The digital evolution of the world's energy industry is becoming increasingly stronger, and my country's power system reform is also being deepened. In order to achieve the goal of carbon peak and carbon neutrality, building a new power system with new energy as the main body is the only way to develop and an inevitable requirement for promoting the energy revolution. The new power system presents the characteristics of deep integration of digital and physical systems, leading and optimizing energy flow and six business flows with data flow, taking data as the core production factor, connecting information in all links of source, grid, load and storage, achieving "comprehensive observability, precise measurability, and high controllability" on the power generation side, forming a cloud-edge integrated control system on the power grid side, and effectively aggregating massive adjustable resources on the power consumption side to support real-time dynamic response. Through massive information data analysis and high-performance computing technology, the power grid has super perception, intelligent decision-making and rapid execution capabilities.

       As the best form of digital grid to carry the new power system, the perception layer it contains is its foundation. However, due to their bulky size, single function and high cost, the existing voltage, current and non-electrical measurement sensors can no longer meet the basic needs of digital grids for comprehensive and real-time perception of information. Small-sized, low-power micro-intelligent sensors and smart devices integrated with advanced sensors can obtain physical information such as voltage, current, temperature, etc. in the power system in real time, provide data support for information networks, and through the acquisition of large-scale data, the use of information networks for interconnection, the use of advanced management and control algorithms, and the combination of cloud computing and edge computing, the information-based power system can realize the digitalization, informatization, and intelligent management of power and energy networks. Building a digital power grid supported by panoramic information is the physical basis and prerequisite for realizing the digitalization of the power grid.

       Microsensors are a type of measuring equipment that is small in size, high in performance, and easy to mass produce. Microsensors generally have the following characteristics: (1) Small size. Compared with traditional measuring equipment such as mutual inductors, the volume of microsensors is greatly reduced. (2) High performance. Compared with traditional measuring equipment, microsensors have high performance in terms of measurement range, sensitivity, resolution, etc. (3) Standardized preparation process. Microsensors are often miniaturized based on micromachining technology to achieve specific functions while reducing the production cost of sensors; (4) Integration. Microsensors use an integrated approach to integrate microprocessors, information detection and processing, memory and logic judgment functions into a single chip, while also having powerful communication functions.

       In the power system, there are three main categories of micro sensors, namely micro current sensors, micro voltage sensors and non-electrical sensors. Among them, micro current sensors are mainly used for current measurement of power lines. The measurement principle is mainly based on the magnetic field established by the measured current, that is, the measurement of power line current is converted into the measurement of the magnetic field excited by the power line current, which is indirectly achieved by measuring magnetic density, magnetic flux or magnetic potential. According to different measurement principles, the main micro current sensors include magneto-optical current sensors, fluxgate current sensors, giant magnetoresistance current sensors, etc.

       The measurement principle of micro voltage sensors is mainly based on electric field information. Electric field signals contain a large amount of information about power grid and equipment operation, which is of great significance for realizing information management of power systems. On the one hand, multi-point electric field measurement can be used for voltage information inversion, thereby replacing traditional voltage transformers and realizing non-contact measurement of high voltages. The micro voltage sensors currently used mainly include micro electric field sensors based on electro-optical effect, micro electric field sensors based on induced charge, micro electric field sensors based on inverse piezoelectric effect, and micro electric field sensors based on electrostatic force.

       In new power systems that require full perception, in addition to monitoring electrical signals such as voltage and current, non-electrical sensors that detect auxiliary information such as gas, temperature, and displacement are also needed. For example, by using micro-infrared sensors to detect gas and temperature, that is, based on the principle of infrared spectrum absorption, it can be used to check the SF6 leakage of GIS devices; using MEMS ciliary vector hydrophones, it can be used to monitor the wind direction and wind speed of overhead lines, the tilt of pole towers, and the dancing of conductors and other environmental conditions; MEMS acceleration sensors use micro-machining methods to collect particle acceleration and can be used to monitor the vibration environment of power systems. At present, quantum sensors have also received more and more attention. The so-called quantum sensors are based on the laws of quantum mechanics, that is, quantum coherence, quantum entanglement, quantum statistics and other characteristics, which can achieve high-precision measurement of physical quantities such as electromagnetic fields, temperature, and pressure.

The future development of micro-intelligent sensors will explore new methods and technologies to meet the future needs of new power systems and the current shortcomings of micro-sensors, mainly including:

1) To adapt to complex measurement environments, consider the impact of changes in temperature, air pressure, and humidity on the working characteristics of sensors, and make improvements in principle design, signal processing methods, and packaging methods;

2) In view of the problem of limited measurement frequency, it is necessary to further study the electric field sensing principle, improve the measurement frequency range of electric field sensors, and expand the scope of application of electric field sensors;

3) For the problem of difficult practical application and poor effect, further breakthroughs are needed in sensor principles, coupling mechanisms, sensor structures, new materials, micro-machining technologies, and integrated coordination;

4) To increase the service life of micro-sensors, passive structures can be used to study the use of self-powered micro-energy collection and wireless sensing technology to provide the necessary energy for sensors.

       Micro-intelligent sensors will adapt to the development of new power systems, and gradually be promoted and applied in an all-round way from a new technical equipment, helping to achieve full perception of the power system, effectively supporting the digitalization and transparency of the power system, and ultimately helping to achieve the country's dual carbon goals.