The invention relates to a unified power
energy quality controller based on the serial-connection multiplicity of transformers and a
chain structure, which belongs to the technical filed of flexible AC transmission and distribution of an
electric power system and the power electronic. The unified
power quality controller comprises a single-phase serial-connection multiple
transformer bank and a single-phase chain
H bridge converter, wherein the
transformer bank consists of m single-phase transformers which form the serial-connection multiple
transformer bank together with n
voltage source
converters connected with n secondary windings of m single-phase transformers respectively; the single-phase chain
H bridge converter is provided with n chains and is formed by connecting n
DC voltage supporting units and n power source
converters, and an AC port of the n-chain single-phase chain
H bridge converter is directly connected with the
electric fence through a reactor, m and n are signless integrals equal to or more than 2, and m is less than or equal to n. The invention can realize accurate current control, has high dynamic responding speed, and can solve the problems of the
traction substation of an electrified railway that the three-phase
voltage is unstable and fluctuates, the
power factor is low and the
harmonic pollution exists, and the like.