DC Testing Systems

Evergreen High Voltage DC Test Systems

Evergreen High Voltage modular DC generators are designed for rigorous requirements of testing high voltage electrical apparatus. The main requirement for these power supplies includes uninterrupted operation in the presence of continual flashovers and a mechanically compact package. Additionally, very high voltages are required with stable voltage regulation and small voltage drop during transient or steady state changes in load impedance. All modular UHV DC test systems exceed the requirements as specified in IEEE STD 4-2013 and IEC60060 Part I and II. The systems can reverse polarity, under specified capacitive loads, in less than one minute in accordance with IEC requirements for DC testing of power apparatus.

The design of EVERGREEN HIGH VOLTAGE UHV DC test systems uses the magnetically coupled insulated primary, insulated core design. This design has the following advantages over other methods for generating HV DC:

  • Modular, cylindrical mechanical package uses less floor space, has a lower height for a given voltage and weighs less than multiplier schemes.
  • The modular design is easy to transport for use in the field in fair weather. In the factory, systems up to 1.6MV can be moved on smooth floors by two people.
  • Expansion to higher voltage can be done by simply adding modules without reducing the current rating of the system
  • The system can be overloaded to provide more current for short term charging of large capacitive loads.
  • All HV components are mounted inside an oil filled cylinder to prevent any influence from the environment.
  • Each module contains a motorized polarity switch which can discharge the load and reverse polarity in less than one minute. Resistor energy ratings are available for any size capacitive load.
  • Each module is mounted in a high quality FRP cylinder with silicon rubber sheds for increased surface tracking distances.