The latest test standards EN50530, CGC/GF004 & Sandia have provided a procedure for testing patterns of the dynamic MPPT efficiency of inverters, those standards can accelerate the MPP tracking algorithm mechanism to the optimal for PV inverter manufactures. The advanced Dynamic MPPT Test function complies with EN50530, CGC/GF004, Sandia test regulations and can be controlled via the graphical softpanel by selecting CGC/GF004 or Sandia or EN50530 I-V mathematical expressions and test items. This function simulates the irradiation intensity and temperature change of the I-Vcurve under actual weather variations to test the PV inverter’s dynamic MPPT performance. The GUI will calculate the MPPT performance for analysis after running the test. A test data recording function is integrated into the software where users can edit and control the test parameters to be recorded such as voltage, current, power, watt and MPPT performance along with the sampling interval (1 – 10,000s) and total time length to facilitate the analysis and validation of the PV inverter.
The 62000H-S Solar Array Simulator offers optional graphical user interface software through remote digital interface (USB / GPIB / Ethernet / RS232) control. The user can easily program the I-V curve of the Solar Array Simulator as well as the I-V & P-V curves for real-time testing. In addition it will display the MPPT status for the PV inverter.
The purpose of the PV inverter is to convert the dc voltage (from solar array) to the ac power (utility). The better a PV inverter can adapt to the various irradiation & temperature conditions of sun, the more power that can be fed into the utility grid over time. So, the MPPT performance is a very important factor for PV generation system. The model 62150H-600S/1000S is capable of simulating different types of standard crystalline, multi-crystalline and thin-film fill factor* parameters to verify the MPPT tracking algorithm mechanism and efficiency.
*Fill Factor = (Imp*Vmp)/(Isc*Voc)
Dynamic MPPT Efficiency Testing
Shadow IV Curve Simulation
The table mode allows the user to create 128 points of I-V curve data consisting of voltage and current in Excel file format. This information is uploaded to the DC Power Supply memory via the softpanel. The user is able to program various I-V curves such as the shadow I-V curve simulation, which is used to verify the maximum power tracking capability of the PV inverter based on the I-V curve when the solar cell is shaded by clouds or trees.
Static MPPT Efficiency Testing
The solar array simulation softpanel can program the I-V curve through SAS mode and table mode easily and up to 100 I-V curves can be stored in the unit. The user can recall the I-V curve from a 62000H afterwards for testing and monitoring the MPPT performance of a PV inverter with the real-time tracking feature. The softpanel allows the user to set the duration for static MPPT efficiency testing. Each curve test time should be set at between 60s-600s for best MPPT efficiency performance analysis.
Evaluating The PV Inverters Conversion Efficiency *
The photovoltaic I-V curve model of Sandia Lab and EN50530’s built in the softpanel allows the user to input the maximum dc input power (Pmax), I-V Fill Factor, Vmin, Vnom and Vmax desired to test the PV Inverter. Click the maximum power percentage value (5%, 10%, 20%, 25%, 30%, 50%, 75%, 100%) desired directly, and the softpanel will produce the tested solar cell I-V curve automatically. Next, download it to the standalone unit to start simulating the I-V curve for the PV Inverter to test the conversion efficiency.
*Requires an additional power meter.
Real World Weather Simulation
The real world weather simulation function allows the user to import real conditions of irradiation and temperature profiles of a whole day from excel file to Softpanel, in order to simulate the irradiation intensity and temperature level from early morning to nightfall. It can also set the interval time resolution to 1s for I-V curve update rate and enable the user to perform MPPT tracking tests under the simulation of actual weather environments.
Auto Run Function Of Static & Dynamic MPPT Testing
In order to easily test the static & dynamic MPPT performance of standard EN50530 & Sandia for PV inverter, the SoftPanel has an auto run function, which the user only has to set the Vmin, Vnom, Vmax, Pmax, Stabilization time &Testing period time parameter and testing items of EN50530 & Sandia, then the softpanel can run tests automatically and generate reports after finished
The softpanel also provides data recording capabilities, which include: voltage, current, power, energy and MPPT efficiency and the corresponding parameter sampling time (1s~10000s) for the recording process. The report can be utilized for R&D design characterization verification, QA verification and production quality control.