Kinetic energy recovery wind-wave integrated system
This invention introduces a kinetic energy recovery wind-wave integrated system for offshore wind power generation. The system consists of a semi-submersible platform equipped with a fan and an internal wave energy device. The device includes a shell housing a Power Take-Off (PTO) system, featuring a permanent magnet synchronous linear motor and an active controller. The motor's stator is fixed inside the shell, while its mover is connected to a counterweight block outside the stator, linked to the shell's top via a spring. Limiters are installed at both ends of the shell to restrict the counterweight block's movement. This system utilizes the wave energy device to absorb kinetic energy, which otherwise affects wind turbine stability, and converts it into usable electrical energy via the PTO system. This enhances the stability and safety of offshore wind turbine power generation.
1 . A kinetic energy recovery wind-wave integrated system comprising:
a semi-submersible platform with an installation groove;
a fan arranged on the semi-submersible platform;
a wave energy device arranged inside the installation groove of the semi-submersible platform, wherein the wave energy device comprises:
a sliding rod;
at least two counterweight blocks, each one is fixed on either ends of the sliding rod;
a shell configured to be received within the installation groove, wherein the shell is configured to receive a PTO system, wherein:
the PTO system comprises an active controller and a permanent magnet synchronous linear motor comprising a stator and a mover;
the stator is fixedly connected to the shell;
the mover is fixed on the sliding rod;
the at least two counterweight blocks are disposed outside the permanent magnet synchronous linear motor; one of the at least two counterweight blocks is connected to top portion of the shell via a plurality of springs, wherein one end of the plurality of springs are connected to the one of the at least two counterweight blocks and another end of the plurality of springs are connected to the top portion of the shell; and
at least two limiters, wherein one limiter is disposed towards interior of the shell and fixedly connected to the top portion of the shell and the other limiter is disposed towards the interior of the shell and fixedly connected to bottom portion of the shell; wherein the sliding rod is disposed in the shell along an axial direction of the shell; one end of the sliding rod passes through the one limiter and the top portion of the shell and is connected to the one limiter and the top portion of the shell in a sliding manner, the other end of the sliding rod passes through the other limiter and the bottom portion of the shell and is connected to the other limiter and the bottom portion of the shell in a sliding manner; and
a battery, wherein the battery is configured to store electrical energy converted by the wave energy device, wherein:
the active controller is electrically connected to the limiters and the battery;
the wave energy device is configured to operate in any one of a working mode or a survival mode using the electrical energy stored in the battery wherein:
in the working mode, the wave energy device is configured to turn on a power generation mode of the wave energy device; and
in the survival mode, the active controller in the wave energy device is configured to turn off the power generation mode of the wave energy device; and
the at least two limiters are configured to mechanically limit movement of the at least two counterweight blocks during the working mode and the survival mode of operation of the wave energy device.
2 . The kinetic energy recovery wind-wave integrated system according to claim 1 , wherein:
the semi-submersible platform comprises at least three pontoon structures and an installation rod wherein each pontoon structure comprises:
a lower pontoon wherein, an inner part of the lower pontoon comprises an installation groove for installing the wave energy device;
an upper pontoon disposed on an upper part of the lower pontoon; and
a base disposed towards a bottom portion of the lower pontoon;
the fan is arranged on the installation rod;
at least one upper intermediate rod connects each of the upper pontoons of the at least three pontoon structures to an upper part of the installation rod;
at least one lower intermediate rod connects a first portion of the base of each of the at least three pontoon structures to a lower part of the installation rod;
at least one upper connecting rod connects adjacent upper pontoons of each of the at least three pontoon structures;
at least one lower connecting rod connects a second portion of each of the adjacent bases of the at least three pontoon structures; and
at least one slant beam connects a lower part of the installation rod to the upper pontoon of each of the at least three pontoon structures.
3 . The kinetic energy recovery wind-wave integrated system according to claim 2 , wherein each pontoon structure comprises a multi-resonance system formed by the at least two counterweight blocks and the shell, wherein,
a mass of the shell and a damping of the shell within water form one set of resonant systems, and a damping provided by the at least one counterweight block and a damping of the spring forms another set of resonance system; and the multi-resonance system comprises a plurality of means to obtain a mass of the wave energy device, a force of the shell in water and a force between the PTO system and the shell, wherein the multi-resonance system is configured to provide a measure of the motion of the multi-resonance system as follows:
{
(
M
-
m
+
A
)
x
¨
outer
=
F
water
-
F
PTO
m
x
¨
inner
=
F
PTO
}
wherein M is the mass of the wave energy device, m is a mass of the counterweight block, and A is an additional mass, {umlaut over (x)} inner is a motion acceleration of each of the at least two counterweight blocks, {umlaut over (x)} outer is a motion acceleration of the shell, F water is the force of the shell in the water, and F PTO is the force between the PTO system and the shell.
4 . The kinetic energy recovery wind-wave integrated system according to claim 1 , wherein the system comprises a wave sensor to enable the wave energy device to operate in any one of the working mode and the survival mode wherein:
the active controller is configured to turn ON the wave energy device to enable the wave energy device to operate in the working mode when the wave sensor senses an effective wave height H s of a sea wave, thereby enabling the wave energy device to generate electricity.
5 . The kinetic energy recovery wind-wave integrated system according to claim 4 , wherein the wave energy device is configured to operate in survival mode upon detection of a freak wave, wherein the freak wave is detected by the wave sensor when a maximum wave height H m is two times larger than the effective wave height H s .