| The rectifier circuit between the AC-DC converter of the conventional air conditioner compressor drive system is usually composed of an diode-based uncontrolled rectifier circuit.A large value electrolytic capacitor is used on the DC-link to filter low frequency harmonics.However,uncontrolled rectifier circuits result in low grid side power factor(PF)and high grid side current total harmonic distortion(THD).Low grid side PF will reduce the operating efficiency of the equipment,which causes energy waste to the grid.Besides,high grid current THD brings serious pollution to the grid.In order to solve the above problems,a totem-pole bridgeless boost PFC circuit topology based on GaN HEMT can be used to replace the uncontrolled rectifier circuit in the air conditioner compressor drive system.The proposed system can increase the grid side PF,reduce the grid side current THD and improve the circuit efficiency,which is of great significance for reducing air conditioning energy consumption and energy saving.In order to complete the design of the overall scheme of the totem-pole bridgeless boost PFC converter,the working mode of the circuit is firstly analyzed,and the control system is designed.The control system uses a voltage-current double loop control system,and the circuit operates in the average current mode in CCM.Secondly,the hardware design of the converter is mainly to select the components of the converter and verify the parameters of them.Finally,the loss calculation of the selected magnetic components and power devices is proposed to verify the designed converter meets the design requirements.Studying the high PF closed-loop control strategy of the totem-pole bridgeless boost PFC converter,the power level transfer function of the converter is firstly obtained by the state-space averaging method.Then,the voltage and current loop controllers are designed based on the small signal model of the voltage and current loop,respectively.Secondly,the Bode diagram is used to analyze the performance of the voltage and current loop control system,and the simulation verification is carried out.The influence of parasitic parameters on the driving performance of GaN HEMT is very important,the performance of GaN HEMT is firstly analyzed.Then,the working principle of the driving circuit is analyzed.Secondly,the drive circuit is designed according to the characteristics of the device.Finally,the d ouble-pulse circuit based on GaN HEMT is verified in the PSpice simulation environment,and the experimental verification is carried out on the double-pulse circuit experimental platform.The totem-pole bridgeless boost PFC converter is verified in the MATLAB/Simulink simulation environment.Meanwhile,the stability of the system is also verified in the simulation environment when the grid voltage and the load change abruptly.Finally,a prototype of a totem-pole bridgeless boost PFC converter based on GaN HEMT for an 1.5-horse power air conditioner system is proposed.The experimental verification is carried out under different power levels and the effectiveness of the proposed method is verified. |
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