Zero-sequence characteristic quantity-based power distribution network grounding fault section positioning method

Abstract

The invention relates to a zero-sequence characteristic quantity-based power distribution network grounding fault section positioning method, which comprises the following steps of S1, acquiring zero-sequence voltage and zero-sequence current magnitude of a line by utilizing a terminal, starting the terminal and reading a constant value; S2, if the zero-sequence voltage is greater than the starting constant value, determining that a grounding fault occurs; S3, after time delay, if the ratio of the zero-sequence characteristic quantity calculated by the terminal to the zero-sequence characteristic quantity of the adjacent terminal is greater than a setting value, locating the terminal with the greater zero-sequence characteristic quantity in the terminal and the adjacent terminal at the upstream of the fault point, otherwise, locating the terminal at the same side of the fault point; S4, enabling each terminal to upload a judgment result to the distribution automation master station; and S5, enabling the distribution automation master station to output a section determination result according to the judgment result of each terminal and remotely controls to remove a fault section. The method can be used for positioning the grounding fault section of the resonant grounding power distribution network, and has the characteristics of wide adaptability, high sensitivity and high calculation speed.

Description

Technical field[0001]The present invention relates to the field of resonant distribution network fault sections, and more particularly to a distribution method based on a distribution mesh for a zero-sequence feature amount.Background technique[0002]The distribution network is used as the end of the power network, directly affects user safety, quality, economic and other electricity energy indicators. With the continuous development of my country's power distribution network, users put forward higher requirements for power supply, power supply, and power supply safety, once the distribution network is faulty, it is necessary to quickly fail positioning and isolation, restore users in short time powered by. Since the distribution network uses non-effective grounding operation, the ground fault current is small, and it is difficult to achieve fast and reliable isolation of the fault point. In recent years, with the increase in the chances of matching the distribution of the distributi...

AI Technical Summary

Problems solved by technology

[0003] The existing small-resistance grounding method has a relatively obvious protection dead zone. When the single-phase grounding transition resistance exceeds 100 ohms, the zero-sequence current is less than the set value and cannot operate.

The arc suppression coil is connected in parallel with a small resistance grounding method, and there is a problem of capacity expansion and transformation, which cannot solve the problem of high resistance grounding

The zero-sequence current method uses the amplitude and phase characteristics of the zero-sequence current of the line to locate the fault section, but it is still difficult to detect high-resistance faults

The neutral point resistance required by the medium resistance method is difficult to design, requires high investment, and artificially increases the ground current, which increases system safety hazards and interferes with the communication system, which is not conducive to personal safety, and this method cannot Detects momentary and intermittent ground faults

The transient zero-mode current waveform similarity method only needs the transient zero-mode current signal, which avoids the problems caused by the installation of voltage transformers, and has high detection sensitivity and is not affected by the neutral point operation mode. The communication network requirements of the system are relatively high, and the amount of communication data is large

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