Low Voltage DC System with Storage and Distributed Generation Interfaced Systems

The worldwide energy demand is increasing due to increase in population and economic growth. The grid is gradually replaced by Distributed generation systems (DGs). Recently low voltage DG interfacing converter on the non linear load compensation is performed by unified power flow converter. The proposed control technique is analyzed for Simultaneous control of voltage and power under unbalanced load condition using MATLAB/SIMULINK software

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Study on Protection Scheme for Low-voltage Distribution Network with Distributed Generation

Information Technology Journal ◽

10.3923/itj.2013.3655.3659 ◽

2013 ◽

Vol 12 (16) ◽

pp. 3655-3659 ◽

Cited By ~ 1

Author(s):

Zhu Xueling ◽

Zhou Ning ◽

Han Fei ◽

Li Qiang ◽

Li Daokuan

Keyword(s):

Distributed Generation ◽

Low Voltage ◽

Distribution Network ◽

Voltage Distribution ◽

Protection Scheme

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Accurate Assessment of Decoupled OLTC Transformers to Optimize the Operation of Low-Voltage Networks

Energies ◽

10.3390/en12112173 ◽

2019 ◽

Vol 12 (11) ◽

pp. 2173

Author(s):

Álvaro Rodríguez del Nozal ◽

Esther Romero-Ramos ◽

Ángel Luis Trigo-García

Keyword(s):

Distributed Generation ◽

Optimization Problem ◽

Low Voltage ◽

Optimal Solution ◽

Distribution Networks ◽

Voltage Regulation ◽

Rigorous Approach ◽

Tap Changer ◽

Load Tap Changer ◽

Active Distribution Networks

Voltage control in active distribution networks must adapt to the unbalanced nature of most of these systems, and this requirement becomes even more apparent at low voltage levels. The use of transformers with on-load tap changers is gaining popularity, and those that allow different tap positions for each of the three phases of the transformer are the most promising. This work tackles the exact approach to the voltage optimization problem of active low-voltage networks when transformers with on-load tap changers are available. A very rigorous approach to the electrical model of all the involved components is used, and common approaches proposed in the literature are avoided. The main aim of the paper is twofold: to demonstrate the importance of being very rigorous in the electrical modeling of all the components to operate in a secure and effective way and to show the greater effectiveness of the decoupled on-load tap changer over the usual on-load tap changer in the voltage regulation problem. A low-voltage benchmark network under different load and distributed generation scenarios is tested with the proposed exact optimal solution to demonstrate its feasibility.

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A Control Method for Balancing the SoC of Distributed Batteries in Islanded Converter-Interfaced Microgrids

Advances in Power Electronics ◽

10.1155/2016/8518769 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

Spyros I. Gkavanoudis ◽

Konstantinos O. Oureilidis ◽

Georgios C. Kryonidis ◽

Charis S. Demoulias

Keyword(s):

Distributed Generation ◽

Control Method ◽

Low Voltage ◽

Renewable Energy Sources ◽

Intermediate Frequency ◽

Nonlinear Loads ◽

Time Duration ◽

Detailed Simulation ◽

Filter Operation ◽

A Current

In a low-voltage islanded microgrid powered by renewable energy sources, the energy storage systems (ESSs) are considered necessary, in order to maintain the power balance. Since a microgrid can be composed of several distributed ESSs (DESSs), a coordinated control of their state-of-charge (SoC) should be implemented, ensuring the prolonged lifespan. This paper proposes a new decentralized control method for balancing the SoC of DESSs in islanded microgrids, without physical communication. Each DESS injects a current distortion at 175 Hz, when its SoC changes by 10%. This distortion is recognized by every DESS, through a phase-locked loop (PLL). In order to distinguish the origin of the distortion, each DESS injects a distortion of different time duration. This intermediate frequency has been selected in order to avoid the concurrence with the usual harmonics. The DESSs take advantage of this information and inject a current proportional to the SoC. Implementing this strategy, a comparable number of charging/discharging cycles for each DESS are achieved. Furthermore, an active filter operation, implemented in the dq rotating frame for each individual harmonic, is integrated in the control of the distributed generation units, supplying nonlinear loads with high-quality voltage. The effectiveness of this method is verified by detailed simulation results.

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