Automatic system for regulating the frequency and power of the 500 MW coal-dust power generating units at the Reftinskaya GRÉS

Abstract

The monitoring and control systems at the 500 MW coal-dust power generating units No. 7, 8, and 9 at the Reftinskaya GRÉS have been modernized using information-regulator systems. Layouts for instrumental construction of these systems and expanded algorithmic schemes for the automatic frequency and power control system and for the boiler supply and fuelling are discussed. Results from tests and normal operation of the automatic frequency and power control system are presented.Keywords: Reftinskaya GRÉS, 500 MW coal-dust power generating unit, information-regulator system, automatic frequency and power control system.The largest coal-dust power plant in Russia, the Reftinskaya GRÉS (State Regional Electric Power Plant), has 6300 MW and 5500 MW power generating units. In 1997, experts from the Reftinskaya GRÉS and "Interavtomatika" modernized the existing monitoring and control systems by installing a full-scale microprocessor process control system based on Siemens' Teleperm ME-OM650 devices. Even today, this system is unique in terms of the level of automation achieved on power generating equipment in Russia, especially a plant as complicated as this large coal-dust unit where the coal dust is injected directly [1 -3].Unfortunately, because of some well known financial difficulties, for a long time it was not possible to extend these results to the remaining 500 MW power generation units. A definite step in this direction, but limited in extent, has been taken in the last few years (2006 -2008) by partial modernization of the monitoring and control system for the 500 MW power generation units No. 7, 8, and 9 by installing so-called information-regulator systems in them.The main goal in installing the information-regulator systems was to create an automatic frequency and power regulation system within the range of specifications for common primary frequency regulation and to solve a number of information-computational problems using modern technical means previously developed by experts at the Reftinskaya GRÉS for the previous generation of equipment (M60 -M6000 systems), while taking into account the experience gained in installing a process control system on unit No. 10.Both for regulating the frequency and power and for the purpose of substantially improving the quality of the regulation processes for the power generation units, this modernization project was based on a new functional level (at least as high as that achieved for unit No. 10) for all the boiler regulators (both for normal operation, and for startup-shutdown, including temperature programmers for the primary and secondary loops) and a number of important regulators for the turbine units and the condensate-feed loop.The configuration of the information-regulator system. The information-regulator system for the 500 MW generator unit at the Reftinskaya GRÉS is based on program support of the Siemens Simatic PCS7 PS. At the lowest, controller level, the information-regulator system for each generator unit (Fig. 1) includes three controllers:-a backu...