Gradient Detection Starting Controlled Photovoltaic Sourced BLDCM Drive Without Position Sensors

An accurate commutation for position estimation is the main challenge in brushless (BL) permanent magnet (PM) type direct current (DC) motor drive in motion sensorless mode. A rugged position sensorless control with an accurate rotational direction control-based algorithm is presented here for solar photovoltaic (PV) array fed submersible and surface mounted centrifugal and helical water pumping. In this method, an initial accurate rotational direction control along with starting current control is implemented. No current sensor is used for mechanical rotor position estimation to make the system cost effective as it is mainly designed for agricultural applications. The reliability and dynamic performance of the system are validated through both simulation and experimental results on a laboratory prototype and in industrial test facility using commercial prototype with low cost Delfino DSP processor. The economical solution proves best fit for agricultural as well as household purpose water pumping.