Computation of milestones for decision support during system restoration

Abstract

System restoration involves status assessment, optimization of generation capability, and load pickup. The optimization problem needs to take complex constraints into consideration, and therefore, it is not practical to formulate the problem as one single optimization problem. The other critical consideration for the development of decision support tools is its generality, i.e., the tools should be portable from a system to another with minimal customization. This paper reports a practical methodology for construction of system restoration strategies. The strategy adopted by each power system differs, depending on system characteristics and policies. A new method based on the concept of "generic restoration milestones (GRMs)" is proposed. A specific restoration strategy can be synthesized by a combination of GRMs based on the actual system conditions. The decision support tool is expected to reduce the restoration time, thereby improving system reliability. The proposed decision support tool has been validated with cases based on a simplified Western Electricity Coordinating Council (WECC) 200-Bus system and Hawaiian Electric Company system.

Orthogonal genetic algorithm based power system restoration path optimization

“…Before calculating fitness value, the individual should be corrected if the topological constraint is not satisfied. The detailed correcting method can be found in Hou et al…”

“…The system restoration process consists of 3 stages: preparation, system restoration, and load recovery . The objectives and constraints of the 3 stages are different, and a multistage optimization model is usually used for system restoration . In the second stage, optimization of the restoration path is the foundation of system restoration and can accelerate system restoration.…”

Increasing Black Start Capacity by Fast Cut Back Function of Thermal Power Plants

“…To accomplish these GRMs, a series of detailed actions are necessary. For this purpose, the concept called Generic Restoration Actions (GRAs), which is proposed in [6], will be employed.…”

“…For example, for fossil units, startup power requirement and critical maximal interval are necessary; for super-critical-once-through (SCOT) units, startup power requirement and critical minimum interval should be considered; for black start units, such as hydro units, startup power requirement and time from cranking to parallel are zero [5], [8]. A generic model of generating unit [6] may be illustrated as Fig. 1, and the parameters are listed in Table 1.…”

“…It should be notified that at this stage, load restoration is only a means to the end. As a result, the implementation is decoupled into two sub-problems [6]:…”