A Secure Distributed Computation of Combined Heat and Power Dispatch Based on Transformation Method

The widespread utilization of combined heat and power (CHP) units creates a tight couple between the power transmission system (PTS) and district heating systems (DHS). Since PTS and DHS are always managed by different operators with information security concerns, there has been a growing interest in implementing distributed solutions for combined heat and power dispatch (CHPD). However, existing distributed algorithms require an exchange of information, such as CHP output and dual multipliers, between PTS and DHS, posing a potential risk of information leakage. To address this issue, we introduce a transformation-based method to mask the CHPD model, thereby masking the real economic and physical coefficients using random nonsingular matrices. We discuss the selection principle for encryption matrices to diminish the additional computational burden caused by transformation. Then, we develop an improved Benders decomposition method by introducing valid inequalities and strengthening Benders cut to efficiently solve the masked CHPD problem in a distributed manner. The proposed secure analysis proves that the proposed method can resist two common threat models in information security, including semi-honest adversaries and external eavesdroppers. Numerical simulations are conducted to illustrate the effectiveness and scalability of the proposed method.