Medium and High voltage inverter anti-jamming common measures and maintenance

- Nov 20, 2017 -

High-voltage inverter anti-jamming common measures:

(1) The high-voltage inverter E-side and the control cabinet and the motor shell connected to be secured, grounding resistance should be less than 100Ω, can absorb surge interference.

(2) The input or output of high-voltage inverter is equipped with inductive ring filter. Flat and around 3-4 laps, helps to suppress higher harmonics (this method is simple, inexpensive).

(3) The above-mentioned magnetic ring filter can also be added according to the scene in the high-voltage inverter control signal terminal or analog signal to the input terminal.

(4) In the control cabinet equipped with high-voltage inverter, the power line and signal line should be separately run through the pipe, and the metal hose should be grounded well.

(5) analog signal line to use shielded cable, single-ended high-voltage inverter at the simulation.

(6) Interference can also be improved by adjusting the carrier frequency of the high-voltage inverter. The lower the frequency, the less interference, but the greater the electromagnetic noise.

(7) RS485 communication port connected with the host computer must use optical isolation transmission, in order to improve the communication system resistance

Interference performance.

(8) The power supply of the computer or instrument should be separated from the power supply of the high voltage inverter to avoid sharing an internal transformer.

(9) In the interference of instrumentation equipment should also be an independent shield, the market thermostat, PID regulator, PLC, sensors or transmitters and other instrumentation, should be equipped with metal shield shell and connected with the security. If necessary, the inductive magnetic ring filter described above can be retrofitted at the input of such meters.


High-voltage inverter installation environment in general requirements: the minimum ambient temperature -5 ℃, the maximum ambient temperature 40 ℃. A large number of studies have shown that the failure rate of high-voltage inverters increases exponentially with increasing temperature, and the service life decreases exponentially with increasing temperature. When the ambient temperature rises by 10 ° C, the service life of high-voltage inverters will be halved. In addition, the operation of high-voltage inverter is good, and the degree of environmental cleanliness also has a lot to do. Summer is a high voltage inverter failure period, only through good maintenance work, can reduce the occurrence of equipment failure, please be sure to pay attention to the user.

During the summer high-voltage inverter maintenance, should pay attention to the temperature of the inverter installation environment, regularly clean the dust inside the inverter to ensure smooth cooling air duct. Strengthen inspection to improve the frequency converter, motor and the surrounding environment. Check whether the fastening, to ensure the correct and reliable connection of all electrical circuits, to prevent unnecessary downtime.

Folding precautions

1, carefully monitor and record the display parameters of the inverter man-machine interface and found that anomalies should be immediately reflected

2, carefully monitor and record the ambient temperature of the frequency conversion room, the ambient temperature should be between -5 ℃ ~ 40 ℃. Phase-shift transformer temperature can not exceed 130 ℃

3, when the summer temperature is higher, the ventilation and heat dissipation of the inverter installation site should be strengthened. Make sure the ambient air does not contain excessive amounts of dust, acids, salts, corrosive and explosive gases

4, the summer is a rainy season, should prevent the rain water inside the inverter (such as rainwind outlet into the air duct)

5, the filter on the cabinet door should usually be cleaned once a week; such as more dust in the working environment, the cleaning interval should be shortened according to the actual situation

6, Inverter normal operation, a standard thickness of A4 paper should be able to firmly adsorbed on the door inlet filter

7, frequency conversion room must be kept clean and tidy, cleaning should be based on the actual situation at any time.

8, ventilation room, lighting must be good, ventilation and cooling equipment (air conditioning, ventilation fans, etc.) to normal operation.

Collapse maintenance items

1, with a plastic suction nozzle to thoroughly clean the cabinet inside and outside the vacuum cleaner to ensure that no dust around the equipment.

2, check the ventilation of the inverter room, lighting equipment to ensure that the ventilation equipment to normal operation.

3, check the connection between the inverter cable should be correct and reliable

4, check all the grounding in the inverter cabinet should be reliable, no rust at the grounding point

5, every six months (within) should be tightened once the inverter cable internal connection nut

6, After the inverter resumes operation for a long time, it should measure the inverter (including phase-shifting transformer and main circuit of bypass cabinet) and should use 2500V megger. After the test insulation qualified, can start the frequency changer

7, check the tightness of all electrical connections to see whether there is any abnormal traces of the discharge circuit, whether there is a smell, discoloration, cracks, damage and so on

8, after each maintenance of the inverter, it is necessary to carefully check for missing screws and wires, etc., to prevent small metal objects caused by short-circuit inverter. In particular, major changes to the electrical circuit to ensure that the electrical connection cable connection is correct and reliable, to prevent 'anti-power transmission' accident.

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