Development Of Voltage And Current Logger In High-power Electrical Transmission Device

In Multi-channel Transient Electromagnetic Method(MTEM) exploration, electrical power transmitter is an important part, the accuracy and stability of the send and receive signals do convolution depending on the quality assessment of the transmitter. Use a voltage and current logger to monitoring the high-power electrical transmitter is essential in MTEM. The voltage and current logger development will affect the quality of the data inversion results. In this paper, use high-speed high-precision AD conversion chip, high-speed FPGA master core chip and high-speed USB device, invent a voltage and current logger for high-power electrical transmission device.Voltage and current logger mainly constitute by the analog amplifier circuit, high-speed AD conversion circuit, low-speed AD conversion circuit, high precision clock circuit and FPGA master circuit. Analog amplifier circuit used to divider the high voltage signal by the resistor, to acquire the high current signal by the sampling resistor. For low-speed part, conditioning amplify through the low-power instrument amplifier INA128, for high-speed part, use the high-speed instrument AD8429 and high-speed amplifier opa695 to conditioning amplify, then transmitted to the AD sampling circuit. AD sampling circuit selected the high-speed AD9226 and low-speed ADS1271 sampling as high speed and low speed sampling analog to digital converter chip, after conversion, the signal transmitted to FPGA through magnetic coupling for electrical isolation. Precision clock module use the MSP430 chip to ask the work status of atomic clock module SA.45 S. Use atomic clock as the global clock for FPGA circuit in order to improve the stability and accuracy of the FPGA data transmission. FPGA control circuit communicates via high-speed USB Cypress chip to PC host computer, for data acquisition PC real-time display and storage.In this paper, based on the voltage and current logger functional requirements, use uartus II, CCS, VS2010 software to write software programs. Realize high speed data acquisition and real-time data transmission from FPGA to PC host computer.Through each circuit board testing and stability testing after assembly, the acquisition of voltage and current reached the functional requirements of the indicators, through a series of indoor and outdoor testing and collection to verify the stability and recorder reliability.