JP2017060355A - System controller and system stabilization system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system controller capable of appropriately handling various types of uncertain factor in a power system, while mitigating a processing load of online type prior calculation.SOLUTION: A system controller comprises: a storage unit 160 that stores a plurality of models constituted by combinations of a plurality of uncertain factors in a power system; and a prior calculation unit 150 that performs prior calculation using online information on the power system. The prior calculation unit executes stability calculation on each of a plurality of models in a supposed accident for a time shorter than a predetermined reference time; and, on the basis of a result of the stability calculation having been executed for a short time, selects one model from the plurality of models. The prior calculation unit executes stability calculation on the selected one model for the reference time; and, on the basis of a result of the stability calculation having been executed for the reference time, generates a control pattern for a power generator of a control target for the supposed accident.SELECTED DRAWING: Figure 7

Description

  The present disclosure relates to a system control device and a system stabilization system.

  When an accident occurs in the power system, a so-called out-of-step phenomenon may occur in which the generator cannot maintain synchronous operation and enters an unstable operation state. If this step-out phenomenon is neglected, it may cause a chain stop of the generators of the entire system, which may be expanded to a major power outage. For this reason, the power system is designed to stabilize the entire system by shutting down the required number of generators in the event of an accident (hereinafter also referred to as electric control) to minimize the generator step-out phenomenon. A grid stabilization system is provided.

  One of the calculation methods applied to the system stabilization system is a pre-calculation method. In the pre-calculation method, calculations that assume various accident / tidal current patterns are performed before the accident so that various accidents can be dealt with. Specifically, a simulation of the stability of the power system is performed, the stability is determined based on the simulation result, and the necessary control amount for electric control is calculated. And when accident occurrence is detected, electric control is performed according to the state of the electric power system before an accident by referring to said calculation result.

  Such a pre-calculation method is classified into an offline method and an online method depending on the difference in data used for the calculation. In the offline method, calculations performed under the harshest conditions (for example, setting the line power flow to near the operating limit) so that the system state (system configuration, power flow condition) can be reliably stabilized. Execute electronic control based on the result. On the other hand, the online method collects online information such as system configuration and tidal current state and reflects it in the calculation.

  As a technique related to the on-line system, for example, Japanese Patent Laid-Open No. 7-298498 (Patent Document 1) discloses a power system that maintains the stability of a system for a plurality of assumed failure cases of a power system that is supplied with power from a plurality of generators. A method for stabilizing a power system that predetermines control conditions is disclosed. This stabilization method is based on online data periodically sampled from the power system, and selects a generator whose phase angle or phase angle change exceeds a predetermined threshold value in each of a plurality of assumed failure cases. Perform detailed stability calculation of the system.

JP 7-298498 A

  Here, in recent years, distributed power sources such as solar cells have attracted attention, and it is expected that a large amount of distributed power sources will be introduced into the power system. Uncertainties that cannot be determined (for example, accident points, load drop due to voltage drop at the time of an accident) tend to increase. However, in the online pre-calculation method according to Patent Document 1, these uncertain elements are not taken into consideration, and there is a problem that various uncertain elements in the power system that are expected to increase in the future cannot be appropriately handled. is there.

  Further, when considering an uncertain element, it is conceivable to perform a pre-calculation based on a plurality of assumptions, but the condition to be assumed increases as the uncertain element increases. For this reason, there is a problem that the calculation load in the pre-computation increases, which may lead to an increase in necessary computing devices and a cost increase.

  The present disclosure has been made in view of the above-described problems, and an object in one aspect is to appropriately reduce various on-line pre-computation processing loads as well as various uncertain factors in the power system. A system control device and a system stabilization system that can cope with the problem are provided.

  According to an embodiment, there is provided a system control device for stabilizing the power system by controlling the output from the generator to be controlled in accordance with the situation of the power system accident. The system control device includes a storage unit that stores a plurality of models configured by combinations of a plurality of uncertain elements in the power system, and a pre-calculation unit that performs pre-calculation using online information of the power system. The pre-calculation unit executes stability calculation for each of a plurality of models in an assumed accident for a time shorter than a predetermined reference time, and performs stability for a short time for each of the plurality of models. One model is selected from a plurality of models based on the calculation result. The pre-calculation unit executes stability calculation for a selected model for a predetermined reference time, and based on the result of stability calculation for a predetermined reference time for one model, A control pattern of a generator to be controlled with respect to an assumed accident is generated.

  According to the present disclosure, it is possible to appropriately cope with various uncertain factors in the power system while reducing the processing load of online pre-calculation.

It is a figure which shows an example of the whole structure of the system | strain stabilization system according to this Embodiment. It is a figure which shows an example of the drop-off characteristic of the load in an electric power grid | system. It is a figure which shows an example of the output characteristic of a power conditioner. It is a figure which shows an example of the output characteristic of a power conditioner. It is a figure which shows an example of the uncertain element model according to this Embodiment. It is a block diagram which shows the hardware structural example of the system | strain control apparatus according to this Embodiment. It is a schematic diagram which shows the function structure which concerns on the system | strain stabilization system according to this Embodiment. It is a figure which shows an example of a motion of the slip average value of the generator after accident occurrence. It is a figure which shows an example of a motion of the output average value of the generator after accident occurrence. It is a figure which shows an example of the control table according to this Embodiment. It is a flowchart which shows the process sequence of the system | strain control apparatus according to this Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same or corresponding portions are denoted by the same reference numerals, and the description thereof may not be repeated. In the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential for the present invention unless otherwise specified.

<System stabilization system>
When an accident occurs in the power system, the system stabilization system according to the present embodiment stabilizes the power system by controlling the output from the controlled generator according to the situation of the accident.

  FIG. 1 is a diagram showing an example of the overall configuration of the system stabilization system according to the present embodiment. Referring to FIG. 1, system stabilization system 1000 is mainly configured by system control device 10, system stabilization device 20, and a plurality of terminal devices 30A and 30B.

  Each device included in the system stabilization system 1000 is given a status according to its role and function. Specifically, the system control device 10 that is functionally located at the upper level is disposed at the power supply command station 1, and the system stabilization device 20 that is functionally located at the middle position is disposed at the substation 2, and is functionally lower. Terminal devices 30 </ b> A and 30 </ b> B located in are located in the power plant 3 and the switching station 4, respectively. For example, the system controller 10 and the system stabilizer 20 may be referred to as “master station” and “slave station”, respectively.

  The power supply command station 1 is a command station that supervises generator control of the entire power plant in the jurisdiction section. The substation 2 is one arbitrarily selected from a plurality of substations. Note that any one of the other substations can replace the substation 2 that is functionally located in the middle. In the example of FIG. 1, only one power plant is shown, but a configuration having a plurality of power plants may be used.

  The system control device 10 and the system stabilization device 20 are connected via a communication line 50. The system stabilizing device 20 and the terminal devices 30A and 30B are connected via a communication line 60. Note that the communication lines 50 and 60 do not have to be dedicated lines as long as predetermined communication requests are satisfied, and public lines or the like may be used.

  In the electric power system shown in FIG. 1, terminal devices 30A and 30B are arranged in association with buses 6 and 8, respectively. The bus 6 and the bus 8 are connected by a power transmission line 7 (for example, 3 lines). Hereinafter, when the configurations and functions common to each of the terminal devices 30A and 30B are described, they are collectively referred to as “terminal device 30”.

  A plurality of generators G1 to G3 are connected to the bus 6, and transformers TR1 to TR3 and circuit breakers CB1 to CB3 are connected between the bus 6 and the generators G1 to G3, respectively. From the bus 8, for example, power is supplied to a load (not shown) via a transformer (not shown). Typically, the generators G1 to G3 are an acceleration-side generator group (an unstable generator group) in the vicinity of the accident that has occurred as a control target.

  The system control device 10 collects information in the power system at regular intervals (for example, every 30 seconds) and is necessary for each accident assumed in advance according to the system state determined from the collected information. Perform pre-computation. The pre-computation is performed based on the power flow distribution in the power system, the output and phase angle of each generator. A detailed stability calculation is used for the pre-calculation. The system control device 10 distributes information (control table, etc.) that defines the stabilization control amount and the control target for each accident calculated in advance to the system stabilization device 20 and updates the contents at regular intervals. To do.

  The system stabilization device 20 collects information in the power system from the plurality of terminal devices 30A and 30B that are the management (control) targets, and transmits the information to the system control device 10 at regular intervals (for example, every 30 seconds). . When an accident occurs in any part of the control target range of each terminal device 30, the system stabilization device 20 executes stabilization control based on a control table distributed in advance. Typically, when the system stabilization device 20 determines that an accident has occurred based on the relay information from the terminal device 30, the terminal device 30 is configured to give a break command to the breaker corresponding to the generator designated in advance. The generator is disconnected from the power system. Or the system stabilization apparatus 20 may instruct | indicate the terminal device 30 to give the interruption | blocking instruction | command to the circuit breaker corresponding to a power transmission line, and may open an accident line. Thus, the grid stabilization apparatus 20 performs the operation | movement for maintaining a transient stability, when some accident generate | occur | produces in an electric power grid | system.

  The terminal device 30 collects information in the electric power system from various sensors in the control target range, and transmits the collected information to the system stabilizing device 20 at regular intervals (for example, every 30 seconds). Specifically, the terminal device 30A targets the power plant 3 including the bus 6 and collects the bus voltage value of the bus 6 from the transformer VT1, which is a sensor for taking in the voltage value, and also calculates the current value. The transmission line current values flowing through each line of the transmission line 7 are collected from the current transformers CT1, CT2, CT3 which are sensors for capturing. The terminal device 30B controls the switching station 4 including the bus bar 8, collects the bus voltage value of the bus bar 8 from the transformer VT2, and flows through each line of the transmission line 7 from the current transformers CT4, CT5, and CT6. Collect wire current values.

<Stabilization control by pre-calculation method>
Here, the operation of the stabilization control by a typical online type pre-calculation method will be described. The system control device 10 generates a control table that defines stabilization control amounts respectively corresponding to accidents that are assumed in advance (that is, accidents to be controlled) by pre-calculation, and sends the control table to the system stabilization device 20 at regular intervals. To be delivered to.

  It is assumed that some kind of accident has occurred in the power system in a situation where such pre-calculation is executed at regular intervals. For example, it is assumed that a ground fault has occurred in one transmission line 7. In such a case, the terminal device 30A in the vicinity of the accident point detects the occurrence of an accident due to a sudden change in a measurement element such as a decrease in the bus voltage value or an increase in the zero-phase voltage value, and stabilizes the detection result (relay information). The device 20 is notified. The relay information includes power line protection relay operation information, electric quantity information, and the like.

  The system stabilizing device 20 determines an accident point, an accident type (accident case), and the like based on the relay information from the terminal device 30A. The grid stabilization device 20 compares the control table distributed in advance (including support information for determining the degree of stability with respect to the accident point, the type of accident, etc.) to stabilize the power system after the accident has occurred. Determine which is unstable. When it is determined that the power system is unstable, the system stabilizing device 20 refers to the control table and controls the corresponding terminal device (in this case, the generators G1 to G3 to be controlled). To the terminal device 30A). Typically, the system stabilization device 20 instructs the terminal device 30A to give a disconnection command to the circuit breaker corresponding to the power generator that is destabilizing the power system.

  30 A of terminal devices give the interruption | blocking instruction | command to the circuit breaker corresponding to a generator based on the said control instruction | indication, and disconnect the said generator from an electric power grid | system, and maintain transient stability.

<Issues>
As mentioned above, indefinite factors are expected to increase with the introduction of large amounts of distributed power sources such as solar cells into the power system in the future. preferable. In the present embodiment, as an uncertain factor, for example, a case is considered in which load drop characteristics, output characteristics of a power conditioner (PCS), and an accident point are considered.

  FIG. 2 is a diagram illustrating an example of a load drop characteristic in the power system. The horizontal axis in FIG. 2 indicates the load drop rate, and the vertical axis in FIG. 2 indicates the bus voltage [p. u. ] Is shown. When the bus voltage drops to the drop-off start voltage V1 (for example, 0.80), the load starts to drop off. Further, when the bus voltage drops to the drop-off saturation voltage V2 (for example, 0.45), the load with the load drop-off rate X (for example, 20%) drops and tends to be saturated.

  3 and 4 are diagrams illustrating an example of output characteristics of the power conditioner. Specifically, FIG. 3 shows the output characteristics of the power conditioner when the residual voltage is equal to or higher than a certain ratio (here, 30%). FIG. 4 shows the output characteristics of the power conditioner when the residual voltage is less than a certain ratio. This power conditioner is for renewable energy such as a solar battery.

  Referring to FIG. 3, when the voltage drop at which the remaining voltage at the time of the accident is 30% or more continues for a time Ta (time t1 to time t2) (see FIG. 3 (a)), it is for renewable energy The gate block is not performed by the power conditioner and the operation is continued (see FIG. 3B). Typically, the residual voltage characteristic and the output characteristic of the power conditioner have the same tendency.

  On the other hand, referring to FIG. 4, when the voltage drop with the residual voltage of less than 30% at the time of the accident continues for time Ta (time t1 to time t2) (see FIG. 4 (a)), the power condition is The gate block is performed by N (see FIG. 4B). Then, at time t3 after the phase confirmation time Tb (for example, 1 second) from time t2, the power conditioner starts an output return operation and returns it to 80% of the output before the voltage drop. Eventually, the output of the power conditioner returns to the output before the voltage drop at time t4 after time Tc (for example, 10 seconds) from time t3.

  When considering the presence or absence of the load drop characteristic as shown in FIG. 2, the presence or absence of the output characteristic of the power conditioner as shown in FIGS. 3 and 4, and the accident point (power transmission end and power reception end), for example, It is conceivable to perform detailed stability calculation for each of the eight uncertain element models as shown in FIG.

  FIG. 5 is a diagram showing an example of the uncertain element model according to the present embodiment. Referring to FIG. 5, the presence or absence of load drop characteristics, the presence or absence of output characteristics of the inverter (corresponding to “Yes” or “No” in the PCS characteristics in FIG. 5), and the fault point (transmission end or reception end) Accordingly, eight models MD1 to MD8 are prepared. For example, the model MD1 is a model that assumes the case where the accident point is the power transmission end without considering the load drop characteristics (see FIG. 2) and the output characteristics of the power conditioner (see FIGS. 3 and 4). The model MD4 is a model that assumes a case where the accident point is the power transmission end in consideration of the load drop characteristic and the output characteristic of the power conditioner.

  If the detailed stability calculation is performed for each of the eight uncertain factor patterns for each accident type at each monitoring point, the calculation amount becomes enormous. In addition, the amount of calculation increases exponentially as the number of uncertain elements increases. For this reason, there are problems such as an increase in calculation time and an increase in cost due to an increase in the number of necessary calculation devices and higher performance of the calculation devices.

  Therefore, the system control apparatus 10 according to the present embodiment solves the above-described problems by adopting a pre-calculation method as described below. Hereinafter, the configuration and processing procedure of the system control device 10 will be mainly described in detail.

<Hardware configuration>
(System controller)
FIG. 6 is a block diagram showing a hardware configuration example of the system control apparatus 10 according to the present embodiment. FIG. 6 shows a configuration in which the system controller 10 is realized by a processor executing a program as a typical example, but all or part of the system controller 10 may be mounted using a dedicated hard-wired circuit or logic circuit. Good.

  The system control device 10 includes a processor 102, a main storage device 104, a secondary storage device 106, an interface 108, an input device 110, and an output device 112 as its components. These components are communicably connected to each other via an internal bus 114.

  The processor 102 is typically an arithmetic processing unit such as a CPU (Central Processing Unit) or an MPU (Multi Processing Unit), and reads the power system stabilization program 120 stored in the secondary storage device 106 to It is executed while being expanded in the storage device 104.

  The main storage device 104 is typically a volatile storage medium such as a dynamic random access memory (DRAM), and the power system stabilization program 120 in addition to the code of the power system stabilization program 120 executed by the processor 102. Holds various work data required for execution. The secondary storage device 106 is a nonvolatile storage medium such as a hard disk or an SSD (Solid State Drive), and holds various setting values in addition to the power system stabilization program 120.

  The interface 108 receives data indicating the measured value of the electric quantity from an external device (for example, the system stabilization device 20) and outputs a command signal related to the control operation. As the interface 108, a component conforming to a general communication protocol can be adopted, or a component conforming to a dedicated communication protocol can be employed.

  The input device 110 typically includes a keyboard and a mouse, and receives various settings and operations from the user. The output device 112 typically includes a display, a printer, and the like, and outputs a calculation result by the processor 102 to the outside.

(System stabilization device, terminal device)
The system stabilization device 20 typically has a processor such as a CPU for executing various processes, a storage device for storing various data, and external devices (for example, the system control device 10 and the terminal device 30). And an interface for transmitting and receiving various data. The terminal device 30 has a hardware configuration similar to that of the system stabilizing device 20, for example.

<Functional configuration>
FIG. 7 is a schematic diagram showing a functional configuration related to the system stabilization system according to the present embodiment. Referring to FIG. 7, system control device 10 includes a pre-calculation unit 150 and a data storage unit 160 as functional configurations. Typically, the pre-calculation unit 150 is realized by the processor 102 executing the power system stabilization program 120 stored in the secondary storage device 106. The data storage unit 160 is realized by the main storage device 104 and the secondary storage device 106.

  The pre-computation unit 150 performs pre-computation (detailed stability calculation) using online information (system information) of the power system. Specifically, the preliminary calculation unit 150 includes a detailed stability calculation unit 152 and a selection unit 154.

  The detailed stability calculation unit 152 obtains online information from the system stabilization device 20 and stores a plurality of uncertain element models (see FIG. 5) composed of combinations of a plurality of uncertain elements in the power system as a data storage unit. Read from 160. The detailed stability calculation unit 152 may be configured to acquire online information directly from the terminal device 30 or another external device without going through the system stabilization device 20. Moreover, you may employ | adopt arbitrary well-known methods about the collection method of the online information in an electric power grid | system. The online information includes voltage, current, generator active power, reactive power, breaker on / off information, etc. at each point of the power system.

  The detailed stability calculation unit 152 uses the online information for each of a plurality of uncertain element models (for example, models MD1 to MD8) for each assumed accident, and the detailed stability calculation reference time Trf ( For example, the detailed stability calculation is performed for a time Tsh (for example, 1.5 seconds) shorter than 10 seconds. The reference time Trf is set to a detailed stability calculation time that is normally required to generate (determine) a control pattern. The time Tsh is set to a time during which the approximate stability can be determined. The reference time Trf and the time Tsh may be arbitrarily set by a user or the like. Moreover, about a detailed stability calculation method, arbitrary well-known methods are employ | adopted.

  The detailed stability calculation unit 152 executes a detailed stability calculation using a predetermined stability index (an index for determining whether the power system is stable or unstable) for a time Tsh. For example, as the stability index, the average value of the slips (rotations) of the generators G1 to G3 or the output average value of the generators G1 to G3 is used. When the slip average value is used as the stability index, the detailed stability calculation unit 152 performs the detailed stability calculation for each of the models MD1 to MD8 for the time Tsh, as shown in FIG. Calculate the simulation result (movement of the sliding average value). Further, when the output average value is used as the stability index, the detailed stability calculation unit 152 performs the detailed stability calculation for each of the models MD1 to MD8 for the time Tsh, as shown in FIG. Such a simulation result (movement of output average value) is calculated.

  FIG. 8 is a diagram illustrating an example of the movement of the average slip value of the generator after an accident occurs. FIG. 9 is a diagram showing an example of the movement of the output average value of the generator after the occurrence of the accident.

  Referring to FIG. 8, it is possible to grasp the movement of the slip average value of the generators G1 to G3 in time series for each of the models MD1 to MD8. The difference in the average slip value between before and after the accident indicates that the power system becomes more unstable as the value after the accident is larger than the value before the accident. The model with the most severe stability (the lowest stability and unstable) among MD1 to MD8 is model MD3. In addition, at the time of 1.5 seconds, the model having an average (intermediate) stability among the models MD1 to MD8 is the model MD4.

  Referring to FIG. 9, the movement of the output average value of the generators G1 to G3 can be grasped in time series for each of the models MD1 to MD8. As for the difference between the average output values after the accident and before the accident, the power system becomes unstable as the value after the accident decreases with respect to the value before the accident. The model with the highest stability among the models MD1 to MD8 is the model MD3. In addition, at the time of 1.5 seconds, the model having the average stability among the models MD1 to MD8 is the model MD4.

  In the above description, the configuration in which the generator slip or the output value is used as the stability index has been described. However, the present invention is not limited to this. For example, as the stability index, a generator phase angle, a generator phase angle deviation, a generator kinetic energy, a generator frequency, or the like may be used.

  Referring again to FIG. 7, the selection unit 154 uses the detailed stability calculation results (for example, FIGS. 8 and 9) performed for each of the models MD1 to MD8 for the time Tsh to One model is selected from the models MD1 to MD8. Selection criteria for selecting one model is stored in the data storage unit 160. Typically, this selection criterion is a criterion of “selecting the model with the strictest stability among the models MD1 to MD8”.

  When the average value of the generator slip is used as the stability index, the selection unit 154 selects one of the models MD1 to MD8 based on the detailed stability calculation result shown in FIG. The model MD3 with the strictest stability is selected. When the output average value of the generator is used as the stability index, the selection unit 154 selects a plurality of models MD1 to MD8 based on the detailed stability calculation result and the selection criterion shown in FIG. Model MD3 is selected from

  When the detailed stability calculation unit 152 performs the detailed stability calculation using a plurality of stability indexes, the selection unit 154 comprehensively determines the detailed stability calculation results. Alternatively, the model may be selected.

  Specifically, the plurality of models MD1 to MD8 are scored according to the stability (for example, 8 points, 7 points,..., 2 points, 1 point in order of strict stability). A plurality of models MD1 to MD8 are scored based on the detailed stability calculation result (see FIG. 8) when the slip average value of the generator is used. For example, the strictest model MD3 is 8 points. Similarly, a plurality of models MD1 to MD8 are scored based on the detailed stability calculation result (see FIG. 9) when the output average value of the generator is used. For each model MD1 to MD8, a total value obtained by adding the score when using the average slip value of the generator and the score when using the average output value of the generator is calculated. Then, the selection unit 154 selects the model having the highest total value among the models MD1 to MD8 as the model having the strictest overall stability. This makes it possible to select a model based on the overall stability considering a plurality of stability indices.

  The detailed stability calculation unit 152 executes the detailed stability calculation for the model selected by the selection unit 154 for the reference time Trf. That is, the detailed stability calculation unit 152 performs detailed stability calculation of the reference time Trf necessary for determining a control pattern for an assumed accident. And the detailed stability calculation part 152 produces | generates the control pattern of the generators G1-G3 of a control object about the assumed accident based on this detailed stability calculation result.

  The detailed stability calculation unit 152 generates the control pattern of the generators G1 to G3 to be controlled as described above for each of a plurality of assumed accidents. A control table in which is associated is generated.

  FIG. 10 shows an example of the control table according to the present embodiment. According to the control table shown in FIG. 10, when a two-phase three-wire ground fault (2φ3LG) occurs in the transmission line 7 that is an accident monitoring point, a control pattern that shuts off all the generators G1 to G3 It has become. Further, when a one-phase two-wire ground fault (1φ2LG) occurs, the control pattern is to shut off the generator G1. When a three-phase three-wire ground fault (3φ3LG) occurs, the control pattern does not require any generator to be shut off. This means that the stability of the power system can be maintained without shutting off the generator. According to this control table, when a two-phase three-wire ground fault or a one-phase two-wire ground fault occurs, the power system is unstable, and when a three-phase three-wire ground fault occurs, the power system Can be judged to be stable.

  The detailed stability calculation unit 152 may generate a control pattern in consideration of a predetermined control priority order of the generators G1 to G3. For example, it is assumed that the control priority is higher in the order of the generators G1, G2, and G3. In this case, when the detailed stability calculation unit 152 determines that it is necessary to shut off the two generators based on the detailed stability calculation result, the detailed stability calculation unit 152 generates a control pattern that shuts off the generators G1 and G2. When it is determined that one generator needs to be shut off, a control pattern for shutting off the generator G1 is generated. The control priority order is determined in consideration of the ease of restarting the generators G1 to G3, economic efficiency, and the like.

  Again referring to FIG. 7, detailed stability calculation unit 152 transmits a control table (see FIG. 10) in which the accident and the control pattern are associated to system stabilization device 20.

  The system stabilization device 20 includes a system information collection unit 202, a stabilization control unit 204, and a data storage unit 206 as functional configurations. Typically, the system information collection unit 202 and the stabilization control unit 204 are realized by a processor executing a program stored in a storage device.

  The system information collection unit 202 collects online information (system information) in the power system from the terminal device 30, and uses the collected online information as a detailed stability calculation unit 152 and a stabilization control unit 204 of the system control device 10. Output to.

  When an accident occurs in any part of the control target range of each terminal device 30, the stabilization control unit 204 executes stabilization control based on a control table distributed in advance. Specifically, the stabilization control unit 204 determines the accident type based on the relay information from the terminal device 30, and specifies the control pattern of the generators G1 to G3 corresponding to the accident type with reference to the control table. To do. The stabilization control unit 204 performs control to shut off the generator according to the specified control pattern. Specifically, the stabilization control unit 204 instructs the terminal device 30 to give a break command to the breaker corresponding to the generator. For example, when the stabilization control unit 204 determines that the accident type is a two-phase three-wire ground fault, the circuit breakers CB1 to CB3 corresponding to the generators G1 to G3 are referred to with reference to the control table shown in FIG. The terminal device 30A is instructed to shut off. The terminal device 30A disconnects the generators G1 to G3 from the power system by giving a break command to the breakers CB1 to CB3 based on the instruction.

  The data storage unit 206 stores a control table transmitted from the system control device 10 (detailed stability calculation unit 152) at regular intervals.

  In the above description, the case has been described in which the selection criterion is the criterion “select the model with the strictest stability among the models MD1 to MD8”. According to this, since the shutoff of the generator is executed according to the control pattern using the detailed stability calculation executed for the strictest model, it is possible to prevent insufficient control.

  However, for example, if it is known that the possibility of insufficient control is sufficiently low without selecting the most severe model and performing detailed stability calculation, over-control ( It is thought that the generator will be shut off too much). Therefore, the selection criterion may be a criterion of “selecting a model having an average stability among the models MD1 to MD8”. In this case, for example, the pre-calculation unit 150 (selection unit 154) has an average stability among a plurality of models MD1 to MD8 based on the detailed stability calculation result and the selection criterion shown in FIG. Select MD4. According to this, since excessive control can be suppressed, economic loss due to shutting off the generator can be reduced.

<Processing procedure>
FIG. 11 is a flowchart showing a processing procedure of system control apparatus 10 according to the present embodiment. Typically, each step shown in FIG. 11 is executed by the processor 102 of the system control device 10. The following steps are executed for each predetermined calculation cycle. Here, the power transmission line 7 is assumed as an accident monitoring point, and the generators G1 to G3 are controlled.

  Referring to FIG. 11, system control device 10 selects one model from a plurality of models MD1 to MD8 prepared in advance as uncertain element models (step S2). Specifically, the system control device 10 selects one model among the plurality of models MD1 to MD8 that has not performed the detailed stability calculation in step S4 described later.

  The system controller 10 performs the detailed stability calculation for the one model selected in step S2 for a time Tsh that is shorter than the reference time Trf (step S4). Subsequently, the system control device 10 determines whether or not there is a model not selected in Step S2 among the plurality of models MD1 to MD8 (Step S6). If the model exists (YES in step S6), system control device 10 repeats the processing from step S2. By a series of processes in steps S2 to S6, detailed stability calculation is executed for each of the plurality of models MD1 to MD8 for a time Tsh. Thereby, for example, a detailed stability calculation result as shown in FIG. 8 or FIG. 9 is obtained.

  When the model does not exist (NO in step S6), the system control device 10 includes a detailed stability calculation result for each of the plurality of models MD1 to MD8 obtained by a series of processes in steps S2 to S6, One model is selected from a plurality of models MD1 to MD8 based on a predetermined selection criterion (step S8). As a specific example, let us consider a case where the selection criterion is set to “select the model with the strictest stability among a plurality of models MD1 to MD8”. In this case, the system control device 10 selects the model MD3 with reference to the result shown in FIG. 8 or FIG.

  Next, the system control device 10 selects one accident type from a plurality of accident types (accident cases) assumed in advance (step S10). For example, the system control device 10 selects a two-phase three-wire ground fault (2φ3LG) as the fault type.

  The system controller 10 executes the detailed stability calculation for the model (selected model) selected in step S6 for the reference time Trf (step S12). The system controller 10 has already performed the detailed stability calculation for the selected model for the time Tsh (step S4), but does not perform the detailed stability calculation from the middle, but again the detailed stability from the beginning. Repeat the degree calculation. However, the system control device 10 may be configured to execute the detailed stability calculation from the middle (that is, after the time Tsh).

  The system control device 10 generates a control pattern of the generators G1 to G3 for the accident type selected in step S10 based on the detailed stability calculation result obtained in step S12 (step S14). The system controller 10 registers the accident type and the control pattern in association with each other in the control table (step S16). For example, as shown in FIG. 10, a control pattern for “shut off” the generators G <b> 1 to G <b> 3 is associated with a two-phase three-wire ground fault (2φ3LG) and registered in the control table.

  The system controller 10 determines whether or not there is an accident type that has not been selected in step S10 among a plurality of accident types assumed in advance (step S18). If the accident type exists, the system control device 10 repeats the processing from step S2. If the accident type does not exist, the system control device 10 ends the process.

<Modification>
In the above-described embodiment, basically, the selection criterion K1 “select the model having the strictest stability among the plurality of models MD1 to MD8” is employed in order to prevent insufficient control. In the case where the possibility is sufficiently low, in order to suppress over-control, it has been described that the selection criterion K2 “select a model having an average stability among the models MD1 to MD8” may be adopted. However, in case of a shortage control in the case where this selection criterion K2 is adopted, the system stabilizing device 20 further performs additional control by post-operation necessary for stabilizing the power system from the system state after the accident occurs. May be executed.

  Specifically, referring to FIG. 7, system control device 10 (pre-calculation unit 150) notifies system stabilization device 20 of information indicating which selection criterion is used to generate the control table. deep. For example, the pre-calculation unit 150 may transmit the adopted selection criterion to the system stabilization device 20 in association with the control table, or may independently transmit the adopted selection criterion.

  In addition, when a selection criterion other than the selection criterion K1 “select the model with the strictest stability” is adopted, the system stabilization device 20 (stabilization control unit 204) prepares for shortage control, You may be comprised so that the additional control by a post calculation may be performed. In this case, the pre-computation unit 150 determines whether or not the model with the lowest power system stability is selected from the models M1 to M8 as a model to be subjected to the detailed stability calculation for the reference time Trf (ie, the selection is performed). Information indicating whether or not the standard K1 is adopted is transmitted to the system stabilizing device 20 (stabilization control unit 204). When the system stabilization device 20 (stabilization control unit 204) determines that the model having the lowest power system stability is not selected based on the information (the selection criterion K1 is not adopted), Perform necessary post-calculations.

  For example, when additional control by post-computation is executed by the system stabilization device 20, the outline of the operations of the system stabilization device 20 and the terminal device 30 before and after the occurrence of the accident is as follows. The system stabilizing device 20 determines the occurrence of an accident based on the relay information from the terminal device 30. The grid stabilization device 20 refers to the control table, identifies the control pattern of the generator corresponding to the accident type, and instructs the terminal device 30 to give a break command to the breaker corresponding to the identified generator. . The terminal device 30 disconnects the corresponding generator from the power system by giving a break command to the breaker according to the instruction.

  Thereafter, the system stabilizing device 20 collects online information after the occurrence of the accident from the terminal device 30 and executes a post-operation to determine whether it is necessary to further shut down the controlled generator. When it is determined that the generator needs to be shut down, the system stabilizing device 20 further instructs the terminal device 30 to give a shut-off command to the circuit breaker corresponding to the generator. The terminal device 30 disconnects the corresponding generator from the power system by giving a break command to the breaker according to the instruction.

  Here, an example of the control method executed by the system stabilizing device 20 after the occurrence of an accident will be described. For the following control method, refer to Japanese Patent Application Laid-Open No. 2011-254608.

  The system stabilizing device 20 takes out the data of the previous sway from the actual measurement data collected after the occurrence of the accident, and calculates or calculates data at a plurality of points necessary for estimating the power phase difference angle curve based on the taken out data. Prepare by means such as prediction. Next, the system stabilizing device 20 estimates the unknown coefficient of the power phase difference angle curve (P-δ curve) using the prepared data at a plurality of points in time. Subsequently, the system stabilizing device 20 calculates acceleration energy VA and deceleration energy VD from the estimated power phase difference curve and measurement data.

  Next, the system stabilization device 20 compares the acceleration energy VA and the deceleration energy VD. If the deceleration energy VD is larger, the system stabilization device 20 determines that the power system is stable and ends the process. On the other hand, when the acceleration energy VA is larger, the system stabilization device 20 determines that the power system is unstable, selects a control pattern that minimizes the amount of shutoff of the generator, and performs the control. Acceleration energy VA # and deceleration energy VD # after patterning are calculated (energy recalculation processing).

  System stabilizing device 20 compares acceleration energy VA # and deceleration energy VD # to determine whether or not the power system is stable (stability determination processing). When deceleration energy VD # is larger, system stabilizing device 20 determines that the control by the selected control pattern is stable. And the system | strain stabilization apparatus 20 instruct | indicates the terminal device 30 to give the interruption | blocking instruction | command to the circuit breaker corresponding to a generator based on the said control pattern, and complete | finishes a process.

  On the other hand, when the acceleration energy VA # is larger, the system stabilizing device 20 determines that the control energy is unstable even after the control by the selected control pattern. Therefore, the system stabilizing device 20 selects the control pattern having the next largest cutoff amount, and again performs the energy recalculation process and the stability determination process to a control pattern in which the deceleration energy VD # exceeds the acceleration energy VA #. Run continuously until

<Advantages>
According to the present embodiment, even when the uncertainties in the pre-calculation increase due to the introduction and expansion of photovoltaic power generation and distributed power sources in the power system, appropriate stability determination and calculation of the stability control amount Can be executed. Therefore, it is possible to appropriately cope with various uncertain factors in the power system.

  Further, according to the present embodiment, an optimal uncertain element model is selected from a plurality of uncertain element models by detailed stability calculation in a short time, and the details at the reference time are selected for the selected model. Stability calculation is performed. Therefore, it is possible to reduce the processing load related to the online type pre-calculation, and it is possible to suppress an increase in the number of necessary servers and cost.

[Other embodiments]
In the embodiment described above, in FIG. 1, a plurality of terminal devices 30A and 30B are provided for the system stabilizing device 20, and each terminal device is in charge of inputting information from various sensors, outputting cutoff commands, and the like. The configuration example has been described. However, the present invention is not limited to this, and a configuration example in which information from various sensors is directly input to the system stabilizing device 20 and a cutoff command is directly output from the system stabilizing device 20 may be used.

  The configuration illustrated as the above-described embodiment is an example of the configuration of the present invention, and can be combined with another known technique, and a part of the configuration is omitted without departing from the gist of the present invention. It is also possible to change the configuration.

  In the above-described embodiment, the processing and configuration described in the other embodiments may be adopted as appropriate.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 Power Supply Command Station, 2 Substation, 3 Power Station, 4 Switch Station, 6, 8 Bus, 7 Transmission Line, 10 System Controller, 20 System Stabilizer, 30A, 30B Terminal Equipment, 50, 60 Communication Line, 102 Processor, 104 Main storage device, 106 Secondary storage device, 108 Interface, 110 Input device, 112 Output device, 114 Internal bus, 120 Power system stabilization program, 150 Pre-calculation unit, 152 Detailed stability calculation unit, 154 Selection unit , 160, 206 Data storage unit, 202 System information collection unit, 204 Stabilization control unit, 1000 System stabilization system, CB1-CB3 circuit breaker, CT1-CT6 current transformer, G1-G3 generator, TR1-TR3 transformer , VT1, VT2 transformer.

Claims (5)

A system controller for stabilizing the power system by controlling the output from the generator to be controlled according to the situation of the power system accident,
A storage unit that stores a plurality of models configured by a combination of a plurality of uncertain elements in the power system;
A pre-calculation unit that performs pre-calculation using online information of the power system,
The pre-calculation unit is
For each of the plurality of models in the assumed accident, the stability calculation is performed for a time shorter than a predetermined reference time,
Selecting one model from among the plurality of models based on the result of the stability calculation performed for each of the plurality of models for the short period of time;
Performing the stability calculation on the selected one model for the predetermined reference time;
The system control apparatus which produces | generates the control pattern of the said generator of the control object with respect to the said assumed accident based on the result of the said stability calculation performed with respect to the said 1 model for the predetermined reference time.   The system controller according to claim 1, wherein the pre-calculation unit selects a model having the lowest stability of the power system as the one model among the plurality of models.   The system controller according to claim 1, wherein the pre-calculation unit selects, as the one model, a model having an average power system stability among the plurality of models.   The pre-computation unit stabilizes the power system from the system state after the accident, using information indicating whether or not the model having the lowest power system stability among the plurality of models is selected as the one model. The system control apparatus according to any one of claims 1 to 3, wherein the system control apparatus transmits to a system stabilization apparatus capable of executing a post-calculation necessary for the conversion. A system stabilization system for stabilizing the power system by controlling the output from the generator to be controlled according to the situation of the power system accident,
A system control device;
A system stabilization device configured to be communicable with the system control device,
The system controller is
A storage unit that stores a plurality of models configured by a combination of a plurality of uncertain elements in the power system;
A pre-computation unit that performs a pre-computation using online information of the power system,
The pre-calculation unit is
For each of the plurality of models in the assumed accident, the stability calculation is performed for a time shorter than a predetermined reference time,
Selecting one model from among the plurality of models based on the result of the stability calculation performed for each of the plurality of models for the short period of time;
Performing the stability calculation on the selected one model for the predetermined reference time;
Based on the result of the stability calculation executed for the predetermined reference time for the one model, generating a control pattern of the controlled generator for the assumed accident,
The system stabilization device is a system stabilization system that performs control to shut off the generator to be controlled according to the control pattern when the assumed accident occurs.