Solar Powering Single Phase Motors

There are more than 100 million fossil fuel based gen-sets worldwide that are running inductive loads, mainly pumps and compressors below 5kW of power range. In this power band, almost all of gas/diesel gen-sets are running single phase loads. In India, fossil fuel gen-sets running water pumps for agriculture contribute to 17% of total carbon emissions nationally.

 

The PicoCell controller is among the rarest devices in the world, in that it can run single phase inductive load: pump, compressor, and fan for both 120Vac and 230Vac and either 50 or 60Hz frequency. Furthermore, the same device can even run 3-wire single phase motors that are very popular in North America, hence displacing the so called “control box” that is consisting of a relay and starting capacitor.


The true technology breakthrough is in the PicoCell’s control algorithm that is embedded in the firmware. Instead of utilizing a relay and capacitors for starting the single phase motors, PicoCell provides variable frequency drive capability with true sinewave of variable voltage magnitude and frequency so to run the single phase inductive loads even when they are powered from solar, wind or even DC low voltage AGM batteries. If single phase motors are driven by PicoCell that is connected to both electrical grid and solar, wind or diesel, PicoCell enables power factor correction, so to present unity power factor for the electrical grid.

Industrial VFDs don’t have an ability of running single phase AC loads because they are designed to be grid connected, so the power factor correction (PFC) and DC link circuits in industrial VFDs are designed for three phase motor loads only. However, PicoCell’s hardware design is flexible and has an additional set of hardware – Boost circuit, that has dual functionality: enables wide input voltage range from solar PV, but also filters a ripple from single phase AC motor loads. This filtering algorithm is embedded in PicoCell’s firmware.