Views:205 Author:Site Editor Publish Time: 2021-07-06 Origin:Site
In recent years, the accurate fault current indicator installed in 10 kV lines of power enterprises has played a positive role in fault line inspection, locking fault range, improving line inspection efficiency, reducing labor intensity, and improving power supply reliability. However, it is often found that the automated fault current indicator is unstable and loses function after a period of operation.
The damage rate of reliable fault current indicator is more than 98% after 1-6 months of operation, which mainly shows that the circuit cannot be overturned or cannot be reset after overturning. The main reason is that the application range of its rated current is small, which affects its own life. The starting value of sudden change current of line is set according to the data provided by the line load. The short-circuit capacity of 10kV line fault point will directly affect the change of short-circuit current value, which means that the instantaneous current can far exceed the rated current starting value of digital fault current indicators. Therefore, the internal chip of the product will cause fatal damage and cause the indicator to mis-operate or refuse to operate.
The stability of the chip and the accuracy of detection are related to the stability of the power supply, while the power supply of the chip embedded in the advanced fault current indicator is a button lithium battery. Due to the limitation of its capacity, the capacity of the battery will gradually decline after working for a period of time, so that the chip cannot work normally or make the program disordered. In operation practice, it is found that the life of accurate cable fault passage indicators with small load is longer (5-10 months) and that of products with larger load is shorter (3-5 months), which is because the fault frequency of line with small load is much lower than that of line with large load. The more the number of line faults, the greater the battery energy consumption.
l It is suggested that the manufacturer should install a high current signal isolation circuit in the chip to prevent it from being damaged when the short circuit exceeds the rated current starting value set by the automated cable fault passage indicator.
l The power supply mode of advanced cable fault passage indicators is improved to provide stable and reliable power supply. Now the solar charging technology is very mature, so the solar panel can be installed on the inner wall of the digital cable fault passage indicator to convert the solar energy into electric energy, thus providing an uninterrupted charging power supply for the chip battery and ensuring the normal operation of the chip power demand.
The reset mode of reliable cable fault passage indicator is improved to make it more humanized. The fixed reset time should be changed to dynamic reset setting, so the reset of indicator after overturning is not limited by time when the line fault occurs. Once the power supply of the line is restored, the indicator can return to normal immediately. Moreover, it will not appear that the fault indicator is still in the wrong state of overturning when the power supply of the line is restored.