University of South Wales Master of Sciences Thesis
Fig. 4.12 VSC converter Result
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- 4.3. Wind Turbine
| Fig. 4.12 VSC converter Result
• From t=0 sec to t= 0.05 sec, pulses to Boost and VSC converters are blocked. PV voltage corresponds to open-circuit voltage (Nser*Voc=5*64.2=321 V, The three-level bridge operates as a diode rectifier and DC link capacitors are charged above 500 V • At t=0.05 sec, Boost and VSC converters are de-blocked. DC link voltage is regulated at Vdc=500V. Duty cycle of boost converter is fixed and sun irradiance is set to 1000 W/m2. Steady state is reached at t=0.25 sec. Resulting PV voltage is therefore V_PV = (1-D)*Vdc= (1-0.5)*500=250V. The PV array output power is 96 kW whereas maximum power with a 1000 W/m2 irradiance is 100.7 kW • At t=0.4 sec MPPT is enabled. The MPPT regulator starts regulating PV voltage by varying duty cycle in order to extract maximum power. Maximum power (100.7 kW) is obtained when duty cycle is D=0.453. At t=0.6 sec, PV mean voltage =274 V as expected from PV module specifications (Nser*Vmp=5*54.7= 273.5 V). • From t=0.7 sec to t=1.2 sec, sun irradiance is ramped down from 1000 W/m2 to 250 W/m2. Standalone hybrid generation system for the remote area of Thar, Pakistan MPPT continues tracking maximum power. At t=1.2 sec when irradiance has decreased to 250 W/m2, duty cycle is D=0.485. Corresponding PV voltage and power are Vmean= 255 V and Pmean=22.6 kW. Note that the MMPT continues tracking maximum power during this fast irradiance change. 4.3. Wind Turbine The wind turbine used is this system is ENERCON E33 wind turbine which has rated power of 330 KW and is using Permanent magnet synchronous generator (PMSG). The reason for using PMSG is already explained in depth in chapter-2. tải về 6.62 Mb. Chia sẻ với bạn bè của bạn:
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