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The ease of expansion of power system and lowered cost made the use of modular converters in Renewable Energy System more common. Different configurations are implemented depending on the applications. Control strategies like fuzzy logic, droop method and charge control scheme are developed for achieving sharing of current and voltages among the converters. In this paper new modularization architecture...
How to improve the efficiency of power system stability and the whole system is the main problem facing the photovoltaic power system, based on the real system experiments and the digital simulation platform for the limitations of the study, this article from the photovoltaic power generation system semi physical simulation research of power system simulation software based on the use of advanced...
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 distribution network, with the installed of photovoltaic (PV), bought many problems. One of the most concerned problems is the overvoltage in the terminal bus of distribution network. It is caused by the reverse power flow which brought out by the increase of the PV sources penetration. In this paper, an improved PQ-Q (V) control strategy is proposed to alleviate such problem. The economic performance...
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...
Distributed generation systems interconnected to a power system are required so as to recover their output power immediately after the voltage sag caused by a fault in the power system. The purpose of this work is to develop a control strategy of for a photovoltaic inverter so as to maintain the output current during the voltage sag and recover the output power rapidly after the voltage sag. The proposed...
This paper presents a novel consensus-based control strategy of multiple photovoltaic connected virtual synchronous generators (PV-VSG) in microgrid frequency control. The control object is to achieve a fair allocation of active power between different PV-VSGs and control the system frequency to converge to a reference value. Based on the consensus algorithm, a closed control loop is designed and...
The photovoltaic-battery hybrid power system is a kind of flexible renewable power generation system, which is composed of a photovoltaic array and a battery connected to an output DC bus via power converters. The system can work with multiple structures and multiple operating modes due to the source and load states. Particularly, the nonlinear nature of the constant power load will destablize the...
In this paper, a new coordination photovoltaic/battery micro-grid control strategy is proposed to improve the micro-grid fault ride-through capability. Under normal condition, the proposed strategy can restrain the influence of load fluctuations. When symmetrical grid fault happens, the micro-grid can ride through it by the proposed strategy. The DC-link bus voltage and AC current could be kept stable...
The presence of a significant proportion of renewable power plants in the Romanian National Power System has led to the need for renewable generation to contribute more significantly to power system voltage and reactive power control. This paper has theoretical and practical contributions on the operation in a complex, interconnected power system through secondary voltage-reactive power (U-Q) control...
Instability problem is known to be a big issue of the DC distributed power system (DC DPS). The impedance-based stability-assessment methods have turned out to be very effect tools and are proposed for “voltage-source system” and “current-source system”, respectively. However, these methods may not be suitable choices in standalone photovoltaic (PV) system with battery energy storage. Due to variation...
This paper presents a simplified mathematical model of photovoltaic generation system which can be used to perform various power system studies. First the relation between solar radiation and PV output is presented. Then the power electronics inverter control employed in PV system is described. Finally the performance of detail model and simplified model of PV system is compared and commented. The...
Stability of distribution system can be influenced by numerous of installed photovoltaic power plants (PVs). Voltage variations are caused in the connection point of PV due to dynamic variability of power flow from these renewable, but intermittent energy sources. This voltage variation can have wide-spread impact to stability of distribution network, where is PV connected. This paper deals with analysis...
Standalone photovoltaic-battery hybrid power systems are attractive renewable power generation systems, a popular form of which is based on a photovoltaic system and a battery connected to an output dc bus via a buck converter and a bidirectional buck/boost converter, respectively. Due to variation of the available sunlight intensity, the battery voltage and load condition, the system's structures...
The development of newer technologies in concentrating solar power (CSP) plants, particularly plants using dish Stirling systems, as well as changes in the design of photovoltaic (PV) inverters is creating new challenges in the design of low- and medium-voltage collector systems for large solar power plants. Furthermore, interconnect requirements for reactive power, voltage, and ramp rate control...
In order to improve the efficiency of photovoltaic (PV) systems and to extend the application of PV power generation, a new architecture to connect the solar plant to the grid suitable for large PV plant is proposed discussing benefits and drawbacks respect to the other usually adopted architectures. Furthermore an EMTP-ATP model is developed to analyze the transient and steady state behavior of the...
This paper presents a Matlab/simulink model of grid-connected photovoltaic (PV) system, including a PV array, a control system, a distribution network and a load. Based on the accurate modeling system, optimum control and stability analysis are studied. The current control strategy can regulate the current at the point of common coupling to achieve the power factor control. The voltage control strategy...
This work presents the design of a sliding-mode based current controller for a Cascade Full Bridge Multilevel Inverter grid connected PV system. The design also includes a modulation strategy to share the control action among the cascade-connected bridges in order to concurrently synthesize a multilevel waveform and to keep each of the PVG at its maximum operating point. Experimental results are included...
Grid-connected photovoltaic (PV) systems are developing increasingly in recent years due to many associated economic and environmental factors and provoking control and operation problems to utilities. Most of all, it also touches the essence of management mechanism of power systems. Concerning with voltage and frequency stability, electricity quality and short-term load forecasting, the possible...
A micro-grid can increase the reliability of energy supplies by disconnecting from the grid in the case of network faults or reduced power quality. The techniques that have been investigated to control micro-grids in both modes are summarized as well as those proposed to maintain stability during the transitions from one mode to the other. This paper first introduces the micro-grid planning structure...
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