Operating Reserves and Variable Generation. A Comprehensive Review of Current Strategies, Studies, and Fundamental Research on the Impact that Increased Penetration of Variable Renewable Generation has on Power System Operating Reserves

摘要

Power system operators have a number of responsibilities that focus on maintaining reliability. System generation must be as close as possible to the system load and electrical losses to ensure that system frequency is maintained at or very close to nominal levels (60 Hz in North America, 50 Hz in Europe and many other areas throughout the world). In areas that are a part of a larger synchronous interconnection it must be ensured that tie-line flows between areas are kept at their scheduled flows. This is achieved through numerous procedures on different time scales using both economic response and deployment of reliability reserves with both centralized control and autonomous response. Power flows must be kept below the maximum limits on equipment such as transmission lines and transformers through the dispatch of generating units and through direct flow control with phase shifting transformers and flexible AC transmission system (FACTS) devices. Voltage levels throughout the power system must also be kept within nominal levels at all locations on a network. This is achieved through reactive power management of generators as well as by controlling transmission system devices including voltage regulators, transformer taps, capacitors, reactors, static VAR compensators, statcoms, and synchronous condensers. Systems must also be able to withstand contingency events with preventive control actions holding reserves and limiting pre-contingency flows so that the system will survive the event and normal operations can be fully restored shortly following these events.