JPS59123431A - Frequency controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a frequency control device, and particularly to a frequency control device that maintains the frequency of a power system at a reference value.

[Technical background of the invention]

A frequency control device (hereinafter referred to as AFC device) has the function of supplying high-quality power at a constant frequency by controlling generators in the power system so that the amount of power demanded and the amount of power supplied in the power system are equal. have. A conventional method for maintaining the frequency at a reference value will be explained with reference to the drawings.

FIG. 1 is a system block diagram of a conventional system when implementing frequency control. In FIG. 1, l FiAFC
an information transmitting device 3c for the power system 4;
3 d , .= 3 n and information receiving device 2 c +
Measured values of the power system frequency and interconnection line power flow are input via 2dr...2n, the control amount of each generator's output is calculated based on this input information, and control is performed according to the control amount. The signal is sent to the generator output adjustment device 7a+7b,...7m through the information transmitting device 5a H5b+...5m and the information receiving device 5a r6by...6m9,
The generator output adjusting devices 7a+7b+...7m are configured to adjust the generators sa+sbt...8m based on the control signal.

Figure 2 is a block diagram of the AFC device.
is composed of an AR3'il-peak portion 11 and a control amount calculation section 12. Then, the AR calculation unit 11 calculates the AR based on the frequency of the power system and the measured value of the interconnection line power flow, and sends it to the control amount calculation unit 12. On the other hand, the control amount calculation unit 12 calculates the AR that has been sent to the power system. The control amount of the output of each generator according to AR is calculated by a method such as proportional distribution using the maximum output change rate of each generator in b+...It is designed to send to 5m.

Here, from the measured value of the power flow of the interconnection line and the measured value of the frequency within the power system, Alt is set to 32. The output method is as follows (
1) According to formula.

AR=Σ(PTo-PT)+K (FO-F) −
=−・−・・−・・(1) However, Σ(PTo−PT) is the sum of the differences between the reference value and the measured value of the power flow of all interconnection lines, F is the measured value of the frequency of the power system, and Fo is the power The reference value of the frequency of the system, K is a constant.

In addition, from the AR mentioned earlier, the control amount ΔP of the output of each generator
f: Calculation is based on the following equation (2).

However, 1ΔP is the output control amount of the j'th generation rate + cooking in the power system, pc is the maximum output change rate of the jth generator in the power system, and C1 is the total power of all generators in the power system The sum of the maximum output change rates of , is .

[Problems with background technology]

According to the method of calculating the control amount that is proportionally distributed based on the maximum output change rate of each generator in the power system as described above, the output of the generator whose output change rate is fast changes as the power demand changes. From the point of view of economically supplying electricity,
Individual generators may not always produce the desired output. That is, in the conventional AF''C device, it is possible to perform control such that the output of the less efficient generator is increased and the output of the more efficient generator is decreased.

[Purpose of the invention]

The present invention has been made with the aim of solving the above-mentioned problems.When calculating the control amount of each generator, the economic efficiency of each generator is taken into consideration, and A
The purpose is to provide FC equipment.

[Summary of the invention]

In the present invention, when the surplus/deficiency between the power 9n4 and the supply is calculated in the AR calculation unit, and the load is distributed to each generator via the control amount calculation unit based on this, the economic efficiency of each generator is calculated. The considered priority coefficient and target output value are obtained in the economic load distribution section, and this information is taken into account to generate an output command value for each generator to maintain the frequency.

[Embodiments of the invention]

Embodiments will be described below with reference to the drawings. FIG. 3 is a lock diagram of one embodiment of a system in which frequency control is performed using the AFC device according to the present invention.

Reference numerals 8 to 8 in the figure correspond to those in FIG.

9&, 9b, -9m are information transmitting devices, lOa
.

10b, . . . , lOm are information receiving devices. In the case of this embodiment, the measured values of the respective outputs (hereinafter referred to as actual outputs) of the generators 8 a + 8 b H...8m are the information transmitting devices 9a, 9b, =9m and the information receiving device 10a.

10b, . . . 10m to be input to the AFC device. The rest of the configuration is the same as the uL 1 diagram.

FIG. 4 is a detailed diagram of one embodiment of the AFC device.

The AFC device l in the figure is an AR calculation unit 11. Controlled amount calculation unit 12
and an economic load distribution section 20 (hereinafter referred to as the ELD section). Then, the measured value F of the frequency within the power system and the measured values PT, -PT of the power flow of the interconnection line with other power systems are inputted to the AR calculation unit 11, and after calculating the AR, the control amount calculation unit The sending to 12 is as described above6.
The actual outputs P1 to Prrl of each generator are input to the ELD section 20, and the target outputs PE1 to PEm of each generator, the priority coefficients PU1' to pum' of each generator when the output increases, and the priority when the output decreases. The degree coefficients PL1 to PLm are calculated and sent to the control amount calculation section 12, respectively. Therefore, the control amount calculation unit 12
The actual output Pl -Pm of each generator, the AR from the AR calculation section 11, the target output value PE, -P, E of each generator in the ELD section 2 upper 0, when the output of each generator increases Priority coefficients P0.1' to PUJm' and priority coefficients PLl to PLm at the time of output reduction are input, respectively. Then, the control amount calculation unit 12 determines output command values PG, ~PG for each generator from the input information described above, and sends control signals corresponding to PG] to PGm to the information transmitting devices 5a, 5. b,...5rrl
It is now sent to.

Next, the operation of the AFC device 1 shown in FIG. 4 will be explained.

The AR calculation section 11 calculates the AR in a conventional manner, such as by using the first equation, and sends it to the control amount calculation section 12. EL
D Part 2 Part 0 Calculate the target output PEl-PEm of the generator from the actual output Pl-Pm of the electric machine, and calculate the priority when increasing the output of each generator according to the power generation cost characteristic formula (described later) for each generator. Coefficients PU1 to PU and m.

The priority coefficients PL, -PLm at the time of output reduction are calculated.

FIG. 5 is a detailed block diagram of the economic load distribution section 2o.

As shown in the figure, the economic load distribution section 2° is composed of a load calculation section 21 and a distribution section 22. Then, the load calculation unit 21 calculates the demand amount PR of the stain power based on the actual outputs P1 to Pm of each generator.

Although various methods for calculating this are possible, the following equation is shown as an example.

PR,=CXPR,-1+(1-C)XΣp,
・------(3 (-) indicates the demand for electricity in the previous cycle, PR5 is the amount of electricity demanded in the current cycle, C, is a constant, and 0(C(value of 1, is the total value of the practical power P1 to P of the generators 8a, 8b, . . . 8m.

The method described above has been described in which the demand amount of electric power is predicted and calculated from the actual outputs P1 to P of the generators, but any other method may be used.

Then, the demand for one E power calculated in this way: P
R can be sent to the distribution section 22. The distribution unit 22 distributes the electric power demand iPR to each of the generators 8a, . . . Priority coefficient PU1'~
Priority coefficients PL1 to PLm at the time of PU and output decrease are calculated.

Generally, when power demand PR is supplied by m generators, it is most economical to determine the output of f generators according to the law of economic load distribution.

The above-mentioned law of economic load distribution refers to the following equations (4) and (5).

40PR-ΣP ・・・・・・・・・・・・
...(5) However, F is the power generation cost of the j-th generator, P is the output of the j-th generator, and λ is a constant (hereinafter referred to as incremental power generation cost).

FIG. 6 is a diagram showing the relationship between each output of the a-th, b-th, . . . , m-th generators and the incremental fuel cost.

And Equations (4) and (5) are the electricity demand PR (-8:P
In order to supply a0Pb+...+Pm), the a-th and b-th
...The output of each m-th generator is Pa, Pb...Pm
If so, it represents economic benevolence. This is because J, 11'rp, Par Pb+..., Prrl may be set as the target outputs PE1 to PEm.

Next, the target output PE of the generator is determined from the electric power demand 1' amount PR.

A method for calculating ~PErn will be explained.

That is, the power generation cost F of the j-th generator can be calculated as the power generation output, for example, according to the power generation cost characteristic equation shown in the following equation.

Here, FIG. 7 is a flowchart showing an algorithm for calculating the target output in the distribution section. In FIG. 7, step 40 calculates the initial value of the incremental fuel cost λ. Stellar f50 calculates the target output PE corresponding to λ, and calculates the following formula. ``Step 60 is to correct the target output PEj to the upper limit value and lower limit value when the target output PE deviates from the upper limit output value or the lower limit output value.Step 70 is to correct the target output PEj to the upper limit value and the lower limit value. , is in balance with the electric power demand f PR, and ε is a constant. If the balance is maintained here (YES), the process ends. or,
If the balance is not maintained, the process moves to step 80, and the correction direction for correcting the incremental fuel cost λ is determined so that the total target output Σ circle DJ (!l: is balanced with the electric power demand PR. That is, , Tf of electric power when the target output is fully opened: ij
If it is larger than the amount r (YES), the process moves to step 90a and the correction value Δλ is decreased from the incremental fuel cost λ. If the total target output is smaller than the demand for electric power by 1 (No), the process moves to Stellan 090b and the correction value Δλ is added to the incremental fuel cost λ. After the correction, the process returns to step 50 and the above operations are repeated. Note that the target outputs PE, ~P- calculated by the above method are sent to the control amount calculation section 12.

The approximation as a j, P ''h + b jP j + Cj is for the convenience of explanation, and even if a more precise approximation formula is used, the flowchart in Fig. 7 can be achieved in a similar manner. Outputs PE1 to PEm can be calculated.

Next, we will explain how to calculate the ambiguity coefficient PU, ~PUm when the output of the generator increases and the priority coefficient PL, ~PLmf when the output decreases: zo jth When the power generation cost Fj of the generator is approximated as in equation (6), the priority coefficient PUj when the output increases and the priority coefficient PL when the output decreases of the j-th generator are calculated as follows. Ru.

PU・=P/aj PLj= Loj However, R and are constants. In this way, when the output of the generator increases, the generator with the highest power generation efficiency has the largest priority coefficient, and conversely, when the output of the generator decreases, the generator with the highest power generation efficiency has the largest priority coefficient. The least efficient generator will have the highest priority factor.

Here, the power generation cost is Fj=” ajPj + bjPj+
The reason for approximating C4 to [II] is for the same explanation as above, and even if a more strict approximation formula is used, the priority coefficients P01 to PL□ when the output of the generator increases can be calculated using the same method as above.
.

and the priority coefficients PL, ~PLm when the output decreases can be calculated.

Therefore, the control amount calculation unit 12 receives the AR input from the AR calculation unit 11 and the input from the ELD unit 2o.
E1 ~ P theft, priority coefficient PU when increasing generator output, ~
PUm and priority coefficient when decreasing output 1) T, ... PLm
The actual outputs P1 to PrTl of the generators input from the information receiving devices 10a, 10b-1 and Om are used to determine the outputs PG and PGm.

First, using the priority coefficients PU, ~PUrn when the output of the generator increases and the priority coefficients PL1 to PLm when the output decreases, which are input from the ELD unit 2o, from the AR input from the A and R calculation unit 11. The control amount Δ'P of the output of each generator is calculated as shown in the following equation.

When A, R≧0, AR (when 0, ΔP is the output control amount ΣPU of the j-th generator in the power system, and i is the priority coefficient of the output increase of all generators in the power system. The division ΣPLj is the sum of the priority coefficients of all generators in the power system when the output is reduced.

Further, target outputs PE1 to P input from the KLD section 2o
Em and information receiver fit 10a, 10b-
The basic output values PB, .about.PBm are calculated from the actual outputs P, .about.Pm of the generator input from 10 m, as shown in the following equations.

However, PBj is the basic output value ΣPE of the j-th generator in the power system, and ΣPj is the abutment of the target amount chi calculated by the ELD section 20 of all generators in the power system. (The sum of the actual outputs θ is a constant O≦θ<1, and the value δ is a constant O<δ<1.

Target output value prg1-P- input from the ELD section 20
If there is a large difference between the actual output P1~Pm of the generator and the actual output P1~Pm, the range of change is corrected and the basic output
To calculate 'i, the above equation (9) is used.

And each shot calculated by equation (7) or (8)
h.

Output command values PC, PGm of each generator are determined from the output control amounts ΔP1 to ΔPm of the generators and basic output values PB, PBm calculated by equation (9) as shown in the following equation.

PGj−ΔP3+PB□j・・・・・・・・・
・αO Output command value PG, ~PGm determined in this way
Based on this, the control amount calculation unit 12 outputs a control signal.

Note that the above control signal is sent to the information transmitting devices 5a, 5'b.

...5m, and is sent to the generator output adjustment devices 7a, 7b...7m by the information receiving devices 6a, 6b...6m,
The generator 8a is also generated based on this received control signal.

8b...Adjust 8m.

FIG. 8 is a block diagram of another embodiment of the AFC device according to the present invention.

In this example, when the frequency is relatively stable, the total power generation cost is controlled to be low, and when the frequency deviation from the reference value is large, the frequency control response is good even if it sacrifices economic efficiency. This is an attempt to control the situation.

In the AFC device 1 shown in FIG. 8, reference numeral 11.
12 and 20 correspond to FIG. However, everything is the same as in FIG. 4 except for the configuration in which two frequencies are sent to the AR calculation section 11 and the control amount calculation section 12. Therefore A
The method of calculating AR in the R calculating section 11 and the method of calculating the target output values PE1 to PEm, priority coefficients PU1 to PUITl at the time of output increase, and priority coefficients PL1 to PLm at the time of output decrease in the ELD section 20 are as described above. This is the same method as in the example described above.

When the control amount calculation unit 12 determines the output command values PG1 to PGm for each generator, the following steps are performed.

First, when the frequency is relatively stable, that is, F, <F<
When at F2 (where F and F2 are the predetermined lower limit and upper limit of the frequency set in advance), the output for each generator is controlled so that the total power generation cost is low as explained above. Determining the command values PC1 to PGm is as described above.

Next, when the frequency deviation from the reference value is large, that is, F≦F
1 or F≧F2, the generator control with a fast output change rate (formula (2)) is performed as already explained in the prior art section.
Implement. That is, the generator output command value PG, , (P
G, ~PGm) is the control amount ΔPj (ΔP1 ~ ΔPm) (fast ascending control needle) of each Happetsu beach calculated by equation (2) and the actual output Pl of each generator, (Pl-Pm) It is determined as follows.

PGj - ΔPj 0 Pj (j=1 to m) Next, other embodiments of the AFC device according to the present invention will be explained. The configuration diagram is omitted because it is similar to the system block diagram shown in FIG. 4.

In this example, when the difference between power demand and supply is small, control is performed so that the total power generation cost is low, and when the difference is large, control is performed so that frequency control response is improved even at the expense of economic efficiency. This is what we are trying to do.

Therefore, the method of calculating AR in the AR calculation section 11 and the target output value PE in the ELD section 20.

The method of calculating ~PEm and the priority coefficient PU when the output increases, ~PUm and the priority coefficient PL when the output decreases, ~PLm is the same as the method of the above-described embodiment.

The control amount calculating section 12 determines the output command values PG1 to PGrrl for each power generating bag as follows.

First, when the difference between electricity demand and supply is small, that is, AR
l (AR (when in AR2 (however, ARl and AR2 are the predetermined lower limit value and predetermined upper limit value of AR set in advance)
Is it issued as already explained? The output command value PG, ~PGm for each generator is controlled so that the total cost is low.
Determining is as described above.

Next, when the difference between electricity demand and supply is large, that is, AR≦
When AR1 or AR≧AR2, as already explained in the prior art section, the generator control ((
2) Execute equation). That is, the output command value PGj of the generator
(PG, ~PGm) is the control value ΔP of each generator calculated using equation (2)9, (ΔP, ~ΔPm) (controlled variable with quick response) and the actual output P3 of each generator. (131~pm) and K as follows.

PGj-ΔPj+Pj (j-1~m) [Effects of the Invention] As explained above, according to the present invention, the surplus and deficiency between the IKf and supply of electric power is determined as a-, and the surplus and deficiency are distributed to each generator. When generating power, the system is configured to allocate the power by taking into account the priority that takes into account the efficiency of each generator, so it is possible to allocate the power to the most economically efficient generator, reducing the total power generation cost of all generators while increasing the frequency. A frequency control device that can adjust the frequency to a reference value can be provided.

[Brief explanation of drawings]

Fig. 1 is a system block diagram when performing conventional frequency control, Fig. 2 is a block diagram showing a conventional frequency control device, and Fig. 3 is a system block diagram when performing frequency control using the frequency control device according to the present invention. System block diagram, Fig. 4 is a detailed block diagram of one embodiment of the frequency control device, Fig. 5 is a detailed block diagram of the economic load distribution section, and Fig. 6 shows the relationship between the output of each generator and the incremental fuel cost. 7 is a Mizuko flowchart of an algorithm for calculating the target output in the distribution section, and FIG. 8 is a block diagram of another embodiment according to the present invention. 1... Frequency control device 4... Power system 9 a
, 9b-9m 7a, 7b,...7m... Generator adjustment device 8
a, 8b,...8m...generator 11...A
R calculation section 12...Controlled amount calculation section 20...Economic load distribution section 21...Work 1 load calculation section 22...Distribution section Patent applicant Tokyo Shibaura Electric Co., Ltd. Agent Patent attorney Norio Ishii lJ/)a,,Pb/J treatment (Fig. 7

Claims (3)

[Claims] (1) Measuring the frequency within the power system in a frequency control device configured to determine an output command value for each generator based on the excess or deficiency between the demand and supply of power within the power system. ARJ calculates the amount of surplus and deficiency between power demand and supply by inputting the value and the power flow of interconnection lines with other power systems! The target output of each generator according to the law of equal incremental fuel cost and the output increase and output of each generator according to the power generation cost characteristic formula from the total power to be supplied by inputting the actual output of each generator and the actual output of each generator. an economic load distribution unit that calculates a priority coefficient at the time of reduction, an amount of excess or deficiency of electric power from the ARK output unit, a target output of each generator from the economic load distribution unit, the priority coefficient, and each power generation; Each generator is equipped with a control amount calculation unit that derives an output command value considering the economic efficiency of each generator based on the actual output from the generator, and calculates the economic efficiency for each generator based on the above inputs. 1. A frequency control device that determines an output command value in consideration of (2) Measuring the frequency within the power system in a frequency control device configured to determine the output command value for each generator based on the excess or deficiency between the demand and supply of power within the power system. an AR calculation unit that receives input values and power flows of interconnection lines with other power systems, calculates an amount of excess or deficiency between power demand and supply, and outputs a measured value of frequency together with the amount of excess or deficiency;
The actual output of each generator is input, and from the total power to be supplied, the target output of each generator is determined according to the law of equal incremental fuel costs, and priority is given to each generator when increasing or decreasing the output based on the power generation cost characteristic formula. an economic load distribution unit that calculates the priority coefficient and the measured values of power surplus/deficiency and frequency from the AR calculation unit, the target output of each generator from the economic load distribution unit, and the priority coefficient and A control amount calculation unit that derives an output command value that takes into account the economical efficiency of each generator and determines whether the frequency is within a predetermined value after inputting the actual output from each generator. If the frequency is within a predetermined value, an output command value is issued to the generator that takes economic efficiency into consideration, and if the frequency is outside the predetermined value, an output command is issued to the generator with a fast output change rate. A frequency control device characterized by emitting a value. (3) Measurement of the frequency in the power system in a frequency control device configured to determine an output command value for each generator based on the amount of excess or deficiency between the power demand in the power system and the L supply. AR calculation unit which inputs the value and power flow of the interconnection line with other power grids and calculates the amount of excess or deficiency between the demand and supply of electricity, and the actual output of each generator is input and calculates the total power to be supplied. an economic load distribution unit that calculates a target output of each generator according to the law of equal incremental fuel cost and a priority coefficient for output increase and output reduction of each generator according to a power generation cost characteristic formula; The amount of power surplus or deficiency from the calculation section, the target output of each generator from the economic load distribution section, the priority transfer, and the actual output from each generator are combined to calculate the economy of each generator. 1. A control amount calculation unit that derives an output command value that takes into account the power consumption and an output that determines whether the amount of excess or deficiency of electric power is within a predetermined value.1. If the surplus or shortage of power is within a predetermined value, an output command value is issued to the generator that takes economic efficiency into consideration, and if it is outside the predetermined value, an output command value is issued to the generator with a fast output change rate. A frequency control device characterized by emitting.