The brains of photovoltaic systems: MPPT solar controller

The full name of the MPPT controller is the Maximum Power Point Tracking solar controller, which is an upgraded product of the traditional solar charge and discharge controller. The MPPT controller can detect the power generation voltage of the solar panel in real time, and track the voltage and current value, so that the system can charge the battery with power output. Applied in solar photovoltaic system, it is the brain of photovoltaic system to coordinate the work of solar panel, battery and load.

The power point tracking system is an electrical system that adjusts the working state of the electrical module to enable the photovoltaic panel to output more electrical energy. Domestic and industrial electricity consumption in remote areas and tourist areas will not cause environmental pollution.

What is the role of MPPT?

Since solar cells are affected by external factors such as light intensity and the environment, their output power varies, and the light intensity emits more electricity. The inverter with MPPT power tracking is to make full use of solar cells to make them run at power point. That is to say, under the condition of constant solar radiation, the output power after MPPT will be higher than that before MPPT, which is the role of MPPT.

Principle of Power Point Tracking

With the development of electronic technology, the MPPT control of the current solar cell array is generally completed through the DC/DC conversion circuit. The photovoltaic cell array is connected to the load through a DC/DC circuit, and the power tracking device continuously detects the current and voltage changes of the photovoltaic array, and adjusts the duty cycle of the PWM drive signal of the DC/DC converter according to the change.

Block diagram of MPPT system

For linear circuits, when the load resistance is equal to the internal resistance of the power supply, the power supply has power output. Although both photovoltaic cells and DC/DC conversion circuits are strongly nonlinear, they can be considered linear circuits for a very short period of time. 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 output of the photovoltaic cell can be realized, and the MPPT of the photovoltaic cell is also realized.