1. Hybrid Offshore-wind and Tidal Turbine (HOTT) Energy Conversion II (6-Pulse GTO Rectifier DC connection and Inverter) Mohammad Lutfur Rahman Yasuyuki Shirai Kyoto University Graduate school of energy science, Department of energy science and technology, Yoshida honmachi, Sakyo-ku, Kyoto- 606-8501, Japan

2. Introduction  The innovative renewable energy conversion system called “Hybrid Offshore-wind and Tidal Turbine” (HOTT) Conversion was proposed. The research includes tidal turbine and offshore-wind turbine, new turbine designs and, turbine control of tidal energy and offshore-wind energy absorption. HOTT will be entire five turbines, four turbines will be tidal turbine and one turbine will offshore- wind turbine arrangement. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 2

3. Offshore Wind Turbine Where P w is power in watts for wind turbines, A d is air density, r w is rotor radius, V w is wind speed, C pw is coefficient of performance (might be changed depending on the real system) C gw is the generator efficiency and power conditioning efficiency (might be also changed depending on the real system). 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 35/23/20153 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology

4. it will shows that the offshore-wind turbine simulation output using PSCAD/EMTDC. It shows the active power, wind speed, torque output and AC voltage L-L (RMS) 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 4

5. Offshore Wind Turbine Simulation results for wind turbine. Its show the Active power,wind speed, output torque of the turbine and wind AC voltage L-L (RMS) 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 5 V W-CON-L-L (RMS) [kV] P wind [MW] W wind [m/s] Tm wind [pu]

6. Starting point (~ 0.20s): The wind generator is in starting up condition. Noise amplitude controlling parameter 1rad/s, number of noise components 30 Ramp wind starts at 6sec for number of ramp 3, ramp period when the machine delivering 2.78 MW+ of power to the system. Gust wind starts at 10sec number of gust 3, when the machine delivering 2.68 MW+ of power to the system. The Power fluctuation is between 1.54 MW to 3.0MW Offshore-wind torque when wind speed at reference height 8m/s+. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 6

7. Tidal Turbine where P t is power in watts for tidal turbines, W d is sea water density, r t is rotor radius, V t is sea water speed, C pt is coefficient of performance (might be changed depending on the real system) and C gt is the generator efficiency and power conditioning efficiency (might be also changed depending on the real system). 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 7

8. It will shows that the tidal turbine simulation output using PSCAD/EMTDC. Its show the active power, torque output, torque output form the turbine and AC voltage L-L (RMS). 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 8

9. Tidal Turbine 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 9 Simulation results for tidal turbine. Its show the active power, torque output of the turbine, torque of the turbine and AC voltage L-L (RMS). P tidal [MW] Tm tidal [pu] V T-CON-L-L (RMS) [kV] W tidal [m/s]

10. Starting point (~ 0.20s): The tidal generator is in starting up condition When generator condition getting 2.88 m/s tide speed, 0.87 sec the tidal turbine bring to the line to adjust the turbine. At t=1.48 sec to t=15 sec the speeds of the machine become 2.88 m/s when the power systems become steady condition and delivering real power 4.11MW to 4.20MW. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 10

11. Hybrid Offshore-wind and Tidal Turbine (HOTT) Energy Conversion II. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 11

12. P hybrid total power in watts for hybrid turbine system of the tidal and the offshore-wind turbines P t is power in watts for tidal turbines, P w is power in watts for wind turbines, 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 12

13. A huge coefficient of performance loss and distribute-energy-producing flows are low percentage. That’s why; if only offshore-wind turbine must be connected with the huge capacity size battery for continuous flow and for power system steady unless wind power will be an unacceptable consequence that may threaten the power system stability. The tidal energy conclude that tidal stream capacity factors are significantly greater than for wind energy. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 13 Why hybrid

14. The integration of wind power in the Offshore-wind turbine system leads to minimum load problems at high levels of installed wind power capacity, in their blades has contributed to low rotational inertia. The proposed HOTT is more flexible than the single system, so that the stable generation ranges of the wind/tidal conditions can extended by adequate system control strategy. The advance simulation study have to be carried out to ensure stability and also gives a better understanding of the control aspects required to make it more efficient. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 14

15. HOTT 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 15

16. 6 pulse GTO rectifier DC side connection and inverter configuration using PSCAD/ EMTDC 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 165/23/201516 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology

17. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 17

18. A Induction Generator supplies the ac power at the sending end and controls the ac voltage at the sending end. The inverter controls the ac voltage magnitude, and the dc voltage. Pulse width modulation are employed to control the operation of the converters at both ends. The control system is designed such that the sending end (or the rectifier end) controls the amount for wind/tidal and the power transferred across the dc link, and the receiving end (or the inverter end) controls the dc voltage. So a constant dc power in the system, the voltage at the dc line should be constant. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 18

19. It will shows the hybrid turbine simulation output using PSCAD/EMTDC, form top to bottom, the DC transmission power (P DC ), AC voltage line to line (RMS) (V INV-AC ), the converter DC voltage (V CON-DC ) and current (I CON-DC ), the inverter DC voltage (V INV-DC )and current(I INV-DC ). 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 19

20. Hybrid 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 20 Simulation results for GTO 6 pulse rectifier and inverter P DC [pu] V INV-L-L (RMS) [kV]

21. Simulation results for GTO 6 pulse rectifier and inverter 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 21 I CON-DC [pu] I INV-DC [pu] V CON-DC [kV] V INV-DC [kV]

22. the converter DC voltage is 0.22kV to 29kV the graph this happens at t=0.16 sec to t=0.35 sec when generator is in starting up condition. 22 kV set point DC voltage become steady- state at t=0.51 sec to t=15 sec. AC voltage line to line (RMS) offshore-wind turbine rectifier side 5.8 kV, AC voltage line to line (RMS) tidal turbine rectifier side 8 kV and inverter side AC voltage line to line (RMS) 77 kV. The DC transmission line power is per unit 0.42. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 22

23. ADVANTAGE HOTT (Entire system) 1) Offers better stability and control. 2) The capital cost of civil works is reducing. 3) Disruption to ecosystems and boating is minimized. 4) Ocean currents, wind-induced currents and as well as tidal flows can be used. There is no need for a large tidal rise and fall. 5) No fuel-absence of CO 2 emissions, radiation and particulate matter pollution 6)No waste of disposal requirements, and no danger of spillage or other environmental damage 7) No noise pollution. No visual pollution. 8) No negative impact on marine life. In fact, can encourage growth of marine life and reduces shoreline erosion. 5/23/201523 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology

24. Conclusion The PSCAD simulation results with a HOTT 6.3 MW+ test system demonstrate satisfactory operation for a range of wind and tidal speeds using 6-pulse GTO rectifier DC connection and inverter, it was successfully simulated by PSCAD/EMTDC. The key techniques of offshore-wind and tidal power estimation, electric transmission and connection, system and stability operation, system investigation, reactive power and voltage control strategy, the interaction between offshore-wind and tidal turbine. HOTT will be competitive lead in its field, together with the most efficient technology and uniquely practical methods for servicing it. In short we believe our technology meets a huge new need, and can deliver energy in future, as predictably as the tides that drive it and with minimal risk to the local environment. 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 24

25. Thank You I appreciate for you valuable time and pay attention. Any Questions Or Suggestions Or Comments? 5/23/2015 Kyoto University, Graduate School of Energy Science, Department of Energy Science and Technology 25