Frequency inverter circuit maintenance and fault case analysis are important contents in the field of electrical engineering. The following is an overview of inverter circuit maintenance and an analysis of some fault examples:

1.Frequency inverter circuit maintenance overview

Frequency inverter circuit maintenance involves the detection, diagnosis and repair of the internal circuit of the inverter. Due to the complexity of the internal circuit of the inverter, and involves high voltage, high frequency and other characteristics, special care needs to be taken during maintenance. During the repair process, the following steps are usually followed:

1. Troubleshooting: First of all, by observing the operating status and alarm information of the inverter, the type of fault is initially determined. Then, professional detection tools are used to detect the circuit and determine the fault point.

2. Circuit analysis: After determining the fault point, it is necessary to analyze the relevant circuit to understand the working principle of the circuit and the possible causes of the fault.

3. Fault repair: According to the circuit analysis results, take appropriate repair measures. This may include replacing damaged components, repairing broken lines, or adjusting circuit parameters.

4. Test and verification: After the repair is completed, the inverter needs to be tested and verified to ensure that the fault has been completely eliminated and the inverter can operate normally.

2.Fault case analysis

Example 1: The frequency inverter module is damaged

● Fault phenomenon: The inverter suddenly stops during operation and cannot be started again. The inverter module is found to be damaged.

● Fault analysis: Inverter module damage may be caused by overload, overvoltage, overheating and other reasons. In addition, the failure of the drive circuit may also cause damage to the inverter module.

● Maintenance measures: Replace the damaged inverter module, and thoroughly check the drive circuit. Ensure that the drive circuit is normal, and then the main circuit electrical test machine.

Example 2: Frequency converter black screen fault

● Fault phenomenon: The frequency converter suddenly has a black screen after normal operation for a period of time and cannot be operated.

● Fault analysis: black screen failure is usually related to the power circuit. The capacity of the power filter capacitor may be insufficient or damaged, resulting in the failure of stable output of the power supply.

● Maintenance measures: Replace the damaged power filter capacitor, and test the stability of the power circuit. After ensuring that the power circuit is normal, the inverter is powered on.

Example 3: Frequency converter overcurrent tripping

● Fault phenomenon: frequency converter in the start or operation process frequently appear over current tripping phenomenon.

● Fault analysis: over-current trip may be caused by motor gridlock, excessive load, cable short circuit and other reasons. In addition, improper parameter setting of the inverter may also lead to overcurrent tripping.

● Maintenance measures: check whether the motor and load are normal, eliminate cable short circuit and other faults. At the same time, adjust the parameter Settings of the inverter to ensure that it matches the load characteristics.

Example 4:Frequency inverter alarm parameters are abnormal

● Fault phenomenon: The frequency converter displays abnormal alarm parameters during operation, such as DC bus undervoltage, DC overvoltage, etc.

● Fault analysis: Abnormal alarm parameters are usually related to the power circuit, detection circuit or control circuit of the inverter. It may be caused by damage to related components or poor circuit connection.

● Maintenance measures: Check the relevant circuits and components according to the alarm parameters. Replace damaged components, repair broken lines or adjust circuit parameters. At the same time, the inverter is comprehensively tested and verified to ensure that the fault has been completely eliminated.

3.Summarize

Frequency inverter circuit maintenance needs to have certain professional knowledge and practical experience. In the maintenance process, it is necessary to carefully analyze the fault phenomenon and alarm information, combined with the circuit diagram and related data to judge and repair. At the same time, it is necessary to pay attention to safe operation norms to avoid dangerous accidents such as electric shock. Through continuous learning and practice, we can improve the skill level of inverter circuit maintenance and provide a strong guarantee for the production and operation of enterprises.