How to detect inductive, capacitive and resistive load?

Question

microprocessor will detect it, then operate the power factor corrector according to load,it is capacitive, inductive of resistive load.. am i really need to detect the load?

Answer 1

just sample voltage and current maybe 100 times a second, easy for a microprocessor. Then you can reconstruct the waveforms and calculate the angle between the two, and from that decide on the power factor and what correction.

You can detect the voltage via a large value series resistor and an A-D, and the current via a small value shunt resistor and either another A-D or the same one multiplexed.

There are lots of other alternatives, but this is the simplest, at least in concept.

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Answer 2

so long as you can sample source voltage-current before the load element, you can develop a process!

investigate PFC pre-regulators for clues; common techniques includes a precise low value resistor and end of load element  to compare the voltages (Vin average against Vr average)

a series element, purely resistive voltage divider (low Z), could minimize phase displacement and still allow sampling of  leading lagging voltage against a sensed current