Development of Broadband Resistive–Capacitive Parallel–Connection Voltage Divider for Transient Voltage Monitoring

Abstract

The on-site measurement of transient voltages is of great significance in analyzing the fault cause of power systems and optimizing the insulation coordination of power equipment. Conventional voltage transformers normally have a narrow bandwidth and are unable to accurately measure various transient voltages in power systems. In this paper, a wideband parallel resistive–capacitive voltage divider is developed, which can be used for online monitoring of transient voltages in a 220 kV power grid. The structures of the high-voltage and low-voltage arms were designed. The internal electric field distribution of the high-voltage arm was analyzed. The influence factors and improvement techniques of the upper frequency limit were studied. The parameters of the elements of the divider were determined. The voltage withstand performances and scale factors under lightning impulses and AC and DC voltages, the temperature stabilities of scale factors and the step response and bandwidth of the developed voltage divider were tested. The results show that the deviations of the scale factors under various voltage waveforms and different temperatures ranging from −20 to 40 °C are within 3%. The withstand voltage meets the relevant requirements specified in IEC60071-1-2011. The step response 10~90% rise time is approximately 29 ns, and the 3 dB bandwidth covers the range of DC to 10 MHz.

Development and Experimental Research of VFTO Measuring Sensor

“…In general, using the capacitive divider sensor is the most effective way to obtain a fast transient voltage signal among all measurement methods. The performance parameters of measurement bandwidth are excellent, with a wide-band cut-off frequency ranging from several hundred Hz to 1 GHz [ 17 , 18 , 19 , 20 ]. This kind of sensor is widely used in medium-voltage (MV) networks, which provide accurate voltage measurements for intelligent electronic devices [ 21 , 22 , 23 ].…”

“…Xie et al used a wide-band parallel resistive–capacitive voltage divider for online monitoring of transient voltages in a 220 kV power grid. The step response 10~90% rise time of this sensor is approximately 29 ns, and the 3 dB bandwidth only covers the range of DC to 10 MHz, which is unable to meet VFTO measurement requirements [ 17 ]. Wang et al used a capacitive voltage divider and differentiating–integrating circuit to make a miniaturized VFTO measurement system, which can be applied to actual VFTO measurements [ 24 ].…”

A Comprehensive Survey of HVDC Protection System: Fault Analysis, Methodology, Issues, Challenges, and Future Perspective

“…This is due to the resonance effects that occur in the connected parallel RC groups of the voltage divider that is used to reduce the primary voltage amplitude. These effects can restrict the operational bandwidth of the device, particularly at higher frequencies [13,14]. Similarly, in the case of DC measurement devices, the bandwidth is limited to a range of a few kHz to MHz because of the dependence on fiber optic cables.…”