Direct current micro-grid system supplying power in looped network mode

Abstract

The invention provides a direct current micro-grid system supplying power in a looped network mode. The direct current micro-grid system supplying the power in the looped network mode comprises looped-network-shaped direct current buses with different voltage levels, a mixed current circuit breaker connected between bus sections, a photovoltaic power generation system, an energy storage power source, an internal-combustion engine, a convertor, direct current loads and alternating current loads, wherein the photovoltaic power generation system, the energy storage power source, the internal-combustion engine, the convertor, the direct current loads and the alternating current loads are connected to the direct current buses. The energy storage power source and the photovoltaic power generation system are connected with the looped-network-shaped direct current buses with the different voltage levels through the convertor. The mixed current circuit breaker acts when a fault point occurs to a certain section line of the direct current buses, and a solid-state switch of the mixed current circuit breaker breaks the fault point. The internal-combustion engine is connected with the looped-network-shaped direct current buses with the different voltage levels through the convertor, and provides backup power for the direct current loads and the alternating current loads of the direct current micro-grid system when the mixed current circuit breaker acts. According to the direct current micro-grid system supplying power in the looped network mode, when faults occur to a certain part of lines, the mixed current circuit breaker acts timely to isolate the fault part, and a large-area power outage accident is avoided.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a DC micro-grid system powered in the form of a ring network. Background technique [0002] Microgrid refers to a small power generation and distribution system composed of distributed power sources, energy storage devices, energy conversion devices, related loads and monitoring and protection devices. It is an autonomous system that can realize self-control, protection and management. It can run in parallel with the large power grid, and can also run in island mode. [0003] At present, microgrids mainly exist in the form of AC microgrids. Compared with the AC microgrid, the DC microgrid does not need to track the phase and frequency of the voltage, and its reliability is greatly improved, so it is more suitable for the access of DERs and loads. Theoretically, a DC microgrid only needs a primary converter to easily realize the connection with the DER and the load, and ...

AI Technical Summary

Problems solved by technology

The voltage level of this system is relatively high. When supplying power to DC loads, it needs to go through multiple energy transformations, and when a certain line fails, the normal power supply to the load cannot be guaranteed. In addition, during the operation of the diesel engine, the system will cause certain environmental pollution

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