RS and Schneider Electric Enable Solar-Powered Motor Control

­RS, a high-service global product and service solutions provider for industrial customers, offers Schneider Electric’s Altivar Solar ATV320 variable speed drives (VSDs) for solar powered pumping applications.   

VSDs — also widely known as variable frequency drives (VFDs) and adjustable frequency drives (AFDs) — are power conversion devices designed to control the speed, deceleration, and torque of electric motors without the aid of mechanical components, like gearboxes. VSDs enable more flexible, precise, and repeatable motor control and require significantly less maintenance than mechanical motor control solutions. They can also offer remote monitoring capabilities and deliver substantial energy savings, especially when they’re used to regulate the speed of centrifugal pumps and fans. For example, if you use a control valve to reduce a pump’s flow from 100% to 90%, you might achieve a negligible 1–2% energy savings. But if you use a VSD to achieve the same flow reduction by reducing the pump’s speed, you’ll achieve energy savings of around 27% and eliminate the need for the control valve, which also eliminates extra cost, system wear and tear, and maintenance. 

Standard VSDs are designed for use with stable, regulated AC voltage supplies. So, in order to use them with solar arrays — which generate variable DC voltage depending on the season, time of day, and weather — you need to pair them with a battery storage solution and an AC inverter, which adds equipment, engineering, and maintenance costs, negating many of the advantages of using VSDs instead of mechanical motor control solutions. 

Schneider Electric solved this challenge with the introduction of its Altivar Solar ATV320 VSDs — purpose-built solar drives engineered to accept highly varied DC supply voltages and adapt drive and motor performance to that variable power without the added equipment, engineering, and maintenance costs required to use standard VSDs with solar arrays. This makes them especially well-suited for pumping applications in remote settings, as they eliminate the need for an accessible electrical power supply and minimize maintenance. And while it’s true that they can’t deliver the constant, full-speed performance of standard drives with stable, regulated AC power supplies, they do consistently operate at the maximum speed possible with the available power. 

As part of Schneider Electric’s Altivar VSD product line, Altivar Solar ATV320 VSDs are backed by decades of VSD R&D experience — spanning small, quarter-horsepower motor controllers to medium-voltage drives designed for both general-purpose and application-specific use — and field-proven performance in applications extending throughout virtually every industrial segment, including water and wastewater, oil and gas, HVAC, agriculture, food and beverage, pharmaceutical manufacturing, and logistics. 

Altivar VSDs are widely renowned for their durability, reliability, and efficiency and the sophistication of their software and application control functions, and Altivar Solar ATV320 VSDs — which are also backed by nearly 10 years of field-proven performance in remote, solar-powered pumping applications — are no exception. 

Schneider Electric's Altivar Solar ATV320 VSDs for solar powered pumps are compatible with a wide range of pumps and solar arrays and increase the reliability, sustainability, energy efficiency, and service life of these systems compared to standard VSDs and mechanical motor control solutions while requiring less maintenance. They adjust pump flow in accordance with available energy, have a wide DC voltage range to maximize energy harvesting and power availability, and can connect to both the grid and a solar array to optimize availability in pumping applications that require more consistent operation. They have self-preserving dry-run and anti-jam functions, diagnostic capabilities, and a suite of safety features to reduce operating risks, protect assets, optimize performance, minimize maintenance, and keep pumps running. They feature integrated support for Modbus RJ45 and CANopen RJ45 communication protocols and optional support for Ethernet IP and Modbus TCP protocols, which enable remote control by I/O. These smart VSDs also support intuitive programming and commissioning with ATVLogic — integrated software that allows users to program complex automation tasks using function block diagrams — and feature a maximum power point tracking (MPPT) algorithm that efficiently and accurately detects solar panel parameters to further ease configuration and commissioning.

Altivar Solar ATV320 VSDs are available in:

• Single-phase models rated for 150–374VDC or 200–240VAC inputs, 0.37–2.2kW or 0.5–3HP motors, and 4–24A line currents
• Three-phase models rated for 150–374VDC or 200–240VAC inputs, 3–15kW or 4–20HP motors, and 15.7–79.7A line currents
• Three-phase models rated for 280 – 778VDC inputs or 380–500VAC inputs, 0.37–15kW or 0.5–20HP motors, and 1.6–67.1A line currents

They’re also rated for operating temperatures extending from -15°C to +50°C without derating or +60°C with derating and IP20 environmental protection since they’re designed for use in control cabinets.

ATV320 VSDs are compatible with synchronous, asynchronous, and permanent magnet (PM) motors, utilize open-loop controls to adjust motor torque and speed control, and support six motor control methods: 

• Sensorless vector control, which precisely controls AC motor speed and torque without a physical feedback device, like an encoder or resolver
• Standard V/f control, which maintains a constant voltage-to-frequency ratio to control motor speed
• Five-point V/f control, which allows users to define a V/f curve with five or more voltage and frequency points to create custom, non-linear relationships ideal for applications with high-inertia loads
• Synchronous motor control, which adjusts power supply voltage and frequency to precisely control motor speed and torque
• Variable torque control, which adjusts the motor’s speed and torque based on load demands and is ideal for fan and pump motors
• Hermetically sealed, energy-saving relays, which are ideal for hazardous environments, including offshore mining installations, oil refineries, and chemical manufacturing facilities

Ideal applications for Altivar Solar ATV320 VSDs — which are also designated as RS Better World products proven to support more sustainable industrial operations — include sprinklers, micro, drip, and flood irrigation systems, submersible, surface-mounted, and water storage tank pumps, off-grid, solar powered water systems, and water treatment systems.

For more information, go here.