A ZW-126/D2000-40 type single-break vacuum circuit breaker (VCB) with controlled switching technology is designed and produced in this paper. The results of type tests based on IEC and GB standards are presented. A 126 kV single-break vacuum interrupter (VI) with 3/4 coil axial magnetic field (AMF) contacts is used in the VCB

which can interrupt short currents of 40 kA. The external insulation of the VI is provided by SF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6 at 0.1 MPa. In order to match the 126 kV single-break VI and controlled switching device

a long-stroke electro-magnetic force actuator (EMFA) with 16 kN closing holding force and 3.5 m/s average opening speed is designed. Moreover

a position tracking controlled switching device based on closed-loop control using the technology of a fuzzy control algorithm and pulse width modulation is applied to the controlled switching device. This device is applied to control the coil current of EMFA and the electromagnetic force

so as to control the EMFA to follow the ideal position curve. The type tests of 126 kV VCB are all passed according to the IEC62271-100 and GB1984-2014

including dielectric tests

basic short-circuit tests

short-line fault tests

out-of-phase tests

etc. The strong capacitive current breaking capacity and mechanical strength of the VCB are proved by the capacitive current switching test of class C2

electrical endurance test of class E2 and mechanical endurance test of class M2. The electromagnetic compatibility (EMC) tests are passed according to the IEC61000-4. The controlled switching test of capacitive current was successful according to IEC62271-302 and GB/T30846-2014

and the controlled switching accuracy is less than ± 0.5 ms. The test results show that the VCB has excellent performance

which has broad application prospects in special occasions at a 126 kV voltage level

such as a switching capacitor and no-load transformer

etc.