Pmu memories: looking back over 40 years [in my view]

I am often asked how the phasor measurement unit (PMU) idea originated and how the technology has evolved over the years. This story is intimately connected with my work and that of my colleagues over the last 40 years. I am going to recount the events of these 40 years as faithfully as I can, but inevitably there may be some omissions-in particular, the names of my graduate students and colleagues-for which I apologize in advance. Omissions are not intentional; they are just artifacts of memory loss due to advancing age.