JPH10225177A - Method and device for controlling brushless dc motor speed for electric motor car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for controlling a brushless DC motor speed for an electric motor car. SOLUTION: An accelerator signal 11 on an electric motor car is acquired and processed, this signal 11 is compared with a default voltage value of a brushless DC motor speed control device. In the case when signal voltage from an accelerator is smaller than this default voltage, the accelerator is returned to a 0(zero) position; in the case when the signal voltage is larger than the default voltage value, the accelerator is not returned to the 0 position. By combination of an interface circuit 6, signal processing circuit 7, brake drive circuit 8, reset circuit 9, current signal processing circuit 10, etc., when the accelerator is located in the 0 position, the speed control device of a brushless DC motor is operated by an energy regenerative brake mode. When the accelerator is not returned to the 0 position, the device is operated by a non-energy regenerative mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for controlling the speed of a brushless DC motor for an electric vehicle, and applies the speed control device for a brushless DC motor to an electric vehicle when traveling on different road conditions. By that
A relatively good ride feeling is obtained, and further efficiency and safety are obtained.

[0002]

2. Description of the Related Art A commonly used speed control device for a brushless DC motor has one pulse width modulation (PWM) circuit for speed control. A general brushless DC motor speed controller for electric vehicles has two types of pulse width modulation circuits in control modes. One of them is “limited unipolar pulse width modulation” (Li
This is called a “mitted Unipolar PWM” circuit, and the kinetic energy of the motor during deceleration is not reproduced on the DC power supply side (DC BUS), and the deceleration time is relatively long. The other is called "unipolar pulse width modulation" (Unipolar PWM) circuit, which regenerates the kinetic energy at the time of motor deceleration to the DC power supply side and shortens the deceleration time relatively.

[0003]

Now, let us take a motorcycle as an example. When the pulse width is modulated by the “unipolar pulse width modulation” circuit, when decelerating under normal driving conditions, there is a feeling of “crack” and the ride is not very good. However, when the pulse width is modulated by the "limited unipolar pulse width modulation" circuit, the riding feeling under normal driving conditions is relatively good, but kinetic energy is not regenerated on downhill, so it is not very safe. is not.

[0004] It is therefore an object of the present invention to provide a method and an apparatus which meet the above two requirements. In other words, an object of the present invention is to provide a speed control method and apparatus for a brushless DC motor for an electric vehicle, which can provide a relatively good ride feeling and further efficiency and safety even when traveling on different road surface conditions. I do.

[0005]

SUMMARY OF THE INVENTION A method of controlling the speed of a brushless DC motor for an electric vehicle according to the present invention uses a signal of an accelerator on the electric vehicle to process the signal and to provide a default value for the speed control device of the brushless DC motor. Compare the voltage values. If the accelerator signal voltage is less than the default voltage value, the accelerator is said to have returned to the zero position, and if the accelerator signal voltage is greater than the default voltage value, the accelerator is not said to have returned to the zero position. When the accelerator on the electric vehicle is returning to the zero position, the speed controller of the brushless DC motor is operated in the energy regeneration brake mode. And
When the accelerator on the electric vehicle has not returned to the zero position, it operates in the non-energy regeneration mode.

The speed controller for a brushless DC motor for an electric vehicle according to the present invention receives a signal of a rotor position detector and a signal of an accelerator of the brushless DC motor through an interface circuit, processes the signal, and inputs the processed signal to a signal processing circuit. Such an analog signal is converted into a digital signal through a microcontroller, and a numerical value is determined. The phase is determined based on the rectified signal, and an appropriate duty cycle and a waveform are sent out again. After amplifying the control signal through the brake driving circuit, the inverter is operated. If this speed control device for a brushless DC motor is applied to an electric vehicle when traveling on different road conditions, a relatively good ride feeling, further efficiency and safety can be obtained.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a main circuit diagram of a speed control device of a general brushless DC motor for an electric vehicle. One of them is a battery, 2 is a capacitor, 3 is a current detector, and T1 to T6 are one inverter (Inverter) 4 by the combination of power devices, thereby controlling the brushless DC motor 5. I do.

FIG. 2 shows a diagram of a brushless DC motor speed control apparatus according to the present invention. The interface circuit 6, the signal processing circuit 7, the brake driving circuit 8, the reset circuit 9, the current signal processing circuit 10, etc. It consists of. First, the signal 11 of the accelerator and the signal 12 of the rotor position detector are input to the interface circuit 6 and processed. After processing, the accelerator signal 11 becomes a command signal 14, and the rotor position detector signal 12 is raised (Pull signal).
High), after low-frequency filtering circuit processing, HAPS, HBP
It becomes a rectified signal 15 such as S or HCPS. These two signals 14 and 15 are processed again by the signal processing circuit 7, and after converting the analog / digital signal and judging the numerical value, the reproduced driving signal 16 of the next level is sent to the brake driving circuit 8 again. Amplify, and finally, this
Is sent to the inverter 4 to operate the inverter 4. In addition, the reset circuit 9 resets the signal processing circuit 7. When the signal processing circuit 7 employs a microcontroller, the microcontroller is immediately reset and the execution of the control program is started. Then, the current signal processing circuit 10 has a function of receiving the current detection signal 13 and protecting the passing current. Inverter 4
This protects the above-mentioned rate-of-work devices T1 to T6.

As shown in FIG. 3, a commutation signal of a rotor position sensor of a brushless DC motor is indicated by HA, HB, and HC. In order to clarify the relationship between the rectified signal and the inverter drive signal according to the present invention, it can be understood from the phase diagrams of FIGS. 4 and 5. When the accelerator has not returned to the zero position, it operates in "non-energy regeneration mode" (as shown in FIG. 4). When the method of "limited unipolar pulse width modulation" is adopted, T1, T2, and T3 of the inverter 4 therein are controlled to pulse width modulation signals. When the accelerator returns to the 0 position, it operates in the "energy regeneration brake mode" (as shown in FIG. 5). The anti-potential at the time of rotation of the brushless DC motor is determined by the T in the switching inverter 4 having a constant frequency (Constant Frequency) and a constant efficiency cycle (Constant Duty).
4. Regenerate energy to the DC power supply side by three of T5 and T6.

FIGS. 6 to 10 are circuit diagrams of a speed control device for a brushless DC motor according to an embodiment of the present invention. At the same time, referring to the diagram of FIG. 2, the present device converts the rectified signal 12 of the rotor position detector of the brushless DC motor.
Import to HA, HB, HC, RP2 of interface circuit 6
A, RP2B, RP2C signal pull up (Pull High) and R27,
After being composed of R28 and R29 and C24, C25 and C26, they pass through a low-frequency filtering circuit and become rectified signals 15 such as HAPS, HBPS and HCPS. Again, this HAPS, HBPS, HCPS rectified signal 15
Is input to the signal processing circuit 7. Ie microcontroller
This is the input point of U14. After the accelerator (that is, throttle position sensor TPS, Throttle Position Sensor) signal 11 is processed by the interface 6, it becomes a command signal VC14.
This command signal 14 again receives the input protection of the dipoles D5 and D6 before entering the analog / digital converter input of the microcontroller U4. The signal processing circuit 7 is INTEL N8.
7C196MC is adopted and the embedded microcontroller U4 (Em
bedded Micro-controller). And it has an internal analog / digital converter (A / D Converter) and a waveform reproducer (Waveform Generator). The analog / digital converter converts the analog signal sent from the accelerator into a digital signal, and this signal is used in "non-energy regeneration mode" or "energy regeneration brake mode".
Make a decision to enter. This determination method is completed by the interrupt subprogram of the microcontroller. First, the speed controller of the brushless DC motor reads the analog signal of the accelerator, converts the signal into a digital signal, and compares it with the default digital voltage value again. If the digital value of the accelerator signal is less than the default voltage value, the accelerator is considered to have returned to the 0 position and the "energy regeneration brake mode" is entered at this time. The pulse width modulated signal is a switching inverter with a constant frequency and a constant efficiency cycle. If the digital value of the accelerator signal is greater than the default voltage value, it is assumed that the accelerator has not returned to the zero position and the "non-energy regeneration mode" is entered at this time. The efficiency cycle of the pulse width modulated signal is proportional to the magnitude of the accelerator analog signal voltage. The operation of the waveform regenerator can also control the inverter 4 with a waveform that is appropriate for regeneration and operate it in "non-energy regeneration mode" and "energy regeneration brake mode". Command signal VC14 and HAPS,
The rectified signal 15 of HBPS and HCPS is processed by the signal processing circuit 7, and then becomes a drive signal 16 of the next level. It's UU,
The drive signals are divided into six drive signals UD, VU, VD, WU, and WD, and are separately input into the brake drive circuit 8. Equipment in it
IR2110 (that is, U3, U5, U7) is a buffer circuit (Buffer), and amplifies the next level drive signal 16 of the signal processing circuit 7. After the drive signal 16 at this level is processed by the brake drive circuit 8, the drive signal 17 (ie, BU, E
U, BX, EX, BV, EV, BY, EY, BW, EW, BZ, EZ, etc.). The inverter 4 is operated by this signal. The reset circuit 9 starts executing the program of the microcontroller U4. Another current signal processing circuit 10 has a function of receiving the current detection signal and protecting the current passing therethrough. This protects the engineering devices T1 to T6 on the inverter. However, it is an operation of a well-known technique, and it can be achieved by a combination of various circuits to achieve its specific effect, but it is not the emphasis that the present invention seeks to address and will not be described further here.

The microcontroller (U4) has one interrupt subprogram of the waveform reproducer WG COUNTER ISR inside. The digital value of the accelerator is mainly read to determine whether to enter the “non-energy regeneration mode” or the “energy regeneration brake mode”. Then, according to the phase judgment of the rectified signal, an appropriate efficiency cycle and waveform are sent again to control the inverter 4. In the present invention, the operation flowchart shown in FIGS. First, after the interrupt subprogram captures the amplitude value, it is determined whether the voltage value of the input signal is not smaller than 0.7V or not equal. If the voltage is 0.7 V or less, the accelerator is considered to have returned to the 0 position, and the "energy regeneration brake mode" is entered at this time (as shown in FIG. 12). The pulse width modulated signal is a switching inverter with a constant frequency and a constant efficiency cycle. At this time, the amplitude is a constant value N2, and then the value of the rectified signal PORT2 is read to determine which phase it is at this time. If it is the first phase, WG COMPARE1 is equal to the amplitude value and the WG OUTPUT value is a 0105H constant value. At this time, an operation corresponding to the set value of the interrupt subprogram is performed. If the phase is not the first phase, it is determined whether the phase is the second phase, and the program continues to determine in the same manner, and the analogy is made based on this. Each different phase has its own WG OUTPU
There is a T value and each different WG OUTPUT value represents its corresponding operation. If the voltage value of the input signal is larger than 0.7 V, the operation enters the “non-energy regeneration mode” (FIG. 1).
3). The efficiency cycle of the pulse width modulated signal is proportional to the magnitude of the accelerator analog signal voltage. The amplitude at this time is a value obtained by subtracting the base value N1 from the amplitude (amplitude = amplitude−N1). Next, the value of the rectified signal PORT2 is read, and at this time it is determined which phase it is. If it is the first phase, WG COMPARE1 is equal to the amplitude value and WG OUTPUT
The value is a 0106H constant value. At this time, an operation corresponding to the set value of the interrupt subprogram is performed. If the phase is not the first phase, it is determined whether the phase is the second phase, and the program continues to determine in the same manner, and the analogy is made based on this. Each different phase has a respective WG OUTPUT value, and each different WG OUTPUT value represents a respective corresponding operation. Therefore, the speed control of the brushless DC motor for an electric vehicle can be operated and switched under one of these two modes. Of course, the invention is not limited to taking and processing accelerator signals, but any use of, for example, a brake signal on an electric vehicle or a single-blade switch can be applied in the method of the invention.

In summary, the "speed control method and apparatus for a brushless DC motor for an electric vehicle" of the present invention solves the drawbacks of the prior art, presents an effective solution, and is convenient for many consumers. Gives sex and practicality. Although the embodiments of the present invention have been described in detail, the above is only a comparatively excellent embodiment of the present invention, and cannot limit the scope of the present invention. All equivalent variations and decorations from the claims filed by the present invention should be included within the scope of the present patent.

[Brief description of the drawings]

FIG. 1 is a main circuit diagram of a general brushless DC motor speed control device.

FIG. 2 is a diagram of a speed control device for a brushless DC motor according to the present invention.

FIG. 3 is an explanatory diagram of a rectified signal of a rotor position detector of the brushless DC motor of the present invention.

FIG. 4 is a relationship diagram between a rectified signal and an inverter drive signal according to the present invention.

FIG. 5 is a relationship diagram between a rectified signal and a drive signal of an inverter according to the present invention.

FIG. 6 is a diagram showing a part of a circuit diagram of a speed control device of the brushless DC motor of the present invention.

FIG. 7 is a diagram showing a part of a circuit diagram of a speed control device for a brushless DC motor of the present invention.

FIG. 8 is a diagram showing a part of a circuit diagram of a speed control device for a brushless DC motor of the present invention.

FIG. 9 is a diagram showing a part of a circuit diagram of a speed control device for a brushless DC motor of the present invention.

FIG. 10 is a circuit diagram of a speed control device for a brushless DC motor according to the present invention.

FIG. 11 is a flowchart for determining an interrupt sub-program of a waveform reproducer (WG COUNTER) inside the microcontroller of the present invention.

FIG. 12 is an operation flowchart of an interrupt subprogram “energy regeneration brake mode” of a waveform regenerator (WG COUNTER) in the microcontroller of the present invention.

FIG. 13 is an operation flowchart of an interrupt subprogram “non-energy regeneration mode” of the waveform reproducer (WG COUNTER) in the microcontroller of the present invention.

[Explanation of symbols]

 Reference Signs List 6 Interface circuit 7 Signal processing circuit 8 Brake drive circuit 9 Reset circuit 10 Current signal processing circuit 11 Accelerator signal 12 Rotor position detector signal 13 Current detection signal 14 Command signal 15 Rectification signal 16 Drive signal 17 Efficiency device drive signal

Claims (5)

[Claims] 1. A method for controlling the speed of a brushless DC motor for an electric vehicle, comprising the following steps (1), (2), and (3). (1) Take the signal voltage of the accelerator on the electric vehicle, compare it with the default voltage value of the speed control device of the brushless DC motor, and when the signal voltage of the accelerator is smaller than the default voltage value, return the accelerator to position 0. When the signal voltage of the accelerator is higher than the default voltage value, it is considered that the accelerator has not returned to the zero position. (2) When the accelerator is returning to the zero position, the speed controller of the brushless DC motor operates in the energy regeneration brake mode. (3) When the accelerator has not returned to the zero position, the speed controller of the brushless DC motor operates in the non-energy regeneration mode. 2. An interface circuit, a signal processing circuit,
The interface circuit includes a brake drive circuit and a reset circuit. The interface circuit receives and processes the rectified signal and the accelerator signal with the rotor position detector of the brushless DC motor, and then inputs the processed signal to the signal processing circuit. Is converted into a digital signal, and this signal is used to determine whether to enter the "non-energy regeneration mode" or the "energy regeneration brake mode". The speed control of the brushless DC motor for an electric vehicle is characterized in that a feed circuit, a brake drive circuit, a buffer circuit, amplify a control signal of the signal processing circuit and operate an inverter, and a reset circuit resets the signal processing circuit. apparatus. 3. The brushless DC motor for an electric vehicle according to claim 2, wherein said signal processing circuit employs a microcontroller and has an analog / digital converter and a waveform reproducer therein. Speed control device. 4. The speed control method for a brushless DC motor for an electric vehicle according to claim 1, wherein the signal of the accelerator can be replaced with a brake signal or a single blade switch. 5. The speed control method for a brushless DC motor for an electric vehicle according to claim 1, wherein the control mode switching between the non-energy regeneration mode and the energy regeneration brake mode is achieved by a software program.