Electric vehicle controller fault repair

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By measuring the power supply voltage or signal voltage of the electric vehicle controller connecting component line, it can be analyzed and judged that the electric vehicle controller is repeated three times. The following are the detection and troubleshooting methods for common controller faults.

1. The power supply of the electric vehicle brush controller control unit is abnormal.

The internal power supply of the electric vehicle controller generally adopts a three-terminal voltage regulator integrated circuit, generally using 7805, 7806, 7812, 7815 three-terminal voltage regulator integrated circuits, and their output voltages are 5V, 6V, 12V, 15V, respectively. Set the multimeter to the DC voltage +20V (DC) position, and place the multimeter black and red pens on the black and red lines of the handle respectively to observe whether the multimeter readings match the nominal voltage, and the voltage difference between them should not be More than 0.2V. Otherwise, the controller's internal power supply has failed. Generally, the brush controller can eliminate the fault by replacing the three-terminal voltage regulator integrated circuit.

Second, the electric car brush controller has no output

Set the multimeter to the +20 (DC) position and measure the high and low potentials of the brake output signal. If the brake lever has a potential change of more than 4V when the brake is applied, the brake will be eliminated. Then, according to the common function of the brush controller, the circuit analysis is performed with the measured voltage value of the master control logic chip, and the values ​​of the peripheral devices (resistors, capacitors, diodes) of each chip and the component surface are checked. The identification is consistent, checking for failure of peripheral devices or integrated circuits. We can troubleshoot by replacing the same type of device.

Third, the electric vehicle brushless controller lacks phase

The failure of the brushless controller power supply and the brake lever of the electric vehicle can be ruled out by referring to the troubleshooting method of the brush controller. For the brushless controller, there are also unique fault phenomena, such as phase loss. The phase loss phenomenon of the brushless controller of electric vehicles can be divided into two cases: main phase phase loss and Hall phase loss.

The detection method of the main phase phase loss can refer to the electric vehicle brush controller flying vehicle fault elimination method to detect whether the MOS tube breaks down. The brushless controller MOS tube breakdown is generally a pair of upper and lower MOS tubes of a certain phase simultaneously Wear and replace when making replacement. Check the measurement points.

The Hall phase of the electric vehicle brushless controller shows that the controller cannot recognize the motor Hall signal. The detection method is: unplug the controller and the brushless motor's Hall lead. When the controller is powered on, use the multimeter's +20V DC (DC) file and place the black test lead on the black line of the controller's Hall lead. The red meter pen measures the controller's other Hall leads. There should be a voltage above +5V, otherwise the controller's internal Hall output circuit will be faulty. The fault location is further determined by measuring the filter capacitance of the Hall lead and the corresponding pin of the main control. Replace the filter capacitor or replace the main control chip to eliminate the fault.

The voltage comparison method is used to measure the voltage of each marked point to determine the specific component that causes the phase loss fault.

Fourth, the electric vehicle brushless controller has no output at all.

Refer to the main phase check measurement diagram of the brushless motor controller, and use the multimeter DC voltage +50V file to detect whether the gate voltage of the 6-way MOS transistor is corresponding to the rotation angle of the turntable. If not, it means that the PWM circuit or MOS tube drive circuit in the controller is faulty. Referring to the main phase check chart of the brushless controller, it is determined whether the voltage of the input/output pin of the chip has a corresponding relationship with the rotation angle of the switch, and it can be determined which chips are faulty. Replace the same type of chip to eliminate the fault.

Five, speed

Flying faults are generally caused by MOS tube breakdown. When judging whether the MOS tube is good or bad, the three pins of the MOS tube can be measured by the diode position of the multimeter, and there should be no short circuit. If the MOS tube is damaged, you can troubleshoot by replacing the same type of device.

Sixth, circuit components replacement methods and precautions

When it is detected that the integrated circuit and the MOS transistor are damaged, it is necessary to replace the integrated circuit and the MOS transistor. Here's a look at the common methods of operation:

1, disassemble the integrated circuit

When disassembling, use an alcohol lamp flame outer flame to heat the printed circuit board to solder the integrated circuit pin pads, and quickly and evenly move the printed circuit board until the solder of all the pads melts, and the integrated circuit is removed from the printed circuit board with tweezers. When soldering, clean the solder in the soldering hole, insert the integrated circuit, and quickly solder the pins with a well-grounded soldering iron. Be careful not to cause excessive local soldering time and damage to the circuit or pad due to long soldering time.

2, disassemble the power device

When disassembling, the MOS tube or three-terminal regulator is cut and then soldered to their pins, which avoids damage to the printed circuit board pads when removing large pin components.

3, welding integrated circuits, power devices

After disassembling the integrated circuit and the power tube, the pads are cleaned, the excess solder is removed, and the pads are exposed. After inserting the integrated circuit and the power device into the corresponding position, solder the solder and the corresponding pad with a soldering iron of 30 W or less. Note that when soldering, it is best to solder it once. The soldering iron is sprinkled on a pin for too long, so that heat is not transmitted to the inside of the component and the internal circuit of the component is damaged.