Background: To get maximum output of solar cells performance, but also allows solar cells to play the best work efficiency, and choose the most suitable for work, it has become the most important key. However, because the Earth's solar sunshine does not mean, the most effective place of work, often with the environment, the time change, which can not be sustained in the greatest power output, so a long time to maintain solar cells can be maintained In maximum power, must be ready to adjust its work cycle to effective use of solar energy, the production of low-cost, large area, high power conversion rate of solar cells, which in the past few years solar energy industry by pursuing the long-term goals and The key technology.
Fig said: solar cell output of the main strength is subject to sunshine, and solar surface temperature and other factors, because in different intensity and different surface temperature of the solar output characteristic curve is different; the product for solar energy Charger.
From the solar power conversion principle, as long as the sun directly through the photoelectric power generation semiconductor chip, as long as the proper sunlight, can be instantaneous output voltage and current, and solar cells is the equivalent output impedance load - The equivalent input impedance, the solar cell sent by the power of the largest, which is the maximum power transfer the basic principles, but the next step is to track how the solar panels work of the greatest power point »
Tracking solar maximum power conversion
Judging from the current solar cell technology development, has many ways to achieve goals, such as: incremental conductivity (Incremental and Conductance), disturbance observation (Perturbation and Observeation method), curve approximation (Curve Fitting), and type Neural learning (Neural Learning); disturbance which again is the observation of solar cells up to track the maximum power conversion technology (Maximum Power Point Tracking; MPPT), and the manner required by the relatively simple hardware architecture, can greatly Lower manufacturing costs, so this is the most mature and also the most was the technology.
However, the technology is the greatest shortcomings in the process of tracking power, once the atmospheric conditions changed, the reaction rate if not timely adjustments easy for the slow track speed of change, power will be wear and tear. University system and ship the Electrical and Mechanical Engineering Institute Professor Zhao Rumin said that in response to tracking solar maximum power designed to track, can have a single set of variables in the extreme two-track calculus, only through the measurement Can be reached on a single variable, from the structure, including: sensors, converters, the demand will become relatively less, in addition to lower manufacturing costs, but also get the most power, to reduce unnecessary disturbance in the atmosphere phenomenon , The power loss caused by the situation.
Solar and DC and AC current system diagram
Map: from solar energy into electric energy exchange, or DC, to supply the demand load, the conversion of the system components include: charge controller or inverter, cables and switches and other equipment and arrester.
Software and hardware technology to maintain optimal efficiency of solar cells
However, through the software technology to improve the situation is one kind of way; Professor Zhao Rumin mentioned, this is the best use interface software development platform and platform to write algorithms to give the system of self-adjustment of the speed of reaction function. Simply put, is to use software algorithms to achieve the maximum power of the solar track, and then through the use of algorithms FPGA module, to achieve the fastest performance, and at a higher frequency of the system, so that solar energy Battery to maintain maximum power tracking the best efficiency.
Solar Energy Conversion Systems organization chart
In addition, the hardware on the angle, measured by volume measurement modules to solar panels with the current changes in temperature, followed by RT and FPGA computing software module, which is real-time processing, since the last PWM mode Group maximum power output of Duty Cycle point to buck circuit, the output voltage at this time is the point of maximum power generated by the voltage, and provides battery-powered motor or load, such as through the above process can be further solar maximum power The track.
Generally speaking, if the controller through the various signals to show the measurement values, in order to measure signal FPGA chips implanted in a single variable calculus action can be tracking the implementation of the greatest power, and then controlled by the PWM output to drop Pressure DC / DC converters, the power switch, changed Duty Cycle achieve maximum power tracking results, which including the monitoring of the RT network processor to increase system reliability and practicality, on the one hand can also reduce the R & D results To the market commercialization of development time.