ZGR DECENTRALISED THREE-PHASE STRING SOLAR INVERTERS FOR ELIMINATING POLARISATION PROBLEMS IN PHOTOVOLTAIC PLANTS
Some photovoltaic plants suffer from parasitic currents that cause performance losses in the solar panels.
This problem is common in installations with old inverters and increases the operation and maintenance costs.
To avoid this problem, the photovoltaic plant in Lebrija uses the Zigor Solar XTR3 inverters that allow it to work at maximum power.
The solution provided by ZGR increases the performance of the plant, adapts the equipment to the installation environment and reduces maintenance costs.
The Lebrija plant supplies 20% of the population of this locality, operating with a generation power of 3.8 MW and reducing CO2 emissions to the atmosphere by 2440 tonnes.
Some photovoltaic plants suffer from parasitic currents or induced polarisation (Potential Induced Degradation – PID) that cause performance losses in the solar panels. This happens especially when there are high voltage conditions and extreme weather situations (high relative humidity or high temperatures). This problem, common in installations with old inverters, considerably increases the operation and maintenance costs. For this reason, the string inverters must be modernised and their number reduced while maintaining the same performance.
The Lebrija photovoltaic plant supplies 20% of the population of this locality. It has been operating since 2008 with a 3.8 MW generation power and uses photovoltaic panels combined with a horizontal tracker. This plant, which has a surface area of 14 ha, produces around 7.5 MWh, which is equivalent to reducing CO2 emissions to the atmosphere by 2440 tonnes.
THE ZIGOR SOLAR INVERTERS ELIMINATE POLARISATION PROBLEMS
With the aim of eliminating the polarisation problems in the plant’s panels, ZGR has supplied 37 three-phase wall string inverters, the Zigor Solar XTR3, with a connection capacity of up to 20 kW photovoltaic power and with three independent MPPTs (Maximum Power Point Tracker). This configuration allows it to work with the maximum power of the installed panels. Each new inverter replaces four existing units in the previous installation.
Furthermore, ZGR has proposed the installation of aluminium transformers for galvanic isolation, adapted to the conditions requested by the customer as regards the size, arrangement and integration in the plant.
The Zigor Solar XTR3 is a three-phase solar inverter without transformer. Its mission is to convert the DC voltage generated by the photovoltaic panels into three phase AC voltage suitable for being delivered to the electrical energy distribution grid. It can be used both as a support to consumption as well as an electrical production system. The inverter box is constructed for operation indoors or outdoors.
The ZGR Series XTR3 inverters, and their 2021 update in the Series STR, are string type three-phase power converters. They allow the development time and commissioning of a plant to be optimised as far as possible thus eliminating potential current disruptions. Furthermore, they adapt the configuration of the panels to the engineering requirements. It is solution designed for working with bifacial solar panels that are high-efficiency and resistant to severe changes of temperatures and humidities, which results in a more effective plant OPEX.
