Triple frequency generator working principle and using method
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The device is composed of three single-phase transformers, and its working principle is shown in Figure 1:
The primary windings of the three single-phase transformers are connected in a star shape, and the secondary windings are connected in an open triangle. Because the voltage applied to the primary winding is high and the core is saturated, the fundamental frequency components and times of the three single-phase transformer fluxes are The frequency withstand voltage tester component, the three single-phase transformer secondary open delta connection cancels the fundamental frequency component, thereby implementing the voltage output of the open-frequency multi-frequency withstand voltage tester, and the external single-phase voltage regulator can be realized through the winding Adjustment of the multiplier output voltage.
A, B, C frequency doubling voltage tester console power input three-phase 380V, A2, B2, C2 octave voltage tester three-phase input 0-425V, XA, XC single-phase input 150HZ, XA1, XC1 single phase Output 150HZ
QF air switch / KA AC contactor / ST stop button / SB2 timing switch / SB1 start button / SQ1 zero switch / KA current relay / T regulator / V2 frequency multiplier withstand voltage output voltmeter / HL2 start signal / HL1 stop Signal light / KT time relay / HA alarm / A frequency doubled withstand output current meter.
1. Connect the power supply and the tested product according to the wiring diagram. The power supply A, B, C is connected to the AC three-phase 380V, A2, B2, C2 to the input terminal of the multi-frequency withstand voltage tester, XA, XC connected to the multi-frequency withstand voltage The output terminal of the tester, XA1, XC1 is connected to the low voltage side a （or b, c） phase of the transformer and 0, and the remaining bc and A, B, and C phases are suspended, and the equipment is grounded.
2. Turn on the power, close the air switch, the multi-frequency withstand voltage tester is energized （no output）, the voltage regulator is regulated on the secondary side of the multi-frequency withstand voltage tester, the green indicator light of the console is on, and the time relay is set as required. The withstand voltage time is generally 40 seconds.
3. Return the regulator to zero and activate the red button （if the regulator is not at the zero position, the red button will not start）, turn the regulator clockwise, and there is a voltage output.
4. Adjust the voltage regulator to the voltage required for the test, open the pressure timer switch, closely monitor the ammeter and voltmeter on the test object and the console, and make detailed records. After the time has elapsed, the buzzer is called, the time relay is turned off, the voltage regulator is stepped back to zero, the test is over, and the withstand voltage passes.
5. During the test, when the test article shows inter-turn, inter-layer or inter-segment, phase-to-phase insulation breakdown, the test current increases in the control loop, and the overcurrent relay immediately trips and loses power, indicating that the withstand voltage test failed.
6. The use time is preferably no more than 1 hour.
The output of the device is a 150Hz single-phase voltage. If the single-phase test product can be completed at one time, if it is a three-phase transformer, the voltage applied by the test is relative ground, and the rotation is generally three times to complete the induction withstand voltage test of one transformer. The order is a0, b0, c0.
L1 stop signal / KT time relay / HA alarm / A frequency doubled withstand output current meter
Triple frequency generator considerations