Stabilization and control of power systems using under frequency load shedding due to spinning reverse

Frequency is one of the important components of the power system, which must be within the allowable range. With the occurrence of a severe disturbance, the governor system and rotating storage of power plants do not have the necessary ability to prevent a rapid drop in frequency. Under frequency load, shedding plans are one of the most important protection plans that are responsible for keeping the frequency within the permissible range in the event of severe disturbances. In this paper, while accurately calculating the active power required to keep the frequency constant, by affecting the spinning reverse energy of power systems in the load shedding stages, the minimum load is calculated to recover the frequency of the power system and the load is cut off. Designed for 4 stages of load shedding operations, in each stage, the amount of power deficit compensated by the rotating storage energy is checked and then the load is cut off. As an example, for a disturbance of 0.8 per unit, the amount of 0.3 per unit is compensated by the stored energy and only 0.5 per unit of load is disconnected from the network. In order to show the effectiveness of the proposed plan, the simulation results of using this plan for an island system have been compared with the simulation results of two common offloading plans. The results show that the proposed design shows more reliable and appropriate performance than the other two common designs. In this paper, while accurately calculating the active power required to keep the frequency constant, by affecting the spinning reverse energy of power systems in the load shedding stages, the minimum load is calculated to recover the frequency of the power system and the load is cut off. Designed for 4 stages of load shedding operations, in each stage, the amount of power deficit compensated by the rotating storage energy is checked and then the load is cut off. As an example, for a disturbance of 0.8 per unit, the amount of 0.3 per unit is compensated by the stored energy and only 0.5 per unit of load is disconnected from the network. In order to show the effectiveness of the proposed plan, the simulation results of using this plan for an island system have been compared with the simulation results of two common offloading plans. The results show that the proposed design is more reliable and appropriate performance than the other two common designs.