基于希尔伯特-黄变换的直流微电网母线电压振荡检测

Oscillation detection for bus voltage of DC microgrid based on Hilbert Huang transform

直流母线电压稳定是直流微电网运行控制的目标之一,但由于直流微电网特殊的物理架构,易出现母线电压振荡现象.依据IEEE对电压振荡参数的规定,建立直流母线电压振荡信号的数学模型.考虑希尔伯特黄变换的模态混叠弊端,采用一种基于掩膜信号的改进希尔伯特-黄变换对母线电压振荡仿真信号进行检测.检测结果显示,该方法可以快速判断直流母线电压振荡的发生和结束时间,相对误差在0.378%以下,表明通过准确提取电压振荡信号的时频信息,希尔伯特-黄变换可实现对直流微电网母线振荡的检测与分析.

One of the aims for microgrid operational control is to maintain the stabilization of DC bus voltage.However,the oscillation existence of bus voltage cannot be easily eliminated owing to the special physical architecture of DC microgrid.According to the IEEE provisions on voltage oscillation,the mathematical oscillation signal model of DC bus voltage is established.An improved Hilbert Huang transform with masking singal is adopted to detect the oscillation of DC bus voltage simulation signal.The starting and ending time and end of the voltage oscillation can be quickly detected,and its relative error is below 0.378%.The time-frequency information has accurately been obtained by Hilbert Huang transform applied to this signal,which has verified that Hilbert Huang transform can realize the measurement and analysis for DC microgrid bus oscillation.