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As an effective method of saving energy and avoiding market risks, generation rights trade has been carried out in some provinces and regional power companies. This paper analyzes the existing generation rights trade models and their algorithms, points that the results calculated by high-low match mode are not the optimal, because the trade order is inherent characteristic owned by this mode, which...
Geomagnetically induced currents (GIC) flowing in technological networks at the Earth's surface are ground effects of space weather. During geomagnetic storms, such currents cause bias fluxes in transformers, resulting in half-cycle saturation. Severely distorted exciting currents which contain enormous amounts of harmonics threaten the safe operation of other equipment and even the whole power system...
This paper presents a complementary distributed generation (DG) with wind and photovoltaic powers. And it gives a detailed analysis of the effects for the various states of this DG to the island's voltage and frequency, and presents an optimization strategy called under-frequency load shedding in the island to increase the accuracy of model. On this basis, it builds a reliability analysis and calculation...
With the widely installation of Phasor Measurement Units (PMUs) in power system and the increasing requirement of the real-time monitoring and control, a novel power system topology analysis algorithm is proposed with high precise information from PMUs to improve the performance of current network topology analysis. First of all, a method of identifying switch status is established to correct the...
As a promising renewable resource, wind power is highly expected to contribute a significant part of generation in power systems in the future, but this also brings new integration related power quality issues due to its unconventional characteristics. To solve frequency fluctuating problems of wind power integration, this paper proposes an idea that it is possible and reasonable to use HVDC lines...
A new transformer protection theory based on spectral entropy characteristics is put forward in this paper. First, the algorithm of empirical mode decomposition (EMD) and entropy are developed, and variation trends of spectral entropy characteristics are analyzed in the case of inrush currents and internal fault currents. EMD algorithm is used to conduct the accurate location of current breaks and...
Digital based data processing and protection and control system along with digital communication networks introduces new structures for substation protection and control systems and new methods for intelligent protection and control systems. This paper presents a unique vision for the future integration of protection and control systems. Firstly, the basic concept and configuration of the developed...
In this paper, carrier based islanding protection is taken as the research objects, and the signal injection equipment and the islanding protection equipment are designed to implement the protection. First, it makes demands on signal injection equipment, and chooses proper signal injection mode, signal frequency and signal source according to the demands; then, it makes demands on islanding protection...
A complex domain projection method of analysis is proposed based on the transient representation of electro-magnetic traveling wave (EM) for transmission line. Considering the impact of distributed parameters and the characteristics of electro-magnetic wave, the transmission line model is built. The instantaneous voltage equation and the fault location function are derived and obtained and the former...
In load model verification process, the accuracy of model and its parameters makes the actual operating conditions unable to reappear in simulation. The information deviation between measured data and verifiable simulation data makes it impossible to ensure the descriptive power of measurement-based load model for real load characteristics. With this problem, the paper applies closed-loop verification...
Distributed generation (DG) that uses renewable energy sources has an unstable output and this can negatively affect existing electric power systems. In order to reduce above impact, we need to develop an energy control system to control the output through individual DG installed in a micro-grid. First, this paper designs a grid-connected Photovoltaic (PV) system and introduces the operation principle...
This paper presents a simple and effective approach based on two dynamic matrixes of node-relay matrix (NRM) and relay-incidence matrix (RIM) to determine minimum break point set (MBPS) for coordination of the directional relays. Firstly, the NRM and RIM are defined and their calculation methods are developed. Then, some optimization operations for network reduction and special structure are presented...
Limiting the short-circuit current is of great significance to keep the safe and steady running of the power system. A novel fault current limiter (FCL) is presented. A high speed switch is used to rapidly break the short-circuit current. A triggered vacuum switch (TVS) is used to discharge a precharged pulse capacitor so as to quench the arc in the high speed switch quickly and to realize the active...
The microgrid is a potential solution for future distributed generation systems. It aggregates many distributed energy resources (DERs) and loads together as an autonomous entity. As the penetration of DERs is increasing and their characteristics are very distinct, the control of DERs in microgrid is still a complex task. In this paper, a multi-agent system (MAS) approach, as a branch of distributed...
Distributed generator (DG), with its flexible power generation, environment-friendly advantages has been more widely used in distribution system, which has brought some influence to the traditional distribution network reliability evaluation. In this paper, two different models for conventional DG and wind turbine generator (WTG) are established for reliability evaluation, based on different energy...
With the development of HVDC project in State Strong Smart Grid, the Faraday magneto-optical effect optical current transformer has been paid more and more attention to. However, the signal to noise bands overlap in original Faraday effect DC optical current transformer causes its measurement accuracy to decrease. Therefore, this paper presents a Faraday magneto-optical effect DC optical sensing method...
Since Microgrid located downstream in distribution network, voltage sags caused by short circuit have become common power quality events that users of Microgrid have to face. According to where the short circuits occurred, voltage sags can be divided into two categories, interior voltage sag and exterior voltage sag. Exterior voltage sag caused by short circuit taking place in distribution network,...
The integration of photovoltaic generation into the power grid is one of the most significant measures for the guarantee of national energy security, the construction of low-carbon society and the enforcement of National Twelfth Five Years Plan in China. Based on the in-depth surveys, this paper presents the framework of the infrastructure construction planning of photovoltaic generation from the...
This paper theoretically analyzes the compound control apparatus for current quality compensation which is designed as differentiation cascaded H bridge type with two modules: fundamental-frequency module and high-frequency module. The detection algorithm calculates the harmonic current and fundamental-frequency current of the load current which serve as the command current. For the purpose of eliminating...
In this paper, concerning the limitations of this method which can not meet the current needs of the development of large-scale power system, a new electromechanical transient simulation model based on dynamic equivalent is proposed. It develop a new vision for the electromechanical transient and electromagnetic transient hybrid simulation, which presents the application of dynamic hybrid simulation...
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