JP5177382B2 - Power system frequency controller using natural energy power generation equipment - Google Patents

Description

  The present invention relates to a control device that adjusts the frequency of a power system using a natural energy power generation device, and more particularly to a power system frequency control device that stabilizes the system frequency using characteristics of a wind power generation device.

  In recent years, from the viewpoint of global warming prevention and depletion of fossil fuel resources, a large number of natural energy power generation facilities using wind energy and solar energy have been connected to the power system. Even on the remote islands, there are many independent power systems in which a large number of wind power generation facilities are installed for heavy oil diesel power generation, which is the main power source. On remote islands, there are many areas where good winds can be obtained throughout the year, suitable for wind power generation, and wind power generators can be operated with high facility utilization.

However, since natural energy fluctuates irregularly, when a large number of natural energy power generation facilities are introduced into the power system, the power system frequency and system voltage will fluctuate. Wind energy is irregular, and the output power of the wind power generator fluctuates greatly due to fluctuations in wind speed.
Since there is a demand from the consumer to maintain the power quality, the power system with the natural energy power generation facility must maintain the system frequency and system voltage constant. Therefore, even when a wind power generation facility with a large single-machine capacity is introduced in a small-scale power system such as in a remote island, countermeasures for frequency fluctuations corresponding to this are required.

On the other hand, conventionally, a method for solving the problem by introducing a large-capacity energy storage device has been developed. This is a method in which the fluctuation energy of the natural energy power generation facility is absorbed by the energy storage device, and the constant power is injected into the system.
However, frequency fluctuation countermeasures using such power storage equipment increase the equipment cost and make profitability a problem. In order to reduce the storage battery capacity, a method of stabilizing the system frequency by suppressing the output power fluctuation using the adjustment method on the wind power generator side, such as a method using variable speed wind turbine, pitch angle control, wind turbine inertia, etc. has been proposed. . In addition, a method for reducing the capacity of a storage device by compensating only a component having a large variation by the energy storage device has been proposed.

For example, in Patent Document 1, the transfer characteristic from the inflow wind speed to the generator output and the transfer characteristic from the pitch angle to the generator output are modeled, and the generator output is controlled to the rated output with respect to the measured inflow wind speed. Therefore, a pitch angle control method using feedforward control is disclosed that compensates for dynamic characteristics of a wind turbine by calculating a pitch angle necessary for this and feed-forwarding to suppress fluctuations in the output of the wind turbine generator.
However, the disclosed method does not consider the effect of parameter changes in the wind power generation system or the effect of wind share generated in the wind power generation facility. Therefore, there is a possibility that the control characteristics are changed due to the change of parameters or the occurrence of windshare, and the output cannot be effectively adjusted and the output becomes unstable.
In addition, since wind power generators have strong non-linearity, if they are directly modeled, extremely high-order equations are required, and the computational load is excessive for executing online control, so that the practicality is not yet sufficient.

Furthermore, Patent Document 2 discloses that the generated power is leveled by using the pitch angle control for the entire operation region including the small output operation region below the rated output for the wind power generator in the wind farm. A leveling device is disclosed.
The disclosed apparatus includes a generator connected to a wind turbine that performs rotation adjustment with a pitch angle of a blade, a pitch angle controller, and a wind farm control device that supplies a setting value to the pitch angle controller, and a wind farm output power command value The output power command value is calculated and supplied for each wind power generator based on the wind farm output power deviation by subtracting the wind farm output power, and the output power compensation value for each wind power generator is calculated. A value added to the output power command value is supplied as a total output power command value to the pitch angle controller of each wind power generator. In the disclosed device, even if the output of a generator suddenly decreases due to the uneven distribution of wind, the decrease is distributed to other generators with sufficient margin, so the power output state of the entire wind farm is leveled. Smooth.

However, each of these methods is mainly aimed at leveling the output power of the wind power generator, and output power leveling is achieved by these methods, but it is an essential purpose of output power control. The suppression of system frequency fluctuation is not a sufficient solution.
Since the power system frequency changes not only due to fluctuations in the generated power of the natural energy power generation facility but also due to fluctuations in the load power, it is required to control the system frequency while reflecting the state of the power system.
JP 2002-048050 A JP 2007-032488 A

  Therefore, the problem to be solved by the present invention is to provide a power system frequency control device that performs accurate frequency control reflecting the state of the power system in a power system that combines an internal combustion engine generator and a natural energy generator. It is.

In order to solve the above problems, an electric power system frequency control device according to the present invention includes a disturbance estimation observer and an output power command device in an electric power system combining an internal combustion engine generator and a natural energy generator, and includes an internal combustion engine generator control device. Controls the power generation amount of the internal combustion engine generator by feeding back the power system frequency, the disturbance estimation observer generates the load power estimation value, and the output power command device enables the short-cycle signal and natural energy possible generation in the load estimation value The command signal obtained by adding the long-period signal of the power is output, and the control device of the natural energy generator controls the output power of the natural energy generator with this command signal as a set value, so that the frequency of the power system is It is characterized by adjusting.
The disturbance estimation observer is preferably a minimum dimension observer that inputs the power system frequency deviation of the power system and the command value of the internal combustion engine generator control device and estimates the load power of the power system.

In particular, in a power system comprising a combination of a diesel generator and a wind power generator, load frequency control is performed by controlling the pitch angle of the wind generator in accordance with a command signal generated based on the estimated load power value. Features.
When a generalized predictive controller (GPC) is used in a pitch angle control system of a wind power generator, high-performance pitch angle control can be achieved and good control results can be obtained.

According to the power system frequency control device of the present invention, in a power system combining an internal combustion engine generator and a natural energy generator, a short-period signal component of the power system load power that becomes a disturbance and a long-term signal of generated power obtained from natural energy The components are compensated by output power control of a responsive natural energy generator and the remaining load power is supplied by the internal combustion engine generator, so that power deviation is well compensated and the deviation of the power system frequency is kept small. can do.
In particular, small-scale power systems combining diesel generators and wind power generators that are often used on remote islands, etc., compensate for short-period signal components of load power using pitch angle control of wind turbines with good response. By doing so, it becomes possible to easily maintain the system frequency at a value close to the target value.
Since the power system frequency control device of the present invention does not use an expensive power storage device that has been widely used in the past, the cost can be greatly reduced.

The power system frequency control apparatus of the present invention will be described below in detail with reference to the drawings and based on embodiments.
1 is a conceptual diagram of a small-scale power system according to the present embodiment, FIG. 2 is a block diagram of the power system model of the present embodiment, FIG. 3 is a detailed diagram of the wind power generation system in FIG. 2, and FIG. FIG. 5 is a block diagram illustrating the configuration of the disturbance estimation observer in FIG. 2, and FIG. 6 is a block diagram illustrating the output power command system in FIG. FIG.

(Small power system)
The present invention is particularly suitable for small-scale power systems. In this embodiment, an example will be described in which the diesel generator 2 and the wind power generator 3 are combined as shown in FIG. 1 and applied to a small-scale power system 4 that satisfies the load power demand 1 in the local area.
For example, on a remote island, unlike a microgrid, it is not connected to a large-scale power system, but is a small-scale power system that is always operated independently. In remote islands, good winds are often obtained throughout the year, and in independent power systems on remote islands, there are many examples where environmentally friendly wind power generation is introduced to reduce the environmental impact of heavy oil diesel power generation, which is the main power source. .

FIG. 2 is a block diagram by transfer function expression regarding the small-scale power system of the present embodiment created by applying the conventional technique.
The small-scale power system in FIG. 2 includes a diesel generator 20, a wind power generator 30, and a load power system 10. In the small scale power system 4 of the present embodiment, the output power Pd of the diesel generator 20 and the output power Pg of the wind power generator 30 are supplied to the power demand Pl of the load power 1. The power supply / demand imbalance becomes the power deviation Pe, which is input to the power system 10 having the inertia coefficient M and the braking coefficient D and transformed, and appears as the frequency deviation Δf of the power system.

As a frequency control method for the power system, a constant frequency control method that is often used in a single system is used. The constant frequency control system has an integral control loop in which a controller 26 in which an integrator 27 and a proportional unit 28 are connected in parallel is arranged in a feedback path, and an operation function u is calculated so that the frequency deviation Δf becomes zero. By supplying the governor 21 of the diesel generator 20, the system frequency is controlled. The output Pd of the diesel generator 23 connected in series with the governor 21 is supplied to the load power demand 1 after passing through the output limiter 25 so as not to change suddenly.
Note that the transfer functions of the governor 21 and the diesel generator 23 can be approximated by first-order delays of time constants Tg and Td, respectively.

The disturbance estimation observer 40 estimates the load power Pl that becomes a disturbance in the power system. The output power command device 50 receives the load power estimated value ^ Pl and the wind speed Vw, generates an output power command value Pgo having a change equivalent to the change in the load power, and gives it to the wind power generator (WTG) 30.
The wind power generator (WTG) 30 inputs the output power command value Pgo and the wind speed Vw, and outputs a wind power generator output Pg that makes the fluctuation of the supply power deviation Pe zero.

FIG. 3 is a block diagram illustrating a wind power generator system 30 that is subject to pitch angle control. A generalized predictive controller (GPC) is used for pitch angle control.
A control system including a pitch angle controller 32 and a hydraulic servo system 33 is assembled to the wind turbine and the generator 31 directly connected to the wind turbine to equalize the output power. By applying a self-tuning regulator (STR), which is an adaptive control device, to the pitch angle controller 32, higher performance control is achieved. The STR includes a generalized predictive controller (GPC) 34 and a parameter identifier 35 which are compensation controllers.

A deviation e between the output power command value Pgo and the output power Pg is obtained, and the pitch angle command value β _CMD is determined by the pitch angle controller 32 and the GPC 34. When the pitch angle command value β _CMD is supplied to the hydraulic servo system 33, the hydraulic servo system 33 operates the blades of the windmill to change the blade pitch angle β to control the output power Pg.
The hydraulic servo system is very complicated due to various operations of the mechanical system and nonlinear elements, but can be approximated by a first-order lag system with a time constant of 1.0 second. In addition, there are various types of wind power generators such as a permanent magnet synchronous generator, a wound-type induction generator, and a synchronous generator. In this embodiment, the structure is simple and robust. Is adopted.

The windmill output Pw is expressed by the following equation.
Pw = d1 + d2Vw ²
Here, d1 and d2 are coefficients.
If the energy loss of the induction generator is ignored, the rotational energy output Pw of the windmill is equal to the output power Pg in the steady state.
The STR compensates a portion of the output deviation e that cannot be compensated by the feedback control with the control compensation command value u2 calculated by the GPC.

The GPC 34 calculates the control compensation command value u2 by inputting the output deviation e and applying it to a control equation including parameters. The control compensation command value u2 is added to the operation output u1 calculated by the pitch angle controller 32 of the feedback control system to obtain a pitch angle command value β _CMD to be given to the hydraulic servo system 33.
The parameter identifier 35 receives the generator output deviation e and the control compensation command value u2 of the GPC 34, and uses the expected value of the sum of the weighted square integrated values of the generator output deviation e and the control compensation command value u2 as an evaluation function J. A parameter vector that minimizes is calculated. The GPC 34 adjusts the arithmetic expression so that it matches the parameter vector calculated by the parameter identifier 35.
Note that the modeling of the wind power generation system and the GPC control law in the present embodiment are the same as those described in detail in Patent Document 2.

In the conventional pitch angle control law, since the pitch angle is fixed at the starting wind speed or more and the rated wind speed or less, the output of the wind power generator fluctuates in proportion to the cube of the wind speed Vw below the rated wind speed. Therefore, in the load frequency control using the wind power generator in the present embodiment, the control law as shown in FIG. 4 is adopted in order to expand the pitch angle control region to the entire operation region.
FIG. 4 is a diagram showing an example of the wind turbine output characteristics, and shows an adjustment range of the wind turbine output Pw and the pitch angle β with respect to the wind speed Vw. In the example of FIG. 4, the pitch angle β is set to 90 ° in the region where the cut-in wind speed is 5 m / s or less, and the output is maintained at 0. From the cut-in wind speed to the rated wind speed, the pitch angle β is set to 10 °, which is the most efficient. In order to ensure safety in the range from the rated wind speed to the cut-out wind speed, the pitch angle β is limited to 90 ° or less so as not to exceed the rated output value, and for the cut-out wind speed of 24 m / s or more, the pitch angle β is 90 Prevent the windmill from breaking by preventing the generator from operating.

(Disturbance estimation observer)
In the frequency control apparatus of the present embodiment, the wind power generator is provided by using the disturbance estimation observer 40 and the output power command device 50 to provide a power power command value Pgo that estimates the load power and makes the supply power deviation Pe zero. Active output power control is performed to control the output power Pg.
FIG. 5 is a block diagram illustrating the configuration of the disturbance estimation observer 40.
The disturbance estimation observer 40 is composed of a minimum dimension observer 41, and a frequency which is a governor operation input u and an output y which are inputs of the power system frequency control system 10 including the diesel generator and the power system shown in FIG. From the deviation Δf, the load power Pl that is a disturbance in the power system frequency control system is estimated. Note that the load power state variable dPl / dt is assumed to be zero for simplicity.

（３）

（４） Ｃ＝[１ ０ ０ ０]
ここで、ｘは状態変数ベクトル（ｘ１は周波数偏差Δｆ、ｘ２はディーゼル発電機系の出力Ｐｄ、ｘ３はガバナー出力、ｘ４は負荷電力Ｐｌ）、ｕは制御入力ベクトルとしてのガバナー入力信号、ｙは出力変数ベクトルの系統周波数偏差Δｆである。また、Ａはシステム行列、Ｂは制御行列、Ｃは出力行列である。 The power system frequency control system 10 represented by the plant state equation of Expression (1) is represented as a control object 45 in the figure.
(1) dx / dt = Ax + Bu
y = Cx
(2)

(3)

(4) C = [1 0 0 0]
Where x is a state variable vector (x1 is a frequency deviation Δf, x2 is a diesel generator system output Pd, x3 is a governor output, x4 is a load power Pl), u is a governor input signal as a control input vector, y is This is the system frequency deviation Δf of the output variable vector. A is a system matrix, B is a control matrix, and C is an output matrix.

The minimum dimension observer 41 is a basic textbook (for example, Zenta Iwai et al. “Observer” Corona, pp. 206-221, 1990, or Hiroshi Ogo et al. “Introduction to System Control Theory”, pp. 121-126, 1999), it can be configured according to equation (5).
(5) dω / dt = ^ Aω + Ky + ^ Bu
^ X = Dω + Hy
Here, ^ indicates an estimated value. K is a gain matrix, and D and H are coefficient matrices that satisfy the conditions for becoming an observer of the Luenberger. The integration of equation (5) is executed by the integrator 42.

Note that there is a matrix M satisfying ^ AM = MA-KC and In = DM + HC from the condition of the observer, and this M can be used to obtain an estimated value of B ^ B = MB. Further, ω is an estimated value of Mx.
The observer poles are eigenvalues of ^ A. By selecting these as γ1 = −8, γ2 = −0.2, and γ3 = −10, good simulation results were obtained.
X4 of the obtained state variable vector x is the estimated value ^ Pl of the load power Pl.

(Output power command device)
FIG. 6 is a block diagram showing the configuration of the output power command device 50.
The output power command device 50 supplies the wind power generator 30 with an output power command value Pgo that generates an output power Pg that makes the supply power deviation Pe zero. In order to make the power deviation Pe zero, it is preferable that the output power Pg of the wind power generator has a fluctuation equivalent to the fluctuation of the load power Pl that becomes a disturbance. Further, since the wind power generator output varies greatly depending on the wind speed condition, it is necessary to consider the wind speed Vw.
Therefore, the output power command device 50 inputs the load power estimated value ^ P1 output from the disturbance estimation observer 40 and the wind speed Vw measured in the vicinity of the wind turbine, and outputs the reference value Pbase of the output power command value based on the wind speed Vw. The output power command value Pgo is obtained by adding the variation Δ ^ Pl of the load power estimated value.

  The estimated load power Pl is usually larger than the rated output of the wind power generator. Further, it is not preferable to compensate all the fluctuation components in the entire frequency region of the load power Pl with the wind power generator output power Pg because the change width of the wind power generator output power required for the load frequency control is increased. . In addition, since the wind turbine output is limited depending on the wind speed, it may be difficult to control.

Therefore, the component of the load power Pl to be compensated by the wind power generator is only a deviation Δ ^ P1 from the moving average value of the load power estimated value ^ P1, as shown in Expression (6).
(6) Δ ^ Pl = ^ Pl−∫ _{(t = tT˜t)} ^ Pldt / T
Here, t is the current time, T is the integration interval, and ∫ _{(t = tT to t)} [F] dt represents the integration of the function F from t−T to t. Since the diesel generator output Pd corresponds to the long-period component of the load power Pl, the integration time T is set to 100 seconds so as to reduce the output fluctuation of the diesel generator. This calculation is executed by the calculator 51 of Expression (6).

Next, the output power command value Pg of the wind power generator is determined according to the following equation.
(7) Pgo = Pbase + Δ ^ Pl
(8) Pbase = Pg-max × 0.5 / (10 s + 1)
(9) Pg-max = d1 + d2Vw ²
Here, Pbase is the reference value of the output power command value, and Pg-max is the power (0 to 1 pu) that can be acquired from the wind energy at the wind speed Vw. Pg-max is calculated by the calculator 52 of the equation (9).

The reference value Pbase of the output power command value is determined by passing the output possible power Pg-max through the primary delay filter 53.
The filter time constant was selected to be 10 seconds, and the diesel generator system was operated gently to make the frequency fluctuation zero with respect to the change in the long-period component of the wind power generator output power Pg. The filter gain was set to 0.5 by selecting the center value of the obtainable power Pg-max. This prevents the output power command value Pgo from swinging downward according to the variation Δ ^ Pl and falling below 0 pu, and swinging upward due to a rapid decrease in the wind speed so as not to exceed the obtainable power Pg-max. Can do.
In the adder 54, the output power command device 50 adds the reference value Pbase of the output power command value based on the wind speed Vw and the variation Δ ^ P1 of the estimated load power value, and outputs it as the output power command value Pgo.

  The power system frequency control apparatus of the present embodiment performs frequency control using an integral control loop by a diesel generator control system, and uses a frequency deviation Δf and a control variable u by a disturbance estimation observer 40 to estimate a load power value ^ The pitch of the wind power generator is calculated so that the fluctuation of the supplied power deviation Pe is zero using the wind power generator output power command value Pgo determined by the fluctuation Δ ^ Pl of the estimated load power and the wind speed Vw. Perform angle control.

In the power system frequency control apparatus according to the present embodiment, it is possible to compensate for a short period fluctuation of the supplied power deviation Pe in the wind power generator control system by using the load power estimated value ^ P1 estimated by the disturbance estimation observer. At the same time, long-term fluctuations are compensated by the diesel generator control system.
Since the pitch angle control used in the wind power generator control system has good responsiveness, it is possible to effectively suppress short-cycle fluctuations in the supplied power deviation Pe and suppress fluctuations in the power system frequency.

(simulation result)
A simulation was performed in order to confirm the performance of the power system frequency control device of this example. In the simulation, the performance was confirmed by comparing the conventional method in which the pitch angle β is fixed at 10 ° in order to generate the maximum output in the low wind speed region and the method of this example. Although the simulation was executed by simulating a wind power generator with a rated output of 275 kW and standardized with a rated output of 275 kW as 0.4 pu, it goes without saying that the same conclusion can be applied to a large machine.

The table of FIG. 7 shows the parameters of the power system, windmill, induction generator, and GPC used in the simulation. The integration interval T is 100 seconds, the GPC sampling period is 1 ms, and the GPC design parameter Λ2, maximum prediction interval N, control interval NU, order m, n, etc., achieve good control based on the simulation results. The value was determined.
FIG. 8 shows changes in the load power Pl applied to the simulation and the load power estimated value ^ Pl by the disturbance estimation observer. As can be seen from the figure, the estimated load power value {circumflex over (Pl)} almost coincides with the load power Pl.
FIG. 9 shows changes in the wind speed Vw applied to the simulation. The long-cycle component of the wind speed changes gently in the range sandwiching the rated wind speed, and the short-cycle component changes sharply and greatly.

FIG. 10 shows a simulation result when the conventional method is used, and FIG. 11 shows a simulation result when the power system frequency control device of this embodiment is used.
10A and 11A show changes in the wind power generator output power Pg, the output power command value Pgo, and the output power Pg-max obtained from the wind energy. (B) The figure shows the change of the pitch angle β, and (c) The figure shows the change of the diesel generator output power Pd. Further, (d) shows the change in the supplied power deviation Pe.

  In the conventional method, as shown in FIG. 10 (a), since the wind power generator is always given a command value Pgo as a rated output, a wind speed equal to or higher than the rated wind speed is obtained, for example, in a section of 100 to 230 seconds. Even when the outputtable power Pg-max is large, the wind power generator output power Pg maintains the rated output. Also, in the region above the rated wind speed, as shown in FIG. 10B, the pitch angle β is made larger than 10 ° to reduce the input energy and maintain the rated output. Further, in order to obtain the maximum output power in the region below the rated wind speed, the pitch angle β is fixed at 10 °, so that the wind power generator output power Pg is displayed in FIG. 9 as shown in FIG. It fluctuates following the wind speed fluctuation.

On the other hand, the diesel generator output power Pd fluctuates in a direction to compensate for the difference between the wind power generator output power Pg and the load power Pl, as shown in FIG. Observing the period of 100 to 230 seconds, it can be seen that the change in the diesel generator output power Pd corresponds to the change in the load power Pl shown in FIG. This is because the wind power generator output power Pg maintains the rated output.
Referring to FIG. 10D, it can be seen that the supplied power deviation Pe fluctuates violently in a range of approximately ± 0.05 pu. As a result, a large frequency fluctuation occurs in the power system. Although the wind power generator output power Pg is decreasing rapidly with respect to the decrease in wind energy in the vicinity of 100 seconds, the output increase operation is delayed due to the large time constant of the diesel generator system, resulting in a large power deviation Pe. Yes.

  On the other hand, when the power system frequency control device of the present embodiment shown in FIG. 11 is used, the wind power generator output power command value Pgo is determined by the output power command device 50 as shown in FIG. Therefore, the slow periodic component Pbase obtained by subtracting the moving average from the slow periodic component Pbase obtained by passing the output possible power Pg-max that fluctuates based on the wind speed fluctuation and the load power change estimated value, and Δ ^ Pl It is determined as a composite signal. The wind power generator output power Pg closely follows the output power command value Pgo. This is because the pitch angle control region falls within the range of 15 ° to 25 ° and the pitch angle β is well controlled in the entire operation region, as can be seen from FIG.

The diesel generator output Pd draws a gentle waveform so as to correspond to the long period component of the load power Pl, as shown in FIG. On the other hand, short-term fluctuations in load power are mainly handled by wind generators that can respond quickly.
For this reason, it can be seen that the supplied power deviation Pe shown in FIG. 11D is significantly smaller than that according to the conventional method of FIG.

FIG. 12 is a graph showing a comparison between the system frequency deviation Δf obtained by the conventional method and the control device of this embodiment.
In the conventional method, for example, a large frequency fluctuation occurs when there is a sudden output power fluctuation of the wind power generator so that a frequency fluctuation of about 0.4 Hz is observed in the vicinity of 100 seconds. Further, in the period of 100 to 200 seconds, since the output power Pg of the wind power generator is operating at almost the rated output, a frequency deviation of about ± 0.2 Hz occurs corresponding to the fluctuation of the load power.
In contrast, in the system using the system frequency control device of this example, the frequency deviation was within ± 0.06 Hz, and the effectiveness of the present invention was confirmed.

  Wind power generators can easily control generated power by using responsive pitch angle control, variable speed wind turbines, etc., so that fluctuations in load power can be effectively compensated to stabilize the system frequency. be able to. Also in the photovoltaic power generation apparatus, the generated power can be easily controlled by controlling the operating voltage. In this way, the natural energy power generation device can easily control the generated power by changing the operating point, and by using a power generation device that is not sufficiently responsive, such as a diesel generator, the power system frequency fluctuations can be greatly increased. It is possible to reduce.

  By using the system frequency control device of the present invention, the power system frequency can be controlled without using an expensive energy storage device, and the system cost can be reduced.

It is a conceptual diagram of the small scale electric power system which concerns on one Example of this invention. It is a block diagram of the electric power system model of a present Example. FIG. 3 is a detailed view of the wind power generation system in FIG. FIG. 4 is a diagram for explaining a pitch angle control law over the entire operation region in the pitch angle control of FIG. It is a block diagram showing the structure of the disturbance estimation observer of a present Example. It is a block diagram explaining the output electric power command system of a present Example. It is a table | surface which shows the parameter of the electric power grid | system, windmill, induction generator, and GPC which were used by simulation. It is a graph showing the load electric power applied to the simulation, and the change of the load electric power estimated value by a disturbance estimation observer. It is a graph of the wind speed change applied to simulation. It is a graph showing the simulation result when a conventional method is used. It is a graph which shows a simulation result when the power system frequency control apparatus of a present Example is used. It is a graph which compares the system frequency deviation obtained by the conventional method and the control apparatus of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Load electric power demand 2 Diesel generator 3 Wind generator 4 Small scale power system 10 Load 20 Diesel generator 21 Governor 23 Diesel generator 25 Output limiter 26 Diesel generator control device 27 Integrator 28 Proportional device 30 Wind generator 40 Disturbance Estimation Observer 41 Minimum Dimension Observer 42 Integrator 45 Control Target 50 Output Power Command Device 51 Arithmetic Unit 52 Arithmetic Unit 53 Filter 54 Adder

Claims (4)

In an electric power system combining an internal combustion engine generator that compensates for a long-term component of load power and a natural energy generator that compensates for a short-term component of load power , a disturbance estimation observer and an output power command device are provided, and the internal combustion engine generator controller is to control the amount of power generated by the internal combustion engine generator by feeding back the power system frequency, disturbance estimation observer generates a load power estimate signal component output power command device that put on the load power estimate And a command signal obtained by adding a signal component related to electric power that can be acquired from natural energy by the natural energy generator, and the control device of the natural energy generator uses the command signal as a set value to A power system frequency control apparatus, wherein the frequency of the power system is adjusted by controlling output power.   The disturbance estimation observer is a minimum dimension observer, and inputs the power system frequency deviation of the power system and the command value of the internal combustion engine generator control device, and estimates the load power of the power system. 2. The power system frequency control device according to claim 1, wherein   The internal combustion engine generator is a diesel generator, the natural energy generator is a wind power generator, and the control device of the wind power generator adjusts the pitch angle of the natural energy generator using the command signal as a set value. 3. The power system frequency control device according to claim 1, wherein output power control is performed as described above.   The power system frequency control device according to claim 3, wherein the wind power generator control device uses a generalized predictive controller (GPC).

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