Industries with high motor usage such as milling, bottling plants, plastic manufacturing, and refrigeration often struggle with electrical inefficiencies that lead to increased costs and potential equipment damage. Many of these businesses are unaware of the impact of electrical harmonics – additional, unwanted frequencies created by nonlinear loads like computers, variable speed drives and LED lighting. These harmonics cause overheating, equipment malfunctions and overall poor power quality, leading to higher operational costs and reduced equipment lifespan.
Alpha Power Solutions addresses these challenges with its advanced harmonic power analyser. This state-of-the-art equipment offers precise harmonic analysis, allowing them to design and implement effective harmonic filtration strategies. By reducing harmonic distortion, they help businesses optimise their electrical systems, ensuring smoother operations and substantial cost savings.
Understanding electrical harmonics
Electrical harmonics are additional frequencies that occur alongside the fundamental frequency (50 Hz in RSA) in power systems. These harmonics are produced by nonlinear loads such as computers, variable speed drives, inverters, UPS systems and lighting, which draw current in abrupt pulses rather than smooth sine waves.
In an ideal power system, alternating current (AC) flows in a sinusoidal waveform with a single frequency, known as the fundamental frequency. However, nonlinear loads distort this ideal waveform by drawing current in short bursts that create additional frequencies. These additional frequencies, known as harmonics, are multiples of the fundamental frequency (2nd harmonic, 3rd harmonic, etc.).
Harmonics have an impact in a number of ways:
• Overheating: Harmonics increase the current flow through electrical components beyond the expected levels, leading to overheating of transformers, cables and other equipment. This reduces their lifespan and can cause failures.
• Equipment malfunction Sensitive electronic equipment, including control systems, communication devices, and measurement instruments, can malfunction or operate erratically in the presence of harmonics as they interfere with the normal operation of these devices.
• Power quality issues: Harmonics cause voltage distortion, altering the sinusoidal waveform of the voltage supplied to equipment. This can lead to voltage fluctuations and instability, impacting the performance and efficiency of electrical systems.
However, there are a number of mitigation strategies that can help:
• Passive filters: These include reactors and capacitors that absorb or block harmonics from entering the electrical system, effectively reducing harmonic distortion and improving power quality.
• Active filters: These are advanced devices that actively monitor the electrical system and inject corrective currents to cancel out harmonic currents in real time. They are highly effective, but more complex and expensive than passive filters.
• Isolation transformers: These isolate sensitive equipment from harmonic-producing loads, protecting them from potential damage and ensuring a cleaner power supply.
• Load management: Managing and scheduling loads to avoid simultaneous switching of high-power equipment can help reduce harmonic distortion in the electrical system.
• Compliance and standards: Adhering to standards such as IEEE 519 ensures that harmonic distortion levels in electrical systems are within acceptable limits, minimising potential issues with equipment and power quality.
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