Efficiency counts
The magnetic material for the boost inductor in solar inverters has almost always been ferrite and typically a ferrite toroid. In today’s solar inverters, efficiency has become a critical measurement. Increasing efficiency 1% or even 0.5% is extremely important. Replacing ferrite in the boost inverter with Nanoperm® reduces core losses and copper losses increasing the efficiency. The ferrite material used in the boost inductor is either a power material (ui~2400) or a high perm material (ui~10000). A comparison of the different materials used in the boost inductor is shown here:
| Magnetic Material | Perm @10KHz | Perm @100KHz | Bsat (mT) @25°C | Bsat (mT) @100°C | Tc |
|---|---|---|---|---|---|
| Power ferrite | 2,400 | 2,400 | 500 | 440 | 220 |
| High Perm ferrite | 10,000 | 10,000 | 380 | 230 | 120 |
| Nanoperm® | 30,000 | 20,000 | 1200 | 1180 | 600 |
Using a Nanoperm® toroid allows the toroid to be smaller because of the higher permeability. Nanoperm® core loss at this frequency is lower than ferrite. Also a smaller core allows for less copper reducing the copper loss. The end result is a more efficient inductor.