- December 17, 2014 -
Harmonics by definition are distortion of the
fundamental frequency (50 Hz). Harmonic
distortion of current occurs when sinusoidal voltage is applied to a
non-linear load (ex. electronic ballast, PLC, adjustable-speed drive, arc
furnace, any ac/dc converter UPS, VFD’s). The result is a distortion of the
fundamental current waveform.
1. Response time-should be in µs (micro seconds) to react the rapid change in load
2. Power losses-Energy required to operate the system
3. Modularity – Any changes in the load pattern in future the Harmonic percentage may vary. To handle that situation the Harmonics filter should have the modular (adding filter in parallel) function of any combination.
4. Adaptive to load variation- Active filter should compensate for individual disturbance patterns in a targeted manner and should be automatically adapts to changing network topologies.
5. Harmonic compensation capacity- majority of harmonic currents found in a distribution system are odd-order harmonics. Capacity of filter should be able to compensate from 3rd order to 49th order. Harmonics above 50th order are more difficult to measure and that won’t cause serious impact to the system.
6. Operating Voltage (3 or 4 wire technology)- Active harmonics filter are available in a voltage range of 200V-240V, 380V-415V, up to 480V and higher voltages up to 600V and 690V also available.
7. IP/NEMA class and cooling system- Active filters are available from IP20 to IP54 which suites industry environment. Both Air and liquid cooling are available depending on the current rating.
8. Human machine interface and Network accessibility – Active filter should have a built in power and power quality meter to calculate the required compensation current. All the parameters to be read through directly in the meter available in AHF. It also to be accessed (full control) from remote through RS 485/Ethernet cable connecting in to AHF.
9. Commissioning software – Whether AHF have built in commissioning software. Some suppliers have an extra charge for the necessary software. Minimum required functionality should be that the system performs a self-check of Voltage and CT phase order, CT polarity check, self-diagnosis, and self-calibration. Such features will quickly find installation errors before they can cause problems and will also shorten the needed commissioning time.
In ideal condition harmonic should be studied at the individual load point or at the point of common coupling (PCC)
As per EN50160 standard Class ‘A’should be used for harmonic study. Central Electrical Authority, CEA and Tamil Nadu Electricity Board, TNEB adopts the EN50160 standards. So harmonic should be studied with the meter compliance with Class ‘A’ standard
To know the impact of harmonics in the system and to improve the quality of the power, improve the reliability of the all/sensitive equipment
In industry load current is combination of linear and nonlinear equipment’s connected at the downstream of the transformer. Depends upon the ratio of linear and nonlinear equipment’s load current and corresponding Harmonics (THDi %) will vary; the variation of Harmonic distortion is not necessarily proportional to the load current. To size a harmonic filter to work at all varying load condition 24hrs study is required
Harmonic distortion of current occurs when sinusoidal voltage is applied to a non-linear load (ex. electronic ballast, PLC, adjustable-speed drive, arc furnace, any ac/dc converter UPS, VFD’s). The result is a distortion of the fundamental current waveform.
In case of passive, the filter should be selected based on the maximum load KW/Current consumed by the load, while we go for active type the size of the filter is only for the amount of harmonics present in the system for eg., Load Current is 300A and THDi is 10% then 30A ECOsine is sufficient to limit the harmonics
In ideal condition harmonic filter should be connected at the individual load point or at the point of common coupling (PCC). If space or spare feeder is not available at the PCC point please contact JL SEAGULL
Current Transformer, CT should be connected at the PCC point I.e., before all the load in the system
All the features are menu driven
Harmonic filter should have very fast response time to eliminate the harmonics in the high load varying system. With an advance technology ECOsine Active is having a response time of 300µs (300 micro seconds) which could able to mitigate the harmonics around 30times in an half cycle.
In industry load current is combination of linear and nonlinear equipment’s connected at the downstream of the transformer. Harmonic will be generated very fast at any instant of the waveform. To mitigate the harmonics at the generating instant itself; response time of the filter should be very fast.
ECOsine Active have varying range of products from Current range - 30A to 300A and Voltage range 200V to 690V.
Overcurrent, Fan Error, Power Failure, CT error Over Temperature, IGBT module temperature, Harmonic resonance and internal hardware etc.,
With a single current transformer we can connect 5 no’s of ECOsine active can be connected in parallel
ECOsine Active have a special features, for parallel operation we can connect any/same combination of filter like 30+60A, 100+100A, 100+30A, 120+100A up-to 5No’s in parallel with a single set of CT.