JP2000217255A - Method of stabilizing frequency of power system and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method of stabilizing the frequency of a power system and a device thereof capable of being more adaptable to th structure of the system and maintaining the frequency within the stabilized operation range of a generator. SOLUTION: A central processing unit 14N is provided, which calculates a leveling-out frequency after the rise of a frequency based on the tidal current value of a linked line, the speed adjusting and fixing rate of each generator 1A, 1B and the L.L. width of each generator 1A, 1B, if it is detected with a sensor 5, which detects the tidal current value of a linked line and the linkage state between a main system and another system 20 in which the tidal current value of the linked line is cut from the system, when power is transmitted from the main system to the other one 20, and limits the power generation by the generator 1A, 1B, if the leveling-out frequency deviates from the stabilized operation range of the generators 1A, 1B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency stabilizing method for a power system and a device for controlling a frequency anomaly which is recognized when the power system is separated by occurrence of system disconnection, by limiting a power supply or a load. .

[0002]

2. Description of the Related Art FIG. 10 is a block diagram showing a conventional frequency stabilizing device for an electric power system. In the figure, reference numerals 1A and 1B denote generators (power plants), 2A to 2D denote buses in the system, and 3A to 3D.
D is a transmission line, and the transmission line 3A is a connection line with another system 20 connected to this system. 4A is a measuring terminal, 4B-
4E is a control terminal, 4N is a central processing unit, 5 is a sensor for detecting disconnection of the interconnection line route, and detects the interconnection flow value and interconnection state of the transmission line 3A. 6A to 6D are circuit breakers, 7A to 7E are control cables, 8A to 8
E and 8N are information signal transmission lines, 9 is a central power supply command center, 10
A and 10B are loads.

Next, the operation will be described. When the interconnection line route breakage accident occurs when the transmission line 3A is transmitted toward another system 20 connected to the main system, the sensor 5
Detects the disconnection accident of the interconnection line route of the transmission line 3A,
The signal is transmitted to the measuring terminal 4A through the control cable 7A.
A is transmitted to the central processing unit 4N through A. The central processing unit 4N recognizing that the interconnection route disconnection accident has occurred,
The system constant of the generator is calculated by the following equation (1) from the power flow value of the interconnection line sent so far by the detection of the sensor 5 and the information from the central power supply command center 9, and then the calculated power generation Based on the system constant of the machine, the rising frequency ΔF is calculated by the following equation (2).

[0004]

(Equation 1)

FIG. 5 is a characteristic diagram showing a region of stability and instability when the frequency rises. The central processing unit 4N determines each power generation based on whether the calculated frequency ΔF falls within the stable region shown in FIG. The stability of the machine is determined, and when it is determined that the machine becomes unstable, the control terminals 4B and 4C are instructed through the information signal transmission lines 8B and 8C based on the cutoff pattern that makes the machine stable, and the control terminals 4B and 4C A trip signal is output to the circuit breaker 6A or 6B through the control cables 7B and 7C to control the maximum value of the transient frequency rise and the destination of the calm. In addition, as a technical document related to such a conventional technology, “Development and practical application of a new system stabilization method in consideration of plant characteristics” (IEEJ Power Technology Research Group,
(Issued in October 1994).

[0006]

Since the conventional power system frequency stabilizing apparatus is configured as described above, the frequency stabilizing method is performed by determining the operating power generation when calculating the system constant _KHG of the generator. It is obtained from the total power generation (output setting value of the generator) P _OG in the control target system normalized by the sum M _OG of the inertia constants of the machine, and is adapted to the actual frequency response characteristic during the operation of the generator. In addition, since the difference in frequency response characteristics of each generator is not taken into account, there has been a problem that optimal frequency control adapted to the system state cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a frequency stabilization method for a power system capable of maintaining a frequency within a stable operation region of a generator by adapting to a system configuration. And to obtain the device.

[0008]

SUMMARY OF THE INVENTION A frequency stabilization method for an electric power system according to the present invention is characterized in that when an unbalance of excess power generation occurs in a separated system, a supply-demand imbalance amount and a speed regulation rate of each generator are provided. , And based on the difference between the governor opening of each generator and the load limiter opening, the frequency at which the frequency rises is settled down, and the power supply is limited according to the settled frequency.

A frequency stabilization method for an electric power system according to the present invention is characterized in that when an unbalance due to power generation shortage occurs in a separated system, the frequency is stabilized based on a supply / demand imbalance amount and an output increase amount of each governor-free machine. The lowest frequency of descending is obtained, and the load is limited according to the lowest frequency.

According to the frequency stabilization method for a power system according to the present invention, when an unbalance of excessive power generation occurs in a separated system, a detected output value of a generator, an inertia constant of the generator, a supply / demand imbalance rate, And a system constant calculation constant is obtained based on the rated output of the generator, then the system constant calculation constant, and a system constant of the generator approximated by a power based on the predetermined constant are obtained. The frequency at which the frequency rises is settled is determined based on the output set value of the generator and the system constant of the generator, and the power supply is limited according to the settled frequency.

According to the frequency stabilization method for a power system according to the present invention, when an unbalance of excessive power generation occurs in a separated system, a detected output value of the generator, an inertia constant of the generator, a supply / demand imbalance rate, And a system constant calculation constant is determined based on the rated output of the generator, and then a constant classified according to the supply and demand imbalance amount, and a system constant of the generator that is linearly approximated based on the system constant calculation constant, Further, the frequency at which the frequency rises is settled is determined based on the supply / demand imbalance amount, the output setting value of the generator, and the system constant of the generator, and the power supply is limited according to the settled frequency.

The power system frequency stabilizing apparatus according to the present invention provides an interconnecting line power flow value when the system is disconnected during power transmission.
Based on the speed regulation rate of each generator and the difference between the governor opening and the load limiter opening of each generator, the calming destination frequency of the frequency rise is calculated, and the power source is limited according to the calming destination frequency. It is provided with operation control means for performing.

A power system frequency stabilizing apparatus according to the present invention provides an interconnecting line power flow value,
And a calculation control means for calculating the lowest frequency of the frequency decrease based on the output increase amount of each governor-free machine, and performing load limitation according to the lowest frequency.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a configuration diagram showing a frequency stabilizing device of a power system according to Embodiment 1 of the present invention. In the drawing, 1A and 1B are generators (power plants), 2A to 2D are buses in the system, and 3A to 3D. 3D is a transmission line, and the transmission line 3A is a connection line with another system (second power system) 20 connected to the main system (first power system). 4A is a measuring terminal, 4B
Reference numerals 4E to 4E are control terminals, and 5 is a sensor (interconnection detection means) for detecting a disconnection of the interconnection line route, which detects an interconnection line power flow value and an interconnection state of the transmission line 3A. 6A to 6D are circuit breakers, 7A to 7E are control cables, 8A to 8
E and 8N are information signal transmission lines, 9 is a central power supply command center, 10
A and 10B are loads. Reference numeral 14N denotes a central processing unit (arithmetic control means), which increases the frequency when the sensor 5 detects that the power flow value of the interconnection line of the transmission line 3A is disconnected from the main system to the other system 20 when the system is disconnected. Is calculated, and the settled frequency is calculated by the generator 1
When the generators 1A and 1B are out of the stable operation range,
B, the power supply is limited, and the sensor 5 controls the transmission line 3A.
When the power flow value of the interconnecting line is detected as being disconnected from the power system from the other system 20 to the main system, the lowest frequency of the frequency decrease is calculated, and the lowest frequency determines the stable operation region of the generators 1A and 1B. When it deviates, the load of the loads 10A and 10B is limited.

Next, the operation will be described. The interconnection state of the transmission line 3A is always detected by the sensor 5 and output to the measurement terminal 4A through the control cable 7A. The central processing unit 14N always takes in the power flow value of the interconnection line and the information of the interconnection state from the measuring terminal 4A through the information signal transmission line 8A, and the generator from the control terminals 4B and 4C through the information signal transmission lines 8B and 8C. The power generation information of 1A and 1B is periodically taken in, and further, the information of the total load is periodically taken in from the central power supply commanding station 9 through the information signal transmission line 8N. Further, the central processing unit 14N transmits the power supply limiting signal or the load limiting signal as necessary to the information signal transmission lines 8B to 8B.
E to the control terminals 4B to 4E.
In 4E, the generator 1A, 1B or the load 10A, 10B is selected from the content of the received signal and a trip signal is output according to the power supply restriction signal or the load restriction signal. For example, when a route disconnection accident occurs in the transmission line 3A, the central processing unit 14N enters a start-up state, and the detection of the route disconnection accident from the information from the sensor 5 is kicked, and the power supply limitation or the load limitation stabilization. Perform control.

FIG. 2 is a flowchart showing the operation of the central processing unit, and the detailed operation will be described based on the drawing. In FIG. 2, if a route disconnection accident is detected by the sensor 5, the central processing unit 14N enters an activated state (step ST
1), a time reset process based on the point of occurrence of a failure is performed (step ST2), and removal of the failure is detected (step ST3). Next, it is determined whether the interconnection flow detected by the sensor 5 is power transmission or power reception as viewed from the main system (step ST4). If power transmission is performed, the process proceeds to step ST5. Otherwise, the process proceeds to step ST11. .

In the case of power transmission, the power flow value of the interconnection line detected by the sensor 5, the speed regulation rate of each of the generators 1A and 1B,
The frequency at which the frequency rises is settled down is determined in consideration of the difference between the governor opening of each of the generators 1A and 1B and the load limiter opening (hereinafter referred to as the LL width) (step ST5). Then, it is determined whether or not the frequency to which the frequency rise has settled exceeds the value required for power supply restriction (step ST).
6) If power supply restriction is required, the stabilization control amount (power supply restriction amount) is determined by a predetermined algorithm (step ST7). Then, it is determined whether or not a generator pattern corresponding to the determined power supply restriction amount exists (step ST8), and if present, a cutoff pattern corresponding to the determined power supply restriction amount is selected from the generators 1A and 1B ( Step ST9) According to the selected selection pattern, information is transmitted to the control terminals 4B and 4C through the information signal transmission lines 8B and 8C, and a trip signal is output from the control terminals 4B and 4C to the circuit breakers 6A and 6B. The process is restricted (step ST10), and the process ends (step ST1).
7).

On the other hand, in the case of power reception, the lowest frequency of the frequency decrease is determined in consideration of the interconnection flow detected by the sensor 5 and the output increase of the governor-free machine among the generators 1A and 1B. (Step ST11). Then, it is determined whether or not the lowest frequency of the frequency drop is lower than a value required for load limiting (step ST12). If load limiting is required, a stabilization control amount (load limiting amount) is determined in advance. (Step ST
13). Then, it is determined whether or not a load pattern corresponding to the determined load limit exists (step ST14).
If there is, a cutoff pattern corresponding to the determined load limiting amount is selected from the loads 10A and 10B (step ST1).
5) According to the selected selection pattern, information is transmitted to the control terminals 4D and 4E through the information signal transmission lines 8D and 8E, and a trip signal is output from the control terminals 4D and 4E to the circuit breakers 6C and 6D, thereby limiting the load. Then (step ST16), the process ends (step ST17).

As described above, according to the first embodiment, the frequency abnormalities due to the imbalance in supply and demand observed when the interconnection route between the electric power systems is cut off, cause the generator 1 after the occurrence of the accident.
Since the calculation is performed in consideration of the respective frequency response characteristics of A and 1B, there is an effect that more accurate stabilization control can be performed.

Embodiment 2 The second embodiment is different from the first embodiment in that when the route of the interconnection line breaks during power transmission, the power flow value of the interconnection line, the speed regulation rate of each of the generators 1A and 1B, and the
A, 1B L. L. A specific embodiment will be described in which a settled frequency of a frequency rise is determined in consideration of a width, and further, a required power supply restriction amount is determined.

Next, the operation will be described. FIG. 3 is a characteristic diagram showing the relationship between the generator characteristics and the frequency. The frequency of the system can be obtained at the intersection of the generator characteristics and the load characteristics. If the generator is L. L. In the case of operation, since the generator output does not change even if the frequency fluctuates to some extent, the generator characteristics are as shown in FIG. 3A, and the frequency is point A in the figure. If the power flow of the interconnecting line is power transmission from the viewpoint of the control target system, and the interconnecting line causes a route disconnection accident, the load characteristics after the accident change as shown in FIG. It changes to ΔF ₁ (point B). Further, the output change ΔP _G of the generator due to the system disconnection is represented by the following equation (3).

[0022]

(Equation 2)

The change ΔP of the load due to the frequency fluctuation
_L is expressed by the following equation from the system constant K _L of the load (4). ΔP _L = K _L · P _L · ΔF ₁ (4) Here, P _L : load before frequency fluctuation In the governor-free machine, it is sufficient to consider L = 0. ) And equation (4), the system frequency ΔF ₁ is represented by the following equation (5).

[0024]

(Equation 3)

However, equation (5) is obtained from the static characteristics of the generator and the load, and attempts to maintain the generator output by the response of the plant when the frequency increases. FIG. 4 is a characteristic diagram showing the relationship between the calculated value and the actual frequency. As shown in FIG. 4, since the actual frequency is larger than the calculated value, the equivalent of each generator considering the plant response is considered. Speed regulation rate R _i and L.V. L. The width _Li is obtained and corrected by the following equation (6). ΔF _1Z = a · ΔF ₁ + b (6) where ΔF _{1Z is the} corrected system frequency. That is, if the constants a and b in the equation (6) are set in advance by simulation, a calm destination when the frequency rises The frequency can be calculated with high accuracy in consideration of the state of the system. Further, the calculated corrected system frequency ΔF _1Z
However, the stability is determined based on whether or not it is within the stable region shown in FIG. 5, and when it is determined that the power supply is unstable, the power supply is limited by a stable cutoff pattern.

As described above, according to the second embodiment, when the frequency rises when the interconnection line route between the electric power systems is cut off, the individual speed regulation rates R _i and L of the generators 1A and 1B are increased. . L. Width L _i can be determined in consideration with restless-to frequency and the required power limit amount, so that the effect of the possible optimum frequency control adapted to the system state.

Embodiment 3 In the third embodiment, when the interconnection line route breaks during power reception, the lowest frequency of the frequency decrease is considered in consideration of the interconnection line power flow value and the increase in the output of the governor-free machine that is recognized in the case of a frequency decrease. Asked,
Further, a specific embodiment for obtaining the required load limiting amount will be described.

Next, the operation will be described. FIG. 6 is a characteristic diagram showing the frequency at the time of disconnection of the interconnection line route. If the interconnection line causes a route disconnection accident when the interconnection line power flow is received from the control target system, the system frequency is shown in FIG. 6 (b), and the minimum value ΔF ₂ can be calculated as follows. Figure 7 is a characteristic diagram showing the relationship between the generator characteristics and the frequency, the output of the generator is as shown in FIG. 7 in the case of the governor free machine, the output of the generator by line cutting increases P _U, supply and demand imbalance rate R _U in the case of considering the output increment is represented by the following formula (7).

[0029]

(Equation 4)

Here, the output increase amount P _U of the governor-free machine
Is approximately several tens of the governor-free capacity, but differs depending on the plant, and is set in advance by simulation. FIG. 8 is a characteristic diagram showing the relationship between the supply and demand unbalance rate and the frequency. As shown in FIG. 8, the relationship between the supply and demand unbalance rate _RU and the frequency is approximated by a linear function expressed by the following equation (8). it can. _{ΔF 2 = a · R U +} b ... (8) Furthermore, when the target frequency after load limiting and [Delta] F _Lset, necessary load shedding amount P _L can be calculated by the following equation (9).

[0031]

(Equation 5)

That is, if the output increase amount P _U of the governor-free machine in the equation (7) and the constants a and b in the equation (8) are set in advance, the transitional minimum value at the time of the frequency drop is determined by the state of the system. Is calculated, and the required load limiting amount can be easily calculated from Expression (9).

As described above, according to the third embodiment, when the interconnection line route between the power systems is cut off, the transitional minimum value at the time of the frequency drop is necessary in consideration of the output increase of each governor-free machine. The load limiting amount can be obtained, and as a result, there is an effect that optimal frequency control adapted to the system state can be performed.

Embodiment 4 In the fourth embodiment, when the interconnection line route breaks during power transmission, the settled frequency of the frequency rise is obtained using the system constant of the generator calculated based on the output detection value of the generator, and further, An embodiment for obtaining a required power supply restriction amount will be described.

Next, the operation will be described. If the interconnecting line causes a route disconnection accident when the interconnecting line power flow value is transmission from the viewpoint of the control target system, the system frequency shows a waveform as shown in FIG. 6 (a), and the settled frequency ΔF ₁ becomes It can be calculated from the following equation (10).

[0036]

(Equation 6)

Here, the load system constant K _L is determined in advance by appropriate means as in the prior art.
The system constant K _H of the generator is obtained as follows. Since the system constant K _H of the generator depends on the operating state of the generator in the control target, as shown in FIG. 9A, the system constant K _H is represented by a system constant calculation constant X represented by the following equation (11). Expressing the system constant of the generator, power approximation can be obtained by the following equation (12).

[0038]

(Equation 7)

[0039] Here, the output detection value P _OG of the generator is obtained control terminal 4B, information signal transmission path through 8B 4C, the generator 1A through 8C, by incorporating periodically as a generator information 1B . Further, as shown in FIG. 9B, by dividing the system constant calculation constant X into cases according to the supply and demand unbalance rate, the system constant K _H of the generator can be linearly approximated by the following equation (13). . K _H = a ₂ · X + b ₂ (0 ≦ X <C ₁ ) K _H = a ₃ · X + b ₃ (C ₁ ≦ X <C ₂ ) K _H = a ₄ · X + b ₄ (X ≧ C ₂ ) (13) Here, a _{2 to} a ₄ , b _{2 to} b ₄ , C ₁ , C ₂ : constants, that is, coefficients a ₁ and b _{1 in} equation (12) or a _{2 to} a ₄ , b in equation (13) _{2 to} b ₄ , and C ₁ and C ₂
Is set in advance by simulation, the system constant K _H of the generator can be calculated.
Can easily calculate the destination frequency ΔF ₁ . The stability is determined based on whether or not the calculated ΔF ₁ is in the stable region shown in FIG. 5. If it is determined that the calculated ΔF ₁ is unstable, the power supply is limited in a stable cutoff pattern.

As described above, according to the fourth embodiment, when the frequency rises when the interconnection line route between the electric power systems is broken, the generator calculated based on the output detection value _PG of the generator The calm destination frequency and the required power supply restriction amount can be obtained by using the system constant K _H of this example, and as a result, there is an effect that optimal frequency control adapted to the system state can be performed.

[0041]

As described above, according to the present invention, the frequency rise is stabilized based on the speed regulation rate of each generator and the difference between the governor opening and the load limiter opening of each generator. Since the configuration is such that the destination frequency is obtained, if the power supply is limited in accordance with the obtained destination frequency, there is an effect that optimal frequency control suitable for the system state can be performed.

According to the present invention, since the lowest frequency of the frequency decrease is determined based on the output increase of each governor-free machine, if the load is limited according to the determined minimum frequency, the system status There is an effect that optimal frequency control adapted to the above can be performed.

According to the present invention, the system constant calculation constant is obtained based on the output detection value of the generator, and the system constant of the generator approximated to the power is obtained based on the system constant calculation constant and the predetermined constant. Since the target frequency of the frequency increase is calculated based on the supply and demand imbalance, the generator output set value, and the generator system constant, the power supply is limited according to the calculated target frequency. For example, there is an effect that optimal frequency control adapted to a system state can be performed.

According to the present invention, the system constant calculation constant is determined based on the output detection value of the generator, the constant classified according to the supply and demand imbalance amount, and the generator linearly approximated based on the system constant calculation constant Find the system constant of
Furthermore, since the settled frequency of the frequency rise is calculated based on the supply and demand imbalance amount, the output setting value of the generator, and the system constant of the generator, the power supply restriction is set according to the calculated settled frequency. If performed, there is an effect that optimal frequency control adapted to the system state can be performed.

According to the present invention, the settled frequency of the frequency rise is calculated based on the speed regulation rate of each generator and the difference between the governor opening and the load limiter opening of each generator.
Since it is configured to include the arithmetic control means for limiting the power supply according to the settled frequency, there is an effect that, when it is detected that the system is disconnected at the time of power transmission, it is possible to perform optimal frequency control adapted to the system state. .

According to the present invention, the lowest frequency of the frequency drop is calculated based on the output increase amount of each governor-free machine,
Since the arithmetic control means for limiting the load in accordance with the lowest frequency is provided, there is an effect that, when it is detected that the system has been disconnected at the time of receiving power, optimal frequency control adapted to the state of the system can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a power system frequency stabilization device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of the central processing unit.

FIG. 3 is a characteristic diagram showing a relationship between a generator characteristic and a frequency.

FIG. 4 is a characteristic diagram showing a relationship between a calculated value and an actual frequency.

FIG. 5 is a characteristic diagram showing regions of stability and instability when the frequency rises.

FIG. 6 is a characteristic diagram showing a frequency when the interconnection line route is disconnected.

FIG. 7 is a characteristic diagram showing a relationship between a generator characteristic and a frequency.

FIG. 8 is a characteristic diagram showing a relationship between a supply and demand unbalance rate and a frequency.

FIG. 9 is a characteristic diagram showing a relationship between a system constant calculation constant and a system constant.

FIG. 10 is a configuration diagram showing a conventional power system frequency stabilization device.

[Explanation of symbols]

1A, 1B generator, 5 sensors (interconnection detection means), 1
0A, 10B load, 14N central processing unit (operation control means), 20 other systems (second power system).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideharu Oshida 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Sanbishi Electric Co., Ltd. (72) Inventor Yasuhiko Terao 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 Inside Ryo Denki Co., Ltd. (72) Kazuhito Kibi 2-5-2, Otemachi, Chiyoda-ku, Tokyo Mitsui Electric Engineering Co., Ltd. (72) Koji Sakaguchi 1, Wadazakicho, Hyogo-ku, Kobe-shi, Hyogo No. 1-2 Inside Melco Power Systems Co., Ltd. (72) Kazuo Shiraishi 2-5 Marunouchi, Takamatsu-shi, Kagawa Prefecture Inside Shikoku Electric Power Company (72) Yoshihiro Miyamoto 2-5 Marunouchi, Takamatsu-shi, Kagawa Prefecture Shikoku Electric Power (72) Inventor Masakazu Hirota 2-5 Marunouchi, Takamatsu City, Kagawa Prefecture Inside Shikoku Electric Power Company (72) Inventor Shinya Nishimatsu 2109-8 Yashima Nishimachi, Takamatsu City, Kagawa Prefecture F-term in Shikoku Research Institute, Ltd. (reference) 5G066 AA05 AD04 AD09

Claims (6)

[Claims] When a power supply system is disconnected from a power system and an unbalance of excess power generation of the generators is generated between a power generation amount and a load amount of the plurality of generators in the separated system, the plurality of power generation amounts are unbalanced. The frequency rise and fall are based on the imbalance between the power generation and the load of the generator, the speed regulation rate of each generator, and the difference between the governor opening and the load limiter opening of each generator. A frequency stabilization method for a power system for obtaining a destination frequency and, when the destination frequency deviates from a stable operation region of the plurality of generators, restricting a power source of the plurality of generators. 2. When the power system is disconnected from the power system and an unbalance of the power generation shortage of the generators is generated between the power generation amounts and the load amounts of the plurality of generators in the separated system, the plurality of power generation units are disconnected from each other. The lowest frequency of the frequency drop is obtained based on the supply and demand imbalance between the power generation amount and the load amount of the generator, and the output increase amount of each governor-free machine among the plurality of generators. A method for stabilizing the frequency of a power system in which a load is limited when the generator is out of a stable operation range. 3. When the power system is disconnected from the power system and an unbalance of excess power generation of the generators is generated between the power generation amounts and the load amounts of the plurality of generators in the separated system, the plurality of power generation systems are disconnected. Generator constants based on the detected output of the generators, the inertia constants of the multiple generators, the imbalance between the power generation and the load of the multiple generators, and the rated output of the multiple generators Then, the system constant calculation constant, and the system constant of the generator approximated to the power based on the predetermined constant, the system constant of the generator, furthermore, the supply and demand imbalance between the power generation amount and the load amount of the plurality of generators, Based on the output set values of the plurality of generators and the system constants of the generators, a settled frequency of the frequency increase is obtained, and when the settled frequency is out of the stable operation region of the plurality of generators, the plurality of settled frequencies are determined. A frequency stabilization method for a power system that limits the power supply of a generator. 4. When a power supply system is disconnected from the power system and an unbalance of excess power generation of the generators occurs between the power generation amounts and the load amounts of the plurality of generators in the separated system, the plurality of power generation systems are disconnected from each other. Generator constants based on the detected output of the generators, the inertia constants of the multiple generators, the imbalance between the power generation and the load of the multiple generators, and the rated output of the multiple generators Then, the constants divided by the supply and demand imbalance between the power generation amount and the load amount of the plurality of generators, and the system constant of the generator linearly approximated based on the system constant calculation constant, further,
Based on the supply-demand imbalance amount, the output set values of the plurality of generators, and the system constants of the generators, a settled frequency of the frequency rise is obtained, and the settled frequency determines a stable operation region of the plurality of generators. A method for stabilizing the frequency of a power system that limits the power of the plurality of generators when the power goes off. 5. An interconnection detection for detecting an interconnection power flow value and an interconnection state between a first electric power system to which a plurality of generators and loads are connected and a second electric power system other than the first electric power system. Means, and the interconnection line power flow value is determined by the interconnection detection means.
When it is detected that the power system has been disconnected during power transmission from the power system to the second power system, the power flow value of the interconnection line, the speed regulation rate of each of the generators, and the governor opening of each of the generators Calculates the settled frequency of the frequency increase based on the difference with the load limiter opening, and when the settled frequency is out of the stable operation region of the plurality of generators, calculates the power supply of the plurality of generators. A power system frequency stabilizing device comprising a control unit. 6. An interconnection detection for detecting an interconnection power flow value and an interconnection state between a first electric power system to which a plurality of generators and loads are connected and a second electric power system other than the first electric power system. Means for detecting the power flow value of the interconnection line when the interconnection detection means detects that the interconnection line has been disconnected at the time of receiving power from the second electric power system to the first electric power system. Calculation control means for calculating the lowest frequency of the frequency decrease based on the output increase amount of each governor-free machine of the machine, and when the lowest frequency is out of the stable operation region of the generator, the load control of the load. Power system frequency stabilization equipment equipped.