| Summary: | Distributed generation (DG) is a generation system which is functioned as
additional generating plants in addition to the main generating plants. Generally,
DG uses induction motor operated as a generator (MISG). However, there might
be a problem when the supply from the main power interrupted (loss of grid) or
MISG supplys overload.
This simulation aims to determine the characteristics of MISG (Induction
Motor As Generator) and maintain MISG to keep supplying power under loss of
grid condition.
Simulations conducted in three conditions, i.e. : under loss of grid
condition without dividing the value of load, under loss of grid condition with
equal loads, and under loss of grid condition with load variations. Moreover,
simulations performed to determine the critical point under loss of grid condition
and variations of capacitors used for the voltage improvement. Load applied in
the simulations is resitif load.
As the results, when connected to grid, MISG operated in stable condition,
both the voltage and frequency, since MISG received sufficient active power and
reactive power. While under loss of grid condition, MISG does not receive
reactive power, so it is necessary to add capacitor as a source of reactive power
in order to operate the MISG. Voltage will drop due to overload when loss of grid
occurs, therefore load shedding is necessary to prevent voltage drop. Sequence of
load shedding affects the stability of the system. Capacitor value also affects the
output voltage after loss of grid condition. There is maximum time limit in
performing load shedding after loss of grid condition and if it is too long then
MISG will fail to operate.
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