Wyniki 1-2 spośród 2 dla zapytania: authorDesc:"Bardhyl SYLEJMANI"

An experimental study for the islanding detection by the harmonic distortion method and protection system of the inverter DOI:10.15199/48.2019.04.44

Czytaj za darmo! »

The problem of islanding of photovoltaic systems interconnected with utility grid has been the main challenge in implementing distributed generation of electricity. Islanding is a condition in which a portion of the utility system, which contains both load and operating generation. The distributed generation of electricity is an option that is being considered seriously around the world, especially in countries where the centralized power generation system is very old and causes large environmental pollution. Distributed generation, as defined by Karlsson is “…an electrical power generation source connected directly to the distribution grid or on the customer side of the meter". One of the main problems encountered in distributed generation is the possible formation of isolation conditions (areas called the island) that can continue to work normally even if the electrical grid is disconnected. For applications without detection and correction, it is better to combine more methods for detection of islanding detection based on other work processes [1, 2]. This unity power factor condition combined with passive parameters of parallel RLC load and frequency is considered the worst case for islanding detection when the active power of load matches to the output power of distributed generation [3, 4]. Is describes an anti-islanding control technique for use in utilityinterconnected photovoltaic systems. The technique can be used to prevent islanding in any distributed generation resource that uses a static inverter as the interface device [5]. The ability to protect from the creation of islanding circumstances is an important request for distributed generation. It is necessary to detect when the system works under insulation conditions and disconnect from the network as soon as possible [6]. Detecting the islanding is important for all DG systems. In the last decade, many algorithms have been developed for such detect[...]

An experimental study of passive methods for islanding detection and protection system of the inverter operation DOI:10.15199/48.2018.02.28

Czytaj za darmo! »

The distributed generation of electricity is an option that is being considered seriously around the world, especially in countries where the centralized power generation system is very old and causes large environmental pollution. Distributed generation, as defined by Karlsson [1] is “…an electrical power generation source connected directly to the distribution grid or on the customer side of the meter". One of the main problems encountered in distributed generation is the possible formation of isolation conditions (areas called the island) that can continue to work normally even if the electrical grid is disconnected [2]. For applications without detection and correction, it is better to combine more methods for detection of islanding detection based on other work processes [3]. The distribution generation is considered to be in unity power factor operation [4]. This unity power factor condition combined with passive parameters of parallel RLC load and frequency, as given in (1)-(4), is considered the worst case for islanding detection when the active power of load matches to output power of distribution generation. 1. The power generated by DG should match the RLC load power, DP = 0 and DQ = 0. 2. A resonant frequency of the RLC load is the same as grid line frequency (f = 50Hz). 3. The quality factor Qf of RLC load is set to be 2.5. The quality factor is defined as that the reactive power stored in L or C is at times the active power consumed in R. Load definition can be represented as (1) 1 2 f  LC  (2) V 2 R P  (3) 2 2 f L V  fQ P  (4) 2 2 f Q P C  fV  where: R - effective load resistance [W], L - effective load inductance [H], C - effective load capacitance [F], P - active power [W], Qf - quality factor, f - grid frequency [Hz]. The values of frequency and magnitude of the voltage at the point of common coupling (PCC) after grid d[...]

 Strona 1