Generate grid disturbances
Voltage dips, swells and programmable waveforms create defined disturbance conditions for repeatable testing of connected equipment.
N75500 – Regenerative Grid Simulator up to 25 kVA in 3U
For grid fault, regeneration and anti-islanding tests on grid-connected power electronics.
The N75500 combines programmable grid simulation with bidirectional power flow in a 19-inch, 3U enclosure. It supplies the device under test and returns absorbed energy to the utility grid. Different phase configurations and superimposed AC/DC signals enable controlled reproduction of real supply conditions.
Analyse harmonics
Simulation up to the 50th order at 50/60 Hz and voltage and current analysis support investigation of distorted grid signals.
Test anti-islanding behaviour
A dedicated test mode simulates loads using RLC or power parameters and measures the duration of islanding operation.
Automate test systems
LAN, USB, CAN, RS232 and RS485, together with analogue programming and digital triggers, enable integration into test sequences.
Personal project consultation
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Select the appropriate technical configuration or access product documentation directly.
ART. NO.
Description
Current [A]
Power [P]
Voltage [V]
N75525-350-105
|
Description
N75525-350-105 Bidirectional regenerative AC/DC grid simulator, 25 kVA / 25 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±105 A, 3U
|
Current [A]
105
|
Power [P]
25000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75506-350-105
|
Description
N75506-350-105 Bidirectional regenerative AC/DC grid simulator, 6 kVA / 6 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±105 A, 3U
|
Current [A]
105
|
Power [P]
6000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75509-350-105
|
Description
N75509-350-105 Bidirectional regenerative AC/DC grid simulator, 9 kVA / 9 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±105 A, 3U
|
Current [A]
105
|
Power [P]
9000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75512-350-105
|
Description
N75512-350-105 Bidirectional regenerative AC/DC grid simulator, 12 kVA / 12 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±105 A, 3U
|
Current [A]
105
|
Power [P]
12000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75518-350-105
|
Description
N75518-350-105 Bidirectional regenerative AC/DC grid simulator, 18 kVA / 18 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±105 A, 3U
|
Current [A]
105
|
Power [P]
18000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75536-350-210
|
Description
N75536-350-210 Bidirectional regenerative AC/DC grid simulator, 36 kVA / 36 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±210 A, 6U
|
Current [A]
210
|
Power [P]
36000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75550-350-210
|
Description
N75550-350-210 Bidirectional regenerative AC/DC grid simulator, 50 kVA / 50 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±210 A, 6U
|
Current [A]
210
|
Power [P]
50000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75554-350-315
|
Description
N75554-350-315 Bidirectional regenerative AC/DC grid simulator, 54 kVA / 54 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±315 A, 9U
|
Current [A]
315
|
Power [P]
54000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75575-350-315
|
Description
N75575-350-315 Bidirectional regenerative AC/DC grid simulator, 75 kVA / 75 kW, AC 350 V L-N / 606 V L-L, DC ±500 V, ±315 A, 9U
|
Current [A]
315
|
Power [P]
75000
|
Voltage [V]
350
|
AC Source/ Load (1/3ph)
Technical Data
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
N75500 regenerative grid simulator overview
The N75500 is a programmable four-quadrant grid simulator for powering and testing inverters, rectifiers and other power electronics. Five models cover 6 to 25 kVA in AC operation. The instruments supply energy to the device under test and absorb and regenerate energy delivered by it. Single-phase and three-phase operation are complemented by reverse-phase and split-phase configurations. Split-phase mode provides three independently programmable channels. AC, DC and superimposed signals address different test requirements; the available coupling modes depend on the phase configuration. Voltage, frequency, phase angle and waveform can be adjusted individually. Sequences, grid disturbances, harmonics and RLC/PQ islanding simulation provide repeatable test conditions. Measurement functions and data recording support evaluation directly on the instrument or through the PC software.
Key benefits
Bidirectional power flow
Source and sink operation in one instrument: regenerative DUTs can operate while absorbed energy is returned to the utility grid.
Compact test equipment
Up to 25 kVA in AC operation at 20–500 Hz is available in a 19-inch enclosure occupying 3U.
Reproduce line impedance
Programmable resistance and inductance change the output voltage with load current to simulate the effect of supply wiring.
Repeat test sequences
Stored sequences vary voltage, frequency and waveform. Time and trigger control enable repeatable test steps.
Amplify external signals
Analogue inputs support amplitude control and real-time power amplification for integration into PHIL test setups.
Measure at the DUT
Remote sense compensates for lead voltage drops: up to 20 V in DC operation or 20 V peak in AC operation.
Operating principle and output configuration
| Configuration | Output range | Coupling and current limits |
|---|---|---|
| Single-phase | AC: 0–350 V; DC: −500 to +500 V | AC, AC+DC, DC, DC+AC; up to 105 A RMS in AC or ±105 A in DC. |
| Three-phase | AC: 0–350 V L–N; up to 606 V L–L | AC and AC+DC; up to 35 A RMS per phase; balanced or unbalanced settings. |
| Reverse-phase | AC: up to 700 V L–L; DC: −1,000 to +1,000 V | AC, AC+DC, DC, DC+AC; up to 35 A RMS or ±35 A; reduced total power. |
| Split-phase | AC: 0–350 V per channel; DC: −500 to +500 V per channel | Three independent channels; AC, AC+DC, DC, DC+AC; up to 35 A RMS or ±35 A per channel. |
AC+DC adds a DC component to an AC voltage; DC+AC adds an AC component of up to 10% of the rated value to a DC voltage. Voltage, current and power limits must all be observed; maximum values are not simultaneously available at every operating point.
Models and power range
| Model | Total AC, 20–500 Hz | AC per phase, 20–500 Hz | Total AC+DC | Single-phase DC |
|---|---|---|---|---|
| N75506-350-105 | 6 kVA | 2 kVA | 6 kVA | 6 kW |
| N75509-350-105 | 9 kVA | 3 kVA | 9 kVA | 9 kW |
| N75512-350-105 | 12 kVA | 4 kVA | 12 kVA | 12 kW |
| N75518-350-105 | 18 kVA | 6 kVA | 15 kVA | 18 kW |
| N75525-350-105 | 25 kVA | 8.3 kVA | 15 kVA | 25 kW |
Total AC ratings apply to single-phase or three-phase operation. At 1–19.99 Hz, the N75525-350-105 AC rating decreases to 21 kVA total or 7 kVA per phase. Reverse-phase operation provides 4 / 6 / 8 / 12 / 16.6 kVA AC at 20–500 Hz, depending on the model. Ratings apply with high-voltage mains input; derating must be considered at lower input voltages.
Dynamic behaviour and signal quality
Output frequency is adjustable from 1 to 500 Hz. Selectable control-loop speeds adapt the response to the DUT; switch-on and switch-off phase angles are programmable from 0 to 360°. Voltage THD is below 0.5% at 1–100 Hz and below 1% at 100.01–500 Hz with a purely resistive load at full rated power. For the N75525-350-105, dynamic response is 1 ms in DC mode with fast loop control and DUT capacitance below 10 µF.
Programmable test and measurement functions
| Function | Operation and purpose |
|---|---|
| Sequence and sweep | Up to ten sequence files, each with up to 200 steps in single-phase/reverse-phase or 66 steps in three-phase mode. Sweep changes voltage and frequency step by step. |
| Waveforms and harmonics | Sine, square, triangle, sawtooth and trapezoidal waveforms, plus user-defined waveforms. 30 preset harmonic profiles; individual amplitudes and phases up to the 50th order at 50/60 Hz. |
| Interharmonics | Adjustable frequency, amplitude and phase for disturbance components at non-integer multiples of the fundamental frequency. |
| Surge & Sag | Time- or phase-controlled voltage dips and swells. Available in single-phase, three-phase and reverse-phase AC/AC+DC operation; unavailable in split-phase mode. Phase dimming and external programming are disabled while active. |
| Islanding | RLC or PQ load simulation to investigate anti-islanding behaviour of grid-connected inverters, including time measurement. |
| IEC test profiles | AC: IEC 61000-4-11/-4-13/-4-14/-4-28, plus -4-27 in three-phase mode only. DC+AC: -4-17/-4-29; DC: -4-29. AC standard tests require sine output; test setup and parameters must match the test requirements. |
| Measurement and recording | Measure voltage, current, active, reactive and apparent power, THD and waveforms. Recorder with up to six traces and CSV or TDMS export. |
Typical applications
Grid-connected inverters
Reproduce grid conditions and power absorption, and investigate anti-islanding detection using adjustable load simulation.
Storage and grid converters
Generate bidirectional power flows and distorted grid voltages for testing converters in energy storage systems.
On-board chargers and charging infrastructure
Supply the AC side with adjustable voltage and frequency; absorb returned energy from bidirectional DUTs.
Rectifiers and power supplies
Provide defined AC supply conditions, voltage changes and sweep sequences to investigate operating behaviour under changing grid conditions.
Interfaces, software and integration
| Equipment | Function and classification |
|---|---|
| LAN, USB, CAN, RS232, RS485 | Standard remote-control interfaces. USB supports TMC/VCP and SCPI/Modbus-RTU; CAN supports CANopen and CAN DBC. |
| GPIB | Optional via an RS232 converter. |
| PROG | Standard connector for ±10 V analogue programming, voltage/current monitoring and digital I/O. Real-time power amplification over 1–500 Hz; optional PROG cable. |
| PC software | Instrument configuration, waveform editing, sequences, measurement displays and historical data through the N75500 application software. |
| Remote sense and accessories | Three phase-specific sense connections. Sense cable, test leads and rack mounting kit are optional accessories. |
Installation and protection functions
The regular mains connection uses three phases at 340–480 V AC, 47–63 Hz. The instrument occupies 3U; width and depth including the protective cover are 482 × 755 mm, with a net weight of 42 kg. Operating temperature is 0–40 °C. Unobstructed airflow and an electrical infrastructure suitable for regenerative operation must be considered during integration.
Overvoltage, overcurrent, overpower and overtemperature monitoring can shut down the output. Current and power limiting are intended for resistive load conditions. Digital I/O provides output inhibit, triggers and status signals. Protection thresholds and shutdown behaviour are configured to suit the DUT.
N75500 frequently asked questions
Is 25 kVA available in every operating mode?
No. The N75525-350-105 provides 25 kVA in AC operation at 20–500 Hz and 21 kVA at 1–19.99 Hz. AC+DC is limited to 15 kVA total. Single-phase DC operation provides up to 25 kW.
Can the N75500 regenerate energy?
Yes. It absorbs energy from the DUT and returns it to the local utility grid, enabling tests with changing power-flow direction.
Is 105 A available per phase?
No. The 105 A RMS limit applies in single-phase mode. Three-phase, reverse-phase and split-phase modes are limited to 35 A RMS per phase or channel.
How do reverse-phase and split-phase differ?
Reverse-phase increases the voltage range between two outputs to up to 700 V AC or ±1,000 V DC. Split-phase provides three independently programmable channels.
Can user-defined waveforms be used?
Yes. User-defined waveforms and harmonic profiles can be edited, stored, imported and exported.
How are test-lead voltage drops compensated?
Remote sense measures voltage at the DUT. Maximum compensation is 20 V DC or 20 V peak in AC operation; sense wiring must match the phase configuration.
Can inverter anti-islanding protection be tested?
Yes. Islanding mode simulates RLC or PQ load conditions and measures islanding duration to investigate detection and shutdown behaviour.
Can rectifiers be tested under disturbed grid conditions?
Yes. Programmable waveforms, voltage dips, swells and frequency changes provide defined conditions for investigating their operating behaviour.
Technical consultation and project enquiry
Tell us about your DUT, phase configuration, AC/DC voltage, current and power requirements, together with grid disturbances, regenerative operation and required interfaces. We will help clarify the appropriate instrument configuration and integration into your test system.
