Design and Performance of a Cost-Effective BLDC Drive for Water Pump Application

This paper presents a promising solution to the problem of the bad environmental impacts of the induction-motor-based water pumps. Due to the low wire-to-water efficiency of the current residential water heaters (around 30%), a high energy cost is paid by every household in North America and even worldwide. The contribution of this paper comes in twofolds. The first is the development of a mapping algorithm that relates the pressure head $H$ and the water flow rate $Q$ to a corresponding torque and speed under the chart of best efficiency point, which was programmed to the controller. The second is the development of a cost-effective brushless direct-current (BLDC) motor through an extensive numerical analysis technique. The proposed motor solution designs the BLDC with minimal pulsating torque by comparing two different designs. The new controller is based on a modified field-oriented control. The controller printed circuit board is of two layers to offer a cost-effective solution. The proposed pump eliminates the need of a battery for the controller as the control voltage is fed directly from the line together with the motor. The motor simulation model and the controller design procedure are presented with simulation results of two possible prototypes. An experimental prototype for a 150-W residential pump was built, and preliminary results are given to highlight the merits of the work.