Brief History of State Estimation

Summarizing half a century of state estimation history into a brief digest has been facilitated, indeed made possible, by the fact that, unlike the power system operating reliability monitoring and control, which unfolded via long, distinct step function-like stages, from the pioneering years, when systems were dispatched by telephone, to the current SCADA/EMS (Supervisory Control And Data Acquisition/Energy Management System) paradigm, the state estimation began with a false start, so to speak, but instantly underwent a course correction and quickly got settled to what it still is today: a fast and dependable function that converts real-time readings into a mathematical model that approximates the current system state for the main purpose of simulating postulated operating scenarios. This brief chapter also shows that what was originally perceived as a complex interactive application ended up being ran silently in the background—indispensable, of course, but requiring almost no tweaks from the operator. The original algorithm nuts and bolts did evolve, but these and other solution technique details and improvements form the subject of the remaining chapters of this book.