Intelligent Protection Scheme of Electrical Energy Distribution Systems in the presence of Distributed Generation Sources using Agent-Based Distributed Controller

The ever-increasing of renewable distributed generation sources in distribution networks, as well as increasing network size, have faced agent-based protection schemes with a heavy communicational load. Accordingly, despite the fast and reliable nature of multi-agent systems, they have the possibility of improper performance, especially in centralized protection systems. This paper presents an intelligent self-healing method that has the ability to replace common multi-agent systems during fault conditions. Therefore, protection tasks are performed in a single control level, without dependence on higher communicational levels, to clear the fault. Decentralized operation of this structure is provided by using intelligent electronic devices and distributed communications. In this way, the proposed scheme is described with high-speed peer-to-peer communication capability using the IEC-61850 GOOSE protocol. Then, a penetration-free algorithm, without the help of a central controller, is provided by using GOOSE message capabilities, to prevent any electricity interruption due to insufficient protection settings. Finally, by planning different scenarios and simulating a practical distribution network via ETAP software, the accuracy of the proposed algorithm has been proven

Design and Implementation of a New Current Fed Converter With Zero Current Switching Conditions

In this paper a new soft switching current-fed converter for high voltage high power applications is presented. This converter utilizes parasitic components of high voltage transformers as resonant elements and employs fixed frequency phase shift PWM control to implement soft switching condition, so the implementation of control circuit is easy and cheap. Every six switches turn on at zero current condition (ZCS) and it has high efficiency. The detailed steady state analysis of the converter is presented by computer simulation and analytical method. Finally the experimental results certificate analysis and simulation results of this converter

Reliability Evaluation of Power System SVC Types Using a Markov Chain

Static reactive power compensator (SVC) plays an important role in power system reliability stems. In evaluations of reliability, only reactive power is considered as a constraint network is placed in the SVC Brrsy‌Ha impact on power system reliability evaluation techniques are still not considered. This type of SVC, the TCR-FC, TSC and TCR-TSC examined and the information wrong or repair parts of the states of the user. μ) is expressed.This type of SVC, the TCR-FC, TSC and TCR-TSC examine the error occurs and information Halt‌Hay or repair parts used by our participants .Static reactive power compensator (SVC) plays an important role in power system reliability stems. Thus it is clear that λ is a parameter that indicates the error to each component, and μ is a parameter which indicates the service or go into the same circuit components and repair goes wrong. After the static reactive power compensator (SVC) plays an important role in power system reliability

Stability Analysis and Control of DFIG Based Wind Turbine Using FBC Strategy

Doubly fed induction generator has numerous advantages in wind power generation over other types of generators. Once a DFIG is subjected to a large voltage dip, a large rotor voltage induces in the rotor windings. This leads to a large transient current in rotor circuit and the dc-link overvoltage, and may block power electronic converter operation. This paper first discusses dynamic modeling of DFIG wind turbines with the stator flux orientation. Then, by small signal analysis, it is found that the dynamic behavior of the DFIG based WT during voltage dip, is strongly affected by the stator dynamics. Next, a nonlinear control strategy based on flatness is proposed to improve the DFIG transient performance. The main interest of this control method is the possibility to define the behavior of the state variable system in the steady state as well as in transients. Since the DFIG electrical dynamics are nonlinear; better control performance is achieved with nonlinear control, compared with the linear control scheme. The proposed approach stabilizes the stator dynamics through rotor and grid side filter voltage control. The results of time domain simulations validate the effectiveness the nonlinear control strategy during voltage dip of generator terminal

Transient Performance Improvement of Wind Turbines with Doubly Fed Induction Generators Using Active Damping Control Strategy

This paper Analytically investigates the effects of system and controller parameters and operating conditions on the dynamic and transient behavior of wind turbines (WTs) with doubly-fed induction generators (DFIGs) under voltage dips and wind speed fluctuations. Also, it deals with the design considerations regarding rotor and speed controllers. The poorly damped electrical and mechanical modes of the system are identified, and the effects of system parameters, and speed/rotor controllers on these modes are investigated by modal and sensitivity analyses. The results of theoretical studies are verified by time domain simulations. It is found that the dynamic behavior of the DFIG-based WT under voltage dips is strongly affected by the stator dynamics. Further, it is shown that the closed loop bandwidth of the rotor current control, rotor current damping, DFIG power factor and the rotor back-emf voltages have high impact on the stator modes and consequently on the DFIG dynamic behavior. Moreover, it is shown that the dynamic behavior of DFIG-based WT under wind speed fluctuation is significantly dependent on the bandwidth and damping of speed control loop

Short-Term Load Forecasting of Distribution Power System for Weekdays Using Old Data

Estimation of daily load in distribution companies which is performed to present the results to the DMS, is necessary. Daily load forecasting of power systems has traditionally been considered. Because load patterns are influenced by several factors such as climate, economy and society, it is difficult to predict the load exactly. That's why in recent years the use of intelligent algorithms to predict it, is growing. In this project, the short-term load forecasting is performed in a hybrid approach. Due to the different behavior in different days, various methods have been used to predict the load. With studying different methods of load prediction, finally, finally exponential smoothing algorithm was used to predict the exact load in the weekdays

Fuse saving coordination scheme for active distribution systems: State‐of‐the‐art and a novel quasi‐voltage current based scheme

Abstract Increasing the penetration level of distributed generation (DG) units requires overcoming the technical challenges associated with their integration into the distribution systems, especially protection problems. Change in the current profile of the distribution system due to the presence of DG units disrupts the operation of the conventional fuse saving coordination (FSC) scheme. The first objective of this paper is to provide an overview of the state‐of‐the‐art of FSC schemes in distribution systems with distributed generators that has not been systematically presented yet. In addition to comparing the features of reliability, cost, speed, implementation, calculation burden, and requirements, the impact of presence of distributed generations on the performance of the conventional FSC scheme is investigated in details. The second objective of this paper is to propose an FSC restoration scheme for minimizing the challenges of previous works. Using a quasi‐voltage current term, the proposed scheme modifies the adjustable time coefficient of the recloser in two ways of pro and plus. The former scheme provides an approximate FSC with a simple setting while the latter scheme provides complete coordination at the expense of a more complex setting. No need for voltage measurement makes its implementation practical in available distribution systems. The effective performance of the proposed FSC scheme is verified through extensive simulation studies in the ETAP environment

Evaluation of the Trajectory Sensitivity Analysis of the DFIG Control Parameters in Response to Changes in Wind Speed and the Line Impedance Connection to the Grid DFIG

Economic and environmental conditions often make large stations and transmission lines, restrictions are placed. Small and medium-sized production units connected to existing systems as a strategy is in progress. These units are usually near the center of the load placed and distributed generators (DG) famous are the DG are allowed types vary, such as induction generators rack squirrel-connected wind turbines, generators fed induction double mounted wind turbines, fuel cells connected to the system by power electronic converters or synchronous generator connected to the turbine combustion [10]. This way sensitivity analysis in systems of distributed generation (DG) is assessed. It is shown that the method can detect the effect of control parameters listed wind turbine connected to a double-fed induction generator (DFIG) Badoou the impedance of the changing the speed of on the stability of the transmission line useful system invested. The control parameters of the importance of influencing the behavior of DFIG are divided