The problem
Solar water pumps under government schemes such as PM-KUSUM and Har Ghar Jal run in hard conditions. The input is a solar array whose power changes by the minute. The pumps come from several makers with different motors. Cable runs to borewell pumps can be long, and many sites are far from any service engineer.
The manufacturer we worked with was maintaining a separate firmware build for each pump rating and motor family. Every new motor meant a new build, and a start failure at a remote site usually meant a site visit.
What we built
- One universal firmware on a Qorvo PAC5250 motor-control platform, covering sensorless field-oriented control of PMSM and BLDC pump motors from 0.5 to 10 HP.
- Self-learning motor start. When a start does not succeed, the controller adjusts its own starting parameters, retries, and keeps the values that work for that pump and cable. Later starts use what it has learned, so a site rarely needs manual tuning.
- Solar-aware operation: maximum power point tracking on the array, so the pump delivers the most water the sun allows through the day.
- Field diagnostics: numbered fault codes on the display and over Modbus, dry-run and overload protection, and clear status for operators and service staff.
- A motor library and flashing tool. Each pump model is a set of parameters, not a new build. A licensed flashing tool loads the right image in the factory or the field and keeps an audit trail.
How we worked
We audited the existing firmware line by line before changing anything. Every finding was reported, approved and then fixed one change at a time, with bench tests on real motors and field trials before each release. That discipline matters on a product shipped in thousands. A stacked change that regresses in the field is far more expensive than a slow release.
Results
- More than 2,000 controllers in the field since the first shipments in 2024.
- Installations in Maharashtra, Ladakh, Chhattisgarh, Odisha, Jharkhand and Madhya Pradesh, from hot plains to high-altitude sites.
- New pump models are added by configuration, without a new firmware branch.
The manufacturer and installers are not named, by agreement. Technical details beyond this page are available under NDA.