CTP-1000B variable frequency transformer tester is a new generation of CT and PT testing instrument developed on the basis of traditional voltage transformer volt ampere characteristic tester based on voltage regulator, voltage booster and current transformer, after widely listening to users' opinions, after a lot of market research and in-depth theoretical research. The device adopts high-performance DSP and FPGA, and advanced manufacturing technology to ensure stable and reliable product performance, complete function, high degree of automation, high test efficiency and is in the leading level in China. It is a professional test instrument for transformer in power industry.
Resistance | excitation | transformation ratio | load | description | wiring diagram |
√ | Measurement of CT secondary winding resistance and excitation | Figure 2.1 | |||
√ | √ | Figure 2.1 | |||
√ | √ | Figure 2.1 | |||
√ | √ | √ | Figure 2.1 | ||
√ | Figure 2.2 |
Parameter | Description | P | TPY | Metering | PR | PX | TPS | TPX | TPZ |
Rated primary current | Used to calculate the exact actual current ratio | √ | √ | √ | √ | √ | √ | √ | √ |
Rated load power factor | Rated load on the rating plate with power factor of 0.8 | √ | √ | √ | √ | √ | √ | √ | √ |
Rated accuracy limit factor K | The default value on the name plate is 10. It is used to calculate the limit electromotive force and its corresponding compound error | √ | |||||||
Rated symmetrical short circuit current coefficient K_{ssc} | The default value on the name plate is 10. It is used to calculate the limit electromotive force and the corresponding peak instantaneous error | √ | √ | √ | √ | ||||
Primary time constant | default: 100ms | √ | √ | √ | |||||
Secondary time constant | default: 300ms | √ | √ | ||||||
Work cycle |
C-t1-0 or C-t1-0-tfr-C-t2-0, Default : C-t1-0 cycle |
√ | √ | ||||||
t1 | First current passing time, Default: 100 ms | √ | √ | ||||||
ta11 | Time for primary flow to maintain accurate limits, Default: 40ms | ||||||||
tfr | Time delay for first opening and reclosing, Default: 500ms. Select C-t1-0-tfr-C-t2-0 cycle to display | √ | √ | ||||||
t2 | Second current passing time, default: 100. Select C-t1-0-tfr-C-t2-0 cycle to display | √ | √ | √ | |||||
ta12 |
Time for secondary flow to maintain accurate limits, Default: 40ms. Select C-t1-0-tfr-C-t2-0 cycle to display. |
√ | √ | ||||||
Safety factor of rated instrument | The default value on the name plate is 10. It is used to calculate the limit electromotive force and its corresponding compound error | √ | |||||||
Rated calculation coefficient | √ | ||||||||
Rated inflection point potential Ek | √ | ||||||||
le corresponding to EK | √ | ||||||||
Area coefficient | √ | ||||||||
Rated Ual | Rated equivalent secondary limiting voltage | √ | |||||||
Ial corresponding to Ual | √ |
Test Result | Discription | P | TPY | Metering | PR | PX | TPS | TPX | TPZ | |
Load | Measured load | Unit: VA, CT secondary side measured load | √ | √ | √ | √ | √ | √ | √ | √ |
Power factor | measured load power factor | √ | √ | √ | √ | √ | √ | √ | √ | |
Impedance | Unit: Ω, measured impedance of CT secondary side | √ | √ | √ | √ | √ | √ | √ | √ | |
resistance | Resistance(25℃) | Unit: Ω, resistance at current temperature | √ | √ | √ | √ | √ | √ | √ | √ |
Resistance(75℃) | R, Unit: Ω, Converted to the resistance at 75℃ | √ | √ | √ | √ | √ | √ | √ | √ | |
Excitation | Inflection point voltage and inflection point current | Unit: V and A respectively. According to the standard definition, when the inflection point voltage increases by 10%, the inflection point current increases by 50% | √ | √ | √ | √ | √ | √ | √ | √ |
Unsaturated inductance L | Unit: H, average inductance of linear section of excitation curve | √ | √ | √ | √ | √ | √ | √ | √ | |
Remanence coefficient K | ratio of residual flux to saturation flux | √ | √ | √ | √ | √ | √ | √ | √ | |
Quadratic time constant T | Unit: s, time constant of CT secondary connection with rated load | √ | √ | √ | √ | √ | √ | √ | √ | |
Limit electromotive force E | Unit: V, limit electromotive force calculated according to CT rating plate and 75 ℃ resistance | √ | √ | √ | √ | √ | √ | |||
Composite error ε | Composite error under the limit electromotive force E or rated inflection point potential E_{K} | √ | √ | √ | √ | |||||
Peak instantaneous error ε | Peak instantaneous error under the limit electromotive force E | √ | √ | √ | ||||||
Accuracy limit coefficient | Accurate limit coefficient measured | √ | √ | |||||||
Instrument safety factor | Measured instrument safety factor | √ | ||||||||
Symmetrical short circuit current multiple K_{ssc} | Measured symmetrical short circuit current multiple | √ | √ | √ | √ | |||||
Transient area coefficient | Actual transient area factor | √ | √ | √ | ||||||
Calculation coefficient K_{x} | Actual calculation coefficient | √ | ||||||||
Rated inflection point potential E_{k} | Measured excitation dia corresponding to rated inflection point potential | √ | ||||||||
Ie corresponding to Ek | √ | |||||||||
Rated Ual | rated equivalent secondary limiting voltage | √ | ||||||||
Ial corresponding to Ual | Measured excitation current corresponding to rated equivalent secondary limiting voltage | √ | ||||||||
Error curve | 5% (10%) error curve | √ | √ | √ | √ | √ | √ | √ | ||
Transformer Ratio | Transformer Ratio | Actual current ratio at rated load | √ | √ | √ | √ | √ | √ | √ | √ |
Turn ratio | Actual turn ratio of secondary winding to primary winding under test | √ | √ | √ | √ | √ | √ | √ | √ | |
Ratio difference | Current error under rated load | √ | √ | √ | √ | √ | √ | √ | √ | |
phase difference | Phase difference at rated load | √ | √ | √ | √ | √ | √ | √ | √ | |
Polarity | There are two kinds of polarity relations between CT primary and secondary, i.e., homopolarity/ -(reduced polarity) and reverse polarity/+ (additive polarity) | √ | √ | √ | √ | √ | √ | √ | √ | |
Turn ratio error | Relative error between measured turn ratio and rated turn ratio | √ | √ | |||||||
Standard error | Table of current error and phase error of international inspection current point under rated load and lower limit load | √ |