计及多能流运行时序性的电-气互联系统协同状态估计

电-气互联综合能源系统可灵活实现多区域能源交互，但其多能流子系统存在的信息交互壁垒、量测延迟等时序不统一因素会给系统精准监测与调度带来不利影响。针对多能流子系统不同的运行时间尺度，构建计及统一时间尺度的顺序协同估计框架，并考虑多源量测设备采样周期的延迟问题，将量测时延融合思想引入估计框架中以矫正多源量测数据的时序不同步。提出基于改进卡尔曼滤波的综合能源系统实时估计算法，通过引入基于改进交替投影的对称正定理论，避免实时估计过程中因误差传播出现非正定导致的估计失败问题。仿真结果与对比分析验证了所提协同状态估计策略能够有效实现对电-气互联综合能源系统的在线精准监控，且估计结果具备更强的数值稳定性。

Coordinated state estimation for electricity and gas integrated system considering timing sequence of multi-energy flow operation

The electricity and gas integrated energy system can realize multi-regional energy interaction flexibly, but the time-sequence unified elements such as information interaction barrier of its multi-energy subsystem and measurement delay etc. have negative effects on accurate monitoring and scheduling of system. Aiming at the different operation time-scales of multi-energy subsystem, the sequential cooperative estimation framework with unified time-scales is built, and considering the time-delay issue of the sample period for the multi-source measurement equipment, the concept of measurement time-delay fusion is introduced to the estimation framework to address the time-sequence discrepancy between the multi-source measurement data. The real-time estimation algorithm of integrated energy system based on modified Kalman filter is proposed. Avoiding the issue of estimation failure caused by the error propagation that is non-positive definite in progress of real-time estimation by the introduction of the enhanced alternating projection-based symmetric positive definite theory. The simulative results and comparison analysis show that the proposed coordinated state estimation strategy can realize the online accurate monitoring of the electricity and gas integrated energy system effectively, and the estimation results have greater numerical stability.