Understand why the low voltage frequency converter has failed

Low-voltage inverters and high-voltage inverters are all types of inverters. The inverter is a kind of power control system that can play a role in energy saving and power saving. In the process of using the low voltage frequency converter, some faults may occur. After the fault is found, the cause of the fault can be quickly solved. Here's a look at the causes of the low voltage frequency converter's failure.

External electromagnetic interference can cause malfunctions:

If there are interference sources around the inverter, they will invade the inverter through radiation or power lines, causing the control circuit to malfunction, causing abnormal operation or shutdown, and even damaging the inverter in severe cases. It is very necessary to take noise suppression measures outside and eliminate interference sources. Specific solutions are: First, to minimize the control circuit wiring distance, and its separation from the main line; Second, the inverter ground terminal should be carried out in accordance with regulations, can not be mixed with welding, power grounding; three is the inverter input installation Noise filter to avoid interference from incoming power lines.

Faults caused by environmental problems:

The frequency converter belongs to the electronic device device, and there are requirements for detailed installation and use environment in its specifications. Vibration is the main cause of mechanical damage to electronic devices. For areas with large vibration shocks, vibration isolation measures such as rubber should be used; moisture, corrosive gases, dust, etc. will cause electronic devices to rust, poor contact, and low insulation. Short circuit; temperature is an important factor affecting the life and reliability of electronic devices, especially semiconductor devices, should be installed according to the environmental conditions required by the device or avoid direct sunlight.

It is necessary to regularly check the air filter and cooling fan of the inverter. At present, the cooling fan of the inverter used in the oil plant is seriously damaged, and part of the frequency conversion working environment is relatively poor, which seriously affects the heat dissipation and air circulation, resulting in the inverter tripping and overheating alarm in the hot season.

Parameter settings and device-induced faults:

Faults mainly occur in low-voltage inverters used for injection pumps. The main manifestations of failures are that they do not immediately trip when starting, but trip during operation. The possible reasons are unstable pump operating conditions, excessive line pressure, too short acceleration time setting, too short deceleration time setting, large torque compensation setting, excessive no-load current at low speed, and electronic thermal relay. Improper setting, the operating current is set too small, causing malfunction.

Motherboard and main circuit failure:

Due to the long service life and some unexpected reasons, the main board and the main circuit are damaged. This kind of failure will inevitably cause the damage and scrap of the components, which is the main part of the inverter maintenance cost. There are damage to the rectifier block, damage to the charging resistor, burn-out of the inverter module, damage to the filter capacitor, damage to the motherboard power board, and failure due to improper maintenance.

Most of the inverter overheating alarm failure, in addition to the reasons for the damage of the cooling system fan, there is a main reason is the lack of routine maintenance, inverter radiator dust accumulation is serious, affecting heat dissipation.