Through effective control strategy, the direct current provided by the power storage battery is converted into alternating current, and the forward and reverse rotation control of the motor is realized. In the deceleration/braking process, the alternating current generated by the motor is converted into direct current, which can be recycled to supply power to the battery, or provided to energy storage equipment such as super capacitors for secondary braking.
2. Drive motor?
An electrical device that converts electrical energy into mechanical energy and provides driving force for vehicle running. The device also has the function of converting mechanical energy into electrical energy.
3. Drive motor controller
The device for controlling the energy transfer between the power supply and the driving motor consists of a control signal port circuit, a driving motor control circuit and a driving circuit.
4.DC bus?
DC input device of voltage-driven motor system.
5. Rated voltage?
Nominal voltage of DC bus.
6. How much is maximum working voltage?
Maximum value of DC bus voltage.
7. Input and output characteristics
Represents the relationship between the parameters such as speed, torque and current of the drive motor, the drive motor controller or the drive motor system. The reduction of power, efficiency, voltage and price will be different.
8. Continuous torque?
The specified maximum and long-term working torque.
9. Sustained motivation
The specified maximum power for long-term operation.
10. Operating voltage range?
Can work normally in the voltage range.
1 1. Torque-speed characteristics?
The speed characteristic is generally a curve describing the frequency, and the torque characteristic is a curve to determine the maximum torque that the driving motor can achieve when the voltage rises, and it can work trouble-free for a short time.
12. peak torque motor
The adjoint product identifies the torque when the rotating speed of mechanical equipment is zero (locked).
13. Locking torque
High power, high efficiency and high brightness.
14. Maximum working speed?
Maximum speed at maximum power.
What are the characteristics requirements of electric vehicles for driving motors? Different from the traditional industrial drive motor, the drive motor of electric vehicle usually requires frequent starting and stopping, acceleration and deceleration, high torque at low speed/climbing, low torque at high speed and wide speed range.
The requirements of electric vehicles for two-seat children's motors with rated power for two years can be summarized as follows: In order to make full use of the limited on-board space and reduce the vehicle quality and energy consumption, the volume and mass of the driving motor should be reduced as much as possible. The driving motor can be made of aluminum alloy shell, and various control devices and cooling systems are also required to be as portable and miniaturized as possible.
1. High power density and light weight. Using high voltage as much as possible within the allowable range can reduce the size of the driving motor and the size of the controller, wires and other equipment, especially the cost of the inverter.
2. Full-speed and efficient operation-the cruising range of secondary charging is long, especially in the case of frequent start-stop or variable-speed operation of vehicles, the driving motor should have high efficiency.
3. Low speed, large torque, high speed and wide speed regulation Even if there is no transmission, the driving motor itself should be able to meet the required torque characteristics in order to obtain the power and torque requirements under various working conditions such as starting, accelerating, driving, decelerating and braking.
The driving motor should have the function of automatic speed regulation, which can reduce the driver's operation intensity, improve driving comfort and achieve the same control response as the traditional diesel locomotive. Compared with low-speed motor, high-speed drive motor has smaller volume and mass, which is beneficial to reduce the quality and comfort of vehicle equipment.
4。 High reliability, the driving motor should have high reliability under any working conditions to ensure the driving safety of the vehicle.
5. Safety performance: The working voltage of high-voltage components such as power storage battery and drive motor can reach above 300V, which puts forward higher requirements for the safety of electrical system and control system. The driving motor of new energy vehicles must meet the safety performance standards and regulations of relevant vehicle electrical control.
6. Low cost and low noise In order to reduce the use cost of new energy vehicles, the service life of the drive motor should be consistent with that of the vehicle, so as to truly achieve the goal of energy conservation and environmental protection. At the same time, the driving motor also requires good temperature resistance and moisture resistance, low operating noise, simple structure, low cost, suitable for mass production and convenient use and maintenance.
7. Energy recovery. The energy recovery system is of great significance for improving the energy utilization rate of electric vehicles. The requirements for driving motor and motor controller are higher.
Question guide 2:
What are the main types of driving motors?
Driving motors can be divided into two categories, namely, brushed motors and brushless motors. Traditionally, DC motor with commutator is simply called DC motor.
Because of its mature technology and simple control, DC motor once occupied a prominent position in the field of electric drive. In fact, all kinds of DC motors, including series excitation, shunt excitation and separate excitation, and permanent magnet DC motors have been used in electric vehicles, but their brushes and commutators need frequent maintenance and have low reliability, and are being replaced by AC brushless motors.
Commutatorless motors include asynchronous motors, permanent magnet synchronous motors, permanent magnet brushless motors and switched reluctance motors.
Commutatorless motor is obviously superior to traditional DC motor in efficiency, power density, operating cost and reliability, so it is widely used in modern electric vehicles. The driving motors are classified as follows:
Permanent magnet DC motor brush motor series excitation DC motor parallel excitation DC motor cage asynchronous motor wound rotor electric excitation brushless motor synchronous motor permanent magnet synchronous reluctance permanent magnet brushless motor switched reluctance motor.
Question guide 3:
How to choose the driving motor for new energy vehicles?
The key to the selection of driving motor for new energy vehicles is the mechanical characteristics of the motor.
Up to now, the main driving motors used in electric vehicles are: DC motor, AC asynchronous motor, permanent magnet synchronous motor, DC brushless motor and switched magnetic anode motor. Mechanical characteristics can be expressed by torque-speed characteristics and power-speed characteristics curves, which can be used as a reference for selecting motors.
When selecting a drive motor for a new energy vehicle, various required performance parameters can be put forward to the motor manufacturer as the basis for motor design. In fact, in most cases, manufacturers of new energy vehicles choose ready-made motors according to the technical performance parameters provided by the motor manufacturers.
There are many kinds of motors available for electric vehicles, and the power range is very large. New energy vehicles have higher requirements for the speed range, reliability and working ability of the driving motor in harsh environment.
1. Selection of rated voltage The selection of motor voltage is mainly based on the requirements of the overall parameters of the vehicle. Only after the self-weight of the vehicle and the related number of batteries are determined can the voltage and speed of the motor be determined, that is, when the self-weight of the vehicle is determined, the number of batteries is determined, and the voltage level of the motor is determined.
But the general requirement is to raise the voltage level as much as possible, so that the power and current of the motor can be reduced while meeting the driving requirements, and the capacity selection, installation space and installation mode of the battery are easier to handle.
2. Selection of Rated Speed According to the requirements of speed and power performance of electric vehicles, it is necessary to select driving motors with different speeds.
(1) low-speed motor?
The speed of the low-speed motor is 3000 ~ 6000 rpm. The low-speed motor in the extended constant power area has high rated torque, large rotor current, large motor size and mass, large corresponding frequency converter and controller, large loss of various electrical appliances, but small speed ratio of reducer.
Generally, low-speed motors have large moment of inertia and slow response, which is not suitable for electric vehicles.
(2) Medium speed motor
The speed of medium-speed motor is 6000 ~ 10000r/min, and its parameters are between low-speed motor and high-speed motor.
(3) high-speed motor?
The rotating speed of high-speed motor is 10000~ 15000r/min. The expanded constant power range is wider, the volume and mass are smaller, the corresponding converters and controllers are smaller, and the inherent losses of various electrical appliances are also smaller. However, the speed ratio of its reducer needs to be greatly improved, and planetary gear transmission mechanism is usually needed.
The use of high-speed motors is mainly limited by the performance of electromagnetic materials and the bearing capacity of high-speed bearings. Generally, high-speed motors have small moment of inertia, fast start and fast stop, and electric vehicles often use high-speed motors as driving motors.