New energy island overvoltage control method and converter station pole control system

Abstract

The invention provides a new energy island overvoltage control method and a converter station pole control system. The method comprises the following steps: firstly judging whether the fault of an alternating current circuit in a new energy system is a three-phase short-circuit fault by the converter station pole control system; then when the fault of the alternating current circuit is the three-phase short-circuit fault, issuing a dropout voltage reference value to an outer ring power controller in the converter station pole control system by the converter station pole control system, so thatthe outer ring power controller and an inner ring current controller in the converter station pole control system are used for performing outer ring power control and inner ring current control respectively until the voltage and power of a point of common coupling are greater than a first voltage threshold value and a first power threshold value, and issuing a recovery voltage reference value tothe outer ring power controller by the converter station pole control system. The method is simple in process and easy to realize, the voltage output by a converter station port after the three-phaseshort-circuit fault is solved can be rapidly controlled below 1.0 pu, the voltage output by the converter station port after the system is stabilized is recovered to be 1.0 pu, and finally fault rid-through of a new energy unit is realized.

Description

technical field [0001] The invention relates to the field of new energy technology, in particular to a new energy island overvoltage control method and a converter station extreme control system. Background technique [0002] When the new energy system works in an island operation mode and is sent directly through the flexible DC transmission system, the wiring mode of the new energy system and the converter station is as follows: figure 1 As shown, among them, SM is a sub-module, U c ∟θ c Indicates the output voltage of the port of the converter station, U s ∟θ s Indicates the voltage of the point of common connection (Point Of Common Coupling, PCC), U w ∟θ w Indicates the output voltage of the new energy unit port, P s and Q s is the active and reactive power sent to the converter station, Z w ∟α represents the equivalent reactance from the public connection point to the new energy unit, L arm is the bridge arm reactance. At this time, the converter station needs...

AI Technical Summary

Problems solved by technology

After the short-circuit fault disappears, the output voltage drop of the converter station is re-established. When the new energy power is restored, since the initial value of the reference voltage is the basic voltage of 1.0p.u., a recovery voltage will be superimposed on the basic voltage during the recovery process of the new energy power. , will lead to overvoltage at the new energy port, and in severe cases, it will cause the new energy to go off-grid

The scale of existing engineering converter stations connected to new energy is small, and the overvoltage problem is not serious. When the converter station is connected to large-scale new energy units, the overvoltage problem is prominent, and the existing technology lacks research on such problems.

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