JP2008029100A - Device for estimating amount of drop of inverter type power source in subordinate system contraction model of power system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for estimating the amount of drop of inverter power which can estimate the reaction of an inverter type power source in the subordinate system contraction model of a power system. <P>SOLUTION: This device computes the partial drop property of the section of a contraction model of inverter type power source from the voltage remainder rate of a node (S2), and computes the amount of drop of the inverter type power source in the contraction model, making use of this sectional drop property and the accepted rate of angle change (S3). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drop-off amount estimating device for estimating a drop-out amount of an inverter-type power supply in a sub-system contraction model of a power system, and in particular, a drop-out amount of an inverter-type power supply in a sub-system reduction model including a large amount of distributed power supplies. The present invention relates to a dropout amount estimation apparatus for estimating the dropout amount.

  In order to grasp in detail the impact of the distributed power supply on the main power system, it is necessary to perform analysis using data simulated up to the system to which the distributed power supply is connected. Cannot be calculated.

Therefore, conventionally, a load supply system including a distributed power source is represented by one reduced model equivalently reduced (hereinafter referred to as “system reduced model”), and this system reduced model is used. Quantitatively grasping the influence of the distributed power source on the backbone system is performed (see Patent Document 1).
JP 2003-143756 A

  Although there are various types of rotating machines included in the lower system, induction machines and synchronous machines can be represented equivalently in the system contraction model by their representative machines. In the model, the response of the inverter type power supply cannot be expressed in an equivalent manner, so when the subordinate system contains a large number of inverter type power supplies, the influence of the subordinate system on the main system cannot be accurately estimated. There was a problem.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inverter power supply dropout estimation device capable of estimating the response of an inverter power supply in a subordinate system reduction model of a power system. .

  According to the first aspect of the present invention, in the inverter-type power supply dropout estimation device in the subordinate system contraction model of the power system, the voltage remaining rate and the angle change amount of the node in the subsystem contraction model of the power system are received. Means, storage means for storing the induction machine load ratio setting value and phase jump setting value with respect to the total load of the node, the voltage remaining ratio of the received node, the stored induction machine load ratio setting value and phase jump setting value Based on the value, a means for calculating a partial dropout characteristic indicating a partial dropout amount of the inverter type power supply of the subordinate system reduction model, and using the calculated partial dropout characteristic, the input angle change amount is calculated. And a means for estimating the dropout amount of the inverter type power supply of the corresponding subordinate system reduction model.

  According to the second invention of the present invention, in the first invention, the estimated dropout amount is calculated based on the estimated minimum values of the plurality of past dropouts and the estimated past dropouts. The inverter-type power supply further includes means for correcting the drop-off amount in consideration of the drop-off after the drop-off confirmation time after the drop-off determination.

  Further, according to a third invention of the present invention, in the second invention, based on the corrected dropout amount, the dropout amount calculated one time ago, and the corrected dropout amount before a predetermined time, The apparatus further comprises means for correcting the corrected dropout amount to a dropout amount considering the return of the inverter type power supply.

  ADVANTAGE OF THE INVENTION According to this invention, the drop-off amount estimation apparatus of the inverter type power supply which can estimate the response of an inverter type power supply in the sub-system contraction model of an electric power system can be provided.

  Hereinafter, an inverter type power supply dropout estimation device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an example of a system contraction model.

  In the figure, a contracted model of a subordinate system of the load bus 1 of the main system is shown, and transformers 3-1 to 3-4 are connected in parallel via a coil 2. One end of the transformer 3-1 is connected to the coil 2, and the other end is connected to one end of the resistor 4-1 and the capacitor 6-1. The other ends of the resistor 4-1 and the capacitor 6-1 are grounded.

  One end of the transformer 3-2 is connected to the coil 2, and one end of the induction machine 5, the resistor 4-2, and the capacitor 6-2 is connected in parallel to the other end. The other ends of the resistor 4-2 and the capacitor 6-2 are grounded. One end of the transformer 3-3 is connected to the coil 2, and the other end is connected to the synchronous machine 7. In addition, one end of the transformer 3-4 is connected to the coil 2 and the other end is connected to the inverter type power source 8. The inverter type power supply in the present embodiment is an inverter type power supply mainly using sunlight, for example.

  As described above, conventionally, the induction machine 5 and the synchronous machine 7 can be equivalently expressed in the system contraction model by the respective representative machines, but are included in the lower system in the present embodiment. A large number of inverter type power supplies are simulated by one inverter type power supply 8.

  Next, the basic response of a normal inverter type power supply will be described with reference to FIG.

  The inverter type power supply is dropped when a disturbance of the system is detected. If the return condition is satisfied when the return time has elapsed, the inverter type power supply is recovered. If the return condition is not satisfied, the inverter type power supply is permanently dropped. Whether or not to drop off is almost determined by the voltage at the detection point and the amount of change in the voltage angle. That is, when a large number of inverter-type power supplies are connected to a certain system, each inverter-type power supply operates independently because each detection point is different.

  The operation of each inverter type power supply is as described with reference to FIG. 2. Next, the basic response of the inverter type power supply in the system contraction model will be described.

  In the case of an actual inverter type power supply, whether or not it is dropped is simply an on / off relationship, but in the case of a reduced model, only a part of the inverter type power supply in the reduced system is dropped. It is necessary to simulate that.

In the embodiment of the present invention, what percentage of inverter-type power supply drops at a voltage remaining rate V [%] and angle change amount Δδ [deg] at a certain node is expressed by the following equations (1) to (1). Simulate by (4). FIG. 3 is a diagram showing the drop-off amount characteristics obtained by the equations (1) to (4).

here,
W: Difference between the maximum and minimum values of angle change of the same polarity [deg]
δj: settling value of phase jump dropout M: ratio of induction machine load to total load of node [%]
That is, in the embodiment of the present invention, the angle change amount at which the inverter-type power supply starts dropping (will be) using the expressions (1) to (4) from the voltage residual ratio V [%] of the node. And the amount of change in angle at which all the inverter-type power supplies will fall off (to be expected) to calculate the drop-off amount characteristic. Then, using this calculated drop-off amount characteristic, the drop-off amount of the current angle change amount Δδ [deg] is determined. In addition, the formula which shows drop-off amount characteristics is not restricted to these, It can change in the range which does not deviate from the meaning of this invention.

  FIG. 4 is a diagram showing a hardware configuration of an inverter-type power supply dropout estimation apparatus in the subordinate system reduction model of the power system according to the embodiment of the present invention.

  As shown in the figure, in the dropout amount estimation device 10, a CPU 12, a communication unit 13, a display unit 14, a memory 15, an input unit 16, and a storage device 17 are connected to a bus 11.

  The CPU 12 controls the entire process according to the embodiment of the present invention in cooperation with the dropout amount estimation program 22 stored in the storage device 17.

  The communication unit 13 controls communication with an external device via a network.

  The display unit 14 displays a result related to the dropout amount estimation process, and is a liquid crystal display, for example.

  The memory 15 is used as a work area required when the dropout program 22 is executed.

  The input unit 16 is an interface for inputting numerical values and the like necessary for estimating the dropout amount, and is, for example, a keyboard.

  The storage device 17 is for storing data, programs, and the like required for the dropout amount estimation process, and is, for example, a hard disk drive (HDD). The storage device 17 stores an OS (Operating System) 21, a dropout amount estimation program 22, and a database 23.

  The OS 21 controls the entire dropout amount estimation apparatus 1.

  The dropout amount estimation program 22 is an application program that runs on the OS 21 and implements the dropout amount estimation processing according to the embodiment of the present invention in cooperation with the CPU 22. FIG. 5 is a flowchart for explaining the operation of the dropout amount estimation program.

  The database 23 stores coefficients necessary for estimating the dropout amount, and the voltage remaining rate of the node input by the input unit 16, the angle change amount, and the induction machine load ratio setting with respect to the total load of the node. The value and the phase jump settling value are stored.

  Next, the operation of the dropout amount estimation apparatus according to the embodiment of the present invention will be described with reference to the flowchart of FIG. 5 and the dropout amount calculation algorithm of FIG.

  First, the voltage remaining rate and the angle change amount of the node input by the input unit 16 are received (S1). After that, based on the voltage remaining ratio of the node received in S1, the induction machine load ratio setting value and the phase jump setting value stored in the database 23 of the storage unit 17, the expressions (1) to (4) are used. The partial dropout characteristic is calculated (S2).

  After that, using the partial dropout characteristic calculated in S2, the dropout amount of the inverter type power supply of the lower system contraction model with respect to the accepted angle change amount is estimated (S3). As a result, it is possible to correctly reproduce the phenomenon when only a part of the inverter type power supply to be simulated is dropped.

  By the way, although the output value of the dropout amount estimated by the partial dropout characteristic of the inverter type power supply in the system contraction model calculated in S2 changes with time, the actual inverter type power supply has a certain confirmation time after the dropout determination. There is a type that falls off. When simulating this type of inverter type power supply with a reduced inverter type power supply model, if the output value of the dropout amount determined by the partial dropout characteristic changes during the dropout confirmation time, the exact dropout amount cannot be estimated. .

  In addition, the actual inverter type power supply recovers (hereinafter referred to as “recovery”) after a certain period of time has elapsed after dropping, so this operation is also simulated to estimate the amount of dropping more accurately. be able to.

  In S4, when simulating an inverter type power supply that drops after such a drop-off confirmation time, a buffer type is added during the process of changing the output, thereby estimating an accurate drop-off amount. . In addition, the dropout amount is estimated in consideration of the return of the inverter type power supply. That is, in S4, the dropout amount is calculated in consideration of the dropout confirmation time and return time of the inverter type power supply with respect to the dropout amount estimated in S3.

  Specifically, the amount of dropout considering the dropout confirmation time is calculated based on the following formula (5).

P ' _next = 1-p _next (5)
here,
_{p = 1-P, p 0} = 1-P 0
_{Δp = p 0 - Min (p} i)
p _next = p ₀ + Δp (−1 ≦ Δp ≦ 0)
= P ₀ (Δp <−1, Δp> 0)
Next, the dropout amount P ′ _next considering the calculated dropout confirmation time is corrected in consideration of the return time of the inverter type power supply.

Specifically, the dropout amount _Pnext is calculated based on the following formula (6) in consideration of the return time.

P _next = P ′ _next + P ₀ −P ″ _next (return condition established)
= P ' _next + P ₀ (return condition not established) (6)
here,
P _'next: amount falling considering dropping confirmation time _P''next:P' value of a certain time before the _{next P} 0: 1 single dropping amount above in consideration of the calculated dropping confirmed time and recovery time before (6 ) Is realized by the algorithm shown in FIG. As shown in the figure, the dropout amount P ′ _next considering the dropout confirmation time is delayed by a predetermined time (for example, 5 seconds) by a timer. The dropout amount considering the dropout confirmation time delayed by the predetermined time is defined as P ″ _next . The P _{'' next,} when the return condition of the inverter-type power supply is satisfied, P 'is subtracted from the _next, if the return condition is not satisfied, P'_'next is P' does not contribute to the _next.

Further, the Delay from dropping amount _{P next} considering the falling confirmation time and recovery time, the falling amount of delayed by 1 calculation period and _{P 0. P 0} falling off amount calculated before this one is added to P _'next. Thereby, Formula (6) is obtained.

  Therefore, according to the inverter-type power supply dropout estimation device according to the embodiment of the present invention, it is possible to estimate the response of the inverter-type power supply in the subordinate system reduction model of the power system. Further, according to the embodiment of the present invention, even if the inverter type power supply is a type that drops after the drop confirmation time, an accurate drop amount can be calculated in consideration of the drop confirmation time. Furthermore, according to the embodiment of the present invention, it is possible to calculate an accurate dropout amount in consideration of the return time.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  In addition, the method described in the embodiment uses, as a program (software means) that can be executed by a computer (computer), for example, a magnetic disk (hard disk, etc.), an optical disk (CD-ROM, DVD, MO, etc.), a semiconductor memory, etc. It can also be stored in a recording medium such as (ROM, RAM, flash memory, etc.), or transmitted and distributed via a communication medium. The program stored on the medium side includes a setting program that configures software means (including not only the execution program but also a table and data structure) in the computer. A computer that implements this apparatus reads a program recorded on a recording medium, constructs software means by a setting program as the case may be, and executes the above-described processing by controlling the operation by this software means. The recording medium referred to in this specification is not limited to distribution, but includes a storage medium such as a magnetic disk or a semiconductor memory provided in a computer or a device connected via a network.

It is a figure which shows an example of a system | strain reduction model. It is a figure for demonstrating the basic response of a normal inverter type power supply. It is a figure which shows the drop-off amount characteristic calculated | required by Formula (1) thru | or Formula (4). It is a figure which shows the hardware constitutions of the drop-off amount estimation apparatus of the inverter type power supply in the subordinate system reduction model of the electric power system which concerns on embodiment of this invention. It is a flowchart for demonstrating operation | movement of the drop-off amount estimation apparatus which concerns on embodiment of this invention. It is a figure which shows the algorithm of dropout amount calculation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Drop-off amount estimation apparatus, 11 ... Bus, 12 ... CPU, 13 ... Communication part, 14 ... Display part, 15 ... Memory, 16 ... Input part, 17 ... Storage device, 21 ... OS, 22 ... Drop-off amount estimation program, 23 ... Database.

Claims (10)

Means for receiving a voltage residual ratio and an angle change amount of a node in a subordinate system reduction model of a power system;
Storage means for storing the induction machine load ratio setting value and the phase jump setting value with respect to the total load of the node;
Based on the received voltage residual ratio of the node, the stored induction machine load ratio setting value and the phase jump setting value, a partial dropout characteristic indicating a partial dropout amount of the inverter type power supply of the subordinate system reduction model is calculated. Means to
Means for estimating a dropout amount of an inverter-type power supply of the subordinate reduction model corresponding to the input angle change amount using the calculated partial dropout characteristic. For estimating the amount of inverter-type power supply loss in the subordinate system reduction model. The dropout amount estimation device according to claim 1, wherein the partial dropout characteristic is determined by the following equation.

here,
W: Difference between the maximum and minimum values of angle change of the same polarity [deg]
δj: Settling value of phase jump dropout M: Ratio of induction machine load to total load of node [%]
V: Voltage residual ratio of the node in the subordinate system reduction model of the power system   Based on the estimated minimum dropout value and the estimated past dropout amount, the estimated dropout amount is considered to drop after the inverter confirmation time has elapsed after the inverter type power supply has decided to dropout. 2. The dropout amount estimating apparatus according to claim 1, further comprising means for correcting the dropout amount. 4. The dropout amount estimation device according to claim 3, wherein the corrected dropout amount P ′ _next is corrected based on the following equation.
P ' _next = 1-p _next
here,
_{p = 1-P, p 0} = 1-P 0
_{Δp = p 0 - Min (p} i)
p _next = p ₀ + Δp (−1 ≦ Δp ≦ 0)
= P ₀ (Δp <−1, Δp> 0)   Based on the corrected dropout amount, the previous dropout amount calculated, and the corrected dropout amount of a predetermined time ago, the corrected dropout amount is made into a dropout amount considering the return of the inverter type power supply. 4. The dropout amount estimation apparatus according to claim 3, further comprising a correcting unit. 6. The dropout amount estimation device according to claim 5, wherein the corrected dropout amount _Pnext is calculated based on the following equation.
P _next = P ′ _next + P ₀ −P ″ _next (return condition established)
= _{P 'next} + P ₀ (return conditions are not satisfied) In the dropout amount estimation method in the dropout amount estimation device for the inverter type power supply in the subordinate system contraction model of the power system comprising the storage means for storing the induction machine load ratio setting value and the phase jump setting value with respect to the total load of the node,
Accept the voltage residual ratio and angle change amount of the node in the power system subordinate system reduction model,
Based on the received voltage residual ratio of the node, the stored induction machine load ratio setting value and the phase jump setting value, a partial dropout characteristic indicating a partial dropout amount of the inverter type power supply of the subordinate system reduction model is calculated. And
A dropout amount estimation method, wherein the dropout amount of the inverter type power supply of the subordinate system reduction model corresponding to the input angle change amount is estimated using the calculated partial dropout characteristic.   Based on the estimated minimum dropout value and the estimated past dropout amount, the estimated dropout amount is considered to drop after the inverter confirmation time has elapsed after the inverter type power supply has decided to dropout. 8. The dropout amount estimation method according to claim 7, further comprising correcting the dropout amount.   Based on the corrected dropout amount, the previously calculated dropout amount, and the corrected dropout amount a predetermined time ago, the corrected dropout amount is corrected to a dropout amount considering the return of the inverter type power supply. The dropout amount estimation method according to claim 8, further comprising: Inverter-type power supply dropout estimation device in the inverter-type power supply dropout estimation apparatus in the subordinate system reduction model of the power system having storage means for storing the induction machine load ratio setting value and the phase jump setting value with respect to the total load of the node In the dropout estimation program to be performed,
The dropout amount estimation program is provided in the dropout amount estimation device.
Accept the voltage residual ratio and angle change amount of the node in the power system subordinate system reduction model,
Based on the received voltage residual ratio of the node, the stored induction machine load ratio setting value and the phase jump setting value, a partial dropout characteristic indicating a partial dropout amount of the inverter type power supply of the subordinate system reduction model is calculated. Let
A dropout amount estimation program for estimating the dropout amount of the inverter type power supply of the subordinate system reduction model corresponding to the input angle change amount using the calculated partial dropout characteristic.

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