A distributed order PID controller for load frequency control in a two-area diverse-unit power system

Until recently the conventional PI and PID controllers have been widely used in the load frequency control (LFC) problem. However, in today's modern power system those controllers cannot cope effectively with the increasing complexity of the power system resulting in system performance degradation. To tackle this problem, this paper proposes the application of two distributed order PID (DOPID) controllers which cover the whole range of integrals and derivatives of order -1 to order 1. Those controllers comprise with numerous fractional integrators and differentiators. The gains of the proposed controllers are optimized using the newly introduced marine predators algorithm (MPA). The analysis of the controllers is conducted in a realistic two area interconnected power system having diverse sources of power generation including communication delay, HVDC link and a geothermal power plant (GTPP) in both areas. A performance evaluation is conducted among various controllers like PIDN and FOPID with the proposed controllers and it is found that the DOPID controllers exhibit the best dynamic performance. Moreover, the transient response of the system is tested under the presence of wind power generation (WTG).