Review of Power Control Methods for a Variable Average Power Load Model Designed for a Microgrid with Non-Controllable Renewable Energy Sources

Microgrid systems may employ various combinations of system designs to connect generating units, and the number of different system designs increases exponentially upon adding different brands of inverters to a system. Each of the different microgrid system designs must be set up in a way that it works in balance. An example of an unbalanced microgrid system is given in this paper, with the main issue being the non-predictive excess power, which causes a frequency rise and faulty conditions in the microgrid system. There are many simple options for controlling excess power in a microgrid system; however, none of these options solve the issue permanently while ensuring excess power control without affecting the system’s accumulated energy—the battery state-of-charge (SOC) level. Therefore, there is a need to create a variable average power load (VAPL) device to utilize the excess power at a rate it is changing to avoid a reduction in accumulated energy. The main goal of this study is to review average power control methods for the VAPL device and provide guidance to researchers in selecting the most suitable method for controlling excess power. A key finding of the paper is a suggested optimal average power control method ensuring that the VAPL device is versatile to implement, economically attractive, and not harmful to other devices in a microgrid system.