The starting, running, accelerating, decelerating and stopping of the electric vehicle motor are all controlled by the controller. Therefore, the controller of the range extender, similar to the human brain, is the core component of the electric vehicle, and its performance and quality determine the overall performance of the electric vehicle.
Regardless of whether there is a brush controller or a brushless controller, it must have the main function to ensure the normal running and working of the electric vehicle.
1. Speed regulation function
Turning the speed control handle during operation can change the output voltage of the Hall sensor or the viewpoint sensor, so that the stepless speed control of the electric vehicle can be realized as required.
2. Power off brake function
Contact switches (mechanical or electronic) are installed on both caliper brake handlebars on the handlebars of electric vehicles. When the electric vehicle brakes, the switch is pushed to close or open to change the original switch state. The high (or low) level signal formed by the number is sent to the control circuit, and the circuit sends out instructions according to the preset program; immediately cuts off the gate (or base) driving current of the function switch tube, so that the power tube is turned off and stops the operation of the motor. Power supply, realize first power off and then brake.
3. Undervoltage protection function
In order to ensure the normal charge and discharge of the battery and prolong the service life of the battery, the range extender controller scheme, in the load state first, when the battery reaches the post-discharge stage, the battery voltage is close to the discharge termination voltage, Anhui range extender controller, controller panel ( or the instrument display panel) that shows insufficient power, reminding the rider to pay attention to the continuous formation of polarization. When the battery voltage reaches the end-of-discharge voltage (24v battery is 21v, 36v battery is 31.5v, 48v battery is 41v), the voltage sampling resistor will input the separation information to the comparator, and the under-voltage protection current will issue a command according to the preset program, The electric motor is powered off and does not work, and the protection of electronic devices and power supply (battery) is realized.
4. Overcurrent protection function
When the current flowing through the DC electric vehicle or a series of components in the circuit exceeds a certain value for some reason, the current will cause damage or even burn, which should be avoided. In the controller circuit, all should have this overcurrent protection function, that is, when the overcurrent occurs, the power supply will be cut off after a certain delay.
5. Overload protection function
Overload protection and overcurrent protection are the same, overweight will inevitably cause the current to exceed the limit. The overweight capacity is specially indicated in the manual of the electric vehicle. If the rider does not pay attention to it, or deliberately overloads with the intention of trying it out, if the controller does not have this protection function, a certain link will be damaged due to excessive current. , the first to be damaged will be the power switch tube. The function switch tube is damaged, and the brushed motor loses its control function; the power switch tube of the brushless controller burns out, and the brushless motor becomes powerless after it becomes a two-phase power supply, and the rider immediately feels abnormal pulsation. If you continue to ride, the second and third power switch tubes will be burned out. If the two-phase power switch tube is burned, the brushless electric vehicle stops running. It can be seen that overcurrent caused by overload is very dangerous. After the controller has set the over-current protection and overload over-limit protection circuits, once the circuit current exceeds the preset value, it will automatically cut off the power supply.
6. Speed limit protection function
The specified speed of the electric vehicle does not exceed 20km/h. The rated speed of the electric vehicle has been set during the design, and the control current has also been designed. The electric vehicle runs intelligently under the state of not exceeding this speed. When the speed of the electric vehicle exceeds the set value, the speed limit protection circuit of the controller immediately cuts off the battery supply circuit to ensure driving safety.
7. Display function
In order to keep abreast of the instantaneous state of the motor, battery and vehicle body, and to ensure the safe and reliable operation of the electric vehicle, the controllers all have corresponding display functions. Economical electric vehicles are equipped with light-emitting diodes to display the remaining power of the battery, while luxury electric vehicles use liquid crystal displays or related instruments to display the remaining battery power and driving speed.