Investigation of effect on load - frequency control of high voltage direct current connection line in multi area power system

Interconnected systems are created by parallel linking of multiple power systems in order to provide electrical energy produced at production points to consumers in a quality and reliable way. By the interconnected systems, economical, minimally interrupted and efficient energy transfer is provided to the consumers. In recent years, with the increase in industrialization and world population, electrical energy has become one of the most needed energy types in the world. The need to meet the increasing energy demand at a stable and low cost requires the creation of larger and more reliable interconnected power systems. Reliable power systems are expected to continuously monitor and control the supply-demand relationship between producers and consumers, and to self-repair and optimize. In this context, the most important parameters to be controlled in interconnected systems are frequency and voltage control. The most important parameter that determines the stability of power systems is frequency. In power systems, the frequency change must be kept within certain limits, which can be achieved by providing a balance between the power produced and the power consumed. In this study, the effect of a High Voltage Direct Current (HVDC) transmission line parallel to the Alternating Current (AC) transmission line on the power system frequency control in a power system formed by sub-areas connected by High Voltage Alternating Current (HVAC) transmission line was investigated. For this purpose, a multi region power system respectively compatible with the circumstances in Turkey was modeled in MATLAB environment. The effects of the addition of one or more HVDC connection lines to the load frequency control were investigated. In this study, the Optimal-Inspired Optimization method which is the current heuristic optimization method was used to determine the optimal values of the gain of the controllers. The controller gains determined by OIO were simulated for model time domain responses generated and the results were analyzed.