Four-quadrant operation
The unit can source or absorb active and reactive power and regenerate recovered energy to the utility grid.
N75500 – Regenerative Grid Simulator up to 25 kVA in 3 U
For repeatable grid, disturbance and regenerative testing of grid-connected power electronics.
The compact 3U architecture combines a six-wire output structure with a separate return conductor for each phase. This supports different DUT wiring configurations, while remote sensing compensates cable voltage drops of up to 20 V directly at the load connection.
Programmable grid disturbances
Sequences, sweeps, surge and sag events, interharmonics and user waveforms reproduce different grid conditions.
Anti-islanding testing
Programmable RLC, active-power and reactive-power parameters support verification of islanding detection and shutdown behaviour.
Remote control and protocols
USB, CAN, LAN, RS232 and RS485 are standard, with support for SCPI, Modbus RTU and CANopen.
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 overview
The N75500 is a programmable four-quadrant regenerative grid simulator designed for both source and sink operation. The N75525-350-105 model provides up to 25 kVA in AC operation and up to 25 kW in DC operation. Depending on its configuration, the unit supports single-phase, three-phase, reverse-phase and three independently controlled split-phase outputs. Its operating range extends to 350 V L–N, 606 V L–L in three-phase mode and 700 V L–L in reverse-phase mode. DC output voltages of up to ±1,000 V are also available. The series combines programmable grid conditions, regenerative energy absorption, integrated measurement and analysis functions and standard remote-control interfaces in a compact 3U, 19-inch enclosure. Typical DUTs include PV and energy-storage inverters, on-board chargers, charging stations, power converters, UPS systems and other grid-connected power-electronic equipment.
Key benefits
Bidirectional power flow
Source and sink operation for active and reactive power supports DUTs with changing directions of energy flow.
Regenerative energy feedback
Up to 25 kVA can be absorbed and returned to the grid with a regenerative efficiency of up to 90%.
High power density
The 19-inch enclosure provides the full unit output within 3U, reducing the required test-rack space.
Wide frequency range
Programmable frequencies from 1 to 500 Hz support grid, aerospace, converter and frequency-deviation tests.
Harmonic simulation and analysis
Simulation and measurement up to the 50th order support detailed investigation of distorted voltage and current waveforms.
Integrated measurement functions
Meter, oscilloscope, recorder, harmonic and vector analysis functions support evaluation and troubleshooting directly at the unit.
Operating principle of the regenerative grid simulator
In voltage-source mode, the N75500 operates across all four quadrants. It supplies active and reactive power to the DUT or absorbs energy produced by an inverter, converter or other regenerative component. Absorbed energy is not continuously converted into heat but is returned to the local utility grid as a synchronised current.
The output structure comprises terminals A, NA, B, NB, C and NC. In single-phase mode, the three line terminals and the three return terminals are connected in parallel for current sharing. Three-phase mode supports star- and delta-connected loads. Reverse-phase mode increases the voltage available between two output phases, while split-phase mode provides three independently programmable output pairs.
Supported output couplings are AC, DC, AC+DC and DC+AC. The available coupling modes and output ratings depend on the selected phase configuration.
Power range and operating characteristics
The available voltage, output current and usable power depend on the phase configuration, coupling mode and output frequency. Reduced AC power ratings apply below 20 Hz. Reverse-phase operation increases the usable output voltage while reducing the available total power compared with single-phase or three-phase operation.
| Operating mode | Output voltage | Output current | Maximum power |
|---|---|---|---|
| AC, single-phase | 0–350 V AC L–N | 105 A RMS, 315 A peak | 25 kVA at 20–500 Hz; 21 kVA at 1–19.99 Hz |
| AC, three-phase | 0–350 V AC L–N; 0–606 V AC L–L | 35 A RMS per phase, 105 A peak | 25 kVA at 20–500 Hz; 21 kVA at 1–19.99 Hz |
| AC, reverse-phase | 0–700 V AC L–L | 35 A RMS, 105 A peak | 16.6 kVA at 20–500 Hz; 14 kVA at 1–19.99 Hz |
| AC, split-phase | Three output pairs, each providing 0–350 V AC | 35 A RMS per output, 105 A peak | 8.3 kVA at 20–500 Hz; 7 kVA at 1–19.99 Hz |
| AC+DC, single- or three-phase | AC component with superimposed DC component | Mode-dependent | 15 kVA |
| AC+DC, reverse-phase | AC component with superimposed DC component | Mode-dependent | 10 kVA |
| AC+DC, split-phase | AC component with superimposed DC component | Mode-dependent | 5 kVA |
| DC, single-phase | −500 to +500 V DC | −105 to +105 A DC | 25 kW |
| DC, reverse-phase | −1,000 to +1,000 V DC | −35 to +35 A DC | 16.6 kW |
| DC, split-phase | Three output pairs, each providing −500 to +500 V DC | −35 to +35 A DC per output | 8.3 kW per phase |
At 50 or 60 Hz, a crest factor of up to 5 is available provided that the permitted peak current is not exceeded. At full current and full power, the specified maximum crest factor is 3.
Dynamic and control behaviour
Dynamic response
The specified dynamic response is 1 ms in DC mode with a DUT capacitance not exceeding 10 µF.
Voltage rise rate
The voltage rise rate is at least 2 V/µs for a change across the full voltage range.
Programmable change rates
Voltage and frequency changes can be executed with programmable slew rates up to 3,000 V/ms and 3,000 Hz/ms.
Adjustable control loop
Different loop-speed settings provide a balance between stability, rapid signal changes and high crest-factor requirements.
With a purely resistive load at full power, the specified voltage THD is below 0.5% from 1 to 100 Hz and below 1% from 100.01 to 500 Hz.
Operating modes and programmable test functions
Sequence mode
Up to ten sequence files manage programmed voltage, frequency, timing, phase and waveform steps with different trigger sources.
Waveform editor
Sine, square, triangle, sawtooth, trapezoidal, clipped, rectified and custom 1,024-point waveforms are available.
Harmonics and interharmonics
Thirty stored distortion profiles and user-defined components up to the 50th order support power-quality and immunity testing.
Surge and sag
Programmable overvoltage and undervoltage events reproduce short-term grid deviations with defined timing and phase parameters.
Islanding simulation
Resistance, inductance, capacitance, active power and reactive power can be programmed for anti-islanding tests.
Output impedance
Programmable resistance and inductance reproduce voltage drop, line impedance and current-dependent grid behaviour.
| Function | Scope | Typical benefit |
|---|---|---|
| Sequence mode | 10 files; up to 200 steps in single- or reverse-phase mode and up to 66 steps in three-phase mode | Automated test profiles using time, bus, phase or external triggering |
| Standard tests | IEC 61000-4-11, IEC 61000-4-13, IEC 61000-4-14, IEC 61000-4-27 and IEC 61000-4-29 | Repeatable testing of defined voltage, frequency and unbalance events |
| Sweep mode | Stepped sweeps of AC voltage, DC voltage and frequency | Automated investigation of the DUT across a defined operating range |
| Phase control | Turn-on, turn-off and sequence transitions at programmable phase angles | Targeted investigation of phase-dependent switching and start-up events |
| Phase dimming | Leading- or trailing-edge control from 0 to 180° | Testing of phase-controlled loads and their impact on the supply network |
Typical applications
Combined source, sink and grid-simulation operation is suitable for components that consume energy from an AC or DC grid or feed energy back into it.
PV inverters and grid simulation
The DUT can feed energy back while voltage, frequency, harmonics, impedance and grid disturbances are applied reproducibly.
Energy storage and power conversion systems
Four-quadrant operation reproduces charging, discharging, reactive-power and regenerative states of bidirectional storage converters.
On-board chargers and e-mobility
Unidirectional and bidirectional OBCs can be tested at different grid voltages, frequencies, phase angles and disturbance profiles.
AC and DC charging stations
Programmable grid conditions and regenerative operation support functional, power and fault testing of charging infrastructure.
UPS, drives and power supplies
Surge and sag events, frequency changes, phase jumps and non-sinusoidal waveforms verify operation under disturbed supply conditions.
Power Hardware-in-the-Loop
External analogue signals can be amplified via the PROG interface and reproduced as real power waveforms in PHIL systems.
Interfaces, software and automation
The series can be operated locally from the front panel, through the PC software or remotely within automated test systems. Digital, serial, network and analogue control paths are provided.
| Interface or function | Status | Technical scope |
|---|---|---|
| LAN | Standard | RJ45 network interface for remote control and multi-unit communication; UDP communication is used by default |
| USB Device | Standard | Selectable TMC or VCP operation with support for SCPI and Modbus RTU |
| RS232 | Standard | Serial remote control at 9,600, 19,200, 38,400 or 115,200 baud |
| RS485 | Standard | Serial bus communication with a switchable 120 Ω termination resistor |
| CAN | Standard | CANopen and CAN DBC support, configurable CAN ID and switchable 120 Ω termination |
| GPIB | Optional | Connection through an RS232-to-GPIB converter |
| PROG | Standard | Analogue inputs and outputs, digital I/O, triggers, output status, external programming and monitor signals |
| Remote sense | Standard | Separate sense terminals for phases A, B and C with specified compensation up to 20 V |
| PC software | Standard function | Device search, connection, running-data monitoring, parameter configuration and voltage-source operation |
| Protocols | Standard | SCPI, Modbus RTU and CANopen |
Parallel operation and power scaling
The N75500 supports parallel operation for applications requiring higher output power. The maximum number of units depends on the individual system design. The quantity of units, wiring, synchronisation, protection concept and grid connection must therefore be engineered for the individual application.
LAN and serial communication also support multi-unit connections. Communication-based control of multiple units must be distinguished from electrical paralleling of the power outputs.
Installation and infrastructure
| Characteristic | Requirement or value | Note |
|---|---|---|
| High-voltage AC input | 3-phase 340–480 V AC, 47–63 Hz, ≤70 A | The specified rated performance is based on the high-voltage input range. |
| Low-voltage AC input | 3-phase 180–264 V AC, 47–63 Hz, ≤70 A | Relevant performance parameters must be derated when operating from the low-voltage input range. |
| Protective earth | Separate PE connection required | The protective-earth connection must be securely established before operation. |
| Enclosure | 19 inch, 3U | Requires a sufficiently deep and load-rated test rack. |
| Dimensions | 132 × 482 × 755 mm | Height × width × depth including the protective cover |
| Net weight | 42 kg | Suitable lifting and rack-installation equipment should be provided. |
| Operating temperature | 0–40 °C | Unrestricted cooling-air intake and exhaust must be maintained. |
| Relative humidity | 5–90%, non-condensing | Condensation and liquid ingress must be prevented. |
| Altitude | Below 2,000 m | No specified operating data is provided for higher altitudes. |
| Output connection | A, NA, B, NB, C, NC | Cable cross-sections and wiring must match the operating mode and output current. |
At high ambient temperature, operation near rated power or when generating higher-order harmonics, the sound-pressure level at a distance of one metre may exceed 70 dB. The cooling vents must not be obstructed.
Protection and safety functions
Electronic monitoring
Integrated protection functions include OVP, OCP, OPP, OTP, SOCP, MF and monitoring of the remote-sense connection.
External output inhibit
The PROG interface provides digital inputs for output inhibit, triggering and clearing protection messages.
Defined output-off state
The disabled output can be configured for relay disconnection or a high-impedance DC state.
Isolation
Isolation test values are specified between the input, output, enclosure and three-phase output circuits.
Connection, installation and maintenance work must only be performed by qualified personnel with the unit de-energised. After switching off, a waiting period of at least 30 minutes is required before opening or servicing the unit.
N75500 FAQ
What is the maximum available AC voltage?
Up to 350 V L–N, 606 V L–L in three-phase mode and 700 V L–L in reverse-phase mode.
Can the N75500 operate as a DC source and sink?
Yes. Depending on the phase configuration, DC operation provides up to ±1,000 V, ±105 A and 25 kW.
Is absorbed energy returned to the grid?
Yes. Maximum regenerative power is 25 kVA, with a regenerative efficiency of up to 90%.
Can the unit perform anti-islanding tests?
Yes. Resistance, inductance, capacitance, active power and reactive power can be programmed to test islanding detection and shutdown.
Which interfaces are included as standard?
USB, CAN, LAN, RS232 and RS485 are standard. GPIB is available through an optional RS232 conversion.
Can custom grid disturbances be generated?
Yes. Sequences, surge and sag events, sweeps, interharmonics, programmable impedance and custom waveforms are supported.
Can the output power be expanded?
Parallel operation for higher power is supported. The quantity of units and system design are defined for the individual project.
What AC input connection is required?
The three-phase input ranges are 340–480 V AC and 180–264 V AC, each at 47–63 Hz and up to 70 A.
Technical consultation and project enquiry
The appropriate phase configuration, output rating, AC input and interface integration depend on the DUT and planned test procedure. ET System supports device selection, wiring concepts, parallel scaling and integration into automated test systems.
