Sampling design of voltage and current under brushless doubly fed generation system

MA Shiyang,CHEN Hao
（School of Information and Electrical Engineering， China University of Mining and Technology, Xuzhou 221008, China）

Abstract:  In order to realize sampling the voltage and current signals accurately and timely, and solve the problems of the versatility of various signal sampling circuit in the control board, DC sampling was applied, and the method of isolating the tested circuit and the control circuit which using highspeed linear optocoupler HCNR201 was used. Through the  theoretical analysis of the designed circuit, the transfer function between the sampled data of voltage and the sampled data of current Hall sensor was created. After the analysis, the experiment was conducted in the brushless doubly fed wind power generation system experimental platform. The actual transfer function between the sampled data of voltage and the sampled data of current Hall sensor was given. Theoretical fitting curve of the transfer function and the actual fitting curve of the transfer function were compared. The results indicate that the designed detection method has small error and good reliability, and lays a foundation for the next experiment.
Key words: sampling of voltage and current; brushless doubly fed generation system; optocoupler; voltage and current test