The power grid load frequency control method combined with multiple types of energy storage system

In order to cope with the depletion of fossil energy, access to renewable energy has greatly eased the power supply pressure of the power grid. However, its intermittency and unpredictability have changed the structure of the traditional power grid. In order to solve the frequency control problem that the power grid will face in the future, this chapter adds energy storage equipment on the basis of traditional frequency regulation (FR) units to provide stable and efficient FR auxiliary services for the power system. As an important indicator to measure power quality, the change of grid frequency is of great significance to the stable and safe operation of the power system. One of the basic purposes of automatic generation control (AGC) and load frequency control (LFC) is to achieve grid frequency stability. In recent years, proportional-integral-derivative (PID) control has been extended from the integer-order field to the fractional order field and has achieved good control results. The fractional order PID (FOPID) controller has the characteristics of high adjustment accuracy and easy engineering application. However, the setting of its parameters directly affects the final control effect. The pumped-storage power system (PPS) and battery energy storage system (BESS) have been widely used to achieve FR in auxiliary power grids to make up for the problem of traditional units unsatisfactory LFC in recent years. Although these systems have good development prospects and application value, their limitations of geographical location and high cost mean that they cannot be applied on a large scale. The hybrid energy storage system (HESS) refers to the combination of two or more energy storage systems with complementary performance, which is an effective way to solve the economic inadequacy of a single BESS. The HESS can provide FR auxiliary services for the power grid in a flexible and high-quality manner. In summary, in order to achieve better FR service, this chapter first uses a heuristic algorithm to tune the optimal control parameters of the FOPID controller, and then introduces the HESS, composed of batteries and supercapacitors, into the power grid with PPS. The FR process is assisted, and finally the effectiveness and practicability of the proposed control method are verified by simulation.