A framework for black start and power system restoration

Abstract

This paper introduces the concept of a new framework for power system restoration. Its objective is to minimize the large number of time-domain simulations that is usually necessary in order t o find a suitable restoration sequence. T h e new method is based o n rules that deal with specific problems encountered during restoration and that are formulated an the frequency and Laplace domain. Once a suitable restoration sequence is found, it can be verified by a single set of time-domain simulations. As a n example for a specific rule, the assessment of motor starts during a n emergency and black start procedure for thermal power plants is investigated. Simple analytical rules are developed that help to predict motor start-up times, currents, and voltage drops. T h e validity of the results is confirmed by time-simulations carried out with the Electromagnetic Transients Program ( EMTP) . 0-7803-5957-7/00/$10.00 0 2000 IEEE 153

A Study on the Tolerance Band of Voltage Drop during Motor Startup for Refineries and Chemical Plants with Isolated Power Systems

“…In this study, field tests and simulations set at conditions identical to those of the field tests were conducted on industrial plants with the majority of the load of the power system composed of induction motors. Through the analysis, 70% of rated voltage was proposed for possible motor startup in consideration of the rated torque on breakdown torque regarding motor terminal voltage, even in cases with different motor capacities and impedances used at the industrial plant [9,24,28].…”

“…However, according to reference literature, a normal motor startup was achieved even with a 38% voltage drop during motor start-up [28]. Furthermore, the allowed terminal voltage during motor startup has been set at 75% for a starting torque of 100%, as well as for the maximum torque condition of 200% [29].…”

Determining the best sequence of load pickup during power system restoration

“…Even if service interruption is a rare event, it is essential for an electric utility to prepare itself to face such emergencies, developing strategies to minimize the impact and to restore energy to the users as quickly as possible [5]. During the initial phase of restoration, black-start turbines are often considered as remote cranking sources for the start-up of steam electric stations [6]. This paper investigates hydro power plants and steam turbine units in black start regime for the case of load insertion and based on all the possible simulation results, determines the best way of loading the power plants.…”

Computation of milestones for decision support during system restoration

“…Few, if any, system-wide decision support tools are available to dispatchers and restoration planners at present. Restoration plans are developed with basic simulation tools for power flow, dynamics [3], [9], [10], and electromagnetic transients [11], [12]. These plans developed offline are used as guidelines for dispatchers in an online environment [13], [14].…”