Power Systems and Control Devices

Abstract

To provide a power system with a high reliability.SOLUTION: A power system 100 comprises a synchronous phase modifier 11 that has an armature coil 11a electrically connected with a utility grid P1, and a field coil 11b functioning as an excitation circuit. At a normal time of the utility grid P1, a power is supplied from the utility grid P1 to the field coil 11b. At an abnormal time of the utility grid P1, a supply source of the power to the field coil 11b is switched from the utility grid P1 to the utility grid P2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power system and control device Regarding. [Background technology]

[0002] Regarding the excitation of a synchronous machine, for example, there is known a technology described in Patent Document 1. That is, Patent Document 1 describes that "the charging voltage is determined so that the field current reaches a predetermined value required for the initial excitation after a predetermined time has elapsed since the start of the initial excitation at a predetermined rotation speed." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-147214 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, if a fault such as a ground fault occurs in the power system that supplies power to the synchronous machine, the voltage of the power system drops. Note that for a while after the fault occurs in the power system, the voltage of the power system is maintained at a predetermined level by the induced electromotive force of the synchronous machine, but thereafter the voltage of the power system drops, and accordingly the voltage of the field winding (excitation circuit) of the synchronous machine also drops.

[0005] As a result, for example, when a synchronous machine functions as a phase modifier, if a problem occurs in the power grid from which the synchronous machine supplies power, the reactive power adjustment capability of the synchronous machine decreases. Therefore, it is desirable to further improve the reliability of power supply via the power grid, but Patent Document 1 does not describe such a technology.

[0006] Therefore, the present invention provides a highly reliable power system. etc. The objective is to provide the following. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, The power system according to the present invention includes a synchronous phase modifier having an armature winding electrically connected to a first power system and a field winding functioning as an excitation circuit, and when the first power system is in a normal state, power is supplied from the first power system to the excitation circuit, and when the second power system is in a normal state, power is supplied from the second power system to the excitation circuit. Orthodox When an abnormality occurs in the first power system, the source of power supply to the excitation circuit is the second power system. Unification It is configured to be a first power converter that converts AC power supplied from the first power system into DC power and outputs the converted DC power to the excitation circuit; a second power converter that converts AC power supplied from the second power system into DC power and outputs the converted DC power to the excitation circuit; and a control device that controls the first power converter and the second power converter, wherein the control device drives the first power converter and the second power converter so that voltages on the output sides of the first power converter and the second power converter are equal when the first power system is normal, and continues driving at least the second power converter when the first power system is abnormal. It is characterized by: Other details will be explained in the embodiments. Effect of the Invention

[0009] According to the present invention, a highly reliable power system etc. can be provided. [Brief description of the drawings]

[0010] [Figure 1] 1 is a configuration diagram of a power system according to a first embodiment. [Diagram 2] FIG. 11 is a configuration diagram of a power system according to a second embodiment. [Diagram 3] FIG. 11 is a configuration diagram of a power system according to a third embodiment. [Figure 4] FIG. 11 is a configuration diagram of a power system according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First Embodiment <Power system configuration> FIG. 1 is a configuration diagram of a power system 100 according to the first embodiment. In FIG. 1, power lines are shown by solid lines, while signal lines are shown by dashed lines. Moreover, the first embodiment is a reference embodiment. 1 is a system that adjusts reactive power of a power system P1 (first power system) that is a main system by a synchronous phase modifier 11. The power system 100 also has a function of switching the source of power supply to the field winding 11b (excitation circuit) of the synchronous phase modifier 11 from the power system P1 to a power system P2 (second power system) when a ground fault or the like occurs in the power system P1.

[0012] The power systems P1 and P2 are facilities that transmit and distribute electric power (three-phase AC power) generated by a predetermined power generation facility (not shown) to the consumer side. Even if an abnormality such as a ground fault occurs in the power system P1, it is assumed that the other power system P2 is hardly affected.

[0013] As shown in FIG. 1, the power system 100 includes a synchronous phase modifier 11 and the like. The synchronous phase modifier 11 is a synchronous motor that is driven without load, and has a function of adjusting reactive power of a power system P1. As shown in FIG. 1, the synchronous phase modifier 11 includes an armature winding 11a and a field winding 11b. The armature winding 11a is a winding wound around a stator core (not shown), and is electrically connected to the power system P1 via a transformer 12. Note that, in the example of FIG. 1, the armature winding 11a is not particularly connected to another power system P2.

[0014] The field winding 11b functions as an excitation circuit of the synchronous phase modifier 11, and is wound around a field core (not shown). The field winding 11b (excitation circuit) is connected to an electric power system P1 (first electric power system) via a circuit breaker 14 (first circuit breaker) and the like, and is also connected to an electric power system P2 (second electric power system) via another circuit breaker 23 (second circuit breaker) and the like.

[0015] When a predetermined excitation current (DC current) flows through the field winding 11b, a rotor (not shown) including the field winding 11b and a field core (not shown) rotates, and a predetermined AC voltage is generated in the armature winding 11a. Note that a configuration in which a predetermined brush (not shown) is in sliding contact with a slip ring (not shown) that rotates integrally with the rotor of the synchronous phase modifier 11 may also be used.

[0016] For example, when the field of the synchronous phase modifier 11 is overexcited, the field winding 11b functions as a capacitor that absorbs a leading-phase current from the power system P1. On the other hand, when the field of the synchronous phase modifier 11 is underexcited, the field winding 11b functions as a reactor that absorbs a lagging-phase current from the power system P1. The field of the synchronous phase modifier 11 and the like are adjusted by a control device 30, which will be described later.

[0017] Also, a predetermined DC circuit (not shown) may be provided for initial excitation of the field winding 11b of the synchronous phase modifier 11. Then, after starting the synchronous phase modifier 11 using the DC circuit for initial excitation, the power supply panel 15 may close the circuit breaker 14 near the rated operation, and power for excitation may be supplied from the power system P1 to the field winding 11b.

[0018] The power system 100 shown in FIG. 1 includes a transformer 12, an excitation transformer 13, a circuit breaker 14 (first circuit breaker), a power supply panel 15, and a power converter 16 as components used to supply power from a power system P1, which is a main system, to a synchronous phase modifier 11. The transformer 12 is a device that adjusts the level of the AC voltage between the power system P1 and the synchronous phase modifier 11. A primary side of the transformer 12 is connected to the power system P1, while a secondary side of the transformer 12 is connected to the armature winding 11a of the synchronous phase modifier 11.

[0019] The excitation transformer 13 is a device that adjusts the level of the AC voltage between the AC side of the power converter 16 and the transformer 12. The primary side of the excitation transformer 13 is connected to the secondary side of the transformer 12, while the secondary side of the excitation transformer 13 is connected to the circuit breaker 14. The circuit breaker 14 switches between connection and disconnection between the power system P1 and the field winding 11b (excitation circuit). For example, when electrically connecting the power system P1 and the field winding 11b, the circuit breaker 14 is closed. On the other hand, when electrically disconnecting the power system P1 and the field winding 11b, the circuit breaker 14 is opened.

[0020] The power supply panel 15 opens and closes the circuit breakers 14 and 23 based on a signal from the control device 30. As shown in Fig. 1, the power supply panel 15 is connected to an electric power system P1 via the circuit breaker 14 and the like, and is also connected to an electric power system P2 via another circuit breaker 23 and the like. The power supply panel 15 is also connected to the field winding 11b via a power converter 16, which will be described next.

[0021] The power converter 16 is a device that converts an AC voltage applied to itself via the circuit breaker 14 or the like into a predetermined DC voltage. For example, a thyristor rectifier is used as this power converter 16. The AC side of the power converter 16 is connected to the power supply panel 15, while the DC side is connected to the field winding 11b (excitation circuit). When a predetermined DC current flows through the field winding 11b, the synchronous phase modifier 11 is excited.

[0022] The power system 100 also includes a transformer 21, an excitation transformer 22, and a circuit breaker 23 (second circuit breaker) as components used to supply power from the power system P2, which is a backup system, to the field winding 11b of the synchronous phase modifier 11. The transformer 21 is a device that adjusts the level of the AC voltage when the power system P2 is used as an excitation power source for the synchronous phase modifier 11. The primary side of the transformer 21 is connected to the power system P2, while the secondary side of the transformer 21 is connected to the primary side of the excitation transformer 22.

[0023] The excitation transformer 22 is a device that adjusts the level of the AC voltage between the AC side of the power converter 16 and the transformer 21. The primary side of the excitation transformer 22 is connected to the secondary side of the transformer 21, while the secondary side of the excitation transformer 22 is connected to the circuit breaker 23. The circuit breaker 23 switches between connection and disconnection between the power system P2 and the field winding 11b (excitation circuit). For example, when electrically connecting the power system P2 and the field winding 11b, the circuit breaker 23 is closed. On the other hand, when electrically disconnecting the power system P2 and the field winding 11b, the circuit breaker 23 is opened.

[0024] In addition to the above-mentioned components, the power system 100 also includes a control device 30. Although not shown, the control device 30 is configured to include electronic circuits such as a central processing unit (CPU), read only memory (ROM), random access memory (RAM), and various interfaces. A program stored in the ROM is read out and expanded in the RAM, and the CPU executes various processes.

[0025] The control device 30 has a function of outputting a predetermined gate signal to the power converter 16 (e.g., a thyristor rectifier) ​​based on the status of the power system P1 and adjusting the excitation of the synchronous phase modifier 11. In addition, the control device 30 determines whether the voltage (effective value) of the power system P1 has dropped below a predetermined value based on, for example, a detected value of the voltage of the power system P1, and outputs a predetermined signal corresponding to the determination result to the power supply panel 15.

[0026] Next, the operation of the power system 100 when the power system P1 is normal or abnormal will be described. For example, when it is determined that the power system P1 is normal based on the detected value of the voltage of the power system P1, the control device 30 outputs a predetermined signal indicating that the power system P1 is normal to the power supply panel 15. Based on this signal, the power supply panel 15 maintains the circuit breaker 14 in an on state, while maintaining the other circuit breaker 23 in an open state. As a result, power is supplied from the power system P1 to the field winding 11b (excitation circuit) of the synchronous phase modifier 11 via the transformer 12, the excitation transformer 13, the circuit breaker 14, the power supply panel 15, and the power converter 16 in this order. As a result, the reactive power of the power system P1 is adjusted to a predetermined value by the synchronous phase modifier 11.

[0027] In this way, when the power system P1 (first power system) is operating normally, the circuit breaker 14 (first circuit breaker) is in a closed state, while the other circuit breaker 23 (second circuit breaker) is in an open state, and power is supplied from the power system P1 to the field winding 11b (excitation circuit).

[0028] On the other hand, when it is determined that an abnormality has occurred in the power system P1 based on the detected value of the voltage of the power system P1, the control device 30 outputs a predetermined signal indicating that the power system P1 is abnormal to the power source panel 15. Note that abnormalities in the power system P1 include a ground fault, a disconnection, a short circuit, an open phase, and the like.

[0029] When an abnormality occurs in the power system P1, if the power supply source to the field winding 11b (excitation circuit) remains the power system P1, the reactive power of the power system P1 continues to be adjusted for a while by the induced electromotive force caused by the inertia of the synchronous phase modifier 11. However, when the voltage of the power system P1 drops, the DC voltage applied to the field winding 11b also drops, and the ability of the synchronous phase modifier 11 to adjust the reactive power also drops.

[0030] Therefore, in the first embodiment, when an abnormality occurs in the power system P1 (first power system), the power supply panel 15 opens the circuit breaker 14 (first circuit breaker) while closing the other circuit breaker 23 (second circuit breaker). In other words, the power system 100 is configured such that when an abnormality occurs in the power system P1, the source of power supply to the field winding 11b (excitation circuit) of the synchronous phase modifier 11 is switched from the power system P1 (first power system) to the power system P2 (second power system).

[0031] More specifically, when a signal indicating an abnormality in power system P1 is received from control device 30, power supply panel 15 opens circuit breaker 14 on the power system P1 side and then closes circuit breaker 23 on the power system P2 side. By thus eliminating the time during which both circuit breakers 14, 23 are closed, it is possible to prevent voltages of different phases from being applied to power converter 16 simultaneously.

[0032] After the circuit breaker 14 is opened, the time during which both of the two circuit breakers 14, 23 are open is relatively short in the process of closing the other circuit breaker 23. Even if the voltage applied to the field winding 11b (excitation circuit) of the synchronous phase modifier 11 temporarily drops during this time, the induced electromotive force caused by the inertia of the synchronous phase modifier 11 maintains a predetermined reactive power adjustment capability. After the circuit breaker 23 is closed, a predetermined DC voltage is applied to the field winding 11b from the power system P2 via the power converter 16 and the like. As a result, the excitation voltage of the synchronous phase modifier 11 is maintained high, so that the reactive power in the power system P1 can be appropriately adjusted.

[0033] <Effects> According to the first embodiment, in a configuration in which power is supplied from the power system P1 to the field winding 11b (excitation circuit) of the synchronous phase modifier 11, if an abnormality occurs in the power system P1, the source of power supply to the field winding 11b is switched from the power system P1 to the power system P2. This maintains a predetermined excitation voltage of the synchronous phase modifier 11, so that the reactive power adjustment capability of the synchronous phase modifier 11 can be fully utilized even after the voltage of the power system P1 drops. As a result, the synchronous phase modifier 11 appropriately adjusts the reactive power of the power system P1, so that the reliability of the power system 100 can be improved.

[0034] Also, for example, it is possible to effectively utilize power supply equipment and reduce equipment costs by using a generator of a nuclear power plant or the like as the synchronous phase modifier 11. Furthermore, the adjustment of reactive power using the synchronous phase modifier 11 can also be applied to the transmission and distribution of power generated by renewable energy, thereby contributing to society.

[0035] Second Embodiment The second embodiment differs from the first embodiment in that a circuit breaker or power panel for switching the source of power supply to the field winding 11b (excitation circuit) of the synchronous phase modifier 11 (see FIG. 2) is not particularly provided. The second embodiment also differs from the first embodiment in that a large-capacity storage battery 41 (see FIG. 2) is used as a backup power source for supplying power to the field winding 11b. The rest of the second embodiment is similar to the first embodiment. Therefore, only the parts that differ from the first embodiment will be described, and a description of the overlapping parts will be omitted.

[0036] FIG. 2 is a configuration diagram of a power system 100A according to the second embodiment. The second embodiment is a reference embodiment. As shown in FIG. 2, the power system 100A includes a synchronous modifier 11, a transformer 12, an excitation transformer 13, a power converter 17 (first power converter), a large-capacity storage battery 41 (storage battery), a power converter 42 (third power converter), and a control device 30A.

[0037] The components used to supply power from the power system P1, which is the main system, to the synchronous phase modifier 11 include a transformer 12, an excitation transformer 13, and a power converter 17. Power converter 17 (first power converter) is a device that converts AC power supplied from power system P1 (first power system) into DC power and outputs the converted DC power to field winding 11b (excitation circuit).

[0038] An AC side of the power converter 17 is connected to the secondary side of the excitation transformer 13 via a power line W1. On the other hand, a DC side of the power converter 17 is connected to the field winding 11b of the synchronous phase modifier 11 via power lines W2 and W3 in this order.

[0039] 2, no circuit breaker is provided in the power line W1 on the AC side of the power converter 17, and no circuit breaker is provided in the power lines W2, W3 on the DC side of the power converter 17. In other words, no circuit breaker is provided on either the AC side or the DC side of the power converter 17 (first power converter).

[0040] The large-capacity storage battery 41 (storage battery) is a secondary battery used as a backup power source for the synchronous phase modifier 11, and is connected to the power converter 42 via a power line W5. The large-capacity storage battery 41 has a capacity such that even if the voltage of the power system P1 drops, the voltage of the field winding 11b is maintained as it is by the DC voltage of the large-capacity storage battery 41 (the voltage is maintained at the same level as when the power system P1 is normal).

[0041] The power converter 42 (third power converter) is a DC-DC converter that adjusts the DC voltage of the large-capacity storage battery 41 (storage battery) by stepping up or down, and applies the adjusted DC voltage to the field winding 11b (excitation circuit). The input side of the power converter 42 is connected to the large-capacity storage battery 41 via a power line W5. On the other hand, the output side of the power converter 42 is connected to the field winding 11b via power lines W4 and W3 in this order.

[0042] 2, no circuit breaker is provided in the power line W5 on the input side of the power converter 42, and no circuit breaker is provided in the power lines W4, W3 on the output side of the power converter 42. In other words, no circuit breaker is provided on either the large-capacity storage battery 41 (storage battery) side or the field winding 11b (excitation circuit) side of the power converter 42 (third power converter).

[0043] The control device 30A controls the power converter 17 (first power converter) and the power converter 42 (third power converter) in a predetermined manner. For example, when the power system P1 (first power system) is normal, the control device 30 drives the power converters 17, 42 so that the voltages on the output sides of the power converter 17 (first power converter) and the power converter 42 (third power converter) are equal. As a result, when the power system P1 (first power system) is normal, power is supplied from the power system P1 to the field winding 11b (excitation circuit), and power is also supplied from the large-capacity storage battery 41 (storage battery) to the field winding 11b.

[0044] Furthermore, the control device 30A continues to drive at least the power converter 42 (third power converter) when an abnormality occurs in the power system P1 (first power system). For example, when an abnormality occurs in the power system P1 and the voltage on the DC side of the power converter 17 drops, the voltage on the output side of the other power converter 42 becomes relatively high. As a result, a predetermined DC voltage continues to be applied to the field winding 11b from the large-capacity storage battery 41 via the power converter 42, so that the voltage of the field winding 11b hardly drops. In this way, the power system 100A is configured such that when an abnormality occurs in the power system P1 (first power system), the source of power supply to the field winding 11b (excitation circuit) becomes the large-capacity storage battery 41 (storage battery).

[0045] Note that the control device 30A may continue to drive the power converter 17 in a predetermined manner not only when the power system P1 is normal, but also when the power system P1 is abnormal. Even when such control is performed, since the voltage of the power system P1 is low, almost no current flows through the power converter 17, but there is no particular problem in continuing to drive the power converter 17. Alternatively, for example, when an abnormality occurs in the power system P1, the control device 30A may stop driving the power converter 17.

[0046] <Effects> According to the second embodiment, when an abnormality occurs in the power system P1 and the voltage of the power system P1 drops, the power supply source to the field winding 11b of the synchronous phase modifier 11 is immediately switched to the large-capacity storage battery 41. As a result, fluctuations in the DC voltage applied to the field winding 11b are compensated for by the voltage of the large-capacity storage battery 41, and therefore, compared to the first embodiment using the circuit breakers 14, 23 (see FIG. 1), the transient stability of the voltage is higher and the voltage fluctuations of the field winding 11b can be suppressed. Furthermore, regardless of the presence or absence of an abnormality in the power system P1, the control device 30A only needs to continue to drive the power converters 17, 42 in a predetermined manner, and therefore the processing of the control device 30A can be simplified.

[0047] Third Embodiment The third embodiment differs from the second embodiment (see FIG. 2) in that another power system P2 is used as a backup power supply for exciting the field winding 11b when an abnormality occurs in the power system P1 (see FIG. 3). The third embodiment also differs from the second embodiment in that a power converter 24 converts an AC voltage that has been transformed to a predetermined level by a transformer 21 (see FIG. 3) into a DC voltage. The rest of the third embodiment is similar to the second embodiment. Therefore, only the parts that differ from the second embodiment will be described, and a description of the overlapping parts will be omitted.

[0048] FIG. 3 is a configuration diagram of a power system 100B according to the third embodiment. As shown in Fig. 3, the power system 100B includes a transformer 12, an excitation transformer 13, and a power converter 17 (first power converter) as components used for power supply from a power system P1, which is a main system, to a synchronous phase modifier 11. In the example of Fig. 3, similarly to the second embodiment (see Fig. 2), no circuit breaker is particularly provided on either the AC side or the DC side of the power converter 17 (first power converter).

[0049] The power system 100B also includes a transformer 21 and a power converter 24 (second power converter) as components used to supply power from the power system P2, which is a backup system, to the field winding 11b (excitation circuit) of the synchronous phase modifier 11.

[0050] The transformer 21 is a device that adjusts the level of the AC voltage when the power system P2 is used as an excitation power source for the synchronous phase modifier 11. The power converter 24 (second power converter) is a device that converts AC power supplied from the power system P2 (second power system) into DC power and outputs the converted DC power to the field winding 11b (excitation circuit). For example, a thyristor rectifier is used as the power converter 24.

[0051] An AC side of the power converter 24 is connected to the secondary side of the transformer 21 via a power line W6. On the other hand, a DC side of the power converter 24 is connected to the field winding 11b via power lines W7 and W3 in this order. In the example of Fig. 3, no circuit breaker is provided on either the AC side or the DC side of the power converter 24 (second power converter).

[0052] The control device 30B controls the power converter 17 (first power converter) and the power converter 24 (second power converter) in a predetermined manner. For example, when the power system P1 (first power system) is normal, the control device 30B drives the power converters 17, 24 so that the voltages on the output sides of the power converter 17 (first power converter) and the power converter 24 (second power converter) are equal. As a result, when the power system P1 (first power system) is normal, power is supplied from the power system P1 to the field winding 11b (excitation circuit), and power is also supplied from the power system P2 (second power system) to the field winding 11b.

[0053] Furthermore, the control device 30B continues to drive at least the power converter 24 (second power converter) when an abnormality occurs in the power system P1 (first power system). For example, when an abnormality occurs in the power system P1 and the voltage on the DC side of the power converter 17 drops, the voltage on the DC side of the other power converter 24 becomes relatively high. As a result, a predetermined DC voltage continues to be applied to the field winding 11b from the power system P2 via the power converter 24, so that the voltage of the field winding 11b hardly drops. In this way, the power system 100B is configured such that when an abnormality occurs in the power system P1 (first power system), the source of power supply to the field winding 11b (excitation circuit) is the power system P2 (second output system).

[0054] Note that the control device 30B may continue to drive the power converter 17 in a predetermined manner not only when the power system P1 is normal, but also when the power system P1 is abnormal. Even when such control is performed, since the voltage of the power system P1 is low, almost no current flows through the power converter 17, but there is no particular problem in continuing to drive the power converter 17. Alternatively, for example, when an abnormality occurs in the power system P1, the control device 30B may stop driving the power converter 17.

[0055] <Effects> According to the third embodiment, when an abnormality occurs in the power system P1 and the voltage of the power system P1 drops, the power supply source to the field winding 11b (excitation circuit) of the synchronous phase modifier 11 is immediately switched to the power system P2. Therefore, compared to the first embodiment using the circuit breakers 14, 23 (see FIG. 1), the voltage fluctuation of the field winding 11b can be suppressed. Moreover, regardless of the presence or absence of an abnormality in the power system P1, the control device 30B only needs to continue to control the power converters 17, 24 in a predetermined manner, so that the processing of the control device 30B can be simplified. Moreover, since there is no particular need to provide a large-capacity storage battery for backup, the equipment cost can be reduced compared to the second embodiment (see FIG. 2).

[0056] Fourth Embodiment A power system 100C according to the fourth embodiment (see FIG. 4) has a configuration that combines the second embodiment (see FIG. 2) and the third embodiment (see FIG. 3). That is, in the fourth embodiment, when the voltage of the power system P1 (see FIG. 4) drops, power is supplied to the field winding 11b (excitation circuit) of the synchronous phase modifier 11 from both the large-capacity storage battery 41 (see FIG. 4) and the power system P2 (see FIG. 4). Note that descriptions of parts that overlap with the second and third embodiments will be omitted as appropriate.

[0057] FIG. 4 is a configuration diagram of a power system 100C according to the fourth embodiment. 4, the power system 100C includes a transformer 12, an excitation transformer 13, and a power converter 17 (first power converter) as components used for supplying power from a power system P1, which is a main system, to the synchronous phase modifier 11. The power converter 17 (first power converter) is a device that converts AC power supplied from the power system P1 (first power system) into DC power and outputs the converted DC power to the field winding 11b (excitation circuit).

[0058] The power system 100C also includes the large-capacity storage battery 41 and a power converter 42 (third power converter) as components used for supplying power from the large-capacity storage battery 41 to the field winding 11b of the synchronous phase modifier 11. The power converter 42 (third power converter) is a device that adjusts the DC voltage of the large-capacity storage battery 41 (storage battery) by stepping it up or down, and applies the adjusted DC voltage to the field winding 11b (excitation circuit).

[0059] The power system 100C also includes a transformer 21 and a power converter 24 (second power converter) as components used to supply power from the power system P2 to the field winding 11b of the synchronous phase modifier 11. The power converter 24 (second power converter) is a device that converts AC power supplied from the power system P2 (second power system) into DC power and outputs the converted DC power to the field winding 11b (excitation circuit).

[0060] The control device 30C controls the power converters 17, 24, 42 in a predetermined manner. For example, when the power system P1 (first power system) is normal, the control device 30C drives the power converters 17, 24, 42 so that the voltages on the output sides of the power converter 17 (first power converter), the power converter 24 (second power converter), and the power converter 42 (third power converter) are equal. As a result, power is supplied from the power systems P1 and P2 and the large-capacity storage battery 41 to the field winding 11b (excitation circuit).

[0061] Furthermore, when an abnormality occurs in the power system P1 (first power system), the control device 30C continues to drive at least the power converter 24 (second power converter) and the power converter 42 (third power converter). For example, when a ground fault or the like occurs in the power system P1 and the DC voltage on the output side of the power converter 17 drops, the DC voltage on the output side of the remaining power converters 24, 42 becomes relatively high. As a result, the DC voltage continues to be applied to the field winding 11b (excitation circuit) from the power system P2 and the large-capacity storage battery 41, so that the voltage of the field winding 11b hardly drops.

[0062] <Effects> According to the fourth embodiment, when an abnormality occurs in the power system P1 and the voltage of the power system P1 drops, the power supply source to the field winding 11b (excitation circuit) of the synchronous phase modifier 11 is immediately switched to the power system P2 or the large-capacity storage battery 41. Therefore, compared to the first embodiment using the circuit breakers 14, 23 (see FIG. 1), the voltage fluctuation of the field winding 11b can be suppressed. Moreover, regardless of the presence or absence of an abnormality in the power system P1, the control device 30C only needs to continue to control the power converters 17, 24, 42 in a predetermined manner, and therefore the processing of the control device 30C can be simplified.

[0063] Furthermore, even if the voltage on the output side of the power converter 24, other than the power converter 17, drops instantaneously, a DC voltage is applied to the field winding 11b from the large-capacity storage battery 41 via the power converter 42. Therefore, compared to the second and third embodiments, a predetermined DC voltage can be stably and continuously applied to the field winding 11b of the synchronous phase modifier 11.

[0064] <<Variations>> Although the power system 100 according to the present invention has been described above with reference to the respective embodiments, the present invention is not limited to these descriptions and various modifications can be made. For example, in the first embodiment, a case has been described in which a thyristor rectifier is used as the power converter 16 (see FIG. 1), but the present invention is not limited thereto. That is, other types of power converters, such as a rectifier having an IGBT (Insulated Gate Bipolar Transistor), may be used as the power converter 16 (see FIG. 1). The same can be said for the power converter 17 (see FIGS. 2 to 4) described in the second to fourth embodiments, the power converter 42 (see FIGS. 2 and 4) described in the second and fourth embodiments, and the power converter 24 (see FIGS. 3 and 4) described in the third and fourth embodiments.

[0065] In the first embodiment, the control device 30 (see FIG. 1) switches the circuit breakers 14 and 23 (see FIG. 1), but the present invention is not limited to this. For example, when an abnormality occurs in the power system P1, an administrator may manually operate the circuit breakers 14 and 23.

[0066] In the second embodiment, a configuration has been described in which a circuit breaker is not particularly provided on the power line W2 on the output side of the power converter 17 (see FIG. 2) or the power line W4 on the output side of the power converter 42 (see FIG. 2), but this is not limited thereto. That is, a circuit breaker may be provided appropriately on the power lines W2 and W4. The same can be said about the third and fourth embodiments.

[0067] Furthermore, each embodiment can also be applied to facilities of power plants, such as nuclear power plants, thermal power plants, and hydroelectric power plants. Moreover, in each embodiment, the synchronous phase modifier 11 including the brush and the slip ring has been described, but the present invention can also be applied to a synchronous phase modifier of a brushless excitation type. Moreover, each embodiment can be applied to a synchronous machine such as a synchronous motor in addition to the synchronous phase modifier 11.

[0068] In addition, each embodiment is described in detail to explain the present invention in an easily understandable manner, and is not necessarily limited to having all of the configurations described. In addition, it is possible to add, delete, or replace some of the configurations of the embodiments with other configurations. In addition, the above-mentioned mechanisms and configurations are those that are considered necessary for explanation, and do not necessarily show all of the mechanisms and configurations in the product.

[0069] In addition, the power lines and signal lines shown are those that are considered necessary for the explanation, and not all power lines and signal lines in the product are necessarily shown. In reality, it can be considered that almost all components are connected to each other. [Explanation of symbols]

[0070] 11 Synchronous phase modifier 11a Armature winding 11b Field winding (excitation circuit) 12. Transformers 13 Excitation transformer 14 Circuit Breaker (First Circuit Breaker) 15 Power panel 16 Power Converter 17 Power converter (first power converter) 21 Transformer 22 Excitation transformer 23 Circuit breaker (second circuit breaker) 24 Power converter (second power converter) 30, 30A, 30B, 30C Control device 41 Large capacity storage battery (storage battery) 42 Power converter (third power converter) 100, 100A, 100B, 100C Power System P1 power system (1st power system) P2 power system (second power system)

Claims

1. a synchronous phase modifier including an armature winding electrically connected to a first power system and a field winding functioning as an excitation circuit, When the first power system is in a normal state, power is supplied from the first power system to the excitation circuit, and power is also supplied from the second power system to the excitation circuit; When an abnormality occurs in the first power system, a power source for the excitation circuit is the second power system, a first power converter that converts AC power supplied from the first power system into DC power and outputs the converted DC power to the excitation circuit; a second power converter that converts AC power supplied from the second power system into DC power and outputs the converted DC power to the excitation circuit; a control device that controls the first power converter and the second power converter, The control device includes: driving the first power converter and the second power converter so that voltages on the output sides of the first power converter and the second power converter are equal to each other when the first power system is normal; When an abnormality occurs in the first power system, at least the second power converter is allowed to continue to be driven. A power system characterized by:

2. a circuit breaker is not provided on either the AC side or the DC side of the first power converter, No circuit breaker is provided on either the AC side or the DC side of the second power converter. The power system according to claim 1 .

3. a synchronous phase modifier having an armature winding electrically connected to a first power system and a field winding functioning as an excitation circuit, When the first power system is in a normal state, power is supplied from the first power system to the excitation circuit, and power is also supplied from the second power system and the storage battery to the excitation circuit; When an abnormality occurs in the first power system, a power supply source for the excitation circuit is the second power system and the storage battery. a first power converter that converts AC power supplied from the first power system into DC power and outputs the converted DC power to the excitation circuit; a second power converter that converts AC power supplied from the second power system into DC power and outputs the converted DC power to the excitation circuit; a third power converter that adjusts the DC voltage of the storage battery by stepping up or stepping down and applies the adjusted DC voltage to the excitation circuit; a control device that controls the first power converter, the second power converter, and the third power converter, The control device includes: driving the first power converter, the second power converter, and the third power converter so that voltages on the output sides of the first power converter, the second power converter, and the third power converter are equal to each other during a normal state of the first power system; When an abnormality occurs in the first power system, at least the second power converter and the third power converter are continuously driven. A power system characterized by:

4. A control device included in a power system including a synchronous phase modifier having an armature winding electrically connected to a first power system and a field winding functioning as an excitation circuit, When the first power system is in a normal state, power is supplied from the first power system to the excitation circuit, and power is also supplied from the second power system to the excitation circuit; the power system is configured such that, when an abnormality occurs in the first power system, a power source for the excitation circuit becomes the second power system; The control device includes: a first power converter that converts AC power supplied from the first power system into DC power and outputs the converted DC power to the excitation circuit; a second power converter that converts AC power supplied from the second power system into DC power and outputs the converted DC power to the excitation circuit; driving the first power converter and the second power converter so that voltages on the output sides of the first power converter and the second power converter are equal to each other when the first power system is normal; When an abnormality occurs in the first power system, at least the second power converter is allowed to continue to be driven. A control device comprising:

5. A control device included in a power system including a synchronous phase modifier having an armature winding electrically connected to a first power system and a field winding functioning as an excitation circuit, When the first power system is in a normal state, power is supplied from the first power system to the excitation circuit, and power is also supplied from the second power system and the storage battery to the excitation circuit; the power system is configured such that, when an abnormality occurs in the first power system, a power supply source for the excitation circuit is the second power system and the storage battery; The control device includes: a first power converter that converts AC power supplied from the first power system into DC power and outputs the converted DC power to the excitation circuit; a second power converter that converts AC power supplied from the second power system into DC power and outputs the converted DC power to the excitation circuit; a third power converter that adjusts the DC voltage of the storage battery by stepping up or stepping down and applies the adjusted DC voltage to the excitation circuit; driving the first power converter, the second power converter, and the third power converter so that voltages on the output sides of the first power converter, the second power converter, and the third power converter are equal to each other during a normal state of the first power system; When an abnormality occurs in the first power system, at least the second power converter and the third power converter are continuously driven. A control device comprising:

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