The same principle also applies to the installation of utility-scale projects. However, most public projects involving large-scale ground mounted PV array, and with many inverters can quickly boost to medium pressure (4160 to 13.8 kV). Further, the conventional inverters require a separate isolation transformer with each inverter pair, and this accounts for up to two unnecessary loss in efficiency point.
In a 1 MW module, can be 1-4 conventional inverters placed in a separate backing plate, and each inverter is connected with the pressure. Medium pressure connection cost is high, perform this task electricians need to accept a higher level of training and certification. Requires the use of larger equipment pad or utility chassis. If the electric field has a tracker in operation, then the need for a separate power supply transformers for these trackers. Thus, the system balancing equipment, materials and installation costs will increase rapidly.
Traditional inverters self-interference, through the public line (such as various VAR generation) to detect islanding condition. When the inverter in parallel with a number of such interference will be in all inverters difference between the VAR beat frequency, the resulting electric field will close the false tripping. A plurality of conventional inverters and their triangular capacitor will produce a large instability and absorb large amounts of harmonic currents.
These problems can be transformerless inverter technology to avoid. Transformerless inverters can be connected in parallel to a separate medium-voltage transformer windings. Each inverter requires only a single, standard specifications of 1000, 1500 or 2500 kVAR medium-voltage transformer. This is configured for the site offers many possibilities. Due to its current than conventional inverter current, so placement of inverters and transformers way there are more flexible options.
Transformerless inverter size is approximately half of conventional inverters, can be directly converted into a higher voltage, which reduces the required floor space, cost of transport and lifting equipment (device plus incremental plate or Public enclosure construction costs) and the size and number of windings connected. In addition, a transformerless inverter is connected to a standard distribution board in the case without a separate transformer power supply to the tracker. Reduction of the transformer, the reactance components of the system be reduced, in order to achieve the most stable state of operation. Additionally, each modified sine wave inverter are both automatic and independent Ethernet addressing, thus eliminating any interference problem.
In addition, the completely passive anti-islanding technology (anti-islanding technique) does not interfere with the utility voltage deviations VAR, nor on the course set other transient, thus enabling efficient, smooth, stable power supply, which together are to Relative reduction in installation costs.