JP2017169360A - Operation continuous control apparatus at time of system disturbance and operation continuous control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation continuous control apparatus at the time of a system disturbance reducing the number of times of unnecessarily putting a generator stabilizer in service.SOLUTION: An operation continuous control apparatus at the time of a system disturbance according to one embodiment comprises: a linkage point voltage measurement device 11 measuring a voltage of a linkage point 3a between an external power transmission system 1 and power station facilities 3; blocking devices 6 and 10 capable of electrically blocking between the external power transmission system 1 and the power station facilities 3; a generator stabilizer 15 balancing mechanical input and electrical output of a generator 7 installed in a power station 3; and an operation continuous control section 13 detecting a disturbance occurring in the external power transmission system 1 by comparing a voltage measurement value of the linkage point 3a measured by the linkage point voltage measurement device 11 and a set voltage set beforehand, and performing control for opening the blocking devices 6 and 10 or putting the generator stabilizer 15 in service when the voltage measurement value or duration time of the disturbance satisfies predetermined conditions.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to an operation continuation control device for a generator and an operation continuation control method thereof when a power system is disturbed.

  In recent years, the transient stability of the power system has been reduced due to the addition of a power supply with low inertia such as solar power generation and wind power generation to the power system. Against this background, in large-capacity steam power plants with high inertia, is reactive power supplied to the power system without being disconnected from the power system even in the event of a one-line, three-phase ground fault, etc. Or, it is becoming a requirement to connect the power system to promptly return the output of active power after the accident is resolved.

  In order to cope with this, power generation companies have introduced a generator stabilization device that is controlled by an operation continuation control device in the event of a system disturbance, as a countermeasure for a step-out of the generator or a countermeasure for recovering the output. The generator stabilizing device is a device that controls the balance between the mechanical input and the electrical output of the generator, such as the braking resistor on / off control or the high-speed valve opening / closing control.

  In general, the operation continuation control device during system disturbance controls the generator stabilization device according to the state of the generator, such as the imbalance between the machine input and the electrical output, or the rotational speed of the generator shaft, In many cases, it is intended to avoid.

  As such an operation continuation control device at the time of system disturbance, there is, for example, a braking resistor control system. This control method detects the rotational speed of a rotating machine, compares the detected rotational speed with a preset rotational speed, outputs the comparison result as binary information, and generates power based on the binary information. This is a method for controlling the opening and closing of the machine stabilizer (braking resistor).

  In addition, other operation continuation control devices detect the signal of the ground fault protection relay of the transmission line, and control the braking resistor that performs the on / off control of the generator stabilization device (braking resistor) by this detection signal There is a method.

JP 58-139647 A Japanese Patent Application Laid-Open No. 60-131035

  By the way, the conventional operation continuation control device at the time of the disturbance of the system described above performs step-out avoidance regardless of the situation of the power system, and therefore generates power even in a situation where it may be disconnected according to the rules and regulations of the power transmission company. The machine stabilizer will be activated. Here, each of the generator stabilizing devices greatly shortens the life of the device each time it is used, so it is necessary to avoid unnecessary operations.

  The problem to be solved by the present embodiment is to provide an operation continuation control device and an operation continuation control method thereof at the time of a system disturbance that can reduce the number of times that a generator stabilizing device is unnecessarily introduced.

  In order to solve the above-mentioned problem, an operation continuation control device during grid disturbance according to the present embodiment includes a connection point voltage measurement device that measures a voltage at a connection point between a power system and a power plant, and the power system. Generated in the power system, a shut-off device that can be electrically shut off from the power plant, a generator stabilization device that balances the mechanical input and electrical output of the generator installed in the power plant, and The detected disturbance is detected by comparing the voltage measurement value of the interconnection point measured by the interconnection point voltage measuring device with a preset voltage, and the duration of the voltage measurement value or the disturbance is constant. An operation continuation control unit that performs control to open the shut-off device or turn on the generator stabilizing device when the above condition is satisfied.

  The operation continuation control method at the time of system disturbance according to the present embodiment is an electrical connection between the power grid and the power plant, and a grid voltage measuring device that measures the voltage at the grid power and the power plant. Operation continuation control for performing operation continuation control at the time of system disturbance, comprising a shutoff device capable of shutting off at a time and a generator stabilization device that balances mechanical input and electrical output of the generator installed in the power plant In this method, the disturbance generated in the power system by the operation continuation control unit is determined by comparing the voltage measurement value of the interconnection point measured by the interconnection point voltage measuring device with a preset set voltage. A disturbance detecting step for detecting, a determination step for determining whether the voltage measurement value or the duration of the disturbance satisfies a certain condition, and the voltage measurement value or the duration of the disturbance being a constant condition. If you meet Serial operation continuation control section is characterized by and a control step of performing control to put the open or the generator stabilizer the blocking device.

  According to this embodiment, it is possible to extend the life of the generator stabilization device by operating the generator stabilization device only when necessary.

It is a single line connection figure which shows the structure of the driving | operation continuation control apparatus at the time of system | strain disturbance of 1st Embodiment. It is a flowchart which shows the control logic of the generator circuit breaker of 1st Embodiment, and a power receiving circuit breaker. It is a wave form diagram which shows the relationship between a regulation voltage and time in 1st Embodiment. It is a wave form diagram which shows the relationship between a regulation voltage and accident continuation time in 1st Embodiment. It is a flowchart which shows the control logic of the generator stabilization apparatus of 1st Embodiment. It is a single line connection figure which shows the structure of the driving | operation continuation control apparatus at the time of system | strain disturbance of 2nd Embodiment. It is a flowchart which shows the control logic of the generator stabilization apparatus of 2nd Embodiment.

  Hereinafter, the operation continuation control apparatus and the operation continuation control method during a system disturbance according to the present embodiment will be described with reference to the drawings.

(First embodiment)
(Constitution)
FIG. 1 is a single-line connection diagram illustrating a configuration of an operation continuation control device during a system disturbance according to the first embodiment.

  As shown in FIG. 1, the primary side of the main transformer 4 of the external power transmission system 1 that is a power system and the power plant facility (power plant) 3 is connected to the connection point 3 a through the external power transmission line 2. The power plant facility 3 includes a main transformer 4, a main generator 7, and a station transformer 8. The secondary side of the main transformer 4 and the main generator 7 are connected by a main circuit phase separation bus 5.

  The main circuit phase separation bus 5 is provided with a generator circuit breaker 6. The main circuit phase separation bus 5 is branched so that the secondary side of the main transformer 4 is connected to the primary side of the in-house transformer 8. The secondary side of the in-house transformer 8 is connected to the in-house power receiving breaker 10 using the in-house phase non-separated bus 9.

  The operation continuation control device at the time of system disturbance of this embodiment includes a generator circuit breaker 6, an in-house power reception breaker 10, an interconnection point voltage measurement device 11, an operation continuation control unit 13, and a generator stabilization device 15. .

  The connection point voltage measuring device 11 is connected to the connection point 3 a of the external power transmission line 2. The connection point voltage measuring device 11 measures the voltage at the connection point 3a. The connection point voltage signal 12 measured by the connection point voltage measuring device 11 is output to the operation continuation control unit 13.

  The operation continuation control unit 13 uses the connection point voltage signal 12 measured by the connection point voltage measuring device 11 to generate a generator circuit breaker control signal 14 and a generator when a system disturbance occurs according to certain conditions described later. The stabilizer control signal 16 or the in-house power receiving breaker control signal 17 is output, and the on / off control of the generator circuit breaker 6, the generator stabilizing device 15, or the in-house power receiving breaker 10 is performed, respectively.

  The operation continuation control unit 13 is constituted by a microcomputer including resources such as a CPU (Central Processing Unit), a storage device, and an input / output device, for example.

(Work)
Next, the operation of this embodiment will be described.

  FIG. 2 is a flowchart showing the control logic of the generator circuit breaker and the in-house power receiving breaker of the first embodiment. FIG. 3 is a waveform diagram showing the relationship between the specified voltage and time in the first embodiment. FIG. 4 is a waveform diagram showing the relationship between the specified voltage and the accident duration in the first embodiment. 2 is repeatedly executed after the operation continuation control unit 13 is activated.

  As shown in FIG. 2, the operation continuation control unit 13 first determines whether the connection point voltage signal 12 is smaller than a preset connection point voltage set value (step S101).

  Next, when the power transmission rule or the like describes the operation continuation request with the connection point voltage and the time history from the occurrence of the accident as the above-mentioned constant condition, it falls below the connection point voltage set value (step S101; Yes) ), The process proceeds to step S102.

  In this step S102, the operation continuation control unit 13 creates a curve C1 indicating the relationship between the prescribed voltage for power plant disassembly shown in FIG. And determine whether the system voltage is lower than the curve C1. Here, the power transmission rule is also referred to as a grid code and is a rule defined by the power transmission company and requested from the power generation company by the power transmission company.

  When it falls below the curve C1 indicating the relationship between the prescribed voltage for power plant disconnection and time at a certain time (step S102; Yes), the operation continuation control unit 13 sets the generator circuit breaker control signal 14 to At the same time, the in-house power receiving breaker control signal 17 is output (step S105). As a result, the generator circuit breaker 6 is opened, and the in-house power receiving breaker 10 is opened, thereby disconnecting the in-plant facility 3 from the external power transmission system 1.

  On the other hand, if the power transmission rule or the like describes the operation continuation request with the interconnection point voltage and the accident duration as the above-mentioned constant condition, the step is performed when the value is lower than the interconnection point voltage set value (step S101; Yes). The process proceeds to S103. In step S <b> 103, the operation continuation control unit 13 performs an accident average voltage calculation using the interconnection point voltage signal 12.

  Then, for example, the accident time is defined by using a curve C2 that shows the relationship between the predetermined voltage for power plant disconnection and the accident duration shown in FIG. It is determined whether or not the waveform is longer than the waveform indicating the relationship between the voltage and the accident duration (step S104).

  When the voltage falls below the curve C2 indicating the relationship between the specified voltage for power plant disconnection and the accident duration at a certain time (step S104; YES), the generator circuit breaker control signal 14 is output and The power receiving breaker control signal 17 is output (step S105). As a result, the generator circuit breaker 6 is opened, and the in-house power receiving breaker 10 is opened, thereby disconnecting the in-plant facility 3 from the external power transmission system 1.

  In addition, when it is not lower than the connection point voltage set value in step S101 (step S101; No), it is not lower than the curve C1 indicating the relationship between the power plant disconnecting voltage and the time at a certain time in step S102. (Step S102; No), and when it does not fall below the curve C2 indicating the relationship between the power plant disconnection voltage and the accident duration at a certain time (Step S104; No), the process ends.

  FIG. 5 is a flowchart showing the control logic of the generator stabilizing device of the first embodiment. In the processing of the flowchart shown in FIG. 5, the same processing as the processing of the flowchart shown in FIG. 2 will be described using the same step number. Further, each process shown in FIG. 5 is repeatedly executed after the operation continuation control unit 13 is activated, similarly to the process of the flowchart shown in FIG.

  The flow chart shown in FIG. 5 is divided into control for immediately turning on the generator stabilizing device 15 and control for turning on after waiting time. The control for immediately turning on the generator stabilizing device 15 uses the connection point voltage signal 12 constantly measured by the connection point voltage measuring device 11, and the operation continuation control unit 13 uses the voltage as a preset voltage. A comparison is made to determine whether immediate input is necessary (step S201). Here, the preset voltage is a preset voltage value calculated in advance by analysis.

  When immediate input is necessary (step S201; Yes), the operation continuation control unit 13 outputs the generator stabilization device control signal 16 to the generator stabilization device 15 and inputs the generator stabilization device 15. . In addition, a process is complete | finished when immediate input is unnecessary in step S201 (step S201; No).

  On the other hand, the control to be applied after waiting time is determined by the interconnection point voltage signal 12 to determine whether the interconnection point voltage signal is smaller than a preset interconnection point voltage set value (step S101).

  Measured from the time when the set point voltage falls below the set value (step S101; Yes) and then falls below the set value, and the linked point voltage up to that point after a predetermined time with reference to the system fault removal time, etc. The signal 12 is used to compare the voltage with a preset voltage, and it is determined whether delay input is necessary (step S202).

  When the delay input is necessary (step S202; Yes), the operation continuation control unit 13 outputs the generator stabilization device control signal 16 to the generator stabilization device 15 and turns on the generator stabilization device 15. .

  If it is determined in step S101 that it is not lower than the connection point voltage set value (step S101; No), or if delay input is not required in step S202 (step S202; No), the process ends.

  Therefore, in the present embodiment, when an electrical accident occurs in the external power transmission system 1, the effect of this is to change the voltage of the interconnection point 3 a electrically connected through the external power transmission line 2, and Influence.

  When the voltage at the interconnection point 3a decreases, the electrical output sent from the power plant equipment 3 through the external transmission line 2 to the external power transmission system 1 decreases, the load on the main generator 7 decreases rapidly, and the main generator 7 becomes unbalanced with the machine input to 7, so the main generator 7 accelerates.

  Moreover, when the voltage of the connection point 3a falls, the connection point voltage signal 12 measured by the connection point voltage measuring device 11 falls. The operation continuation control unit 13 determines whether or not the interconnection point voltage signal 12 is smaller than a preset set value as shown in FIG. When the interconnection point voltage signal 12 falls below the set value, it is determined whether the voltage shown in FIG. 3 is lower than the waveform C1 indicating the relationship between the specified voltage and time.

  When the interconnection point voltage signal 12 falls below the set value, the operation continuation control unit 13 executes the average voltage calculation during the accident, and the accident time shown in FIG. It is determined whether the waveform is longer than the waveform C2 indicating the relationship.

  When the waveform C1 indicating the relationship between the voltage and the time created in advance by adding the design margin or the like to the power transmission rule or the like, or the waveform C2 indicating the relationship between the voltage and the accident duration, the operation continuation control is performed. The unit 13 outputs a generator circuit breaker control signal 14 and an in-house power receiving breaker control signal 17. As a result, the power plant equipment 3 is disconnected from the external power transmission system 1 and the influence of the electrical accident is removed.

  Further, as shown in FIG. 5, when the voltage at the interconnection point 3a decreases by a certain level or more, the voltage is compared with a preset voltage to determine whether immediate application is necessary. In addition, the voltage is compared with a preset voltage, and it is determined whether delay input is necessary. In the case of a voltage drop that is determined to require immediate application or delayed application compared to the preset voltage, the generator stabilization device control signal 16 is output. As a result, the generator stabilizing device 15 is turned on to balance the mechanical input to the main generator 7 and the electric output, and the acceleration of the main generator 7 is suppressed.

(Effect)
As described above, according to the present embodiment, when a voltage drop occurs in the external power transmission system 1 due to a power transmission line accident or the like, it is possible to take a minimum measure according to the power transmission rules and the like. Therefore, the generator stabilizing device 15 can be operated only when necessary, and the generator circuit breaker 6 and the in-house power receiving breaker 10 can be operated when they can be disconnected. As a result, the life of the generator stabilizing device 15 can be extended.

  Most transmission line accidents have a high residual voltage, and are accidents with a short accident duration in which the failure point is separated by a protective relay and breaker provided in the transmission system. In such an accident, it becomes possible to forego the introduction of the generator stabilizing device 15.

(Second Embodiment)
Next, the operation continuation control apparatus at the time of system disturbance according to the second embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the structure same as the said 1st Embodiment, and the overlapping description is abbreviate | omitted.

(Constitution)
FIG. 6 is a single-line connection diagram illustrating the configuration of the operation continuation control device during system disturbance according to the second embodiment.

  In the second embodiment, the connection point voltage measurement device 11 of the first embodiment is used as the connection point voltage and active power measurement device 20, and the connection point voltage signal 12 is used as the connection point voltage signal and active power signal 21. Replaced.

  Specifically, the connection point voltage and active power measuring device 20 is connected to the connection point 3 a of the external power transmission line 2. The interconnection point voltage and active power measuring device 20 measures the voltage and active power at the interconnection point 3a. The connection point voltage signal and active power signal 21 measured by the connection point voltage and active power measuring device 20 are output to the operation continuation control unit 13.

  In the second embodiment, a reactive power measuring device 18 is provided between the generator circuit breaker 6 and the main generator 7, and a circuit that outputs a reactive power signal 19 from the reactive power measuring device 18 to the operation continuation control unit 13. Is added.

  Specifically, the reactive power measuring device 18 measures the reactive power output from the main generator 7. The reactive power signal 19 measured by the reactive power measuring device 18 is output to the operation continuation control unit 13.

(Work)
FIG. 7 is a flowchart showing the control logic of the generator stabilizing device of the second embodiment. In the processing of the flowchart shown in FIG. 7, the same processing as the processing of the flowchart shown in FIGS. 2 and 5 will be described using the same step number. Further, each process shown in FIG. 7 is repeatedly executed after the operation continuation control unit 13 is activated, similarly to the processes of the flowcharts shown in FIGS. 2 and 5.

  FIG. 7 is obtained by adding the active power and reactive power determination processing to the flowchart shown in FIG. The flowchart shown in FIG. 7 is divided into control that immediately turns on the generator stabilization device 15 and control that turns on after waiting for a standby time, as in the flowchart shown in FIG.

  In the control for immediately turning on the generator stabilizing device 15, the active power, the reactive power, and the voltage are compared with the preset voltage, and it is determined whether immediate turning on is necessary (step S301).

  Is the control for delaying the generator stabilizing device 15 after the connection point voltage set value lower than the set value (step S101; Yes), comparing the active power, reactive power, and voltage with the preset voltage, and whether delay input is required? Is determined (step S302).

  Therefore, in the present embodiment, whether or not the generator stabilization device 15 is input differs depending on the active power sent to the external power transmission system 1 immediately before the accident and the reactive power output from the generator 7.

(Effect)
As described above, according to the present embodiment, when the active power value sent to the external power transmission system 1 immediately before the accident is small, or when the advance of the reactive power output from the generator 7 is small or delayed. Therefore, it is not necessary to turn on the generator stabilizing device 15, so that a region where the generator stabilizing device 15 is not needed is widened. That is, by adding active power and reactive power to the determination process, the number of times the generator stabilizing device 15 is turned on can be further reduced, and the life of the generator stabilizing device 15 can be extended.

(Other embodiments)
Although the embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope of the present invention and the gist thereof, and are also included in the invention described in the claims and the equivalent scope thereof.

  DESCRIPTION OF SYMBOLS 1 ... External power transmission system (electric power system), 2 ... External power transmission line, 3 ... Facility in power plant (power plant), 3a ... Connection point, 4 ... Main transformer, 5 ... Main circuit phase separation bus, 6 ... Power generation Circuit breaker (breaker), 7 ... Main generator (generator), 8 ... Internal transformer, 9 ... Internal phase non-separated bus, 10 ... In-house power incoming breaker (breaker), 11 ... Interconnection point voltage Measuring device, 12 ... Link point voltage signal, 13 ... Operation continuation control unit, 14 ... Generator circuit breaker control signal, 15 ... Generator stabilizer, 16 ... Generator stabilizer control signal, 17 ... In-house power reception Breaker control signal, 18 ... reactive power measuring device, 19 ... reactive power signal, 20 ... linkage point voltage and active power measurement device, 21 ... linkage point voltage signal and active power signal

Claims (5)

A connection point voltage measuring device that measures the voltage at the connection point between the power system and the power plant;
A disconnecting device capable of electrically disconnecting between the power system and the power plant;
A generator stabilization device that balances mechanical input and electrical output of a generator installed in the power plant;
A disturbance generated in the power system is detected by comparing a voltage measurement value of the interconnection point measured by the interconnection point voltage measuring device with a preset set voltage, and the voltage measurement value or the disturbance is detected. An operation continuation control unit that performs control to open the shut-off device or to turn on the generator stabilization device when the continuous time of a certain condition is satisfied,
An operation continuation control device in the event of a system disturbance.   2. The operation continuation control device at the time of system disturbance according to claim 1, wherein the constant condition of the operation continuation control unit is determined according to an operation continuation request for a power system fault determined by a power transmission company of the power system. .   The operation continuation control unit compares the voltage measurement value of the interconnection point with a preset voltage calculated by analysis in advance, and determines whether the generator stabilization device needs to be turned on immediately or delayed. The operation continuation control device according to claim 1, wherein the operation continuation control device is disturbed.   The operation continuation control unit uses the active power value sent from the power plant to the power system immediately before the disturbance and the reactive power value sent from the generator as the constant condition. Item 4. The operation continuation control device according to any one of Items 1 to 3 when the system is disturbed. A connection point voltage measuring device that measures the voltage at the connection point between the power system and the power plant, a shut-off device that can be electrically disconnected between the power system and the power plant, and installed in the power plant A generator stabilization device that balances mechanical input and electrical output of the generator, and an operation continuation control method for performing operation continuation control at the time of system disturbance,
A disturbance detection step in which the operation continuation control unit detects a disturbance generated in the power system by comparing a voltage measurement value of the interconnection point measured by the interconnection point voltage measurement device with a preset voltage. When,
A step of determining whether the operation continuation control unit satisfies a certain condition for the voltage measurement value or the duration of the disturbance;
A control step of performing control to open the shut-off device or turn on the generator stabilization device when the voltage measurement value or the duration of the disturbance satisfies a certain condition;
The operation continuation control method at the time of system disturbance characterized by having.

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