Electronic Voltage Transformer (EVT)

Electronic voltage transformers with capacitive divider (EVTCD) is an alternative to the conventional capacitive voltage transformer (CVT) for high-precision voltage measurement and power quality control, between 72.5 kV to several hundreds of kV on HV overhead power lines. This innovative capacitor divider, developed in conjunction with selected customers, is characterized by a low voltage output (3.5 V to 100 V) with a simple connection permitting a direct digital treatment of the signal, a very high stability over a large temperature range, and optimal performances over an increased frequency bandwidth compared to conventional measurement methods.

Maxwell’s EVTCD can be delivered as an internal part ready to be installed in a composite or porcelain insulator by the customer. Dividers directly in a composite or porcelain insulator with single or alternating long-short sheds in full compliance with IEC 61815 are also available on demand.

Product Features
Synthetic oil-based capacitor technology
Capacitance 300pF and higher
Low capacitance variation versus temperature
Nominal voltage Un from 72.5kV to 800kV 50/60Hz
Highest quality and reliability
Very Low voltage output 50 to 200V
Insulator in reinforced epoxy resin; porcelain or composite on request
Test voltage up to 810kV 50/60Hz
Maintenance free
Lightning impulse voltage up to 1300kV 1.2/50µs
Proven sealed construction
Switching impulse voltage up to 1000kV 250/2500µs
Corrosion resistance
Lightning impulse voltage chopped wave up to 2000kV 1.2/2µs
Cantilever strength from 5kNm to 25kNm