Experimental Research and Control Strategy of Pumped Storage Units Dispatching in the Taiwan Power System Considering Transmission Line Limits

Abstract

Taiwan's power system is isolated and not supported by other interconnected systems. Consequently, the system frequency immediately reflects changes in the system loads. Pumped storage units are crucial for controlling power frequency. These units provide main or auxiliary capacities, reducing the allocation of frequency-regulating reserve (FRR) and further reducing generation costs in system operations. Taiwan's Longmen Nuclear Power Plant is set to be converted for commercial operations, which will significantly alter the spinning reserves in the power system. Thus, this study proposes a safe and economic pumped storage unit dispatch strategy. This strategy is used to determine the optimal FRR capacity and 1-min recovery frequency in a generator failure occurrence at the Longmen Power Plant. In addition, this study considered transmission capacity constraints and conducted power flow analysis of the power systems in Northern, Central, and Southern Taiwan. The results indicated that, in the event of a failure at Longmen Power Plant, the proposed strategy can not only recover the system frequency to an acceptable range to prevent underfrequency load-shedding, but can also mitigate transmission line overloading.

Peak Operation of Cascaded Hydropower Plants Serving Multiple Provinces

“…Thus, the above load shedding algorithm can easily produce an initial transmission schedule shown in Figure 5b. However, this solution violated the power balance constraint in Equation (7). Therefore, the second part will improve this solution.…”

“…The main goal is to find a feasible and practical solution for this problem to alleviate the increasing peak-shaving pressures of receiving power grids in eastern and coastal China. Mathematically, the above problem is a highly nonlinear and nonconvex optimization problem with the nonlinear objective function of peak shaving and large amounts of spatial-temporal coupling system and plant operation constraints [6,7]. The simplification of such complex objective functions and constraints make it hard to obtain directly an analytic solution or a discrete optimum using linear programming [8,9], nonlinear programming [10][11][12], or dynamic programming [13][14][15].…”

Study on Nested-Structured Load Shedding Method of Thermal Power Stations Based on Output Fluctuations

“…Step 3: With the peak shaving capacity and the typical daily generated energy of thermal power station j being constrained, use the ILSM [3] to shed the power system's varying load to get the peak shaving output process and typical daily generated energy of thermal power station j.…”

“…Based on the ILSM [3] and the idea of a nested structure, the typical daily output process of a single thermal power station can be divided into two parts: the peak shaving output process, and the non-peak shaving output process. It can be regarded as the output process that is worked out with peak-shaving capacity and non-peak-shaving capacity of the thermal power station by using the ILSM.…”

“…The balance of electric power and energy is one of the important calculations in the planning and design of power grids, as well as in forecasting the schedule and operation of future power systems [1][2][3]. In this calculation, what is mainly studied is how power stations can cooperate with each other in a power system when the power supply conditions change within a period of time.…”