1 / 16

Interharmonic Levels at a DC Arc Furnace Installation

Interharmonic Levels at a DC Arc Furnace Installation. Erich W. Gunther Electrotek Concepts, Inc. Load and Supply Characteristics. DC Arc Furnace Contract demand of 100 MW 345 kV PCC, 7811 MVA SC SVC on 34.5 kV Bus 2nd, 3rd, 5th, 7th, 12th (HP) filters. Load Current Statistics.

liberty
Download Presentation

Interharmonic Levels at a DC Arc Furnace Installation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Interharmonic Levels at a DC Arc Furnace Installation Erich W. Gunther Electrotek Concepts, Inc.

  2. Load and Supply Characteristics • DC Arc Furnace • Contract demand of 100 MW • 345 kV PCC, 7811 MVA SC • SVC on 34.5 kV Bus • 2nd, 3rd, 5th, 7th, 12th (HP) filters

  3. Load Current Statistics

  4. Model 9010/9020 8V/8I Snapshot Waveform Three Phase Wye Model 9010/9020 8V/8I Snapshot Waveform Three Phase Wye 295KV 100.0A 303KV 250.0A 2 2 4 4 6 6 0.0V 0.0A 0.0V 0.0A -295KV -100.0A -303KV -250.0A 0.00ns 1.67 ms/div 33.33ms 0.00ns 1.67 ms/div 33.33ms BMI Meter 04/02/98 01:06:34.00 PM BMI Meter 04/02/98 11:55:34.00 AM Load Current Waveforms Light Load Heavy Load

  5. Arc Furnace Generated Waveform Distortion • Difficult to classify and separate phenomena • Attributes of both transient and steady state phenomena • Waveform distortion characteristics change rapidly • Observed interharmonic levels may be due to actual interharmonic injection, a side effect due to the changing load, or both • Use appropriate analysis method based on expected impact to system • Harmonic, Interharmonic, Transient, Flicker, Unbalance

  6. Interharmonic Impacts • Makes filter design more difficult • Adverse impact on control systems • Can excite low frequency oscillations in mechanical systems • Communications interference • Light flicker

  7. IEC Measurement Method

  8. Model 9010/9020 8V/8I Snapshot Waveform Three Phase Wye 298KV 250.0A Ia 0.0V 0.0A -298KV -250.0A 0.00ns 10.00 ms/div 200.00ms 04/26/98 01:35:14.00 AM 12 Cycle Snapshot

  9. Spectrum of Snapshot

  10. Interharmonic Metrics • Total Interharmonic Distortion (TID) • RSS of IEC based interharmonic components • Normalized by fundamental for voltages • Normalized by peak demand for currents • IEC statistical approach used - report 95% CP • Individual Interharmonic Interval Levels

  11. Results for Currents

  12. More Current Results

  13. Results for Voltages

  14. More Voltage Data

  15. More Voltage Data

  16. Conclusions • IEC measurement methods are relatively easy to apply - similar level of effort as for harmonic measurements • Measured levels are low • Difficult to measure accurately (A/D resolution) • Statistical techniques required (many samples) • Low levels can cause observable impacts • More work on relating impacts to measured levels required

More Related