The Design And Implementation Of The High-power Supply Based On Power-i

In recent years, in the petroleum, chemical and other dangerous areas, the application of fieldbus are increasingly widely. Intrinsically safe technology for its small size, high reliability, low cost, and can be operating in dangerous places made it to be the first choice of explosion-proof type in fieldbus systems. To be different with the conventional intrinsically technology, fieldbus intrinsically safe system with multi-load characteristics and requirements to meet the "interchangeability" and "interoperability", that is, allow the bus electrical equipment can be produced by different manufacturers and articulated in the same bus. For fieldbus technology, however, we hope that the load can be connected the more, the better, but in order to meet the technical requirements of security, the power output voltage and current must be limited in a certain level, thus causing the reduction of load number that connected to the bus.Power supply as an important part of fieldbus intrinsically safe system, having a major impact on the number of devices and cost performance of the system. In this article, we put forward the realization of a fast turn-off function circuit based on Power-i.The core idea is a rapid shutdown circuit is used to identify the electrical system failure (for example a spark), cut off the power supply in a very short period of time at the beginning of the failure occurred, and ensure that energy supply required for an ignition is withdraw from the spark. This will allow the electrical connection parameters much larger than the allowed values of the national standard. In the resistive circuit, any safety critical conditions are directly related to the current rate of change, this current changes must be detected, and realize fast shutdown. This current change detecting can’t received adverse effects from the other components of the entire system, such as load, cables etc.Finally, we will process the test based on the "Power-i" technology and will configure the typical security spark experimental device prove that the use of intrinsically safe power supply output terminal that configuration the fast shutdown circuit can meet intrinsically safe requirements, and effectively improve the output power,thereby increasing the load capacity of the fieldbus intrinsically safe system.