Instrument Transformers
High Voltage Current Transformers -Oil-paper insulation -Gas insulation -Dry insulation
qúatro-grid® Oil-paper insulation /Gas insulation /Dry insulation Current Transformers up to 800 kV have been designed for a 30-year lifetime and, thanks to the profound technical concepts, many well out-live this service life. The oil is hermetically sealed from the air by a stainless-steel diaphragm assembly and all external parts are of corrosion-resistant material.
Current transformers are designed to provide a scaled down replica of the current in the HV line and isolate the measuring instruments, meters, relays, etc., from the high voltage power circuit.
Oil-paper insulation /Gas insulation /Dry insulation Current Transformers
- 72.5 to 800 kV
- Up to 5,000 A
- In short-circuit: up to 120 kA1” (Isc dyn: 324 - kA peak)
- Secondary cores: up to 8
- Oil level indicator
- Available high and extended range accuracy design (ERCT)
- Compliance with IEC and IEEE or equivalent standards
- DC current transformers available
POWER VOLTAGE TRANSFORMERS Oil-paper insulation Gas insulation
qúatro-grid offers a Power Voltage Transformers also known as Substation Service Voltage Transformers (SSVT) are used to supply Low Voltage power directly from a High Voltage line up to 550 kV.They offer all the benefits of a potential transformer with the applications of a distribution transformer.
Power Voltage Transformers (SSVT) are developed in both oil and SF6 insulation.
Their main application is the power supply of different type of subtations (switching, renewable and conventionals). They also assure the rural electrification, power supply of telecommunication towers in remote areas and temporary power supply when its needed.
The main advantages of Power Voltage Transformers (SSVT) are:
- Robust design
- Cost effective
- Maintenance-free
- Reliable power supply
- Design flexibility
- High seismic performance
- Reduced environmental impact
- 72.5 to 550 kV
- Up to 5,000 A
- In short-circuit: up to 80 kA1” (Isc dyn: 200 - kA peak)
- Secondary cores: up to 8
- Oil expansion by stainless-steel bellows
- Oil level indicator
- Compliance with IEC and IEEE or equivalent standards
- DC current transformers available
High Voltage Inductive Voltage Transformers up to 550 kV
qúatro-grid Inductive voltage transformers are designed to provide a scaled down replica of the voltage in the HV line and isolate the measuring instruments, meters, relays, etc., from the high voltage power circuit. Some of it's characteristics:
- Voltage input to different types of protection relays.
- Ideal for installation at metering points due to its very high accuracy class.
- Suitable for the discharge of high-voltage lines and capacitor banks.
- Up to 550kV
High Voltage Capacitive Transformers and Coupling Capacitors up to 1000 kV
Capacitive voltage transformers isolate the measuring instruments, meters, relays, protections, etc., from the high voltage power circuit and provide a scaled replica of the voltage in the HV line.
They enable transmission of high frequency signals through the high voltage (HV) lines.
Coupling capacitors are only used for coupling high frequency communication signals, making them equivalent to the capacitive part of a Capacitive Voltage Transformer.
- Voltage input to different types of protection relays.
- Ideal for installation at metering points dueto its very high accuracy class and extremely steady capacitance.
- Transmission of high-frequency signals through the high voltage lines (PLC)
- Helps to reduce voltage peaks in the line.
- Harmonic measurement in conjunction with Sensor
High Voltage Combined Transformers up to 550kV
qúatro-grid solution has developed combined transformers,
Combined instrument transformers contain a current transformer and an inductive voltage transformer within the same body.
Thus they are used in the same applications as their respective independent transformers; they separate meters, counters, relays, etc., from the high voltage circuit, and provide a scaled replica of the current and voltage in the HV line.
Combined transformers are suitable for use in substations where space or installation costs make using independent Transformers difficult.
- Ideal for installation at metering points due to their very high accuracy class, both in current and voltage.
- Suitable for the discharge of high-voltage lines and capacitor banks.
- Excellent frequency response; ideal for monitoring power quality and measuring harmonics.
SF6 INSULATED COMBINED INSTRUMENT TRANSFORMERS
qúatro-grid’s F6 insulated combined instrument transformers are used to convert high transmission line voltages and currents (voltage up to 800kV and current up to 6000 A) to standardized low and easily measurable values, which will be used for metering, protection and control of the high voltage system. As such, the need for accurate and reliable voltage and current transformation is essential.
The reliability and security of qúatro-grid’s gas-insulated instrument transformers is based on many years of innovation with gas-insulated units operating under a wide range of environmental conditions. Combined instrument transformers also ensure suitable electrical insulation between high voltage and low voltage measuring equipment.
Our gas-insulated combined transformers are compliant to the latest international safety standard requirements in terms of explosion-proof, insulating material multiple chopped ageing, seismic qualification and extreme temperature conditions.
Modern production and testing facilities guarentee not only short delivery times but also a reliable operation for many years.
GRADING CAPACITORS
Capacitor Products, such as Coupling Capacitors, Transient Recovery Voltage Capacitors or Grading Capacitors are used within HV networks for various purposes. Examples are: coupling high frequency carrier signals to the power line as well as (in combination with CB) reducing transient overvoltages, ensuring uniform voltage distribution or increasing the switching capacity of a breaker.
OPTICAL CURRENT TRANSFORMERS
qúatro-grid’s optical current transformers do not contain electronic parts and do not use oil or SF6 as insulation media. Long-term sustainability and no environmental compromises – The optical current transformers are tested and available for worldwide applications.
