Resonant Power Frequency Converter and Application in High-Voltage and Partial Discharge Test of a Voltage Transformer

Abstract

This paper presents application of a resonant power frequency converter for high-voltage (HV) and partial discharge (PD) test of a voltage transformer. The rating voltage, power, and frequency of the system are 70 kVrms, 40 kVA, and 200 Hz, respectively. The testing system utilized the converter feeding to an HV testing transformer connected to a conventional partial discharge detection system. The converter system comprising a rectifier and insulated-gate bipolar (IGBT) switches with the H-bridge configuration was applied as a low-voltage source instead of a conventional motor-generator test set which requires large space and high cost. The requirements of the test according to the standards are quality of the test voltage and the background noise level. The required voltage must have the different voltage (DV) and total harmonic distortion (THDv) in the acceptable values of less than 5%. The DV is defined as the difference of the root mean square and peak voltages in percent. The required background noise level must be lower than 2.5 pC. Simulations and experiments were performed for verification of the developed system performance in comparison with those of the previously developed system based on the pulse width modulation converter. It is found that the developed system can provide the testing voltage with the DV and the THDv of lower than 1% and the background noise level of lower than 1 pC. Considering this achievement of promising performance, the developed system is an attractive choice for the HV and PD testing of voltage transformers in real practice.

Discharging state recognition method of intelligent ring network cabinet based on audio signal spectrum analysis

“…In equation ( 3), ( ') yn to consider the pre emphasis audio signal of time domain signal; () xm is the audio signal sampling value at time m; w is the window function bandwidth. In this paper, the bandwidth of the window function is leaked, and the bandwidth of the signal main lobe is widened to ensure the high frequency division [25] of spectrum analysis. The window function expression is as follows:…”

The Parametric Optimization of Voltage Multiplier

“…For example, in [1][2][3] the electronic converter dynamic properties were analyzed in a specific usage but there is no analysis of the influence of the parameters on the converter work dynamic. In [4][5][6][7][8] a DC voltage rectifier with a triple band was proposed. In comparison with other similar constructions, it is highly efficient and compact.…”

Accurate Circuit Parameter Determination of a Resonant Power Frequency Converter for High-Voltage and Partial Discharge Tests

“…However, some parameters cannot be measured accurately in real practice. In the design process of [14], the parameters in the simulation were adjusted to obtain results that were consistent with the experimental ones. It would be advantageous for the system design if the circuit parameters could be determined accurately.…”

“…Lately, there have been attempts to develop the HV and PD tests of HV equipment. In [6][7][8][9], a power frequency converter based on pulse-width modulation (PWM) techniques was developed as a low-voltage source for the HV testing transformer for the HV and PD tests. It was found that the commercial and self-developed frequency converters with a voltage filter can generate an almost-pure sinusoidal voltage waveform, but the PWM switching generates a high noise level, which is higher than the acceptable level (2.5 pC) of the PD test.…”