Design and Implementation of Integrative Device for Power Supply and Measurement with Single Winding Current Transformer

In order to reduce the additional input of resources such as multi-winding current transformer, UPS and DC screen power supply during the use of microcomputer protection device in electric power transmission and distribution, a design method of integrative device for power supply and measurement with single winding current transformer is proposed. On the one hand, the output of single winding current transformer is used to provide power for microcomputer protection device, during which process, power supply/collection isolation module, rectifier and filter, voltage regulator and other modules are used in the design. Besides, dynamic voltage compensation is adopted to make up power supply gap when the current is small, while rechargeable supercapacitor is prepared as backup power. On the other hand, the output of single winding current transformer is used to provide current signal acquisition, using dynamic current compensation to supply the current which is used for providing voltage, ensure the accuracy of the current acquisition. The test results show that the implementation of the scheme can not only ensure the stable operation of microcomputer protection devices, but also reduce the use of resources such as multi-winding current transformer, UPS and DC screen power supply. Moreover, it can promote the usage of single winding current transformer, reduce costs, and improve economic benefits.