What is the design method of solar photovoltaic power generation system?The input energy of the solar photovoltaic power generation system is irregularly changing solar energy. Solar energy changes all the time, and its cumulative value is not necessarily; the performance of solar cells is not fixed. Therefore, the design of solar photovoltaic power generation system is quite complicated. In this chapter, try to clarify the principles of several design methods of solar photovoltaic power generation system. Among them, a method that is particularly worthy of recommendation is not to directly deal with irregular matters, but to adopt the method of stereotyped empirical formula, that is, the method of parameter analysis.
Generally speaking, the design method of solar photovoltaic power generation system,It can be roughly parameter analysis methods and simulation methods.
For the analytical method, the algebraic formula that expresses the dynamics of the system must be established first, and then a computer or design drawing line is used to solve the formulas in order in order to find the unknowns necessary in the design. However, due to the irregular changes of various state quantities and coefficients, it is quite difficult to directly deal with it. One of the processing methods is to describe the system as a probability variable. This method is flexible as a theoretical treatment, but it can be said to lack practicality when used. A representative such method is the LOLP (Loss of Load Probability) method, Loss of Load Probability method can be used to reflect the power failure probability of an independent system in the design.
The second approximation method of the analytical method is the parameter analysis method. This method simplifies the work of a complex nonlinear solar photovoltaic power generation system into a linear system. First of all, as a premise, the performance is to replace all the parameters with the average energy of a certain period. Of course, doing so will cause contradictions in some parts, but you can import correction parameters. According to this method, the listed formulas can be used directly in the design, so the design becomes extremely simple.
Parametric analysis method is easy to understand even for beginners in system design. Especially in the preliminary planning stage of the system, the research can be carried out quickly and repeatedly, which is a method with high practical value. This is the reason why the parameter analysis method is recommended in this book.
The simulation method is to dynamically represent the state of the system as a model of solar radiation and load, etc., and actually reproduce the working state of the system. It is a method suitable for computers. Generally speaking, just like the theoretical formula represented by the characteristics of solar cells and storage batteries, calculating the state of the system for 30 minutes can simulate the operation of the system within one year. As particularly important data, it is necessary to use 30min of irradiance and load power consumption or even longer time for calculation.
With this method, since the deviation between the insolation model and the load model can be accurately expressed, the comparative parameter analysis method can be used to evaluate the system more accurately in advance. For the basic design that has used the parameter analysis method, the simulation method can often be used for further confirmation. In addition, it is also possible to study the simulation results first, and then use them to determine the parameters in the parameter analysis method.