake pedal increases. Obtaining the hydraulic brake force required to decelerate the electric vehicle and the regenerative brake force according to the operation amount from the operation amount of the brake pedal of the electric vehicle, and subtracting the regenerative brake force from the hydraulic brake force Transmitting to the hydraulic control device of the electric vehicle;
Determining the rotational speed of the SR motor for driving the wheels in the electric vehicle;
The brake torque command indicating the operation amount of the brake pedal acquired from the required torque unit, the rotation speed of the SR motor obtained by the rotation speed detection unit, and the current command value that is the target value of the current output to the SR motor An excitation current command map unit having an excitation current command map stored therein, and an excitation current determination unit that selects a current command value according to the brake torque command and the rotation speed from the excitation current command map, A process of calculating a current command value of a current flowing through the SR motor in regenerative control;
Controlling the current flowing through the SR motor based on the current command value selected by the excitation current determining unit to generate a braking torque in the SR motor;
A step in which the hydraulic control device controls hydraulic pressure of hydraulic brakes of wheels of the electric vehicle based on the result from the required torque unit;
An electric vehicle braking method comprising: