A three-phase to single-phase power supply method and system for a communication base station

Abstract

The present invention discloses a method and system for converting three-phase power supply to single-phase power supply in a communication base station. The method includes the following steps: (1) Selecting an access mode for converting three-phase power supply to single-phase power supply; (2) Selecting an electric energy metering method and wiring mode; (3) Selecting a new conductor diameter and laying a new conductor for single-phase line voltage power transmission for the new wire according to the access mode of converting three-phase power supply to single-phase power supply, or performing parallel connection processing and transformation on the original wire; (4) Adding a dynamic voltage regulation and compensation device in the communication base station. The system includes a single-phase line voltage output power supply access and electric energy metering unit, a power transmission line, a voltage regulation and compensation device, and a base station load. The present invention solves the problem of three-phase imbalance of the base station load, improves the power supply reliability and power supply capacity, reduces the line power loss of three-phase load imbalance, reduces the equipment failure rate, and reduces the operation and maintenance cost of the base station.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply and consumption systems, and more specifically, to a three-phase to single-phase power supply method and system for communication base stations. Background Art

[0002] At present, three-phase four-wire or three-phase three-wire power supply methods are commonly used in communication base stations in China. Due to the unbalanced three-phase load of the base stations, phase loss faults often occur, some loads cannot work properly, the equipment failure rate is high, the operation and maintenance cost is large, and the power loss of the line also increases, resulting in energy waste. In addition, compared with other power users, the power consumption of the base station load is very small. Therefore, it is necessary to convert the three-phase four-wire or three-phase three-wire power supply method of the communication base station into a single-phase voltage power supply method.

[0003] However, the current problem with the three-phase to single-phase voltage power supply method for communication base stations is that since the three phases A, B, and C are respectively connected to the neutral line N, and three 220V single-phases carry three different loads, when the total power supply capacity does not exceed the standard, the power supply capacity of each of the three phases is one-third. When the three-phase load is unbalanced, one phase will be overloaded, and the other phase or two phases will be underloaded, and even a phase loss fault may be triggered, and the load of the fault phase will be powered off. At the same time, due to the unbalanced three-phase load and the transmission of electric energy by the 220V phase voltage, the line loss is increased.

[0004] Therefore, there is an urgent need for a three-phase to single-phase power supply method and system for communication base stations to overcome the problems existing in the three-phase to single-phase voltage power supply method, solve the problem of unbalanced three-phase load of the base station, improve the power supply reliability, reduce the line power loss of the unbalanced three-phase load, reduce the equipment failure rate, and reduce the operation and maintenance cost of the base station. Summary of the Invention

[0005] The purpose of the present invention is to provide a three-phase to single-phase power supply method and system for communication base stations, which solves the problem of unbalanced three-phase load of the base station, improves the power supply reliability and power supply capacity, reduces the line power loss of the unbalanced three-phase load, reduces the equipment failure rate, and reduces the operation and maintenance cost of the base station.

[0006] To achieve the above object, a three-phase to single-phase power supply method for communication base stations is provided, including the following steps:

[0007] (1) Select a power supply access method for converting a three-phase power supply into a single-phase power supply;

[0008] (2) Select an electric energy metering method and wiring method;

[0009] (3) According to the power supply access method for converting a three-phase power supply into a single-phase power supply, select a new conductor diameter and lay a new conductor for single-phase line voltage electric energy transmission for the new wire, or perform parallel connection processing and transformation on the original wire;

[0010] (4) Install a dynamic voltage regulation and compensation device in the communication base station; the dynamic voltage regulation and compensation device adopts: a. Dynamic step-down voltage regulation mode: After the 400V line voltage of the commercial power is transmitted to the base station through the line, it is stepped down to a 220V single-phase power supply for parallel power supply to the three-phase load, ensuring that there are no overloading and single-phase fault phenomena; b. Dynamic step-up voltage regulation mode: After the 220V phase voltage generated by the generator is attenuated and transmitted to the base station through the line, it is stepped up to a 220V single-phase power supply for parallel power supply to the three-phase load, ensuring that there are no overloading and single-phase fault phenomena; c. Compensate the starting current of the air-conditioning equipment through the dynamic reactive power compensation device, stabilize the terminal voltage of the air-conditioning equipment, ensure the normal operation of the air-conditioning equipment and prevent system over-current tripping.

[0011] Specifically, in step (1), the access methods for converting the three-phase power supply to a single-phase power supply include the three-phase four-wire system access method, the three-phase three-wire system access method, and the single-phase two-wire system access method;

[0012] The three-phase four-wire system access method and the three-phase three-wire system access method are used for the single-phase power supply access of communication base stations in the technical transformation projects of 4G, 4G to 5G, and 5G communication base stations; the single-phase two-wire system access method is used for the single-phase power supply access of newly built communication base stations.

[0013] Specifically, in step (2), the electric energy measurement method and wiring method include the three-phase four-wire system measurement wiring method, the three-phase three-wire system measurement wiring method, and the single-phase two-wire system measurement wiring method; the three-phase four-wire system measurement wiring method and the three-phase three-wire system measurement wiring method are used for the electric energy measurement of the single-phase power supply of communication base stations in the technical transformation projects of 4G, 4G to 5G, and 5G communication base stations; the single-phase two-wire system measurement wiring method is used for the electric energy measurement of the single-phase power supply of newly built communication base stations;

[0014] The three-phase four-wire system measurement wiring method uses the three-meter method for the electric energy measurement method, and the wiring method is that the three phases at the power output end of the three-phase four-wire system are respectively connected to the same-name ends of the current coils and voltage coils of the three meters, the different-name ends of the current coils are connected to the power supply access end of the communication base station, and the disconnected ones without connection are left open. The different-name ends of the voltage coils of the three meters are respectively connected to the neutral line;

[0015] The three-phase three-wire system measurement wiring method uses the two-meter method for the electric energy measurement method, and the wiring method is that the two phases for accessing the single-phase power supply of the communication base station on the low-voltage side of the three-phase three-wire system power supply are respectively connected to the same-name ends of the current coils and voltage coils of the two meters, and the different-name ends of the current coils are connected to the two phases of the power supply access end of the communication base station; the different-name ends of the voltage coils of the two meters are respectively connected to the non-access phases of the communication base station power supply;

[0016] The single-phase two-wire system measurement wiring method uses the single-meter method for the electric energy measurement method, and the wiring method is the two phases with relatively light loads on the low-voltage side of the three-phase three-wire system or the three-phase four-wire system.

[0017] Specifically, the access methods for converting a three-phase power supply to a single-phase power supply in step (3) include the access method of transforming a three-phase four-wire system line into a single-phase power supply, the access method of transforming a three-phase three-wire system line into a single-phase power supply, a single-phase two-wire system, and the access method of changing a high-voltage special transformer into a public transformer single-phase power supply;

[0018] The access method of transforming a three-phase four-wire system line into a single-phase power supply includes a public transformer access method and a special transformer access method; the public transformer access method of the three-phase four-wire system access method is that the single-phase power supply of the communication base station is connected from two phases with a lighter load on the low-voltage side of the public transformer, and the unconnected phase and the neutral line N are disconnected at the output side of the three-phase four-wire power supply side and the input side of the communication base station respectively; the special transformer access method of the access method of transforming a three-phase four-wire system line into a single-phase power supply is to disconnect the middle phase on the high-voltage side of the special transformer;

[0019] The access method of transforming a three-phase three-wire system line into a single-phase power supply includes a public transformer access method and a special transformer access method; the public transformer access method of the access method of transforming a three-phase three-wire system line into a single-phase power supply is that the single-phase power supply of the communication base station is connected from two phases with a lighter load on the low-voltage side of the public transformer, and the unconnected phase is disconnected at the output side of the three-phase three-wire power supply side and the input side of the communication base station respectively; the special transformer access method of the access method of transforming a three-phase three-wire system line into a single-phase power supply is to disconnect the middle phase on the high-voltage side of the special transformer;

[0020] The single-phase two-wire system includes a public transformer access method and a special transformer access method; the public transformer access method of the single-phase two-wire system is that the single-phase power supply of the communication base station is connected from two phases with a lighter load on the low-voltage side of the public transformer; the special transformer access method of the single-phase two-wire system is to disconnect the middle phase on the high-voltage side of the special transformer;

[0021] The access method of transforming a three-phase four-wire system line into a single-phase power supply, the access method of transforming a three-phase three-wire system line into a single-phase power supply, a single-phase two-wire system, and the access method of changing a high-voltage special transformer into a public transformer single-phase power supply: Specifically, for the access method of transforming a three-phase four-wire system line into a single-phase power supply, the non-electric energy transmission phase line and the neutral line N that are disconnected are respectively connected in parallel in pairs at both ends of the two electric energy transmission lines; specifically, for the access method of transforming a three-phase three-wire system line into a single-phase power supply, the non-electric energy transmission phase line disconnected at the low-voltage side of the transformer is connected in parallel in pairs at both ends of one of the two electric energy transmission lines;

[0022] For the single-phase two-wire line transformation, the specific access method for single-phase power supply is as follows: For connection to a public transformer: The single-phase power supply of the communication base station is connected from the two phases with lighter loads on the low-voltage side of the public transformer; the unconnected phase is disconnected. For connection to a dedicated transformer: Disconnect the middle phase on the high-voltage side of the dedicated transformer. The cross-sectional area of the conductor of the power transmission line should meet the overload capacity of twice the maximum load power of the communication base station and the requirements for controlling the power loss of the line.

[0023] The specific method for changing the power supply mode from a dedicated high-voltage transformer to a public transformer is as follows: Change the power supply mode of the dedicated transformer on the 10kV line with low power supply reliability, high failure rate, and high maintenance cost in the communication base station to the single-phase line voltage power supply mode on the low-voltage side of the public transformer. According to the actual situation, utilize the disconnected 10kV line and add some laid single-phase power supply transmission lines. When using the 10kV line, use the two outer-phase lines as part of the transmission lines for the low-voltage single-phase power supply, and the middle phase of the 10kV line is left disconnected.

[0024] Particularly, in step (4), the voltage regulation and compensation device added to the base station includes: a voltage regulation transformer and a reactive power compensation device.

[0025] Particularly, the primary side of the voltage regulation transformer can select the boost mode or the buck mode, and the secondary side is in the voltage regulation mode. The voltage regulation range meets the requirements of qualified voltage quality for power supply with a line voltage over a distance of no more than 2000 meters in the urban area and for power supply with a phase voltage during generator operation.

[0026] Particularly, the designed capacity and switching groups of the reactive power compensation device meet the reactive power compensation requirements for air conditioner startup and normal operation, and ensure that the power factor of the communication base station is not less than 0.95.

[0027] A three-phase to single-phase power supply and metering system for a communication base station, characterized by comprising a single-phase line voltage output power supply access and electric energy metering unit, a power transmission line, a voltage regulation and compensation device, and a base station load.

[0028] The single-phase line voltage output power supply access and electric energy metering unit includes the access of the base station single-phase power supply that is transformed from the three-phase four-wire system or three-phase three-wire system on the low-voltage side of the public transformer or dedicated transformer and the access of the corresponding electric energy metering electric meter.

[0029] The power transmission line includes a two-wire power transmission line that is transformed from the three-phase four-wire system or three-phase three-wire system on the low-voltage side of the public transformer or dedicated transformer to a single-phase line voltage output. For the technical transformation of the base station, the original line needs to be merged or the line needs to be transformed accordingly.

[0030] Particularly, the voltage regulation and compensation device includes a voltage regulation transformer and a reactive power compensation device.

[0031] Specifically, the base station load includes the power supply equipment, communication equipment, storage battery, lighting equipment, air conditioning equipment, and other auxiliary electrical equipment of the base station.

[0032] The beneficial effects of the present invention are as follows:

[0033] Compared with the prior art, the present invention has the advantages of high power supply reliability, strong overload capacity, wide voltage regulation range, good voltage quality, high electric energy utilization efficiency, small line loss, high utilization rate of diesel generator and air conditioning equipment, and little influence of load characteristics on safe operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0035] Figure 1 is a flowchart of the method embodiment related to the present invention.

[0036] Figure 2 is a three-phase four-wire system structure block diagram of the system embodiment related to the present invention.

[0037] Figure 3 is a three-phase three-wire system structure block diagram of the system embodiment related to the present invention.

[0038] Figure 4 is a single-phase two-wire system structure block diagram of the system embodiment related to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following will elaborate on the preferred embodiments of the present invention in conjunction with the drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0040] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0041] It should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention patent product is customarily placed during use. It is only for the convenience of describing the invention patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the invention patent. In addition, terms such as "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0042] In addition, terms such as "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0043] As Figure 1 shown, a three-phase to single-phase power supply method for a communication base station according to an embodiment of the present invention includes the following steps:

[0044] (1) Select a three-phase power supply to single-phase power supply access method;

[0045] (2) Select an electric energy metering method and wiring method;

[0046] (3) According to the three-phase power supply to single-phase power supply access method, select a new conductor diameter and lay a single-phase line voltage power transmission line for the new conductor, or perform parallel connection processing and transformation on the original conductor;

[0047] (4) Add a dynamic voltage regulation and compensation device to the communication base station; the dynamic voltage regulation and compensation device adopts: a. Dynamic voltage reduction regulation mode: After the 400V line voltage of the commercial power is transmitted to the base station through the line, it is stepped down to 220V single-phase power supply for parallel power supply to the three-phase load to ensure that there are no overloading and phase loss fault phenomena; b. Dynamic voltage increase regulation mode: After the 220V phase voltage of the generator power generation is attenuated and transmitted to the base station through the line, it is stepped up to 220V single-phase power supply for parallel power supply to the three-phase load to ensure that there are no overloading and phase loss fault phenomena; c. The dynamic reactive power compensation device compensates the starting current of the air conditioning equipment, stabilizes the terminal voltage of the air conditioning equipment, and ensures the normal operation of the air conditioning equipment and that there is no system overcurrent tripping.

[0048] In step (1), the three-phase power supply to single-phase power supply access methods include a three-phase four-wire system access method, a three-phase three-wire system access method, and a single-phase two-wire system access method;

[0049] The three-phase four-wire access mode and the three-phase three-wire access mode are used for the single-phase power supply access of communication base stations in the technical transformation projects of 4G, 4G to 5G, and 5G communication base stations; the single-phase two-wire access mode is used for the single-phase power supply access of newly built communication base stations.

[0050] In step (2), the electric energy measurement method and wiring method include the three-phase four-wire measurement wiring method, the three-phase three-wire measurement wiring method, and the single-phase two-wire measurement wiring method; the three-phase four-wire measurement wiring method and the three-phase three-wire measurement wiring method are used for the electric energy measurement of the single-phase power supply in the technical transformation projects of 4G, 4G to 5G, and 5G communication base stations; the single-phase two-wire measurement wiring method is used for the electric energy measurement of the single-phase power supply of newly built communication base stations.

[0051] In step (3), the access mode of converting three-phase power to single-phase power supply includes the access mode of transforming a three-phase four-wire line to a single-phase power supply, the access mode of transforming a three-phase three-wire line to a single-phase power supply, the single-phase two-wire system, and the access mode of changing a high-voltage special transformer to a common transformer for single-phase power supply.

[0052] The three-phase four-wire access mode includes the public transformer access mode and the special transformer access mode.

[0053] For the public transformer access mode of the three-phase four-wire access mode, the single-phase power supply of the communication base station is connected from two phases A and B with lighter load on the low-voltage side of the public transformer, or B and C, or C and A. The unconnected phase and the neutral line N are disconnected at the output side of the three-phase four-wire power supply side and the input side of the communication base station respectively.

[0054] For the special transformer access mode of the three-phase four-wire access mode, the middle phase B of the high-voltage side of the special transformer is disconnected; for example: when B is disconnected, the single-phase power supply of the communication base station is connected from the two side phases A and C, and the unconnected phase B; phase B and the neutral line N are disconnected at the output side of the three-phase four-wire power supply side and the input side of the communication base station respectively.

[0055] The three-phase three-wire access mode includes the public transformer access mode and the special transformer access mode.

[0056] For the public transformer access mode of the three-phase three-wire access mode, the single-phase power supply of the communication base station is connected from two phases A and B with lighter load on the low-voltage side of the public transformer, or B and C, or C and A. The unconnected phase C; A; B are disconnected at the output side of the three-phase three-wire power supply side and the input side of the communication base station respectively.

[0057] For the special transformer access mode of the three-phase three-wire access mode, the middle phase of the high-voltage side of the special transformer: B is disconnected. For example: when B is disconnected, the single-phase power supply of the communication base station is connected from the two side phases A and C, and the unconnected phase B is disconnected at the output side of the three-phase three-wire power supply side and the input side of the communication base station respectively.

[0058] The single-phase two-wire system includes the connection method of a public transformer and the connection method of a dedicated transformer;

[0059] For the connection method of a public transformer in the single-phase two-wire system, the single-phase power supply of the communication base station is connected from the two relatively lightly loaded phases A and B, or B and C, or C and A on the low-voltage side of the public transformer;

[0060] For the connection method of a dedicated transformer in the single-phase two-wire system, the middle phase on the high-voltage side of the dedicated transformer is disconnected. For example, phase B is disconnected, and the single-phase power supply of the communication base station is connected from the two outer phases A and C on the low-voltage side of the dedicated transformer, and the unconnected phase B on the low-voltage side is disconnected.

[0061] For the three-phase four-wire metering connection method, the electrical energy metering method uses the three-meter method. The wiring method is that phase A, phase B, and phase C at the output end of the three-phase four-wire power supply are respectively connected to the same-named ends of the current coils and voltage coils of three meters. The opposite-named ends of the current coils are connected to the power supply access ends of the communication base station, and those without a connection relationship are disconnected. The opposite-named ends of the voltage coils of the three meters are respectively connected to the neutral line N;

[0062] For the three-phase three-wire metering connection method, the electrical energy metering method uses the two-meter method. The wiring method is that the two phases where the single-phase power supply of the communication base station is connected on the low-voltage side of the three-phase three-wire power supply, for example, phases A and C, are respectively connected to the same-named ends of the current coils and voltage coils of two meters. The opposite-named ends of the current coils are connected to phases A and C of the power supply access ends of the communication base station; the opposite-named ends of the voltage coils of the two meters are respectively connected to the non-connected phase of the communication base station power supply, that is, phase B.

[0063] For the single-phase two-wire metering connection method, the electrical energy metering method uses the single-meter method. The wiring method is that one of the two relatively lightly loaded phases on the low-voltage side of the three-phase three-wire system or the three-phase four-wire system, for example, one of phases A and C, for example, phase A, is connected to the same-named ends of the current coil and voltage coil of the meter. The opposite-named end of the current coil of the meter is connected to phase A of the power supply access end of the communication base station, and the opposite-named end of the voltage coil of the meter is connected to the other phase on the low-voltage side of the three-phase three-wire system or the three-phase four-wire system, that is, phase C.

[0064] The connection methods for the transformation of the three-phase four-wire system to single-phase power supply, the transformation of the three-phase three-wire system to single-phase power supply, the single-phase two-wire system, and the transformation of the high-voltage dedicated transformer to the single-phase power supply of the public transformer specifically include:

[0065] A. For the connection method of the transformation of the three-phase four-wire system to single-phase power supply, the non-electric energy transmission phase line and the neutral line N that are disconnected are respectively connected in parallel in pairs at both ends of the two electric energy transmission lines;

[0066] For the connection method of the transformation of the three-phase three-wire system to single-phase power supply, the non-electric energy transmission phase line disconnected on the low-voltage side of the transformer is connected in parallel in pairs at both ends of one of the two electric energy transmission lines;

[0067] For the renovation of single-phase two-wire lines and the connection method of single-phase power supply, specifically, if it is connected to a public transformer: the single-phase power supply of the communication base station is connected from the two relatively lightly loaded phases A and B, or B and C, or C and A on the low-voltage side of the public transformer; the unconnected phase C; A; B is disconnected; if it is connected to a dedicated transformer: disconnect the middle phase on the high-voltage side of the dedicated transformer. For example: disconnect phase B, and the single-phase power supply of the communication base station is connected from the two side phases A and C on the low-voltage side of the dedicated transformer, and the unconnected phase B on the low-voltage side is disconnected. The cross-sectional area of the conductor of the power transmission line should meet the requirements of the overload capacity twice that of the maximum load power of the communication base station and the control of the power loss of the control line.

[0068] The specific method for changing the power supply mode of the high-voltage dedicated transformer to the public transformer power supply is as follows: change the power supply mode of the dedicated transformer on the 10kV line with low power supply reliability, high failure rate, and high maintenance cost of the communication base station to the single-phase line voltage power supply mode on the low-voltage side of the public transformer. According to the actual situation, utilize the disconnected 10kV line and add part of the laid single-phase power supply power transmission line; when using the 10kV line, use the two side phases of the line as part of the power transmission line for the low-voltage single-phase power supply, and the middle phase of the 10kV line is disconnected and not used.

[0069] In step (4), the voltage regulation and compensation device added to the base station includes: a voltage regulation transformer and a reactive power compensation device.

[0070] The primary side of the voltage regulation transformer can select the boost mode or the buck mode, and the secondary side is in the voltage regulation mode. The voltage regulation range meets the requirements of qualified voltage quality for the power supply of the urban wire voltage at a distance of no more than 2000 meters and the phase voltage power supply of the generator set.

[0071] The designed capacity and switching groups of the reactive power compensation device meet the reactive power compensation requirements for the start-up and normal operation of the air conditioner, and ensure that the power factor of the communication base station is not less than 0.95.

[0072] A three-phase to single-phase power supply and metering system for a communication base station, characterized in that it includes a single-phase line voltage output power supply access and electric energy metering unit, a power transmission line, a voltage regulation and compensation device, and a base station load;

[0073] The single-phase line voltage output power supply access and electric energy metering unit includes the access of the base station single-phase power supply converted from the three-phase four-wire system or three-phase three-wire system on the low-voltage side of the public transformer or dedicated transformer and the access of the corresponding electric energy metering meter.

[0074] The power transmission line includes a two-wire power transmission line converted from the three-phase four-wire system or three-phase three-wire system on the low-voltage side of the public transformer or dedicated transformer to a single-phase line voltage output. The renovated base station needs to perform corresponding line parallel connection or line renovation on the original line.

[0075] The voltage regulating and compensating device includes a voltage regulating transformer and a reactive power compensating device.

[0076] The base station load includes the power supply equipment, communication equipment, storage battery, lighting equipment, air conditioning equipment and other auxiliary electrical equipment of the base station.

[0077] After the power transmission lines are combined, the total resistance value of the lines decreases, the power loss decreases, and the transmission capacity may increase. The specific situations are as follows:

[0078] A. Three-phase four-wire system: Four lines, two in parallel with each other. The total resistance value of the lines after parallel connection is shown in Equation (1), and the power transmission capacity increases accordingly.

[0079]

[0080] B. Three-phase three-wire system: Three lines, two in parallel and one unchanged. The total resistance value of the lines after parallel connection is shown in Equation (2), and the power transmission capacity remains unchanged.

[0081]

[0082] In Equations (1) and (2), R iL , i = A, B, C are the resistances of the phase A, phase B and phase C lines respectively, and RNL is the resistance of the neutral line.

[0083] C. The single-phase power transmission lines are the phase A and phase C lines. R L is the total resistance of the phase A and phase C lines of the single-phase power transmission line.

[0084] By controlling the total resistance value of the line through the selection of the line conductor, the power loss of the line is controlled. The power loss of the single-phase power transmission line is ΔP L :

[0085] ΔP L = R L I 2

[0086]

[0087] In Equation (3): P is the output active power (W) of the single-phase power supply connected to the base station, I is the line current (A), RL is the total resistance of the line (Ω), U is the single-phase power supply voltage (V), is the output power factor of the single-phase power supply connected to the base station.

[0088] ΔP L (%) < the allowable value specified by the country or industry (meeting the requirements of national and industrial energy conservation and emission reduction).

[0089] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, the patent owner may make various deformations or modifications within the scope of the appended claims. As long as the protection scope is not exceeded as described in the claims of the present invention, it should be within the protection scope of the present invention.

Claims

1. A three-phase to single-phase power supply method for a communication base station, characterized in that, It includes the following steps: (1) Select the power supply access mode of converting three-phase power supply to single-phase power supply; (2) Select the electric energy metering method and wiring mode; (3) According to the power supply access mode of converting three-phase power supply to single-phase power supply, select the new conductor diameter and laying of the single-phase line voltage power transmission line for the new conductor, or conduct parallel connection treatment and transformation on the original conductor; (4) Add a dynamic voltage regulation and compensation device to the communication base station; the dynamic voltage regulation and compensation device adopts: a. Dynamic step-down voltage regulation mode: After the 400V line voltage of the commercial power is transmitted to the base station through the line, it is stepped down to 220V single-phase power supply for parallel power supply to the three-phase load to ensure that there are no overloading and phase loss fault phenomena; b. Dynamic step-up voltage regulation mode: After the 220V phase voltage of the generator power is attenuated and transmitted to the base station through the line, it is stepped up to 220V single-phase power supply for parallel power supply to the three-phase load to ensure that there are no overloading and phase loss fault phenomena; c. Compensate the starting current of the air conditioning equipment through the dynamic reactive power compensation device, stabilize the terminal voltage of the air conditioning equipment, and ensure the normal operation of the air conditioning equipment and no system overcurrent tripping; In step (1), the power supply access mode of converting three-phase power supply to single-phase power supply includes three-phase four-wire system access mode, three-phase three-wire system access mode and single-phase two-wire system access mode; The three-phase four-wire system access mode and three-phase three-wire system access mode are used for the single-phase power supply access of communication base stations in the technical transformation projects of 4G, 4G to 5G and 5G communication base stations; the single-phase two-wire system access mode is used for the single-phase power supply access of newly built communication base stations; In step (3), the power supply access mode of converting three-phase power supply to single-phase power supply includes the single-phase power supply access mode of three-phase four-wire system line transformation, the single-phase power supply access mode of three-phase three-wire system line transformation, single-phase two-wire system and the single-phase power supply access mode of converting a high-voltage special transformer to a public transformer; The single-phase power supply access mode of three-phase four-wire system line transformation includes public transformer access mode and special transformer access mode; the public transformer access mode of the three-phase four-wire system access mode is that the single-phase power supply of the communication base station is accessed from two phases with lighter load on the low-voltage side of the public transformer, and the unconnected phase and the neutral line N are disconnected at the output side of the three-phase four-wire system power supply side and the input side of the communication base station respectively; The special transformer access mode of the single-phase power supply access mode of three-phase four-wire system line transformation is to disconnect the middle phase of the high-voltage side of the special transformer; The single-phase power supply access mode of three-phase three-wire system line transformation includes public transformer access mode and special transformer access mode; the public transformer access mode of the single-phase power supply access mode of three-phase three-wire system line transformation is that the single-phase power supply of the communication base station is accessed from two phases with lighter load on the low-voltage side of the public transformer, and the unconnected phase is disconnected at the output side of the three-phase three-wire system power supply side and the input side of the communication base station respectively; the special transformer access mode of the single-phase power supply access mode of three-phase three-wire system line transformation is to disconnect the middle phase of the high-voltage side of the special transformer; The single-phase two-wire system includes a common transformer access mode and a dedicated transformer access mode; the common transformer access mode of the single-phase two-wire system is that the single-phase power supply of the communication base station is connected to the two phases with lighter loads on the low-voltage side of the common transformer; the dedicated transformer access mode of the single-phase two-wire system is to disconnect the middle phase on the high-voltage side of the dedicated transformer; The access modes of single-phase power supply for the transformation of three-phase four-wire system lines, the access modes of single-phase power supply for the transformation of three-phase three-wire system lines, the single-phase two-wire system, and the transformation of high-voltage dedicated transformers to common transformer single-phase power supply access modes: Specifically, for the access mode of single-phase power supply for the transformation of three-phase four-wire system lines, the non-electric energy transmission phase line and the neutral line N that are disconnected are respectively connected in parallel in pairs at both ends of the two electric energy transmission lines; Specifically, for the access mode of single-phase power supply for the transformation of three-phase three-wire system lines, the non-electric energy transmission phase line disconnected at the low-voltage side of the transformer is connected in parallel in pairs at both ends of one of the two electric energy transmission lines; Specifically, for the access mode of single-phase power supply for the transformation of single-phase two-wire system lines, if it is a common transformer access: the single-phase power supply of the communication base station is connected to the two phases with lighter loads on the low-voltage side of the common transformer; The unconnected phase is disconnected; If it is a dedicated transformer access: disconnect the middle phase on the high-voltage side of the dedicated transformer, and the cross-sectional area of the conductor of the electric energy transmission line should meet the overload capacity of 2 times the maximum load power of the communication base station and the requirements for controlling the electric energy loss of the line; The specific method for transforming the high-voltage dedicated transformer to a common transformer power supply mode is: the dedicated transformer power supply mode of the 10kV line with low power supply reliability, high failure rate, and high maintenance cost in the communication base station is changed to the single-phase line voltage power supply mode of the low-voltage side of the common transformer. According to the actual situation, use the disconnected 10kV line and add some laid single-phase power supply electric energy transmission lines; when using the 10kV line, use the two side phases of the line as part of the electric energy transmission lines for low-voltage single-phase power supply, and the middle phase of the 10kV line is disconnected and not used.

2. The three-phase to single-phase power supply method for a communication base station according to claim 1, wherein: In step (2), the electric energy metering method and wiring method include the three-phase four-wire metering wiring method, the three-phase three-wire metering wiring method, and the single-phase two-wire metering wiring method; the three-phase four-wire metering wiring method and the three-phase three-wire metering wiring method are used for the electric energy metering of the single-phase power supply in the technical transformation projects of 4G, 4G to 5G, and 5G communication base stations; the single-phase two-wire metering wiring method is used for the electric energy metering of the single-phase power supply in newly built communication base stations; The three-phase four-wire metering wiring method is that the electric energy metering method uses the three-meter method, and the wiring method is that the three phases at the output end of the three-phase four-wire power supply are respectively connected to the same-name ends of the current coils and voltage coils of the three meters. The different-name ends of the current coils are connected to the power supply access end of the communication base station, and the disconnected ones without connection are disconnected. The different-name ends of the voltage coils of the three meters are respectively connected to the neutral line; The three-phase three-wire metering connection method uses the two-meter method for the electrical energy metering method. The connection method is that for the two phases connected to the single-phase power supply of the communication base station on the low-voltage side of the three-phase three-wire power supply, the same-name ends of the current coils of two meters and the same-name ends of the voltage coils are respectively connected, and the opposite-name ends of the current coils are connected to the two phases of the power supply access end of the communication base station; the opposite-name ends of the voltage coils of the two meters are respectively connected to the non-access phases of the communication base station power supply. The single-phase two-wire metering connection method uses the single-meter method for the electrical energy metering method. The connection method is for the two phases with relatively light loads on the low-voltage side of the three-phase three-wire system or the three-phase four-wire system.

3. A three-phase to single-phase power supply method for a communication base station according to claim 1, characterized in that: In step (4), the voltage regulation and compensation device added to the base station includes: a voltage regulation transformer and a reactive power compensation device.

4. A three-phase to single-phase power supply method for a communication base station according to claim 3, characterized in that: The primary side of the voltage regulation transformer can select the boost mode or the buck mode, and the secondary side is in the voltage regulation mode. The voltage regulation range meets the requirement of qualified voltage quality for the supply of the line voltage of the urban power line with a distance of no more than 2000 meters and the phase voltage supply of the diesel generator.

5. A three-phase to single-phase power supply method for a communication base station according to claim 1, characterized in that: The designed capacity and switching groups of the reactive power compensation device meet the reactive power compensation requirements for the start-up and normal operation of the air-conditioning equipment, and ensure that the power factor of the communication base station is not less than 0.

95.

6. A three-phase to single-phase power supply system for a communication base station, which uses any one of the three-phase to single-phase power supply methods for a communication base station according to claims 1-5, characterized in that, It includes a single-phase line voltage output power supply access and electrical energy metering unit, a power transmission line, a voltage regulation and compensation device, and a base station load; the single-phase line voltage output power supply access and electrical energy metering unit includes the access of the base station single-phase power supply converted from the low-voltage side of the public transformer or the special transformer from the three-phase four-wire system or the three-phase three-wire system to the single-phase line voltage output and the access of the corresponding electrical energy metering meter. The power transmission line includes a two-wire power transmission line converted from the low-voltage side of the public transformer or the special transformer from the three-phase four-wire system or the three-phase three-wire system to the single-phase line voltage output. For the technical transformation of the base station, the original line needs to be correspondingly merged or the line needs to be transformed.

7. The three-phase to single-phase power supply system for a communication base station according to claim 6, wherein: The voltage regulation and compensation device includes a voltage regulation transformer and a reactive power compensation device.

8. A three-phase to single-phase power supply system for a communication base station according to claim 6, characterized in that: The base station load includes the power supply equipment, communication equipment, storage battery, lighting equipment, air-conditioning equipment, and other auxiliary electrical equipment of the base station.

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