采用GPS/北斗双星同步采集技术的分布式无线高压绝缘带电测试的研究

Study of Implementing GPS/BD PPS Pulse to Synchronize Sampling in a Disturbed Wireless System for Insulation Live Testing

随着智能电网建设和状态检修工作的开展,需要及时掌握电容型设备、避雷器等的绝缘状态。但目前绝缘在线监测、带电检测技术在检测精度、设备可靠性等方面存在不足,并未被电力部门广泛应用。文中研究了基于高精度GPS/北斗双星同步采集和分布式无线便携式带电测试系统,以提高绝缘检测的精度和便捷性。文中介绍了该系统实现的原理,GPS/北斗的PPS秒脉冲直接硬件控制的方式启动Σ-Δ型AD数据采集,和软件流程的时序协同控制,利用改进的迭代—正交算法,极大的降低了相对介损测量误差,提高了数据的重复性与稳定性。对算法的影响、PPS硬件同步性能进行了比对研究,并对整个系统的性能进行了测试。结果表明:该系统实现了对相对介损的高精度采集测量,相对介损的误差<0.05%,完全满足现场绝缘带电检测的要求。该带电测试系统,已经成功地应用于变电站容性设备、避雷器的带电测试中,提高了测试的效率和性价比。

With the development of smart grid and CBM, it＇ s important to get the insulation status of capacitive devices and MOA. The on-line testing and live testing are still insufficient in precision and equipment＇s reliability, so they aren＇t used widely by power companies. In this article, a portable live testing system which based on high-precision synchronize sampling with GPS/BD and wireless is studied to improve the precision and convenience of test. The systems theory is introduced, the technologies which apply hardware of GPS/BD-s PPS to start sampling of∑-△ type AD, and coordinate with timing under flow control of software, and improve iteration-orthogonal algorithm, reduces the error of relative dielectric loss test, improves the repeatability and stability of data. The algorithm and synchronize performance are studied with comparison. The system＇s performance is tested. The result shows that this system can measure relative dielectric loss with very high precision which-s error less than 0.05%. This system has been used successfully in a substation＇ s capacitive devices and MOA test, and it improves the test efficiency and cost performance greatly.