Optimal day ahead scheduling of combined heat and power units with electrical and thermal storage considering security constraint of power system

What is it about?

The use of Combined Heat and Power (CHP) with an overall efficiency from 70 to 90% is one of the most effective solutions to optimize the energy consumption. Mainly due to interdependence of the power and heat in these systems, the optimal operation of CHP systems is a complex optimization problem that needs powerful solutions. This paper addresses optimal day-ahead scheduling of CHP units with Electric Storage Systems (ESSs) and Thermal Storage Systems (TSSs) considering security constraints. Basically, the optimal scheduling of CHP units problem is a Mixed Integer Non Linear (MINLP) problem with many stochastic and deterministic variables. In this paper, linearization techniques are adopted to linearize equations and a two-stage Stochastic Mixed-Integer Linear programming (SMILP) model is utilized to solve the problem. The first stage models behavior of operation parameters and minimizes the operation costs meanwhile the second stage considers the system's stochastic contingency scenarios. The proposed method is applied to 18-bus, 24-bus IEEE test systems. The effectiveness of the proposed algorithm has been investigated.

Featured Image

Why is it important?

This paper proposed a model for CHP scheduling considering a static safety constraint (tripping out units and lines) in the presence of energy and thermal storage. Moreover, the model is proposed to consider the problem of purchased and sold electricity from/to the upstream network. The proposed formulation for the scheduling was a complex problem with two-step. The scheduling constraints of the CHP unit and the network constraints are considered in step 1 and the security constraints including the scenarios of tripping out units and lines are considered in step 2.