Laboratories of the professorship
Table of contents
Dynamic network model
The dynamic network model is a realistic replica of a 220kV overhead line with two systems and 150km line length.
The dynamic network model works with model voltages and currents (mU = 1/500, mI = 1/20) at a network frequency of 50Hz. The coupling of both overhead line systems is done by air coils and capacitors. Two rotating converters represent the power plants in the grid and various R-L-C banks represent the load and consumers of the model grid. The model is equipped with modern protection and control technology.
Verwendung
The dynamic model is mainly used in teaching. Here the main focus is on:
- Identification of line parameters
- Station and network control technology
- Distance protection and staggering of protection systems
Combined Energy Lab
The Combined Energy Lab was created out of the motivation to enable comprehensive investigations of heat generators from both thermal and electrical points of view. This is realized by two separately operating network emulators, the building and low voltage network emulator. From the point of view of the heat generators, these emulators act like real networks. In this context one speaks of Hardware-in-the-Loop (HIL) tests.
Both emulators have in common that they consist of a hardware and a software component. On the hardware side, the building emulator is characterized by a variable hydraulic circuit with the possibility of integrating various heat accumulators and implementing hydraulic circuits. By means of a superimposed simulation based on a 3D building model, the target return temperature and the volume flow rate are determined depending on the current operating state of the heat generator and the current heat demand in the simulated building and are specified in the hardware components by means of suitable actuators. Thereby the complete heating system of any property as well as any building with the parameters e.g. thermal insulation standard or geometry can be emulated. A climatic chamber can be connected to the emulation test bed, which allows investigations of thermal comfort.
The Combined Energy Lab is extended by the low voltage network emulator to a complete HIL test field. It enables the test of 1-phase or
3-phase heat generators connected to the low voltage network. The aim is to realize the simulation of an electrical network in interconnected and isolated operation with its characteristic properties. This makes it necessary to enable fast voltage and frequency changes. For this purpose three 1-phase power amplifiers are used, which act as "network formers" to specify voltage and frequency. For 3-phase connected heat generators an additional motor-generator set is integrated in the trainer, which can be used for active power feedback into the public power supply network but also for reactive power compensation. Superimposed on the hardware is a comprehensive control and regulation regime, which takes over the control of the trainer and machine set. In addition, a real-time capable network simulation is implemented, whereby variable voltage and frequency values are achieved.
The application spectrum of the Combined Energy Lab ranges from the test of individual heat generators under ideal boundary conditions and the evaluation of these with regard to start-up behaviour, grid feedback, efficiency and utilisation rate to the test of hybrid supply structures, e.g. micro-CHP systems in connection with battery storage.
Technical configuration
- Low voltage network emulator
- 3 x 4-quadrant power amplifierr
- Motor-generator set
- Real-Time-PXI-System
- Heat network emulator:
- Serial buffer storage
- Parallel buffer storage
- Climate room for comfort examination
Technical data
- Stationary parameters:
- Ub = 400V ± 15%
- fb = 42,5Hz ... 57,5Hz
- Electrical limits:
- Pel,max,3ph = -10kW ... 20kW (dynamischer Betrieb)
- Pel,max,1ph = -4kW ... 5kW (dynamischer Betrieb)
- Thermical limits:
- Pth,max = 30kW
- Voltage steps: ΔU ≥ ± 10% Ub
- Frequency change: df / dt ≥ 4Hz / s
- Other features:
- Default freely selectable voltage frequency spectra
- Simulation of any low voltage network (freely selectable network impedance)
- Test of 1-phase and 3-phase test systems, hybrid supply structures
- Reproduction of any building in TRNSYS-TUD
- Fields of application (among others):
- Analysis of the internal system control
- Determination of efficiency and standard utilization ratio
- Evaluation of the grid compatibility of decentralized generators (start-up behavior, harmonic emission)
- Analysis of voltage and frequency dependence
- Analysis of the forecast quality for energy marketing
Electric vehicle and photovoltaic laboratory
Research objectives
- Determination of the system perturbations of powerful electronic devices in single and combined operation
Technical equipment
- 3 freely programmable 4-quadrant power amplifiers (15 kVA each)
- 2 charging boxes for electric vehicles
- 2 simulators of PV panels (10kW and 5kW)
- 8 different PV inverters
- Transient recorder up to 1kV and 125A (16 channels with 1MHz sampling rate each)
Household Appliance Laboratory
Research objectives
- Study of network perturbations, input and output impedances and the interaction of mass market devices
Technical equipment
- Freely programmable power amplifier (2.25 kVA)
- Network simulation according to standard (IEC 61000-4-7 Annex B, CISPR-16) and with optimized parameters, automatic switching between impedances
- Transient recorder up to 1kV and 125A (16 channels with 1MHz sampling rate each)
General measuring laboratory
Research objectives
- Accuracy testing of measurement technology
- Transmission behaviour of voltage and current transducers
- Preparation of field measurements (e.g. time synchronous measurement)
- Testing of PQ-measuring instruments for standard conformity with IEC 61000-4-30 according to IEC 62586
Technical equipment
- Measuring system for the frequency-dependent transmission behavior of current and voltage sensors
- 23 data loggers for (long-term) network measurements according to IEC 61000-4-30 with integrated evaluation according to DIN EN 50160, (interval ≥ 1 s, up to 40 kHz frequency resolution)
- Calibrated test generator for three-phase currents and voltages for testing measuring instruments
- High precision AD-/DA-converters with 2Mhz sampling rate and suitable signal conditioning, input range from 10mV to 1kV
- 2 power amplifiers up to 2.25kVA, 270V, 12.5A and 150kHz
- 1 power amplifier 5.25kVA three-phase, 300V, 5kHz
- 4 transient recorders up to 1kV and 125A (16 channels with 1MHz sampling rate each)
- Harmonics test load
Internship Experiments
An overview of the professorship's internship attempts can be found here.