scholarly journals Optimal Individual Phase Voltage Regulation Strategies in Active Distribution Networks with High PV Penetration Using the Sparrow Search Algorithm

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8370
Author(s):  
Yih-Der Lee ◽  
Wei-Chen Lin ◽  
Jheng-Lun Jiang ◽  
Jia-Hao Cai ◽  
Wei-Tzer Huang ◽  
...  
Keyword(s):  
Distribution System ◽  
Search Algorithm ◽  
Fitness Function ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Phase Voltage ◽  
Individual Phase ◽  
Voltage Variation ◽  
Regulation Strategies ◽  
Pv Penetration

This study aimed to propose individual phase voltage regulation strategies using the sparrow search algorithm (SSA) in the IEEE 8500-node large-scale unbalanced distribution network with high photovoltaic (PV) penetration. The proposed approach is capable of individual phase regulation, which coordinates the on-load tap changer (OLTC), voltage regulator (VR), switched capacitor bank (SCB), and volt–var setting controlled by a smart inverter to improve voltage variation and unbalance. Consequently, the change time of VRs, the switched times of SCBs, and the individual phase voltage magnitude and unbalance ratio are considered in the fitness function for the SSA. The simulation scenarios fully consider the unbalanced load conditions and PV power output patterns, and the numerical results demonstrate that the voltage variation and unbalance are clearly improved, by 15% and 26%, respectively. The fitness values, operation times of OLTC, VR, and SCB, and the settings of the volt–var controlled smart inverter are also optimized by the SSA. The outcomes of this study are helpful for distribution system operators in formulating voltage control strategies corresponding to different system conditions.

scholarly journals Unified Framework for the Analysis of the Effect of Control Policies on Automatic Voltage Regulators

2021 ◽  
Author(s):  
Iker Garcia ◽  
Roberto Santana
Keyword(s):  
Smart Grids ◽  
Control Policy ◽  
Real Data ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Unified Framework ◽  
Main Requirement ◽  
Distribution Transformers ◽  
Voltage Variation ◽  
New Policies

<p>With the advent of smart grids, voltage fluctuation has increased, especially in active distribution networks with a high penetration of distributed energy resources and a large deployment of electric vehicles. In this context, on-load tap-changer (OLTC) distribution transformers have become a key component, mainly because they provide automatic voltage regulation capability. In order to maximise the lifetime of OLTC devices, the number of tap operations should be minimised, avoiding unnecessary changes, but ensuring the main requirement: to keep the voltage within the limits permitted. Therefore, when the automatic mode is active, the control policy followed by the automatic voltage regulator is decisive. This paper presents a novel form of functional approximation of these policies. Furthermore, by means of a unified framework, a methodology for the simulation of policies based on control theory is proposed. The unified framework has been validated using real data. The results confirm the ability of the introduced framework to simulate different scenarios, optimising and validating both existing and new policies by observing their effect on transformer behavior. In addition, it allows the determination of the best fit policies depending on characteristics such as the pre-selected voltage set point or the voltage variation between transformer taps.</p>

scholarly journals Investigation on Using Low Voltage Automatic Regulation to Minimize the Impacts of Charging Plug-in Electric Vehicles in Distribution Systems

2021 ◽  
Vol 19 ◽  
pp. 85-90
Author(s):  
Priscila Costa Nascimento ◽  
◽  
Michel Girotto de Oliveira ◽  
José Carlos M. Vieira
Keyword(s):  
Steady State ◽  
Electric Vehicles ◽  
Distribution System ◽  
Distribution Systems ◽  
Low Voltage ◽  
Electric Energy ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Automatic Regulation ◽  
Electric Energy Storage

The growth of micro and mini distributed generation and, more recently, the use of electric energy storage systems and the incentives for electric mobility are important examples of the transformations that distribution networks have been going through. In this context, this paper firstly presents the impacts of uncoordinated plug-in electric vehicles (PEVs) charging in a real Brazilian distribution system. Four scenarios were elaborated with different PEVs penetration levels and the results show increased voltage unbalance, system losses, and violations of the steady-state voltage limits, even in the presence of an automatic voltage regulator installed in the medium voltage network. Then, as the main contribution, the potential usage of automatic voltage regulation at the low voltage network was investigated to minimize the negative impacts of uncontrolled PEV charging on distribution system steady-state operation. It is important to highlight that this is not a common practice of utilities in Brazil. The obtained results showed that regulating the voltage at the low voltage side could be an effective solution to keep the voltages within statutory limits.

scholarly journals Electric Vehicle–Grid Integration with Voltage Regulation in Radial Distribution Networks

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1802 ◽  
Author(s):  
Chong Cao ◽  
Zhouquan Wu ◽  
Bo Chen
Keyword(s):  
Electric Vehicle ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Networks ◽  
Voltage Regulation ◽  
Grid Integration ◽  
Distribution Grid ◽  
Voltage Compensation ◽  
Control Schemes ◽  
Grid Level

In this paper, a vehicle–grid integration (VGI) control strategy for radial power distribution networks is presented. The control schemes are designed at both microgrid level and distribution level. At the VGI microgrid level, the available power capacity for electric vehicle (EV) charging is optimally allocated for charging electric vehicles to meet charging requirements. At the distribution grid level, a distributed voltage compensation algorithm is designed to recover voltage violation when it happens at a distribution node. The voltage compensation is achieved through a negotiation between the grid-level agent and VGI microgrid agents using the alternating direction method of multipliers. In each negotiation round, individual agents pursue their own objectives. The computation can be carried out in parallel for each agent. The presented VGI control schemes are simulated and verified in a modified IEEE 37 bus distribution system. The simulation results are presented to show the effectiveness of the VGI control algorithms and the effect of algorithm parameters on the convergence of agent negotiation.

scholarly journals Optimal Network Reconfiguration in Active Distribution Networks with Soft Open Points and Distributed Generation

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4172 ◽  
Author(s):  
Ibrahim Diaaeldin ◽  
Shady Abdel Aleem ◽  
Ahmed El-Rafei ◽  
Almoataz Abdelaziz ◽  
Ahmed F. Zobaa
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
Distribution Systems ◽  
Search Algorithm ◽  
Distribution Networks ◽  
Mixed Integer ◽  
Network Reconfiguration ◽  
Efficient Manner ◽  
Optimal Network ◽  
Network Losses

In this study, we allocated soft open points (SOPs) and distributed generation (DG) units simultaneously with and without network reconfiguration (NR), and investigate the contribution of SOP losses to the total active losses, as well as the effect of increasing the number of SOPs connected to distribution systems under different loading conditions. A recent meta-heuristic optimization algorithm called the discrete-continuous hyper-spherical search algorithm is used to solve the mixed-integer nonlinear problem of SOPs and DGs allocation, along with new NR methodology to obtain radial configurations in an efficient manner without the possibility of getting trapped in local minima. Further, multi-scenario studies are conducted on an IEEE 33-node balanced benchmark distribution system and an 83-node balanced distribution system from a power company in Taiwan. The contributions of SOP losses to the total active losses, as well as the effect of increasing the number of SOPs connected to the system, are investigated to determine the real benefits gained from their allocation. It was clear from the results obtained that simultaneous NR, SOP, and DG allocation into a distribution system creates a hybrid configuration that merges the benefits offered by radial distribution systems and mitigates drawbacks related to losses, power quality, and voltage violations, while offering a far more efficient and optimal network operation. Also, it was found that the contribution of the internal loss of SOPs to the total loss for different numbers of installed SOPs is not dependent on the number of SOPs and that loss minimization is not always guaranteed by installing more SOPs or DGs along with NR. One of the findings of the paper demonstrates that NR with optimizing tie-lines could reduce active losses considerably. The results obtained also validate, with proper justifications, that SOPs installed for the management of constraints in LV feeders could further reduce losses and efficiently address issues related to voltage violations and network losses.

scholarly journals Reactive Power Compensation with PV Inverters for System Loss Reduction

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4062 ◽  
Author(s):  
Vlahinić ◽  
Franković ◽  
Komen ◽  
Antonić
Keyword(s):  
Distribution System ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Active Power ◽  
Operating Conditions ◽  
Positive Energy ◽  
Loss Reduction ◽  
Pv System ◽  
Pv Penetration ◽  
Power Provisioning

Photovoltaic (PV) system inverters usually operate at unitary power factor, injecting only active power into the system. Recently, many studies have been done analyzing potential benefits of reactive power provisioning, such as voltage regulation, congestion mitigation and loss reduction. This article analyzes possibilities for loss reduction in a typical medium voltage distribution system. Losses in the system are compared to the losses in the PV inverters. Different load conditions and PV penetration levels are considered and for each scenario various active power generation by PV inverters are taken into account, together with allowable levels of reactive power provisioning. As far as loss reduction is considered, there is very small number of PV inverters operating conditions for which positive energy balance exists. For low and medium load levels, there is no practical possibility for loss reduction. For high loading levels and higher PV penetration specific reactive savings, due to reactive power provisioning, increase and become bigger than additional losses in PV inverters, but for a very limited range of power factors.

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