-line Monitoring Of Low-frequency Oscillations Based On Wide Area Measurement System Software Development

The inter-area low frequency oscillation caused by the interconnection of weakly coupled power systems badly threaten the security and stability of the interconnected power systems, and greatly restricted the power transmission capability. With the growing scale and complexity of power systems, power systems need WAN synchronization information to analyze and control the characteristics of oscillations. Therefore, the real-time monitoring and analysis of the low frequency oscillations is especially important for the power systems. The rapid development and applications of wide area measurement system (WAMS) is the basis for the on-line monitoring of the stability in power systems. Currently, the analysis of the low frequency oscillations in power systems are mostly off-line analysis, and can not meet the requirements for the stability of the modern power systems. Based on the principle of WAMS, this dissertation mainly studies on the on-line monitoring of the low-frequency oscillations in power systems, including:1. According to the requirement for extending the function of WAMS, this dissertation designs the on-line monitoring software of the low frequency oscillation, which is based on the improved Prony algorithm for the core. We introduce the system structure and modules of the on-line monitoring software, and explain the design and implementation of the function modules in detail.2. In this dissertation, the core algorithm for the online monitoring of the low-frequency oscillation is discussed in detail and verified by simulation. A five-machine simulation system with be imposed a small disturbance produces the oscillation mode data. Then we analyze the oscillation mode data by using the improved Prony algorithm. And the results verify the feasibility of the improved Prony algorithm.3. The monitoring software is tested and simulated in this dissertation. We analyze the results, and verify the feasibility of software design and the improved algorithm. Thus, our work provides an effective method for researching on the low frequency oscillation.