For microgrids, energy storage, and inverter test applications, the TerraSAS™ series photovoltaic (PV) simulators are specifically designed to emulate the dynamic electrical behavior of a terrestrial PV solar array. They offer low output capacitance and high closed loop bandwidth to keep up with the advanced Maximum Power Point Tracking (MPPT) algorithms used in today’s grid-tied inverters. The Embedded TerraSAS (ETS) is a high performance solution in a small form factor that combines an agile power supply with an innovative I-V curve generator in a single standalone unit.
- ETS 600 / 1000: For isolated and non-isolated string inverters up to 1000Vdc Voc.
- ETS 60 / 80 / 150: For use with micro-inverters or DC optimizers up to 150Vdc Voc.
Advanced Features
- Low output capacitance
- High bandwidth up to 30kHz
- High resolution I-V curve simulates static and dynamic conditions
- Designed for high speed Maximum Power Point Tracking (MPPT)
- Can be integrated into a multi-channel system for higher power testing
- Low voltage, high bandwidth version for DC Power Optimizers
- EN50530 support
TerraSAS (ETS Series) Application:
- Solar Inverter AC Ripple: Many solar inverters generate AC ripple on their DC input connected to the photovoltaic array. This ripple frequency is twice the line frequency (120 Hz for US models) for single-phase inverters
- Simulator Power Supply Requirements: The simulator's power supplies must not suppress this AC ripple through their regulation loop.
- Modern Inverter MPPT Technique: An increasing number of inverters, especially micro-inverters, accurately measure the amplitude and phase of the ripple voltage and current. This allows them to quickly track the Maximum Power Point (MPP) of the array.
- Faster MPP Tracking, Higher Efficiency: This approach offers significantly faster MPP tracking compared to conventional dithering techniques (also called perturbate-and-observe). Faster MPP tracking translates to much higher overall efficiency in cloudy conditions, where the irradiance is constantly changing.
- Future of Inverter Technology: It’s likely that all solar inverters will use this approach in the near future, since end users are very sensitive to the overall efficiency of their solar energy installations.
- PV Simulator Requirement: To meet this requirement, the PV simulator must be capable of reproducing the voltage/current behavior of a solar array at the ripple frequency.
- Standard Power Supply Limitations: Most standard switching power supplies employ very large output capacitors and inductors in their output circuits and are unable to deliver the required performance - regardless of the response speed of the I-V curve controller.
- Elgar TerraSAS Solution: The Elgar TerraSAS line of PV simulators are based on high speed versions of our standard products, where output capacitors and other speed-limiting components have been adjusted.
- High-Performance Design: This results in a speed improvement of 10 times or better. Proprietary features built into the PV controller hardware and firmware, combined with our high speed power supplies, deliver the required performance. This technology was extensively tested on micro-inverters and is ready to test the next generation of inverters.
- High-Speed Power Supply Technology: The required performance is delivered by high speed switching power supplies and advanced Digital Signal Processing (DSP) techniques.
- MOSFET Advantage: In some conditions traditional DC power sources using IGBT technology do not meet MPPT response speed requirements, depending on the MPPT principles. Our power supplies use Power MOSFETs, which typically switch ten times as fast as the most recent IGBTs. Higher switching frequency translates to smaller output capacitors and inductors - which is the key to a successful high speed power supply design.
