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The working principle of photovoltaic MPPT

The photovoltaic inverter is the core component of the photovoltaic power generation system, and MPPT technology is the core technology of the photovoltaic inverter. So, what is photovoltaic MPPT?

MPPT (Maximum Power Point Tracking, referred to as MPPT) is a system by adjusting the operation state of the electrical module, photovoltaic panels can output more power DC electrical system of the solar cell panel can be emitted efficiently stored in a battery, It can effectively solve the domestic and industrial electricity consumption in remote areas and tourist areas that cannot be covered by conventional power grids, without causing environmental pollution.

The MPPT controller can detect the voltage generated by the solar panel in real-time, and track the maximum voltage and current value (VI) so that the system can charge the battery with the maximum power output. Used in solar photovoltaic systems to coordinate the work of solar panels, batteries, and loads, it is the brain of the photovoltaic system.

 

 1 The role of solar inverter MPPT

Regarding the role of MPPT, it can be reflected in one sentence: the output power of the photovoltaic cell is related to the working voltage of the MPPT controller, and its output power will have a unique maximum value only when it works at the most suitable voltage.

Since the solar cells receive the impact of external factors such as light intensity and the environment, the output power is changed, the electric light intensity emitted by the more with MPPT. MPPT inverter is to make full use of solar energy battery, make Run at the maximum powerpoint. That is to say, under the condition of constant solar radiation, the output power after MPPT will be higher than that before MPPT.

 

 2 Principles of MPPT

MPPT control is generally completed by a DC/DC conversion circuit. The photovoltaic cell array is connected to the load through a DC/DC circuit. The maximum power tracking device continuously detects the current and voltage changes of the photovoltaic array, and based on its changes, the DC/DC converter is The duty cycle of the PWM drive signal is adjusted.

For linear circuits, when the load resistance is equal to the internal resistance of the power supply, the power supply has the maximum power output. Although both photovoltaic cells and DC/DC conversion circuits are strongly non-linear, they can be considered linear circuits in a very short period. Therefore, as long as the equivalent resistance of the DC-DC conversion circuit is adjusted so that it is always equal to the internal resistance of the photovoltaic cell, the maximum output of the photovoltaic cell can be achieved, and the MPPT of the photovoltaic cell can be realized.

In general, the MPPT controller will track the maximum power point in the solar panel in real-time to maximize the efficiency of the solar panel. The higher the voltage, the more power can be output through maximum power tracking, thereby improving the charging efficiency. In this sense, the MPPT solar charge and discharge controller is bound to eventually replace the traditional solar controller.

solar inverter diagram