GB2561182B

GB2561182B - Power converting apparatus

Info

Publication number: GB2561182B
Application number: GB1705354.7A
Authority: GB
Inventors: Sung Yongjun; Youn Kim Jong
Original assignee: Ingine Wave Energy System Ltd; Ingine Inc
Current assignee: Ingine Wave Energy System Ltd; Ingine Inc
Priority date: 2017-04-03
Filing date: 2017-04-03
Publication date: 2019-11-20
Anticipated expiration: 2037-04-03
Also published as: GB201705354D0; GB2561182A

Description

POWER CONVERTING APPARATUS

Technical Field

One or more example embodiments relate to a power converting apparatus. Background Art A power generating system may be a system for rotating a generator using energy of power resources and generate electric energy based on a rotary motion of the generator. Recently, interest in a power generating system that generates electric energy using natural energy has been growing. For example, there is a. wave power generating system for converting kinetic energy based on wave movements into electric energy.

To generate the electric- energy based on the energy of power resources, a process of converting the energy of power resources into a form of rotary motion may be required. Thus, a variety of power converting apparatuses has been developed to efficiently convert energy into a form of rotary motion.

The conventional power converting apparatus may be to transmit a movement of a power source in a form of linear power using a tensile force transmitting member and convert the linear power into rotational power. In this case, a generating efficiency may decrease when the tensile force of the tensile force transmitting member is not sufficiently maintained.

Also, when the power converting apparatus is used in an underwater environment, efforts to maintain the power converting apparatus and a size of the power converting apparatus may increase due a design tor water repellency of a housing,

Accordingly, there is a desire for a power converting apparatus with ease of maintenance and increased generating efficiency.

Disclosure of invention

Technical Goals

An aspect provides a power converting apparatus that is easily maintained.

Another aspect also provides a power converting apparatus configured to store a portion of rotational power as an electric energy.

Still another aspect also provides a power converting apparatus configured to maintain a tensile force of a tensile force transmitting member based on a bidirectional rotation of a motion converter,

Technical solutions

According to an aspect, there is provided a power converting apparatus including a housing, a motion converter provided at the housing to be exposed externally and configured to convert an energy of a power source to a rotary motion, a power transmitter connected to the motion converter, and an energy storage connected to the power transmitter such that a power exchange is performed between the energy storage and the motion converter, wherein the energy storage is configured to store a rotational power of the motion converter as an electric energy and to provide a rotational power to the motion transmitter using an electric energy, wherein the energy storage includes a motor connected to the power transmitter to generate an electric power and a battery configured to be charged with the electric power generated by the motor, and wherein when the rotary motion of the motion converter is than a predetermined value the energy storage is configured to charge the battery with a regenerative power based on a rotation of the motor.

The power transmitter may include an output axis member configured to transmit rotational power of the motion converter to a generator and an energy transmitting axis member configured to connect the motion converter and the energy storage.

The output axis member may be configured to transmit a power based on a one-directional rotary motion of the motion converter to the generator.

The power transmitter may further include a fixed axis member configured to connect the motion converter and the housing, and the motion converter may be bearing-connected to the fixed axis member so as to be rotatable relative to the fixed axis member.

The housing may include a receiver recessed inwardly from an outer lace and the motion converter may be provided in the receiver so as to be located outside the housing.

The power transmitter may be penetratively connected io the outer face of the housing so as to be located in the receiver, and a penetrated portion of the housing may be waterproofed.

According io an aspect, il is possible to easily maintain a power converting apparatus by positioning a motion converter externally to a housing.

According to another aspect, it is possible to increase an efficiency of a power converting apparatus by storing a portion of rotational power as an electric energy.

According to still another aspect, it is possible to maintain a tensile force of a tensile force transmitting member based on a bidirectional rotation of a motion converter.

Effects related to a power converting apparatus of the present disclosure are not limited to the aforementioned effects and thus, further discussed in the following description to be apparently understood by those skilled hi the art.

Brief Description of Drawings

These and/or other aspects, features, and advantages of the invention will become apparent and more readily appreciated from the following description of example embodiments, taken, in conjunction with the accompanying drawings of which; FIG, 1 illustrates an example of a power generating system including a power converting apparatus according to an example embodiment; FIG. 2 illustrates another example of a power generating system including a power converting apparatus according to an example embodiment; FIG. 3 illustrates an example of a power converting apparatus according to an example embodiment; FIG. 4 illustrates another example of a power converting apparatus according to an example embodiment; FKI 5 illustrates still another example of a power converting apparatus according to an example embodiment; FIG. 6 is a block diagram illustrating a power converting apparatus according to an example embodiment; and FIG. 7 is a flowchart illustrating an example of controlling a power converting apparatus according to an example embodiment.

Best Mode for Carrying Out the invention

Hereinafter, some example embodiments will be described in detail with reference to the accompanying drawings. Regarding the reference numerals assigned to the elements in the drawings, it should he noted that the same elements will he designated by the same reference numerals, wherever possible, even though they are shown in different drawings. Also, in the description of embodiments, detailed description of well-known related structures or functions will be omitted when if is deemed that such description will cause ambiguous interpretation of the present disclosure.

Terms such as first, second. A, B, (a), (b), and the like may be used herein to describe components. Each of these terminologies is not used to define an essence, order or sequence of a corresponding component but used merely to distinguish the corresponding component from other component(s). It should be noted that if it is described in the specification that one component is "connected," "coupled," or "joined" to another component, a third component may be "connected," "coupled,” and "joined" between the first and second components, although the first component may be directly connected, coupled or joined to the second component.

When describing the examples with reference to the accompanying drawings, like reference numerals refer to like constituent elements and a repeated description related thereto will he omitted. When it is determined detailed description related to a related known function or configuration they may make the purpose of the examples unnecessarily ambiguous in describing the examples, the detailed description will be omitted here. FIG. 1 illustrates an example of a power generating system including a power converting apparatus according to an example embodiment and FIG 2. illustrates another example of a power generating system including a power converting apparatus according to an example embodiment.

Referring to FIGS. 1 and 2, a power generating system may generate an electric power based on a movement of a power source. The power generating system may perform power generation that absorbs a natural energy and converts the natural energy into an electric energy. The natural energy absorbed by the power generating system may be. for example, a power resource. The power generating system may absorb various forms of energy based on types of power resources to be used. The power generating system may be applicable to, for example, thermal power generation that absorbs thermal energy, hydroelectric power generation that absorbs potential energy based on a water drop, wind power generation that absorbs wind energy, and wave power generation that absorbs wave energy. Hereinafter, an example in which the power generating system is applied to the wave power generation will be described for ease of description. The present disclosure is not limited thereto but applicable to various examples. A power generating system may include an energy absorbing member 11, a power converting apparatus 10, a transmission 12, and a generator 1.3.

The energy absorbing member 11 may absorb energy of power resources, for example, a dynamic energy of a wave. As described with reference to FIG. 2, the energy absorbing member 11 may have kinetic energy by moving by waves. For example, the energy absorbing member 11 may move vertically or horizontally based on a movement of the wave while floating on a sea surface. When the energy absorbing member 11 is floating on the sea surface, the energy absorbing member 11 may perform a 6-degree-of freedom motion including x-axial, y-axiai, and z-axial translations and yawing, pitching, and rolling rotations.

The energy absorbing member 11 may also absorb an energy based on a change in pressure on the sea surface. When the energy absorbing member 11 is under the sea surface, a pressure applied to the energy absorbing member 11 may vary based on a change in depth from the sea surface and thus, the energy absorbing member 11 may absorb an energy based on a difference in pressure.

The power converting apparatus 10 may be connected to the energy absorbing member 11 and convert, the energy of the energy absorbing member 11 into a rotary motion. For example, when the energy absorbing member 11 is capable of performing a multi-degree-of-freedom motion, the power converting apparatus 10 may convert the multi-degree-of-freedom motion of the energy absorbing member 11 into a one-degree-of-freedom motion and output an energy obtained based on a converted rotary motion.

The generator 13 may generate an electric energy using a rotary motion energy output from the power converting apparatus 10. The transmission 12 may connect the power converting apparatus 10 and the generator 13. Also, the transmission 12 may adjust a torque of the rotary motion energy transmitted to the generator 13 such that the generator 13 efficiently generates the electric energy, or block an energy transmission to prevent a damage of the generator 13. A. single generator may be connected to a single power converting apparatus. For example, when a single energy absorbing member is connected to a plurality of tensile force transmitting members 105, the power converting apparatus 10 may be provided tor each of the tensile force transmitting members .105 and the generator 13 may be provided for each of the power converting apparatuses 10. That is, by connecting the single tensile force transmitting member 105 to the single generator 13, a motion of each of the tensile force transmitting members 105 may be efficiently converted into the electric power.

Referring to FIG. 3, the power converting apparatus 10 may convert an energy received from a power source into a rotational power, output the rotational power to a power generating apparatus, and store a portion of the rotational power. The power converting apparatus 10 may include a housing 101, a motion converter 102, the tensile force transmitting member 105, a power transmitter 103, and an energy storage 104.

The motion converter 102 may be provided at the housing 101 to he exposed externally. The housing 101 may include a receiver 1011 recessed inwardly from an outer face. The motion converter 102 may be provided in the receiver 1011. That is, the receiver 1011 provided in the motion converter 102 may be located outside the housing 101.

The receiver 1011 may have a shape corresponding to a shape of the motion converter 102. For example, when die motion converter 102 is a drum 1021 in a cylindrical shape, the receiver 1011 may have a shape corresponding to the cylindrical shape. The receiver 1011 may be greater in size than the motion converter 102 such that the motion converter 102 is easily installed. In the above structure, since the motion converter 102 is located outside the housing 101, the motion converter 102 may be easily maintained and replaced,

The motion converter 102 may convert an energy of a power source to a rotary’ motion. The motion converter 102 may include the drum 102.1 configured to move based on a movement of the power source. The tensile force transmitting member 105 connected to the energy absorbing member 11 may be wound around the drum 1021. In this example, the drum 1021 may rotate by a linear movement the tensile force transmitting member 105 based on a movement of the energy absorbing member 11. That is, the drum 1021 may rotate based on the linear movement of the tensile force transmitting member 105 to convert the energy of the power source into a form of the rotary motion.

Although not shown, a plurality of grooves may be formed on a circumferential face of the drum 1021 in a rotating direction of the drum 1021. The grooves may he formed to be inclined with respect to a longitudinal direction of the drum 1021 to prevent the tensile force transmitting member 105 having wound around the drum 1021 from being unwound.

The power transmitter 103 may be rotatably connected to the motion converter 102. The power transmitter 103 may be connected to the motion converter 102 by penetrating an outer lace of the housing 101 so as to be located in the receiver 1011. When the power transmitter 103 is connected to the drum 1021 by penetrating the housing 101, the power transn titter 103 may transmit the rotational power of the drum 1021 located outside the housing 101 to an inside of the housing 101. A penetrated portion of the housing 101 .may be waterproofed. Through this, elements in the housing 101 may also be protected even when the power converting apparatus 10 is used in an underwater environment.

The power transmitter 103 may receive a rotational power based on the rotation of the drum 1021 or transmit a rotational power to the drum 102.1. The power transmitter 103 may be connected to a rotation axis of the drum 1021 so as to perform a power exchange with the drum 1021. The power transmitter 103 may Include an energy transmitting axis member 1031 and an output axis member 1032.

The output axis member 1032 may output the rotational power of the motion converter 102 externally. The output axis member 1032 may be connected to the rotation axis of the drum 1021 and transmit the rotational power based on the rotation of the drum 1021 to the generator 13. That is, the output axis member 10.32 may function to transmit a rotation torque of the drum 1021 for a power generation of the generator 13.

The output axis member 1032 may transmit a one-directional rotation power of the motion converter 102 to the generator 13. The output axis member 1032 may be connected to the drum 1021 via a one-directional rotating 1033 member that allows only a one-directional rotation. The one-directional rotating 1033 may be, for example, a latch clutch. The output axis member 1032 may transmit a stable rotational power to a power generation apparatus by outputting the rotational power of the drum 1021 only when the drum 1021 rotates in one direction. When the drum 1021 rotates in a direction in which the tensile force transmitting member 105 is unwound from the drum 1021, the output axis member 1032 may output the rotational power externally. When the drum 1021 rotates in a direction in which the tensile force transmitting member 105 is wound around the drum 102.1., the output axis member 1032 may not output the rotational power externally. In the above structure, when the drum 1021 rotates in the direction in which the tensile force transmitting member 105 is wound, a power for rotating the drum 1021 may not he output. Thus, a rotation of the drum 1021 may he efficiently performed for maintaining a tensile force of the tensile force transmitting member 105. Also, a turbine of the power generation apparatus connected to the output axis member 1032 may be prevented from reversely rotating and thus, the power generating apparatus may efficiently perform power generation.

The energy transmitting axis member 1031 may connect the motion converter 102 and the energy storage 104. One side of the energy transmitting axis member 103.1 may be connected so as to rotate in conjunction with the drum 1021, and another side of the energy transmitting axis member 1031 may be connected to the energy storage 104. For example, when the energy transmitting axis member 1031 is attached to the drum 1021, the energy transmitting axis member 1031 may rotate at the same angular velocity as the drum 1021. Accordingly, the energy transmitting axis member 1031 may transmit the rotational power based on the rotation of the drum 1021 to the energy storage 104. or rotate the drum 1021 using a power provided from the energy transmitting axis member 1031.

The energy storage 104 may be connected to the power transmitter 103 so as to perform a power exchange with the motion converter 102. The energy storage 104 may store the rotational power of the motion converter 102 as an electric energy. For example, the energy storage 104 may receive a rotary motion energy of the drum 1021 through the energy transmitting axis member 1031, convert an torque-based energy into the electric energy, and store the electric energy. Specifically, when the tensile force transmitting member 105 is unwound from the drum 1021 in response to a movement of the energy absorbing member 11, the energy storage 104 may receive a portion of the rotary· motion energy of the drum 1021 and store the portion of the rotary motion energy as the electric energy.

The energy storage 104 may use the electric energy to enable the energy transmitting axis member 1031 to generate a rotatory torque, thereby providing a rotational power to the motion converter 102, For example, the energy storage 104 may provide a power based on the electric energy to allow the drum 1021 to rotate in a direction in which the tensile force transmitting member 105 is wound around the drum 1021 such that a tensile force of the tensile force transmitting member 105 is maintained.

In the above structure, the tensile force of the tensile force transmitting member 105 wound around the drum 1021 may be maintained by the energy storage 104. Thus, the tensile force transmitting member 105 may efficiently transmit an energy based on the movement of the energy absorbing member 11 to the drum 1021. The energy storage 104 may include a motor 1041 connected to the power transmitter 103 to generate an electric power and a battery-1042 to be charged with the electric power generated by the motor 1041.

The motor 1041 may be rotatably connected to the power transmitter 103 to convert the rotational power of the drum 1021 into an electric energy. The motor 1041 may generate a regenerative power using a counter electromotive voltage generated based on a rotation of the drum 1021, and charge the charger 1042 with the regenerative power.

The motor 1041 may assist a power generation of the generator 13 when the power transmitter 103 rotates in one direction, for example, a direction in which the generator 13 is driven. In this example, the motor 1041 may have a generating capacity less than that of the generator 13. In the above structure, when the drum 1021 has a rotation speed insufficient to efficiently drive the generator 13, the energy storage 104 may charge the battery 1042 with the regenerative power based on a rotation of the motor 1041 thereby improving a generating efficiency of a power generating apparatus.

The motor 1041 may also rotate the power transmitter 103 in an opposite direction, for example, a direction in which the rotational power is not transmitted to the generator 13, In this example, the motor 1041 may generate a torque such that the drum 1021 rotates in a direction in which the tensile force transmitting member 105 is wound around the drum 1021. Through this, the motor 104.1 may maintain the tensile force of the tensile force transmitting member 105.

When the drum 1021 rotates in a direction in which the generator 13 is driven, the energy storage 104 may obtain a backup power using the motor 1041 or rotate the drum 1021 in the direction in which the tensile force transmitting member 105 is wound such that the power converting apparatus 10 efficiently converts an energy of a power source. FIG. 4 illustrates an example of a power converting apparatus according to an example embodiment.

Referring to FIG. 4, a power converting apparatus 20 may include a housing 201, a motion converter, a power transmitter 203, and an energy storage 204,

The power transmitter 203 may include an energy transmitting axis member 2031 connected to. for example, a drum 2021 and an output axis member 2032 connected to one end of the energy transmitting axis member 2031.

The energy transmitting axis member 2031 may be connected to the motion converter by penetrating the housing 201, for example, a receiver 2011. In this ease, the energy transmitting axis member 2031 may be connected to a center of rotation of the drum 2021 of the motion converter so as to rotate in conjunction with the drum 2021. One end of the energy transmitting axis member 20.31 may be connected to the energy storage 204, and the other end of the energy transmitting axis member 2031 may be connected to the output axis member 2032,

The output axis member 2032 may receive a rotational power through the energy transmitting axis member 2031. In this ease, the output axis member 2032 and the energy transmitting axis member 2031 may be connected by a one-directional rotation member 2033. 'Fhe output

axis membet 2032 and the energy transmitting axis member 203i may be connected in the housing 20 L

When the energy transmitting axis member 203; rotates in one direction based on a rotation of the drum 20.2 i, the output axis member 2032 may rotate in conjunction with the energy transmitting axis member 203 i. When the energy transmitting axis member 2031 rotates in an opposite direction, the output axis member 2032 may be prevented from rotating by the one-directional rotation member 2033 so as to receive a power selectively. FIG 5 illustrates an example of a power converting apparatus according to an example embodiment.

Referring to FIG, 5, a power converting apparatus 30 may include a housing 301, a motion converter 302, a power transmitter 303, and an energy storage 304.

The power transmitter 303 may include a fixed axis member 3034, an outpui axis member .3032, arid an energy transmitting axis member 3031.

The fixed axis member 3034 may connect the housing 301 and a drum 3023 of the motion converter 302. As illustrated in FIG. 5, the fixed axis member 3034 may be connected to both sides of a receiver by penetrating the drum 302] around which a tensile force transmitting member 305 is wound. In this case, the fixed axis member 3034 may be attached to the receiver to maintain a position of the drum 3021 in the receiver. The drum 3021 may rotate based on the fixed axis 3034 member. For example, the drum 302 i may be bearing-connected to be rotatable relative to the fixed axis member 30.34. The drum .3021 may rotate while sliding along an outer face of the fixed axis member .3034. Through this, a frictional force against the outer face of the fixed axis member 3034 may be minimized even when the drum 3021 rotates.

The output axis member 3032 may be connected to one side of the drum 302 ; at one side so ss to rotate based on a rotation of the drum 3021. In this case, a one-directional rotation member 30.33 may be provided in the output axis member 3032 such that a one-directiotiai rotation power of the drum 302 { is output. 'Fhe energy transmitting axis member 3031 may connect the energy transmitter 304 to another side of the drum 3021. FIG. 6 is a block diagram illustrating a power converting apparatus according to an example embodiment and FIG. 7 is a flowchart illustrating an example of controlling a power converting apparatus according to an example embodiment.

Referring to FIG. 6, a power converting apparatus 40 may include a motion converter 402, an energy storage 404, a controller 406, and a sensor 407.

The sensor 407 may sense a. rotation state of a drum 4021. The sensor 407 may sense information on the rotation state of the drum 4021 such as a rotation speed, a rotational acceleration, a number of rotations per unit time, a temperature, and the like of the dram 4021, for example.

The controller 406 may control the energy storage 404, For example, the controller 406 may control an operation of a motor 4041 of the energy storage 404, or a rotation speed and a rotating direction of the motor 4041, The controller 406 may set a generating efficiency reference value to control an operation of the energy storage 404. The controller 406 may calculate a predicted generating efficiency of the generator 13 based on sensing information of the sensor 407 or information on a state of a power source, tor example, a wave energy, compare a calculated value to a reference value, and control the operation of the energy storage 404.

When a value calculated for the generating efficiency of the generator 13 is less than the reference value, the controller 406 may control the energy storage 404 to generate an electric energy, thereby improving a generating efficiency of a power generating apparatus.

When a value calculated for the generating efficiency of the generator 13 is greater than or equal to the reference value, the controller 406 may control the energy storage 404 not to participate in power generation such that a torque of the motion converter 402 is concentrated on the generator 13. In this example, the motor 4041 of the energy storage 404 may charge a charger 4042 with a regenerative power based on a counter electromotive voltage.

The controller 406 may rotate the motor 4041 in a direction in which a tensile force transmitting member is wound around the drum 402 i to maintain a tensile force of the tensile force transmitting member.

The controller 406 may determine whether to drive the motor 4041, a rotation speed of the motor 4041, a rotational acceleration of the motor 4041 based on the sensing information of the sensor 407 so as to control the motor 4941 to efficiently rotate the drum 4021. In this example. the generator 13 may receive a one- directional rotation power of the drum 4021. Thus, the rotational power of the motor 4041 may be concentrated to maintain the tensile force of the tensile force hansnut-lng member.

Referring to FIG. 7, a control method may include operation 910 to calculate a calculation value of a generating efficiency, operation 920 to compare the calculation value to a preset reference value, operation 930 to control an energy storage not io participate in power generation, and operation 940 to generate an electric· energy using the energy storage.

In operation 910, the controller 496 may calculate a calculation value predicted for a generating efficiency of a generator based on sensing information of the sensor 407. 'Hie controller 406 may use information on, for example, a rotation speed, a rotating direction, a rotational acceleration, and a number of rotations per unit time of the drum 4021 sensed by the sensor 407 to calculate a torque transmitted through an output ax is member and calculate a predicted generating efficiency of the generator. The controller 406' may correct the calculation value of the generating efficiency in response to receiving information on a state of a power source affected by, for example, weather and season.

In operation 920, the controller 496 may compare the calculation value of the generating efficiency to a preset reference value. The reference yalue may be, for example, an index indicating that the generator generates the electric energy with sufficient efficiency.

In operation 930, when the calculation value is greater than or equal to the reference value, the controller 406 may control the energy storage 494 not to participate in power generation and transmit a great portion of rotational power io the motion converter 402 such that the generator efficiently generates an electric power.

In operation 940, when tire calculation power is less titan the reference value, the controller 406 may control the energy storage 404 to generate an electric energy to assist the generator with generating the electric power. In. general, the motor 4041 of the energy storage 404 may have a capacity less than that of the genera tor. Thus, when a rotation of the drum 4021 is insufficient to generate a required amount of power, a portion of the rotational power of the drum 4021 may he transmitted to the energy storage 404 to be used for assisting an efficient electric energy generation. A number of example embodiments have been described above. Nevertheless, it should be understood that various modifications may be made to these example embodiments. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A power converting apparatus comprising: a housing; amotion converter provided at the housing to be exposed externally, and configured to convert an energy of a power source to a rotary motion; a power transmitter connected to the motion converter; and an energy storage connected to the power transmitter such that a power exchange is performed between the energy storage and the motion converter, wherein the energy storage is configured to store a rotational power of the motion converter as an electric energy and provide a rotational power to the power transmitter using an electric energy, wherein the energy storage includes: a motor connected to the power transmitter to generate an electric power; and a battery configured to be charged with the electric power generated by the motor, and wherein when the rotary motion of the motion converter is less than a predetermined value the energy storage is configured to charge the battery with a regenerative power based on a rotation of the motor.

2. 'The power converting apparatus of claim 1, wherein the power transmitter includes: an output axis member configured to transmit rotational power of the motion converter to a generator; and an energy' transmitting axis member configured to connect the motion converter and the energy storage.

3. The power converting apparatus of claim 2, wherein the output axis member is configured to transmit a power based on a one-directional rotary motion of the motion converter to the generator.

4. The power converting apparatus of claim 2, wherein the power transmitter further includes a fixed axis member configured to connect the motion converter and the housing, and the motion converter is bearing-connected to the fixed axis member so as to be rotatable relative to the fixed axis member.

5. The power converting apparatus of claim 1, wherein the housing includes a receiver recessed inwardly from an outer face, and the motion converter is provided in the receiver so as to be located outside the housing.

6. The power converting apparatus of claim 5, wherein the power transmitter is penetratively connected to the outer face of the housing so as to be located in the receiver, and a penetrated portion of the housing is waterproofed.