Stability Boundary of Current Closed-Loop Control of Two-Quadrant H-Half Bridge Converter in SGBES

This paper presents a two-quadrant H-half bridge converter used as the field current amplifier of ac exciter in the synchronous generator brushless excitation system (SGBES). Differing from the conventional amplifier, the exciter field winding can be supplied with positive and negative voltage to help increase the response speed of the excitation system. However, there will be some problems of stability when the converter is used in the current closed-loop control system. To prevent the converter from working in the unstable area, the stability of the linear area has been analyzed. Finally, it is verified by the experimental results. These can provide a valuable theoretical and practical basis for the design of parameters for the current closed-loop control system used by the converter.