Distributed Load Shedding considering the Multicriteria Decision-Making Based on the Application of the Analytic Hierarchy Process

Figure 4

The relationship between frequency deviation and output power deviation [34]. Characteristic lines (A), (C), and (E) show the characteristic of the output power of a generator within a governor relating to the normal operating case, after the outage of the generator and after controlling the primary and secondary; characteristic lines (F) and (G) show the characteristic of the load power in the normal operating conditions and during load shedding, respectively; and characteristic lines (B) and (D) show the characteristic of the output power of a generator without a governor corresponding to the normal operating case, after the outage of the generator. PG_n and PG_n − 1 are the total value of the output power in the normal operating conditions and during the outage of the generator, respectively. f₀ is the rated frequency in the normal operating conditions. f₁’ is the frequency when the outage of the generator (in case of the generator without a governor); f₂ is the frequency of the system after the primary and secondary control; and f_allow is the restored frequency (59.7 Hz for power grids with a rated frequency of 60 Hz).