An improved power decoupling strategy based on Newton interpolation for electric locomotive drive

The well-known double line frequency ripple power is a critical issue for single-phase power electronics systems and considering some application of single-phase converter whose output power is not a constant, such as the photovoltaic and electric locomotive, this paper introduces an improved power decoupling strategy based on Newton interpolation with power tracking. A classical power decoupling topology is that a buck-boost converter is connected as an auxiliary circuit at the output of a single-phase converter. Traditional decoupling strategy of this topology is modified and the Newton interpolation prediction method is used to improve the control accuracy of the auxiliary circuit to realize the deadbeat control algorithm. When the output power of the system is changing, dynamic response of the single-phase PWM rectifier is a critical issue. This paper introduces power feed-forward control in the inner current control loop. Finally, the improved algorithm is compared with traditional power decoupling strategy in a series of simulation and the results shown that the proposed algorithm is correct and effective.