Flexible resource optimization to mitigate operational problems from variable generation

Increased penetration of variable resources mainly in the form of wind and PV plants creates new challenges to power system operation, in the form of increased thermal unit cycling, ramping requirements and increased capacity reserve requirements. One approach is to address these issues by utilizing the increased flexibility offered by energy storage devices (utility and customer owned), distributed responsive load and thermally controlled loads. The flexible resources come with their own set of physical and customer convenience constraints to their flexibility. In this paper, the flexible power system operation problem is cast as a multi-step OPF problem which includes transition constraints of flexible dynamic resources and customer requirements. The flexible resource constraints are derived from their physically-based model and imposing the “no customer inconvenience” requirement. Model, objectives and constraints are expressed with quadratized models (objects) leading to an object-oriented quadratic flexible OPF. An efficient solution algorithm with good convergence properties is presented. Initial results in a sample system are also presented.