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This paper provides a new methodology for setting harmonic limits in power systems. This approach is designed to replace the existing harmonic limits detailed in IEC 61000.3.6 and IEEE 519. The methodology provides for replacing the ∼40 or more individual harmonic with three new limits. The new limits are low frequency weighed VTHD, high frequency weighed VTHD and the even harmonic components of V...
Harmonic standards give limits for individual harmonics and for voltage THD. Guidelines are given for the allocation of individual harmonic current but no allowance is made for the control of THD in IEC standards. The paper shows how voltage THD can be controlled within its limit by means of the authors' previously proposed Voltage droop approach. Two main concepts are required to develop an allocation...
A considerable body of literature examines assessment, from measurements, of whether it is the network or a customer installation which makes the greater contribution to harmonic distortion at a point of common coupling. However, the customer contribution to harmonic distortion at a point of common coupling depends heavily upon the definition chosen for that contribution. For example, expressing contributions...
Continuous power quality (PQ) surveys of electricity networks generate large amounts of data that must be condensed for the purpose of interpretation and reporting. In this paper, summary indices for continuous PQ disturbances are calculated from distribution network data, and the relationship between these indices and the known physical characteristics of the site is investigated. Results from this...
Reliability measures of SAIDI (system average interruption duration index) and SAIFI (system average frequency index) are well established industry standards used world wide. While both measures have their limitations, they give a broad indication of average reliability that allows comparison within networks and across networks world wide. No such industry standard indices exist for voltage sags....
During the past two decades, there has been a considerable number of power quality (PQ) monitoring programs completed throughout the world. The information collected during these surveys can provide a detailed picture of the expected electrical environment help utilities to plan their future networks in relation to power quality performance. The mass of data gathered for a sample of sites of a large-scale...
Methods of allocating harmonic emission limits to customer installations have evolved considerably, as evidenced by the development of harmonic guides such as IEEE-519 and IEC/TR 61000-3-6. However, there is only limited consensus on appropriate techniques validating compliance of installations with those limits. Existing techniques are reviewed and related problems are examined. Conditions which...
IEC Technical Report 61000-3-6 gives principles to be applied to ensure acceptable harmonic levels in power systems. Detailed analysis methods have been developed to apply these principles to both distribution and transmission systems. At the transmission/distribution interface, it is found that transmission harmonic allocations can be as little as one third of the allocation which would be given...
Four-level computer modeling is proposed for computer-aided design and analysis (CADA) of DC-machine topology on SPICE2 to meet different simulation requirements. The models account for the magnetic saturation, armature reaction phenomena, current dependence of winding circuit parameters, and eddy current effects. The approach enables designers to simulate the static and dynamic characteristics of...
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