The present invention relates generally to the field of power conversion, and particularly to power conversion circuits used in power electronic equipment such as welding systems, plasma cutters, and so forth.
Many power electronic machines used in industry employ circuitry for converting power from one useful form to another. For example, welding and plasma cutting systems generally receive alternating current (AC) power from a source, such as the power grid or an engine generator. The power is typically converted to direct current (DC) power via rectifiers, then distributed on a DC bus to further power conversion circuitry. This further power conversion circuitry may include inverters, buck converters, boost converters, or various combination of these, which in general will convert the power to a different DC form or AC power for a load. In the case of welders and plasma cutters, the output power may be either DC or AC, depending upon the process utilized. Some systems are capable of outputting both AC and DC power for selected processes, adding to their utility and versatility.
In systems that employ rectifiers, a challenge exists in appropriate packaging of the rectifier components. In automotive applications, for example, alternators create AC power that is converted to DC power by diode modules that are integrated into the alternator itself. In industrial equipment, surface mounted or lead frame packages are commonly utilized. However, these arrangements are not always suitable for certain types of equipment. Moreover, these may require particular designs for either the power generation components, circuit packages, and so forth that may add additional cost and time required for assembly. Further, certain of these designs are not sufficiently robust for given applications, particularly for equipment that is mobile that is thus subjected to the environment or that may be subjected to vibration, such as engine generator applications.