This paper proposes a multiport bidirectional non-isolated converter topology that provides advantages in terms of simultaneous multiple operations,single-stage conversion,high power density and reduced power losses d...This paper proposes a multiport bidirectional non-isolated converter topology that provides advantages in terms of simultaneous multiple operations,single-stage conversion,high power density and reduced power losses due to the lower number of switches.The proposed multiport converter uses a centralized non-linear controller known as a finite control set model predictive controller to manage the flow of power between different ports.It deals with the parallel operation of photovoltaic and battery energy storage systems for stand-alone alternating current(AC)systems.The converter connects the lower voltage battery to the photovoltaic port using a bidirectional buck/boost converter and the photovoltaic port is linked to the stand-alone AC load through a three-phase full-bridge inverter.Each leg of the three-phase converter will act as a bidirectional direct current(DC)/DC converter as well as an inverter simultaneously.Only six switches manage the power transfer between all the connected ports of photovoltaic-battery energy storage system linked to the stand-alone AC load.The proposed multiport converter is mathematically modelled and controlled by a finite control set model predictive controller.The system is validated in simulation(1-kW rating)and experimental environment(200-W rating).The hardware prototype is developed in the laboratory and the controller is implemented on the field-programmable gate array board.Two independent case studies are carried out to validate the efficacy of the system.The first scenario is for a change in solar irradiance,while the second scenario is for a change in the output load.展开更多
Among various DC/AC matrix converters,the isolated single-phase DC to three-phase AC matrix converter has attracted significant research attention due to its advantages of low loss,simple topology and modulation.PI co...Among various DC/AC matrix converters,the isolated single-phase DC to three-phase AC matrix converter has attracted significant research attention due to its advantages of low loss,simple topology and modulation.PI control is widely used in industrial manufacturing,but the increase in control target error and environmental factors will lead to decline of control system accuracy.We introduce a finite-control-set model predictive control(FCS-MPC)to predict the d-and q-axis currents in a high-frequency link matrix DC/AC converter(HFLMC)with a loosely coupled high-frequency transformer(LCHFT).The modulation and commutation modes of the HFLMC are introduced,transmission power of the HFLMC with air gap is given,and the output side compensated predictive model is also established.Design of LCHFT is given.The coupling coefficient of LCHFT under different air gap affects transmission efficiency.Finally,experiment results on a 300 W prototype verify correctness of the theoretical analysis and simulation.展开更多
储能电感位于原边的全桥DC/DC变流器（full bridgeconverter with primary side energy storage inductor,FB-PESI）,采用传统的固定频率、移向控制（phase-shift,PS）方式时主要工作于断续导通模式（discontinuous conductionmode,DCM...储能电感位于原边的全桥DC/DC变流器（full bridgeconverter with primary side energy storage inductor,FB-PESI）,采用传统的固定频率、移向控制（phase-shift,PS）方式时主要工作于断续导通模式（discontinuous conductionmode,DCM）,不适合应用于宽范围电压输入的场合。为克服PSFB-PESI变流器的这一缺点,提出一种新型的采用变频（variable frequency,VF）控制策略的FB-PESI DC/DC变流器（VFFB-PESI）。该VFFB-PESI变流器不仅保留了PSFB-PESI变流器宽范围软开关、高效率、高功率密度的优点,还可始终工作于临界导通模式（critical continuous operation mode,CrCM）,从而在宽输入电压范围内均可获得较高的变换效率。同时给出了针对该VFFB-PESI变流器的损耗分析方法和优化设计流程。通过制作的300 W、200~400 V输入、12 V输出样机实验,验证了理论分析的正确性。展开更多
文摘This paper proposes a multiport bidirectional non-isolated converter topology that provides advantages in terms of simultaneous multiple operations,single-stage conversion,high power density and reduced power losses due to the lower number of switches.The proposed multiport converter uses a centralized non-linear controller known as a finite control set model predictive controller to manage the flow of power between different ports.It deals with the parallel operation of photovoltaic and battery energy storage systems for stand-alone alternating current(AC)systems.The converter connects the lower voltage battery to the photovoltaic port using a bidirectional buck/boost converter and the photovoltaic port is linked to the stand-alone AC load through a three-phase full-bridge inverter.Each leg of the three-phase converter will act as a bidirectional direct current(DC)/DC converter as well as an inverter simultaneously.Only six switches manage the power transfer between all the connected ports of photovoltaic-battery energy storage system linked to the stand-alone AC load.The proposed multiport converter is mathematically modelled and controlled by a finite control set model predictive controller.The system is validated in simulation(1-kW rating)and experimental environment(200-W rating).The hardware prototype is developed in the laboratory and the controller is implemented on the field-programmable gate array board.Two independent case studies are carried out to validate the efficacy of the system.The first scenario is for a change in solar irradiance,while the second scenario is for a change in the output load.
基金supported by the National Natural Science Foundation of China(52577048).
文摘Among various DC/AC matrix converters,the isolated single-phase DC to three-phase AC matrix converter has attracted significant research attention due to its advantages of low loss,simple topology and modulation.PI control is widely used in industrial manufacturing,but the increase in control target error and environmental factors will lead to decline of control system accuracy.We introduce a finite-control-set model predictive control(FCS-MPC)to predict the d-and q-axis currents in a high-frequency link matrix DC/AC converter(HFLMC)with a loosely coupled high-frequency transformer(LCHFT).The modulation and commutation modes of the HFLMC are introduced,transmission power of the HFLMC with air gap is given,and the output side compensated predictive model is also established.Design of LCHFT is given.The coupling coefficient of LCHFT under different air gap affects transmission efficiency.Finally,experiment results on a 300 W prototype verify correctness of the theoretical analysis and simulation.
