High frequency pipe welding machine is an electromechanical system that realizes high-frequency welding. The high-frequency welding pipe machine consists of a welding pipe machine and a welding pipe forming machine. The high-frequency welding pipe machine generally consists of two parts: a high-frequency generator and a feeding device. The function is to generate high-frequency current and control it. The forming machine consists of an extrusion roller frame. Its function is to squeeze the parts melted by high-frequency current, remove the oxide layer and impurities on the surface of the steel plate, and make the steel plate fully fuse into one.
According to the specific load, the frequency range of the AC power supply is between 100.1 and 50KH. In order to adjust the inverters according to the load, all inverters are connected in parallel to the matching transformer. The transformer has several parallel main windings and one secondary winding. The turn ratio of a transformer is fixed. The output capacitor consists of several parallel capacitor modules. The capacitor is connected in series with the inductance coil, so the output circuit is also compensated in series. The function of a capacitor is to compensate for reactive power according to the requirements of the induction coil, and through this compensation, the resonant frequency of the output circuit reaches the required value. The frequency control system aims to ensure that the transistor always operates at the resonant frequency of the system. The resonant frequency is determined by measuring the frequency of the output current. Then use this frequency as the time base signal for opening the transistor.
The output power of the induction heating system is controlled by controlling the output current of the inverter. The above control is completed by the power control card used to control the transistor driver. The output power reference value is provided by the power reference potentiometer on the IMC control panel, or output to the control system from an external control panel.
After transmitting this value to the system controller, it will be compared with the DC power value measured by the rectifier unit measurement system. The controller includes a limiting function that calculates a new output current setting based on the comparison between the reference power value and the DC power measurement value. The output power set value calculated by the controller is sent to the power control card, which will limit the output current based on the new set value. The alarm system operates based on the input signals of the alarm card in IMC and the signals sent by various monitoring devices in IMC and CRU, and the alarm will be displayed on the workbench.
