High-capacity energy storage power station connected with grids by synchronous motors

Abstract

The invention provides a high-capacity energy storage power station connected with grids by synchronous motors, and is applicable to constructing hundred megawatt level battery energy storage power stations. High-capacity and natural grid-friendly grid connection characteristics of the synchronous motors in electric power systems are used for reference. The high-capacity energy storage power station comprises one or more power station unit. The power station units comprise energy storage systems, PCS (process control systems), first motors, couplings and second motors. The high-capacity energy storage power station has the advantages that the first motors and the second motors not only can be operated as motors, but also can be operated as power generators, and motor groups can be formed by the first motors and the second motors via the couplings; the second motors are the synchronous motors and are connected into the medium-voltage and high-voltage grids; operation states of the first motors can be quickly regulated by the PCS, excitation systems of the second motors can be regulated by the second motors, active power and reactive power can be transmitted to the alternating-current grids or can be absorbed, accordingly, bidirectional flowing and four-quadrant operation can be carried out on energy, and the high-capacity energy storage power station participates in frequency modulation, peak regulation and voltage regulation of the electric power systems and can be used as a black start power source for the electric power systems.

Description

technical field [0001] The present invention relates to the field of an energy storage power station using a battery pack and a supercapacitor as an energy storage device, in particular to a large-capacity energy storage power station similar to a pumped storage power station using a battery pack and a supercapacitor as an energy storage device , use synchronous motors to connect to the grid, and assist the grid to perform peak regulation, frequency regulation, voltage regulation, and black start. Background technique [0002] my country has built a number of 10-million-kilowatt-level new energy power generation bases. With the rapid development of the Energy Internet, large-scale energy storage technology has become a key supporting technology for the utilization of new energy generation with randomness, gaps, and volatility. For the access of large-scale new energy power generation, on the one hand, reduce its randomness and improve its adjustability through the combinati...

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Problems solved by technology

[0007] However, the application of virtual synchronous machines also encounters inherent limitations. The adaptability of large-scale access to the power grid is still unclear, and it also faces the problems of associated coupling and mutual excitation under complex power electronic environment conditions; when a short-circuit fault occurs in the power grid, the traditional synchronous motor can It supports a large short-circuit current, while the virtual synchronous machine cannot support a large short-circuit current due to the limitation of the overcurrent characteristics of power electronic devices; limited by the overload capacity, the voltage control ability is not as good as that of the conventional synchronous motor set

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