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The Harmonic Testing And Mitigation Service
What is harmonic and what are its effects? How to fix them? Our harmonic filtering solution will help you.
The power grid system can be damaged by many different causes. A potential risk that hinders operation and wears out equipment but is little known is harmonics.
The threat of harmonics to the power system
What are harmonics?
Harmonics are the products of modern electronic and mechanical devices such as computers, power storage systems, inverters, arc furnaces, renewable energy converters, and many others
Harmonics combined with fundamental waves will create distorted, distorted waves in the power distribution system.
Causes of harmonics
- Electronic devices (such as motor speed regulators, control rectifiers, computers, …) have caused many problems related to harmonics in the power system. For the power transmission system, the main effect is due to the nonlinear magnetizing reactance of transformers, arc equipment such as electric arc furnaces, welding machines, and electric reactors in equipment operating on the basis of electromagnetic induction.
- For unbalanced operating conditions between phases such as unbalanced system voltage, system impedance, or unbalanced load, each harmonic component can occur in three components (forward, reverse, zero). In addition, the compensation capacitors in the power grid are often combined with the grid reactance to create a resonant circuit that amplifies the harmonic currents with frequencies close to the resonant frequency existing in the grid.
In particular, for systems using backup generators or used on ships and drilling rigs, when running the machine, due to the higher inductive properties of the generator than conventional transformers, harmonics will be amplified 3 to 4 times more severely, causing serious damage to the equipment system and even generator fires, which is very dangerous and costly.
Harmonics cause many serious problems for the electrical system and equipment of the factory such as:
- Power loss.
- Equipment and machinery damage causing operational delays.
- Explosions endanger the life of the operator, etc.
- Some effects of harmonics
- With motors, harmonics will generate non-working torques, causing power loss, and it can also vibrate the motor
- With transformers, harmonics will cause power loss in the form of heat
- With the neutral wire in a 3-phase, 4-wire system, if harmonics appear, the system will be unbalanced, causing the neutral wire to have a very large current flowing through it, causing damage to the system
- With measuring devices, computer systems, and loads that require high voltage quality, if there are high-order harmonics, they can cause them to operate incorrectly
- High-order harmonics also reduce the system power factor
- For capacitor banks, the capacitive reactance of the capacitors decreases as the frequency increases. Therefore, capacitors are often very sensitive to the frequency of the power supply. In practice, this means that only a small value of voltage harmonics can create a large current through the capacitor circuit. The effect of harmonic components on the capacitor bank is a higher increase in dielectric temperature.
OTECH’s solution to harmonic filtering
With a team of professional engineers and modern survey equipment, OTECH will mitigate the harmonic situation of medium and low-voltage customers.
Reference: Schneider Electric
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For more information about the harmonic testing and mitigation service, please contact us through the information below:
OTECH JOINT STOCK COMPANY
- Hotline: 1800 9472
- Phone number: (+84) 28 6686 3565
- Email: service@otech.com.vn
- Address: 02 Street 15, Van Phuc 1 Residential Area, Hiep Binh Phuoc Ward, Thu Duc City, Ho Chi Minh City, Vietnam.
