单相接地故障是电力系统中最主要的故障形式，占据到故障总数的70％以上。小电流接地系统发生单相接地故障时，会产生弧光过电压，长期运行可能会损坏其绝缘，引发严重的相间故障。在电网的中性点与大地之间加装消弧线圈，可使容性电流得到补偿，从而使接地点的电流减小。 本文首先分析了分布电容对电网运行的影响，接着对中性点不接地电网正常运行和发生单相接地故障时的运行特点进行了理论分析，由此进一步分析了中性点经消弧线圈接地电网正常运行时的运行特点，以及中性点经消弧线圈接地电网单相接地时消弧线圈的消弧补偿原理。 在以上理论研究的基础上，本课题设计了以DSP2812为核心，具有自动跟踪补偿功能的调容式自动消弧装置，该装置由2.2kVar／220V消弧线圈、控制器和2kVar电容调节柜组成。本文对装置的一次设备进行了选型设计，分别对控制器的硬件和软件模块进行了设计。 本文还针对调容式自动消弧装置的控制算法进行了研究，提出了一种用改进的两点法测量电容电流的方法；确定了自动消弧装置的单相接地故障判据；确定了采用“随调式”过补偿控制的补偿方式。为了提高采样精度，采用了基于FFT的电网参数计算方法和自适应跟踪电网频率调整采样间隔的方案，并设计了同步采频单元。 最后，在实验室进行了实验与测试工作。通过软硬件功能测试，证明了控制器的软硬件设计合理，达到了预期的功能要求。在消弧补偿模拟实验中，通过分析实验数据，发现实测值与理论值有较大误差，结合伏安特性数据，将该模拟实验的测量数据反馈到控制器软件部分进行了修正，可以大大提高消弧线圈补偿的精度。通过该实验与测试工作表明，自动消弧控制系统能够可靠稳定工作，可以精确测量电网参数并对电容器进行有效的投档操作，且晶闸管投切单元、投切速度快、冲击小。

The single-phase ground fault is the most important form of failure in the power system, occupy more than 70% of the total number of fault. Small current grounding system single-phase ground fault occurs, it will produce the arc over-voltage, long-term operation may damage the insulation, causing serious phase fault. The grid neutral point between the earth and the installation of arc suppression coil capacitive current can be compensated for, so that the ground point current is reduced. This paper analyzes the impact of the distributed capacitance of the power grid, then ungrounded the grid normal operation and the operating characteristics of single-phase ground fault occurs theoretical analysis, thus further analysis of the neutral point arc suppression coil groundingthe operating characteristics of the normal operation of the power grid, as well as the neutral point arc suppression coil grounding power single-phase ground arc arc suppression coil compensation principle. On the basis of the above theoretical study, the design of this project DSP2812 core, with automatic tracking compensation function tuning capacitors automatic arc suppression device, the device by 2.2kVar/220V arc suppression coil, the controller and 2kVar capacitor regulator cabinet composition. Means a device to carry out the selection of design, to design the hardware and software modules of the controller, respectively. This article also Arc Extinguishing Device control algorithm automatically tuning capacitors were studied, a using a modified two-point method for measuring capacitive current method；single-phase ground fault criterion to determine automatically the arc extinguishing device；determined using“with the adjustable”over-compensation control compensation. In order to improve the accuracy of sampling, adjust the sampling interval based on the the FFT grid parameters calculation method and the adaptive tracking grid frequency and synchronization mining frequency unit. Finally, experiments were carried out in the laboratory and testing. Hardware and software functional testing to prove reasonable hardware and software design of the controller to achieve the desired functional requirements. Compensation simulation of the arc, by analyzing the experimental data and found that the measured value and the theoretical value greater error, combined with the volt-ampere characteristic data, measurement data is fed back to the controller of the simulation software part of the amendment, can greatly improve arc suppression coil compensation accuracy. By the experiment and test work has shown that automatic arc suppression control system reliable and stable work，the network parameters can be measured accurately and capacitor effective Toudang operation and thyristor switching unit, switching speed, the impact is small.