ABB ACS800-67, Описание системы и руководство по запуску

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System description 39
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Grid connection procedure
A typical procedure required to connect the wind generator to the grid is as follows:
•
The system is operational if the rotor speed is in the predetermined normal operating
range (eg, from 70% to 130% of the synchronous speed).
•
MCB2 is closed to start the converter and to establish the DC link for the rotor-side
converter. MCB3 is still open.
•
The rotor-side converter measures the grid voltage (input side of MCB3) and the stator
voltage.
•
The rotor-side converter shifts to synchronization mode. The rotor-side converter
magnetizes the rotor windings so that the induced stator voltage is synchronized with
the grid voltage (same frequency and magnitude as for the grid voltage).
•
MCB3 is closed and the controller shifts to the torque control mode. Now it is ready to
accept the user's torque and power factor (pf) commands. The net power generated to
the grid (from the stator port + the rotor port) is relative to the product of the torque and
the mechanical speed.
The normal shut-down procedure is as follows:
•
The system is assumed to be in the torque control mode and the rotor speed in the
predetermined normal operating range (eg, from 70% to 130% of the synchronous
speed).
•
After receiving the shut-down command, converter program sets the rotor-side
converter torque reference to zero and power factor command to 1. (Under these
conditions the stator current is zero.)
•
MCB3 is opened when the converter detects 0 voltage and 0 current across it.
•
The rotor-side converter and then the grid-side converter modulation is stopped.
ISU
INU
G
MCB3
MCB2
Turbine
transformer