In the photovoltaic off-grid system, the role of the solar photovoltaic controller is to convert the electricity from the photovoltaic components and store it in the battery. In addition, it also has the functions of protecting the battery and preventing the battery from overcharging. At present, the controller mainly has two technical routes: pulse width debugging (PWM) mode and maximum power point tracking (MPPT) mode. Each method has its advantages and disadvantages, which can be selected according to different scenarios.
Both PWM and MPPT controllers have their own unique advantages and disadvantages. Which solution to choose depends on the design characteristics, cost and external environment of the solar photovoltaic array. When we choose, we should focus on the following factors:
The PWM method has mature technology, simple and reliable circuit, and low price, but the utilization rate of components is low. The utilization rate of modules is about 80% or more; MPPT solar controller refers to a solar controller with maximum power point tracking function. There is a BUCK step-down circuit between the module and the battery, and the utilization rate of the module is about 90% or more.
The main users of small off-grid systems below 2kW are poor areas without electricity, such as remote mountainous areas and some poor countries in Africa. They mainly solve the needs of lighting. The users are very price-sensitive. Therefore, it is recommended to use a PWM controller to correct the wave. Inverter, the controller, inverter and battery are integrated. This method has simple structure, high efficiency, convenient connection for users, and low price. There is no problem in driving light bulbs, small TVs, and small fans.
For off-grid systems above 2kW, MPPT controller is recommended, which has high component utilization, high overall machine efficiency and flexible component configuration. Generally speaking, no technology is the best, so for users, they should listen to the opinions of experts and ensure that they choose the correct controller to meet their needs.
solar power systems
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