The so-called "automatic anti interference", namely instrument inside a detection device, can detect external disturbance signal amplitude and phase, and the related information transmitted to the CPU, CPU output instructions to "reverse interference source control device", this device will produce a within an instrument and disturbance signal amplitude values are the same but opposite phase of "anti interference signals", and "interference signals" superposition offset, in order to achieve the purpose of anti-jamming. Because throughout the test process, "anti interference source" automatic generation, users need intervention, which we call "automatic anti interference source".

Dielectric loss Angle tangent also called dielectric loss factor or simply as dielectric loss. Measure dielectric loss factor is a sensitivity high test items, it can be found that electric power equipment insulation overall damp or degradation metamorphic and small volume subjects were not connected device transfixion and local defects. For example: some Taiwan transformer casing, normal tg value for 0.5%, and when damp tg value of 3.5%, after two data are 7 times, But with measuring insulation resistance testing, damp before and after the numerical varies slightly.
Due to measure dielectric loss factor to reflect such flaws with high sensitivity, so in electrical manufacturing and power equipment transferring and preventive test have been widely used. Transformer, generators, breaker etc of electrical equipment testing "rules" dielectric loss is the rules.

The dielectric loss of tester technology develops very quickly, before in power system is widely used in QS1 furbenicillin bridge is being intelligent dielectric loss tester replaced, the new generation of dielectric loss tester are built-in booster equipment and standard capacitance, and have the operation is simple, accurate data, test result read is convenient wait for a characteristic. Although at present the dielectric loss test technology develops very quickly, but compared with international level, and in many ways is still a big gap, gap mainly manifested in the following aspects:
(1) the anti-interference ability
Due to the dielectric loss testing is a sensitivity high project, thus testing data also vulnerable to external electric field of interference, at present the dielectric loss tester take anti-interference methods are mainly: pour phase method, phase shifting method, different frequency method, etc. Although these methods can resolve in a certain extent under disturbance, but when outside interference strong circumstance, still can produce large deviation.
(2) reverse connect method measurement precision problem
On-site many electric power equipment have been grounded, and therefore must use reverse connect method for testing, but the reverse connect, the influence factors of test data more, often data can have very large deviation, especially when subjects were smaller (such as product capacity casing), high voltage wires mopping the floor during test (some dielectric loss to the selection of high pressure tester, although can mop the floor wire is used, but on earth leakage current larger), the serious influence testing accuracy.

1, pour mutually method
The instrument work power positive and negative twice in testing, will pour two test results analyze and process the anti-interference techniques purpose, this method in interference is very weak circumstances have certain effect.
2, phase shifting method
Thinking price-per-barrel "pour mutually method", just will work power pour phase to phase shifting to interference signals same phase and achieve abate the effects of interference purpose, practice shows that the interference in strong cases, data still deviation is bigger.
3, different frequency method
This is in last few years developed a kind of method, its basic principle is not work power frequency 50Hz, namely and power frequency sampling signal is different, so for two different frequency signals (test current and interference current) of superposition, through the simulation filters and digital filter for signal frequency signal attenuation filtering, work, in order to achieve the purpose of anti-jamming, practice shows that this method is better than the anti-interference ability of "pour mutually method" and "phase shifting method", but in some occasions, due to disturbance effect, the data are still deviation, appear even a negative value. In addition, due to their own principle characteristics exist several aspects of contradiction:
(1) the frequency of selection problem: frequency and power frequency closer, anti-interference ability weaker, but the better equivalence, Frequency and power frequency more far, anti-interference ability stronger, but the worse equivalence.
(2) to enhance equivalence, some instrument used the "double frequency", and then choose two kind of frequency testing, such as 40Hz and 60Hz, but the problem is two kinds of frequency test results do not agree to do? Only a simple average process can and power frequency equivalent?
(3) there are simulated filter phase shift problem, fixed phase shift by computer compensation, but when the temperature co

Insulation resistance and size, can effectively reflect the overall moisture insulation, impurity and severe defects such as overheated aging, and use ZhaoOuBiao measuring insulation resistance operation is simple, safe, clear concept and ZhaoOuBiao cheap price, etc, so in high voltage electrical equipment insulation testing in the most widely used ZhaoOuBiao.
But the use of ZhaoOuBiao test insulation, has the following obvious disadvantages:
(1) general dc voltage ZhaoOuBiao 2.5 KV than some below, the working voltage of electric equipment is much lower, when the equipment has some defect, high-pressure leakage current than under low pressure much, i.e. under high pressure insulation resistance than low resistance of a much smaller.
(2) general dc current output in the ZhaoOuBiao 2mA below that, when test equipment of the equivalent capacitance larger (such as power transformer, generator), charging speed is slow, difficult to measure accurate data.

Try as our special TE3805 type hv insulation tester, not only has the test absorption than and polarization index function outside, still have polarization curve shows and print function, can reflect the whole process of insulation resistance testing the change process for the analysis judgment equipment insulation provides a good method.

TE3805 type hv insulation tester built-in CPU can according to different ambient temperature automatic conversion insulation resistance to standard temperature of numerical.

Add: oil-immersed transformer insulation resistance of the temperature conversion coefficient table
Temperature difference (0 c) 5 10 15 20 25 30 35 40 45 50 55 60
Scaling factor 1.2 1.5 1.8 2.3 2.8 3.4 4.1 5.1 6.2 7.5 9.2 11.2

TE100 type of maximum output current is TE200 type for 200A 100A, TE600 type, for 600A. Compared with similar products in the current source, difference is very big still:
1, large current and deft and perfect union, for example: TE200 type in guarantee 200A output current at the same time, the weight only 5.5 kg or so, and other companies to achieve similar products 100A type 15kg.
2, can long time continuous output large current, and some similar products only can instantly output large current, namely "pulsing" power, at breakdown &switch contacts oxidation film, the difference on the ability is huge.
3, nc constant-current source type, output current output by software options, no mechanical adjusting devices, stable and reliable.

Measuring insulation resistance is understanding the electrical equipment insulation of the easiest one of the most commonly used methods. Large capacity test of product by measuring than and polarization index can absorb more accurately reflect the insulation situation, but try product polarization curves for the relative insulation resistance changes over time curves can be more accurately reflect the insulation, try product, therefore, for some high-capacity try product test of insulation resistance, but also test polarization curves.

High voltage circuit breaker mainly depends on the resistance of the conductive circuit breaker dynamic and static contacts the contact resistance between. The existence of contact resistance, increase the conductor at the time constant of the loss, make the contact point, the temperature of the size of its value directly affects the normal work of current-carrying capacity, in a certain extent influence of short-circuit current cutting ability. Therefore, breaker each phase conductive loop resistance is breaker installation and maintenance, quality checking an important data