International Journal of Power Electronics and Drive System (IJPEDS) Vol. 8, No. 4, December 2017, pp. 1714~1722 ISSN: 2088-8694, DOI: 10.11591/ijpeds.v8i4.pp1714-1722  1714 Journal homepage: http://iaesjournal.com/online/index.php/IJPEDS Digital Control for a PV Powered BLDC Motor Slamet Riyadi Department of Electrical Engineering, Soegijapranata Catholic University Semarang, Indonesia Article Info ABSTRACT Article history: Received Sep 17, 2017 Revised Nov 7, 2017 Accepted Nov 22, 2017 Stand-alone applications of Photovoltaic (PV) can be found in water pumping systems for rural area. The proper electric motor must be chosen for optimal considerations. One of the modern electric motor called brushless motor (BLDC) can be an alternative for this application although it has complexity in control. Powering such a motor by using electric energy generating by PV modules will be an interesting problem. In this paper, a PV powered BLDC motor system is proposed. The PV modules must produce maximum power at any instant time and then this power must be able to rotate the motor. By combining sequential stator energizing due to a rotor detection and a PWM concept, the speed of BLDC can be controlled. Meanwhile, to get maximum power of PV modules, detection of voltage and current of the modules are required to be calculated. Digital Signal Control (DSC) is implemented to handle this control strategy and locks the width of the PWM signal to maintain the PV modules under maximum power operation. The effectiveness of the proposed system has been verified by simulation works. Finally the experimental works were done to validate Keyword: Brushless DC motor Digital Control Inverter Photovoltaic PWM Copyright © 2017 Institute of Advanced Engineering and Science. All rights reserved. Corresponding Author: Slamet Riyadi, Department of Electrical Engineering, Soegijapranata Catholic University, Pawiyatan Luhur IV-1, Bendan Dhuwur, Semarang 50234, Indonesia. email: s_riyadi672003@yahoo.com 1. INTRODUCTION Photovoltaic (PV) can be implemented in stand-alone applications or in PV grid systems. Most of the stand-alone applications can be found in water pumping systems. The systems commonly implement AC induction motors to rotate the water pump with or without batteries. Although the AC motor requires higher voltage rating for operation, this kind of motor is more preferable. PV has characteristic that a combination between current and voltage sources, so the operation of PV modules should regard the maximum power point (MPP), it is a point where the PV modules produce maximum power. Solar irradiance and temperature take effect the location of its MPP. Application of PV modules commonly require a maximum power point tracker (MPPT) to ensure the maximum power will be generated. Some methods of these have been described [1],[2]. Some applications of PV powered water pumping system utilize AC motors to drive water pumps. Two converter was also used in the system, the push-pull converter was operated as a MPPT and to increase the voltage level, the inverter was implemented to convert DC voltage into AC [3]. Implementation the standard DC-DC was applied for its simplicity [4],[5]. For high power rating, three phase AC induction motors were often used. These motors required three phase inverters to drive as the second converter and a MPPT can apply push-pull converter [6]. An induction motor doesn’t have characteristic as good as the characteristic of a DC motor but the induction motor has some advantages. The problem of a DC motor is due to its commutator, but as the power electronics and digital technology advance the commutator can be replaced by an electronic circuit. An electric motor which adopts this concept then is called brushless DC