Research And Design On The Hardware Of Multifunctional Digital Protection Device Based On DSP

In the last decade the development of digital protection technique is quick, and various different digital protection devices are used extensively in power system. With the development of microcomputer and its applied technique, new digital protection devices are produced continuously. But these devices which have been in operation do not allow to be used to do some experiments, so a multi-functional digital protection device used technical training of electric dispatchers and technical personnel can improved their digital protection technique level, which has very important meanings for maintaining power system working safely and reliably.Under such a background Hunan University proposed to develop the multi-functional digital protection system with cooperation of Hunan Ultrahigh Voltage Transmission and Transfer power Company, and the project gains the support of Electric Power Co. of Hunan Province. The system regards a microprocessor relay protection testing equipment as the signal source, and finishs many kinds of protection experiments through the multi-functional digital protection device. The paper studies the multi-functional digital protection device mainly, and proposes hardware design plans of double CPU based TMS320LF2407 DSP. Taking full advantage of the in-application programming characteristic of 32K word Flash program memory in TMS320LF2407, the device can do multifarious protection experiments through carrying out the programme which are downloaded in Flash through a personal computer by making use of RS232 serial communication interface, and thus it breaks the traditional protection devices' limitation of single function, and realizes collecting many kinds of protection experiments in a set of device.The paper studies and designs the hardware of multi-functional digital protection device, and analyses the principle and function of every hardware circuit module, and the anti-interference technology that the device adopted in detail. In addition the paper puts forward a new way of downloading programme. The multi-functional digital protection device is designed by way of modularizing hardware, and has the characteristics of simple structure, powerful function, strong anti-interference ability. So it is not only suitable for digital protection training in power system but also suitable for teaching experiments of electrical engineering colleges, and it is a digital protection device with extensive actual value.