Studies On Real Time Voltage Regulation Strategies Of A Wind Farm

As a renewable energy, wind power generation develops in a rapid manner, whichhas great impact on grid. Both researchers and policy-makers should know positive andnegative effect on the grid. WTs with doubly fed induction generators (DFIG) are able tocontrol active and reactive power independently. The voltage/negative power control isalways a research focus.The paper is as a part of projects "software development for controlling energystorage type wind power station", which belongs to Beijing huadian tianren electriccontrol technology company. According to State grid corporation of china’s Grid" windfarm connecting to power grid technical regulation" and "wind power running controltechnology requirements", the paper has studied Liaoning Jinzhou Fangshan windfarm(mainly doubly-fed induction generator) accessed to network, researched on voltageand reactive power control strategy, achieved the effective controlling of wind power bywind farm/top, protecting wind power sustainable and healthy development.Theresearch results are as follows:(1) The paper has analyzed the current situation of voltage/reactive powercontrolling of wind farm, including basic principle of variable speed constant frequencyof DFIG, voltage adjustment features of OLTC，voltage/reactive adjustment features ofSVC, studied the active power&reactive power character of DFIG.(2) The paper has proposed the two-level voltage/reactive coordinated controlstrategy, first level of which are realized through optimizing adjustment, and second levelof which adopts slope algorithm to distribute reactive power in wind farm.(3) First level voltage control includes allocating charged DFIG groups, reactivepower of various reactive power compensation device and tap position of boostsubstation OLTC; second level voltage control aims at realizing the inner reactive powerslope allocation by offline calculation studies the influence extent voltage wind turbinegroups in different locations to PCC voltage.(4) Establish a simulation model based on Jinzhou Fangshan wind farm, verifysituation of PCC voltage and wind turbine groups at the actual wind speed before andafter voltage control. Build simulation model using simulink, acquire influence extentwind turbine groups for different distances to PCC voltage and get the slope parameter.Compare reactive power allocation under slope allocation and conventional way.