Daily inspection and maintenance of frequency converter


Inverter is a kind of power control equipment which uses frequency conversion technology and microelectronics technology to control AC motor by changing the frequency mode of motor working power supply.The inverter is mainly composed of rectifier (AC to DC), filter, inverter (DC to AC), braking unit, driving unit, detection unit, micro processing unit, etc.The inverter adjusts the voltage and frequency of the output power supply by breaking the internal IGBT, and provides the required power supply voltage according to the actual needs of the motor, so as to achieve the purpose of energy saving and speed regulation. Because of long-term high frequency use, the frequency converter of the factory must be inspected, maintained and maintained.

Now let's talk about the inspection contents and maintenance methods.

  • Daily inspection of frequency converter Hearing, vision, touch and smell, etc. General inspection contents include:

(1) Whether the surrounding environment, temperature and humidity meet the requirements.

(2) Whether the air inlet and outlet of the frequency converter are blocked by dust.

(3) Whether the noise, vibration and smell of the inverter are within the normal range.

(4) Whether the operation parameters and panel display of frequency converter are normal.

  • Maintenance of low voltage small inverter

Low voltage small inverter refers to the low-power inverter working on the low-voltage power grid 380V (220V). Most of them are installed in the control cabinet in the form of vertical wall hanging, and their regular maintenance mainly includes:

(1) Regular inspection of dust removal

(2) Regularly check the main parameters of the circuit, such as: the main circuit and control circuit voltage is normal.

(3) Regularly check the peripheral circuit and facilities of the inverter, such as whether the brake resistance and contactor are normal, and whether the wire connection is loose.

(4) According to the maintenance information to judge the life of components, such as electrolytic capacitors and fans, when the service time exceeds the life, they should be replaced in time.

  • Regular maintenance of high voltage cabinet inverter High voltage inverter refers to the inverter whose working voltage is above 6kV
  • Generally, they are cabinet type, and their regular maintenance and repair refer to the above maintenance and repair terms of low-voltage inverter, as well as the following contents:

(1) Regular maintenance of bus bar: deformation, looseness and insulation damage.

(2) Regularly check the rectifier and inverter of the main circuit, such as regularly measure the power semiconductor devices with a multimeter.

(3) Check the wiring block, such as whether the terminal block is aging or loose, and whether the wire skin is damaged.

(4) If possible, the filtered DC waveform, inverter output waveform and input power harmonic component can be measured.