JP2009060764A - Controller and control method of electric power system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an overload that occurs with electric power facilities without causing a supply trouble at the time when a route interruption failure or the like occurs in the electric power system having a loop structure. <P>SOLUTION: A controller of an electric power system includes first and second power routes 41 that supply electric power from a generator to loads and with a third power route 42 that connects these routes. A circuit breaker 52 provided on the third power route 42 is usually operated in an opened state (an interruption state). In this controller, when a circuit breaker 51 provided on the first power route 41 is opened (interrupted) by a failure that occurs in the first power route 41, the circuit breaker 52 provided on the third electric route 42 is thrown (closed). Also, the circuit breaker 52 provided on the third power route is thrown within a prescribed period of time after the circuit breaker 51 provided on the first power route 41 is interrupted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device and a control method for an electric power system, and more particularly to a technique for preventing an electric power facility from being overloaded without causing a supply failure when an accident occurs.

  In a power system having a power path with a loop structure, power facilities such as power transmission lines and transformers constituting the power system may be overloaded when an accident such as a route break occurs. For example, in the power system 1 illustrated in FIG. 4A, there are two transformers 71 and 72 on the path connecting the generator 2, the load 31, and the load 32, but the power path connecting the node bc is disconnected. As shown in FIG. 4B, the transformer 72 may be overloaded.

Here, in order to prevent the overload, there is a method of installing a system stabilizing device (SSC: System Stabilizing Controller) (see, for example, Patent Document 1). However, in this case, it is necessary to prevent the supply from being disturbed. (For example, refer to Patent Document 2).
JP 9-182319 A JP-A-7-107656

  When the above system stabilizing device is used, since it is necessary to capture a tidal current in a power facility such as a transmission line or a transformer, the facility becomes large-scale, and installation costs and operation costs increase. Further, in the conventional method using the system stabilizing device, the power path leading to the load and the generator is interrupted when an accident occurs, which causes a supply trouble.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a control device and a control method for an electric power system capable of preventing a supply failure when an accident such as a loop break occurs.

  The invention described in claim 1 for achieving the above object includes a first and a second power path for supplying power from a generator to a load, and a first power path for connecting the first and second power paths. 3 is a power system control device that is operated in a normally disconnected state with a circuit breaker provided in the third power path, and due to an accident that occurred in the first power path, When the circuit breaker provided in the first power path is interrupted, the circuit breaker provided in the third power path is turned on.

  The invention according to claim 2 of the present invention is the power system control device according to claim 1, and is provided in the first power path due to an accident occurring in the first power path. The circuit breaker provided in the third power path is turned on within a predetermined time after the circuit breaker provided in the first power path is turned off when the circuit breaker is shut off. And

  According to a third aspect of the present invention, there is provided a first power path for supplying power from a generator to a load, and a third power path connecting the first power path and the second power path. A power system control method comprising a power path, wherein the circuit breaker provided in the third power path is normally operated in a cut-off state, and the first power path causes an accident caused by the accident When the circuit breaker provided in one power path is interrupted, the circuit breaker provided in the third power path is turned on.

  According to a fourth aspect of the present invention, the power system control method according to the third aspect is provided in the first power path due to an accident occurring in the first power path. The circuit breaker provided in the third power path is turned on within a predetermined time after the circuit breaker provided in the first power path is turned off when the circuit breaker is shut off. And

  According to the present invention, it is possible to prevent a supply failure when an accident such as a loop break occurs.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1A shows a schematic configuration of a power system 1 described as an embodiment of the present invention. As shown in the figure, the power system 1 is composed of a generator 2 that is a power supply source and power equipment such as a transmission line, and a power path 4 that guides the power supplied from the generator 2 to loads 31 and 32. And a transformer 71 provided on a path connecting the nodes cd and a transformer 72 provided on a path connecting the nodes fg. In addition, power is supplied from the generator 7 to the node c.

  As shown in the figure, the electric power system 1 includes a loop structure. For example, the path connecting the generator 2 and the load 31 includes two paths: a path passing through the node abcd (first power path) and a path passing through the node aefghid (second power path). There are two routes connecting the load 2 and the load 32, a route passing through the node abcdihg and a route passing through the node aefg.

  Of the paths constituting the power path, a path connecting the nodes bc (hereinafter, this path is referred to as A line 41) is provided with a first circuit breaker 51. A second circuit breaker 52 is provided on a path connecting the nodes cjkf (hereinafter, this path is referred to as a B line 42 (third power path)). The B line 42 is an auxiliary route that is temporarily used during work or test operation. For this reason, the 2nd circuit breaker 52 is normally open | released (break | disconnection), and the B line 42 is not energized. If the A line 41 and the B line 42 are energized at the same time, the short-circuit capacity increases and exceeds the rated breaking capacity, and the induction voltage to the communication line under the line may exceed the allowable value due to the increase in the one-line ground fault current. There is.

  Opening / closing control (breaking / closing) of the first circuit breaker 51 and the second circuit breaker 52 is performed by the control unit 6 (control device) that is communicably connected thereto. FIG. 2 shows the configuration of the control unit 6. As shown in the figure, the control unit 6 includes an A-line relay panel 61, an A-line route break determination panel 62, and a B-line relay panel 63. The A-line relay panel 61 includes a ratio differential relay 611 (87 relay) that controls opening and closing of the first circuit breaker 51. The A-line route break determination panel 62 relays a signal (hereinafter referred to as an accident notification signal) indicating whether or not an accident has occurred in the A-line 41 in accordance with the trip signal input from the ratio differential relay 611. The determination circuit 621 is input to the circuit 631. The B-line relay panel 63 has a relay circuit 631 that turns on the second circuit breaker 52 when an accident notification signal indicating that an accident has occurred in the A-line 41 is input from the determination circuit 621.

  Next, specific control of the first circuit breaker 51 and the second circuit breaker 52 performed by the control unit 6 when an accident such as a route break occurs in the A line 41 will be described together with the timing chart shown in FIG. To do.

  First, when an accident such as a route interruption occurs in the A line 41 and a large accident current flows (t1), the ratio differential relay 611 is turned on (t2), and a trip signal is output from the ratio differential relay 611 (t3). ). Subsequently, the first circuit breaker 51 is opened (t4) (cutoff state), and the power supply path (A line 41) connecting the nodes bc is cut off. When a trip signal is input from the ratio differential relay 611, the determination circuit 621 outputs an accident notification signal indicating that an accident has occurred in the relay circuit 631 (t3). When receiving the accident notification signal from the determination circuit 621, the relay circuit 631 turns on (closes) the second circuit breaker 52 (t5).

  Here, if the time (t4 → t5) from when the first circuit breaker 51 is opened to when the second circuit breaker 52 is turned on is long, the phase angle (phase difference angle) at both ends of the second circuit breaker 52 is increased. When the second circuit breaker 52 is turned on, a large torque may be applied to the shaft of the generator 7 that supplies power to the node c when the second circuit breaker 52 is turned on, causing the generator 7 to break. For this reason, the time (t4 → t5) from when the first circuit breaker 51 is opened until the second circuit breaker 52 is turned on is the time (t4 → t5) until the phase difference angle has an adverse effect on the generator 7 ( Hereinafter, it is preferably referred to as a predetermined time.

  Therefore, in the present embodiment, as shown in FIG. 3, the accident notification signal is input from the determination circuit 621 to the relay circuit 631 at the same time when the trip signal is output from the ratio differential relay 611 (t3), thereby The circuit breaker 52 is turned on as soon as possible (t5) to suppress the influence on the generator 7. Specifically, the predetermined time, that is, the time (t4 → t5) from when the first circuit breaker 51 is opened until the second circuit breaker 52 is turned on is set to 100 ms or less.

  FIG. 1B shows a state of power supply in the power system 1 after the second circuit breaker 52 is inserted. During the period from t4 to t5, the load 32 is supplied with electric power from the generator 2 through the node aefg, and the load 31 is supplied from the generator 2 through the node aefghi. For this reason, supply trouble does not arise in the load 31 during the period from t4 to t5 when both the first circuit breaker 51 and the second circuit breaker 52 are open.

  Thus, according to the present embodiment, there is no supply trouble to the load when an accident such as a loop break occurs. Moreover, since the time (t4 → t5) from when the first circuit breaker 51 is opened to when the second circuit breaker 52 is turned on is short, the influence on the generator 7 due to the switching of the path can be suppressed. In addition, since the above mechanism is a simple mechanism in which the control unit 6 controls the first circuit breaker 51 and the second circuit breaker 52, it can be implemented easily and inexpensively.

  The above description of the embodiment is for facilitating the understanding of the present invention, and does not limit the present invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

It is a structure of the electric power grid | system 1 demonstrated as one Embodiment of this invention, and is a figure which shows a normal operation state. It is a structure of the electric power grid | system 1 demonstrated as one Embodiment of this invention, and is a figure which shows the operation state at the time of accident occurrence. It is a figure which shows the structure of the control part 6 demonstrated as one Embodiment of this invention. It is a timing chart explaining the specific control of the 1st circuit breaker 51 and the 2nd circuit breaker 52 by the control part 6 demonstrated as one Embodiment of this invention. It is an example of the electric power grid | system 1, and is a figure which shows a normal operation state. It is an example of the electric power grid | system 1, and is a figure which shows the operation state at the time of accident occurrence.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric power system 2 Generator 31 Load 32 Load 4 Electric power path 41 A line 42 B line 51 1st circuit breaker 52 2nd circuit breaker 6 Control part 61 A line relay panel 611 Ratio differential relay 62 A line route break determination Panel 621 Judgment circuit 63 B-line relay panel 631 Relay circuit 7 Generator

Claims (4)

A first power path and a second power path for supplying power from the generator to the load, and a third power path for connecting the first power path and the second power path are provided. The third power path is provided in the third power path. A power system control device that is normally operated as a circuit breaker,
The circuit breaker provided in the third power path is turned on when the circuit breaker provided in the first power path is interrupted due to an accident occurring in the first power path. Power system control device. A power system control device according to claim 1,
The closing of the circuit breaker provided in the third power path, which is performed when the circuit breaker provided in the first power path is interrupted due to an accident occurring in the first power path, A power system control device, wherein the control is performed within a predetermined time after the circuit breaker provided in one power path is cut off. A first power path and a second power path for supplying power from the generator to the load, and a third power path for connecting the first power path and the second power path are provided. The third power path is provided in the third power path. A power system control method that operates the circuit breaker in a normally disconnected state,
The circuit breaker provided in the third power path is turned on when the circuit breaker provided in the first power path is interrupted due to an accident occurring in the first power path. To control the power system. It is a control method of the electric power system according to claim 3,
The closing of the circuit breaker provided in the third power path, which is performed when the circuit breaker provided in the first power path is interrupted due to an accident occurring in the first power path, A method for controlling an electric power system, which is performed within a predetermined time after a circuit breaker provided in one electric power path is interrupted.

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