Design Of Low Power UPS Base On Bi-directional DC/DC Converter

SMEs choose the right power protection products to be an effective solution to their dependence on modern office methods,and power in the following 10KVA UPS just small power of the SMEs in the meet this demand.So the application of UPS status has become increasingly important and widespread.However,traditional small interactive on-line UPS power inherent shortcomings,design of a small power line interactive UPS is improved in this paper,using inductively coupled with the bi-direetional DC/DC converter circuit as the UPS battery charge and discharge circuit. It has omitted the frequency transformer,the rechargeable lead-acid battery management,increased battery life,stability,DC bus voltage to achieve the advantages of two-way flow of energy.In this paper,working principle of the converter and parameter design of master circuit has been analysed detailed.In the duty cycle of 35%to 55%,and the turns ratio N = 6,battery voltage 48V has been increased to DC bus voltage 360V.In addition, the two-way flow of energy has been achieved,Simulation and experimental confirmed the feasibility of the programme.In the battery detection,measuring battery internal resistance using AC-method,real-time monitoring of the battery operating parameters has been realized.In addition,Synthesized digital control algorithm using the combination of repetitive control and PI control used in the UPS master control system,the stability and robustness of the system has been enhanced.