An Investigative Study on Impact of Frequency Dynamics in Load Modeling

2020 ◽  
Vol 01 (01) ◽  
Author(s):  
Musa Mohammed ◽  
◽  
Abubakar Abdulkarim ◽  
Adamu Sa’du Abubakar ◽  
Abdullahi Bala Kunya ◽  
...  
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Low Voltage ◽  
Model Performance ◽  
System Stability ◽  
Normal System ◽  
Area Network ◽  
Load Modeling ◽  
Feed Forward Neural Network ◽  
Load Model

Load modeling plays a significant impact in assessing power system stability margin, control, and protection. Frequency in the power system is desired to be kept constant, but in a real sense, it is not constant as loads continually change with time. In much literature, frequency dynamics are ignored in the formulation of load models for the basic assumption that it does not affect the models. In this paper, the composite load model was formulated with Voltage-Frequency Dependency (V-FD) on real and reactive powers and applied to estimate the load model. 2- Area network 4- machines Kundur test network was used for testing the developed model. The model was trained with measurements from a low voltage distribution network supplying the Electrical Engineering department at Ahmadu Bello University, Zaria. Both training and testing data were captured under normal system operation (dynamics). To evaluate the V-FD model performance, Voltage-Dependent (VD) model was examined on the same measured data. The work makes use of the Feed Forward Neural Network (FFNN) as a nonlinear estimator. Results obtained indicate that including frequency dynamics in modeling active power reduces the accuracy of the model. While in modeling reactive power the model performance improves. Hence, it can be said that including frequency dynamics in load modeling depends on the intended application of the model.

Dynamic Load Modeling Based on Extreme Learning Machine

2012 ◽  
Vol 195-196 ◽  
pp. 1043-1048
Author(s):  
Zhong Hui Liu ◽  
Zhen Shu Wang ◽  
Mei Hua Su
Keyword(s):  
Power System ◽  
Extreme Learning Machine ◽  
Dynamic Simulation ◽  
Dynamic Load ◽  
Reactive Power ◽  
Power Model ◽  
Load Modeling ◽  
Load Model ◽  
Load Characteristics ◽  
Learning Machine

The dynamic load characteristics have significant impact on the power flow, transient stability computation, voltage stability calculation of the power system, and so on. Noticing that traditional mechanism loads model has difficulty in precisely describing the dynamic characteristics of synthetic load, this paper presents a non-mechanism dynamic load model based on Extreme Learning Machine (ELM). The Power Fault Recorder and Measurement System (PFRMS) is used to obtain data for load modeling. Take voltage and real/reactive power with different time delay as inputs, and take real/reactive power as output, train the ELM using the samples formed by fault data, the real power model and reactive power model are established respectively. The number of hidden layer nodes which has impact on the ELM model is also discussed. Dynamic simulation experiment is conducted at power system dynamic simulation laboratory. The simulation result shows that the ELM load model is simple and flexible, its parameters are easy to be identified. The ELM load model can describe the dynamic load characteristics accurately.

scholarly journals Steady State and Transient Analysis of FSIG and DFIG Integration to Grid for Different Penetration Levels using VSC-HVDC

2020 ◽  
Vol 8 (6S) ◽  
pp. 53-59
Keyword(s):  
Power System ◽  
Wind Energy ◽  
Wind Power ◽  
Reactive Power ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Simulation Software ◽  
System Stability ◽  
Induction Generator ◽  
Hvdc System

Among all the Renewable Energy Sources Wind energy is the fastest growing energy source over the last decade mainly due to crucial developments of technology in wind energy. Nowadays, the penetration of wind energy is increasing in many countries in the world including India. The power system stability with large penetration of wind power is a concern for many electrical utilities. The common technical issues with increased penetration of wind energy are voltage and reactive power control, frequency control and Low Voltage Ride Through (LVRT) capability. The VSC-HVDC system with its benefit of independent control of active and reactive power promises to enhance the system stability at high penetration levels. The maximum wind penetration levels in to the grid is analysed for Fixed Speed Induction Generator (FSIG) & Doubly Fed Induction Generator (DFIG). The penetration levels are further enhanced by considering the evacuation of wind power with VSC-HVDC system without losing system stability. Different controllers for VSC-HVDC system are used to improve the stability and LVRT capability. Standard Benchmark System is considered, and the simulations are performed by using power system simulation software SIMPOW. Results shows that wind power evacuated through VSC-HVDC system has better stability and LVRT Capability compared to AC system at high wind penetration levels.

scholarly journals Dynamic load modeling of some low voltage devices

2009 ◽  
Vol 22 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Lidija Korunovic ◽  
Dobrivoje Stojanovic
Keyword(s):  
Induction Motor ◽  
Dynamic Load ◽  
Low Voltage ◽  
Supply Voltage ◽  
Incandescent Lamp ◽  
Mercury Lamp ◽  
Load Modeling ◽  
Load Model ◽  
Fluorescent Lamps

This paper presents the results of dynamic load modeling for some frequently used low voltage devices. The modeling of long-term dynamics is performed on the basis of step changes of supply voltage of the heater, incandescent lamp, mercury lamp, fluorescent lamps, refrigerator, TV set and induction motor. Parameters of dynamic exponential load model of these load devices are identified, analyzed and mutually compared.

Research on the Reactive Power Optimization

2013 ◽  
Vol 385-386 ◽  
pp. 991-994
Author(s):  
Yan Yan Wang ◽  
Yan Song Li
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Power Optimization ◽  
Low Voltage ◽  
Pso Algorithm ◽  
Reactive Power Optimization ◽  
Voltage Level ◽  
Line Network ◽  
Improved Pso

The power system is facing line losses, low voltage level and some other issues, this article begin with the point of the reactive power optimization, and through with the improved PSO algorithm, we find a way to reduce the line network loss.

Solving realistic reactive power market clearing problem of wind-thermal power system with system security

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sravanthi Pagidipala ◽  
Sandeep Vuddanti
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Power Market ◽  
Operating Conditions ◽  
Objective Functions ◽  
Market Clearing ◽  
Load Model ◽  
Multi Objective ◽  
Reactive Power Market ◽  
Single Objective

Abstract This paper proposes a security-constrained single and multi-objective optimization (MOO) based realistic security constrained-reactive power market clearing (SC-RPMC) mechanism in a hybrid power system by integrating the wind energy generators (WEGs) along with traditional thermal generating stations. Pre-contingency and post-contingency reactive power price clearing plans are developed. Different objective functions considered are the reactive power cost (RPC) minimization, voltage stability enhancement index (VSEI) minimization, system loss minimization (SLM), and the amount of load served maximization (LSM). These objectives of the SC-RPMC problem are solved in a single objective as well as multi-objective manner. The choice of objective functions for the MOO model depends on the load model and the operating condition of the system. For example, the SLM is an important objective function for the constant power load model, whereas the LSM is for the voltage-dependent/variable load model. The VSEI objective should be used only in near-critical loading conditions. The SLM/LSM objective is for all other operating conditions. The reason for using multiple objectives instead of a single objective and the rationale for the choice of the appropriate objectives for a given situation is explained. In this work, the teaching learning-based optimization (TLBO) algorithm is used for solving the proposed single objective-based SC-RPMC problem, and a non-dominated sorting-based TLBO technique is used for solving the multi-objective-based SC-RPMC problem. The fuzzy decision-making approach is applied for extracting the best-compromised solution. The validity and efficiency of the proposed market-clearing approach have been tested on IEEE 30 bus network.

scholarly journals Accurate Load Modeling Based on Analytic Hierarchy Process

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Zhenshu Wang ◽  
Xiaohui Jiang ◽  
Shaorun Bian ◽  
Yangyang Ma ◽  
Bowen Fan
Keyword(s):  
Power System ◽  
Analytic Hierarchy Process ◽  
Load Modeling ◽  
Analytic Hierarchy ◽  
Load Model ◽  
Load Models ◽  
Power Load ◽  
Hierarchy Process ◽  
Weight Coefficients ◽  
Traction Power

Establishing an accurate load model is a critical problem in power system modeling. That has significant meaning in power system digital simulation and dynamic security analysis. The synthesis load model (SLM) considers the impact of power distribution network and compensation capacitor, while randomness of power load is more precisely described by traction power system load model (TPSLM). On the basis of these two load models, a load modeling method that combines synthesis load with traction power load is proposed in this paper. This method uses analytic hierarchy process (AHP) to interact with two load models. Weight coefficients of two models can be calculated after formulating criteria and judgment matrixes and then establishing a synthesis model by weight coefficients. The effectiveness of the proposed method was examined through simulation. The results show that accurate load modeling based on AHP can effectively improve the accuracy of load model and prove the validity of this method.

Study on Loss Reduction of Large Scale Wind Power Concentrated Integration on Power System

2013 ◽  
Vol 380-384 ◽  
pp. 3051-3056 ◽  
Author(s):  
Xiao Dan Wu ◽  
Wen Ying Liu
Keyword(s):  
Power System ◽  
Wind Power ◽  
Power Loss ◽  
Large Scale ◽  
Wind Farm ◽  
Reactive Power ◽  
Low Voltage ◽  
Main Step ◽  
Loss Reduction ◽  
Wind Generators

In this paper, starting from the active network loss formulas and wind characteristics, it is pointed out the reactive power loss and reactive flow is the major impact of wind power integration on power system loss. The reactive power loss formulas of box-type transformer, main step-up transformer, wind farm collector line and connecting grid line are analyzed. Next the reactive power loss of transformer and transmission line is described in detail. Then put forward the loss reduction measures that installing SVC on the low voltage side of the main step-up transformer and making the doubly-fed wind generators send out some reactive power at an allowed power factor. Use the case of Gansu Qiaodong wind farm to verify the effectiveness of the proposed measures.

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