Four-quadrant operation
The optional regenerative configuration enables bidirectional energy flow and operation as a grid simulator.
ESA – Configurable High-Power AC Power Source from 30 kVA to 10 MVA
For application-specific test systems in power electronics, research and industrial validation.
The modular cabinet platform combines independently controlled phases with a high-performance DSP and FPGA control architecture. Output ranges, cooling and topology are configured for each project, while measurement waveforms can be displayed and stored in real time at a sampling rate of 10 kS/s.
Programmable grid events
Sequences, phase jumps, harmonics and LVRT or HVRT profiles can be programmed for repeatable testing.
Automated control
LAN and RS485 are standard, while Modbus, SCPI and optional RS232 or analogue control support test automation.
Master-slave scaling
Identically configured units can optionally be coordinated through optical-fibre communication and connected in parallel.
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.
ART. NO.
Description
Current [A]
Power [P]
Voltage [V]
ESA 45-300-68
|
Description
ESA 45-300-68 Bidirectional programmable AC source, 45 kVA, 300 V L-N, 68 A/phase
|
Current [A]
91
|
Power [P]
45000
|
Voltage [V]
300
|
AC Source/ Load (1/3ph)
Technical Data
Product category
AC Bidirectional
AC Electronic Load
AC Power Supply
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
ESA 60-300-91
|
Description
ESA 60-300-91 Bidirectional programmable AC source, 60 kVA, 300 V L-N, 91 A/phase
|
Current [A]
182
|
Power [P]
60000
|
Voltage [V]
300
|
AC Source/ Load (1/3ph)
Technical Data
Product category
AC Bidirectional
AC Electronic Load
AC Power Supply
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
ESA 180-300-273
|
Description
ESA 180-300-273 Bidirectional programmable AC source, 180 kVA, 300 V L-N, 273 A/phase
|
Current [A]
273
|
Power [P]
180000
|
Voltage [V]
300
|
AC Source/ Load (1/3ph)
Technical Data
Product category
AC Bidirectional
AC Electronic Load
AC Power Supply
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
ESA 240-300-364
|
Description
ESA 240-300-364 Bidirectional programmable AC source, 240 kVA, 300 V L-N, 364 A/phase
|
Current [A]
364
|
Power [P]
240000
|
Voltage [V]
300
|
AC Source/ Load (1/3ph)
Technical Data
Product category
AC Bidirectional
AC Electronic Load
AC Power Supply
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
ESA 300-300-455
|
Description
ESA 300-300-455 Bidirectional programmable AC source, 300 kVA, 300 V L-N, 455 A/phase
|
Current [A]
455
|
Power [P]
300000
|
Voltage [V]
300
|
AC Source/ Load (1/3ph)
Technical Data
Product category
AC Bidirectional
AC Electronic Load
AC Power Supply
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
ESA Custom
|
Description
ESA Customized Customized bidirectional AC source, project-specific configuration
|
Current [A]
10000
|
Power [P]
10000000
|
Voltage [V]
50000
|
AC Source/ Load (1/3ph)
Technical Data
Product category
AC Bidirectional
AC Electronic Load
AC Power Supply
Type of AC Load
Regenerative Load
Type of AC source
Source + Load
Grid simulator
Single-/Three-phase
ESA series overview
The ESA series is a modular, configurable high-power AC power source for three-phase supply, grid-simulation and load-testing applications. Project-specific power ratings range from 30 kVA to 10 MVA. The standard output range extends to 300 V L–N, while customised configurations can reach 50 kV L–N and 10 kA per phase. All three output phases can be programmed independently. With the -R option, the system provides four-quadrant operation with bidirectional energy flow and can be used as a grid simulator. Further options add regenerative AC load operation, DC outputs, line-impedance simulation, single-phase output or specialised grid-testing functions. The cabinet system is dimensioned according to the required power, voltage, current and cooling configuration.
Key benefits
Application-specific operating range
Power, output voltage and phase current are configured for the device under test, supporting both high-voltage and high-current applications.
Independent phase control
Voltage, phase angle and further parameters can be set independently for phases A, B and C to reproduce unbalance and fault conditions.
Regenerative power flow
The -R option adds four-quadrant operation and returns absorbed energy to the utility grid rather than dissipating it as heat.
Fast voltage transitions
Rise and fall times below 1 ms with the standard topology support repeatable grid-fault and ride-through testing.
Harmonics up to the 50th order
Harmonic amplitude and phase can be programmed separately for each output phase and combined with interharmonic components.
Integrated measurement and control
The Windows-based touch interface combines setpoint control, sequences, measurements, waveform display, diagnostics and data storage.
High-power AC source operating principle
The standard topology includes an input transformer for isolation and phase shifting, filter stages, PWM AC/DC converters feeding the DC bus and separate DC/AC power modules for the three output phases. This architecture provides independent control of phases A, B and C.
Source operation
In CV or CC mode, the system generates programmable three-phase voltage or current profiles with adjustable frequency and phase relationships.
Four-quadrant grid simulation
The regenerative option transfers power in both directions and reproduces grid connection points and dynamic utility conditions.
Regenerative AC load
The load option supports CC, CP, CR and rectifier-load simulation. The -R option is additionally required for regenerative load operation.
Optional DC operation
The -DC option provides three phase-related DC channels with separate source and regenerative current or power limits.
Power range and operating envelope
The permissible combination of output voltage, current and apparent power is defined for each system configuration. In addition to standard cabinet models, customised operating envelopes can be designed for high-voltage operation at reduced current or high-current operation at lower voltage. The final voltage-current envelope is defined for the individual project.
| Technical characteristic | ESA series |
|---|---|
| Output power | Configurable from 30 kVA to 10 MVA |
| Output voltage | Configurable; 0 to 300 V L–N as standard, customised up to 50 kV L–N |
| Output current | Configurable up to 10 kA per phase |
| Output frequency | 30 to 100 Hz as standard; extended frequency ranges available as options |
| Phase relationship | Phases B and C relative to phase A from 0.0° to 360.0° |
| Output modes | AC as standard; AC+DC and DC with the -DC option |
| Harmonic generation | Up to the 50th order |
| Output-voltage THD | <1% FS with a resistive load at 50/60 Hz |
Standard models
| Model | Power | Voltage | Current | Dimensions W × D × H | Weight |
|---|---|---|---|---|---|
| ESA 45-300-68 | 45 kVA | 300 V | 69 A | 800 × 800 × 2,000 mm | 770 kg |
| ESA 60-300-91 | 60 kVA | 300 V | 91 A | 800 × 800 × 2,100 mm | 980 kg |
| ESA 120-300-182 | 120 kVA | 300 V | 182 A | 1,600 × 900 × 1,700 mm | 1,400 kg |
| ESA 180-300-273 | 180 kVA | 300 V | 273 A | 1,600 × 900 × 2,100 mm | 1,800 kg |
| ESA 240-300-364 | 240 kVA | 300 V | 364 A | 1,800 × 900 × 2,100 mm | 2,100 kg |
| ESA 300-300-455 | 300 kVA | 300 V | 455 A | 2,000 × 1,000 × 2,100 mm | 2,700 kg |
Model-selection note: Voltage, current, power, dimensions and weight may differ from the standard models in customised systems. The system configuration is defined individually for each project.
Dynamic performance, accuracy and regulation
The dynamic characteristics support grid-fault, frequency and phase testing. The specified rise and fall times describe changes in output voltage and must not be interpreted as settling time or voltage slew rate.
| Characteristic | Standard topology | -TR transformer output topology |
|---|---|---|
| Voltage rise time, 0 to 90% | <1 ms | <2 ms |
| Voltage fall time, 90 to 0% | <1 ms | <2 ms |
| Load regulation | 0.2% FS | 0.2% FS |
| Line regulation | 0.1% FS | 0.1% FS |
| Voltage accuracy | 0.1% FS | 0.2% FS |
| Current accuracy | 0.2% FS | 0.2% FS |
| Power accuracy | 0.3% FS | 0.3% FS |
| Frequency accuracy | 0.01 Hz | 0.01 Hz |
| Phase accuracy | ±0.3° at 50 Hz | ±0.3° at 50 Hz |
Programming resolutions are 0.01 V for voltage, 0.1 A for current, 0.1 kW for power, 0.01 Hz for frequency and 0.1° for phase. The optional -FHR configuration increases frequency resolution to 0.005 Hz with a maximum frequency of 70 Hz.
Operating modes and programmable test functions
Voltage and frequency sequences
Multi-step profiles include voltage or current, frequency, phase angle, ramp time and dwell time. Sequences can be saved and re-imported.
Ride-through testing
Interruptions, dips, swells and low- or high-voltage ride-through profiles can be generated under repeatable conditions.
Harmonics and interharmonics
Harmonic order, amplitude and phase are configured independently for each phase. Multiple interharmonics can be superimposed simultaneously.
Programmable waveforms
The waveform factor generates sinusoidal, clipped and rectified waveforms during source or regenerative load operation.
RLC and RCD load simulation
The load option provides twelve RLC and four RCD topologies with phase-specific R, L, C, R2 and R3 settings.
List Mode and SCPI sequences
Complex tests combine AC, DC, harmonic and interharmonic commands with loops, trigger angles and individual execution times.
| Option | Function | Technical note |
|---|---|---|
| -R | Regenerative four-quadrant operation | Required for bidirectional grid-simulator and regenerative load operation |
| -LD | Regenerative AC load | CC, CP, CR, rectifier, RLC and RCD load functions; used together with -R |
| -DC | Independent DC output | DC and AC output from 0 to 100 Hz; up to 50% power and current derating below 30 Hz |
| -1P | Single-phase output | Parallel connection of the three phase outputs to increase available single-phase current |
| -IMP | Line-impedance simulation | Programmable R and L; Rmax = 0.2 × Urated / Irated and Lmax = Rmax / 314 |
| -62116 | Island mode for IEC 62116 testing | RLC load simulation for anti-islanding tests with a sinusoidal 50/60 Hz input |
| -PQ | PQ control mode | Independent active- and reactive-power control for bidirectional power flow |
| -FPD | Fixed phase difference | Optional operating mode with a defined phase relationship |
| -TR | Transformer output topology | Different frequency range and voltage accuracy compared with the standard topology |
| -HFXXX | Extended output frequency | Available in CV mode only; the specific range is defined for the project |
| -W | Water cooling | Alternative to the standard forced-air cooling system |
Typical applications
Depending on its configuration, the ESA series supplies, simulates the grid for or regeneratively loads the device under test. Independent phase control and programmable disturbances support both static and dynamic validation.
PV inverter and grid simulation
Grid-connected inverters are tested with voltage, frequency, unbalance, harmonic, LVRT and HVRT profiles.
Distributed energy resources
Solar, wind and other distributed sources can be validated using programmed active- and reactive-power profiles and grid events.
Power electronic converters
Inverters, converters and other AC components are operated with defined voltage, phase and non-sinusoidal utility conditions.
Motor-drive systems
The source provides repeatable three-phase supply conditions for development, functional testing and validation of drive electronics.
Anti-islanding testing
The -62116 option reproduces RLC behaviour using power-related parameters or direct R, L and C settings.
Regenerative loading of AC equipment
Power supplies, generators and converters are loaded using constant-current, constant-power, resistive or nonlinear rectifier profiles.
Interfaces, software and automation
Local operation is provided through a TFT touch panel of at least 12 inches with a Windows-based GUI. The same software can be installed on a connected control PC for remote operation.
| Interface or function | Status | Purpose |
|---|---|---|
| LAN | Standard | Remote control and internal communication with the touch panel |
| RS485 | Standard | Serial remote control and multi-drop communication |
| Modbus and SCPI | Supported | Automated setpoint control, status queries and integration into test software |
| TTL output | Standard | Trigger signal during voltage or frequency transitions for acquisition by an oscilloscope |
| Remote sense | Standard | Compensation of voltage drops between the output and DUT for each phase |
| External emergency stop | Standard | Connection of an external emergency-stop switch |
| RS232, -232 option | Optional | Point-to-point remote communication |
| ATI analogue input, -ATI option | Optional | Analogue control of output setpoints through BNC connectors |
| Master-slave, -MS option | Optional | Optical-fibre communication between identically configured systems connected in parallel |
Measurement and harmonic analysis
The GUI displays input and output voltage, current, power, frequency, phase, DC-bus values and IGBT temperatures.
Waveform and fault recording
Input and output waveforms can be displayed and stored in real time. Status changes and faults are recorded in the RunLog.
Parallel operation and system scaling
Identically configured ESA systems can be operated in parallel using the optional master-slave function. Communication between the master and slave is provided by optical fibre. A slave without its own touch panel additionally requires a network connection to the user interface.
- Parallel operation is intended for suitably configured systems of the same type.
- Selection of “Parallel Master” or “Parallel Slave” in the system configuration.
- Parallel connection of the corresponding input and output conductors.
- Central control and display of combined phase currents and power at the master system.
- Project-specific complete systems up to 10 MVA.
No universal maximum number of units is defined for parallel operation. The unit count, cabling, protection concept and total power are determined individually for each system project.
Installation and infrastructure
| Requirement | Specification or note |
|---|---|
| AC input voltage | 380 V, 400 V or 480 V L–L, each ±10%, depending on the ordered input configuration |
| AC input connection | 3P+N+PE or 3P+PE; configuration must be specified when ordering |
| Input frequency | 47 to 63 Hz |
| Power factor | 0.95 |
| Input-current THD | ≤3% |
| Efficiency | ≥90% |
| Cooling | Forced-air cooling as standard; water cooling with the -W option |
| Operating temperature | 0 to 40°C |
| Storage temperature | -20 to 85°C |
| Relative humidity | 20 to 90% RH, non-condensing |
| Power connections | Copper bars for the AC input and AC output inside the cabinet |
| Transport and installation | Cabinet construction with lifting eyes and castors; space and weight depend on the selected model |
The utility supply and upstream switching devices must be de-energised before installation. Protective earth must be connected before all other input and output conductors. Cable cross-sections, terminals and circuit protection must be selected using the project-specific system ratings.
Protection and safety functions
Overvoltage protection
The output is switched off when the instantaneous output voltage exceeds the configured peak-voltage limit.
Overcurrent protection and limiting
An adjustable RMS shutdown threshold and a separate peak-current limit protect the system and device under test.
Overpower protection
The output is switched off if the configured RMS power limit is exceeded.
Overtemperature protection
Temperatures of the principal power components are continuously monitored and displayed by the GUI.
Local and external emergency stop
In addition to the front-panel emergency stop, a standard terminal is provided for an external safety switch.
Status and fault monitoring
Communication, power modules, temperatures and system states are monitored, with faults displayed in the GUI and RunLog.
CE conformity covers EN 62040-1 and EN 62040-2. The system design, marking and technical documentation are adapted to the agreed project configuration.
ESA series FAQ
Is every ESA configuration bidirectional?
No. Bidirectional energy flow and four-quadrant operation are provided by the regenerative -R option.
Can the ESA series operate as a regenerative AC load?
Yes. The -LD and -R options are required. Available functions include CC, CP, CR, rectifier, RLC and RCD load simulation.
How are voltage and current ratings selected?
The required voltage-current operating points are defined first. These determine the operating envelope and cabinet configuration.
Can all three phases be programmed independently?
Yes. Voltage or current, phase, sequences, harmonics and further parameters can be configured independently for each phase.
Which frequency ranges are available?
The standard range is 30 to 100 Hz. The -HFXXX and -FHR options and the -TR transformer output topology cover special frequency requirements.
Is DC output available?
Yes. The -DC option provides independent DC outputs and AC operation from 0 Hz. Up to 50% power and current derating applies below 30 Hz.
Can multiple ESA systems be connected in parallel?
Identically configured systems can be coordinated as master and slave over optical fibre and connected in parallel using the -MS option.
Which interfaces support test automation?
LAN, RS485, TTL, external emergency stop and remote sense are standard. RS232 and analogue control are optional, while Modbus and SCPI are supported.
Technical consultation and project enquiry
The ESA series is configured according to the required power, voltage, current, frequency, operating mode, dynamic performance, cooling and utility infrastructure. A reliable system design requires the intended operating points, test procedures and connection conditions.
- Required source and regenerative power
- Voltage and current range per phase
- Required grid-simulation and load functions
- Utility connection, cooling and available installation space
- Interfaces and integration into the test system
Discuss your requirements with our technical sales team through the ET System contact page.
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