Insulating oil dielectric loss tester measuring range and test procedure

Insulation oil dielectric loss tester, professional manufacturer, professional production technology, manufacturing professional quality, Shanghai 100 Test Electric Technology Co., Ltd. is one of the few production-oriented enterprises in East China, choose 100 test, is to choose to rest assured.

1, dielectric loss

What is the dielectric loss: The energy loss caused by the hysteresis effect of the dielectric conductance and the dielectric polarization of the insulating material under the electric field. Also called medium loss, referred to as dielectric loss.

2, dielectric loss angle δ

Under the action of the alternating electric field, the included angle (power factor angle Φ) between the current phasor and the voltage phasor flowing in the dielectric (δ). Referred to as the dielectric loss angle.

3, dielectric loss tangent tgδ

Also known as the dielectric loss factor, refers to the dielectric loss tangent, referred to as dielectric loss tangent. The dielectric loss factor is defined as follows:

If you obtain the current phasor and voltage phasor of the sample, you can get the following phasor map:

The total current can be decomposed into the combined capacitance current Ic and resistance current IR, so:

This is the tangent of the loss angle δ=(90°-Φ). Therefore, the current digital instrument is essentially a dielectric loss factor measured by measuring δ or Φ.

Measuring dielectric loss is a traditional and very effective method for judging the insulation of electrical equipment. The decrease in insulation capacity is directly reflected in the increase in dielectric loss. Further analysis can be made of the reasons for the drop in insulation, such as: moisture in the insulation, contamination of the insulating oil, aging deterioration, and so on.

While measuring the dielectric loss, the capacitance of the test sample can also be obtained. If one or more of the multiple capacitive screens are shorted or disconnected, the capacitance will change significantly. Therefore, the capacitance is also an important parameter.

4, power factor cosΦ

The power factor is the cosine of the power factor angle Φ, which means the proportion of the active power P in the total apparent power S of the tested product. The power factor is defined as follows:

Some dielectric loss testers are accustomed to display power factor (PF: cosΦ) instead of dielectric loss factor (DF: tgδ).

General cosΦ

The standard channel of the high-voltage capacitance bridge inputs the standard capacitor current, and the sample channel inputs the sample current. The tgδ is measured by comparing the current phase difference, and the capacitance of the test sample is measured by the output current ratio. Therefore, using a bridge to measure the dielectric loss also requires carrying a standard capacitor, a boost PT, and a voltage regulator. Wiring is also very cumbersome.

6, high pressure dielectric loss measuring instrument

The abbreviation dielectric loss meter refers to a new type of instrument that uses the principle of bridges and applies digital measurement technology to automatically measure the tangent of dielectric loss and the capacitance. Generally include three parts of high voltage bridge, high voltage test power supply and high voltage standard capacitor.

The FS3001 utilizes the latest anti-jamming principle and adopts Fourier change digital waveform analysis technology to calculate the standard current and the sample current. The FS3001 has strong anti-interference ability and accurate and stable measurement results.

7, external application

Use an external high-voltage test power supply and a standard capacitor for the test. Calculate the result of the dielectric loss meter according to a certain proportional relationship.

8, internal facilities

Use the high-voltage power supply inside the dielectric loss meter and the standard device to test and obtain the measurement result directly.

9, positive connection

The method used to measure ungrounded samples. The dielectric circuit measurement circuit is at ground potential.

10, anti-wiring

The method used to measure the grounded test sample, the dielectric loss tester measuring circuit is at a high potential during the measurement, and he bears all test voltages with the housing.