大功率链式STATCOM电磁暂态快速等效建模和误差评估

针对含有大量模块的大功率链式静止同步补偿器(STATCOM)存在的电磁暂态仿真速度缓慢的问题,提出一种链式STATCOM级联H桥拓扑的等效建模方法,以提高仿真效率。主要开展了以下的研究:对比分析了经典电磁暂态建模和快速等效建模的原理;推导出级联H桥换流链电压、电流之间的数学模型;结合换流链数学模型及其控制方法,设计出基于MATLAB/Simulink的仿真流程;分析主要电气量如功率模块直流电压、换流链电流和功率等的理论误差。比较精确模型和等效模型的仿真精度和仿真速度,结果表明所提的等效模型与精确模型的仿真误差小于1.2%,仿真时间缩短了80%。可见所提的大功率链式STATCOM电磁暂态快速等效建模和误差评估方法,可以在精度允许范围内大幅降低仿真时间并精确评估模型,具有较强的科学和工程应用价值。

Electromagnetic transient equivalent fast modeling and error estimate of high power chain circuit STATCOM

Aiming at the slow speed of electromagnetic transient simulation of high power chain circuit STATCOM(STATic synchronous COMpensator) with a large number of modules, an equivalent modeling method for chain circuit STATCOM with cascaded H-bridge topology is proposed to improve the simulation efficiency. Firstly, the principles of classical electromagnetic transient modeling and fast equivalent modeling are compared and analyzed, and the mathematical model between voltage and current of the cascaded H-bridge converter chain are formulated. Secondly, the simulation process based on MATLAB/Simulink is designed with the mathematical model and control method of the converter chain. Then, the theoretical errors of main electrical quantities such as power module DC voltage, commutation chain current and power are analyzed. Finally, by comparing the simulation accuracy and speed of the exact model and the equivalent model, the results indicate that the simulation error between the proposed equivalent model and the exact model is less than 1.2%,while the simulation time is reduced by 80%. Therefore, the proposed electromagnetic transient fast equivalent modeling and error estimate method of high power chain circuit STATCOM greatly reduce the simulation time and accurately evaluate the model within the allowable range of accuracy, which has promising scientific and engineering application value.