根据实测数据对电力系统低频振荡模态进行辨识,有助于实现电力系统有效的阻尼控制,从而提高电网的稳定性。文中介绍了利用Prony算法辨识低频振荡模态参数的原理,针对Prony算法对噪声干扰敏感以及模型阶数辨识困难导致出现伪模态的缺点,提出了一种基于差分正交匹配追踪(DOMP)和Prony算法相结合的低频振荡模态参数辨识方法。EPRI-36节点系统和实际系统相量测量单元数据算例的仿真结果表明,所述方法能够准确地辨识出系统低频振荡模态参数。通过与Prony算法结果对比验证表明,该方法辨识结果更加准确,能够满足低频振荡模态参数辨识要求。
The identification of power system low-frequency oscillation modes based on measured signals is beneficial to effective control of system damping to improve the stability of the power grid.The principle of identification of the low-frequency oscillation modal parameters using Prony algorithm is described.For the appearance of the pseudo mode due to the Prony algorithm being sensitive to the noise of analyzed data and the difficulty in identifying the order of the model,a low frequency oscillation identifying method is proposed by combining difference orthogonal matching pursuit (DOMP) with Prony algorithm.The proposed method is applied in simulation of a case study on an EPRI-36 system and phasor measuring unit (PMU) data from an actual system.The results show that the low-frequency oscillation modal parameters can be accurately recognized.Comparison of the proposed method with the Prony algorithm shows that the proposed method is able to provide relatively precise analysis results up to requirement of identification of power system low-frequency oscillation modal parameters.