Research And Implementation Of The Software For Programmable Power Supply

With the wide application of electrified equipment,the increase of various kinds of non-linear loads leads to the deterioration of power quality in the power grid.Meanwhile,high-end manufacturing fields,such as chip manufacturing,precision motor control and special material processing,need high quality power supply.A high quality programmable power supply between power grid and power equipment can effectively avoid various problems caused by the quality of power supply.Compared with abroad high-end product,domestic programmable power products still have a big gap in functions and technical indicators.The lack of high-quality programmable power supply will greatly hinder the development trend of domestic manufacturing industry from lowend manufacturing to high-end manufacturing.Therefore,high quality programmable power supply has a wide application prospect and high research value.Firstly,the overall design scheme of software system for programmable AC power supply is introduced in this paper.OMAP-L138 dual-core processor is selected as the main control chip in this project.The DSP program is responsible for the generation and control of the output signal,and the ARM program is responsible for the realization of the human-computer interaction system.The generation and transmission of output waveform is the difficulty and key to the realization of programmable functions in this project.Based on the analysis and research of DSP thread management mechanism and frequency synthesis technology,a method combining DDS technology and multi-thread programming technology is used to generate the digital waveforms and the waveforms is transformed synchronously and isolated through the multi-channel digital audio interface built in OMAP-L138 chip.Sampling the output signal to form a closed-loop system is of great significance to improve the accuracy and stability of the system.In this paper,the methods of improving the accuracy of output voltage in software system in programmable power source are discussed and analyzed in detail.In this project,a two-channel “coarse tuning + fine tuning” gain configure method is adopted,and a feedforward + PI control system is introduced to ensure that the system can meet the requirements of output accuracy and load adjustment ability in the indicators.Finally,a prototype of programmable AC power supply is made and a test platform of the prototype is built.The programmable functions and related indicators such as the harmonic distortion,frequency accuracy,voltage accuracy of output signal of the prototype are tested.According to the measurement results,the programmable functions such as arbitrary waveform output,sequential waveform output and abnormal waveform output of the prototype all work normally.The harmonic distortion of output signal is less than 0.06%,which is much lower than 0.2% of the target requirement.The accuracy of output frequency,voltage and load adjustment ability all meet the requirements of the project target.