1. Precautions
a、 Before using the variable frequency power supply, it is necessary to carefully read this manual, especially strictly follow the precautions specified in the instructions, otherwise it may cause damage to the variable frequency cabinet.
b、 This device must be operated by professionals, and special attention should be paid to safety during use.
c、 Due to the fact that the working power supply of the variable frequency power supply is directly obtained from the 380V AC power supply without isolation treatment, both output terminals of the variable frequency power supply cannot be directly grounded or short circuited, otherwise it will cause damage to some components in the variable frequency cabinet.
d、 The leakage protector must be removed from the working power supply, otherwise the leakage current to ground when the variable frequency power supply device is started will cause the leakage protection switch to operate and lose power.
e、 During the series resonance test, if the initial boost does not find the resonance point, do not raise the output voltage of the frequency converter cabinet too high to avoid a rapid increase in voltage near the resonance point and difficulty in controlling the boost speed. Generally, after finding the resonance point at low voltage, the voltage is raised to the specified value. It is recommended to use the "Fine Adjustment" button.
f、 During the experiment, if the variable frequency power supply needs to work for a long time and the output voltage is low, it will cause an increase in the transistor consumption of the amplification circuit. It is necessary to maintain its output voltage not lower than 300V. This problem can be solved by adjusting the transformation ratio of the excitation transformer and other methods.
g、 The load capacity of the variable frequency cabinet must be within the range specified by the curve in Figure 32, and it is strictly prohibited to carry high current loads at low voltage. The lower part of the curve is the safe zone. Exceeding this area will increase the transistor loss, and in severe cases, it may cause damage to the transistor in the amplification circuit. When the curve is exceeded and working above the curve, the output voltage and output current on the screen will flash as prompts. If the experiment continues, a trip signal will be issued in the frequency conversion cabinet, and the screen will display "power curve protection", and an alarm sound of "beep beep beep" will be heard in the control box. At this point, it is necessary to change the transformation ratio of the intermediate boosting transformer or reduce the load current in order to continue the test.
h、 It must be emphasized that taking the 450kW variable frequency power supply as an example: the output power of this variable frequency power supply is 450kW instead of 450kva, and it is strictly prohibited to carry pure capacitive or pure inductive loads. If pure reactive load is required, it is strictly prohibited to exceed 450kva, otherwise it may cause excessive consumption of the transistor in the amplification circuit and damage.
i、 After the experiment is completed, the voltage should be reduced to zero before opening the circuit.
j、 The working frequency of the frequency conversion cabinet is in the range of 20-300Hz, and frequencies below 20Hz and above 300Hz are prohibited from use.
k、 After the variable frequency power supply stops working, do not immediately touch the conductive parts of the variable frequency power supply. The charge on the capacitor components in the variable frequency power supply cabinet may not be released immediately, which may endanger personal safety.
l、 Before conducting maintenance on the variable frequency power supply, please confirm that the charges of each capacitor component have been fully discharged.
m、 When the protection action of the variable frequency power supply is activated, the power supply should be disconnected first to check the hardware circuit and equipment, and then powered on after confirming that the equipment and wiring are correct. Start the variable frequency power supply without load and confirm that the equipment itself has no problems before continuing the power on test.
n、 Disconnect the power supply and wait for ten seconds before restarting the power supply for this device to function properly.
o、 The control circuit switch labeled as "control switch" is used to control small current circuit power supply. When in the disconnected position, the variable frequency power supply cannot start, and the control box issues an alarm of "communication failure of variable frequency power supply".
2. Daily maintenance
① Try to avoid prolonged operation of the variable frequency power supply device under severe detuning conditions.
② Regularly check the internal wiring and screw fastening of each contact of the frequency conversion cabinet device to prevent loosening.
③ This device should be stored in a dry, clean area that is not easily exposed to rain. When not in use, cover with a dust cover to prevent dust from entering the cabinet through the air duct.
④ During transportation, the frequency conversion cabinet is secured with specialized straps to prevent loosening and slipping.
⑤ When the frequency converter cabinet malfunctions and cannot be handled, it should be promptly reported to Changsha Wote Electric Co., Ltd.
⑥ The display screen of the control box should not be exposed to direct sunlight. The control box should have anti vibration measures during transportation.
⑦ The connectors in the device are prone to damage, so care should be taken during use to prevent dirt from blocking them.
⑧ When using fiber optic cables, attention should be paid to preventing bending, twisting, and squeezing of the fiber optic cables; And stay away from sources of fire. When using the plug, align it with the positioning notch and do not apply too much force. After use, the fiber optic cable should be properly stored and placed in an appropriate location to prevent moisture.
The non-partial discharge variable frequency power supply can be used for AC withstand voltage test and partial discharge test of all electrical equipment. The excitation transformer is used to excite the series or parallel resonant circuit. By adjusting the output frequency of the variable frequency power supply, the inductance L of the reactor in the circuit and the capacitance C of the test object resonate. The resonant voltage is the voltage applied to the test object. Or it is directly output to the primary of the transformer through the intermediate transformer for inductive withstand voltage test.
The non-partial discharge variable frequency power supply is the main component of the complete test system. The test system is suitable for:
1. Inductive withstand voltage and partial discharge test of power transformers.
2. AC withstand voltage and partial discharge test of mutual inductors, etc.
3. AC withstand voltage test of power cables.
4. AC withstand voltage test of GIS combined electrical appliances.
5. AC withstand voltage test of capacitive equipment such as circuit breakers, disconnectors, insulators, bushings, etc.
6. Suitable for power frequency withstand voltage test of large generator sets.
7. Suitable for power supply for large ground grid testing.
Kvtester Electronics Technology Co.,Ltd. is a high-tech enterprise specializing in power testing, testing, research and development, production, and sales of testing equipment. It has been engaged in the electrical testing industry for many years, and its products are of high quality. We welcome customers to come and purchase. Service hotline: 0086-27-81778799, to learn more, visit the official website: www.kvtester.com
