(1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China;2. CAS Key Laboratory of Renewable Energy, Guangzhou 510640, China;3. Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China)

According to the characteristics of the hydraulic power generation system(HPGS), the rotation rate is determined by the accumulator pressure and the power generator load, which are variables and cannot make the HPGS always work at the optimal speed curve without control. Especially, when the HPGS is fed into a DC microgrid on an island by a rectifier, the rotation rate is only determined by the grid voltage. This paper introduces a Boost converter for HPGS to control the rotation rate in real time. A maximum efficiency converting control strategy is proposed to ensure that the HPGS is always working at the optimal speed curve in the whole power generation process. The converting mechanism of the Boost converter for HPGS is derived, and the optimal speed curve obtained by experiment. A simulation model of the interleaved boost converter for HPGS to be fed into the DC microgrid is developed. The experimental results show that HPGS is always working at the optimal speed curve under the control of the Boost converter in achieving the maximum efficiency converting control strategy for HPGS. This work is supported by Strategic Priority Research Program(Class A)of Chinese Academy of Sciences(No. XDA13040301)and Guangdong Provincial Natural Science Foundation of China(No. 2015A030313717).