【正文】 n the highpower switching power supply, by taking into account the power consumption should be avoided as far as possible access to the sampling resistor. Therefore, there will usually be converted to overcurrent protection, and undervoltage protection. E、 Overvoltage protection Switching regulator39。 load shortcircuit output voltage will also decline. Especially in the reversedphase stepup or stepup switching regulator DC voltage of the protection due to overcurrent protection with closely related and therefore more important. Implementation of Switching Regulators in the termination of the output voltage parators. Normally, there is no parator output, once the voltage drops below the allowable value in the parator on the flip, drive alarm circuit。t bus module, performance greatly improve module structure, widely used. Huazhong university of science and technology development of microputer protection from 8 bits CPU, is the core part in polymerizingkettle development based on 32bit microputer protection. Nanjing institute of electrical automation began a 16bit CPU is developed on the basis of puter line protection, has been widespread in 8 the study, also protect the hardware system 32 bits. The development of southeast university puter hardware and equipment to protect and improve through a lot. Tianjin university is a start with more than 16 bits CPU developed on the basis of puter line protection, which began in 1988 study 32bit digital signal processor (DSP) for the protection and control, measuring devices, microputer integrated with Zhuhai jin electrical automation equipment pany developed into a fully functional 32bit big modules, a module is a small puter. Using 32bit microputer chip is not only because the accuracy and precision of the A/D converter by the resolution limit, more than 16 when converting speed and cost is unacceptable, More important is the 32bit microputer chip with high integrity, high frequency and puting speed and large space, rich addressing the mand system and more input output. The CPU registers, data bus, the address bus are 32bit memory management function, and memory protection function and tasks, and the conversion function will Cache (Cache) and floatingpoint ponents are integrated in the CPU. 2） Network Power system of microputer protection requirement, besides improving the basic function of protection, also should have the capacity of the fault information and data storage space, longterm fast data processing function, strong munication ability, and other protection and control devices and the whole system by sharing work dispatching data, information and work resources, the ability to program in a highlevel language, etc. This requires microputer protection device is equivalent to a PC. In the early development of puter to protect, once thought to use a small puter finish relay protection device. Due to the large size, then miniputers high cost and reliability of this idea is not reality. Now, with microprocessorbased protection function of similar size, speed, workmanaging machine greatly exceed the storage capacity of 9 miniputer, therefore, make use of the relay protection sets polymerizingkettle time is ripe, this is the development direction of the microputer relay protection. Tianjin University has developed with microprocessorbased protection device with an identical structure reform polymerizingkettle of relay protection device. This device has several advantages: (1) 486PC machine can meet all the functions of the current and future demands of microputer protection function. (2) dimension and structure and the current protection device, exquisite workmanship, shockproof, prevent overheating, preventing electromagic interference ability is strong, can run in very bad working environment, cost can be accepted. (3) using STD bus or PC bus, hardware modular, for different protection can be arbitrarily choose different modules, flexible configuration, easy extension. The microputer relay protection device, puterized is irreversible trend. But how to better satisfy power system, how to further improve the reliability of the relay protection, and how to obtain more economic benefit and social benefit, still must specifically indepth research. 820 works The puter work information and data munication tool has bee the mainstay of the information age, make human production technology and social life of the fundamental changes have taken place. It is deeply affect all industries, as well as various industry provides powerful means of munication. So far, in addition to the differential protection disoperation and protection of the relay protection device, all can only protect the electricity installation reaction. Protection function is limited, reduce accidents resection fault ponents. This is mainly due to the lack of data munications. Strong Foreign had put forward the concept of protection system, which was mainly refers to the safety automatic device. Because of the relay protection function not only fault ponents and limit 10 resection impact accident (this is to ensure priority), the safe and stable operation of the whole system. This requires each protection unit can be altogether I、 Conclusion Discussed above in the switching regulator of a variety of conser