Protective device for disconnection of neutral line in low-voltage power system

Abstract

The invention discloses a protective device of a broken zero line for a low-pressure power utilization system. The protective device of the broken zero line for the low-pressure power utilization system comprises capacitors, a detecting device, a controller and a relay. Three capacitors of the same size are connected by a star connection mode. The detecting device detects a voltage between a capacitive neutral point and a load neutral point, converts the voltage into a voltage signal and transmits to the controller. The voltage signal which is received by the controller conducts proportional conversion and transmits a control signal to the relay. The relay is arranged between a power source and a load and conducts motion according to the control signal. The detecting device detects the voltage between the capacitive load neutral point and the load side neutral point and then converts into the voltage signal and transmits to the controller. After the controller conducts the proportional conversion on the voltage signal, the controller transmits the control signal according to setting. The relay which is arranged between the power source and the load conducts motion. When a zero line breaks, the protective device timely cuts off connection between the power source and the load so as to avoid damage on power equipment.

Description

technical field [0001] The invention relates to the technical field of electric power systems, and more specifically, relates to a protection device for disconnection of a neutral line in a low-voltage power consumption system. Background technique [0002] The low-voltage power consumption system refers to the power consumption system of three-phase 380V or single-phase 220V. In the low-voltage power consumption system, a three-phase four-wire system is generally used for power supply, that is, three phase lines and one neutral line. The neutral line plays a very important role in the low-voltage power supply system. After its disconnection, if the three-phase load is unbalanced (in fact, the three-phase load cannot be completely balanced), the neutral line voltage will shift; if the imbalance is greater The greater the offset of the neutral line voltage, the higher or lower the voltage of a certain phase will cause damage to the electrical equipment. [0003] However, due...

AI Technical Summary

Problems solved by technology

The neutral line plays a very important role in the low-voltage power supply system. After its disconnection, if the three-phase load is unbalanced (in fact, the three-phase load cannot be completely balanced), the neutral line voltage will shift; if the imbalance is greater The greater the offset of the neutral line voltage, the higher or lower the voltage of a certain phase will cause damage to the electrical equipment.

[0003] However, due to the low voltage on the neutral line, the neutral line may be stolen in some areas

If the disconnection of the zero line cannot be detected in time, it will easily lead to damage to the electrical equipment.

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