Active harmonic filter introduction Active harmonic filter (AHF) is a new active electronic harmonic filtering device to reduce voltage harmonic and current harmonics and improve power quality. Based on voltage source inverter, it's connected in parallel with non-linear loads which need to...
1. Active harmonic filter introduction
Active harmonic filter (AHF) is a new active electronic harmonic filtering device to reduce voltage harmonic and current harmonics and improve power quality.
Based on voltage source inverter, it's connected in parallel with non-linear loads which need to compensate.
For compensating harmonic current which is with changing Amp and frequency and reactive power, it overcomes the shortcomings of traditional passive filter. It has the advantages of high compensation accuracy and fast dynamic response etc.
2. Why need Active Harmonic Filter?
Because harmonic exist caused by non linear components such as UPS, Switching power supply, Rectifier, Frequency inverter, Frequency adjustable air conditioner, Inductive heating furnace, Electronic computer, Charger and Lights etc.
Harmonicwill bring below problems, thats why the active harmonic filter is required?
Bad effect to power grid and power equipments
Effect to power capacitor-1.add power loss, 2.get abnormal hot, 3.shorten lifespan.
Effect to Transformer-1.increase copper loss,2.shorten lifespan, 3.cause burnt down
Effect to power cable-1.less current conduction ability, 2.cause resonance.
Effect to power distribution circuit-1.affect line stable and safe running, 2.distortion of current and voltage waveform
Effect to power equipments-1. low voltage switching equipments misact, 2. cause power trip.
Effect to motor-1.shorten lifespan,2.increase power loss, 3.damage motor
Bad effect to surrounding equipments
Reduce relay protection system and automatic system reliability
Interference to communication system-cause distortion of image, data treatment error, damage equipments computer, TV etc.
More power loss, increase power cost
Harmonic generates extra harmonic power and increase company's power.
Harmonic's skin effect on cable cause very big cable temperature rise, power changes to heat on cable and cause power waste, and cause insulation damage, cause discharge to earth.
Transformer's iron loss and copper loss are increased, cause transformer's noise and heat.
3. Where need Active harmonic filter?
Subway, airport, highway, hospitals, sea platform etc.
These places have high harmonics, and have very high requirement to electricity, once power quality problems happen, it will cause huge loss.
Green Power Active Harmonic Filter is the optimized solution to solve power quality problems, it will compensate 2-50 harmonic and also solve other power quality problems.
Port, Vehicle manufacturing, metallurgy, Petrifaction,Data center etc.
These places have big reactive power, or serious 3 phase imbalance, or great impact to power network, or reactive power and harmonic etc. Problems, Green Power APF and SVG is the best option.
Photovoltaic, Shopping mall, General Factory etc.
4. Application case of the Active harmonic filter
Case 1: Metallurgyindustry
Main load is inductive heating power supply, have high harmonics, and the transformer capacity is relative small, current harmonic distortion THDi up to 31%, and voltage distortion up to 21% because of current harmonic’s interference, power factor as low as 0.55. Site ventilation is not well, much dust, is complex and harsh working conditions of “current harmonic+voltage harmonic+serious reactive power+dust pollution+high temperature”.
Use Green Power products with strong anti interference ability, compensate current harmonic to normal and improve voltage harmonic distortion, THDi reduces to 4.3%, THDv reduces to 4.5%. Power factor up to 0.98. shown below.
Case 2: welding industry
The main load is hanging spot welding, mechanical arm, pipeline and motor, spot welding use single-phase power, when it’s working, the current fluctuation is large and have serious imbalance. The A phase current (yellow) is 0, B and C are 278A and 317A, the power factor is 0.52, the current distortion rate is 40%, because most of the unbalanced current flows through the neutral line, resulting in serious heat. It is a complex and harsh working condition with "current harmonic + imbalance and serious reactive power".
After compensation to harmonic and reactive power, the effect of comparison is as follows, three-phase current unbalance disappeared, the neutral current is 0, voltage and current harmonics disappeared, THDi decreased to 2.7%, the power factor is increased to 0.98.
5. Whats special of Green Power?
Modules independent running, in case of any module break-down, other modules are not affected.
Easy maintenance and repairt.
Strong anti pollution ability
Except fans, all conductive components are isolated with outside, suitable for dust, salt and alkali, wet and serious harsh occasions. The module inside pictures:
Simple on-site installation
The user can choose above bus bar or below cables, can choose the load or grid side for external current sampling CT.
APF,SVG,C 3 types, different specification of modules could be combined together, APF, SVG could also used together with capacitors to save cost, and no resonance occurs.
Very high power density
Modular design APF or SVG could match 600mm wide cabinet, 600mm deep cabinet, 600mm wide*600mm deep cabinet or any bigger cabinet, one cabinet capacity could be up to 900A/600kvar, while the mainstream industry is<600A/400kvar. Higher power density could save floor area and reduce cost.
Very low loss
Active power<2.5%, others <3%~4%.
Very low noise
High quality soft magnetic reactor, as well as the scientific wind tunnel design, at full load working noise is not more than 60dB, while the mainstream industry noise<70dB.
Very high Current loop bandwidth
First reached a quasi natural sampling and continuous control, the equivalent switching frequency to 80K Hz, the current band width reaches 4kHz, the inhibition rate on the interference reaches more than 4 times of other companies in the industry, while the industry mainstream index were 20kHz/1kHz. Equipment has higher current loop bandwidth, the protection will be more timely, remains stable work even under very bad situation, you can achieve the effect of parallel with the pure capacitor will not happen resonance.
6. Technical parameters of the Active harmonic filter
400V/690V（-20% ~ +15%）
50Hz（-10% ~ +10%）
100:5 ~ 10000:5
2-13 (50% of rated current)
Harmonic filter rate
Reactive power compensation
3 phase imbalance compensation
100% imbalance compensation
RS232, 485, Modbus protocol, TCP/IP optional
RS485, internet interface
Yes, all parameters are set on computer
Yes, record 500 alarm information most
Support modules independent monitor or one cabinet central monitor
Total response time
Active power loss
Intelligent air cooling
Equivalent switching frequency
Current loop cut-off frequency
Over voltage, under voltage, over heat, over current, short circuit etc. more than 20 protections
CT installation place
Load side/grid size optional
Wall mounting size
Same as rack type
<5000m(above 1000, every 100m more, capacity reduce 1%)
<95% no condensation
IP20, custom design for higher level
Above size is 150A APF, 50A module width is 480mm, others are the same.
Wall mounting type is the same as rack type for the same rating.
7. Features of the Active harmonic filter
Reliable harmonic and reactive power compensation
International advanced technology
Reliable control system: fully digital control
Compensate harmonic and reactive power
Filter 2-50 harmonics or specified harmonic
Fast response, response time<50us
8. Outdoor use solution of the Active harmonic filter
Stainless steel enclosure, IP44 rating.
Looking for 400v 230v 480v 690v active harmonic filter 50a 100a 150a module reduce harmonic less than 5% filter 2-50 harmonics? Green Power Technology is one of the professional manufacturers and suppliers. We have been dedicated to this field for over 20 years and already exported products to India, USA, Germany, etc. Equipped with a productive factory, we warmly welcome you to buy our high quality products made in China at competitive price or try our customized service.