CN2376398Y - Electric vehicle controller - Google Patents

Abstract

The utility model discloses a controller for an electric vehicle, which relates to a uniform-speed linear starting control technology for an electric vehicle. In order to solve the problems of sudden jump in speed, excessive instantaneous current and damage to the battery when starting with ordinary controllers, a constant speed linear starting controller is provided. For this reason, the utility model utilizes an integrated operational amplifier for multiple given voltage integral operations, and controls the pulse width to increase linearly from narrow to wide, thereby reducing the starting impulse current and increasing the motor speed linearly. It is composed of proportional integral operational amplifier, pulse width modulator, power switch tube and so on. Because the motor can be started linearly at a constant speed, the starting current can be reduced, the mileage can be increased, and the purpose of preventing interference and misoperation can be achieved, so it has a broad application prospect.

Description

An electric vehicle controller

The utility model relates to a uniform-speed linear starting control technology for electric vehicles (including electric scooters and electric tricycles).

At present, the starting of electric vehicles generally adopts pulse width modulation technology or pulse frequency modulation technology. During its starting process, due to the sudden increase of the given signal, the pulse width increases too fast. And because the armature winding resistance of the DC motor is very small, the motor speed is zero at the moment of starting. If the pulse width increases too fast at this time, the motor will start at zero speed and full voltage. As a result, the starting current of the electric vehicle is too large, the battery is damaged, the speed suddenly jumps, and the riding is uncomfortable.

The purpose of this utility model is to solve the technical problems of sudden jump in speed and excessive instantaneous current when ordinary controllers start, and damage the battery, and provide a controller for electric vehicles with uniform-speed linear start control, so that the starting current of electric vehicles can be reduced during the starting process of electric vehicles. It is greatly reduced, the speed does not jump suddenly, the riding is comfortable, the driving range is increased, and the battery is protected.

In order to achieve the above object, the utility model adopts the following technical measures:

It can be seen from the basic equation of the DC motor that when the electric vehicle starts, because the speed W is zero, its back electromotive force E is also zero. Since the armature winding resistance of the DC motor is very small, if the rated voltage is directly applied to both ends of the armature at this time, the starting current often greatly exceeds the allowable current of the motor, which seriously threatens the service life of the DC motor; When starting the motor, a variable resistor is often connected in series in the armature circuit. When starting the motor, the resistance value changes from large to small, so that the motor starts and accelerates at a constant speed. However, it is obviously unreasonable to use this method on electric vehicles that rely on storage batteries as the main energy source. At present, the PWM adjustment scheme is widely used, and the adjustment handle is gradually rotated slowly, and the PWM pulse width value is gradually changed from narrow to wide, so as to achieve the purpose of starting and accelerating at a constant speed. This is theoretically feasible, but the actual situation is not the case. The user often turns the speed control handle to the highest speed in a short period of time after opening the switch of the electric vehicle, (because the maximum rotation angle of the speed control handle is ≤60°, this is an inherent motorcycle operating habit and is also a practical operation It is necessary, and at the same time, it is impossible to require each operator to slowly and linearly rotate the operating handle when starting) to cause the motor to accelerate and start suddenly, and the current is too large.

The utility model utilizes an integrated operational amplifier to perform multiple integral operations of a given voltage, and the control pulse width increases linearly from narrow to wide, thereby reducing the starting impulse current and increasing the motor speed linearly. Even if the rider turns the speed control handle to the highest speed in a short period of time, the motor can only gradually rise from zero speed to the rated speed at the start, achieving the purpose of small starting current, large torque, stable operation and comfortable riding .

Compared with the prior art, the utility model has the following advantages and effects:

The starting current of the electric vehicle is reduced. Since the braking and starting of the electric vehicle are very frequent in the actual process, according to the statistical data of the electric bicycle road mileage competition at the "Second National Electric Bicycle Information Exchange Conference", the electric vehicle is in the During driving, every time the car is started, the driving distance will be reduced by 1 km on average. If the starting current can be reduced, the mileage will undoubtedly be increased, and at the same time, the battery will be better protected. Under the same vehicle, same battery, and same load conditions, we have done the following experiments, and the data are as follows:

Different electric vehicle starting current test report Category car Original car no-load starting current No-load starting current of the utility model Original car load starting current Starting condition of the original vehicle load The load starting current of the utility model Load starting condition of the utility model Ningbo "Huajia" electric bicycle 6A 2.5A 20A Speed jump, powerful start 9A Uniform and powerful Guangxi "Magway" electric bicycle 8A 2.2A 12A It is difficult to start, and the speed suddenly jumps after being unable to overcome the resistance torque. 8A Uniform and powerful Note: ①. Guangxi "Magway" electric bicycle has a current-limiting control when starting with load. Therefore, the load starting current is not very large, but it is difficult to start and weak to climb.

②. Experiment time: April 3, 1999, place: Wuhan Side Control Technology Co., Ltd.

③ Measuring instruments: DC10A1.5 level (for no-load starting current test), DC 30A1.5 level (for load starting current test).

Describe in detail below in conjunction with accompanying drawing:

Fig. 1 is a schematic diagram of the circuit structure of the utility model, and Fig. 2 is a waveform diagram related to LC3.

Among them: IC1-proportional integral operational amplifier, IC3-pulse width modulator, BG1-power switch tube, R-resistor, C-capacitor, W-potentiometer, E1, E2-battery, VCC-power supply, GND-ground, M -Motor, 1-linearly increasing pulse width, 2-ΔV gradually linearly increasing DC voltage through two integrations, 3-sawtooth wave output by pin 9 of IC3.

It can be seen from Fig. 1 that the utility model is mainly composed of a proportional integral operational amplifier IC1, a pulse width modulator IC3 and a power switch tube BG1. Pin 1 of proportional-integral operational amplifier IC1 is connected to pin 1 of sawtooth oscillator IC3 through R5, R10. Pin 9 of the pulse width modulator IC3 is connected to the base of the power switch tube BG1.

The upper end of the resistor R1 is connected to the VCC power supply, and the lower end of the speed regulating potentiometer W1 is connected to the GND. The voltage division ratio between R1 and W1 is the given speed voltage, and the speed of the electric vehicle can be adjusted by adjusting W1. Its given voltage is connected to IC1 through R2: pin 3 of the non-inverting terminal of A-LM324, R4 and C1 are connected in parallel between pin 2 and pin 1 of LM324, and R3 is a proportional resistor, which is also connected to pin 2 of LM324. Adjust the resistance value of W1, the non-inverting input voltage of LM324 increases, through IC1: A and R4, C1, R3 for proportional integral operation amplification, the output voltage of pin 1 gradually increases, because the left end of R5 is connected to pin 1 of LM324, R5's The right terminal is connected to the positive pole of C2, the negative pole of C2 is connected to GND, and the integral voltage output by pin 1 of LM324 is RC integrated through R5 and C2, which avoids the malfunction of signals such as interference and improves the reliability. R6 is connected, and the lower end of R6 is also connected to GND, which controls the highest amplitude of the output voltage, and R10 is also connected to the right end of R5.

R10 is connected to pin 1 of IC3 sawtooth oscillator and pulse width modulator ASIC TL494, pin 2 of TL494 is connected to R9, pin 3 is connected to integrating capacitor C3 and R11, the left end of C3 is connected in series with R8, and the left end of R8 Connected with R9, R7. Pin 1 of TL494 is the non-inverting input terminal of the internal error amplifier, pin 3 is the feedback terminal of the internal error amplifier, pin 2 is the inverting input terminal of the internal error amplifier, the non-inverting voltage integration operation is formed through R9, R8, and C3, and R7 is a proportional Resistor, the lower end is grounded. In this way, the voltage signal sent by R10 after the previous two integrations will be integrated again, and its slow linear growth DC voltage will be compared with the sawtooth wave voltage generated inside TL494. Pin outputs a sawtooth wave oscillator signal that increases slowly and linearly (see Figure 2), controls the conduction ratio of the BG1 power switch transistor, and makes the voltage obtained by the motor M gradually increase slowly, so that the starting current is small, the speed increases linearly and uniformly, and the operation is stable. the goal of.

In Figure 1, C4 and R12 are respectively connected to pin 5 and pin 6 of IC3-TL494. The main function is to adjust the frequency and slope of the sawtooth oscillator IC3. The upper end and pin 15 of TL494 are connected to the right end of C5, the left end of C5 is connected to R11, and the left end of R11 is also connected to pin 3 of the feedback terminal. The main functions of R13 and R14 are the output voltage of the voltage divider, which form an integral operation with R11 and C5, and are ready to receive the fault protection signal sent to pin 16 of IC3 at any time. When the protection signal is sent to pin 16 of TL494, it will be closed immediately The 9-pin output pulse of IC3 prevents the expansion of the accident.

A multi-integral control scheme and a practical circuit are used for the starting of an electric vehicle, which can obtain a linear start of the motor at a uniform speed, reduce the starting current, increase the driving range, and prevent interference from malfunctioning.

Claims (3)

1, a kind of controller for electric vehicle is characterized in that it is made up of proportional integral (PI) op amp (IC1), pulse width modulator (IC3) and power switch pipe (BG1); 1 pin of proportional integral (PI) op amp (IC1) links to each other by 1 pin of R5, R10 and pulse width modulator (IC3); 9 pin of pulse width modulator (IC3) link to each other with the base stage of power switch pipe (BG1).

2, by the described a kind of controller for electric vehicle of claim 1, it is characterized in that be connected in parallel between 2 pin of proportional integral (PI) op amp (IC1) and 1 pin R4, C1, its 2 pin has also connected proportion resistor R3; Its 1 pin also links to each other with 5 pin of pulse width modulator (IC3) by R5, C2, C4.

3, by the described a kind of controller for electric vehicle of claim 1, it is characterized in that 3 pin of pulse width modulator (IC3) are connected to integrating capacitor C3 and R8,2 pin are connected to R9.

Images