礦井小電流接地系統(tǒng)選擇性漏電保護(hù)的Simulink仿真研究及其應(yīng)用.pdf

1、The power supply system of the most of distribution network and large-scale industrial and mining enterprises in our country is NUGS. The power system of coal mine was NUS in the past few decade. In the recent years, as

2、the increasing of the capacitance current in the mine, the ground fault neutralizer has been widely applied in power system of coal mine. And the ground fault neutralizer is mainly used in series or paralleled with resis

3、tance. The change of the neutral grounding of power system impact the selectivity of the leakage protection device in use. And even threat the security and the reliability in the power supply in coal mine. For the improv

4、ement of the security and the reliability in the power supply in coal mine, that finding a selective leakage protection theory which could suit the coal mine power system well and research selective leakage protection de

5、vice with high reliability, sensitivity and rapidity really have practical significance. Generally speaking, electrical leakage is widely used to indicate all kinds of ground fault in the power grid of coal mine. In this

6、 paper, combining with brief theoretical analysis, the simulation models of the electrical leakage faults are build by using dynamic simulation toolbox Simulink based on Matlab7.1. In the following chapter, several selec

7、tive leakage protection theory that can be used in coal mine power grid are analysed on the base of abundant referance and analysis. In this section, the emphasis is putting on analysis about two selective electrical lea

8、kage protection theroy--zero sequence current active component direction theroy and zero sequence power direction theroy--combining with simulation and algorithm analysis. The simulink model of both above-mentioned thero

9、y are build, and was applied to the simulation models of the electrical leakage faults to observe theirs performance. Finally, the simulation resuelt indicates that in underground NUS both zero sequence current active co

10、mponent direction theroy and zero sequence power direction theroy could get the fault line accurately. But, in NES, the zero sequence power direction theroy can not work. Still the zero sequence current active component

11、direction theroy can still suit the all running mode and compensating state of NES in the low voltage power system of coal mine. The resuelts of simulation indicate that the accuracy of the zero sequence current active c

12、omponent direction theroy is affected obviously by the phase characteristic of the current and voltage transformer. Ideally, that engage the criterion at 10ms after the ground-fault appears could limit the calculation er

13、ror below 6％. But in practice, nearly all kinds of current and voltage transformer has phase difference between their input and output signal. And this phase difference may lead to unacceptable error of the criterion. To

14、 solve this problem a compensation is carried out according to the substance of the zero sequence current active component direction theroy. Consequently, the errors brought by the phase difference of the current and vol

15、tage transformer are removed. In this paper, Simulink embed in Matlab is used to built the simulation model of both ground fault and protection arithmetic, which can not only validate the feasibility of protection arithm

16、etic, but also to analyse the protection arithmetic detailedly. A new manner of simulation research of selective leakage protection device is advanced. At present, MCU technology continue to mature. And with its help the

17、 electrical leakage protection devices in coal mine will dramatically improve their reliability and accuracy. In the fourth chapter of this paper, a mine low-voltage communicatable two-stage selective electrical protecti

18、on device based on zero sequence current active component direction theroy is designed. ARM7 MCU LPC2103 and sigle-chip-machine STC12C4052AD are used as control core respectively to low-stage and up-stage. In the course

19、of designing, Anti-jamming measures are seriouly considered to adapt the severe environment in mine. Unique communication function between the two-stage electrical leakage protection could achieve the opening of up-stage