Comparative Analysis of the Modified Perturb & Observe with Different MPPT Techniques for PV Grid Connected Systems Saad A. Mohamed Abdelwahab* , ***‡, Abdallah Mohamed Hamada **, Walid S.E. Abdellatif * , **** * Electrical Department, Faculty of Industrial Education, Suez University, Suez, Egypt. ** Electrical Department, Alex. Technological Collage, Min. of Higher Education, Alex., Egypt. *** High Institute of Electronic Engineering, Ministry of Higher Education, Bilbis- Sharqiya, Egypt. ****Department of Electronics and Electrical Communications Engineering, Higher Institute of Engineering and Technology, Ministry of Higher Education – Kafr Elsheikh, Egypt. (saad.abdelwahab@suezuniv.edu.eg, abdallahmhe@yahoo.com, walid.abdellatif@suezuniv.edu.eg) ‡ Saad A. Mohamed Abdelwahab; Electrical Department, Faculty of Industrial Education, Suez University, 43527 Suez, Egypt, Tel: +201096250375, Fax: +20629203469, saad.abdelwahab@suezuniv.edu.eg Received: 04.01.2019 Accepted:07.02.2020 Abstract- The maximum power point tracking (MPPT) techniques are used in photovoltaic (PV) systems to fully utilize the PV array output power that depends on the change in PV radiation and ambient temperature. In this paper, modified perturb and observe (MP&O) algorithm is proposed to be more efficient for MPPT of grid-connected PV system. The results of this MP&O algorithm are shown to track the maximum energy under fast-changing weather conditions at two cases of solar radiation changes, the first case is the solar radiation change in ramp mode, and the second case is the displaying under random change of solar radiation. The maximum power point (MPP) can be obtained by controlling the operating period that is fed on the MOSFET gate within the boost converter. In addition, the control technique used with the three-phase inverter is a dynamic-based PI controller. The MP&O algorithm is built on the determination of the maximum effective point on the property curve and is similar to the traditional scheme. The idea of this comparison is to use the change in solar radiation to determine the difference between the working point of the PV solar array and the number of sectors. The performance is estimated and compared by mathematical investigation and simulation analysis. The proposed method offers high performance and accurate tracking in rapidly varying weather environments. Keywords Maximum power point tracking, perturb and observe algorithm, MP&O and grid connected PV system. 1. Introduction Photovoltaic (PV) energy depends on converting sunlight into electricity. In recent years, the price of PV array has decreased dramatically until, which led to an increase in PV generation in recent years. Many studies rely on PV systems to simulate the development of PV algorithms, maximum power point (MPP) tracking, and control strategies. Standalone PV systems must be connected to the solar energy storage system, while in the PV grid connected system does not need energy storage systems and this is what distinguishes it from stand-alone PV systems. Researchers in the PV system need to be easy and reliable ways to track the maximum power of the PV power generated under different conditions of solar radiation and temperature [1]. The increasing demand for electric energy around the world is a result of the increased use of new and renewable energy sources. One of the best renewables that have been studied extensively in recent times is PV energy. PV energy has many obvious advantages, among which it is a clean energy source that has no polluting effect, very reliable and flexible in size, and requires minimal maintenance [1-2]. The low efficiency of the PV system is a driving force for tracking the maximum power generated by PV systems. Many papers are classified as a development of the PV system with MPPT methods in the last few years. MPPT of direct methods