The mechanical characteristic tester for high-voltage switches is a specialized device used to measure and analyze various mechanical and electrical time parameters of high-voltage switchgear (mainly circuit breakers) during the opening and closing operations. This equipment can be used to assess whether the mechanical performance of the switch is good, whether the operation is reliable, and to promptly detect latent faults (such as mechanism jamming, poor buffering, coil faults, etc.), thereby ensuring the safe operation of the power grid.
I. Main Test Items
(1) Time Parameters
Opening/Closing Time: The time from when the coil is energized to when the contacts complete their movement.
Synchronization
Same-phase Synchronization: The time difference between the actions of each phase.
Same-phase Breaker Synchronization: For multi-breaker circuit breakers (such as double-breaker or four-breaker), the time difference between the actions of each break within the same phase. This is a very important indicator, as a large synchronization difference can lead to abnormal arc extinction.
Closing-Opening Time (Metal Short-Circuit Time): The time from the moment the contacts just touch during the closing operation to the moment they just separate during the opening operation. This parameter is related to the short-circuit closing capability.
Opening-Closing Time (Automatic Reclosing No-Current Interval Time): The time interval between the opening and the subsequent closing during the automatic reclosing operation.
(2) Speed and Travel Parameters
Initial Opening/Closing Speed: Usually refers to the average speed of the contacts in the overtravel section (a specified distance before and after separation or contact), which is a key indicator for judging whether the operating mechanism has sufficient energy.
Maximum Opening/Closing Speed.
Opening Distance: The distance between the breaks after opening.
Overtravel (Contact Travel): The compression travel of the contact spring after closing, representing the contact pressure.
Total Travel: The entire movement distance of the moving contact from opening to closing.
Time-Travel Characteristic Curve: As the most core curve, it can visually display the relationship between displacement and time throughout the entire operation process, containing all mechanical state information.
(3) Operation Process Status
Opening/Closing Coil Current Waveform: By analyzing the current waveform, issues such as whether the electromagnetic core is jammed, whether there is a short circuit between the coil turns, and whether the auxiliary contact switching timing is normal can be determined.
Opening/Closing Coil Voltage.
Main Contact Action Waveform: Usually collected through the break signals, it is used to display the actual opening and closing status of the contacts.
II. Working Principle and Key Technologies
(1) Signal Acquisition
Time Measurement: Uses an internal high-precision crystal oscillator as the time reference.
Break Signal: By connecting to each break of the switch, the change in their opening and closing states (on/off) is detected.
Travel Measurement
Rotary Sensor: The most widely used, it couples the gear on the sensor with the rotating shaft of the switch operating mechanism (such as a horizontal or vertical connecting rod), converting linear displacement into rotational angle, and then converting it into linear travel. When in use, the transmission ratio must be accurately input.
Linear Sensor: Directly installed on the linear moving part of the moving contact, it has high measurement accuracy but sometimes the installation conditions are restricted.
Accelerometer/IMU: A new measurement technology, it does not require installation coupling and calculates displacement through integration, but has higher requirements for installation methods and algorithms.
Coil Current: A clamp-on current transformer is placed around the coil circuit to achieve non-invasive measurement.
(2) Data Processing and Analysis
The internal microprocessor of the high-voltage switch mechanical characteristic tester synchronously collects all channel signals, automatically calculates various parameters, draws characteristic curves, and compares the calculation and drawing results with preset standards or historical data.
Post time: Jan-14-2026