Transformer No-Load Current Short Circuit No Load Resistance Tester

Product details

I. Overview

The short-circuit impedance is an important parameter of the transformer. The short-circuit impedance method is the traditional method to judge the winding deformation. According to the regulations of GB1094.5-2003 and IEC60076-5:2000, the change of the short-circuit reactance is the only criterion for judging whether the transformer winding is deformed.

The low-voltage short-circuit impedance test is the most direct way to determine whether the transformer is impacted by short-circuit current during operation, or the transformer is impacted by mechanical force during transportation and installation. It is the most direct method to check whether the winding is deformed. It is important for judging whether the transformer can be put into operation. Significance is also one of the basis for judging whether the transformer requires disassembly inspection.

Transformer low-voltage short-circuit impedance tester, suitable for low-voltage load impedance testing in power transformers (single-phase or three-phase) delivery, overhaul, pre-test and handover test. The principle of the basic item in the conventional test project is to test the short-circuit impedance (%) of the power transformer on site and compare it with the nameplate value or factory value. After the factory test, the serious fault current during transportation, installation and operation can be found. Defects caused by winding displacement and deformation.

The transformer short-circuit impedance tester is a new generation transformer parameter tester independently developed by our company. It is an instrument for low-voltage short-circuit impedance measurement of main transformers of 35KV and above under field and laboratory conditions. The instrument is designed with exquisite design, superior performance and powerful functions. The internal use of the latest domestic and foreign single-chip testing technology and advanced A/D synchronous AC sampling and digital signal processing technology, the measurement data is accurate; the external use large-screen color LCD display, Chinese menu Reminder, simple operation, equipped with high-speed thermal printer, designed with storage function, convenient for data storage and printing; the saved data can be transferred to the computer via USB. The instrument is small in size, light in weight, easy to carry, and extremely convenient to use on site, which greatly reduces the labor intensity of test personnel and improves work efficiency.

With the input parameters of this transformer, single-phase and three-phase tests can be performed and the dynamic and stable state parameters of the transformer windings (Zke, Zk, Xk, Lk) can be automatically calculated. The test results are very intuitive. It is a fast testing instrument for field testing of transformer winding deformation.

II. Features

1. Measurement of three-phase short-circuit impedance:

Display three-phase voltage, three-phase current, three-phase power; three-phase short-circuit impedance (zk), three-phase short-circuit reactance (XK), three-phase short-circuit inductance (LK), three-phase short-circuit impedance voltage (zke), automatically calculate the percentage of transformer impedance voltage converted to rated temperature and rated current, and the error percentage with the nameplate impedance. It can be used to check the single-phase defects of three-phase transformer. The instrument can record the data of three single-phase measurements, and calculate the impedance voltage and impedance voltage percentage error of transformer according to different connections of transformer. After three single-phase tests, the calculation results of three-phase short-circuit impedance can be displayed.

Automatic conversion of test results, with frequency correction, temperature conversion, current conversion, improve the comparability of test data.

2. Measurement of single phase short circuit impedance:

In addition to measuring the short-circuit impedance of single-phase transformer and the error percentage between the short-circuit impedance and the nameplate impedance, the impedance, reactance, resistance and inductance of the transformer are also measured for the convenience of user data comparison.

3. Measurement of zero sequence impedance:

The zero sequence impedance measurement is applicable to the transformer with neutral point in star connection at high voltage side. The instrument can record zero sequence impedance, zero sequence reactance, zero sequence inductance, impedance angle and zero sequence resistance.

4. It can be directly measured within the allowable measurement range of the instrument, and external voltage transformer can be connected beyond the measurement range. The instrument can set the transformation ratio of external voltage transformer to directly display the applied voltage value.

5. The instrument adopts large screen color high resolution touch LCD, Chinese menu, Chinese prompt, easy to operate.

6. The instrument is equipped with 232 interface, which can be extended.

7. The instrument has its own printer, which can print and display data.

8. Built in non power down memory can store 160 groups of measurement data.

9. The instrument is equipped with U disk interface for accessing test data.

10. Permanent calendar, clock function, time calibration.

11. The instrument has wide measuring range, high precision, good stability, small volume, light weight and convenient measurement.

III.Technical Parameters

(1) Basic range (maximum range)

(2) Expand the range

The voltage can be expanded to any value required by the voltage transformer (PT), and the other quantities can be adjusted automatically according to the transformer magnification. 

(3) Other parameters of the instrument 

1. Ambient temperature: -10℃~45℃

2. Relative humidity: ≤90%RH

3. Warm-up time:<5 minutes

3. Power supply: AC 220V±10% 50Hz±5Hz

4. Built-in power consumption<2200VA

5. Dimensions: 405×330×180mm

6. Instrument weight: 9.5Kg (not including test wire)

(4) Instrument test wiring:

1. Standard configuration: (4mm2+1.6mm2) Parallel sheath wire*10 meters, 1 yellow, green and red each (suitable for internal power supply test).

2. Optional: (6mm2+1.6mm2) Parallel sheath wire*10 meters, 1 yellow, green and red (for internal and external power supply testing).