A Novel Apparatus for Adjusting the Insertion Voltage of Transmission Line Based on Variable Inductors

A novel apparatus based on variable inductors to control the insertion compensating voltage of the transmission line is proposed in this paper. The apparatus can change the alternative voltage into the desired alternative voltage directly by using the control strategy proposed in this paper and insert the voltage into the line. Since the amplitude and the phase angle of the voltage supplied by the apparatus can be adjusted continuously and independently, the apparatus can control the real- and reactive- power flow independently and realize the direct voltage regulation (DVR) and the phase angle regulation (PAR) of the transmission line. The control methods suited for the proposed apparatus about the independent control of real and reactive power flow in the transmission line and the DVR and the PAR are also proposed. The control strategy and methods are verified with experimental results and simulation results.

I. Introduction

Electric Power flow through an ac transmission line depends on the state of the transmission line. It is a function of the amplitudes of the sending-end voltage and the receiving-end voltage , and the phase angle , between voltages of and . At the same time, it is also the function of the line impedance .