Multi-time scale fuzzy chance constrained dynamic economic dispatch model for power system with wind power

Fuzzy uncertainty of wind power output increases difficulty of dispatching decision. This paper used fuzzy parameters to express wind power and load forecast. Based on credibility theory, traditional deterministic system constraints were transformed into fuzzy opportunity constraints. Because accuracy of wind power and load forecasting improves with shortening of forecasting time scale. Therefore, this paper set fuzzy confidence level as incremental vector to reflect change of forecast accuracy. A fuzzy chance constrained dynamic economic dispatch model with multiple fuzzy parameters in multi-time scale was established. Multi-time scale dispatching plan was divided into a day-ahead 24-hour plan, an intra-day 4-hour rolling plan, a real-time 15-minute plan and automatic generation control (AGC). Dispatching plan of each time scale was in harmonic coordination, and balanced economy and reliability. Rolling amendment of original generation plan and absorption of forecast deviation step by step according to the latest forecast information of wind power and system load were achieved. An example of an actual wind field data in Shanxi Province was calculated to verify that this model effectively reduced uncertainty impact of wind power and load forecasting and relieved adjustment pressure of dispatchers and AGC units. © 2016, Power System Technology Press. All right reserved.