Sandia and EN50530
Static and dynamic test procedures reproduce defined PV characteristics and changes in irradiance.
NS91000 – PV Array Simulation Software with Eight Test Modes
For reproducible characteristic-curve and MPPT testing of photovoltaic inverters.
Calculated I-V and P-V characteristics are coupled with the supported N35100, N35200 and N35500 bidirectional DC power supplies. This enables direct comparison between theoretical curves and the measured operating points of a connected inverter.
Custom characteristics
Up to 17 custom I-V curves can be created, imported, exported and executed individually.
Weather and shading
Temperature, irradiance and shading profiles test MPPT behaviour under changing environmental conditions.
Flexible device connection
The DC power supply can communicate with the software via LAN, RS232, CAN or RS485.
Personal project consultation
Do you need support selecting the right power supply? Our technical specialists will provide personal advice tailored to your application.
Select the appropriate technical configuration or access product documentation directly.
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NS91000 overview
NS91000 is PV array simulation software for the N35100, N35200 and N35500 series of bidirectional programmable DC power supplies. It calculates I-V and P-V characteristics from parameters such as maximum power point voltage and power, open-circuit voltage, short-circuit current, fill factor, irradiance and temperature. The connected power supply outputs the resulting operating point while the software visualises theoretical curves together with measured operating values. Static and dynamic Sandia and EN50530 procedures are particularly suited to evaluating the MPPT efficiency of photovoltaic inverters. Custom characteristics, curve sequences, weather profiles and shading tests extend testing to user-defined and environment-dependent scenarios. Test data can be logged, retrieved by date, analysed and exported. The available voltage, current and power ranges are determined by the connected device model.
Key benefits
Two curve models
Sandia and EN50530 models provide distinct parameter sets for static and dynamic PV testing.
Static and dynamic testing
Defined operating points and irradiance changes support reproducible evaluation of maximum power point tracking behaviour.
Detailed custom curves
Seventeen curve memories support individual profiles, with two memories holding up to 2,048 parameter points each.
Multi-step sequences
Up to ten sequences with ten steps each combine stored characteristics into timed test procedures.
Variable environmental profiles
Weather and shading tests vary irradiance and temperature for realistic MPPT scenarios.
Integrated analysis
Measured values and test parameters are stored, retrieved by date, analysed together and exported in tabular form.
PV array simulation principle
A test begins by selecting the required characteristic model and entering its parameters. Depending on the mode, these may include Vmp, Pmp, Voc, Isc, fill factor, irradiance, temperature and temperature coefficient. NS91000 uses these values to generate theoretical I-V and P-V curves and transfers the operating parameters to the connected DC power supply.
During the test, the user interface displays the calculated characteristics together with the measured operating point. This shows how the connected inverter responds to static setpoints, ramps, changing environmental conditions or custom curves. An adjustable initial delay accommodates inverter start-up before MPPT evaluation begins.
Device-dependent operating range: The maximum programmable voltage, current and power are limited by the ratings of the connected N35100, N35200 or N35500 power supply.
Simulation and test modes
| Mode | Parameters and procedure | Technical purpose |
|---|---|---|
| Static Sandia | Calculates a fixed I-V/P-V characteristic from four basic parameters or an extended parameter set. | Compares the theoretical curve with the measured operating point under constant conditions. |
| Static EN50530 | Static characteristic with basic or extended parameters for crystalline or thin-film behaviour. | Static MPPT evaluation based on the EN50530 curve model. |
| Dynamic Sandia | Slow, fast or triangular irradiance changes with cycles, ramps and dwell periods. | Examines dynamic tracking behaviour under defined irradiance profiles. |
| Dynamic EN50530 | Low- and high-irradiance changes plus start/stop profiles with cycles, slopes, ramps and dwell periods. | Dynamic MPPT testing with predefined reference values. |
| Customized Curve | Creates, imports, exports and individually executes user-defined I-V curves. | Reproduces custom module or array characteristics from specified curve points. |
| Curve Sequence | Runs stored custom curves in a timed sequence with configurable repetition. | Automates transitions between multiple characteristics within one test procedure. |
| Weather Test | Uses predefined weather profiles or imported irradiance and temperature curves with up to 960 points based on Sandia or EN50530. | Tests inverter behaviour under time-varying environmental conditions. |
| Shadow Test | Configures shaded areas within a PV array with separate irradiance and temperature values. | Evaluates MPPT response to partial or moving shading. |
Custom curves and sequences
Custom characteristics enable testing beyond the predefined Sandia and EN50530 procedures. Curve data can be created in the software, loaded from the device, and imported or exported as CSV files. Stored curves are available both for individual execution and as steps within a sequence.
| Function | Capacity | Configuration |
|---|---|---|
| Curve memories 1 to 15 | Up to 256 parameter points each | CSV import and export, loading from the device and direct execution |
| Curve memories 16 and 17 | Up to 2,048 parameter points each | For characteristics requiring a higher point count |
| Curve sequences | Up to 10 sequences with up to 10 steps each | Curve number and execution time are selected for every step |
| Step execution time | 1 to 60,000 s | Independent execution time for each curve in a sequence |
| Cycle count | 0 to 20,000 | Number of repetitions for the configured sequence |
| Initial delay | 0 to 600 s | Delays the start of the test procedure |
Typical applications
The available curve models and profile types support targeted investigation of photovoltaic inverter behaviour and PV-related energy systems.
MPPT efficiency of PV inverters
The inverter tracks simulated I-V/P-V characteristics while static and dynamic modes capture its maximum power point behaviour.
Dynamic irradiance transitions
Defined ramps and dwell periods test how quickly and steadily the inverter follows changing irradiance conditions.
Partial shading of PV arrays
Configurable shaded areas generate modified characteristics to assess MPPT behaviour during local power reduction.
Weather-dependent PV profiles
Irradiance and temperature time series examine inverter response to changing environmental conditions.
Custom module and array curves
Imported or manually defined curves reproduce project-specific PV characteristics for repeatable comparison tests.
Distributed PV system simulation
Configurable array characteristics support system simulation and core component testing in microgrid and distributed PV systems.
Interfaces, software and data management
| Area | Supported function | Practical purpose |
|---|---|---|
| LAN | Device connection using IP address, port and device ID | Network communication with the PC and device assigned different IP addresses within the same network segment. |
| RS232 | Supported communication interface | Serial connection to a compatible DC power supply. |
| CAN | Supported communication interface | CAN-based communication with a suitably equipped power supply. |
| RS485 | Supported communication interface | Serial device connection via RS485. |
| System configuration | Storage location, data logging and retention period | Central configuration of measurement data management for recurring tests. |
| Curve files | CSV import and export of custom characteristics | Transfer of external curve points and reuse of created profiles. |
| Historical data | Date-based search, external file opening and tabular export | Subsequent analysis of test parameters and results. |
Basic LAN configuration: The device IP address, port and ID are entered in the hardware configuration. Port 7000 and device ID 160 are provided as defaults.
Supported devices and PC requirements
| Category | Requirement or support | Note |
|---|---|---|
| DC power supply | NGI N35100, N35200 and N35500 | Devices with I-V/P-V curve simulation capability are supported. |
| Processor | 2.0 GHz, dual-core or higher | Recommended PC configuration |
| Memory | 4 GB or more | Recommended PC configuration |
| Hard disk | 80 GB or more | Recommended PC configuration |
| PC port | Ethernet port | For network-based device communication |
| Operating system | Microsoft Windows 7 or later | Standby mode should be disabled while tests are running. |
Measurement data and analysis
During an active test, the information area displays measured values from the connected power supply. After the procedure is stopped, stored data sets can be opened from the history list or found by date. The analysis view presents the test parameters and recorded results together.
Test data can be exported in tabular form for further processing, with both the storage location and file name selected by the user. Results can therefore be archived, compared or transferred to project-specific analysis workflows outside the software.
NS91000 FAQ
Which DC power supplies are supported?
NS91000 supports the N35100, N35200 and N35500 series of bidirectional programmable NGI power supplies with PV curve simulation capability.
Can static and dynamic MPPT tests be performed?
Yes. Static and dynamic modes with their associated parameters and profiles are available for both Sandia and EN50530.
Can custom I-V characteristics be used?
Yes. Up to 17 curves can be managed. Curves 1 to 15 support 256 points each, while curves 16 and 17 support 2,048 points each.
How are multiple characteristics executed automatically?
Sequence mode combines up to ten stored curves in each sequence. A total of ten sequences can be configured.
Which environmental conditions can be reproduced?
Weather Test processes irradiance and temperature profiles. Shadow Test reproduces partial or moving shading within a PV array.
Which communication interfaces are available?
LAN, RS232, CAN and RS485 are provided for communication with a supported DC power supply.
Can test data be exported?
Yes. Test parameters and results can be analysed and exported in tabular form to a user-selected storage location.
What determines the electrical operating range?
The maximum available voltage, current and power are determined by the ratings of the connected device model.
Technical consultation and project enquiry
To select a suitable N35100, N35200 or N35500 configuration, we can review the required voltage, current and power range, planned PV characteristics and preferred device communication with you.
Useful details for system sizing: maximum open-circuit voltage, short-circuit current, MPP power, required test modes and available interface.
Send a technical enquiry
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