Distributed electrical current sensing for DC power networks

近几十年来，由于电力电子技术使直流电可以很容易地转换为交流电，因此高压直流输电的使用日益增多。在接下来的十年里，由于采用海上发电的增长以及将输电损耗降至最低的愿望日益强烈，预计对基于高压直流输电的电力系统的需求将大幅上升。鉴于高压直流输电市场(主要是用于海上发电的互连器和出口电缆)的这种增长，需要开发系统来提高直流输电平台的可靠性。Synaptec的仪器技术集成了光纤和压电技术，便于使用预装光纤对传输线上的电压和电流进行新颖的分布式测量。这以低成本提供了前所未有的电力系统可见性，使新的控制和保护功能能够在复杂电路上实施。然而，目前成功用于交流电流测量的技术不适用于直流电流测量，需要新的方法和创新来将该平台扩展到直流电路。在本项目中，NPL将对适合作为Synaptec广域分布式传感器平台一部分的直流电流测量技术进行文献综述。我们将比较各种可能的方法的优缺点，并利用这种分析的结果来确定是否可以实现一种合适的方法。选定的方法将与Synaptec合作进行实践。这项工作的目的是为Synaptec提供一个潜在的解决方案，可以进一步开发成原型产品。进入直流输电市场将对Synaptec的增长产生重大影响，该项目的成功将通过开发新的IP使英国经济受益，并有可能提高清洁发电和长途输电的可靠性和效率。

"The use of High-Voltage Direct Current (HVDC) power transmission has grown over recent decades as power electronics have enabled DC power to be converted easily to AC, which is a more usable form of electricity. Over the coming decade, demand for HVDC based power systems is expected to rise substantially due to growth in adoption of offshore power generation and an increasing desire to minimise transmission losses. Given this growth in the HVDC transmission market (primarily interconnectors and export cables for offshore generation), it is desirable to develop systems to improve the reliability of DC power transmission platforms.Synaptec's instrumentation technology integrates optical fibre and piezoelectric technologies to facilitate novel distributed measurements of voltage and current along transmission lines using the pre-installed optical fibres. This offers unprecedented power system visibility for a low cost, enabling new control and protection functions to be implemented on complex circuits. However, present techniques that are successfully employed to measure AC current will not work for measurement of DC current, and new approaches and innovations are required to extend this platform to DC circuits.In this project, NPL will conduct a literature review of DC current measurement techniques that may be appropriate to be used as part of Synaptec's wide area distributed sensor platform. The merits and drawbacks of potential methods will be compared and the results of this analysis will be used to establish if a suitable method can be realised. Selected methods will be reduced to practice in collaboration with Synaptec. The aim of the work will be to provide Synaptec with a potential solution that can be further developed into a prototype product.Accessing the DC power transmission market would have significant impact on Synaptec's growth, and the success of this project will benefit the UK economy through development of new IP with the potential to improve the reliability and efficiency of clean power generation and transmission over long distances."