CAJ | 학술논문

针对海上风电场采用柔性直流输电(voltage source converter based high voltage DC，VSC-HVDC)接入陆上电网的技术方案，提出利用直流电容和风电机组转子动能去模拟同步发电机惯量的协同控制策略。通过网侧换流器直流电压滑差控制，在电网扰动下，直流电容能相应地吸收或释放能量。两端 VSC 交流系统频率通过风场侧换流器(wind farm VSC，WFVSC)的变频控制实现人工耦合，可以省去两端换流站之间的通信。为响应WFVSC的频率变化，风电机组功率控制器将调整功率指令值，使转子转速相应变化。通过一系列协同控制，海上风电场将参与电力系统频率控制。在允许的风电机组转速和直流电压变化范围内，该协同控制策略可提供大范围的惯量，增加系统稳定性。通过对负荷变化、风速变化和交流系统故障等工况的仿真，验证所提控制策略的有效性。
침대해상풍전장채용유성직류수전(voltage source converter based high voltage DC，VSC-HVDC)접입륙상전망적기술방안，제출이용직류전용화풍전궤조전자동능거모의동보발전궤관량적협동공제책략。통과망측환류기직류전압활차공제，재전망우동하，직류전용능상응지흡수혹석방능량。량단 VSC 교류계통빈솔통과풍장측환류기(wind farm VSC，WFVSC)적변빈공제실현인공우합，가이성거량단환류참지간적통신。위향응WFVSC적빈솔변화，풍전궤조공솔공제기장조정공솔지령치，사전자전속상응변화。통과일계렬협동공제，해상풍전장장삼여전력계통빈솔공제。재윤허적풍전궤조전속화직류전압변화범위내，해협동공제책략가제공대범위적관량，증가계통은정성。통과대부하변화、풍속변화화교류계통고장등공황적방진，험증소제공제책략적유효성。
Based on the technical solution of large-scale offshore wind farm integrating into onshore grid by voltage source converter based HVDC (VSC-HVDC) transmission, this paper proposed a new coordinated control strategy. The strategy used electrical energy stored in HVDC capacitors and kinetic energy stored in wind turbine generator rotors to emulate the inertia of the synchronous generator (SG). The HVDC link capacitors released or absorbed energy by the proposed droop DC voltage control of the grid side VSC (GSVSC). No remote communication was needed since the artificial coupling of the frequency of the two-side AC systems was obtained through the variable frequency control of the wind farm VSC (WFVSC). The rotor speed of the wind turbine generator changed with the power reference of its power controller in response to the frequency change of the WFVSC. As a result, the wind turbine generators were utilized to keep the grid frequency stable. Within the permissible variations of the wind turbine generator rotor speed and the DC voltage, the proposed coordinated control strategy can provide a wide range of inertia time constants, which improves the overall stability of the system. Simulation results of three operation conditions, i.e. sudden load changes, variations of wind speeds, and AC system faults, validate the effectiveness of the proposed control strategy.