Itech IT7900E series regenerative grid emulators

The Itech IT7900E series regenerative grid emulators is an extension in the IT7900 series of AC/DC power supplies from Itech. The IT7900E goes a step further in power (21kVA in 3U) than the standard IT7900 series. And in a master/slave configuration we can also go to 231kVA power in a 37U high 19” rack. With parallel connection of racks we get to more than 1MVA of power.

Specifications IT7900E series regenerative grid emulators

Let’s start with some basic specifications. The unit can be used as a single phase and three phase regenerative AC power supply. The voltage of each phase is adjustable up to 350V LN and the frequency range is from 16Hz – 150Hz + DC. The phases are also individually adjustable from 0° – 360°, which can be used to simulate an unbalanced grid. In AC grid emulator mode, all kinds of grid pollution and harmonics can be generated, even arbitrary waveforms.

The grid emulator can both supply and absorb power, with this power being fed back into the grid. There is also an accurate Power Analyzer built in with a multitude of measurements including harmonic distortion. With the built-in datalogger function you can also store the measurement results in the internal memory for a long time.

The multifunctional IT7900E AC power supply gives the user the choice of no less than four different output modes, namely AC, DC, AC + DC and DC + AC. So there is the possibility to simulate both an AC grid and a DC grid. But also an AC grid where a DC offset applies. Even simulating a DC grid with an AC ripple is possible. With the help of the analog interface option, Power Hardware In the Loop (PHIL) applications are also possible.

Functionality and Standardization Testing

To save the user time, the power supply is equipped with pre-programmed routine tests for the IEC61000-4-11, 13, 14, 17 and 28 standards. Pre-compliance tests such as LVRT, a phase jump and frequency variations are also possible. All possible grid distortions and events can be applied to the waveforms. Think of spikes, dips, interrupts, sags and surges. The various simulations can also be linked using the STEP, LIST and PULSE modes. Harmonic distortions (up to 50st at 50 or 60Hz) and interharmonic distortions can also be generated.
The output impedance is also adjustable.

Measurement options

The IT7900E also features an accurate and comprehensive Power analyzer. Parameters such as Crest factor, power factor, active, reactive and apparent power are measured and optionally also stored in the internal memory for trend research. With the trend analysis function, these measured values can then be made graphically visible in detail.

Control IT7900E high power programmable AC/DC power supply

Setting the correct test values is extremely easy using the 5-inch touchscreen display with menu structure, the keypad, the arrow keys and the rotary knob. If you want to operate the unit remotely, this can be done via the standard USB, LAN or CAN interface. Optionally, there is also a GPIB interface and RS232+ analog interface.

Settings can also be easily implemented via the PC via the LAN interface and the internal web browser.