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.
Summary form only given. Passive filters have been a very effective solution for power system harmonic mitigation. These filters have several topologies that give different frequency response characteristics. The current industry practice is to combine filters of different topologies to achieve a certain harmonic filtering goal. However, there is a lack of information on how to select different filter...
A method for real-time detection and extraction of individual harmonic and inter-harmonic components in a power signal with potentially time-varying characteristics is presented. The proposed method which is based on the concept of adaptive notch filter (ANF), adaptively decomposes the measured power signal into its constituting components independent of where their frequencies are located. The algorithm...
Summary form only given: Frequency is an important indicator for the quality of electric power. Accurate spectral decompositions rely much on the correct identification of frequencies of the measured signals. An efficient procedure that includes a high-resolution Prony-based method in conjunction with the down-sampling technique for harmonics and interharmonics detection of the measured power signal...
We propose a new approach to current differential protection of transmission lines. In this approach, we transform the instantaneous line current(s) by using a moving window averaging technique. If the time span of moving window is equal to one-cycle time, then the steady-state value of the transformed current is zero for a periodic signal which is composed of fundamental and harmonic frequencies...
This paper presents an overview of assessment techniques recommended by IEEE Std 519-1992 and the EuroNorm 50160-2009. It also examines reporting requirements for harmonic distortion and voltage fluctuations by the Norwegian NVE 1557 and the Colombian CREG 047 regulations. The paper also presents typical values for harmonic distortion and voltage fluctuations from the three electric utility distribution...
This paper discusses the difficulties related to interharmonic measurement and characterization. A simple FFT-based signal processing tool is proposed to analyze time-varying interharmonics. This tool is generally effective in determining interharmonic frequencies and magnitudes for many signaling applications, overcoming some of the issues related to interharmonic measurement. The problem of interharmonic...
This paper has analyzed the impact of distribution power quality, especially unbalancing and triplen harmonic, on DG interconnection protection. We explored that the unbalanced single phase loads increase neutral current at DG interconnect transformer by analysis of measured data and simulation of PSCAD/EMTDC. An impact of triplen harmonic on DG interconnection transformers which are grounded wye...
This paper presents a smart metering network for monitoring energy consumption and power quality of building integrated electric vehicle charging network. The smart metering network consists of smart metering devices, a ZigBee communication network, and a central system for power calculation and power quality analysis. The smart metering device captures current and/or voltage waveform and performs...
Frequency is an important factor for power system harmonics measurement. Accurate spectral analysis relies much on the correct identification of frequencies of the measured signals. In this paper, several commonly used methods for power system stationary and time-varying harmonics measurement are reviewed and compared according to the aspect of frequency identification. Recommendations for adopting...
This paper presents an alternative for the calculation of the switching function matrix in periodic steady state computations including harmonics/interharmonics. The basis of the methodology is the decomposition of the signals under interest through the discrete Fourier transform (DFT). This permits to include both harmonics and interharmonics simultaneously. Additionally, the DFT allows calculating...
The combination of extensive cable networks and wind turbine converters has been identified as a potential cause of resonances. A modelling approach for a doubly fed induction generator and a full power converter fed generator for harmonic penetration studies is developed and discussed. An example offshore wind farm is then studied in the simulation package IPSA using the detailed wind turbine generator...
This paper explores a new technique of load modeling and estimation on distribution systems. With the emerging AMI technology real-time data about customer loads will be available and hence an estimate of loads on the distribution feeder can be made for system monitoring and control. With this data, a load model predicting the real-time load variations can be made. This paper elaborates the statistical...
With more and more photovoltaic (PV) panels, energy storage devices and other small generators being put into service, it is necessary to integrate them into power systems. Grid integration provides a reliable means for customers to use renewable energy such as solar at its maximum and to use other sources as backup. Inverters are widely used as interfaces for these distribution resources. In this...
Harmonics is a growing concern to both electric utilities and their customers. Nonlinear loads in large-scale industries are important causes for the harmonic currents and voltage distortion. In modern steel manufacturing facilities, Arc furnaces and rolling mill loads are the two major nonlinear loads. They generate significant harmonic currents that flow through the plant and utility power system...
A new approach to harmonic state estimation is proposed by firstly classifying the network nodes into four types. Classification of a particular node into one of the four types is based on the availability or otherwise of node voltage and nodal harmonic injection current measurement at the node. Algebraic expressions to determine all the remaining unknown node harmonic voltages and nodal harmonic...
This paper studies the DFT-based algorithm for the phasor measurement application and investigates its performance for off-nominal frequency conditions, harmonics, inter-harmonics, and out-of-band interfering signals. It is mathematically shown that the DFT technique can provide accurate estimation of the phasors in off-nominal frequency conditions when a three-phase balanced system is concerned....
Based on the steady state's parameters of the HVDC system, this paper presents an algorithm to calculate the three-pulse harmonic voltage source in the DC side. In the algorithm, various asymmetries in firing angle, commutation reactance and transformer winding as well as the imbalance of ac voltage are considered. According to the state of valves, the waveform of the three-pulse voltage can be divided...
The Distributed Power Flow Controller (DPFC) is a new device within the FACTS family. It is emerged from the UPFC and has relatively low cost and a high reliability. The DPFC consists of two types of converters that are in shunt and series connected to grids. The common dc link between the shunt and the series converters is eliminated. The active power exchange between the shunt and series converters...
The number of installed distributed generation (DG) in residential areas rapidly increases, specifically in the form of photovoltaics (PV), causing some undesired side effects such as voltage rise. Overvoltage can damage critical loads, but is also disadvantageous for the owner because inverters switch off in case of overvoltage, resulting in output loss. Since grid connected inverters essentially...
This paper discusses two aspects of the impact of windparks on the waveform distortion in the power system: emission and resonances. The paper gives a general overview of the emission and shows measurement results from a small but modern windpark connected to a 10-kV feeder and estimates the need for network strength to limit the resulting voltage distortion. The paper also gives a general overview...
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.