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Maximum Power Point Tracker

Current-voltage curve of a PV module

Maximum Power Point Tracker (MPPT) enables the use of all available power offered by a photovoltaic module. MPPT continuously adjusts operating point in order to transfer maximal possible power to load. Operating point changes mainly because of different irradiation and temperature of the PV module.

The MPP tracker developed in our laboratory is used in our PV module test site. MPPT enables a PV module to operate in maximum power point, the same mode used in solar plants. This enables to obtain realistic results when measuring module characteristics. Besides operation in maximum power point the tracker also enables a module to be put in short circuit or open circuit.

In addition to tracking of the maximum power point it also enables module temperature measurement in multiple points. It is also possible to operate the module at an elevated potential. All the operating parameters can be read over a bus connecting multiple trackers.

The tracker features galvanic isolation which provides safety and also enables the PV module to operate at an elevated potential, thus enabling study of potential induced degradation.

Besides enabling realistic measurements, the tracker can also be used as a platform for the development of tracking algorithms. The choice of the algorithm is important especially in aspect of dynamic conditions in module operation. Fast change in irradiation, caused by passage of cloud, can confuse some algorithms, resulting in lower energy yield.

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Basic specifications

Input

  • Voltage: up to 95 or 200 V
  • Current: up to 17, 10 or 4.5 A
  • Power: up to 550 W
  • Connection: 2- or 4-wire
  • Potential: up to 1000 V (built-in source)

Sensors

  • Temperature and humidity: up to eight 1-wire sensors

Output

  • Voltage: 150 - 280 V, nominal: 250 V
  • Galvanic isolation

Communication:

  • RS-485

 

 

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Contact

Boštjan Glažar, e-mail: bostjan.glazar@fe.uni-lj.si, Tel.: +386 1 4768 953