WO2021017697A1

WO2021017697A1 - Local side device, power supply system and electric shock protection method and apparatus

Info

Publication number: WO2021017697A1
Application number: PCT/CN2020/098071
Authority: WO
Inventors: 张雪霁; 熊立群; 陈保国
Original assignee: 华为技术有限公司
Priority date: 2019-07-31
Filing date: 2020-06-24
Publication date: 2021-02-04
Also published as: CN112310938A; CN112310938B

Abstract

Provided in the embodiments of the present invention are a local side device, a power supply system and an electric shock protection method and apparatus, ensuring safe power supply to a remote device, and preventing the occurrence of an electric shock accident. A local side device may comprise: a power source, a first switch connected to the power source in series, a first control circuit coupled to the first switch, and a sampling circuit coupled to the first control circuit, wherein the power source is used for providing a first voltage for a remote device connected to the power source insofar as the first switch is turned on; the sampling circuit is used for performing, within a target period T, sampling M times on a first current of the remote device under the first voltage, and feeding back M sampling results to the first control circuit; and the first control circuit is used for controlling, according to the M sampling results, whether the first switch is turned off. According to the present application, the power supply safety problem in a high-voltage direct current remote power supply process to the remote device is solved, and the occurrence of an electric shock accident is effectively avoided.

Description

Central office equipment, power supply system, electric shock protection method and device

Technical field

The present invention relates to the field of communication and energy, and in particular to a central office equipment, a power supply system, and an electric shock protection method and device.

Background technique

With the development of 5G communication technology, the number of wireless sites has soared and power consumption has increased. If the traditional 48V voltage is used to supply power to remote devices (such as base stations), it will cause the problem of insufficient extension capacity due to excessive transmission cable loss. Therefore, 280V high-voltage DC power supply is derived to meet the long-distance power supply. Demand, while reducing line loss. However, because 280V is a non-safe voltage, it is necessary to add corresponding electric shock protection measures in the long-distance power supply system to avoid safety accidents such as human electric shock.

At present, in order to avoid electric shock accidents during high-voltage DC transmission, the following two electric shock protection schemes are generally adopted:

1. Solution 1: By comparing the current difference between the central office (including central office equipment) and the remote end (including remote equipment), the current change on the line after a high-voltage electric shock is detected to cut off the central office’s power output to achieve electric shock protection. Specifically, please refer to Figure 1. Figure 1 is a schematic diagram of a prior art electric shock protection scheme 1 provided by an embodiment of the present invention; as shown in Figure 1, the central office equipment includes a power supply, a first sampling circuit, a control circuit, and Switch Q1, the remote device includes a second sampling circuit, a tank circuit and a load. After the power is turned on, the first sampling circuit of the central office will sample the current I1 of the central office and feed it back to the control circuit of the central office; the second sampling circuit will sample the remote current I2 and establish communication with the central office equipment by means of synchronous signal transmission. The remote current I2 is fed back to the control circuit of the central office equipment; by comparing the current difference between the central office output current I1 and the remote input current I2 (under normal circumstances, that is, when no electric shock occurs, both I1 and I2 The difference is 0). If the current difference exceeds a certain preset threshold (such as 50mA), it means that an electric shock accident may have occurred on the line. At this time, the switch Q1 is quickly turned off (or called off) to cut off the output voltage of the central office equipment, thereby ensuring the safety of the electric shocker. However, because the electric shock current (such as 50mA) is relatively small compared to the remote load current (0～5A), and dynamically fluctuates with the load, the detection accuracy of the mA-level electric shock current is too high; and because of the need to compare the detection at the same time For the two currents (ie I1 and I2), the remote end needs to feed back the sampled current signal to the remote central office immediately, so the timeliness and accuracy of the current are very high; in scenarios with large load current fluctuations , May cause misjudgment due to insufficient detection response; therefore, this scheme 1 cannot be practically applied due to factors such as high cost, easy misjudgment, and difficulty in detection.

2. The second scheme adopts the method of adding an electric control switch Q2 to the remote device, and realizes electric shock protection by judging the output current of the central office power supply when the electric control switch Q2 is off. Specifically, please refer to Figure 2. Figure 2 is a schematic diagram of a prior art electric shock protection scheme 2 provided by an embodiment of the present invention; as shown in Figure 2, the central office equipment includes a power supply, a sampling circuit, a control circuit and a switch Q1 ; The remote device includes a drive circuit (or a control circuit similar to the central office, Figure 2 takes the drive circuit as an example), a storage circuit, a load, and a switch Q2; after the power supply is powered on, the sampling circuit samples the current I on the line, and feedback To the control circuit; during the period in which the drive circuit controls the on and off of the switch Q2, when the switch Q2 reaches the preset on-time T _on , the switch Q2 is turned off, and after it is turned off, after the preset off-time T _{off is} reached, then Turn on the input power, and repeat this process. It is determined whether the output current of the power supply is greater than the predetermined reference current every time the input power is turned off. If so, the switch Q1 of the central office is turned off to cut off the power output. Among them, the preset on-time Ton can be 50ms, and the off-time T _off can be 5ms, resulting in a detection response time of 54ms or longer. Therefore, in the case of human body electric shock, there will be organ damage and even death. . Even after the control switch Q1 cuts off the power output, the high voltage discharges slowly on the human body impedance, which still harms the human body. Moreover, at the moment of power-on, the remote end may break down the switch Q2 due to the instantaneous charging current of the tank circuit, resulting in poor reliability of the entire protection circuit. To sum up, although the second scheme reduces the circuit cost, the switching cycle is too long, which leads to long detection time, long turn-off time, weak load carrying capacity, and poor reliability of the protection scheme.

It can be seen that in the power supply system of 280V high voltage direct current remote power supply, there is a lack of mature and reliable electric shock protection schemes that meet practical applications.

Therefore, how to ensure safe power supply to remote devices and avoid electric shock accidents has become an urgent problem to be solved.

Summary of the invention

The embodiment of the present invention provides a central office equipment, a power supply system, an electric shock protection method and a device, which solves the problem of power supply safety in the process of high-voltage direct current remote power supply to a communication site, and effectively avoids electric shock accidents.

In the first aspect, an embodiment of the present invention discloses a central office device, including a power supply, a first switch connected in series with the power supply, a first control circuit coupled with the first switch, and a first control circuit coupled with the first control circuit. Sampling circuit;

The power supply is configured to provide a first voltage to a remote device connected to the power supply when the first switch is turned on;

The sampling circuit is configured to sample the first current of the remote device at the first voltage M times within a target period T, and feed back the M sampling results to the first control circuit; Wherein, the target period T includes a preset turn-on time T _{on when} the remote device and the power supply are turned on once and a preset turn-off time T _off when the remote device is turned off once, and M is an integer greater than 1;

The first control circuit is configured to control whether the first switch is turned off according to the M sampling results; wherein, when the first switch is turned off, the remote device is disconnected from the power supply open.

In the embodiment of the present invention, by controlling the remote switch (that is, the second switch) to be turned on once within the preset on time and turned off once within the preset off time, one switching cycle of the remote switch is formed; During the period of time, according to the preset sampling interval T _scan , detect

Sub-current; sampling in multiple switching cycles, the current obtained by accumulating N sampling times exceeds the predetermined threshold current I _th ,

Then the control central office switch (ie, the first switch) is turned off. Through the on-off control of the remote switch, the electric shock current is easy to detect when the switch is off, and is not affected by the load status, which greatly reduces the current detection cost and improves the detection accuracy; multiple detections during the switching cycle, especially It detects the current during the disconnection period of the remote switch to reduce the detection error. Moreover, there is no need for communication between the central office and the remote, and they are completely independent of each other, which reduces the circuit cost and misjudgment rate, and at the same time improves the flexibility of networking. Different from the prior art, it is necessary to synchronously compare the current information of the central office and the remote current information transmitted to the central office as much as possible, and control the switch according to the current difference between the central office and the remote end, which is not required in the embodiment of the present invention. The central office communicates with the remote end, and requires low current detection accuracy. Different from the prior art, which only judges the output current when the switch is turned off in the remote switching period, the embodiment of the present invention performs multiple current detections in the remote switching period, and turns off immediately after the accumulated value reaches the threshold. The central office switch improves the accuracy of detecting electric shock. Furthermore, since the remote switch period is significantly shorter than the remote switch period in the prior art, the detection response speed is greatly accelerated, thereby enabling rapid protection. Optionally, a discharge circuit is added to speed up the voltage discharge; the power-on sequence control method is adopted to avoid switch breakdown.

In a possible implementation manner, the first control circuit is specifically configured to: within the target period T, sequentially receive the M sampling results fed back by the sampling circuit; and determine whether each sampling result exceeds The preset threshold current, if the preset threshold current is exceeded for N times, the first switch is controlled to be turned off; where 1<N≦M, and N is an integer. In the embodiment of the present invention, the current on the line is sequentially sampled M times by the sampling circuit, and the value of M may have a preset upper limit number of times. The specific value is related to the period and the sampling period, which is not limited in the embodiment of the present invention. When the accumulated N times exceeds the preset threshold current, the first control circuit at the central office opens the first switch of the central office. Wherein, the first control circuit may include a digital control chip and related auxiliary circuits. The first switch may be controlled by the high and low levels of the input and output interfaces of the digital control chip. The specific first switch form may include a triode or a relay. A control circuit can adjust the related control output according to the specific selected transistor type or relay, which is not limited in the embodiment of the present invention; the embodiment of the present invention does not limit the specific circuit form of the switch in the circuit.

In a possible implementation manner, the remote device is connected to or disconnected from the power supply through a second switch; the power supply is also used to: after the first switch is turned off, and the first switch When a switch is turned on again and the second switch is turned on, a second voltage is provided to the remote device; when the second switch is turned off, the second voltage is switched to the first Voltage, the second voltage is lower than the first voltage. In the embodiment of the present invention, the power supply system (or the corresponding one or more remote devices) is first powered on based on a safe voltage through the central office power supply; in the power supply system, switch Q1 (that is, the first switch), switch Q2 (that is, the first switch) When the second switch is turned on, the remote switch Q2 switches according to the period T, and at the same time, the central office power supply switches the output voltage (that is, the aforementioned safe voltage) to a DC high voltage. In the control of the system, the power-on sequence control process is added, which can charge the remote energy storage circuit first when the low voltage is powered on, avoiding the instantaneous power-on surge current from breaking down the remote switch and improving the remote switch’s performance. Reliability, thereby enhancing the overall reliability of the protection circuit.

In a possible implementation manner, the central office device further includes a discharge circuit, the discharge circuit includes a third switch and a discharge resistor; the power supply is connected to the remote device through a transmission cable; the first control The circuit is further configured to: when the first switch is off, control the third switch to turn on, so that the discharge resistor is combined between the positive and negative ends of the transmission cable, and the discharge resistor It is connected in parallel with the positive and negative ends of the transmission cable; the discharge circuit is used for discharging the voltage on the transmission cable through the discharge resistor. In the embodiment of the present invention, by adding a discharging circuit and controlling the third switch (or combined switch) in the discharging circuit through the first control circuit, rapid protection can be realized in a short time (such as 10ms) .

In a possible implementation, the sampling circuit includes a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the power supply, and the operational amplifier is connected with the sampling resistor; the sampling circuit is specifically used for: In each sampling process of the M samplings, the first current flowing through the sampling resistor is amplified by the operational amplifier; according to the sampling interval T _scan , M times are obtained sequentially within the target period T A second current, the second current includes the amplified first current; and the M second current is fed back to the first control circuit in sequence. The embodiment of the present invention collects and amplifies the current flowing through the sampling resistor on the line through the sampling circuit including the combination of the sampling resistor and the operational amplifier, so as to facilitate subsequent comparison with the reference current. The sampling circuit may also include a current sensor to sample the line circuit. The embodiment of the present invention does not limit the specific sampling circuit structure and the location of the current sampling point on the transmission cable.

In a possible implementation manner, the sampling interval T _{scan is} less than the preset off time T _off . In the embodiment of the present invention, by setting the value of the sampling interval less than the off time, it is ensured that the line current is collected at least once during the switch off time; in order to avoid misjudgment, the sampling interval can be adjusted reasonably according to the actual situation to increase the off time. The number of samples in the time period T _off .

In a possible implementation manner, the central office equipment further includes a diode, which is connected in series with the power supply; and the diode is used for turning off the first switch when the first switch is off. The current oscillation generated during the current sudden change is suppressed to zero. In the embodiment of the present invention, a diode is connected in series on the transmission cable, and the unidirectional conductivity of the diode is used to realize that the current quickly reaches zero when the central office switch (that is, the first switch) is turned off, which improves the current detection accuracy and reduces misjudgment. Possible.

In a second aspect, an embodiment of the present invention provides a power supply system, including a central office device, and at least one remote device connected to the central office device, wherein:

The central office equipment includes a power supply, at least one first switch connected in series with the power supply, a first control circuit coupled with the at least one first switch, and at least one sampling circuit coupled with the first control circuit; The remote device includes a second switch connected in series with the power supply, and a second control circuit coupled with the second switch;

The sampling circuit is configured to sample the first current of the remote device under the first voltage for M times within a target period T, and feed it back to the first control circuit; wherein, the target The period T includes a preset turn-on time T _{on when} the remote device is turned on once with the power supply through the second switch and a preset turn-off time T _off when the remote device is turned off once, and M is an integer greater than 1;

The first control circuit is configured to control whether the first switch is turned off according to the results of M samplings; wherein, when the first switch is turned off, the remote device is disconnected from the power supply;

The second control circuit is configured to periodically control the second switch to be turned on during the preset on time T _on and turned off during the preset off time T _off ; wherein, the second switch is turned off In the case of on, the remote device is disconnected from the power supply.

In a possible implementation manner, the first control circuit is specifically configured to:

Within the target period T, sequentially receiving the M sampling results fed back by the sampling circuit;

It is determined whether each sampling result exceeds the preset threshold current, and if the preset threshold current exceeds the preset threshold current N times, the first switch is controlled to be turned off; where 1<N≦M, and N is an integer.

In a possible implementation manner, the remote device is connected to or disconnected from the power supply through a second switch; the power supply is also used for:

After the first switch is turned off, and the first switch is turned on again and the second switch is turned on, providing a second voltage to the remote device;

When the second switch is turned off, the second voltage is switched to the first voltage, and the second voltage is lower than the first voltage.

In a possible implementation manner, the central office device further includes a discharge circuit, the discharge circuit includes a third switch and a discharge resistor; the power supply is connected to the remote device through a transmission cable; the first control Circuit, also used for:

When the first switch is off, the third switch is controlled to be turned on, so that the discharge resistor is combined between the positive and negative ends of the transmission cable, and the discharge resistor is connected to the transmission cable. The positive and negative terminals are connected in parallel;

The discharge circuit is used to discharge the voltage on the transmission cable through the discharge resistor.

In a possible implementation manner, the sampling circuit includes a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the power supply, and the operational amplifier is connected with the sampling resistor;

The sampling circuit is specifically used for:

In each sampling process of the M samplings, amplify the first current flowing through the sampling resistor by the operational amplifier;

According to the sampling interval T _scan , the second current is sequentially acquired M times within the target period T, and the second current includes the amplified first current;

The M second currents are fed back to the first control circuit in sequence.

In a possible implementation manner, the sampling interval T _{scan is} less than the preset off time T _off .

In a possible implementation manner, the central office equipment further includes a diode, and the diode is connected in series with the power supply;

The diode is used to suppress the current oscillation generated during the sudden change of the first current to zero when the first switch is off.

In a possible implementation manner, the power supply system includes K remote devices; the central office device includes K first switches and K sampling circuits; wherein, K remote devices The terminal device, the K first switches, and the K sampling circuits have a one-to-one correspondence, and K is an integer greater than 1.

In a possible implementation manner, the power supply is specifically configured to provide the first voltage to a load of a remote device connected to the power supply when the first switch is turned on;

The remote device further includes an energy storage circuit connected in parallel with the load;

The tank circuit is used to maintain the load operation within the preset off time T _off .

Specifically, at the beginning of the preset off time T _off , the load is provided with the first voltage. Due to the discharge of the capacitor, the voltage will drop, but the time for the energy storage circuit to function is very short in the second switch. In the switching period T, the time is shorter, so it can basically maintain the normal operation of the load. There is an energy storage circuit behind the switch that is connected across the positive and negative bus bars, that is, the energy storage circuit can be set between the remote second switch connected in series with the remote load, the central office power supply, and the load. The remote energy storage circuit is an energy storage capacitor, which can be an electrolytic capacitor built into the RRU or AAU, or it can be externally added to ensure that the power source can supply power to the load when the remote switch is turned off; The specific content and form are not limited.

In a possible implementation manner, the remote device further includes a protection circuit connected in series between the power supply and the second switch, and the protection circuit is used to protect the remote device.

In a third aspect, an embodiment of the present invention provides an electric shock protection method, which is applied to a central office device. The central office device includes a power source, a first switch connected in series with the power source, and a first switch coupled to the first switch. A control circuit and a sampling circuit coupled with the first control circuit; the method includes:

When the first switch is turned on, provide the first voltage to the remote device connected to the power source through the power source;

In the target period T, the first current of the remote device at the first voltage is sampled M times by the sampling circuit, and the M sampling results are fed back to the first control circuit; wherein, The target period T includes a preset conduction time T _{on when} the remote device is connected to the power supply once and a preset disconnection time T _off when the remote device is disconnected once, and M is an integer greater than 1;

Through the first control circuit, control whether the first switch is turned off according to the M sampling results; wherein, when the first switch is turned off, the remote device is disconnected from the power supply .

In a possible implementation manner, the controlling whether the first switch is turned off according to the M sampling results through the first control circuit includes:

In the target period T, sequentially receive the M sampling results fed back by the sampling circuit through the first control circuit;

It is determined by the first control circuit whether each sampling result exceeds the preset threshold current, and if the preset threshold current exceeds the preset threshold current N times, the first switch is controlled to be turned off; where 1<N≤M, N is Integer.

In a possible implementation manner, the remote device is connected to or disconnected from the power supply through a second switch; the method further includes:

After the first switch is turned off, and the first switch is turned on again and the second switch is turned on, providing a second voltage to the remote device through the power supply;

When the second switch is turned off, the second voltage is switched to the first voltage through the power supply, and the second voltage is lower than the first voltage.

In a possible implementation manner, the central office device further includes a discharge circuit, the discharge circuit includes a third switch and a discharge resistor; the power supply is connected to the remote device through a transmission cable; the method further includes :

When the first switch is turned off, the third switch is controlled to be turned on by the first control circuit, so that the discharge resistor is combined between the positive and negative ends of the transmission cable, and the discharge The resistance is connected in parallel with the positive and negative ends of the transmission cable;

The voltage on the transmission cable is discharged through the discharge resistor.

In the target period T, sampling the first current of the remote device under the first voltage by the sampling circuit M times, and feeding back the M sampling results to the first control circuit, include:

According to the sampling interval T _scan , the second current is sequentially acquired M times within the target period T by the sampling circuit, and the second current includes the amplified first current;

The M second current is fed back to the first control circuit in sequence through the sampling circuit.

In a possible implementation manner, the central office equipment further includes a diode, and the diode is connected in series with the power supply; the method further includes:

When the first switch is off, the current oscillation generated during the sudden change of the first current is suppressed to zero by the diode.

In a fourth aspect, an embodiment of the present invention provides an electric shock protection device, which is applied to central office equipment. The central office equipment includes a power supply, a first switch connected in series with the power supply, and a first switch coupled with the first switch. A control circuit, a sampling circuit coupled with the first control circuit; the device includes:

A power supply unit, configured to provide a first voltage to a remote device connected to the power supply through the power supply when the first switch is turned on;

The sampling unit is configured to sample the first current of the remote device at the first voltage through the sampling circuit M times within the target period T, and feed back the M sampling results to the first Control circuit; wherein, the target period T includes a preset on-time T _{on for} the remote device and the power supply to be turned on once and a preset off-time T _off for once _off , and M is an integer greater than 1. ；

The first control unit is configured to control whether the first switch is turned off according to the M sampling results through the first control circuit; wherein, when the first switch is turned off, the remote The device is disconnected from the power source.

In a possible implementation manner, the first control unit is specifically configured to:

In a possible implementation manner, the remote device is connected to or disconnected from the power supply through a second switch; the device further includes a power-on unit for:

Before the next target period T, the second voltage is switched to the first voltage by the power supply, and the second voltage is lower than the first voltage.

In a possible implementation manner, the central office equipment further includes a discharge circuit, the discharge circuit includes a third switch and a discharge resistor; the power supply is connected to the remote equipment through a transmission cable; the device further includes The second control unit is used to:

The sampling unit is specifically used for:

According to the sampling interval Tscan, the second current is sequentially acquired M times within the target period T by the sampling circuit, and the second current includes the amplified first current;

In a possible implementation manner, the central office equipment further includes a diode, which is connected in series with the power supply; and the device further includes an oscillation suppression unit for:

In a fifth aspect, an embodiment of the present invention provides a control device, the control device is connected to the power supply of the central office, and the control device includes a first switch connected in series with the power supply, and a first switch coupled with the first switch. A control circuit, a sampling circuit coupled with the first control circuit;

In a sixth aspect, an embodiment of the present invention provides a chip system, which may include: the control device as described in the fifth aspect.

In a seventh aspect, an embodiment of the present invention provides a chip system, which may include: the control device as described in the fifth aspect, and an auxiliary circuit coupled to the control device.

In an eighth aspect, an embodiment of the present invention provides an electronic device, which may include: the control device as described in the fifth aspect, and a discrete device coupled to the outside of the control device.

In a ninth aspect, the present application provides a chip system that can execute any method involved in the above third aspect, so that related functions can be realized, for example, receiving or processing the current signal and the current signal involved in the above method. /Or information. In a possible design, the chip system further includes a memory, and the memory is used to store necessary program instructions and data. The chip system can be composed of chips, or include chips and other discrete devices.

In a tenth aspect, the present application provides a computer storage medium for storing computer software instructions for the electric shock protection device provided in the fourth aspect, which may include a program designed to execute the above aspect.

In an eleventh aspect, an embodiment of the present invention provides a computer program. The computer program may include instructions. When the computer program is executed by a computer, the computer can execute the method for protecting against electric shock in any one of the third aspects. The process.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings that need to be used in the description of the embodiments.

1 is a schematic diagram of the principle of a prior art electric shock protection scheme 1 provided by an embodiment of the present invention;

2 is a schematic diagram of the principle of a prior art electric shock protection scheme 2 provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of an application scenario of central office equipment provided by an embodiment of the present invention;

4 is a schematic diagram of another central office equipment application scenario provided by an embodiment of the present invention;

Figure 5 is a schematic diagram of yet another central office equipment application scenario provided by an embodiment of the present invention;

Figure 6 is a schematic diagram of a power supply system provided by an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a central office device provided by an embodiment of the present invention;

FIG. 8 is a working flowchart of a first control circuit provided by an embodiment of the present invention;

9 is a schematic diagram of the hardware structure of a first control circuit provided by an embodiment of the present invention;

FIG. 10 is a schematic diagram of the degree of influence of current on the human body according to an embodiment of the present invention;

FIG. 11 is a diagram of a reference table of human body impedance according to an embodiment of the present invention;

12 is a schematic structural diagram of another central office equipment provided by an embodiment of the present invention;

FIG. 13 is a schematic structural diagram of another central office equipment applied to a power supply system according to an embodiment of the present invention;

Figure 14 is a schematic structural diagram of a power supply system provided by an embodiment of the present invention;

15 is a schematic structural diagram of another power supply system provided by an embodiment of the present invention;

16 is a schematic structural diagram of another power supply system provided by an embodiment of the present invention;

17 is a schematic flowchart of an electric shock protection method provided by an embodiment of the present invention;

18 is a schematic flowchart of another electric shock protection method provided by an embodiment of the present invention;

Figure 19 is an electric shock protection device provided by an embodiment of the present invention;

Fig. 20 is a schematic diagram of a control device provided by an embodiment of the present invention.

Detailed ways

The embodiments of the present invention will be described below in conjunction with the drawings in the embodiments of the present invention.

The terms "first", "second", "third" and "fourth" in the description and claims of the application and the drawings are used to distinguish different objects, rather than describing a specific order . In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes unlisted steps or units, or optionally also includes Other steps or units inherent to these processes, methods, products or equipment.

Reference to "embodiments" herein means that a specific feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art clearly and implicitly understand that the embodiments described herein can be combined with other embodiments.

The terms "component", "module", "system", etc. used in this specification are used to denote computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, the component may be, but is not limited to, a process, a processor, an object, an executable file, an execution thread, a program, and/or a computer running on a processor. Through the illustration, both the application running on the computing device and the computing device can be components. One or more components may reside in processes and/or threads of execution, and components may be located on one computer and/or distributed among two or more computers. In addition, these components can be executed from various computer readable media having various data structures stored thereon. The component may be based on, for example, a signal having one or more data packets (such as data from two components interacting with another component in a local system, a distributed system, and/or a network, such as the Internet that interacts with other systems through signals) Communicate through local and/or remote processes.

First, some terms in this application are explained to facilitate the understanding of those skilled in the art.

(1) The remote radio unit (RRU) is a supplementary technology for base station coverage. It has the advantages of scalable system capacity, fast site construction period, and flexible networking. It also overcomes the inability of optical fiber repeaters to transmit delay Compensation causes problems such as handover and difficulty in initiating calls, and overcomes the reverse interference of the introduction of wireless repeaters on the donor base station, thereby improving the reverse capacity of the donor base station. The RRU will separate the baseband unit of the base station from the radio frequency unit (or called the transmitting unit), and the baseband signal unit and radio frequency unit will be transmitted between the two (baseband signal unit and radio frequency unit) by light or the Internet over a long distance. The outdoor antenna receives and transmits radio frequency signals, and the indoor baseband processing unit (Building Baseband Unit, BBU) receives and transmits optical signals, so the BBU and antenna need to pass through the RRU as an intermediate bridge to process the signals accordingly.

When receiving a signal, the RRU filters the radio frequency signal from the antenna, amplifies it with low noise, and converts it into an optical signal, which is then transmitted to the indoor processing equipment. Filtering, linear power amplification and other operations are converted into radio frequency signals, and finally sent out through the antenna. There are many types of RRU, and the number of interfaces for each model is different, but generally there are the following interfaces: power interface, DC power distribution unit (Building Baseband Unit, DCDU) through the power interface to supply power to the RRU; optical port, BBU Connect with RRU through optical port; interface with antenna, etc.

(2) The baseband processing unit (Building Baseband Unit, BBU) is connected to the remote radio unit (RRU) through optical fiber. One BBU can support multiple RRUs. The BBU+RRU multi-channel solution can well solve the indoor coverage of large venues.

(3) Active antenna unit (AAU) is a highly integrated radio frequency unit and antenna, which moves the radio frequency function in the distributed base station system to the antenna end. Specifically, part of the physical layer processing function of the BBU is combined with the original RRU and passive antenna to form an AAU.

(4) The remote power system refers to the use of cables or optical cables in long-distance wired communications to transport electric energy from central office stations or manned relay stations to remote stations (which can be unmanned base stations). End station power supply system. The DC power supply is remotely input to the remote device through the cable, and is used by the load device after being monitored by the remote power supply.

(5) General-purpose input/output (GPIO), whose pins can be freely used by the user under program control, and the PIN pin (or pin or pin) can be used as a general-purpose input according to actual considerations (General-purpose input, GPI) or general-purpose output (GPO) or general-purpose input and output (i.e. GPIO). When a pin can be used for input, output or other special functions, the corresponding existence register is used to select these functions. For input, you can read a register to determine the level of the pin potential; for output, you can also write to a register to make the pin output a high or low potential; for other special functions, you can have another register To control them.

(6) Operational amplifier, abbreviated as operational amplifier, is a circuit unit with very high magnification. In actual circuits, a certain functional module is usually combined with a feedback network. It is an amplifier with a special coupling circuit and feedback. The output signal can be the result of mathematical operations such as addition, subtraction, differentiation, and integration of the input signal. The op amp is a circuit unit named from a functional point of view, which can be realized by a discrete device or in a semiconductor chip. With the development of semiconductor technology, most operational amplifiers exist in the form of a single chip. There are many types of operational amplifiers, which are widely used in the electronics industry.

(7) Direct current distribution unit (DCDU), in actual application, is a kind of weak current product, specifically it can be a kind of DC power distribution box, which is generally used in industrial communication devices. DCDU distributes direct current to wireless main equipment, such as: BBU, RRU, microwave equipment and IPRAN transmission equipment, etc.; according to different equipment, the output port provided is different. For example, one DC is input to the DCDU, and the DCDU outputs multiple DCs.

(8) Remote technology, which generally includes three technologies: RF remote, IF remote, and baseband remote. TD-SCDMA optical fiber remote technology is mainly used in RF remote and baseband remote. RF remote is to transmit RF signals with optical fiber for long-distance transmission through photoelectric coupling components. The remote part includes photoelectric coupling components, power amplifier equipment, and smart antennas. The baseband extension is the same as the WCDMA baseband extension method. It is divided into a baseband part (BBU) and a radio frequency part (RRU). Optical fiber is used for signal transmission in the middle. This method is sometimes called a distributed base station or remote radio (BBU). +RRU). Among them, BBU and RRU are both base station equipment for wireless communication, and they are closely related to each other, and both play an important role in the base station.

(9) The base station, which can be regarded as a wireless modem, is responsible for the reception and transmission of mobile signals. Generally, in a certain area, multiple sub-base stations and transceiver stations (mobile phones) form a cellular network with each other, and transmit and receive mobile communication signals by controlling the mutual transmission and reception of signals between the transceiver and the transceiver. A base station usually includes BBU (mainly responsible for signal modulation), RRU (mainly responsible for radio frequency processing), feeder (connecting RRU and antenna) and antenna (mainly responsible for the conversion between the guided wave on the cable and the space wave in the air).

To facilitate the understanding of the embodiments of the present invention, the following exemplarily enumerate the application scenarios of the central office equipment and the electric shock protection method in the present application, which may include the following three application scenarios.

Scenario 1: Powering a single remote device through the central office device:

Refer to Figure 3. Figure 3 is a schematic diagram of a central office equipment application scenario provided by an embodiment of the present invention. The application scenario includes central office and remote end. The central office may include central office equipment, and the remote end may include remote equipment. . Among them, the central office equipment can be applied to power supply stations or power plants, etc. The central office equipment can include power supplies, diodes, sampling circuits, control circuits, discharge circuits, and shutdown switches, and the remote end can include control circuits and shutdown switches. Wait. The embodiment of the present invention does not limit the specific circuit devices and circuit structures included in the central office equipment and the remote equipment, and the application site of the central office equipment and the remote equipment. Under certain circumstances, it can be considered that the central office is equivalent to the central office equipment, or the central office has some technical designs such as auxiliary equipment on the premise that the central office equipment is included. The central office (in Figure 3, the power supply station is the application site of the central office equipment, and the power supply of the central office equipment is the power generation equipment as an example), the remote (in Figure 3, the communication base station is the application site of the remote equipment, the remote equipment The load is RRU or AAU as an example). Power transmission can be carried out through transmission cables. For example, the power supply station (that is, a kind of central office) provides high-voltage power supply (that is, a kind of remote) through a transmission cable. ). Among them, a one-to-one matching relationship can be established between the central office device and at least one remote device, for example, the remote device’s unique identifier (such as identification code or legal account information) is used for matching. After the matching is completed, the central office and The matched remote devices can cooperate to execute the procedure of the electric shock protection method provided in this application. So as to realize the electric shock monitoring of the entire power supply system and avoid the occurrence of safety accidents.

Scenario 2: Powering multiple remote devices through the central office device:

Refer to Figure 4. Figure 4 is a schematic diagram of another central office equipment application scenario provided by an embodiment of the present invention. The application scenario includes central office and remote end. The central office may include central office equipment, and the remote end may include multiple central office equipment. Remote, each remote corresponds to a remote device; as shown in Figure 4, it can include W remotes, such as remote 1, remote 2, etc.; W is an integer greater than 1, the embodiment of the present invention is suitable for this application scenario The number of remote ends in is not limited. Under certain circumstances, it can be considered that the central office is equivalent to the central office equipment, or the central office has some technical designs such as auxiliary equipment on the premise that the central office equipment is included. Among them, the central office equipment can be applied to power supply stations or power plants, etc. The central office equipment can include power supplies, diodes, sampling circuits, control circuits, discharge circuits, and shutdown switches, and the remote end can include control circuits and shutdown switches. Wait. The embodiment of the present invention does not limit the specific circuit devices and circuit structures included in the central office equipment and the remote equipment, and the application site of the central office equipment and the remote equipment. Central office (in Figure 4, the power supply station is the application site of the central office equipment, and the power supply of the central office equipment is the power generation equipment as an example), remote (in Figure 4, the communication base station is the application site of the remote equipment, the remote equipment The load is RRU or AAU as an example). Power transmission can be carried out through transmission cables. For example, a power supply station (a type of central office) provides high-voltage power supply (that is, a type of remote end) to multiple base stations (that is, a remote end) through transmission cables. Power transmission). Among them, a one-to-one matching relationship can be established between the central office device and at least one remote device, for example, the remote device’s unique identifier (such as identification code or legal account information) is used for matching. After the matching is completed, the central office and Matching remote devices can cooperate to implement the procedures of the electric shock protection method provided in this application; thereby realizing the monitoring of the electric shock situation of the entire power supply system, responding to the electric shock situation on one or more lines in time, and reducing major safety The probability of an accident.

Scenario 3: Power is supplied to a single remote device containing multiple loads through the central office device:

Refer to Figure 5. Figure 5 is a schematic diagram of another central office equipment application scenario provided by an embodiment of the present invention. The application scenario includes central office and remote end. The central office may include central office equipment, and the remote end may include remote The device, specifically, in this application scenario, the remote device includes a DC power distribution unit DCDU. The aforementioned DCDU is used to distribute a single DC line into multiple DC lines to supply power to a remote load. Among them, the central office equipment can be applied to sites such as power supply stations or power plants. The central office equipment can include power supplies, diodes, sampling circuits, control circuits, discharge circuits, and shutdown switches, and the remote can also include control circuits and shutdown switches. Switch etc. The embodiment of the present invention does not limit the specific circuit devices and circuit structures included in the central office equipment and the remote equipment, and the application site of the central office equipment and the remote equipment. Under certain circumstances, it can be considered that the central office is equivalent to the central office equipment, or the central office has some technical designs such as auxiliary equipment on the premise that the central office equipment is included. The central office (in Figure 5, the power supply station is the application site of the central office equipment, and the power supply of the central office equipment is the power generation equipment as an example), remote (in Figure 5, the communication base station is the application site of the remote equipment, and the remote equipment The load is RRU or AAU as an example). Power transmission can be carried out through transmission cables. In this application scenario, a single remote can include multiple loads (as shown in Figure 5, the multiple loads can be Y loads, such as Load 1, load 2, etc.; Y is an integer greater than 1). For example, a power supply station (a type of central office) provides high-voltage power supply (that is, electric energy transmission) to the base station through a transmission cable: first, the remote DC power distribution unit performs DC distribution, and the distributed current is transmitted to the load of each base station , To ensure the normal operation of the load. Among them, a one-to-one matching relationship can be established between the central office device and at least one remote device, for example, the remote device’s unique identifier (such as identification code or legal account information) is used for matching. After the matching is completed, the central office and The matched remote devices can cooperate to execute the procedure of the electric shock protection method provided in this application. So as to realize the electric shock monitoring of the entire power supply system and avoid the occurrence of safety accidents.

It can be understood that the application scenarios in Figs. 3, 4, and 5 are only several exemplary implementations in the embodiment of the present invention, and the application scenarios in the embodiment of the present invention include but are not limited to the above application scenarios.

In combination with the above application scenarios, one of the systems based on the embodiments of the present invention will be described below first. Please refer to FIG. 6. FIG. 6 is a schematic diagram of a power supply system provided by an embodiment of the present invention. The electric shock protection method proposed in this application can be applied to the system. The system can be divided into two parts, including central office equipment and remote equipment. Among them, the network elements of central office equipment can include power supply, switch Q1 (ie the first switch), sampling circuit and first control circuit; The network element of the device may include a load, a tank circuit, a second control circuit, and a switch Q2 (ie, the second switch). The sampling circuit may include a sampling resistor and an operational amplifier, or the sampling circuit may include a current sensor to sample the current I at the position shown in the figure. It can be understood that the embodiment of the present invention does not limit the current sampling position. The first control circuit mainly includes a digital control chip and a driver. The digital control chip may include internal modules such as a comparator, a counter, and general-purpose input/output GPIO. Among them, the energy storage circuit is used to supply power to the remote downstream load within the off time T _off of the target period T to ensure the normal operation of the load. Optionally, the central office equipment may also include a diode and/or a discharge circuit; in the system shown in FIG. 6, what is described is only a basic system that can ensure that the embodiments involved in this application implement the corresponding protection functions, with additional optimizations The equipment or components of the system (such as the aforementioned diode and discharge circuit) are not shown in the figure, and may be combined with the description and drawings of other embodiments of the present application. Among them, the diode is used to suppress the current oscillation caused by the parasitic inductance and capacitance during the sudden change of the current on the line to 0 when the second switch is turned off, so that the current can drop to 0 quickly; the discharge circuit is used in the A certain output bus (the output bus is a transmission cable used for high-voltage transmission, or has other similar names, which is not limited in the embodiment of the present invention.) After the power is cut off, the discharge resistor is combined (that is, in parallel) to The bus. The busbars, cables, transmission cables or other similar descriptions mentioned in the foregoing description and mentioned elsewhere in this application are essentially the same, and they all play the role of transmitting electrical energy (or high-voltage DC long-distance transmission). The embodiment of the present invention does not specifically limit the form and content of the aforementioned transmission cable; and the aforementioned transmission cable is part or all of the application of the prior art, and does not involve the core solution of the embodiment of the present invention. The diagrams corresponding to the respective embodiments of the invention do not additionally mark the transmission cable. In this application, only the connection relationship and function of the transmission cable with the central office equipment and the remote equipment are appropriately mentioned, without excessive explanation.

It can be understood that the system in FIG. 6 is only an exemplary power supply system in the embodiment of the present invention, and the power supply system in the embodiment of the present invention includes but is not limited to the above power supply system.

Based on the above-mentioned technical problems, combined with the above-mentioned application scenarios, system architecture, and the embodiments of the central office equipment provided in this application, the technical problems proposed in this application are specifically analyzed and solved below.

Please refer to FIG. 7, which is a schematic structural diagram of a central office device provided by an embodiment of the present invention. It can be understood that the ellipse on the left side of the first switch identification position in the figure indicates the position of a current sampling point ; When the central office equipment is not connected to the power supply system or is not powered on, the sampling current does not start to sample the cable current. The aforementioned central office equipment can be applied to the aforementioned power supply system (including the aforementioned system architecture). Please refer to Figure 6 and the corresponding descriptions, which will not be repeated here, and the symbols shown in Figure 7 will not be marked in Figure 6 And related signs, and the aforementioned power supply system is applicable to the several application scenarios shown in Figs. 3 to 5 above. The central office equipment 70 may include a power supply 701, a first switch 702 connected in series with the power supply 701, a first control circuit 703 coupled with the first switch 702, and a first control circuit 703 coupled with the first control circuit 703. The sampling circuit 704. The remote device as shown in FIG. 6 may include a switch Q2 (ie, a second switch), a second control circuit, a tank circuit, and a load. The embodiment of the present invention does not limit the specific content of the remote device involved in the power supply system. For related illustrations and descriptions of the specific remote device, refer to the system embodiment of the present application, which will not be repeated here.

The power supply 701 is configured to provide a first voltage to a remote device connected to the power supply 701 when the first switch is turned on.

Specifically, the power supply may be in the central office equipment or in the central office but not configured in the central office equipment; under the premise that the first switch and the second switch of the remote device are both turned on (or closed), The central office equipment and the remote equipment form a line that meets the voltage transmission through the transmission cable. The power supply can provide voltage to the remote device according to actual power-on requirements, such as 280V voltage and a safe voltage for the human body (wherein, the safe voltage can be a safe voltage for the human body or a safe voltage in other situations. Voltage, the embodiment of the present invention does not limit this and the specific values involved) and so on. In the above transmission cable, if any switch connected in series with the power supply is disconnected, the power supply will stop supplying power to the devices on the corresponding one or more lines, but the power supply itself will not be affected. In the case that the aforementioned series-connected switches are all turned on, the battery continues or re-powers the remote device. The specific form of the power supply may be various, which is not limited in the embodiment of the present invention.

The sampling circuit 704 is configured to sample the first current of the remote device at the first voltage M times within the target period T, and feed back the M sampling results to the first control circuit 703; wherein the distal end of the target period T comprising the device and the power source is turned a preset on-time T _on and off a preset OFF time T _off, M is an integer greater than 1.

Specifically, when the central office switch is turned on and the remote switch is periodically turned on and off (this situation includes multiple target periods T), the current at the central office sampling point on the preselected cable (ie, the first current) Sampling is performed M times. From the beginning of the aforementioned period, the sampling result is fed back to the control circuit of the central office in time for each detection, and the upper limit of M is determined according to the sampling interval T _scan , for example,

It is the upper limit value of the number of detections in the target period (that is, within the sampling refresh window or within one on-off period of the remote switch); the sampling circuit repeatedly samples and feeds back in this way, and the central office switch is disconnected by the control circuit. Continue sampling. It can be understood that when an abnormal current value is actually detected (that is, when an electric shock may occur and the target line needs to be powered off), the upper limit of the number of detections of M times may not be reached. Wherein, under the condition that the detection effect is not affected, the embodiment of the present invention does not limit the sampling points on the line. A target period can be composed of a preset on-time that is turned on once by the remote device and the power supply and a preset off-time that is turned off once. The remote device and the power supply can be periodically switched on and off between the remote device and the power supply through a remote switch or other remote hardware and software methods. Since the sampling point and the control circuit are both at the central office, the feedback of the sampling results has high timeliness, which is beneficial to improve the rapid power-off protection response when an electric shock occurs; and the cycle time of the remote device is significantly shorter than the time set in the prior art. The value of, greatly accelerates the detection response speed. The sampling circuit may include a combination of an operational amplifier and a resistor, or a current sensor or the like to achieve the purpose of sampling, which is not limited in the embodiment of the present invention.

Optionally, after the first switch is turned off, the sampling circuit may stop sampling the current on the cable. It can be understood that when the first switch is off and when the first switch is in the off state, in the power supply system including transmission cables, central office equipment, and remote equipment, the transmission current is basically zero, and Does not have the value of sampling. When the first switch is opened and closed again, the sampling circuit can intelligently determine the situation and resume sampling. The embodiment of the present invention does not limit the specific implementation of how the sampling circuit intelligently judges the situation.

Optionally, the target period T, on time T _on , off time T _off , and sampling interval T _scan can all be adjusted according to actual applications. The size of the aforementioned target period T determines the protection response speed, which should be less than 10ms as much as possible. (which is

) And the rear-stage tank circuit (i.e., the mentioned tank circuit) related to the T _off time to ensure that the tank circuit to ensure that the power stage load; meeting energy recovery period T _on, i.e., the storage capacitor discharge can.

The first control circuit 703 is configured to control whether the first switch is turned off according to the M sampling results; wherein, when the first switch is turned off, the remote device is connected to the power supply disconnect.

Specifically, the first control circuit successively receives M sampling results fed back by the sampling circuit, and immediately turns off the first switch on the corresponding line after reaching the preset condition for turning off the first switch. For example, by comparing the received sampling current with a preset reference current (or threshold current), it can be judged at the same time whether the detected sampling current is greater than the predetermined threshold current I _th , if it is greater than the predetermined threshold current I _th (for example, 100 mA), Then the count is increased by 1, when the counted number of times is greater than N(

Considering the detection error, etc., if N=54) times are selected, it is judged that the human body has an electric shock, and then Q1 is controlled to be turned off. Illustratively describe the electric shock protection process and working principle based on the first control circuit. The power supply of the central office first outputs a safe voltage, controls the switch Q1 (i.e., the first switch) and switch Q2 (i.e., the second switch) to conduct, and transfers energy to the energy storage The circuit is charged; the turn-off switch Q2 is turned on and off according to the on time in the target period T. For example, the period T can be 3ms, the on time can be 2.5ms, and the off time can be 0.5ms. At the same time, the output voltage of the power supply at the central office is switched to DC high voltage; the central office sampling circuit samples the current according to the sampling interval. For example, the sampling interval Tscan can be 50us, and the sampling refresh window can be equal to the target period T of the aforementioned turn-off switch Q2, then every Detect 60 in cycles T (ie

) Secondary current. Use the first control circuit to determine whether the detected current is greater than the predetermined threshold current Ith. If it is greater than the predetermined threshold Ith (such as 100mA), the count is increased by 1. When the counted number of times is greater than N times, it can be judged as a human body electric shock. In turn, the switch Q1 is turned off. Specifically, please refer to FIG. 8, which is a working flowchart of a first control circuit according to an embodiment of the present invention. Refer to FIG. 9 for the hardware structure of the first control circuit. FIG. 9 is a schematic diagram of the hardware structure of a first control circuit provided by an embodiment of the present invention. As shown in FIG. 9, the first control circuit mainly includes a digital control chip and Auxiliary devices (such as drivers) and related circuits. The digital control chip includes comparators, counters, and GPIO input/output ports (default output, that is, in the initial state or preset state, it is output 1, and when the count reaches 0, it outputs 0 ); Specifically, in conjunction with the flowchart shown in FIG. 8 and the chip hardware structure shown in FIG. 9, the working conditions of the first control circuit are exemplarily described as follows:

As shown in Figure 8, the circuit state is initialized, and the GPIO of the digital control chip outputs a high level (corresponding to GPIO output 1 in the figure, where 1 means high level); the current flowing through the sampling resistor is sampled and then operated Amplify and input to the digital control chip. The comparator in the digital control chip compares the current obtained with the reference current, and judges whether it is greater than the reference current, if not (corresponding to the "No" in the figure, the "No" mentioned below and other similar expressions, the basic meaning is The same here, no further explanation), continue to judge the next sampling current; if it is greater than the reference current (corresponding to the "Yes" in the figure, the following mentions "is greater than", "is reached" and other similar expressions, basically The meaning is the same as here, no further explanation), then control the counter to increase the count value by 1 (here "1" is the preset value); within the sampling period, determine whether the count value is greater than N; if not, continue to The next time the current is sampled for judgment and other cyclic operations, until it is greater than N, the GPIO outputs 0, and the control driver turns off the first switch. For example, when the number of times recorded is greater than N(

Consider the detection error and other factors. For example, if a reasonable value of N can be 54) times, it is judged that there is a human body shock on the line, and the GPIO is controlled to output low level (optionally, the default GPIO output is 1, and when the count reaches, it will output 0), so that the driver drives the first switch to turn off. Among them, while initializing the GPIO output high level, start the timer timing, after the timer completes a sampling refresh window time (value equal to the remote switch switching period T, or called the target period T) timing (corresponding The timer value reaches the predetermined value), clear the timing data and restart the timing of the next sampling time. If not, continue timing. It is understandable that the timer may not be a hardware module inside the chip, but a timer function implemented by a program stored in the chip based on an internal clock.

It can be understood that the first control circuit of the central office judges the on-off signal of the output central office switch by comparing the sampled current with the reference current, which may include a comparator, analog-to-digital conversion, master control, drive, etc. The embodiment of the present invention compares the first The specific structure inside the control circuit is not limited.

Optionally, the first control circuit can be understood as an independent control circuit module, and can also be understood as a general term for all circuits and modules in the power supply system and related control circuits. For example, the sampling circuit may include a current sensor and a built-in control module. The built-in control module can identify when the first switch is open and when it is closed, and intelligently controls whether to start sampling according to the closed and open conditions of the first switch. The embodiment of the present invention does not limit the specific content of the first control circuit.

Optionally, after the first control circuit of the central office controls the first switch of the central office to open, the switch can be closed again by the first control circuit when certain preset conditions are met, or after certain preset conditions are met, The corresponding maintenance personnel send a reminder message, so that the maintenance personnel can manually close the first switch when they know that the switch can be closed again and arrive at the location of the central office equipment in time.

Optionally, when a human body electric shock situation occurs, the human body electric shock situation is confirmed according to the threshold current I _th . Among them, I _th is a determination threshold value set according to the current of the human body electric shock, and the threshold current is less than or equal to the human body electric current. It is understandable that if there is no electric shock in the human body, the line current is reflected in the presence or absence of current. When there is no electric shock, the current on the cable is 0, and when the human body is electrocuted (that is, the electric shock that is harmful to the human body), the current is the least. It is 90mA, so the threshold current should be less than or equal to 90mA. The purpose is to leave a certain margin to avoid electric shock failure due to current detection error. Under this premise, the embodiment of the present invention does not specifically limit the value of the specific threshold current.

According to the IEC60479 standard (including the effects of electric current on the human body and livestock), the relationship between the electric shock current of the human body and the response time is shown in Fig. 10. Fig. 10 is a schematic diagram of the degree of electric current on the human body provided by an embodiment of the present invention, as shown in Fig. 10 As shown, the abscissa represents the human body state that increases with the current I (specifically, each current value interval corresponds to a certain human body state), and the ordinate represents the electric shock time t. It can be seen from the figure that it falls between DC-1 and The DC-2 interval has no effect on the human body. It is understandable that the other less relevant content shown in Figure 10 will not be repeated here, and the specific figures are combined with the IEC60479 standard. According to the reference table diagram of human body impedance of 95% of the population under different DC voltages, please refer to FIG. 11. FIG. 11 is a reference table diagram of human body impedance provided by an embodiment of the present invention. As shown in FIG. 11, under different voltage values, (Unit: V) Corresponding to different human body resistance values (unit: ohm, ie Ω); in the case of high-voltage DC power supply (about 200-380V), the human body impedance is about 1870-2200, and the electric shock current is between 90-200mA , And the electric shock protection time is required to be between 50ms and 10ms. Therefore, the value of Ith should be less than 90 mA. In the embodiment of the present invention, Ith may be 50 Ma; the embodiment of the present invention does not limit the value of Ith.

Optionally, when an electric shock occurs in animals other than humans and livestock, and the aforementioned standards cannot be followed, the corresponding actual standards are adopted to adjust the methods involved in the preset protection scheme and the specific parameters of the equipment (such as threshold current), Effectively judge the electric shock situation.

Optionally, when a circuit short circuit occurs, the solution can also be further adjusted to meet actual usage requirements, which will not be repeated here. On the premise of not contradicting each embodiment in the present application, the embodiment of the present invention does not specifically limit under what circumstances the protection is performed.

Please refer to Figure 12, which is a schematic structural diagram of another central office device provided by an embodiment of the present invention; the ellipse on the left side of the first switch identification position in the figure indicates the position of a current sampling point. The implementation of the present invention The example does not limit the location of the aforementioned sampling point; it is understandable that when the central office equipment is not connected to the power supply system or is not powered on, the sampling current does not start sampling the cable current. The central office equipment can be applied to the aforementioned power supply system (including the above-mentioned system). Please refer to FIG. 13. Figure 13 is a schematic structural diagram of another central office equipment applied to a power supply system according to an embodiment of the present invention, and is suitable for the above-mentioned figure. 3- Several application scenarios shown in Figure 5. The central office device 12 may include a power supply 1201, a first switch 1202 connected in series with the power supply 1201, a first control circuit 1203 coupled with the first switch 1202, and a first control circuit 1203 coupled with the first control circuit 1203. Sampling circuit 1204; the central office device 12 may also include a discharge circuit 1205 and a diode 1206. The remote device as shown in FIG. 14 may include a second switch, a second control circuit, a tank circuit, and a load. The embodiment of the present invention does not limit the specific content of the remote device involved in the power supply system. For related illustrations and descriptions of the specific remote device, refer to the system embodiment of the present application, which will not be repeated here.

The power supply 1201 is configured to provide a first voltage to the remote device connected to the power supply when the first switch is turned on; specifically, please refer to the central office device corresponding to FIG. 7-8 The relevant description of the power supply will not be repeated here.

The sampling circuit 1204 is configured to sample the first current of the remote device under the first voltage M times within the target period T, and feed back the M sampling results to the first control circuit ; Wherein, the target period T includes a preset conduction time T _{on when} the remote device is connected to the power supply once and a preset disconnection time T _off when disconnected once, M is an integer greater than 1;

Specifically, please refer to the related description of the sampling circuit in the central office equipment corresponding to FIG. 7 to FIG. 8, which will not be repeated here.

The first control circuit 1203 is configured to control whether the first switch is turned off according to the M sampling results; wherein, when the first switch is turned off, the remote device is connected to the power supply disconnect.

Specifically, please refer to the related description of the first control circuit in the central office equipment corresponding to Figs. 7-8, which will not be repeated here.

In a possible implementation manner, the first control circuit 1203 is specifically configured to: within the target period T, sequentially receive the M sampling results fed back by the sampling circuit; and determine whether each sampling result is If the preset threshold current is exceeded, if the preset threshold current is exceeded for N times, the first switch is controlled to turn off; where 1<N≦M, and N is an integer.

Specifically, the first control circuit successively receives M sampling results fed back by the sampling circuit, and immediately turns off the first switch on the corresponding line after reaching the preset condition for turning off the first switch. For example, by comparing the received sampling current with a preset reference current (or threshold current), it can be judged at the same time whether the detected sampling current is greater than the predetermined threshold current I _th , if it is greater than the predetermined threshold current I _th , the count is increased by 1. , When the number of times recorded is greater than N

Then, it can be judged that the human body is electrocuted, and the switch Q1 is controlled to be turned off. For detailed related explanations, please refer to the related descriptions of the first control circuit in the central office equipment corresponding to FIGS. 7-8, which will not be repeated here. In the embodiment of the present invention, the current on the line is sequentially sampled M times by the sampling circuit, and the value of M may have a preset upper limit number of times. The specific value is related to the period and the sampling period, which is not limited in the embodiment of the present invention. When the accumulated N times exceeds the preset threshold current, the first control circuit at the central office opens the first switch of the central office. Among them, the first control circuit may include a digital control chip and related auxiliary circuits. The first switch may be controlled by the high and low levels output by the digital control chip GPIO. The specific first switch may include a transistor or a relay; implementation of the present invention The example does not limit the specific circuit form of the switch in the circuit.

In a possible implementation manner, the remote device is connected to or disconnected from the power supply through a second switch; the power supply 1201 is also used to: after the first switch is turned off, and the When the first switch is turned on again and the second switch is turned on, a second voltage is provided to the remote device; when the second switch is turned off, the second voltage is switched to the first A voltage, the second voltage is lower than the first voltage.

Specifically, in a two-wire electric shock protection scheme for the central office to transmit DC power to the remote end of the embodiment of the present invention, the power supply is powered on with a safe voltage first to protect the switches Q1 and Q2 in the power supply system from being turned on, and at the same time to the energy storage The circuit is charged, and then the remote switch Q2 is switched according to the cycle T, and the output voltage of the central office is switched to DC high voltage. Among them, the moment when switching to the first voltage (that is, the high voltage used for transmission) starts, has nothing to do with the switching cycle, and is a fixed delay of power-on; for example, the power-on is a safe voltage power-on, and this period of time lasts for a certain period of time ( Generally, the unit of the duration is ms); the selection of the duration value should satisfy that at the end of the duration, the energy storage circuit is expected to be fully charged; in the control of the power supply system, the power-on sequence control is added, and the power-on sequence is added first when the low-voltage power-on Charge the energy storage circuit to avoid the instantaneous power-on surge current from breaking down the remote switch and improve the reliability of the remote switch. In the embodiment of the present invention, power is supplied to the power supply system through the central office power supply (or the corresponding one or more remote devices) are first powered on based on a safe voltage; in the power supply system, switch Q1 (ie, the first switch), switch Q2 ( That is, when the second switch is turned on, the remote switch Q2 is switched on and off according to the period T, and at the same time, the central office power supply switches the output voltage (that is, the aforementioned safe voltage) to a DC high voltage. In the control of the system, the power-on sequence control process is added, which can charge the remote energy storage circuit first when the low voltage is powered on, avoiding the instantaneous power-on surge current from breaking down the remote switch and improving the remote switch’s performance. Reliability, thereby enhancing the overall reliability of the protection scheme.

It is understandable that when the power supply system is safely powered on for the first time, the status of the switch changes from open to closed, forming a closed transmission loop. The power supply starts to provide a safe voltage and charges the energy storage circuit at the same time. After that, the remote switch Q2 is switched on and off according to the cycle T, and at the same time the output voltage of the central office (that is, the safe voltage) is switched to DC high voltage. The difference with the content of the foregoing invention embodiment lies in the situation before power-on, and there is no substantial difference in other parts.

In a possible implementation manner, the central office device 12 further includes a discharge circuit 1205, and the discharge circuit 1205 includes a third switch and a discharge resistor; the power supply 1201 is connected to the remote device through a transmission cable; The first control circuit 1203 is further configured to: when the first switch is off, control the third switch to be turned on, so that the discharge resistor is combined to between the positive and negative ends of the transmission cable The discharge resistor is connected in parallel with the positive and negative ends of the transmission cable; the discharge circuit is used to discharge the voltage on the transmission cable through the discharge resistor. Specifically, the discharging circuit of the central office may close the combining switch under the command control of the first control circuit, so that the discharging resistor is combined to the target output bus (that is, the transmission cable that is de-energized). Among them, the discharge circuit of the central office is connected in parallel between the positive and negative buses after the central office switch, that is, the parallel position of the discharge circuit is between the central office switch and the remote device. In the embodiment of the present invention, by adding a discharging circuit and controlling the third switch (or combined switch) in the discharging circuit through the first control circuit, rapid protection can be realized in a short time (such as 10ms) .

Optionally, in the embodiment of the present invention, a discharge circuit may be provided on each transmission cable according to actual requirements, that is, the discharge circuit (including the switch and the discharge resistor) on each cable corresponds to the respective cable. In the embodiment of the present invention, each discharge circuit is connected in parallel to the positive and negative ends of the respective bus.

In a possible implementation manner, the sampling circuit 1204 includes a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the power supply 1201, and the operational amplifier is connected with the sampling resistor; the sampling circuit 1204 specifically Used to: in each sampling process of the M samplings, amplify the first current flowing through the sampling resistor through the operational amplifier; according to the sampling interval T _scan , sequentially within the target period T Obtain M second currents, where the second current includes the amplified first current; and sequentially feed back the M second currents to the first control circuit. Specifically, the connection relationship between the sampling circuit and the circuit, as well as the connection relationship with the first control, please refer to Figure 10. The inverting input terminal and the non-inverting input terminal of the op amp are connected in parallel to both ends of the sampling resistor, and the output terminal of the op amp can be It is connected with the digital control chip of the first control circuit, for example, the output terminal is connected with the I/O port of the chip. The operational amplifier calculates the current of the input operational amplifier to obtain a converted current (that is, the second current) of the input current, and output the second current. For example, the first current collected is I, and the current value output by the amplifier can be calculated as a value obtained by a function or formula about I. Among them, the current is sampled by the voltage of the sampling resistor (that is, I multiplied by R). The embodiment of the present invention does not limit the specific sampling circuit. Because there are many kinds of sampling circuits, for example, Hall sensors can also sample current; in terms of purpose, the sampling circuit can sample the current on the cable and feed it back to the control circuit. The embodiment of the present invention collects and amplifies the current flowing through the sampling resistor on the line through the sampling circuit including the combination of the sampling resistor and the operational amplifier, so as to facilitate subsequent comparison with the reference current. The sampling circuit may also include a current sensor to sample the line circuit. The embodiment of the present invention does not limit the specific sampling circuit structure and the location of the current sampling point on the transmission cable.

Optionally, when the sampling circuit includes a current sensor, current sampling is performed by the current sensor. In terms of implementation effects, there is no essential difference from the foregoing embodiment. The embodiment of the present invention does not limit the specific implementation details of the sampling circuit.

In a possible implementation manner, the sampling interval T _{scan is} less than the preset off time T _off . For example, the requirement of Tscan is much smaller than T _off , which can ensure that not only can the current be sampled at least once, but also multiple currents during the switch off time; in order to avoid misjudgment, it is also necessary to increase the number of samples in the T _off period as much as possible . In the embodiment of the present invention, by setting the value of the sampling interval less than the off time, it is ensured that the line current is collected at least once during the switch off time; in order to avoid misjudgment, the sampling interval can be adjusted reasonably according to the actual situation to increase the off time. The number of samples in the time period T _off .

In a possible implementation manner, the central office device 12 further includes a diode 1206, which is connected in series with the power supply 1201; the diode 1206 is used for when the first switch is off, The current oscillation generated during the sudden change of the first current is suppressed to zero. Specifically, the connection method of the diode can be referred to the foregoing architecture and schematic diagrams of the central office equipment, as shown in FIG. 12, FIG. 13 and FIG. 14, which will not be repeated here. For example, by connecting a diode in series with the power supply on the bus, the anode of the diode is connected to the positive output of the power supply, and the negative current is suppressed during the suppression process, and the current value due to the parasitic inductance and capacitance is reduced, so that it gradually becomes smaller and eventually becomes 0 . The current quickly reaches zero when the switch is turned off, which improves the accuracy of current detection and reduces the possibility of misjudgment. The embodiment of the present invention does not limit the specific serial position of the diode at the central office. Optionally, the diode at the central office can be multiplexed with the diode in the power supply oring circuit, or can be additionally added as required. In the embodiment of the present invention, a diode is connected in series on the transmission cable, and the unidirectional conductivity of the diode is used to realize that the current quickly reaches zero when the central office switch (that is, the first switch) is turned off, which improves the current detection accuracy and reduces misjudgment. Possible.

Optionally, as shown in FIG. 12, it is a series connection mode of diodes in the central office equipment. The embodiment of the present invention includes the aforementioned series connection mode, but is not limited to the series connection mode. Based on the unidirectional conductivity of the diode, other similar connection methods that can suppress the current oscillation function are specifically designed, so as long as the anode of the diode is consistent with the current forward flow direction of the power supply output, for example, the diode of the central office is connected in series with the power output positive terminal ( (Or anode), specifically, the anode of the diode is connected to the positive output terminal of the power supply; or, alternatively, the description of another connection method: the diode of the central office is connected in series with the negative output (or cathode) of the power supply, specifically the cathode of the diode It is connected to the negative output terminal of the power supply, and in essence, the anode of the diode is connected to the positive terminal of the power supply.

Then the control central office switch (ie, the first switch) is turned off. Through the on-off control of the remote switch, the electric shock current is easy to detect when the switch is off, and is not affected by the load status, which greatly reduces the current detection cost and improves the detection accuracy; multiple detections during the switching cycle, especially It detects the current during the disconnection period of the remote switch to reduce the detection error. Moreover, there is no need for communication between the central office and the remote, and they are completely independent of each other, which reduces the circuit cost and misjudgment rate, and at the same time improves the flexibility of networking. Different from the prior art, it is necessary to synchronously compare the current information of the central office and the remote current information transmitted to the central office as much as possible, and control the switch according to the current difference between the central office and the remote end, which is not required in the embodiment of the present invention. The central office communicates with the remote end, and requires low current detection accuracy. Different from the prior art, which only judges the output current when the switch is turned off in the remote switching period, the embodiment of the present invention performs multiple current detections in the remote switching period, and turns off immediately after the accumulated value reaches the threshold. The central office switch improves the accuracy of detecting electric shock. Furthermore, since the remote switch period is significantly shorter than the remote switch period in the prior art, the detection response speed is greatly accelerated, thereby enabling rapid protection. Optionally, a discharge circuit is added to speed up the voltage discharge on the cable; the power-on sequence control method is adopted to avoid the breakdown of the switch.

Further, the remote device is connected to or disconnected from the power supply through a second switch; the power supply is also used for turning off the first switch and turning on the first switch again and the second switch When the switch is turned on, a second voltage is provided to the remote device; when the second switch is turned off, the second voltage is switched to the first voltage. Supply power to the power supply system through the central office power supply, first power on based on a safe voltage; when the first switch and the second switch in the power supply system are turned on, the remote switch switches on cycle T, and at the same time, the central office power supply will output voltage (That is, the aforementioned safe voltage) is switched to DC high voltage. In the control of the system, the power-on sequence control process is added, which can charge the remote energy storage circuit first when the low voltage is powered on, avoiding the instantaneous power-on surge current from breaking down the remote switch and improving the remote switch’s performance. Reliability, thereby enhancing the overall reliability of the protection scheme (or protection circuit).

Further, the central office equipment further includes a discharge circuit (the discharge circuit includes a third switch and a discharge resistor); the first control circuit is also used to control the first switch when the first switch is off The three switches are turned on, so that the discharge resistance is combined between the positive and negative ends of the transmission cable; the discharge circuit is used to discharge the voltage on the transmission cable through the discharge resistance. By adding a discharging circuit, and controlling the third switch (or combined switch) in the discharging circuit through the first control circuit, rapid protection can be realized in a relatively short time (such as 10 ms).

Further, the central office equipment further includes a diode, which is connected in series with the power supply; and the diode is used to reduce the voltage generated during the sudden change of the first current when the first switch is off. The current oscillation is suppressed to zero. By connecting a diode in series on the transmission cable, the unidirectional conductivity of the diode is used to realize that the current quickly reaches zero when the central switch (ie, the first switch) is turned off, which improves the current detection accuracy and reduces the possibility of misjudgment.

The relevant central office equipment of the embodiment of the present invention is described in detail above, and the power supply system of the embodiment of the present invention corresponding to the relevant central office equipment is provided below.

Please refer to FIG. 14, which is a schematic structural diagram of a power supply system according to an embodiment of the present invention. The power supply system includes a central office device 140 and at least one remote device 141 connected to the central office device 140. The power supply system in the implementation of the present invention may be a high-voltage direct current remote power supply electric shock protection system. The embodiment of the present invention does not limit the details related to the specific internal structure of the system. As shown in FIG. 14, it is an exemplary connection relationship of the power supply system. The power supply system includes a central office 140. The central office 140 may include a diode 1401, a sampling circuit 1402, a first control circuit 1403, and a discharge A circuit 1404, a first switch 1405, and a power supply 1406; a remote end 141, which may include a second control circuit 1411, a protection circuit 1412, a second switch 1413, a storage circuit 1414, and a load 1415. As shown in the figure, the central office diode is connected in series between the positive terminal output of the power supply and the output bus, the central office switch (i.e., the first switch, or Q1) is connected in series between the negative terminal of the power supply and the output bus, and the central office discharge circuit is connected in parallel in the office. Between the positive and negative bus bars after the end switch, the sampling circuit samples the output current from the negative end bus bar of the power supply (ie, the current I shown in the figure) and feeds it back to the first control circuit. The remote switch (that is, the second switch, or Q2) is connected in series on the negative bus bar behind the remote protection circuit, and there is a storage circuit behind the switch that is connected across the positive and negative bus bars. It is understandable that the second switch is connected in series with the load of the remote device, and when all the switches connected in series with the power supply are closed, the central office power supply charges the energy storage circuit of the remote device.

Wherein, the central office equipment 140 includes a power supply 1406, at least one first switch 1405 connected in series with the power supply 1406, a first control circuit 1403 coupled with the at least one first switch 1405, and the first control circuit At least one sampling circuit 1402 coupled to 1403;

The remote device 141 includes a second switch 1413 connected in series with the power supply 1406 and a second control circuit 1411 coupled with the second switch 1413; wherein, the second switch 1413 is on the remote device side of the remote.

It can be understood that the remote device in the embodiment of the present invention may include a communication station (or a wireless station, or a communication base station, etc.). The embodiment of the present invention does not limit the specific physical form of the remote device.

The power supply 1406 is configured to provide a first voltage to a remote device connected to the power supply when the first switch is turned on;

The sampling circuit 1402 is configured to sample the first current of the remote device under the first voltage M times within the target period T, and feed it back to the first control circuit; wherein, the The target period T includes a preset turn-on time T _{on when} the remote device is turned on once with the power supply through the second switch and a preset turn-off time T _off when the remote device is turned off once, and M is an integer greater than 1;

The first control circuit 1403 is configured to control whether the first switch is turned off according to the results of M sampling; wherein, when the first switch is turned off, the remote device is disconnected from the power supply ；

The second control circuit 1411 is configured to periodically control the second switch to be turned on during the preset on time T _on and turned off during the preset off time T _off ; wherein, in the second switch In the case of disconnection, the remote device is disconnected from the power supply.

In a possible implementation, the first control circuit 1403 is specifically configured to: within the target period T, sequentially receive the M sampling results fed back by the sampling circuit; and determine whether each sampling result is If the preset threshold current is exceeded, if the preset threshold current is exceeded for N times, the first switch is controlled to turn off; where 1<N≦M, and N is an integer.

In a possible implementation, the remote device 141 is connected to or disconnected from the power supply through a second switch; the power supply 1406 is also used to: after the first switch is turned off, When the first switch is turned on again and the second switch is turned on, a second voltage is provided to the remote device; when the second switch is turned off, the second voltage is switched to the The first voltage, the second voltage is lower than the first voltage.

In a possible implementation, the central office device 140 further includes a discharge circuit 1404, and the discharge circuit 1404 includes a third switch and a discharge resistor; the power supply is connected to the remote device through a transmission cable; the The first control circuit 1403 is further configured to: when the first switch is off, control the third switch to turn on, so that the discharge resistor is combined to between the positive and negative ends of the transmission cable, The discharge resistor is connected in parallel with the positive and negative ends of the transmission cable; the discharge circuit is used to discharge the voltage on the transmission cable through the discharge resistor.

In a possible implementation, the sampling circuit 1402 includes a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the power supply, and the operational amplifier is connected with the sampling resistor; the sampling circuit 1402 specifically uses Yu: During each sampling process of the M samplings, the first current flowing through the sampling resistor is amplified by the operational amplifier; according to the sampling interval T _scan , the first current is sequentially obtained within the target period T M times the second current, the second current includes the amplified first current; the M times the second current is fed back to the first control circuit in turn.

In a possible implementation manner, the central office device 140 further includes a diode 1401, and the diode 1401 is connected in series with the power supply 1406;

The diode 1401 is used to suppress the current oscillation generated during the sudden change of the first current to zero when the first switch is off.

In a possible implementation manner, the power supply system includes K remote devices; the central office device includes K first switches and K sampling circuits; wherein, K remote devices The terminal device, the K first switches, and the K sampling circuits have a one-to-one correspondence, and K is an integer greater than 1. Please refer to Figure 15, which is a schematic structural diagram of another power supply system provided by an embodiment of the present invention; as shown in Figure 15, there are two loads in the power supply system structure (as shown in the figure, the first load and the The second load, the embodiment of the present invention does not limit the specific form of the load), that is, K=2; the power supply system corresponds to the application scenario shown in Figure 4, and multiple remote devices can be macro stations (or called pull Remote site), that is, the power of the remote device is relatively large, so a central office device is connected to multiple remote devices through multiple transmission cables to transmit voltage. The system can be an electric shock protection system that powers multiple remote devices with high-voltage direct current. It includes: a diode at the central office, a sampling circuit, a first control circuit, a discharge circuit and a first switch (Q1, Q3..., in the figure) Shown is an exemplary description, and does not specifically limit the number of switches), and the remote second control circuit (such as the second control circuit 1, the second control circuit 2) and the second switch (Q2, Q4...). Among them, the diode is connected in series between the positive output of the power supply and the output bus, the first switch (Q1, Q3...) of the central office is connected in series between the negative of the power supply and the output bus, the discharge circuit is connected in parallel between the positive and negative bus, and the sampling circuit samples The output current of the power supply is given to the control circuit. The remote second switch (Q2, Q4...) is connected in series on the negative bus between the protection circuit of the original RRU or AAU and the energy storage circuit, and the energy storage circuit behind the switch is connected across the positive and negative bus.

Among them, the central office network element is installed on the DCDU unit, and the central office diode can reuse the power oring circuit (that is, the design of the redundant circuit, the specific circuit content is not closely related to the embodiment of the present invention, and will not be described in detail in this application) The diodes can also be added to the DCDU unit. If an electric shock is detected on the corresponding line of each remote device in the multiple remote devices, the corresponding central office switch Q1 or Q3 is disconnected, and the discharge circuit is combined to the corresponding positive and negative ends of the bus. Specifically, the system is first powered on with a safe voltage, all the switches (Q1, Q2, Q3, Q4...) in the protection system are turned on, the energy storage circuit is charged, and then the remote switches (Q2, Q4...) switch according to the cycle T, At the same time, the output voltage of the central office is switched to DC high voltage. The switching period of the remote switch (Q2, Q4...) is T=3ms, the on time _Ton can be 2.5ms, the off time T _off can be 0.5ms, and the sampling interval T _scan of the central office sampling circuit is 50us. The refresh window is equal to the switching cycle T of the remote switch (Q2, Q4...), so the current is detected 60 times in each cycle, and it is judged whether the current detected by each branch is greater than the predetermined threshold current Ith, if it is greater than the predetermined threshold current Ith( For example, 100mA), the count is increased by 1. When the counted number of times is greater than N times, it is judged as a human body electric shock, and then the corresponding central office switch Q1 or Q3 is controlled to disconnect, and the discharge circuit is connected at the same time to realize rapid reduction of human body electric shock current and protect the human body. Getting hurt.

Other detailed explanations will not be repeated here. Please refer to the description of the application scenario corresponding to FIG. 4 and the relevant description of each related embodiment of the present application; it is understandable that the content shown in FIG. 15 is a part of the solution shown in FIG. For this kind of expansion, the specific label, the newly added part and the related description can be referred to Fig. 14, which will not be repeated here.

In a possible implementation manner, the power supply 1406 is specifically configured to provide the first voltage to the load of the remote device connected to the power supply when the first switch is turned on;

The remote device 141 further includes an energy storage circuit 1414 connected in parallel with the load 1415;

The tank circuit 1414 is configured to maintain the load operation within the preset off time T _off .

Optionally, the energy storage circuit of the remote device is an energy storage capacitor connected between the positive and negative bus bars, or it can be an electrolytic capacitor built in the RRU or AAU, or it can be added additionally.

In a possible implementation manner, the remote device 141 further includes a protection circuit 1412, the protection circuit 1412 is connected in series between the power supply 1406 and the second switch 1413, and the protection circuit 1412 is used to protect The remote device. For example, when an outdoor switch encounters a thunderstorm, the switch is protected by lightning protection through a protective circuit. It is understandable that the protection circuit can be a part of the original built-in remote device, or it can be additionally added. In general, the remote device will have its own protective circuit.

In a possible implementation manner, the remote device 141 includes multiple loads 1415. For example, the remote device is connected to multiple low-power loads. Please refer to Figure 16, which is a schematic structural diagram of another power supply system provided by an embodiment of the present invention; the power supply system can be a high-voltage direct current remotely extended to multiple RRUs/AAUs (ie multiple loads) at a single remote end. The electric shock protection system includes: a diode at the central office, a sampling circuit, a first control circuit, a discharge circuit and a first switch, and a remote second control circuit, a protection circuit and a second switch. Among them, the diode is connected in series between the positive output of the power supply and the output bus, the first switch of the central office is connected in series between the negative of the power supply and the output bus, the discharge circuit is connected in parallel between the positive and negative buses, and the sampling circuit samples the output current of the power supply to the control circuit. . The remote second switch is stringed on the negative bus bar behind the protection circuit of the DCDU or the junction box, and the energy storage circuit is connected across the positive and negative bus bars behind the switch. Among them, the central office network element is installed on the DCDU unit, and the central office diode can reuse the diode in the power oring circuit, or it can be added to the DCDU unit. In this system, the safety voltage is first powered on, all the switches in the protection system are turned on, and the energy storage circuit is charged, and then the remote switch is switched according to the cycle T, and the output voltage of the central office is switched to DC high voltage.

As shown in Figure 16, the power supply system structure corresponds to the application scenario shown in Figure 5, a remote device contains multiple low-power loads (such as RRU1 and AAU2, etc.), that is, the power of the remote device is small, so The voltage is transferred as shown in the figure. The application scenario may also include the application scenario of converging light pole stations, and may include smart street lights installed with micro base stations. The embodiment of the present invention does not limit the specific actual form and corresponding application scenario of the low-power load. The detailed description will not be repeated here, please refer to the description of the application scenario corresponding to Figure 5; it is understandable that the content shown in Figure 16 is an extension of the solution shown in Figure 14, with specific labels and new parts and For related description, please refer to FIG. 14, which will not be repeated here.

It should be noted that the power supply system described in the embodiment of the present invention can refer to the related description of the corresponding central office equipment in the central office equipment invention embodiment described in Figure 7 or Figure 12, which will not be repeated here.

The foregoing describes in detail the relevant central office equipment and the corresponding power supply system of the embodiment of the present invention. The following provides the relevant method of the embodiment of the present invention.

Please refer to FIG. 17, which is a schematic flowchart of an electric shock protection method provided by an embodiment of the present invention, which is applied to a central office device, and the central office device includes a power supply, a first switch connected in series with the power supply, and The first control circuit coupled to the first switch, and the sampling circuit coupled to the first control circuit; the method may include step S1701-step S1703. For specific descriptions involved in the method, please refer to the other embodiments in this application. I will not repeat them here.

Step S1701: When the first switch is turned on, provide a first voltage to the remote device connected to the power source through the power source.

Step S1702: In the target period T, the first current of the remote device under the first voltage is sampled M times by the sampling circuit, and the M sampling results are fed back to the first control circuit . Wherein, the target period T includes a preset conduction time T _{on when} the remote device is connected to the power supply once and a preset disconnection time T _off when the remote device is disconnected once, and M is an integer greater than 1.

In a possible implementation manner, the sampling circuit includes a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the power supply, and the operational amplifier is connected with the sampling resistor; in the target period T, passing The sampling circuit samples the first current of the remote device at the first voltage for M times, and feeds back the M sampling results to the first control circuit, including: sampling at the M times In each sampling process, the first current flowing through the sampling resistor is amplified by the operational amplifier; according to the sampling interval T _scan , the sampling circuit obtains the second M times in the target period T sequentially. The second current includes the amplified first current; the second current is fed back to the first control circuit M times through the sampling circuit in turn.

Step S1703: Through the first control circuit, control whether the first switch is turned off according to the M sampling results. Wherein, when the first switch is off, the remote device is disconnected from the power supply.

In a possible implementation manner, the controlling whether the first switch is turned off according to the M sampling results through the first control circuit includes: passing the first switch within the target period T A control circuit sequentially receives the M sampling results fed back by the sampling circuit; determines whether each sampling result exceeds the preset threshold current through the first control circuit, and if the accumulated N times exceed the preset threshold current, control The first switch is off; where 1<N≦M, and N is an integer.

Please refer to FIG. 18, which is a schematic flowchart of another electric shock protection method provided by an embodiment of the present invention, which is applied to a central office device, and the central office device includes a power supply, a first switch connected in series with the power supply, and The first control circuit coupled to the first switch and the sampling circuit coupled to the first control circuit; the method includes steps S1801-step S1808, optional steps include step S1801, step S1802, step S1806, step S1807 and Step S1808: It is understandable that the electric shock protection method described in the embodiment of the present invention can be used in the subsequent situation that the first switch is controlled and turned off, that is, the power supply of the central office is safely powered on under the premise that the first switch is turned off. ; Control the remote second switch to be turned on and off periodically, and detect the current on the cable during the switching period of the second switch; once the preset disconnection condition is reached during the detection process, the first controller circuit The first switch is controlled to be turned off again; for specific description, please refer to the various embodiments in this application, which will not be repeated here.

Step S1801: After the first switch is turned off, and the first switch is turned on again and the second switch is turned on, a second voltage is provided to the remote device through the power supply. Wherein, the remote device is connected to or disconnected from the power supply through the second switch.

Step S1802: When the second switch is turned off, switch the second voltage to the first voltage through the power supply. Wherein, the second voltage is lower than the first voltage, and the remote device is connected to or disconnected from the power supply through the second switch.

Step S1803: When the first switch is turned on, provide the first voltage to the remote device connected to the power source through the power source.

Step S1804: In the target period T, the first current of the remote device under the first voltage is sampled M times by the sampling circuit, and the M sampling results are fed back to the first control circuit . Wherein, the target period T includes a preset conduction time T _{on when} the remote device is connected to the power supply once and a preset disconnection time T _off when the remote device is disconnected once, and M is an integer greater than 1.

Step S1805: Through the first control circuit, control whether the first switch is turned off according to the M sampling results. Wherein, when the first switch is off, the remote device is disconnected from the power supply.

Step S1806: When the first switch is turned off, the first control circuit controls the third switch to turn on, so that the discharge resistor is combined between the positive and negative ends of the transmission cable. Wherein, the central office equipment further includes a discharge circuit, the discharge circuit includes a third switch and a discharge resistor; the power source is connected to the remote device through a transmission cable; the discharge resistor is connected to the positive and negative of the transmission cable Terminals are connected in parallel.

Step S1807: Discharge the voltage on the transmission cable through the discharge resistor. Wherein, the central office equipment further includes a discharge circuit, and the discharge circuit includes a third switch and a discharge resistor; the power supply is connected to the remote equipment through a transmission cable.

Step S1808: When the first switch is turned off, the current oscillation generated during the sudden change of the first current is suppressed to zero by the diode. Wherein, the central office equipment further includes a diode, and the diode is connected in series with the power supply.

It should be noted that, for the electric shock protection method described in the embodiment of the present invention, reference may be made to the related description of the central office equipment in the method embodiment described in FIG. 7 and FIG. 12, which will not be repeated here.

The foregoing describes the method of the embodiment of the present invention in detail, and the relevant apparatus of the embodiment of the present invention is provided below.

Please refer to Figure 19, which is an electric shock protection device provided by an embodiment of the present invention, which is applied to central office equipment. The central office equipment includes a power supply, a first switch connected in series with the power supply, and the first switch A first control circuit coupled to a first control circuit, a sampling circuit coupled to the first control circuit; the device 19 includes: a power supply unit 1901, a sampling unit 1902, a first control unit 1903, a power-on unit 1904, a second control unit 1905, and Vibration suppression unit 1906; optional units may also include a power-on unit 1904, a second control unit 1905, and a vibration suppression unit 1906.

The power supply unit 1901 is configured to provide a first voltage to a remote device connected to the power supply through the power supply when the first switch is turned on;

The sampling unit 1902 is configured to sample the first current of the remote device under the first voltage through the sampling circuit M times within the target period T, and feed back the M sampling results to the first current A control circuit; wherein, the target period T includes a preset on-time T _{on when} the remote device is connected to the power supply once and a preset off-time T _off when the remote device is disconnected once, and M is greater than 1. Integer

The first control unit 1903 is configured to control whether the first switch is off according to the M sampling results through the first control circuit; wherein, when the first switch is off, the remote The end device is disconnected from the power supply.

In a possible implementation manner, the first control unit 1903 is specifically configured to:

In a possible implementation manner, the remote device is connected to or disconnected from the power supply through a second switch; the device further includes a power-on unit 1904 for:

In a possible implementation manner, the central office equipment further includes a discharge circuit, the discharge circuit includes a third switch and a discharge resistor; the power supply is connected to the remote equipment through a transmission cable; the device further includes The second control unit 1905 is used for:

The sampling unit 1902 is specifically configured to:

In a possible implementation manner, the central office equipment further includes a diode, and the diode is connected in series with the power supply; the device further includes an oscillation suppression unit 1906 for:

It should be noted that, for the electric shock protection device described in the embodiment of the present invention, refer to the related description of the central office equipment in the method embodiment described in FIG. 7 and FIG. 12, which will not be repeated here.

The foregoing describes in detail the electric shock protection device related to the embodiment of the present invention, and the control device related to the embodiment of the present invention is provided below.

Please refer to FIG. 20, which is a schematic diagram of a control device provided by an embodiment of the present invention. The control device 20 is connected to the power supply of the central office. The control device 20 may include a first switch 201 connected in series with the power supply. A first control circuit 202 coupled to the first switch 201, and a sampling circuit 203 coupled to the first control circuit 202;

The sampling circuit 203 is configured to sample the first current of the remote device under the first voltage M times within the target period T, and feed back the M sampling results to the first control circuit 202; wherein, the target period T includes a preset on-time T _{on when} the remote device is connected to the power supply once and a preset off-time T _off when the remote device is disconnected once, M is an integer greater than 1;

The first control circuit 202 is configured to control whether the first switch 201 is disconnected according to the M sampling results; wherein, when the first switch is disconnected, the remote device and the The power is disconnected.

It should be noted that the control device described in the embodiment of the present invention is an exemplary description. For specific related description, please refer to the description of the foregoing embodiment (such as the central office device embodiment shown in FIG. 7), which will not be repeated here. .

The embodiment of the present invention also provides a chip system, which may include: the control device described in the foregoing control device embodiment.

An embodiment of the present invention also provides a chip system, which may include: the control device as described in the foregoing control device embodiment, and an auxiliary circuit or discrete device coupled to the control device.

An embodiment of the present invention also provides an electronic device, which may include: the control device as described in the foregoing control device embodiment, and a discrete device coupled to the outside of the control device.

The present application also provides a chip system, which can execute any electric shock protection method involved in the above method embodiment, so that related functions can be realized, for example, receiving or processing the current signal and the current signal involved in the above method embodiment. /Or information. In a possible design, the chip system further includes a memory, and the memory is used to store necessary program instructions and data. The chip system can be composed of chips, or include chips and other discrete devices.

An embodiment of the present invention further provides a computer storage medium, wherein the computer storage medium may store a program, and the program may execute part or all of the steps including any one of the foregoing method embodiments.

The embodiment of the present invention also provides a computer program, the computer program includes instructions, when the computer program is executed by a computer, the computer can execute part or all of the steps of any one of the foregoing method embodiments.

In the above-mentioned embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in an embodiment, reference may be made to related descriptions of other embodiments.

It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations, but those skilled in the art should know that this application is not limited by the described sequence of actions. Because according to this application, some steps may be performed in other order or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the involved actions and modules are not necessarily required by this application.

In the several embodiments provided in this application, it should be understood that the disclosed device may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the above-mentioned units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or integrated. To another system, or some features can be ignored, or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical or other forms.

The units described above as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, the functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of this application essentially or the part that contributes to the existing technology or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , Including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc., specifically a processor in a computer device) execute all or part of the steps of the foregoing methods of the various embodiments of the present application. Among them, the aforementioned storage medium may include: U disk, mobile hard disk, magnetic disk, optical disk, read-only memory (Read-Only Memory, abbreviation: ROM) or Random Access Memory (Random Access Memory, abbreviation: RAM), etc. A medium that can store program codes.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present application, not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, a person of ordinary skill in the art should understand that: The technical solutions recorded in the embodiments are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

A central office equipment, characterized by comprising a power supply, a first switch connected in series with the power supply, a first control circuit coupled with the first switch, and a sampling circuit coupled with the first control circuit;

The power supply is configured to provide a first voltage to a remote device connected to the power supply when the first switch is turned on;

The sampling circuit is configured to sample the first current of the remote device at the first voltage M times within a target period T, and feed back the M sampling results to the first control circuit; Wherein, the target period T includes a preset turn-on time T on when the remote device and the power supply are turned on once and a preset turn-off time T off when the remote device is turned off once, and M is an integer greater than 1;

The first control circuit is configured to control whether the first switch is turned off according to the M sampling results; wherein, when the first switch is turned off, the remote device is disconnected from the power supply open.
The central office equipment according to claim 1, wherein the first control circuit is specifically configured to:

Within the target period T, sequentially receiving the M sampling results fed back by the sampling circuit;

It is determined whether each sampling result exceeds the preset threshold current, and if the preset threshold current exceeds the preset threshold current N times, the first switch is controlled to be turned off; where 1<N≦M, and N is an integer.
The central office device according to claim 1 or 2, wherein the remote device is connected to or disconnected from the power supply through a second switch; the power supply is further used for:

After the first switch is turned off, and the first switch is turned on again and the second switch is turned on, providing a second voltage to the remote device;

When the second switch is turned off, the second voltage is switched to the first voltage, and the second voltage is lower than the first voltage.
The central office equipment according to any one of claims 1-3, wherein the central office equipment further comprises a discharge circuit, and the discharge circuit comprises a third switch and a discharge resistor; The remote device is connected; the first control circuit is also used for:

When the first switch is off, the third switch is controlled to be turned on, so that the discharge resistor is combined between the positive and negative ends of the transmission cable, and the discharge resistor is connected to the transmission cable. The positive and negative terminals are connected in parallel;

The discharge circuit is used to discharge the voltage on the transmission cable through the discharge resistor.
The central office equipment according to any one of claims 1-4, wherein the sampling circuit comprises a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the power supply, and the operational amplifier is connected to the sampling resistor in series. connection;

The sampling circuit is specifically used for:

In each sampling process of the M samplings, amplify the first current flowing through the sampling resistor by the operational amplifier;

According to the sampling interval T scan , the second current is sequentially acquired M times within the target period T, and the second current includes the amplified first current;

The M second currents are fed back to the first control circuit in sequence.
The central office equipment according to claim 5, wherein the sampling interval T scan is less than the preset disconnection time T off .
The central office equipment according to any one of claims 1-6, wherein the central office equipment further comprises a diode, and the diode is connected in series with the power supply;

The diode is used to suppress the current oscillation generated during the sudden change of the first current to zero when the first switch is off.
A power supply system, characterized in that it comprises a central office device, and at least one remote device connected to the central office device, wherein:

The central office equipment includes a power supply, at least one first switch connected in series with the power supply, a first control circuit coupled with the at least one first switch, and at least one sampling circuit coupled with the first control circuit; The remote device includes a second switch connected in series with the power supply, and a second control circuit coupled with the second switch;

The power supply is configured to provide a first voltage to a remote device connected to the power supply when the first switch is turned on;

The sampling circuit is configured to sample the first current of the remote device under the first voltage for M times within a target period T, and feed it back to the first control circuit; wherein, the target The period T includes a preset turn-on time T on when the remote device is turned on once with the power supply through the second switch and a preset turn-off time T off when the remote device is turned off once, and M is an integer greater than 1;

The first control circuit is configured to control whether the first switch is turned off according to the results of M samplings; wherein, when the first switch is turned off, the remote device is disconnected from the power supply;

The second control circuit is configured to periodically control the second switch to be turned on during the preset on time T on and turned off during the preset off time T off ; wherein, the second switch is turned off In the case of on, the remote device is disconnected from the power supply.
The system according to claim 8, wherein the power supply system includes K remote devices; the central office device includes K first switches and K sampling circuits; wherein K The remote devices, the K first switches, and the K sampling circuits have a one-to-one correspondence, and K is an integer greater than 1.
The system according to claim 8 or 9, wherein the power supply is specifically configured to provide the first switch to the load of a remote device connected to the power supply when the first switch is turned on. A voltage;

The remote device further includes an energy storage circuit connected in parallel with the load;

The tank circuit is used to maintain the load operation within the preset off time T off .
The system according to any one of claims 8-10, wherein the remote device further comprises a protection circuit, the protection circuit is connected in series between the power supply and the second switch, and the protection circuit Used to protect the remote device.
An electric shock protection method, characterized in that it is applied to central office equipment, said central office equipment includes a power supply, a first switch connected in series with the power supply, a first control circuit coupled with the first switch, and A sampling circuit coupled to the first control circuit; the method includes:

When the first switch is turned on, provide the first voltage to the remote device connected to the power source through the power source;

In the target period T, the first current of the remote device at the first voltage is sampled M times by the sampling circuit, and the M sampling results are fed back to the first control circuit; wherein, The target period T includes a preset conduction time T on when the remote device is connected to the power supply once and a preset disconnection time T off when the remote device is disconnected once, and M is an integer greater than 1;

Through the first control circuit, control whether the first switch is turned off according to the M sampling results; wherein, when the first switch is turned off, the remote device is disconnected from the power supply .
The method according to claim 12, wherein the controlling whether the first switch is turned off according to the M sampling results through the first control circuit comprises:

In the target period T, sequentially receive the M sampling results fed back by the sampling circuit through the first control circuit;

It is determined by the first control circuit whether each sampling result exceeds the preset threshold current, and if the preset threshold current exceeds the preset threshold current N times, the first switch is controlled to be turned off; where 1<N≤M, N is Integer.
The method according to claim 12 or 13, wherein the remote device is connected to or disconnected from the power supply through a second switch; the method further comprises:

After the first switch is turned off, and the first switch is turned on again and the second switch is turned on, providing a second voltage to the remote device through the power supply;

When the second switch is turned off, the second voltage is switched to the first voltage through the power supply, and the second voltage is lower than the first voltage.
The method according to any one of claims 12-14, wherein the central office equipment further comprises a discharge circuit, the discharge circuit comprises a third switch and a discharge resistor; the power supply is connected to the remote through a transmission cable The end device is connected; the method further includes:

When the first switch is turned off, the third switch is controlled to be turned on by the first control circuit, so that the discharge resistor is combined between the positive and negative ends of the transmission cable, and the discharge The resistance is connected in parallel with the positive and negative ends of the transmission cable;

The voltage on the transmission cable is discharged through the discharge resistor.
The method according to any one of claims 12-15, wherein the sampling circuit comprises a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the power supply, and the operational amplifier is connected with the sampling resistor;

In the target period T, sampling the first current of the remote device under the first voltage by the sampling circuit M times, and feeding back the M sampling results to the first control circuit, include:

In each sampling process of the M samplings, amplify the first current flowing through the sampling resistor by the operational amplifier;

According to the sampling interval T scan , the second current is sequentially acquired M times within the target period T by the sampling circuit, and the second current includes the amplified first current;

The M second current is fed back to the first control circuit in sequence through the sampling circuit.
The method according to claim 16, wherein the sampling interval T scan is less than the preset off time T off .
The method according to any one of claims 12-17, wherein the central office equipment further comprises a diode, and the diode is connected in series with the power supply; and the method further comprises:

When the first switch is off, the current oscillation generated during the sudden change of the first current is suppressed to zero by the diode.
An electric shock protection device, characterized in that it is applied to central office equipment, the central office equipment includes a power supply, a first switch connected in series with the power supply, a first control circuit coupled with the first switch, and A sampling circuit coupled to the first control circuit; the device includes:

A power supply unit, configured to provide a first voltage to a remote device connected to the power supply through the power supply when the first switch is turned on;

The sampling unit is configured to sample the first current of the remote device at the first voltage through the sampling circuit M times within the target period T, and feed back the M sampling results to the first Control circuit; wherein, the target period T includes a preset on-time T on for the remote device and the power supply to be turned on once and a preset off-time T off for once off , and M is an integer greater than 1. ；

The first control unit is configured to control whether the first switch is turned off according to the M sampling results through the first control circuit; wherein, when the first switch is turned off, the remote The device is disconnected from the power source.
The device according to claim 19, wherein the first control unit is specifically configured to:

In the target period T, sequentially receive the M sampling results fed back by the sampling circuit through the first control circuit;

It is determined by the first control circuit whether each sampling result exceeds the preset threshold current, and if the preset threshold current exceeds the preset threshold current N times, the first switch is controlled to be turned off; where 1<N≤M, N is Integer.
The device according to claim 19 or 20, wherein the remote device is connected to or disconnected from the power supply through a second switch; the device further comprises a power-on unit for:

After the first switch is turned off, and the first switch is turned on again and the second switch is turned on, providing a second voltage to the remote device through the power supply;

Before the next target period T, the second voltage is switched to the first voltage by the power supply, and the second voltage is lower than the first voltage.
The device according to any one of claims 19-21, wherein the central office equipment further comprises a discharge circuit, the discharge circuit comprises a third switch and a discharge resistor; the power supply is connected to the remote through a transmission cable The end device is connected; the device also includes a second control unit, configured to:

When the first switch is turned off, the third switch is controlled to be turned on by the first control circuit, so that the discharge resistor is combined between the positive and negative ends of the transmission cable, and the discharge The resistance is connected in parallel with the positive and negative ends of the transmission cable;

The voltage on the transmission cable is discharged through the discharge resistor.
The device according to any one of claims 19-22, wherein the sampling circuit comprises a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the power supply, and the operational amplifier is connected with the sampling resistor;

The sampling unit is specifically used for:

In each sampling process of the M samplings, amplify the first current flowing through the sampling resistor by the operational amplifier;

According to the sampling interval Tscan, the second current is sequentially acquired M times within the target period T by the sampling circuit, and the second current includes the amplified first current;

The M second current is fed back to the first control circuit in sequence through the sampling circuit.
The device according to claim 23, wherein the sampling interval T scan is less than the preset off time T off .
The device according to any one of claims 19-24, wherein the central office equipment further comprises a diode, and the diode is connected in series with the power supply; and the device further comprises an oscillation suppression unit for:

When the first switch is off, the current oscillation generated during the sudden change of the first current is suppressed to zero by the diode.
A control device, characterized in that the control device is connected to the power supply of the central office, and the control device includes a first switch connected in series with the power supply, a first control circuit coupled with the first switch, and A sampling circuit coupled to the first control circuit;

The sampling circuit is configured to sample the first current of the remote device at the first voltage M times within a target period T, and feed back the M sampling results to the first control circuit; Wherein, the target period T includes a preset turn-on time T on when the remote device and the power supply are turned on once and a preset turn-off time T off when the remote device is turned off once, and M is an integer greater than 1;

The first control circuit is configured to control whether the first switch is turned off according to the M sampling results; wherein, when the first switch is turned off, the remote device is disconnected from the power supply open.
A chip system, characterized by comprising: the control device according to claim 26.
A chip system, characterized by comprising: the control device according to claim 26, and an auxiliary circuit coupled to the control device.
An electronic device, characterized by comprising: the control device according to claim 26, and a discrete device coupled to the outside of the control device.
A chip system, characterized in that the chip system is implemented by executing the method according to any one of claims 12-18.
A computer storage medium, characterized in that the computer storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 12-18 is realized.
A computer program, characterized in that the computer program includes instructions, which when the computer program is executed by a computer, cause the computer to execute the method according to any one of claims 12-18.