Optimized Fuzzy PID Controller Design to Reduce Low Frequency Oscillations using the Improved Cryogenic Search Virus Algorithm

In this paper, the modeling of the system under study was first proposed and then a fuzzy-PID controller was designed considering the downstream filter for optimal system performance to simulate the stability of a nonlinear system and to simulate low frequency oscillations. In designing the proposed controller, the parameters of controller and fuzzy members were considered as the variable, which ultimately turns into an optimization issue. The controlling structure of the proposed PID is such that, regardless of type and structure of the system under study, it can guarantee the stability of the system and minimize the volatility and frequency fluctuations. The most important feature of the proposed method is its independence on the structure of the system and operating conditions. On the other hand, this paper attempts to reduce the frequency deviation of the dynamic mode by improving the frequency controller and implementing a new method. The new method is based on minimizing total sum of summing time, peak time, peak value, and permanent error state over load changes using the virus search optimization algorithm. Investigations done by different criteria in time and frequency domains, using the proposed algorithm shows high efficiency in comparison with other methods in the articles. Also, the proposed fuzzy controller has a better performance for damping system disturbances in bad situations.