This paper presents an investigation of five-Level Cascaded H – bridge (CHB) Inverter as Distribution Static Compensator (DSTATCOM) in Power System (PS) for compensation of reactive power and harmonics. The advantages of CHB inverter are low harmonic distortion, reduced number of switches and suppression of switching losses. The DST ATCOM helps to improve the power factor and eliminate the Total Harmonics Distortion (THD) drawn from a Non-Liner Diode Rectifier Load (NLDRL). The D-Q reference frame theory is used to generate the reference compensating currents for DSTATCOM while Proportional and Integral (PI) control is used for capacitor dc voltage regulation. A CHB Inverter is considered for shunt compensation of a 11 kV distribution system. Finally a level shifted PWM (LSPWM) and phase shifted PWM (PSPWM) techniques are adopted to investigate the performance of CHB Inverter. The results are obtained through Matlab/Simulink software package.
- Level shifted Pulse width modulation (LSPWM)
- Phase shifted Pulse width modulation (PSPWM)
- Proportional-Integral (PI) control
- CRB multilevel inverter
- D-Q reference frame theory
Fig. 1 Schematic Diagram of a DST ATCOM
Fig. 2 Block diagram of 5-level CHB inverter model
EXPECTED SIMULATION RESULTS:
Fig. 3 five level PSCPWM output
Fig. 4 Source voltage, current and load current without DSTATCOM
Fig. 5 DC Bus Vooltage
Fig. 6 Phase-A source voltage and current
Fig. 7 Harmonic spectrum of Phase-A Source current without DSTATCOM
Fig. 8 Harmonic spectrum of Phase-A Source current with DSTATCOM
A DSTATCOM with five level CHB inverter is investigated. Mathematical model for single H-Bridge inverter is developed which can be extended to multi H Bridge. The source voltage , load voltage , source current, load current, power factor simulation results under nonlinear loads are presented. Finally Matlab/Simulink based model is developed and simulation results are presented.
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