梅州干式变压器：高压试验梅州干式变压器的用途和特点

高压试验梅州干式变压器的用途和特点 　　
1.用途和特点
高压试验梅州干式变压器简称为试验梅州干式变压器。电气设备出厂、交接或大修后，应当进行交流耐压试验，实际考核设备绝缘承受过电压的绝缘水平。所以无论在制造部门、运行部门的高压实验室或试验现场，应设有交流耐压试验设备。
试验梅州干式变压器一、二次绕组具有很大的电压比，一次电压为0.4kV，3kV，6kV，10kV不等，二次电压可制成100—2000k V或更高，容量可为3—9000kVA.
高压试验梅州干式变压器可用于作工频、冲击和直流耐压试验。这里主要叙述工频耐压试验梅州干式变压器。这种试验梅州干式变压器利用其二次侧所感应的工频高电压，对各种电工产品和绝缘材料等进行绝缘性能试验。
试验梅州干式变压器和梅州干式变压器的原理相同，所不同的是试验梅州干式变压器的工作电压高，使用时间短，温升小.一般没有散热器.另外，试验梅州干式变压器的负载较小，且多为电容性负载，试验梅州干式变压器的容量比梅州干式变压器相对的要小。

试验梅州干式变压器的特点是:
1)高电压，小电流。其二次额定电压根据被试品所要求的试验电压而定.单台试验梅州干式变压器的额定电压为50kV， l00kV, 1500V, 250kV, 500kV, 750kV。在额定电压下，应无局部放电量。电压超过750kV的试验梅州干式变压器，通常采用多台串级式结构。
2)一般为单相，户内装置(也有做成户外装置的).油浸自冷式，高压绕组通常一端接地。
3)二次绕组首末端绝缘水平不同。首端为高电位，而末端直接接地或通过电流表接地。
4)产品多为短时工作制，允许使用时间为半小时.但对于某些试验，例如瓷套管的外绝缘污秽试验、线路的电晕减脸以及电统试验等，则要求试验梅州干式变压器的使用时间为数小时乃至长期连续使用。
5)制造时设计和工艺要求较高，由于工作电压高，绝缘结构对试验梅州干式变压器的整体尺华盈非晶合金变压器有限公司寸有决定性的影响.因为绝缘层厚，器身一般均要求真空干操, 100kV以上要求真空注油。
6)试验梅州干式变压器输出电压波形应尽量接近正弦波。为了减少由于空载电流的谐波分量通过调压器和梅州干式变压器的阻抗以后，产生波形畸变，磁通密度应选在铁心磁化曲线的线性段；同时要选用波形畸变小的调压设备，必要时加滤波装置。
7)阻抗电压不宜过大。试验梅州干式变压器的二次电流一般为电容性电流，当二次电流流经调压器和试验梅州干式变压器的阻抗时，将导致输出电压超过由电压比所确定的效值，所以试验梅州干式变压器的阻抗电压不宜太大.否则可能影响测试结果的准确性，同时还会降低试验设备的短路容量.但如太小，短路电流可能过大.故单台梅州干式变压器的阻抗电压一般为4.5%—10%.多台串级时，则可达40%左右。

Uses and characteristics of high voltage test transformer

(1) Uses and Features
High voltage test transformer is referred to as the test transformer. Electrical equipment factory, the AC voltage test should be conducted after the handover or the overhaul, the actual assessment of equipment insulation withstand voltage insulation level. Therefore, regardless of the manufacturing sector, running, high pressure laboratory or test site should be equipped with the AC voltage test equipment.
A lot of voltage test transformer primary and secondary windings than once voltage is 0.4kV, 3kV, 6kV, 10kV range, the secondary voltage can be made of 100-2000k V or higher capacity for 3-9000kVA.
High voltage test transformer can be used to conduct their frequency, impact, and the DC voltage test. Here mainly describes the power frequency withstand voltage test transformer. Such a test transformer secondary side sensing power frequency high voltage insulation performance tests on a variety of electrical products and insulation materials.
Test transformers and power transformers on the same principle, the difference is that the test transformer voltage, use a short time, a small temperature rise. Generally do not have radiator. In addition, the test transformer load is small, and mostly capacitive load test transformer capacity than the power transformer to.

The characteristics of the test transformer is:
1) high-voltage, low current. The secondary rated voltage of the test items required by the test voltage and a single test transformer rated voltage of 50kV, l00kV, 1500V, 250kV, 500kV, 750kV. At rated voltage should be no partial discharge. Voltage over 750kV transformer of the test, usually with multiple cascade structure.
2) is generally single-phase, indoor installations (also made of the outdoor unit). Oil-immersed self-cooled, high voltage winding is usually grounded at one end.
3) secondary winding first end of the insulation level. The first side of the high potential terminal directly to ground or through the ammeter ground.
4) The products are mostly short-time working allows the use of time and a half hours but for some tests, such as external insulation of the ceramic casing contamination test, the line corona minus the face and the electrical system test requires the test transformer The use of time for a few hours and even long-term continuous use.
5) manufacturing design and process requirements higher, due to the high operating voltage, insulation structure have a decisive impact on the overall size of the test transformer insulation thickness, the body of generally require a vacuum to dry operation, 100kV vacuum oiling the above requirements.
6) Test transformer output voltage waveform should be as close as possible to a sine wave. In order to reduce no-load current harmonic after the voltage regulator and transformer impedance, resulting in waveform distortion, the flux density should be selected in the linear section of the core magnetization curve; to use the waveform distortion of the voltage regulator device, if necessary when you add a filtering device.
7) the impedance voltage is not too large. Test the transformer secondary current is generally capacitive currents when the impedance of the secondary current flowing through the regulator, and test the transformer will cause the output voltage exceeds the voltage ratio as determined by the efficiency value, so the test transformer impedance voltage should not be too or may affect the accuracy of test results, while also reducing short-circuit capacity of the test equipment. However, if too small, short-circuit current may be too large. single transformer impedance voltage is generally 4.5% -10% more than one string level, up to 40%.