Select PWM controller or MPPT controller

In the solar power generation system, it is mainly composed of PV module, storage battery, solar controller and load. Although the cost of solar energy controller is only a small part of the PV system, the choice of the controller can optimize the system to a large extent.At present, the popular solar controller on the market is mainly ordinary solar controller, PWM solar controller and MPPT solar controller. Ordinary solar controller is the first generation technology, due to the factors of the internal resistance of battery, it is difficult to charge batteries fully, and solar panels is not fully utilized, the MPPT tracking efficiency is only 70%-76%, so it has been out of the market. PWM solar controller is the most popular used, solar MPPT controller is nowadays trend, so more and more people in the industry have to make a choice between PWM solar controller and MPPT solar controller.

PWM solar controller is the second generation technology, it use the PWM control mode, compared with ordinary solar controller, has been improved a lot. Pulse width modulation (PWM) is an effective technique to control analog circuits by digital output. In the PWM solar controller, the battery pack is not only the storage of the electric energy, but also the voltage regulator of the solar system. Real time monitoring of battery potential by controller, and the number of potential solar access control or cut out of the sub matrix (or duty cycle rate), so as to adjust the charging current charge into the battery, in order to control the battery potential; The load obtains a relatively stable voltage from both ends of the battery pack. PWM solar controller can solve the problem of battery dissatisfaction, MPPT tracking efficiency of 75 ~ 80%, but the solar panels are still not fully utilized.

Solar MPPT charge controller is the third generation technology, is now the most high-end solar controller, the current use is relatively little, but very hot in the industry. MPPT solar controller, referring to the “maximum power point tracking” function, is the upgrading of PWM solar controller. The MPPT solar controller can detect the voltage and current of the solar panel in real time, and continuously track the maximum power (P=U*I), so that the system can always charge the battery with the maximum power. The tracking efficiency of MPPT is 99%, and the efficiency of the whole system is up to 97%, and the battery charging phase can be divided into MPPT charging, constant voltage equalizing charging and constant voltage floating charging.

In theory, the efficiency of the solar power generation system using MPPT controller will be 50% higher than the efficiency of solar controller using traditional one, but in the test, there is the impact of the surrounding environment and a variety of energy loss, though the efficiency did not reach the theoretical value, but also can improve 20%-30%. As the promotion of photovoltaic technology , coupled with energy saving and cost saving concept, I believe there will be more and more people in the industry tend to MPPT solar controller.