Zonal Inertia Constrained Generator Dispatch Considering Load Frequency Relief

Abstract

Synchronous generators are operating for less time than before or being decommissioned in the National Electricity Market (NEM) of Australia, due to the proliferation of asynchronous wind and solar generation. Sub-networks of the NEM will face inertia shortages in the near future. This paper develops a formulation of zonal inertia constrained generator dispatch for power systems with a diversified generator portfolio including synchronous generators, synchronous condensers, inverter-interfaced generators and energy storages. Zonal inertia constraints are formulated in unit commitment and optimal power flow to limit the rate of change of frequency (RoCoF) in the event of network separation. Load frequency relief is also considered to reduce the ramp rate requirement of primary reserve. The proposed formulation can reduce the average cost of primary reserve and maintain zonal inertia adequacy to constrain RoCoF in case of the trip of the interconnector(s). Index Term-Inertia, load frequency relief, unit commitment, optimal power flow, renewable energy, power system.

Minimum inertia estimation of power-electronized power system considering multi-resource frequency response characteristics

“…where R, α, and kpf are the equivalent differential adjustment coefficient of the governor of the thermal power generator, the droop coefficient of HVDC transmission, and the primary frequency adjustment coefficient of the wind turbine under the aggregation of the multi-machine model, and the parameters satisfy: (12) Assuming that all power generation units in a certain system participate in FR, the relationship between the absolute value of steady-state frequency deviation and the active power disturbance of the load and the FR coefficient of traditional thermal power is drawn based on (11), as shown in Fig. 2.…”

“…Compared with the traditional synchronous power system, the power electronic power sources represented by wind power and high voltage direct current (HVDC) transmission in the PEPS are connected to the grid on a large scale [5][6][7]. However, due to the replacement of a high proportion of traditional synchronous inertia and the decoupling characteristics of power electronic power supplies [8], the inertia level of the power system is sharply reduced and the FR capability is relatively weakened, which will lead to a series of power system frequency operation safety problems [9][10][11]. Once a large active power disturbance occurs in the power grid (e.g.…”

Area inertia estimation of power system containing wind power considering dispersion of frequency response based on measured area frequency

“…Therefore, the RoCoF in the low inertia area after the disturbance can be much larger than that of the whole system. So it is necessary to meet the minimum inertia requirement of each area to improve the overall frequency stability [27].…”

Exploring the Utilization of Energy Storage Systems for Frequency Response Adequacy of a Low Inertia Power Grid

“…Therefore, they generally do not provide inertia and governor response (also known as primary frequency response) unless additional control strategy is implemented [3]. As such, frequency response after a major contingency is likely to become more vulnerable under high wind power penetration [4]. Situations can arise where a system has substantial wind penetration while it imports bulk amount of power through high voltage AC (HVAC) interconnection from adjacent grid.…”