State Estimation and Fast Fault Detection For Ship Electrical Systems

In this paper, the advantages of state estimation on ship power systems are demonstrated and extended to perform fast fault detection. For more-electric ships it becomes critical to monitor the system and respond to faults within milliseconds to limit damage from the fault and transfer to an intact supply. A compact ship allows syncronization of sampled real time voltage and current data from electrical sensors to compute the phase angle and voltage magnitude at every bus on the system. On a ship power system the data samples can be collected every 0.5 milliseconds by the central computer. Bad data analysis, smoothed values for the operating condition, and differential current sensing are performed within milliseconds. An example of state estimation is done for an LPD17 assault ship. Other examples of using phase data and fault detection are given in the paper. Algorithms for remedial action may be activated by the results of the state estimation and fault detection.