Practical wide area damping controller design based on ambient signal analysis

Frequency response and residue are the two popular methods of designing damping controller. However, due to practical limitations, the former is limited to local controller design, which is not preferable for damping inter-area modes. Although the latter benefits wide area control, it strongly relies on the open loop dynamic model of power system which, for large systems, is hard to obtain. This paper, therefore, combines the two methods to design a wide area damping controller which obviates the need for identifying the open loop dynamic model. The method includes feedback loop selection, residue phase calculation and power system stabilizer (PSS) tuning using modal decomposition control (MDC). The core issue, residue phase calculation, has been validated in a two-area four-machine system and the whole procedure for wide area damping controller design was performed in a real power system, China Southern Grid. Results demonstrate that the proposed method is feasible and effective in real power systems.