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.
In this work, a method to design STIM for sensor network system is proposed. Hardware selects TMS320F28335 as main controller. A common software implementation method is also presented. Electronic spreadsheet and independent interface configuration is the key research points to realize hot-plug function. After testing, system can be used in electric transmission line leakage current and voltage detection...
This work investigates a linear model predictive control (MPC) in conjunction with a voltage source inverter with a grid-interfacing passive filter. In an ideal grid, standard linear MPC demonstrates fast transient and excellent steady-state performance while respecting the imposed constraints. Nevertheless, its direct application onto the grid-connected converters operating with a distorted grid...
Industrial tests of high voltage equipment insulation at impulse voltages are carried out following rigorously described procedures and require, as a rule, long time duration and, implicitly, significant costs. Reducing the duration of these tests, as well as the possibility of disruptive voltage prediction has been always an objective of interest. This paper involved the rigorous statistical processing...
We present a summary of the results of an intercomparison of high voltage capacitance between the National Metrology Institutes of Argentina (INTI) and Uruguay (UTE). The traveling standard was a 400 kV, 50 pF capacitor, SF6-isolated. This capacitor was calibrated in each laboratory against their own standards, comparing the results.
There are many problems in traditional verification of transformer turns ratio tester such as switching manually, low efficiency, error prone, manual recording data, and great workload. This paper introduces an automatic verification device and method for transformer turns ratio tester, the device adopts the logic control chip control signals, turns the switch by the relay automaticity, realizes the...
The paper deals with the on-line monitoring system integrated by the Italian TSO (Terna S.p.A.) in the HV substations. Arose from the long experience achieved, the latest integrated system is the SMOAT (acronym for Monitoring System for HV, in Italian). Infrastructure introduced by the online monitoring system, integrated into the Terna's existing expert systems (PSE, MBI) are also presented as well...
Precise control methods of the electric drives with induction machines like field oriented control (FOC) or direct torque control (DTC) need an accurate model of the machine they control. Certain parameters of the model have to be obtained with sufficient accuracy before the drive can be put into the operation. This article concerns an offline parameter identification method that is suitable for on-site...
A system for evaluating instrument current transformer errors using a lock-in amplifier is described in the paper. The difference between the standard and the transformer under test is evaluated as the ratio error and the phase displacement. The attention is focused to measurement of errors at the range of primary currents less than 20% of the nominal value. The measurement accuracy of current and...
This paper presents two improvements concerning a newly-developed fault ride through (FRT) strategy based on the direct phase-coordinates approach for the distributed energy resources (DER). Taking into account the unsymmetrical three-phase voltage phasors at the point of common coupling, one improvement is on eliminating the double-frequency output power ripples through a generalized reference current...
Recently, modular multilevel conterters (MMC) are also considered for medium voltage (MV) applications, where the number of modules and the switching frequency are relatively low compared to high voltage (HV) applications. In this context, standard modulation methods can cause relatively large output voltage errors. This effect is amplified even more, if the value of the module capacitances is decreased...
Current methods of topology estimation rely on breaker statuses to obtain accurate results. However, due to the lack of availability of time stamped breaker status data in many electric systems, as well as the errors associated with this data, these methods are very limited in their current scope. Additionally, synchrophasor measurements can be used to supplement information on the connectivity between...
The Phasor Measurement Unit (PMU) is a modern instrument that measures magnitude, phase angle, frequency and rate of change of frequency (ROCOF) from voltage and current signals in electric networks. It is designed to be used in the monitoring and control of electric transmission systems. For each measurement, the PMU assigns a timestamp from an accurate time source; in this way, it is possible to...
Renewable energy resources have become an integral part of the power and energy industry in the world today. Photovoltaic (PV) systems are one of the most common and established forms of renewable energy technologies. With the increased installation of PV systems both on a small and large scale, it is critical that the impacts and operations of PV systems are accurately modeled, simulated and studied...
An estimator of the dynamic state of an electric power system (EPS) is presented in this paper. The developed algorithm involves two stages which are based on the weighted least square (WLS) technique. The first stage uses conventional measurements (delivered by RTU — SCADA meters) and synchronized phasor measurements (delivered by PMU meters) in order to estimate the state of the system forming an...
The reproducibility of the Absorber Lined Shielded Enclosure (ALSE) radiated emission test method, defined in the standard CISPR 25, is evaluated through an interlaboratory comparison (ILC). The ILC started on September 2016 and concluded on February 2017. Nineteen data sets have been received. The investigated frequency range is from 1 MHz to 1000 MHz. The most critical (worst reproducibility) frequency...
• Make sure that you specify the calibration you need • Periodic validation of all equipment is a must • Chambers and Test Sites are equipment • If you take care of your equipment, it will take care of you
In today's high-speed interconnect design, crosstalk is a critical parameter and the accurate measurement is very important. However, in the calibration procedure, the fixture crosstalk is usually ignored to avoid over-complicated de-embedding algorithms. This leads to certain levels of error in the de-embedded results of crosstalk value. Engineers have been struggling in assessing the quality of...
According to the problem of high cost of standard apparatuses and complex operating for the traditional AC current measurement, this paper introduces a method to measure the AC current with high performance which is based on using digitizing system and the AC-DC difference calculable resistance. Compared verification tests indicate a maximum deviation of 2.3 × 10−5 between the digital sampling measurement...
Based on measurement of AC impedance, this paper presents a new method for evaluating measurement uncertainty of AC impedance. The method of equal potential measurement is introduced, which can calibrate AC impedance and trace to voltage ratio standard and phase standard by adjusting the current in the circuit. What's more, the measurement data of 1 kHz, 100 Ω is given in the paper, whose measurement...
The increasing conducted interference caused by modern electronic equipment is causing more problems for electronic, or static, energy meters. These meters are called smart meters when equipped with a communication link, and are replacing the conventional electromechanical meters. It is known that conducted electromagnetic interference, for instance due to active infeed converters as used in photo-voltaic...
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.