Abstract : Static frequency converters used for starting pumped storage units typically employ ordinary thyristors in their rectifier-inverter bridge. This paper establishes a mathematical model of the static frequency converter for pumped storage units under closed-loop control of current and frequency. During the modeling process, the commutation overlap angle of the thyristors on the inverter side of the frequency converter was simplified, and a control scheme for voltage and frequency regulation by continuously adjusting the rectifier-side control angle while maintaining a constant inverter-side control angle is proposed. Simulations reveal the variation patterns of various physical quantities in the static frequency converter starting system of the pumped storage unit. Keywords : static frequency converter; pumped storage generator set; simulation; starting[b][align=center]Modeling and Simulation of the Variable Frequency Starting Process of Pumped Storage Generating Units HE Xiong—kai, M AO Cheng-xiong, LU Ji-ming (College of Electrical & Electronic Engineering, Huazhong University of Science and Technology, W uhan 430074, China)[/align][/b] Abstract: The static frequency converter used in pumped storage units generally adopts common thyristor as the rectifying inverting bridge． In this paper． a mathematical model of static frequency converter starting with current and frequency closed·loop control for pumped storage units is established． In the thyristor inverting process, converting overlap angel at freq uency converter's inverting side has been simplified． A controlling scheme of continuously adjusting rectifying side'S controlling angle with static inverting side'S control angle is proposed to realize the frequency modulation and voltage regulation． The results of each physical quantity of the static frequency converter starting system are obtained by simulation. Key words : static frequency converter; pumped storage machine; simulation; starting . Introduction The main characteristic of pumped storage unit operation is frequent start-stop. Starting technology is one of the key technologies for large pumped storage units. Among the starting methods for large pumped storage units, the static frequency converter starting method is a popular choice. During the starting process, the frequency and voltage gradually rise from zero to the rated value, generally taking 2-10 minutes. Regarding the static frequency converter starting problem of pumped storage units, there have been some domestic studies in recent years. Since the proposal to start synchronous units with static frequency converters in the 1960s, the 1980s saw comparisons of various starting methods and studies on the starting process and time. [b][align=center]For more details, please click: Modeling and Simulation of Variable Frequency Starting Process of Pumped Storage Generator Units[/align][/b]