The disadvantages of the Brushless DC Motor over the AC motors are:
higher maintenance (due to brushes)
more expensive
In addition to the above the Brushless DC Motors have the same advantages over AC motors but they also have more advantages over Brushed DC Motors
lower maintenance (no brushes)
even higher starting torque ( Due to rare earth magnets)
even higher efficiency (over 90%) on sub fractional motors
even more compact design
better heat dissipation
lower noise
The dynamic performance of a permanent magnet brushless DC (PMBDC) motor connected to photovoltaic (PV) array through an inverter is analyzed. The mathematical models of PV array, inverter/motor and controller are developed. The photovoltaic array is represented by an equivalent circuit whose parameters are computed using experimentally determined current-voltage (I–V) characteristics. The necessary computer algorithm is developed to analyze the performance under different conditions of the solar insolation for pump load. The study also examines the effectiveness of the drive system both for starting and DC link voltage fluctuations caused by varying solar insolation.
