The Effects Study and Simulation Tests of Harmonics on Solid-State Distance Relays
碩士 === 中原大學 === 電機工程研究所 === 89 === This study presents the effects study and simulation tests of harmonics on solid-state distance relays. There are different types of solid-state distance relays at present day, but based on tripping designs ,they can be separated into two types：rectifier type and...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2001
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| Online Access: | http://ndltd.ncl.edu.tw/handle/46235507752066948552 |
| Summary: | 碩士 === 中原大學 === 電機工程研究所 === 89 ===
This study presents the effects study and simulation tests of harmonics on solid-state distance relays. There are different types of solid-state distance relays at present day, but based on tripping designs ,they can be separated into two types：rectifier type and phase-comparator type. These two types are taken into simulation. The effects study of harmonics and fault resistance to the solid-state distance relay is done first. Then the results are compared with the simulation results.
A new method for the simulation of distance relays is presented. EMTP is used to build the transmission line model and to simulate the grounding fault situations. Then the output voltage and current values of EMTP are saved in Microsoft Excel data type. The advantage of this method is the unnecessary data can be deleted before simulation for saving simulation time and reducing errors. Different kinds of harmonics combinations are used as inputs of the simulation system to study the effects on solid-state distance relays built from MATLAB. From the simulation results, we learn that the solid-state distance relay did not perform well at harmonic environments. The tripping time of the relay is delayed for both types of distance relays. This means the protection zone of the distance relay will change and misoperations may happen.
Extensively study is the suggestions of the function of distance relay in an environment with harmonics. This paper proposes two methods to reduce the misopearations of the relay at such environment. First method is how to adjust the settings of protection resistance of the distance relay at specific conditions to ensure that the relay trip properly at fault situations. The second method is to equip low pass filter to the relay.
The results of this research can provide valuable references and assistance in applying and designing of distance relays’ protective schemes.
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