A current and voltage state monitoring method and device based on fundamental wave zero sequence characteristics

Abstract

The invention discloses a current and voltage state monitoring method and device based on fundamental wave zero sequence characteristics. The current and voltage state monitoring method comprises the following steps: obtaining three input variables, that is, a three-phase voltage fundamental wave zero sequence value, a three-phase current fundamental wave zero sequence value, and a zero-sequence current and neutral current difference absolute value; inputting the three input variables into a preset fuzzy inference system, wherein the fuzzy inference system comprises a mapping relation between the three input variables and fault type diagnosis results serving as output variables; and finally, obtaining the fault type diagnosis results. The current and voltage state monitoring device comprises an input variable obtaining program unit and a fuzzy inference program unit in full correspondence to the steps of the method. The current and voltage state monitoring method and device based on the fundamental wave zero sequence characteristics can accurately judge various faults under different conditions, are high in detection accuracy, do not cause false alarm, and can realize fault alarm and effective fault removal, thereby ensuring safety and stability of the power supply system.

Description

technical field [0001] The present invention relates to a voltage loss and current loss monitoring technology in a power system, in particular to a current and voltage state monitoring method and device based on fundamental wave zero-sequence characteristics, which are used to identify current and voltage fundamental wave zero-sequence characteristics under different conditions , so as to realize the judgment of the failure of voltage loss, current loss and zero line disconnection, and accurately identify the fault phase, and give an alarm to the abnormality. Background technique [0002] With the development of my country's economy and the sharp increase in electricity consumption, the stability of power supply and distribution is becoming more and more important. However, the imbalance of the three-phase four-wire system has seriously affected the power supply and distribution system, so it is necessary to monitor the current and voltage status of the secondary side of the...

AI Technical Summary

Problems solved by technology

However, in actual operation, there are defects in the loss of voltage and current loss device, which are mainly manifested in the following points: 1) For the situation that the neutral line of the secondary voltage circuit is not connected to the electric energy meter and the alarm device, the alarm device itself shows that the voltage is slightly lower than that of the alarm device. Balanced (obvious zero-sequence component), but not lower than the alarm threshold, at this time, the loss of pressure and flow device cannot detect the failure of the zero line disconnection

2) For some special lines (such as lines sent to high-speed rail traction substations), the three-phase current is often "negative-sequence component" much higher than "positive-sequence component", resulting in an extremely low phase of the three-phase current, which A normal operating condition may trigger the alarm device

The traditional loss of voltage and current alarm devices start from the definition of voltage loss and current loss, and monitor the state of voltage and current. Since the definition has not changed with the times, many false alarms have been brought about.

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