A New Switching Impulse Generator Based on Transformer Boosting and Insulated Gate Bipolar Transistor Trigger Control

Abstract

Abstract:To make the switching impulse (SI) generator more compact, portable and feasible in field tests, a new approach based on transformer boosting was developed. To address problems such as triggering synchronization and electromagnetic interference involved with the traditional spark gap, an insulated gate bipolar transistor (IGBT) module with drive circuit was employed as the impulse trigger. An optimization design for the component parameters of the primary winding side of the transformer was realized by numerical calculation and error correction. Experiment showed that the waveform parameters of SI and oscillating switching impulse (OSI) voltages generated by the new generator were consistent with the numerical calculation and the error correction. The generator was finally built on a removable high voltage transformer with small size. Thus the volume of the generator is significantly reduced. Experiments showed that the waveform parameters of SI and OSI voltages generated by the new generator were basically consistent with the numerical calculation and the error correction.

Effect of shield placement for transient voltage mitigation due to switching surges in a 33/11 kV transformer windings

“…The only difference between SSI and OSI generator circuit is the absence of wave modulating inductance L, i.e., L = 0. An OSI was generated with peak time, T p = 50 μs, half-peak time, T 2 of 1000 μs and the amplitude of output voltage, U m = 556 V and f = 10 kHz, which can be seen in Fig 3(B) and its parameters given in Table 2 [ 38 ]. The oscillations in the OSI waveform can be varied through variation of L .…”

“…The frequency of OSI depends on L , C 1 , C 2 , and R 2 . The oscillatory frequency, f can be determined by Eq ( 1 ) and T p in OSI is the oscillation period [ 38 ]: …”

“…A SSI of 250/2500 μs as per IEEE Std C57.98-2011 [37] was simulated based on the impulse generator Simulink circuit, as shown in Fig 2(A) and its parameters are shown in Table 1 [38]. The resultant SSI is shown in Fig 2(B).…”

“…The oscillations in the OSI waveform can be varied through variation of L. The frequency of OSI depends on L, C 1 , C 2 , and R 2 . The oscillatory frequency, f can be determined by Eq (1) and T p in OSI is the oscillation period [38]: https://doi.org/10.1371/journal.pone.0240368.g002 Table 1. Impulse generator circuit specification for standard switching impulse.…”

Electromagnetic force distribution computations due to switching surge in disc-type winding

“…The impulse waveshape can be generated with a combination of a series RLC circuit under over damped condition. Figure 1 shows the SSI of 250/2500 µs that was generated by using the impulse generator circuit [36]. The generator Simulink circuit is demonstrated in Figure 1(a) and the 165 kV magnitude SSI waveform is presented in Figure 1(b).…”