Communication power supply auxiliary protection method applicable to integrated power supply system

Abstract

According to the communication power supply auxiliary protection method suitable for the integrated power supply system, a communication power supply part comprises a communication direct current bus, a plurality of DC / DC modules are connected to the communication direct current bus, and the communication direct current bus is further connected with a plurality of communication lines; a communication feeder circuit breaker and communication equipment connected with the communication feeder circuit breaker are arranged on each communication line; a bus current sensor used for current sampling is connected in series between the DC / DC module and the cathode communication DC bus, and a communication current sensor used for current sampling is connected in series below an outgoing line of a communication feeder circuit breaker in each communication line. And output signals of the bus current sensor and the communication current sensor are connected to the communication power supply auxiliary protection device. Under the condition that protection of the direct current circuit breaker does not act, the device can be used as an auxiliary protection device for reliably and quickly removing faults, so that power supply of a communication power supply is automatically recovered, and the safety of equipment such as a communication power supply DC / DC module is guaranteed.

Description

Technical Field

[0001] The present invention relates to the research on the auxiliary protection principle of the communication power supply system in the integrated power supply system of the substation. The auxiliary protection ensures the reliable operation of the DC circuit breaker and reduces its operation time, thereby improving the protection function and thus improving the power supply reliability of the communication power supply. Background Art

[0002] Currently, substations are usually not equipped with a separate communication power supply system. Instead, the communication power supply is combined into an integrated power supply system. The communication power supply is not equipped with a separate battery pack, but shares the battery pack of the DC power supply system.

[0003] Because telecom power supplies lack independent battery packs, when a short circuit occurs on the telecom power feeder, the short-circuit current is exclusively supplied by the telecom DC / DC module. 35kV to 110kV substations typically utilize 90-150A telecom DC / DC modules. These DC / DC modules have a certain overload capacity. When a short circuit is detected, they typically limit the output current to 1.5 to 2 times the DC / DC module's rated current, or employ other protection mechanisms, to protect the equipment.

[0004] Telecom power supplies primarily serve communications equipment such as SDH. The full power of SDH equipment approaches 2000W, and the instantaneous startup current of SDH equipment can reach 3 to 7 times the rated current of the actual load. To ensure that the SDH equipment does not trip the feeder circuit breaker during normal startup, the communications industry typically requires the feeder circuit breaker for SDH equipment to be rated at 63A. According to the DL / T5044-2014 standard, the instantaneous tripping range of a DC circuit breaker with a Type B trip unit is 4In to 7In, where In is the rated current of the DC circuit breaker. Calculating the reliable tripping value of 7In, 7 × 63 = 441A, while (90 to 150) × (1.5 to 2) = 135 to 300A. Therefore, the current output by the DC / DC module cannot guarantee reliable operation of the DC feeder circuit breaker during a short-circuit fault. To solve this problem, charging capacitors can be deployed in the communication power supply system. Since charging capacitors are energy storage elements, they can provide short-circuit current support when a short-circuit fault occurs in the communication power feeder, thereby ensuring that the instantaneous quick-trip protection of the feeder circuit breaker is sensitive and can operate reliably. However, the addition of charging capacitors requires charging and discharging management, which complicates the communication power supply. Therefore, the deployment of charging capacitors for communication power supply is rarely used at present.

[0005] When a short circuit occurs on the telecom power feeder, if the DC / DC module can stably output 1.5 to 2 times its rated current for a long period of time, the long-delay protection of the B-type DC circuit breaker with an In of 63A will activate. The activation time is approximately 1 to several tens of seconds. If the long-delay protection of the DC circuit breaker activates too long, it can cause thermal stability issues in the DC / DC module and adversely affect the operation of SDH equipment due to prolonged power outages. When a short circuit occurs on the telecom power feeder, if the DC / DC module enters periodic start-stop protection mode or directly shuts down its output, the long-delay protection of the B-type DC circuit breaker with an In of 63A will not activate. Power can only be restored after on-site personnel have completed the incident. Summary of the Invention

[0006] The technical problem to be solved by the present invention is: the present invention deploys an auxiliary protection device in the communication power supply of the integrated power supply system to solve the problem that the instantaneous quick-break protection of the communication power feeder circuit breaker in the integrated power supply system cannot operate reliably and the long-delay protection operation time is too long or may not operate at all, affecting the power supply reliability.

[0007] To solve the above problems, the present invention is achieved through the following technical solutions: A communication power supply auxiliary protection method applicable to an integrated power supply system, wherein the communication power supply portion includes a communication DC bus, to which are connected several DC / DC modules, and the communication DC bus is also connected to several communication lines, each of which is provided with a communication feeder circuit breaker and communication equipment connected thereto; A busbar current sensor for current sampling is connected in series between the DC / DC module and the negative communication DC busbar. A communication current sensor for current sampling is connected in series below the outgoing line of the communication feeder circuit breaker in each communication line. The output signals of the busbar current sensor and the communication current sensor are connected to the communication power auxiliary protection device. The communication power auxiliary protection device includes a current sampling plug-in, a voltage sampling plug-in, an output plug-in, an alarm plug-in, a communication plug-in and a power plug-in; The protection method includes the following steps: Step 1: Configure the number and parameters of DC / DC modules: Step 2: Analyze the fault scope; Step 2.1: When the communication DC bus voltage U1T is less than the set value Uset, start analyzing whether the communication power supply part has a fault and the fault location; Step 2.2: Collect the currents of the bus current sensor and the communication current sensor in real time and perform vector sum calculations. The current output by the bus current sensor is the total output current IM1 of the DC / DC module, and the current output by the communication feeder circuit breaker in each communication line is the communication line current I1 to I30. Step 2.3: Fault Analysis: When ①.U1T<Uset; ②.IM1<Iset1, the DC / DC module output is faulty; When ①.U1T<Uset; ②.IM1>Iset2; ③.|I∑|>Iset3 are satisfied, the communication DC bus voltage is low and the communication DC bus is faulty; When ①.U1T<Uset; ②.IM1>Iset2; ③.|I∑|<Iset3; ④.I1>Iset4, the communication DC bus voltage is low and the communication line is faulty. Among them, Iset1 is the first set threshold of the total output current; Iset2 is the second set threshold of the total output current; Iset3 is the communication DC bus current threshold; Iset4 is the communication line current threshold; |I∑| is the absolute value of the current vector sum.

[0008] Step 1 includes: Step 1.1: Calculate the total communication power load Ifh of the communication power supply section; Step 1.2: Select the rated output current Ie of a single DC / DC module; Step 1.3: Calculate the number of DC / DC modules. Round up the result of Ifh ÷ Ie to N. Add one spare module, and the final number of DC / DC modules is N+1.

[0009] The set value Uset is 60% times the rated voltage Ue of the communication power supply.

[0010] The first set threshold value of the total output current Iset1 is 10% times the total rated output current N×Ie of the DC / DC module; The second set threshold value of the total output current Iset2 is equal to the total rated output current N×Ie of the DC / DC module; The communication DC bus and current threshold Iset3 is 10% times the total rated output current N×Ie of the DC / DC module; The communication line current threshold Iset4 is 1.2 times the rated current In of the circuit breaker of this line.

[0011] After determining that a short circuit fault has occurred in the communication line of the communication power supply, the communication feeder circuit breaker of the communication line will be tripped when the delay t>tset condition is met and the fault current has not returned; at the same time, the auxiliary protection device of the communication power supply will output a protection action signal; if the fault current returns within the tset delay time, it will not be tripped and no protection action signal will be output.

[0012] Compared with the prior art, the present invention has the following beneficial effects: the communication power auxiliary protection device of the present invention, combined with a logical calculation method, determines the circuit in which a fault occurs in the communication power DC feeder circuit, and trips the DC circuit breaker of the faulty feeder circuit after a set time. The communication power auxiliary protection device of the present invention can serve as an auxiliary protection device to reliably and quickly cut off the fault when the DC circuit breaker protection does not operate, thereby automatically restoring the communication power supply, ensuring the safety of equipment such as the communication power DC / DC module, and improving the power supply reliability of communication equipment such as SDH. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A simplified diagram of the current integrated power supply system related to DC power supply and communication power supply system; Figure 2 A schematic diagram of a communication power supply system related to the integrated power supply system of the present invention; Figure 3 This is a diagram of the communication interface, power supply circuit, and alarm signal circuit of the communication power auxiliary protection device of the present invention; Figure 4 This is a voltage and current loop principle diagram of the communication power auxiliary protection device of the present invention; Figure 5 A circuit schematic diagram of the auxiliary protection device for communication power supply of the present invention is provided; Figure 6 This is a schematic diagram of the back plug-in of the communication power auxiliary protection device of the present invention. DETAILED DESCRIPTION

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0015] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0016] like Figure 1 、 Figure 2 As shown, the integrated power supply system includes a DC power supply part and a communication power supply part.

[0017] The DC power supply consists primarily of a rectifier module 11, a battery pack 12, and a DC feeder circuit breaker 13. These are connected via DC busbars 1L+ and 1L-. The DC busbar's rated voltage is 220V DC. The DC busbar connects to the communications power supply via several feeder loops, each equipped with a DC feeder circuit breaker 13. The DC busbar connects to the AC power distribution unit via the rectifier module 11, and to the battery pack 12 via a fuse.

[0018] The communications power supply consists of communication DC busbars 1T+ and 1T-, connected to which are several DC / DC modules 15. These busbars are also connected to several communication lines, each equipped with a communication feeder circuit breaker 16 and associated communication equipment. The communication DC busbar 1T+ is directly grounded, and the rated voltage of the communication power supply is DC-48V.

[0019] When a short circuit occurs at point K1 in a feeder loop of the DC power supply section, the battery pack 12, an energy storage element, can be considered a voltage source. Since the loop resistance from the battery pack 12 to the short-circuit point K1 is relatively low, the battery pack 12 can stably and continuously output a relatively large short-circuit current, thereby ensuring reliable operation of the instantaneous quick-trip protection of the DC feeder circuit breaker 13.

[0020] However, when a short circuit occurs at point K2 in a communication line of the communication power supply part, since there are no energy storage elements such as battery packs and energy storage capacitors, only the DC / DC module 15 provides it with short-circuit current. In order to avoid damage to the DC / DC module 15, its excessive output current is usually limited. If the rated current of the communication feeder circuit breaker 16 is large, its instantaneous quick-break protection has no sensitivity and will not operate. The DC / DC module 15 cannot act as a voltage source, and the voltage of the communication DC bus will decrease, causing communication equipment such as SDH to lose normal operating power supply, affecting the power supply reliability of the equipment.

[0021] Therefore, in order to solve the problems of the instantaneous quick-break protection of the communication power feeder circuit breaker in the integrated power supply system not being able to operate reliably and the long-delay protection operating time being too long, the present invention deploys an auxiliary protection device in the communication power supply of the integrated power supply system. For this purpose, the communication power supply system structure is supplemented, and a bus current sensor 17 for current sampling is connected in series between the DC / DC module 15 and the negative communication DC bus 1T-, and a communication current sensor 18 for current sampling is connected in series under the outgoing line of the communication feeder circuit breaker 16 in each communication line, and the output signals of the bus current sensor 17 and the communication current sensor 18 are connected to the communication power auxiliary protection device.

[0022] Communication power auxiliary protection device includes current sampling plug-in, voltage sampling plug-in, output plug-in, alarm plug-in, communication plug-in, power plug-in, etc. Figure 6 As shown in the figure, the configuration includes 11# current sampling plug-in to 12# current sampling plug-in, a total of 2 current sampling plug-ins; 10# voltage and current sampling plug-in; 6# output plug-in to 8# output plug-in, a total of 3 output plug-ins; 1 3# alarm plug-in; 1 2# communication plug-in; 1 1# power plug-in; 3# spare plug-ins, 3# spare plug-ins, 4# spare plug-in, and 9# spare plug-in, a total of 3 spare plug-ins.

[0023] Figure 3 The diagram shows the communication interface, power circuit, and alarm signal circuitry of the communication power auxiliary protection device of the present invention. The device's communication plug-in #2 includes a B-code timing interface, an RS232 serial port, an RS485 serial port, and four RJ45 interfaces. A single power circuit is connected to the device's power plug-in #1. Alarm signals include power loss alarms output by plug-in #1 and device fault, communication fault, protection action, busbar fault, branch fault, and busbar voltage low signals output by plug-in #5.

[0024] Figure 4 The diagram shows the voltage and current circuit principle of the communication power auxiliary protection device of the present invention: DC voltage circuit 0V-1 and -48V-1 are connected to Figure 2 The communication DC bus 1T+ bus voltage and 1T- bus voltage, 0V-2, -48V-2 are standby, used to access the second communication DC bus voltage; the current acquisition circuit IM1+ / IM1- is connected to Figure 2 The current output by the bus current sensor 17, the current acquisition loop IM2+ / IM2- is a standby, used to access the total current output by the second DC / DC module 15; the current acquisition loops I1~I30 are connected one by one Figure 2 The current output by each communication current sensor 18 connected in series below the outgoing line of the communication feeder circuit breaker 16 in each communication line can be connected to the current collection of up to 30 feeder loops.

[0025] Figure 5 The diagram shows the circuit principle of the auxiliary protection device for communication power supply of the present invention: outlets 1 to 30 are connected one by one. Figure 2 The tripping circuit of the communication feeder circuit breaker 16 in each communication line can be connected to the tripping circuits of up to 30 communication feeder circuit breakers 16.

[0026] like Figure 2 As shown, a communication power auxiliary protection method applicable to an integrated power supply system includes the following steps: Step 1: Configure the number and parameters of the DC / DC modules 15: Step 1.1: Calculate the total communication power load Ifh of the communication power supply section; Step 1.2: Select the rated output current Ie of the single DC / DC module 15; Step 1.3: Calculate the number of DC / DC modules 15. Round up the result of Ifh ÷ Ie to N. Add one spare module, and the final number of DC / DC modules 15 is N+1. Therefore, when the communication power supply is operating normally, the total output current of the DC / DC modules 15 will not exceed N × Ie.

[0027] Step 2: Analyze the scope of the fault.

[0028] Step 2.1: When the communication DC bus voltage U1T is less than the set value Uset, start analyzing whether a fault occurs in the communication power supply part and the fault location.

[0029] Since the communication power supply part has no energy storage elements such as battery packs or charging capacitors, when a short circuit occurs, the voltage will drop to a very small value, and the output current of the DC / DC module 15 will also increase to the maximum value allowed by the module, usually 1.5 to 2 times Ie. Figure 4 The 0V-1 and -48V-1 of the voltage and current plug-in shown are connected to the Figure 2 The communication DC bus 1T+ bus voltage and 1T- bus voltage are defined as U1T. When U1T is less than the set value Uset, a communication power supply failure is determined. The set value Uset can be set as 60% of the rated communication power supply voltage Ue, i.e., Uset = 60% × 48 = 28.8V.

[0030] Step 2.2: The currents of the bus current sensor 17 and the communication current sensor 18 are collected in real time, and vector sum calculation is performed.

[0031] Figure 4 As shown, IM1+ / IM1- in the current sampling plug-in corresponds to the current output by the bus current sensor 17, which is the sum of the output currents of all DC / DC modules 15. This current is defined as the total DC / DC module output current IM1. Figure 4 As shown, I1~I30 in the current sampling plug-in are connected one by one Figure 2 The current output by the communication feeder circuit breaker 16 in each communication line is defined as communication line currents I1 to I30.

[0032] The communication power auxiliary protection device of the present invention performs vector sum calculation on the total output current IM1 of the DC / DC module and the communication line current I1~I30, that is, I∑=IM1+I1+I2+...+I29+I30. Due to the need to perform vector sum calculation, it is required Figure 2 The polarities of the busbar current sensor 17 and the communication current sensor 18 are matched based on the busbar.

[0033] Step 2.3: Fault analysis.

[0034] When ①.U1T<Uset; ②.IM1<Iset1, the DC / DC module 15 output is faulty; When ①.U1T<Uset; ②.IM1>Iset2; ③.|I∑|>Iset3 are satisfied, the communication DC bus voltage is low and the communication DC bus is faulty; When ①.U1T<Uset; ②.IM1>Iset2; ③.|I∑|<Iset3; ④.I1>Iset4 are satisfied, the communication DC bus voltage is low and a certain communication line is faulty.

[0035] Figure 2 As shown, when a short circuit occurs at point K3, the K3 short-circuit point is between the bus current sensor 17 and the DC / DC module 15. The short-circuit current does not flow through the bus current sensor 17, and the total DC / DC module output current IM1 of the bus current sensor 17 is less than the set value Iset1. Iset1 can be set to 10% times the total rated DC / DC module output current, that is, Iset1 = 10% × N × Ie. When a short circuit occurs at point K3, the communication DC bus voltage decreases. Therefore, the communication power auxiliary protection device of the present invention determines that a fault has occurred at point K3 using the following two logics: ①. U1T < Uset; ②. IM1 < Iset1. If these two logics are met, the communication power auxiliary protection device of the present invention outputs a "communication DC bus voltage low" alarm signal.

[0036] Figure 2As shown, when a short-circuit fault occurs at point K4, the short-circuit point K4 is between the communication feeder circuit breaker 16 and the bus current sensor 17, and the short-circuit current will flow through the bus current sensor 17. The total output current IM1 of the DC / DC module of the bus current sensor 17 is greater than the set value Iset2. Iset2 can be set according to the overall output rated current of the DC / DC module, that is, Iset2=N×Ie; and the absolute value of the current vector sum of each loop related to the communication DC bus 1T-|I∑|> the set value Iset3. Since the value of |I∑| is very small during normal operation or a short-circuit fault outside point K4, and the theoretical value is close to 0, Iset3 can be set to a smaller value. Iset3 can be set according to 10% times the overall output rated current of the DC / DC module, that is, Iset3=10%×N×Ie. When a short circuit occurs at point K4, the DC bus voltage decreases. Therefore, the communication power auxiliary protection device of the present invention determines that a fault has occurred at point K4 using the following three logical conditions: ①. U1T < Uset; ②. IM1 > Iset2; ③. |I∑| > Iset3. If these three logical conditions are met, the communication power auxiliary protection device of the present invention outputs a "low DC bus voltage and bus fault" alarm signal.

[0037] Figure 2 As shown, when a short-circuit fault occurs at point K2 of the communication power DC feeder, a short-circuit fault at point K2 of the first communication line of the communication power part is taken as an example for detailed description: at this time, the short-circuit current will flow through the bus current sensor 17, and the total output current IM1 of the DC / DC module of the bus current sensor 17 is greater than Iset2, and the setting value of Iset2 is the same as above; the absolute value of the current vector sum of each loop related to the DC bus 1T-|I∑|<Iset3, and the setting value of Iset3 is the same as above; when a short-circuit fault occurs at point K2 of the first communication line, the short-circuit current will flow through the communication current sensor 18 of this communication line, and the current I1 of the communication current sensor 18 is greater than the setting value Iset4, and Iset4 can be set to 1.2 times the rated current In of the DC circuit breaker 16 of the first feeder branch loop, that is, Iset4=1.2×In. When a short circuit occurs at point K2, the DC bus voltage decreases. Therefore, the auxiliary protection device for the communication power supply of the present invention determines that a fault has occurred at point K2 on the first communication line of the communication power supply using the following four logical conditions: ①. U1T < Uset; ②. IM1 > Iset2; ③. |I∑| < Iset3; ④. I1 > Iset4. If these four logical conditions are met, the auxiliary protection device of the present invention outputs a "low DC bus voltage and a certain communication line fault" alarm signal.

[0038] After determining that a short circuit fault occurs at point K2 of the first communication line of the communication power supply, if the delay t>tset condition is met and the fault current does not return, Figure 5 The output 1 shown is tripped Figure 2The communication feeder circuit breaker 16 of the first communication line shown, while the communication power auxiliary protection device of the present invention outputs a protection action signal, does not operate and does not output a protection action signal if the fault current returns within the tset delay time. The instantaneous quick-trip protection time of the communication feeder circuit breaker 16 is generally less than 0.01s, and tset can be set to 0.3s, which meets the requirements for the instantaneous quick-trip protection differential of the communication feeder circuit breaker 16. It also avoids the startup surge time of the load, such as SDH equipment, and prevents the auxiliary protection device from accidentally disconnecting due to the equipment startup surge current.

[0039] In addition to outputting alarm signals, the communication power auxiliary protection device of the present invention can also exchange detailed fault information with other systems through the communication interface: when a short circuit fault occurs at point K3, detailed information such as the short circuit occurrence time, short circuit current value, bus voltage value, and fault range of the DC / DC module outlet can be uploaded; when a short circuit fault occurs at point K4, detailed information such as the short circuit occurrence time, short circuit current value, bus voltage value, bus fault, and fault range of the communication power DC bus can be uploaded; when a short circuit fault occurs at point K2, detailed information such as the short circuit occurrence time, short circuit current value, bus voltage value, branch fault, and which branch of the communication power DC feeder the fault range is can be uploaded.

[0040] The communication power auxiliary protection device of the present invention also reserves the ability to trip the DC / DC module incoming line DC circuit breakers 1QD01~1QD03 at the outlet. When a short circuit fault is detected at point K3 or point K4, the reserved spare plug-in outlet can be used to trip the DC / DC module incoming line DC circuit breaker.

[0041] The communication power auxiliary protection device of the present invention combines calculation and logical judgment methods to analyze the fault circuit of the communication power DC feeder and, after a set time, trip the DC circuit breaker of the faulty feeder circuit. Even if the DC circuit breaker's instantaneous quick-trip protection fails, the communication power auxiliary protection device of the present invention can reliably and quickly clear the fault, thereby automatically restoring the communication power supply, ensuring the safety of equipment such as communication power DC / DC modules, and improving the power supply reliability of communication equipment such as SDH.

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several changes and improvements can be made without departing from the overall concept of the present invention, and these should also be regarded as the scope of protection of the present invention.

Claims

1. A communication power supply auxiliary protection method applicable to an integrated power supply system, characterized by: The communication power supply section includes a communication DC bus, a plurality of DC / DC modules (15) are connected to the communication DC bus, and the communication DC bus is also connected to a plurality of communication lines, and a communication feeder circuit breaker (16) and a communication device connected thereto are provided on each communication line; A busbar current sensor (17) for current sampling is connected in series between the DC / DC module (15) and the negative communication DC busbar, a communication current sensor (18) for current sampling is connected in series below the outgoing line of the communication feeder circuit breaker (16) in each communication line, and the output signals of the busbar current sensor (17) and the communication current sensor (18) are connected to the communication power auxiliary protection device; The communication power auxiliary protection device includes a current sampling plug-in, a voltage sampling plug-in, an output plug-in, an alarm plug-in, a communication plug-in and a power plug-in; The protection method includes the following steps: Step 1: Configure the number and parameters of DC / DC modules (15): Step 2: Analyze the fault scope; Step 2.1: When the communication DC bus voltage U1T is less than the set value Uset, start analyzing whether the communication power supply part has a fault and the fault location; Step 2.2: The currents of the bus current sensor (17) and the communication current sensor (18) are collected in real time, and vector sum calculation is performed; the current output by the bus current sensor (17) is the total output current IM1 of the DC / DC module, and the current output by the communication feeder circuit breaker (16) in each communication line is the communication line current I1 to I30; Step 2.3: Fault Analysis: When ①.U1T<Uset; ②. When IM1<Iset1, the DC / DC module (15) output fails; When ①.U1T<Uset; ②.IM1>Iset2; ③. When |I∑|>Iset3, the communication DC bus voltage is low and the communication DC bus is faulty; When ①.U1T<Uset; ②.IM1>Iset2; ③.|I∑|<Iset3; ④. When I1>Iset4, the communication DC bus voltage is low and the communication line is faulty; Among them, Iset1 is the first set threshold of the total output current; Iset2 is the second set threshold of the total output current; Iset3 is the communication DC bus current threshold; Iset4 is the communication line current threshold; |I∑| is the absolute value of the current vector sum.

2. The communication power supply auxiliary protection method applicable to the integrated power supply system according to claim 1, characterized in that: Step 1 includes: Step 1.1: Calculate the total communication power load Ifh of the communication power supply section; Step 1.2: Select the rated output current Ie of a single DC / DC module (15); Step 1.3: Calculate the number of DC / DC modules (15), round up the result of Ifh÷Ie to N, and add one spare module. The final number of DC / DC modules (15) is N+1 configuration.

3. The communication power auxiliary protection method applicable to an integrated power supply system according to claim 1, characterized in that: The set value Uset is 60% times the rated voltage Ue of the communication power supply.

4. The communication power auxiliary protection method applicable to an integrated power supply system according to claim 1, characterized in that: The first set threshold value of the total output current Iset1 is 10% times the total rated output current N×Ie of the DC / DC module; The second set threshold value of the total output current Iset2 is equal to the total rated output current N×Ie of the DC / DC module; The communication DC bus and current threshold Iset3 is 10% times the total rated output current N×Ie of the DC / DC module; The communication line current threshold Iset4 is 1.2 times the rated current In of the circuit breaker (16) of this line.

5. The communication power auxiliary protection method applicable to an integrated power supply system according to claim 1, characterized in that: After determining that a short circuit fault occurs in the communication line of the communication power supply, the communication feeder circuit breaker (16) of the communication line is tripped when the delay t>tset condition is met and the fault current does not return; at the same time, the auxiliary protection device of the communication power supply outputs a protection action signal; if the fault current returns within the tset delay time, the circuit breaker is not tripped and the protection action signal is not output.

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