Research on Methods of Reactive Compensation for Unbalanced Current in Three-Phase Four-Wire Low-Voltage Distribution System

2011 ◽  
Vol 347-353 ◽  
pp. 1156-1160
Author(s):  
Xue Ling Zhu ◽  
Wen Si Cao ◽  
Xiao Ming Zhou
Keyword(s):  
Distribution System ◽  
Reactive Power ◽  
Low Voltage ◽  
Neutral Current ◽  
Reactive Power Compensation ◽  
Current Phase ◽  
Voltage Distribution ◽  
Phase Current ◽  
Reactive Compensation ◽  
Three Phase

Different condition of unbalanced current of three-phase four-wire low-voltage distribution system is analysed in this paper. The model of unbalanced reactive power compensation is built which is fit for the three-phase four-wire system ,Using phase-to-phase or phase-to-earth capacitance or inductance can transfer active power. Control the neutral current to be zero and three-phase current balanced by means of reactive power compensation. A compensating phase judgment approach is presented, the mathematic model of calculating phase current, phase compensating capacity line current and line-to-line compensating capacity is gave. Simulation result of physical system shows that the neutral current can be controlled to be zero and the phase current balanced. It substantiate that this compensation method is valid and optimize the operation condition of loads.

scholarly journals Robust Optimal Allocation of Decentralized Reactive Power Compensation in Three-Phase Four-Wire Low-Voltage Distribution Networks Considering the Uncertainty of Photovoltaic Generation

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2479 ◽  
Author(s):  
Shunjiang Lin ◽  
Sen He ◽  
Haipeng Zhang ◽  
Mingbo Liu ◽  
Zhiqiang Tang ◽  
...  
Keyword(s):  
Single Phase ◽  
Optimal Allocation ◽  
Reactive Power ◽  
Low Voltage ◽  
Reactive Power Compensation ◽  
Optimization Models ◽  
Voltage Distribution ◽  
Uncertain Variables ◽  
Three Phase ◽  
Voltage Deviation

Due to the unbalanced three-phase loads, the single-phase distributed photovoltaic (PV) integration, the long feeders, and the heavy loads in a three-phase four-wire low voltage distribution network (LVDN), the voltage unbalance factor (VUF), the network loss and the voltage deviation are relatively high. Considering the uncertain fluctuation of the PV output and the load power, a robust optimal allocation of decentralized reactive power compensation (RPC) devices model for a three-phase four-wire LVDN is proposed. In this model, the uncertain variables are described as box uncertain sets, the three-phase simultaneous switching capacity and single-phase independent switching capacity of the RPC devices are taken as decision variables, and the objective is to minimize the total power loss of the LVDN under the extreme scenarios of uncertain variables. The bi-level optimization method is used to transform the robust optimization model with uncertain variables into bi-level deterministic optimization models, which could be solved alternately. The nonlinear programming solver IPOPT in the mature commercial software GAMS is adopted to solve the upper and lower deterministic optimization models to obtain a robust optimal allocation scheme of decentralized RPC devices. Finally, the simulation results for an actual LVDN show that the obtained decentralized RPC scheme can ensure that the voltage deviation and the VUF of each bus satisfied the secure operation requirement no matter how the PV output and load power changed within their own uncertain sets, and the network loss could be effectively reduced.

Improved Equivalent Resistance Method for Low-Voltage Distribution Line Loss Calculation

2014 ◽  
Vol 1008-1009 ◽  
pp. 417-420 ◽  
Author(s):  
Xiao Hui Liu ◽  
Lin Ma ◽  
Yun Song Shi ◽  
Yu Jiang Wang ◽  
Jun Hua Li
Keyword(s):  
Low Voltage ◽  
Equivalent Resistance ◽  
Voltage Distribution ◽  
Phase Current ◽  
Resistance Method ◽  
Loss Calculation ◽  
Three Phase ◽  
Distribution Line ◽  
Line Loss

Aiming at the insufficiency of Equivalent Resistance Method for a low-voltage distribution line loss calculation, this article has been improved. Then this paper presents the method of using three-phase quantity of electricity to calculate three-phase current, it can calculate the three-phase unbalanced line loss without current date and facilitate the application of Three-phase Unbalanced Method. It develops our own program based on Visio to calculate low-voltage distribution line loss. The results showed: Improved Equivalent Resistance Method improves the accuracy; in the three-phase unbalanced the method of using three-phase quantity of electricity to calculate three-phase current is more easily modified and more practical value.

scholarly journals A complete state estimation algorithm for a three-phase four-wire low voltage distribution system with high penetration of solar PV

2021 ◽  
Vol 124 ◽  
pp. 106332 ◽  
Author(s):  
Wele Gedara Chaminda Bandara ◽  
Dilini Almeida ◽  
Roshan Indika Godaliyadda ◽  
Mervyn Parakrama Ekanayake ◽  
Janaka Ekanayake
Keyword(s):  
State Estimation ◽  
Distribution System ◽  
Low Voltage ◽  
Estimation Algorithm ◽  
Solar Pv ◽  
Voltage Distribution ◽  
High Penetration ◽  
Three Phase ◽  
Complete State
Sign in / Sign up

Export Citation Format

Share Document