A pivotal element in any solar power system is the solar inverter, responsible for converting DC energy from solar arrays into usable AC power. These inverters can handle a wide range of DC outputs, typically between 100 VDC and 600 VDC, from solar panels connected in parallel. For residential applications, these inverters generate 3 – 12 kW of single-phase, two-phase, or three-phase AC power, using a technique known as Maximum Power Point Tracking (MPPT) to maximize energy extraction from the solar arrays, potentially delivering up to 8000 W based on sunlight availability.

For effective testing of these solar inverters, EA Elektro-Automatik’s EA-PSI 9750-20 3U auto-ranging power supply serves as an ideal solution to simulate the solar array. This unit offers up to 5 kW at voltages as high as 750 VDC and currents up to 20 ADC. Unlike traditional power supplies, where a pricier 15 kW unit would be required to achieve this range, our auto-ranging power supply provides a cost-effective and efficient alternative.

In the commercial sector, solar inverters often operate within a 30-1MW range, handling solar array DC input voltages as high as 1500 VDC to produce three-phase AC power. Given these power levels, a single array input isn’t feasible. Instead, these inverters feature multiple Maximum Power Point Tracking (MPPT) inputs that aggregate at the DC/DC level before conversion to AC. To rigorously test such inverters, multiple autoranging power supplies are employed, each corresponding to a different input.

EA Elektro-Automatik offers versatile programmable power supplies ranging from as low as 1 kW per channel to as high as 2 MW per unit, with a peak output voltage of 2,000 VDC. There’s no restriction on the number of supplies you can deploy for this application. Moreover, each DC supply can be programmed independently to mimic varying irradiance conditions. For example, one input can simulate a solar array under full sun, while another can replicate a partially or fully shaded solar panel.

To maximize power extraction from a solar array, MPPT inverters need to adeptly track the array’s output as sunlight conditions fluctuate. A mere static DC voltage connection to the inverter won’t suffice for comprehensive testing; both static and dynamic solar-array simulations are essential.

The EA PSI Series comes equipped with an integrated function generator, enabling you to emulate the dynamic behavior of a solar array under diverse conditions—essentially, you have control over a virtual sun. This built-in feature allows programming of up to 4096 data points to mimic basic solar array curves based on key parameters like Isc, Voc, Vmpp, and Impp. For more intricate solar simulations, Elektro-Automatik’s EA Power Control (EAPC) software offers an intuitive interface for setting up Sandia, EN50530, or custom test profiles.

A crucial element in both residential and commercial solar setups is the battery storage system. These systems enable the capture and storage of solar or wind energy for use during non-peak hours. Solar inverters in these configurations must be versatile, capable of both feeding power back to the grid and managing battery charge and discharge cycles.

For effective testing of such inverters, you’ll need to simulate both the solar array and the battery system. The battery simulator should be bi-directional to mimic charge and discharge cycles accurately. The EA PSI Series serves as an excellent solar array simulator, while the EA PSB Series functions as a bi-directional, programmable DC battery simulator. The PSB Series can both source and sink power, supplying energy to the inverter when needed and absorbing it during charging. Utilizing the PSI and PSB Series for your solar array and battery simulations ensures comprehensive, repeatable testing