Comprehensive Research On Fault Diagnosis And Condition Assessment Of Pv Module With Hot Spot Based On ?-? Curve

With the urgent demand for renewable energy applications,humans continue to explore the development and application of solar energy.As an important part of solar power generation applications,photovoltaic power plants of various sizes have been put into use.With the long-term operation of photovoltaic power plants,the main carrier of photovoltaic power generation modules has gradually exposed many problems.Among them,hot spot failure has become the most concerned because it not only affects the power generation of photovoltaic modules but also causes the temperature of the modules to be too high,accompanied by hidden fire risks.One of the problems of photovoltaic module failure.Understanding the formation mechanism of hot spot faults,the impact of heat generation,and quickly diagnosing hot spot faults and judging its degree of heat generation during normal operation of the photovoltaic system are of great significance for improving the power generation capacity of the photovoltaic power plant and the safety and stability of the system operation.The paper mainly analyzes the formation mechanism of conventional hot spot failure and unconventional hot spot failure,combined with the influence of mismatch of photovoltaic cells on the conduction of the bypass diode of the photovoltaic module and using the curve composite principle to derive the evolution of the ?-? curve characteristics of the hot spot module;The simulation and experimental simulations obtained the ?-? curve of the photovoltaic module output under different mismatch conditions,and analyzed the causes of various curve characteristics.For the specific hot spot module,the proposed photovoltaic cell simplified ?-? curve was used to derive the determination method of R_sh+and k₃in the experimental simulation operation;summarize the ?-? curve type of the hot spot module,propose a five-point intercept method to identify the characteristics of the curve step,and accordingly propose a method for diagnosing the hot spot fault of the photovoltaic module.Diagnosis algorithm accuracy rate and recall rate,and analyzes the reasons for misjudgment and missed judgment;the power loss calculation method of hot spot battery is derived based on the photovoltaic cell equivalent circuit model,and the actual working current and ?-? curve are combined to calculate the power The specific size of the loss can then evaluate the severity of fever.