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A robust high-speed sliding mode control (SMC) of three phase permanent magnet synchronous motor (PMSM) is presented. The SMC served for inner speed control while a simplified hysteresis current control (HCC) scheme was used in the outer current control to generate gating signals for the inverter switches. The present research leverages on the ability of SMC to directly access system speed error which it attempts driving to zero by cancelling modelling uncertainties and disturbances. Performance comparison was done for the SMC model and an existing model having classical PI controller. With the initial positive speed command of 200 rpm at 5 Nm constant loading, rotor speed with SMC neatly settled to the reference speed at 0.085 seconds without overshoot while the rotor speed of the model with PI controller settled at 0.217 seconds after overshoot. This translates to 155.3% speed enhancement. Similar superior speed performance of the SMC was also observed during recovering from sudden speed reversal. While the SMC model recovered and settled to the reference speed of -200 rpm at 0.369 seconds, the model with PI controller settled at 0.482 seconds. From the results, it can be seen that SMC demonstared superiority over the conventioanl PI controller for complex drives systems.

Energy, which is required to run space satellites, is as old as space technology itself. The location of these satellites has made it more applicable for unconventional means of energy generation to run them. The Sun being the universal and greatest source of all forms of energy, as well as the closest energy source to space satellites, has been so appropriately trapped using solar cells. Solar power satellites are designed to capture solar energy and transmit that energy to receiving stations using wireless power transmission mechanism. This paper is written to rehearse the immediate and associated usefulness of solar energy trapped from space as an alternative for electricity generation for the future; it is also an attempt to appraise the prospects of this scientific conviviality.

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