ABSTRACT:
Linear droop control can realize power sharing among
generators in DC microgrid without relying on critical communication links.
However, the droop relationship between output power and voltage magnitude of
renewable power generate system is nonlinear with uncertainties and
disturbances from renewable sources and loads in practical DC microgrid. A
novel droop scheme is proposed for an isolated DC microgrid to solve the nonlinear
problem. The control strategy is proposed by using the Takagi-Sugeno (T-S)
fuzzy model and sliding mode algorithm. The nonlinear droop characteristics can
be represented by T-S model through taking advantage of locally measured output
variables. The sliding mode droop controller is designed for compensating the uncertainties
and disturbances to derive accurate power sharing based on T-S fuzzy model. The
proposed scheme is proved to be effective under variable operating conditions
through PSIM/Matlab simulation.
KEYWORDS
1. Droop control
2. Autonomous power sharing
3. DC microgrid
4. T-S fuzzy model
5. Sliding mode control (SMC)
SOFTWARE:
MATLAB/SIMULINK
CONCLUSION:
The
novel droop control strategy is proposed for accurate power sharing considering
system parameters uncertainties and load disturbances. The technique is
designed by using sliding mode controller based on T-S fuzzy model of the DC
MG. The overall system stability can be assured. The conclusion is drawn that
load changes of the DC MG can be regulated more adaptively. Meanwhile, the
proportional load power sharing can be accurately achieved without any
communication. The proposed method is verified in PSIM/Matlab simulation.
Future extensions of the method can include nonlinear sliding mode droop
control of multiple batteries or in AC/DC hybrid MG.
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