TWI436578B - Motor control and regenerative braking system - Google Patents

Description

Motor control and brake recharging system

The present invention relates to a motor control system, and more particularly to a motor control system that can utilize energy storage during braking.

Common motor control systems are based on the needs of fixed speed control motor products, such as handicapped scooters or electric bicycles, which provide reliable and safe electronic speed control, and DC brushless motors can be used to convert electrical energy at the same time. For kinetic energy, or the conversion of kinetic energy into electrical energy, as energy reuse is gradually taken seriously, improving the energy efficiency of electric vehicles is the goal of research in this field.

The traditional control method for the energy storage and reuse of the brakes is to separate the motor drive control from the regenerative brake system, but the cost is high, and the three-phase power module is used as the motor drive control and the buck-boost converter is integrated in the system. Although the component cost is low, it is limited by the circuit structure and working characteristics of the three-phase power module, and it is difficult to achieve the best efficiency charging control, and the conventional method is that when the system works in the regenerative braking mode, the buck-boost conversion The device operates in the boost mode to recharge the energy to the electrical energy storage unit. When the system is operating in the motor drive mode, the buck-boost converter operates in the buck mode, and the drive motor operates, so that the energy is recharged due to the buck. Loss of some energy, resulting in poor energy conversion efficiency.

The technical problem to be solved by the present invention is to provide a motor control and brake recharging system to solve the problem of poor charging efficiency of the conventional electronic brake.

In order to solve the above technical problem, one technical solution of the present invention provides a motor control and brake recharging system, which is applicable to an electric vehicle motor, and includes a Hall sensing unit, a control module, a bidirectional conversion circuit, and a driving device. a power module and a rectifier circuit, wherein the control module is coupled to the Hall sensing unit; the bidirectional conversion circuit is coupled to the control module and the rectifier circuit; and the driving power module and the control module respectively And the bidirectional conversion circuit is coupled.

The Hall sensing unit generates a Hall signal according to the operation of a motor; the control module outputs a first control signal and a second control signal according to the Hall signal; the bidirectional conversion circuit outputs the first control signal according to the first control signal An operating voltage; the driving power module controls the rotation speed of the motor according to the operating voltage and the second control signal; the rectifier circuit converts a back electromotive force of the motor into a DC voltage, and the bidirectional conversion circuit converts the DC voltage After boosting, it is output to an energy storage unit.

Thereby, the motor control and brake recharging system of the present invention operates in the buck mode or the boost mode according to the state of the motor operation through the bidirectional conversion circuit, and operates in the boost mode and charges the energy storage unit when the motor brakes, thereby It can achieve effective energy use and control the drive power module with a simple six-step square wave signal to reduce chopping torque and current ripple. In this way, the problem of poor charging efficiency of the conventional motor control system can be solved, and the battery life can be increased.

The above summary and the following detailed description are exemplary in order to further illustrate the scope of the claims. Other objects and advantages of the present invention will be described in the following description and drawings.

The invention controls the brushless motor by a motor control and brake recharging system, and uses the counter electromotive force generated when the motor is braked to be charged to charge an energy storage unit to achieve the effect of effectively utilizing energy.

In order to provide a more detailed description and explanation, the present invention will be described with reference to the accompanying drawings in order to illustrate The effect.

Please refer to the first figure, which is a block diagram of an embodiment of a motor control and brake recharging system provided by the present invention. As shown in the first figure, the motor control system 20 is coupled to the motor 10, and the motor control and brake recharging system 20 controls the rotational speed of the motor 10 and recovers the energy of the motor 10 when the vehicle is braked for driving the motor 10.

In one embodiment, the motor 10 is a DC brushless motor, which has the characteristics of high efficiency, low noise and long life. The motor control and brake recharging system 20 includes a Hall sensing unit 201, a control module 203, and a The energy storage unit 205, an auxiliary power source 2051, a bidirectional conversion circuit 207, a driving power module 209 and a rectifier circuit 211, the Hall sensing unit 201 is coupled to the motor 10; and the control module 203 and Hall sensing respectively The unit 201 and the bidirectional conversion circuit 207 are coupled to each other; the auxiliary power source 2051 is coupled to the control module 203 and the energy storage unit; the bidirectional conversion circuit 207 is coupled to the energy storage unit 205; and the driving power module 209 is coupled to the bidirectional conversion circuit 207 and The control module 203 is coupled; the rectifier circuit 211 is coupled to the motor 10 and the bidirectional conversion circuit 207, respectively.

The Hall sensing unit 201 detects the operation of the motor 10 and generates a Hall signal. The Hall signal can be the speed feedback. The energy storage unit 205 stores an electric energy. In an embodiment, the energy storage unit 205 is a capacitor. Parallel to a battery (not shown), and the capacitor is a super capacitor and the battery is a lead-acid battery, using a super capacitor as an auxiliary power storage unit, and a lead-acid battery as an auxiliary power source; the control module 203 is based on Hall The signal outputting a first control signal and a second control signal; the bidirectional conversion circuit 207 steps down the voltage according to the first control signal to output an operating voltage; the driving power module 209 is configured according to the operating voltage and the second control signal. The rotation speed of the motor 10 is controlled; the rectifier circuit 211 converts a back electromotive force of the motor 10 into a DC voltage, and the bidirectional conversion circuit 207 boosts the DC voltage to charge the energy storage unit 205; the auxiliary power source 2051 receives the energy storage unit 205. The electrical energy is provided, and the control module 203 is provided to operate the power.

Referring to the first figure, the control module 203 includes a micro control circuit 2031 and a driving circuit 2033. The micro control circuit 2031 is coupled to the Hall sensing unit 201 and the driving circuit 2033, respectively. The driving circuit 2033 is coupled to the bidirectional conversion circuit 207. The micro-control circuit 2031 outputs a pulse width modulation signal according to the Hall signal, and the driving circuit 2033 controls the bidirectional conversion circuit 207 to operate in the buck mode or the boost mode according to the pulse width modulation signal. as follows.

Please refer to the second figure, which is a block diagram of an embodiment of a motor control and brake recharging system operating in a motor drive mode according to the present invention. As shown in the second figure, when the motor control and brake recharging system 20 is operated in the motor driving mode, the Hall sensing unit 201 detects the phase of the rotor (not shown) of the motor 10 and generates a Hall signal. H _a , H _b , H _c , the control module 203 generates a first control signal and a second control signal according to the Hall signals H _a , H _b , H _c , wherein the first control signal is a buck command signal, The bidirectional conversion circuit 207 is operated in the buck mode. In an embodiment, the micro control circuit 2031 adjusts the duty cycle (Duty) of the pulse width modulation signal by detecting the rotation speed command and the rotation speed feedback size. The speed control, the driving circuit 2033 generates the step-down command signal according to the pulse width modulation signal; in an embodiment, the second control signal is a six-step square wave signal U _H , U _L , V _H , V _L , W _H W _L , when the drive power module 209 drives the power module 209, the chopper torque and current ripple of the motor 10 are small, so the following six-step square wave signals U _H , U _L , V _H , V _L , W _H , W _L illustrates the role of the second control signal. The bidirectional conversion circuit 207 operates in the buck mode according to the buck command signal, and decompresses the energy stored in the energy storage unit 205 to generate an operating voltage; the driving power module 209 receives the operating voltage and according to the six-step square wave signal U _H , U _L , V _H , V _L , W _H , W _L output motor control signals U, V, W to control the rotor speed of the motor 10.

Please refer to the third figure, which is a block diagram of an embodiment of a motor control and brake recharging system operating in a regenerative braking mode. As shown in the third figure, when the motor control and the brake recharging system 20 are operated in the regenerative braking mode, the Hall sensing unit 201 detects the phase of the rotor (not shown) of the motor 10 and generates a Hall signal. H _a , H _b , H _c , the control module 203 generates a first control signal according to the Hall signals H _a , H _b , H _c , in this mode the first control signal is a boost command signal, the bidirectional conversion circuit The 207 operates in the boost mode according to the boost command signal. In an embodiment, the micro control circuit 2031 adjusts the duty cycle (Duty) of the pulse width modulated signal by the phase of the rotor to achieve constant current control and the driving circuit. 2033 generates the boost command signal according to the pulse width modulation signal; the rectifier circuit 211 rectifies the counter electromotive forces V _U , V _V , V _W when the motor 10 is operated in the regenerative braking mode, and outputs a DC voltage, and the bidirectional conversion circuit 207 boosts the DC voltage and then charges the energy storage unit 205.

Please refer to FIGS. 4A to 4C, which are circuit diagrams of an embodiment of a bidirectional conversion circuit provided by the present invention. As shown in FIG. 4A, the bidirectional conversion circuit 207 used in the motor control and brake recharging system 20 includes a first capacitor C1, a second capacitor C2, a first switching transistor S1, and a second switching transistor. S2 and an inductor L, the bidirectional conversion circuit 207 has a first end ab and a second end cd, and the first capacitor C1 and the second capacitor C2 are respectively connected to the first end ab and the second end cd, and the first switch is electrically connected. The crystal S1 is coupled to the first capacitor C1 and the inductor L, and the second switch transistor S2 is coupled between the first switch transistor S1 and the inductor L. The inductor L is coupled to the first switch transistor S1 and the second capacitor. Between C2, the first switching transistor S1 has a first body diode D1, and the second switching transistor S2 has a second body diode D2.

When the first control signal received by the bidirectional conversion circuit 207 is a buck command signal, the bidirectional conversion circuit 207 operates in a buck mode. As shown in FIG. 4B, the bidirectional conversion circuit 207 uses the first switching transistor S1 as an active switch. And the second switching transistor S2 is equivalent to the second body diode D2, the input voltage V _IN is input from the first end ab, and the direction of the output current I _O is directed from the first end ab to the second end cd, and the output The voltage V _O is output from the second terminal cd, and the relationship between the input voltage and the output voltage is Where D is the duty cycle ratio of the first switching transistor S1, that is, the time ratio of conduction in one cycle.

When the first control signal received by the bidirectional conversion circuit 207 is a boost command signal, the bidirectional conversion circuit 207 operates in a boost mode. As shown in FIG. 4C, the bidirectional conversion circuit 207 uses the second switching transistor S2 as an active switch. The first switching transistor S1 is equivalent to the first body diode D1, and the input voltage V _IN is input from the second terminal cd, and the direction of the output current I _R is directed from the second terminal cd to the first terminal ab, and the output The voltage V _O is output from the first terminal ab, and the relationship between the input voltage and the output voltage is Where D' is the duty cycle ratio of the second switching transistor S2, that is, the time ratio of conduction in one cycle.

Please refer to FIG. 5A, which is a block diagram of an embodiment of a control module according to the present invention, and cooperates with the fourth B to C C diagrams. As shown in FIG. 5A, the control module 203 includes a micro control circuit 2031, a driving circuit 2033, and a level rising circuit 2035. The level lifting circuit 2035 is coupled between the micro control circuit 2031 and the driving circuit 2033. The driving circuit 2033 has an input terminal e, a first output terminal f and a second output terminal g. In an embodiment, the micro control circuit 2031 is a low voltage operation and a low noise microcontroller, such as Renesas Micro. Controller or other microcontroller for low power applications, the drive circuit 2033 is a half bridge drive circuit or a full bridge drive circuit, such as a half bridge drive IC IR2111, wherein the first output terminal f is coupled to the first switch transistor S1 The second output terminal g is coupled to the second switching transistor S2, whereby the driving circuit 2033 drives the first switching transistor S1 and the second switching transistor S2, respectively. In an embodiment, the first output terminal f is The output signal of the second output terminal g has a specific rest time, for example, about 650 ns, that is, the first switching transistor S1 and the second switching transistor S2 are turned on in turn, and the output signal of the first output terminal f and the input terminal e Input signal has the same phase Waveform, and the output signal of the second output terminal g and the input signal of the input terminal e have opposite phase waveforms, or the output signal of the first output terminal f and the input signal of the input terminal e have opposite phase waveforms, and The output signal of the two output terminals g has the same phase waveform as the input signal of the input terminal e.

One of the implementations of the level boosting circuit 2035 is shown in FIG. 5B. The level boosting circuit 2035 includes three bipolar junction transistors Q1, Q2, Q3. In one embodiment, the bipolar junction transistor Q3 The two-pole junction transistors Q1 and Q2 are coupled to the bipolar junction transistor Q3, and the driving circuit 2033 is coupled between the bipolar junction transistors Q1 and Q2. The micro-control circuit 2031 outputs a pulse width modulation signal as a TTL logic gate level, and determines one of the first switching transistor S1 and the second switching transistor S2 to be turned on by the positive and negative of the pulse width modulation signal, and is driven by the level lifting circuit. The 2035 boosts the pulse width modulation signal to drive the first switching transistor S1 or the second switching transistor S2, and adjusts the on-time of the first switching transistor S1 or the second switching transistor S2 to adjust the period in a fixed period. The magnitude of the operating voltage output by the bidirectional conversion circuit 207, that is, the voltage of the input motor 10, is stabilized to stabilize the rotational speed of the motor 10.

Please refer to the sixth figure, which is a circuit diagram of an embodiment of a driving power module according to the present invention. As shown in the sixth figure, the driving power module 209 of the present invention comprises six transistors B1, B2, B3, B4, B5, B6. In one embodiment, the transistors (IGBT) B1, B2, B3, B4 , B5, B6 are insulated gate bipolar transistors (IGBT), respectively receiving control from the second control signals U _H , U _L , V _H , V _L , W _H , W _L , by the second control signal U _H , U _L , V _H , V _L , W _H , W _L operate the driving power module 209 in six modes, wherein the transistors B3 and B6 are turned on and the other are turned off, and the transistors B2 and B3 are turned on. When the transistors B2 and B5 are turned off, the transistors B4 and B5 are turned on and the others are turned off. The transistors B4 and B5 are turned on and the others are turned off. The transistors B1 and B4 are turned on and the others are turned off. The transistors B1 and B6 are turned on and the others are turned off, thereby outputting the motor control signal U, V, W drive the motor 10 rotor in six different phases.

Please refer to the seventh figure, which is a block diagram of an embodiment of a rectifier circuit provided by the present invention. As shown in the seventh figure, the rectifier circuit 211 of the present invention includes six diodes D3, D4, D5, D6, D7, D8. When the motor 10 is operated in the regenerative braking mode, the rectifier circuit 211 reverses the three of the motor 10. The electromotive forces V _U , V _V , and V _{W are} converted into a DC voltage, and the DC voltage is boosted via the bidirectional conversion circuit 207 operating in the boost mode, and the energy storage unit 205 is charged.

According to the above-mentioned embodiments, it can be seen that the present invention integrates with a driving power module by using a bidirectional conversion circuit to achieve the purpose of driving the motor and recovering the braking energy, and boosting the energy of the motor when the motor is operating in the braking mode. After storage, the motor control and brake recharging system of the present invention can solve the problem of poor charging efficiency of the conventional electronic brake.

The drawings and the descriptions of the present invention are only examples of the present invention, and are not intended to limit the present invention. Anyone skilled in the art can make various changes and refinements according to the above description, if any other. The spirit of the present invention and the technical means for not substantially changing the present invention are within the scope of protection covered by the present invention.

10‧‧‧ motor

20‧‧‧Motor control and brake recharging system

201‧‧‧ Hall sensing unit

203‧‧‧Control Module

2031‧‧‧Micro Control Circuit

2033‧‧‧Drive circuit

2035‧‧‧Level boost circuit

Q1, Q2, Q3‧‧‧ bipolar junction transistor

205‧‧‧ Energy storage unit

2051‧‧‧Auxiliary power supply

207‧‧‧Bidirectional conversion circuit

S1‧‧‧first switching transistor

D1‧‧‧ first body diode

S2‧‧‧Second switch transistor

D2‧‧‧Second body diode

C1‧‧‧first capacitor

C2‧‧‧second capacitor

L‧‧‧Inductance

I _R , I _O ‧‧‧ output current

V _IN ‧‧‧ input voltage

V _O ‧‧‧Output voltage

209‧‧‧Drive power module

B1, B2, B3, B4, B5, B6‧‧‧ transistors

211‧‧‧Rectifier circuit

D3, D4, D5, D6, D7, D8‧‧‧ diodes

Schematic description:

1 is a block diagram of an embodiment of a motor control and brake recharging system of the present invention; and FIG. 2 is a block diagram of an embodiment of the motor control and brake recharging system of the present invention operating in a motor drive mode; 3 is a block diagram of an embodiment of a motor control and brake recharging system of the present invention operating in a regenerative braking mode; FIG. 4A is a circuit diagram of an embodiment of a bidirectional conversion circuit of the present invention; The circuit diagram of one embodiment of the bidirectional conversion circuit of the present invention operating in the buck mode; the fourth C is a circuit diagram of an embodiment of the bidirectional conversion circuit of the present invention operating in the boost mode; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 5B is a circuit diagram of an embodiment of a leveling circuit of the present invention; and FIG. 6 is a circuit diagram of an embodiment of a driving power module of the present invention; Figure 7 is a circuit diagram of an embodiment of a rectifier circuit of the present invention.

10. . . motor

20. . . Motor control and brake recharging system

201. . . Hall sensing unit

203. . . Control module

2031. . . Micro control circuit

2033. . . Drive circuit

205. . . Energy storage unit

2051. . . Auxiliary power

207. . . Bidirectional conversion circuit

209. . . Drive power module

211. . . Rectifier circuit

Claims (16)

A motor control and brake recharging system, comprising: a Hall sensing unit, generating a Hall signal according to operation of a motor; a control module coupled to the Hall sensing unit, and outputting according to the Hall signal a first control signal and a second control signal; a bidirectional conversion circuit coupled to the control module, outputting an operating voltage according to the first control signal; a driving power module, and the control module and the The bidirectional conversion circuit is coupled to control the rotation speed of the motor according to the operating voltage and the second control signal; and a rectifier circuit coupled to the motor and the bidirectional conversion circuit to convert a back electromotive force of the motor into a a DC voltage, the bidirectional conversion circuit boosts the DC voltage and outputs the same to an energy storage unit, whereby the bidirectional conversion circuit operates in a step-up or step-down mode according to a state of the motor to improve charging efficiency; The control module includes a micro control circuit, a driving circuit and a level lifting circuit, and the level lifting circuit is coupled to the micro control circuit and the driving circuit respectively, and The first PWM signal and a second PWM signal so that the lifting drive circuit may drive the bidirectional converter circuit. The motor control and brake recharging system of claim 1, wherein the micro control circuit is coupled to the Hall sensing unit and the driving circuit, and the driving circuit is coupled to the bidirectional conversion circuit. The motor control and brake recharging system of claim 2, wherein the Hall signal can be a speed feedback. The motor control and brake recharging system according to claim 3, wherein when the motor control and the brake recharging system are operated in a motor driving mode, the micro control circuit returns a size according to a rotational speed command and the rotational speed. The first pulse width modulation signal is output. The motor control and brake recharging system of claim 4, wherein the driving circuit outputs the first control signal according to the first pulse width modulation signal, and the first control signal is a buck command signal, To control the bidirectional conversion circuit to operate in a buck mode and output the operating voltage. The motor control and brake recharging system of claim 3, wherein the micro control circuit outputs the second according to a phase of a rotor of the motor when the motor control and the brake recharging system operate in a regenerative braking mode Pulse width modulation signal. The motor control and brake recharging system of claim 6, wherein the driving circuit outputs the first control signal according to the second pulse width modulation signal, and the first control signal is a boost command signal. The bidirectional conversion circuit is controlled to operate in a boost mode and to charge the energy storage unit. The motor control and brake recharging system according to claim 2, wherein the driving circuit is a half bridge driving circuit. The motor control and brake recharging system of claim 1, wherein the bidirectional conversion circuit is coupled between the rectifier circuit, the energy storage unit, and the control module and the driving power module, and the The bidirectional conversion circuit includes a first capacitor, a second capacitor, a first switching transistor, a second switching transistor, and an inductor, the first switching transistor is coupled to the first capacitor and the inductor, and the second switching transistor is coupled to the first Between the switching transistor and the inductor, the inductor is coupled between the first switching transistor and the second capacitor. The motor control and brake recharging system of claim 1, wherein the energy storage unit is coupled to the bidirectional conversion circuit, and the energy storage unit stores an electrical energy. The motor control and brake recharging system of claim 10, wherein the energy storage unit comprises a battery and a capacitor. The motor control and brake recharging system of claim 11, wherein the battery is connected in parallel with the capacitor. The motor control and brake recharging system of claim 1, wherein the driving power module comprises an insulated gate bipolar transistor. The motor control and brake recharging system of claim 1, wherein the motor is a DC brushless motor. The motor control and brake recharging system of claim 1, wherein the driving circuit is a half bridge driving circuit. The motor control and brake recharging system of claim 1, wherein the second control signal is a six-step square wave signal.