The grid system can be harmed by many factors, among which, a potential risk impedes the operation and wear of equipment but little is known, which is harmonics. To overcome that, Hao Phuong has provided an effective harmonic filter solution.
What is harmonics?
Harmonic is a form of unwanted noise, directly affecting the quality of power and should be paid attention to higher voltage or current than allowed.
Harmonic type and Harmonic order
Harmonics are sinusoidal voltages or currents whose frequency is a multiple of the industrial frequency (fundamental frequency), due to the presence of nonlinear loads in the grid. For example, a harmonic current of 250 Hz on a 50 Hz network is a fifth harmonic.
What is affected by the harmonics ?
In the case of many motors running at the same time, if there is no measure to control harmonics, it can overload the electricity system, increase power demand and stop the machine (due to power overload).
Harmonics affects the whole electrical system
To remedy this situation, it is imperative to replace damaged equipment. Costly for businesses.
How harmful is harmonics?
Circular 39 Ministry of Industry and Trade issued on November 18, 2015 regulating electricity distribution system.
The total voltage harmonic distortion at all connection points shall not exceed the limits specified in Table 1 as follows:
| Voltage level | Total harmonic distortion | Individual harmonics |
| 110 kV | ≤ 3,0% | ≤ 1,5% |
| Medium and low voltage | ≤ 6.5% | ≤ 3.0% |
Table 1. Voltage harmonic distortion
Exceeding the above limits will cause harms such as:
The harmonic components add phantom power to the total power consumption of the transformer, causing the transformer to overload, heat, and burn even though the load only consumes average power.
- Heating, burning leads to serious losses in the electrical system.
- The neutral conductor in a 3-phase system is heated or burnt.
- N-G (neutral-ground) voltage is too large.
- The breaker jumps for unknown reasons.
- Failure capacitor PF reactive power compensation.
- Noise in the communication system. Capacitors and reactors can make LC circuit resonate harmonics up to many times. Overloading capacitors and transformers, leading to explosion of capacitors and transformers.
Harm of harmonic
In particular, with systems using standby generators or on ships, drilling rigs:
When running the machine, due to the resistance characteristics of the transmitter are higher than conventional transformers.
The harmonics will be amplified 3 to 4 times more seriously
==> Serious damage to equipment systems and even generator fires are dangerous and costly.
Methods to reduce harmonics?
- Replace damaged equipment
- Use AC reactor or DC reactor for inverter
- 12-pulse rectifier solution
- Use inverter with low harmonics
- Use filters
Using filters to minimize harmonics
Use the Circutor’s AFQ filter to minimize harmonics
The multifunctional parallel filter AFQ from Circutor (Spain) is the most complete solution to solve power quality problems. Specifically in industrial or commercial facilities. Not only by harmonics but also for current imbalances, and even counter-power consumption (mainly power factor):
- Reducing harmonics current up to step 50 (2500 Hz). Users select harmonically filtered frequencies for greater efficiency.
- Adjust the unbalanced current consumption between power system phases.
- Reactive power compensation. Either inductance or capacitance.
- These filters provide configurable priority functions for optimal use of filtering capabilities according to installation needs. In cases where higher filtration is required, up to 8 filters can be connected in parallel (parallel coupling filters must have the same capacity).
Wide range of applications of the Circutor AFQ Filter:
- The automatic factory
- shopping mall
- Paper machines of all kinds
- Hotel, cinema
- Especially where there are limited waves like hospitals and airports.
Circutor AFQ filters are multidisciplinary
To achieve business goals, enterprises need to do well the work of limiting harms of harmonics. Therefore, choosing to use AFQ filter of Circutor is one of the most effective ways today!
Hao Phuong is a provider of solutions for reducing harmonics. Using Hao Phuong’s AFQ filter will help businesses optimize their devices. At the same time minimize unwanted damage. And, saving costs, reducing labor in production …
For customers / partners who want to use Circutor’s AFQ filter solution, please contact:
Mr. Bao – Technical advice
Email: bao@haophuong.com
