(373b) An Efficient Method for Leak Detection and Isolation in Natural Gas Pipelines Using Dual Unscented Kalman Filter

Pipelines are efficient and economic ways for transporting and distributing water, natural gas, and petroleum products; these are extensively used all over the world. Monitoring the integrity of the pipeline systems has become an important issue for the safety and economical operation, and environmental protection.  In this paper, an efficient and reliable leak detection and isolation method has been proposed for on-line monitoring of a natural gas pipeline system. Dual unscented Kalman filter (DUKF) was employed for the on-line estimation of the states and parameters, simultaneously.  Small leaks, which are usually masked by the background noise, pose a challenge to all existing leak detection methods.  The proposed leak detection method can adjust the parameters online according to the changes in the operating conditions, and thus was able to detect small leaks accurately, even with a normal transient state and with noisy measurement data. Simulation results demonstrated the capability of the proposed methodology to detect and locate the leak quickly, and accurately.  Comparison studies of the extended Kalman filter (EKF), unscented Kalman filter (UKF), and DUKF show the superiority of DUKF over EKF and UKF for leak detection and location of the leaks in natural gas pipelines.  Industrial data are used to validate the results.