High-safety low-voltage direct current system

Abstract

The invention discloses a high-safety low-voltage direct-current system which comprises a direct-current bus, and a bus protection device and an insulation resistance monitoring device are arranged onthe direct-current bus. The direct-current bus is connected with the power supply unit and the power utilization unit. In the power supply unit, distributed photovoltaic power generation equipment isconnected with the direct-current bus through a photovoltaic incoming line protection device, energy storage equipment is connected with the direct-current bus through an energy storage incoming lineprotection device, and mains supply is connected with the direct-current bus through an AC / DC rectifier protection device. In the power utilization unit, power utilization equipment is connected witha direct current bus through a load short circuit protection device, each load branch is further provided with a leakage current sensor, and the leakage current sensors are connected with an insulation resistance monitoring device through signal cables. The low-voltage direct-current system comprises power supply protection, bus protection and branch protection, and comprehensive protection of the direct-current system can be achieved.

Description

technical field [0001] The invention relates to a high-safety low-voltage direct current system, which belongs to the technical field of power electronics. Background technique [0002] From the point of view of the DC system, both the type of fault and the consequences of the fault are different from the AC system. In practice, the relevant protection lacks both standards and operating experience. In terms of low-voltage DC system protection, the application of DC circuit breakers in DC power distribution systems can greatly improve the reliability of system power supply, and there are already applicable products in low-voltage and medium-voltage levels. However, the current commercially available DC circuit breakers have limited capacity and are expensive. Therefore, scholars have proposed several other isolation devices that can be applied to DC power distribution systems, such as fuses, circuit breakers, and fast disconnecting switches. Fuses are based on the principle ...

AI Technical Summary

Problems solved by technology

The protection scheme based on the circuit breaker has been widely used in DC system applications, but due to the slow response speed of the circuit breaker, the fault is often not cleared in time; the DC protection solution based on the solid state circuit breaker can realize fast DC fault protection at a speed close to 8μs

However, cost and loss are still outstanding problems for solid-state circuit breakers, and low-voltage solid-state circuit breakers are still in the research stage

The quick isolating switch is a purely mechanical switch and does not have the ability to switch on and off

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