KR102400606B1 - Energy regeneration system and method for ship - Google Patents

Abstract

The present invention relates to an energy regeneration system for a ship, which can prevent a system from being electrically damaged by an excessive reverse current which is generated during deceleration or braking of a ship, and can safely store a regeneration energy to improve energy efficiency. To this end, the present invention comprises: a propulsion motor (10) of a ship; a first current sensor (110); a safety switch (50); a bidirectional inverter (20); a battery pack (40); and a control unit (100), which are sequentially connected. The control unit (100), during the deceleration or the braking of the propulsion motor (10), turns off the safety switch (50) when the reverse current generated in the first current sensor (110) is above a predetermined value, so as to prevent the energy regeneration system of a ship from being electrically damaged by an excessive current, while storing the regeneration energy.

Description

Ship's energy regeneration system and method

The present invention relates to a ship energy regeneration system and method, and more particularly, to a ship energy regeneration system and method that can prevent electrical damage from occurring due to overcurrent and safely improve energy efficiency.

Recently, interest in environmental problems such as global warming and environmental pollution including fine dust is increasing along with the problem of depletion of fossil energy. Even in ships, research on electric propulsion ships as eco-friendly ships is in progress.

The electric propulsion system of many electric propulsion ships uses fuel cells to generate electric energy to drive the propulsion motor.

In such an electric propulsion system, in order to improve energy efficiency, research on an energy regeneration system for storing energy regenerated by a reverse current generated during deceleration or braking of a ship is also being continuously conducted.

As an example, there is an energy regenerative system in a ship (hereinafter referred to as a prior art) presented in Korean Patent Application Laid-Open No. 10-2016-0016094.

The energy regeneration system in the ship shown in the prior art is a bow propulsion motor 10 as shown in FIG. 1; a battery pack 30 for supplying power to the motor; a bidirectional inverter 20 installed between the battery pack and the motor to act as a bidirectional current source; a supercapacitor 60 serving as a chargeable DC voltage source; a buck-boost converter 40 for charging and discharging the super capacitor; Current sensors 51 and 52 for detecting a reverse current flowing through the bidirectional inverter during braking of the motor; and a control unit 70 for controlling them.

The prior art is configured to store the energy regenerated by the reverse current in the supercapacitor 60 and the battery pack 30, so that energy efficiency can be improved.

However, the prior art is an energy regenerative system applied to a small bow thruster installed in the bow, and when this is applied to the electric propulsion system of a large electric propulsion ship, the bidirectional inverter 20 and the battery pack 30 due to overcurrent And there is a problem that electrical damage may occur in at least one of the supercapacitor 60 .

In addition, in order to prevent such damage, each of the above components may be installed in a large capacity, but compared to a large installation space required for manufacturing a vessel and a large cost increase, in the case of a vessel, unlike a general train or automobile, braking operation does not occur frequently. The amount of regenerative energy is also small, so there is a problem in that economic efficiency is significantly lowered.

Due to this problem, a method of installing a winding capable of consuming reverse current as heat is also being considered, but this is also limited in solving the initial overcurrent problem, and economical problems due to additional cost still exist.

Unexamined Patent Publication No. 10-2016-0016094 (published on February 15, 2016)

The technical problem to be solved by the present invention is an energy regenerative system for a ship that can prevent electrical damage to the system by excessive reverse current generated during deceleration or braking of a ship and safely store regenerative energy to improve energy efficiency and to provide a method.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. There will be.

In order to achieve the above technical problem, the energy regeneration system of the ship according to the embodiment shown in the present invention, the ship's propulsion motor (10); a battery pack 40 capable of supplying power to the propulsion motor 10 or storing regenerative energy generated by a reverse current generated in the propulsion motor 10; a bidirectional inverter 20 installed between the propulsion motor 10 and the battery pack 40; a safety switch 50 installed between the propulsion motor 10 and the bidirectional inverter 20; a first current sensor 110 installed between the propulsion motor 10 and the safety switch 50; and a control unit 100, wherein the control unit 100 controls the safety switch 50 when the reverse current generated from the first current sensor 110 is greater than or equal to a set value when the propulsion motor 10 is decelerated or braked. ) is characterized in that it is configured to be electrically cut off by turning off (Off).

In addition, a rotation sensor 120 for measuring the rotation speed or rotation speed of the thruster shaft 2 connected to the propulsion motor 10; is additionally provided, and the control unit 100 is When the measured rotation speed or rotation speed of the thruster shaft 2 is less than or equal to a set value, the safety switch 50 may be turned on again to be electrically reconnected.

In addition, a torque sensor 130 for measuring the torque of the thruster shaft 2; is additionally provided, and the control unit 100 is the torque or torque of the thruster shaft 2 measured by the torque sensor 130 When the rate of change per hour of is less than or equal to a set value, the safety switch 50 may be turned on again to be electrically reconnected.

In addition, a switching board 30 installed between the bidirectional inverter 20 and the battery pack 40; may be additionally formed.

Another embodiment of the ship energy regeneration method shown in the present invention, (a) decelerating or braking the propulsion motor 10 of the ship; (b) determining whether the reverse current generated in the propulsion motor 10 is equal to or greater than a set value; and (c) when the reverse current is less than the set value, regenerative energy is charged to the battery pack 40 connected through the propulsion motor 10 and the bidirectional inverter 20 as a medium, and the reverse current is equal to or greater than the set value , the step of electrically blocking by turning off the safety switch 50 installed between the propulsion motor 10 and the bidirectional inverter 20;

In addition, (d1) the step of checking whether the number of rotations or rotational speed of the thruster shaft (2) coupled to the propulsion motor (10) is less than a set value; And (e1) when the rotational speed of the thruster shaft (2) is less than the set value, the step of electrically reconnecting by turning the safety switch 50 back on (On); may include.

In addition, (d2) the step of checking whether the torque of the thruster shaft (2) coupled to the propulsion motor (10) or the rate of change of the torque per hour is less than or equal to a set value; and (e2) when the torque of the thruster shaft 2 or the rate of change of torque per hour is less than or equal to a set value, the safety switch 50 is turned on again to electrically reconnect; and (f) charging regenerative energy to the battery pack 40 .

The energy regenerative system of a ship shown in the present invention is equipped with a safety switch controlled by a current sensor, a rotation sensor, or a torque sensor. Since it is possible to prevent electrical damage to the system due to overcurrent by fundamentally blocking the electrical connection with the energy regeneration system, and to store the energy regenerated after the overcurrent generation time has elapsed, there is an advantage in implementing a stable energy regeneration system.

The energy regenerative system of a ship shown in the present invention is provided with the safety switch capable of responding to excessive reverse current, so that the capacity and size of the battery and the bi-directional inverter can be configured to be relatively small compared to the overcurrent, making it a compact energy regenerative system It has the advantage of being able to implement

Figure 1. A schematic diagram of an energy regenerative system in a ship according to the prior art.
Figure 2. A block diagram of an energy regeneration system for a ship according to the present invention.
Figure 3. A flow chart of a method for regenerative energy of a ship according to the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in several different forms, and thus is not limited to the embodiments described herein.

Throughout the specification, when a part is said to be “connected (connected, contacted, coupled)” with another part, it is not only “directly connected” but also “indirectly connected” with another member interposed therebetween. "Including cases where In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention.

2 is a block diagram conceptually illustrating the configuration of a ship's energy regeneration system according to the present invention.

Referring to Figure 2, the energy regeneration system of the ship of the present invention, the ship's propulsion motor (10); bidirectional inverter 20; switching board 30; battery pack; safety switch 50; control unit 100; All or part of the first and second current sensors 110 and 111 , the rotation sensor 120 and the torque sensor 130 are included.

The propulsion motor 10 of the ship is a driving source for driving the thruster 1 by being coupled to the thruster shaft 2 of the ship as shown in FIG. 2 .

In addition, the propulsion motor 10 functions as a generator during deceleration or braking of the propulsion unit 1, and at this time, a reverse current flowing in the reverse direction is generated.

The battery pack 40 is a power supply supplying power to the propulsion motor 10 . Also, when a reverse current is generated in the propulsion motor 10 , the battery pack 40 may store regenerative energy regenerated by the reverse current.

The bidirectional inverter 20 may be installed between the propulsion motor 10 and the battery pack 40 to supply current in both directions. That is, when the vessel operates, the current flows in the forward direction from the battery pack 40 to the propulsion motor 10, and when the vessel is decelerated or braked, the reverse current generated from the propulsion motor 10 is transferred to the battery. It flows to the pack 40 so that regenerative energy is stored in the battery pack 40 .

The switching board 30 is a component that supplies power suitable for each facility so that various electrical facilities of the entire ship can operate.

The switching board 30 may receive power from the battery pack 40 or may receive power from another generator installed on a ship.

The first current sensor 110 is installed to measure the current between the propulsion motor 10 and the bi-directional inverter 20, and is installed between the bi-directional inverter 20 and the battery pack 40 as necessary. A second current sensor 111 for measuring current may be additionally installed, and it will be possible to additionally install other current sensors.

The rotation sensor 120 provided in the present invention is preferably installed so as to measure the number of rotations or rotational speed of the thruster shaft 2 as shown in FIG. 2 .

In addition, in the present invention, a torque sensor 130 may be provided. As shown in FIG. 2 , it is installed on the thruster shaft 2 to measure the torque generated from the thruster shaft 2 . It is preferable to have

The safety switch 50 provided in the present invention is installed between the propulsion motor 10 and the bidirectional inverter 20, and as shown in FIG. 2, the first current sensor 110 and the propulsion motor ( 10) may be installed in between.

The safety switch 50 may be operated by receiving power from the battery pack 40, but a battery other than the battery pack 40 of the energy regenerative system (not shown) or another generator provided on the ship ( It would be more preferable to configure it to operate by receiving power from (not shown).

The safety switch 50 is turned on when current flows in the forward direction from the battery pack 40 to drive the propulsion motor 10 so that the propulsion motor 10 and the bidirectional inverter 20 are electrically designed to be connected.

When the ship decelerates or brakes, a large change occurs in the rotation speed or rotation speed of the thruster shaft 2 at the initial stage, and the braking torque may also have a large value. In the initial stage of deceleration or braking of a vessel in which such a phenomenon occurs, an excessively large reverse current may be instantaneously generated with a sudden change while not being stable in the propulsion motor 2 .

The excessive reverse current generated at the initial stage of deceleration or braking of the vessel is at least one of the components such as the bidirectional inverter 20 and the switching board 30 and the battery pack 40 provided in the energy regeneration system of the vessel. may cause electrical damage to

In the present invention, in order to solve this problem, when the reverse current in the propulsion motor 10 is excessively generated by more than a set value during deceleration or braking of the ship, the safety switch 50 is controlled to be off. As such, when the safety switch 50 is turned off, the propulsion motor 10 and the bidirectional inverter 20 are electrically cut off, thereby preventing the energy regeneration system from being electrically damaged.

The set value serving as a reference for the excessive reverse current may vary depending on the capacity of the energy recovery system. Below the set value, energy regenerated in the installed battery pack 40 can be safely stored, and the bidirectional inverter 20 ) and the switching board 30, it would be desirable to set the magnitude of the reverse current that can safely operate without electrical damage as a set value.

On the other hand, in order to regenerate energy, it is necessary that the safety switch 50 is turned on again. In the present invention, the rotation speed or rotation speed of the thruster shaft 2 measured by the rotation sensor 120 is less than or equal to the set value. , so that the safety switch 50 is turned on again to electrically reconnect the propulsion motor 10 and the bi-directional inverter 20 to stably store regenerative energy in the battery pack 40 It works.

The operation of the safety switch 50 may also be controlled through a signal from the torque sensor 130 . That is, when the torque of the thruster shaft 2 measured by the torque sensor 130 or the rate of change of torque per time becomes less than or equal to a set value, the safety switch 50 may be controlled to be turned on again.

In addition, when both the signals of the rotation sensor 120 and the torque sensor 130 are less than or equal to each set value, it will be possible to control the safety switch 50 to be turned on again.

The control unit 100 controls forward rotation, deceleration and braking of the propulsion motor 10 , and receives signals from the respective sensors 110 , 111 , 120 , 130 to control the operation of the safety switch 50 . perform the function The control unit 100 may also receive power from the battery pack 40, but it will also be possible to be configured to receive power from another battery (not shown) or another generator (not shown) provided in the ship. .

The energy regeneration method of a ship using the ship energy regeneration system of the present invention having such a configuration is as follows.

As shown in FIG. 3 , the method of regenerative energy of a ship of the present invention first includes (a) decelerating or braking the propulsion motor 10 of the ship.

Since reverse current does not occur in the propulsion motor 10 in the stage in which the ship is propulsion normally, step (a) represents a deceleration or braking stage, which is a situation in which a reverse current is generated in the propulsion motor 10 .

Next, (b) checking whether the reverse current generated in the propulsion motor 10 is equal to or greater than a set value; there is.

This is a step in which the reverse current generated by the propulsion motor 10 is measured by the first current sensor 110, and the value is confirmed by comparing the measured value with the reverse current set value received from the control unit 100 and set in advance. .

Next, (c) when the reverse current is smaller than the set value, regenerative energy is charged to the battery pack 40 connected via the propulsion motor 10 and the bidirectional inverter 20 as a medium, and the reverse current is set at the set value In this case, there is a step of electrically blocking by turning off the safety switch 50 installed between the propulsion motor 10 and the bidirectional inverter 20 .

This step is a step of determining whether to save energy or electrically cut off to prevent damage at the initial stage when the reverse current generated in the propulsion motor 10 is generated. When the magnitude of the reverse current generated by the propulsion motor 10 is smaller than the set value, the safety switch 50 is turned on because electrical damage does not occur to the energy regeneration system by the reverse current. Energy that is regenerated by maintaining the state may be stored in the electrically connected battery pack 40 to improve energy efficiency.

On the other hand, when the reverse current is greater than or equal to a set value, it is a step of controlling the safety switch 50 to be turned off immediately. When the safety switch 50 is turned off, the propulsion motor 10 and the bi-directional inverter 20 are electrically cut off, so in this step, an excessive amount of reverse current is generated between the bi-directional inverter 20 and the battery pack ( 40) It can fundamentally block the flow to the back and cause electrical damage.

Next, (d1) the step of checking whether the number of rotations or rotational speed of the thruster shaft (2) coupled to the propulsion motor (10) is less than a set value; and/or (d2) checking whether the torque of the thruster shaft 2 coupled to the propulsion motor 10 or the rate of change of torque per hour is less than or equal to a set value; there is.

This is a step of measuring the number of rotations and torque of the thruster shaft 2 from the rotation sensor 120 or the torque sensor 130 .

In the present invention, one or both of the rotation sensor 120 and the torque sensor 130 may be installed.

It is suitable to directly measure the reverse current in the propulsion motor 10 , but since the safety switch 50 is in an off state, the reverse current cannot be directly measured from the first current sensor 110 .

Therefore, in this step, the number of rotations or the rotational speed of the thruster shaft (2) whether or not the time when the reverse current having an excessive magnitude indirectly occurs has elapsed; and/or torque or a rate of change per hour of torque;

Next, (e1) when the rotation speed or rotation speed of the thruster shaft (2) is less than a set value, the step of electrically reconnecting by turning the safety switch (50) on (On); and/or (e2) when the torque of the thruster shaft 2 or the rate of change of the torque per time is less than or equal to the set value, the safety switch 50 is turned on and electrically reconnected.

When the ship decelerates or brakes, the rotation speed and torque of the thruster shaft 2 are large and change rapidly in the initial transient region, but gradually decrease in size and change over time.

In this step, when the rotation sensor 120 is installed, when the rotation speed and/or rotation speed of the thruster shaft 2 reaches the set value or less, the safety switch 50 is turned on again, and the torque sensor 130 is installed, when the torque value of the thruster shaft 2 or the rate of change of torque reaches the set value or less, the safety switch 50 is turned on again to re-electrical the propulsion motor 10 and the bidirectional inverter 20 It is a reconnection step.

At this time, when the safety switch 50 is turned on, the amount of reverse current generated in the propulsion motor 10 does not cause electrical damage to the energy recovery system. It is necessary to set the value to be a value when it becomes a non-existent value, and it would be preferable to input it to the control unit 100 in advance through experimentation or analysis.

In addition, when both the steps (e1) and (e2) are satisfied by installing the rotation sensor 120 and the torque sensor 130 together, the step of turning on the safety switch; may be set.

Next, there is a step of (f) charging the regenerative energy in the battery pack 40; which is electrically by turning on the safety switch 50 in the steps (e1) and/or (e2). Indicates a step of storing regenerative energy in the battery pack 40 when reconnected.

Through the method of regenerative energy of a vessel shown in the present invention including the steps described above, it will be possible to configure an energy regenerative system for a vessel that can safely and efficiently store regenerative energy while having a compact structure.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

1: thruster 2: thruster shaft 10: thruster motor
20: bidirectional inverter 30: main switching board
40: battery pack 50: safety switch 100: control unit
110: first current sensor 111: second current sensor
120: rotation sensor 130: torque sensor

Claims (7)

the propulsion motor 10 of the ship;
a battery pack 40 capable of supplying power to the propulsion motor 10 or storing regenerative energy generated by a reverse current generated in the propulsion motor 10;
a bidirectional inverter 20 installed between the propulsion motor 10 and the battery pack 40;
a safety switch 50 installed between the propulsion motor 10 and the bidirectional inverter 20;
a first current sensor 110 installed between the propulsion motor 10 and the safety switch 50; and a control unit 100,
The control unit 100 turns off the safety switch 50 when the reverse current generated by the first current sensor 110 is greater than or equal to a set value during deceleration or braking of the propulsion motor 10 to electrically configured to block
a rotation sensor 120 for measuring the number of rotations or rotational speed of the thruster shaft 2 connected to the propulsion motor 10;
a torque sensor 130 for measuring the torque of the thruster shaft 2; and
A switching board 30 installed between the bidirectional inverter 20 and the battery pack 40; is additionally provided,
The control unit 100,
The rotational speed or rotational speed of the thruster shaft 2 measured by the rotation sensor 120 is less than or equal to the set value,
When the torque of the thruster shaft 2 measured by the torque sensor 130 or the rate of change of torque per hour is less than or equal to the set value,
The energy regeneration system of a ship, characterized in that it is configured to electrically reconnect by turning the safety switch (50) back on (On).
delete delete delete In the energy regeneration method of a ship using the energy regeneration system of the ship according to claim 1,
(a) decelerating or braking the propulsion motor 10 of the vessel;
(b) measuring the reverse current generated by the propulsion motor 10 with the first current sensor 110 to determine whether the reverse current is equal to or greater than a set value; and
(c) charging the regenerative energy to the battery pack 40 connected via the propulsion motor 10 and the bidirectional inverter 20 as a medium when the reverse current is smaller than the set value,
When the reverse current is equal to or greater than the set value, electrically blocking the safety switch 50 installed between the propulsion motor 10 and the bi-directional inverter 20 by turning it off;
The step of electrically blocking the safety switch 50 by turning off (Off) in the step (c); Since the
(d1) confirming whether the number of rotations or rotational speed of the thruster shaft (2) coupled to the propulsion motor (10) is less than or equal to a set value; and
(d2) confirming whether the torque of the thruster shaft (2) coupled to the propulsion motor (10) or the rate of change of torque per hour is less than or equal to a set value;
(e) when the number of revolutions or rotational speed of the thruster shaft 2 is less than or equal to the set value, and the torque of the thruster shaft 2 or the rate of change of torque per hour is less than or equal to the set value, turn on the safety switch 50 again ( On) to electrically reconnect; and
(f) charging the regenerative energy to the battery pack (40); energy regenerative method of a ship comprising a. delete delete

Images