CN111384752A

CN111384752A - Power distribution device, power distribution system and power distribution method

Info

Publication number: CN111384752A
Application number: CN202010180974.8A
Authority: CN
Inventors: 余鹏; 罗欣儿; 田杰; ***
Original assignee: Shenzhen Power Supply Bureau Co Ltd
Current assignee: Shenzhen Power Supply Bureau Co Ltd
Priority date: 2020-03-16
Filing date: 2020-03-16
Publication date: 2020-07-07

Abstract

The application relates to the power distribution device, the power distribution system and the power distribution method, wherein the power distribution device comprises power distribution transformer equipment, AC/DC converter equipment, an acquisition circuit and a processing module. The total current is collected through the collecting circuit, and the processing module controls the AC/DC converter equipment to carry out AC/DC conversion according to the total current when the load of the power distribution network does not exceed the preset load so as to realize DC power supply; and when the load of the power distribution network exceeds the preset load, controlling the AC/DC converter equipment to stop AC/DC conversion so as to stop DC power supply. The power distribution device provided by the application not only can reduce the load pressure and burden of a power distribution network, but also has the load peak eliminating effect; and for the charging equipment which carries out the peak valley price system, the charging at the peak of the power utilization can be avoided, the charging cost is reduced, the load valley filling function is realized, and the optimal social benefit is realized.

Description

Power distribution device, power distribution system and power distribution method

Technical Field

The present application relates to the field of power equipment technologies, and in particular, to a power distribution apparatus, a power distribution system, and a power distribution method.

Background

An electrical distribution device refers to a device used to meter and control the distribution of electrical energy. The power distribution device is mainly installed in a power plant, a transformation and distribution substation, and the like. At present, the main function of a power distribution device of a power distribution station (also called a power distribution room) is to convert high-voltage alternating current (generally 10KV) provided by a power supply office into low-voltage alternating current (generally 380V), and provide the low-voltage alternating current to each electric load or terminal.

However, with the rapid development of electric vehicles, the demand for charging electric vehicles is increasing, and the influence on the power distribution network is also increasing. Especially, when the load of the distribution network is large, the load of the distribution network is further increased by charging the electric automobile.

Disclosure of Invention

In view of the above, it is desirable to provide a power distribution apparatus, a power distribution system, and a power distribution method.

An electrical distribution apparatus comprising:

the distribution transformer equipment is used for converting high-voltage alternating current into multi-path low-voltage alternating current;

the AC/DC converter equipment is electrically connected with the output end of the distribution transformer equipment and is used for converting at least one path of low-voltage alternating current into direct current;

the acquisition circuit is electrically connected with the input end or the output end of the distribution transformer equipment and is used for acquiring the total current of the input end or the output end of the distribution transformer equipment;

and the processing module is in signal connection with the acquisition circuit, is in signal connection with the AC/DC convertor equipment, and is used for determining whether the load of the power distribution network exceeds a preset load according to the total current, controlling the AC/DC convertor equipment to perform AC/DC conversion to realize DC power supply if the load of the power distribution network does not exceed the preset load, and controlling the AC/DC convertor equipment to stop AC/DC conversion to stop DC power supply if the load of the power distribution network exceeds the preset load.

In one embodiment, the processing module comprises:

the comparison unit is in signal connection with the acquisition circuit and is used for comparing the total current with a preset current threshold value, and if the total current is less than or equal to the preset current threshold value, outputting a first comparison result; if the total current is larger than the preset current threshold, outputting a second comparison result;

the processing unit is in signal connection with the comparison unit and is used for outputting a direct current power supply control signal according to the first comparison result and outputting a direct current power supply stop signal according to the second comparison result;

and the control unit is in signal connection with the processing unit, is in signal connection with the AC/DC convertor equipment, and is used for controlling the AC/DC convertor equipment to perform AC/DC conversion according to the DC power supply control signal so as to realize DC power supply and controlling the AC/DC convertor equipment to stop AC/DC conversion according to the DC power supply stop signal so as to stop DC power supply.

In one embodiment, the AC/DC converter device is a bidirectional AC/DC converter device, and the AC/DC converter device is also used for power quality management.

In one embodiment, the processing unit is further in signal connection with the acquisition circuit, and the processing unit is further configured to control the acquisition circuit to acquire a total voltage at an input end or an output end of the distribution transformer device according to the second comparison result, and output an electric energy management control signal according to the total current and the total voltage;

the control unit is also used for controlling the AC/DC convertor equipment to carry out power quality treatment according to the power treatment control signal.

A power distribution system, comprising:

a power distribution apparatus as described above;

and the DC/DC conversion device is electrically connected with the output end of the AC/DC conversion equipment.

A method of distributing power using a power distribution apparatus as described above, comprising:

collecting the total current of the input end or the output end of the distribution transformer equipment;

determining whether the load of the power distribution network exceeds a preset load or not according to the total current;

if the load of the power distribution network does not exceed the preset load, controlling the AC/DC converter equipment to carry out AC/DC conversion so as to realize DC power supply;

and if the load of the power distribution network exceeds the preset threshold value, controlling the AC/DC convertor equipment to stop AC/DC conversion so as to stop DC power supply.

In one embodiment, the determining whether the load of the power distribution network exceeds a preset load according to the total current includes:

if the total current is less than or equal to the preset current threshold, determining that the load of the power distribution network does not exceed the preset load;

and if the total current is larger than a preset current threshold value, determining that the load of the power distribution network exceeds a preset load.

In one embodiment, the AC/DC converter device is a bidirectional AC/DC converter device, and the method further includes:

if the load of the power distribution network exceeds the preset threshold value, acquiring the total voltage of the input end or the output end of the power distribution transformation equipment;

determining whether a power quality problem exists according to the total current and the total voltage;

and if the power quality problem exists, controlling the AC/DC convertor equipment to carry out power quality treatment.

In one embodiment, the power quality problem includes at least one of a low power factor problem, a large current harmonic problem, and a three-phase current imbalance problem.

In one embodiment, the controlling the AC/DC converter device to perform power quality management includes:

and controlling the AC/DC convertor equipment to perform at least one of reactive power compensation, active filtering and three-phase current unbalance compensation.

In the power distribution device, the power distribution system and the power distribution method, the power distribution device comprises power distribution transformation equipment, AC/DC converter equipment, an acquisition circuit and a processing module. The total current is collected through the collecting circuit, and the processing module controls the AC/DC converter equipment to carry out AC/DC conversion according to the total current when the load of the power distribution network does not exceed the preset load so as to realize DC power supply; and when the load of the power distribution network exceeds the preset load, controlling the AC/DC converter equipment to stop AC/DC conversion so as to stop DC power supply. When the load of the power distribution network is too heavy, the power distribution device does not provide direct current power supply, so that the direct current power utilization equipment is prevented from further power utilization when the load of the power distribution network is too heavy. Therefore, the load pressure and the load of the power distribution network can be reduced, and the load peak eliminating effect is achieved; and for the charging equipment which carries out the peak valley price system, the charging at the peak of the power utilization can be avoided, the charging cost is reduced, the load valley filling function is realized, and the optimal social benefit is realized.

Drawings

FIG. 1 is a schematic diagram of a power distribution apparatus according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a three-phase two-level converter according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a three-phase three-level converter according to an embodiment of the present application;

fig. 4 is a block diagram of a control device according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a power distribution system according to an embodiment of the present application;

FIG. 6 is a schematic flow chart of a power distribution method provided by an embodiment of the present application;

FIG. 7 is a schematic flow chart diagram of a power distribution method provided by an embodiment of the present application;

fig. 8 is a schematic flow chart of a power distribution method according to an embodiment of the present application.

Element number description:

a power distribution system: 10;

a power distribution device: 100, respectively;

distribution transformer equipment: 110; a distribution transformer: 111; and (3) alternating current bus: 112, a first electrode; an alternating current feeder line: 113; an alternating current switch: 114, and a carrier;

AC/DC converter equipment: 120 of a solvent; AC/DC converter: 121, a carrier; and D, direct current bus: 122; a direct current feeder line: 123;

the control device: 130, 130; the acquisition circuit: 131;

a processing module: 132; a comparison unit: 1321; a processing unit: 1322; a control unit: 1323;

DC/DC conversion device: 200.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the power distribution apparatus, the power distribution system and the power distribution method of the present application are further described in detail by the embodiments and with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be considered as limiting the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

An embodiment of the present application provides a power distribution apparatus 100, which can be disposed in a power distribution substation, and is configured to convert high-voltage ac power in a power distribution network into low-voltage ac power and low-voltage dc power for distribution.

The distribution station in the traditional technology can only convert 10KV high-voltage alternating current into multi-path 380V low-voltage alternating current for each user to use. Such distribution station can't directly set up and fill electric pile, realizes supplying electric automobile to charge and uses, has awkward problem. Therefore, in the conventional art, a charging pile for charging an electric vehicle includes an AC-DC conversion device (AC/DC conversion device) for converting 380V AC power into 750V DC power, and then converting the voltage into DC power having a voltage required for charging the electric vehicle by the DC/DC conversion device. Therefore, the structure of the charging pile in the traditional technology is complex and the size is huge.

Referring to fig. 1, in one embodiment, the power distribution apparatus 100 includes a distribution transformer device 110 and an AC/DC converter device 120. The AC/DC converter device 120 is electrically connected to the output of the distribution transformer device 110.

The distribution transformer device 110 is used to convert the high-voltage ac power into multiple low-voltage ac powers. The distribution transformer 110 includes an input end and an output end, the input end of the distribution transformer 110 is also referred to as a high voltage end, and the output end of the distribution transformer 110 is also referred to as a low voltage end. The input of the distribution transformer 110 is electrically connected to a distribution network. The output of the distribution transformer 110 is electrically connected to the input of the AC/DC converter 120. The type and configuration of the distribution transformer 110 may vary as desired. In one embodiment, the distribution transformer device 110 may be a 10KV/380V distribution transformer device for converting 10KV ac power to 380V ac power, as required by the application. The output of the distribution transformer 110 may be multiplexed. In use, each output terminal may be electrically connected to an ac load F1 for supplying ac power to the ac load F1.

The AC/DC converter device 120 is electrically connected to one or more output terminals of the distribution transformer device 110, and is configured to convert at least one low-voltage AC power into a DC power. The AC/DC converter device 120 includes an input and an output, and the input of the AC/DC converter device 120 is electrically connected to the output of the distribution transformer device 110. The output end of the AC/DC converter device 120 is used for connecting a direct current load F2. The AC/DC converter equipment 120 may be of different types and configurations as desired. In one embodiment, the AC/DC converter device 120 may be a 380V/750V converter device for converting 380V AC power into 750V DC power according to the use requirement.

The power distribution device provided by the embodiment can realize alternating current power distribution and direct current power distribution, and also realizes alternating current and direct current integrated power distribution. The alternating current can be further used for production and life, and the direct current can be further used for electric automobiles and other equipment needing the direct current. Use electric automobile as an example, when setting up to fill electric pile, only need set up DC/DC conversion device, need not to set up AC/DC conversion device, reduced the volume that fills electric pile, simplified the structure that fills electric pile, practice thrift the cost.

In this embodiment, the power distribution apparatus 100 includes the distribution transformer device 110 and the AC/DC converter device 120. Alternating current distribution can be realized by the distribution transformer 110, and direct current distribution can be further realized by the AC/DC converter 120. That is to say, the power distribution device 100 provided by this embodiment realizes the integrated alternating current and direct current power distribution, improves the utilization rate of equipment, and solves the problem that direct current electric equipment such as an electric automobile is inconvenient to use electricity. Meanwhile, the power distribution device 100 is used for power distribution, and an AC/DC conversion device is not required to be arranged for charging piles, so that the size of the charging piles is reduced, the structure of the charging piles is simplified, and the cost is saved.

With continued reference to fig. 1, in one embodiment, the distribution transformer apparatus 110 includes a distribution transformer 111, an ac bus 112, a plurality of ac feeders 113, and a plurality of ac switches 114. The distribution transformer 111 is used to convert high-voltage ac power to low-voltage ac power. The ac bus 112 is electrically connected to the low-voltage end of the distribution transformer 111. The plurality of alternating current feeders 113 and the AC/DC converter device 120 are respectively connected to the alternating current bus 112. That is, the low-voltage AC power output by the distribution transformer 111 is output to the AC feeders 113 and the AC/DC converter device 120 through the AC bus 112, so as to be used by the multiple AC loads F1 and the AC/DC converter device 120. The plurality of ac switches 114 may be respectively disposed on the plurality of ac feeder lines 113. In one embodiment, each ac feeder 113 is electrically connected to one ac switch 114, so as to control each low-voltage ac power. The plurality of ac switches 114 may be provided through a switchgear for use.

In one embodiment, the AC/DC converter apparatus 120 includes an AC/DC converter 121, a DC bus 122, a plurality of DC feeders 123, and a plurality of DC switches 124. The AC/DC converter 121 is configured to convert at least one path of the low-voltage AC power into a DC power. The output end of the AC/DC converter 121 is connected to the DC bus 122. The plurality of dc feeder lines 123 are electrically connected to the dc bus 122, respectively. The DC power output from the AC/DC converter 121 is transmitted to the plurality of DC feeders 123 through the DC bus, and is further supplied to a plurality of DC loads F2 through the plurality of DC feeders 123. The plurality of dc switches 124 may be respectively disposed on the plurality of dc feeders 123. In one embodiment, each of the dc feeder lines 123 is electrically connected to one of the dc switches 124, so as to control the dc power of each circuit. The plurality of dc switches 124 may be provided through the switchgear for use.

In one embodiment, the power distribution apparatus 100 further includes a control device 130. The distribution apparatus 100 is respectively connected to the distribution transformer 110 and the AC/DC converter 120. The control device 130 is configured to control the AC/DC converting device 120 to stop or start the AC/DC converting operation. Specifically, the control device 130 determines whether the load of the power distribution network exceeds a preset load, and if not, controls the AC/DC converter device 120 to perform AC/DC conversion, where at this time, DC power supply may be performed. And if the load of the power distribution network exceeds a preset load (that is, the load of the power distribution network is greater than the preset load), controlling the AC/DC converter device 120 to stop the AC/DC conversion, so as to stop the DC power supply. The size of the preset load can be set according to actual requirements. It should be noted that the load may be characterized by one of a plurality of parameters, such as current, load, voltage, or a combination of a plurality of parameters. In this embodiment, the control device 130 may implement its functions through a hardware circuit, may implement its functions through a software program, and may implement its functions through a combination of software and hardware.

In this embodiment, the control device 130 is arranged to control the operating state of the AC/DC converter device 120, so that when the load of the distribution network is too heavy, no DC power is supplied, and charging of the DC power consuming device is avoided when the load of the distribution network is too heavy. Therefore, the load pressure of the power distribution network can be reduced, and the load peak eliminating effect is achieved; and for the charging equipment which carries out the peak valley price system, the charging at the peak of the power utilization can be avoided, the charging cost is reduced, the load valley filling function is realized, and the optimal social benefit is realized.

In one embodiment, the AC/DC converter device 120 is a bidirectional AC/DC converter device. The bidirectional AC/DC converter device is also called AC/DC bidirectional converter device. The bidirectional AC/DC converter equipment can comprise an AC/DC converter and a DC/AC converter. The AC/DC converter is used to convert alternating current to direct current and also acts as a rectifier. DC/AC converters are used to convert direct current into alternating current, also referred to as inverters. The bidirectional AC/DC convertor equipment can realize the treatment of the power quality and solve the problem of the power quality besides realizing the conversion between alternating currents. The power quality problem may include, but is not limited to, a low power factor problem, a large current harmonic problem, a three-phase current imbalance problem, and the like. The bidirectional AC/DC converter equipment can realize the functions of reactive power compensation, active filtering, three-phase current unbalance compensation and the like.

In an embodiment, the control device 130 is further configured to control the bidirectional AC/DC converter device to perform power quality management when there is a power quality problem in the power output from the power distribution network, so as to improve the power quality. It should be noted that the power quality control and the dc power supply may be performed simultaneously. Of course, according to the requirement, a certain priority can be set, and the direct current power supply is preferentially carried out or the electric energy quality is preferentially controlled.

Referring to fig. 2 and fig. 3, the bidirectional AC/DC converter apparatus may be a three-phase two-level converter, or a three-phase three-level converter. The bidirectional AC/DC converter equipment can realize four-quadrant operation of active power and reactive power, and realize capacitive reactive power and inductive reactive power. The capacitive reactive, i.e. current, leads the voltage by 90 deg., and the inductive reactive, i.e. current, lags the voltage by 90 deg.. The bidirectional AC/DC converter equipment can output compensation harmonic waves, namely harmonic currents with equal amplitudes and opposite directions, and reactive power compensation is achieved. Meanwhile, the bidirectional AC/DC converter equipment can realize active filtering. Regarding the problem of three-phase current unbalance, the bidirectional AC/DC convertor equipment outputs negative sequence current and zero sequence current with equal amplitude and opposite directions, so that the unbalance current is counteracted.

The structure and function of the control device 130 are further explained below with reference to the following embodiments:

referring to fig. 4, in one embodiment, the control device 130 includes an acquisition circuit 131 and a processing module 132. The input end of the collecting circuit 131 is connected to the input end or the output end of the distribution transformer device 110. The output end of the acquisition circuit 131 is in signal connection with the processing module. The collecting circuit 131 is used to collect the total current at the input end or the output end of the distribution transformer 110. When the collecting circuit 131 is connected with the input end of the distribution transformer 110, the current value input to the distribution transformer 110 by the distribution network is collected, and when the collecting circuit 131 is connected with the output end of the distribution transformer 110, the total current of the low-voltage alternating current converted by the distribution transformer 110 is collected. The total current at the input or output of the distribution transformer 110 reflects the load condition of the distribution network. The collection circuit 131 may include a hall element, and current collection is achieved through the hall element.

The processing module 132 is configured to determine whether the load of the power distribution network exceeds the preset load according to the total current, control the AC/DC converter device 120 to perform AC/DC conversion to implement direct current power supply if the load of the power distribution network does not exceed the preset load, and control the AC/DC converter device 120 to stop AC/DC conversion to stop direct current power supply if the load of the power distribution network exceeds the preset load.

In this embodiment, the power distribution apparatus 100 includes a distribution transformer device 110, an AC/DC converter device 120, an acquisition circuit 131, and a processing module 132. The total current is collected by the collecting circuit 131, and the processing module 132 controls the AC/DC converter device 120 to perform AC/DC conversion according to the total current when the load of the power distribution network does not exceed the preset load, so as to implement DC power supply; and when the load of the power distribution network exceeds the preset load, controlling the AC/DC converter device 120 to stop alternating current-direct current conversion so as to stop direct current power supply. The power distribution device 100 provided in this embodiment does not provide dc power when the power distribution network is overloaded, so as to prevent further power utilization of the dc power utilization equipment when the power distribution network is overloaded. Therefore, the load pressure and the load of the power distribution network can be reduced, and the load peak eliminating effect is achieved; and for the charging equipment which carries out the peak valley price system, the charging at the peak of the power utilization can be avoided, the charging cost is reduced, the load valley filling function is realized, and the optimal social benefit is realized.

With continued reference to fig. 4, in one embodiment, the processing module 132 includes a comparing unit 1321, a processing unit 1322 and a control unit 1323. The input end of the comparing unit is in signal connection with the output end of the acquisition circuit 131, and the output end of the comparing unit is connected with the input end of the processing unit 1322. An output of the processing unit 1322 is connected to an input of the control unit 1323. The output terminal of the control unit 1323 is connected to the control terminal of the AC/DC converter device 120.

The comparing unit 1321 is configured to compare the total current with a preset current threshold, and output a first comparison result if the total current is less than or equal to the preset current threshold; and if the total current is greater than the preset current threshold, outputting a second comparison result. The first comparison result is used for representing that the load of the power distribution network is lighter at present, and the second comparison result is used for representing that the load of the power distribution network is heavier at present. The comparing unit 1321 may be implemented by a hardware circuit, may be implemented by a software program, and may be implemented by a combination of a hardware circuit and a software program. In one embodiment, the comparing unit 1321 may be a comparator.

The processing unit 1322 is configured to output a dc control signal according to the first comparison result, and output a dc control signal according to the second comparison result. That is, when receiving that the output result of the comparing unit 1321 is the first comparison result, the processing unit 1322 outputs a signal indicating that dc power supply is performed by the control unit 1323; when receiving that the output result of the comparing unit 1321 is the second comparison result, the processing unit 1322 outputs a signal indicating that the dc power supply is stopped to the control unit 1323. The processing unit 1322 may be implemented by a hardware circuit, a software program, or a combination of a hardware circuit and a software program. In one embodiment, the processing unit 1322 may be a processor, microprocessor, chip, or the like.

The control unit 1323 is configured to control the AC/DC converter device 120 to perform AC/DC conversion according to the DC power supply control signal, so as to implement DC power supply; and controls the AC/DC converter device 120 to stop AC/DC conversion according to the DC supply stop signal to stop AC power supply. The control unit 1323 may be implemented by a hardware circuit, a software program, or a combination of a hardware circuit and a software program. In one embodiment, the control unit 1323 may be a microprocessor, a chip, or the like including control circuitry.

In an embodiment, when the AC/DC converter device 120 is a bidirectional AC/DC converter device, the output terminal of the processing unit 1322 is further connected to the control terminal of the acquisition circuit 131. The processing unit 1322 is further configured to control the collecting circuit 131 to collect the total voltage at the input end or the output end of the distribution transformer apparatus 110 according to the second comparison result, and output an electric energy governance control signal according to the total current and the total voltage. The control unit 1323 is further configured to control the AC/DC converter device 120 to perform power quality management according to the power management control signal.

That is, when the comparison result received by the processing unit 1322 is the second comparison result, that is, the distribution network is overloaded currently, the processing unit 1322 further controls the collecting circuit 131 to collect the total voltage, and determines whether there is a power quality problem according to the total current and the total voltage. If the current is present, the processing unit 1322 outputs the electric energy governance control signal to the control unit 1323, and the control unit 1323 controls the AC/DC converter device 120 to perform electric energy quality governance. In this way, the power distribution apparatus 100 provided in this embodiment can not only stop the dc power supply when the load of the power distribution network is heavy, but also further perform power quality management on the power quality problem, thereby improving the power quality output by the power distribution apparatus 100.

Referring to fig. 5, an embodiment of the present application further provides a power distribution system 10, where the power distribution system 10 includes the power distribution apparatus 100 and the DC/DC conversion apparatus 200 as described above. An input terminal of the DC/DC converter 200 is electrically connected to an output terminal of the AC/DC converter apparatus 120. The DC/DC conversion apparatus 200 may be plural and connected to the plural DC feeders 123, respectively. The specific structure, model, parameters, etc. of the DC/DC conversion device 200 can be set according to the requirements of the DC charging equipment, for example, according to the requirements of the electric vehicle on the DC voltage during charging, so that the voltage and current output by the DC/DC conversion device 200 can meet the charging requirements of the electric vehicle. The power distribution system 10 provided in this embodiment can realize direct charging of the dc power consumption device, further simplify or save charging pile, save resources, and can improve the device utilization rate.

Referring to fig. 6, an embodiment of the present application provides a method for power distribution using the power distribution apparatus 100 as described above, and the method can be applied to the control apparatus 130.

In one embodiment, the method comprises:

s10, collecting the total current of the input end or the output end of the distribution transformer 110;

s20, determining whether the load of the power distribution network exceeds a preset load according to the total current;

if the load of the power distribution network does not exceed the preset load, S30 controls the AC/DC converter device 120 to perform AC/DC conversion to implement DC power supply.

If the load of the power distribution network exceeds the preset threshold value, S40, the AC/DC converter device 120 is controlled to stop AC/DC conversion, so as to stop DC power supply.

The collecting circuit 131 collects the total current of the input end or the output end of the distribution transformer 110 and sends the total current to the processing module 132. The processing module 132 determines whether the load of the distribution grid exceeds a preset load according to the total current. The larger the total current, the heavier the load of the distribution network. If the load of the power distribution network exceeds the preset load, the processing module 132 controls the AC/DC converter device 120 to stop the AC/DC conversion, otherwise, the AC/DC conversion is continued.

In a specific embodiment, the processing module 132 includes the comparing unit 1321, the processing unit 1322, and the control unit 1323 as described above. The comparing unit 1321 compares the total current with a preset current threshold, and outputs a first comparison result if the total current is less than or equal to the preset current threshold. And if the total current is greater than the preset current threshold, outputting a second comparison result. The first comparison result is used for representing that the load of the power distribution network is lighter at present, and the second comparison result is used for representing that the load of the power distribution network is heavier at present. The processing unit 1322 outputs a dc power supply control signal according to the first comparison result, and the processing unit 1322 outputs a dc power supply stop signal according to the second comparison result, and transmits the dc power supply stop signal to the control unit 1323. When receiving the DC power supply control signal, the control unit 1323 controls the AC/DC converter device 120 to perform AC/DC conversion, so as to implement DC power supply. The control unit 1323 controls the AC/DC converter device 120 to stop AC/DC conversion when receiving the DC power supply stop signal, so as to stop DC power supply.

In this embodiment, by collecting the total current of the input end or the output end of the distribution transformer device 110, and determining whether the load of the distribution network exceeds a preset load according to the total current, when the load of the distribution network does not exceed the preset load, the AC/DC converter device is controlled to perform AC/DC conversion, so as to implement DC power supply; and if the load of the power distribution network exceeds the preset threshold value, controlling the AC/DC converter equipment to stop AC/DC conversion so as to stop DC power supply. The method provided by the embodiment can stop direct current power supply when the load of the power distribution network is too heavy, so that further power utilization of direct current power utilization equipment when the load of the power distribution network is too heavy is avoided. Therefore, the load pressure and the load of the power distribution network can be reduced, and the load peak eliminating effect is achieved; and for the charging equipment which carries out the peak valley price system, the charging at the peak of the power utilization can be avoided, the charging cost is reduced, the load valley filling function is realized, and the optimal social benefit is realized.

The present embodiment relates to a possible implementation manner of determining whether the load of the power distribution network exceeds a preset load according to the total current, that is, S20 includes:

s210, if the total current is less than or equal to the preset current threshold, determining that the load of the power distribution network does not exceed the preset load;

s220, if the total current is larger than a preset current threshold value, determining that the load of the power distribution network exceeds a preset load.

The preset current threshold value can be set to different values according to different collection positions of the total current, and can also be set to different values according to different parameters of the power distribution network. The total current can represent the load of the power distribution network, so that whether the power distribution network is overloaded or not can be accurately and simply determined by judging the total current.

Referring to fig. 7, in an embodiment, the AC/DC converter device is a bidirectional AC/DC converter device, and if the load of the power distribution network exceeds the preset threshold, the method further includes:

s50, collecting the total voltage of the input end or the output end of the distribution transformer equipment 110;

s60, determining whether the power quality problem exists according to the total current and the total voltage;

if the power quality problem exists, S70, the AC/DC converter device 120 is controlled to perform power quality control.

When the load of the distribution network is heavy, the processing module 132 sends a signal to the acquisition circuit 131 to control the acquisition circuit 131 to further acquire the total voltage. The acquisition circuit 132 sends the acquired total voltage to the processing module 132. The processing module 132 determines whether there is a power quality problem according to the total current and the total voltage.

In one embodiment, the power quality problem includes at least one of a low power factor problem, a high current harmonic problem and a three-phase current imbalance problem, and the performing the power quality management on the AC/DC converter device 120 includes controlling the AC/DC converter device 120 to perform at least one of reactive power compensation, active filtering and three-phase current imbalance compensation.

Referring to fig. 8, in an embodiment, if the load of the distribution network exceeds the preset load, the processing module 132 determines whether there is a problem of power quality, which may be performed by the following steps, that is, S60 and S70 include:

s610, determining whether a problem of low power factor exists;

if the problem of low power factor exists, S710, controlling the AC/DC converter device 120 to perform reactive power compensation;

if the problem of low power factor does not exist, S620, determining whether the problem of large current harmonic exists;

if the current harmonic is large, S720, controlling the AC/DC converter device 120 to perform active filtering;

if the problem of determining whether the current harmonic is large does not exist, S630, determining whether the problem of three-phase current imbalance exists;

if the three-phase current imbalance problem exists, S730, controlling the AC/DC convertor equipment 120 to compensate the three-phase current imbalance; and returns to perform step S20;

if there is no three-phase current imbalance problem, the process returns to step S20.

In this embodiment, the specific method for determining whether the problem of low power factor, the problem of large current harmonic, and the problem of unbalanced three-phase current exist according to the total current and the total voltage is not limited at all, and may be selected according to actual requirements as long as the function can be implemented. In a specific embodiment, it is possible to determine whether there is a problem of low power factor by detecting the fundamental reactive component of the total current; determining whether there is a problem of large current harmonics by detecting harmonic currents of the total current collected a plurality of times (for example, may be 20 times to 50 times); by detecting the negative sequence current component and the zero sequence current, the low power factor, the large harmonic wave, the three-phase imbalance and the like are obtained. The method of detection may be, but is not limited to, using a fourier analysis FFT.

And determining the reactive condition through the high and low of the total voltage, wherein the voltage is high if the capacitive reactive condition exists, and the total voltage is low if the inductive reactive condition exists. When light load is generally represented as capacitive reactive, the total voltage is high. When heavy load is applied, inductive reactive power is generally shown, and the total voltage is low.

In one embodiment, if the load of the distribution network does not exceed the preset load, the method further comprises the following steps:

s80, determining whether a charging device requests charging;

if no charging pile requests charging, returning to execute the step S20;

if the charging pile requests charging, S90 sends a charging command to the charging pile.

And after receiving the charging instruction, the charging pile executes charging to realize charging of the charging equipment.

It should be understood that, although the steps in the respective flowcharts are shown in sequence as indicated by the arrows, the steps are not necessarily performed in sequence as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in the flowchart may include multiple sub-steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of performing the sub-steps or stages is not necessarily sequential, but may be performed alternately or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An electrical distribution apparatus, comprising:

a distribution transformer device (110) for converting high-voltage alternating current into multiple paths of low-voltage alternating current;

the AC/DC converter equipment (120) is electrically connected with the output end of the distribution transformer equipment (110) and is used for converting at least one path of low-voltage alternating current into direct current;

the acquisition circuit (131) is electrically connected with the input end or the output end of the distribution transformer equipment (110) and is used for acquiring the total current of the input end or the output end of the distribution transformer equipment (110);

and the processing module (132) is in signal connection with the acquisition circuit (131), is in signal connection with the AC/DC converter device (120), and is configured to determine whether a load of the power distribution network exceeds a preset load according to the total current, control the AC/DC converter device (120) to perform AC/DC conversion if the load of the power distribution network does not exceed the preset load, so as to implement direct-current power supply, and control the AC/DC converter device (120) to stop AC/DC conversion if the load of the power distribution network exceeds the preset load, so as to stop direct-current power supply.

2. The electrical distribution apparatus of claim 1, wherein the processing module (132) comprises:

the comparison unit (1321) is in signal connection with the acquisition circuit (131) and is used for comparing the total current with a preset current threshold value, and if the total current is smaller than or equal to the preset current threshold value, outputting a first comparison result; if the total current is larger than the preset current threshold, outputting a second comparison result;

the processing unit (1322) is in signal connection with the comparison unit (1321) and is used for outputting a direct current power supply control signal according to the first comparison result and outputting a direct current power supply stop signal according to the second comparison result;

and the control unit (1323) is in signal connection with the processing unit (1322), is in signal connection with the AC/DC converter device (120), and is used for controlling the AC/DC converter device (120) to perform AC/DC conversion according to the DC supply control signal so as to realize DC supply and controlling the AC/DC converter device (120) to stop AC/DC conversion according to the DC supply stop signal so as to stop DC supply.

3. The power distribution arrangement according to claim 2, wherein the AC/DC converter device (120) is a bidirectional AC/DC converter device, and wherein the AC/DC converter device (120) is further used for power quality management.

4. The power distribution apparatus according to claim 3, wherein the processing unit (1322) is further in signal connection with the collecting circuit (131), and the processing unit (1322) is further configured to control the collecting circuit (131) to collect a total voltage at an input end or an output end of the distribution transformer device (110) according to the second comparison result, and output a power management control signal according to the total current and the total voltage;

the control unit (1323) is further configured to control the AC/DC converter device (120) to perform power quality governance according to the power governance control signal.

5. An electrical distribution system, comprising:

the power distribution device (100) of any of claims 1 to 4;

and the DC/DC conversion device (200) is electrically connected with the output end of the AC/DC conversion equipment (120).

6. A method of distributing power using the power distribution apparatus of any of claims 1 to 4, comprising:

collecting a total current at an input or an output of the distribution transformer device (110);

if the load of the power distribution network does not exceed the preset load, controlling the AC/DC converter equipment (120) to carry out AC/DC conversion so as to realize DC power supply;

and if the load of the power distribution network exceeds the preset threshold value, controlling the AC/DC converter equipment (120) to stop AC/DC conversion so as to stop DC power supply.

7. The method of claim 6, wherein determining whether the load on the distribution grid exceeds a predetermined load based on the total current comprises:

8. The method of claim 6, wherein the AC/DC converter device (120) is a bidirectional AC/DC converter device, the method further comprising:

if the load of the power distribution network exceeds the preset threshold value, collecting the total voltage of the input end or the output end of the power distribution transformation equipment (110);

and if the power quality problem exists, controlling the AC/DC convertor equipment (120) to carry out power quality treatment.

9. The method of claim 8, wherein the power quality issues include at least one of low power factor issues, large current harmonics issues, and three-phase current imbalance issues.

10. The method according to claim 9, wherein said controlling said AC/DC converter device (120) for power quality management comprises:

and controlling the AC/DC convertor equipment (120) to perform at least one of reactive power compensation, active filtering and three-phase current unbalance compensation.