The Study On Differential Protection Device For Transformers Based On DSP

With the rapid development of power industrial in our country, the protection device for transformers whether can exactly, timely, reliably act, which is one of the important factors for power grid to guarantee running securely in modern electric system. So high-performance and secure relay protection devices are needed for power transformers. Especially microcomputer relay protection devices, with software's agility, find a wide application in protection of power transformers.Firstly, the author discusses the situation and problem of protection system of power transformer at present. Secondly, author makes detailed study on the main aspects of protection principle of power transformer (including inrush current, the unbalance electric current, differential protection etc.), at the same time the in-depth study for the algorithms which are commonly used in the protection of microcomputer relay protection systems provides a theoretical basis for the design of this paper.In this paper, a microcomputer relay set for power transformer is designed under summarizing the protection theory. DSP owns rapid instruction periods, address buses separated from data buses, which can excellently adapt to the rapid digital signal process. Besides, it has abundance of hardware resources, strong instructions, excellence developing circumstance and corresponding with developing platform, which greatly improve performance of protection products. In order to satisfy the request of real-time processing for faults of power transformer, a digital signal processing chip (DSP), TMS320VC33 chip of TI Company is used as the hard core in this design. And this paper proposes a designing scheme of deffirential protection device for transformer, which includes measurement,protection,control and communication etc.