1、1Research on Electric Vehicle Motor Control Technology Based on Non-SensorAbstract: In the concept of energy-saving, emission reduction and green environmental protection idea, electric cars emerge as the times require. Its appearance makes the driving system of vehicle change from the original fuel
2、 engine into electric energy, which can be regarded as the milepost of automobile manufacturing industry. The promotion and usage of electric vehicle not only greatly reduces fuel consumption, but also further reduces the pollution of the environment. In the electric vehicle research and development
3、 process, the motor control is a key technology; and the previous designs adopted the sensor technology. Although this method is simple and convenient, yet the sensor increases the cost, but also influences the reliability of the control system. Therefore, it is necessary to explore a motor sensorle
4、ss control technology. Based on this point, this paper makes a research on electric vehicle motor control technology based on non-sensor. Keywords: electric vehicle; non-sensor technology; permanent magnet synchronous motor; 21. The research significance of non-sensor motor control of electric vehic
5、le In the background of global energy crisis and the increasingly serious environmental pollution, it puts forward new requirements for modern automobile manufacturing industry, which makes the domestic and foreign fields increase the new energy automotive research and development efforts, and the e
6、lectric car is the product in this context. According to the power source of electric vehicles, it can be divided into three types: pure electric, hybrid and fuel cell. Pure electric vehicle takes electrical energy as the main driving force. Therefore, the traction motor is the key part of the entir
7、e electric vehicle, and the key technology of traction motor control strategy in the process of testing the development of electric cars is the fundamental guarantee to further improve electric vehicle drive performance and overall vehicle reliability. China has a vast territory and abundant resourc
8、es, with rich rare earth resources, which greatly promotes the development and application of rare earth permanent magnet motor. Compared with the asynchronous motor, permanent magnet synchronous motor doesnt need non power excitation current, and the power factor is relatively high, 3without rotor
9、copper loss during the operation, and it can keep higher operation efficiency. It is because of these advantages of permanent magnet synchronous motor that is widely used in pure electric vehicle manufacturing, which has achieved good results. Typically, the permanent magnet synchronous motor are mo
10、stly used in vector control system, and changes of coordinates in the system, through the use of position signal, obtain the rotor to realize the electric drive current vector and the rotor magnetic field direction orthogonal in space, so as to produce the maximum electromagnetic torque. Therefore,
11、to obtain accurate rotor position is the key to control the permanent magnet synchronous motor. With the continuous development and improvement of sensor technology, the application range of the sensor is wider, which can use the sensor to make accurate location of the rotor position, and also can d
12、etect the speed, thus simplifying the design of motor control system to a certain extent. 2Research status of non sensor technology Sensorless technology specifically refers to the mathematical model of the motor and the detected motor current, voltage and other data, to estimate the rotor position
13、of motor. The most significant advantage of this technology is not need 4to make reform for the motor, and it doesnt need to configure the expensive sensor. Influenced by bad working environment, the operation and maintenance cost is greatly reduced. Since 1970s, some developed countries abroad cond
14、uct profound and specific research on non-sensor AC speed control system, and the slip frequency estimation method was proposed at that time. This method speed range can reach 10:1, but because it takes steady-state equation as the core, the speed range is relatively small. Since then, scholars can
15、use method of rotor tooth harmonic to detection of motor speed, but due to technical limitations, control ability of control chip cannot meet the requirement of practical application. In 1983, R.Joetten referred to the previous experience and their own unremitting efforts, first implementing the spe
16、ed sensorless vector control, after 40 years, a large number of experts and scholars make the in-depth and specific research of on the sensorless control of AC motor technology at home and abroad, as a well-known USA university research team use the high frequency signal injection method to detect r
17、otor of permanent magnet synchronous motor information issue in 1993,and some achievements have been achieved. 3Research on electric car motor control strategy based on 5the non sensor (1) The sensorless control technology applied to middle and high speed 1) Back EMF zero crossing detection method.
18、This method is currently the most widely used, and the mature technology is easy to realize the rotor position detection technology. Although the method has a strong dependence on the parameters of the motor, yet in high speed, it has a good dynamic performance. Due to zero or low speed under the co
19、nditions, the counter electromotive force is relatively small, so it is easy to cause the information of rotor estimation of failure. Therefore, this method is not suitable for low speed or zero speed. 2) Flux position estimation method. When the motor is running stable, general stator and rotor flu
20、x will rotate synchronously, and between fluxes, the difference is a power angle. Because the flux itself is not the direct measuring method, therefore to obtain flux signal, it can only be measured through the phase voltage and current of the motor, then combines with resistance to calculate the fl
21、ux. In practical application, it must ensure the accuracy of the motor parameters. The main reason for the method is not suitable for low speed, so when speed is low, the back EMF is smaller, the 6useful signal to noise ratio of produce is relatively low at this time, thus it is not easy to extract,
22、 and it will result in failure of the rotor position and speed detection, which cannot be completed the information of rotor in full range of effective detection. 3) Estimation method of model reference location. The method is referred to as MRAS, and it is to have two identical physical meaning of
23、the model as the basis, one as a reference model, the model does not contain unknown parameters, and another model is as the adjustable model, which contains the parameters to be estimated, with the help of error between two model output adaptive law, the adjustable parameters model are for real-tim
24、e regulation, in order to achieve output adjustable model tracking the output of reference model objective, finally according to the stability theory, it can obtain the rotor speed and the adaptive law. 4) Observer estimation method. This is a kind of state observer as the main means of estimating m
25、ethod; it is based on the theory-modern control theory. At present, the more commonly used in the observer are the following kinds: full order state observer, sliding mode variable structure observer and Calman filter etc. 7(2)Suitable for zero speed or low-speed sensorless control technology At the
26、 present stage, the high frequency signal injection technique is zero or low speed sensorless control of widely applied methods. Through this method, it can ensure the reliable run at zero speed or low speed state, but the motor must have a certain degree of salience. The working principle of the hi
27、gh frequency signal injection technology are the following: The high frequency voltage or current signal is injected into the motor, then the current or voltage of motor corresponding to the response of the detection, in order to determine the rotor saliency position. According to the different char
28、acters of high frequency signals, the method can be divided into two kinds of rotation and vibration. 4 Conclusion To make a long story short, motor is the core part of electric vehicle, which has an important effect on vehicle performance. Control system is a main part of motor, and the system stab
29、ility, reliability, cost and other aspects are factors that must be considered in the design of the motor. In the design of the motor control system, the application of sensor makes certain benefits, but from a long-term perspective, 8if you dont use the sensor, which not only can reduce the cost of
30、 control system, but also can effectively improve the reliability of the system, improving motor efficiency and vehicle performance is of great significance. References 1ZHAO Tao, Research of a new hybrid electric vehicle of power system design, simulation and motor drive systemD.HeFei University of
31、 Technology.2010(5). 2LIN Hui. Research on Fuzzy self-tuning PID control method in wheel motor drive electric vehicle brakeD.Jilin University.2013(6). 3LI Liyi. TAN Guangjun. LIU Jiaxi. Kou Baoquan, Study of no sensor technology of high speed PMSM based on Luenberger observerJ.Micro Motor2013(4). 4D
32、U Yi, Study on permanent magnet synchronous motor control system based on the hybrid electric vehicleD.Jiangsu University.2007(4). 5LI Zhiqiang. Research on Pure electric vehicle AC asynchronous motor and development of Technology of vehicle assembly controller D.Hunan University.2011(7). 6ZHOU Fu, Research and application of high performance Sensorless PMSM control systemD.Donghua University.2008(10). 97YANG Jianfei, Study on some key problems of the direct torque control system of permanent magnet synchronous motorD.Nanjing University of Aeronautics & Astronautics.2011(3).
