To solve the problem of negative-sequence and reactive power in electrified railway, this paper proposes a comprehensive compensation method based on V/v transformers and electromagnetic single-phase var compensator (ESVC) for co-phase power supply. First, based on the principles of static var generator (SVG) and single-phase rotary phase shifting transformer (SRPST), the topology and model of ESVC have been established, and the compensation mechanism has been analyzed. Second, the topological structure and mathematical model of co-phase power comprehensive compensation device (CPCD) are put forward based on the principles of V/v transformers and ESVC, and the operation mode of CPCD in multiple scenarios is designed. Then the strategy of CPCD with double closed loop control is analyzed: corresponding compensation mode is selected according to negative-sequence unbalance degree and expected power factor value. In this strategy, the compensated current output by ESVC is taken as the quantity of external loop control, and the rotation angle of ESVC is taken as the quantity of internal loop control to realize double-closed loop control of CPCD. Finally, the comprehensive CPCD compensation model is built on the simulation platform and validated the accuracy of the mathematical model and the effectiveness of the control strategy.

With the rapid development of active distribution networks, the “petal”-type distribution network has become the mainstream power supply structure. To ensure the safe and reliable power supply of a distribution system, power control methods for active distribution networks should be further studied. An electromagnetic rotary power flow controller (RPFC) is a feasible solution for active distribution network power control. However, when testing the effectiveness of the PQ decoupled control method for RPFC based on instantaneous reactive power theory, difficulties were encountered with the synchronous control of the rotor position angle of two rotating-phase transformers, and the accuracy of power control was unsatisfactory. Given this condition, PQ control is improved in three ways. First, the system periodic oscillation problem is solved via variable speed control. Second, the servo motor–rotary phase-shifting transformer synchronous rotation scheme is designed, reducing power control error and improving stability. The overshoot phenomenon in power control is improved using the variable domain fuzzy proportional–integral adaptive method. Experimental results show that the proposed advanced control scheme exhibits good dynamic and static performance in power control scenarios and achieves effective improvement of RPFC.