scholarly journals Photovoltaic Maximum Penetration Limits on Medium Voltage Overhead and Underground Cable Distribution Feeders: A Comparative Study

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3843
Author(s):  
Sultan Sh. Alanzi ◽  
Rashad M. Kamel
Keyword(s):  
Power System ◽  
Power Factor ◽  
Distribution System ◽  
Power Flow ◽  
Underground Cables ◽  
Overhead Lines ◽  
Medium Voltage ◽  
Load Power ◽  
Bus Voltage ◽  
Pv Penetration

This paper investigates the maximum photovoltaic (PV) penetration limits on both overhead lines and underground cables medium voltage radial distribution system. The maximum PV penetration limit is estimated considering both bus voltage limit (1.05 p.u.) and feeder current ampacity (1 p.u.). All factors affect the max PV penetration limit are investigated in detail. Substation voltage, load percentage, load power factor, and power system frequency (50 Hz or 60 Hz) are analyzed. The maximum PV penetration limit associated with overhead lines is usually higher than the value associated with the underground cables for high substation voltage (substation voltage = 1.05 and 1.04 p.u.). The maximum PV penetration limit decreases dramatically with low load percentage for both feeder types but still the overhead lines accept PV plant higher than the underground cables. Conversely, the maximum PV penetration increases with load power factor decreasing and the overhead lines capability for hosting PV plant remains higher than the capability of the underground cables. This paper proved that the capability of the 60-Hz power system for hosting the PV plant is higher than the capability of 50 Hz power system. MATLAB software has been employed to obtain all results in this paper. The Newton-Raphson iterative method was the used method to solve the power flow of the investigated systems.

Research on Power Flow Control of UPFC Based on PSASP/UPI

2013 ◽  
Vol 385-386 ◽  
pp. 1078-1081 ◽  
Author(s):  
Fang Zhang ◽  
Jian Ping Chen ◽  
Chuan Dong Li ◽  
Yan Juan Wu
Keyword(s):  
Power System ◽  
Flow Control ◽  
Power Flow ◽  
System Analysis ◽  
Unified Power Flow Controller ◽  
Power Flow Control ◽  
Engineering Research ◽  
Good Convergence ◽  
Practical Engineering ◽  
Bus Voltage

The main objective of power flow control for unified power flow controller (UPFC) is to increase the transmission capacity over the existing transmission corridor or line. This paper presents a practical engineering methodology of embedding the power flow control model of UPFC into the commercial software -- power system analysis software package (PSASP) based on its user program interface (UPI) function. In the proposed methodology, the interface currents of UPFC series side and UPFC shunt side between the UPFC device and the network are used to control the transmission line power flow and UPFC bus voltage, respectively. In UPFC series side, the current of UPFC series branch is calculated from the power target equation of the controlled line. In UPFC shunt side, the shunt reactive current of UPFC is used to control the bus voltage. Simulation results on a practical power system show that the proposed methodology can be efficiently applied to the engineering research and analysis of the real power grid with UPFC with good convergence and only one control parameter needed to be prescribed.

Application of Tabu Search for Optimal Placement and Sizing of Distributed Generation for Loss Reduction

2012 ◽  
Vol 433-440 ◽  
pp. 7190-7194 ◽  
Author(s):  
Nattachote Rugthaicharoencheep ◽  
Thong Lantharthong ◽  
Awiruth Ratreepruk ◽  
Jenwit Ratchatha
Keyword(s):  
Tabu Search ◽  
Distributed Generation ◽  
Distribution System ◽  
Power Loss ◽  
Power Flow ◽  
Search Algorithm ◽  
Optimal Placement ◽  
Loss Reduction ◽  
Placement Problem ◽  
Bus Voltage

This paper presents the optimal and sizing of distributed generation (DG) placement in a radial distribution system for loss reduction. The main emphasis of this paper is to identify proper locations for installing DGs in a distribution system to reduce active power loss and improve bus voltages. Nevertheless, proper placement and sizing of DG units are not straightforward to be identified as a number of their positions and capacities need to be determined. It is therefore proposed in this paper to solve a DG placement problem based on a Tabu search algorithm. The objective function of the problem is to minimize the system loss subject to power flow constraints, bus voltage limits, pre specified number of DGs, and their allowable total installed capacity, and only one distributed generator for one installation position. The effectiveness of the methodology is demonstrated by a practical sized distribution system consisting of 69 bus and 48 load points. The results show that the optimal DG placement and sizing can be identified to give the minimum power loss while respecting all the constraints.

OPTIMAL POWER FLOW AND FAULT ANALYSIS USING UPFC

2020 ◽  
Vol 5 (8) ◽  
Author(s):  
Anuj Singh ◽  
Dr. Sandeep Sharma ◽  
Karan Sharma ◽  
Flansha Jain ◽  
Shreyanshu Kumar Jena
Keyword(s):  
Power System ◽  
Power Electronics ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Reactive Power ◽  
Impedance Control ◽  
Fault Analysis ◽  
Unified Power Flow Controller ◽  
Bus Voltage ◽  
Power Flow Controller

A Power System is actually a vast system that requires an outstanding plan for maintaining the continual flow of electricity. When a fault occurs at the power system, number of difficulties arises because of transients in system. so to attenuate these transients, power electronics based devices like FACTS are utilized. A unified power flow controller (UPFC) is one among different power electronics controller which can dispense VAR compensation, line impedance control and phase shifting. The thought is to see potential of UPFC to require care of active and reactive power movement within the compensated line (including UPFC) and to shrink the falloff of the bus voltage in case of grounding fault within the cable. power system block consisting of simulink is used for numerical analysis. Simulation outcomes from MATLAB reflects major improvement in the overall system’s behaviour with UPFC in sustain the voltage and power flow even under severe line faults by proper injection of series voltage into the cable at the point of connection. outcomes shows how the UPFC contributes effectively to a faster regaining of the power system to the pre-fault conditions.

scholarly journals An Effective Method to Calculate Frequency Response of Distribution Networks for PLC Applications

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 649 ◽  
Author(s):  
Hongshan Zhao ◽  
Weitao Zhang ◽  
Yan Wang
Keyword(s):  
Frequency Response ◽  
Distribution Networks ◽  
Dynamic Changes ◽  
Binary Function ◽  
Underground Cables ◽  
Overhead Lines ◽  
Medium Voltage ◽  
Response Characteristics ◽  
Network Topologies ◽  
Propagation Matrix

Modelling and estimating power-line communication (PLC) channels are complicated issues due to the complex network topologies, various junctions, and changeable loads. This paper focuses on the frequency response characteristics (FRCs) of medium-voltage (MV) PLC networks with special consideration of two scenarios that are often neglected but generally exist. In the first scenario, the MV distribution network is of the ring topology. In the second scenario, the MV overhead lines and underground cables join at junctions, and the shields of underground cables are grounded with nonzero grounding impedances at the junctions. These conditions lead to the failure of currently popular methods to different degrees. For this reason, we developed an effective method to calculate the FRCs of distribution networks for PLC applications. With this method, the frequency responses of nodes are simply expressed as the binary function of the overall tube propagation matrix and overall node scattering matrix, which is convenient for calculations and analyses. The proposed method was validated by the agreement between the calculated and measured FRCs. The results of two test examples showed that the proposed method performed better in comparison with the traditional approximate method when nonideal grounding conditions were taken into account. The proposed method is also independent of the network topology, so it can adapt to the dynamic changes of the network structure.

scholarly journals Dual-Mode Photovoltaic Bidirectional Inverter Operation for Seamless Power Transfer to DC and AC Loads with the Grid Interface

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
M. Srikanth ◽  
B. Pakkiraiah ◽  
Poonam Upadhyay ◽  
S. Tara Kalyani
Keyword(s):  
Distribution System ◽  
Output Voltage ◽  
Power Flow ◽  
Boost Converter ◽  
Power Transfer ◽  
Dual Mode ◽  
Point Tracking ◽  
Dc Bus ◽  
Bus Voltage ◽  
Power Point

This paper develops the photovoltaic bidirectional inverter (BI) operated in dual mode for the seamless power transfer to DC and AC loads. Normal photovoltaic (PV) output voltage is fed to boost converter, but in space application, boost converter is not so preferable. To overcome this, buck and boost converters are proposed in this paper. Duty cycle to this converter is provided with the help of the outcome of the maximum power point tracking (MPPT) controller. This can be implemented by using perturbation and observation method. The MPPT will operate the switch between buck and boost modes. When the output voltage of a PV array is close to the dc bus voltage, then the bidirectional inverter can fulfill both rectification and grid connected mode. To control the power flow between dc bus and ac grid, a dc distribution system is used to regulate the dc bus voltage to a convinced level. Moreover, the bidirectional inverter must fulfill grid connection (sell power) and rectification (buy power) with power factor correction (PFC) to control the power flow between dc bus and ac grid. The simulations and hardware experimental results of a 2.5 kVA circuit are presented to validate the performance of the proposed dual-mode seamless power transfer.

Photovoltaic Planning with Considering its Probabilistic Output in Distribution System

2011 ◽  
Vol 347-353 ◽  
pp. 481-486
Author(s):  
Li Fang Sun ◽  
Yu Qin Xu ◽  
Li Zhang ◽  
Kang Guo ◽  
Jian Fang Yue
Keyword(s):  
Distribution System ◽  
Power Flow ◽  
Solution Algorithm ◽  
Planning Model ◽  
Clearness Index ◽  
Random Expectation ◽  
Expectation Model ◽  
Bus Voltage ◽  
Environment Cost ◽  
Operation Cost

A large number of PVs can produce security and economic influence for distribution system, for its probabilistic and intermittent output. The solar radiation which PV component receives is easily influenced by clouds. The clearness index can reflect this. So a PV output stochastic model is built based on clearness index. In this paper the probabilistic output of PVs and loads are both considered and expressed by stochastic variables. A random expectation model has been built considering annual saved environment cost. The objective function is the minimum expected value of annual investment and operation cost. The operation constraints are to ensure the reliability and economy of power system. The solution algorithm is PSO combining with probabilistic power flow. Qualification rates of bus voltage and line power flow are examined after planning. At last the calculation example manifests this planning model can get good result under the condition of reflexing the probabilistic output of PVs and randomness of power loads.

Study on Electrical Characteristics of Metal-Oxide Surge Arresters in Medium Voltage Power System

2014 ◽  
Vol 960-961 ◽  
pp. 1073-1076
Author(s):  
Li Zhang ◽  
Kun Yang ◽  
Li Mei He
Keyword(s):  
Metal Oxide ◽  
Power System ◽  
Distribution System ◽  
Operating Voltage ◽  
Electrical Characteristics ◽  
Protection Level ◽  
Power Distribution System ◽  
Medium Voltage ◽  
Surge Arresters ◽  
Overvoltage Protection

The index system for electrical characteristics of metal-oxide surge arresters is proposed and established, which is based on rated voltage (Ur), continuous operating voltage (Uc), nominal discharge current (In), overvoltage protection and insulation coordination including lightning overvoltage protection level, operating overvoltage protection level and coordination coefficient (Ks). The study considers both selection and application of overvoltage protection devices for the electrical equipments in 3-35kV medium voltage power system, and comparatively calculates and analyzes the main parameters between two types metal-oxide surge arresters (without gaps and containing series gapped structures), and illustrates their technical features and puts forward suggestions on how to improve the effective utilization. The results of 10kV power distribution system are simulated to show that the conclusions are feasible and available in the practical engineering application.

scholarly journals Integrating Photovoltaic Systems in Power System: Power Quality Impacts and Optimal Planning Challenges

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Aida Fazliana Abdul Kadir ◽  
Tamer Khatib ◽  
Wilfried Elmenreich
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Quality ◽  
Distribution System ◽  
Power Flow ◽  
Harmonic Distortion ◽  
Integrated System ◽  
Optimal Planning ◽  
High Penetration ◽  
Bidirectional Power Flow

This paper is an overview of some of the main issues in photovoltaic based distributed generation (PVDG). A discussion of the harmonic distortion produced by PVDG units is presented. The maximum permissible penetration level of PVDG in distribution system is also considered. The general procedures of optimal planning for PVDG placement and sizing are also explained in this paper. The result of this review shows that there are different challenges for integrating PVDG in the power systems. One of these challenges is integrated system reliability whereas the amount of power produced by renewable energy source is consistent. Thus, the high penetration of PVDG into grid can decrease the reliability of the power system network. On the other hand, power quality is considered one of the challenges of PVDG whereas the high penetration of PVDGs can lead to more harmonic propagation into the power system network. In addition to that, voltage fluctuation of the integrated PVDG and reverse power flow are two important challenges to this technology. Finally, protection of power system with integrated PVDG is one of the most critical challenges to this technology as the current protection schemes are designed for unidirectional not bidirectional power flow pattern.

scholarly journals Optimal capacitor placement in a distribution system using ETAP software

2019 ◽  
Vol 15 (2) ◽  
pp. 650
Author(s):  
M. J. Tahir ◽  
Badri. A. Bakar ◽  
M. Alam ◽  
M. S. Mazlihum
Keyword(s):  
Power System ◽  
Objective Function ◽  
Power Factor ◽  
Distribution System ◽  
Voltage Drop ◽  
Optimization Technique ◽  
Voltage Profile ◽  
Power Losses ◽  
Capacitor Placement ◽  
Optimal Capacitor Placement

<p>Mostly loads are inductive in nature in content of distribution side for any power system. Due to which system faces high power losses, voltage drop and reduction in system power factor. Capacitor placement is a common method to improve these factors. To maximize the reduction of inductive load impact, optimal capacitor placement (OCP) is necessary with the objective function of system cost minimization for voltage profile enhancement, power factor improvement and power losses minimization. As OCP is a non-linear problem with equality and inequality limitations, so the stated objective depends upon he placement and sizes of the capacitor banks. Electrical transient analyzer program (ETAP) software is used for the evaluation and modelling the power systems and genetic algorithm (GA) is used as an optimization technique for the minimization of the objective function. In this paper, to show the effectiveness of the technique IEEE 4bus,33bus system and NTDC 220KV real time grid system is modelled and evaluated in terms of objective minimization i-e maximum cost saving of the power system</p>

scholarly journals Power Flow Analysis of Weakly Meshed Distribution Network Including DG

2018 ◽  
Vol 8 (5) ◽  
pp. 3398-3404 ◽  
Author(s):  
A. Al-Sakkaf ◽  
M. AlMuhaini
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Power Flow ◽  
Distribution Systems ◽  
Flow Analysis ◽  
Load Flow ◽  
Power Distribution Systems ◽  
Power Flow Analysis ◽  
Bus Voltage ◽  
Flow Study

Power flow is one of the essential studies in power system operation and planning. All steady-state parameters for power distribution systems, such as bus voltage magnitudes, angles, power flows, and power losses, can be calculated by conducting power flow analysis. Distribution system features differ from those of transmission system, rendering conventional load flow algorithms inapplicable. In this paper, three distribution power flow techniques are presented and tested to evaluate their performance when applied to a networked distribution system including distributed generation (DG). These are the distribution load flow (DLF) matrix, the enhanced Newton Raphson (ENR), and the robust decoupled (RD) method. IEEE 33-bus system is adopted for implementing the above methods. Radial and weakly meshed configurations are applied to the tested system with DG inclusion to investigate their influence on the power flow study findings.

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