发电电焊机及其控制系统设计与分析

采用具有全程调速器的内燃发动机、发电机、逆变弧焊电源，以及二次控制系统构成发电电焊两用机。发电机每相电枢绕组由四个子绕组构成，通过转换开关使子绕组串联时，可作为常规发电机使用，切换转换开关使子绕组并联时，可提供较低交流电压给逆变电源，使逆变电源不需要高频变压器。分析计算表明，谐波含量较高时电压有效值与平均值存在明显差别，又由于负载变化时整流桥输出电压随之变化，因而设计使发电机励磁调节器的反馈输入电压取自逆变电源的整流滤波环节后的直流电压，使发电电焊机稳定性和动态特性突出，逆变弧焊电源部分可实现复杂和高级的控制。

Design and analysis of engine-drive arc welding inverter and its control system

Generating and welding dual use set consists of generator, welding inverter, automatic control system, and internal-combustion engine controlled by speed regulator. Each winding of the generator consists of four parts. When the parts were connected in series by shifting switch, the set can serve as general generator, when they are in parallel, the set serves lower AC voltage to welding inverter. Thus high frequence transformer is not needed anymore in welding inverter. Analysis and calculation show that harmonic waves can lead to obvious difference between effective value and mean value of voltage, and the output voltage rectified by diode bridge varies with load. So the controller for excitation system is designed to collect the voltage rectified by diode bridge as its input. Hence the dual use set has proved to be low cost, multifunctional, reliable, stable, easy to maintain and have a good dynamic characterisics, which also provides the foundations for more advanced control.