JP2019216495A - Exciting device - Google Patents

Abstract

To provide an exciting device capable of preventing operation stoppage by detecting contact failure occurring at a connector part connecting a rectifier circuit unit to the exciting device.SOLUTION: In an exciting device 1 allowing exchange of a rectifier circuit unit 4 by connecting the rectifier circuit unit 4 with a connector part 5, insulating amplifiers 80A, 80B for measuring the voltage of a movable contact 42 side of the connector part 5 and the voltage of a stationary contact 52 side are provided, and contact failure of the connector part 5 is detected from the variation of the output voltage of the insulating amplifiers 80A, 80B.SELECTED DRAWING: Figure 1

Description

  The present application relates to an exciter that detects a contact failure of a connector unit provided to make a rectifier circuit unit that supplies an exciting current to a field circuit of a synchronous machine of a power generation facility replaceable.

  An exciting device 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 a field circuit of the synchronous machine. The rectifier circuit unit has a replaceable configuration by including a connector portion connected to the excitation device. The exciter uses a large fan to handle a large amount of electric power and to take in air from the outside to cool it. Depending on the installation environment, impurities such as sand and dust may enter the connector. For this reason, when a contact failure occurs, the connector is damaged, and the supply of the excitation current from the excitation device is stopped, which may eventually stop the operation of the synchronous machine.

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

JP-A-2-46149 (page 296, upper right column, line 20-lower right column, line 2; page 297, upper right column, line 15-lower left column, line 6, and FIG. 1)

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

  The present application discloses a technique for solving the above-described problem, and detects an imperfect contact that occurs in a connector portion that connects a rectifier circuit unit to an exciter, thereby preventing an operation stop. The purpose is to provide.

  The excitation device disclosed in the present application is configured such that the rectification circuit unit is replaceable by connecting the rectification circuit unit with the connector portion, and the voltage on the movable contact side and the voltage on the fixed contact side of the connector portion are reduced. Each insulation amplifier to be measured is provided, and a contact failure of the connector is detected from a change in the output voltage of each insulation amplifier.

  Further, in the excitation device disclosed in the present application, in the excitation device in which the rectification circuit unit is replaceable by connecting the rectification circuit unit with the connector portion, the voltage on the movable contact side of the connector portion and the voltage on the fixed contact side are changed. Each hole CT for converting a voltage into a current and measuring the voltage is provided, and a contact failure of the connector is detected from a change in an output current of each hole CT.

  Further, the excitation device disclosed in the present application is a photodetector that detects an arc on the fixed contact side of the connector portion in the excitation device in which the rectification circuit unit is replaceable by connecting the rectification circuit unit with the connector portion. To detect a contact failure of the connector from a change in the output signal of the photodetector.

  The excitation device disclosed in the present application is provided with each insulation amplifier for measuring the voltage on the movable contact side and the voltage on the fixed contact side of the connector section, and detects a contact failure of the connector section from a change in the output voltage of each insulation amplifier. Therefore, it is possible to prevent the excitation device from malfunctioning and stopping due to damage to the connector portion, and to continue supplying power.

  Further, the excitation device disclosed in the present application is provided with each hole CT for converting the voltage of the movable contactor side and the voltage of the fixed contactor side of the connector portion into a current and measuring the current. Since the contact failure of the connector portion is detected, it is possible to prevent the excitation device from failing and stopping due to damage to the connector portion, and to continue supplying power.

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

FIG. 2 is a configuration diagram centered on a contact failure detection circuit of a connector unit according to the excitation device according to the first embodiment. FIG. 3 is a configuration diagram of a rectifier circuit unit according to the excitation device according to the first embodiment. FIG. 3 is a block diagram of a circuit for determining a contact failure of a connector unit according to the excitation device according to the first embodiment; FIG. 4 is an explanatory diagram of a voltage behavior at the time of a contact failure of the connector unit according to the excitation device according to the first embodiment. FIG. 4 is an explanatory diagram of a voltage behavior at the time of a contact failure of the connector unit according to the excitation device according to the first embodiment. FIG. 8 is a configuration diagram centered on a contact failure detection circuit of a connector unit according to an excitation device according to a second embodiment. FIG. 13 is a configuration diagram centering on a contact failure detection circuit of a connector unit according to an excitation device according to a third embodiment. FIG. 14 is a block diagram of a contact failure determination circuit of a connector section according to an excitation device according to a fourth embodiment.

Embodiment 1 FIG.
The first embodiment relates to an exciter having a structure in which the rectifier circuit unit is replaceable by connecting the rectifier circuit unit with a connector unit, wherein each of the insulators for measuring the voltage on the movable contact side and the voltage on the fixed contact side of the connector unit. The present invention relates to an exciter that includes an amplifier and detects a contact failure of a connector unit from a change in an output voltage of each insulation amplifier.

  Hereinafter, the configuration and operation of the excitation device according to the first embodiment will be described with reference to FIG. 1 which is a configuration diagram focusing on a contact failure detection circuit of a connector unit, FIG. 2 which is a configuration diagram of a rectifier circuit unit, and FIG. A description will be given based on FIG. 3 which is a block diagram of the determination circuit, and FIGS.

First, the configuration of the excitation device according to the first embodiment will be described with reference to FIG. 1, including the relationship with a synchronous machine such as a generator.
In FIG. 1, an 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 excitation device 1 includes a rectifier circuit unit 4 that rectifies AC obtained from a three-phase AC main circuit (alternating current (AC) main circuit) into DC. In FIG. 1, the exciting current converted (rectified) from AC to DC by the rectifying circuit unit 4 is supplied to the field winding 3 in the exciting main circuit 2.
Here, the rectifier circuit unit 4 is installed in the exciter 1, but is connected via the connector unit 5, and thus has a replaceable structure.

  Note that a plurality of rectifier circuit units 4 are installed in parallel in the excitation device 1 to provide a redundant configuration. For this reason, even if a part (for example, one) of the rectifier circuit units 4 is stopped, the function of the exciter 1 is not lost. The excitation device 1 can continue the operation and supply an excitation 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 for each phase (three phases in FIG. 2). The alternating current supplied from the AC main circuit is converted into direct current by controlling the gate signal of the thyristor of each phase. In FIG. 2, the connector section 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 exchange unit of the rectifier circuit unit is not limited to the example of FIG. For example, one thyristor can be used, or two rectifier circuit units 4 shown in FIG. 2 can be combined into one rectifier circuit unit.

Next, the structure of the connector section 5 will be described.
The connector section 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 a contact failure occurs, the contact resistance 53 between the movable contact 42 and the fixed contact 52 may increase.
Insulating amplifiers 60A and 60B are provided to measure the voltage at both ends of the connector section 5 (the movable contact 42 side and the fixed contact 52 side).
In FIG. 1, details of a connector section for connecting the rectifier circuit unit 4 and the AC main circuit are omitted, but the configuration is the same as that of the connector section 5 for connecting the rectifier circuit unit 4 and the excitation main circuit 2. is there.

Next, the function and operation of the excitation device 1 according to the first embodiment will be described focusing on detection of a contact failure of the connector unit 5.
The insulation amplifier 60A measures the voltage V1 on the movable contact 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 potential of the insulating amplifiers 60A and 60B is set to the control common 62, that is, the ground 61. However, the connection is not limited to this connection form, as long as it can be compared with a certain reference potential.

FIG. 3 is a block diagram of the contact failure determination circuit 70 using voltages measured by the isolation amplifiers 60A and 60B.
The voltage V1 on the movable contact 42 and the voltage V2 on the fixed contact 52 are added by an adder 73 through a buffer 71 and an inverter 72, respectively. The buffer 71 outputs the measured voltage as it is to the adder 73, and the inverter 72 inverts the sign and outputs it 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 supplying the exciting current to the field winding 3 of the synchronous machine.

FIG. 4 shows the behavior of the voltage when the contact failure is detected.
The voltage V1 on the rectifier circuit unit 4 side, that is, the movable contact 42 side shows a constant rectified waveform regardless of the contact failure. On the other hand, a voltage difference occurs between the voltage V2 on the excitation main circuit 2 side, that is, on the fixed contact 52 side when a contact failure occurs.
Therefore, a difference voltage (voltage V1−voltage V2) is generated which is obtained by adding the voltage V2 on the fixed contact 52 side inverted by the inverter 72 and the voltage V1 on the movable contact 42 side.
Although FIG. 4 shows a waveform like a sawtooth wave, the waveform of the voltage difference may actually be a pulse shape.

  The contact failure determination circuit 70 sets a certain threshold for determining contact failure, and determines that a contact failure has occurred when the difference voltage (voltage V1−voltage V2) exceeds this value. Further, it is also possible to determine a 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 when a contact failure is detected when a DC current flows through the connector unit 5.
An alternating current flows through the connector section 5 connecting the rectifier circuit unit 4 and the AC main circuit. FIG. 5 is an explanatory diagram of the behavior of the voltage when a contact failure is detected when an alternating current flows through the connector unit 5.
When an alternating current flows through the connector section 5, the voltages (the voltage V1 on the movable contact 42 and the voltage V2 on the fixed contact 52) measured by the insulating amplifiers 60A and 60B have a sine wave shape.
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 excitation device 1 of the first embodiment can detect a contact failure of the connector unit 5 and stop and replace only the rectifier circuit unit 4 including the connector unit 5 in which the contact failure has occurred. it can. For this reason, it is possible to prevent failure and stoppage of the operation of the excitation device 1 due to poor contact of the connector portion 5, and to continue power supply.

As described above, in the first embodiment, in the excitation device having a structure that can be replaced by connecting the rectifier circuit unit by the connector, the voltage on the movable contact side and the fixed contact The present invention relates to an excitation device provided with each insulation amplifier for measuring a voltage and detecting a contact failure of a connector unit from a change in an output voltage of each insulation amplifier.
Therefore, the excitation device according to the first embodiment can prevent the excitation device from failing and stopping due to damage to the connector portion, and can continue to supply the excitation current to the field winding of the synchronous machine.

Embodiment 2. FIG.
In the excitation device of the first embodiment, in order to detect a contact failure of the connector section, each of the isolation amplifiers for measuring the voltage on the movable contact side and the fixed contact side of the connector section is provided. In the excitation device of the second embodiment, the voltage on the movable contact side and the voltage on the fixed contact side of the connector section are measured by using a Hall CT (current transformer) instead of the insulating amplifier.

Hereinafter, the configuration and operation of the excitation device according to the second embodiment will be described focusing on the difference from the first embodiment based on FIG. Will be described. 6, the same or corresponding parts as those in FIG. 1 of the first embodiment are denoted by the same reference numerals.
It should be noted that the excitation device 100 is used for distinction from the first embodiment. In addition, FIG. 3 of the first embodiment is appropriately referred to.

The function and operation of the excitation device 100 according to the second embodiment will be described focusing on detection of a contact failure of the connector 5.
In the first embodiment, the voltages at both ends of the connector section 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 section 5 is converted into a current, and then measured using the Hall CTs 80A and 80B.

Specifically, a high impedance resistor 81 is installed at both end portions (movable contact 42, fixed contact 52) of the connector portion 5, and the magnitude of the current passing through the through portions 82A, 82B of the holes CT 80A, 80B is reduced by the Hall effect. Measured by
After the current is measured by the Hall CTs 80A and 80B, the current is converted to 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 of the movable contact 42 is set to a voltage V3, and the output of the amplifier 83B corresponding to the voltage of the fixed contact 52 is set to a voltage V4.

The block diagram of the contact failure determination circuit after converting the currents measured by the hall CTs 80A and 80B into voltages 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 CT 80A, that is, the output voltage V3 of the amplifier 83A, and the input of the inverter 72 is the Hall CT 80B, that is, the output voltage V4 of the amplifier 83B.

In the excitation device 100 according to the second embodiment, the voltage at both ends of the connector unit 5 is converted into a current, and this current is measured by the Hall CT. Poor contact can be detected.
The excitation device 100 according to the second embodiment uses the inexpensive Hall CTs 80A and 80B as the measuring means compared to the insulated amplifiers 60A and 60B, so that the cost is lower than the excitation device 1 according to the first embodiment. Can be reduced.

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

Embodiment 3 FIG.
In the excitation device according to the third embodiment, a photodetector is provided in the connector to detect a contact failure of the connector.

Hereinafter, the configuration and operation of the excitation device according to the third embodiment will be described focusing on differences from the first embodiment based on FIG. 7 which is a configuration diagram centering on a contact failure detection circuit of a connector unit according to the excitation device. Will be described. 7, the same or corresponding parts as those in FIG. 1 of the first embodiment are denoted by the same reference numerals.
It should be noted that the excitation device 200 is used for distinction from the first embodiment.

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

First, the structure of the connector unit 205 of the excitation device 200 according to the third embodiment will be described.
The connector section 205 includes a movable contact 242 and a fixed contact 252. The connector section 205 has a structure in which insulation from the outside is achieved by an insulator 243 on the movable contact side and an insulator 253 on the fixed contact side.
Then, the photodetector 90 is provided on the insulator 253 of the fixed contact 252 of the connector section 205.

Since a large current flows through the connector unit 205, when a contact failure occurs in the contact unit, light is generated by an arc. The light detector 90 detects the light due to the arc.
The output of the photodetector 90 is compared with a predetermined set value by the contact failure determination circuit 270, and outputs a stop signal as in the case of the excitation device 1 of the first embodiment.
It is clear that the configuration of the contact failure determination circuit 270 is the same as that of the contact failure determination circuit 70 of FIG. 3 except that the inverter 72 and the adder 73 are omitted.

  In the excitation device 200 according to the third embodiment, since the photodetector 90 is provided in the connector portion 205, there is no need 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 excitation device of the third embodiment, a photodetector is provided in the connector to detect a contact failure of the connector.
Therefore, the excitation device of the third embodiment can prevent the excitation device from failing and stopping due to damage to the connector portion, and can continue to supply the excitation current to the field winding of the synchronous machine. Furthermore, it can be easily applied to existing systems.

Embodiment 4 FIG.
The excitation device according to the fourth embodiment has a configuration in which the contact failure determination circuit of the excitation device 1 according to the first embodiment generates an alarm signal as well as a stop signal when a contact failure occurs.

Hereinafter, the configuration and operation of the contact failure determination circuit of the excitation device according to the fourth embodiment will be described focusing on differences from the first embodiment based on FIG. 8 which is a block diagram of the contact failure determination circuit of the connector unit. I do. 8, the same or corresponding parts as those in FIG. 3 of the first embodiment are denoted by the same reference numerals.
Note that the contact failure determination circuit 370 is provided in order to be distinguished from the first embodiment. In addition, FIG. 1 of the first embodiment is appropriately referred to.

  In the contact failure determination circuit 70 of the excitation device 1 according to the first embodiment, the output voltage of the adder 73 and the set value A of the setter 75 are compared by the comparator 74 as described with reference to FIG. When the output voltage is higher 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 supplying the exciting current to the field winding 3 of the synchronous machine.

In the poor contact determination circuit 370 of the excitation device according to the fourth embodiment, a comparator 101, a setting device 102, and a control circuit (alarm) 103 are added to the configuration of FIG.
The comparator 101 compares the output voltage of the adder 73 with the set value B of the setter 102, and outputs an alarm signal to the control circuit (alarm) 103 when the output voltage of the adder 73 is larger than the set value B.

Here, the set value A is a value at which the damage of the connector unit 5 becomes severe, and the set value B is a value at which the damage of the connector unit 5 can be determined to be slight.
The contact failure at the connector section 5 does not occur suddenly but occurs stepwise. Therefore, by detecting the slight damage of the connector section 5 beforehand, it is possible to grasp the sign of the contact failure. Thereby, there is an effect that maintenance and replacement time of the connector portion 5 can be determined early.
Further, when the rectifier circuit unit 4 is connected to the excitation device 1, the movable contact 42 of the connector section 5 is inserted into the fixed contact 52, and there is also an effect that a contact failure at the time of the insertion can be immediately grasped.

In the above description of the excitation device according to the fourth embodiment, the contact failure determination circuit of the excitation 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, when applied to the excitation device of the second embodiment, the contact failure determination circuit of the excitation device 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. it can.

The excitation device according to the fourth embodiment has a configuration in which the contact failure determination circuit of the excitation device 1 according to the first embodiment generates an alarm signal as well as a stop signal when a contact failure occurs.
Therefore, the excitation device according to the fourth embodiment can prevent the excitation device from failing and stopping due to damage to the connector portion, and can continue to supply the excitation current to the field winding of the synchronous machine. Further, it is possible to grasp the sign of the contact failure of the connector portion, and to improve the maintainability.

Although this application describes various exemplary embodiments and examples, various features, aspects, and functions described in one or more embodiments may be applied to particular embodiments. The present invention is not limited to this, and can be applied to the embodiments alone or in various combinations.
Accordingly, innumerable modifications not illustrated are envisaged within the scope of the technology disclosed in the present application. For example, the case where at least one component is deformed, the case where the component is added or omitted, the case where the at least one component is extracted and combined with the component of another embodiment are included.

1,100,200 excitation device, 2 excitation main circuit, 3 field winding,
4 rectifier circuit unit, 5,205 connector part, 42,242 movable contact,
52,252 fixed contact, 53 contact resistance, 60A, 60B insulated amplifier,
61 ground, 62 control common, 70, 270, 370 contact failure judgment circuit,
71 buffer, 72 inverter, 73 adder, 74, 101 comparator,
75, 102 setting device, 76 control circuit (stop), 80A, 80B Hall CT,
81 High impedance resistance, 82A, 82B penetration part, 83A, 83B amplifier,
90 photodetector, 103 control circuit (alarm), 243,253 insulator.

Claims (9)

By connecting the rectifier circuit unit by a connector portion, in the excitation device in which the rectifier circuit unit is replaceable,
Provide each insulation amplifier for measuring the voltage on the movable contact side and the fixed contact side of the connector section,
An exciter for detecting a contact failure of the connector section from a change in an output voltage of each of the insulating amplifiers. By connecting the rectifier circuit unit by a connector portion, in the excitation device in which the rectifier circuit unit is replaceable,
Provide each hole CT for converting the voltage on the movable contact side and the voltage on the fixed contact side of the connector section into a current and measuring the current,
An exciter for detecting a contact failure of the connector portion from a change in an output current of each of the holes CT. By connecting the rectifier circuit unit by a connector portion, in the excitation device in which the rectifier circuit unit is replaceable,
Providing a photodetector for detecting an arc on the fixed contact side of the connector section,
An exciter for detecting a contact failure of the connector from a change in an output signal of the photodetector. From the change in the output voltage of each of the insulation amplifier, determine the state of poor contact of the connector portion,
The exciting device according to claim 1, wherein an alarm signal or a stop signal is output according to a state of the contact failure of the connector section. From the change in the output current of each of the holes CT, determine the state of poor contact of the connector portion,
The excitation device according to claim 2, wherein an alarm signal or a stop signal is output according to a state of the contact failure of the connector portion. The excitation device according to claim 1, wherein a contact failure of the connector unit is detected from a difference between changes in output voltages of the respective isolation amplifiers. The exciting device according to claim 2, wherein a contact failure of the connector portion is detected from a difference between changes in output current of each of the holes CT. From the difference between the changes in the output voltage of each of the insulating amplifiers, determine the state of poor contact of the connector portion,
The exciting device according to claim 4, wherein an alarm signal or a stop signal is output according to a state of the contact failure of the connector portion. From the difference between the changes in the output current of each of the holes CT, the state of the contact failure of the connector portion is determined,
The excitation device according to claim 5, wherein an alarm signal or a stop signal is output according to a state of the contact failure of the connector portion.

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