The ubiquitous power Internet of Things (UPIoT) uses modern information technology and advanced communication technologies to realize interconnection and human-computer interaction in all aspects of the power system. UPIoT has the characteristics of comprehensive state perception and efficient information processing, and has broad application prospects for transformation of the energy industry. The fundamental facility of the UPIoT is the sensor-based information network. By using advanced sensors, Wireless Sensor Networks (WSNs), and advanced data processing technologies, Internet of Things can be realized in the power system. In this paper, a framework of WSNs based on advanced sensors towards UPIoT is proposed. In addition, the most advanced sensors for UPIoT purposes are reviewed, along with an explanation of how the sensor data obtained in UPIoT is utilized in various scenarios.

The requirements for the construction of a new power system inevitably pose significant challenges and changes to the operation and maintenance of the power grid. To ensure the safe and stable operation of ultra-high voltage (UHV) transmission equipment, this work reports on the principles and preliminary results of using electroluminescence (EL)-based photon counting (PC) methods for early detection of micro-defects in GIS/GIL insulation spacer. In this study, the impact of voltage, gas pressure, and gas composition on the photon response of insulation is examined. Furthermore, the corresponding relationship between defect status and photon response characteristics is explored, along with the discussion of the EL mechanism and its evolution induced by defects. The research results demonstrate that PC measurement exhibits high sensitivity to variations in millimeter-scale defect size, position, and morphology at lower electric fields before partial discharge (PD) initiation. With this regard, this paper reveals promising prospects for the early detection of micro-defects in UHV transmission equipment using PC measurement-based methods.

A field-grading composite with a low switching field, stable nonlinear conductivity performance, and excellent mechanical and thermal properties was prepared by using hybrid ZnO micro-spherical varistors of different particle sizes as the fillers and silicone rubber as the matrix. The hybrid effects of particle size on the electrical, mechanical, and thermal properties of ZnO micro-spherical varistors composites are investigated. An increase in the ZnO micro-spherical varistor size in the composites will lower the switching field but lead to degradation of the mechanical properties and stability of the nonlinear conductivity properties. The silicone rubber is incorporated with a mixture of hybrid ZnO micro-spherical varistors of different sizes at an optimal mass ratio range exhibited low switching field, stable nonlinear conductivity performance, and excellent mechanical and thermal properties. Our findings are helpful to comprehensively regulate performance of advanced field-grading materials and increase stability and durability of electronic and electrical devices.

The construction of the future energy structure of China under the 2050 carbon-neutral vision requires compact direct current (DC) gas-insulation equipment as important nodes and solutions to support electric power transmission and distribution of long-distance and large-capacity. This paper reviews China's 10-year progress in DC gas-insulated equipment. Important progresses in basic research and industry perspective are presented, with related scientific issues and technical bottlenecks being discussed. The progress in DC gas-insulated equipment worldwide (Europe, Japan, America) is also reported briefly.

Smart dielectric materials with bioinspired and autonomous functions are expected to be designed and fabricated for next-generation electrical insulation. Similar to organisms, such dielectrics with self-adaptive, self-reporting, and self-healing capabilities can be employed to avoid, diagnose, and repair electrical damage to prevent catastrophic failure and even a blackout. Compared with traditional dielectrics, the utilization of smart materials not only increases the stability and durability of power apparatus but also reduces the costs of production and manufacturing. In this review, researches on self-adaptive, self-reporting, and self-healing dielectrics in the field of electrical insulation, and illuminating studies on smart polymers with autonomous functions in other fields are both introduced. The principles, methods, mechanisms, applications, and challenges of these materials are also briefly presented.

Polypropylene (PP)-based recyclable materials have attracted tremendous interest for HVDC cable insulation applications due to their superior electrical properties, e.g., high thermal stability and superior recyclability. Compared with crosslinked polyethylene (XLPE), PP-based materials exhibit the advantages of not only higher working temperatures but also facile and efficient cable manufacturing with reduced costs, which are highly desirable in HVDC cable manufacturing. Considering their promising advantages, PP-based materials have received significant attention from both academia and industry in the field of HVDC cable insulation. In order to adopt PP as a cable insulation material, the mechanical flexibility of PP should be improved. However, regulations of the mechanical properties inevitably influences the electrical properties of PP. So extensive research has been conducted on the regulation of the mechanical and electrical properties of PP. This review summarizes the research progress on recyclable PP-based materials for HVDC cable insulation applications. Particular attention is placed on the electrical property regulations and material structure-property relationships. The challenges that remain to be addressed and the opportunities for future studies on PP-based recyclable HVDC cable insulation materials are also presented.