Selecting the Right CT for Active Harmonic Filter (AHF)

How to Select the Right CT for Active Harmonic Filter (AHF)

Choosing the appropriate current transformer (CT) is crucial for the effective operation of active harmonic filters (AHFs) in harmonic mitigation applications. This article provides guidance on selecting the right CT for AHFs and highlights Enjoypowers’ versatile AHF modules with flexible CT installation options.

Factors to Consider When Choosing CTs for AHF:

1. Rated Current: Select CTs with a rated current that matches or slightly exceeds the maximum load current of the electrical system. This ensures accurate measurement and monitoring of harmonic currents.
2. Accuracy Class: Choose CTs with an appropriate accuracy class to meet the accuracy requirements of the AHF system. Higher accuracy classes are recommended for precise harmonic current measurement and compensation.
3. Installation Location: Determine whether the CTs will be installed on the load side (open-loop) or grid side (closed-loop) of the AHF system. The installation location affects the CT’s wiring configuration and measurement accuracy.
4. Compatibility: Ensure compatibility between the CTs and AHF modules to facilitate seamless integration and reliable operation. Enjoypowers’ AHF modules are designed to work with a wide range of CTs, offering flexibility and compatibility.

Enjoypowers’ AHF Module CT Installation Options:

Enjoypowers’ AHF modules offer versatile CT installation options to suit different application scenarios:

1. Load-Side Installation (Open-Loop): CTs can be installed on the load side of the AHF system, allowing for direct measurement of harmonic currents generated by the load.
2. Grid-Side Installation (Closed-Loop): Alternatively, CTs can be installed on the grid side of the AHF system, enabling closed-loop control for more precise harmonic mitigation. Enjoypowers recommends installing an additional set of CTs at the output terminals of the AHF to measure the load’s harmonic currents accurately.

When multiple AHF modules are operated in parallel, they can share the same set of CTs. For systems where CTs are installed on the grid side, Enjoypowers recommends installing an additional set of CTs at the AHF’s output terminals to enhance compensation accuracy. By subtracting the currents measured by the two sets of CTs, the AHF calculates the precise magnitude of the load’s harmonic currents.

Enjoypowers’ AHF solutions offer flexibility, reliability, and precision in harmonic mitigation, ensuring optimal performance and power quality in diverse electrical systems.

For more information on Enjoypowers’ AHF modules and CT installation options, visit our website.