CN113009264A - High-speed railway traction substation pavilion direct-current magnetic bias monitoring system and method - Google Patents
High-speed railway traction substation pavilion direct-current magnetic bias monitoring system and method Download PDFInfo
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- CN113009264A CN113009264A CN202110286060.4A CN202110286060A CN113009264A CN 113009264 A CN113009264 A CN 113009264A CN 202110286060 A CN202110286060 A CN 202110286060A CN 113009264 A CN113009264 A CN 113009264A
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- 238000012544 monitoring process Methods 0.000 title claims abstract description 60
- 238000000034 method Methods 0.000 title claims abstract description 21
- 238000007405 data analysis Methods 0.000 claims abstract description 16
- 238000010168 coupling process Methods 0.000 claims abstract description 14
- 238000005859 coupling reaction Methods 0.000 claims abstract description 14
- 238000009529 body temperature measurement Methods 0.000 claims abstract description 5
- 230000005284 excitation Effects 0.000 claims description 18
- 238000005192 partition Methods 0.000 claims description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 14
- 230000004907 flux Effects 0.000 description 11
- 238000004804 winding Methods 0.000 description 10
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- 238000000354 decomposition reaction Methods 0.000 description 2
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- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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- G—PHYSICS
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- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
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Abstract
The application discloses a high-speed railway traction substation pavilion direct current magnetic biasing monitoring system and a method, wherein the system comprises a monitoring host, a plurality of data analysis devices and temperature measurement sensors, wherein the data analysis devices and the temperature measurement sensors are respectively arranged in a substation, a self-coupling substation and a subarea substation; the data analysis device acquires current signals acquired by high-voltage side and low-voltage side current transformers installed in a system to which the data analysis device belongs, calculates exciting current and second harmonic components of the exciting current and transmits the exciting current and the second harmonic components to the monitoring host; the temperature measuring sensor collects temperature data of the transformer core; if any one or more of the substation, the autotransformer and the sub-substation meets the condition that the peak value of the exciting current exceeds a first preset value, the second harmonic component exceeds a second preset value and the temperature data is higher than a third preset value, the monitoring host generates a direct-current magnetic biasing alarm signal; the invention fully utilizes the existing equipment of the traction substation pavilion, comprehensively judges the DC magnetic biasing state of the transformer through multiple dimensions, and is suitable for analyzing the influence degree of the DC grounding electrode on the long-distance high-speed rail traction substation pavilion.
Description
Technical Field
The application relates to the technical field of power supply, in particular to a direct-current magnetic bias monitoring system and method for a high-speed railway traction substation pavilion.
Background
The high-speed railway traction substation is widely distributed and has complex surrounding environment, and the inside of the substation is in a high-voltage and strong magnetic field environment. In order to monitor the influence of the ground current of the extra-high voltage direct current grounding electrode on the direct current magnetic biasing of the transformer of the pavilion of the nearby railway traction substation, a direct current magnetic biasing monitoring system needs to be constructed.
The existing transformer direct current magnetic bias monitoring system mostly adopts means of adding a special current and voltage sensor, a noise measurement sensor and the like, for example, a direct current sensor is generally added at a neutral point of a transformer, or a current transformer is connected in parallel at a feeder line side, and a transformer noise monitoring mode is added.
The modes do not utilize equipment in the existing substation, the complexity of a secondary system of the substation is increased, the monitoring cost is improved, meanwhile, the environment complexity of a railway traction station pavilion is not fully considered, and the reliability of a monitoring result is directly influenced by the stability of the sensor.
Disclosure of Invention
The invention provides a system and a method for monitoring direct current magnetic biasing of a high-speed railway traction substation pavilion, aiming at least one defect or improvement requirement in the prior art, wherein a set of reliable and practical direct current magnetic biasing monitoring system is established by utilizing the characteristic of a direct current path formed by a traction substation, an autotransformer and a subarea of a high-speed railway traction power supply system, and the influence of a direct current grounding electrode on the direct current magnetic biasing of a transformer of the traction substation pavilion in a range is efficiently and accurately analyzed.
In order to achieve the above object, according to one aspect of the present invention, there is provided a dc magnetic bias monitoring system for a high-speed railway traction substation kiosk, the system includes a monitoring host, and a plurality of data analysis devices and temperature measurement sensors respectively disposed in a substation, an autotransformer, and a sub-substation under a same power supply arm;
each data analysis device is used for acquiring a first current signal acquired by a high-voltage side current transformer and a second current signal acquired by a low-voltage side current transformer which are installed in a system to which the data analysis device belongs, calculating exciting current and second harmonic component according to the first current signal and the second current signal and transmitting the exciting current and the second harmonic component to a monitoring host;
the temperature measuring sensor is used for acquiring temperature data of a transformer core in a system to which the temperature measuring sensor belongs and transmitting the temperature data to the monitoring host;
the monitoring host monitors the peak value of the exciting current, the second harmonic component and the temperature data of the transformer core of the substation, the autotransformer and the substation in real time, and if any one or more of the substation, the autotransformer and the substation meets the condition that the peak value of the exciting current exceeds a first preset value, the second harmonic component exceeds a second preset value and the temperature data is higher than a third preset value, a direct-current magnetic biasing alarm signal is generated.
Preferably, in the direct-current magnetic bias monitoring system for the high-speed railway traction substation pavilion, the first preset value is a preset multiple of no-load current.
Preferably, in the direct-current magnetic bias monitoring system for the high-speed railway traction substation kiosk, the second preset value is a preset multiple of the fundamental wave.
Preferably, in the direct current magnetic bias monitoring system for the high-speed railway traction substation kiosk, the data analysis device is a device having a fast fourier transform function.
According to another aspect of the invention, a method for monitoring direct current magnetic bias of a high-speed railway traction substation pavilion is also provided, which comprises the following steps:
respectively acquiring a first current signal acquired by a high-voltage side current transformer and a second current signal acquired by a low-voltage side current transformer in a substation, an autotransformer and a subarea substation under the same power supply arm, and respectively calculating the corresponding exciting current and second harmonic component of each of the substation, the autotransformer and the subarea substation according to the first current signal and the second current signal;
acquiring temperature data of transformer cores in a substation, an autotransformer and a subarea substation under the same power supply arm;
respectively judging whether the peak values of the exciting currents of the substation, the autotransformer and the subarea station exceed a first preset value and whether the second harmonic component exceeds a second preset value, if so, further judging whether the temperature data are higher than a third preset value;
and if any one or more of the substation, the autotransformer and the subarea station meets the condition that the peak value of the exciting current exceeds a first preset value, the second harmonic component exceeds a second preset value and the temperature data is higher than a third preset value, generating a direct-current magnetic biasing alarm signal.
Preferably, in the method for monitoring dc magnetic biasing of the high-speed railway traction substation kiosk, the first preset value is a preset multiple of no-load current.
Preferably, in the method for monitoring dc magnetic biasing of the high-speed railway traction substation kiosk, the second preset value is a preset multiple of fundamental waves.
Preferably, the above method for monitoring dc magnetic biasing of a high-speed railway traction substation kiosk, wherein calculating respective corresponding exciting currents and second harmonic components of a substation, a self-coupling substation, and a sub-substation according to the first current signal and the second current signal includes:
calculating the respective corresponding exciting currents of the substation, the autotransformer and the subarea station according to the first current signal and the second current signal;
and carrying out fast Fourier transform on the exciting current to obtain a second harmonic component.
In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:
(1) the system and the method for monitoring the direct current magnetic bias of the high-speed railway traction substation pavilion utilize the characteristic that a direct current path is formed by the traction substation, the autotransformer and the subareas of the high-speed railway traction power supply system, take the exciting current and the second harmonic component of the transformer and the temperature of the iron core of the transformer as monitoring indexes, and comprehensively judge the direct current magnetic bias state of the transformer through multiple dimensions, so that the system is high in reliability; the system design fully utilizes the existing equipment of the traction substation pavilion, and only adds a temperature measuring sensor. The invention provides a solution for quantifying the influence of the ground current of the extra-high voltage direct current grounding electrode on the traction transformer, and ensures the safe and reliable operation of the high-speed railway power supply equipment.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a schematic diagram of a dc magnetic bias monitoring system according to the present embodiment;
fig. 2 is a schematic diagram of a dc path formed by the high-speed railway traction substation, the AT autotransformer and the partition provided in this embodiment;
fig. 3 is a logic block diagram of the dc magnetic bias monitoring system of the high-speed railway traction substation kiosk according to the present embodiment;
FIG. 4 is a schematic structural diagram of a power supply system loop of a high-speed railway traction substation pavilion;
fig. 5 is a schematic flow chart of the method for monitoring dc magnetic bias in the high-speed railway traction substation kiosk according to this embodiment.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.
The terms "first," "second," "third," and the like in the description and claims of this application and in the above-described drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.
The monitoring system fully utilizes the existing equipment information of the traction substation pavilion, comprehensively judges the direct-current magnetic bias state and the influence degree of the transformer through multiple dimensions, and is more suitable for quantitatively analyzing the influence degree of the direct-current grounding electrode on the long-distance high-speed railway traction substation pavilion.
Specifically, the direct current magnetic bias monitoring system is designed by utilizing the characteristic that transformers of a traction substation, an AT station and a subarea station of a railway traction power supply system uniformly form a direct current path and the phenomena of exciting current distortion and iron core loss increase during direct current magnetic bias of the transformers.
1) When the transformer is biased by DC, the exciting current is distorted and even harmonic wave appears
When a direct current flows through the transformer winding, the core magnetic flux is composed of a magnetic flux generated by an excitation current flowing through the winding and a magnetic flux generated by the direct current in a superimposed manner.
φ＝φdc+φac
Where φ represents the total magnetic flux of the transformer core; phi is adcIndicating dc current generationThe magnetic flux of (a); phi is aacRepresenting the magnetic flux generated by the excitation current;
the induced electromotive force of the winding is approximately equal to the input voltage, and the induced electromotive force of the winding comprises the following components:
then
Wherein e represents the induced electromotive force of the transformer winding; u represents an input voltage; n represents the number of turns of the transformer coil; w represents an angular frequency;
when the total magnetic flux of the transformer core is larger than the critical saturation magnetic flux, the positive half-cycle excitation characteristic enters a saturation region, the negative half-cycle excitation characteristic is in an unsaturated region, the excitation current waveform is distorted, and the harmonic content is increased; meanwhile, as the iron core enters an excitation saturation region, the excitation current has no half-wave symmetry any more, the Fourier decomposition is carried out on the excitation current, and even harmonics appear in the excitation current.
Calculating exciting current according to high-low voltage side current
Wherein i1Represents the high side current; i.e. i2Represents the low side current; k is a radical of1Representing the number of turns of the high-voltage side winding; k is a radical of2Representing the number of low-voltage side winding turns;
fourier decomposition and harmonic analysis are carried out on the exciting current, and the second harmonic component of the exciting current can be obtained.
2) The DC magnetic bias causes the magnetic flux of the iron core to be saturated and the loss to be increased
When the direct current is large, the magnetic flux inside the transformer enters a saturation region, the exciting current is increased, the iron loss of the iron core is increased due to the increase of the leakage magnetic flux, and the temperature rise is increased.
3) High-speed railway direct current path
Fig. 1 is a schematic diagram of a principle of a dc magnetic bias monitoring system provided in this embodiment, fig. 2 is a schematic diagram of a dc path formed by a traction substation, an AT autotransformer, and a partition provided in this embodiment, and referring to fig. 1, a dc path of a power supply system of a high-speed railway is formed by a substation transformer winding (corresponding to a position a in fig. 2), a traction grid, an AT autotransformer (corresponding to a position B in fig. 2), a partition (corresponding to a position C in fig. 2), an autotransformer winding, a steel rail, and a PW protection line, referring to fig. 2, when a grounding electrode is operated in a single-pole ground, an earth current flows through the dc path, and a dc current appears in the traction substation, the AT substation, and the partition transformer winding. And simultaneously monitoring the direct current magnetic biasing states of a substation, an AT station and a subarea station under the same power supply arm, and comprehensively determining the direct current magnetic biasing influence on each transformer of the traction power supply system.
Fig. 3 is a logic block diagram of the dc magnetic bias monitoring system for the high-speed railway traction substation kiosk according to this embodiment, referring to fig. 3, the system includes a monitoring host, and a plurality of data analysis devices and temperature measurement sensors respectively disposed under the same power supply arm in the substation, the autotransformer, and the sub-substation;
fig. 4 is a schematic structural diagram of a power supply system loop of a high-speed railway traction substation kiosk, and as shown in fig. 4, a current transformer is arranged on a high-voltage side and a low-voltage side of each transformer in the system, and the current transformers are respectively used for detecting current signals on the high-voltage side and the low-voltage side of the transformer; on this basis, this embodiment has increased iron core temperature sensor in the system newly, comes the temperature value of gathering transformer core, realizes the real-time detection of transformer temperature.
The data analysis devices in the substation, the autotransformer and the subarea substation are used for acquiring a first current signal acquired by a high-voltage side current transformer and a second current signal acquired by a low-voltage side current transformer which are installed in the substation to which the data analysis devices belong, calculating exciting current and second harmonic component according to the first current signal and the second current signal and transmitting the exciting current and the second harmonic component to the monitoring host; the data analysis device in this embodiment is a device having a fast fourier transform function.
The temperature measuring sensors of the iron core temperature sensors in the transformer substation, the autotransformer and the subarea substation are used for acquiring temperature data of the iron core of the transformer in the substation to which the temperature measuring sensors belong and transmitting the temperature data to the monitoring host.
The monitoring host monitors the peak value and the second harmonic component of the exciting current corresponding to the transformer substation, the autotransformer and the subarea substation in real time and temperature data of the transformer core, and if any one or more of the transformer substation, the autotransformer and the subarea substation meets the condition that the peak value of the exciting current exceeds a first preset value, the second harmonic component exceeds a second preset value and the temperature data is higher than a third preset value, a direct-current magnetic biasing alarm signal is generated.
In this embodiment, the first preset value is a preset multiple of no-load current, and the second preset value is a preset multiple of fundamental waves. In one specific example, the peak value I of the transformer exciting current of a traction substation, an AT station and a subarea stationmOver 1.5 times of no-load current I0And the second harmonic component exceeds 0.25 times of the fundamental wave, the harmonic analysis data is uploaded to a monitoring host in the traction substation. And if the temperature sensor monitors that the temperature rise of the iron core exceeds 30K, uploading the temperature real-time data to the monitoring host. The monitoring host stores the data into a historical database, so that the later backtracking is facilitated.
In an alternative example, the monitoring host is placed in a traction substation, and the monitoring host analyzes the direct-current magnetic bias state of the traction transformer by combining the data analysis device and the iron core temperature curve.
The embodiment also provides a direct current magnetic bias monitoring method for a high-speed railway traction substation pavilion, and referring to fig. 5, the method comprises the following steps:
s1: respectively acquiring a first current signal acquired by a high-voltage side current transformer and a second current signal acquired by a low-voltage side current transformer in a substation, a self-coupling substation and a subarea substation under the same power supply arm, and respectively calculating the respective corresponding exciting currents and second harmonic components of the substation, the self-coupling substation and the subarea substation according to the first current signal and the second current signal, specifically comprising:
firstly, calculating the respective corresponding exciting currents of a substation, an autotransformer and a subarea substation according to a first current signal and a second current signal;
and then carrying out fast Fourier transform on the exciting current to obtain a second harmonic component.
S2: respectively judging whether the peak values of the exciting currents of the substation, the autotransformer and the subarea substation exceed a first preset value and whether the second harmonic component exceeds a second preset value, if so, entering the next step;
in this embodiment, the first preset value is a preset multiple of no-load current, and the second preset value is a preset multiple of fundamental waves. In one specific example, the peak value I of the transformer exciting current of a traction substation, an AT station and a subarea stationmOver 1.5 times of no-load current I0And the second harmonic component exceeds 0.25 times of the fundamental wave, the harmonic analysis data is uploaded to a monitoring host in the traction substation.
S3: acquiring temperature data of transformer cores in a substation, an autotransformer and a subarea substation under the same power supply arm, and judging whether the temperature data is higher than a third preset value;
in a specific example, if the temperature rise of the iron core monitored by the iron core temperature sensor exceeds 30K, the temperature real-time data is uploaded to the monitoring host.
S4: and if any one or more of the substation, the autotransformer and the subarea station meets the condition that the peak value of the exciting current exceeds a first preset value, the second harmonic component exceeds a second preset value and the temperature data is higher than a third preset value, generating a direct-current magnetic biasing alarm signal.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
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Cited By (1)
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