Continuous assessment of voltage stability is vital to ensure a secure operation the power system. Several indicators have been developed in an attempt quantify proximity collapse. Some them are computationally expensive, whereas others reported not perform as expected under all conditions. This study proposes new normalized indicator called P-index that robust and based on solid theoretical foundations. The index was tested IEEE 14-, 57-, 118-bus systems compared well-established L-index...

Electric power utilities employ "smart" re-closing devices capable of capturing electrical disturbance (ED) waveforms in real-time. These are digitally sampled, transmitted back to the utility, and stored text files that comply with IEEE COMmon format for TRAnsient Data Exchange (COMTRADE) standard. An average 2,100 ED events recorded, by 850 devices, on a monthly basis within Power Board's distribution network. Due operational restraints such as: time, money, person power, only 2% these...

This article proposes a new method called the Compensated Distributed-Parameter Line Decoupling (CDLD) method, and used for decoupling distribution networks among parallel processing cores in real-time multi-core environment. Due to short length of grid lines, network is challenging approaches such as Stublines State Space Nodal (SSN) solvers have been proposed. Both limitations proposed this work addresses these implement improvements. Specifically, CDLD can be an enhanced Stubline...

Accurate zero-sequence transformer data is important for correct fault analysis and protection settings. Utilities have been forced to approximate impedances many three-legged core power transformers in service today that did not undergo testing at the factory before site installation. Where approximation of from positive sequence insufficient accuracy, on-site tests proposed. However, these usually involve measurements high-voltage windings, which are either expensive with high test...

A number of computer program packages have been developed for the solution numerical methods. The main objectives paper were: to explore benefit packages-that problems based on methods-in solving mathematical models, solve fundamental equations Laplace's and Poisson's which are known in mathematics as boundary value problems, plot voltage stress over a porcelain insulator-which represents model - predict power frequency breakdown voltages. Use was made COMSOL/M package finite element method....

Primary open-phase faults on station auxiliary transformers (SATs) are characterized by the presence of voltage unbalance at equipment level that could lead to protective device tripping, increased motor acceleration times, overheating or failure start critical safety loads, particularly in nuclear power industry. The transformer primary ground zero sequence impedance has a profound impact balance secondary (equipment) but its effects not been fully analyzed context plant operation. This...

The knowledge of the critical loading point a power system is essential to assess its voltage stability condition. This conventionally obtained through continuation flows which are relatively accurate but requires considerable processing time. In this work, search for formulated as constrained optimization problem solved using robust scheme known Dog-leg Trust Region. technique mainly characterized by reliability and fast convergence it combines merits classical algorithms removes their...

Many station auxiliary transformers (SATs) in service today were not tested for complete zero sequence impedance data prior to installation. It is impractical send them a testing facility, and on-site using standard methods difficult perform. While it has been customary approximate the impedances from positive data, need accurate increasingly felt, particularly analysis of an unbalanced power system such as during open-phase fault. This paper proposes new method determine primary-tertiary...

This paper deals with a finite-element method based design of liquid-rheostat reduced-voltage starter for three phase squirrel-cage induction motors which typically drive irrigation pump loads. A commercial software package named COMSOL Multiphysics 3.4, on the computational concept finite element was used to liquid rheostat, and study effect tank material starting resistance case study. The objective use calculate required electrolyte solution, analyze value resistance, finally different...

The purpose of this paper is to present the analysis outcome two incidents in EPB's (of Chattanooga) distribution network which have been attributed unique conditions hitherto undocumented literature. first observation was recorded by an S&C IntelliRupter® using its new PulseClosing® technology adopted EPB as part smart-grid deployment. second incident involves actual wye-connected capacitor bank a cascade events involving phase failure, loss neutral, and single switches led downstream...

This work presents a method for improving the numerical stability of trapezoidal solver in discretized power system simulations. The approach identifies appropriate physical locations to apply optimized damping networks that mitigate spurious oscillations. identification procedure is based on concept state participation weak modes. State determined using matrix, borrowed from stability. tested standard benchmark and results are compared with backward Euler method. Comparison shows applied...

In this work, we investigate observed limitations that render the L-index voltage stability indicator unreliable for accurate assessment of maximum power transfer margin. The approach favors a qualitative over quantitative system study. We observe two problems, guided by examples on minimal system, with parallels IEEE 14-bus system: underreported Thevenin impedance, resulting in an overestimation transfer, and overcorrected load from bus to critical bus. conclude these difficulties need be...

A nuclear power plant (NPP) auxiliary system and connected loads associated with safety features are essential for protecting the public health safety. Online monitoring of this can produce many advantages in terms safety, operability operating costs. However, most NPP would require retrofit modifications to install online monitoring, these being more costly than other industries due strict scrutiny ensure regulatory compliance. Digital Real-Time Simulators (DRTS) have ability emulate...

This work presents a method for simulating power networks in real-time on general purpose personal computers. Real-time simulation of is mature industry, with big players dominating the market. However, implementation limited to dedicated high-end hardware and software. effort benefits researcher small-scale user who may wish explore applications without making large investment. The approach offers further insight into workings computing, particular parallel processing using methods similar...

A method for fast line outage detection and identification in partially observed PMU networks is presented. It suitable application to voltage stability analysis that uses the full network topology, its chief advantage it detects outages using limited measurements. relies on applying measured system states a pre-outaged network, detecting an by observing nodal injection errors. then defines subnetwork surrounded border buses proceeds carry out search within identify outaged element. The was...

A number of computer program packages have been developed for the solution numerical methods. The main objectives paper were: to explore benefit -that problems based on methods in solving mathematical models, solve fundamental- equations Laplace`s and Poisson`s which are known mathematics as boundary value problems, plot voltage stress over a porcelain insulator -which represents model - predict power frequency breakdown voltages. Use was made COMSOL MULTIPHYSIS package finite element...

This work develops and applies an improved approach for estimating the point of voltage collapse based on P-index method. The is a stability monitoring prediction tool that was proposed in recent research effort. Prediction distance to original method assumes linear approximation voltage-load relationship. has provided enhanced precision over most recognized indices. However, it also resulted inaccuracies because actual behavior general not but rather more complex. new model here accurate...

This work develops expressions for estimating the change in active and reactive power industrial motors response to voltage frequency variations around operating point. Magnetizing circuit saturation is accounted by using incremental reactance. The are simplified a quick estimate stator measurements parameters. validated simulation, further, test was carried out nuclear plant determine sensitivities experimentally. Both simulation show that capable of yielding fair estimation required sensitivities.

This paper proposes a new method called the Compensated Distributed-Parameter Line Decoupling (CDLD) method, and used for decoupling distribution networks among parallel processing cores in real-time multi-core environment. Due to short length of grid lines, network is challenging approaches such as Stublines State Space Nodal (SSN) solvers have been proposed. Both limitations proposed this work addresses these implement improvements. Specifically, CDLD can be an enhanced Stubline...

This work proposes improvements to the Radial Equivalent Independent (REI) reduction approach originally proposed by Dimo. REI equivalency is typically used for reducing external systems, although other uses have been reported. Some early literature suggests that method may offer reduced accuracy compared Extended Ward method. The suggested in this aim enhance and are centered on generator grouping equivalent system voltage correction. These tested an example subject typical control center...

This paper develops a method for decoupling and simulating distribution networks using Raspberry Pis as free-communicating parallel processing agents to solve decoupled network equations. work establishes framework towards real-time or near simulation of such networks. Real-time power has traditionally required high-cost, dedicated hardware software. Computation with offers an economical entry point researchers interested in applications, it advances the understanding computing purposes. The...