scholarly journals Reactive Power Management Based on Voltage Sensitivity Analysis of Distribution System with High Penetration of Renewable Energies

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1493 ◽  
Author(s):  
SeokJu Kang ◽  
Jaewoo Kim ◽  
Jung-Wook Park ◽  
Seung-Mook Baek
Keyword(s):  
Sensitivity Analysis ◽  
Steady State ◽  
Power Management ◽  
Distribution System ◽  
Reactive Power ◽  
Voltage Sensitivity ◽  
Transient Conditions ◽  
Voltage Variation ◽  
High Penetration ◽  
Management Method

The high penetration of distributed energy resources (DERs) in the distribution system brings new challenges related to voltage variations and reverse power flow. The sudden changes in electric power generation from the DERs due to climate conditions or their internal malfunction might cause high fluctuations in system voltage. To enhance the voltage stability when a disturbance occurs, this paper proposes a new reactive power management method to control each DER based on voltage sensitivity analysis. The voltage variation has the different features in both steady-state and transient conditions. In particular, its transient behavior depends on the type of DERs. Therefore, the particular optimal control for improving the dynamic response of voltage is difficult to apply for all types of DERs. In contrast, the voltage variation in steady-state can be controlled with the reactive power management by the sensitivity analysis between reactive power generation and system voltage. Even though this paper focuses on the reduction of voltage variation in steady-state, the relationship between the voltage variations in steady-state and transient conditions is also analyzed. The effectiveness of the proposed method is verified with several case studies on the practical distribution system in South Korea by using the time-domain simulation based on the PSCAD/EMTDC software. The results show that the proposed reactive power management method can improve the dynamic voltage responses in both steady-state and transient conditions when the distribution system has the high penetration of renewables.

Optimal Capacitors Placement of Distribution Systems Using 2nd Order Power Loss Sensitivity Analysis and Hierarchical Clustering

2014 ◽  
Vol 986-987 ◽  
pp. 377-382 ◽  
Author(s):  
Hui Min Gao ◽  
Jian Min Zhang ◽  
Chen Xi Wu
Keyword(s):  
Sensitivity Analysis ◽  
Hierarchical Clustering ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Reactive Power ◽  
Digital Simulation ◽  
Second Order ◽  
First Order ◽  
The Impact

Heuristic methods by first order sensitivity analysis are often used to determine location of capacitors of distribution power system. The selected nodes by first order sensitivity analysis often have virtual high by first order sensitivities, which could not obtain the optimal results. This paper presents an effective method to optimally determine the location and capacities of capacitors of distribution systems, based on an innovative approach by the second order sensitivity analysis and hierarchical clustering. The approach determines the location by the second order sensitivity analysis. Comparing with the traditional method, the new method considers the nonlinear factor of power flow equation and the impact of the latter selected compensation nodes on the previously selected compensation location. This method is tested on a 28-bus distribution system. Digital simulation results show that the reactive power optimization plan with the proposed method is more economic while maintaining the same level of effectiveness.

scholarly journals Application-Oriented Reactive Power Management in German Distribution Systems Using Decentralized Energy Resources

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4949
Author(s):  
Haonan Wang ◽  
Markus Kraiczy ◽  
Denis Mende ◽  
Sebastian Stöcklein ◽  
Martin Braun
Keyword(s):  
Power Management ◽  
Distribution System ◽  
Distribution Systems ◽  
Reactive Power ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Measurement Data ◽  
Power Exchange ◽  
High Investment ◽  
Decentralized Energy

Due to higher penetration of renewable energy sources, grid reinforcements, and the utilization of local voltage control strategies, a significant change in the reactive power behavior as well as an increased demand for additional reactive power flexibility in the German power system can be predicted. In this paper, an application-oriented reactive power management concept is proposed, which allows distribution system operators (DSO) to enable a certain amount of reactive power flexibility at the grid interfaces while supporting voltage imitations in the grid. To evaluate its feasibility, the proposed concept is applied for real medium voltage grids in the south of Germany and is investigated comprehensively in different case studies. The results prove the feasibility and reliability of the proposed concept, which allows the DSO to control the reactive power exchange at grid interfaces without causing undesired local voltage problems. In addition, it can be simply adjusted and widely applied in real distribution grids without requiring high investment costs for complex information and communication infrastructures. As a significant contribution, this study provides an ideal bridging solution for DSOs who are facing reactive power issues but have no detailed and advanced monitoring system for their grid. Moreover, the comprehensive investigations in this study are performed in close cooperation with a German DSO, based on a detailed grid model and real measurement data.

scholarly journals Reactive Power Management Considering Stochastic Optimization under the Portuguese Reactive Power Policy Applied to DER in Distribution Networks

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4028 ◽  
Author(s):  
Abreu ◽  
Soares ◽  
Carvalho ◽  
Morais ◽  
Simão ◽  
...  
Keyword(s):  
Power Management ◽  
Distribution System ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Distribution Network ◽  
Real Data ◽  
Distribution Networks ◽  
System Operator

Challenges in the coordination between the transmission system operator (TSO) and the distribution system operator (DSO) have risen continuously with the integration of distributed energy resources (DER). These technologies have the possibility to provide reactive power support for system operators. Considering the Portuguese reactive power policy as an example of the regulatory framework, this paper proposes a methodology for proactive reactive power management of the DSO using the renewable energy sources (RES) considering forecast uncertainty available in the distribution system. The proposed method applies a stochastic sequential alternative current (AC)-optimal power flow (SOPF) that returns trustworthy solutions for the DSO and optimizes the use of reactive power between the DSO and DER. The method is validated using a 37-bus distribution network considering real data. Results proved that the method improves the reactive power management by taking advantage of the full capabilities of the DER and by reducing the injection of reactive power by the TSO in the distribution network and, therefore, reducing losses.

Effect of Capacitors on Frequency of OLTC Tap Changes in the Presence of Wind Generation

2015 ◽  
Vol 16 (4) ◽  
pp. 385-395 ◽  
Author(s):  
Neelakanteshwar Rao Battu ◽  
Nilanjan Senroy ◽  
A. R. Abhyankar
Keyword(s):  
Mathematical Model ◽  
Distribution System ◽  
Reactive Power ◽  
Wind Generation ◽  
Voltage Sensitivity ◽  
Distributed Generator ◽  
System A ◽  
Wear And Tear ◽  
Tap Changer ◽  
Load Tap Changer

Abstract Installation of a wind power distributed generator in a distribution system alters the reactive power drawn by the system. This affects the load bus voltages. Any deviation in load bus voltages from their limits is sensed by an on load tap changer of a transformer and it responds to maintain the bus voltages within their limits. The reactive power requirements of a wind generator vary due to the intermittent behaviour of wind, which will in turn vary the bus voltages. This has an affect on number of tap changings of a transformer. Frequent tap changing of a transformer increases wear and tear of it and ultimately reduces the life of it. A mathematical model is developed to analyze the voltage sensitivity at a load bus to the tap change of a transformer under different scenarios and conditions in the distribution system. A possible solution to reduce the number of tap changings is presented in this paper.

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