CN103163433A - Method for monitoring insulation condition of generator stator and power distribution network on line and performing fault line selection - Google Patents
Method for monitoring insulation condition of generator stator and power distribution network on line and performing fault line selection Download PDFInfo
- Publication number
- CN103163433A CN103163433A CN2013100681431A CN201310068143A CN103163433A CN 103163433 A CN103163433 A CN 103163433A CN 2013100681431 A CN2013100681431 A CN 2013100681431A CN 201310068143 A CN201310068143 A CN 201310068143A CN 103163433 A CN103163433 A CN 103163433A
- Authority
- CN
- China
- Prior art keywords
- distribution network
- generator stator
- power distribution
- insulation
- grounding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000009413 insulation Methods 0.000 title claims abstract description 151
- 238000012544 monitoring process Methods 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000007935 neutral effect Effects 0.000 claims abstract description 50
- 230000001629 suppression Effects 0.000 claims description 22
- 238000010187 selection method Methods 0.000 claims description 12
- 238000010586 diagram Methods 0.000 description 10
- 238000001514 detection method Methods 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
Images
Landscapes
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The invention discloses a method for monitoring the insulation condition of a generator stator and a power distribution network on line and performing fault line selection, belongs to the method for monitoring the insulation condition of the generator stator or the power distribution network on line and aims to provide the method for accurately monitoring the insulation condition of the generator stator or the power distribution network on line. According to the method, a resistor is connected in series on a neutral point circuit of the generator stator or the power distribution network or between a neutral point of a voltage transformer and ground, and a voltage signal is applied to the resistor, so that a voltage signal is externally applied to the generator stator or the power distribution network; and the insulation value of the generator stator or the power distribution network relative to the ground can be calculated by measuring electrical parameters of the voltage signal, and the insulation condition can be judged according to the magnitude of the insulation value. The method is not influenced by the running mode, the distributed capacitance, the power network structure, the ground type and the like, is the method for monitoring the insulation condition of the generator stator or the power distribution network on line and performing fault line selection and avoids the accidents of the power network.
Description
Technical Field
The invention relates to a method for monitoring the insulation condition of a generator or a power distribution network on line, in particular to a method for monitoring the insulation condition of a stator of the generator on line, the insulation condition of the power distribution network on line and the branch grounding line selection of the power distribution network.
Background art:the generator stator is an important part of a generator, and the generator stator and a connecting wire thereof are required to be insulated from an iron core or the ground; similarly, the distribution network also requires insulation from the ground, so the insulation conditions of the generator stator and the distribution network are directly related to the generator and the distribution networkThe operation of the power grid is safe. The neutral point of the generator stator or the distribution network transformer is not directly grounded generally, and is grounded through an arc suppression coil or a resistor. At present, the insulation on-line monitoring and grounding line selection of a generator stator or a power distribution network mainly comprise the following methods:
1) and judging the insulation condition of the generator stator or the power distribution network according to the voltage of the zero sequence voltage transformer or the symmetry of the three-phase voltage. When the ground resistance is high or the insulation symmetry is reduced, it is difficult to accurately judge the insulation condition because the zero sequence voltage is low or the three-phase voltage is basically symmetrical.
2) A capacitor is connected in series between the neutral point of the transformer of the generator stator or the distribution network or the neutral point of the voltage transformer and the ground, and a direct current signal is applied to the capacitor to monitor the insulation condition of the generator stator or the distribution network. But this capacitance will form a series resonance with the inductance in these devices, causing overvoltage, compromising the grid safety. For the neutral point to be grounded through an arc suppression coil or a grounding resistor, when the neutral point of the voltage transformer is also grounded, the direct current resistor of the transformer is monitored, but not the insulation resistor in the power grid to which the voltage transformer belongs; although the dc current can be isolated by connecting a capacitor in series with the transformer neutral, it will also form a series resonance with the transformer inductance, compromising the grid safety.
3) The insulation condition of the generator stator or the power distribution network is monitored by applying an alternating current signal of more than 10Hz to the generator stator or the power distribution network through a neutral point of a transformer of the generator stator or the power distribution network or a voltage transformer according to a transformer principle mode. The method can be influenced by the distributed capacitance of a generator stator or a power distribution network, so that only low-resistance grounding can be monitored generally; when the neutral point of the voltage transformer is grounded, the influence of the direct current resistance of the voltage transformer is large, and the detection precision is low.
4) The small current grounding line selection method realized by the principles of zero sequence current amplitude, zero sequence power direction, quintic harmonic, first half wave, alternating current injection and the like is not high in correct line selection rate due to the influence of operation mode, distributed capacitance, power grid structure and grounding type.
The invention content is as follows:aiming at the defects in the prior art, the invention aims to provide a method for monitoring the insulation of a generator stator and a power distribution network on line and selecting the grounding line of the generator stator and the power distribution network on line; the method not only can accurately monitor the insulation level of the generator stator or the power distribution network in real time, but also can realize accurate grounding line selection.
In order to achieve the purpose, the method adopts the following technical scheme: when only a neutral point of a voltage transformer is grounded to form a first grounding loop, or only a neutral point of a generator stator or a distribution network transformer is grounded through an arc suppression coil or a grounding resistor to form a second grounding loop, a resistor is connected in series with the first grounding loop or the second grounding loop, and a direct current or alternating current signal is applied to two ends of the resistor; according to current flow to generator stator or distribution networkICurrent flowing to each branch distribution networkI n And a voltage applied across the resistorUCalculating the total insulation resistance of the generator stator or the distribution networkR d Insulation resistance of each branch power distribution networkR dn And the insulation state of the generator stator or the distribution network is detected based on the insulation state; if total insulation resistanceR d If the insulation degree of the generator stator or the distribution network is smaller than the preset setting value, the insulation degree of the generator stator or the distribution network can be judged to be reduced or a ground fault occurs; if the insulation resistance of a branch distribution networkR dn If the value is less than the preset setting value, the insulation degree of the branch power distribution network can be judged to be reduced or a ground fault occurs.
In the above technical solution, when only the neutral point of the voltage transformer is grounded, the resistor is connected in series to the first ground loop, and if the electrical signal applied to the two ends of the resistor is a dc signal, the total insulation resistance of the generator stator or the distribution network
Insulation resistance of each branch power distribution network
(ii) a If the electrical signal applied across the resistor is an AC signal, the total insulation resistance of the generator stator or the distribution network is
Insulation resistance of each branch power distribution network
。
When only the neutral point of the generator stator or the distribution network transformer is grounded through the arc suppression coil or the grounding resistor, the resistor is connected in series on the second grounding loop, if the electric signals applied to the two ends of the resistor are direct current signals, the total insulation resistance of the generator stator or the distribution network is the direct current signal
The insulation resistance of each branch power distribution network is
(ii) a If the electrical signal applied across the resistor is an AC signal, the total insulation resistance of the generator stator or the distribution network is
Insulation resistance of each branch power distribution network
。
When the neutral point of the generator stator or the distribution network transformer is grounded through an arc suppression coil or a grounding resistor to form a second grounding loop, and the neutral point of the voltage transformer is also grounded to form a first grounding loop, a resistor is connected in series on the first grounding loop or the second grounding loop, and a current transformer or a method for changing the grounding connection line is used for the first grounding loop and the second grounding loopThe influence of one of the ground loop resistances is eliminated; applying a DC or AC signal across the resistor in response to current flowing to the generator stator or the distribution networkICurrent flowing to each branch distribution networkI n And a voltage applied across the resistorUCalculating the total insulation resistance of the generator stator or the distribution networkR d Insulation resistance of each branch power distribution networkR dn And the insulation state of the generator stator or the distribution network is detected based on the insulation state; if total insulation resistanceR d If the insulation degree of the generator stator or the distribution network is smaller than the preset setting value, the insulation degree of the generator stator or the distribution network can be judged to be reduced or a ground fault occurs; if the insulation resistance of a branch distribution networkR dn If the value is less than the preset setting value, the insulation degree of the branch power distribution network can be judged to be reduced or a ground fault occurs.
In the above technical solution, the first ground loop and the second ground loop simultaneously pass through the current transformer, and if the electrical signals applied to the two ends of the resistor are direct current signals, the total insulation resistance of the generator stator or the distribution network
Insulation resistance of each branch power distribution network
(ii) a Total insulation resistance of generator stator or distribution network if the electrical signal applied across the resistance is an alternating current signal
Insulation resistance of each branch power distribution network。
The influence of one of the grounding loop resistors can be eliminated by connecting the neutral point of the voltage transformer with the second grounding loop in parallel and then penetrating through the voltage transformer; at this time, if the electrical signal applied to both ends of the resistor is straightFlow signal, total insulation resistance of generator stator or distribution network
Insulation resistance of each branch power distribution network
(ii) a Total insulation resistance of generator stator or distribution network if the electrical signal applied across the resistance is an alternating current signal
Insulation resistance of each branch power distribution network
。
The secondary coil of the current transformer and the secondary coil of the compensating current transformer can be connected in series or in parallel, and the influence of the resistance of one grounding loop can be eliminated by respectively passing the first grounding loop and the second grounding loop through the current transformer and the compensating current transformer. At this time, if the electric signal applied to both ends of the resistor is a direct current signal, the total insulation resistance of the generator stator or the distribution network
Insulation resistance of each branch power distribution network
(ii) a Total insulation resistance of generator stator or distribution network if the electrical signal applied across the resistance is an alternating current signalInsulation resistance of each branch power distribution network
。
In each of the above technical solutions, when the electrical signal applied to both ends of the resistor is a dc signal,U is prepared fromA direct current voltage is applied across the resistor,Ifor direct current to the generator stator or the distribution network,I n in the direction of flow tonThe direct current of the strip branch power distribution network,nis the serial number of branch distribution networks in a certain distribution network,nis an integer of 1 or more. When the electrical signal applied across the resistor is an ac signal,
、
、
，U is the amplitude of the alternating voltage applied to the two ends of the resistor,IIn the amplitude of the alternating current flowing to the generator stator or to the distribution network,
is the phase difference between the ac voltage and the ac current,I n in the direction of flow tonThe amplitude of the alternating current of the strip branch power distribution network, n is an alternating voltage and a currentnThe phase difference between the alternating currents of the strip branch distribution network,nis the serial number of a certain branch power distribution network,nis an integer of 1 or more.
In each technical scheme, because the resistances or impedances and the ground resistance of the voltage transformer, the generator stator or the distribution network transformer, the branch distribution network and the arc suppression coil are all low, the resistances or impedances and the ground resistance are ignored.
Compared with the prior art, the method of the invention adopts the technical scheme, not only can monitor the integral insulation level of the generator stator and the distribution network system in real time, but also can accurately realize grounding line selection; the method is not influenced by the operation mode, the distributed capacitance, the power grid structure and the grounding type.
Description of the drawings:
FIG. 1 is a schematic structural diagram of a generator stator or a power distribution network when only a neutral point of a voltage transformer is grounded and a direct current signal is applied;
FIG. 2 is a schematic structural diagram of a generator stator or a power distribution network when only a neutral point of a voltage transformer is grounded and an alternating current signal is applied;
FIG. 3 is a schematic structural diagram of the generator stator or the distribution network when only the neutral point of the generator stator or the distribution network transformer is grounded through an arc suppression coil or a ground resistor and a direct current signal is applied;
FIG. 4 is a schematic structural diagram of the generator stator or the distribution network when only the neutral point of the generator stator or the distribution network transformer is grounded through an arc suppression coil or a ground resistor and an alternating current signal is applied;
FIG. 5 is a first schematic structural diagram of the generator stator or the distribution network when a neutral point of a transformer of the generator stator or the distribution network is grounded through an arc suppression coil or a ground resistor, a neutral point of a voltage transformer is also grounded, and a direct current signal is applied;
FIG. 6 is a second schematic structural diagram of the generator stator or the distribution network when the neutral point of the transformer of the generator stator or the distribution network is grounded through an arc suppression coil or a ground resistor, the neutral point of the voltage transformer is also grounded, and a direct current signal is applied;
FIG. 7 is a third schematic structural diagram of the generator stator or the distribution network when the neutral point of the transformer of the generator stator or the distribution network is grounded through an arc suppression coil or a ground resistor, the neutral point of a voltage transformer is also grounded, and a direct current signal is applied;
FIG. 8 is a first schematic structural diagram of the generator stator or the distribution network when the neutral point of the transformer of the generator stator or the distribution network is grounded through an arc suppression coil or a grounding resistor, the neutral point of a voltage transformer is also grounded, and an alternating current signal is applied;
FIG. 9 is a second schematic structural diagram of the generator stator or the distribution network when the neutral point of the transformer of the generator stator or the distribution network is grounded through an arc suppression coil or a ground resistor, the neutral point of the voltage transformer is also grounded, and an alternating current signal is applied;
fig. 10 is a third schematic structural diagram of the generator stator or the distribution network when the neutral point of the transformer of the generator stator or the distribution network is grounded through an arc suppression coil or a grounding resistor, the neutral point of a voltage transformer is also grounded, and an alternating current signal is applied.
In the figure: generator stator or distribution network transformer 1 branch distribution network 2 current transformer 3 resistance 4 direct current signal 5 voltage transformer 6 arc suppression coil or grounding resistance 7 alternating current signal 8 compensation current transformer 9
The specific implementation mode is as follows:the invention will be further described with reference to the following drawings and specific examples:
example 1
As shown in fig. 1: the generator stator or the distribution network transformer 1 is electrically connected with the branch distribution network 2, and the voltage transformer 6 is connected between the output end of the generator stator or the distribution network transformer 1 and the ground to form a first grounding loop; the resistor 4 with the direct current signal 5 applied to two ends is connected in series between the neutral point of the voltage transformer 6 and the ground (i.e. the resistor 4 is connected on the first grounding loop). The current mutual inductor 3 is used for respectively measuring the current flowing to the stator of the generator or the transformer 1 of the distribution networkITo the firstnCurrent of strip branch distribution network 2I n And according to the voltage applied across the resistor 4UThe total insulation resistance of the generator stator or the distribution network transformer 1 with respect to the ground is calculated without counting the resistance of the voltage transformer 6
And a firstnInsulation of strip branch power distribution network 2 relative to groundResistance (RC)；nIs the serial number of the distribution network 2 of a certain branch,nis an integer of 1 or more.
To be provided withR d Based on the detection of the insulation state of the generator stator or the distribution networkR dn The insulation state of each branch power distribution network 2 is detected according to the insulation state; if total insulation resistanceR d If the insulation degree of the generator stator or the distribution network transformer 1 is smaller than the preset setting value, the insulation degree is reduced or a ground fault occurs; if the insulation resistance of a certain branch of the distribution network 2R dn If the insulation degree of the branch power distribution network 2 is smaller than the preset setting value, the insulation degree of the branch power distribution network 2 can be judged to be reduced or the ground fault occurs.
Example 2
As shown in fig. 2: based on the embodiment 1, the AC signal 8 is used to replace the DC signal 5, and the total insulation resistance of the generator stator or the distribution network transformer 1 relative to the ground is calculated under the condition of considering the distributed capacitance influence and not counting the impedance of the voltage transformer 6
And a firstnInsulation resistance of strip branch power distribution network 2 relative to ground
。
In the above two formulae:
、
，
、
；Ufor the amplitude of the alternating voltage applied across the resistor 4,Iin order to obtain an amplitude of the alternating current flowing to the generator stator or distribution network transformer 1,is the phase difference between the ac voltage and the ac current,I n in the direction of flow tonThe alternating current amplitude of the strip branch distribution network 2,
n is an alternating voltage and a currentnThe phase difference between the alternating currents of the strip branch power distribution network 2,nis the serial number of the distribution network 2 of a certain branch,nis an integer of 1 or more.
Example 3
As shown in fig. 3: the generator stator or the distribution network transformer 1 is electrically connected with the branch distribution network 2, the neutral point of the generator stator or the distribution network transformer 1 is grounded through an arc suppression coil or a grounding resistor 7 to form a second grounding loop, and a resistor 4 with a direct current signal 5 applied to two ends is connected between the neutral point of the generator stator or the distribution network transformer 1 and the ground in series or between the neutral point of the generator stator or the distribution network transformer 1 and the arc suppression coil or the grounding resistor 7 in series (namely, the resistor 4 is connected on the second grounding loop). The current mutual inductor 3 is used for respectively measuring the current flowing to the stator of the generator or the transformer 1 of the distribution networkITo the firstnCurrent of strip branch distribution network 2I n And according to the voltage applied across the resistor 4UCalculating the total insulation resistance of the generator stator or the distribution network transformer 1 relative to the ground
And a firstnInsulation resistance of strip branch power distribution network 2 relative to ground；nIs the serial number of the distribution network 2 of a certain branch,nis an integer of 1 or more.
To be provided withR d Based on the detection of the insulation state of the generator stator or the distribution networkR dn The insulation state of each branch power distribution network 2 is detected according to the insulation state; if total insulation resistanceR d If the insulation degree of the generator stator or the distribution network transformer 1 is smaller than the preset setting value, the insulation degree is reduced or a ground fault occurs; if the insulation resistance of a certain branch of the distribution network 2R dn If the insulation degree of the branch power distribution network 2 is smaller than the preset setting value, the insulation degree of the branch power distribution network 2 can be judged to be reduced or the ground fault occurs.
Example 4
As shown in fig. 4: based on the embodiment 3, the AC signal 8 is used to replace the DC signal 5, and the total insulation resistance of the generator stator or the distribution network transformer 1 relative to the ground is calculated under the condition of considering the distributed capacitance influence and not counting the impedance of the generator stator or the distribution network transformer 1 and the arc suppression coil or the grounding resistance 7
And a firstnInsulation resistance of strip branch power distribution network 2 relative to ground
。
In the above two formulae:
、
，
、
；Ufor the amplitude of the alternating voltage applied across the resistor 4,Iin order to obtain an amplitude of the alternating current flowing to the generator stator or distribution network transformer 1,
is the phase difference between the ac voltage and the ac current,I n in the direction of flow tonThe alternating current amplitude of the strip branch distribution network 2,
n is an alternating voltage and a currentnThe phase difference between the alternating currents of the strip branch power distribution network 2,nis the serial number of the distribution network 2 of a certain branch,nis an integer of 1 or more.
Example 5
As shown in fig. 5: a generator stator or a distribution network transformer 1 is electrically connected with a branch distribution network 2, a neutral point of the generator stator or the distribution network transformer 1 is grounded through an arc suppression coil or a grounding resistor 7 to form a second grounding loop, and a neutral point of a voltage transformer 6 is grounded to form a first grounding loop; the first grounding loop and the second grounding loop simultaneously pass through a current transformer 3 to offset the grounding current of a neutral point grounding loop of the first grounding loop, and a resistor 4 with a direct current signal 5 applied to two ends is connected in series between the neutral point of a generator stator or a distribution network transformer 1 and the ground, or between the neutral point of the generator stator or the distribution network transformer 1 and an arc suppression coil or grounding resistor 7 (namely the resistor 4 is connected on the second grounding loop), or connected in series on the first grounding loop. The current mutual inductor 3 is used for respectively measuring the current flowing to the stator of the generator or the transformer 1 of the distribution networkITo the firstnCurrent of strip branch distribution network 2I n And according to the voltage applied across the resistor 4U(disregarding the first ground return path and the second ground connection)Resistance of ground loop), the total insulation resistance of the generator stator or distribution network transformer 1 with respect to the ground is calculatedAnd a firstnInsulation resistance of strip branch power distribution network 2 relative to ground
；nIs the serial number of the distribution network 2 of a certain branch,nis an integer of 1 or more.
To be provided withR d Based on the detection of the insulation state of the generator stator or the distribution networkR dn The insulation state of each branch power distribution network 2 is detected according to the insulation state; if total insulation resistanceR d If the insulation degree of the generator stator or the distribution network transformer 1 is smaller than the preset setting value, the insulation degree is reduced or a ground fault occurs; if the insulation resistance of a certain branch of the distribution network 2R dn If the insulation degree of the branch power distribution network 2 is smaller than the preset setting value, the insulation degree of the branch power distribution network 2 can be judged to be reduced or the ground fault occurs.
Example 6
As shown in fig. 6: on the basis of the embodiment 5, the neutral point of the voltage transformer 6 can be connected in parallel with the second grounding loop and then passes through the voltage transformer to eliminate the influence of the resistance of one grounding loop.
Example 7
As shown in fig. 7: on the basis of the embodiment 5, the secondary coil of the current transformer 3 and the secondary coil of the compensating current transformer 9 can be connected in series or in parallel, and the first grounding loop and the second grounding loop respectively pass through the current transformer 3 and the compensating current transformer 9 to eliminate the influence of one grounding loop resistor.
Example 8
As shown in fig. 8: in addition to the embodiment 5, the ac signal 8 is used to replace the dc signal 5, and the total insulation resistance of the generator stator or the distribution network transformer 1 with respect to the ground is calculated under the condition that the distributed capacitance influence is considered and the first ground loop and the second ground loop impedance are not counted
(ii) a And the firstnInsulation resistance of strip branch power distribution network 2 relative to ground。
In the above two formulae:
、
，、
；Ufor the amplitude of the alternating voltage applied across the resistor 4,Iin order to obtain an amplitude of the alternating current flowing to the generator stator or distribution network transformer 1,is the phase difference between the ac voltage and the ac current,I n in the direction of flow tonThe alternating current amplitude of the strip branch distribution network 2, n is an alternating voltage and a currentnThe phase difference between the alternating currents of the strip branch power distribution network 2,nis the serial number of the distribution network 2 of a certain branch,nis an integer of 1 or more.
Example 9
As shown in fig. 9: on the basis of the embodiment 8, the neutral point of the voltage transformer 6 can be connected in parallel with the second grounding loop and then passes through the voltage transformer to eliminate the influence of the resistance of one grounding loop.
Example 10
As shown in fig. 10: on the basis of the embodiment 8, the secondary coil of the current transformer 3 and the secondary coil of the compensating current transformer 9 can be connected in series or in parallel, and the first grounding loop and the second grounding loop respectively pass through the current transformer 3 and the compensating current transformer 9 to eliminate the influence of one grounding loop resistor.
Claims (12)
1. A method for on-line monitoring of insulation of a generator stator and a power distribution network and grounding line selection of the generator stator and the power distribution network is characterized by comprising the following steps: when only a neutral point of a voltage transformer is grounded to form a first grounding loop, or only a neutral point of a generator stator or a distribution network transformer is grounded through an arc suppression coil or a grounding resistor to form a second grounding loop, a resistor is connected in series with the first grounding loop or the second grounding loop, and a direct current or alternating current signal is applied to two ends of the resistor; according to current flow to generator stator or distribution networkICurrent flowing to each branch distribution networkI n And a voltage applied across the resistorUCalculating the total insulation resistance of the generator stator or the distribution networkR d Insulation resistance of each branch power distribution networkR dn And the insulation state of the generator stator or the distribution network is detected based on the insulation state; if total insulation resistanceR d If the insulation degree of the generator stator or the distribution network is smaller than the preset setting value, the insulation degree of the generator stator or the distribution network can be judged to be reduced or a ground fault occurs; if the insulation resistance of a branch distribution networkR dn If the value is less than the preset setting value, the insulation degree of the branch power distribution network can be judged to be reduced or a ground fault occurs.
2. The generator stator, the distribution network insulation on-line monitoring and the grounding line selection method thereof according to claim 1, characterized in that: a resistor connected in series with the first ground loop, the electric signal applied to both ends of the resistor being DC signal, the total insulation resistance of the generator stator or the distribution network
Insulation resistance of each branch power distribution network；nIs the serial number of a certain branch power distribution network,nis an integer of 1 or more.
3. The generator stator, the distribution network insulation on-line monitoring and the grounding line selection method thereof according to claim 1, characterized in that: a resistor connected in series with the first ground loop, an electric signal applied to both ends of the resistor being an AC signal, the total insulation resistance of the generator stator or the distribution network
(ii) a Wherein,
、
，
is the phase difference between the alternating voltage and the alternating current; insulation resistance of each branch power distribution network
(ii) a Wherein,
、
，
n is an alternating voltage and a currentnThe phase difference between the alternating currents of the individual branch distribution networks,nis the serial number of a certain branch power distribution network,nis an integer of 1 or more.
4. The generator stator, the distribution network insulation on-line monitoring and the grounding line selection method thereof according to claim 1, characterized in that: a resistor connected in series with the second ground loop, the electric signal applied to both ends of the resistor being DC signal, the total insulation resistance of the generator stator or the distribution network
Insulation resistance of each branch power distribution network
；nIs the serial number of a certain branch power distribution network,nis an integer of 1 or more.
5. The generator stator, the distribution network insulation on-line monitoring and the grounding line selection method thereof according to claim 1, characterized in that: a resistor connected in series with the second ground loop, the electric signal applied to both ends of the resistor being an AC signal, the total insulation resistance of the generator stator or the distribution network(ii) a Wherein,
、
，
is the phase difference between the alternating voltage and the alternating current; insulation resistance of each branch power distribution network(ii) a Wherein,
、
，
n is an alternating voltage and a currentnThe phase difference between the alternating currents of the individual branch distribution networks,nis the serial number of a certain branch power distribution network,nis an integer of 1 or more.
6. A method for on-line monitoring of insulation of a generator stator and a power distribution network and grounding line selection of the generator stator and the power distribution network is characterized by comprising the following steps: when the neutral point of the generator stator or the distribution network transformer is grounded through an arc suppression coil or a grounding resistor, a second grounding loop is formedWhen the circuit and the neutral point of the voltage transformer are grounded to form a first grounding loop, resistors are connected in series on the first grounding loop or the second grounding loop, and the influence of the resistor of one grounding loop is eliminated on the first grounding loop and the second grounding loop by using a current transformer or by changing the grounding connection line; applying a DC or AC signal across the resistor in response to current flowing to the generator stator or the distribution networkICurrent flowing to each branch distribution networkI n And a voltage applied across the resistorUCalculating the total insulation resistance of the generator stator or the distribution networkR d Insulation resistance of each branch power distribution networkR dn And the insulation state of the generator stator or the distribution network is detected based on the insulation state; if total insulation resistanceR d If the insulation degree of the generator stator or the distribution network is smaller than the preset setting value, the insulation degree of the generator stator or the distribution network can be judged to be reduced or a ground fault occurs; if the insulation resistance of a branch distribution networkR dn If the value is less than the preset setting value, the insulation degree of the branch power distribution network can be judged to be reduced or a ground fault occurs.
7. The generator stator, distribution network insulation on-line monitoring and grounding line selection method according to claim 6, characterized in that: the first grounding loop and the second grounding loop simultaneously pass through the current transformer, the electric signals applied to two ends of the resistor are direct current signals, and the total insulation resistance of the generator stator or the power distribution network
Insulation resistance of each branch power distribution network；nIs the serial number of a certain branch power distribution network,nis an integer of 1 or more.
8. Generator stator, distribution network insulation on-line monitoring and grounding route selection method according to claim 6The method is characterized in that: the neutral point of the voltage transformer is connected with the second grounding loop in parallel and then passes through the voltage transformer, the electric signals applied to two ends of the resistor are direct current signals, and the total insulation resistance of the generator stator or the power distribution networkInsulation resistance of each branch power distribution network
；nIs the serial number of a certain branch power distribution network,nis an integer of 1 or more.
9. The generator stator, distribution network insulation on-line monitoring and grounding line selection method according to claim 6, characterized in that: connecting the secondary coil of the current transformer and the secondary coil of the compensating current transformer in series or in parallel, respectively passing the first grounding loop and the second grounding loop through the current transformer and the compensating current transformer, wherein the electric signals applied to two ends of the resistor are direct current signals, and the total insulation resistance of the generator stator or the power distribution network
Insulation resistance of each branch power distribution network
；nIs the serial number of a certain branch power distribution network,nis an integer of 1 or more.
10. The generator stator, distribution network insulation on-line monitoring and grounding line selection method according to claim 6, characterized in that: the first grounding loop and the second grounding loop simultaneously pass through the current transformer, the electric signals applied to two ends of the resistor are alternating current signals, and the total insulation resistance of the generator stator or the power distribution network
(ii) a Wherein,
、，
is the phase difference between the alternating voltage and the alternating current; insulation resistance of each branch power distribution network
(ii) a Wherein,
、
， n is an alternating voltage and a currentnThe phase difference between the alternating currents of the individual branch distribution networks,nis the serial number of a certain branch power distribution network,nis an integer of 1 or more.
11. The generator stator, distribution network insulation on-line monitoring and grounding line selection method according to claim 6, characterized in that: the neutral point of the voltage transformer is connected with the second grounding loop in parallel and then passes through the voltage transformer, the electric signals applied to two ends of the resistor are alternating current signals, and the total insulation resistance of the generator stator or the power distribution network
(ii) a Wherein,
、
，
is the phase difference between the alternating voltage and the alternating current; insulation resistance of each branch power distribution network
(ii) a Wherein,
、
， n is an alternating voltage and a currentnThe phase difference between the alternating currents of the individual branch distribution networks,nis the serial number of a certain branch power distribution network,nis an integer of 1 or more.
12. The generator stator, distribution network insulation on-line monitoring and grounding line selection method according to claim 6, characterized in that: connecting the secondary coil of the current transformer and the secondary coil of the compensating current transformer in series or in parallel, respectively passing the first grounding loop and the second grounding loop through the current transformer or the compensating current transformer, wherein the electric signals applied to two ends of the resistor are alternating current signals, and the total insulation resistance of the generator stator or the power distribution network
(ii) a Wherein,、，is the phase difference between the alternating voltage and the alternating current; insulation resistance of each branch power distribution network
(ii) a Wherein,
、
，
n is an alternating voltage and a currentnThe phase difference between the alternating currents of the individual branch distribution networks,nis the serial number of a certain branch power distribution network,nis an integer of 1 or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013100681431A CN103163433A (en) | 2013-03-05 | 2013-03-05 | Method for monitoring insulation condition of generator stator and power distribution network on line and performing fault line selection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013100681431A CN103163433A (en) | 2013-03-05 | 2013-03-05 | Method for monitoring insulation condition of generator stator and power distribution network on line and performing fault line selection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103163433A true CN103163433A (en) | 2013-06-19 |
Family
ID=48586685
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2013100681431A Pending CN103163433A (en) | 2013-03-05 | 2013-03-05 | Method for monitoring insulation condition of generator stator and power distribution network on line and performing fault line selection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103163433A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439656A (en) * | 2013-06-27 | 2013-12-11 | 广东电网公司电力科学研究院 | Generator stator winding and electric major loop grounding fault diagnosis method of generator stator winding based on flow direction of failure current |
| CN108872779A (en) * | 2017-08-28 | 2018-11-23 | 武汉都市环保工程技术股份有限公司 | A kind of single-phase earth fault line selection device and method |
| CN109991467A (en) * | 2017-12-29 | 2019-07-09 | 西门子股份公司 | The confirmation of overvoltage |
| CN110596583A (en) * | 2019-07-09 | 2019-12-20 | 国网江苏省电力有限公司徐州供电分公司 | Variable frequency motor stator fault detection system based on zero sequence voltage analysis and detection method thereof |
| CN111103501A (en) * | 2018-10-09 | 2020-05-05 | 长沙理工大学 | Method and system for measuring ground insulation parameters of ungrounded neutral point power distribution network |
| CN111965425A (en) * | 2019-11-04 | 2020-11-20 | 中国石油大学(华东) | Selection method for insulation descending loop of three-phase three-wire system low-voltage power distribution system |
| CN112180290A (en) * | 2020-09-29 | 2021-01-05 | 西安热工研究院有限公司 | Generator stator ground fault positioning method |
| CN113949319A (en) * | 2021-09-23 | 2022-01-18 | 华中科技大学 | Generator stator single-phase earth fault arc extinction method and system |
| CN118465619A (en) * | 2024-07-09 | 2024-08-09 | 贵阳新光电气有限公司 | Insulation on-line monitoring grounding positioning method and device for generator motor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1584612A (en) * | 2004-06-07 | 2005-02-23 | 山东大学 | DC power supply system grounded fault detecting method and circuit |
| JP2009204600A (en) * | 2008-02-01 | 2009-09-10 | Sanyo Denki Co Ltd | Motor control system, and electrical insulation deterioration detecting method of motor |
| CN101799518A (en) * | 2010-02-05 | 2010-08-11 | 贵阳新光电气有限公司 | Online monitoring and grounding protection methods of insulation of generator stator core tightening screw rods |
| CN101937024A (en) * | 2010-08-04 | 2011-01-05 | 济南奥诺数控设备有限公司 | Capacitance measurement method and measurement device for power distribution network with neutral point grounded through arc suppression coil |
| CN102692583A (en) * | 2012-06-19 | 2012-09-26 | 国电大渡河检修安装有限公司 | Finding method of multi-branch-circuit power generator stator winding grounded short circuit point |
-
2013
- 2013-03-05 CN CN2013100681431A patent/CN103163433A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1584612A (en) * | 2004-06-07 | 2005-02-23 | 山东大学 | DC power supply system grounded fault detecting method and circuit |
| JP2009204600A (en) * | 2008-02-01 | 2009-09-10 | Sanyo Denki Co Ltd | Motor control system, and electrical insulation deterioration detecting method of motor |
| CN101799518A (en) * | 2010-02-05 | 2010-08-11 | 贵阳新光电气有限公司 | Online monitoring and grounding protection methods of insulation of generator stator core tightening screw rods |
| CN101937024A (en) * | 2010-08-04 | 2011-01-05 | 济南奥诺数控设备有限公司 | Capacitance measurement method and measurement device for power distribution network with neutral point grounded through arc suppression coil |
| CN102692583A (en) * | 2012-06-19 | 2012-09-26 | 国电大渡河检修安装有限公司 | Finding method of multi-branch-circuit power generator stator winding grounded short circuit point |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439656B (en) * | 2013-06-27 | 2015-11-18 | 广东电网公司电力科学研究院 | The generator unit stator winding flowed to based on fault current and electrically major loop ground method for diagnosing faults |
| CN103439656A (en) * | 2013-06-27 | 2013-12-11 | 广东电网公司电力科学研究院 | Generator stator winding and electric major loop grounding fault diagnosis method of generator stator winding based on flow direction of failure current |
| CN108872779A (en) * | 2017-08-28 | 2018-11-23 | 武汉都市环保工程技术股份有限公司 | A kind of single-phase earth fault line selection device and method |
| CN109991467A (en) * | 2017-12-29 | 2019-07-09 | 西门子股份公司 | The confirmation of overvoltage |
| CN111103501A (en) * | 2018-10-09 | 2020-05-05 | 长沙理工大学 | Method and system for measuring ground insulation parameters of ungrounded neutral point power distribution network |
| CN110596583B (en) * | 2019-07-09 | 2023-10-17 | 国网江苏省电力有限公司徐州供电分公司 | Variable frequency motor stator fault detection system and detection method based on zero sequence voltage analysis |
| CN110596583A (en) * | 2019-07-09 | 2019-12-20 | 国网江苏省电力有限公司徐州供电分公司 | Variable frequency motor stator fault detection system based on zero sequence voltage analysis and detection method thereof |
| CN111965425A (en) * | 2019-11-04 | 2020-11-20 | 中国石油大学(华东) | Selection method for insulation descending loop of three-phase three-wire system low-voltage power distribution system |
| CN112180290A (en) * | 2020-09-29 | 2021-01-05 | 西安热工研究院有限公司 | Generator stator ground fault positioning method |
| CN112180290B (en) * | 2020-09-29 | 2024-03-08 | 西安热工研究院有限公司 | Positioning method for generator stator ground fault |
| CN113949319A (en) * | 2021-09-23 | 2022-01-18 | 华中科技大学 | Generator stator single-phase earth fault arc extinction method and system |
| CN113949319B (en) * | 2021-09-23 | 2023-11-14 | 华中科技大学 | Single-phase earth fault arc extinction method and system for generator stator |
| CN118465619A (en) * | 2024-07-09 | 2024-08-09 | 贵阳新光电气有限公司 | Insulation on-line monitoring grounding positioning method and device for generator motor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103163433A (en) | Method for monitoring insulation condition of generator stator and power distribution network on line and performing fault line selection | |
| CN103207352B (en) | Route selection impedance magnitude characteristic is utilized to realize wire selection method for power distribution network single phase earthing failure | |
| CN103840437B (en) | The quick diagnosis of power distribution network ferromagnetic resonance and singlephase earth fault and processing method | |
| EP1890369A1 (en) | Ground fault detection | |
| CN103207354B (en) | Maximum line selection coefficient principle based single-phase earth fault line selection method for power distribution network | |
| CN102901878B (en) | Ground wire supervision equipment with impedance measurement | |
| CN103116115B (en) | Network-distribution single-phase failure line selection method based on virtual active power increment maximal principle | |
| CN104917148A (en) | Generator injection type stator grounding protection method and protection device | |
| CN110244192B (en) | Electric power overhead line ground fault distance measurement method | |
| CN104280664A (en) | Online insulation monitoring and line selecting method for resonant grounded system | |
| CN106908692B (en) | A kind of adaptive reclosing judgment method of transmission line one-phase earth fault | |
| CN102879710B (en) | System and method for detecting single-phase ground fault point of power distribution line | |
| CN105866608A (en) | Power distribution network fault line selection method based on unique through-flow characteristic of resistive current | |
| CN111141945A (en) | Method for measuring capacitance current of three-phase unbalanced system | |
| CN104280663A (en) | Online monitoring and line selecting method for single-phase earth faults of small current grounding system | |
| CN104833841B (en) | A kind of transformer station invades Zenith tracking method | |
| Tang et al. | Faulty feeder detection based on the composite factors in resonant grounding distribution system | |
| CN202956482U (en) | Small current system single-phase grounding fault detection verifying device | |
| CN104375031B (en) | On-line measurement device for power supply system surge protection device insulation resistance | |
| JP5529300B1 (en) | High voltage insulation monitoring method and high voltage insulation monitoring device | |
| CN114814409B (en) | High-voltage cable protector fault online detection method based on sheath current angle difference | |
| CN106019054B (en) | Localization method suitable for DC ice melting line single phase grounding failure | |
| CN106786521B (en) | It is a kind of meter and single-phase wire break resonance overvoltage power distribution network weakness branch judgment method | |
| CN108258668A (en) | Disturbance DC component line selection apparatus based on silicon-controlled generation during single-phase earthing | |
| RU2631121C2 (en) | Method of selective identification of outgoing line with single-phase earth fault in distribution networks with voltage of 6-35 kv |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20130619 |