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Harmonics & Energy Saving Analysis of VFDs used for HVAC System: A Case Study in Oman
Abstract
In this paper the methodology for harmonic and energy saving analysis for a laboratory building at the university campus in Oman have been proposed. The harmonics generated by the two variable frequency drives used for heating, ventilating and air conditioning of the building was modelled and simulated using SOLV and ETAP simulation software. The current and voltage distortion levels were measured under different loading scenarios. It is observed that lower order odd harmonics are dominating and can be mitigated using advanced universal harmonic filter to compliance the IEEE519 standard. The simulated results have revealed that about 10% of total energy consumed by induction motors can be saved by using VFDs along with extenuating all prevailing harmonics of the HVAC system.
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The power electronic component has been widely used in the current industrial era. It has been considered more efficient than the previous devices as it saves more space and uses less power. One example of power electronic components is the variable speed drive for speed regulation of electric motors in the industrial world. Another application of power electronic components is to be used in energy-saving lamps. The use of power electronic components in these two loads generates harmonic distortion and reduces network power quality. In this paper, the authors analyzed the harmonics in both loads. As a result, the total harmonic distortion (THD) current for four energy-saving lamps is 88.3%. Meanwhile, the THD current at the 50 Hz, 5 A, and variable speed drive is 46.2%. After mixing the two loads, the THD current decreases by around 35%.</span
Voltage/frequency (V/f) drive of a three-phase induction motor plays a crucial role in a flour mill for energy saving. Wheat consumption in India is increasing day by day, which reached 105,000 metric ton (MT) in 2021. India’s high wheat consumption and production increase flour mills. Thus, energy efficiency in a flour mill is a must in the present situation. Hence, V/f drives are widely used in flour mills. Apart from the advantages of V/f drive, electronic circuits in a drive induce harmonics in a power system. Power quality plays a vital role in a modern power system. Harmonics by V/f drive increase the current consumption, causing increased losses, cable overheating, and motor overheating, which necessitates a filter for harmonic mitigation. In this paper, an artificial neural network controller-based hybrid power filter is proposed for harmonic mitigation. A hybrid power filter (HPF) is presented to overcome the problems and achieve the active and passive power filter’s benefits. Harmonic mitigation of the proposed hybrid power filter is compared with the passive and active filter-based drives. This paper analyzes harmonic mitigation for three-phase induction motors with V/f drive installed in a 300-ton/day wheat flour mill’s purifier fan. The performance of the suggested system is analyzed under various speeds in the aspects of harmonic mitigation, reduction in current consumption, and energy saving using various filters. The entire system is developed and analyzed using MATLAB/Simulink. Energy saving is increased by around 10.97 kWh per year by HPF by means of reducing harmonics and current consumption compared to an active power filter, while it is increased by around 28.16 kWh/year compared to a passive power filter. Along with the harmonic mitigation, energy saving is also validated for various filters under various speeds.
The paper presents a power-quality analysis in the utility low-voltage network focusing on harmonic currents' pollution. Usually, to forecast the modern electrical and electronic devices' contribution to increasing the current total harmonic distortion factor () and exceeding the regulation limit, analyses based on tests and models of individual devices are conducted. In this article, a composite approach was applied. The performance of harmonic currents produced by sets of devices commonly used in commercial and residential facilities' nonlinear loads was investigated. The measurements were conducted with the class A PQ analyzer (FLUKE 435) and dedicated to the specialized PC software. The experimental tests show that the harmonic currents produced by multiple types of nonlinear loads tend to reduce the current total harmonic distortion factor (). The changes of harmonic content caused by summation and/or cancellation effects in total current drawn from the grid by nonlinear loads should be a key factor in harmonic currents' pollution study. Proper forecasting of the level of harmonic currents injected into the utility grid helps to maintain the quality of electricity at an appropriate level and reduce active power losses, which have a direct impact on the price of electricity generation.
This paper presents a novel control system for chiller plants that is decentralized and flat-structured. Each device in chiller plant system is fitted with a smart node. It is a smart agent, which collects, handles and sends out information to its neighbours. All the smart nodes form a network that can realize self-organization and self-recognition. Different kinds of control strategies can be converted into series of decentralized computing processes carried on by the smart nodes. The principle and mechanism of this decentralized, flat-structured control system for chiller plants are described in detail. Then a case study is presented to show how to build the decentralized, flat-structured control system actually. The measured data shows that the decentralized control method is energy efficiency. Moreover, it is much more flexible and scalable compared with the traditional centralized control method.
Most industrial loads are inductive in nature and therefore absorb Volts Ampere Reactance (VARs) leading to lagging power factor. Some inductive loads also produce current and voltage signals with frequencies in integer multiples of the 50 or 60 Hz fundamental frequencies called harmonics. Harmonics in power system causes several problems ranging from overheating, premature equipment failure, false tripping of protective relays resulting in unnecessary down time in industrial production. This work compared the use of series and parallel resonant harmonic filters in suppressing harmonics using Simulink model of the power system of NICHEMTEX, a Textile industry in Nigeria as a case study. Mathematical analysis representing current harmonics distributions on industrials loads with and without capacitor banks were presented. From the analysis, series resonant filter mitigated the total harmonic distortion from 30.080% to 3.460%. The installation of capacitor bank along with the series resonant filter in the industrial facility, further reduced the total harmonic distortion to 0.001% and power factor compensated from 0.860 to 0.894.However, the use of parallel resonant filter mitigated the harmonic distortion to 8.107% and a reduction in the power factor from 0.860 to 0.840. With the parallel resonant filter connection with the capacitor bank, harmonic distortion was mitigated to 0.140%, and the power factor reduced to 0.553, the value which is very low. Hence, it is observed that for this sample case, the use of series resonant filter mitigated the harmonics distortion and maintained power factors within the acceptable IEEE standard values.
Keywords: Industrial inductive loads, Harmonics, Harmonic distortions, Power factor correction, Series resonant filter, Parallel resonant filter
Power Quality assessment is today one of the main ways to improve energy efficiency. International standards tend to restrict the way this assessment is done, by defining the measurements methods that should be adopted by an instrument. This work describes some of the constrictions and requirements assumed for the design of the high performance Power Quality data logger PQ1000, taking into account the international standards IEC 61000-4-30 Class A and the IEC 61000-4-15 published in August 2010. Trough it, the most important demands of the IEC 61000-4-30 class A instruments are exposed. Details of the hardware components are also shown, and the most important points of the signal processing path are explained. The performance in the RMS values determination is given, also the frequency response for harmonics measurement are shown, and a detailed analysis of fulfillment of the tests given in the IEC 61000-4-15 ed. 08-2010 are given in the final section. Before the publication of this ed.08-2010 the Cigre C4.1.01/CIRED 2 CC02/UIE WG2 - 2004 protocol was the reference document that in addition with the IEC standard was used for the evaluation of digital flicker meters. This protocol aim is to guarantee a higher degree of compatibility between instruments of different manufacturers and models. The tests here presented intend to submit the equipments to a more real situation, and try to show possible hardware or firmware defects. The results given by the PQ1000 widely surpasses the standards exigencies.
IEEE Std 519-1992 is a useful document for understanding harmonics and applying harmonic limits in power systems. Despite many years of good use there is still some confusion about how to apply certain aspects of the standard. This paper discusses some of those, as well as related issues that are helpful in working with harmonic limits. There is considerable debate as to precisely how some elements of IEEE Std 519-1992 should be interpreted. This paper presents the authors' views on some of the more ambiguous elements of the standard and on the application of harmonic limits in general
In era of automation, the power quality disturbances are increasing day by day with use of electronics components or devices which are source of harmonics. Residential, commercial and industrial consumers are affected by deprived power quality. Levels of power quality disturbances depend upon type of loading in a system. Newly installed equipment or good quality equipment also get affected by other old equipments in electrical network. It happens due to shared infrastructure. Power quality monitoring and analysis of electrical network is important to maintain stability and reliability of power system. It also helps to reduce the heavy financial losses to customer and major breakdown of system equipment. The aim of this study is to identify and measures power quality disturbances like voltage, current imbalance, harmonics, quality of power factor and reactive power factor in educational institute campus. This paper present the results of study conducted on power quality analysis for military college of engineering Pune. Readings are taken with help of power quality analyzer. Readings are obtained in form of excel file in exponential format. Study and analysis of obtained readings is done for power quality parameters.
The Authority for Electricity Regulation (AER) Oman is addressing the nationally important issue of energy efficiency in residential premises. Reducing energy use in Oman’s residential sector has the potential to reduce the cost of energy subsidies, the consumption of indigenous gas resources and the cost of constructing the infrastructure required to meet growing peak demand. Improving the efficiency of the residential stock may also create benefits for the Omani public through more comfortable living conditions and reduced energy costs. In order to deliver these benefits, it is first necessary to measure and evaluate the current state of the built stock to understand how energy is used. This is not a simple task because energy use at the residential level is driven by the complex interaction between the household’s demands for energy services, the building fabric and its systems. In recognition of this challenge, AER contracted PassivSystems (an innovative home energy management services company) and the Energy Institute, University College London (a world-leading centre of energy research) to carry out a
A Study on Variable frequency Drive and its Applications
- Y Y Garud
- S R Gole
- R T Jadhav
- S U Deoghare
Y. Y. Garud, S. R. Gole, R. T. Jadhav, and S. U. Deoghare, "A Study on Variable frequency Drive and its
Applications," Int. J. Innov. Res. Sci. Eng. Technol. An ISO, vol. 3297, pp. 3079-3084, 2007.
Power quality analysis of variable frequency drives connected to a reactively compensated mixed load system
- T Taufik
- M Muscarella
- D Sawitri
T. Taufik, M. Muscarella, and D. Sawitri, "Power quality analysis of variable frequency drives connected
to a reactively compensated mixed load system," Proc. -2016 Int. Semin. Appl. Technol. Inf. Commun.
ISEMANTIC 2016, no. March 2018, pp. 261-266, 2017.
Harmonic level measurements and analysis at higher education buildings
- T A Papadopoulos
- G C Christoforidis
- K C Chatzisavvas
- G K Papagiannis
T. A. Papadopoulos, G. C. Christoforidis, K. C. Chatzisavvas, and G. K. Papagiannis, "Harmonic level
measurements and analysis at higher education buildings," IET Conf. Publ., vol. 2012, no. 613 CP, 2012.
Application of Innovative Technologies during Continuous Commissioning
- I Joo
- M Liu
- J Wang
- K Hansen
I. Joo, M. Liu, J. Wang and K. Hansen, "Application of Innovative Technologies during Continuous
Commissioning," Proceedings of the 3 rd International Conference for Enhanced Building Operations, Berkeley,
California, pp. 3-8, 2003.