Single-phase or three-phase electromagnetic series power transmission line power flow control topology circuit

Abstract

The invention discloses a single-phase or three-phase electromagnetic series power flow controller topology circuit, and belongs to the field of power transmission and distribution grids and distributed power supply grid connection. The single-phase or three-phase electromagnetic series power flow controller topology circuit mainly comprises a three-phase power supply of a power distribution system and an electromagnetic series power flow controller. The electromagnetic power flow controller comprises a three-phase voltage phase shift part and an electromagnetic voltage regulation transformer part; the voltage phase shift part consists of a closed iron core magnetic circuit, a primary winding, a secondary winding and a phase shifting mechanism; the voltage regulation transformer part consists of a closed iron core magnetic circuit, a primary winding, a multi-tap regulating winding and an on-load voltage regulation tap switch; double electromagnetic induction conversion is carried out through a single-phase or three-phase electromagnetic series power flow controller topology circuit, so that active power flow and reactive power flow control of a line is realized, vicious events caused by power flow transfer during an accident are avoided, mutual power transformation, power transmission and mutual standby between two power supplies are realized, and the reliability is high. And the uninterrupted power supply of the important load is ensured.

Description

technical field [0001] The invention belongs to the technical field of power transmission and distribution grids and grid-connected distributed power sources, and particularly relates to the problem of power flow regulation of the power grid after the high penetration rate of distributed power sources is connected. Background technique [0002] After the distributed power supply is connected to the distribution network from the load end, the electrical network structure of the distribution network is changed, and the distribution network is changed from a single power supply radial network structure to an active two-way network structure all over the power supply. The changes have a significant impact on the distribution of active and reactive power flows in the distribution network. When the penetration rate of distributed power generation represented by photovoltaics and wind power into the medium and low voltage distribution network exceeds a certain value, during the per...

AI Technical Summary

Problems solved by technology

When the penetration rate of distributed power generation represented by photovoltaic and wind power into the medium and low voltage distribution network exceeds a certain value, during the period of high occurrence of distributed power generation, active power transfer will be inevitable, thus changing the energy unidirectionality of traditional distribution network The characteristics of circulation, and the intermittent, fluctuating, and space-time characteristics of photovoltaic and wind power further increase the complexity and difficulty of regulating the active and reactive power flows of the distribution network, which may lead to excessively high or excessively high node voltages in the distribution network. Problems such as low voltage, overload of hub lines or power flow sections, or severe power imbalance pose threats to the safe operation of distribution networks and their electrical equipment

[0003] When the unified power flow control device (UPFC) of pure power electronics technology is used, the power electronic switch control is flexible, the modulation is convenient and accurate, and the regulation of the line flow can be well realized, but the pure power electronic system has small heat capacity, poor tolerance, and shock resistance. The ability is weak and the cost is high, so it is difficult to adapt to the natural environment of thunderstorms and snowstorms and the severe heat and cold, as well as the complex load nature conditions faced by the distribution network and distribution lines

[0004] Thyristor Controlled Series Compensation (TCSC) devices are used to adjust the line reactance, which can compensate the reactance voltage component of the line. It is suitable for voltage regulation of high-voltage lines (high inductance, small or even negligible line resistance), and indirectly changes the flow of the line. , but it is not suitable for voltage regulation of medium and low voltage lines (resistance-inductive, even high-resistance, line resistance cannot be ignored), and it is difficult to indirectly change the power flow of the line, and this method cannot achieve precise control of active and reactive power flows

[0005] The conventional on-load tap-changing transformer or auto-coupling tap-changer can be used to change the transformation ratio through the control of the on-load tap changer, thereby adjusting the secondary voltage and indirectly changing the power flow of the line, but this kind of voltage regulator is a cascaded structure. , its capacity must be greater than or equal to the total capacity of the object to be regulated, resulting in a corresponding increase in equipment investment costs. At the same time, this method cannot achieve independent and precise control of active and reactive power flows

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