A NOVEL DYNAMIC ERROR DRIVEN TRACKING CONTRLLER FOR PV POWERED PMDC MOTOR DRIVES A.M. Sharaf* E. Elbakush* I. H. Altas** e-mail: sharaf@unb.ca e-mail: e.elbakush@unb.ca e-mail: ihaltas@ktu.edu.tr *Dept. of Electrical and Computer Engineering, University of New Brunswick Fredericton, Canada **Dept. of Electrical and Electronics Engineering, Karadeniz Technical University Trabzon,Turkey Key words: - Photovoltaic Energy, PMDC Motor, Dynamic PID Controller ABSTRACT This paper presents a robust different control strategy for a photovoltaic PV-powered permanent magnet DC (PMDC) motor drive system that ensures speed reference tracking and energy utilization efficiency, drive reliability and operation flexibility. A low cost Type- B (DC-DC) chopper is employed to control the power transfer from the PV array to the PMDC motor. A novel dynamic tri loop error driven controller is designed and utilized in the proposed PV powered-PMDC motor drive system. The dynamic performance of the tri-loop controller is digitally simulated and validated using the Matlab/Simulink/Sim-Power Software Environment. All unified study system sub-models comprising the PV array, DC-DC converter, PMDC motor, interface filters and dynamic controller are fully discussed. I. INTRODUCTION Photovoltaic PVA-solar powered electrical systems comprise different components and subsystems to be controlled separately. Since the generated solar power is dependant on uncontrollable environmental conditions, it requires extra caution to design controllers that handle unpredictable events and maintain efficient load matching power. In this study, a PV solar array model is developed for Matlab/Simulink GUI environment and controlled using the proposed PID controller. The dynamic PID controller’s performances is enhanced using tri loop activation to improve PV array-load bus maximum power matching condition, maintaining the DC load bus voltage at constant value as well as tracking a given reference trajectory such as moving a robot arm, a door, or a radar at a certain position. The novel tri-loop error driven controllers has flexible design criteria’s so that they can easily be modified and extended for controlling different systems [1]. One of the key challenging issues of PV array schemes is the power matching problem between the PV array and the load. Since the power generated by PV array is unpredictable due to changing solar irradiation level and ambient temperature, it is an important task to maintain a constant load voltage and power. Besides, the load being powered from the PV array may have excursions and switch on/off cases that affect the power matching. Since the output voltage of a PV array also depends on the current drawn from the array, load switching and excursions affect the array output voltage. Therefore the control problems in a PV array system are multi- dimensional and require multi-loop dynamic error driven approaches to extend the single input single output (SISO) controllers for handling systems that require multi input multi output (MIMO) controllers. The use of dynamic error loop supported PID controller turns the MIMO control problem into a SISO control problem eliminating and replacing the complexity by a simpler process [2]. The PMDC motor is used to drive a constant torque load, a pump type load or a position system, which may be radar, a door, or a robot arm positioning system. Each one of these load types requires different control strategies and different controller parameters. Therefore the controllers used in such a system must handle all the cases with an adaptive property in nature. The addition of dynamic error driven loops the controller structures increases the ability of the controllers to handle the changes occurring in the overall system [3]. The tri-loop PID control has been used in three different parts of the solar PV powered PMDC motor drive scheme studied here. One of these parts is the speed reference tracking, DC load bus voltage control and the third part is the optimal maximum power utilization by matching the PV source array to the dynamic load Volt-Ampere Characteristic. The tri-loop dynamic error driven PID controller has been used in three different parts of the solar PV powered PMDC motor drive scheme studied here. These parts are the speed reference tracking, DC load bus voltage control and the optimal maximum power utilization by matching the PV source array power to the dynamic load volt- ampere characteristics. The third part here deals with PV array maximum power point (MPP) tracking which is a hot issue in PV array utilization, so that many research have been going on [4-14] related to this topic. The MPP