If you are considering installing a harmonic air filter for your facility, it is essential to understand the types of filters available on the market. You should understand the different types of filters, including Single-tuned, double-tuned, and series resonance air filters. You should also know about C-type, High pass shunt, and Series resonance filters. The following information will help you choose the right product for your facility.
Single-tuned or double-tuned filters
Single-tuned or double-tuning harmonic air filters may not be configured to remove two or more frequencies. The frequency of the filter may be chosen based on the desired level of harmonic reduction, and its cost is determined by the amount of space it requires. A double-tuned filter may not require a damping resistor. The cost per bank may also differ between double-tuned and single-tuned filters.
Generally, a harmonic filter will eliminate 60Hz, 70Hz, or 120Hz, but the frequency should be tuned to at least one of these frequency bands.Â
Series resonance filters
A series resonance air filter uses three components: a resistor, a capacitor, and a load. The resistor becomes the filter’s load, and the capacitor serves as the source. The filter’s damping factor is chosen based on the desired bandwidth, with a larger value corresponding to a wider bandwidth. In series resonance air filters, the designer has three degrees of freedom: two for the resonant frequency and bandwidth and one for the size of the components. For example, the external circuitry can determine the resistor’s size, allowing him to scale the filter accordingly.
High pass shunt filters
Shunt active power filters can dynamically compensate for the presence of high-order harmonics. On the other hand, the passive high pass filters do not dynamically compensate for harmonics and are characterized by a complex design process involving more than second-order equations. The parameters of passive high pass filters are usually selected through trial and error. A simplified design procedure for shunt active power filters is also presented. It helps filter high-order harmonics in electrical systems.
A single-tuned harmonic filter should achieve a minimum DC voltage of 500 kV with an alpha firing angle of 19 degrees. If more than one harmonic exceeds the maximum permissible harmonic level set by a power supply authority, more than one harmonic filter should be installed. The more filters are used, the greater the risk of undesirable resonances.Â
C type filters
As with all high-pass filters, C-type filters must be tuned to reduce the power loss associated with harmonic distortions. The best frequency to use is three to fifteen percent below the system’s fundamental frequency. When selecting an inductor, account for the frequency bandwidth and any possible filter detuning. It is also essential to consider the filter performance at different frequencies and under normal conditions.
To size a Harmonic C type air filter effectively, it is essential to know some basic information about the local power system. Different filters have different electronic components and block unwanted harmonic currents from transmitting to the earth. The harmonic filter reduces distortion in power systems by deflecting harmonic currents and correcting the power factor.
Hybrid filters
The use of hybrid air filters has many advantages. They have the potential to remove particulate matter more efficiently than conventional bags and electrostatic precipitators, which are the most commonly used methods for collecting airborne pollutants. However, they have some drawbacks, including higher energy requirements and longer filter cycles.Â
As the name suggests, hybrid air filters combine several different materials. Their surface area differs, but they do the same job. The BAFs of hybrid filters are made from two different materials: hydrophobic and hydrophilic. The former had the highest specific surface area and thus the highest removal efficiency for PM2.5, while the latter was less efficient than the former. However, they are still superior to traditional paper-based filters regarding PM2.5 removal.
3rd harmonic blocking filters
3rd harmonic blocking filters block high-frequency power, which blocks harmonics that produce voltage flat-tops. Typically, these filters are used in installations where single-phase loads are distorting. The negative impact of 3rd harmonics is that they can interfere with data transmission and cause equipment to overheat. Therefore, you should check your installation carefully before purchasing a 3rd harmonic blocking filter.
Although conventional methods mitigate the effects of high-frequency harmonics, the effect is often temporary. In the long run, harmonics cause computer load problems and cause random circuit breaker tripping. The 3rd harmonic blocking filter prevents this from happening. This device is also UL-listed, making it safe and standard-compliant. It’s essential to keep in mind that the amount of harmonics generated by 3rd harmonic blocking filters vary.
