Mining and Metallurgical Facility in Eastern Siberia

Challenge

Development of design documentation for power quality parameters under conditions of incomplete input data on harmonic spectra of electrical loads.

At the same time, key characteristics of harmonic sources were known, including the pulse number of rectifiers used in variable frequency drives (VFDs) planned for installation.

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Impact

• risk of exceeding allowable harmonic distortion limits
• non-compliance with applicable standards
• potential adverse effects on electrical equipment operation

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Studies Performed

• harmonic analysis
• resonance analysis

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Methodology and Standards

The calculations were performed in accordance with applicable requirements for:

• power quality standards
• harmonic distortion limits
• electromagnetic compatibility (EMC)

The calculated parameters were verified against:

• GOST 32144-2013 – power quality standards
• IEEE Std 519-2022 – harmonic control in electric power systems
• IEC TR 61000-3-6 – emission limits for disturbing installations

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System Analysis

Due to the lack of complete data on load harmonic spectra, harmonic profiles were calculated for multiple scenarios based on:

• thyristor firing angle variations
• commutation reactance of rectifiers

Harmonic and resonance analyses were performed across several operating scenarios to identify the most critical case.

Special attention was given to:

• harmonic components exceeding standard limits
• harmonic levels approaching 90% of allowable thresholds

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Results

• design documentation developed in accordance with applicable standards
• harmonic distortion and resonance analysis completed
• critical operating conditions identified
• engineering solutions proposed to maintain power quality within acceptable limits