Rubicon solution improves power quality at industrial site
At an industrial site in Gqeberha, a Rubicon power quality project using an Elspec Equalizer improved average power factor from approximately 0.96 to 0.999 and reduced measured current and voltage distortion. The original power quality audit had already identified the need for harmonic mitigation and additional electrical protection, but the client elected to implement the Equalizer as the first phase of the solution. Electrical network problems can go unnoticed until they result in equipment failures, production downtime or increased operating costs. For industrial facilities, understanding power quality is an important part of protecting equipment and reducing operational risk.
Rubicon Industrial Automation helps businesses identify these risks through power quality audits under real operating conditions. The findings help determine the most suitable solutions, which are then installed and commissioned by trusted system integrator partners. Ongoing monitoring then verifies improvements and tracks network performance.
At an industrial site in Gqeberha, a 300 kVAr conventional power factor correction (PFC) system was replaced with a 450 kVAr Elspec Equalizer. The assessment recorded improvements in reactive power compensation, power factor and harmonic conditions. It also identified remaining harmonic current and recommended a second phase of work to further reduce electrical stress.
Project details
The table below identifies the assessment period, equipment and technical report on which this case study is based.
Project or measurement detail |
Recorded information |
|
|
|
|
Analysis period |
7 May to 7 June 2026 |
|
Equipment commissioned |
Elspec AR450 |
|
Commissioning dates |
24 to 26 May 2026 |
|
Assessment analyser |
Elspec Pure BB Handheld |
The challenge with the existing PFC system
The site’s existing power factor correction (PFC) system used a contactor-based capacitor bank that switched in fixed steps. As a result, the system struggled to respond quickly enough to the plant’s rapidly changing reactive power requirements.
Power factor indicates how effectively the electrical supply is being used, with a value closer to 1 generally being better. Reactive power compensation helps improve power factor by supplying the reactive power that equipment needs locally.
Traditional capacitor banks can interact with harmonic currents already present in the electrical network, potentially causing resonance, amplifying harmonic distortion and introducing switching transients. These effects can negatively impact power quality and sensitive equipment.
Photo 1. Elspec Equalizer AR450 dynamic reactive power compensation system.
An Elspec G4420 power quality analyser was also permanently installed as part of the solution. It continuously records every electrical parameter, allowing maintenance teams and engineers to monitor network performance and investigate disturbances after they occur, without relying on preset triggers or event recording.
It also allows teams to generate automated NRS 048 and IEEE 519 compliance reports and support long-term energy management initiatives aligned with ISO 50001.
How the upgrade was assessed
A before-and-after assessment compared apparent power, reactive power, power factor and harmonic performance following replacement of the conventional PFC system.
Measurements covered four operating conditions: the conventional PFC system running, the conventional system switched off, the Equalizer being commissioned, and normal operation after commissioning.
Photo 2. Elspec Pure BB Handheld power quality analyser used for the assessment.
The assessment covered reactive power, power factor, non-fundamental current, Total Demand Distortion (TDD) and Total Harmonic Voltage Distortion (THDv).
Measured improvements in power factor and distortion
Measurements taken after the Equalizer was commissioned showed the following improvements over those recorded with the conventional PFC system:
- Average power factor improved from approximately 0.96 to 0.999.
- Average reactive power moved from approximately 200 kVAr to approximately −11 kVAr, close to zero.
- Average non-fundamental current fell from approximately 100 A to approximately 59 A.
- Average Total Demand Distortion (TDD) fell from approximately 9% to approximately 5.6%, while average Total Harmonic Voltage Distortion (THDv) fell from approximately 3.6% to approximately 2.6%.
The recorded averages show how the network performed with the conventional system on and off, and with the Equalizer operating after commissioning.
Measured parameter |
Conventional PFC on |
Conventional PFC off |
Elspec Equalizer on |
|
Average reactive power (kVAr) |
≈200 |
≈330 |
≈−11 |
|
Average power factor |
≈0.96 |
≈0.89 |
0.999 |
|
Average non-fundamental current (A) |
≈100 |
≈75 |
≈59 |
|
Average Total Demand Distortion (TDD) |
≈9% |
≈6.5% |
≈5.6% |
|
Average Total Harmonic Voltage Distortion (THDv) |
≈3.6% |
≈3.0% |
≈2.6% |
Values are approximate averages reported in the assessment.
Reducing risk to equipment and production
Poor power quality can place unnecessary stress on motors, drives, transformers and other electrical infrastructure. Improving power quality helps protect these assets and reduce the risk of electrical disturbances affecting production.
For this site, the assessment verified better reactive power performance and lower measured distortion. It also provided evidence to guide the next investment in protection.
Power factor improved as reactive power moved close to zero
With the Equalizer operating, average reactive power was close to zero and average power factor was close to the ideal value of 1. The graph below shows the change across the four operating conditions, including the commissioning period.
Figure 1. Reactive power, power factor and apparent power across the four operating conditions.
Lower current and voltage distortion
TDD is a measure of harmonic current distortion, while THDv measures voltage distortion. The lower readings show an improvement in the measured harmonic conditions.
Distortion levels also fell when the conventional capacitor bank was switched off. This indicates that the bank was contributing to elevating the harmonic conditions through its interaction with harmonic currents already on the network. The remaining harmonic content is associated with the site’s existing non-linear loads.
Figure 2. Non-fundamental current, Total Demand Distortion (TDD) and Total Harmonic Voltage Distortion (THDv) across the four operating conditions.
Recommended filters and transient protection
Harmonic current remains present because of the site’s non-linear loads. The recommended next phase is to install two Active Power Filters (APFs) alongside the Equalizer, so harmonic currents can be reduced closer to the equipment producing them.
Two SineTamer units are also recommended to help reduce high-frequency transient disturbances and provide additional protection for the electrical network. This proposed second phase is intended to further reduce harmonic current, improve overall power quality and reduce electrical stress on the installation.
Contact Rubicon Industrial Automation for a power quality assessment to identify risks and recommend the right solution based on measured site data. Visit industrial.rubicon.tech or call +27 80 782 4266.
Disclaimer
While every effort has been made to ensure the accuracy and reliability of the information presented herein, the Rubicon Group makes no representations or warranties, express or implied, regarding the completeness, accuracy, or suitability of the information. Users of this report are encouraged to verify and evaluate the information independently. Neither Rubicon Group, nor any of its employees, officers, or agents of the Rubicon Group of companies, including the authors hereof, shall be liable for any errors, omissions, or damages resulting from the use of this report and the information contained herein. Furthermore, the information provided herein is based on the data available at the time site investigations were concluded and may not reflect the latest developments in the field and/or the investigated site.