Enhancing Power Quality in Public Utilities

As cities continue to expand and digitalize, public utility systems have become more complex and more dependent on stable electricity. Water plants, sewage treatment stations, street lighting networks, and waste-to-energy facilities all rely on sensitive electrical equipment. However, this rapid modernization also brings an often-overlooked challenge: Power Quality deterioration.

Harmonics, reactive power imbalance, and voltage instability now appear frequently across thepublic utilities Power System, creating risks that can impact millions of residents. Ensuring high-quality, stable power is no longer optional—it is fundamental to urban safety and reliability.

In this article, we explore why public utilities face power quality problems, what risks occur if they remain untreated, and how modern SVG AHF solutions can restore efficiency, reliability, and grid compliance.

Why Power Quality Problems Are Increasing in Public Utilities

Public utilities operate with many nonlinear loads. Equipment such as pumps, blowers, LED drivers, inverters, and combustion control systems inherently generate harmonics. These harmonics distort the current waveform and reduce power efficiency.

Common sources include:

• Waterworks and pumping stationswhere motors and VFDs introduce strong 5th and 7th harmonics.
• Sewage treatment facilities, where aeration blowers and automation systems cause high reactive power demand.
• Urban night lighting, especially gas-discharge lamps and LED drivers, which produce considerable 3rd harmonics.
• Waste-to-energy plants, where incinerators, induced draft fans, and power control units generate both harmonics and severe reactive fluctuations.

In most utility grids, the dominant harmonic orders are 3rd, 5th, 7th, 11th, and 13th. Without proper harmonic filter equipment, they accumulate and degrade the entire public utilities power system.

The Hidden Risks of Poor Power Quality

1. Protection System Malfunctions

High harmonic distortion may trigger:

• False operation of relays
• Inaccurate protection signals
• Unexpected shutdown of key facilities

For public utilities, even a brief interruption can cause serious consequences, such as water supply failures or sewage overflow.

2. Measurement Inaccuracies

Power meters and sensors rely on clean electrical signals. Harmonics affect:

• Energy billing
• Load monitoring
• Operational analysis

Over time, this leads to misjudgment in maintenance planning and increased operating expenses.

3. Overheating of Neutral Conductors

Lighting networks commonly generate large 3rd harmonics. These do not cancel out but add together in the neutral conductor, causing:

• Excessive heating
• Cable insulation damage
• Potential fire hazards

4. Accelerated Equipment Aging

Harmonics increase:

• Transformer losses
• Motor vibration and heat
• Cable temperature
• Overall power consumption

In a large public utilities power system, even a small percentage of extra loss can create significant economic waste.

Case Study: Improving Power Quality for a Waste-to-Energy Plant

A waste incineration power plant in Jiaxing, China, operates with combined waste treatment, electricity generation, and heating supply. After years of operation, the site faced serious power quality issues due to heavy nonlinear loads.

Problems Identified

• High 5th and 7th harmonic currents
• Reactive power shortage
• Power factor only around 0.85
• Current total harmonic distortion (THDi) as high as 16.4%

These issues caused inefficiency, overheating, and unstable grid performance.

YT Electric's SVG AHF Solutions

To address these challenges, YT Electric provided a tailored combination of Active Harmonic Filter (AHF) and reactive power compensation (SVG + hybrid banks).

System Configuration

• 200A Active Harmonic Filterunder each transformer
• Targets major harmonics
• Real-time detection and compensation
• 150 kVar hybrid reactive power compensation system
• SVG ensures dynamic and accurate reactive power control
• Capacitor-reactor banks provide cost-efficient base compensation

This configuration is ideal for fluctuating loads commonly found in public utilities.

Results: Significant Power Quality Improvement

After installation, the site achieved remarkable performance improvements:

• THDi reduced from 16.4% to 1.9%
• Power factor improved from 0.85 to 1.00
• Harmonics fully controlled
• Reactive power stabilized
• Equipment heating and losses greatly reduced

The SVG AHF solutions ensured continuous, safe, and efficient operation of the facility, delivering long-term economic and technical benefits.

Conclusion: Power Quality Defines the Reliability of Modern Cities

As urban infrastructure continues to develop, maintaining power stability in public utilities becomes more important than ever. Harmonics and reactive power issues can disrupt essential services, reduce equipment life, and cause operational risks.

Using advanced technologies such as harmonic filters, SVG, and hybrid reactive power compensation systems helps public utilities maintain a clean, efficient, and compliant power environment. YT Electric will continue providing reliable power quality and SVG AHF solutions to support the safe development of modern urban energy systems.