JP3913917B2 - Field shorting verification device for field winding in synchronous machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a field winding verification device for a synchronous machine that verifies whether or not a layer short has occurred in the field winding of the synchronous machine.
[0002]
[Prior art]
Conventionally, there is a gap magnetic flux measurement test as a method for verifying the presence or absence of a field short circuit in a synchronous generator, but a special sensor is required to perform the test, and hydrogen is required for the installation. In a gas cooling type generator, it is necessary to perform gas replacement to be in an atmospheric state, and furthermore, the armature winding needs to be short-circuited in three phases, which causes physical and time restrictions.
[0003]
As another method for verifying the presence or absence of a short-circuit in the field winding, there is an AC impedance measurement method. However, depending on the state of the slot wedge, the damper, and the short-circuit ring that are the rotor structure of the synchronous generator, Changes, it may be difficult to determine that the field winding is a short-circuit.
[0004]
[Problems to be solved by the invention]
In order to verify the presence or absence of a rare short-circuit in a conventional field winding as described above, there are methods of measuring air gap magnetic flux and measuring AC impedance by installing a special sensor in the machine. In the case of a generator of the type, it is necessary to short-circuit the gas replacement and armature windings in three phases, resulting in physical and time constraints. The latter is the structure of the rotor, such as slot wedges, dampers, short-circuit rings. Since the impedance changes depending on the state of the field winding, it may be difficult to determine the field short of the field winding.
[0005]
The present invention has been made in view of the above circumstances, and it is possible to determine the presence or absence of a field short of a field winding without being affected by the structure of the rotor of the synchronous machine. An object is to provide a verification device.
[0006]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a variable direct current and alternating current power supply unit for supplying an alternating current including a direct current component to a field winding during a period until the synchronous machine reaches a rated rotational speed from a stopped state, and the field the input voltage when the winding is energized, the input current, the input and filter unit for inputting the rotation speed, the input and the voltage input from the filter unit, a calculating unit for calculating the impedance from the current, the operation A comparison unit that compares the impedance change with respect to the rotation speed change calculated by the unit, and an output unit that outputs a comparison result of the comparison unit.
[0007]
According to a second aspect of the present invention, the variable DC and AC power supply sections energize the field windings of the synchronous machine simultaneously with a constant DC and AC current.
[0008]
In the invention corresponding to claim 3, the calculation unit calculates the direct current component and the impedance of the alternating current component of the input voltage and the input current divided by the filter unit.
[0009]
In the invention corresponding to claim 4, the calculation unit calculates the DC impedance and the AC impedance at each rotational speed at the same time.
[0010]
In the invention corresponding to claim 5, the comparison unit compares the change in the DC impedance and the change in the AC impedance with respect to the change in the rotational speed, and determines whether or not there is a short-circuit in the field winding.
[0011]
According to a sixth aspect of the present invention, the comparison unit uses the rotor data of the machine under test when determining the field short of the field winding.
[0012]
Therefore, in the field winding verification apparatus in the synchronous machine of the invention corresponding to the first to sixth aspects of the invention, the DC and AC impedances of the field winding of the synchronous machine are measured, and both the rotational changes are measured. By comparing and determining the change in impedance, it is possible to determine the field short of the field winding without being affected by the structure of the rotor of the synchronous machine.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0014]
FIG. 1 is a block diagram showing a first embodiment of a field short-circuit verification apparatus for a field winding in a synchronous generator according to the present invention.
[0015]
In FIG. 1, reference numeral 1 denotes a rotor shaft of a synchronous generator. A pair of collector rings 2 are attached to the rotor shaft 1, and these collector rings 2 are connected to field windings (not shown) via current leads (not shown). Electrically connected.
[0016]
The collector ring 2 is provided with a voltage measuring brush (pilot brush) 3 and a current conducting brush 4 in contact with each other. The rotor shaft 1 is provided with a rotation detector 5 (not shown). The rotation detector 5 detects the number of rotations of the rotor having field windings.
[0017]
On the other hand, 6 is a variable direct current and alternating current power supply section, and this variable direct current and alternating current power supply section 6 supplies an alternating current including a direct current component to a field winding (not shown) through the current energizing brush 4 and the collector ring 2. belongs to.
[0018]
Reference numeral 7 denotes a rotation signal of the generator field winding from the rotation detection unit 5 and an input voltage of the field winding of the synchronous generator from the voltage measuring brush 3, and a variable DC and AC power source unit 6. This is a filter unit to which the input current of the field winding is input, and this filter unit 7 has a function of dividing the input voltage and the input current into a direct current component and an alternating current component.
[0019]
Further, 8 is an arithmetic unit to which an input voltage and an input current divided into a DC component and an AC component are input from the filter unit 7, and this arithmetic unit 8 calculates DC and AC impedances based on the input voltage and the input current. Is. Reference numeral 9 denotes a comparison unit that compares the DC and AC impedances obtained by the calculation unit 8 with changes in the rotational speed of the DC and AC impedances based on previously input data to determine the presence or absence of a field short in the field winding. is there.
[0020]
Further, 10 is a display unit for displaying the comparison result in the comparison unit 9, and 11 is an output unit for outputting input data at each rotation speed compared in the comparison unit 9, a determination result, and a calculation result in the calculation unit 8. is there.
[0021]
Next, the operation of the field short-circuit verification device for the field winding in the thus configured synchronous generator will be described.
[0022]
During the period from when the synchronous generator is stopped until the rated rotational speed is reached, a DC component is applied to the field winding of the rotor (not shown) from the variable DC and AC power supply 6 via the current energizing brush 4 and collector ring 2. An alternating current including the current is supplied, and the input voltage of the field winding at this time is input to the filter unit 7 via the collector ring 2 and the voltage measuring brush 3, and at the same time, the field detection coil (rotation) The input signal for current measurement is input from the rotation detection signal and the variable DC and AC power supply unit 6.
[0023]
In the filter unit 7, the input voltage and current to the field winding are divided into a direct current component and an alternating current component and input to the calculation unit 8. In this calculation unit 8, the direct current and alternating current impedances are calculated, and the direct current and alternating current impedances are input to the comparison unit 9 and compared with the data inputted in advance for the rotational speed change of the direct current and alternating current impedances. The presence or absence of a rare short of the field winding is determined depending on whether it is large.
[0024]
The direct current and alternating current impedances determined by the arithmetic unit 8 and the presence or absence of the layer short-circuit of the field winding determined by the comparison unit 9 are the rotational speed, direct current voltage and current, alternating current voltage and current input from the filter unit 7. At the same time, it is displayed on the display unit 10.
[0025]
In addition, input data, calculation results, and determination results at each rotation speed are output from the output unit 11.
[0026]
Thus, in the first embodiment, the DC voltage and current and the AC voltage and current input to the field winding in the rotating synchronous generator are measured, and the DC and AC impedance are calculated by the calculation unit 8. Then, the direct current and alternating current impedance obtained by the calculation unit 8 are compared with changes in the rotational speed of the direct current and alternating current impedance in accordance with previously inputted data. Since the presence / absence is determined, it is possible to reliably determine whether or not the field winding is short-circuited without being affected by the structure of the generator rotor.
[0027]
In the first embodiment, an AC current containing a DC component is supplied to the field winding of the synchronous generator from the variable DC and AC power supply unit 6. A constant DC component and an AC component may be output to energize the field windings simultaneously.
[0028]
Further, in the first embodiment, the direct current and alternating current impedances are simply obtained by the computing unit 8, but the direct current impedances and alternating current impedances at the respective rotation speeds may be computed simultaneously.
[0029]
FIG. 2 is a block diagram showing a second embodiment of the field winding layer short verification apparatus in the synchronous generator according to the present invention. The same parts as those in FIG. Only the differences will be discussed here.
[0030]
In the second embodiment, as shown in FIG. 2, the comparison unit 9 is provided with a data input unit 12 for inputting the rotor data or determination value of the machine under test.
[0031]
With such a configuration, it is possible to automatically determine the presence or absence of a layer short in the field winding by inputting the rotor data of the machine under test to the comparison unit 9.
[0032]
Further, it is also possible to make a determination by inputting a determination value instead of the rotor data.
[0033]
In the above embodiment, the case where the presence or absence of the field winding in the synchronous generator is determined is described. However, the presence or absence of the layer short is also determined in the case of the field winding of the synchronous motor as described above. can do.
[0034]
【The invention's effect】
As described above, according to the present invention, a field winding layer in a synchronous machine that can reliably determine the presence or absence of a field short in the field winding without requiring any special processing for the synchronous machine in operation. A short verification device can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of a field short-circuit verification apparatus for a field winding in a synchronous generator according to the present invention;
FIG. 2 is a block configuration diagram showing a second embodiment of a field short-circuit verification apparatus for a field winding in a synchronous generator according to the present invention;
[Explanation of symbols]
1 ... Rotor shaft 2 ... Collector ring 3 ... Brush for voltage measurement (pilot brush)
4 …… Brush for current application 5 …… Rotation detection unit 6 …… Variable DC and AC power supply unit 7 …… Filter unit 8 …… Calculation unit 9 …… Comparison unit 10 …… Display unit 11 …… Output unit 12 …… Data input section

Claims (6)

During the period from when the synchronous machine is stopped to the rated rotational speed, the variable DC and AC power supply section that supplies an AC current containing a DC component to the field winding, and when the field winding is energized input voltage, input current, and input and filter unit for inputting the rotation speed, the input and the voltage input from the filter unit, a calculating unit for calculating the impedance from the current, with respect to the rotational speed change calculated by the calculating section A rare-short verification device for a field winding in a synchronous machine, comprising: a comparison unit that compares impedance changes; and an output unit that outputs a comparison result of the comparison unit. 2. The field winding in a synchronous machine according to claim 1, wherein the variable DC and AC power supply units are configured to simultaneously energize the field winding of the synchronous generator with a constant DC and AC current. Rare short verification equipment.   2. The apparatus for verifying a short-circuit in a field winding in a synchronous machine according to claim 1, wherein the arithmetic unit calculates impedances of the direct current and the alternating current of the input voltage and the input current divided by the filter unit.   2. The field short-circuit verification apparatus for a field winding in a synchronous machine according to claim 1, wherein the calculation unit simultaneously calculates a DC impedance and an AC impedance at each rotation speed.   2. The field of a synchronous machine according to claim 1, wherein the comparison unit compares the change in the direct current impedance and the change in the alternating current impedance with respect to the change in the rotational speed to determine whether or not the field winding has a short circuit. Winding rare short verification device.   6. The field winding short-circuit verification apparatus for a synchronous machine according to claim 5, wherein the comparison unit performs the use of the rotor data of the machine under test when determining the field short-circuit of the field winding.

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