逆变弧焊电源峰值电流模式双闭环控制系统

Double close loops control system of peak current mode of inverter arc welding power supply

采用电压模式单闭环控制系统的逆变弧焊电源,系统动态响应速度慢,不能对主电路功率器件进行实时电流控制,中频变压器无抗偏磁能力,因此可靠性较差。所研制的逆变弧焊电源采用双闭环控制系统,内环实现了在每个开关周期对功率器件的峰值电流进行实时控制,提高了系统动态响应速度,消除了中频变压器偏磁现象;外环控制输出的平均电流,提高了输出电流的精度和系统的可靠性。

For the arc welding inverter, the voltage mode was usually adopted, which contained only one control loop. For this mode, the transient response was slow, and it couldn't provide the flux balance of the main transformer and current limited of power devices, which decreased the reliability of the power supply. In this paper, the peak current mode is adopted, which contains two loops. The inner loop controls the peak current, while the outer loop controls the average current. In each period, the peak current of IGBTs is controlled, therefore the flux balance is obtained and the transient response is greatly improved, while the precision of the output current and reliability of system are improved.