Overview
The induction withstand voltage test of transformers and transformers is an important test to ensure that the quality of the transformer meets national standards. The longitudinal insulation induction withstand voltage test of the transformer winding's inter-turn, inter-layer, inter-segment and inter-phase insulation is an important item in the transformer insulation test. Based on the particularity of the longitudinal insulation test, it is necessary to apply a frequency multiplier power supply device to increase the test voltage of the insulation between windings to achieve the purpose of the withstand voltage test.
The triple frequency generator is designed and manufactured to meet the above requirements. It has been proven by the majority of users that it is simple to operate, has reliable performance, and can better meet the needs of the induction withstand voltage test of transformers and mutual inductors.
According to the national test standard "GB311.1-97", the induction test voltage of power transformers and voltage transformers should be approximately 2 to 3 times the maximum operating phase voltage. As we all know, the iron core of a transformer is close to saturation at rated frequency and rated voltage. If a test voltage greater than the rated voltage is applied to both ends of the winding of the tested transformer using a power frequency power supply, the no-load excitation current will increase sharply and reach an impermissible level. , it can be seen from the relational expression of induced potential that in order to apply a test voltage greater than the rated voltage without saturating the iron core, the method of increasing the power supply frequency (f) can be used, and a triple frequency power generator must be used.
Collapse and edit the working principle of this paragraph
The device is composed of three single-phase transformers. The primary windings of the three single-phase transformers are connected in a star shape and the secondary windings are connected in a star shape. Open delta, because the voltage applied to the primary winding is high and the iron core is saturated, the magnetic flux of the three single-phase transformers has fundamental frequency components and triple frequency components. The secondary open delta connection of the three single-phase transformers makes the fundamental frequency The components cancel each other out, thereby achieving open-triangle frequency-multiple voltage output, and by connecting an external single-phase voltage regulator to the winding, the triple-frequency voltage regulation can be achieved.