Improvement Of Reactive Power Sharing in Islanded AC Microgrid

نوع: Type: thesis

مقطع: Segment: Masters

عنوان: Title: Improvement Of Reactive Power Sharing in Islanded AC Microgrid

ارائه دهنده: Provider: Alireza Vafaeifar

اساتید راهنما: Supervisors: Dr. Mohammad Amin Ghasemi

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Dr.Shahbazi & Dr.Razini

زمان و تاریخ ارائه: Time and date of presentation: 21/2/2022

مکان ارائه: Place of presentation: Faculty of Engineering

چکیده: Abstract: Development of technology and evolution in lifestyle, increase the need for energy resources in human societies. Generating electricity through small-scale sources as well as the use of renewable energy sources in electricity generation has created new concepts in this industry like microgrids. Providing power to consumers in the microgrid along with maintaining voltage and frequency within the defined range is the most fundamental task of power generation resources in the microgrid. Meantime, to avoid overloading generators, the share active and reactive power for each one must be specified. The droop control method is used as a simple method in dividing power between distributed sources. Despite the simplicity of implementation and the lack of complex equipment to communicate between network elements, this method has disadvantages such as deviation of the voltage and frequency range from the nominal values, as well as the lack of proportional distribution of reactive power among generators. In this research, while describing the droop control method in active and reactive power sharing in output power of electronic converters, the disadvantages of this method in reactive power distribution due to differences in the output impedance of converters have been investigated. In the next section, while presenting a proposed method in modifying the droop control method, its effect on improving the sharing of reactive power among manufacturers in a microgrid in an islanded mode is discussed. After identifying load change, this method according to the unity of the frequency in the microgrid, during three steps estimates the reference value of reactive power for each unit. After performing the conventional droop control method in the first step, in the next step, by creating a ratio between the sum of active and reactive power with frequency in the network by changing the droop control logic, the reference value of reactive power for each generator unit is obtained. In the third step, the difference between the reactive power output of the distributed generator and the calculated reference value is eliminated. Thus the reactive power consumption of the network is divided between the sources as desired. There is no need to measure the output impedance of each unit. Other features are the ease of use and the lack of dependence on communication lines between microgrid elements. Keywords: Droop Control, Distributed Generation, Electrical Inventers, Microgrid, Active Power Sharing, Reactive Power Sharing