Showing results: 31 - 45 of 45 items found.
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R Series -
Hilkar
Load banks are devices which contain resistive, inductive and/or capacitive loads, apply the load to an electrical power source and dissipate the power of the electrical source. Portable and stationary resistive load banks incorporate as low as 1 kW load step increments for testing small to large generating sets. The fine control resolution ensures accurate load control and power factor targeting adjustments.
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Hilkar
Line and load reactors are generally serial-connected to the input and/or output terminals of three phase equipment such as motor speed controllers, inverters and UPS systems. These equipment make use of semiconductor switches such as IGBTs, thyristors, and diodes and therefore create harmonic distortion and high switching over-voltages (dv/dt). Use of such equipment has been becoming more widespread as the technology advances. However, the negative effects of these equipment should not be overlooked.
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Hilkar
Arc Furnace Reactors are serially connected reactors that are installed in the supply systems of arc furnace transformers to stabilize arc and limit the unstable arc furnace current and voltage drop which optimize their melting process. These buffer reactors are connected in series to the primary side of the furnace transformer. Typically these reactors are tapped coils and manufactured as per customer'stap requirements.
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Hilkar
Iron core Oil-immersed Shunt Reactors act as an absorber of reactive power to increase energy efficiency of the power system.
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Hilkar
Line Traps are used in transmission and distribution networks and they are the key components in Power Line Carrier (PLC) systems used for remote control signals, voice communication, remote metering and control between substations in the electrical T&D networks.
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Resistive Voltage Dividers -
Hilkar
NGR Sensing Resistors are attached in parallel to the neutral grounding resistor. The sensing resistor allows a protective relay to detect a resistor failure in a continuous manner. Sensing Resistors are used in combination with neutral grounding resistor monitor relays. The relay measures neutral grounding resistance, neutral grounding resistor current and neutral to ground voltage. The relay continuously measures neutral grounding resistor ohmic value in an unfaulted system and it trips on if neutral grounding resistance varies from its calibrated value.
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Hilkar
Smoothing Reactors are serially connected reactors inserted in DC systems to reduce harmonic currents and transient over currents and/or current ripples in DC systems. They are necessary in order to smooth the direct current wave shape to reduce losses and improve system performance.
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Hilkar
Sine Wave Output Filter Modules provide satisfactorily smoothed sinusoidal waveform with low residual ripple form square waveform with high voltage spikes, present at the output of motor drives.
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Hilkar
Since the rise time of IGBTs are in the range of a few tens of nanoseconds (between 50ns-200ns), even short cables between PWM motor drives and motors cause voltage doubling at the motor terminals due to Travelling Wave Phenomenon as in transmission lines. The insulation of motor windings are prone to failure due to high voltage spikes if necessary precautions are not sufficiently taken. RC Type Output Filter Modules reduce these high voltage spikes to protect motors by connecting to stator terminals.
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Hilkar
Line and load reactors are generally serial-connected to the input and/or output terminals of three phase equipment such as motor speed controllers, inverters and UPS systems. These equipment make use of semiconductor switches such as IGBTs, thyristors, and diodes and therefore create harmonic distortion and high switching over-voltages (dv/dt). Use of such equipment has been becoming more widespread as the technology advances. However, the negative effects of these equipment should not be overlooked.
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Hilkar
Grounding Transformers are designed for providing an artificial neutral point for ungrounded three phase power systems. During the line-to-ground faults, grounding transformers provide an easy path to ground faults to limit the fault currents and transient overvoltages.
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L-Series -
Hilkar
L-series inductive load banks are devices which contain inductive loads, apply the load to an electrical power source and dissipate the reactive power of the electrical source. L-series load banks are designed for portable and fixed applications. Hilkar brand L-series load banks have robust design and are specifically designed for corrosive environments. Load banks can be controlled via local, remote, wireless remote or automatic control systems.
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Hilkar
HRG systems limit the fault current by placing high resistance between neutral point of transformer (or generator) and ground. As it is not possible to locate the fault point in delta connected systems, an artificial neutral point is created and delta connected system can be grounded. This allows a fault current of a few amperes thus locating the fault point gets easy. When the neutral point is grounded thru high resistance, both continuity of operation is provided during fault condition and sufficient current (typically between 2 A and 10 A) flow is provided for ease of locating the fault point.
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Hilkar
Crowbar resistors are three phase resistance banks which are connected to the rotor windings of the DFIG (Doubly-Feed Induction Generator) such as wind power generator. They are used to prevent damage to the inverter circuits attached to rotor side when a fault occurs in the grid. DFIG power converter, which has a restricted over-current limit, needs special attention during faults in the grid. If the rotor current or DC link voltage reaches the threshold value, crowbar resistors disconnect the converter in order to prevent the generator turning into a squirrel cage induction machine. By crowbar resistors, the DFIG could stay connected to the grid and continue its operation.
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Rotor Starter -
Hilkar
The Slip-Ring Motor Starters are based on the series of resistors that are applied to the rotor circuit to control the speed/torque characteristics of the motor. Rotor starters are mainly used for the motor starting applications requiring high-starting torque like loaded belt conveyors in mining industry. By external resistors, it is possible to shift the motor maximum (break-down) torque up to starting torque point for motors under heavy loads during start-up. The resistors are splitted into some steps and controlled via contactors by motor starting control system. As the motor speed increases, the external rotor resistors are eliminated by shorting contactors until all external resistors are shorted out.
