Scheduling of Power Generation [antikvár]

1.1 General Characteristics of Electric Power Systems An electric power system is a combination of power-producing units, transmission lines, international cooperation, transformers, and a distribution network supplying customers with power under joint supervision and control. The development of the system and its further modifications according to customers' long-term needs is the task of system planning. The task of generation control is, however, to operate the existing generating and electric apparatus as a whole at an optimal level. This book is related to the subject of central generation control, which must meet the following main requirements: 1. The time-varying demand for active and reactive power must be met. The energy corresponding to active power cannot be stored in the system. This demand passes through the network in microseconds and manifests itself at the power plant generators. Fortunately, due to the composition of consumption, the power demand can be considered constant on the time scale of 1 min, and this is much larger than the reaction time of the controllers of the generators. The small fluctuations corresponding to time intervals shorter than 1 min are compensated by these devices. An additional characteristic of the system is that the production side has hardly any influence on consumption, which manifests itself for the production as an external factor 2. Generated power should also comply with the quality requirements of a technical nature. • The frequency of the alternating current may only deviate from the nominal value (50 Hz) within a prescribed tolerance range. This is a significant factor with regard to the operation and stability of a system since in power plants power is generated by synchronous generators. In addition, some power consumption devices (synchronous motors, electric clocks, railway safety devices) are also calibrated for nominal frequency. A. Prékopa et al Scheduling of Power Generálion, Springer Series in Operations I Research and Financial Engineering, DOI 10.1007/978-3-319-07815-1_1, © Springer International Publishing Switzerland 2014