The Ministry of New and Renewable Energy (MNRE) has issued draft specifications and testing procedures for universal solar pump controllers (USPC). The draft is up for comments up to April 19, 2019.

These controllers are expected to help increase the utility of the solar photovoltaic (PV) system installed for solar water pumps.

According to the MNRE, the universal solar pump controllers should be designed to run at least four equipment among these: Apple grading and polishing system, wheat (grain) flour grinding machine, cutter/chaff, deep-fridge/cold storage, blower fan for cleaning of grains, any other standard voltage (400/415V) three-phase motor.

This equipment should range between 3 HP to 10 HP.  It must have a robust system protection features and remote fault monitoring. The controller should also have the facility to interface batteries according to the user’s needs and based on applications and capacity requirement.

To ensure the energy efficiency of solar PV systems and to maintain the reliability of PV installations against the aging effect, module mismatch with time, partial shading, the controller must have maximum power point tracking (MPPT) with specific configurations. The MMPT should be equal to or more than 98% during operation of 10% to 100% of rated standard test conditions (STC) PV power, to maintain MPPT irrespective of variation in solar energy or irradiance.

Considering the effect due to aging and environmental damages, the controller should have MPPT channels as an integral part of the system (or externally connected part) with a wide range of input PV voltage for MPPT tracking of the PV panels.

As a single phase supply is available at many places, the universal solar pump controller should have a provision to couple with single phase add-ons to run the motor pump set even when solar irradiation is not available. Auto-changeover should be possible to switch from PV to the grid and from the grid to PV depending upon the status of solar irradiation.

There should be no manual changeover, and the selection of an application by the user should be through software and keyboard. Universal solar agriculture controller should have multiple outputs, precisely four in number. The output can be permanently connected to any of the applications and selection of application must be through a keyboard.

The controller should have inbuilt individual application specific software to select and run any one of the above applications.

Recently, the central government approved the launch of the Kisan Urja Suraksha evam Utthaan Mahabhiyan (KUSUM) program for farmers. This program is aimed at helping the farmers install solar pumps and grid-connected solar power projects, which in turn would provide financial and water security to farmers. USPC will help increase the utility of the solar PV system installed for solar water pumps.