Industry: Geothermal Power Generation
Application: Sine-Wave Filtering For Geothermal Well-Pump Motors
Equipment: 1600 A, 400 V Sine-Wave Filter
Design and Manufacturing: Ergun Elektrik
Measurement instrument: A. Eberle PQ-Box 300 Class A Power Quality Analyzer
Project Background and Overview
To ensure the successful commissioning of geothermal well-pump motors, the electrical supply must satisfy the motors’ operating requirements.
This project addressed voltage waveform distortion associated with cable runs of up to 400–500 meters between the variable frequency drives and the motors, as well as with the drives’ output conditions.
Based on on-site measurements and technical evaluations, Ergun Elektrik designed and manufactured a custom 1600 A, 400 V sine-wave filter to improve the voltage waveform supplied to the motors.
The Challenge: Voltage Waveform Distortion
On-site measurements at the output of the variable frequency drive revealed substantial deviations from an ideal sinusoidal voltage waveform. High-frequency voltage harmonic components were observed across a broad frequency range, extending to 20 kHz.
These findings indicated that the high-frequency components were significantly distorting the output voltage waveform.
Given the cable runs of up to 400–500 meters between the VFDs and the geothermal well-pump motors, together with the drive output conditions, improving the voltage waveform quality supplied to the motors was essential.
A filtering solution was therefore required to attenuate the high-frequency components and bring the output voltage waveform closer to a sinusoidal form.
Figure 1
High-Frequency Voltage Harmonic Components Measured Over A Frequency Range Of
Up To 20 kHz Before Installation Of The Sine-Wave Filter
Measurement Procedures and Technical Assessment
At the customer’s request, Ergun Elektrik conducted on-site measurements using an A. Eberle PQ-Box 300 Class A power quality analyzer.
The measurements identified substantial distortion in the voltage waveform at the variable frequency drive output, with high-frequency voltage harmonic components distributed across a broad frequency range.
Based on these findings and technical evaluations conducted in collaboration with the customer, a sine-wave filter was proposed to improve the voltage waveform and attenuate the high-frequency components.
Implementation of the Proposed Solution
Following customer approval, Ergun Elektrik designed and manufactured a custom 1600 A, 400 V sine-wave filter. The filter was installed between the variable frequency drive and the geothermal well-pump motors to improve the voltage waveform and attenuate high-frequency components.
Following commissioning of the filter, the motors were started, and system performance was assessed through post-installation measurements.
Post-Installation Measurement Results
Post-installation measurements were conducted at the sine-wave filter output under conditions comparable to those of the initial measurements. The results showed that the voltage waveform had become smoother and more closely approximated a sinusoidal waveform.
Comparison of the harmonic spectra further indicated a substantial reduction in the high-frequency voltage harmonic components observed in the 2 kHz–20 kHz range before filter installation. The geothermal well-pump motors were subsequently commissioned, and post-installation measurements were used to assess the filter’s effectiveness in mitigating the voltage waveform distortion identified during the on-site evaluation.
Successful motor start-up confirmed that the intended operating conditions had been achieved.
Figure 2
Voltage Harmonic Components Measured Over A Frequency Range Extending To
20 kHz Following Installation Of The Sine-Wave Filter
Figure 3
Comparison Of Voltage Waveforms Measured
Before And After Installation Of The Sine-Wave Filter
Final Outcome
In this project, Ergun Elektrik developed a customized solution to address voltage waveform distortion associated with long cable runs and variable frequency drive output conditions in a geothermal well-pump motor application.
A 1600 A, 400 V sine-wave filter was designed, manufactured, and commissioned. Post-installation measurements indicated a substantial reduction in high-frequency voltage harmonic components and an improvement in the voltage waveform, which more closely approximated a sinusoid. The successful commissioning of the geothermal well-pump motors further confirmed that the intended operating conditions had been achieved.
Overall, the project demonstrates Ergun Elektrik’s application of power quality engineering through on-site measurement, technical assessment, customized design and manufacturing, and post-installation performance evaluation.
Berkay Enes İŞBİLİR
Electrical Engineer
Ergun Elektrik
