CAJ | 학술논문

针对大规模风电经直流外送存在的风电功率频繁波动导致送端系统频率和电压稳定问题，以某地风火打捆经特高压直流外送输电系统为研究对象，提出了一种适用风电功率波动的直流输电控制策略及相应的无功投切方法。首先，利用直流输电系统有功功率、无功功率、直流电流及直流电压的数学关系，推导出有功、无功表示的电压电流整定公式；其次，根据直流系统功率因数变化限制，提出一种功率因数限制无功功率分阶段控制方法，并配合无功补偿装置投切；最后，理论分析了所提策略对直流系统参数的影响。PSCAD/ EMTDC仿真表明：直流系统可以快速跟随风电功率波动，功率因数限制无功功率分阶段控制能有效维持交流电压稳定。
침대대규모풍전경직류외송존재적풍전공솔빈번파동도치송단계통빈솔화전압은정문제，이모지풍화타곤경특고압직류외송수전계통위연구대상，제출료일충괄용풍전공솔파동적직류수전공제책략급상응적무공투절방법。수선，이용직류수전계통유공공솔、무공공솔、직류전류급직류전압적수학관계，추도출유공、무공표시적전압전류정정공식；기차，근거직류계통공솔인수변화한제，제출일충공솔인수한제무공공솔분계단공제방법，병배합무공보상장치투절；최후，이론분석료소제책략대직류계통삼수적영향。PSCAD/ EMTDC방진표명：직류계통가이쾌속근수풍전공솔파동，공솔인수한제무공공솔분계단공제능유효유지교류전압은정。
In view of problems of system frequency fluctuation and voltage stability when large-scale wind power is delivered with HVDC, taking wind-thermal-bundled system as object, the paper proposes a HVDC control strategy and corresponding reactive switching method suitable for wind power fluctuations. The mathematical relationships among active power, reactive power, DC current and DC voltage are analyzed theoretically and both voltage and current of control system settings are deduced. Based on power factor limits, sectionalized reactive power setting curve is developed with reactive power compensation device switching. PSCAD/EMTDC simulation results show DC system power fluctuates following wind power quickly and sectionalized reactive power setting curve ensures voltage stability. The control strategies reduce sending end system spinning reserve capacity, frequency regulation unit capacity and switching frequency of reactive power compensation devices, which has certain significance for actual delivery of large-scale wind power project.