Scope of application
The increasing number of alternative power sources like solar, wind driven or biological energy systems call for consistent and well demanding regulations for energy feed into the utility grid. Manufacturers of such systems have to test and to prove the compliance of their equipment. Grid simulators form an electronic equivalent circuit for the grid, but allow to vary all relevant parameters in order to test the behaviour and response of the equipment under test.
- Variation of frequency
- Variation of phase angle
- Variation of amplitude
- Step changes of base frequency
- Asymmetric three phase voltages
- Micro-ruptures and flicker
- Periodic and single shot under- and overvoltages
- Voltage drops either three phase or each single phase
- Superimposed harmonic and inter-harmonic voltages up to 5 kHz bandwidth
- Specialized programs for EMC characterisation
REGATRON grid simulator systems use a top-of-the-art multilevel double inverter technology. The main advantages over existing linear systems are a substantial reduction of power losses, full 4-quadrant operation, very compact power units and the modular, cost-effective architecture. This allows the user to choose a system size well fitting his requirements, including the possibility for future power expansions and/or splitting-up of the system into several standalone subsystems. The basic three-phase power units of 50 kVA may be expanded by simply paralleling further blocks even to big systems reaching 1 MVA. Even higher power levels may be achieved by means of multi-system operation. With the availability of the active neutral string, any single phase or asymmetric condition can be simulated. Additionally, the neutral can be connected to Protective Earth (PE), if required. The system will allow for all relevant testing according to the grid-feed-in regulations (CENELEC, DIN,IEC), like for example EN 61000-4-11, EN 61000-4-14, EN 61000-4-27, EN 61000-4-28 and EN 61000-4-34. Both the operation as a grid simulator as also as triphase full 4-quadrant voltage amplifier are possible.
An intuitive, application based software will allow for manual operation, programming and for automated test runs of the system. Provisions are made for data acquisition, storage and visualisation throughout the system. The software also offers the documentation of test results.
The Grid Simulator as a Building Block of a Complete Test Environment
Owing to the full 4-quadrant capability of the TC.ACS system, almost all AC power equipment can be tested with the appropriate test procedures. One of the most interesting application fields today is testing of solar inverter equipment. An integrated test environment for solar inverters is composed of a Solar Array Simulation block (SAS), the device under test (DUT) and the grid simulator system (GRS). While the REGATRON SAS components allow for simulation of a user-defined solar array of any order under arbitrary conditions, the GRS simultaneously defines the different test conditions with respect to the grid connection.
By the addition of the bidirectional DC power supply TC.GSS to such a test environment, even the role of a battery pack within the setup may be experienced.
REGATRON offers complete and modular SAS systems based on the widespread, field-proven TopCon Quadro power supplies on the one hand as well as complete GRS simulation on the other hand. Modern switched-mode technology ensures very compact and reliable systems with high overall efficiency.
Pic. 1 Example of a Solar Inverter test bench with grid simulator