The Study of a Convenient Method of Low-Voltage-Ride-Through Upgrading for the l.5MW Wind-power Generator Systems

摘要

In this paper,a novel and convenient method is presented for the LVRT upgrading of the l.5MW wind-power generator system.This method do not require to upgrade the main control system,the pitch control system and the converter,but only put a LVRT control equipment in series with the wind-power generator in the point of connection to the Grid,then the equipment enables the wind-power generator system to meet the GB19963-2011's LVRT requirements.The LVRT control equipment consists of the bypass circuits and the voltage regulator.Under normal operation condition,the bypass circuit transfers the power from the wind-power generator to the grid.When the grid voltage dip occurs,the bypass circuit turn off instantly,at the same time,the voltage regulator generate the reactive power to stabilize the grid voltage and supply normal operation voltage for the converter to stabilize its speed and output power.When the Ride-Through finished,the active power of the generator is transferred through the bypass circuit again,and the voltage regulator stays in ready state.This convenient upgrading method for LVRT is especially suitable for the old type l.5MW wind-power generator systems,because their upgrading for LVRT costs too much,or even unable to upgrade.By using this method,some wind-power farms in Shanxi have passed the LVRT verification test of the Electric Power Research Institute.