System background:
In the long run, the 10/35kV switchgear in the power grid is caused by various objective reasons, such as electric connection point fever, operating mechanism failure, partial discharge and other faults, using new technical means to monitor the switchgear, discover the fault and hidden trouble of the switch cabinet in time, which is of great significance to improve the power supply stability of the distribution network.
Technical principles:
It is difficult to detect the type and point of equipment fault in time and accurately, so it is necessary to monitor the temperature of the key points of the high voltage switchgear, the condition of partial discharge and the state of the operating mechanism, so as to effectively improve the rate and accuracy of the fault discrimination of the switchgear.
The state intelligent monitoring system of the power switch cabinet can monitor the switch cabinet through the temperature of the switch cabinet, the electric connection point, the current transient waveform of the closing mechanism and the partial discharge characteristic quantity in the switchgear, and upload the data to the cloud to carry out processing and analysis, so as to realize the on-line monitoring of the comprehensive state of the switchgear cabinet. Fault diagnosis and early warning of switchgear, and finally the state maintenance of equipment.
Application status:
1, the overheating fault of the contact head
In the long run, the contacts and busbar connections of the high voltage switchgear are heated by aging or too large contact resistance, and the temperature rises continuously. If the temperature of the heating parts can not be monitored in real time, it may eventually lead to the occurrence of fire and large area blackout.
To solve the problem of overheating in the process of equipment operation is the key to prevent such accidents. Therefore, on-line monitoring of temperature is an important means to ensure the safe operation of high voltage equipment.
2. Internal insulation failure
According to incomplete statistics, the number of accidents caused by the insulation failure of switchgear in 2013 accounted for 64% of the total number of switchgear accidents. (Note: this data is from the 2014 annual report of State Grid Corporation).
Partial discharge is the symbol of the integrity degradation of insulation performance. By monitoring the partial discharge status of the switchgear cabinet, the early fault of the equipment can be found effectively, and the major accidents can be avoided. It is an important means of condition maintenance for high voltage switchgear.
3. Statistical failure statistics of operating mechanism
According to the statistics of defects in circuit breakers in 2009 - 2013, the defect of operating mechanism accounts for a considerable proportion, which is the main cause of circuit breakers' faults. (Note: this data is from the 2014 annual report of State Grid Corporation).
Solution：
technical advantages
It can realize on-line monitoring of switchgear comprehensive status and ensure the safety of power switchgear.
The online monitoring of power switch cabinet from multi dimension can effectively improve the fault discrimination rate and accuracy of switchgear.
Based on multidimensional data analysis, the switch cabinet fault is predicted and early warning is realized, and the condition based maintenance of the equipment is finally realized.
Product after sale
1. Technical maturity
On the basis of cooperation with foreign manufacturers, a AW temperature measuring product developed independently has been formed to solve the technical defects of foreign products in the aspects of anti-interference, electromagnetic compatibility, transmission distance and stability.
2. Technical standards
As the lead and the main compilation unit, it has participated in the formulation of the electric power industry standard "the technical specification for the on-line monitoring device for the contact temperature of the substation equipment".
3, market and sales
It is the largest market share of SAW passive wireless temperature measurement in the domestic power industry.
4, application
Different application solutions have been formed for switchgear, distribution transformer, power cable, disconnector and so on. Two working modes of on-line temperature monitoring and inspection are formed.
5, technical guarantee
It has a large number of excellent technicians who have long been engaged in the development, implementation and service of SAW technology and power industry monitoring devices. It has formed good cooperation with China Academy of electrical science, South power grid, and universities, providing strong technical support for product R & D and application.
