Q1: What is a current transformer analyzer?
A1: Current transformer analyzer is a multi-functional field test instrument specially designed for testing voltammetric characteristics, ratio, polarity, error curve, inflection point calculation, and secondary side circuit check of transformers.
Q2: How to use the current transformer analyzer?
A2: In the experiment, just set the test voltage and current values, and the device can automatically boost voltage/flow, and can quickly display the volt-ampere characteristic curve of the transformer or the experimental results of the ratio and polarity, etc. It supports data saving and on-site printing. sisico current transformer analyzer not only eliminates the tedious labor of manual voltage regulation, manual recording, and curve drawing but also allows you to upload the test data to your computer through the USB interface on the computer for editing, saving, or printing. It is simple and convenient to operate and improves working efficiency.
Q3: How to judge the polarity of the current transformer?
A3: There are many ways to measure the polarity of current transformers, and we often use the following three test methods in our work: the DC method, the AC method, and the instrumentation method.
Tips: Why is it necessary to measure the polarity of CT?
The polarity of the current transformer must be checked before and after the handover and overhaul. In addition, when the differential protection, and power direction protection malfunctions or the watt-hour meter is reversed during operation, the polarity of the CT should also be checked. It is because if the polarity of the current transformer is wrongly connected during wiring, the following hazards will occur:
- The current transformer used in the relay protection circuit will cause the relay protection device to malfunction or reject, affecting the operation monitoring and accident handling of the power system, and even endangering equipment and personal safety in severe cases.
- If the current transformer is used in the instrument measurement circuit, various instruments, instrument indication, and power measurement will be incorrect.
- If the current transformer with an incomplete star connection is used, if the polarity of any phase is reversed, it will cause the current transformer to not be connected to one phase (usually in the same phase), and then the current of the other phase will increase by the picture multiple.
- Using a current transformer with two phases reversed in an incomplete star connection, although the secondary side of the three-phase current can still be balanced, the phase angle difference of the primary side corresponding to the current is 180°, which will make the meter reverse.