A Practical Impedance Matching Device and Parameter Design Method Under Nonlinear Current

Due to the requirement of country development, geological surveys must be developed from shallow to deep. Correspondingly, the output power of transient electromagnetic method (TEM) transmitter devices, the necessary power electronic equipment in the geological survey, has to be increased. However, in the process of improving output power, the reactive power of the load occupies a large portion of the output power. Then, this part of reactive power should be compensated by the impedance matching device. The biggest difference of impedance matching devices in the geological survey is the operating environment. The operating environment is under square nonlinear current. The square nonlinear current can be decomposed into a sum of several different frequency harmonics. Previously, almost all impedance matching devices are designed to compensate for the reactive power under a single frequency. There is seldom research to tell the users the method of how to match the several impedances under a sum of several different frequency harmonics. Thus, this paper proposed a topology to match impedance in nonlinear current environments first. Then, a design method is proposed to optimize the topology parameters for better performance. At last, a comparative simulation is given to tell the advantages of the proposed topology and its design method.