Abstract
This paper presents the closed loop DC-DC flyback converter with multi-level cascaded H-bridge inverter (MCHI) for transformer-less static synchronous compensator (STATCOM) system. The STATCOM system is proposed to be controlled using decoupled dq vector control incorporating the new reactive current reference algorithm and multi-level selective harmonic elimination pulse width modulation (MSHEPWM) technique. This ensures transient performance enhancement as well as simpler control and modulation technique implementation for dynamic systems. As the proposed MSHEPWM solely depends on adjustable DC-link voltage levels, flyback converter is designed for that purpose to suit wider applications. In current work, a single phase five-levels CHI based STATCOM system incorporated with the aforementioned converters are presented to compensate the reactive power (VAR) at the point of common connection (PCC). The dynamic as well as the transient performances of the developed STATCOM control system and the proposed voltage closed loop control of each converter are investigated to meet different VAR demands at balanced loading conditions. Simulation studies are performed to verify the effectiveness and theoretical analysis of the approaches presented.
Highlights
High penetration of distributed power generation with increased renewable energy capacity has introduced efficiency and power quality concerns into modern power networks due to poor power flow management
This restricts maximum active power transfer and results in further power losses to the power networks [1]. Power disturbances such as swells, sags, variations and transients that are induced by low power factor (PF), non-linear and abrupt load fluctuations commit to electronic components defection, electrical disruption and malfunction of modern process control [2]-[3]
Unequal single phase loads over three phase distribution systems cause unbalanced power flow
Summary
High penetration of distributed power generation with increased renewable energy capacity has introduced efficiency and power quality concerns into modern power networks due to poor power flow management. The flyback converter has an advantage of outputting higher and lower voltage than its input voltage VSO when compared with other DC-DC converter topologies; enabling the STATCOM to provide lagging and leading VAR compensation to the PCC, respectively This beneficial to those low levels photovoltaic (PV) based cascaded/non-cascaded converter/inverter system where multiple series-connected PV cells are needed to achieve high power output rating. The five-levels SHE-PWM voltage waveform is constructed by constant switching angles with a distribution ratio of 3/8 (i.e., for every quarter-cycle) and linear pattern of DC-link voltage levels over the specify mi range as reported in [18] This makes the switching frequency of the inverter equals to 2.2 kHz (i.e., 44x50 Hz); offering substantially less losses, less cooling as well as reducing the weight and the volume of the overall system. The technique effectively eliminates the twelve low order non-triplen harmonics (i.e., 5th, 7th, 11th, 13th, 17th, 19th, 23rd, 25th, 29th, 31st, 35th and 37th) while controlling the fundamental component at pre-defined value
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
