A Protection Scheme for Short Circuit Fault in DC Power Distribution System

A short-circuit fault and DC power distribution technology, which is applied to emergency protection circuit devices, electrical components, etc., to achieve the effects of reduced energy consumption, simple topology, and high power quality

CN104009452BInactive Publication Date: 2016-10-12TIANJIN UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2016-10-12
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to the field of power system relay protection, in particular to a protection scheme for a direct current distribution system short-circuit fault. The scheme includes the steps that firstly, if the sudden-change amount of the direct voltage exceeds a setting value, bus and circuit protection is started; secondly, after the bus protection is started, if the differential current is larger than the differential protection current setting value, bus protection actions are carried out, and direct current breakers at all power supply sides are tripped off; thirdly, after circuit protection is started, if the circuit currents are larger than the instantaneous quick-break protection current setting value or after protection is started for a period of time and the circuit currents are still larger than the time limit quick-break protection current setting value, a circuit is judged to break down, and the direct current breakers on the faulty circuit is disconnected immediately. The protection scheme has the advantages of being simple in protection principle, good in rapidity when faults occur and high in reliability.
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Description

Technical field

[0001] The invention relates to the field of relay protection of power systems, in particular to a protection scheme for short-circuit faults of DC power distribution systems. Background technique

[0002] Smart grid is the latest trend in the development and transformation of the power system in the world today, and it is a major technological innovation and development trend of the power system in the 21st century. The future development direction of the smart grid is mainly concentrated in the distribution network, and the forward-looking research in the field of distribution network is being actively carried out internationally.

[0003] At present, more and more household appliances and office appliances are based on electronic products, and the final form of power consumption is DC, such as mobile phones, LCD monitors, computers, electric vehicles, etc.; increasing household loads and industrial loads use frequency conversion technology to improve effic...

Examples

Embodiment Construction

[0018] The topology diagram of a typical DC power distribution system is attached figure 1 As shown, a 110kV AC large system is used as the main power supply, which is rectified into 10kV DC by a power distribution converter station composed of 110 / 6.3kV transformers and rectifiers, and directly connected to the 10kV DC bus; at the same time, the distributed power supply is connected to the The DC bus transmits power to the system; the load is connected to the DC bus through a DC cable. There are three types of loads in the system model, which are medium-voltage DC loads, low-voltage AC loads, and low-voltage DC loads. Among them, voltage conversion devices, namely DC / DC converters and inverters, are required to supply power to low-voltage DC loads and low-voltage AC loads.

[0019] Technical scheme of the present invention is as follows:

[0020] Utilize the DC voltage and DC current information collected at the protection installation of distributed power outlets and DC bus...