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In this paper, the experience in engineering, logic development, testing and commissioning of bus bar protection relay applicable for 400kV and 220kV substations, for a complicated bus arrangement executed at Madhya Pradesh power transmission corporation limited (MPPTCL) is discussed. For decades, the isolator/disconnector position from switch yard is replicated in the bus bar protection relay for...
The mode information of the low frequency oscillation (LFO) is of vital importance for the security and stability of the power system. In this paper, we propose a method to identify low frequency oscillation parameter using the correlation function of ambient data based on the random response theory of power system. We studied the general procedure of this method. By comparing with the widely used...
With worldwide promotion of electric vehicles (EVs), it is possible to make flexible EV dispatch to support power grid operation, even assisting accommodation of intermittent renewable power. Under the framework of time-of-use (TOU) pricing mechanism, this paper focuses on how to determine a reasonable TOU price to influence the EV's charging habits for the purpose of load leveling. Firstly, EV load...
A capacity credit calculation method for wind and PV bundled power is proposed in this paper. The reliability models for wind power, PV power and load are set up by hourly data and stochastic probability distribution. The correlation between different renewable power and the correlation between renewable power and load are modeled in detail. And the complementarity between wind power and PV power...
The harmonics produced by the voltage source converters (VSCs) will be a challengeable power quality problem in modern power system. The digital simulation is an important approach to analyze the harmonic problems of the power electronic devices. The time step of simulation is the key point which affects the accuracy of the harmonic analysis of discrete signals in the digital simulations. This paper...
This paper develops an injection shift factors for reactive power (QISF) which is dependent on network topology only to achieve a fast linear power flow estimation after multiple loads surges including unexpected large machines inrush and peak hours surges. The proposed approach can estimate power flow subject to surges at an extreme fast speed with acceptable loss of accuracy, which can help system...
The paper presents the improved control strategy of balanced and sinusoidal doubly fed induction generator (DFIG) stator current with repetitive control (RC) under grid voltage unbalanced fundamental (the grid voltage fundamental negative component) and unbalanced harmonic distortion (all the harmonic distortion components contain positive and negative sequence). The proposed strategy aims at ensuring...
Accurate estimation of power network investment demand is of great importance for a power network company to develop the optimal investment strategy, optimal planning scheme and the optimal operation strategy. The investment demand presents obviously different characteristics under different stages of power network development. In this paper, a self-adaptive bell curve model with a density dependence...
The introduction of life cycle management (LCM) into power system asset management is very helpful for maintaining the secure and economic operation of the power system concerned, reducing the life cycle cost (LCC) and improving the management of electric power assets. Given this background, a brief survey is first made on the state-of-the-art of LCM in power system asset management, including cost...
This paper describes MATLAB/Simulink implementation of Coordination of Directional Over-Current Relays (DOCR) using 3 bus and 4 bus test models. These simulation models are developed to support and enhance Power System protection courses at the undergraduate level. This study helps students to acquire a clear understanding of this topic.
Variable Speed (VS) Pumped Storage Plants (PSP) equipped with large asynchronous (Doubly-Fed Induction) machines is an emerging technology nowadays. Motoring mode of operation of Doubly-Fed Induction Machine (DFIM) is essential and techno-economical in this application due to: (i) its uniqueness in active power controllability, (ii) bulk power handing capability with less rated power converters in...
Due to the randomness and rapid fluctuation of turbulent wind, the effects of turbulence on maximum power point tracking (MPPT) of wind turbine should be focused on. Previous work was mainly concerned with two characteristics of turbulent wind, i.e. mean wind speed and turbulence intensity. It has been found that besides the aforementioned two factors, turbulence frequency is also included in the...
This study implements the system impact analyses when a large amount of renewable generation is integrated into the Taiwan grid; these analyses include power flow, fault current, and transient stability. The simulation utilizes actual system parameters in Taiwan. According to the simulation results, this study proposes practical coping strategies for improving system frequency stability. They include...
The smart grid is arguably one of the most complicated cyber-physical system in human society. With the wide development of the measurement devices, a smart grid needs to aggregate and manage big data from a large number of data sources. The data security and integrity is therefore a critical requirement of the reliable operation of the smart grid. This paper introduces the quantum cryptography technique...
Wind power development is urgently required to facilitate development of Islands in South China Sea. Meteorological data of 6 islands are investigated in this paper. Weibull distribution is utilized to assess wind power resource. Potential wind power generation of 4 small wind turbines is analyzed. The generalized Pareto distribution based Peak over threshold approach is utilized to estimate wind...
To enhance the performance of doubly fed induction generator (DFIG) wind turbine during low voltage events, a battery energy storage system (BESS) together with advanced control schemes are proposed. The novel control strategy utilizes the existing devices within the DFIG wind turbine system to achieve low voltage ride through (LVRT) by controlling rotor and grid side converters and BESS. The advanced...
This paper proposes a direct load control (DLC) model which aims to maximize the power consumption reduction of the thermostatically controlled loads (TCLs) over the dispatch horizon. The ISO standard thermal comfort model is employed as penalty item in the objective function, so as to ensure the occupants' thermal comfort degree within an acceptable range. The TCLs are organized into multiple groups...
Modular multilevel converter (MMC) is a novel multilevel converter in the technical field of high voltage direct current based on voltage sourced converter (VSC-HVDC). This paper presents a high density sub module, which uses the series-connected IGBTs technique, in order to increase voltage level or power transmission capability for MMC. The topology of MMC and the working principle of sub module...
Precise short-term load forecasting is a very important task for power system operation. This paper presents three cascaded modules for short-term load forecasting: kernel-based clustering, decision tree and support vector regression. Kernel-based clustering classifies the input data into clusters efficiently. The data in every cluster have more similarity than in the original dataset. Decision tree...
Due to the increasing penetration of distributed renewable generators in a distribution network, it is important to have the reliable and stable operation of an anti-islanding protection method to ensure the safety of personnel and equipment. This paper presents a detailed investigation on the performance of a Rate-Of-Change-Of-Frequency (ROCOF) method. A distributed generator system is simulated...
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