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Phase-Locked-Loop (PLL) plays important role in grid connected power electronics system. A good PLL system can detect the grid phase angle and frequency fast and accurately, and additionally it can extract the positive sequence exactly. In real applications, source signal (voltage or current) usually includes harmonic distortion, unbalanced components. Conventional PLL strategy cannot solve the unbalanced...
Most energy management system applications are based on the positive sequence network model. Since most systems do not operate under fully-balanced operating conditions, methods to minimize the impact of the balanced operation assumption on the network applications must be developed. This paper studies the impact of load imbalances on state estimation results by comparing state estimates using different...
This paper presents an optimization framework for a load aggregator with electric energy storage (EES) to determine its net imported power in electricity markets. The EES is operated by the load aggregator. The imported power from both day-ahead and real-time markets is a combination of the load and the EES power charging and discharging. The load aggregator's objective is to minimize its energy cost...
A novel multi-step coordinated control approach for microgrid management is proposed considering economic and environmental aspects. The proposed concept consists of a two-layer control algorithm, the component-layer and the top-layer controls. Both are based on look-ahead multi-step optimization techniques. Assuming the availability of renewable power forecasting methods, future states of the microgrid...
DFIG (Doubly Fed Induction Generator) based wind farm is gaining popularity these days because of its inherent advantages like variable speed operation and independent controllability of active and reactive power over conventional Induction Generators. When interconnected into power grid, it brings voltage stability problems during grid-side disturbances. So integration of DFIG-based wind farm to...
A coordinated controller for generator excitation and STATCOMs is studied based on the Hamiltonian function method. The Hamiltonian realization structure for multimachine power systems including STATCOMs is developed leading to a proposed coordinated scheme of excitation control and STATCOM control. Simulation results illustrate the effectiveness of the proposed control strategy.
This paper presents a critical review of the static three phase induction motor models that have been proposed in the literature for power flow and long term voltage stability studies. The need for including static induction motor models in these two classes of studies is due to: a) Initializing dynamic induction motor models in time-domain stability studies; b) Assessing the effect of induction motor...
The power oscillation flow method is a small signal sensitivity method which is able to determine an index that assesses the degree of participation of the power flowing at each transmission element, or being consumed at each load of the power system, in the formation of each swing mode. In this way, the power oscillation flow method is an extension of the participation factors traditionally used...
The FREEDM grid utilizes solid state transformers (SST) and solid state fault interruption devices (FID) which may lead to unfavorable operating losses as compared to a conventional grid. Various SST topologies and switching techniques are identified for minimizing losses and a performance evaluation is made to determine the efficiency of the FREEDM distribution network to improve the overall efficiency...
In this paper we deal with shipboard power system (SPS) reconfiguration with an integrated power system (IPS) and distributed generator. The objective of reconfiguration is to determine the status of the switches such that power is delivered to the vital loads even under fault conditions. We have used a model-free reinforcement technique called Q-learning for solving the reconfiguration problem. We...
Photovoltaic power plants pose some challenges when integrated with the power grid. The PV plants always focus on extracting the maximum power from the arrays. This makes the PV system unavailable for helping in regulating the grid frequency as compared to conventional generators. The objective of this paper is to introduce a pseudo power point tracking which provides frequency regulation functionality...
In an electric power network, initial loss of a transmission line may create transient overloads in other lines, inducing cascading failures, and possibly system wide outage. Full time domain simulations to credibly predict the wide range of possible switching actions that can lead to cascading failure events under transient conditions is extremely costly. As an alternative, this work proposes a bi-stable...
The major subject of this paper is the analysis and simulation of market-based coordination of variable resources with storage systems such as aggregated Plug-in Hybrid Electric Vehicles (PHEVs). Starting from our recent work on modeling and model predictive scheduling of conventional generation, variable generation, and battery storage systems, we further develop in this paper a look-ahead multi-layered...
Quite often because of the complexity in the design of large industrial motors, the theoretical motor parameter calculations do not match actual results from laboratory tests. Thus, it becomes important to predict the amount of discrepancy between the two methods to develop confidence in the motor parameter calculations. This paper discusses the development of multiple artificial neural networks (ANNs)...
With the concern of possible climate change caused by greenhouse gas emissions from fossil fuel, the world as a community has taken several monumental steps to encourage the development and implementation of renewable technologies and products, mainly wind power, in order to reduce the emission of greenhouse gas. Among countries, the US and China, both with significant wind power capacity, have adopted...
An interconnected power system is made of several areas that can exchange power through tie lines. These tie lines are equipped with Phase Shifting Transformers (PSTs) for active power flow control. In a multi-area power system operation, an operator within a control area should know the maximum power that can be imported to the area for the best possible operation of the system. AC power flow method...
Low frequency inter-area oscillation is a major problem in power system operation. If not damped, these oscillations prolong, grow, and decrease transmission capacity of the tie-lines, causing interruption in energy supply. Several methods for damping of these oscillations are reported in literature. The damping may be provided by appropriate control of different components in power system such as...
This paper presents the process of updating and tuning the automatic voltage regulators of two synchronous micro machines (round rotor and salient pole) of a micro network power system simulator. This micro network is an important part of the Laboratory Power Systems Simulator, which is being developed by the Electric Machines and Power System Dynamics research group of SEPI-ESIMEZ-IPN. Basics of...
This paper presents the analyzed results of an integrated offshore wind farm (OWF) and seashore wave farm (WAF) connected to an onshore large power grid through a high-voltage direct current (HVDC) link to simultaneously achieve power-fluctuation mitigation and dynamic-stability enhancement. The performance of the studied OWF is simulated by an equivalent aggregated 80-MW doubly-fed induction generator...
As new wind energy assets are installed at an accelerated pace and wind turbine technology continues to mature, permanent magnet synchronous generators (PMSG) are increasingly being utilized to derive electricity within wind energy conversion systems (WECS). Attractive as renewable sources, unfortunately WECS can introduce electrical instabilities into some power systems due to the intermittent nature...
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