Enhanced type railway power regulation device

Abstract

The invention discloses an enhanced type railway power regulation device which comprises a VSC1, a VSC2, a capacitor and an enhanced type controller. The enhanced type railway power regulation device is suitable for a traction substation adopting an SCOTT transformer, electrical quantity of the high-voltage side of the SCOTT transformer is collected directly, closed-loop comprehensive compensation is carried out on negative-sequence currents and reactive power injected into a power grid according to a decoupling principle, the AC side of the VSC1 and the AC side of the VSC2 are connected to the two low-voltage ends of the SCOTT transformer, active power is transmitted through DC circuits, and the reactive power of the VSC1 and the reactive power of the VSC2 are regulated respectively to enable the negative-sequence current injected into the power grid from the high-voltage side to be zero and to improve a power factor. Compared with an existing railway power regulation device adopting an indirect control mode, the enhanced type railway power regulation device is better in compensation effect, and has broad application prospect along with the rapid development of electrified railways, high-speed rails, urban subways and other projects of China.

Description

technical field [0001] The invention belongs to the field of electric energy quality control applied to power grids by power electronics technology, and relates to a negative-sequence and reactive power control device for traction substations, which is suitable for traction substations using SCOTT transformers. The measured electrical quantity on the high-voltage side) is a state feedback quantity, which is directly controlled by a closed loop, and is an enhanced railway power conditioner (ERPC, Enhanced Railway Power Conditioner). Background technique [0002] The negative-sequence and reactive power compensation control strategy of the traditional railway power conditioner (RPC, Railway Power Conditioner) is: on the two low-voltage sides of the SCOTT transformer (balanced traction transformer), respectively perform reactive power compensation and active power compensation. exchange. Its control goal is to make the equivalent load connected to the two low-voltage sides equ...

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Problems solved by technology

[0003] However, such a control system is an indirect closed-loop control structure, and the actual operation effect will be disturbed by many uncertain factors.

For example, the manufacturing process of the transformer itself makes the parameters of the two low-voltage windings not completely consistent, the transformer itself needs to consume a certain amount of reactive power, and the characteristics of the two single-phase VSCs are not completely symmetrical, etc.

Therefore, the compensation effect is not ideal, and the current injected into the high-voltage side grid still contains negative sequence components, and the power factor of the high-voltage side cannot reach 1.

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