Research And Application Design Of Non-contact Integrated Voltage And Current Transducer

Accurate online real-time monitoring of power quality parameters of overhead lines in distribution network is the key technology to realize smart power grid.The voltage transducer and current transducer are important data acquisition equipment for real-time state monitoring of power signals.The accuracy of signal measurement,transmission,and processing is of great significance for improving the automatic control of energy measurement and the intelligent warning of relay protection.Most of the traditional power transformers have the disadvantages of being difficult to achieve single-ended ground measurement,inconvenient installation,high insulation requirements,susceptibility to ferromagnetic resonance and susceptibility to harmonics.Therefore,the principle and signal processing algorithm of PCB non-contact voltage and current transducers are researched,and a PCB non-contact integrated voltage and current transducer is designed,and an online monitoring system of power quality is constructed by using the transducer.Firstly,The non-contact measurement circuit principle,structure design and integration method of voltage transducer and current transducer are studied,and an open type integrated voltage and current transducer is designed in PCB for easy installation.Secondly,The complex trapezoidal integration algorithm is combined with error compensation measures to realize the integral reduction and digital output of the voltage and current signals.What’s more,the improved FFT algorithm with Hanning window double-spectrum line interpolation and all-phase is used to obtain the harmonic signal when the electronic transducer is connected to the network.Finally,the STM32F407 microcontroller is used as the main control chip to design the hardware circuit and software control program for each module of the non-contact integrated voltage and current transducer application system,and to communicate with the host computer through the RS485 bus to achieve effective data analysis in the background,so as to complete accurate online real-time monitoring of power parameters.Experimental results show that the non-contact voltage transducer and current transducer based on PCB both have high measurement accuracy and linearity,reaching the 0.5 level standard of measuring transducer,and have high harmonic analysis ability.The transducer has high accuracy,good sensitivity,and the basic test functions of the experiment can be achieved,which meets the requirements of smart power grid for miniaturization,convenience and intelligence of the electronic transducer.