Comparison Study in Various Controllers in Single-Phase Inverters Abstract-This paper explains the comparison of the controllers that suitable to be used in single phase inverter for studying purposes. This controller can easily been developed and tested using MATLAB/Simulink and implemented on the real time application. The controllers that have been developed are the Proportional Integration (PI)-dq controller, Proportional Resonant (PR) controller, and PR- Repetitive controller. The controller output will be connected to the pulse width modulation (PWM) generator to generate signal to the single phase inverters. All these controllers have been tested with the same load and simulation time. Keywords- PI, PR, PWM I. Introduction Single-phase inverters are the converter which transform the DC input to the AC output. The inverters can be cascade to be 3-phase inverters, which is suitable for grid connection. The outputs for the single-phase inverter are the voltage output (V O ) and the inductor current (I L ) and by controlling the I L the inverter can be used as a grid connection. This paper is focused on the current control method which is used in the renewable energy application. The current control for AC signal is not easy to implement due to time invariant current [1]. Other issues need to be consider are to maintain the stability and power quality [8] when it is connected to the renewable energy in achieves good grid connection. The best solution is to has an active feedback control with current feedback. This feedback control can be model in many ways. As been reported, its used deadbeat control, sliding control, state feedback control, and dq transformation with the PI control as the classic approach to the control current [3]. As known, the outputs are the AC signal which is related to the frequency that not suitable for PI control if no changing has been made on the controller mode. This paper analyses the single-phase inverter which is known as Voltage Source Inverter (VSI). This has been chosen because it is widely used and easy to develop. The controllers presented in this paper are the PI-dq controller, the PR controller and the PR-Repetitive controller. For the first controller it is based on Park transformation where it is used in three phase system but with some modification in order to obtain time-invariant variables [2] in single phase. This transformation creates the new imaginary signal [1] in the frame. It can be generated by the Phase Look Loop (PLL) application The second controller is the PR control and is based on the resonant frequency of the inverter output, where it has 50Hz frequency. This controller gives an advantage in performance at the fundamental frequency and ignore other frequency [3]. For the third controller it is based on the PR-Repetitive control that has ability to synthesize the error to minimize the low-order harmonic to the control signal [3,5]. This controller has ability to minimize the periodic error appear in the single phase PWM inverter [4]. Fig. 1 shows the controller diagrams that have been used in this paper. a) PI-dq synchronous rotating frame b) Presonant stationary reference frame c) Repetitive PR control Figure 1: Various controllers Shamsul Aizam Zulkifli * . Md Zarafi Ahmad ** *Department of Electrical Engineering and Electronics, University of Liverpool, UK. Email:s.aizam@yahoo.com ** Jabatan Kejuruteraan Kuasa Elektrik, Universiti Tun Hussein Onn Malayia, Malaysia. Email: zarafi@uthm.edu.my Proceedings of 2010 IEEE Student Conference on Research and Development (SCOReD 2010), 13 - 14 Dec 2010, Putrajaya, Malaysia 978-1-4244-8648-9/10/$26.00 ©2010 IEEE