阻抗隔离型中压供电质量综合提升系统输出电压控制策略

Output Voltage Control Strategy of Impedance-isolated Medium-voltage Power Supply Quality Comprehensive Improvement System

针对高敏感、大容量用户的供电需求,阻抗隔离型中压供电质量综合提升系统拓扑在输出功率、运行损耗、检测性能要求等方面具有优势。以实现供电质量综合提升和兆瓦级功率输出为目标,提出了一种适用于该系统并网和离网运行的输出电压控制策略。详细分析了系统运行原理,并建立了系统含升压变压器的数学模型;结合系统通过电抗器对电网隔离的特性,为稳定负载电压和提升系统惯性,提出了电压–功率自主控制,并实现有功功率稳态输出无静差;引入了滤波电容电流反馈的系统阻尼优化控制,以抑制电网等扰动变化时的暂态谐振,同时提升系统稳定性;定量分析系统数学模型中输出电流对负载电压稳定的扰动影响,对此提出了基于虚拟串联阻抗的输出电压优化控制以实时提升电能质量。研究结果表明:当兆瓦级负载功率变化和电网发生多种电能质量问题时,系统能够实时保证负载电压高质量稳定输出和提供功率支撑,并通过仿真对比验证了所提控制的有效性。

In response to the power supply needs of highly sensitive and large-capacity users,the impedance-isolated medium-voltage power supply quality comprehensive improvement system topology has advantages in output power,operating loss,and detection requirements.With the goal of achieving power supply quality improvement and MW-level power,an output voltage control suitable for grid-connected and off-grid operation of the system is proposed.The operating principle and mathematical model of the system are analyzed.Combined with the isolation of the grid through reactors,the voltage-power autonomous control is proposed to stabilize the load voltage and increase the inertia of the system,and the steady-state output of active power is realized without static difference.The system damping optimization control based on filter capacitor current feedback is introduced to suppress the transient resonance and improve the stability of the system.In the mathematical model,the impact of the output current on the load voltage stability is quantitatively analyzed,and the output voltage optimization control based on the virtual series impedance is proposed to improve the load power quality in real time.The results show that the system can maintain high quality load voltage output and power support in real time when the megawatt load power changes and various power quality problems occur in the grid.And the effectiveness of the proposed control is verified by simulation comparison.