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FEATURED IN THIS ISSUE OF HARMONIC INSIGHTS

Say Goodbye to Costly Harmonic Studies: Download SOLV™ 6.5 Today


SOLV™ is a powerful simulation program that will calculate current and voltage distortion levels by simulating Adjustable Speed Drive (ASD) applications based on your load requirements. It includes models of the Mirus Lineator™ AUHF, the leading passive harmonic filter for ASD’s. By simply entering some basic information about your source and ASD system, MIRUS' SOLV™ will help you find the right solution for your ASD application by accurately predicting the performance level you can expect without the need of a costly harmonic study.

SOLV™ also allows you to perform energy analysis by providing evidence of how energy can be saved by removing harmonic losses introduced by ASDs and justifying the use of Lineators based on energy savings. Its kW calculation includes all harmonic losses in transformers and cables and provides total kW, kVA and kVAR at the Point of Common Coupling (PCC) and Distribution Panel in the Summary Report. Dual scenario simulation capability allows you to compare two different configurations. SOLV™ eliminates the guesswork in evaluating the best performing solution for your harmonic challenges.

A Useful Tool for any Power Quality Professional
This software is a valuable tool for consulting and specifying engineers, utility operators, OEMs and anyone who needs to
evaluate and compare solutions for treating harmonics in ASD applications. A trusted tool since 2004, SOLV™ is used by power quality professionals that represent a wide spectrum of industries including Oil & Gas, Marine, HVAC, water/Wastewater, Industrial, Government, Education, to name a few.

Downloading is Easy . . . and it’s Free!
SOLV™ is a complimentary software from Mirus International. To get your copy of SOLV™ visit mirusinternational.com and register for a free download.

Canada Steamship Lines Turns to Mirus International for Harmonic Mitigation Solutions

Headquartered in Montreal, Quebec, The CSL Group Inc. (CSL) is a Canadian-based, privately-owned shipping company with affiliate offices in Halifax, Winnipeg, Hamilton (Canada), Beverly (USA), Windsor (UK), Bergen (Norway), Singapore and Sydney (Australia). It is a leading provider of marine dry bulk cargo handling and delivery services and the world’s largest owner and operator of self-unloading vessels.

CSL had nine Panamax ships being manufactured by Chengxi Shipyard Co. Ltd.of Jiangyin City, China, located 150km south of Shanghai. For international transport, CSL’s Panamax ships were required to meet compliance standards for Lloyds Registry and the American Bureau of Shipping, which call for total harmonic voltage distortion THD(V) limits on the electrical supply system of less than 5%. During sea trials in China, CSL discovered that the THD(V) limits on its ships exceeded what was permitted by almost 30%.

Read this Project Snapshot and learn how Mirus International reduced the THD(V) on CSL's ships to well within the required limits of <5% THD(V).

ARTICLE

Active Harmonic Filter: Can the Cure be Worse than the Disease?
by Tony Hoevenaars, President and CEO


When considering an appropriate method of harmonic mitigation for any application, one should be aware that some forms of treatment can introduce their own problems. For example, simple line reactors can be effective, to some extent, in reducing harmonics generated by variable speed drives (VSD’s), but too much impedance can cause the VSD to be ‘starved’ for voltage. Also, harmonic filters that have too much capacitive reactive power can cause the excitation controls on generator systems to malfunction. It is important, therefore, that the applied harmonic ‘cure’ not be worse than the ‘disease’.

I was recently asked to help diagnose a problem at a solar power manufacturing facility in Toronto. A 48 Vdc power supply in a solar panel tester began to fail shortly after a new solar inverter line had been installed. The cause of the failure was believed to be poor power quality, though it remained undetermined in what form. When I visited the site, I found that they had by-passed the power supply and were providing 48 Vdc from a separate power source.

Voltage and current measurements were taken at the input to the 48 Vdc power supply. Relatively high levels of high frequency components were found in the voltage waveform, while the overall voltage distortion was very low at < 1%. The high frequency components were in the range of the 39^th to 43^rd harmonic (2300Hz to 2600Hz). The input current waveform of the 48 Vdc power supply showed evidence of resonance at the same high frequency harmonics. Appearance of these harmonics is often indicative of the presence of Active Front-end VSD’s or parallel Active Harmonic Filters (AHF’s) and is due to the switching frequency of the IGBT rectifiers.

An Active Harmonic Filter (AHF) associated with the solar inverter test line was found to be the source of the high frequency voltage distortion. When it was turned off, all high frequency noise disappeared from the voltage waveform and the 48 Vdc power supply drew much lower levels of harmonic current. With the AHF shutoff, the power supply ran without its circuit breaker tripping or the power supply overheating. The AHF manufacturer attempted to eliminate the problem by modifying their input EMI filter but to no avail. The ultimate solution was to simply turn off the AHF.