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Photovoltaic generators can provide several benefits for distribution networks, such as power loss reduction, and improvements in voltage level. However, high penetration of these generators can cause voltage rise problems in the distribution network. In this way, voltage control strategies are necessary so that the voltage levels are within the range of operation for any load and generation conditions...
A recent report from the German Energy Agency analyzes the possible introduction of the blockchain technology in energy transactions in power distribution. The issue deserves attention since the extensive digitalization of business models puts new challenges to utilities in the power sector. The German decision makers in the energy field claim that blockchain appears as a close perspective and, at...
In this paper, a class of coordination control problems of power system in distribution networks is addressed. The multiple photovoltaic generators (PVs) in network are expected to be operated in a certain level, namely Fair Utilization, in order to provide reliable power of high quality. In other words, the occupancy ratios of all PVs that are determined by the current active and reactive power outputs...
In Grid-Connected PV system should not be limited injecting the active power into the grid. However, it must be able to absorb or to generate sufficient reactive power for a certain amount of time according to the grid demand and maintain the grid voltage. This paper proposes sliding mode control that controls powers respectively the active and the reactive power for a Three-Phase Grid-Connected PV...
In this paper is presented the current situation of the photovoltaic power plants in Romania. Also, is analyzed the impact of two photovoltaic (PV) power plants, which are installed in the Mureş County, on a Medium Voltage Line. The PV power plants are connected to the Sovata-Fântânele 20 kV Overhead Medium Voltage line. The case study contains an analysis of the active and reactive power losses across...
The expanding installation of photovoltaic (PV) resources into power systems continue to grow which affects both structural and dynamics of power systems. The effects of large-scale grid-connected PV on the stability of power systems becomes a serious concern, because of the different dynamic behaviour of the power system with a considered portion of inertialess of the P-V based systems. This paper...
This paper concentrates on the control of power flow in single stage photovoltaic energy conversion system. The conversion structure has a twofold requirement that consists in ensuring that the current injected to both load and grid obeys to the grid connection standards and sets the DC bus voltage similar to the reference voltage given by the MPPT algorithm. The advanced functions that can be added...
The objective of the paper is to present the modelling of the single phase grid connected Photovoltaic (PV) generation and its impact on low voltage grid. The network model has been developed in PSCAD software. The designed system includes low voltage network, single phase voltage source inverter (VSI) to control active (P) and reactive power (Q) flow to the grid and PV panel as the main source of...
Distribution networks are not perfectly balanced all time due to the nature of dynamic loads in the system. Photovoltaic (PV) systems started to be integrated into these distribution networks as distributed generators (DG) through inverters. In addition, wind turbines also started to be integrated but not as distributed as PVs. Both DGs have a fluctuating power outputs due to the intermittent resources...
This paper explores the possibility of optimizing two control strategies currently available for photovoltaic (PV) plants, namely additional reactive power and active power reduction. As the penetration of PV plants is expected to increase, controlling such plants during faults becomes increasingly important. The stability of the power system during a fault and immediately after is affected by the...
Extensive penetration of single phase distributed generators (DGs) such as photovoltaic generations may cause serious phase unbalance problems in distribution networks. The phase unbalance condition will make voltage/VAR optimization problem difficult to be solved by using traditional model and methods for balanced distribution networks. A three-phase unbalanced voltage/VAR optimization model for...
When alternative power sources are connected to the utility grid the core characteristics of the system are changed. This fact is especially true for intermittent, volatile power sources such as photovoltaic (PV) systems. In recent years, PV power systems have become increasingly cost competitive leading to greater penetrations of both large and small scale PV systems. The large scale integration...
The Photovoltaic microgrid is one of the most important and developing research area in the power system and around the world. Photovoltaic microgrid has demonstrated the ability to provide higher reliability and power quality than utility power system and improves energy utilization. The main requirements of photovoltaic microgrid should maintain constant voltage and frequency, balanced real and...
The worldwide increasing demand for electricity, coupled with governmental policy changes for "green" energy has led to significant interest in distributed generation (DG). Integrating DG into an electricity network, especially close to load centres, has many significant benefits but also brings with it many drawbacks such as voltage drop, and power losses. In this paper the impact of three...
Appropriate operating conditions allow to take advantage of the resources more efficiently, in particular, in electrical systems whose thermal generator fleet may affect the ecosystem. Within this context, a Particle Swarm Optimization in DIgSILENT software is proposed to determine appropriate settings for the elements to control the reactive power. This algorithm reduce the active losses which implying...
Uncertainties in distributed generation with renewable sources, and load fluctuations due to demand response, require the Distribution System Operator to have tools to coordinate supply and demand with an adequate quality of service. A cost optimization method is proposed for this purpose, based on two time-scales: a slow scale were topology changes and transformer taps are varied with their operation...
This paper analyses the 11 kV Medium Voltage (MV) networks using real network and load data. High penetration Photovoltaic (PV) connected to a MV feeder is modeled using RETScreen to estimate the output power based on meteorological and geographical data. Simulations are run across 24 hour period to see the voltage fluctuations, active and reactive power behavior, load profile, power loss and energy...
The operation of photovoltaic generation system (PVGS) is modeled and proposed in this paper. The target of proposed model is to encourage Distributed Generation (DG) or Very Small Power Producer (VSPP) to provide contribution to the connected system, by its operation, especially the voltage regulation. The proposed model allows PVGS to either consume or supply reactive power for maintaining system...
With the increasing number of distributed generators which transform renewable power sources to electricity, PV generators trough invertors, when is usually difficult to make power output regulation from the primary source side, is the problem of the output power adapting according to the consumption requirements increasingly important. Therefore, it will be necessary to involve these sources to the...
With the growing number of Distributed Generators (DGs) in power systems, demand to utilize Photovoltaic (PV) systems has also shown increase. PV systems are equipped with PV inverters in order to convert DC power to AC power. PV inverters are great sources to improve voltage profile in the utility grid using their reactive power injection feature. On the other hand, the current standards do not allow...
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