Photovoltaic power generation, as a new and pollution-free power generation method, has greatly alleviated the demand for traditional electric energy. However, for the grid-connected photovoltaic power generation system, due to its inherent randomness, volatility, and intermittent characteristics, and the grid-connected photovoltaic power generation system contains a large number of nonlinear power electronic components, compared with traditional power generation methods, photovoltaic power generation has The power quality of the grid has a great impact. This article analyzes the harmonics, voltage fluctuations and flickers, DC injection, islanding effect and other problems caused by grid-connected photovoltaic power generation on the power grid, and studies and discusses feasible measures to improve power quality.

This article analyzes the connotation and main characteristics of the ubiquitous power Internet of Things, and conducts a comprehensive discussion on the construction goals, basic architecture, key technologies and future development strategies of the ubiquitous power Internet of Things.

With the increasing demand for electricity, power supply reliability requirements of the power system is becoming higher and higher, many power supply systems have two or more power supply lines. Automatic switching device for backup power supply can effectively improve the reliability of power supply, this type of device can automatically and quickly put thebackup power supply into operation or switch the user to thebackup power supply after the working power supply is disconnected due to a fault. This paper introduces AM5-DB low-voltage automatic switching device for backup power supply, which can provide corresponding protection functions for different power supply modes in Dongting substation project, and can greatly improve the reliability, safety and power supply quality of substation operation, which is conducive to the realization of comprehensive automation of the substation, and the realization of unmanned or fewer people on duty.

The high-voltage switchgear is an important electrical equipment in the substation. It is responsible for the dual functions of closing and disconnecting power lines and protecting the safety of the system. The high-voltage switchgear operates in an environment of high voltage, large current, and strong magnetic field for a long time. Oxidation and contact resistance often cause the contacts to heat up and the temperature is too high. If not discovered and dealt with in time, it may cause serious accidents such as fires, power outages, etc. Therefore, the problem of real-time temperature monitoring in high-voltage switch cabinets has become an urgent problem to be solved in the power system. The article on practical issues proposes a wireless temperature measurement system for high-voltage switch cabinets based on a single-chip microcomputer. The system has the characteristics of simple structure, temperature measurement, and high accuracy.

This article analyzes the connotation and main characteristics of the ubiquitous power Internet of Things, and conducts a comprehensive discussion on the construction goals, basic architecture, key technologies and future development strategies of the ubiquitous power Internet of Things.

Asa part of the urban public transportation system, ailway transportationhas been extensively developed and expanded in the past few decades. It plays an important role in solving urban traffic congestion, reducing environmental pollution, and improving urban sustainability. With the advancement of science and technology,ailway transportationsystems are constantly introducing new technologies and innovations to improve operating efficiency and passenger experience, save energy and reduce operating costs. The monitoring of air-conditioning circuits in rail transit train carriages is one of the important aspects to ensure the comfort and safety of passengers in the train. Monitor the electrical parameters of the air conditioning circuit in real time to determine the operating status of the air conditioner, detect potential faults, and take timely measures when power problems occur to ensure the operation of the air conditioning system. At the same time, monitoring data of the air conditioning loop should be recorded for subsequent analysis and trend observation, which can help identify the long-term performance and health of the system.