BACKGROUND

Technical Field

The present disclosure relates to a transmission and distribution system, and more particularly to a transmission and distribution system with electric shock protection function and a method of operating the same.

Description of Related Art

The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

For supplying power to remote equipment by a base station, since the transmission distance from a transmitting terminal to a receiving terminal is typically far, an AC power is converted into a high-voltage DC voltage at the transmitting terminal, such as 190 volts, and then the high-voltage DC voltage is transmitted through a power transmission line to the receiving terminal, and finally the high-voltage DC voltage is stepped down to a low-voltage DC voltage, such as 48 volts for supplying power to DC loads. Due to the higher transmission voltage and the longer transmission distance, there may be a risk of electric shock caused by accidental touch of the human body or other living things. In the applications of remote transmission product, therefore, it is necessary to meet the requirements of ATIS-0600030, that is, the requirements of protection against electric shock of living things.

In general, if the position where the human body touches is between one end of a DC power and the ground, because part of the current passes through the ground and does not return to the DC power, the current transmitted out is not equal to the current returned. Therefore, the transmitting terminal can be aware that an abnormal grounding has occurred and then the power is thus interrupted. However, if the position where the human body touches is between the positive end and negative end of the DC power, the transmitting terminal fails to determine whether it is a normal load condition or an electric shock occurs when a person touches electricity.

Please refer toFIG. 1, which shows a system block diagram of a conventional transmission and distribution system for detecting an electric shock. The transmission and distribution system has a transmitting terminal (side) and a receiving terminal (side). The receiving terminal receives the power transmitted from the transmitted terminal through a transmission line LX, such as a power transmission line and supplies to a load100. The transmitting terminal includes an AC-to-DC converter12A, a switch14A, a transmitting terminal current measurer16A, and a transmitting terminal controller18A. The receiving terminal includes a DC converter22A, a receiving terminal current measurer24A, and a receiving terminal controller26A.

The AC-to-DC converter12A is a step-up converter for converting an AC input power source VACinto a first DC power VDC1. The first DC power VDC1is, for example but not limited to, a DC high voltage with 190 volts. The switch14A is coupled to an output side of the AC-to-DC converter12A and the transmission line LX. The transmitting terminal current measurer16A is coupled to the transmission line LXand the transmitting terminal controller18A. The transmitting terminal current measurer16A measures a magnitude of a current flowing through the transmission line LXat the transmitting terminal and provides a transmitting terminal current signal SIT. The transmitting terminal controller18A receives the transmitting terminal current signal SITto realize the magnitude of the current flowing through the transmission line LXat the transmitting terminal, and provides a switch control signal SWto turn on or turn off the switch14A, thereby controlling whether the power provided by the transmitting terminal is transmitted to the receiving terminal.

The DC converter22A is a step-down converter for stepping down the first DC power VDC1to a second DC power VDC2. The second DC power VDC2is, for example but not limited to, a DC low voltage with 48 volts. The receiving terminal current measurer24A is coupled to the transmission line LXand the receiving terminal controller26A. The receiving terminal current measurer24A measures a magnitude of a current flowing through the transmission line LXat the receiving terminal and provides a receiving terminal current signal SIR. The receiving terminal controller26A receives the receiving terminal current signal SIRto realize the magnitude of the current flowing through the transmission line LXat the receiving terminal.

Further, a communication line LCis connected between the transmitting terminal controller18A and the receiving terminal controller26A to provide a bi-directional communication. Specifically, the transmitting terminal controller18A can transmit the information of the magnitude of the current flowing through the transmission line LXat the transmitting terminal to the receiving terminal through the communication line LC, or the receiving terminal controller26A can transmit the information of the magnitude of the current flowing through the transmission line LXat the receiving terminal to the transmitting terminal through the communication line LC. Therefore, the transmitting terminal controller18A or the receiving terminal controller26A can determine that a current difference between the transmitting terminal and the receiving terminal.

The aforementioned information transmission manner between the transmitting terminal and the receiving terminal though a network transmission, for example by the above-mentioned communication line LC, is an existing command manner for detecting whether the electric shock occurs on the transmission line LXof the transmission and distribution system.

However, due to the typically long distance between the transmitting terminal and the receiving terminal, problems of setting up the communication line may occur if wired communication is used. Also, even with wireless communication, once the network interruption occurs, the network transmission power is insufficient, or no network is available, the communication line LCwill fail and cannot be used as the communication medium between the transmitting terminal controller18A and the receiving terminal controller26A, and therefore the function of electric shock protection will not work, which may cause human life safety and property loss.

SUMMARY

An object of the present disclosure is to provide a transmission and distribution system with electric shock protection function to solve the above-mentioned problems.

In order to achieve the above-mentioned object, the transmission and distribution system with electric shock protection function includes a transmitting terminal and a receiving terminal. The transmitting terminal transmits a first DC power to the receiving terminal through a transmission line. The transmitting terminal includes a switch, a current measurer, a signal generator, and a controller. The switch is coupled to the first DC power and the transmission line. The current measurer is coupled to the transmission line, and 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 controls the switch accordingly. The receiving terminal includes a filter. The filter is coupled to the transmission line. If the controller determines that the current signal contains the disturbance signal, the controller turns off the switch.

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

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 a resistance is between a positive end and a negative end of the transmission line, the current signal contains the disturbance signal.

In one embodiment, the controller has a high-pass filter, and the high-pass filter is configured to filter and extract the high-frequency voltage signal.

In one embodiment, the current measurer is a Hall sensor.

In one embodiment, the controller performs a Fast Fourier Transform on the current signal to analyze the disturbance signal.

In one embodiment, the receiving terminal further includes a DC converter. The DC converter is coupled to the filter, and steps down the first DC power to a second DC power.

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, if the current measurer does not measure the disturbance signal, the controller turns on the switch.

Accordingly, the transmission and distribution system with electric shock protection function is provided to detect whether a person touches electricity, and once the condition that a person touches electricity is detected, the transmission of the power to the receiving terminal will be interrupted, and therefore the electric shock can be immediately eliminated to achieve the electric shock protection function.

Another object of the present disclosure is to provide a method of operating a transmission and distribution system with electric shock protection function to solve the above-mentioned problems.

In order to achieve the above-mentioned object, the method of operating the transmission and distribution system with electric shock protection function includes steps of: transmitting a first DC power from a transmitting terminal to a receiving terminal through a transmission line, providing a disturbance signal to the transmission line, measuring a current of the transmission line and providing a current signal, and interrupting the first DC power to the receiving terminal if determining that the current signal contains the disturbance signal.

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

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

In one embodiment, when a resistance is between a positive end and a negative end of the transmission line, the current signal contains the disturbance signal.

In one embodiment, a Fast Fourier Transform is performed on the current signal to analyze the disturbance signal.

Accordingly, the method of operating the transmission and distribution system with electric shock protection function is provided to detect whether a person touches electricity, and once an electric shock occurs when a person touches electricity, the transmission of the power to the receiving terminal will be interrupted, and therefore the electric shock can be immediately eliminated to achieve the electric shock protection function.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the present disclosure as claimed. Other advantages and features of the present disclosure will be apparent from the following description, drawings and claims.

