1. The basic concepts of MPPT and PWM

PWM is pulse width modulation, which controls the current by adjusting the duty cycle Q to control the proportional relationship between the output voltage and the battery voltage. MPPT Maximum Powera Point Tracking maximizes the output power of solar panels by gradually adjusting the output voltage to find the optimal operating point.

2. How MPPT and PWM work

PWM control mode

It is generally divided into three charging stages: strong charge, balanced charge and floating charge. The charge controller compares the battery voltage with the load voltage and controls the ripple of the battery voltage within a certain range. The control method is simple and the cost is low, but the efficiency is not high.

MPPT control mode

It is generally divided into charging, constant voltage uniform charging and constant voltage floating charging stages. With maximum power point tracking, it can detect the current and voltage of the solar panel, and continuously track the maximum power, so that the system always charges the battery at maximum power.

The charge controller calculates the output power of the solar panel by detecting the output voltage and current of the solar panel, and then adjusts the output voltage of the control circuit according to the output power, and the way to adjust the output voltage can be analog or digital. The MPPT control method is more efficient, but it is also more costly.

3. Advantages and disadvantages of MPPT and PWM

PWM is simple to control and has a small input voltage range, making it suitable for charge controllers with low power. At the same time, the efficiency of PWM is low and the maximum output power cannot be reached. In addition, PWM has some disadvantages, such as affected battery life, high noise, etc.

Although the control method of MPPT is expensive, it has a wide input voltage range and can achieve the maximum output power, and at the same time, it will not greatly respond to the county Zhongyou Shouhui. In addition, MPPT also has the characteristics of intelligent management, which can be monitored and adjusted through the intelligent management system.

4. Occasions where MPPT and PWM are applicable

In general, in small off-grid systems, such as in homes and small commercial premises, PWM control can be used. Because these fields require less power and are less costly. Generally, in large-scale off-grid systems, such as solar power stations, RVs and other high-power demand places, MPPT control mode is required to achieve the best solar energy utilization efficiency.

MPPT and PWM are both common control methods in solar power system controllers, and suitable control methods should be selected for different places and application requirements.