Design Of Analog And Digital Hybrid Module Based On CompactRIO

In recent years, new energy-microgrid off-grid and grid-connected power generation has become the mainstream in the research and application all over the world, especially for solar pv and wind power. Inverter as the core component of new energy power generation plays an important role in microgrid generation system. Current predictive control technology is one of the inverter control technology among the common control methods, reference currents need to be acquired from the inverter output, inverter switch states of the next moment are calculated through the control algorithm to complete the control of the inverter. Current signal acquisition module and digital switch signal output module are needed in the control method, and their parameters are significant, such as precision and sampling rate.Aiming at the demand of the current tracking control, according to the principle and parameters of data acquisition system, a hybrid module of analog acquisition and digital input&output was designed. Specific work includes:1. The hardware of module was designed, broke it into parts like external signal conditioning circuit, single-ended to differential circuit, A/D conversion circuit, reference voltage circuit, signal isolation circuit, digital input&output circuit and supply part according to the function, and designed them independently. Using ADS1258as a conversion chip, embedded FPGA in National Instrument Compact RIO9073chassis as a controller to complete the function of system:24-bit resolution,16-channel analog acquisition,8-channel digital input&output.2. The driver module was designed, according to the SPI protocol and user manual of NI custom module, completed the EEPROM selection, programmed the EEPROM, ADS1258register and module driver on Labview to simplify the process.3. The experiment was carried out, tested the effect and parameters of module and analysed the results.