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This paper puts forth a vision for scalable distribution grid integration of energy resources such as rooftop photovoltaics (PVs) and electric vehicles (EVs). The output of these resources vary temporally in an unpredicted manner. Therefore, they bring substantial challenges to utilities vis-a-vis massive deployment of such resources. By leveraging the fact that most of the distributed energy resources...
AC voltage regulators, an important family of power conditioners, are intended to reduce line-voltage fluctuations of AC mains at customer premises. Typical designs are based on automatic tap changers, motor-driven variacs, thyristor-based systems, ferro-resonant systems and solid-state versions. Solid-state regulators typically rely on high frequency switching, so have significant RFI/EMI problems,...
Stator inter-turn short circuit fault is one of the common faults in Double Fed Induction Generator (DFIG), the mathematical model of the DFIG is established based on the multi — loop theory, and the model of DFIG is built on the MATLAB / Simulink platform under normal condition and different degrees of inter — turn short circuit. The mathematical model of the grid side converter is analyzed to determine...
A series transistor array-based linear AC regulator was developed in the past and this technique is very fast-responding compared to the popular servo-transformer based AC voltage regulator. It has similar efficiency levels to the ferro-resonant types, but does not have waveform defects or power factor dependency. This patented technique is efficient when the input line voltage is at its lowest possible...
This paper presents a novel modular multilevel DC/DC converter suitable for integrating the oif-shore wind farm with the HVDC transmission system. The proposed converter consists of a wind farm-side three-phase MMC inverter and a series-connected rectifier linked by a special decoupled medium frequency transformer. The transformer decouples the three-phase input voltage into three isolated single-phase...
With penetration of wind turbines, fault ride through capability is unconditionally considered as one of the most remarkable research area. Hence, this paper proposes the fault ride through capability improvement of DFIG wind turbines by using cooperative operation of fuzzy logic voltage regulator and Superconducting Fault Current Limiter (SFCL). BSCCO (Bi-2212) superconducting coil material is fully...
The AC side Single Line to Ground (SLG) fault is one of the most frequent faults in power systems. And, in an HVDC system based on modular multilevel converter it calls for the fault ride through strategy to transmit maximum possible electricity during the fault to secure power system stability. It presents different characteristics of SLG faults at the voltage regulator side and the power dispatcher...
Numerous industrial facilities involve the installation of load transformers with their respective loads. As loads are turned on and off, these transformers are energized and de-energized, respectively, which can cause serious disturbances to sensitive loads. An inrush current, which typically occurs when a transformer is energized, can easily be observed using on-line uninterruptible power supply...
This paper provides an overview of the challenges that utilities will be facing during and after the interconnection of distributed energy resources (DER), especially at high penetration levels when utility distribution systems may be operating outside of the existing design parameters. First, California has adopted smart inverter/converter standards to mitigate potential issues caused by DER but...
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...
With the electronic equipment becoming more and more complicated and integrated, accurate grasp of electronic device's health condition has become increasingly important. In this paper, we think the health condition of the electronic circuits should include health, sub-health and fault, instead of the traditional two health status. For making quantitative evaluation about health condition of electronic...
Fuzzy diagnosis method is easily and widely used in fault diagnosis field. It provides an effective approach to quantify qualitative indicators. The temperature variation and failure cause of the voltage regulator module (VRM) in a power processing printed circuit board (PCB) have fuzzy relation. The fuzzy information is applied to the fault diagnosis of the VRM. The characteristics of the temperature...
In weak grids, an important problem with voltage stability and protections coordination of power plants exists. This problem appears because all the generation groups are connected to the same bus bar. As a result, if a fault occurs in any of the generation groups, or in the bus bar that connect them, the system voltage will have large oscillations. Hence, in weak grids the correct adjustment of AVR...
This paper proposes a new method for line fault analysis of ungrounded distribution systems. The fault condition of a line fault is integrated into the nodal admittance matrix of the faulted line to be modeled. The zero-impedance branch is merged into adjacent impedance branches to be taken into account, and one of its terminal buses with zero neutral-to-ground voltage is chosen as a slave bus when...
The IEEE Test Feeders provide a benchmark for the power distribution systems analysis community. This panel summary will provide a discussion of experiences matching the results published by Kersting and Shirek in this panel. [1] Benchmarking the short circuit currents for the Test Feeders is important to users of the Test Feeders for determining whether the system impedances are defined correctly...
Electrical utilities strive for optimal grid operations while increasing efficiency and maintaining high reliability. With the advent of the Smart Grid, these objectives remain important worldwide. Recently many separate optimization applications for distribution grid operation have been deployed, including FDIR, IVVC, OFR, and DR. These applications may have been developed with sophisticated optimization...
The growing demand for hybrid electric vehicles (HEVs) has increased the need for high-temperature electronics that can operate at the extreme temperatures that exist under the hood. This paper presents a high-voltage, high-temperature SOI-based gate driver for SiC FET switches. The gate driver is designed and implemented on a 0.8-micron BCD on SOI process. This gate driver chip is intended to drive...
The overexcitation limit of synchronous generator plays an important role in the voltage stability of power systems. Achieving maximum use of the overexcitation capability requires adequate coordination between generator control and protection. This paper provides an example of coordination between overexcitation limiter (OEL), field overcurrent protection and automatic voltage regulator (AVR) for...
This paper presents a regulated supply tuning voltage-controlled oscillator with built-in test and calibration. A low-dropout regulator with an integrated low-pass filter operates as a frequency-tuning element with inherent noise suppression. Frequency calibration employs a bias current tuning in three frequency ranges for adjusting an oscillation frequency shift caused by parametric faults. Built-in...
Daily experience with product designers, test and diagnosis engineers it is realized that the depth of interaction among them, ought be high for sucessfull diagnosis of analogue circuits. With this knowledge in mind, a responsibility was undertaken to choose a popular diagnostic method and define a systematic procedure that binds together the knowledge of a product from a design, test and diagnostic...
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