Research On The Digital & Network Technology Of Parallel UPS System

The High Frequency UPS System is efficient highly ,energy-saving and has smaller size,lighter weight. The High Frequency Redundant Parallel UPS System isn't restricted by power capacities, and it can flexibly be used to expand power system capacities and realize high power, improve the flexibleness, lessen the interval of malfunction or maintenance and make it become a true Uninterrupted Power Supply. The digital control technology of high frequency UPS System is studied in this paper. The outer voltage loop is digitally controlled and the inner current loop is controlled by hysteresis band with analog circuit for PFC control in the sect of rectifier, and the design of controller parameters is analyzed. The circuit of half-bridge inverter is adopted in the sect of inverter, the models of SPWM inverter are established and how to design PI controller parameters with voltage RMS feedback is studied. Based on the research of high frequency UPS, models of parallel inverter system are established to analyze the specialty of the circumfluence and the essential principle of the parallel operation. This paper analyzes the feasibility of introducing CAN BUS into the high frequency redundant parallel UPS system, studies the design of the hardware and software of the system based on PeliCAN mode of SJA1000 in the parallel UPS real-time supervision system, gives the interface circuit of DSP and CAN,each node hardware circuit of CAN communication and analyzes the essential principle of double acceptance filter in detail and its application. The real-time supervision system uses ACM240128—large-size Lcd module, realizes the humanizing user's interface. This paper provides the interface circuit of DSP and LCD,describes the methods of related software,the display method of geography and character information. UPS in the network times can support for remote supervision, intelligent management. Two kinds of network supervision scheme are discussed in this paper and the design of RS232 communication interface of UPS is provided, and on this basis, network supervision SNMP communication interface is constructed. At last, this paper introduces the design of supervision software supported for local and remote supervision based on Visual Basic6.0 briefly. The experimental results indicate UPS system operates stably, has good dynamic,steady-state performance ,and UPS network supervision system works reliably, has friendly interface, meets the need of Parallel UPS system network supervision.