The open circuit voltage exceeds 200V DC PWM control is simple

This kind of controller was made in 2007. At that time, it was made on street lamps and used an 8-pin single-chip microcomputer . In fact, this PWM controller is very mature and the market price is very low. Since this control method is actually similar to a switch, it basically does not generate any heat when working.

All PWM is the simplest way, because this is used for 48V 96V. The open circuit voltage of the solar panel may exceed 200V DC. In order to improve reliability, it is necessary to design an independent auxiliary power supply to provide to the CPU and drive circuit. The charging current is 50-100A. Because it is a PWM control method, the loss on the MOSFET is very small, and only a small heat sink is needed to fix the MOSFET.

The following are the actual photos:

In fact, the current PWM control method is simply a set of MOSFET switches. Just think of this MOS as a relay . At night, a set of MOSFETs are turned off to prevent the battery from discharging reversely to the battery board. I used TLP250 as the driver. And this does not require a fan, because the radiator is used for conducting electricity, and there is no air cooling requirement.

The switching frequency on the MOSFET is very low, less than 1KHZ. A set of PWM pulses is generated by the single-chip microcomputer, and then a battery voltage sampling is performed and a PI adjustment is performed, and it is OK. In fact, the duty cycle can reach 100%, because my driver is an optocoupler and a separate isolated power supply is used. When the duty cycle reaches 100%, the MOSFET is equivalent to directly passing through the solar panel and battery voltage.