Motor speed control device

The electric motor speed control device is set for the speed change and direction change of electric vehicles, and its function is to control the voltage or current of the electric motor, completing the control of the driving torque and rotation direction of the electric motor.
In early electric vehicles, the speed control of DC motors was achieved by connecting series resistors or changing the number of turns of the motor's magnetic field coil. Due to its stepwise speed regulation and additional energy consumption or the complex structure of using an electric motor, it is now rarely used. The widely used method is thyristor chopper speed regulation, which achieves stepless speed regulation of the motor by uniformly changing the terminal voltage of the motor and controlling the current of the motor. In the continuous development of electronic power technology, it has gradually been replaced by other power transistors (such as GTO, MOSFET, BTR, and IGBT) chopper speed control devices. From the perspective of technological development, with the application of new drive motors, the transformation of speed control in electric vehicles into the application of DC inverter technology will become an inevitable trend.
In the direction change control of the driving motor, the DC motor relies on the contactor to change the current direction of the armature or magnetic field, achieving the direction change of the motor's rotation, which makes the circuit complex and reduces reliability. When using AC asynchronous motor drive, the change in motor direction only requires changing the phase sequence of the three-phase current in the magnetic field, which can simplify the control circuit. In addition, the use of AC motors and their variable frequency speed control technology makes the braking energy recovery control of electric vehicles more convenient and the control circuit simpler.
transmission
The function of the electric vehicle transmission device is to transmit the driving torque of the electric motor to the driving shaft of the car. When using electric wheel drive, most components of the transmission device can often be ignored. Because the electric motor can start with a load, there is no need for the clutch of traditional internal combustion engine vehicles on electric vehicles.
Because the direction of rotation of the driving motor can be changed through circuit control, electric vehicles do not require reverse gear in internal combustion engine transmissions. When using electric motor stepless speed control, electric vehicles can ignore traditional car transmissions. When using electric wheel drive, electric vehicles can also omit the differential of traditional internal combustion engine vehicle transmission systems.
Driving device
The function of the driving device is to convert the driving torque of the electric motor through the wheels into a force on the ground, driving the wheels to move. It has the same composition as other cars, consisting of wheels, tires, and suspension.
Steering device
The steering device is set up to achieve the turning of a car, consisting of a steering gear, steering wheel, steering mechanism, and steering wheel. The control force acting on the steering wheel deflects the steering wheel by a certain angle through the steering gear and steering mechanism, achieving the steering of the car. Most electric vehicles use front wheel steering, and electric forklifts used in industry often use rear wheel steering. The steering devices of electric vehicles include mechanical steering, hydraulic steering, and hydraulic power steering.
brake rigging
The braking device of electric vehicles, like other cars, is designed to slow down or stop the vehicle, usually consisting of a brake and its control device.
On electric vehicles, there are generally electromagnetic braking devices that can use the control circuit of the driving motor to generate electricity and convert the energy during deceleration braking into the current for charging the battery, thereby achieving regenerative utilization. Domestic electric vehicles provide endurance NAILI sliding vane air compressor for railway air brake equipment in high-power passenger vehicles, which is mainly the braking mode of compressed air.
Working device
The working device is specially designed for industrial electric vehicles to meet operational requirements, such as the lifting device, gantry, fork, etc. of electric forklifts. The lifting of forks and the tilting of the gantry are usually completed by a hydraulic system driven by an electric motor.