High-Power Testing Laboratory
In the high-power testing laboratory circuit breakers and other medium voltage components will be tested for short-circuit making and breaking capacity, capacitive switching capacity, short-time and peak-withstand current and various other tests. A nominal short-circuit current of up to 40 kA at 19 kV can be generated during tests. The power can be adapted to the respective requirements using power transformers and reactors.
- Short-circuit tests for making and breaking capacity of circuit breakers
- Capacitive switching capacity tests
- Short-time and peak-withstand current tests for determination of dynamic and thermal stress
- Load current switching tests
- Motor current switching tests
- Electrical endurance tests for short-circuit currents
- Making capacity tests for earthing switches
- Breaking capacity for normal currents performed as endurance test
Our testing laboratory at a glance:
Specifications
Performance data of the high-power testing laboratory
- Maximum generator output 1300 MVA
- Maximum short-circuit current (single and three phase[peak/rms]) 105/40 kA
- Maximum short time withstand current, 3 s (says 4s below) 72 kA
- Frequency 50/60 Hz
Overview ov the technical equipment
Short-circuit generator
Technical data of short-circuit generator
- Nominal voltage (star/delta) 19 / 11 kV
- Maximum operating voltage 21 kV
- Nominal power 64 MVA
- Nominal speed 3000 / 3600 U/min
- Operating frequency 50 / 60 Hz
- Maximum short-circuit current 40 kA at 19 kV
- Weight of stator 160 t
- Weight of rotor 38 t
- Overall weight 210 t
The heart of the high-power testing laboratory is the formed? by a short circuit generator supplied by Siemens generator plant. The power of 1300 MVA corresponds to a maximum short-circuit current of 40 kA at a source voltage of 19 kV.
A 1.5 MW asynchronous machine fed (controlled?) by a frequency converter operates as the drive engine. The starting time is roughly 10 minutes. Braking to complete stop takes about 40 minutes.
Short-circuit transformer
Electrical characteristics of the transformers
- Manufacturer Siemens
- No. of single-phase units 3
- Nominal design rating of one unit 120 MVA
- Nominal voltages 35/70/140 kV
- Low voltage max. 19 kV
- High voltage, single-phase max. 420 kV
- Nominal frequency 50 Hz
- Max. permissible primary short-circuit current 40 kA
- Max. permissible peak short-circuit current 68 kA
- Weight per unit (filled with oil) 120 t
The transformers are of six-leg type, each of the four central legs being equipped with a 35 kV coil on the high-voltage (HV) side. The two outer legs are unwound and form the return path for the magnetic flux. The four coils can be connected in any combination. Metal-oxide arresters are used to protect the windings against switching over voltages that can appear between phase and ground and phase-to-phase.
