TWI737294B - Transmission and distribution system with electric shock protection function and method of operating the same - Google Patents

Abstract

A transmission and distribution system with an electric shock protection function includes a transmitting terminal and a receiving terminal. The transmitting terminal includes a switch, a current sensor, a signal generator, and a controller. The receiving terminal includes a filter. The switch is coupled to a first DC power source and a transmission line. The current sensor is coupled to the transmission line to sense a current of the transmission line and to provide a current signal. The signal generator provides a disturbance signal to the transmission line. The controller receives the current signal and provides a control signal to control the switch. When the current sensor determines that the current signal involves the disturbance signal, the control signal turns off the switch.

Description

Transmission and distribution system with electric shock protection function and its operation method

The present invention relates to a transmission and distribution system, in particular to a transmission and distribution system with electric shock protection function and an operation method thereof.

The base station’s power supply to the remote equipment is due to the long transmission distance. It converts the AC power source into a high-voltage DC voltage at the transmitting end, and then transmits the high-voltage DC voltage (for example, 190 volts) through a power transmission line. The remote receiving end, and then through the step-down to a low-voltage DC voltage (for example, 48 volts) to supply power to the DC load equipment. And because of the high transmission voltage and long transmission distance, there may be the risk of electric shock caused by human body or other biological accidents. The application of remote transmission products needs to comply with ATIS-0600030, which means that Comply with the regulations of biological induction protection.

Generally speaking, if the contact position of the human body is between a certain end of the DC voltage and the earth, part of the current passes through the earth and does not return to the DC voltage. At this time, the transmitted current and the returned current are not equal, and the transmitting end can Knowing that a ground fault has occurred, the power is cut off. However, if the human body touches the position between the positive and negative terminals of the DC voltage, the transmitting end cannot determine whether it is a normal load or a human body electrical accident. Therefore, how to avoid human body electrical accidents should be considered.

Please refer to Figure 1, which is a block diagram of the existing transmission and distribution system for detecting electric shock. The transmission and distribution system has a transmitting end (side) and a receiving end (side), wherein the receiving end _{receives the power transmitted by the transmitting end through a transmission line L X} , such as a power transmission line, and then supplies power to a load 100 . The transmitting end includes an AC/DC converter 12A, a switch 14A, a transmitting end current measuring device 16A, and a transmitting end controller 18A. The receiving end includes a DC converter 22A, a receiving end current measuring device 24A, and a receiving end controller 26A.

The AC-DC converter 12A is a boost converter for converting an AC input power V _AC into a first DC power V _DC1 , where the first DC power V _DC1 can be, for example, but not limited to 190 volts DC high voltage. The switch 14A is coupled to the output side of the AC-DC converter 12A and the transmission line L _X. The transmitting end current measuring device 16A is coupled to the transmission line L _X and the transmitting end controller 18A for measuring _{the current flowing through the transmission line L X} at the transmitting end and providing a transmitting end current signal S _IT . The transmitting end controller 18A receives the transmitting end current signal S _IT to know the current flowing through the transmission line L _X at the transmitting end, and provides a switch control signal S _W to control the on and off of the switch 14A , And then control whether the power provided by the transmitting end is transmitted to the receiving end.

The DC converter 22A is a step-down converter for stepping down the first DC power source V _DC1 to a second DC power source V _DC2 . The second DC power source V _DC2 may be, for example, but not limited to 48 Volts DC low voltage. The receiving end current measurer 24A is coupled to the transmission line L _X and the receiving end controller 26A for measuring _{the current flowing through the transmission line L X} at the receiving end and providing a receiving end current signal S _IR . The receiving end controller 26A receives the receiving end current signal S _IR to know the magnitude of the current flowing through the transmission line L _{X at the receiving end.}

Further, the transmitting-end communication controller 18A via a bidirectional communication line L _C with the receiving end of the system controller 26A. Specifically, the transmitting end controller 18A can transmit information about the magnitude of the current flowing through the transmission line L _{X at the transmitting end to the receiving end through the communication line L C} , or the receiving end controller 26A may transmit the information about the current flow through the transmission line L X to the receiving end through the communication line L C. L _C transmits information on the magnitude of the current flowing through the transmission line L _X at the receiving end to the transmitting end, whereby the transmitting end controller 18A or the receiving end controller 26A determines the amount of current flowing through the transmitting end the difference between the two current magnitude of the current size of the transmission line L _X and L _X flowing through the transmission line at the receiving end.

In the existing transmission and distribution system, the method (method) used to detect electric shock is to use the network between the transmitting end and the receiving end to transmit current information, and then to detect _{whether the transmission line L X} between the two has occurred. Accidents of personnel touching electric shocks by mistake.

However, in the existing transmission and distribution system, due to the long distance between the transmitting end and the receiving end, if wired communication is used, there will be problems with the erection of communication lines. Even if wireless communication is used, once the network is interrupted, the network transmission power is insufficient or If there is no network available, the communication line L _C will fail and cannot be used as the communication between the transmitting end controller 18A and the receiving end controller 26A. This will not achieve the function of electric shock protection, which will result in the safety of life and property of personnel. loss.

The purpose of the present invention is to provide a transmission and distribution system with electric shock protection function to solve the problems of the prior art.

In order to achieve the aforementioned purpose, the transmission and distribution system with electric shock protection provided by the present invention includes a transmitting terminal and a receiving terminal. The transmitting end transmits a first DC power source to the Receiving end. The transmitting end includes a switch, a current measuring device, a signal generator and a controller. The switch is coupled to the first DC power source and the transmission line. The current measuring device is coupled to the transmission line, measures a current of the transmission line, and provides a current signal. The signal generator provides a disturbance signal to the transmission line. The controller receives the current signal and provides a control signal to control the switch. The receiving end includes a filter. The filter is coupled to the transmission line. When the controller determines that the current signal has the disturbance signal, the control signal controls the switch to turn off.

In one embodiment, the disturbance signal is carried on the first DC power source.

In one embodiment, the disturbance signal is a high-frequency voltage signal.

In one embodiment, the disturbance signal has at least one frequency.

In one embodiment, when there is an impedance between a positive terminal and a negative terminal of the transmission line, the current signal has the disturbance signal.

In one embodiment, the controller has a high-pass filter to filter out the high-frequency voltage signal.

In one embodiment, the current measuring device is a Hall effect sensor.

In one embodiment, the controller performs fast Fourier transform on the current signal to analyze whether there is the disturbance signal.

In one embodiment, the receiving end further includes a DC converter. The DC converter is coupled to the filter for stepping down the first DC power source into a second DC power source.

In one embodiment, the DC converter is a switch-mode power supply, and a maximum switching frequency of the switch-mode power supply is less than a frequency of the disturbance signal.

In one embodiment, when the current measuring device does not measure the disturbance signal, the control signal controls the switch to be turned on.

With the proposed transmission and distribution system with electric shock protection function, it can detect whether personnel accidentally touched or sensed electricity, and when the accidental touch or electricity occurred, the power supply can be interrupted immediately, and the accidental touching of electricity can be eliminated immediately , In order to achieve the function of electric shock protection.

Another object of the present invention is to provide an operation method of a transmission and distribution system with electric shock protection function to solve the problems of the prior art.

In order to achieve the foregoing purpose, the operation method of the transmission and distribution system with electric shock protection function proposed by the present invention includes: transmitting a first DC power source from a transmitting end to a receiving end through a transmission line; and providing a disturbance signal to the transmission line Measure a current of the transmission line and provide a current signal; and when it is determined that the current signal has the disturbance signal, the first DC power source is turned off and sent to the receiving end.

In one embodiment, the disturbance signal is carried on the first DC power source.

In one embodiment, the disturbance signal is a high-frequency voltage signal and has at least one frequency.

In an embodiment, when there is an impedance between a positive terminal and a negative terminal of the transmission line, it is determined that the current signal has the disturbance signal.

In one embodiment, fast Fourier transform is performed on the current signal to analyze whether there is the disturbance signal.

With the proposed operation method of the transmission and distribution system with electric shock protection function, it can detect whether a person's accidental touch or electric shock occurs, and when an accidental electric shock occurs, the power supply can be interrupted immediately, and the accidental touch can be eliminated immediately In order to achieve the function of electric shock protection.

In order to have a better understanding of the technology, means and effects adopted by the present invention to achieve the intended purpose, please refer to the following detailed description and drawings of the present invention. I believe the purpose, features and effects of the present invention The characteristics can be obtained from this in-depth and specific understanding, but the accompanying drawings are only provided for reference and explanation, and are not used to limit the present invention.

V _AC : AC input power

V _DC1 : The first DC power supply

V _DC2 : second DC power supply

L _X : Transmission line

L _C : Communication line

100: load

12A: AC/DC converter

14A: Switch

16A: Transmitting current measuring device

18A: Transmitter controller

22A: DC converter

24A: Receiver current measuring device

26A: Receiving end controller

S _W : switch control signal

S _IT : Transmission terminal current signal

S _IR : Receiver current signal

10: Transmitter

20: Receiving end

12: Controller

14: switch

16: current measuring device

18: signal generator

22: filter

24: DC converter

V _D : Disturbance signal

S _I : current signal

S _W : Control signal

I _X : current value

R _L : Line impedance

R _B : impedance

S11~S14: steps

Figure 1: A block diagram of the existing transmission and distribution system for detecting electric shock.

Figure 2: is a block diagram of the transmission and distribution system with electric shock protection function of the present invention.

Figure 3 is a schematic diagram of a person getting an electric shock in the transmission and distribution system with electric shock protection function of the present invention.

Fig. 4 is a flow chart of the operation method of the transmission and distribution system with electric shock protection function of the present invention.

The technical content and detailed description of the present invention are described below in conjunction with the drawings.

Please refer to FIG. 2, which is a block diagram of the transmission and distribution system with electric shock protection function of the present invention. The transmission and distribution system with electric shock protection function includes a transmitting terminal 10 and a receiving terminal 20, wherein the transmitting terminal 10 and the receiving terminal 20 are far apart, sometimes up to several kilometers. The transmitting end 10 transmits a first DC power source V _DC1 to the receiving end 20 through a transmission line L _X , wherein the transmission line L _X has an equivalent line impedance R _L. The first DC power source V _DC1 is obtained by converting an AC power source (not shown) through an AC/DC converter (not shown), but it is not limited to this. In some embodiments, the first DC power source V _DC1 is obtained by converting a DC power source through a DC-DC converter. The first direct current power source V _DC1 can be a direct current voltage of 190 volts, but the present invention is not limited by this.

The transmitting terminal 10 includes a switch 14, a current measuring device 16, a signal generator 18 and a controller 12. The switch 14 is coupled to the first DC power source V _DC1 and the transmission line L _X. The switch 14 is not limited to a mechanical switch or a power transistor switch. The current measurer 16 is coupled to the transmission line L _X for measuring a current value I _{X of} the transmission line L _X and provides a current signal S _I according to the current value I _{X. The} measurement position is not limited to the positive terminal or Negative end. The current measuring device 16 is a Hall sensor or a Rogowski coil, but it is not limited by this. In this embodiment, the current value I _X is the magnitude of the current flowing from the receiving end 20 to the transmitting end 10.

The signal generator 18 provides a disturbance signal V _D to the transmission line L _X. The disturbance signal V _D and the first DC power source V _DC1 are in a superimposed relationship, that is, the disturbance signal V _{D is} carried on the first DC power source V _DC1 . Compared with the magnitude of the first DC power source V _DC1 (which is 190 volts), the disturbance signal V _D may be 5 volts. In this embodiment, the disturbance signal V _D is a high-frequency voltage signal, such as 500 kHz, but this is not a limitation of the present invention. Or, the disturbance signal V _D has a signal composed of more than two frequencies, and an appropriate disturbance frequency can be selected according to the equivalent impedance model of the human body or other organisms. The controller 12 receives the current signal S _I, and providing a control signal S _W controls the switch 14 is turned on or off (the detailed description to follow).

The receiving end 20 includes a filter 22 and a DC converter 24. The filter 22 is coupled to the transmission line L _X. The filter 22 can be, but is not limited to, an inductor or an EMI filter. The DC converter 24 is coupled to the filter 22 for _{stepping down the first DC power source V DC1} to a second DC power source V _DC2 for powering a load 100. The second DC power source V _DC2 can be a DC voltage of 48 volts, but the present invention is not limited by this. It is worth mentioning that the transmitting end 10 of FIG. 2 is not limited to being a separate module. The transmitting end 10 can also be integrated into the AC-DC converter or DC-DC converter shown in FIG. 1 (depending on whether the input is AC or DC). ); Similarly, the DC converter 24 and the filter 22 of FIG. 2 can also be integrated in the same module or separated.

Hereinafter, the operation principle of the transmission and distribution system with electric shock protection function of the present invention will be explained. As shown in FIG. 2, the power transmitted from the transmitting terminal 10 to the receiving terminal 20 is the first DC power source V _DC1 plus the disturbance signal V _D (ie, V _DC1 +V _D ). When there is no accidental electric shock, the first direct current power source V _DC1 plus the power source of the disturbance signal V _D is transmitted to the receiving terminal 20. However, through the filter 22, the disturbance signal V _D of the high-frequency signal will be filtered out, so the obtained first direct current power supply V _DC1 passes through the filter 22 to the direct current converter 24. The DC converter 24 steps down the first DC power source V _{DC1 to} obtain 48 volts and the second DC power source V _DC2 supplies power to the load 100 (for example, a DC load).

In this case, because of the existence of the filter 22, the high-frequency disturbance signal V _D cannot form a corresponding current in the loop, and the current value I _X measured by the current measuring device 16 does not have obvious high frequency. The current caused by the disturbance signal V _D. Therefore, when the current measuring device 16 measures the current value I _X , the current measuring device 16 provides the current signal S _I to the controller 12. _{The controller 12 can perform calculations on the current signal S I} through, for example, Fast Fourier Transform (FFT), but without this limitation, it can analyze whether there is a high frequency component of _{the disturbance signal V D. In this embodiment, since the current value I X} flowing from the receiving terminal 20 to the transmitting terminal 10 does not have a significant current caused by the high-frequency disturbance signal V _D , the current signal S _I is controlled by the 12 performs fast Fourier transform does not resolve the disturbance having the high frequency component of the signal V _D, so that the controller 12 provides the control signal S _W controls the switch 14 is turned on, the first DC power supply such that the normal V _DC1 And it is continuously transmitted to the receiving end 20 to supply power to the load 100.

In another embodiment, the current measuring device 16 can be used to measure the _{ripple of the current value I X.} For example, some induction coil type current sensors are used to measure the magnitude of the fluctuating current and provide the current signal. S _I to the controller 12, the controller 12 sets a threshold value, determined when the value of the current ripple signal S _I is below a threshold, the controller 12 provides the control signal S _W controls the switch 14 is turned on, so that The first DC power source V _DC1 can be normally and continuously transmitted to the receiving terminal 20 to supply power to the load 100.

Please refer to FIG. 3, which is a schematic diagram of a person getting an electric shock in the transmission and distribution system with electric shock protection function of the present invention. The power transmitted from the transmitting terminal 10 to the receiving terminal 20 is the first DC power source V _DC1 plus the disturbance signal V _D (ie, V _DC1 +V _D ). When a person accidentally touches and induces electricity, the human body will _{have an impedance R B} equivalent to the positive and negative ends of _{the transmission line L X.} Here, a simple resistance is used to illustrate the human body impedance. In this case, flow to the transport direction of the end 10 of the present current value I _X of the high-frequency signal disturbance signal V _D (due to the disturbance signal V _D of the high-frequency signal does not pass through the filter 22, and non-human filtering), through the resistor R _B loop formed flows back to the transmitter 10. Therefore, the current measuring device 16 measures the current value I _X , and the current measuring device 16 provides the current signal S _I to the controller 12. At this time, the _{ripple value of the current signal S I} will also increase. The controller 12 can determine that the ripple value has exceeded the threshold, or the controller 12 internally _{calculates the current signal S I} through fast Fourier transform, and can analyze the high frequency components with the disturbance signal V _D.

Mistakenly feel due to the occurrence of the power controller 12 such that it is determined that the disturbance signal having a high frequency component V _D, so that the controller 12 provides the control signal S _W controls the switch 14 is turned off to interrupt the first DC The power supply V _{DC1 is} transmitted to the receiving terminal 20, so that the accident of a person's accidental touch and electric shock is immediately eliminated, so as to achieve the function of electric shock protection.

It is worth mentioning that the DC converter 24 converts the first DC power supply V _DC1 into the voltage required by the load 100. The DC converter 24 can use, for example, a linear regulator or a switch mode power supply (Switch Mode Power Supply, SMPS) and so on. When using a switch mode power supply, regardless of whether the switching frequency is variable frequency control or fixed frequency control, the current will have a switching frequency component. Therefore, the frequency selection of the disturbance signal V _D must be able to distinguish the switching frequency to avoid false detection. For example, when the maximum switching frequency of the DC converter 24 is around 100kHz, the frequency of the disturbance signal V _D can be 500kHz which is greater than 100kHz, but it is not limited to this, as long as the maximum switching frequency of the DC converter 24 The frequency is less than the frequency of the disturbance signal V _D. Frequency closer make more complex the design of the controller, through proper design of the perturbation frequency signal V _D, the controller 12 can be provided through a simple high pass filter the specific frequency of the current signal S _I (e.g., The frequency of the disturbance signal V _D ) is filtered out, and it is judged whether it exceeds a set threshold. Or, by performing calculations on the current signal S _I through fast Fourier transform, the high frequency components with the disturbance signal V _{D can be analyzed.}

Please refer to FIG. 4, which is a flowchart of the operation method of the transmission and distribution system with electric shock protection function of the present invention. The transmission and distribution system with electric shock protection function includes a transmitting end and a receiving end, and the transmitting end and the receiving end are connected through a transmission line. The operation method includes the following steps: first, a first DC power source is transmitted from the transmitting end to the receiving end through the transmission line (S11). The first DC power source is obtained by converting an AC power source through an AC-DC converter, or the first DC power source is obtained by converting a DC power source through a DC-DC converter.

Then, a disturbance signal is provided to the transmission line (S12). The disturbance signal is generated through a signal generator, wherein the disturbance signal and the first DC power source are in a superimposed relationship, that is, the disturbance signal is carried on the first DC power source. The disturbance signal is a high-frequency voltage signal, such as 500 kHz, but the present invention is not limited by this. Or, the disturbance signal has a signal composed of more than two frequencies, and an appropriate disturbance frequency can be selected according to the equivalent impedance model of the human body or other organisms.

Then, a current of the transmission line is measured, and a current signal is provided (S13). A current measuring device coupled to the transmission line is used to measure the current of the transmission line, and the current signal is provided according to the current.

Finally, when it is determined that the current signal has the disturbance signal, the first DC power source is turned off and transmitted to the receiving terminal (S14). When there is no accidental electric touch, the first direct current power source plus the power source of the disturbance signal is transmitted to the receiving end. However, because the receiving end has a filter coupled to the transmission line, the disturbance signal of the high-frequency signal will be filtered out through the filter, so the obtained first DC power source passes through the filter to reach the Receiving end. In this case, because of the existence of the filter, the high-frequency disturbance signal cannot form a corresponding current in the loop. The current measured by the current measuring device is not caused by the obvious high-frequency disturbance signal. Current. Therefore, when the current measurer measures the magnitude of the current, the current measurer provides the current signal to a controller. The controller can perform calculations on the current signal through, for example, Fast Fourier Transform (FFT), but without this limitation, it can analyze whether there is a high-frequency component of the disturbance signal. When the magnitude of the current flowing from the receiving end to the transmitting end does not have a significant current caused by the high-frequency disturbance signal, the controller controls a switch connected to the transmission line to turn on, so that the first DC power source It can be normally and continuously transmitted to the receiving end to supply power to a load. In another embodiment, the current measuring device can be used to measure the ripple of the current value. For example, some induction coil-type current sensors are used to measure the fluctuating current and provide the current signal to the control. The controller sets a threshold value. When it is determined that the ripple value of the current signal is lower than the threshold value, the control signal provided by the controller controls the switch to be turned on, so that the first DC power source can be normally and continuously transmitted to The receiving end supplies power to the load.

When a person accidentally touches and senses electricity, the human body will have an impedance equivalent to the positive and negative ends of the transmission line. In this case, the magnitude of the current flowing in the direction of the transmission end has the disturbance signal of the high-frequency signal (because the disturbance signal of the high-frequency signal does not pass through the filter, and the human body does not have a filtering function), the disturbance signal passes through the impedance. The formed loop flows back to the transmitting end. Therefore, the current measuring device measures the magnitude of the current, and the current measuring device provides the current signal to the controller. At this time, the ripple value of the current signal will also increase. The controller can determine that the ripple value has exceeded the threshold, or the controller internally performs calculations on the current signal through fast Fourier transform, and can analyze the high frequency components with the disturbance signal. The controller judges that there is a high-frequency component of the disturbance signal due to the occurrence of a person’s false touch, so the controller controls the switch to turn off to interrupt the transmission of the first DC power source to the receiving end, thereby causing the person to accidentally touch The situation of electric shock is eliminated immediately to achieve the function of electric shock protection.

In summary, the present invention has the following features and advantages:

1. By simply providing a disturbance signal to be loaded on the power supply, it is possible to judge whether a person is touched by mistake or not.

2. Once a person's accidental touch or electric shock occurs, the power supply will be cut off immediately, so that the accident of the person's accidental electric shock will be eliminated immediately, so as to achieve the function of electric shock protection.

The above are only detailed descriptions and drawings of the preferred embodiments of the present invention. However, the features of the present invention are not limited to these, and are not intended to limit the present invention. The full scope of the present invention should be covered by the following patent application scope As the standard, all embodiments that conform to the spirit of the patent application of the present invention and similar changes should be included in the scope of the present invention. Anyone familiar with the art in the field of the present invention can easily think of changes or Modifications can be covered in the following patent scope of this case.

10: Transmitter

20: Receiving end

12: Controller

14: switch

16: current measuring device

18: signal generator

22: filter

24: DC converter

V _D : Disturbance signal

S _I : current signal

S _W : Control signal

I _X : current value

R _L : Line impedance

R _B : impedance

Claims (14)

A transmission power distribution system with electric shock protection function includes a transmission terminal and a receiving terminal, wherein the transmission terminal transmits a first DC power source to the reception terminal through a transmission line, and the transmission power distribution system includes: the transmission terminal includes: A switch, coupled to the first DC power supply and the transmission line; a current measuring device, coupled to the transmission line, measuring a current of the transmission line, and providing a current signal; a signal generator, providing a disturbance signal to The transmission line; and a controller that receives the current signal and provides a control signal to control the switch; the receiving end includes: a filter coupled to the transmission line; and a DC converter coupled to the filter to control the switch; The first DC power source is stepped down into a second DC power source; wherein when the controller determines that the current signal has the disturbance signal, the control signal controls the switch to turn off. The transmission and distribution system with electric shock protection function according to claim 1, wherein the disturbance signal is carried on the first DC power source. The transmission and distribution system with electric shock protection function according to claim 1, wherein the disturbance signal is a high-frequency voltage signal. The transmission and distribution system with electric shock protection function according to claim 1, wherein the disturbance signal has at least one frequency. The transmission and distribution system with electric shock protection function according to claim 1, wherein when there is an impedance between a positive end and a negative end of the transmission line, the current signal has the disturbance signal. The transmission and distribution system with electric shock protection function according to claim 3, wherein the controller has a high-pass filter for filtering out the high-frequency signal of the voltage. The transmission and distribution system with electric shock protection function according to claim 1, wherein the current measuring device is a Hall effect sensor. The transmission and distribution system with electric shock protection function according to claim 1, wherein the controller performs fast Fourier transform on the current signal to analyze whether there is the disturbance signal. The transmission and distribution system with electric shock protection function according to claim 1, wherein the DC converter is a switch mode power supply, and a maximum switching frequency of the switch mode power supply is less than a frequency of the disturbance signal. The transmission and distribution system with electric shock protection function according to claim 1, wherein when the current measuring device does not measure the disturbance signal, the control signal controls the switch to be turned on. An operation method of a transmission and distribution system with electric shock protection function includes: transmitting a first DC power source from a transmitting end to a receiving end through a transmission line; providing a disturbance signal to the transmission line; measuring a current of the transmission line, And provide a current signal; and when it is determined that the current signal has the disturbance signal, the first DC power source is turned off and sent to the receiving end; wherein, the current signal is subjected to fast Fourier transform to analyze the disturbance signal. The operation method of the transmission and distribution system with electric shock protection function according to claim 11, wherein the disturbance signal is carried on the first DC power source. The operation method of the transmission and distribution system with electric shock protection function according to claim 11, wherein the disturbance signal is a voltage high-frequency signal and has at least one frequency. The operation method of a transmission and distribution system with electric shock protection function according to claim 11, wherein when there is an impedance between a positive end and a negative end of the transmission line, it is determined that the current signal has the disturbance signal.

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