AC Reactor

ABOUT LINE FREQUENCY INDUCTORS

Line frequency inductors operate with a fundamental frequency of 50/60Hz and are found in most electrical power conversion applications. In its simplest form a coil is wound around a magnetic core creating a magnetic field which is known as its inductance. This magnetic field is present only when current is flowing through the coil. For line frequency inductors we use magnetic cores with low loss grain-oriented silicon steel for the best performing inductors. Insulative material is used to create isolation from winding to winding and winding to core. One application for inductors is in LC circuits which contains both inductance and capacitance. The stored magnetic energy in the inductor is transformed into the electrical energy of the capacitor, and can be released or absorbed whenever the value of the current changes. An inductor is a source of impedance in an AC circuit.
Our inductors are designed to thermal class A, B, F or H depending on application or standards needed.
Insulation / Thermal Class Max temperature (°C) Reference max ambient temperature (°C) Max temperature rise (°C)
A 100 40 75
E 115 90
B 120 95
F 140 115
H 165 140
C >165 >140
Insulation class takes into account the temperature rise of the windings and insulation above the existing ambient temperature. These classes describe the insulating materials operating temperature ratings. Letter classifications are used for different designations of system temperatures in degrees Celsius. The system temperature is the maximum temperature at the hottest spot in the winding. Standard features of our magnetics include insulation voltages up to 6kV, 50/60Hz operation, double insulated materials, and class F (155°C) or class H (180°C) insulation. For cost sensitive applications aluminum windings are also an available option. For high power inductors with physical size typically over 12 inches cooling channels may be utilized to create airflow between the windings, in order to enhance the heat transfer from the inductor winding to the ambient air. Design parameters needed for an inductor:
  1. Voltage and frequency.
  2. Inductance.
  3. Current.
Capacity or energy stored in the magnetic field of an inductor can be derived by: W = 1/2 L I2 Where:
W = energy stored (J, joules) L = inductance (H, henrys) I = current (A, amps)

DC INDUCTORS

DC Link Chokes DC link chokes attenuate AC input line current harmonic distortion by absorbing DC bus voltage spikes, and assisting in controlling the DC bus voltage and current in an inverter. DC link chokes also add filter protection by increasing circuit inductance without causing an AC input line voltage drop.
DC Filter Chokes DC filter chokes are used in AC to DC conversion circuits to provide an inductive voltage drop (filter) to the AC component of a rectified current. These components function effectively (without saturation) in the presence of the DC current. A DC filter choke can also be used in conjunction with capacitors to reduce ripple in DC circuits. Considering the impact of ripple frequency, we will identify and analyze ripple frequency through calculations using the frequency of the supply and the conversion configuration.

AC REACTORS / INDUCTORS

AC Reactors, AC Chokes, and Line/Load Reactors are used primarily to limit current. Both single-phase and three-phase versions are available. They also can be designed for 50Hz, 60Hz, 50/60Hz or 400Hz.
Line and Load Reactors Line Side and Load Side lower harmonics caused by high peak voltage and fast rise time voltage pulses from IGBTs, to create PWM waveforms used in inverters. Reactors absorb these complex waveforms and power line disturbances to minimize the input total harmonic current distortion (THID). In addition, they offer excellent absorption of transient voltage spikes. These reactors a reliable solution reducing harmonic distortion and minimizing the effects of long lead lengths operating on both the input (line) side and output (load) side. AC chokes can also be used as buck/boost inductors.
Smoothing Chokes These are used to filter the AC ripple in a low-frequency DC power supply. Inductors are used to filter out RFI (Radio Frequency Interference). In another application they are used as current-limiting reactors for overload and short-circuit protection, or to limit high inrush currents that might occur on the startup of an electric motor. Wide-band inductors are used at a multitude of frequency levels to filter out unwanted frequency noise leaving a clean fundamental signal. Inductors come in virtually all windings and constructions dictated by the frequency and current they are able to handle. Swinging chokes are similar to filter chokes except it has two inductance ratings at two currents.

SINGLE-PHASE INDUCTORS

These are used for switching, power factor correction, and filters. Inductance up to 15mH Current up to 200A IP (Ingress Protection): IP00 Applicable Standards: CEI 14-5 IEC 60076-6 EN 61558-2-20

THREE-PHASE INDUCTORS

These are used for switching, power factor correction, and filters. Inductance up to 25mH Current up to 300A IP (Ingress Protection): IP00 Applicable Standards: CEI 14-5 IEC 60076-6 EN 61558-2-20

RAILWAY MAGNETICS

The proper functioning of the railway signaling depends on top quality components to ensure the safe transport of people and goods. For rail transport applications we make special magnetics to support railway signaling lights or electro- mechanical devices for switching or rail heating. We provide the following types of magnetics for these applications:
  • Transformer: three-phase, single-phase.
  • Impregnated transformers.
  • High voltage transformers.
  • 1000V rated transformers.
  • Coil interphase.
  • Single-phase transformer low inductance.
  • Low-voltage transformers.
  • Transformer box.
  • Six-phase transformers.
  • Transformers with internal inductance.
These transformers for railway signaling feature:
  • Cooling: AN
  • Insulation class: II
  • Thermal class materials: H
  • Applicable Standards:
  • CEI 14-8
  • CEI EN IEC 60076-11
  • EN 61558-1
  • IS 365 and 2008
  • IP (Ingress Protection): IP40

FOIL WOUND INDUCTORS

Foil wound inductors are used in high current applications. The coil is wound with either copper foil or aluminum foil. These inductors are used when high current is required. Additional benefits include improved temperature dissipation, reduction of hot spots, improved vibration capabilities, and reduced layer-to-layer voltage stress, yielding improved dielectric strength required for rugged applications. The reduced weight of the company’s foil wound inductor ensures that it is the ideal solution for restricted weight and volume challenges.

EDGE WOUND INDUCTORS

Edge Wound Inductor Air Core
Edge Wound Three Phase Inductor
Edge Wound Inductor On I-Core
Edge winding is a technique in which a rectangular magnet wire is wound on its narrow edge. This allows a much greater surface area to dissipate more heat than conventional winding techniques, and produces coils that reduce skin effect and proximity losses compared to traditional winding methods. Edge winding also produces coils with few undesirable parasitic elements making it more appropriate for use in inverters and converters using high frequency silicon carbide (SiC) and gallium nitride (GaN) semiconductors. It also produces lower parasitic capacitance reducing unwanted high frequency noise, which is a concern when passing electromagnetic compatibility (EMC) testing. Edge winding is used mainly in Inductors that have high load currents at lower voltages. Chokes and can be up to 10% lighter and reductions in power losses of up to 25% are achievable when compared to existing winding methods.

VIBRATORY FEEDER COILS

The vibratory inductor is a unique application for a simple choke design, for use in Vibratory Feeding Systems and Sorting Lines or Bowls. Vibrations are set up between an I-armature assembly and an E-armature assembly through the changing magnetic field of the core.
The E-armature is usually secured to the solid equipment base, while the I-armature is secured to the bowl or line to be vibrated. The two armatures are positioned only a fraction of an inch from each other so that the E’s and I's are coupled through the magnetic field. This gap can be variable to change the strength of vibrations. Coils can be provided potted or unpotted and are available with heavy weldments for solid attachment to the vibratory unit. Terminations are provided through flying leads, STO line cords, solder lugs, or quick-connect lugs.