Analysis And Design Of Embedded Power Conditioning Unit For Self-contained Power Supply

Self-contained power supply is the main source of electrical energy for many electrical equipment that is not connected to the power grid.It is usually composed of multiple subsystems,and uses the power conditioning unit(PCU)as the control center.PCU is responsible for controlling and coordinating the stable and reliable operation of the selfcontained power supply.At present,the PCU mainly adopts the way of running bare metal code on the embedded processor and controls the self-contained power supply to work independently.However,the emergence and development of many special equipment have more requirements for self-contained power supply.For example,the self-contained power supply studied in this paper has a strong pulse power burst output,which not only requires the PCU to coordinate and control all devices in the full power supply system to work flexibly and reliably,but also requires the PCU to have a higher level of information And faster response performance.In particular,the time scale of the pulse power output not only has a discharge control process of the order of 100 microseconds,but also has a charge control process of the millisecond level,and the power supply also has a high-frequency repetitive pulse output.Which makes the whole system has extremely high timing control accuracy requirements on the PCU.In order to meet this demand,this paper puts forward the technical ideas and design schemes of PCU based on ARM and μC/OS-III,and builds a flexible and reliable communication and control network based on the composition structure and working principle of self-contained power supply.At the application level,the PCU has functions such as communication,scheduling,capacitor bank charging,discharge control,human-computer interaction,and system state management and operation protection.The communication function is composed of 1553 B,CAN,I/O and serial port.It has a reasonable communication strategy for each communication method.The design has been optimized to ensure its reliability and convenience,including but not limited to the FPGA-assisted communication mechanism of 1553 B,the phase locking mechanism of CAN and the software filtering mechanism of I/O.The capacitor bank charging function takes the voltage value sampling and processing as the core.In response to the delay problem of the traditional moving average filtering algorithm,it innovatively introduces a predictive compensation mechanism,which effectively compensates the phase of the low frequency band while maintaining low algorithm complexity.In addition,other basic functions such as parameter setting,excitation control and screen display are also studied in detail,and specific algorithms or implementation methods are given.Based on the above work,an embedded system architecture with clear logic,distinct levels and low coupling is further built,and then the system tasks are divided and the logical organization structure between tasks is designed.At the same time,the execution logic of each task is analyzed and the implementation plan is given.Through the cooperative work of each task,the reliable operation of the PCU is realized.Finally,the software program of the PCU was actually tested and the experimental results show that the functions of the PCU are work.Meanwhile,the command response delay is about 30 us,the timing control error is about 1.26 us,and the CPU occupancy rate is between 7.3% and 12.6%.This shows that the PCU has a fast response speed,high control accuracy,and a healthy program state,which can meet the needs of self-contained power projects.