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Aim of this work was to create an adaptive method allowing effective use of generator reactive power in coordinated voltage control system independently of its parameters and Automatic Voltage Controller (AVR) type. Two methods were tested, one based on artificial neural networks classification and second based on modifying voltage limiter curve constructed on base of domain experts knowledge.
This paper solves a daily multiobjective optimization model for efficient operation of power distribution systems. The model aims to minimize the voltage deviations, minimize power losses and minimize the energy costs of the distributed generators. The model is implemented on a modified 33 bus distribution system by including: two voltage regulators and four distributed generators. Three different...
In this paper, a robust decentralized controller is designed for automatic voltage regulator (AVR) and load frequency control (LFC) systems of a generator in an islanded microgrid with multiple distributed generation systems. This control strategy can be readily applied to an islanded microgrid which consists of renewable distributed generation and energy storage systems. The control strategy proposed...
In recent years, high density and high speed file memories have become increasingly important for achieving higher performance in computer systems. Multilevel storage dynamic memories offer advantages in terms of speed and density for file usage. An experimental 4Mbit memory has been designed and fabricated utilizing a newly developed multilevel storage scheme and unique peripheral circuits. These...
In the present article is investigated tuning of PI controller parameters for permanent magnet synchronous generator driven by a variable-speed wind turbine. For adjusting of the suggested PI controllers is used detailed mathematical model setting and one of the worst power disturbances — three phase ground fault.
Interconnection of relatively large independent power producers (IPP) in distribution feeders has created new challenges for the system operators and planners. In this paper, issues pertaining to voltage management in the presence of multiple IPPs and voltage regulators are discussed based on years of utility experiences with high penetration of IPPs. A setpoint-free strategy is proposed for voltage...
In this paper, we present a blackout and brownout insensitive energy harvesting ASIC for ultra-low power autonomous sensor applications. It utilizes both RF or DC power inputs to deliver a regulated voltage for on-chip and off-chip devices. A voltage limiter has been integrated for overvoltage protection. As the ASIC utilizes two regulators alternately, a kick-start method has been used for switching...
The increased deployment of Distributed Energy Resources (DER) and their connection to the existing distribution networks influences the feeder voltage profiles and challenges the voltage control in distribution networks. Traditionally, On-Load Tap Changing (OLTC) transformers are the most common voltage control devices. In this paper, the problem of voltage rise mitigation in distribution networks...
Generator Excitation System is used to provide the DC supply to the field winding for producing the magnetic field in the generator. It is considered as a main part and backbone of the generator. Excitation system also provides stability of the power system by controlling the system voltages which can be enhanced for considering some key factors. In this paper performance evaluation of new static...
Although 2.5D IC, in which chips are connected via the interposer, can increase circuit density and performance, power dissipation and thermal effect become serious concerns for 2.5D IC design. Previous researches only focus on the power and thermal management of a single chip. Therefore, in the existing 2.5D IC design flow, the designer has no idea on the power budget of each chip. Based on this...
This paper presents a patent pending [1] load anticipation feature (LAF) which provides an effective improvement in load application performance for diesel generating sets. The large real-power load is measured and a proper feed-forward signal is provided to the governor in order to minimize engine speed deviation. LAF is implemented in the voltage regulator since it recognizes the load changes in...
In this paper a design of a fractional order control imposed by a closed loop reference fractional order model for an automatic voltage regulator (AVR) system is presented. The designed controller is derived using the Internal Model Control approach. The proposed controller thus obtained is a classical PID controller cascaded with a fractional order filter. Simulations were made to test the effectiveness...
This paper presents a distributed control for dc microgrids that minimize the total generation cost and regulate the average voltage at the desired value. The proposed controller includes two modules; lower cost regulator and voltage regulator. In addition, a sparse communication network with a balanced laplacian matrix is used for data exchange between converters as each converter communicates only...
A Volt-VAR control (VVC) strategy by using voltage regulators and reactive power compensators in the modern distribution grid for renewable energy integration is presented in this paper. Currently, the VVC techniques are gaining renewed interest and attention due to the emergence of active distribution grid, which refers to the distribution grid with advanced capability of computation, control and...
Conservation Voltage Reduction (CVR) has been an efficient way to achieve power demand reduction and, consequently, a relief in distribution networks. In this work is presented an assessment of the distributed generation (DG) impacts on the efficiency achieved with the CVR. The DG is considered as a controllable source of active and reactive power through an approach based on an integrated Volt-Var...
Presented is a duty-cycle-based maximum power point tracking (MPPT) scheme with current-sensorless power estimation. Conventional MPPT methods require generated power data involving direct current measurement, or disconnection of source and load for open-circuit voltage measurement. The proposed scheme avoids these disadvantages while retaining MPPT capability. This microcontroller-based approach...
The paper discusses the feasibility studies of a dual stator permanent magnet synchronous generator in stand-alone renewable energy generation. In wind power, fresh water or sewage water stream based power generation, the turbine is driven at variable speed causing either over voltage or under voltage. The paper utilizes the principle of induction regulation for voltage control. FEM analysis has been...
In this paper we present a hierarchical control structure for dynamic management of electrical power networks with distributed generation and storage. The proposed control structure consists of three layers. At the upper level a (dynamic) Optimal Power Flow (OPF) solver computes the optimal power references for distributed generators and storages at slow rate. These references are then transmitted...
A novel power electronic transformer (PET) topology with multiport bidirectional resonant DC-DC converters is proposed where several medium-frequency multi-winding transformers is applied to realize the isolation. The topology is with high power density as well as high efficiency, which is a appropriate solution for electric tracton application like locomotives and high speed EMU trains. The power...
This paper presents a new decentralised fault detection and mitigation system for excitation control systems used in synchronous generators in power grids. The system detects and diagnoses faults in the basic components of the excitation control systems with high accuracy and in almost real time using fuzzy set theory. Once a fault is diagnosed, a mitigation action follows, where the signal out of...
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