Circuit breakers and switches are devices that control the
protection of the power system and the supply of energy. It is
necessary to develop a more reliable product through the process
of designing, manufacturing, evaluating and repeating the steps of
evaluation and supplementation.
However, as the capacity of the circuit breaker increases, the
test for evaluating the breaking performance requires a test
facility requiring a large budget, which increases the expense of
the test and becomes a hindrance factor in the development of
the product. Therefore, there is a need for a more economical
and easy-to-use evaluation technology and evaluation system. The
methods employing short-circuit generators are time-consuming
and expensive to operate and maintain.
Therefore, a simplified synthetic test facility using a resonant
current of a circuit composed of a capacitor and a reactor
instead of a short-circuit generator as a current source is widely
used.
There is no problem in performing the breaking performance
test for the breaker terminal fault test duty for the vacuum
circuit breaker having the minimum arc time (~2-3 ㎳) by using
the existing simplified synthetic test facility.
However, in the case of a gas circuit breaker with a minimum
arc time (~10-12 ㎳), the arc resistance generated by the internal
of the circuit breaker and by the test facility cuts off the current
at the zero point of the current in the second loop. Or the
magnitude of the current in the third loop is greatly reduced. As
a result, it is difficult to carry out a test conforming to the
specification that the test should be performed within 10% of the
current deviation, so it is difficult to equivalently compare it with
the test result through the high power short circuit test.
To solve this problem, the following facilities have been added
to the existing simplified synthetic test facility. That is, The circuit
to prolong arcing, the addition of a current source circuit to
supplement the current in the third current loop, and the
modified TRV circuit for applying an initial transient recovery
voltage rise rate of 20 ㎸/㎲ or more.
The breaking performance test for the short line fault test duty
L  for the rated 170㎸-50㎄-60㎐ gas circuit breaker was carried
out using the simplified synthetic test facility with modified TRV
circuits. We confirmed that all equipments operate normally by
testing.
The Paris Agreement was adopted in 2015 to replace the Kyoto
Protocol, which entered into force in 2005. The Paris Convention
will focus on a new climate change response system to be applied
after 2020. With the adoption of the new climate system, the world
is in the midst of developing eco-friendly, ultra-high-voltage
power equipment. The world heavy equipment industry is paving
the way for research and development to take the lead in the new
- 114 -
eco-friendly power device market, which will replace SF  gas,
which has a global warming index of 23,900 times that of carbon
dioxide.
When developing a gas circuit breaker using environmentally
friendly gas, it is necessary to perform the breaking performance
evaluation for the short line fault with the highest priority in
order to evaluate the thermal recovery characteristics of the gas.
Simplified synthetic test facility with modified TRV circuit with
improved equivalence is expected to play an important role in the
development of gas circuit breaker using environmentally friendly
gases and in various fields.