Smart Dispatch and Demand Forecasting for Large Grid Operations with Integrated Renewable Resources

Abstract

The restructured electric power industry has brought new challenges and concerns for the secured operation of stressed power systems. As renewable energy resources, distributed generation, and demand response become significant portions of overall generation resource mix, smarter or more intelligent system dispatch technology is needed to cope with new categories of uncertainty associated with those new energy resources. The need for a new dispatch system to better handle the uncertainty introduced by the increasing number of new energy resources becomes more and more inevitable. In North America, almost all Regional Transmission Organizations (RTO) such as PJM, Midwest ISO, ISO New England, California ISO or ERCOT, are fundamentally reliant on wholesale market mechanism to optimally dispatch energy and ancillary services of generation resources to reliably serve the load in large geographical regions. Traditionally, the real-time dispatch problem is solved as a linear programming or a mixed integer programming problem assuming absolute certainty of system input parameters and there is very little account of system robustness other than classical system reserve modeling. The next generation of dispatch system is being designed to provide dispatchers with the capability to manage uncertainty of power systems more explicitly. The uncertainty of generation requirements for maintaining system balancing has been growing significantly due to the penetration of renewable energy resources such as wind power. To deal with such uncertainty, RTO’s require not only more accurate demand forecasting for longer-term prediction beyond real-time, but also demand forecasting with confidence intervals. This chapter addresses the challenges of smart grid from a generation dispatch perspective. Various aspects of integration of renewable resources to power grids will be discussed. The framework of Smart Dispatch will be proposed. This chapter highlights some advanced demand forecasting techniques such as wavelet transform and composite forecasting for more accurate demand forecasting that takes renewable forecasting into consideration. A new dispatch system to provide system operators with look-ahead capability and robust dispatch solution to cope with uncertain intermittent resources is presented.