The Esi Main Controller - ABB ESI-S Installation, Operation And Maintenance Instructions

voltage waveform is generated which contains the desired spectral components
(imposed by the inverter controller) as well as high frequency noise (due to the IGBT
switching technology). Coupling impedance consisting of a reactor (3) and a high
frequency rejection inverter (4) ensures that the useful voltage components are
converted into a useful current while the high frequency noise is absorbed. The IGBT-
inverter is equipped with DC capacitors that act as energy storage reservoirs (2).
The battery is connected (8) on the DC/DC converter output. The preload of these DC
capacitors is done thanks to the grid. This avoid inrush current coming from the battery.
All units contain a DC capacitors preloading resistor (5) which charges the DC capacitors
up to the peak AC voltage once the auxiliary fuse box of the unit(s) is closed. This
approach ensures a smooth inverter start-up without excessive inrush currents from the
grid. Later in the start-up sequence the IGBT switching pattern will charge more the DC
capacitors in order to reach a sufficient voltage level to enable properly the DC/DC
converter.

4.4 The ESI main controller

The ESI main controller controls the complete inverter system. Its tasks include:
- Accepting and executing customer requests to stop and start the equipment;
- Calculating and generating IGBT-inverter control references based on the user
requirements and line current measurements ;
- Interfacing to the IGBT-inverters;
- The measurement of system voltages and currents for control, protection and
presentation purposes.
Figure 14 depicts the controller interface diagram of the ESI-S inverter.
Interface to system
controller or to user
Touch-screen
interface
Modbus & PQ-
link interface
Programmable
Digital I/O
CT signals
The customer has to:
- Wire the CT signals (on a designated terminal) if required,
- Connect the AC power lines,
- Connect the DC power line,
18 Hardware description ç Manual Energy Storage Inverter ESI-S
ESI-
Manager
Figure 14: Controller interface diagram of the ESI-S
Measurement
board
ESI main
controller
DC out
(battery
connection)
ESI Power
stage
1~ AC
out