Research on state estimation for combined heat and power networks

Combined heat and power networks effectively improve energy efficiency. It is necessary to get a global solution with high accuracy for the combined networks, which is the basis of the subsequent analysis and optimization. State estimation has been widely adopted in the power system to decrease errors caused by measurements. Similarly, state estimation can also be used in the district heating network. State estimation for the district heating network is developed in this paper with a simplified dynamic model by the weighted least-square method. However, the state estimation for each network individually doesn't give a global solution. So, it is necessary to take coupling components into consideration. The proposed state estimation is for the entire combined power and heat networks. Because of the increased coupling constraints equations, the redundancy of the state estimation increases, which helps to improve the accuracy. This paper shows the comparison between the combined state estimation and the individual state estimation. The combined state estimation gives a global solution with higher precision, which helps the subsequent analysis and optimization.