CN112367566B

CN112367566B - Communication base station high-reliability low-loss alternating current power supply method and device

Info

Publication number: CN112367566B
Application number: CN202011196384.0A
Authority: CN
Inventors: 李晓明
Original assignee: Guangxi Luogui Energy Conservation And Environmental Protection Research Institute Co ltd
Current assignee: Guangxi Luogui Energy Conservation And Environmental Protection Research Institute Co ltd
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2023-03-14
Anticipated expiration: 2040-10-30
Also published as: CN112367566A

Abstract

The invention discloses a high-reliability low-loss alternating current voltage-stabilizing power supply method and device for a communication base station. The method comprises the following steps: (1) converting a three-phase four-wire power supply of a communication base station into a single-phase two-wire power supply; (2) setting a standby power supply and commercial power supply switching device, and switching to the standby power supply when the power grid fails; (3) converting the three-phase four-wire transmission electric energy into single-phase two-wire transmission electric energy; (4) a wide-range bidirectional voltage regulating transformer is arranged, and a power electronic switch controls the voltage tap joint switching of the transformer. (5) The dynamic reactive power compensation device controls the reactive power of the input end of the voltage regulating transformer. (6) The single-phase two-line power supply is divided into two groups of power supplies for supplying power, one group of voltage-regulating power supply single-phase load and the other group of split-phase power supply three-phase load. The device comprises a power supply conversion device, a power supply switching device, single-phase two-wire electric energy transmission, a dynamic voltage regulating device, a reactive power compensation device and a hybrid power supply device. The invention has the advantages of high electric energy utilization rate, low failure rate and small influence of load characteristics on safe operation.

Description

Communication base station high-reliability low-loss alternating current power supply method and device

Technical Field

The invention relates to the field of energy conservation and environmental protection of power supply and utilization systems, in particular to a high-reliability low-loss alternating current power supply method and device for a communication base station.

Background

The reliability of power supply equipment of a communication base station (iron tower) directly influences the communication service quality, and is related to the data transmission of a wide area network, remote voice and video communication, accident rescue, disaster prevention, disaster resistance and the like, the rural areas in vast mountainous areas have multiple and wide sites of the iron tower, the construction and maintenance environment is severe, and the workload is huge. Due to the phenomena of power failure of a power grid, lightning strike failure of a transformer special for an iron tower, high loss of a storage battery of a base station, difficult power generation and the like, the power supply reliability of the base station is not high, the operation quality cannot meet the requirements of customers, and the power supply quality of the base station is urgently required to be improved by an iron tower company so as to fundamentally solve three problems which puzzle the operation of telecommunication enterprises for a long time.

Frequent influence of power failure on customer service index

The power failure times of the whole network of a certain city in the mountain area in 2018 are 158036, according to data provided by a power grid company, 40% of the power failure reasons of the large network fault are caused by line faults of special transformers of iron towers, and therefore the iron tower base stations are out of service in batches, and the deterioration of operation indexes is further aggravated.

The failure rate and maintenance cost of the special transformer are high

Due to the reasons of insufficient coverage of most rural power grids, low transformer capacity and the like, a special transformer is mostly used for supplying power to a base station during station building, but a plurality of adverse factors such as high failure rate, high operation cost and the like are brought. In 2018, the total number of fault maintenance of the special transformer in a certain city is 4929.

(III) difficulty in power generation guarantee is a main factor influencing indexes

After the power grid has a power failure, an iron tower company guarantees that an operator base station normally operates through oil engine power generation, mountains in mountainous areas have a large number of high sites, power generation difficulty is high, and the power generation demand satisfaction rate of customers is always at a low level.

In the face of rapid development of mobile internet and arrival of the 5G era, the demand of large-flow data and the flow of mobile data are increased explosively, a large number of 5G macro stations and micro stations need to be built, about 600 ten thousand communication base stations are needed for national 5G network coverage in nearly 6 to 7 years, and meanwhile, energy-saving, environment-friendly, high-reliability and intelligent efficient power supply equipment for the communication base stations is urgently needed for the existing 3G/4G base stations and newly-built 5G base stations.

Disclosure of Invention

The invention provides a high-reliability low-loss alternating current power supply method and device for a communication base station, which are based on the principle that technologies such as a dynamic voltage regulation compensation technology, a three-phase power supply conversion single-phase power supply technology, a power supply switching technology, a power electronic technology, a measurement and control technology, network communication, artificial intelligent control and the like are comprehensively adopted, and the problems that rural communication base stations in mountainous areas generally have unqualified voltage quality in different degrees, unbalanced three phases of loads, high fault rate of a transformer special for a power grid, high phase-failure fault rate of the base station, low power generation utilization rate of the power grid during power failure, abnormal use of a three-phase air conditioner and the like are effectively solved.

The input end of the power supply conversion device is connected to the low-voltage side of a special or public distribution transformer, a three-phase four-wire power supply is changed into a single-phase two-wire power supply, then the output of the three-phase two-wire power supply is connected to one input end of the power supply switching device, the output of a standby power supply (oil engine power generation) is connected to the other input end of the power supply switching device, and when a power grid normally operates, the operation mode of the power supply switching device is selected to be a commercial power supply mode. When the power grid fails and the power is cut off, the operation mode of the power supply switching device is selected as the standby power supply operation mode (oil engine power generation). The single-phase two-wire electric energy transmission line transmits the electric energy of the operation mode selected by the power supply switching device to the dynamic voltage regulating device, and the dynamic voltage regulating device carries out dynamic voltage regulation according to the actual operation condition. The reactive power compensation device is matched with the dynamic voltage regulating device to realize the functions of providing system power factors and dynamically stabilizing voltage. Two input ends of the hybrid power supply device are respectively connected to a voltage-regulating compensation output end of the dynamic voltage-regulating device and an 80% -110% rated voltage tap of a secondary winding of the voltage-regulating transformer. Two outputs of the hybrid power supply device, namely: the voltage regulating output terminal and the split phase output terminal are respectively connected with a single-phase load and a three-phase load

The purpose of the invention is realized as follows:

a communication base station high-reliability low-loss alternating current voltage-stabilizing power supply device is characterized by comprising a power supply conversion device, a power supply switching device, a single-phase two-wire electric energy transmission line, a dynamic voltage regulating device, a reactive power compensation device and a hybrid power supply device;

the input end of the power supply conversion device is connected to the low-voltage side of a special or public distribution transformer, a three-phase four-wire power supply is changed into a single-phase two-wire power supply, then the output is connected to one input end of the power supply switching device, and the output of the standby power supply is connected to the other input end of the power supply switching device; the single-phase two-wire electric energy transmission line transmits the electric energy of the operation mode selected by the power supply switching device to the dynamic voltage regulating device, and the dynamic voltage regulating device carries out dynamic voltage regulation; the reactive compensation device is connected with the dynamic voltage regulation device; two input ends of the hybrid power supply device are respectively connected to a voltage regulation compensation output end of the dynamic voltage regulation device and an 80% -110% rated voltage tap of a secondary winding of the voltage regulation transformer; two output ends of the hybrid power supply device, namely a voltage regulating output end and a split phase output end are respectively connected into a single-phase load and a three-phase load.

In the above mentioned communication base station high reliability low loss ac voltage stabilization power supply device, the power supply conversion device includes distribution transformers for different connection groups and user properties, specifically, a delta/Y connection dedicated distribution transformer, three windings on the high voltage side are connected into a triangle; the three windings on the low-voltage side are changed into three windings which are connected in series, wherein the homonymous end of any one winding is reversely connected, the homonymous ends of the other two windings are positively connected, a power supply which converts a three-phase four-wire power supply mode into a power supply which has a single-phase two-wire output voltage power supply mode with 2 times of low-voltage winding voltage is formed, and four lines of the original three-phase four-wire system are changed into single-phase two-wire output in a two-wire parallel connection mode.

In the high-reliability low-loss alternating-current voltage-stabilizing power supply device for the communication base station, the power supply conversion device comprises distribution transformers aiming at different connection groups and user properties, specifically a Y/Y connection special distribution transformer or a delta/Y and Y/Y connection public distribution transformer, two-phase line voltage single-phase two-line output with the lightest load is selected, and four lines of the original three-phase four-line system are connected in parallel two by two to be changed into single-phase two-line output.

In the above communication base station high-reliability low-loss alternating current voltage-stabilizing power supply device, the power supply switching device has two input ports and one output port, and the output port is respectively connected to one of the two input ports according to the actual operation requirement through the power electronic or mechanical two-way switch, so as to realize the switching of the power supply modes of the commercial power and the standby power supply; one input port of the two input ports is connected with the single-phase two-wire output of the commercial power, and the other input port is connected with the single-phase output of the standby power supply; one output port is connected with the head end of the single-phase two-wire transmission line, and the tail end of the single-phase two-wire transmission line is connected with the input end of the voltage regulating transformer.

In the above mentioned ac voltage-stabilizing power supply device with high reliability and low loss for communication base station,

for the case where a three-phase four-wire power supply is converted into a single-phase two-wire power supply, the single-phase two-wire power transmission line includes: connecting any two lines of four lines of an original three-phase four-line power supply in parallel, wherein the head end and the head end are connected together, and the tail end are connected together, and connecting two ends of a single-phase two-line power supply to form a two-line transmission line;

alternatively, the first and second liquid crystal display panels may be,

for a newly-built communication base station, the single-phase two-wire power transmission line is a single-phase two-wire transmission line with the transmission line diameter designed according to the lowest voltage and the maximum current.

In the communication base station high-reliability low-loss alternating-current voltage-stabilizing power supply device, the dynamic voltage-regulating device comprises a controller, and a voltage-regulating transformer, a voltage tap, a power electronic switch, a data acquisition unit and a short-circuit prevention protection circuit which are simultaneously connected with the controller;

the voltage tap draws corresponding tap joints from primary and secondary windings of the voltage regulating transformer according to the voltage regulating level N and the voltage regulating level difference delta U required by application;

the power electronic switch is formed by combining short-circuit type conduction characteristic power electronic devices; the voltage tap of the regulating transformer and the current-limiting resistor for preventing the winding from short circuit are respectively connected, and the current-limiting resistor is connected with the voltage-regulating output end of the dynamic voltage-regulating device; the controller controls the trigger circuit to send out trigger pulses according to the requirements of application functions, so that the on-off of the power electronic switch is controlled, and the dynamic voltage regulation function is realized;

the data acquisition unit comprises an analog/digital conversion circuit, a sampling holding circuit, a data memory and a sampling controller, and the sampling speed and the sampling precision are designed according to the conditions meeting the requirements of application functions;

the short-circuit prevention protection circuit comprises a power electronic switch, a current-limiting resistor and a mechanical switch; the power electronic switch is connected in series with the current-limiting resistor for preventing the winding from short circuit to form a series branch circuit, so that short-circuit accidents in the conversion process of the two voltage-regulating branch circuits are prevented; the series branch is connected with the mechanical switch in parallel to form a voltage regulating branch; the series branch is used for switching on and switching off the voltage regulating branch in the dynamic voltage regulating process; the parallel branch is used for short-circuiting the series branch after the voltage regulating branch is connected, so that the power electronic switch does not operate in a long-term electrified mode, and the power loss of the power electronic switch is reduced.

In the above mentioned ac voltage-stabilizing power supply device with high reliability and low loss for communication base station, the reactive compensation device includes a capacitor automatic switching reactive compensation device installed at the output side of the dynamic voltage regulation device, the control quantity is selected as the reactive power input by the dynamic voltage regulation device, so as to improve the system power factor of the communication base station and ensure the qualified voltage quality of the base station as the control target; the capacity of the capacitor is 1.5 to 2 times of the maximum reactive power requirement, and the capacitor is used for compensating reactive load of a base station and reactive power of the voltage regulating transformer, and transmitting certain reactive power to the power grid under the condition that the power grid is insufficient in reactive power, so that the output voltage of the installation point of the dynamic voltage regulating device is prevented from being too high; the voltage at the front end of the high side line drops further.

In a communication base station high reliability low-loss alternating current steady voltage power supply unit of foretell, mixed power supply unit divides into two sets of mains operated to single-phase two line power, and a set of dynamic voltage regulator outputs the single-phase load of supplying power, and another group's regulating transformer output splits the three-phase load of phase power supply, specifically includes:

the power supply of the single-phase load output by the group of dynamic voltage regulating devices is divided into a rectifying branch, a lighting branch and other single-phase load branches, and each branch is separated by an air switch with overcurrent protection; the other group is connected with the output end of the regulating transformer through voltage, a single-phase power supply is a three-phase power supply and is connected with a three-phase air conditioner through an LC phase splitting circuit, and an air switch with overcurrent protection is adopted to be connected with the output end of the regulating transformer;

the LC split-phase circuit is connected with the output end of the regulating transformer through an air switch with overcurrent protection by serially connecting an electric reactor and a capacitor, the leading-out wire of the connecting point of the electric reactor and the capacitor is connected with the B phase of the three-phase air conditioner, the electric reactor connecting end of the output end of the regulating transformer is connected with the A phase of the three-phase air conditioner, and the capacitor connecting end of the output end of the regulating transformer is connected with the C phase of the three-phase air conditioner.

In the above-mentioned communication base station high-reliability low-loss ac voltage-stabilizing power supply device, the reactance value sum of the reactor of the LC split-phase circuitThe capacitive reactance of the capacitors being equal to the equivalent resistance of a single phase of a three-phase air conditioner

Doubling; three leading-out wire ends of the LC split-phase circuit are fixedly connected with a power supply terminal A, B and a C end of a three-phase load; the leading-out wire of the connection point of the reactor and the capacitor is not allowed to be suspended so as to prevent the output end of the voltage regulating transformer from being short-circuited and burning the voltage regulating transformer.

A communication base station high-reliability low-loss alternating current voltage stabilization power supply method is characterized by comprising the following steps:

step one, power supply conversion; the three-phase four-wire power supply of the communication base station is converted into a single-phase two-wire power supply, so that the problems of phase loss faults caused by unbalanced three-phase load and overweight load of a certain phase of the communication base station are solved;

step two, switching power supplies; a standby power supply and commercial power supply switching device is set, and the standby power supply state is switched when the power grid fails, so that the problem of improving the power generation utilization rate of an oil engine of a mountain area communication base station is solved;

step three, high-efficiency transmission; the three-phase four-wire electric energy transmission is converted into single-phase two-wire 2-time winding voltage electric energy transmission, so that the power loss of line transmission is reduced;

step four, dynamic pressure regulation; a wide-range bidirectional voltage regulating transformer is arranged, and a power electronic switch is adopted to dynamically control the voltage tap of the transformer to perform voltage reduction and voltage boosting switching, so that the problem of dynamic voltage stabilization is solved;

step five, reactive compensation; the output end of the regulating transformer is provided with a dynamic reactive power compensation device to control the reactive power of the input end of the regulating transformer, so that the problem of system power factor and voltage reduction after the regulating transformer is installed is solved;

step six, hybrid power supply; the single-phase two-line 2-time phase voltage power supply is divided into two groups of power supplies for supplying power, one group is used for regulating voltage to supply single-phase load, and the other group is used for split-phase three-phase load.

In the above mentioned method for supplying power to a communication base station with high reliability and low loss by ac voltage stabilization, in the first step, the power supply is changed; the method specifically comprises the following steps: aiming at distribution transformers with different connection groups and user properties, the transformation method comprises the following steps:

A. the three windings on the high-voltage side are connected into a triangle so as to reduce the influence of the third harmonic wave of the nonlinear load and the integral multiple of the third harmonic wave on the power grid; the three windings on the low-voltage side are changed into three windings which are connected in series, wherein the homonymous end of any one winding is reversely connected, and the homonymous ends of the other two windings are positively connected, so that a power supply in a three-phase four-wire power supply mode is converted into a power supply in a single-phase two-wire output voltage power supply mode with 2 times of low-voltage winding voltage, and four lines of the original three-phase four-wire system are changed into single-phase two-wire output in a two-wire parallel connection mode;

B.Y/Y is connected with a special distribution transformer or delta/Y and Y/Y are connected with a public distribution transformer, the two-phase line voltage with the lightest load is taken for single-phase two-line output, and four lines of the original three-phase four-line system are connected in parallel two by two to be the single-phase two-line output.

In the above mentioned method for supplying power to a communication base station with high reliability and low loss by alternating current voltage stabilization, the power is switched in the second step; the method specifically comprises the following steps: the power supply switch is provided with two input ports and one output port, and the output port is respectively connected to one input port of the two specified input ports according to the actual operation requirement through a power electronic or mechanical bidirectional change-over switch, so that the power supply mode switching between the commercial power and the standby power supply is realized; one input port of the two input ports is connected with the single-phase two-wire output of the mains supply in the step one, and the other input port is connected with the single-phase output of the standby power supply; one output port is connected with the head end of the single-phase two-wire transmission line, and the tail end of the single-phase two-wire transmission line is connected with the input end of the voltage regulating transformer; the standby power supply is generally provided with a diesel (gasoline) generator, and the conditional base station can be provided with photovoltaic power generation or wind power generation equipment.

In the above mentioned method for supplying power to a communication base station with high reliability and low loss by ac voltage stabilization, in the third step, transmission is performed with high efficiency; the method specifically comprises the following steps:

A. in the case of converting a three-phase four-wire power supply into a single-phase two-wire power supply, any two lines of four lines in the original three-phase four-wire power supply are connected in parallel, the head end and the head end are connected, the tail end and the tail end are connected together, and two ends of the single-phase two-wire power supply are connected to form a two-wire transmission line;

B. and designing a single-phase two-wire transmission line of the transmission line diameter according to the lowest voltage and the maximum current for the newly-built communication base station.

In the above mentioned method for supplying power to a communication base station with high reliability and low loss by alternating current voltage stabilization, in the fourth step, the voltage is dynamically adjusted; the method comprises the following steps: the device comprises a voltage regulating unit, a power electronic switch unit, a protection unit and a control unit;

A. the voltage regulating unit consists of a bidirectional voltage regulating double winding or an autotransformer with a voltage tap (tap) on an original secondary winding; two taps of the primary winding of the regulating transformer set two transformation ratios, namely: 1:1 (for step-down voltage regulation) and 0.5; two groups of taps of the secondary winding of the voltage regulating transformer are provided, and the voltage range of 1 group of taps is 80-110% of the rated voltage of the secondary winding; the voltage range of the other group of taps is 65% -45% of the rated voltage of the secondary side; the number of taps is selected according to the voltage quality standard of the actual application scenario;

B. the power electronic switch unit consists of thyristors in positive and negative parallel connection or other high-power electronic switches, and the on and off of related taps of the voltage regulating transformer are controlled by the controller according to the real-time detected actual voltage level, so that the dynamic voltage regulating function is realized;

C. the protection unit comprises protection of a power electronic switch, short-circuit protection and energy-saving protection; the protection of the power electronic switch sets overvoltage, overcurrent, di/dt and dv/dt protection; the short-circuit protection adopts a method that power electronic switch branches are connected with current-limiting resistors in series, so that the condition that the windings of the voltage regulating transformer are short-circuited or open-circuited in the voltage regulating process is prevented; the energy-saving protection adopts a method of connecting a contactor contact in parallel between a power electronic switch and a current-limiting resistance branch to form a dynamic voltage-regulating execution unit; the contactor contact is in a closed state when the power electronic switch is connected with the transformer tap, and is in an open state when the transformer tap is disconnected; therefore, the risks of power loss and burning caused by heating of the power electronic switch under the condition of normal long-time operation are avoided;

D. the control unit comprises related hardware and software such as data acquisition, detection, monitoring, calculation and display of electrical parameters and power quality, triggering control of the power electronic switch, remote data transmission and communication, fault diagnosis and alarm of the voltage regulating device and the like.

In the above high-reliability low-loss alternating current voltage-stabilizing power supply method for the communication base station, in the fifth step, reactive compensation is performed; install dynamic reactive power compensator at regulating transformer's output, solve power factor and the problem (5) that the front end voltage descends behind the installation regulating transformer, specifically include: a capacitor automatic switching reactive power compensation device is arranged on the output side of the dynamic voltage regulation device, and the control quantity is selected as the input reactive power of the dynamic voltage regulation device, so that the system power factor of the communication base station is improved and the voltage quality of the base station is ensured to be qualified as a control target; the capacity of the capacitor is designed according to the maximum reactive power requirement of 1.5-2 times, and is used for compensating reactive load of a base station and reactive power of the voltage regulating transformer, and certain reactive power is transmitted to the power grid under the condition that the power grid is insufficient in reactive power, so that the output voltage of the installation point of the dynamic voltage regulating device is prevented from being too high; the voltage at the front end of the high side line drops further.

In the above mentioned method for supplying power to a communication base station with high reliability and low loss by alternating current voltage stabilization, in the sixth step, hybrid power supply is performed; divide into two sets of mains operated with single-phase two line power, a set of dynamic voltage regulation device output single phase load of supplying power, another group's regulating transformer output phase-splitting power supply three-phase load (6), specifically include:

A. the power supply of a group of dynamic voltage regulating devices for outputting power supply single-phase loads is divided into a rectifying branch, a lighting branch, other single-phase load branches and the like, and each branch is separated by an air switch with overcurrent protection; the other group is connected with the output end of the regulating transformer through voltage, a single-phase power supply is a three-phase power supply and is connected with a three-phase air conditioner through an LC phase splitting circuit, and an air switch with overcurrent protection is adopted to be connected with the output end of the regulating transformer;

the LC split-phase circuit is connected in series by a reactor and a capacitor and is connected to the output end of the regulating transformer through an air switch with overcurrent protection, a leading-out wire of a connection point of the reactor and the capacitor is connected with the phase B of the three-phase air conditioner, the reactor connection end of the output end of the regulating transformer is connected to the phase A of the three-phase air conditioner, and the capacitor connection end of the output end of the regulating transformer is connected to the phase C of the three-phase air conditioner;

the reactance value of the reactor of the C.LC split-phase circuit is equal to the capacitance reactance value of the capacitor and is equal to the equivalent resistance of the single phase of the three-phase air conditioner

Doubling;

three leading-out wire ends of the LC split-phase circuit are fixedly connected with a power supply terminal A, B and a C end of a three-phase air conditioner; the leading-out wire of the connection point of the reactor and the capacitor is not allowed to be suspended so as to prevent the output end of the voltage regulating transformer from being short-circuited and burning the voltage regulating transformer.

The system has the following technical characteristics and advantages:

1. the three-phase four-wire power supply is converted into a single-phase two-wire power supply, so that the problem of phase loss faults caused by unbalanced three-phase load and overweight load of a certain phase of the communication base station can be effectively solved.

2. A standby power supply and commercial power supply switching device is arranged at a single-phase two-line power supply, and is switched to the standby power supply when a power grid fails, so that the problem of improving the power generation utilization rate of an oil engine of a mountainous area communication base station is solved.

3. Three-phase four-wire transmission electric energy is converted into single-phase two-wire transmission electric energy, and transmission electric energy loss is reduced.

4. A wide-range bidirectional voltage regulating transformer is arranged, and a power electronic switch is adopted to dynamically control the voltage tap of the transformer to reduce voltage and boost voltage for switching, so that the problem of dynamic voltage stabilization is solved.

5. The output end of the regulating transformer is provided with a dynamic reactive power compensation device to control the reactive power of the input end of the regulating transformer, thereby solving the problem of the reduction of the power factor and the front end voltage of a system after the regulating transformer is installed.

6. The single-phase two-line power supply is divided into two groups of power supplies for supplying power, one group of voltage-regulating power supply single-phase load and the other group of split-phase power supply three-phase load, and the problem of mixed power supply of the single-phase load and the three-phase load of the base station is solved.

Compared with the prior art, the invention has the advantages of high alternating current power supply reliability, small loss, wide dynamic voltage regulation range, high oil engine power generation utilization rate, high electric energy utilization rate, low failure rate and small influence of load characteristics on safe operation.

Drawings

Fig. 1 is a flow chart of an embodiment of the method to which the present invention relates.

Fig. 2 is a block diagram of the overall system architecture of the system embodiment to which the present invention relates.

Fig. 3 (a) is a schematic diagram of a power conversion device according to an embodiment of the system according to the present invention (a Δ/Y three-phase four-wire dedicated distribution transformer is converted into a single-phase two-wire distribution transformer, and 460V voltage is output), as shown in fig. 3 (a).

Fig. 3 (b) is a schematic diagram of a power conversion device according to an embodiment of the system of the present invention (Δ/Y, Y/Y three-phase four-wire public and Y/Y private distribution transformer is converted into a single-phase two-wire distribution transformer to output 400V voltage).

Fig. 4 is a schematic diagram of a power switching device according to an embodiment of the present invention.

Fig. 5 (a) is a schematic block diagram of the dynamic voltage adjustment compensation device.

Fig. 5 (b) is a schematic wiring diagram of an embodiment of the dynamic voltage regulation compensation device.

Fig. 6 is a schematic diagram of a hybrid power supply device according to an embodiment of the system of the present invention.

Detailed Description

The following detailed description is made with reference to the accompanying drawings and examples:

1. high-reliability low-loss alternating current power supply method for communication base station

Fig. 1 shows a flowchart of an embodiment of a high-reliability low-loss ac power supply method for a communication base station, and as can be seen from fig. 1:

1. the first step is power supply conversion. The three-phase four-wire power supply of the communication base station is converted into a single-phase two-wire power supply, and the problems of unbalanced three-phase load and open-phase fault redundant operation of the communication base station are solved, namely the problem 1. The method specifically comprises the following steps: aiming at distribution transformers with different connection groups and user properties, the transformation method comprises the following steps:

A. the three windings on the high-voltage side are connected into a triangle so as to reduce the influence of the third harmonic wave of the nonlinear load and the integral multiple of the third harmonic wave on the power grid; the three windings on the low-voltage side are changed into three windings which are connected in series, wherein the homonymous end of any one winding is reversely connected, the homonymous ends of the other two windings are positively connected, a power supply which converts a three-phase four-wire power supply mode into a power supply which has a single-phase two-wire output voltage power supply mode with 2 times of low-voltage winding voltage is formed, and four lines of the original three-phase four-wire system are changed into single-phase two-wire output in a two-wire parallel connection mode.

2. And step two, power supply switching. A standby power supply/oil engine power generation and commercial power supply switching device is set, the standby power supply/oil engine power generation state is switched when the power grid fails, and the problem 2 that the oil engine power generation utilization rate of the mountainous area communication base station is low is solved. The method specifically comprises the following steps: the power supply switch is provided with two input ports and one output port, and the output port is connected to one input port of the two specified input ports according to the actual operation requirement through a power electronic or mechanical bidirectional change-over switch, so that the power supply mode switching between the commercial power and the standby power supply is realized. One input port of the two input ports is connected with the single-phase two-wire output of the mains supply in the step one, and the other input port is connected with the single-phase output of the standby power supply; one output port is connected with the head end of the single-phase two-wire transmission line, and the tail end of the single-phase two-wire transmission line is connected with the input end of the voltage regulating transformer. The standby power supply is generally provided with a diesel (gasoline) generator, and the conditional base station can be provided with photovoltaic power generation or wind power generation equipment.

3. And step three, efficient transmission. Three-phase four-wire power transmission is converted into single-phase two-wire 2-time winding voltage power transmission, and power loss 3 of line transmission is reduced. The method specifically comprises the following steps:

A. in the case of converting a three-phase four-wire power supply into a single-phase two-wire power supply, any two of four wires in the original three-phase four-wire power supply are connected in parallel, the head end and the head end are connected together, the tail end and the tail end are connected together, and two ends of the single-phase two-wire power supply are connected to form a two-wire transmission line.

4. And step four, dynamically regulating the pressure 4. The device comprises a voltage regulating unit, a power electronic switch unit, a protection unit and a control unit.

A. The voltage regulating unit is composed of a bidirectional voltage regulating double winding or an autotransformer with a voltage tap (tap) on an original secondary winding. Two taps of the primary winding of the regulating transformer set two transformation ratios, namely: 1:1 (for step-down voltage regulation) and 0.5. Two groups of taps are arranged on a secondary winding of the regulating transformer, and the voltage range of 1 group of taps is 80-110% of the rated voltage of the secondary winding; the voltage range of the other group of taps is 65% -45% of the rated voltage of the secondary side; the number of taps is selected according to the voltage quality criteria of the actual application scenario.

B. The power electronic switch unit consists of thyristors in positive and negative parallel connection or other high-power electronic switches, and the on and off of relevant taps of the voltage regulating transformer are controlled by the controller according to the actual voltage level detected in real time, so that the dynamic voltage regulating function is realized.

C. The protection unit comprises protection of the power electronic switch, short-circuit protection and energy-saving protection. Protection of power electronic switches sets overvoltage, overcurrent, di/dt, and dv/dt protection. The short-circuit protection adopts a method that a power electronic switch branch circuit is connected with a current-limiting resistor in series, so that the condition of short circuit or open circuit of a winding of a voltage regulating transformer is prevented in the voltage regulating process. The energy-saving protection adopts a method of connecting a contactor contact in parallel between a power electronic switch and a current-limiting resistance branch to form a dynamic voltage-regulating execution unit. The contactor contacts are in a closed state when the power electronic switch is connected to the transformer tap and in an open state when the transformer tap is disconnected. Therefore, the power electronic switch avoids the risks of heating, power loss and burning-out under the condition of normal long-time operation.

D. The control unit comprises related hardware and software such as data acquisition, detection, monitoring, calculation and display of electrical parameters and power quality, power electronic switch trigger control, remote data transmission and communication, fault diagnosis and alarm of the voltage regulating device and the like.

5. And step five, reactive compensation. Install dynamic reactive power compensator at the output of regulating transformer, solve power factor and the decline of front end voltage problem 5 behind the installation regulating transformer, specifically include: a capacitor automatic switching reactive power compensation device is arranged on the output side of the dynamic voltage regulating device, and the control quantity is selected as the input reactive power of the dynamic voltage regulating device, so that the system power factor of the communication base station is improved, and the voltage quality of the base station is ensured to be qualified. The capacity of the capacitor is designed according to the maximum reactive power requirement of 1.5-2 times, and the capacitor is used for compensating reactive load of a base station and reactive power of the voltage regulating transformer, and transmitting certain reactive power to the power grid under the condition that the power grid is insufficient in reactive power, so that the output voltage of the installation point of the dynamic voltage regulating device is prevented from being too high. The voltage at the front end of the high side line drops further.

6. And step six, hybrid power supply 6. The single-phase two-line 2-time phase voltage power supply is divided into two groups of power supplies for supplying power, one group is used for regulating voltage to supply single-phase load, and the other group is used for split-phase three-phase load. The method specifically comprises the following steps:

A. the power supply of a group of dynamic voltage regulating devices for outputting power supply single-phase loads is divided into a rectifying branch, a lighting branch, other single-phase load branches and the like, and each branch is separated by an air switch with overcurrent protection; the other group is connected with the output end of the regulating transformer through voltage, a single-phase power supply is a three-phase power supply and is connected with a three-phase air conditioner through an LC phase splitting circuit, and an air switch with overcurrent protection is adopted to be connected with the output end of the regulating transformer.

And the LC split-phase circuit is connected in series by a reactor and a capacitor and is connected to the output end of the regulating transformer through an air switch with overcurrent protection, a connection point outgoing line of the reactor and the capacitor is connected with the B phase of the three-phase air conditioner, the reactor connecting end of the output end of the regulating transformer is connected to the A phase of the three-phase air conditioner, and the capacitor connecting end of the output end of the regulating transformer is connected to the C phase of the three-phase air conditioner.

And (4) doubling.

And three outlet terminals of the LC split-phase circuit are fixedly connected with a power supply terminal A, B and a C end of the three-phase air conditioner. The leading-out wire of the connection point of the reactor and the capacitor is not allowed to be suspended so as to prevent the output end of the voltage regulating transformer from being short-circuited and burning the voltage regulating transformer.

2. High-reliability low-loss alternating current power supply device of communication base station

1. Overall

As shown in fig. 2, the apparatus includes: the power conversion device 10, the power switching device 20, the single-phase two-wire power transmission line 30, the dynamic voltage regulation device 40, the reactive power compensation device 50, and the hybrid power supply device 60.

The working principle is as follows: the input end of the power conversion device 10 is connected to the low-voltage side of a special or public distribution transformer, the three-phase four-wire power supply is changed into a single-phase two-wire power supply, then the output is connected to one input end of the power switching device 20, the output of the standby power supply (oil engine power generation) is connected to the other input end of the power switching device 20, and when the power grid normally operates, the operation mode of the power switching device is selected to be the mains supply mode. When the power grid fails and the power is cut off, the operation mode of the power supply switching device is selected as the standby power supply operation mode (oil engine power generation). The single-phase two-wire electric energy transmission line 30 transmits the electric energy of the operation mode selected by the power supply switching device to the dynamic voltage regulating device 40, and the dynamic voltage regulating device 40 carries out dynamic voltage regulation according to the actual operation condition. The reactive power compensation device 50 is matched with the dynamic voltage regulating device to realize the functions of providing system power factors and dynamically stabilizing voltage. Two input ends of the hybrid power supply device 60 are respectively connected to the voltage-regulating compensation output end of the dynamic voltage-regulating device 40 and 80% -110% rated voltage tapping points of the secondary winding of the regulating transformer. Two outputs of the hybrid power supply 60, namely: the voltage regulating output end and the split phase output end are respectively connected with a single-phase load and a three-phase load.

2. Sub-device

Fig. 3 shows a power conversion device including:

A. the delta/Y three-phase four-wire dedicated distribution transformer is transformed into a single-phase two-wire distribution transformer, and 460V voltage is output, as shown in fig. 3 (a).

B. The delta/Y, Y/Y three-phase four-wire public and Y/Y private distribution transformer is transformed into a single-phase two-wire distribution transformer outputting 400V voltage, as shown in fig. 3 (b).

Fig. 4, the power switching device is composed of a bidirectional knife switch, when the power grid operates normally, the knife switch is switched on to the mains supply, that is: a dedicated transformer or a utility transformer. When the power failure of the power grid faults occurs, the knife switch is switched on to the standby power supply, namely: and generating electricity by using an oil engine. And the power supply selected by the power supply switching device is transmitted to the dynamic voltage regulation compensation device of the base station through single-phase two-wire electric energy.

Fig. 5 (a), a schematic block diagram of a dynamic voltage regulation compensation device, which includes a voltage regulating transformer 401, a voltage tap 402, a power electronic switch 403, a data acquisition unit 404, a data communication unit 407, a short-circuit protection circuit 405, a controller 406, and a reactive power compensation device 50.

The regulating transformer 401 is characterized in that:

A. single-phase, the two transformation ratios on once side, the multiple transformation ratio on secondary side, wide voltage regulating range, both can step down, can step up again, multistage dynamic voltage regulation. The primary side double transformation ratios are respectively a normal operation transformation ratio 1:1 and an abnormal operation transformation ratio of 0.5. The voltage regulating range is not less than 50% of the secondary side rated voltage.

B. Under the normal operation condition of the regulating transformer, the transformation ratio is 1:1 and the regulating transformer is used as a step-down multistage dynamic regulating transformer; the regulating transformer is connected the single-phase output voltage that three-phase turned into single-phase transformer, under the unusual operational aspect, promptly: when three phases lack one phase, the transformation ratio is 0.5.

C. The voltage regulating level N and the voltage regulating level difference delta U of the voltage regulating transformer are determined according to the principle that when the highest voltage and the lowest voltage appear at the input end of the voltage regulating transformer, the output voltage of the voltage regulating transformer meets the national standard requirement of voltage quality in an application scene.

The voltage tap 402 is characterized by: and drawing corresponding taps from the primary winding and the secondary winding of the regulating transformer according to the regulating stage number N and the regulating stage difference delta U required by the application.

The power electronic switch 403 is characterized in that: the short circuit type conduction characteristic power electronic device is combined; the voltage tap of the regulating transformer and the current-limiting resistor for preventing the winding from short circuit are respectively connected, and the current-limiting resistor is connected with the voltage-regulating output end of the dynamic voltage-regulating device; the controller controls the trigger circuit to send out trigger pulses according to the requirements of application functions, so that the on-off of the power electronic switch is controlled, and the dynamic voltage regulating function is realized.

The data acquisition unit 404 is characterized in that: the device comprises an analog/digital conversion circuit, a sampling holding circuit, a data memory and a sampling controller, wherein the sampling speed and the sampling precision are designed according to the conditions meeting the requirements of application functions.

The short-circuit protection circuit 405 is characterized in that: including power electronic switches 403, current limiting resistors, and mechanical switches. The power electronic switch 403 is connected in series with a current limiting resistor for preventing the winding from short circuit to form a series branch, so as to prevent short circuit accidents in the conversion process of the two voltage regulating branches. The series branch is connected with the mechanical switch in parallel to form a voltage regulating branch. The series branch is used for switching on and switching off the voltage regulating branch in the dynamic voltage regulating process; the parallel branch is used for short-circuiting the series branch after the voltage regulating branch is connected, so that the power electronic switch does not operate in a long-term electrified mode, and the power loss of the power electronic switch is reduced.

The controller 406 is characterized by: the controller adopts a high-performance and high-reliability embedded system, has strong functions of data processing, scientific calculation, data communication, data storage and the like, and the model selection of the embedded system is designed according to the condition meeting the requirement of the application function. The controller 406 performs real-time control on the data acquisition unit 404, the data communication unit 407, the power electronic switch 403, the short-circuit protection circuit 405, the voltage regulating transformer 401, the voltage tap 402, the reactive power compensation device 50, and the like according to application requirements.

The data communication unit 407 is characterized by: and the local area network or the 4G/5G wireless communication network is adopted for remote data transmission and data communication.

Fig. 5 (b), a wiring schematic diagram of an embodiment of the dynamic voltage regulation compensation device, wherein:

DVRT is a two-winding bi-directional regulating transformer with transformation ratios of 1:1 and 0.5. The voltage of the input ends I1-I2 of the primary winding of the regulating transformer is 460V (output voltage of the special transformer and output voltage of the 400V public transformer) and 230V (single-phase voltage of oil engine power generation). Output voltage ends O1-I3 of the dynamic voltage regulation and compensation device: and the voltage regulating end outputs 230V to supply single-phase load. The output voltage end O2-I3 of the dynamic voltage regulation and compensation device is as follows: and a split-phase voltage end outputs 400V, is connected to a split-phase circuit and supplies power to a three-phase load.

PT and CT are voltage transformer and current transformer, which can detect the input and output voltage and current of voltage-regulating transformer.

TH is a thyristor power electronic switch which is connected in parallel positively and negatively and is used for controlling a voltage tap of the voltage regulating transformer. And R is a current-limiting resistor and is used for preventing the short circuit or the open circuit of the transformer winding in the dynamic voltage regulation process.

KM is a contactor and is used for reducing power loss of the power electronic switch in a conducting operation state.

And C is a capacitor for reactive compensation.

DL is a circuit breaker for switching on and off the power supply.

Fig. 6, hybrid power supply. Including dividing into two sets of mains operated on single phase two line power, single-phase load of a set of dynamic voltage regulation device output power supply, another group's regulating transformer output phase-splitting power supply three-phase load specifically includes:

And (4) doubling.

And three outlet terminals of the LC split-phase circuit are fixedly connected with a power supply terminal A, B and a C end of the three-phase air conditioner. The leading-out wire of the connection point of the reactor and the capacitor is not allowed to be suspended so as to prevent the output end of the regulating transformer from being short-circuited and burning the regulating transformer.

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make many possible variations and modifications to the disclosed solution, or to modify equivalent embodiments, without departing from the scope of the solution, using the methods and techniques disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.

Claims

1. A communication base station high-reliability low-loss alternating current voltage-stabilizing power supply device is characterized by comprising a power supply conversion device (10), a power supply switching device (20), a single-phase two-wire electric energy transmission line (30), a dynamic voltage regulating device (40), a reactive power compensation device (50) and a hybrid power supply device (60);

the input end of the power conversion device (10) is connected to the low-voltage side of a special or public distribution transformer, a three-phase four-wire power supply is changed into a single-phase two-wire power supply, then the output is connected to one input end of the power switching device (20), and the output of the standby power supply is connected to the other input end of the power switching device (20); the single-phase two-wire electric energy transmission line (30) transmits the electric energy of the operation mode selected by the power supply switching device to the dynamic voltage regulating device (40), and the dynamic voltage regulating device (40) carries out dynamic voltage regulation; the reactive compensation device (50) is connected with the dynamic voltage regulating device; two input ends of the hybrid power supply device (60) are respectively connected to a voltage-regulating compensation output end of the dynamic voltage-regulating device (40) and an 80% -110% rated voltage tap of a secondary winding of the regulating transformer; two output ends of the hybrid power supply device (60), namely a voltage regulating output end and a split phase output end, are respectively connected into a single-phase load and a three-phase load;

the power supply conversion device (10) comprises distribution transformers aiming at different connection groups and user properties, particularly a delta/Y connection special distribution transformer, and three windings on the high-voltage side are connected into a triangle; the three windings on the low-voltage side are changed into three windings which are connected in series, wherein the homonymous end of any one winding is reversely connected, the homonymous ends of the other two windings are positively connected, a power supply which converts a three-phase four-wire power supply mode into a power supply which has a single-phase two-wire output voltage power supply mode with 2 times of low-voltage winding voltage is formed, and four lines of the original three-phase four-wire system are changed into single-phase two-wire output in a two-wire parallel connection mode.

2. The ac voltage-stabilizing power supply device according to claim 1, characterized in that the power conversion device (10) comprises distribution transformers for different connection groups and user properties, specifically Y/Y connection dedicated distribution transformers or Δ/Y and Y/Y connection common distribution transformers, and the two-phase line voltage single-phase two-wire output with the lightest load is selected, and the four lines of the original three-phase four-wire system are connected in parallel two by two to be the single-phase two-wire output.

3. The alternating current voltage-stabilizing power supply device with high reliability and low loss of the communication base station as claimed in claim 1, wherein the power supply switching device (20) has two input ports and one output port, and the output port is respectively connected to one input port of the two specified input ports according to the actual operation requirement through a power electronic or mechanical bidirectional switch so as to realize the switching of the power supply modes of the commercial power and the standby power supply; one input port of the two input ports is connected with the single-phase two-wire output of the mains supply, and the other input port is connected with the single-phase output of the standby power supply; one output port is connected with the head end of the single-phase two-wire transmission line, and the tail end of the single-phase two-wire transmission line is connected with the input end of the voltage regulating transformer.

4. The high-reliability low-loss AC voltage-stabilizing power supply device of claim 1,

in the case of a three-phase four-wire power supply being converted into a single-phase two-wire power supply, a single-phase two-wire power transmission line (30) includes: connecting any two lines of four lines of the original three-phase four-line power supply in parallel, wherein the head end and the head end are connected together, and the tail end are connected together, and connecting the two ends of the single-phase two-line power supply to form a two-line transmission line;

alternatively, the first and second electrodes may be,

for newly-built communication base stations, the single-phase two-wire power transmission line (30) is a single-phase two-wire transmission line with the transmission line diameter designed according to the lowest voltage and the maximum current.

5. A communication base station high reliability low loss ac voltage stabilization power supply device according to claim 1, characterized in that the dynamic voltage regulation device (40) comprises a controller (406) and a voltage regulation transformer (401), a voltage tap (402), a power electronic switch (403), a data acquisition unit (404) and a short circuit prevention protection circuit (405) which are connected with the controller at the same time;

the voltage tap (402) draws corresponding taps from primary and secondary windings of the regulating transformer according to the regulating stage number N and the regulating stage difference delta U required by application;

the power electronic switch (403) is formed by combining short-circuit type conduction characteristic power electronic devices; the voltage tap of the regulating transformer and the current-limiting resistor for preventing the winding from short circuit are respectively connected, and the current-limiting resistor is connected with the voltage-regulating output end of the dynamic voltage-regulating device; the controller controls the trigger circuit to send out trigger pulses according to the requirements of application functions, so that the on-off of the power electronic switch is controlled, and the dynamic voltage regulation function is realized;

the data acquisition unit (404) comprises an analog/digital conversion circuit, a sample-and-hold circuit, a data memory and a sampling controller, and the sampling speed and the sampling precision are designed according to the conditions meeting the requirements of application functions;

the short circuit prevention protection circuit (405) comprises a power electronic switch (403), a current limiting resistor and a mechanical switch; the power electronic switch (403) is connected in series with the current-limiting resistor for preventing the winding from short circuit to form a series branch circuit, so that short-circuit accidents in the conversion process of the two voltage-regulating branch circuits are prevented; the series branch is connected with the mechanical switch in parallel to form a voltage regulating branch; the series branch is used for switching on and switching off the voltage regulating branch in the dynamic voltage regulating process; the parallel branch is used for short-circuiting the series branch after the voltage regulating branch is connected, so that the power electronic switch does not operate in a long-term electrified mode, and the power loss of the power electronic switch is reduced.

6. The ac voltage-stabilizing power supply device with high reliability and low loss for the communication base station as claimed in claim 1, wherein the reactive compensation device (50) comprises a capacitor automatic switching reactive compensation device installed at the output side of the dynamic voltage regulation device, and the control quantity is selected as the reactive power of the input of the dynamic voltage regulation device, so as to improve the system power factor of the communication base station and ensure the qualified voltage quality of the base station as the control target; the capacity of the capacitor is 1.5 to 2 times of the maximum reactive power requirement, and the capacitor is used for compensating reactive load of a base station and reactive power of the voltage regulating transformer, and transmitting certain reactive power to the power grid under the condition that the power grid is insufficient in reactive power, so that the output voltage of the installation point of the dynamic voltage regulating device is prevented from being too high; the voltage at the front end of the high side line drops further.

7. The ac voltage-stabilizing power supply device with high reliability and low loss for communication base station as claimed in claim 1, wherein the hybrid power supply device (60) is a single-phase two-wire power supply divided into two groups of power supplies, one group of dynamic voltage-regulating devices outputs single-phase power supply load, and the other group of voltage-regulating transformers outputs split-phase power supply three-phase load, specifically comprising:

8. The AC voltage-stabilizing power supply unit as claimed in claim 1, wherein the reactance of the reactor and the capacitance of the capacitor in the LC split-phase circuit are equal to the equivalent resistance of the single phase of the three-phase air conditioner

9. A communication base station high-reliability low-loss alternating current voltage stabilization power supply method is characterized by comprising the following steps:

the method comprises the following steps that firstly, power supply conversion is carried out, a three-phase four-wire power supply of a communication base station is converted into a single-phase two-wire power supply, and the problems of phase loss faults caused by unbalanced three-phase load and overweight load of a certain phase of the communication base station are solved (1);

step two, power supply switching, namely setting a standby power supply and commercial power supply switching device, switching to a standby power supply state when a power grid fails, and solving the problem (2) of improving the power generation utilization rate of an oil engine of a mountain area communication base station;

step three, efficient transmission, namely converting three-phase four-wire electric energy transmission into single-phase two-wire 2-time winding voltage electric energy transmission, and reducing power loss of line transmission (3);

step four, dynamically regulating voltage, setting up a wide-range bidirectional voltage regulating transformer, and dynamically controlling the voltage tap of the transformer to reduce voltage and boost voltage to switch by adopting a power electronic switch, so as to solve the problem of dynamic voltage stabilization (4);

step five, reactive compensation, namely installing a dynamic reactive compensation device at the output end of the regulating transformer to control the reactive power at the input end of the regulating transformer, and solving the problem of system power factor and voltage reduction after the regulating transformer is installed (5);

step six, hybrid power supply, namely dividing a single-phase two-line 2-time phase voltage power supply into two groups of power supplies for supplying power, wherein one group is used for regulating voltage to supply a single-phase load, and the other group is used for split-phase power supply of a three-phase load (6);

in the first step, power supply conversion is carried out; the method specifically comprises the following steps: for distribution transformers of different connection groups and user properties, the transformation method is as follows:

A. the delta/Y connection special distribution transformer is characterized in that three windings on the high-voltage side are connected into a triangle so as to reduce the influence of the third harmonic of the nonlinear load and the integral multiple harmonic of the third harmonic on a power grid; the three windings on the low-voltage side are changed into three windings which are connected in series, wherein the homonymous end of any one winding is reversely connected, and the homonymous ends of the other two windings are positively connected, so that a power supply in a three-phase four-wire power supply mode is converted into a power supply in a single-phase two-wire output voltage power supply mode with 2 times of low-voltage winding voltage, and four lines of the original three-phase four-wire system are changed into single-phase two-wire output in a two-wire parallel connection mode;

10. The method according to claim 9, wherein the step two is power switching; the method specifically comprises the following steps: the power supply switch is provided with two input ports and one output port, and the output port is respectively connected to one input port of the two specified input ports according to the actual operation requirement through a power electronic or mechanical bidirectional change-over switch, so that the power supply mode switching between the commercial power and the standby power supply is realized; one input port of the two input ports is connected with the single-phase two-line output of the commercial power in the step one, and the other input port is connected with the single-phase output of the standby power supply; one output port is connected with the head end of the single-phase two-wire transmission line, and the tail end of the single-phase two-wire transmission line is connected with the input end of the voltage regulating transformer; the standby power supply is generally provided with a diesel (gasoline) generator, and the conditional base station can be provided with photovoltaic power generation or wind power generation equipment.

11. The method of claim 10, wherein in step three, the transmission is performed efficiently; the method specifically comprises the following steps:

12. The method according to claim 10, wherein in step four, the voltage is dynamically adjusted; the method comprises the following steps: the device comprises a voltage regulating unit, a power electronic switch unit, a protection unit and a control unit;

A. the voltage regulating unit consists of a bidirectional voltage regulating double winding or an autotransformer with a voltage tap (tap) on an original secondary winding; two taps of the primary winding of the regulating transformer set two transformation ratios, namely: 1:1 (for step-down and voltage regulation) and 0.5; two groups of taps are arranged on a secondary winding of the regulating transformer, and the voltage range of 1 group of taps is 80-110% of the rated voltage of the secondary winding; the voltage range of the other group of taps is 65% -45% of the rated voltage of the secondary side; the number of taps is selected according to the voltage quality standard of the actual application scenario;

B. the power electronic switch unit consists of thyristors in positive and negative parallel connection or other high-power electronic switches, and the on and off of relevant taps of the voltage regulating transformer are controlled by the controller according to the actual voltage level detected in real time to realize the dynamic voltage regulating function;

C. the protection unit comprises the protection of a power electronic switch, short-circuit protection and energy-saving protection; the protection of the power electronic switch sets overvoltage, overcurrent, di/dt and dv/dt protection; the short-circuit protection adopts a method that power electronic switch branches are connected with current-limiting resistors in series, so that the condition that the windings of the voltage regulating transformer are short-circuited or open-circuited in the voltage regulating process is prevented; the energy-saving protection adopts a method of connecting a contactor contact in parallel between a power electronic switch and a current-limiting resistance branch to form a dynamic voltage-regulating execution unit; the contactor contact is in a closed state when the power electronic switch is connected with the transformer tap, and is in an open state when the transformer tap is disconnected; therefore, the risks of heating, power loss and burning of the power electronic switch under the condition of normal long-time operation are avoided;

13. The method according to claim 10, wherein in step five, reactive compensation is performed; install dynamic reactive power compensator at regulating transformer's output, solve power factor and the problem (5) that the front end voltage descends behind the installation regulating transformer, specifically include: a capacitor automatic switching reactive power compensation device is arranged on the output side of the dynamic voltage regulation device, and the control quantity is selected as the input reactive power of the dynamic voltage regulation device, so that the system power factor of the communication base station is improved and the voltage quality of the base station is ensured to be qualified as a control target; the capacity of the capacitor is designed according to the maximum reactive power requirement of 1.5-2 times, and is used for compensating reactive load of a base station and reactive power of the voltage regulating transformer, and certain reactive power is transmitted to the power grid under the condition that the power grid is insufficient in reactive power, so that the output voltage of the installation point of the dynamic voltage regulating device is prevented from being too high; the voltage at the front end of the high side line drops further.

14. The ac voltage-stabilized power supply method with high reliability and low loss for communication base station of claim 10, wherein in step six, hybrid power supply; divide into two sets of mains operated with single-phase two line power, a set of dynamic voltage regulation device output single phase load of supplying power, another group's regulating transformer output phase-splitting power supply three-phase load (6), specifically include:

Doubling;

three leading-out wire ends of the LC split-phase circuit are fixedly connected with a power supply terminal A, B and a C end of the three-phase air conditioner; the leading-out wire of the connection point of the reactor and the capacitor is not allowed to be suspended so as to prevent the output end of the voltage regulating transformer from being short-circuited and burning the voltage regulating transformer.