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In the last decade, harmonic analysis of Japanese middle voltage (MV) customer and low voltage (LV) customer has been done, the distribution of the fifth harmonic current can be classified MV customer's single phase load, LV customer's three phase and single phase load named group A and MV three phase load named group B, and the amplitude per load kW has been investigated from sum of each current...
In this paper smart operation of micro energy hub is presented. Energy hub system consists of certain energy hubs and interconnectors that are coordinated by energy hub system operator. An energy hub contains several converters and storages to serve demanded services in most efficient manner from available energy carriers. In this paper, the flexibility of energy delivery point is enhanced using micro...
We developed a constrained state estimation method that clarifies the range of the feeder voltage in an unobservable distribution network in which the number of telemetric sensors is smaller than the number of state variables to be estimated. Instead of using pseudo-measurements, whose reliability is affected by unexpected power flow conditions, the method uses constant nominal boundaries as inequality...
Modeling and simulation of power systems for general-purpose transient studies has been receiving significant attention in the literature. Among recently proposed methods, the so-called shifted-frequency analysis (SFA) approach has been shown to facilitate accurate and numerically efficient simulation of electromagnetic and electromechanical transients with the use of dynamic phasors. This paper proposes...
This paper proposes an effective control scheme to improve the transient behavior of VSC-based energy storage systems facing energy saturations. This control is aimed to reduce abrupt transients following energy saturations of the storage device. The WSCC 9-bus test system is used for validating and discussing the proposed controller. In particular, the dynamic response of a battery energy storage...
This paper presents a state estimator based on the use of a particle filter (PF). Unlike other types of filters, a PF is suitable for both nonlinear systems and non-Gaussian error distributions. The proliferation of distributed energy resources such as distributed generators and controllable loads has been accompanied by a high degree of uncertainty because the lack of sensors necessitates the use...
In this paper, a trajectory sensitivity method (TSM) is used to estimate parameters of a synchronous generator model suitable for unbalanced conditions which are typical of distribution systems. The current formulation and mechanical equations which represent the synchronous machine have parameters whose value modification cause significant changes in system's output. Trajectory sensitivity method...
This paper employs impedance-model-based frequency domain analysis to detect subsynchronous resonances (SSR) in Type 3 wind farms with Thyristor Controlled Series Capacitor (TCSC). The contributions of this paper are (i) the derivation of dynamic phasor based TCSC impedance model and (ii) the application of such impedance model in Type 3 wind energy systems for SSR analysis. Impedance models for TCSC...
The boost in intermittent renewable generation increases the constraints on the transmission lines, including the interconnections between neighboring countries. This rises the concerns on the security of supply in the power systems. In addition it damages the efficiency of the electricity market.The modification of the bidding area configuration is often considered as a solution to manage this problematic...
This paper presents the analysis of a distribution system subject to reconfiguration with high wind penetration over a period of 24 hours. In order to meet this objective, the reconfiguration problem is solved through mixed integer linear programming considering the stochasticity of the variables, where the balance between load and generation has to be satisfied at the lowest cost in each period....
Sandia National Laboratories (SNL) and National Renewable Energy Laboratory (NREL) have collaborated to develop the open-source Wave Energy Converter (WEC) modeling tool WEC-Sim, capable of running on a standard personal computer. Its main function is to simulate WECs of arbitrary geometry subject to operational waves; both regular and irregular waves. However, WEC-Sim Version 1.0 models a power take-off...
A regime shift occurs when a dynamical system's state shifts from a nominal equilibrium to an alternative equilibrium. This concept is often used to describe the collapse of ecological systems, but it also appears in many engineering systems; most notably in the voltage collapse of power systems. This paper uses an information theoretic index known as the Fisher Information (FI) as a real-time statistical...
An on-line line switching method based on a three-stage strategy to effectively relieve overloads in power systems is proposed. The proposed method is designed for on-line applications in the control center environment. To balance the requirements of solution speed and of effectiveness, the proposed three-stage method is composed of screening stage, ranking stage and detailed analysis stage. One distinguishing...
This work presents a comparative study of Least Squares Filter, Kalman Filter and Unscented Kalman Filter for estimating the secondary current phasor distorted due to saturation of Current Transformers (CTs). Several distorted current signals were generated in a Real Time Digital Simulator (RTDS) and embedded in noise. Then, these signals were segmented in two kinds of regions, named saturated and...
Transmission line parameter modeling and PMU measurement calibration are important research topics in power system engineering. State estimation is widely used to estimate voltage with assumption of “accurate” system parameters. Various methods have also been proposed to estimate line parameters based on PMU measurements. However, neither system parameters nor system measurements are reliable enough...
Overhead (OH) transmission lines when loaded always consume reactive power. An underground (UG) power cable on the other hand is in itself a huge capacitor and therefore a source of reactive power. This paper highlights the use of UG power cables in conjunction with overhead lines, where the reactive power requirement of overhead line is compensated by UG power cables. To realize this compensation,...
Currently, the standards used to calculate the short circuit (SC) current ignore the contribution of DC systems to the SC current when short-circuit faults occur in an AC systems. With the rapid development of High Voltage Direct Current systems (HVDC), it has become important to determine whether the contribution of the HVDC system can be ignored when calculating the SC current. This study investigates...
This paper proposes a Support Vector Machine (SVM) based methodology to classify the loads into various classes based on the load responses, following a disturbance and other information available from the feeder. The classification is performed after a large disturbance, and the model parameters are estimated by using a variable projection based efficient optimization algorithm. For small disturbances...
Design of voltage source converters (VSC) for high-voltage direct current (HVdc) systems requires extensive simulation tools that are accurate and reliable. Before the installation of VSC-HVdc links, different simulation-based studies need to be performed by different parties and using different electromagnetic transient (EMT) simulation platforms. Previous work shows that even with a pedantic re-implementation...
A major challenge in power system operation is the integration of renewable energy in-feed in large scale. Due to the fluctuating nature and seasonal dependency of these energy carriers, excess energy might be curtailed and shortfalls are covered by conventional generation units, since it is possible that sufficient storage capacities are not always available. In this paper we focus on the Power-to-Gas...
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