JPH11196530A - Generator load distributing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a generator load distributing device capable of cutting cost of fuel for generating power on top of maintaining capability of adjusting frequency to the same level of the conventional system. SOLUTION: A generator load distributing device 101 is made up of a data- reading device 121, which reads observed value of the quantity of state of a controlled power system 111 at an arbitrary time, a command value upper limit changing device 122 which changes the upper limit of the command value of a generator at a future time, a command value determining device 123 which calculates output command value of the generator at a future time, and a command value transmitting device 124 which transmits the calculated output command value of the generator to the generator inside the power system 111.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output command value of a generator at a time according to a state variable observation value measured in an electric power system, a prediction result of a load change at a future time, and a fuel consumption characteristic of the generator. It relates to a generator load distribution device to be calculated.

[0002]

2. Description of the Related Art A conventional generator load distribution device 201 will be described with reference to FIG. Conventionally, the target power system 211
A data reading device 221 for reading a state quantity observation value at an arbitrary time, a command value determining device 222 for calculating a generator output command value at a future time, and a calculated power generator output command value in the power system 211. And a command value transmitting device 223 for transmitting the command value to the device. The command value determination device 222 uses the command value upper limit data 231, load prediction data 232, and generator fuel characteristic data 233 to flow through a transmission line provided to maintain the output upper and lower limits and the voltage stability of the generator. The output command value of the generator at a future time has been calculated by solving an optimization problem of minimizing the fuel cost under the operation constraints 234 such as the upper and lower limits of the active power flow.

[0003]

In the prior art, a fixed value lower than the actual output upper limit is used as the output command value upper limit of the generator in order to maintain the frequency adjustment capability of adjusting the frequency by increasing the output. Was. As a result, the output of the generator with low power generation fuel cost was kept lower than the upper limit, and the output of the generator with high power generation fuel cost was increased accordingly.
This has led to an increase in fuel costs for power generation. SUMMARY OF THE INVENTION It is an object of the present invention to provide a generator load distribution device capable of suppressing generation fuel cost while maintaining the same frequency adjustment capability as that of the related art.

[0004]

In order to solve the above-mentioned problems, according to the present invention, a frequency adjustment capability of a power storage device in a target power system is determined, and an output command value of a generator is determined according to the determined frequency adjustment capability. By changing the upper limit, the output of the generator with low power generation fuel cost is increased, and the output of the generator with high power generation fuel cost is suppressed accordingly.

[0005]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a generator load distribution device according to the present invention.

The generator load distribution device 101 includes a data reading device 121 for reading a state quantity observation value of the target power system 111 at an arbitrary time, a command value upper limit changing device 122 for changing a generator output command value upper limit at a future time, A command value determination device 123 that calculates an output command value of the generator at a future time, and outputs the calculated output command value of the generator to the power system 1.
11 is constituted by a command value transmitting device 124 for transmitting to the generator within. The state quantities read by the data reading device 121 are constants for resistance, induction, and capacity of the transmission line, active power output, reactive power output, load bus voltage, active power load, and reactive power of the generator and the power storage device. FIG. 5 shows an example of a data format for storing the load, the usage of the phase adjustment equipment, the tap ratio of the transformer, the tap set value, and the like. 501
Consists of the transmission line branch constant, the transmission line resistance, the induction, the capacity, and the transformer tap ratio of the target power system. Also,
Reference numeral 502 denotes output data of the generator and the power storage device, data including active power, reactive power, and bus voltage of the load. In the command value upper limit changing device 122, the data reading device 1
The command value upper limit data 131 storing the output command value upper limit of the generator at a future time is changed in accordance with the state quantity observation value received from 21. Details of a method of changing the output command value upper limit of the generator will be described later. Command value upper limit data 1
The change result of 31 is sent to the command value determination device 123. The command value determination device 123 receives the change result of the command value upper limit data 131 from the command value upper limit change device 122, and uses the load prediction data 132 and the generator fuel characteristic data 133,
The output command value of the generator at a future time is calculated by solving an optimization problem that minimizes the power generation fuel cost under the operation constraint condition 134. As a solution of the optimization problem, an equal lambda method or the like is used. For the equal lambda method, see the well-known example “Gonsuke Noda, Electric Power System Control, Denki Shoin, pp.
36, 1986 ". It is of course possible to use an optimization method other than the equal lambda method. The generator fuel characteristic data 133 is a generator fuel characteristic coefficient (secondary / first order / constant) in a case where the power generation fuel cost is approximated by a quadratic expression of the generator output as in the following equation.

[0008]

Cost = a · P ² + b · P + c (Equation 1) Cost: Power generation fuel cost a: Generator fuel characteristic coefficient (secondary) b: Generator fuel characteristic coefficient (primary) c: Generator fuel Characteristic coefficient (constant) P: Generator output It is of course possible to use other generator fuel characteristic data formats. The operation constraint conditions 134 include the upper and lower limits of the active power output of the generator, the upper and lower limits of the reactive power output of the generator, the upper and lower limits of the active power flow of the transmission line, and the upper and lower limits of the bus voltage.

Next, the command value upper limit changing device 122 shown in FIG.
The first embodiment will be described with reference to FIG.

The command value upper limit changing device 122 includes a power storage device adjusting capability evaluation device 301, a frequency adjusting capability total calculating device 302, a generator selecting device 303, and a command value upper limit updating device 3.
04, a frequency adjustment capacity remaining amount calculation device 305. The power storage device adjustment capability evaluation device 301 receives the state quantity observation value from the data reading device 121 and operates the power storage device such as the upper and lower limits of the output of the power storage device, the operation schedule, and the ratio of the output fluctuation width used for frequency adjustment to the output. Using the data 311, the frequency adjustment capability of each power storage device in the target power system 111 is evaluated by the following formula, for example.

[0011]

ΔP _i = C _inow / T ( _Equation 2) ΔP _i : frequency adjustment capability of power storage device i C _inow : current charge amount of power storage device i T: control target time

[0012]

ΔP _i = P _imax −P _inow ( _Equation 3) ΔP _i : frequency adjustment capability of power storage device i P _imax : output upper limit of power storage device i _Pinow : current output of power storage device i

[0013]

Equation 4] _{ΔP i = P ischedule -P inow ...} ( Equation 4) [Delta] P _i: the frequency adjustment capability P _Ischedule power storage device i: Schedule output P _Inow power storage device i: current output of the power storage device i

[0014]

ΔP _i = (C _inow / T) × ratio _i ( _Equation 5) ΔP _i : Frequency adjustment capability of power storage device i C _inow : Current charge amount of power storage device i T: Control target time ratio _i : Ratio of the fluctuation range available for frequency adjustment to the output of the power storage device i

[0015]

ΔP _i = (P _imax −P _inow ) × ratio _i ( _Equation 6) ΔP _i : frequency adjustment capability of power storage device i P _imax : output upper limit of power storage device i P _inow : power storage device i Current output ratio _i : ratio of fluctuation range available for frequency adjustment to output of power storage device i

[0016]

Equation 7] _{ΔP i = (P ischedule -P inow} ) × ratio i ... ( Equation 7) [Delta] P _i: the frequency adjustment capability P _Ischedule power storage device i: Schedule output P _Inow power storage device i: power storage device i The current output ratio _i : the ratio of the fluctuation range that can be used for frequency adjustment with respect to the output of the power storage device i. Frequency adjustment capability total calculation device 3
In step 02, the sum of the frequency adjustment capabilities of the power storage devices received from the power storage device adjustment capability evaluation device 301 is calculated by the following equation.

[0017]

(Equation 8)

ΔP: Sum of the frequency adjustment capabilities of the power storage device P _i : Frequency adjustment capability of the power storage device i n: Number of power storage devices in the target power system The calculation result is sent to the generator selection device 303. The generator selection device 303 receives the information from the frequency adjustment capability total calculation device 302, and selects the generator with the lowest power generation fuel cost using the power generation fuel characteristic data 312. The selection result is sent to the command value upper limit updating device 304 together with the information received from the frequency adjustment capability total calculating device 302. The command value upper limit updating device 304 receives information from the generator selecting device 303 and uses the generator output upper limit data 313 to set a new output command value upper limit of the generator selected by the generator selecting device 303 by, for example, the following formula. And is stored in the command value upper limit data 131.

[0019]

P _{jmax new} = P _{jmax old} + ΔP ( _Equation 9) where P _{jmax new} > P _jmax P _{jmax new} = P _jmax P _{jmax new} : Output command value upper limit of new generator j P _{jmax old} : The current upper limit of the output command value of the generator j P _jmax : The upper limit of the output of the generator j The updated result is sent to the frequency adjustment capacity remaining amount calculation device 305. The frequency adjustment capability remaining amount calculation device 305 receives the information from the command value upper limit update device 304 and calculates the frequency adjustment capability after updating the output command value upper limit of the generator selected by the generator selection device 303 by the following formula. calculate.

[0020]

ΔP _new = ΔP _old − (P _{jmax new} −P _{jmax old} ) ( _Equation 10) ΔP _new : Frequency adjustment capability after changing the upper limit of the command value of generator j ΔP _old : Upper command value of generator j Frequency adjustment capability before change P _{jmax new} : Output command value upper limit of new generator j P _{jmax old} : Current output command value upper limit of generator j If the frequency adjustment capability is greater than 0, the generator is selected Returning to the apparatus 303, the generator for which the output command value upper limit is to be changed is selected. When the frequency adjustment capability becomes 0, the change of the upper limit of the output command value ends, and the process proceeds to the command value determination device 123.

Next, the command value upper limit changing device 122 shown in FIG.
The second embodiment will be described with reference to FIG.

The command value upper limit changing device 122 includes a power storage device adjusting capability evaluation device 401, a block selecting device 402,
Frequency adjustment capability total calculation device 403, generator selection device 4
04, a command value upper limit updating device 405, a frequency adjustment capacity remaining amount calculating device 406, and a command value upper limit change end determining device 407. Power storage device adjustment capability evaluation device 401
Receives the state value observation value from the data reading device 121 and calculates the frequency adjustment capability of each power storage device in the target power system 111 using the power storage device operation data 411. The power storage device operation data 411 is the same as the power storage device operation data 311 in the first embodiment. The method of evaluating the frequency adjustment capability is the same as that of the power storage device adjustment capability evaluation device 301 in the first embodiment. The calculation result is sent to the block selector 4 together with the observed state value.
02. The block selection device 402 selects an arbitrary system block from each system block obtained by dividing the target power system 111 into partial systems using the block division data 414. The block division data 414 contains information indicating to which system block the various facilities in the target power system 111 belong. Information on the selected system block and various equipment included in the system block is sent to the frequency adjustment capability total calculation device 403 together with the information received from the power storage device adjustment capability evaluation device 401. The frequency adjustment capability sum calculation device 403 calculates the sum of the frequency adjustment capability of each power storage device received from the block selection device 402 using the following equation.

[0023]

[Equation 11]

ΔP _k : the sum of the frequency adjustment capabilities of the power storage devices in the system block k ΔP _i : the frequency adjustment capability of the power storage device i m: the number of power storage devices in the system block k The calculation result was selected The information is sent to the generator selection device 404 together with information on various facilities included in the system block. The generator selection device 404 receives information from the frequency adjustment capability total calculation device 403 and uses the generator fuel characteristic data 412 to select the generator with the lowest power generation fuel cost in the system block selected by the block selection device 402. select. The selection result is sent to the command value upper limit updating device 405 together with the information received from the frequency adjustment capability total calculating device 403. The command value upper limit updating device 405 receives information from the generator selecting device 404 and updates the new output command value upper limit of the generator selected by the generator selecting device 404 using the generator output upper limit data 413. It is stored in the command value upper limit data 131. The updating method is the same as that of the command value upper limit updating device 304 in the first embodiment. The updated result is sent to frequency adjustment capability remaining amount calculation device 406. The frequency adjustment capability remaining amount calculation device 406 receives information from the command value upper limit update device 405 and calculates the frequency adjustment capability after updating the output command value upper limit of the generator selected by the generator selection device 404. The calculation method is the same as that of the frequency adjustment capability remaining amount calculation device 305 in the first embodiment. As a result of the calculation, if the frequency adjustment capability is greater than 0, the generator selection device 404
Return to and select the generator whose output command value upper limit is to be changed. When the frequency adjustment capability becomes 0, the change of the upper limit of the output command value in the system block selected by the block selector 402 ends, and the process proceeds to the command value upper limit change end determination device 407. Command value upper limit change end determination device 40
7 determines whether or not the change of the output command value upper limit has been completed for all the system blocks in the target power system 111, and if not completed, returns to the block selection device 402; Select the system block to be changed. When the process has been completed, the change of the output command value upper limit is finished, and the process proceeds to the command value determination device 123.

[0025]

According to the present invention, it is possible to suppress the fuel cost for power generation while maintaining the same frequency adjustment capability as compared with the conventional generator load distribution device.

[Brief description of the drawings]

FIG. 1 is a diagram showing features of the present invention.

FIG. 2 shows a conventional generator load distribution device.

FIG. 3 is a first embodiment of a command value upper limit changing device.

FIG. 4 is a second embodiment of the command value upper limit changing device.

FIG. 5 is an example of a state quantity data storage format.

[Explanation of symbols]

101, 201: generator load distribution device, 111: target power system, 121, 221: data reading device, 12
2 ... command value upper limit changing device, 123, 222 ... command value determining device, 124, 223 ... command value transmitting device, 131, 23
1 ... command value upper limit data, 132, 232 ... load prediction data, 133, 233, 312, 412 ... generator fuel characteristic data, 134, 234 ... operation constraint conditions, 211 ... target power system, 301, 401 ... power Storage device adjustment capability evaluation device, 302, 403: Frequency adjustment capability total calculation device, 303, 404: Generator selection device, 304, 40
5: Command value upper limit updating device, 305, 406: Frequency adjustment capacity remaining amount calculating device, 311, 411: Power storage device operation data, 313, 413: Generator output upper limit data, 40
2 ... Block selection device, 407 ... Command value upper limit change end determination device, 414 ... Block division data, 501 ... Example of storage format of system constant data, 502 ... Example of storage format of generator output / bus load data.

Claims (8)

[Claims] An upper limit of an output command value of a generator and operation of various facilities in the power system using state quantity observation values measured in the power system, load prediction data at a future time, and fuel characteristic data of the generator. In a generator load distribution device that calculates a generator output command value at a future time that satisfies the constraints, a command value upper limit changing device that changes the output command value upper limit of the generator according to the observed state value measured in the power system. A generator load distribution device characterized by having. 2. The generator load distribution device according to claim 1, wherein the upper limit of the output command value of the generator is changed according to the frequency adjustment capability of the power storage device in the power system. 3. The generator load distribution device according to claim 2, wherein the upper limit of the output command value of the generator with low power generation fuel cost is preferentially changed. 4. The generator load distribution device according to claim 2, wherein the upper limit of the output command value of the generator located in the same system block as the power storage device is preferentially changed. apparatus. 5. The generator load distribution device according to claim 2, wherein the frequency adjustment capability of the power storage device is evaluated using the charge amount of the power storage device. 6. The generator load distribution apparatus according to claim 2, wherein a frequency adjustment capability of the power storage device is evaluated using an output possible range of the power storage device. Distribution device. 7. The generator load distribution device according to claim 2, wherein the frequency adjustment capability of the power storage device is evaluated using an operation schedule of the power storage device. Load distribution device. 8. The generator load distribution device according to claim 2, wherein the ratio of the output fluctuation width to the output used for frequency adjustment is evaluated as the frequency adjustment capability of the power storage device. Characteristic generator load distribution device.