Research On DC Power Supply Technology Of Residential Building

Distributed power sources and DC loads are widely used in residential buildings,such as photovoltaic,energy storage,LED light,electric vehicles.the DC power supply system can facilitate the access of distributed power sources and DC loads,and reduce conversion links,reducing system losses and saving operating costs.In addition,the electrical safety of DC systems is inherently superior to AC systems.Because of its economic value and safety advantages,the low voltage DC power supply system has become the future development trend of residential building power supply systems,and has great market potential.The paper takes residential buildings as the research object,researches the power supply mode of low voltage DC power supply system,including voltage level,wiring form,grounding method,electric shock protection,etc.In addition,it also analyzes the safety problems of the system structure and proposes solutions or suggestions.Based on the power supply characteristics of residential buildings,this paper analyzes the voltage level requirements of safety,power supply capability and adaptability.The safety performance of voltage level can be analyzed by the effect of human body current and the impedance of human body.The requirement of power supply capacity on the range of voltage levels is based on the power supply and radius of residential buildings.The technology of equipment also requires the voltage level.Finally,comprehensively consider the above three factors,and refer to the recommended values in the DC voltage standards to complete the voltage selection.By analyzing the electric shock protection performance of the system,the system structure(the wiring form & the grounding mode)is selected.Clarify the protection measures against electric shock and the types of wiring forms and grounding methods,establish a system protection system against electric shock.Combined with typical electric shock accidents,the electric shock protection performance of different system structures are compared and analyzed,and the selection suggestion of system structures is put forward.Finally,the safety problems of the selected system structure are proposed,including the existence of a blind spot in the two-point fault residual current detection,the insulation detection's difficulty in positioning the fault,and the impact of AC leakage current on the detection of the protection device.By analyzing the detection principle and performance of the protection devices,and the characteristics of the safety problems,the system structure and electric shock protection are improved within the allowable range of safety performance,and solutions or suggestions are proposed.