What is an MPPT controller?

The full name of a photovoltaic MPPT controller is the Maximum Power Point Tracker, which is one of the critical factors affecting the power generation efficiency of photovoltaic power stations.

MPPT can detect the power generation voltage of photovoltaic modules in real-time and track the maximum voltage and current values, enabling photovoltaic power stations to track the maximum power point under different sunlight and temperature conditions, resulting in the system outputting the maximum power.

Photovoltaic inverters equipped with MPPT controllers can accurately track the characteristics of each photovoltaic string in practical applications, maximizing the effectiveness of each photovoltaic cell string. If the operating efficiency of a particular or some photovoltaic modules in a photovoltaic power station is poor, it will not affect other photovoltaic modules.

MPPT controller tracking methods:

• Constant Voltage Method: Simple to implement and easy to algorithmically achieve. However, the tracking accuracy is relatively poor, and it may not necessarily be the maximum power point.
• Perturbation and Observation Method: Simple structure, fewer measurement parameters, and easy to implement. Oscillations may occur near the maximum power point, causing energy loss and "misjudgment."
• Incremental Conductance Method: Good following ability, ensuring maximum power output. Complex control algorithm, high detection accuracy requirements, and difficult to choose the step size.

How to choose the MPPT number for photovoltaic inverters?

According to the different terrain and shading conditions of photovoltaic power stations, select photovoltaic inverters with different MPPT architectures to reduce procurement and maintenance costs of the power station and improve economic efficiency.

In flat areas with good lighting conditions and no shading, choosing single-MPPT, single-stage structure inverters can improve system reliability and reduce system costs.

For complex hilly power stations, there are generally inconsistencies in component orientations and partial shading, and different hills have different shading characteristics, which can lead to component mismatch issues. Therefore, inverters with 2 string inputs per MPPT path would be a better choice, featuring no fuse wear parts, high fault location accuracy, and simpler maintenance.

For less complex hilly power stations and rooftop power stations without shading, it is recommended to choose inverters with two MPPT paths and multiple strings, which can balance string mismatch and high efficiency, resulting in more flexible design.