JP6945500B2 - Exciter - Google Patents

Description

The present application relates to an exciting device for detecting a contact failure of a connector portion provided for making a rectifying circuit unit that supplies an exciting current to a field circuit of a synchronous machine of a power generation facility replaceable.

The exciter of a synchronous machine such as a generator rectifies AC power by a rectifier circuit unit, and supplies an exciting current exceeding several thousand A to the field circuit of the synchronous machine. This rectifier circuit unit has a replaceable configuration by providing a connector portion connected to the exciting device. Since the exciter handles a large amount of electric power, a large fan is used to take in air from the outside for its cooling. Depending on the installation environment, impurities such as sand and dust may be mixed in the connector. For this reason, if a contact failure occurs, the connector portion is damaged, and the supply of the exciting current from the exciting device is stopped, which may eventually lead to the operation stop of the synchronous machine.

In order to detect an abnormality in the field circuit of the synchronous machine, a technique for detecting a disconnection in the field winding has been proposed by measuring and comparing the voltage of the field circuit and the field winding (for example). Patent Document 1).

Japanese Unexamined Patent Publication No. 2-46149 (page 296, upper right column, line 20-lower right column, second line, page 297, upper right column, line 15-lower left column, line 6, and FIG. 1)

However, in the technique disclosed in Patent Document 1, since the voltage at one end of the connector portion of the field winding is measured, the contact failure generated in the connector portion cannot be detected, the connector portion is damaged, and the exciter stops operating. There was a point.

The present application discloses a technique for solving the above-mentioned problems, and is an exciting device capable of detecting a contact failure generated in a connector portion for connecting a rectifying circuit unit to an exciting device and preventing an operation stop. The purpose is to provide.

The exciter disclosed in the present application is an exciter in which the rectifier circuit unit can be replaced by connecting the rectifier circuit unit with a connector portion, and the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion are transferred. Each insulation amplifier to be measured is provided, and poor contact of the connector portion is detected from the change in the output voltage of each insulation amplifier.

Further, the exciter disclosed in the present application is an exciter in which the rectifier circuit unit can be replaced by connecting the rectifier circuit unit with the connector portion, and the voltage on the movable contact side of the connector portion and the voltage on the fixed contact side are Each Hall CT that converts a voltage into a current for measurement is provided, and a contact failure of the connector portion is detected from a change in the output current of each Hall CT.

Further, the exciter disclosed in the present application is a photodetector that detects an arc on the fixed contact side of the connector portion in the exciter in which the rectifier circuit unit can be replaced by connecting the rectifier circuit unit with the connector portion. Is provided to detect poor contact of the connector portion from changes in the output signal of the photodetector.

The exciting device disclosed in the present application is provided with each insulating amplifier that measures the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion, and detects poor contact of the connector portion from the change in the output voltage of each insulating amplifier. Therefore, it is possible to prevent the exciting device from malfunctioning and stop operation due to damage to the connector portion, and to continue supplying power.

Further, the exciting device disclosed in the present application is provided with each Hall CT for measuring by converting the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion into a current, and from the change in the output current of each Hall CT. Since the contact failure of the connector portion is detected, it is possible to prevent the exciting device from malfunctioning and stop operation due to the damage of the connector portion, and to continue the power supply.

Further, the exciting device disclosed in the present application is provided with a photodetector that detects an arc on the fixed contact side of the connector portion, and detects a contact failure of the connector portion from a change in the output signal of the photodetector. Therefore, it is possible to prevent the exciter from malfunctioning and stop operation due to damage to the connector portion, and to continue supplying the exciting current to the field winding of the synchronous machine.

It is a block diagram centering on the contact failure detection circuit of the connector part which concerns on the exciting apparatus according to Embodiment 1. FIG. It is a block diagram of the rectifier circuit unit which concerns on the exciter according to Embodiment 1. FIG. It is a block diagram of the contact failure determination circuit of the connector part which concerns on the exciting apparatus according to Embodiment 1. FIG. It is explanatory drawing of the behavior of the voltage at the time of contact failure of the connector part which concerns on the exciting apparatus according to Embodiment 1. FIG. It is explanatory drawing of the behavior of the voltage at the time of contact failure of the connector part which concerns on the exciting apparatus according to Embodiment 1. FIG. It is a block diagram centering on the contact failure detection circuit of the connector part which concerns on the exciting apparatus according to Embodiment 2. FIG. It is a block diagram centering on the contact failure detection circuit of the connector part which concerns on the exciter according to Embodiment 3. FIG. It is a block diagram of the contact failure determination circuit of the connector part which concerns on the exciting apparatus according to Embodiment 4. FIG.

Embodiment 1.
In the first embodiment, in an exciting device having a structure that can be exchanged by connecting a rectifier circuit unit with a connector portion, each insulation that measures the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion. The present invention relates to an exciting device in which an amplifier is provided and a contact failure of a connector portion is detected from a change in the output voltage of each insulating amplifier.

Hereinafter, regarding the configuration and operation of the exciting device according to the first embodiment, FIG. 1 which is a configuration diagram centering on a contact failure detection circuit of the connector portion, FIG. 2 which is a configuration diagram of a rectifier circuit unit, and contact failure of the connector portion. This will be described with reference to FIG. 3 which is a block diagram of the determination circuit, and FIGS. 4 and 5 which are diagrams showing the behavior of the voltage when the contact of the connector portion is poor.

First, the configuration of the exciter of the first embodiment will be described with reference to FIG. 1, including the relationship with a synchronous device such as a generator.
In FIG. 1, the exciting device 1 supplies an exciting current to an exciting main circuit 2 having a field winding 3 installed in a synchronous machine (not shown) such as a generator.
The exciting device 1 includes a rectifying circuit unit 4 that rectifies alternating current obtained from a three-phase alternating current main circuit (AC (alternating current) main circuit) to direct current. In FIG. 1, the exciting current converted (rectified) from alternating current to direct current by the rectifying circuit unit 4 is supplied to the field winding 3 in the exciting main circuit 2.
Here, although the rectifier circuit unit 4 is installed in the exciting device 1, it has a replaceable structure because it is connected via the connector portion 5.

A plurality of rectifier circuit units 4 are installed in parallel in the exciting device 1 in order to have a redundant configuration. Therefore, even if a part (for example, one) rectifier circuit unit 4 is stopped, the function of the exciting device 1 is not lost. The exciter 1 can continue to operate and supply an exciting current to the field winding 3 of the synchronous machine.

Next, a configuration example of the rectifier circuit unit 4 will be described with reference to FIG.
The rectifier circuit unit 4 includes a thyristor in each phase (three phases in FIG. 2). By controlling the gate signals of the thyristors of each of these phases, the alternating current supplied from the AC main circuit is converted into direct current. In FIG. 2, the connector portion 5 is represented by a double circle.

In FIG. 2, the case where the rectifier circuit unit 4 includes three thyristors has been described as an example. The replacement unit of the rectifier circuit unit is not limited to the example of FIG. For example, it may be a unit of one thyristor, or the two rectifier circuit units 4 shown in FIG. 2 can be combined into one rectifier circuit unit.

Next, the structure of the connector portion 5 will be described.
The connector portion 5 includes a movable contact 42 and a fixed contact 52.
When impurities such as sand and dust are mixed in the connector portion 5 and poor contact occurs, the contact resistance 53 between the movable contact 42 and the fixed contact 52 may increase.
Insulation amplifiers 60A and 60B are provided to measure the voltage at both ends of the connector portion 5 (movable contact 42 side and fixed contact 52 side).
Although the details of the connector portion that connects the rectifier circuit unit 4 and the AC main circuit are omitted in FIG. 1, the configuration is the same as that of the connector portion 5 that connects the rectifier circuit unit 4 and the excitation main circuit 2. be.

Next, the function and operation of the exciting device 1 of the first embodiment will be described focusing on the detection of poor contact of the connector portion 5.
The insulation amplifier 60A measures the voltage V1 on the movable contactor 42 side as a potential difference from the control common 62. The insulation amplifier 60B measures the voltage V2 on the fixed contact 52 side as a potential difference from the control common 62.
In FIG. 1, the reference potentials of the insulating amplifiers 60A and 60B are set to the control common 62, that is, the ground 61, but the connection form is not limited to this because it is sufficient if a comparison with a certain reference potential can be made.

FIG. 3 is a block diagram of the contact failure determination circuit 70 using the voltages measured by the insulation amplifiers 60A and 60B.
The voltage V1 on the movable contact 42 side and the voltage V2 on the fixed contact 52 side are added by the adder 73 through the buffer 71 and the reversing device 72, respectively. The buffer 71 outputs the measured voltage to the adder 73 as it is, and the reverser 72 inverts the positive and negative and outputs the measured voltage to the adder 73.
The comparator 74 compares the output voltage of the adder 73 with the set value A of the setter 75, and outputs a stop signal to the control circuit (stop) 76 when the output voltage of the adder 73 is larger than the set value A. ..
The control circuit (stop) 76 stops the gate signal to the rectifier circuit unit 4, and as a result, the rectifier circuit unit 4 stops the supply of the exciting current to the field winding 3 of the synchronous machine.

FIG. 4 shows the behavior of the voltage when poor contact is detected.
The voltage V1 on the rectifier circuit unit 4 side, that is, on the movable contact 42 side shows a constant rectified waveform regardless of poor contact. On the other hand, the voltage V2 on the excitation main circuit 2 side, that is, on the fixed contact 52 side, causes a voltage difference when a contact failure occurs.
Therefore, a difference voltage (voltage V1-voltage V2) is generated by inverting the voltage V2 on the fixed contact 52 side with the reversing device 72 and adding it to the voltage V1 on the movable contact 42 side.
In FIG. 4, a waveform like a sawtooth wave is shown, but in reality, the waveform of the voltage difference may be pulsed.

The contact failure determination circuit 70 sets a certain threshold value for determining contact failure, and when the difference voltage (voltage V1-voltage V2) exceeds this value, it determines that contact failure. It is also possible to determine contact failure based on the area of the waveform of the difference voltage (voltage V1-voltage V2).

FIG. 4 shows the behavior of the voltage at the time of detecting a contact failure when a direct current flows through the connector portion 5.
Alternating current flows through the connector portion 5 that connects the rectifier circuit unit 4 and the AC main circuit. FIG. 5 is an explanatory diagram of voltage behavior when a contact failure is detected when alternating current flows through the connector portion 5.
When alternating current flows through the connector portion 5, the voltages measured by the insulating amplifiers 60A and 60B (voltage V1 on the movable contact 42 side and voltage V2 on the fixed contact 52 side) have a sinusoidal waveform.
When a contact failure occurs, a difference voltage (voltage V1-voltage V2) is generated as in the case of direct current.

As described above, the exciting device 1 of the first embodiment can detect a contact failure of the connector portion 5 and stop and replace only the rectifier circuit unit 4 including the connector portion 5 in which the contact failure has occurred. can. Therefore, it is possible to prevent failure and operation stop of the exciting device 1 due to poor contact of the connector portion 5, and to continue supplying power.

As described above, in the first embodiment, in the exciting device having a structure in which the rectifier circuit unit is connected by the connector portion to be exchangeable, the voltage on the movable contact side of the connector portion and the voltage on the fixed contact side The present invention relates to an exciting device in which each insulating amplifier for measuring a voltage is provided and a contact failure of a connector portion is detected from a change in the output voltage of each insulating amplifier.
Therefore, the exciter of the first embodiment can prevent the exciter from failing and stopping the operation due to the damage of the connector portion, and can continue to supply the exciting current to the field winding of the synchronous machine.

Embodiment 2.
In the exciting device of the first embodiment, in order to detect a contact failure of the connector portion, each insulating amplifier for measuring the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion is provided. In the exciting device of the second embodiment, a Hall CT (current transformer) is used instead of the insulating amplifier to measure the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion.

Hereinafter, the configuration and operation of the exciter according to the second embodiment will be mainly different from the first embodiment based on FIG. 6, which is a configuration diagram centering on the contact failure detection circuit of the connector portion according to the exciter. Explain to. In FIG. 6, the same or corresponding parts as those in FIG. 1 of the first embodiment are designated by the same reference numerals.
The exciting device 100 is used to distinguish it from the first embodiment. Also, as appropriate, refer to FIG. 3 of the first embodiment.

The function and operation of the exciting device 100 according to the second embodiment will be described focusing on the detection of poor contact of the connector portion 5.
In the first embodiment, the voltages at both ends of the connector portion 5 were measured using the insulating amplifiers 60A and 60B. In the second embodiment, as shown in FIG. 6, the voltage at both ends of the connector portion 5 is converted into a current, and then the measurement is performed using the halls CT80A and 80B.

Specifically, high impedance resistors 81 are installed at both end portions (movable contactor 42, fixed contactor 52) of the connector portion 5, and the Hall effect is the magnitude of the current passing through the through portions 82A and 82B of the holes CT80A and 80B. Measured by.
After the current is measured by the halls CT80A and 80B, it is converted into an appropriate voltage value by passing through the amplifiers 83A and 83B.
In FIG. 6, the output of the amplifier 83A corresponding to the voltage on the movable contact 42 side is the voltage V3, and the output of the amplifier 83B corresponding to the voltage on the fixed contact 52 side is the voltage V4.

The block diagram of the contact failure determination circuit after converting the current measured in the halls CT80A and 80B into a voltage is the same as that in FIG. 3, and is not shown.
The difference is that in FIG. 3, the input of the buffer 71 is the hall CT80A, that is, the output voltage V3 of the amplifier 83A, and the input of the reverser 72 is the hall CT80B, that is, the output voltage V4 of the amplifier 83B.

In the exciting device 100 of the second embodiment, the voltage at both ends of the connector portion 5 is converted into a current, and this current is measured by the Hall CT. Contact failure can be detected.
Then, in the exciter 100 of the second embodiment, the cost is higher than that of the exciter 1 of the first embodiment by using the halls CT80A and 80B, which are cheaper than the insulating amplifiers 60A and 60B, as the measuring means. Can be reduced.

In the exciter of the second embodiment, the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion are measured by using the Hall CT instead of the insulating amplifier for the purpose of detecting the contact failure of the connector portion. It is a structure.
Therefore, the exciter of the second embodiment can prevent the exciter from failing and stopping the operation due to the damage of the connector portion, and can continue to supply the exciting current to the field winding of the synchronous machine. Further, the cost can be reduced.

Embodiment 3.
In the exciting device of the third embodiment, a photodetector is provided in the connector portion in order to detect a contact failure of the connector portion.

Hereinafter, the configuration and operation of the exciter according to the third embodiment will be mainly different from the first embodiment based on FIG. 7, which is a configuration diagram centering on the contact failure detection circuit of the connector portion according to the exciter. Explain to. In FIG. 7, the same or corresponding parts as those in FIG. 1 of the first embodiment are designated by the same reference numerals.
The exciting device 200 is used to distinguish it from the first embodiment.

The function and operation of the exciting device 200 according to the third embodiment will be described focusing on the detection of poor contact of the connector portion 205.
In the first embodiment, the voltages at both ends of the connector portion 5 were measured using the insulating amplifiers 60A and 60B.
In the third embodiment, as shown in FIG. 7, a photodetector 90 is installed in the connector portion 205, and the light generated at the time of poor contact is detected to detect the poor contact of the connector portion 205.

First, the structure of the connector portion 205 of the exciter 200 of the third embodiment will be described.
The connector portion 205 includes a movable contact 242 and a fixed contact 252. The connector portion 205 has a structure in which an insulator 243 on the movable contact side and an insulator 253 on the fixed contact side are used to insulate the connector portion 205 from the outside.
Then, the photodetector 90 is provided on the insulator 253 of the fixed contact 252 of the connector portion 205.

Since a large current is flowing through the connector portion 205, light due to an arc is generated when a contact failure occurs in the contact portion. The photodetector 90 detects the light generated by this arc.
The output of the photodetector 90 is compared with a predetermined set value by the contact failure determination circuit 270, and a stop signal is output in the same manner as in the exciting device 1 of the first embodiment.
Since it is clear that the configuration of the contact failure determination circuit 270 is a configuration in which the reversing device 72 and the adder 73 are deleted from the contact failure determination circuit 70 of FIG. 3, the drawings and description are omitted.

In the exciter 200 of the third embodiment, since the photodetector 90 is installed in the connector portion 205, it is not necessary to provide a measurement point in an electric circuit such as a rectifier circuit, and the photodetector 90 is a non-contact type detector. Therefore, it can be easily applied to existing systems.

In the exciting device of the third embodiment, a photodetector is provided in the connector portion in order to detect a contact failure of the connector portion.
Therefore, the exciter of the third embodiment can prevent the exciter from failing and stopping the operation due to the damage of the connector portion, and can continue to supply the exciting current to the field winding of the synchronous machine. Furthermore, it can be easily applied to existing systems.

Embodiment 4.
The exciting device of the fourth embodiment has a configuration in which the contact failure determining circuit of the exciting device 1 according to the first embodiment generates not only a stop signal but also an alarm signal when a contact failure occurs.

Hereinafter, the configuration and operation of the contact failure determination circuit of the exciting device according to the fourth embodiment will be described mainly on the difference from the first embodiment based on FIG. 8 which is a block diagram of the contact failure determination circuit of the connector portion. do. In FIG. 8, the same or corresponding parts as those in FIG. 3 of the first embodiment are designated by the same reference numerals.
In order to distinguish it from the first embodiment, the contact failure determination circuit 370 is used. Also, as appropriate, refer to FIG. 1 of the first embodiment.

In the contact failure determination circuit 70 of the exciter 1 of the first embodiment, as described with reference to FIG. 3, the output voltage of the adder 73 and the set value A of the setter 75 are compared by the comparator 74, and the adder 73 is compared. If the output voltage is larger than the set value A, a stop signal is output to the control circuit (stop) 76. The control circuit (stop) 76 stops the gate signal to the rectifier circuit unit 4, and as a result, the rectifier circuit unit 4 stops the supply of the exciting current to the field winding 3 of the synchronous machine.

In the contact failure determination circuit 370 of the exciting device of the fourth embodiment, the comparator 101, the setting device 102, and the control circuit (alarm) 103 are added to the configuration of FIG.
The output voltage of the adder 73 and the set value B of the setter 102 are compared by the comparator 101, and if the output voltage of the adder 73 is larger than the set value B, an alarm signal is output to the control circuit (alarm) 103.

Here, the set value A is a value at which the damage to the connector portion 5 is severe, and the set value B is a value at which it can be determined that the damage to the connector portion 5 is minor.
The contact failure at the connector portion 5 does not occur suddenly, but occurs in stages. Therefore, a sign of poor contact can be grasped by detecting a slight damage to the connector portion 5 in advance. This has the effect of being able to determine the maintenance and replacement timing of the connector portion 5 at an early stage.
Further, when the rectifier circuit unit 4 is connected to the exciting device 1, the movable contact 42 of the connector portion 5 is inserted into the fixed contact 52, and there is also an effect that a contact failure at the time of insertion can be immediately grasped.

In the above description of the exciting device according to the fourth embodiment, the contact failure determination circuit of the exciting device 1 according to the first embodiment is configured to generate not only a stop signal but also an alarm signal when a contact failure occurs.
Similarly, by applying to the exciter of the second embodiment, the contact failure determination circuit of the exciter 100 according to the second embodiment may be configured to generate not only a stop signal but also an alarm signal when a contact failure occurs. can.

The exciting device of the fourth embodiment has a configuration in which the contact failure determining circuit of the exciting device 1 according to the first embodiment generates not only a stop signal but also an alarm signal when a contact failure occurs.
Therefore, the exciting device of the fourth embodiment can prevent failure and operation stop of the exciting device due to damage to the connector portion, and can continue to supply the exciting current to the field winding of the synchronous machine. Further, it is possible to grasp a sign of poor contact of the connector portion and improve maintainability.

Although the present application describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are applications of a particular embodiment. It is not limited to, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed in the present application. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1,100,200 Excitation device, 2 Excitation main circuit, 3 field winding,
4 Rectifier circuit unit, 5,205 connector, 42,242 movable contacts,
52,252 fixed contacts, 53 contact resistors, 60A, 60B insulated amplifiers,
61 Grounding, 62 Control common, 70, 270, 370 Contact failure judgment circuit,
71 buffer, 72 inverter, 73 adder, 74,101 comparator,
75, 102 setter, 76 control circuit (stop), 80A, 80B Hall CT,
81 High impedance resistor, 82A, 82B penetration, 83A, 83B amplifier,
90 Photodetector, 103 Control circuit (alarm), 243,253 Insulation.

Claims (9)

In an exciting device in which the rectifier circuit unit can be replaced by connecting the rectifier circuit unit with a connector portion.
Each insulating amplifier for measuring the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion is provided.
An exciting device that detects poor contact of the connector portion from changes in the output voltage of each insulated amplifier. In an exciting device in which the rectifier circuit unit can be replaced by connecting the rectifier circuit unit with a connector portion.
Each Hall CT for measuring by converting the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion into an electric current is provided.
An exciting device that detects a contact failure of the connector portion from a change in the output current of each Hall CT. In an exciting device in which the rectifier circuit unit can be replaced by connecting the rectifier circuit unit with a connector portion.
A photodetector that detects an arc is provided on the fixed contact side of the connector portion.
An exciting device that detects poor contact of the connector portion from changes in the output signal of the photodetector. From the change in the output voltage of each of the insulating amplifiers, the state of poor contact of the connector portion is determined.
The exciting device according to claim 1, which outputs an alarm signal or a stop signal depending on the state of poor contact of the connector portion. From the change in the output current of each Hall CT, the state of poor contact of the connector portion is determined.
The exciting device according to claim 2, which outputs an alarm signal or a stop signal depending on the state of poor contact of the connector portion. The exciting device according to claim 1, wherein a contact failure of the connector portion is detected from a difference in a change in the output voltage of each insulating amplifier. The exciting device according to claim 2, wherein a contact failure of the connector portion is detected from the difference in the change in the output current of each Hall CT. From the difference in the change in the output voltage of each of the insulating amplifiers, the state of poor contact of the connector portion is determined.
The exciting device according to claim 4, which outputs an alarm signal or a stop signal depending on the state of poor contact of the connector portion. From the difference in the change in the output current of each Hall CT, the state of poor contact of the connector portion is determined.
The exciting device according to claim 5, which outputs an alarm signal or a stop signal depending on the state of poor contact of the connector portion.

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