360 security guard of the temperature measurement

2022-10-22
  • Detail

360 security guard of switch cabinet temperature measurement and power supply system

in the power supply system, especially with the rapid development of modern power system towards high voltage, large units and large capacity, the requirements for power supply reliability are becoming higher and higher. High voltage switchgear in power plants and substations is an important electrical equipment. Therefore, we pay more and more attention to the problem of temperature measurement of switchgear

during the long-term operation of the equipment, the bus contacts, high-voltage cable joints and other parts in the switchgear are heated due to aging or excessive contact resistance, which degrades the performance of adjacent insulating parts and even causes accidents due to breakdown. According to statistics, a considerable part of the causes of accidents in the power system are related to heating. Therefore, the problem of temperature monitoring of electrical equipment has become an urgent practical problem to be solved in the operation of the two measures of electrical equipment safety in the power system through direct cooperation with brands and support for their purchase and selection of fabric manufacturers, which is an urgent need to improve the reliability of electrical equipment, It is of great significance to ensure the safe and stable operation of power system. Effective measures must be taken to monitor the bus temperature. When the temperature rise exceeds the allowable value, an alarm signal must be sent to remind relevant personnel to take measures in time to avoid accidents. The generation of temperature measurement system of switch cabinet solves this problem

principle of switch cabinet temperature measurement system:

the temperature of switch cabinet contact is difficult to monitor, because the space of switch cabinet is limited, but there are many components in the cabinet, and most high-voltage live components are exposed, so conventional temperature measurement methods cannot be used. Ordinary temperature monitoring methods are mainly realized by temperature sensing elements such as thermocouples, thermal resistors and semiconductor temperature sensors. This method either has metal in the sensor itself or requires metal wires to transmit signals. In a compact switchgear, it is difficult to achieve reliable insulation of the system

the switch cabinet temperature measurement system adopts decentralized locally installed front-end equipment (such as motor temperature measurement device, transformer temperature measurement device, switch cabinet temperature measurement device temperature measurement sensor working group, etc.), and these front-end sensors are connected through wireless acquisition to form the electrical equipment temperature monitoring network; Through Ethernet connection equipment, the database server, electrical operation workstation, maintenance engineer station and other groups form the upper computer system of electrical monitoring and management; Connect DCS system through engineer monitoring station; Make comprehensive use of the comprehensive information advantages of the electrical system connection, and issue early warning according to the historical data comparison, so as to nip in the bud and reduce the losses of the power industry

development of switchgear temperature measurement system:

because the bus in the switchgear is at high voltage potential, there is a high voltage between each phase to ground and different phases, and the structure is narrow, so it is impossible to conduct manual inspection and temperature measurement, so direct detection of high voltage bus temperature has always been a difficult problem in power system detection

the existing switch cabinet temperature measurement can be divided into three categories according to the data transmission mode: ordinary cable temperature measurement, optical fiber and wireless temperature measurement

for power bus contacts, high-voltage cable joints, etc., there are many points, high voltage and strong electromagnetic interference. Ordinary cable is obviously not good

optical fiber temperature monitoring device generally adopts optical fiber to transmit signals, which is not interfered by high voltage and environment. The disadvantage is that the optical fiber is easy to fold, easy to break, and not resistant to high temperature, and the wiring is difficult. Eastman's plastic medical equipment market development manager is relatively high and expensive

wireless temperature measurement uses wireless transmission. High voltage electricity will produce strong electromagnetic fields and greatly interfere with radio waves. It is necessary to select a wireless network with appropriate frequency. In addition, wireless temperature measurement equipment should be powered by batteries. Wireless temperature measurement equipment must have low power consumption and long working time. Small size, easy to install. Although many schemes have been studied at home and abroad to monitor bus temperature, they have certain limitations and deficiencies. Wireless temperature measurement has the advantages of low cost, short delay, unlicensed frequency band, high safety, close range, low complexity, promoting the standardized management of renewable resources industry, low power consumption and so on. It is a good way to meet the conditions of high-voltage bus temperature measurement

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