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In electric vehicle charging equipment, energy metering is a basic function, and the real-time monitoring for the safety of the charging process is essential. Electric vehicle AC charging pile is a convenient and efficient electric vehicle charging equipment, but the internal module of traditional AC charging pile scatters seriously. The volume of the AC charging pile is so large that is not conducive...
This paper describes the implementation of a supervisory system for wind turbine inverters, that incorporates into the frequency inverter the characteristics of the relays necessary for microgeneration. As a result, the inverter added value is increased, as external protective relays are not needed. A diagram depicting the possible inverter operating status and respective control actions is shown...
Several methods have been published aiming to detect islanding in ac distribution networks. On the other hand, islanding detection in dc networks appears more challenging, as many electric parameters, such as frequency and reactive power, are absent and thus, several methods used in ac networks are nonapplicable. This paper proposes a novel islanding detection method (IDM) that is effective in dc...
Local reactive power control of distributed generators (DG) can be used to mitigate the voltage rise effect caused by themselves. In this paper, dynamic interactions between local voltage controllers of the DG units and transformer on load tap changers (OLTCs) are studied using time domain simulations. Studies are conducted with different control modes of DG unit and OLTC control and also secondary...
The hardware/software solution for measuring parameters of optocouplers with output MOSFET transistors using a PXI-platform and NI Labview software is proposed in the article. As an example, a typical connection circuit for an optocoupler is presented and methods of an input current adjustment using a LED and data received from the TDS-2024 oscilloscope are described.
Multifunctional equipment for total ionizing dose testing of different functional types of analog integrated circuits and discrete transistors is developed and described. Corresponding test results for several types of analog devices are presented and discussed.
This paper presents the development of an apparatus for teaching AC-AC converters, specifically voltage stabilizers. Thus, one of the possible topologies for converters with transformer tap selection is studied and experimented, employing relays for 150 VA. The system developed allows students to study how voltage stabilizers work, in addition to performing measurements and comparative of technical...
Batteries are most widely used device to store the energy. The importance of the batteries is increasing especially to store the energy harnessed from renewable energy resources. The application of batteries in hybrid electric vehicles (HEV) is ever demanding and increasing. The batteries when employed in stack, individual cell parameters will be altered due to the effects of temperature gradients,...
In this paper, we present a summary of lightning protection measures aimed at securing a more reliable power supply for a telecom building. Based on an analysis of the entry paths of lightning surges into telecom building, we implemented lightning protection measures for the power receiving facilities by strengthening the equipment's tolerance to overvoltage surges. This was achieved by using a multistage...
This paper introduces a high precision equalization system for lithium-ion batteries based on DSP TMS320F28335, presents a practical circuit to measure the voltage of a single cell in series connected lithium-ion battery pack and an equilibrium state analysis algorithm based on the principle of mode. And it also provides the result of the equilibrium experiments for lithium-ion batteries. The results...
Wind turbines and the belonging converters increase in size and price. A reduction in the number of main components is desirable while it reduces need of space, investments and increases the efficiency. A wind turbine contains both a converter reactor and a step up transformer. The paper presents theory and laboratory measurements for a new control strategy which make it possibly to connect a wind...
The core of semiconductor companies is product and technology development to bear the competitiveness. One of the criteria in product development is electrical lab characterization which is crucial in validating the device's electrical functionality without jeopardizing the evaluation quality and ensuring that it is within the product specifications. Typical lab characterization takes longer time...
The idea of reshaping existing centralized electricity networks to decentralized small scale local power networks namely micro-grids, operating whether autonomous or interconnected to main distribution grid, became an important discussion. Islanding of a generator inside the micro-grid can cause problems in operation and management of the network; therefore proper islanding detection is crucial. This...
Wind generating facilities often require significant reactive power support to maintain voltage and power factor within operating limits prescribed by the transmission grid entity. Many installations include multiple stages of switched capacitor and reactor banks for this purpose. Coordinated control of these capacitor and reactor banks, which are often connected to the point of interconnection via...
Effective voltage control is essential for the satisfactory operation of distribution networks. The increased connection of distributed generation to existing distribution networks challenges the current methods of controlling network voltages. Network voltage is primarily controlled by changing tap position of the primary transformers. The transformer secondary voltage will be automatically increased...
The new communications technology and the newly developed IEC61850 standard for generic object oriented substation events (GOOSE) bring many advantages to the industrial protection and control applications. Some of the applications benefiting the most are the ones associated with the bus transfer and the load shedding schemes, together with more beneficial communication-assisted schemes, like zone-interlocking,...
This paper presents a comparative analysis among the various methodologies of automatic voltage control in electric power distribution substations, by studying the behavior of the steady state voltage. This project was based on a real case study in which three different voltage regulation techniques (Constant Voltage, Load Line, and Line Drop Compensation (LDC)) were implemented in a substation of...
Since Distributed Generation (DG) often involves renewable energy, it is important to facilitate integration of DG into existing networks. This is the aim of the EU FP6 demonstration project ADINE. It is based on the Active Network Management (ANM) concept, where automation, ICT and power electronics are used to integrate more DG by exploiting active resources instead of just reinforcing the network...
Recent misoperations of generation protection during major system disturbances have highlighted the need for better coordination of generator protection with generator capability, generator Automatic Voltage Regulator (AVR) control and transmission system protection. Generator protection misoperations contributed to the 1996 outages in the western U.S. and played a key role in the 2003 U.S. East Coast...
With the implementation of smarter grids, more Intelligent Electronic Devices (IEDs) is likely to comply with the IEC 61850 communication protocols in order to interact with each other seamlessly using GOOSE messages to exchange information amongst devices. In this paper, IEC 61850 messaging scheme will be proposed in one of the voltage control devices i.e. On-Load Tap Changer (OLTC) transformer to...
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