How electric cars work

The composition of electric vehicles includes: electric drive and control systems, mechanical systems such as drive transmissions, and work devices for completing tasks. The electric drive and control system is the core of electric vehicles, and it is also different from the difference of internal combustion engine vehicles. The electric drive and control system consists of a speed control device that drives the motor, the power supply, and the motor. Other devices for electric vehicles are basically the same as those for internal combustion engines.
The power source supplies electrical energy to the drive motor of the electric vehicle, which converts the electrical energy of the power source into mechanical energy, through the transmission or directly drives the wheels and the working device. At present, the most widely used power source for electric vehicles is lead-acid batteries. However, with the development of electric vehicle technology, lead-acid batteries are gradually replaced by other batteries because of lower specific energy, slower charging speed and shorter life. The power sources being developed mainly include sodium-sulfur batteries, nickel-cadmium batteries, lithium batteries, fuel cells, flywheel batteries, etc. The application of these new power sources has opened up broad prospects for the development of electric vehicles.
The function of the drive motor drive motor is to convert the electrical energy of the power source into mechanical energy, through the transmission or directly drive the wheel and the working device. At present, DC series motor is widely used in electric vehicles. This type of motor has "soft" mechanical characteristics, which is in line with the driving characteristics of the car. However, due to the existence of reversing sparks, DC motors have lower specific power, lower efficiency, and large maintenance workload. With the development of motor technology and motor control technology, DC brushless motors (BLDCM) and switched reluctance motors are bound to be gradually adopted. (SRM) and AC asynchronous motor are replaced, such as the non-housing disc type axial magnetic field DC series excitation motor (patent application No. 6, inventor: Du Zhaohui).
Motor speed control device [electric vehicle charging]

The electric vehicle charging motor speed control device is provided for the shifting and direction change of the electric vehicle, and its function is to control the voltage or current of the motor to complete the control of the driving torque and the rotating direction of the motor.
In the early electric vehicles, the speed regulation of the DC motor was achieved by using a series resistor or changing the number of turns of the motor field coil. Because the speed regulation is stepped, and the additional energy consumption or the structure of the motor is complicated, it is rarely used. At present, the thyristor chopper speed regulation is widely used in electric vehicles, and the stepless speed regulation of the motor is realized 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 (into GTO, MOSFET, BTR and IGBT, etc.) chopper speed control devices. From the perspective of technological development, with the application of new drive motors, the application of electric vehicle speed control to DC inverter technology will become an inevitable trend.
In the rotation direction control of the drive motor, the DC motor relies on the contactor to change the direction of the current of the armature or the magnetic field, thereby realizing the direction change of the motor, which makes the circuit complicated and the reliability is lowered. When driven by an AC asynchronous motor, the change of the steering of the motor only needs to change the phase sequence of the three-phase current of the magnetic field, so that the control circuit can be simplified. In addition, the AC motor and its variable frequency speed control technology make the braking energy recovery control of the electric vehicle more convenient and the control circuit is simpler.
Transmission The role of the electric vehicle transmission is to transmit the drive torque of the electric motor to the drive shaft of the vehicle. When the electric wheel is used, most of the components of the transmission are often negligible. Since the electric motor can be started with load, the clutch of the conventional internal combustion engine car is not required on the electric vehicle. Since the direction of rotation of the drive motor can be changed by circuit control, the electric vehicle does not require reverse gear in the internal combustion engine. When the motor is steplessly regulated, the electric vehicle can ignore the transmission of the conventional car. When using an electric wheel drive, the electric vehicle can also omit the differential of the conventional internal combustion engine vehicle transmission system.
The function of the traveling device traveling device is to drive the driving torque of the electric motor to the ground through the wheel and drive the wheel to travel. It is identical to other car electric vehicles and consists of wheels, tires and suspensions.
The steering device steering device is provided for turning a car, and is composed of a steering gear, a steering wheel, a steering mechanism, and a steering wheel. The control force acting on the steering wheel deflects the steering wheel by a certain angle through the steering mechanism and the steering mechanism to realize the steering of the vehicle. Most electric vehicles are front-wheel steering, and electric forklifts used in industry often use rear-wheel steering. Electric vehicle steering gears include mechanical steering, hydraulic steering and hydraulic power steering.
Braking device The braking device of an electric vehicle, like other cars, is provided for deceleration or parking of the car, usually consisting of a brake and its operating device. In an electric vehicle, there is generally an electromagnetic brake device that can realize the power generation operation of the motor by using a control circuit for driving the motor, and convert the energy during the deceleration braking into a current for charging the battery, thereby being recycled.
The working device working device is specially designed for the industrial electric vehicle to complete the operation requirements, such as the lifting device, the door frame and the fork of the electric forklift. The lifting of the fork and the tilting of the gantry are usually done by a motor-driven hydraulic system.