Research And Design Of Solar Lawn Mower And Energy Control Systems

With the development of mowing technology,traditional mowers with the shortcomings of great noise,serious exhaust pollution,great labor intensity of the operators and etc.,gradually are replaced by energy saving mowing products.In this paper,using the solar lawn mower as the research object,based on the study of the photovoltaic system deeply,a solar-powered lawn mower was designed and developed.The completed work and achieved results are generalized as follows:(1)In this paper,the various components composed of the photovoltaic systems were researched and analyzed independently and deeply,including the analysis of the operating characteristics and the critical factors of the photovoltaic cells,the comparison of the types and the performance of the battery,the selection of types of the motor,the control theory of the largest power point tracking and the use of the commonly algorithms.Furthermore,on the basis of the mathematical model of photovoltaic cells using on the project,the simulation model was built,the photovoltaic cells characteristic curve was done by simulation analysis.The simulation results show that the photovoltaic characteristics of the photovoltaic cell is nonlinear.Lighting conditions and the battery temperature directly affect the short-circuit current and open circuit voltage of the photovoltaic cell.(2)This paper analyzes the control idea of the constant voltage method,observation method through disturbance and incremental conductance method,based on the comparison of their respective strengths and weaknesses,a set of the modified observation algorithm through disturbance was founded.The algorithm improves the shortcomings of ignoring the influence of temperature and its low tracking efficiency of the constant voltage method;improves the shortcomings of tracking slowly and easily error tracking direction of the observed perturbation method;improves the shortcomings of track non-adjustable step size of the incremental conductance method.The control idea is simple and easily used for the small independent photovoltaic power generation system conditions.(3)In this paper,the improved perturbation and observation method as a control strategy of the photovoltaic systems,the PIC MCU as the core of the photovoltaic power generation system controller,the Buck circuit as the control of the main circuit,combined with the signal detection circuit,and the driver circuit,the PV controller was developed.The controller has interactive features that can be set artificially control parameters to achieve maximum power output.(4)In this paper,the mechanical structure of the solar mower was rationalized designed and the parameters of elements composed of the photovoltaic systems were selected.The driven approach of the solar mower is the rear-wheel driving,the ellectric drive system is a simple motor,the reducer and differential as one and the system has the low cost.The battery has a large quality,considering its impact on the overall stability,it was placed in the back side of the solar mower and in the bottom of the seat.Non-independent suspension was used as the conventional suspensionsystem,the leaf springs and the spring and the rubber bumpers as the shock absorber were used,two leaf springs and frame rigid were connected on the front and rear axles.The photovoltaic panels were placed on top of the machine and at the same time as receiving sunlight,it were shaded for the driver.The mowing motor were mounted on the frame of the chassis to facilitate mowing operation.The design of the frame references the human comfortable driving posture and body size of adult Chinese national standard GB-10000-88,to determine the overall size of the frame.In the selection of the dynamic component,the photovoltaic power,the battery capacity and drive motor power were calculationed and checked.(5)In this paper,based on a full understanding of mowing machines and photovoltaic theory,developed a test prototype of the solar mower and tested prototype.The experimental results demonstrate the mechanical structure and the power element were correct,the new disturbance observation was feasible and the designing of hardware and software were reasonable.