JP2005094831A - System and method for power grid stabilization control - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power grid stabilization control system capable of appropriately controlling a failure by reinforcing online information from offline information before an accident. <P>SOLUTION: Sensors 4A-4C detect currents of generators 8A-8C. A sensor 5 detects the voltage of a bus line 1A. A central power feeding station supplies a grid quotient index. A grid stabilizer 9A calculates a power flow value that flows in a power transmission line from the detected current and voltage, and then calculates a transient stability index from the power current value. A control amount calculation diagram where the intersection of both indices represents a control amount is generated and updated at a constant cycle, based on the grid quotient index supplied in advance from the central power supply station as well as the calculated transient stability index. If an accident is determined to have occurred based on at least one change of the detected current and voltage, a transient stability index at that time is calculated and a corresponding control amount is calculated from a control amount calculation diagram. If the control amount is in the category of a unstable case, control corresponding to the control amount is applied to the generator. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  This invention is suitable for online information measured immediately after the accident by reinforcing online information measured after the accident with offline information obtained after the accident when an accident (failure) occurs in the power system. The present invention relates to a power system stabilization control system and a power system stabilization control method that cope with a case where calculation of a stabilization control amount is difficult.

  In the conventional system stabilization device, since the stabilization control amount is calculated using the energy method based on the results of online measurement, it is limited to systems that can be equivalently converted to an infinite bus system. (For example, refer nonpatent literature 1).

Suzuki, Yanagibashi, Tomizawa, Goda, Oshida "Development of Online Stabilization Control Method for Large Capacity Power Supply System" IEEJ Transactions B, 110, 8, August 20, 1990, pp. 652-660 page

  In the conventional system stabilizing device as described above, the stability determination and the calculation of the stabilization control amount are performed based on the energy method (performed by estimating the P-Δδ curve). If the system is limited to a system that can be equivalently converted to a system, the target system is relatively large and complex, and there is online information that cannot be measured due to system problems or system configuration, the online system alone can stabilize the system due to an accident. There was a problem that it was difficult to judge the degree appropriately.

  The present invention has been made to solve the above-described problems. The purpose of the present invention is to provide online information after an accident only when there is online information that cannot be measured due to system problems or system configuration. For accidents where it is difficult to properly determine the stability of the system, online information is reinforced by system information before the accident (generator operating status, transmission line connection status) (offline information) A power system stabilization control system and a power system stabilization control method capable of performing appropriate control for the failure are obtained.

  It should be noted that the feature of the present invention is that the accident case that the poor online type stabilization method (post-calculation type) is not transferred to the offline type stabilization method (pre-calculation type), but the stability obtained by online measurement. The purpose is to reinforce the optimization index with prior system information and effectively utilize the merits of the online stabilization method.

  The power system stabilization control system according to the present invention is a power system stabilization control system that stabilizes the power system by controlling the amount of power supplied to the power system when an accident occurs in the power system. The stability of the protection range system varies depending on the first sensor that detects the output current, the second sensor that detects the voltage of the first bus to which the generator is connected, and the system state that cannot be measured online. A system tolerance index supply device for supplying a system tolerance index representing an index, and a second connected to the first bus and the main system side from the current and voltage detected by the first and second sensors The power flow value flowing in the transmission line connected between the buses is calculated, a transient stability index is calculated from the power flow value, and the calculated transient stability index and the system load previously supplied from the system tolerance index supply device are calculated. Degree finger The control amount calculation diagram in which the intersection of the two indices indicates the control amount is created and updated at a constant cycle, and the accident is based on the change in at least one of the current and voltage detected by the first and second sensors. When the control amount is determined to have occurred, the corresponding stability variable is calculated from the control amount calculation diagram by calculating the transient stability index at that time, and according to the control amount only when the control amount is unstable. And a system stabilizing device for controlling a circuit breaker connected to the generator.

  Since the power system stabilization control system according to the present invention reinforces the measurable online information with the off-line information immediately before the accident even when the stability greatly changes depending on the grid state where online measurement is impossible, There is an effect that it is possible to carry out highly accurate control flexibly corresponding to the state.

Embodiment 1 FIG.
A power system stabilization control system and a power system stabilization control method according to Embodiment 1 of the present invention will be described with reference to the drawings. 1 is a diagram showing a configuration example of a power system stabilization control system according to Embodiment 1 of the present invention. In addition, in each figure, the same code | symbol shows the same or equivalent part.

  In FIG. 1, in the protection range system, buses 1A, 1B, 1C and 1D, power transmission lines 2A, 2B and 2C, circuit breakers 3A, 3B, 3C, 3D, 3E, 3F, 3G and 3H, current Sensor (current transformer) (first sensor) 4A, 4B, and 4C, sensor (transformer) (second sensor) 5 for taking in the bus voltage, circuit breaker information, current and voltage Input cables 6A, 6B, 6C and 6D for capturing the power, an output cable 7 for outputting a power restriction (shutoff) output signal, generators 8A, 8B and 8C capable of online measurement, and online measurement is impossible System stabilizer for maintaining transient stability in the system by shutting off the generators 8A to 8C against a failure occurring in the power generator 8D and the transmission lines 2A and 2B or the buses 1A and 1B 9A is provided There. Moreover, the bus 1C in the protection range system and the bus 1E on the main system side are connected by the interconnection line 2D. The system stabilizing device 9A includes a CPU and the like.

  Next, the operation of the power system stabilization control system according to the first embodiment will be described with reference to the drawings. FIG. 2 is a flowchart showing the operation of the system stabilization device of the power system stabilization control system according to Embodiment 1 of the present invention.

  FIG. 3 is a diagram showing a control amount calculation diagram created by the system stabilization device of the power system stabilization control system according to Embodiment 1 of the present invention. In FIG. 3, the horizontal axis represents acceleration energy (transient stability index), and the vertical axis represents system tolerance index. The dynamic stability monitoring area is an area where the transient stability is maintained but the dynamic stability is weakened. In some cases, the generator needs to be shut off.

  Note that the system tolerance index shown in FIG. 3 is, for example, the operating state of the generator 8D that cannot be measured online as shown in FIG. 1, and the voltage phase angle deviation of the pre-bus 1A that changes depending on the operating state, or online measurement. This is an indicator that the stability of the protection range system changes depending on the system status that cannot be measured online, such as the connection status of transmission lines in the impossible protection range system. ) (System tolerance index supply device) and the like, the system stabilization device 9A is taken in beforehand.

  A specific example of the stabilization method based on the transient stability index that is online information after the accident and the system tolerance index that is offline information before the accident will be described.

  The active power flow of the transmission line 2A is constantly calculated by the system stabilizing device 9A by taking in the current and voltage data obtained through the sensors 4A to 4C and the sensor 5 through the input cables 6A and 6B. For example, when a ground fault occurs in the power transmission line 2A, the system stabilizing device 9A performs stabilization control according to the flowchart shown in FIG. 2 with a kick that the voltage of the bus 1A has become a certain value or less.

  First, in step 101 of FIG. 2, the system stabilizing device 9A always uses the sensors 4A to 4C and 5 to detect the power flow values flowing from the current and voltage input by the input cables 6A and 6B to the transmission lines 2A and 2B ( Power amount) is calculated, and a control amount calculation diagram is created and updated at a constant cycle (for example, several minutes) based on the system tolerance index and acceleration energy.

That is, the control amount calculation diagram shown in FIG. 3 is initially created by simulation of the power system. The calculated tidal current value (power amount) flowing through the transmission lines 2A and 2B corresponds to the electrical output P _L (t) of the generator of the equation (2) described later. Acceleration energy (transient stability index) is calculated from Equation (2) and Equation (1) based on the calculated tidal current value (electric energy) at regular intervals, and a control amount calculation diagram is created and updated.

  Next, in step 102, the occurrence of a failure (accident) is determined from the current and voltage data obtained through the sensors 4A to 4C and 5. For example, as described above, when the voltage of the bus 1A becomes a predetermined value or less, it is determined that a ground fault has occurred in the power transmission line 2A or the like. Further, for example, the amount of power is obtained from current and voltage data, and the occurrence of a failure is determined based on the change in the amount of power.

Next, when it is determined in step 103 that a failure (accident) has occurred, a transient stability index is calculated based on the online information of the generators 8A to 8C that can be measured in the protection range system. As the transient stability index, for example, the acceleration energy V _kdet of the generators 8A to 8C is calculated according to the equation (1).

V _kdet = (1/2) ω ₀ M [ω _det / ω ₀ ] ² (1)

Here, M is the inertia constant [sec] of the generator, ω ₀ is the rated angular frequency 2πf ₀ = 120π [rad / sec], ω _det is the generator angular frequency at t _det (final sampling time), and V _kdet is t _It represents the acceleration energy of the equivalent generator at _det . Note that the final sampling time mentioned here indicates a time after a certain time after the accident is removed. The transient stability index such as the acceleration energy V _kdet calculated here indicates the total value of the entire generator.

Further, as a transient stability index, an angular frequency obtained from the equation (2) or a phase angle obtained by further integrating the equation (2) may be used instead of the acceleration energy. The integration range is from 0 to t _det .

ω _det = (ω ₀ / M) ∫ {P _m −P _L (t)} dt (2)

Here, t _det is the accident removal time [sec], and P _m is the mechanical input of the generator [p. u. ], P _L (t) is the electrical output of the generator [p. u. ], M represents the inertia constant [sec] of the generator, and ω ₀ represents the rated frequency 2πf ₀ = 120π [rad / sec]. Note that P _m is equivalent to the generator output just before the accident.

  Next, in step 104, based on the control amount calculation diagram of FIG. 3 created in advance by simulation or the like, from the transient stability index calculated in step 103, the control amount (power generation amount) that is the intersection with the system tolerance index is calculated. ) Is calculated.

  Next, in step 105, it is determined whether or not the controlled variable that is the intersection of the transient stability index calculated in step 104 and the system tolerance index is an unstable case that requires control. If the case is unstable, the process proceeds to the next step 106, and if the case is stable, the process skips step 106 and proceeds to step 107. In FIG. 3, the dynamic stability monitoring region other than the upper left stable region, the one-unit cutoff region, the two-unit cutoff region, and the three-unit cutoff region are unstable cases.

  Next, in step 106, the generators 8A to 8C are controlled in accordance with the control amount for maintaining the transient stability (any one of the generators 8A to 8C, or a combination thereof) according to the calculation result of step 104. It carries out against. That is, the circuit breakers 3 </ b> A to 3 </ b> C are controlled through the output cable 7.

  In step 107, the system stabilizing device 9A stops and returns to the steady state.

  As described above, according to the first embodiment, an appropriate stabilization control amount can be calculated only by kinetic energy (such as angular frequency or phase angle) such as acceleration energy of a generator in a protection range system capable of online measurement. Even when it is difficult (the stability changes depending on the system state other than the generator capable of online measurement), it is possible to calculate an appropriate control amount by combining the system tolerance index immediately before the accident.

Embodiment 2. FIG.
A power system stabilization control system and a power system stabilization control method according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 4 is a diagram showing a configuration example of a power system stabilization control system according to Embodiment 2 of the present invention.

  In FIG. 4, the configuration of the second embodiment is the same as the configuration of the first embodiment shown in FIG. 1 except for the function of the system stabilizing device 9B.

  Next, the operation of the power system stabilization control system according to the second embodiment will be described with reference to the drawings. FIG. 5 is a flowchart showing the operation of the system stabilization device of the power system stabilization control system according to Embodiment 2 of the present invention.

  Moreover, FIG. 6 is a figure which shows the control amount calculation figure produced by the system | strain stabilization apparatus of the electric power system stabilization control system which concerns on Embodiment 2 of this invention. In FIG. 3, the horizontal axis represents normalized acceleration energy (transient stability index), and the vertical axis represents system tolerance index. The dynamic stability monitoring area is an area where the transient stability is maintained but the dynamic stability is weakened. In some cases, the generator needs to be shut off.

  The system tolerance index shown in FIG. 6 is, for example, the operating state of the generator 8D that cannot be measured online as shown in FIG. 1, and the voltage phase angle deviation of the pre-bus 1A that changes depending on the operating state, or online measurement. This is an indicator that the stability of the protection range system changes depending on the system status that cannot be measured online, such as the connection status of transmission lines in the impossible protection range system. ) (System tolerance index supply device) and the like, the system stabilization device 9B is taken in beforehand.

  In the first embodiment, the stabilization method using kinetic energy such as acceleration energy of the generator as online information after the accident has been described. However, the stability may be affected by the operating state of the generator. Therefore, a method that considers the operating state will be described.

  The active power flow of the power transmission line 2A is constantly calculated by the system stabilizing device 9B by capturing current and voltage data obtained through the sensors 4A to 4C and the sensor 5 through the input cables 6A and 6B. For example, when a ground fault occurs in the power transmission line 2A, the system stabilizing device 9B performs stabilization control according to the flowchart shown in FIG. 5 with a kick that the voltage of the bus 1A has become a certain value or less.

  First, in step 201 in FIG. 5, the system stabilizing device 9B always uses the sensors 4A to 4C and 5 to detect the current value (flow current) flowing from the current and voltage input by the input cables 6A and 6B to the transmission lines 2A and 2B. Power amount) is calculated, and a control amount calculation diagram is created and updated at a constant period (for example, several minutes) based on the system tolerance index and the normalized acceleration energy.

That is, the control amount calculation diagram shown in FIG. 6 is initially created by simulation of the power system. The calculated power flow value (power amount) flowing through the transmission lines 2A and 2B corresponds to the electric output P _L (t) of the generator of the above-described equation (2). Control amount calculation diagram by calculating normalized acceleration energy (transient stability index) from equation (2) and equation (3) described later based on the calculated tidal current value (electric energy) for each fixed period Create and update

  Next, in step 202, the occurrence of a failure (accident) is determined from the current and voltage data obtained through the sensors 4A to 4C and 5. For example, as described above, when the voltage of the bus 1A becomes a predetermined value or less, it is determined that a ground fault has occurred in the power transmission line 2A or the like. Further, for example, the amount of power is obtained from current and voltage data, and the occurrence of a failure is determined based on the change in the amount of power.

Next, when it is determined in step 203 that a failure (accident) has occurred, a transient stability index is calculated based on the online information of the generators 8A to 8C that can be measured in the protection range system. As the transient stability index, for example, normalized acceleration energy obtained by dividing the acceleration energy V _kdet of the generators 8A to 8C by the generator initial output P is calculated according to the equation (3).

V _kdet / ΣP = (1/2) ω ₀ M [ω _det / ω ₀ ] ² / ΣP (3)

Here, M is the inertia constant [sec] of the generator, ω ₀ is the rated angular frequency 2πf ₀ = 120π [rad / sec], ω _det is the generator angular frequency at t _det (final sampling time), and V _kdet is t Acceleration energy of the equivalent generator at _det , ΣP represents the total value of the initial outputs of the generator.

  Next, in step 204, based on the control amount calculation diagram of FIG. 6 created in advance by simulation or the like, the control amount (power generation amount) that is the intersection with the system tolerance index is calculated from the transient stability index calculated in step 203. ) Is calculated.

  Next, in step 205, it is determined whether or not the controlled variable that is the intersection of the transient stability index calculated in step 204 and the system tolerance index is an unstable case that requires control. If the case is unstable, the process proceeds to the next step 206. If the case is stable, the process skips step 206 and proceeds to step 207. In FIG. 6, the dynamic stability monitoring region other than the upper left stable region, the one-unit cutoff region, the two-unit cutoff region, and the three-unit cutoff region are unstable cases.

  Next, in step 206, control corresponding to the control amount for maintaining the transient stability (the amount of shutoff of any of the generators 8A to 8C or a combination thereof) according to the calculation result of step 204 is given to the generators 8A to 8C. It carries out against. That is, the circuit breakers 3 </ b> A to 3 </ b> C are controlled through the output cable 7.

  In step 207, the system stabilizing device 9B stops and returns to the steady state.

  As described above, according to the second embodiment, the required stabilization control amount diagram is set and controlled by the normalized acceleration energy obtained by dividing the acceleration energy obtained by the equation (1) by the generator initial output. Since it did in this way, control can be implemented with high precision even when the stabilization control amount changes depending on the initial output of the generator.

Embodiment 3 FIG.
A power system stabilization control system and a power system stabilization control method according to Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 7 is a diagram showing a configuration example of a power system stabilization control system according to Embodiment 3 of the present invention.

  In FIG. 7, the configuration of the third embodiment is the same as the configuration of the first embodiment shown in FIG. 1 except for the function of the system stabilizing device 9C.

  Next, the operation of the power system stabilization control system according to the third embodiment will be described with reference to the drawings. FIG. 8 is a flowchart showing the operation of the system stabilization device of the power system stabilization control system according to Embodiment 3 of the present invention.

  FIG. 9 is a diagram showing a three-phase / two-line configuration of the power system stabilization control system according to Embodiment 3 of the present invention. FIG. 10 is a diagram showing a situation when a one-line / two-phase ground fault occurs in the protection range system of the power system stabilization control system according to Embodiment 3 of the present invention. FIG. 11 is a diagram showing a pattern example of a three-phase / two-line accident in the power system stabilization control system according to Embodiment 3 of the present invention.

  Furthermore, FIG. 12 is a diagram showing a control amount calculation diagram created by the system stabilization device of the power system stabilization control system according to Embodiment 3 of the present invention. 12A and 12B, the horizontal axis represents the transient stability index, and the vertical axis represents the system tolerance index. Further, (a) shows the case of reclosing success, and (b) shows the case of reclosing failure.

  In Embodiments 1 and 2 described above, the system stabilization method for the method of reinforcing the subsequent online information by the method of controlling according to the control amount set in advance has been described, but in this Embodiment 3, the reclosing (success) A method for dealing with an accident case in which the stabilization control amount varies greatly depending on the failure).

  The active power flow of the transmission line 2A is constantly calculated by the system stabilizing device 9C by taking in the current and voltage data obtained through the sensors 4A to 4C and the sensor 5 through the input cables 6A and 6B. For example, when a ground fault occurs in the power transmission line 2A, the system stabilizing device 9C performs stabilization control according to the flowchart shown in FIG. 8 with a kick that the voltage of the bus 1A has become a certain value or less.

  First, in step 301 of FIG. 8, the system stabilizing device 9C always obtains the value of the current flowing from the current and voltage input through the input cables 6A and 6B through the sensors 4A to 4C and 5 to the transmission lines 2A and 2B. The control amount calculation chart is calculated and updated at a constant cycle (for example, several minutes) based on the system tolerance index, acceleration energy, and normalized acceleration energy. Note that the control amount calculation diagram is also set in advance for accident cases (both successful and unsuccessful reclosing) in which the required control amount greatly changes due to reclosing by a prior simulation or the like. That is, a control amount calculation diagram that does not consider reclosing and a control amount calculation diagram that considers reclosing (both success and failure) are created and updated at a constant period (for example, several minutes). The basic operation of this part is the same as in the first embodiment and the second embodiment.

  Next, in step 302, the occurrence of a failure (accident) is determined from the current and voltage data obtained through the sensors 4A to 4C and 5. For example, as described above, when the voltage of the bus 1A becomes a predetermined value or less, it is determined that a ground fault has occurred in the power transmission line 2A or the like. Further, for example, the amount of power is obtained from current and voltage data, and the occurrence of a failure is determined based on the change in the amount of power.

  Here, the accident type and reclosing will be described with reference to the drawings. Although the details of the power transmission are not shown in the system configuration example of FIG. 7, in general, as shown in FIG. In FIG. 9, square (□) marks represent circuit breakers 3D, 3E, 3F, and 3G.

  Each phase (that is, six phases) is insulated. However, if a lightning strike occurs on a power transmission line, a steel tower, etc., the insulation is destroyed and a ground fault or a short-circuit accident occurs. When such an accident occurs, the protection relay for each phase operates to open the circuit breaker for that accident phase, and to perform a process of disconnecting the accident phase from the power system.

  For example, as shown in FIG. 10 (a), when a lightning strike destroys the insulation between the A phase and B phase of one circuit and a one-circuit / two-phase ground fault occurs, the A phase and B phase The breaker is opened and the accident phase is disconnected from the power system. If this is simply expressed, it can be expressed as shown in the right figure from the left figure in FIG. In FIG. 10B, a white circle (◯) represents a healthy phase (a phase in which no accident has occurred), and a black circle (●) represents an accident phase (a state in which an accident has occurred and the circuit breaker has been opened) ( The vertical column represents each line).

  Therefore, as shown in FIG. 11, depending on the state of the accident, the circuit breaker in a combination of three phases and two lines of 6 phases can be considered open, and the magnitude (severity) of the accident differs depending on the state. Come. In FIG. 11, (a) to (c) in the upper part represent a one-line accident, and (d) to (m) in the lower part represent a two-line accident.

  The conditions for reclosing vary depending on the electric power company and the operation status of the power system. However, the reclosing is generally performed under the following conditions. ). (1) When one line is all in a healthy phase, that is, in the case of one line (one line) accident, or (2) Even if the accident spans two lines, two phases remain healthy on one line Is the case. In the example of FIG. 11, (d), (e), (f), (i), and (j) correspond.

  Next, when it is determined in step 303 that a failure (accident) has occurred, the type of accident is determined based on the release information of the circuit breakers 3E and 3G, and the three-phase and two-line (ie, six-phase) sound phases and accidents are determined. Determine the combination of phases (phase where the breaker is open).

  Next, in step 304, it is determined from the determination result in step 303 whether or not the accident case (type of accident) should be considered for reclosing. If the accident case should consider reclosing, the process proceeds to step 308, and otherwise the process proceeds to step 305. In other words, it is much more important to determine whether the determined accident type satisfies the reclosing condition set in advance, and determine the control amount by determining the reclosing success or failure by a prior simulation etc. Cases that can reduce the control amount are extracted. Although the system stability is significantly increased due to the successful reclosing, the control timing is delayed (the circuit breaker is re-introduced after a certain time after the accident phase circuit breaker is opened. In some cases, the amount of control remains almost the same, and even when the reclosing condition is satisfied by a prior simulation, the reclosing is taken into account (seeing the success and failure of the reclosing). It is necessary to determine whether to do it.

  Next, in step 305, a control amount (including stability determination) is calculated by any of the methods shown in the first and second embodiments for an accident case that can be controlled without considering reclosing.

  Next, in step 306, it is determined whether or not the controlled variable that is the intersection of the transient stability index calculated in step 305 and the system tolerance index is an unstable case that requires control. If the case is unstable, the process proceeds to the next step 307. If the case is stable, the process skips step 307 and proceeds to step 310. In FIG. 3 or FIG. 6, the dynamic stability monitoring region other than the upper left stable region, the one-unit cutoff region, the two-unit cutoff region, and the three-unit cutoff region are unstable cases.

  Next, in step 307, the control corresponding to the control amount for maintaining the transient stability (any one of the generators 8A to 8C or a combination thereof) according to the calculation result in step 305 is applied to the generators 8A to 8C. It carries out against. That is, the circuit breakers 3 </ b> A to 3 </ b> C are controlled through the output cable 7. Thereafter, the process proceeds to step 310.

  Next, in step 308, for the accident case (accident type) considering the reclosing determined in step 304, the reclosing success or failure is determined from the information of the circuit breakers 3E and 3G. The corresponding control amount is calculated from FIGS. 12 (a) and 12 (b). That is, the transient stability index is calculated based on the online information of the generators 8A to 8C that can be measured in the protection range system when the accident occurs. From the calculated transient stability index, a control amount (power generation amount) that is an intersection with any one of the system tolerance indices in FIGS. 12A and 12B is calculated.

  Next, in step 309, control corresponding to the control amount for maintaining the transient stability (any one of the generators 8 </ b> A to 8 </ b> C or a combination thereof) according to the calculation result of step 308 is applied to the generators 8 </ b> A to 8 </ b> C. It carries out against. That is, the circuit breakers 3 </ b> A to 3 </ b> C are controlled through the output cable 7.

  In step 310, the system stabilizing device 9C stops and returns to the steady state.

  According to the third embodiment, the accident type is specified in advance by specifying the type of the accident based on the circuit breaker information and the relay information, and the accident case in which the required control amount (stability) changes greatly due to the success or failure of the reclosing. The control amount calculation diagram (in this control amount calculation diagram also reflects the system tolerance index immediately before the accident) is controlled, and in other cases, the control amount is calculated by online information after the accident. Therefore, since the control method according to the characteristics of the accident can be implemented, highly accurate system stabilization control can be implemented.

  As described above, according to each of the above-described embodiments, the stability greatly varies depending on the system state in which online measurement is not possible due to a problem in the system configuration or the system configuration for a complicated system that is not limited to the power supply system. Even in such a case, since the measurable online information is reinforced by the offline information immediately before the accident, it is possible to carry out highly accurate control flexibly corresponding to the state of the accident.

It is a figure which shows the structural example of the electric power grid stabilization control system which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the system stabilization apparatus of the electric power system stabilization control system which concerns on Embodiment 1 of this invention. It is a figure which shows the control amount calculation figure produced by the system | strain stabilization apparatus of the electric power system stabilization control system which concerns on Embodiment 1 of this invention. It is a figure which shows the structural example of the electric power grid stabilization control system which concerns on Embodiment 2 of this invention. It is a flowchart which shows operation | movement of the system | strain stabilization apparatus of the electric power system stabilization control system which concerns on Embodiment 2 of this invention. It is a figure which shows the control amount calculation figure created by the system | strain stabilization apparatus of the electric power system stabilization control system which concerns on Embodiment 2 of this invention. It is a figure which shows the structural example of the electric power system stabilization control system which concerns on Embodiment 3 of this invention. It is a flowchart which shows operation | movement of the system | strain stabilization apparatus of the electric power system stabilization control system which concerns on Embodiment 3 of this invention. It is a figure which shows the structure of the 3 phase 2 line | wire of the electric power system stabilization control system which concerns on Embodiment 3 of this invention. It is a figure which shows a mode when the 1 circuit and 2 phase ground fault generate | occur | produces within the protection range system | strain of the electric power system stabilization control system which concerns on Embodiment 3 of this invention. It is a figure which shows the example of a pattern of the accident of the three-phase / two lines of the electric power grid stabilization control system which concerns on Embodiment 3 of this invention. It is a figure which shows the control amount calculation figure created by the system | strain stabilization apparatus of the electric power system stabilization control system which concerns on Embodiment 3 of this invention.

Explanation of symbols

  1A, 1B, 1C, 1D, 1E Bus, 2A, 2B, 2C Transmission line, 2D Interconnection line, 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H Circuit breaker, 4A, 4B, 4C sensor (variable Flow sensor), 5 sensors (transformer), 6A, 6B, 6C, 6D input cable, 7 output cable, 8A, 8B, 8C, 8D generator, 9A, 9B, 9C System stabilization device.

Claims (8)

When an accident occurs in the power system, in the power system stabilization control system that stabilizes the power system by controlling the power supply amount of the power system,
A first sensor for detecting the output current of the generator;
A second sensor for detecting the voltage of the first bus to which the generator is connected;
A system tolerance index supply device that supplies a system tolerance index representing an index in which the stability of the protected range system changes depending on a system state that cannot be measured online;
By calculating the value of the current flowing in the power transmission line connected between the first bus and the second bus connected to the main system side from the current and voltage detected by the first and second sensors, Based on the calculated transient stability index from the value, and based on the calculated transient stability index and the system tolerance index supplied in advance from the system tolerance index supply device, a control amount calculation diagram in which the intersection of both indices represents the control amount If it is determined that an accident has occurred based on a change in at least one of the current and voltage detected by the first and second sensors, and is created and updated at regular intervals, the transient stability index at that time A system stabilizing device that calculates the corresponding control amount from the control amount calculation diagram and controls the circuit breaker connected to the generator according to the control amount only when the control amount is unstable And with Power system stabilization control system characterized by The power system stabilization control system according to claim 1, wherein the transient stability index is one of kinetic energy, angular frequency, and phase angle of the generator. The power system stabilization control system according to claim 1, wherein the transient stability index is normalized kinetic energy of the generator. The system stabilizing device creates and updates a control amount calculation diagram that takes into account the reclosing of the circuit breaker at a constant period, and at least one of the current and voltage detected by the first and second sensors. If it is determined that an accident has occurred based on the change, the accident type is determined from the information on the circuit breaker inserted in the transmission line. Calculating the degree index and calculating the corresponding control amount from the control amount calculation diagram according to the success or failure of reclosing, controlling the circuit breaker connected to the generator according to the control amount, When it is not an accident type that should consider reclosing, the transient stability index at the time of the accident is calculated, the corresponding control amount is calculated from the control amount calculation diagram, and only when the control amount is unstable, the control amount Depending on the generator Power system stabilizing control system of claim 1, wherein the controlling the connection has been breaker. When an accident occurs in the power system, in the power system stabilization control method of stabilizing the power system by controlling the supply amount of power of the power system,
The value of the power flow flowing in the transmission line connected between the first bus and the second bus connected to the main system side is calculated from the output current of the generator and the voltage of the first bus connected to the generator. Both of these indicators are calculated based on the system stability index and the system stability index indicating the stability stability of the protected system depending on the system stability that cannot be measured online. Creating and updating a control amount calculation diagram in which a crossing point represents a control amount at a constant period;
When it is determined that an accident has occurred based on a change in at least one of the output current of the generator and the voltage of the first bus connected to the generator, a transient stability index at that time is calculated and the control is performed. Calculating a corresponding control amount from the amount calculation diagram;
And a step of controlling a circuit breaker connected to the generator according to the control amount only when the control amount is unstable. The power system stabilization control method according to claim 5, wherein the transient stability index is any one of kinetic energy, angular frequency, and phase angle of the generator. The power system stabilization control method according to claim 5, wherein the transient stability index is normalized kinetic energy of the generator. Creating and updating a control amount calculation diagram taking into account the reclosing of the circuit breaker at a constant cycle; and
When it is determined that an accident has occurred based on a change in at least one of the output current of the generator and the voltage of the first bus to which the generator is connected, the accident is determined from information on the circuit breaker inserted in the transmission line. Determine the type, and if the accident type should consider the reclosing of the circuit breaker, calculate the transient stability index at the time of the accident and calculate the corresponding control amount from the control amount calculation chart according to the reclosing success or failure And controlling a circuit breaker connected to the generator according to the control amount;
When it is not an accident type that should consider the reclosing of the circuit breaker, calculate the transient stability index at the time of the accident and calculate the corresponding control amount from the control amount calculation diagram, and only when the control amount is unstable The power system stabilization control method according to claim 5, further comprising: controlling a circuit breaker connected to the generator according to the control amount.

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