Improved MPPT (Maximum Power Point Tracking) algorithm and LED (Light Emitting Diode) street lamp system based on algorithm

Abstract

The invention relates to a solar LED (Light Emitting Diode) street lamp system. The invention comprises an improved MPPT (Maximum Power Point Tracking) algorithm and an LED street lamp system based on the algorithm. The improved MPPT algorithm comprises the steps of: step 1: setting a maximum power point tracking starting scope as from Vmin to Vmax according to current environmental temperature T and the open-circuit voltage Voc; step 2: measuring the output voltage and the input current of a solar battery panel; step 3: judging whether VPN meets the condition that Vmin is smaller than or equal to VPN which is smaller than or equal to Vmax or not, if so, starting to search for the maximum power point from the midpoint from the Vmax to Vmin; step 4: judging whether the VPN is located in the maximum power point or not in a shorter period of time; step 5: judging whether the VPN is located in the maximum power point or not in a longer period of time, if so, calculating the reference voltage of a PI controller and making the system operate at the maximum power point stably by performing PI adjustment for Vset and VPN, or continuously searching for the maximum power point; and step 6: inquiring whether the VPN is located at the maximum power point or not for a long period of time, if not, returning to the step 2 to continuously track the maximum power point.

Description

technical field [0001] The invention relates to a solar LED street lamp system, in particular to an improved MPPT algorithm and a solar LED street lamp system based on the algorithm. Background technique [0002] Applying LED lamps to the field of street lighting can save energy by more than 50% compared with ordinary high-pressure sodium lamps, and has a longer service life; and the solar LED street lamp system obtained by combining solar energy and LEDs combines the advantages of both, making urban street lamps The lighting system is more energy efficient. [0003] The existing solar LED street light system is mainly composed of several parts such as solar panels, LED lamp holders, control boxes (with controllers and batteries inside) and light poles, among which solar panels are the core part of the solar street light system. Convert the sun's radiation ability into electrical energy, or send it to the storage battery for storage. Among the many solar panels, the most c...

AI Technical Summary

Problems solved by technology

If the output voltage of the solar panel can be controlled at its maximum power point, the system will work at the maximum power point. This method is simple and stable, but the control accuracy is poor, and it can be used in combination with other methods.

[0006] At present, the most widely used method is the perturbation and observation method: the conventional perturbation and observation method is widely used because its algorithm is simple, easy to implement, and does not require high sensor accuracy, but it also has obvious disadvantages: on the one hand, even if the system has been Running near the maximum power point, the disturbance still does not stop, so that the voltage will oscillate with the continuation of the disturbance and cause power loss; on the other hand, when the light intensity or temperature changes rapidly, the system is prone to misjudgment

However, when the external environment changes drastically, misjudgments will still occur

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