scholarly journals Adaptive Droop Based Virtual Slack Control of Multiple DGs in Practical DC Distribution System to Improve Voltage Profile

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1541
Author(s):  
Soo Hyoung Lee

This paper proposes an adaptive droop based virtual slack (ADVS) control for multiple distributed generations (DGs) to improve voltage stability of a practical DC distribution system. Although there have been many researches for optimal sizes of multiple DGs, their solutions are valid only in the particular operating point. Additionally, a previous study proposed a voltage control based optimal operation method, its performance depends on measurement accuracy in practice. The proposed ADVS control operates the system based on the current sensitivities between the DGs and loads, so that it can regulate the system voltages without a large computational effort. This is effective even if measurements are noisy and biased. All DGs contribute to voltage regulation by current control even though they do not directly control voltages. As an additional effect, they effectively share the load. To verify the proposed method, the DC system is modeled based on the real distribution system of the Do-gok area in Seoul, Korea. Then, the Levenberg-Marquardt algorithm determines its operation point. The proposed method is verified based on the electromagnetic transient (EMT) simulation with random loads.

2013 ◽  
Vol 28 (12) ◽  
pp. 5878-5889 ◽  
Author(s):  
Seungmin Jung ◽  
Hansang Lee ◽  
Chong Suk Song ◽  
Jong-Hoon Han ◽  
Woon-Ki Han ◽  
...  

2016 ◽  
Vol 17 (3) ◽  
pp. 351-361 ◽  
Author(s):  
Surender Reddy Salkuti ◽  
Young Hwan Lho

Abstract In this paper, a new heuristic algorithm is proposed for the optimum voltage control, which is applicable for the large Radial Distribution Systems (RDSs). In the RDSs, voltage levels at different buses can be maintained within the specified limits using the conductor grading or placing the Voltage Regulators (VRs) and capacitors at suitable locations. The proposed Back Tracking Algorithm (BTA) proposes the optimal location, number and tap positions of VRs to maintain the voltage profile within the desired limits and decreases losses in the system, which in turn maximizes the net savings in the operation of distribution system. In addition to BTA, an approach using the fuzzy logic called Fuzzy Expert System (FES) is also proposed, and the results of FES are compared with the results of BTA. This heuristic algorithm proposes the optimal location and tap setting of VRs, which contributes a smooth voltage profile along the network. It also used to access the minimum number of initially considered VRs, by moving them in such way as to control the network voltage at minimum possible cost. It is concluded that the FES also gives the optimal placement and the number along with the tap settings of VRs. The proposed FES contributes good voltage regulation, and decreases the power loss which in turn increases the net savings when compared to the BTA. The effectiveness of the proposed heuristic approaches are examined on practical 47 bus and 69 bus Radial Distribution Systems (RDSs).


Author(s):  
Hazim Sadeq Mohsin Al-Wazni ◽  
Shatha Suhbat Abdulla Al-Kubragyi

This paper presents a hybrid algorithm by applying a hybrid firefly and particle swarm optimization algorithm (HFPSO) to determine the optimal sizing of distributed generation (DG) and distribution static compensator (D-STATCOM) device. A multi-objective function is employed to enhance the voltage stability, voltage profile, and minimize the total power loss of the radial distribution system (RDS). Firstly, the voltage stability index (VSI) is applied to locate the optimal location of DG and D-STATCOM respectively. Secondly, to overcome the sup-optimal operation of existing algorithms, the HFPSO algorithm is utilized to determine the optimal size of both DG and D-STATCOM. Verification of the proposed algorithm has achieved on the standard IEEE 33-bus and Iraqi 65-bus radial distribution systems through simulation using MATLAB. Comprehensive simulation results of four different cases show that the proposed HFPSO demonstrates significant improvements over other existing algorithms in supporting voltage stability and loss reduction in distribution networks. Furthermore, comparisons have achieved to demonstrate the superiority of HFPSO algorithms over other techniques due to its ability to determine the global optimum solution by easy way and speed converge feature.


2020 ◽  
Vol 184 ◽  
pp. 01073
Author(s):  
SK. Abdul Pasha ◽  
N. Prema Kumar

Recent developments in FACTS have produced U.P.Q.C to mitigate sag and attenuate THD. U.P.Q.C has been urbanized as a FACTS controller between feeding end & far end of distribution system .The U-P-Q-C is capable of improving the voltage profile & reducing THD of distribution system by regulating the voltage using PR (Proportional-Resonant-Controller) and MPC (Model-Predictive) controller. This work proposes U-P-Q-C for Thirty Three Bus Systems .The objective of this work is to enhance-voltage-profile of T-T-B-S. The T-T-B-S in open loop & closed loop-TTBS- U-P-Q-C using PR and MPC-controllers are-modeled,pretend & their consequences are represented. Responses are estimated as a time of settle and error in steady state. The outcomes indicate that MP Controlled T-T-B-S system has better response than PR controlled T-T-B-S system.


2013 ◽  
Vol 748 ◽  
pp. 477-484 ◽  
Author(s):  
Peng Li ◽  
Tao Li ◽  
Jia Ming Li ◽  
Duo Xu ◽  
Ru Yu Shi

The distributed generation (DG) may lead to a great impact on the reactive power flow, feeder voltage profile and the means of voltage regulation when integrated into a typical distribution system. Therefore, there is possibility that the customers voltage violate the permissible limits. In order to regulate the voltage of the distribution system with DG, local voltage and reactive power control (VQC) based on fuzzy control theory is adopted in substation and the Static Var Compensator (SVC) is installed in the appropriate node in this paper, and the fuzzy controller of VQC has been designed at the same time. A simplified model of a real 10kV radial distribution system has been simulated in MATLAB to illustrate the use of the voltage regulation method, and the simulation results show that the proposed method can regulate the line voltage of distribution system with DG within the regulated voltage ranges.


Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3562 ◽  
Author(s):  
Adam Summers ◽  
Jay Johnson ◽  
Rachid Darbali-Zamora ◽  
Clifford Hansen ◽  
Jithendar Anandan ◽  
...  

Grid operators are now considering using distributed energy resources (DERs) to provide distribution voltage regulation rather than installing costly voltage regulation hardware. DER devices include multiple adjustable reactive power control functions, so grid operators have the difficult decision of selecting the best operating mode and settings for the DER. In this work, we develop a novel state estimation-based particle swarm optimization (PSO) for distribution voltage regulation using DER-reactive power setpoints and establish a methodology to validate and compare it against alternative DER control technologies (volt–VAR (VV), extremum seeking control (ESC)) in increasingly higher fidelity environments. Distribution system real-time simulations with virtualized and power hardware-in-the-loop (PHIL)-interfaced DER equipment were run to evaluate the implementations and select the best voltage regulation technique. Each method improved the distribution system voltage profile; VV did not reach the global optimum but the PSO and ESC methods optimized the reactive power contributions of multiple DER devices to approach the optimal solution.


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