Power Quality Converters

Active Harmonic Filters

AHF3

AHF2 _LEFT


Overview

Energy Efficiency, process improvement and productivity enhancement are driving the need for use of VFDs (Variable frequency Drives) in all Industries from last two decades. Besides that, proliferation of air conditioning equipments, computers, fax and copying equipments, printers and other office equipments, fluorescent lighting and various electronic communications equipments are extensively used in commercial buildings leads to more contribution of non-linear loads as a percentage of overall electricity consumption.

These non-linear loads introduces Harmonics Currents having higher peaks, which could cause Transformers, motors and power cables overheating, nuisance tripping by fuses, Circuit Breakers and other protective devices since they are typically not rated for harmonically rich waveforms. In addition, the life span of many devices can be reduced by elevated temperature.

The Regulatory requirement which was earlier advisory will shortly expected to turn in to mandatory, necessary use for these devices will be

The instantaneous effects of Harmonics

  • Disruption of Controllers used in electronics systems and can adversely affect thyristor switching due to displacement of the zero-crossing of the voltage wave.
  • Vibration and audible noise in electrical machines like motors, reactors, transformers.
  • Reduction in the available capacity of power systems.

The long term effects of Harmonics

  • Capacitors heating and degradation of capacitance value.
  • Input transformers heating due to additional losses.
  • Heating of Busbars, Cables and Equipments.
  • Thermal damage to Induction Motors and Generators.

VC-AHF Active Harmonics filters is the initiative by Veeral Controls as a Power Electronics OEM towards the mission of “Clean Grid”. We have specialised in harmonics mitigation objectives and therefore offering broad range of solutions for every demand in this field. We propose solutions which maximize the savings when balanced with the cost of the harmonic mitigation equipment to get a reasonable Return of Investment (ROI).

Key Features and Applications

VC-AHF Active Harmonic Filters are the most reliable solutions for this Harmonics by their unique step less automatic correction technique for correcting the current harmonics in real time by injecting equal magnitude and opposite phase harmonic currents in the network to get “Clean Grid”.

The unique features of VC-AHF Active Harmonics filters are,

  • Step less automatic adaption to load changes
  • Suitable for all types and mixes of Non-linear Loads
  • Ultra fast response of < Half Cycle
  • Rapid injection of reactive current within 500uSec
  • Selectable / programmable Harmonics and Power Factor
  • Suitable for compliant to IEEE – 519 – 2008 standards for Grid Utility regulations

VC-AHF Active Harmonics filters finds their essentialities at wide industrial areas includes,

  • Process Industries
  • Steel Plants
  • Automotive Industries
  • Glass Industries
  • Oil and Gas Platforms
  • HVAC Applications
  • Wind and Solar Platforms
  • Railways and Metros
  • Paper and Printing Industries

VC-AHF : Technical Specifications

@ System Inputs
1) Rated Operating Voltage 200 – 690 V AC
2) Frequency 50 / 60 Hz ± 5 %
3) Connection System 3 Phase – 3 Wire / 3 Phase – 4 Wire capable of handling unbalanced load
@ Technical Characteristics
1) Topology 3 – Phase, 2 – Level / 3 – Level IGBT Based Inverter Systems
2) Mode Of Operation Harmonics Compensation, Power Factor Correction, Independently or Combined
3) Harmonics Compensation 5th to 49th Harmonics, Global or Selectable (3rd when present can also be eliminated)
4) Reactive Compensation Power Factor Correction (Leading / Lagging) to near Unity up to rated KVAR with selectable set point
5) Response Time ≤ 10 mSec
6) Enclosure Type IP 23 Standard Industrial Floor Mount (IP 43, IP 54 Optional)
7) Controller Latest state of art DSP / FPGA based Controller
8) Control and Indications AHF ON / OFF, AHF Status and Emergency OFF
9) Settable options Power Factor Set point, Selectable Harmonics Compensation, CT Ratios
10) Electrical Parameters Monitoring and Display HMI / Graphical LCD Display for All essential Power Parameters and Harmonics, Oscilloscope mode for Bar Graph Display of Harmonics (Optional)
11) Modularity ‘n’ Numbers of units in parallel for higher capacity
@ Environmental Conditions
1) Operating Temperature 0 to 50 ° C Ambient Temperature
2) Relative Humidity 0 – 95 % RH, Non – Condensing

VC-AHF – Topology

  • 3 – Phase, 2 – Level Power Converter
  • 3 – Phase, 3 - Level Power Converter
  • Transformer coupled VC-AHFs for Compensation on MV/HV Bus

3 – Phase, 2-Level Power Converter

1

  • 2 – Level converters are cost effective and simplify the power and control design
  • All Standard VC-AHFs are working with this topology
  • Disadvantages are limiting Switching Frequency for higher order harmonics compensation due to thermal losses.

3 – Phase, 3 – Level Power Converter

2

  • All Specialized VC-AHFs are working with 3-level topology
  • Ideal for Harmonics Compensation of higher order.
  • Reduces voltage ratings of power devices to half compared to standard 2-level topology and improves efficiency with low switch losses
  • This topology minimizes dv/dt Stresses on Switching Devices, which reduces EMC problems

VC-AHF : Models

Sno Model Code Nominal Voltage (AC RMS) Nominal Current (AC RMS) Connection Dimensions (W x D x H) mm
1) VC-AHF - 415 – 60 – 3W(4W) 380 – 480V 60A 3 Wire (4 Wire) 600x500x1000
2) VC-AHF - 415 – 120 – 3W(4W) 380 – 440V 120A 3 Wire (4 Wire) 600x500x1500
3) VC-AHF - 415 – 240 – 3W(4W) 380 – 440V 240A 3 Wire (4 Wire) 800x600x2000
4) VC-AHF - 415 – 480 – 3W(4W) 380 – 440V 480A 3 Wire (4 Wire) 800x1000x2000

*For Higher ratings ‘n’ numbers of AHFs can be connected in parallel

Please write to us for details.


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