KR101127672B1 - Apparatus and method for controlling distributed power - Google Patents

Abstract

PURPOSE: An apparatus and method for controlling a distributed power is provided to improve the effectiveness of a power system by controlling a distributed power in consideration of the whole state of a distribution line. CONSTITUTION: A storage(110) stores the information of a regulation voltage and a tolerance range of a specific bus line. A sensing unit(120) senses the voltage and current of a distribution line. A current flow calculation part(130) calculates the output limit value of a distributed power A distributed power controller(140) controls so that the output limit value of a distributed power is smaller.

Description

Apparatus and method for controlling distributed power

The present invention relates to a distributed power supply control apparatus and method. In particular, the present invention relates to a distributed power supply control apparatus and method that can flexibly cope with changes in conditions of a distribution system.

Distributed power is designed to reduce energy loss and transmission and distribution facilities by installing small power generation facilities near energy consumers or inside buildings. Such distributed power sources may include photovoltaic power generation, fuel cell power generation, and wind power generation. In addition, with the development of communication technology, it is now possible to implement distributed power on an economic scale through remote automatic operation.

When a plurality of distributed power supplies are installed in the distribution system and the distributed power output is sent to the distribution system, the distribution system may change voltage according to the amount of generation of the distributed power supply. In particular, when a plurality of large-capacity distributed power supplies are operated in connection with one distribution line, the voltage of the distribution line may be out of the range of the specified operating voltage of the distribution line. And, there is a risk that the electrical equipment of each generation that is supplied with electricity from the distribution line can be damaged.

In order to solve the above problems, an object of the present invention is to maintain the voltage of a distribution line within a specified voltage allowable range by appropriately controlling the output of the distributed power supply when a plurality of distributed power supplies are connected to the distribution system.

In addition, an object of the present invention is to maintain the voltage of the distribution line within the specified voltage allowable range without stopping some of the distributed power supplies connected to the distribution system. That is, an object of the present invention is to ensure a stable voltage of the distribution line, and to continuously output a plurality of distributed power sources connected to one distribution system, thereby improving the efficiency of the overall distributed power supply.

In addition, the present invention aims to increase the efficiency of the overall power system by controlling the distributed power supply in consideration of the state of the entire distribution line, rather than controlling the distributed power supply in consideration of the distribution line conditions at some contacts.

In accordance with another aspect of the present invention, there is provided a distributed power supply control device including: a storage unit configured to store information about a specified voltage and a specified voltage allowable range of a specific bus including a distributed power supply; Sensing unit for sensing the voltage of the specific bus, the connection point to the distribution system of the distributed power supply and the voltage and current of the distribution line; When the voltage of the specific bus is out of the specified voltage allowable range, the voltage of the specific bus is maintained within the specified voltage allowable range based on data of voltage and current sensed by the sensing unit. A tidal current calculation unit for calculating the output limit value of the distributed power supply; And a distributed power supply control unit controlling the distributed power supply so that the output value of the distributed power supply is smaller than the output limit value calculated by the tidal current calculator.

At this time, the tidal current calculation unit voltage value of the lead portion of the distribution line and the voltage value of the specific bus, the impedance value of the line between the lead portion of the distribution line and the specific bus, the power consumption value of the specific bus, the dispersion The output limit value may be calculated based on the generated power value of the power source. The distributed power control unit may control the power factor of the distributed power supply to one. In addition, the specified voltage allowable range may be 0.95 times to 1.05 times the specified voltage.

At this time, the tidal current calculator may calculate the output limit value so that the voltage of the specific bus is maintained in the range of 0.96 times to 1.04 times the specified voltage.

In this case, the distributed power supply is a photovoltaic power generation power, and the distributed power supply control unit, the distributed power supply so that when the voltage of the specific bus is within the specified voltage allowable range, the voltage of the specific bus has a maximum value of the specified voltage allowable range Can be controlled.

In addition, the distributed power supply control method according to the present invention for achieving the above object comprises the steps of storing information about the specified voltage and the specified voltage allowable range of the specific bus line including the distributed power; Sensing the voltage of the specific bus, the connection point for the distribution system of the distributed power supply, and the voltage and current of the distribution line; Determining whether the voltage of the specific bus is within the specified voltage allowable range; Calculating an output limit value such that the voltage of the specific bus is maintained within the specified voltage allowable range based on the sensed data of the voltage and current when the voltage of the specific bus exceeds the allowable voltage range; And controlling the distributed power supply so that an output value of the distributed power supply is smaller than the output limit value.

At this time, the step of calculating the current, the voltage value of the lead portion of the distribution line and the voltage value of the specific bus, the impedance value of the line between the lead portion of the distribution line and the specific bus, the power consumption value of the specific bus The output limit value may be calculated based on the generated power value of the distributed power supply. In addition, the power factor of the distributed power supply may be controlled to one. In addition, the specified voltage allowable range may be 0.95 times to 1.05 times the specified voltage.

In this case, in the tidal current calculation of the output limit value, the output limit value may be calculated such that the voltage of the specific bus is maintained in the range of 0.96 times to 1.04 times the specified voltage.

At this time, the distributed power source is a solar power generation power, and the step of controlling the distributed power supply, when the voltage of the specific bus is within the specified voltage allowable range, the voltage of the specific bus is the maximum value of the specified voltage allowable range The distributed power supply can be controlled to have.

According to the present invention, when a plurality of distributed power supplies are connected to the distribution system, the output of the distributed power supplies can be properly controlled to maintain the voltage of the distribution line within the specified voltage allowable range. Therefore, the risk of breakage of each generation of electric equipment supplied with electricity from the distribution line is reduced.

In addition, the present invention can maintain the voltage of the distribution line within the specified voltage allowable range without stopping some of the distributed power supplies connected to the distribution system. Therefore, while ensuring a stable voltage of the distribution line, a plurality of distributed power sources connected to one distribution system can be continuously output, the overall efficiency of the distributed power supply is improved.

In addition, the present invention may not control the distributed power supply in consideration of the distribution line conditions at some of the contacts, but control the distributed power supply in consideration of the state of the entire distribution line, thereby increasing the efficiency of the overall power system.

1 is a diagram illustrating a wiring system to which a distributed power supply control device according to the present invention is applied.
2 is a view for explaining a method for deriving the output limit value of the distributed power supply control apparatus according to the present invention.
3 is a flowchart illustrating a distributed power supply control method according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Here, the repeated description, well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention, and detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more completely describe the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity.

Hereinafter, the configuration and operation of the distributed power supply control apparatus according to the present invention will be described.

1 is a diagram illustrating a wiring system to which a distributed power supply control device according to the present invention is applied. FIG. 2 is a view for explaining a method of deriving an output limit value of the distributed power supply control device according to the present invention.

1 and 2, the distributed power supply control apparatus 100 according to the present invention includes a storage unit 110, a sensing unit 120, a tidal current calculation unit 130, and a distributed power supply control unit 140. In addition, the distributed power supply control device 100 is formed to control a plurality of distributed power when a plurality of distributed power is connected to one distribution system. Hereinafter, the substation 11, the breaker 12, the first switch 13, the second switch 14, the third switch 15, the fourth switch 16, and the fifth switch 17 are included. To describe the operation and configuration of the distributed power supply control device 100 according to the present invention for the configuration in which the first to fourth distributed power sources 21, 22, 23, and 24 are connected to the distribution system 10 formed. do. In addition, FIG. 2 shows the power distribution system 10 of FIG. 1 and the first to fourth distributed power supplies 21, 22, 23, and 24 to the bus line, the first distributed power supply 21, and the distribution line lead-in side. A first bus bus1 including a specific first load 31, a second distributed power supply 22, a second bus bus2 including a specific second load 32, a third distributed power supply 23 and It is a figure defined and reconfigured by the 3rd bus bus3 including the specific 3rd load 33, the 4th distributed power supply 24, and the 4th busbus 4 including the 4th specific load 34. FIG.

The storage unit 110 has a predetermined voltage and a predetermined voltage allowable range of each of the first to fourth buses bus1, bus2, bus3, and bus4 including the first to fourth distributed power sources 21, 22, 23, and 24, respectively. It stores information about it. At this time, the specified voltage allowable range may be 0.95 times to 1.05 times the specified voltage.

The sensing unit 120 includes the voltage V ₀ of the bus line input bus side of the distribution line and the voltages V ₁ , V ₂ , V ₃ , and V _{4 of} the first to fourth busses bus 1, bus 2, bus 3, and bus ₄ . Sensing. In addition, the sensing unit 120 senses voltages and currents of the connection points and the distribution lines of the distribution systems of the first to fourth distributed power sources 21, 22, 23, and 24. In addition, the sensing unit 120 uses the information of the sensed voltage and current and the information of the line type and the positive input on the system, that is, each section of the wiring system, that is, the first to fourth lines 41, 42, 43, and 44. impedance _{(R 1 + jX 1, R} 2 + jX 2, R 3 + jX 3, R 4 + jX 4) and the first to fourth line voltage (V _1, V ₂ of (bus1, bus2, bus3, bus4 ) , V ₃ , V ₄ ) can be derived.

The tidal current calculation unit 130 allows at least one of the voltages V ₁ , V ₂ , V ₃ , and V ₄ of the first to fourth buses bus 1, bus 2, bus 3, and bus 4 to allow a prescribed voltage of the storage 110. If it is out of the range, the output limit values of the first to fourth distributed power supplies 21, 22, 23, and 24 are calculated. The output limit value is the voltage (V ₁ , V ₂ , V ₃ , V ₄ ) of the first to fourth buses bus 1, bus 2, bus 3, and bus 4 based on data of the voltage and current sensed by the sensing unit 120. ) Is an output value of the first to fourth distributed power supplies 21, 22, 23, and 24 so as to be kept within a specified voltage allowable range. In addition, the tidal current calculation unit 130 is the voltage (V ₀ ) of the distribution line lead-in, the voltage (V ₁ , V ₂ , V ₃ , V ₄ ) of the first to fourth bus (bus1, bus2, bus3, bus4), Impedances (R ₁ + jX ₁ , R ₂ + jX ₂ , R ₃ + jX ₃ , R ₄ + jX ₄ ) of the 1 to 4 lines 41, 42, 43, 44, and the first to fourth loads 31, 32. Power consumption (P _L1 + jQ _L1 , P _L2 + jQ _L2 , P _L3 + jQ _L3 , P _L4 + jQ _L4 ) of the first to fourth bus lines bus1, bus2, bus3, and bus4 by The output limit value is calculated based on the generated powers P _g1 + jQ _g1 , P _g2 + jQ _g2 , P _g3 + jQ _g3 , P _g4 + jQ _{g4 of} the first to fourth distributed sources. The specific method of deriving the output limit value is as follows. First, the voltage V ₁ of the first bus line bus1 is converted into the voltage V ₀ of the lead-in bus line bus0 of the distribution line, the impedance R ₁ + jX ₁ of the first line 41, and the first bus line ( The power consumption P _L1 + jQ _L1 of bus1 and the generated power P _g1 + jQ _g1 of the first bus bus1 are expressed by Equation 1 below.

This is derived through the conversion theorem into Equation 3 in Equation 2 below.

Here, the active power P _g1 generated by the first distributed power supply 21 is represented by the equation for the rated output P _r of the first distributed power supply 21 as follows.

Further, in Equation 1, when the voltages of the distribution line inlet bus 0 and the first bus 1 are represented by pu (per unit) and the voltage V ₀ of the first bus 1 is set to 1, It is summarized as in Equation 5.

As shown in Equation 5 above, when the voltage V ₄ at the end of the distribution line, that is, the fourth bus bus4, is expressed as Equation 6 below.

At this time, the voltage of V _{4 in} the equation (6) takes into consideration that the specified voltage allowable range is 0.95 times to 1.05 times the specified voltage, take 1% as a margin ratio, V ₄ Α value can be calculated by defining -1 <0.04. If the power factor of the first to fourth distributed power sources 21, 22, 23, and 24 is controlled to 1, the reactive power is set to 0, and the optimal α value can be calculated by arranging the equation as shown in Equation 7 below. have.

The output limit value is a value obtained by multiplying the rated output of the first to fourth distributed power supplies 21, 22, 23, 24 by the α value obtained by the above equation.

The distributed power supply control unit 140 controls the first to fourth distributed power supplies 21, 22, 23, 24 so that an output value of the first to fourth distributed power sources 21, 22, 23, and 24 is smaller than the output limit value calculated by the tidal current calculator 130. 22, 23, 24). In addition, the distributed power control unit 140 may control the power factor of the first to fourth distributed power sources 21, 22, 23, and 24 to one.

Hereinafter, the distributed power supply control method according to the present invention will be described.

3 is a flowchart illustrating a distributed power supply control method according to the present invention.

Referring to FIG. 3, the distributed power supply control method according to the present invention first stores information about a specified voltage and a specified voltage allowable range of a specific bus including a distributed power supply. In this case, the allowable voltage range may be 0.95 times to 1.05 times the specified voltage. Then, in one distribution system, the distribution station and the distributed power supply start power supply (S310).

In addition, the voltage of the specific bus, the connection point for the distribution system of the distributed power supply and the voltage and current of the distribution line is sensed (S320).

In addition, it is determined whether the voltage of the specific bus is within a specified voltage allowable range (S330). That is, it is determined whether the voltage (V _i) of a particular bus bar is equivalent to 0.95 to 1.05 times the rated voltage (V _r).

In addition, if it is determined in step S330 that the voltage of the specific bus is within the specified voltage allowable range, the distribution line is maintained without any calculation of the output limit value. On the other hand, when it is determined in step S330 that the voltage of the specific bus is out of the allowable voltage allowance range, the voltage of the specific bus is defined based on the data of the voltage and current sensed through step S320. A tidal current output is calculated to keep the voltage within the allowable range (S340). At this time, the tidal current calculation is based on the voltage value of the inlet of the distribution line and the voltage value of the specific bus, the impedance value of the line between the inlet of the distribution line and the specific bus, the power consumption of the specific bus, and the generated power value of the distributed power supply. It can be calculated as At this time, the output limit value can be calculated so that the voltage of the specific bus is maintained in the range of 0.96 times to 1.04 times the specified voltage.

In addition, the output value of the distributed power supply is adjusted based on the output limit value calculated in step S330 (S350). In other words, the distributed power supply is controlled so that the output value of the distributed power supply is equal to or less than the output limit value. At this time, the distributed power source can be controlled so that the power factor is one.

In addition, it is determined whether power is continuously supplied from the distributed power supply, and it is determined whether to continue the distributed power supply control method according to the present invention (S360). If it is determined through step S360 that there is no power supply from the distributed power supply, the distributed power supply control method ends. On the other hand, if it is determined that power is continuously supplied from the distributed power supply through step S360, the process returns to step S320 to continuously monitor the distribution line and the distributed power supply.

As described above, the apparatus and method for controlling distributed power according to the present invention is not limited to the configuration and method of the embodiments described as described above, but the embodiments may be modified in various ways so that various modifications can be made. All or part may be optionally combined.

100; Distributed power control device
110; Storage 120; Sensing Part
130; Bird calculation unit 140; Distributed power control
10; Distribution system
11; Power distribution station 12; breaker
13; First switch 14; 2nd switch
15; Third switch 16; 4th switch
17; 5th switch
21; A first distributed power supply 22; 2nd distributed power supply
23; A third distributed power supply 24; 4th distributed power supply
31; First load 32; Secondary load
33; Third load 34; 4th load
41; First track 42; 2nd track
43; Third track 44; 4th track

Claims (12)

A storage unit which stores information on a specified voltage and a specified voltage allowable range of a plurality of specific buses, each of which includes a plurality of distributed power supplies;
Sensing unit for sensing the voltage of the plurality of specific bus, the connection point for the distribution system of the plurality of distributed power supply and the voltage and current of the distribution line to which the plurality of distributed power supply is connected;
When the voltage of the specific bus is out of the specified voltage allowable range, the voltage of the specific bus is maintained within the specified voltage allowable range based on data of voltage and current sensed by the sensing unit. A tidal current calculation unit for calculating the output limit value of the distributed power supply; And
A distributed power supply control unit controlling the distributed power supply so that an output value of the distributed power supply is smaller than the output limit value calculated by the tidal current calculation unit,
The bird calculation unit
The voltage value of the lead portion of the distribution line and the voltage value of each of the plurality of specific bus lines, the impedance value of the line between the lead portion of the distribution line and the plurality of specific bus lines, the power consumption value of each of the plurality of specific bus lines, the The distributed power supply control device, characterized in that for calculating the output limit value based on the generated power value of each of the plurality of distributed power supplies. delete The method according to claim 1,
The distributed power supply control unit is a distributed power supply control device, characterized in that for controlling the power factor of the distributed power supply. The method according to claim 1,
The regulated voltage allowable range is 0.95 times to 1.05 times the specified voltage distributed control device. The method of claim 4,
The bird calculation unit
And distributing the output limit value so that the voltage of the specific bus is maintained in the range of 0.96 times to 1.04 times the specified voltage. The method according to claim 1,
The distributed power source is a photovoltaic power source,
The distributed power supply controller is configured to control the distributed power so that the voltage of the specific bus has the maximum value of the specified voltage allowable range when the voltage of the specific bus is within the specified voltage allowable range. Storing information about a specified voltage and a specified voltage allowance range of a plurality of specific buses each including a plurality of distributed power supplies;
Sensing voltages of the plurality of specific bus lines, connection points for distribution systems of the plurality of distributed power supplies, and voltages and currents of distribution lines to which the plurality of distributed power supplies are connected;
Determining whether the voltage of the specific bus is within the specified voltage allowable range;
Calculating an output limit value such that the voltage of the specific bus is maintained within the specified voltage allowable range based on the sensed data of the voltage and current when the voltage of the specific bus exceeds the allowable voltage range; And
Controlling the distributed power supply so that an output value of the distributed power supply is smaller than the output limit value,
The calculating of the tidal current may include a voltage value of an inlet of the power distribution line, a voltage value of each of the plurality of specific bus lines, an impedance value of a line between the inlet of the power distribution line and the plurality of specific bus lines, and the plurality of specific bus lines. And calculating the output limit value based on each power consumption value and power generation value of each of the plurality of distributed power supplies. delete The method according to claim 7,
Distributed power supply control method characterized in that the power factor of the distributed power supply is controlled to one. The method according to claim 7,
The specified voltage allowable range is 0.95 times to 1.05 times of the specified voltage distributed control method. The method according to claim 10,
The algae calculation of the output limit value,
And calculating the output limit value so that the voltage of the specific bus is maintained in the range of 0.96 times to 1.04 times the specified voltage. The method according to claim 7,
The distributed power source is a photovoltaic power source,
Controlling the distributed power source,
And if the voltage of the specific bus is within the specified voltage allowable range, controlling the distributed power so that the voltage of the specific bus has a maximum value of the specified voltage allowable range.

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