Research And Development Of Vehicle Solar Cell Controller Based On Ethernet

Under the background of our country’s promotion of carbon peaking and carbon neutrality,the green vehicles and solar photovoltaic industries have broad prospects.However,the application of solar technology in the automotive field is less,and it focuses on the field of commercial vehicles.Applying solar cells to electric vehicles can supplement low-voltage batteries and serve as auxiliary power supply equipment when driving.The solar battery controller is a device that converts the electrical energy generated by photovoltaics into the electrical energy required by the load.In the field of passenger vehicles,there are few vehicle-grade solar controllers that meet automotive electronics standards.Automotive electronic control units usually need to be connected to the vehicle network to realize functions such as vehicle state perception,fault diagnosis and intelligent control.Ethernet is replacing the Controller Area Network(CAN)bus as the backbone of the automotive electrical and electronic architecture.The thesis develops a solar battery controller based on the vehicle Ethernet.The controller is more in line with the needs of passenger cars in terms of hardware design and performance indicators.The software implements the flow priority scheduling strategy of the vehicle Ethernet to alleviate network congestion of the control data.The research content of the thesis is as follows:On the basis of analyzing the design requirements,the thesis developed a solar battery controller hardware system.The modular design of the hardware system mainly includes the physical layer circuit of the vehicle Ethernet,the system power supply and sleep wake-up circuit,the minimum system of the main control chip and the interface protection module.Calculate the parameters of each component and select the product,complete the layout and routing of the printed circuit board,signal integrity design and detail optimization,complete the proofing,welding and debugging of the hardware circuit board,and design the radiator and hull of the controller.Developed the solar cell controller software system.The software system adopts layered thinking,transplants the operating system and network protocol stack,and realizes the functions of network communication,charging state monitoring,maximum power point tracking and output voltage regulation control on the basis of completing the development of the driver layer software.In this thesis,the experimental method is used to carry out system identification on the buck converter(Buck circuit),design and simulate the output regulator PI controller,and optimize the controller parameters combined with the experiment.Realize the flow priority scheduling strategy of vehicle Ethernet.In order to reduce the queuing delay of control data,this thesis adds a priority scheduling mechanism to the existing link layer,and the improvement measures are divided into two parts:the terminal protocol stack and the central gateway software configuration.The terminal protocol stack adopts a priority-based sending strategy for different types of tasks;the central gateway dispatches the data flow of the corresponding IP address and network port to a specific queue.Complete the experimental verification of the solar cell controller.In the output voltage regulation test,the system step response adjustment time is 2.4ms;in the actual vehicle charging test,the maximum power is 51.8W,the conversion efficiency is 94.9%,and the voltage ripple is within ± 150mV.A platform was built for LAN communication comparison experiments.As the bandwidth of infotainment data increases,the queuing delay of control data increases.After optimizing the scheduling strategy in terms of protocol stack and central gateway configuration,the real-time performance of control data is improved.The worst round-trip delay is 49ms.