KR102155627B1 - Elevator wireless power control apparatus - Google Patents

Abstract

The present invention relates to an elevator wireless power control device, a wireless power transmission unit that operates as a constant current source and supplies wireless power necessary for the elevator regardless of changes in the load of the elevator, each comprising the elevator and based on the constant current source. At least one wireless power receiving unit that independently controls power required for the elevator by performing inverse droop control, and connected to each of the wireless power transmitting unit and the at least one wireless power receiving unit, and forming the constant current source It includes a compensation network to control the magnitude of the line impedance. Accordingly, the present invention can ensure constant power transfer to at least one elevator vehicle without communication between the wireless power transmission and reception units.

Description

Elevator wireless power control device {ELEVATOR WIRELESS POWER CONTROL APPARATUS}

The present invention relates to an elevator wireless power control technology, and more particularly, to an elevator wireless power control device that ensures constant power delivery to at least one elevator vehicle without passing through communication between transmission and reception units.

Self-propelled elevator systems, also referred to as ropeless elevator systems, are specific applications where most ropes for a lofted system are extremely heavy and require multiple elevators within a single hoistway. Useful in (for example, high-rise buildings). Elevator cars typically require electric power for ventilation, lighting systems, control units, communication units and to recharge batteries installed on, for example, elevator car controllers. Existing systems use moving cables or current collectors/sliders to connect the mobile elevator car with the power lines distributed along the elevator hoistway.

Korean Patent Laid-Open Publication No. 10-2017-0024562 (2017.03.07) is a secondary resonance coil mounted on an elevator car and an elevator car arranged to move along and arranged on a hoistway and configured to induce an electromotive force and output a voltage or current, And a wireless power transfer system comprising a plurality of primary resonance coils distributed along the hoistway and configured to transmit power to the secondary resonance coil when the primary resonance coil of the plurality of resonance coils is adjacent to the secondary resonance coil and is selectively pressurized. do. The control system of the wireless power transfer system is configured to select and pressurize a plurality of primary resonance coils, and each switch may include a plurality of switches associated with each primary resonance coil of the plurality of primary resonance coils. The plurality of switches are configured to selectively close to pressurize a selected primary resonant coil among a plurality of primary resonant coils associated with the position of the elevator car.

Korean Patent Publication No. 10-2017-0027311 (2017.03.09) includes an elevator car disposed on a hoistway and arranged to move along it. The linear propulsion system of an elevator system comprises a plurality of primary coils configured and arranged to propel an elevator car and being fastened to and distributed along a hoistway generally defined by a stationary structure. The wireless power delivery system of the elevator system is configured to deliver power by induction to the elevator car. The wireless power transmission system includes a secondary coil mounted on an elevator car, is induced by electromotive force by the primary coils, and is configured to output power for the elevator car. The communication system of the elevator system is configured to use a secondary coil and a plurality of primary coils to exchange communication data signals.

Korean Patent Publication No. 10-2017-0024562 (2017.03.07) Korean Patent Publication No. 10-2017-0027311 (2017.03.09)

An embodiment of the present invention is to provide an elevator wireless power control device that guarantees constant power delivery to at least one elevator vehicle without communication between the transmitting and receiving units.

An embodiment of the present invention is to provide an elevator wireless power control device that controls a wireless power transmitter to operate as a constant current source regardless of a change in the load of the elevator through the control of a voltage command.

An embodiment of the present invention is to provide an elevator wireless power control device that compensates for impedance by connecting a serial connector and makes the wireless power transmitter operate as a constant current source.

An embodiment of the present invention is to provide an elevator wireless power control device that independently controls required power without each elevator communicating with a wireless power transmitter.

Among the embodiments, the elevator wireless power control device operates as a constant current source irrespective of changes in the load of the elevator, and a wireless power transmission unit that supplies the necessary wireless power to the elevator, each comprising the elevator and inverses based on the constant current source. Connected to each of at least one wireless power receiver and the wireless power transmitter and the at least one wireless power receiver each independently controlling the power required for the elevator by performing inverse droop control, and to form the constant current source It includes a compensation network unit for controlling the magnitude of the line impedance.

The wireless power transmitter and the wireless power receiver may be configured of an active power semiconductor to enable two-way wireless power transmission in order to utilize regenerative energy generated during an elevator descending motion.

The wireless power transmitter may include a current control module for controlling a line current to the constant current source through control of the magnitude and phase of the output voltage.

The current control module includes a current calculation unit that calculates an actual current, an error control unit that controls the magnitude and phase of the command current, and the difference between the magnitude and phase of the actual current, and PI control for the error, and It may include a PI control unit that determines the magnitude and phase, respectively.

The wireless power receiver may include a power control module that performs the inverse droop control through control of active and reactive power (active power and reactive power).

The power control module controls the active power through the magnitude of the voltage, controls the reactive power through the phase of the voltage, and calculates and calculates the actual active and reactive power, the command active power and the actual active power. An error control unit that calculates an error by controlling the addition or reduction of reactive power, a PI control unit that performs PI control on the error and determines the magnitude and phase of the output voltage, respectively, and the direction of power transmission through the sign of the phase of the output voltage It may include a transmission direction control unit.

The compensation network unit may be implemented as a compensation capacitor connected in series to each of the wireless power transmitter and the at least one wireless power receiver.

The disclosed technology can have the following effects. However, since it does not mean that a specific embodiment should include all of the following effects or only the following effects, it should not be understood that the scope of the rights of the disclosed technology is limited thereby.

The elevator wireless power control apparatus according to an embodiment of the present invention may ensure constant power delivery to at least one elevator vehicle without communication between the transceivers. Through this, it is possible to eliminate the communication line and achieve some savings and lower maintenance costs. In addition, it is possible to conveniently expand the number of elevator vehicles to two or more in the future.

The elevator wireless power control apparatus according to an embodiment of the present invention may control the wireless power transmitter to operate as a constant current source regardless of a change in the load of the elevator through the control of a voltage command.

The elevator wireless power control apparatus according to an embodiment of the present invention may compensate for impedance by connecting a serial connector and cause the wireless power transmitter to operate as a constant current source.

The elevator wireless power control apparatus according to an embodiment of the present invention may allow each elevator to independently control required power without communicating with the wireless power transmitter.

1 is a view showing an elevator wireless power control apparatus according to an embodiment of the present invention.
2 is a block diagram of a current control module of a wireless power transmission unit of the elevator wireless power control device of FIG. 1.
3A is a circuit diagram illustrating a process of calculating power transmitted from a wireless power transmitter operating as a constant current source to a wireless power receiver.
3B is a block diagram of a power control module of a wireless power receiver of the elevator wireless power control device of FIG. 1.
FIG. 4(a) is a diagram showing the configuration of a power transmission coil of the elevator wireless power control device of FIG. 1, and FIG. 4(b) is a view showing a simulation result of the elevator wireless power control device according to an embodiment.

Since the description of the present invention is merely an embodiment for structural or functional description, the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, since the embodiments can be modified in various ways and have various forms, the scope of the present invention should be understood to include equivalents capable of realizing the technical idea. In addition, since the object or effect presented in the present invention does not mean that a specific embodiment should include all of them or only those effects, the scope of the present invention should not be understood as being limited thereto.

Meanwhile, the meaning of terms described in the present application should be understood as follows.

Terms such as "first" and "second" are used to distinguish one component from other components, and the scope of rights is not limited by these terms. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

When a component is referred to as being "connected" to another component, it should be understood that although it may be directly connected to the other component, another component may exist in the middle. On the other hand, when it is mentioned that a certain component is "directly connected" to another component, it should be understood that no other component exists in the middle. On the other hand, other expressions describing the relationship between the constituent elements, that is, "between" and "just between" or "neighboring to" and "directly neighboring to" should be interpreted as well.

Singular expressions are to be understood as including plural expressions unless the context clearly indicates otherwise, and terms such as “comprise” or “have” refer to implemented features, numbers, steps, actions, components, parts, or It is to be understood that it is intended to designate that a combination exists and does not preclude the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

In each step, the identification code (for example, a, b, c, etc.) is used for convenience of explanation, and the identification code does not describe the order of each step, and each step has a specific sequence clearly in context. Unless otherwise stated, it may occur differently from the stated order. That is, each of the steps may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

The present invention can be embodied as computer-readable codes on a computer-readable recording medium, and the computer-readable recording medium includes all types of recording devices storing data that can be read by a computer system. . Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices. Further, the computer-readable recording medium is distributed over a computer system connected by a network, so that the computer-readable code can be stored and executed in a distributed manner.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the field to which the present invention belongs, unless otherwise defined. Terms defined in commonly used dictionaries should be construed as having meanings in the context of related technologies, and cannot be construed as having an ideal or excessive formal meaning unless explicitly defined in the present application.

1 is a view showing an elevator wireless power control apparatus according to an embodiment of the present invention. FIG. 1A is a diagram illustrating an elevator wireless power control device 100, and FIG. 1B is a diagram illustrating the compensation network unit 130 of the elevator wireless power control device 100 of FIG. 1A implemented with a single compensation capacitor.

Referring to FIG. 1, the elevator wireless power control apparatus 100 includes a wireless power transmitter 110, a wireless power receiver 120, and a compensation network unit 130.

The elevator wireless power control device 100 may wirelessly transmit power required for driving the elevator. More specifically, the elevator wireless power control apparatus 100 may implement wireless power transmission through magnetic coupling between the wireless power transmitter 110 and the wireless power receiver 120. In one embodiment, the elevator wireless power control device 100 does not perform communication between the wireless power transmitter 110 and the wireless power receiver 120, and at least one wireless power receiver ( 120) is wirelessly supplied with power, and the plurality of wireless power receiving units 120 are connected in series, and may be configured to transmit power at a switching frequency to minimize passive elements, but to enable bidirectional power transmission. For example, the elevator wireless power control apparatus 100 may be configured as an active power semiconductor so that a wireless power transmitter and a wireless power receiver can transmit wireless power in both directions in order to utilize regenerative energy generated during an elevator descending motion. Here, the power semiconductor serves to control and maintain power so that the elevator can be driven with the minimum required power, and may be implemented with an Insulated Gate Bipolar Transistor (IGBT) or a silicon carbide (SiC) semiconductor. In one embodiment, the elevator wireless power control apparatus 100 may configure both the wireless power transmitter 110 and the wireless power receiver 120 as a full bridge circuit (H-Bridge). Here, the H-Bridge circuit may correspond to a circuit configured in hardware for forward and reverse control that controls the forward and reverse directions of the motor. More specifically, the elevator wireless power control device 100 includes an H-bridge for controlling the line current of the wireless power transmission unit 110 and a compensation network unit 130a, and the H- for power control of the wireless power receiving unit 120. It may be composed of a bridge and a compensation network unit (130b, 13c) and an elevator (load 1 or load 2, 10).

In one embodiment, the wireless power transmission unit 110 may operate as a constant current source regardless of a change in the load of the elevator 10 to supply the necessary wireless power to the elevator 10. The wireless power transmitter 110 can operate as a constant current source by controlling the phase and duty. More specifically, the wireless power transmitter 110 may control the line current with a constant current source as shown in Figure 1.

[Picture 1]

The wireless power transmitter 110 may be made of a DC voltage source, and may be connected to one or more wireless power receivers 120 according to driving conditions. Here, the wireless power receiving unit 120 appears as a variable load connected in series when viewed from the wireless power transmitting unit 110 including the elevator 10, so that at least one wireless power receiving unit 120 is independently operated. For this, the wireless power transmitter 110 must operate like a constant current source. In an embodiment, the wireless power transmitter 110 may operate as a constant current source by controlling the magnitude and phase of the output voltage. More specifically, the wireless power transmitter 110 may control the line current constant through the control of the magnitude and phase of the output voltage to independently operate the wireless power receiver 120. The wireless power transmission unit 110 may operate as a constant current source through the current control module 112. For a detailed description of the current control module 112, refer to FIG. 2.

The wireless power receiver 120 synthesizes each DC link voltage and has a load of each elevator 10. The wireless power receiving unit 120 controls each DC link voltage by controlling power received through varying the magnitude and phase of the voltage. That is, the wireless power receiving unit 120 composed of at least one can independently control the power required for the elevator 10 by performing inverse droop control based on each of the elevators 10 and a constant current source. . Here, the inverse droop control may correspond to a modified form of droop control. Droop control is a control method mainly used in distributed systems such as micro grids. In a distributed power supply, since the system is separated from the large central system, the system with the voltage and frequency as the reference is not visible. Therefore, P (active power) and Q (reactive power) in each power supply are not dependent on the standard. Power). What is used at this time corresponds to droop control. The elevator wireless power control apparatus 100 according to the present invention cannot use the existing droop control because the wireless power receiving unit 120 cannot know the voltage information of the wireless power transmitting unit 110 because separate communication is not performed. Accordingly, the wireless power receiver 120 may use inverse droop control to control voltage and power of the wireless power receiver 120 side.

In an embodiment, since the wireless power receiver 120 does not communicate with the wireless power transmitter 110 separately, a calculation process for detecting a phase during an initial operation may be performed. Thereafter, the wireless power receiver 120 may control the required power according to the operation of the wireless power transmitter 110 corresponding to a constant current source through the control of the active power and the reactive power. That is, the at least one wireless power receiving unit 120 may independently control power transmitted to each elevator without communication with the wireless power transmitting unit 110. The wireless power receiver 120 may control the reactive power Q close to zero in order to increase the efficiency of elevator operation. As a result, the wireless power receiver 120 may control required power by itself based on the power supply of the wireless power transmitter 110. In an embodiment, the wireless power receiver 120 may control power required for the elevator 10 through the power control module 122. More specifically, the power control module 122 may perform inverse droop control through the control of active power P and reactive power Q. See FIG. 3 for a detailed description.

The compensation network unit 130 is connected to each of the wireless power transmission unit 110 and at least one wireless power receiving unit 120 and may control the size of the line impedance to form a constant current source. Here, the fundamental wave size of the output voltage of the H bridge of the wireless power transmission unit 110 is equal to Equation 1. That is, the maximum magnitude of the output voltage can be determined by the DC-Link voltage.

[Equation 1]

For example, in order to transmit 12.5kW of power to the elevator 10, the compensation network unit 130 must have a current size of 70A or more, but the current line impedance is a constant current source. If it is too large to make, control can be performed to reduce the line impedance. More specifically, assuming that the required line current of the wireless power transmission unit 110 is 70A and the input DC-Link voltage is 600V, the maximum output voltage is 764V. And, assuming that one out of two elevator vehicles is operating, the impedance may correspond to j9.35+j9+j(9/2.26)=j20.15. By the way, the voltage required to control 70A is 1410.5V. Therefore, the compensation network unit 130 should reduce the line impedance. In FIG. 1B, the compensation network unit 130 may be implemented as a compensation capacitor 132 connected in series to each of the wireless power transmission unit 110 and the wireless power reception unit 120. For example, the compensation network unit 130 may reduce line impedance by additionally connecting a series capacitor as shown in Figure 2 below.

[Picture 2]

2 is a block diagram of a current control module of a wireless power transmission unit of the elevator wireless power control device of FIG. 1.

Referring to FIG. 2, the current control module 112 may include a current calculation unit 210, an error control unit 220, and a PI control unit 230.

The current control module 112 may control a magnitude and a phase of an output voltage in order to control a constant current source irrespective of an impedance that varies according to a change in the load of the elevator 10. The current calculator 210 may calculate an actual current. Here, the switching frequency of the elevator wireless power control device 100 may correspond to 20 kHz. Meanwhile, current sensing during one period is limited to about 80 kHz by the operation speed of DSP (Digital Signal Processing), and a separate calculation is required to restore sin wave current. Theoretically, to restore the sin wave, it is necessary to sample two points with an interval of π/2, but in the case of the elevator wireless power control device 100, four points are sampled as shown in Figure 3 below in order to minimize the harmonic effect of the current. We can take the average value for the phase. In other words, as shown in Figure 3, the current can be sampled at four points marked with arrows for each switching cycle. For the current sampled at π/2 intervals, the magnitude (A) and phase (θx) of the current can be obtained using Equation 2 below.

[Picture 3]

[Equation 2]

The error control unit 220 may control the magnitude and phase of the command current and the magnitude and phase of the calculated actual current, respectively. In an embodiment, the error control unit 220 may detect an error between an actual current and a phase for each of a fixed command current and phase in order to control with a constant current source.

The PI controller 230 may perform proportional-integral (PI) control for an error and may determine the magnitude and phase of the output voltage, respectively. More specifically, the PI controller may determine the level of the output voltage through PI control of the error with respect to the current level, and may determine the phase of the output voltage through PI control of the error with respect to the current phase. Here, the output voltage may correspond to the command voltage of the wireless power receiver 120. The duty value of the command voltage can be calculated through Equation 3 below.

[Equation 3]

More specifically, the current control module 112 may control the magnitude of the current through a change in the magnitude of the output voltage, and control the phase of the current by changing the phase of the output voltage.

FIG. 3A is a circuit diagram showing the calculation process of power transmitted from the wireless power transmitter operating as a constant current source to the wireless power receiver, and FIG. 3B is a block diagram of the power control module of the wireless power receiver of the elevator wireless power control device in FIG. to be.

In one embodiment, the wireless power transmitter 110 is controlled by a constant current source (ip), and the wireless power transmitted to the wireless power receiver 120 may be calculated from the circuit diagram of FIG. 3A. Referring to FIG. 3A, in (a), when the wireless power transmission unit 110 is operated as a constant current source (ip), equivalent conversion to the wireless power reception unit 120 is the same as (b) and finally (c). Can be simplified as Here, N may correspond to the number of turns of the transformer, Wsw is a switching frequency, Lm is a mutual inductance, and Lik is a leakage inductance of the wireless power receiver.

Through this, the total active power P and reactive power Q can be calculated through Equation 4 below.

[Equation 4]

Here, S2 may correspond to the power of the wireless power receiver 120, and V1 may correspond to the wireless power transmitter voltage V2, the wireless power receiver voltage. The power control module 122 may control active power through control of a voltage level and control reactive power through phase control.

Referring to FIG. 3B, the power control module 122 may include an active/reactive power calculation unit 310, an error control unit 320, a PI control unit 330, and a transmission direction control unit 340.

The effective and reactive power calculation unit 310 may receive the line current i2 sensed by the wireless power receiver 120 to calculate the actual active power P and the actual reactive power Q. The effective and reactive power calculation unit 310 may calculate the actual effective and reactive power through Equation 4.

The error control unit 320 may calculate an error by controlling the addition or subtraction of the command effective and reactive power (P*, Q*) and the calculated actual active and reactive power (P, Q), respectively.

The PI control unit 330 may perform PI control on an error and may determine an output voltage magnitude (v*) and a phase (Wsw), respectively. In an embodiment, the magnitude of the output voltage determined through the control of active power may be calculated as a duty value through Equation 3. In an embodiment, the control value of the reactive power calculated through the PI control may be added or subtracted from the feed forward value (20 kHz) of Wsw,ff as a frequency value to determine the phase Wsw.

일 때에는 무선전력 송신부(110)에서 무선전력 수신부(120) 로 전력이 전송되며

일 때는 무선전력 수신부(120)에서 무선전력 송신부(110)로 전력이 전송될 수 있다. 따라서, 전송 방향 제어부(340)는 전력 전송 방향에 따라 무선전력 수신부(120)의 전압의 부호를 바꿔 줄 수 있다.The transmission direction control unit 340 may control the transmission direction of power through a sign of the phase of the output voltage. For example, the phase θ is

When is, power is transmitted from the wireless power transmitter 110 to the wireless power receiver 120

In the case of, power may be transmitted from the wireless power receiving unit 120 to the wireless power transmitting unit 110. Accordingly, the transmission direction controller 340 may change the sign of the voltage of the wireless power receiver 120 according to the power transmission direction.

FIG. 4(a) is a diagram showing the configuration of a power transmission coil of the elevator wireless power control device in FIG. 1, and FIG. 4(b) is a view showing a simulation result of the elevator wireless power control device according to an embodiment.

In FIG. 4(a), the coil of the wireless power transmission unit 110 of the elevator wireless power control device 100 is installed parallel to the xy-motor rail in which the wireless power reception unit 120 moves, and the wireless power reception unit 120 is Wireless power may be transmitted from the wireless power transmitter 110 through the E-type coil.

In an embodiment, FIG. 4B may show the power control performance of the wireless power receiver 120 including an elevator whose rating is 12.5 kW of the elevator wireless power control device 100. In FIG. 4(b), the elevator wireless power control device 100 can change the active power at a constant slope from 0% to 100% while maintaining the reactive power at 0, and shows the performance at this time.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You will understand that you can do it.

100: elevator wireless power control device
110: wireless power transmitter 112: current control module
120: wireless power receiver 122: power control module
130: reward network unit
210: current calculation unit
220: error control unit
230: PI control unit
310: Active and reactive power calculation unit
320: error control unit
330: PI control unit
340: transmission direction control unit

Claims (6)

A wireless power transmitter for supplying wireless power required to the elevator by operating as a constant current source irrespective of changes in the load of the elevator;
At least one wireless power receiver each including the elevator and independently controlling power required for the elevator by performing inverse droop control based on the constant current source; And
And a compensation network unit connected to each of the wireless power transmission unit and the at least one wireless power receiving unit and controlling a size of a line impedance to form the constant current source,
The wireless power transmitter and the wireless power receiver are composed of an active power semiconductor in the form of a full-bridge circuit to enable two-way wireless power transmission in order to utilize regenerative energy generated during the descending motion of the elevator,
The wireless power receiver
Including a power control module for performing the inverse droop control through the control of active and reactive power (active power and reactive power),
The power control module
Control the active and reactive power of the wireless power receiver according to the following [Equation 1],
An active and reactive power calculation unit that calculates and calculates the actual active and reactive power;
An error control unit for calculating an error by controlling the addition or subtraction of the command valid and reactive power and the actual active and reactive power;
A PI control unit for performing PI control on the error and determining an output voltage level and a phase, respectively; And
And a transmission direction control unit for controlling a power transmission direction of the wireless power transmitter and the wireless power receiver through a phase code of an output voltage.
[Equation 1]

(Where, S2 is the power of the wireless power receiver, V1 is the voltage of the wireless power transmitter, V2 is the voltage of the wireless power receiver,

Is the phase, Leq is the mutual reactance, and

Is the switching frequency.)

The method of claim 1, wherein the wireless power transmitter
And a current control module for controlling a line current to the constant current source through control of the magnitude and phase of the output voltage.
The method of claim 2, wherein the current control module
A current calculation unit that calculates an actual current;
An error controller for controlling the magnitude and phase of the command current and the magnitude and phase of the actual current, respectively; And
And a PI control unit configured to perform PI control on the error and determine the magnitude and phase of the output voltage, respectively.
delete delete The method of claim 1, wherein the compensation network unit
Elevator wireless power control device, characterized in that implemented as a compensation capacitor connected in series to each of the wireless power transmitter and the at least one wireless power receiver.

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