AN2946 Datasheet, PDF (1/38 Pages) STMicroelectronics – Solar-LED streetlight controller with 25 W LED lamp driver

AN2946
Application note
Solar-LED streetlight controller with 25 W LED lamp driver
and 85 W battery charger based on the STM32F101Rx
Introduction
The solar-LED streetlight controller described in this application note is designed to achieve
an 85 W solar energy battery charger and a 25 W LED lamp driver. During the daytime the
controller preserves the electricity energy gathered by the solar module (PV module), then
stores it in the battery. In the evening the controller uses the battery energy to power the
LED streetlight. When the battery runs out of power after several rainy days, the controller
enables the external offline power supply (not included in this system) instead of the battery
to power the LED streetlight until the system battery is fully charged again.
Due to the clean nature of solar energy, and the highly efficient energy conversion of the PV
module and very long operating life of the LED lamp, the solar-LED streetlight controller,
compared to conventional streetlights, can save electricity remarkably, thus abating
greenhouse gas (e.g. CO₂) emission.
This application note is based on the solution of solar-LED streetlight controller architecture,
including a battery charger and LED lamp driver. The description of the architecture involves
hardware and firmware design with design parameter settings. The solar-LED streetlight
controller demonstration board is shown in Figure 1.
Figure 1. Solar-LED streetlight controller demonstration board
September 2010
Doc ID 15473 Rev 2
1/38
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