| From the first time human beings use electricity in their lives,each step in the history of development can not be separated from electricity.The progress of the society is accompanied by a variety of needs,In order to meet the demand of different occasions,high-frequency switching power supply arises at the historic moment.The power supply belongs to the electric energy conversion device,which can convert electric energy into any voltage level and type,and therefore can be widely used in various fields,such as aviation,aerospace,etc.In addition,with the development of society,on the one hand,electronic products emerge in an endless stream,the use of occasions are also different,which led to the continuous improvement of the performance requirements of the power supply;On the other hand,the public's attention to the issue of energy is increasing,which makes the efficiency of electricity become prominent.In order to improve the performance of high frequency switching power supply,we must rely on increasing frequency,reduce the volume of components to achieve.The increase of frequency makes the number of switching times increase in unit time,which is bound to lead to higher switching losses.Therefore,in order to improve the performance while taking into account the efficiency of electricity,it is necessary to explore in the field of high frequency switching power supply,research the new topology,introduce new technology,discover new materials.Through the continuous optimization design,and ultimately meet the requirements of all users.The main task of this thesis is to design the numerical control and uninterruptible DC power supply.The power supply is divided into two kinds of input methods:power grid and battery.The main power supply of numerical control and uninterruptible DC power supply take power from power grid,mainly include the AC-DC boost type power factor correction circuit,half bridge LLC resonant circuit,second step-down circuit.The AC-DC boost power factor correction circuit is mainly used for the rectification of AC and current waveform,the circuit uses NCP1654 as the control chip,the output voltage is 385V DC.The Half bridge LLC resonant circuit with soft switching technology,which uses NCP1397 as the control chip,the output voltage of the first circuit is reduced to 48V.The second step-down circuit is the traditional half bridge circuit,the MC9S12 main control board is directly controlled to complete the adjustable output of the main power of the whole power grid.Battery backup power supply take power from battery,And it can ensure continuous power supply when the power grid or main power circuit fail.The backup power supply only passes through a boost and buck circuit(battery power supply circuit),the control of the boost and buck in the circuit is accomplished by LM3478 chip and NCP1034 chip,the MC9S12 main control board give the feedback signal to NCP1034 chip's FB pin,and through the NCP1034 chip indirectly regulate the output voltage of backup power supply.The main function of the chip power supply circuit is to supply power to the control chip and the chip of the main control board,and the output switching between the main and the backup power supply rely on the chip power supply circuit to complete the power supply of different control chips.MC9S12 main control board take Freescale MC9S12 as the core,and complete whole system protection,detection and output voltage adjustment.In this design,aiming at the research of numerical control and uninterruptible DC power supply at first.Under the premise of the overall functional requirements,it starts with the choice of the topology of each circuit,and completes the circuit design and the calculation of the component parameters.In order to verify its rationality,and then made a Matlab-Simulink simulation.Finally,according to the previous design,the prototype is made,some test results and analysis are given. |
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