WO2007104232A1 - Procédé permettant de détecter la connexion d'une alimentation électrique à distance et procédé et système d'alimentation de ligne électrique - Google Patents

Procédé permettant de détecter la connexion d'une alimentation électrique à distance et procédé et système d'alimentation de ligne électrique Download PDF

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Publication number
WO2007104232A1
WO2007104232A1 PCT/CN2007/000663 CN2007000663W WO2007104232A1 WO 2007104232 A1 WO2007104232 A1 WO 2007104232A1 CN 2007000663 W CN2007000663 W CN 2007000663W WO 2007104232 A1 WO2007104232 A1 WO 2007104232A1
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WO
WIPO (PCT)
Prior art keywords
power supply
remote power
circuit
remote
voltage
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Application number
PCT/CN2007/000663
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English (en)
French (fr)
Inventor
Zhen Qin
Yingjie Zhou
Yuanhong Liang
Jiaqian Zhou
Wenbiao Zhong
Original Assignee
Huawei Technologies Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Huawei Technologies Co., Ltd. filed Critical Huawei Technologies Co., Ltd.
Priority to EP07711034A priority Critical patent/EP1995844B1/en
Priority to DE602007010251T priority patent/DE602007010251D1/de
Priority to AT07711034T priority patent/ATE487319T1/de
Publication of WO2007104232A1 publication Critical patent/WO2007104232A1/zh

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04MTELEPHONIC COMMUNICATION
    • H04M19/00Current supply arrangements for telephone systems
    • H04M19/001Current supply source at the exchanger providing current to substations
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00Data switching networks
    • H04L12/02Details
    • H04L12/10Current supply arrangements

Definitions

  • the present invention relates to the field of electronic and communication technologies, and in particular, to a remote power supply method and system. Background technique
  • FIG. 1 shows the operation of a typical remote power supply system using this method.
  • the remote power supply system includes a central office device and a remote device.
  • the power supply module in the central office device provides a high voltage for the power receiving device in the remote device through a subscriber line, such as a pair of twisted pairs or a coaxial cable.
  • the voltage conversion unit in the central office power supply including but not limited to a transformer, a diode, and a MOS transistor, boosts the input 48V DC voltage, and passes the boosted DC high voltage through a pair or pairs of users.
  • the line supplies power to the remote powered device.
  • the voltage conversion unit steps down the DC high voltage input through the subscriber line, and uses the DC low voltage generated by the step-down as the power source of the remote communication device (not shown).
  • the communication device may be an xDSL device or the like.
  • the dangerous voltage generated by the voltage conversion unit of the central office is generally higher than 60V, and is transmitted to the remote end through the original low-voltage communication network. Because can't It is judged whether the remote end is reliably connected (hereinafter referred to as in-position), so when the remote end is not reliably connected, that is, when the high voltage is output, if the maintenance and use personnel contact the wire end, the probability of electric shock will increase.
  • the remote power supply system includes a central power supply, a remote power supply, and at least four pairs of subscriber lines.
  • the central end power source and the remote power source can communicate through the communication channels A1, A2, Bl, and B2, and the signal processing of the central office power source and the remote power source are respectively controlled by the central end power source and the remote power source.
  • the power conversion circuit is implemented.
  • the communication channels Al, A2, Bl and B2 also carry the transmission of the remote power supply.
  • the central office power supply control power conversion circuit outputs a DC low voltage, which is usually lower than 60V, as a power supply required for the operation of the remote control circuit;
  • the central office and the remote end determine whether the remote end is in place after establishing communication according to a predetermined protocol (which may be a general protocol such as the ADSL protocol or a certain protocol defined by itself);
  • control circuit of the central office controls the power conversion circuit of the central office to output a high power supply, and provides power for the remote power supply.
  • the above scheme can make the communication signal and the power supply share the channel without interference, and realize the coupling of the signal and the power source.
  • By performing the in-position judgment of the distal end before providing the DC high voltage to the distal end it is possible to effectively prevent the maintenance and the user from contacting the wire head.
  • Embodiments of the present invention provide a remote power source in-position detection method and a remote power supply method and system.
  • the embodiment of the present invention provides a remote power supply system, including a central office power supply, a remote power supply, and a subscriber line connecting the central office power supply and the remote power supply.
  • the remote power supply has a characteristic capacitor
  • the central office power supply has a power supply module.
  • Timing control circuit and comparison circuit The comparison circuit, the user line and the characteristic capacitor constitute a resistance-capacitor charge and discharge circuit; the timing control circuit controls the charge and discharge of the charge and discharge circuit by using the output level of the comparison circuit, and only according to the discharge time of the charge and discharge circuit Determine if the remote power supply is in place;
  • the timing control circuit is connected to the power supply module for controlling the output of the power supply module.
  • the power supply module is instructed to supply power to the remote power source.
  • the embodiment of the invention provides a remote power supply method, which includes the following steps:
  • the test low voltage is input to the comparison circuit, and is supplied to the characteristic capacitor through the subscriber line, and charges the charge and discharge loop formed by the subscriber line and the characteristic capacitor;
  • the test low voltage is interrupted under the control of the timing control circuit, the timing is started, and the charge and discharge circuit is discharged;
  • the timing control circuit stops counting, and determines whether the remote power source is in place according to the discharge time
  • An embodiment of the present invention further provides a remote power source in-position detection method, including the following steps: inputting a test voltage into a comparison circuit, and providing a characteristic capacitor to a remote power source through a subscriber line;
  • the test voltage is interrupted under the control of the timing control circuit, the charge and discharge circuits formed by the user line and the characteristic capacitor are discharged, and the timing is started;
  • the timing control circuit stops counting, obtains a discharge time, and determines whether the remote power source is in position according to the discharge time.
  • the principle of resistance-capacitor charging and discharging is used to determine the time difference generated during charging and discharging as a basis for judging whether the remote power source is in position or not.
  • the resistor-capacitor charge and discharge is used to test whether the remote power supply is in place, which is simple to implement, low in cost, and high in reliability;
  • DRAWINGS 1 is a schematic diagram of the operation of an existing remote power supply system
  • FIG. 2 is a schematic diagram of a specific circuit of the remote power supply system shown in FIG. 1;
  • FIG. 3 is a schematic diagram of a specific circuit of another remote power supply system
  • FIG. 4 is a schematic structural diagram of a remote power supply system according to a first embodiment of the present invention.
  • FIG. 5 is a schematic structural diagram of a remote power supply system according to a second embodiment of the present invention.
  • FIG. 6 is a schematic structural diagram of a remote power supply system according to a third embodiment of the present invention.
  • FIG. 7 is a schematic structural diagram of a remote power supply system according to a fourth embodiment of the present invention. detailed description
  • FIG. 4 is a schematic structural diagram of a remote power supply system according to an embodiment of the present invention.
  • the central power supply of the remote power supply system includes a power conversion circuit, a switching circuit, a timing control circuit, and a comparison circuit.
  • the remote power supply includes a characteristic capacitor Ct, and the central end and the remote end are connected by a subscriber line, and the subscriber line can be equivalent to a resistor. Rp and distributed capacitance Cp.
  • the remote power supply is further provided with a diode circuit (or rectifier bridge) Dz.
  • the power conversion circuit is used to generate the test low voltage Vt and the far supply high voltage Vh.
  • the test low voltage Vt is usually lower than 60V
  • the high voltage supply Vh is a DC voltage of 60V or more.
  • two power supply transformer circuits are used in FIG. 4, the test low voltage Vt and the remote power supply voltage Vh are respectively provided, and one of the test low voltage Vt and the far supply high voltage Vh is supplied to the far through the subscriber line through switching of the switching circuit. end.
  • a power conversion circuit may be employed to output the test low voltage Vt and the far supply high voltage Vh by correspondingly transforming the input voltage. It is worth noting that in the test low voltage Vt and the far supply high voltage Vh, only one is supplied to the far end through the subscriber line at the same time.
  • the test low voltage Vt output from the power conversion circuit is input to the comparison circuits 1, 2, respectively.
  • the comparison circuits 1 and 2 are for detecting a voltage input thereto during charge and discharge of the characteristic capacitance Ct, and outputting a corresponding voltage according to a change in the input voltage of the characteristic capacitance Ct.
  • the comparison circuit 1 includes a voltage dividing network composed of resistors R1 and R2, a reference power source, and a comparator.
  • the forward input of the comparator is the terminal voltage of the resistor R2, the reverse input is the internal reference voltage Vs, and the output voltage Vcl is made.
  • the comparison circuit 2 includes a voltage dividing network composed of resistors R3 and R4, and a comparator.
  • the forward input of the comparator is the terminal voltage of the resistor R4, the inverting input is the internal reference voltage Vs, and the output voltage Vc2 is the other input voltage of the timing control circuit.
  • a voltage dividing network composed of R1 and R2, R3 and R4 is used to detect the test low voltage Vt and compare it with the internal reference voltage Vs to output a corresponding high and low level.
  • the output voltage Vcl and the output voltage Vc2 of the comparison circuit 2 are both low;
  • Vtl and Vt2 are not limited to this.
  • the timing control circuit generates a corresponding switching signal QH (from high to low or from low to high) according to the output voltages Vcl and Vc2 generated by the comparison circuits 1 and 2 received, thereby controlling the switching circuit to test the low voltage and the far Switch between high voltages.
  • the timing control circuit also generates a signal KC1 or KC2 for controlling the power conversion circuit based on the output voltages Vcl, Vc2 of the comparison circuits 1, 2 to control the on/off output of the power conversion circuit.
  • the subscriber line is connected at both ends of the remote characteristic capacitor ⁇ , and is charged by the test low voltage vt provided by the central office to perform remote in-position detection.
  • the capacitance value of the characteristic capacitance ⁇ is sufficiently large with respect to the distributed capacitance Cp of the subscriber line, so that the influence of the distributed capacitance Cp of the subscriber line can be ignored when the characteristic capacitance ⁇ is identified during the timing.
  • the characteristic capacitance Ct (converting the capacitance value by charging and discharging i, the diode circuit in the remote power supply) Or rectifier bridge) Dz, used to isolate the characteristic capacitor Ct and the capacitor Cin, so that the recognition speed of the characteristic capacitor Ct is accelerated during the timing.
  • the voltage dividing network formed by R1 and R2, R3 and R4 forms a resistance-capacitor charge and discharge circuit together with the equivalent resistance Rp and the distributed capacitance Cp of the subscriber line and the remote characteristic capacitance Ct.
  • a certain delay is generated during the charging and discharging process for the timing control circuit to control and time.
  • the resistance value in the voltage division network should be sufficiently large with respect to the equivalent resistance Rp of the subscriber line, so that the influence of the line resistance Rp can be ignored during the timing.
  • the timing control circuit obtains the distributed capacitance value of the subscriber line according to the above delay, that is, the time between the start of the discharge timing and the cutoff of the discharge timing, and compares it with the characteristic capacitance Ct (such as luF), if the obtained distributed capacitance value satisfies the advance If the set condition (such as greater than luF), the remote connection is considered normal (in place).
  • the characteristic capacitance Ct such as luF
  • the remote power supply method provided in the embodiment of the present invention includes a low voltage test process and a remote power supply process, where the low voltage test process is the remote power supply in-position judgment process.
  • the timing control circuit first controls the power conversion circuit to output a test low voltage Vt, which is output to the comparison circuit 1, 2, respectively, and supplied to the remote power source through the subscriber line as the terminal voltage of the characteristic capacitor Ct.
  • the test low voltage Vt charges the subscriber line capacitance Cp and the characteristic capacitance Ct by the divided piezoelectric resistance in the comparison circuit and the subscriber line resistance Rp.
  • the output levels Vcl and Vc2 of the comparison circuits 1 and 2 also change accordingly.
  • the timing control circuit starts timing, and at the same time, the timing control circuit outputs the power conversion circuit through the KC2 control, and the user line capacitance Cp and the remote characteristic capacitance Ct pass.
  • the voltage dividing resistor in the comparison circuit and the subscriber line resistance Rp are discharged.
  • the output levels Vcl and Vc2 of the comparison circuits 1 and 2 also change from a high level to a low level.
  • the timing control circuit stops counting, and according to the delay between the start of the timing and the stop of the timing, the circuit is calculated according to the formula (1) (the entire charge and discharge circuit) The total capacitance, and determine whether the remote power supply is in place based on the calculated total capacitance of the line.
  • R is the equivalent resistance of the charge and discharge circuit
  • C is the charge and discharge circuit
  • u c is the termination voltage of the equivalent capacitor
  • U Q is the starting voltage of the equivalent capacitor.
  • the characteristic capacitance Ct If the total capacitance of the line is greater than the characteristic capacitance Ct, it can be judged that the remote power supply has been reliably connected, and then the remote power supply is judged to be in place. Otherwise, judge that the remote power supply is not in place and continue the repeated low voltage test process.
  • the resistance-capacitor charge-discharge principle is used to test whether the remote power source is in place, which is simple to implement, low in cost, and high in reliability.
  • the remote power supply process is entered.
  • the timing control circuit switches the switch in the switching circuit to the output of the power conversion circuit that is far from the high voltage through the QH signal.
  • the timing control circuit controls the power conversion circuit to output the high voltage through the KC1 signal.
  • the subscriber line transmits high voltage power to the far end.
  • the remote power supply is tested during the low voltage test, the remote supply voltage is output when the remote end is reliably connected, thereby effectively preventing the occurrence of electric shock and ensuring the use and maintenance personnel. Safety.
  • FIG. 5 is a schematic structural diagram of a remote power supply system according to a second embodiment of the present invention.
  • the structure of Embodiment 2 is substantially the same as that of Embodiment 1, and the difference between the two is that the remote power source further includes a signal transformer, and the characteristic capacitor Ct is disposed at the center tap of the signal transformer.
  • FIG. 6 is a schematic structural diagram of a remote power supply system according to a third embodiment of the present invention.
  • the structure of Embodiment 3 is substantially the same as that of Embodiment 1, and the difference between the two is that the capacitor Cin used for energy storage and filtering in the remote power supply is directly used as the characteristic capacitor instead of the characteristic capacitor. Ct and diode circuit (or rectifier bridge) Dz.
  • the remote power supply system of the third embodiment can reduce the system design complexity on the basis of achieving a safe power supply, thereby reducing the cost.
  • FIG. 7 is a schematic structural diagram of a remote power supply system according to a fourth embodiment of the present invention.
  • the structure of Embodiment 4 is substantially the same as that of Embodiment 3, and the difference between the two is that the remote power source further includes a signal transformer, and the capacitor Cin is set as a characteristic capacitor Ct at the center tap of the transformer.
  • the remote power supply system of Embodiment 4 can achieve security Power is reduced to reduce system design complexity and thus reduce costs.
  • the two resistor networks in the comparison circuit are connected in parallel and then connected in series, which can be equivalent to a resistor, which is equivalently a loop;
  • the designer may also need to add another network of charge and discharge resistors.
  • the resistance of the parallel circuit of the comparison circuit is much smaller than the resistance value of any of the voltage divider resistors. The resistor, in this way, can ignore the resistance of the comparison circuit when determining whether the remote power supply is in place.
  • one or more sets of comparison circuits may be used to provide an output level as a basis for the charge and discharge control of the timing control circuit.
  • the high-level trigger timing control circuit outputted by the comparison circuit is used to perform the discharge timing, and the low-level trigger timing control circuit of the comparison circuit output stops timing
  • the level trigger timing can also be used. Level trigger stops timing.
  • the forward input and the reverse input of the comparator in the above embodiment may not be limited to the terminal voltage of the voltage dividing resistor as the forward input of the comparator and the reference power supply voltage as the reverse input of the comparator.
  • the same effect can be achieved by using the reference supply voltage as the forward input of the comparator and the terminal voltage of the divider resistor as the inverter's inverting input. It is only necessary to change the trigger level of the timing control circuit.

Description

远端电源在位检测方法以及远程供电方法和系统 本申请要求于 2006 年 03 月 10 日提交中国专利局、 申请号为 200610058189.5、 发明名称为"远程供电系统、 远端电源在位检测方法以及 远程供电方法 "的中国专利申请的优先权, 其全部内容通过引用结合在本申 请中。 技术领域
本发明涉及电子及通信技术领域, 特别涉及一种远程供电方法及系统。 背景技术
随着通信服务需求的不断增长, 在利用现有已经铺设的用户线网络的 基础上, 运营商不断拓展其新的业务到最终的用户, 或者铺设新用户网络, 提供新业务。 一种比较通用的做法是将宽带和窄带产品更加移向用户, 利 用若干对双绞线、 或者同轴电缆作为上行通道, 而在用户侧可以分出更多 的用户和业务。 然而, 在将设备转移到用户侧时, 由于用户环境复杂并且 多数情况不方便提供电源, 因而供电成为不易解决的实际问题。
在这种情况下, 运营商采用通过用户线由局端提供电源的方法 (Line powering )作为其扩展业务和用户的重要技术支撑方案。 图 1所示的是一种 采用这种方法的典型的远程供电系统的工作原理。 该远程供电系统包括局 端设备和远端设备, 局端设备中的供电模块通过用户线, 如多对双绞线或 者同轴电缆为远端设备中的受电设备提供远供高压。
图 2为上述远程供电系统的一种具体电路示意图。 如图 2所示, 局端 电源中的电压变换单元, 包括但不限于变压器、 二极管和 MOS管, 对输入 的 48V直流电压进行升压, 将升压后的直流高压通过一对或者若干对用户 线向远端受电设备供电。 在远端设备中, 电压变换单元对通过用户线输入 的直流高压进行降压, 将降压产生的直流低压作为远端通信设备(图中未 示出) 的电源。 这里, 通信设备可以是 xDSL设备等。
在研究过程中, 发明人发现现有技术中至少存在如下问题:
上述的远程供电系统中由于局端的电压变换单元升压后产生的一般都 是高于 60V的危险电压, 通过原有的低压通信网络传送给远端。 由于不能 判断远端是否可靠连接(后面统一称为在位), 因而在远端未可靠连接即输 出高电压时, 如果维护和使用人员接触线头, 将增加触电的概率。
另一种远程供电系统如图 3 所示, 该远程供电系统包括局端电源、 远 端电源以及至少 4对用户线。 其中, 局端电源和远端电源之间可以通过通 信信道 Al、 A2、 Bl以及 B2进行通信, 而局端电源和远端电源的信号处理 分别由局端电源和远端电源内部的控制电路和电源变换电路实现。 另外, 通信通道 Al、 A2、 Bl以及 B2同时也承载远供电源的传输。
上述通信的目的在于为局端和远端建立电源监控, 具体过程如下: 首先, 局端电源控制电源变换电路, 输出通常低于 60V的直流低压, 作为远端的控制电路工作所需的电源;
局端和远端依据预定的协议(可以是通用协议如 ADSL协议或自己定 义的某种协议)建立通信后, 对远端是否在位进行判断;
在远端在位的情况下, 局端的控制电路控制局端的电源变换电路输出 高电圧, 提供远端电源供电能量。
上述方案可以使通信信号和电源相互不干扰地共享通道, 实现了信号 和电源的耦合。 通过在向远端提供直流高压之前进行远端的在位判断, 可 以有效避免维护和使用人员接触线头触电的情况发生。
然而, 在研究过程中, 发明人发现现有技术中至少存在^下问题: 为了实现局端和远端通信, 必须设计相应通信电路和预定的通信协议, 这样, 无论从硬件还是软件角度讲, 都将大大提高设计复杂度;
由于设计复杂度较高,在软件和硬件的任意一个环节出现问题时都可能 出现通信的异常, 可能导致远端不能启机, 从业务保证角度讲, 可靠性有 所降低。 发明内容
本发明实施例提供一种远端电源在位检测方法以及远程供电方法和系 统。
本发明实施例提供一种远程供电系统, 包括局端电源、 远端电源及连 接局端电源与远端电源的用户线, 所述远端电源具有特征电容, 所述局端 电源具有供电模块、 计时控制电路及比较电路, 所述比较电路、 用户线及特征电容构成电阻 -电容充放电回路; 所述计时控制电路, 利用比较电路的输出电平,控制充放电回路的充放 电, 并才艮据充放电回路的放电时间判断远端电源是否在位;
所述计时控制电路与供电模块相连接, 用于控制供电模块的输出; 当确定远端电源在位时, 指示所述供电模块向远端电源供电。
本发明实施例提供一种远程供电方法, 包括以下步骤:
将测试低压输入到比较电路, 并通过用户线提供给特征电容, 并使得 用户线和特征电容构成的充放电回路充电;
在比较电路的输出电平为第一电平时, 在计时控制电路控制下中断测 试低压, 启动计时, 并使得充放电回路放电;
在比较电路的输出电平为第二电平时, 计时控制电路停止计时, 并根 据放电时间判断远端电源是否在位;
当确定远端电源在位时, 将远供高压通过用户线提供给远端电源。 本发明实施例还提供一种远端电源在位检测方法, 包括以下步骤: 将测试电压输入到比较电路, 并通过用户线提供给远端电源的特征电 容;
在比较电路的输出电平为第一电平时, 在计时控制电路控制下中断测 试电压, 使用户线和特征电容构成的充放电回路放电, 并启动计时;
当所述充放电回路放电使得比较电路的输出电平为第二电平时, 计时 控制电路停止计时, 得到放电时间, 并根据该放电时间判断远端电源是否 在位。
本发明实施例提供的技术方案中, 利用电阻-电容充放电原理, 将充 放电过程中产生的时间差作为判断依据, 实现对远端电源是否在位的逻辑 判断。 在低压测试过程中, 利用电阻-电容充放电对远端电源是否在位进 行测试, 其实现简单, 成本低, 并且可靠性高;
由于在低压测试过程中对远端电源是否在位进行了测试,在远端可靠连 接的情况下才输出远供电压, 从而, 可以有效避免发生触电的情况, 保障 了使用和维护人员的安全。 附图说明 图 1为一种现有的远程供电系统的工作原理图;
图 2为图 1所示的远程供电系统的一种具体电路示意图;
图 3为现有的另一种远程供电系统的具体电路示意图;
图 4为本发明第一实施例中远程供电系统的结构示意图;
图 5为本发明第二实施例中远程供电系统的结构示意图;
图 6为本发明第三实施例中远程供电系统的结构示意图;
图 7为本发明第四实施例中远程供电系统的结构示意图。 具体实施方式
以下将结合附图和实施例具体说明本发明的远程供电系统、 远端电源 在位判断方法以及远程供电方法。
实施例 1
图 4 为本发明实施例中的远程供电系统的结构示意图。 该远程供电系 统的局端电源包括电源变换电路、 切换电路、 计时控制电路以及比较电路, 远端电源包含特征电容 Ct, 局端和远端之间通过用户线连接, 用户线可以 等效为电阻 Rp和分布电容 Cp。 远端电源还进一步设置有二极管电路(或 整流桥 ) Dz。
在局端电源中, 电源变换电路用于产生测试低压 Vt以及远供高压 Vh, 这里测试低压 Vt通常低于 60V, 而远供高压 Vh为 60V以上的直流电压。 虽然图 4中采用了两个电源变压电路,分別提供测试低压 Vt和远供高压 Vh, 并通过切换电路的切换将测试低压 Vt和远供高压 Vh二者中的一个通过用 户线提供到远端。 在本发明实施例中, 也可以采用一个电源变换电路, 通 过对输入电压进行相应地变换从而输出测试低压 Vt和远供高压 Vh。值得注 意的是, 在测试低压 Vt和远供高压 Vh中, 在同一时间只有一个通过用户 线提供到远端。
电源变换电路输出的测试低压 Vt分别输入到比较电路 1、 2中。 比较 电路 1和 2用于在特征电容 Ct的充放电过程中检测输入到其中的电压, 并 且根据特征电容 Ct输入电压的变化输出相应的电压。 其中, 比较电路 1包 括电阻 R1和 R2构成的分压网络, 基准电源以及比较器。 比较器的正向输 入为电阻 R2的端电压, 反向输入为内部基准电压 Vs, 其输出电压 Vcl作 为计时控制电路的输入电压。 比较电路 2包括电阻 R3和 R4构成的分压网 络, 以及比较器。 比较器的正向输入为电阻 R4的端电压, 反向输入为内部 基准电压 Vs, 其输出电压 Vc2作为计时控制电路的另一输入电压。
在比较电路 1和比较电路 2中, R1和 R2、 R3和 R4构成的分压网络, —方面用于检测测试低压 Vt, 并与内部基准电压 Vs的比较, 从而输出相应 的高低电平。
如图 4 所示, 在比较电路 1、 2用于检测测试 4氐压时, 假设测试低压 Vt从 0开始逐渐上升, 则存在以下几种情况:
1 )如果测试低压 Vt小于第一预定电压 Vtl = Vsx ( 1+R1/R2 )和第二 预定电压 Vt2 = Vsx ( 1+R3/R4 ), 即 Vtl>Vt并且 Vt2> Vt时, 比较电路 1 的输出电压 Vcl和比较电路 2的输出电压 Vc2都是低电平;
2 )如果测试低压 Vt满足 Vtl>Vt>Vt2, 则比较电路 1的输出电压 Vcl 为低电平, 而比较电路 2的输出电压 Vc2为高电平; 以及
3 )如果测试低压 Vt满足 Vt > Vtl >Vt2, 则比较电路 1、 2的输出电压 Vcl , Vc2都为高电平。
在此, Vtl与 Vt2的关系并不限于此。
此时,计时控制电路根据接收到的比较电路 1、 2产生的输出电压 Vcl、 Vc2, 产生相应的切换信号 QH (由高变低或由低变高), 进而控制切换电路 在测试低压和远供高压之间切换。 同时, 计时控制电路也根据比较电路 1、 2的输出电压 Vcl、 Vc2产生控制电源变换电路的信号 KC1或 KC2, 来控 制电源变换电路的开 /断输出。
用户线连接在远端特征电容 α的两端,由局端提供的测试低压 vt对其 进行充电, 进而进行远端在位检测。 这里要求特征电容 α的电容值相对于 用户线的分布电容 Cp足够大, 从而在计时过程中对特征电容 α进行识別 时可以忽略用户线的分布电容 Cp的影响。 并且, 为了防止远端电源内部其 他用于储能和滤波的电容 Cin在对特征电容 Ct进行识别 (通过充放电 i十时, 折算电容值) 时产生的影响, 远端电源中的二极管电路(或整流桥) Dz, 用于隔离特征电容 Ct和电容 Cin, 使在计时过程中对特征电容 Ct的识别速 度加快。 在对特征电容 Ct进行识别时, R1和 R2、 R3和 R4构成的分压网络与 用户线的等效电阻 Rp和分布电容 Cp以及远端特征电容 Ct一起组成电阻 - 电容充放电回路, 从而在充放电过程中产生一定延时, 供计时控制电路进 行控制和计时。 这里, 分压网络中的电阻值相对于用户线的等效电阻 Rp应 足够大, 使计时过程中可以忽略线路电阻 Rp的影响。
计时控制电路根据上述延时, 即放电计时开始到放电计时截止之间的 时间, 获得用户线的分布电容值, 将其与特征电容 Ct (如 luF )进行对比, 如果获得的分布电容值满足预先设定的条件(如大于 luF ), 则认为远端连 接正常(在位)。
为了更清楚的理解本发明, 以下结合远程供电系统的工作流程对远端 电源在位判断方法以及远程供电方法进行说明。 在本发明实施例中提供的 远程供电方法, 包括低压测试过程以及远程供电过程, 这里的低压测试过 程即远端电源在位判断过程。
在低压测试过程中, 计时控制电路首先控制电源变换电路输出测试低 压 Vt, 该测试低压 Vt分别输出给比较电路 1、 2, 并通过用户线提供给远 端电源,作为特征电容 Ct的端电压。测试低压 Vt通过比较电路中的分压电 阻和用户线电阻 Rp对用户线电容 Cp和特征电容 Ct充电。
随着测试低压 Vt从 0开始上升, 比较电路 1、 2的输出电平 Vcl、 Vc2 也会相应变化。 当比较电路 1、 2的输出电平 Vcl、 Vc2都为高电平时, 计 时控制电路开始计时, 同时, 计时控制电路通过 KC2控制电源变换电路断 输出, 用户线电容 Cp和远端特征电容 Ct通过比较电路中的分压电阻和用 户线电阻 Rp进行放电。
随着放电过程的进行, 比较电路 1、 2的输出电平 Vcl、 Vc2也将从高 电平变为低电平。 当比较电路 1、 2的输出电平 Vcl、 Vc2都为低电平时, 计时控制电路停止计时, 并根据计时开始到计时停止之间的延时, 依据公 式(1 )计算线路(整个充放电回路)总电容, 并根据计算出的线路总电容 判断远端电源是否在位。
Uc= U0 x Q-t,T ( 1 )
R为充放电回路的等效电阻, C为充放电回路 的等效电容, uc为等效电容的终止电压, UQ为等效电容的起始电压。
如果线路总电容大于特征电容 Ct,则可以判断远端电源已经可靠连接, 进而判断远端电源在位。 否则判断远端电源不在位, 继续反复低压测试过 程。
在上述低压测试过程中 , 利用电阻 -电容充放电原理对远端电源是否 在位进行测试, 其实现简单, 成本低, 并且可靠性高。
当在上述低压测试过程中判断远端电源在位后, 进入到远程供电过程。 在远程供电过程中,计时控制电路通过 QH信号将切换电路中的开关切 换到输出远供高压的电源变换电路的输出端,同时,计时控制电路通过 KC1 信号控制电源变换电路输出远供高压, 通过用户线向远端传输高压电源。
这样, 由于在低压测试过程中对远端电源是否在位进行了测试, 在远 端可靠连接的情况下才输出远供电压, 从而, 可以有效避免发生触电的情 况, 保障了使用和维护人员的安全。
实施例 2
图 5为本发明第二实施例中的远程供电系统的结构示意图。 如图 5所 示, 实施例 2与实施例 1 的结构大体上相同, 二者的区别在于, 远端电源 中进一步包括信号变压器, 特征电容 Ct设置在信号变压器的中心抽头处。
实施例 3
图 6为本发明第三实施例中的远程供电系统的结构示意图。 如图 6所 示, 实施例 3与实施例 1 的结构大体上相同, 二者的区别在于, 实施例 3 中直接使用远端电源内部用于储能和滤波的电容 Cin作为特征电容代替特 征电容 Ct和二极管电路(或整流桥) Dz。 这样, 相对于实施例 1, 实施例 3的远程供电系统可以在实现安全供电的基础上减少系统设计复杂度,从而 降低成本。
实施例 4
图 7为本发明第四实施例中的远程供电系统的结构示意图。 如图 7所 示, 实施例 4与实施例 3的结构大体上相同, 二者的区别在于, 远端电源 中进一步包括信号变压器, 电容 Cin作为特征电容 Ct设置在变压器的中心 抽头处。 这样, 相对于实施例 2, 实施例 4的远程供电系统可以在实现安全 供电的基础上减少系统设计复杂度, 从而降低成本。
从上述各个实施例可以看出, 在充放电过程中, 比较电路中的两个电 阻网络先并联后串联, 可以相当于一个电阻, 从等效意义上讲就是一个回 路; 另外, 在上述相同的测试原理下, 设计者也可以 居需要再增加一个 充放电电阻网络, 例如在上述的充放电回路中的比较电路的电阻上并联电 阻值远小于任一分压电阻的电阻值的一个或者多个电阻, 这样, 可以在判 断远端电源是否在位时忽略比较电路的电阻。
虽然在上述实施例中采用两套比较电路进行说明, 可以采用一套或者 多套比较电路来提供输出电平, 作为计时控制电路进行充放电控制的依据。
另外, 虽然在上述实施例中利用比较电路输出的高电平触发计时控制 电路进行放电计时、 比较电路输出的低电平触发计时控制电路停止计时, 也可以采用^ ί氐电平触发计时, 高电平触发停止计时。
同样, 上述实施例中比较器的正向输入和反向输入也可以不限于分压 电阻的端电压作为比较器的正向输入、 基准电源电压作为比较器的反向输 入这种方式, 相反, 将基准电源电压作为比较器的正向输入、 分压电阻的 端电压作为比较器的反向输入也同样可以达到相同的效果, 只需要改变计 时控制电路的触发电平的高低即可。
以上所述, 仅为本发明的示范性实施方式, 但本发明的保护范围并不 局限于此, 任何熟悉本技术领域的技术人员在本发明揭露的技术范围内, 可轻易想到的变化或等同替换, 都应涵盖在本发明的保护范围之内。

Claims

权 利 要 求
1. 一种远程供电系统, 包括局端电源、 远端电源及连接局端电源与远 端电源的用户线, 其特征在于, 远端电源具有特征电容, 局端电源具有供 电模块、 计时控制电路及比较电路,
所述比较电路、 用户线及特征电容构成电阻-电容充放电回路; 所述计时控制电路, 利用比较电路的输出电平,控制充放电回路的充放 电, 并根据充放电回路的放电时间判断远端电源是否在位;
所述计时控制电路与供电模块相连接, 用于控制供电模块的输出; 当确定远端电源在位时, 指示所述供电模块向远端电源供电。
2. 如权利要求 1所述的远程供电系统, 其特征在于, 比较电路包括分 压电阻, 基准电源, 以及以分压电阻的端电压和基准电源电压作为输入的 比较器, 比较器的比较结果输出到计时控制电路。
3. 如权利要求 1 所述的远程供电系统, 其特征在于, 远端电源中进一 步包括隔离电路, 其跨接在特征电容两端, 用于隔离特征电容与远端电源 中其他的电容。
4. 如权利要求 3所述的远程供电系统, 其特征在于, 所述隔离电路为 二极管电路或者整流桥。
5. 如权利要求 1 所述的远程供电系统, 其特征在于, 所述特征电容为 远端电源中用于储能和 /或滤波的电容。
6. 如权利要求 1或 5所述的远程供电系统, 其特征在于, 远端电源进 一步包括信号变压器, 所述特征电容设置在信号变压器的中心抽头处。
7. 一种远端电源在位检测方法, 其特征在于, 所述方法包括以下步骤: 将测试电压输入到比较电路, 并通过用户线提供给远端电源的特征电 容;
在比较电路的输出电平为第一电平时,在计时控制电路控制下中断测试 电压, 使用户线和特征电容构成的充放电回路放电, 并启动计时;
当所述充放电回路放电使得比较电路的输出电平为第二电平时,计时控 制电路停止计时, 得到放电时间, 并根据该放电时间判断远端电源是否在 位。
8、 如权利要求 7所述的方法, 其特征在于, 所述根据放电时间判断远 端电源是否在位, 具体包括:
根据所述放电时间计算整个充放电回路的总电容,并根据计算出的线路 总电容判断远端电源是否在位, 若所述总电容大于特征电容 Ct, 则判断远 端电源可靠连接, 进而确定远端电源在位。 否则判断远端电源不在位。
9、 如权利要求 8所述的方法, 其特征在于, 按照下列公式计算整个充 放电回路的总电容,
υ =υο χ ~ί Ιτ 其中 i; = RC, R为充放电回路的等效电阻, C为充放电回路的等效电容, Uc为等效电容的终止电压, U。为等效电容的起始电压。
10、 一种远程供电方法, 其特征在于, 所述方法包括以下步骤: 将测试低压输入到比较电路, 并通过用户线提供给特征电容, 并使得用 户线和特征电容构成的充放电回路充电;
在比较电路的输出电平为第一电平时,在计时控制电路控制下中断测试 低压, 启动计时, 并使得充放电回路放电;
在比较电路的输出电平为第二电平时, 计时控制电路停止计时, 并根据 放电时间判断远端电源是否在位;
当确定远端电源在位时 , 将远供高压通过用户线提供给远端电源。
11、 如权利要求 10所述的远程供电方法, 其特征在于, 所述特征电容 为远端电源中用于储能和 /或滤波的电容。
PCT/CN2007/000663 2006-03-10 2007-03-02 Procédé permettant de détecter la connexion d'une alimentation électrique à distance et procédé et système d'alimentation de ligne électrique WO2007104232A1 (fr)

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CN101035178A (zh) 2007-09-12
EP1995844B1 (en) 2010-11-03
EP1995844A9 (en) 2009-06-17
CN101035178B (zh) 2010-06-09
EP1995844A4 (en) 2009-07-22
ATE487319T1 (de) 2010-11-15
DE602007010251D1 (de) 2010-12-16
EP1995844A1 (en) 2008-11-26

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