JP2001177991A - Load-estimating device of power system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the load-estimating device of a power system that can estimate system load in the power system, can calculate the amount of load that matches a current system state, does not require facility fixation information for estimation, and is capable of real-time processing. SOLUTION: A group detection part 3 extracts power facilities for obtaining a power flow value for the power flow value, that has been measured at each measurement point, virtually separates a bus where the power facilities are connected for providing a virtual bus, and follows the electrical connection of the system with the set virtual bus as a center, thus specifying a load estimation group. A load estimation part 5 calculates the power flow for each load estimation group that has been detected by the group detection part 3, obtains a load total value, and calculates each load value with the ratio of the obtained load total value to the power flow value in the load estimation group as the distribution value of each load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load estimating apparatus for a power system for automatically calculating load values of respective load facilities by automatically detecting load facilities to which a power flow value as online information is related and obtaining a load estimation group. About.

[0002]

2. Description of the Related Art Generally, the power flow of transmission lines and transformers in a power system is always measured at a substation side, and there is no measurement data at a customer or a distribution substation due to capital investment. Or, only the measurement data of one hour unit was grasped.

Therefore, when handling load power of a consumer or the like, a real-time value cannot be used.
In particular, in the power flow calculation, the calculation result becomes unreliable unless the load at the terminal of the system is accurately given.

Therefore, recent power system computer systems have a function of generating a power flow or a voltage by using a power flow calculation as a training simulator, or a power flow calculation for detecting an abnormality before the actual operation in the operation control of the system. Or to implement.

[0005] When such a power flow calculation process is performed in real time on-line, a function for instantaneously and accurately calculating a load value is required because no manual operation can be performed on the way.

Conventionally, in such a load value calculation process, in a power system as shown in FIG. 5, for example, a range for determining a load is determined as a first group G1, a second group G2, a third group G3,. In advance, the tidal equipment and load equipment in the group are stored in advance as equipment fixed data. For example, the fixed facility data of the first group G1 in FIG. 5 is as follows: Power facility: TM1, TM2, TM3, TM4, TMG1 Load facility: WH1, WH3 In FIG. 5, TM1 is the first telemeter, TM2
Denotes a second telemeter, TM3 denotes a third telemeter, TM4 denotes a fourth telemeter, and GTM denotes a generator telemeter. G is a generator, B1 is a bus, TL is a transmission line, S
Indicates switches.

As described above, each telemeter TM1, TM
2, the current values measured by TM3, TM4, and TMG1,
The initial values of the loads WH1 and WH3 (power integrated values in units of one hour) are fetched, and the ratio of the total of the initial values of each load (ΣWHi) to the total of the power flow values (ΣTMi) is calculated for each load (WH).
i).

That is, in the power system shown in FIG. 5, an accurate load value has been calculated by the following equation (1).

[0009]

## EQU1 ## Pni = (ΣTMi / ΣWHi) × WHi (1)

[0010]

However, in the above-described conventional load value calculation processing, the groups (first group G1, second group G2,
The data of the tidal facilities and load facilities of the group G3) must be registered as fixed data in advance.
For this reason, the equipment fixed data must be reviewed each time the equipment itself needs to be changed at the time of equipment inspection or when there is a significant load fluctuation, failure of the power generation / transmission system, etc. There is a problem that processing cannot be performed and work efficiency is extremely low.

In addition, when the operation is different from the normal operation because the current connection state of the load cannot be taken into consideration, a correct load value cannot be calculated. For example, even when a power failure occurs at the load WH1 in FIG. 5, there is a problem that power is distributed according to the initial value of the load.

In view of the above circumstances, the present invention can estimate a system load in an electric power system, calculate a load amount matching a current system state, and does not require equipment fixed information for estimation. It is an object of the present invention to provide a load estimation device for a power system that enables processing.

[0013]

According to a first aspect of the present invention, there is provided a power supply system in which online information such as a tidal current value measured at each measurement point of a power system and a state of a switch is obtained by acquiring the information. A group detection unit that automatically detects load equipment related to the power flow value to obtain a load estimation group, and, for each load estimation group obtained by the group detection unit, calculates a load value of each load equipment constituting the load equipment. And a load estimating unit for calculating.

According to a second aspect of the present invention, in the power system load estimating apparatus according to the first aspect, the group detecting section includes:
Equipment extraction means for extracting power equipment whose power flow value is obtained for the power flow value measured at each measurement point, virtual bus setting means for providing a virtual bus by virtually separating the bus to which the power equipment is connected, Load estimating group identifying means for identifying a load estimating group by following the electrical connection of the system around the set virtual bus.

According to a third aspect of the present invention, in the power system load estimating apparatus according to the first or second aspect, the load estimating unit performs a power flow calculation for each of the load estimating groups detected by the group detecting unit. It is characterized in that a total load value is obtained, and each load value is calculated using a ratio of the calculated total load value and a power flow value in the load estimation group as a distribution value of each load.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Configuration of Embodiment> FIG. 1 is a block diagram showing an embodiment of a load estimating apparatus for a power system according to the present invention.

As shown in FIG. 1, the power system load estimating apparatus 1 is composed of a power computer system, and functionally includes an equipment master 2, a group detecting unit 3, a data file 4, a load estimating unit Unit 5.

The equipment master 2 stores information on the equipment constituting the target electric power system, information on the connection state of the electric power system constituted by these equipment, and the like.

The group detecting section 3 executes processing for estimating a group (see FIG. 2) which is a processing range of load estimation with reference to the equipment master 2.

The data file 4 stores power-related data such as a power flow value measured by each telemeter and power consumption collected from load equipment.

The load estimating unit 5 estimates the load value for each group detected by the group detecting unit 2 based on the data stored in the data file 4.

FIG. 2 is an explanatory view schematically showing a power system to which the load estimating device for a power system shown in FIG. 1 is applied. In FIG. 2, the same components as those in the system diagram shown in FIG. 5 are denoted by the same reference numerals.

In FIG. 2, TM1 is a first telemeter,
TM2 is the second telemeter, TM3 is the third telemeter, T
M4 denotes a fourth telemeter, and GTM2 denotes a generator telemeter. Each of the telemeters TM <b> 1 to TM <b> 4 is provided on a transmission side or the like of a large substation, measures a tidal current value, and supplies the measured data to the load estimation device 1. G is a generator, B1 to B3 are buses, B
B1 to BB4 indicate virtual buses, TL indicates a transmission line, and S indicates a switch. WH1 to WH5 denote load facilities, and the power consumption in units of one hour is calculated by the load estimating device 1;
To supply.

<Operation of Embodiment> Next, the operation of this embodiment will be systematically described with reference to the schematic diagram of FIG. 2 and the flowcharts of FIGS.

<< Group Detection Processing >> This group detection processing is executed by the group detection section 3. First, equipment to which the online power flow value belongs is extracted (step ST1). In the example of FIG. 2, the first telemeter T
M1 and a transmission line TL which is equipment to be measured by the telemeter TM1 are extracted.

Next, the switch on the bus side to which the extracted equipment is connected is internally (virtually) separated to provide a virtual bus (step ST2). In the example of FIG. 2, the switch S of the bus B1 to which the transmission line TL is connected is virtually opened on a computer, and a virtual bus BB1 is provided at the illustrated position. Similarly, the imaginary bus BB2 is provided by separating the bus B2, and the bus B3
And virtual buses BB3 and BB4 are provided. Thereby, the range in which the tidal current value measured by the telemeter TM1 is related can be limited. In addition, Kirchhoff's first law can be applied to this range.

Next, the group is estimated by following the electrical connection of the system around the virtual bus (step ST).
3). In the example of FIG. 2, the transmission line TL follows the virtual bus BB1. It can be seen that WH1, WH2, and WH3 are load facilities in this group, and that the generator telemeter GTM2 is connected. This processing is performed for all virtual buses (step ST4).
However, those belonging to the same group, for example, a virtual bus BB
2 is excluded because it belongs to the same group as the virtual bus BB1. In this way, the load equipment to which the power flow value is related is automatically created based on the state of the switch and the power flow value taken in as online information. This is established by Kirchhoff's first law.

The equipment in the range pursued in this way is defined as a load estimation group. In the example of FIG. 2, a first group G1, a second group G2, and a third group G3 are obtained as load estimation groups.

As described above, in this embodiment, a load estimation group can be easily obtained without having special equipment fixed data as in the conventional example.

<< Load Estimation Process >> This load estimation process is executed by the load estimation unit 5. When the load estimation groups are obtained as described above, a load estimation process is executed for each group. That is, since the actual load power consumption is a value on an hourly basis, it is necessary to accurately obtain the load value estimated from the current power flow value.

For this reason, first, the online power flow value is given to the actual connection bus as a load value and to the virtual bus as power generation (step ST11). In the example of FIG.
The power flow value measured by the telemeter TM1 is given to the bus B1 as a load value and to the virtual bus BB1 as power generation. In addition, the initial value of the load of the customer or the like, for example, the initial value of the load of the load equipment WH1 gives data of the result record or the like (step ST12).

Next, a power flow calculation by the DC method is executed for each load estimation group using the virtual bus centered at the center (step ST13). In the example of FIG. 2, the first group G
The power flow calculation of No. 1 is performed around the virtual bus BB1.
Note that the tidal flow calculation by the DC method is a well-known method, and a description thereof will be omitted.

The so-called "wrinkle removing power" in the above-described DC method power flow calculation is set as the total load value in the load estimation group (step ST14). As a result, the total load value in the group can be obtained without performing special equipment fixed data of each load existing in the load estimation group or a process of following the system.

Then, the ratio between the total load value and the power flow value in the load estimation group is set as a distribution value for each load (step ST15). In the example of FIG. 2, the ratio between the total load value (ΣWHi) in the load estimation group G1 and the measurement value of the first telemeter TM1 as the power flow value in the load estimation group G1 is distributed to, for example, the load equipment WH1. Then, the load value is corrected to calculate the load value.

The above load estimation processing is executed for all the load estimation groups G1 to G3 (step ST16).

In the present embodiment, the power flow is calculated by the DC method. However, the power flow may be calculated by the Newton-Raphson method. In this case, the calculation time is longer than that of the DC method, but a more accurate calculation result can be obtained.

[0037]

As described above, according to the present invention, it is possible to calculate a highly accurate load value suitable for the current system state.

Further, even if there is little online information,
Load estimation processing can be performed at high speed and in real time, and equipment fixed information for load estimation is not required. Therefore, it is possible to flexibly cope with system changes.

Further, when the online information is abnormal, the abnormal portion can be excluded and the specified range can be extended.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a load estimation device for a power system according to the present invention.

FIG. 2 is an explanatory diagram schematically showing a power system to which the load estimation device for a power system shown in FIG. 1 is applied.

FIG. 3 is a flowchart illustrating a procedure of a group detection process performed by the load estimation device for a power system illustrated in FIG. 1;

FIG. 4 is a flowchart illustrating a procedure of a load estimating process performed by the load estimating device for the power system illustrated in FIG. 1;

FIG. 5 is an explanatory diagram showing a load estimation process in a conventional power system.

[Explanation of symbols]

 Reference Signs List 1 Power system load estimation device 2 Equipment master 3 Group detection unit 4 Data file 5 Load estimation unit B1 to B3 Bus BB1 to BB4 Virtual bus G Generator G1 to G3 Load estimation group GTM Generator telemeter S Switch TL Transmission line TM1 To TM4 Telemeter WH1 to WH5 Load equipment

Claims (3)

[Claims] 1. A group detection for obtaining a load estimating group by automatically detecting load equipment related to the power flow value and online information such as the state of a switch and the like at each measurement point of the power system. And a load estimating unit that calculates a load value of each load equipment constituting the load equipment for each load estimation group obtained by the group detection unit. Estimation device. 2. The power system load estimating apparatus according to claim 1, wherein the group detection unit extracts power equipment that can obtain a power flow value from a power flow value measured at each measurement point. Means, virtual bus setting means for providing a virtual bus by virtually separating the bus to which the power equipment is connected, and load estimation for specifying a load estimation group by following the electrical connection of the system around the set virtual bus. A load estimating device for a power system, comprising: a group specifying unit. 3. The load estimating device for a power system according to claim 1, wherein the load estimating unit calculates a power flow for each of the load estimating groups detected by the group detecting unit to obtain a total load value. And calculating each load value using a ratio of the calculated total load value and a power flow value in the load estimation group as a distribution value of each load.