The Power Hardware-in-the-Loop Laboratory (PHiLsLab) is jointly operated and used by the Institute of Mechatronics in Mechanics (iMEK) and the  Institute of Electrical Power and Energy Technology (ieet). It is used to develop and test new innovative solutions for the interaction of fluctuating energy generation, consumption and storage. It allows the testing of various hardware components and control strategies in a real-time simulated test environment.

In the PHiLsLab, the Hardware Under Test (HUT) connected to a simulation and its behavior are evaluated. This simulation runs on a real-time simulator that represents the Rest of System (ROS). This can be any complex power system. The simulated behavior of this Rest of System is amplified using power amplifiers to obtain the currents and voltages required to replicate the system. The PHiLsLab is specialized in the simulation of island grids/microgrids and their integration into an electrical grid. Besides the simulation of photovoltaic generators and battery storage systems, it allows the simulation of auxiliary services and the behavior in fault conditions. Extensive safety mechanisms in software and hardware avoid damage during tests of novel components/control strategies.


The laboratory can be used in a variety of ways and is equipped with precise, high-resolution measurement technology to also test a wide range of hardware components. These hardware components can be connected to the simulated ROS using three single-phase linear power amplifiers from Spitzenberger & Spies (22.5 kW in total) and are thus tested in arbitrary states. The simulation can be performed on simple microcontrollers, a programmable logic controller (PLC) or a real-time simulator (OPAL-RT). This enables investigations that would otherwise have to be realized in field tests.

In addition to a network simulation with a short-circuit power of up to 100 kVA, a hybrid storage system with lithium-ion batteries, a photovoltiac simulation and three-phase battery inverters (grid-forming and grid-following/grid-supporting) are available. Furthermore, loads with variable power and variable power factor (pure resistive to inductive and capacitive) are available, which can be operated symmetrically or asymmetrically. Non-linear loads are implemented, which additionally allow the investigation of harmonic effects on the power system.


Currently, the laboratory is being extended with a powerful DC part, so that a wide range of investigations will be possible.

In PHiLsLab the following investigations have been carried out so far, among others:

  • High-current measurements as endurance tests to validate thermal durability

  • Investigation of various controls of battery storage systems in microgrids

  • Testing of innovative solutions for the design of intelligent decentralized energy systems

Selected existing equipment:

  • three single-phase linear amplifiers from Spitzenberger & Spies APS7500, 7.5kWeach
    • AC max. 270V rms, DC max. 425V
    • Modulatable
    • Energy can be recuperated
    • Voltage or current controlled
    • Additional connectable high current transformer with rectifier
    • Frequency of up to 30 kHz
  • Simulators:
  • measuring instruments:
    • Zimmer LMG 670
    • Multi-channel sampling systems up to 250 kSamples
    • Data acquisition software Dasylab 2020®
  • further hardware:
    • Battery inverter Sunny Island (company SMA), 3-phase, 5kVA each, 40 kWh LiFePo battery
    • PV simulator
    • Power simulation
    • Various consumers: L,C, frequency converter, ASM and PMSM, load resistors up to 50kW continuous load, fans, pumps and much more