scholarly journals Analysis of Errors in Active Power and Energy Measurements Under Random Harmonic Distortion Conditions

2021 ◽  
Vol 21 (6) ◽  
pp. 168-179
Author(s):  
Kiril Demerdziev ◽  
Vladimir Dimchev

Abstract As harmonic distortion of voltage and current is reality in the power system, the need for accurate measurement of electrical power and energy goes beyond the instruments’ specifications and calibration procedures regarding pure sine wave signals. Several international standards and recommendations provide test signals for examination of electricity meters under non-sinusoidal conditions, however, not all of the test signal parameters’ possible states are faithfully represented in those documents. Because the high order harmonics may possess random amplitudes and phase shifts in relation to components at fundamental frequency, it is important that the meter’s performance is verified with random waveforms as well. The non-linear dependence between the measured power/energy and the phase shifts, both between fundamental and harmonic components, provides additional complexity of such an analysis. Simple test signals, which are in accordance with the standards’ demands and propositions, are used for determination of the measurement error in case of different harmonic distortion parameter change. In order for a general error function for any measurement device to be determined, mathematical modelling, regarding the results from multiple tests, is performed. The mathematical model presents a strong dependence between a single component’s phase shifts and a meter’s error and it provides a systematization of all signal parameters’ influence on the measurement accuracy.

ACTA IMEKO ◽  
2014 ◽  
Vol 2 (2) ◽  
pp. 86 ◽  
Author(s):  
Ljupco Arsov ◽  
Marija Cundeva-Blajer

In the paper the current state and the establishment of metrology infrastructure and traceability of the measurements of electrical power and energy, i.e. the creation of conditions for unity of power and energy measurements, international comparability of the results and measurements which insure fair trade and consumers' protection are elaborated. Beside the legal, also other aspects are discussed, like the needs for calibration and verification in the field of electrical power and energy, participants in the chain of measurements and trade with electrical energy, the organization, the infrastructure, the methods and the systems of calibration and verification. An organization and certain documents which will contribute to the establishment of a system in accordance with the international standards and practice, as well as traceability and fair trade, are proposed.


2019 ◽  
Vol 4 (1) ◽  
pp. 99
Author(s):  
Nana Heryana ◽  
Handoko Rusiana Iskandar ◽  
Bambang Widodo ◽  
Robinson Purba

Power-electronics based Compact Fluorescent Lamps (CFLs) have been proven to reduce electrical energy consumption for lighting purpose. As in common power-electronics-based electrical devices, CFLs can be categorized as non-linear loads. Therefore, the input current has a non-sinusoidal waveform and contains harmonics. This paper discusses the advantages and disadvantages of CFL application and proposes the attachment of THD value to the product package in order to improve the marketing policy. Total Harmonic Distortion (THD) is a method used to find the percentage value between the total harmonic components and their fundamental components. The percentage of THD causes the greater risk of damage to equipment due to harmonics that occur in current and voltage. Laboratory testing shows that a CFL sample has THD of the input current as high as 67.7%. This THD is relatively high and may degrade the electrical power quality. Moreover, it could lead to the misreading of electrical power and energy meter. Several experiment results are shown and analyzed to confirm the validity of the discussed matter.  


Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1520
Author(s):  
José Teixeira Gonçalves ◽  
Stanimir Valtchev ◽  
Rui Melicio ◽  
Alcides Gonçalves ◽  
Frede Blaabjerg

The hybrid three-phase rectifiers (HTR) consist of parallel associations of two rectifiers (rectifier 1 and rectifier 2), each one of them with a distinct operation, while the sum of their input currents forms a sinusoidal or multilevel waveform. In general, rectifier 1 is a GRAETZ (full bridge) (can be combined with a BOOST converter) and rectifier 2 is combined with a DC-DC converter. In this HTR contest, this paper is intended to answer some important questions about those hybrid rectifiers. To obtain the correct answers, the study is conducted as an analysis of a systematic literature review. Thus, a search was carried out in the databases, mostly IEEE and IET, and 34 papers were selected as the best corresponding to the HTR theme. It is observed that the preferred form of power distribution in unidirectional hybrid three-phase rectifiers (UHTR) is 55%Po (rectifier 1) and 45%Po (rectifier 2). For the bidirectional hybrid three-phase rectifiers (BHTR), rectifier 1 preferably takes 90% of Po and 10% of Po is processed by rectifier 2. It is also observed that the UHTR that employ the single-ended primary-inductor converter (SEPIC) or VIENNA converter topologies in rectifier 2 can present sinusoidal input currents with low total harmonic distortion (THD) and high Power Factor (PF), even successfully complying with the international standards. The same can be said about the rectifier that employs a pulse-width (PWM) converter of BOOST topology in rectifier 2. In short, the HTR are interesting because they allow using the GRAETZ full bridge topology in rectifier 1, thus taking advantage of its characteristics, being simple, robust, and reliable. At the same time, the advantages of rectifier 2, i.e., high PF and low THD, are well used. In addition, this article also points out the future direction of research that is still unexplored in the literature, thus giving opportunities for future innovation.


2021 ◽  
Vol 17 (2) ◽  
pp. 204-211
Author(s):  
Raheel Jawad ◽  
Rawaa Jawad ◽  
Zahraa Salman

In the present-day decade, the world has regarded an expansion in the use of non-linear loads. These a lot draw harmonic non-sinusoidal currents and voltages in the connection factor with the utility and distribute them with the useful resource of the overall performance of it. The propagation of these currents and voltages into the grids have an effect on the electricity constructions in addition to the one of various client equipment. As a result, the electrical strength notable has come to be critical trouble for each client and distributor of electrical power. Active electrical electricity filters have been proposed as environment splendid gear for electrical power pinnacle notch enchantment and reactive electrical strength compensation. Active Power Filters (APFs) have Flipped out to be a possible wish in mitigating the harmonics and reactive electrical electricity compensation in single-phase and three-phase AC electrical energy networks with Non-Linear Loads (NLLs). Conventionally, this paper applied Ant Colony Algorithm(ACO) for tuning PI and reduce Total Harmonic Distortion (THD). The result show reduces THD at 2.33%.


2012 ◽  
Vol 591-593 ◽  
pp. 1579-1584
Author(s):  
Jyh Wei Chen ◽  
Huan Fu Lin

A grid-connected parallel inverter with interleaved phase shift is proposed in this paper. The synchronous are generated by the master module to achieve interleaving phase shift PWM for the parallel inverters connected to grid-tied system that make the inverter to output current to the power line and share the load. TI TMS320F2812 DSP is used for system feedback control with voltage and current by using A/D converters to generate the output current close to sine wave. The expected output current values are determined by the master module and transmitted via CAN (Control area network) between inverter modules. The grid-tied system uses zero-voltage-detection circuit to synchronize the inverter currents with grid voltage. For each switching period, PWM voltage of two inverters are interleaved to reduce the total output current ripple so that the switching frequency can be reduced and the power system EMI problem can be alleviated as well. The experiment results are provided to verify the performance of the proposed system to reduce output current harmonic distortion.


2021 ◽  
Vol 263 (5) ◽  
pp. 1794-1803
Author(s):  
Michal Luczynski ◽  
Stefan Brachmanski ◽  
Andrzej Dobrucki

This paper presents a method for identifying tonal signal parameters using zero crossing detection. The signal parameters: frequency, amplitude and phase can change slowly in time. The described method allows to obtain accurate detection using possibly small number of signal samples. The detection algorithm consists of the following steps: frequency filtering, zero crossing detection and parameter reading. Filtering of the input signal is aimed at obtaining a signal consisting of a single tonal component. Zero crossing detection allows the elimination of multiple random zero crossings, which do not occur in a pure sine wave signal. The frequency is based on the frequency of transitions through zero, the amplitude is the largest value of the signal in the analysed time interval, and the initial phase is derived from the moment at which the transition through zero occurs. The obtained parameters were used to synthesise a compensation signal in an active tonal component reduction algorithm. The results of the algorithm confirmed the high efficiency of the method.


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