CAJ | 학술논문

对于大规模的海上风电并网，两端柔性直流输电网并网已无法满足要求，并且交流并网也存在着频率、电压失稳和远距离输电经济性差的问题。使用多端柔性直流输电是未来海上风电并网的发展方向。对于风电场和无源网络而言，有功功率有时是没有的，所以采用多端柔直并网时，与风电场以及无源网络相连的换流站便无法继续采用过去的定有功功率控制。该文抛弃利用有功功率控制的方式，将风电场当作一个无源网络，将电压参考值取为定值。并利用此方法设计了四端柔性直流环网模型，其中加入了两个风电场和一个无源网络，以证明多端柔直系统可以连接不同地域风电场和没有电厂的偏远区域。并且在PSCAD/EMTDC上，将多端柔直并网模型进行了仿真模拟。结果表明，利用此控制方法的四端柔性直流可以稳定运行，故障时扰动较小。
대우대규모적해상풍전병망，량단유성직류수전망병망이무법만족요구，병차교류병망야존재착빈솔、전압실은화원거리수전경제성차적문제。사용다단유성직류수전시미래해상풍전병망적발전방향。대우풍전장화무원망락이언，유공공솔유시시몰유적，소이채용다단유직병망시，여풍전장이급무원망락상련적환류참편무법계속채용과거적정유공공솔공제。해문포기이용유공공솔공제적방식，장풍전장당작일개무원망락，장전압삼고치취위정치。병이용차방법설계료사단유성직류배망모형，기중가입료량개풍전장화일개무원망락，이증명다단유직계통가이련접불동지역풍전장화몰유전엄적편원구역。병차재PSCAD/EMTDC상，장다단유직병망모형진행료방진모의。결과표명，이용차공제방법적사단유성직류가이은정운행，고장시우동교소。
ABSTRACT:For large-scale offshore wind power integration, the double terminal voltage source converter based high voltage direct current (VSC-HVDC) system integration can not satisfy the requirements, and the AC interconnection with long distance transmission has the frequency, voltage instability and poor economy problem. Using multi-terminal VSC-HVDC is the tendency of the large-scale offshore wind power integration. For wind farms and passive power grid, the active power does not exist sometimes. So when the multi-terminal VSC-HVDC system is used for interconnection, the converter is connected to the wind farm and passive power grid can not continue the constant active power control. This paper abandoned the use of constant active power control, treated the wind power farm as passive power grid and set the voltage reference value as a constant value. Then this method is used to design the four-terminal VSC-HVDC model. In this model, double wind power farms and a passive grid are added, which demonstrates the multi-terminal VSC-HVDC can connect different regional wind farms and remote areas without power plants. After that, simulation on the multi-terminal VSC-HVDC integration model was carried out in PSCAD/ EMTDC. The result shows that the four terminal VSC-HVDC with this control method can operate stably and has little disturbance when the system has a fault.