Inverters have entered a stage of high performance, multi-functionality, miniaturization, and low cost, and are developing towards intelligence. Because inverters are high-tech products that control high-voltage electricity with low-voltage power, the technology they require is more complex. For practical application reference, this paper discusses the overvoltage phenomenon that occurs during inverter application and proposes several solutions. 1. Causes of Inverter Overvoltage Inverter overvoltage refers to a voltage exceeding the rated value, primarily manifested on the DC voltage on the inverter's DC bus. During normal operation, the inverter's DC voltage is the average value after three-phase full-wave rectification. If the line voltage is 380V, the average DC voltage is Ud = 1.35U = 513V. During overvoltage, the energy storage capacitor on the DC bus is charged, and the voltage rises to approximately 760V, triggering the inverter's overvoltage protection and causing a shutdown. Inverter overvoltage is mainly regenerative overvoltage. The main causes of regenerative overvoltage are: the inverter's deceleration time is set too short during heavy load deceleration, the motor is affected by external forces (such as fans) or potential energy loads (elevators, hoisting equipment) being lowered. These cause the actual motor speed to be higher than the inverter's command speed, the motor is in a generating state, the slip is negative, and a braking torque that hinders rotation is generated. The load's kinetic energy is "regenerated" into electrical energy. This electrical energy charges the inverter's DC energy storage capacitor through the inverter's inverter freewheeling diode, causing the bus voltage to rise, i.e., regenerative overvoltage. 2. Several Methods to Solve Inverter Overvoltage Inverters frequently encounter overvoltage phenomena during commissioning and use. To prevent overvoltage from damaging the inverter's internal circuitry, its protection function will activate, causing the inverter to stop running, thus preventing the equipment from working properly. Therefore, measures must be taken to eliminate overvoltage to prevent faults. Overvoltage is one of the most common faults in inverter operation. DC braking and regenerative braking are the most important means to prevent overvoltage, and regenerative braking is the only effective measure to solve the inverter overvoltage caused by the motor being in a generating state due to external forces. Common solutions include: (1) extending the inverter deceleration time; (2) DC braking; and (3) regenerative braking. 2.1 Extending the Inverter Deceleration Time If there are no special requirements for stopping time or location, extending the inverter deceleration time or using a free-stop method can be adopted. [b][align=center]For details, please click: Discussion on Several Solutions to Inverter Overvoltage[/align][/b]