36kV Inductive Voltage Transformer (IVT), also called a Potential Transformer (PT) or Voltage Transformer (VT), is an instrument transformer designed to accurately reduce medium-voltage system voltages (up to 36 kV) to a standardized low voltage (typically 100 V, 110 V, or √3-based secondary voltages) for metering, protection, and control equipment.
Working Principle
An inductive voltage transformer operates on the principle of electromagnetic induction. The primary winding is connected to the high-voltage system, while the secondary winding supplies a proportional low-voltage output.
Main Components
·High-voltage primary winding
·Low-voltage secondary winding(s)
·Laminated silicon steel magnetic core
·Epoxy resin or porcelain insulation
·Primary terminal
·Secondary terminal box
·Earthing terminal
·Mounting base
Typical Technical Specifications
·Highest System Voltage: 36 kV
·Rated Primary Voltage: 33 kV or 34.5 kV
·Rated Secondary Voltage: 100 V, 110 V, 100/√3 V, 110/√3 V
·Frequency: 50 Hz / 60 Hz
·Accuracy Class: 0.1, 0.2, 0.5, 1.0, 3P, 6P
·Rated Burden: 10–200 VA
·Insulation Level: 70/170 kV (Typical)
·Cooling: Natural Air (AN)
·Installation: Indoor or Outdoor
Applications
A 36kV inductive voltage transformer is widely used in:
·Medium-voltage substations
·Utility distribution networks
·Industrial power plants
·Renewable energy systems
·Wind farms
·Solar power plants
·Switchgear panels
·Electrical protection systems
Advantages
·High measurement accuracy
·Excellent electrical isolation
·Reliable operation
·Long service life
·Minimal maintenance
·Suitable for protection and revenue metering
·Cost-effective for medium-voltage systems
Typical Secondary Outputs
Common secondary voltages include:
·100 V
·110 V
·100/√3 V
·110/√3 V
These outputs are compatible with:
·Energy meters
·Protection relays
·Voltage indicators
·Power quality analyzers
·SCADA and automation systems
Common Standards
A 36kV inductive voltage transformer is generally manufactured in accordance with:
·IEC 61869-3 – Instrument Transformers: Additional requirements for inductive voltage transformers
·IEEE C57.13 – Instrument Transformers
·IEC 60044-2 (legacy standard, replaced by IEC 61869)
Typical Applications in a 36kV Substation
·Revenue metering
·Feeder protection
·Busbar voltage measurement
·Synchronizing circuits
·Automatic voltage regulation (AVR)
·SCADA monitoring
·Fault detection
·Power quality monitoring
A 36kV inductive voltage transformer provides a safe, accurate, and isolated representation of the system voltage, making it an essential component for metering, protection, and control in medium-voltage power distribution systems.