And industry, they say, should provide most of that extra investment.Technology Quarterly Expect the unexpected Supercharging the grid Falling, flailing, virtual doll Voltage ahoy Solar cells come down to earth Ups and downs of chip design Nanomaterials move up a notch Soul of a newer machine A web address for every car?
For his efforts, Mr Simonyi nowadays has a nice house next to Bill Gates's mansion.Technology Quarterly Expect the unexpected Supercharging the grid Falling, flailing, virtual doll Voltage ahoy Solar cells come down to earth Ups and downs of chip design Nanomaterials move up a notch Soul of a newer machine A web address for every car?
As seen from the Figure 3, the virtual dc link voltage and rotor voltage signals are fed to the controlling unit.
This is controlling the virtual dc link voltage and eliminating the voltage stress across the PES.
In the case of the proposed work, the virtual dc link voltage is changing as per the required rotor voltage governed by the wind profile.
Table 1 Proposed switching combination and virtual DC link voltage Sextant Clamped switch Modulated switches Virtual DC link voltage 1 R Y' W' vRY vRW 2 W' R Y vRW vYW 3 Y W' R vYW vYR 4 Y W vYRvWR vWR 5 W R' Y' vWR vWY 6 Y' W R vWY vRY.
It is found that if the virtual dc link voltage is controlled and kept low when high rotor voltage is not required, the load current will also change accordingly.
Virtual dc link voltage is controlled in such a way that the voltage stress across the switches remains as low as possible which will help in reducing the on losses, off losses, and the conduction losses in the power electronic switches.
Two-phase alternating voltages (the frequency is 26.276 kHz, the phase difference on time is π/2, the period number is 40, set VL as the virtual value of voltage applied on the longitudinal PZT, and VB as the virtual value of voltage applied on the bending PZT) were applied on the PZT ceramics to accomplish the transient analysis.
Reduction in on losses, off losses, and conduction losses is achieved and is found that the net loss reduction of 32% is achieved by controlling the virtual dc link voltage using proposed SVM technique in comparison to PWM technique without virtual dc link voltage control.
