Harmonic Mitigating Transformers

Working Principle of Harmonic Mitigating Transformers

Harmonic mitigating transformers are designed to address and reduce the harmonic distortions in electrical power systems. Harmonics are voltage or current waveforms that are integer multiples of the fundamental frequency and can cause various issues in electrical networks. The working principle of HMTs involves phase shifting and winding configurations that counteract these harmonics. The primary mechanism of HMTs is to use specially designed windings and magnetic core configurations to create phase shifts that cancel out specific harmonic frequencies. For example, a typical HMT might use a delta-wye or zigzag winding configuration, which inherently cancels triplen harmonics (3rd, 9th, 15th, etc.) by creating opposing phase currents. This phase cancellation effectively reduces the harmonic content in the system.

Moreover, HMTs are designed with low zero-sequence impedance paths to eliminate zero-sequence harmonics further. They also feature dual or multiple secondary windings with phase shifts, which ensure that the load currents are split and phased to mitigate harmonic distortion. The result is a cleaner, more stable power supply, which reduces the risk of overheating, equipment malfunctions, and energy inefficiencies. By improving the power quality, HMTs help prolong the lifespan of electrical equipment, enhance system performance, and reduce maintenance costs.

Types of Harmonic Mitigating Transformers

We provide various types of new, used, and reconditioned dry type harmonic mitigating transformers (HMTs). Understanding these types helps in selecting the right transformer for a given application, ensuring optimal performance and power quality.

• Delta-Wye Transformers: These transformers have a primary winding in a delta configuration and a secondary winding in a wye (star) configuration. The delta primary winding helps trap the triplen harmonics (3rd, 9th, 15th, etc.) and prevents them from propagating into the primary power system. The wye secondary provides a balanced voltage to the load and helps reduce harmonics in the load side.
• Zigzag Transformers: Zigzag transformers are specially designed to provide a low-impedance path for zero-sequence currents, effectively canceling triplen harmonics. They are often used in systems with significant third harmonic content and can be used in grounding applications to stabilize the system.
• Phase-Shifting Transformers: These transformers create phase shifts between primary and secondary windings, typically in 30-degree increments. By introducing phase shifts, they help cancel out certain harmonic orders. This type is useful in systems where multiple transformers can be connected in parallel to distribute the harmonic load.
• Multi-Pulse Transformers: These transformers are offered in 12-pulse or 18-pulse configurations. They reduce harmonics by employing multiple phases. This technique effectively cancels many lower-order harmonics, improving the overall power quality.

Key Attributes of Using Harmonic Mitigating Transformers

Dry type harmonic mitigating transformers offer several key attributes and advantages that make them essential components in modern electrical systems. These attributes help improve power quality, equipment performance, and overall system reliability.

• Harmonic Reduction: HMTs are designed with winding configurations and phase-shifting techniques that effectively reduce harmonic distortions equipment. This ensures a cleaner power supply by minimizing the presence of harmonics in the electrical system.
• Phase Shifting: By creating phase shifts between primary and secondary windings, HMTs help cancel out specific harmonic frequencies. This attribute is crucial for managing harmonics in systems with sensitive electronic equipment.
• Multiple Configurations: HMTs come in various configurations such as delta-wye, zigzag, and multi-pulse designs, each tailored to address specific harmonic challenges. This versatility allows for customization based on the unique needs of the application.
• Enhanced Thermal Capacity: K-rated HMTs are designed to handle non-linear loads without overheating. Their enhanced thermal capacity ensures they can manage the additional heat generated by harmonic currents.
• Low Zero-Sequence Impedance: Some HMTs, like zigzag transformers, are specifically designed to provide low impedance paths for zero-sequence currents, effectively eliminating triplen harmonics.

Benefits of Using Harmonic Mitigating Transformers Offered by Bruce Electric

We take pride in our client list that features some of the most promising startups, small-sized, mid-sized and established corporations. We believe the following benefits of our

• Improved Power Quality: HMTs ensure a more stable and reliable power supply by reducing harmonic distortions. This improvement in power quality minimizes the risk of equipment malfunctions and failures.
• Extended Equipment Lifespan: Harmonics can cause excessive heating and stress on electrical components. Our HMTs mitigate these effects, thereby prolonging the lifespan of connected equipment and reducing maintenance costs.
• Energy Efficiency: By reducing harmonic losses, HMTs enhance the overall energy efficiency of the electrical system. This results in lower operational costs and improved performance.
• Compliance with Standards: HMTs help ensure electrical systems comply with industry standards for harmonic distortion. This compliance is crucial for avoiding penalties and ensuring safe, reliable operation.
• Versatility in Applications: These transformers are suitable for various applications, including industrial plants, data centers, commercial buildings, and any environment with sensitive electronic equipment. Their adaptability makes them an invaluable component in diverse settings.

Applications of Harmonic Mitigating Transformers

We provide dry type harmonic mitigating transformers for the following applications:
 

• Industrial Plants: HMTs reduce harmonics generated by heavy machinery and variable frequency drives (VFDs), ensuring stable power supply for sensitive control systems and automation equipment. They also enhance the lifespan of motors and other critical components by maintaining a cleaner power environment.
• Commercial Buildings: It improves power quality for lighting systems, HVAC units, and office equipment, enhancing the efficiency of electrical infrastructure in high-rise buildings and complexes. They ensure compliance with power quality standards, contributing to overall operational reliability.
• Healthcare Facilities: These transformers provide stable power for sensitive medical equipment and diagnostic devices, reducing the risk of malfunction and ensuring continuous operation of critical systems. They enhance the reliability of power supply in operating rooms and intensive care units, supporting essential medical functions.
• Renewable Energy Systems: Our HMTs can be easily integrated with solar inverters and wind turbines to mitigate harmonics, ensuring smooth and efficient power conversion and distribution. They enhance the reliability and performance of renewable energy installations, contributing to sustainable energy solutions.

Tips to Select the Right Dry Type Harmonic Mitigating Transformers

Selecting the right Harmonic Mitigating Transformer (HMT) ensures optimal performance and power quality in your electrical system. Here are some essential tips to guide you:

• Identify Harmonic Sources: Determine the main sources of harmonics in your system, such as VFDs, SMPS, or industrial equipment.
• Assess Load Types: Understand the types of loads present (linear vs. non-linear) to choose an HMT that effectively mitigates relevant harmonics.
• Evaluate Harmonic Spectrum: Analyze the harmonic spectrum to identify the specific harmonic orders that need mitigation.
• Consider Transformer Rating: Ensure the HMT has the appropriate K-rating to handle the expected harmonic load.
• Check Compliance Standards: Verify that the HMT complies with relevant industry standards for harmonic mitigation.
• Plan for Future Expansion: Choose an HMT that can accommodate potential future increases in harmonic loads.
• Consult with Experts: Seek advice from power quality experts or manufacturers to select the most suitable HMT for your application.

Frequently Asked Questions on Harmonic Mitigating Transformers

• Can HMTs eliminate harmonics from the system?

Yes, they can eliminate harmonics completely from the system. However, they cannot eliminate the harmonic distortion.

• Do you HMT help save energy?

Yes, they do. The secondary windings of these transformers help cancel zero-phase sequence harmonic fluxes, preventing triphlen harmonic currents from being introduced to the primary windings.