Injection Pulse Source Using Linear Magnetic Induction Voltage Superposition

Electromagnetic interference (EMI) problems in substations have become more prominent with the development of smart grids. Exploring the effects of EMI such as very-fast-transient overvoltage (VFTO) on sensors requires high performance injection pulse sources. In this paper, an injection pulse source based on magnetic induction voltage superposition is designed. Particularly, a simulation model of the circuit with the structure of linear transformer driver and the fast action characteristics of MOSFET is built. Moreover, the influences of the main circuit parameters such as load resistance, switch performance and energy storage capacitance on the output pulse waveform are studied. The simulation results show that appropriately increasing the load can reduce the leading and trailing edge time of the pulse. The use of fast-opening switch can speed up the output pulse leading edge, but it also increases the fly-back spikes in the induction output. And the increase of energy storage capacitance can prolong the waveform drop time of the pulse and hardly affect the pulse leading edge within a certain range. On the basis of above, the injection pulse source prototype is developed. The fastest pulse leading edge can reach about 10ns, and the pulse amplitude can be up to 40kV, which can meet the needs of secondary system anti-electromagnetic interference research.