In the operation of photovoltaic power plants, we have always hoped to maximize the conversion of light energy into electrical energy in order to maintain efficient working conditions. So, how can we maximize the power generation efficiency of photovoltaic power plants?
Today, let’s talk about an important factor that affects the power generation efficiency of photovoltaic power plants – maximum power point tracking technology, which is what we often call MPPT.
The Maximum Power Point Tracking (MPPT) system is an electrical system that enables the photovoltaic panel to output more electrical energy by adjusting the working state of the electrical module. It can effectively store the direct current generated by the solar panel in the battery, and can effectively solve the domestic and industrial power 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 generated voltage of the solar panel in real-time and track the highest voltage and current value (VI) so that the system can charge the battery with the maximum power output. Applied in solar photovoltaic systems, coordinating the work of solar panels, batteries, and loads is the brain of the photovoltaic system.
Role of MPPT
The function of MPPT can be expressed in one sentence: the output power of the photovoltaic cell is related to the working voltage of the MPPT controller. Only when it works at the most suitable voltage can its output power have a unique maximum value.
Because solar cells are affected by external factors such as light intensity and the environment, their output power changes, and the light intensity generates more electricity. The inverter with MPPT maximum power tracking is to make full use of solar cells and makes them run at the maximum 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.
MPPT control is generally accomplished through a DC/DC conversion circuit, the photovoltaic cell array is connected to the load through a DC/DC circuit, and the maximum power tracking device is constantly
Detect the current and voltage changes of the photovoltaic array, and adjust the duty cycle of the PWM driving signal of the DC/DC converter according to the changes.
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 nonlinear, they can be considered linear circuits in a very short 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 maximum output of the photovoltaic cell can be achieved, and the MPPT of the photovoltaic cell can also be realized.
Linear, however for a very short time, can be considered a linear circuit. Therefore, as long as the equivalent resistance of the DC-DC conversion circuit is adjusted so that it is always equal to the photovoltaic
The internal resistance of the battery can realize the maximum output of the photovoltaic cell and also realize the MPPT of the photovoltaic cell.
Application of MPPT
Regarding the position of MPPT, many people will have questions: Since MPPT is so important, why can’t we see it directly?
Actually, MPPT is integrated into the inverter. Taking the microinverter as an example, the module-level MPPT controller tracks the maximum power point of each PV module individually. This means that even if a photovoltaic module is not efficient, it will not affect the power generation ability of other modules. For example, in the entire photovoltaic system, if one module is blocked by 50% of the sunlight, the maximum power point tracking controllers of other modules will continue to maintain their respective maximum production efficiency.
If you are interested in MPPT hybrid solar inverter, welcome to contact photovoltaic manufacturer Radiance to read more.
Post time: Aug-02-2023