Discrete Time Modeling and Improved Controller Design for Shunt Active Power Filter

نوع: Type: thesis

مقطع: Segment: masters

عنوان: Title: Discrete Time Modeling and Improved Controller Design for Shunt Active Power Filter

ارائه دهنده: Provider: Sajad chaharmahali

اساتید راهنما: Supervisors: Dr. Mohamad Hasan Moradi

اساتید مشاور: Advisory Professors: Dr. Mohamad Mahdi Shahbazi

اساتید ممتحن یا داور: Examining professors or referees: Dr. Alireza Hatami and Dr Majid Ghanie

زمان و تاریخ ارائه: Time and date of presentation: 2021

مکان ارائه: Place of presentation: Online

چکیده: Abstract: Harmonics are electrical voltages and currents that occur in the power grid due to a variety of electrical loads and can cause problems with telephone transmission lines, damage to conductors and insulation materials for motors and transformers. Harmonic currents have a significant effect on power systems and their power supply equipment, so it is important to pay attention to harmonics when planning to build or modify a system. In addition, to identify the location and size of nonlinear loads, the most important part of maintenance programs is troubleshooting and modifying programs. The occurrence of harmonics in power systems is the first consequence of the presence of nonlinear elements in the network. A nonlinear element is an element whose current is not proportional to the applied voltage. Increasing the voltage by a few percent may cause the current to double and the current to deform, resulting in harmonic distortion. As harmonics increase over the years, follow-up should be done when building or modifying equipment to check for penetration. As a result, it is essential to use the necessary tools to eliminate harmonics that improve power quality. The most effective harmonic removal technique, the active filter, has always been used to increase the power quality with increasing demand. Typically, the active filter control system consists of three parts: 1- Identifying harmonies 2- Voltage regulator on the dc side of the active filter 3- Providing a reference for the active filter switches. The most important part in controlling the active filter is identifying the harmonics and separating them from the main part of the load current and synchronizing the received signals with the mains voltage by PLL. The use of conventional PLLs is efficient when the voltage source is sinusoidal and balanced, otherwise this method does not work well and increases the harmonics in the load current. In this project, a new PLL is used for synchronization, which shows proper performance against network imbalance and distortion, and performs synchronization operations correctly