Lin Wenli

Speed Sensorless Induction Motor Drive Based on EKF and G-1 Model

This paper analyzes the Extend Kalman Filter(EKF)based on ¦£-1-type motor model, and on this basis, the sensor less rotor field-oriented control induction motor drive system is developed. EKF Analysis under ¦£-1-type model simplifies the state matrix and reduces computation of EKF. Changes of motor parameters in EKF are attributed to the state noise. It makes the output values of EKF observe more accurate, and the performance of the vector control system also can be improved. Then, this paper establishes open-loop speed estimator that has a simple structure and is easy to be implemented. At last, the control system is achieved by DSP. Our experiments show the speed-sensor less induction motor drive system has a good static and dynamic performance.

Design of a soft switched 8kW battery charging converter for 100% Low Floor Light Rail Vehicle

100% LFLRV (low floor light rail vehicle) is a new-style, humanized urban rail transit Vehicle. The design challenges for 100% LFLRV BCC (battery charging converter) main circuit were presented. A 20 kHz, 8 kW full bridge ZVS (zero voltage switching) DCDC converter with phase shift PWM control was developed. ldquoDSP + CPLDrdquo mode was employed in control system to perform full process digital management. To avoid the DC bias of high frequency transformer, a full digital control solution was adopted, rather than other traditional solution, such as connecting the blocking capacitors in series in main circuit. The phase shift drive pulses were generated by DSP controller, instead of analog controller like UC3879. Still, the optimal IUOU battery charge characteristics curve was introduced. In the end, the experimental prototype was presented and some experiment waveforms and analysis were given. The conclusions show that the developed full digital control battery charger is stable, reliable and accordant with the 100% LFLRV designing.