Decentralized MPPT Control Proposed for Large-scale Solar Plants

2013/11/20 13:47
Kenji Kaneko, Nikkei BP CleanTech Institute

Tokyo Electron Device Ltd started to lend out its "MPPT controller," which maximizes output from solar panels, for free Nov 19, 2013, following the development and release of the controller in the spring of 2013.

The MPPT controller is targeted at system engineering companies and mega-solar (large-scale solar) power plant facilities manufacturers that install multiple MPPT controllers for a solar power plant. Lending out the controller for evaluation, Tokyo Electron Device, which is based in Yokohama, Japan, expects that it will lead to design and development using the controller as a prototype, volume production services on contract and sales.

MPPT (maximum power point tracking) is an automatic tracking of the maximum power point in a way that always maximizes the output of solar panels. Solar power generation systems are susceptible to changes in weather, temperature and solar irradiation. But with the MPPT function, it becomes possible to improve the efficiency of an entire system. Normally, PV inverters provide an MPPT function.

However, in the case of a mega-solar plant, where large-capacity PV inverters provide an MPPT function, each inverter controls the outputs from many solar panels, increasing the load on the CPU and sometimes making it difficult to carry out the process at high speeds.

In addition, conditions such as solar irradiation differ depending on the location of each panel. Therefore, when each PV inverter is connected to many solar panels, it is sometimes difficult to efficiently perform the MPPT control.

Because the new MPPT controller developed by Tokyo Electron Device is a module focused on the MPPT function, it can track the maximum power point at higher speeds. Also, depending on the scale of a solar power generation system, multiple MPPT controllers can be installed between solar panels and PV inverters. As a result, solar panels in each area can be optimally controlled, realizing a more efficient MPPT control.

As an interface to a PV inverter, the Zigbee wireless technology is used so that measured data such as temperature and the amount of generated electricity can be wirelessly transmitted. And the MPPT controller can be combined with a variety of solar panels, tuned, customized, etc.