The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper proposes a grid-connected digital controller of a diesel-engined generator for a hybrid power system. The grid-connected digital controller is capable of not only connecting a diesel-engined generator in parallel to the utility power by adjusting an electronic oil valve and excitation regulator, but also of adjusting the output power. A 12-KVA diesel-engined generator set with the grid-connected...
The greater demand variability caused by the high penetration of Distributed Generation (DG) challenges the LV grids. Although the DG supports the local load demand, its intermittent nature (i.e. renewables) can create undesired conditions: reverse power flow from the Low (LV) to Medium Voltage (MV) grid in case of low load demand and high power production, or overloading of the substation transformer...
Steam generator tubes has anti-vibration bars in U-bend area for supporting tubes and avoiding unacceptable flow induced vibration or micro vibration induced wear. This article describes anti-vibration bar shift of 55/19B model steam generator and using eddy current inspection to investigate the respective anti-vibration bar shift signal and the gap between tube and anti-vibration bar.
A 10 cavity LTD accelerator has been tested at CEA for flash radiography applications1. This LTD system is configured to deliver a 1MV pulse on a 6Ω electron beam diode. A magnetically insulated transmission line is use to transport the power to a large area diode. This work describes a numerical analysis of this LTD system. The Particle-In-Cell (PIC) code LSP2 is used for modeling the pulsed power...
From time to time a sequence of unexpected and often overlapping contingencies may lead to power system angular instability and even blackouts if not addressed adequately by means of an out-of-step protection system. This paper proposes the out-of-step protection system structure, which is based on generation sources electromotive forces vectors angle control. The protection system consists of several...
Ground faults in generator stator and field/rotor circuits are serious events that can lead to damage, costly repair, extended outage and loss of revenue. This paper explores advances in field/rotor circuit ground fault and stator ground fault protection. [1] These advanced protection strategies employ AC injection, ground differential protection and the use of hybrid grounding to reduce both internal...
Factory acceptance tests performed on High Voltage Direct Current (HVDC) transmission apparatus usually involve the application of high direct voltage and switching impulse voltage in separate withstand tests used to qualify the insulation system. However, the actual stress subjected to the equipment insulation system while in-service on the HVDC transmission system, is a switching surge transient...
Energy generation evolves quickly towards a significant share of renewable sources, with increased challenges regarding the system stability and provision of ancillary services, including the non-mandatory voltage control (NMVC) by generators. Under these circumstances, accurate measurement solutions are required to support competition and increase the quality of such services. Current measurement...
The objective of this study is to examine the cost implication and reactive power generating potential of the synchronous condenser. Universally, increase in electricity demand constitutes new issues for power generation, transmission and distribution. Synchronous condenser solutions are being initiated globally to be instrumental in the best usage of power resources and offer grid systems support...
This paper presents the results of an evaluation of the soil parameters when submitted to high frequencies voltages generated by an impulse generator prototype. First, there was the construction of the device that will generate the impulses. Although the amplitude of the generated signal is low compared to conventional impulse generators, the wave-shape produced is similar to the one of an actual...
In this paper, a distributed intelligence algorithm is used to manage the optimal power flow problem in islanded microgrids. The methodology provides a suboptimal solution although the error is limited to a few percent as compared to a centralized approach. The solution algorithm is multi-agent based. According to the method, couples of agents communicate with each other only if the buses where they...
The rapidly increasing number of implemented photovoltaic (PV) systems in the German distribution grid in recent years has led to power quality issues due to the intermittent generation and reverse power flows in periods of low demand. In order to decrease this impact, different solutions are being investigated. The aim of this study is to analyze the maximum possible grid relief by using residential...
In an electric power system there is a dynamic balance between generation and load in normal operating conditions. A disturbance, such as a power system fault, a sudden change of load or a trip of a generation unit may break the balance, cause the oscillations among the generator's rotor angles and force them to adjust to a new operating condition. Due to the inertia of the generator prime movers,...
This paper proposed a novel approach based on the center of power (COP) applied on a sliding window for predicting real-time network instability. The COP speed reference and two new indices (γ and κ) derived from phasor measurements units serve as predictors in the building of random forest (RF) learning. This approach reduced the number of variables to be analyzed and allowed to decide the state...
This paper is focused on measurement and evaluation of leakage current in insulation during DC voltage stress of insulation stator windings. High emphasis put on evaluation and interpretation of results on life cycle of stator winding of generator and it put on used approximation of measured results.
A 2×VDD I/O buffer with process and voltage (PV) compensation technique is proposed. In this research, the purpose of slew-rate compensation is to maintain slew rate (SR) within predefined ranges regardless PV variations. The reason of temperature variation is not considered is that it is found to be a relatively low correlation factor to slew rate for 90 nm process. All bias voltages in process and...
This paper describes the impact of the operation of distributed energy sources on voltage quality parameters in medium voltage distribution grids. The survey is based on the evaluation of voltage quality measurements which were made in different medium voltage distribution grids with connected wind power plants. These measurements were made in 2014 and were evaluated according to the EN 50160 standard...
With the final objective to assure equivalence between radiated and conducted immunity testing to intense electromagnetic pulses, in this work a circuit model of a typical pulsed current injection (PCI) test setup is derived, implemented in SPICE, and validated by measurement. By virtue of such a model, the parameters of the discharge circuit of the pulse generator can be adjusted to compensate the...
Power system disturbances may cause stable or unstable power swings in the system. As a result, apparent impedance trajectories could enter into distance characteristics during a power swing and cause distance relay mis-operation. A power swing blocking (PSB) function is typically included in modern distance relays to block distance elements from undesired operation due to a power swing.
Many industrial facilities will have on site generation and it is important that the facility design its protection and control system to protect the interconnection between the facility and the utility supply. This paper is a tutorial on the protection necessary to protect the utility from issues within the industrial facility and to protect the facility from issues on the utility supply. Topics...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.