Detecting methods of reactive power and harmonic current in electrified railway systems

In order to detect the reactive power current and harmonic current in electrified railway systems, three detecting methods are proposed in this paper. There are methods based on instantaneous reactive power theory, function orthogonal characteristic and active current separate method. The corresponding detection systems are developed, and simulations are performed which verify the feasibility of the methods proposed. With higher precision and the real-time performance, the second and the third methods are recommended in electrified railway systems.