CN110850223A - Current providing device, power equipment vector testing device and system - Google Patents
Current providing device, power equipment vector testing device and system Download PDFInfo
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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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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
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- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
- H02H7/262—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of switching or blocking orders
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
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Abstract
The invention provides a current providing device, a power equipment vector testing device and a system, wherein the existing parallel connection compensation capacitor is changed into a series connection compensation capacitor in the current providing device, the impedance is mainly reactance due to very small resistance of a transformer, and the reactance of a testing loop can be reduced after a capacitor is connected in series in the testing loop, so that the aim of applying the same testing voltage during the testing to obtain larger testing current can be achieved, the impedance of the compensation capacitor is different from the impedance of the tested power equipment, the resonance caused by the same impedance during series connection is avoided, and the vector testing of a high-impedance transformer can be suitable through the ingenious combination of the measures.
Description
Technical Field
The invention relates to the technical field of vector testing of power equipment, in particular to a current providing device, a vector testing device of power equipment and a vector testing system of power equipment.
Background
When the relay protection phasor inspection test technology which adopts the principle of a voltage regulator and a step-up transformer is used on site, the influence of a site power supply is large, and the output current and voltage are limited. Under the condition that the power supply capacity is not changed, the output of high voltage and the output of large current are contradictory, the construction power supply capacity of a general transformer substation is less than 200kVA, the capacity of the test equipment can not be borne by a field test power supply without limit increase, and the increase of the capacity of the test equipment brings difficulty to the transportation of the test equipment.
When the analog load of the test is inductive, the output current of the test system can be effectively improved by adopting a parallel capacitance compensation method, and meanwhile, the capacity requirement of the test on a field test power supply is obviously reduced. However, for high impedance power equipment, such as a high impedance transformer (determined according to the voltage level and the ct transformation ratio, for example, for a 500kV transformer, a transformer with impedance greater than 500 ohms can be regarded as a high impedance transformer), it is difficult for the testing method to satisfy the voltage current amount required by the phasor test.
The invention provides a current providing device, a power equipment vector testing device and a system, and aims to solve the problem of high impedance power equipment vector testing.
Disclosure of Invention
In order to solve at least one of the above problems, the present invention provides a current supply apparatus for vector testing of power devices, comprising:
the input end of the voltage regulator is coupled with the output end of the test power supply;
a booster having an input coupled to an output of the voltage regulator;
a compensation capacitor having an input coupled to the output of the booster; wherein the content of the first and second substances,
the output end of the compensation capacitor is coupled with one end of a tested electric device, the other end of the tested electric device is provided with a short-circuit point, and at least one end of the tested electric device is coupled with at least one secondary device for detecting the tested electric device;
the impedance of the compensation capacitor is different from the impedance of the electrical device under test.
In certain embodiments, the impedance of the compensation capacitor is less than the impedance of the electrical device under test.
In some embodiments, the current providing device further comprises:
and the controller is used for adjusting the voltage value output by the voltage regulator.
In some embodiments, the current providing device further comprises:
the current transformer is coupled with one end of the controller, and the other end of the controller is coupled with the voltage regulator.
In some embodiments, the output terminal of the compensation capacitor is coupled to the high voltage terminal of the tested power device, and the low voltage terminal of the tested power device is provided with a short contact.
An embodiment of a second aspect of the present invention provides a power equipment vector testing apparatus, including:
the input end of the voltage regulator is coupled with the output end of the test power supply;
a booster having an input coupled to an output of the voltage regulator;
the input end of the compensation capacitor is coupled with the output end of the booster, and the output end of the compensation capacitor is coupled with one end of a tested electric device; and the number of the first and second groups,
the secondary device is coupled to at least one end of the tested electric device and used for detecting the tested electric device; wherein the content of the first and second substances,
the other end of the tested electric equipment is provided with a short contact, and the impedance of the compensation capacitor is different from that of the tested electric equipment.
In certain embodiments, the impedance of the compensation capacitor is less than the impedance of the electrical device under test.
In certain embodiments, the power equipment vector test apparatus further comprises:
and the controller is used for adjusting the voltage value output by the voltage regulator.
In certain embodiments, the power equipment vector test apparatus further comprises: the current transformer is coupled with one end of the controller, and the other end of the controller is coupled with the voltage regulator.
In some embodiments, the output terminal of the compensation capacitor is coupled to the high voltage terminal of the tested power device, and the low voltage terminal of the tested power device is provided with a short contact.
In certain embodiments, the secondary device comprises at least one of:
the voltage transformer is used for detecting the voltage of a branch where the tested electric equipment is located;
the current transformer is used for detecting the current of a branch where the tested electric equipment is located;
the relay protection device judges the fault state by utilizing the voltage and the current of the branch circuit where the tested power equipment is located;
the metering device is used for counting the electric quantity consumption of the tested electric equipment;
and the fault recording device records the voltage and the current of the branch circuit of the tested power equipment when the power grid has a fault.
An embodiment of a third aspect of the present invention provides a power equipment vector testing system, including: tested electric equipment and the vector testing device of the electric equipment.
An embodiment of a fourth aspect of the present invention provides a power device vector testing system, including: the method comprises the following steps: the device comprises a test power supply, the tested electric equipment and the electric equipment vector testing device, wherein the test power supply is coupled with the electric equipment vector testing device.
The invention has the following beneficial effects:
the invention provides a current providing device, a power equipment vector testing device and a system, wherein the existing parallel connection compensation capacitor is changed into a series connection compensation capacitor in the current providing device, the impedance is mainly reactance due to very small resistance of a transformer, and the reactance of a testing loop can be reduced after a capacitor is connected in series in the testing loop, so that the aim of applying the same testing voltage during the testing to obtain larger testing current can be achieved, the impedance of the compensation capacitor is different from the impedance of the tested power equipment, the resonance caused by the same impedance during series connection is avoided, and the high-impedance transformer can be suitable for the high-impedance transformer by skillfully combining the measures.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 shows one of the schematic structural diagrams of a power equipment vector test system in the prior art.
Fig. 2 shows a second schematic structural diagram of a vector test system for power equipment in the prior art.
Fig. 3 shows a schematic structural diagram of a vector test system of a power device in an embodiment of the present invention.
Fig. 4 shows a schematic structural diagram of a test power supply in a specific scenario in the embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 shows one of the structural schematic diagrams of the current mainstream vector test system, and as shown in fig. 1, the system directly adds a voltage across the device under test, which specifically includes a voltage regulator and a voltage booster. A test power supply of a common voltage regulator takes 220V maintenance voltage from a transformer substation site, and the power is about 40kV generally; after the output of the voltage regulator, the voltage is boosted through the booster and applied to the tested transformer, and after the voltage transformer and the current transformer acquire voltage and current values, the voltage and the current values are transmitted to the protection device, the measurement and control device, the metering device and the like. The method has larger defects, and if the impedance of the tested equipment is small, the current is very large when the voltage is increased to be higher, so that the power of the test voltage is very large, and the field is difficult to meet. For example, for a 500kV transformer with 5 Ω impedance, when 500V is applied to the high-voltage side single phase, the current is 100A, the total power of the three phases reaches 150kVA, and the field cannot provide such a large power supply. If the applied voltage is large in the scheme, the power supply power is too large, cables or equipment are burnt, and if the applied voltage is small, the voltage and the current are too small, so that the test cannot be completed.
Fig. 2 shows a second structural schematic diagram of a mainstream vector test system, and as shown in fig. 2, the technical principle of capacitance compensation is to connect a three-phase capacitor in parallel on the output side of the original test system, and the system connected with the capacitor in parallel is regarded as the test system, so that the output current of the test system is the sum of the output current of the test step-up transformer and the capacitance compensation current, the output voltage of the test system is still the output voltage of the test step-up transformer, the current passing through the simulated load is the output current of the test system, and the simulated load is still a three-phase inductor. The capacitance compensation is adopted according to the characteristic that the phase difference between the capacitive current and the inductive current in the circuit is 180 degrees, the simulation load is a pure inductive reactor (or a transformer reactance), after a pure capacitive capacitor is connected in parallel in a loop, the output current IT of the test step-up transformer is IL-IC, and the output current of the test system is IL, so that the output current of the test step-up transformer is obviously reduced, and further the power supply current is obviously reduced. However, this scheme has a disadvantage that when the impedance of the transformer is too high, the current flowing through the transformer is too small, which causes that the secondary current is too small to be monitored, the test cannot be completed, and the vector test cannot be effectively performed on the high impedance transformer.
Fig. 3 shows a current providing apparatus for vector testing of power devices in an embodiment of the present invention, including: a voltage regulator 2, wherein the input end of the voltage regulator 2 (the end on the left side of the voltage regulator 2 in the figure) is coupled with the output end of the test power supply 1; a booster 3, an input terminal of which (one terminal on the left side of the booster 3 in the drawing) is coupled to an output terminal of which 2 (one terminal on the right side of the booster in the drawing); a compensation capacitor 4, an input terminal of the compensation capacitor 4 (one terminal on the left side of the compensation capacitor in the drawing) being coupled to an output terminal of the booster 3 (one terminal on the right side of the booster 3 in the drawing); wherein, the output end of the compensation capacitor 4 (the section on the right side of the compensation capacitor 4 in the figure) is coupled with one end of a tested electric device 5, at least one end of two ends of the tested electric device 5 is coupled with at least one secondary device for detecting the tested electric device 9, and the other end of the tested electric device 5 is provided with a short-circuit point 8; the impedance of the compensation capacitor 4 is different from the impedance of the electrical device under test 5.
According to the current supply device, the existing parallel connection compensation capacitor is changed into the series connection compensation capacitor in the current supply device, the resistance of the transformer is very small, the presented impedance is mainly reactance, after the capacitor is connected in series in the test loop, the reactance of the test loop can be reduced, so that the purpose that the same test voltage is applied during the test period to obtain larger test current can be achieved, the impedance of the compensation capacitor is different from that of the tested electric equipment, resonance caused by the same impedance in series connection is avoided, and the current supply device can be suitable for a high-impedance transformer through ingenious combination of the measures.
The coupling in the present invention may be a direct electrical connection, for example, the electronic component a and the electronic component B are electrically connected through a wire, or a and B are co-located at a node. The coupling may also be an indirect electrical connection, for example an electronic component C is connected between a and B, as long as the electronic component C does not affect the functional role between a and B.
When the device is used specifically, the current providing device is electrically connected with the tested electric equipment connected behind the current providing device, at least one secondary equipment is coupled with at least one of two ends of the tested electric equipment, and the secondary equipment is used for carrying out vector test on the tested electric equipment.
It can be understood that one or more secondary devices may be coupled to one end of the tested power device, for example, the current transformer may be connected to one end of the secondary device, and the secondary device may also be coupled to both ends of the tested power device, for example, the voltage transformer may be coupled to both ends of the tested power device, that is, the secondary device is coupled to one end or both ends of the tested power device may be determined according to specific detection needs, and the number of the secondary devices may also be determined according to the detection needs, which is not described herein again.
In the invention, the impedance of the compensation capacitor can be higher or lower than the impedance of the tested electric equipment as long as the impedance of the compensation capacitor is inconsistent with the impedance of the tested electric equipment.
The transformer impedance is mainly expressed as inductive reactance, the capacitor is expressed as capacitive reactance, if the capacitive reactance of the series compensation capacitor is larger than the inductive reactance of the tested transformer, the impedance of the whole test loop is changed from inductive reactance characteristic to capacitive reactance characteristic, and the current direction is reversed, so that the circuit is complex. In a preferred embodiment, therefore, the impedance of the series compensation capacitor should generally be less than the impedance of the electrical device under test.
The tested power equipment can be equipment with higher impedance such as a high-impedance transformer, and the invention can also be used for power equipment with lower impedance, and is different from the prior art, the invention can be simultaneously suitable for the equipment with high impedance, but the prior art cannot be used for the equipment with higher impedance (generally speaking, the definition of the high impedance is determined according to the voltage grade and the ct transformation ratio, for example, for a 500kV transformer, a transformer with impedance more than 500 ohms can be regarded as a high-impedance transformer), and the defects exist.
The voltage regulator is used for regulating the voltage value output by the test power supply, the input of the voltage regulator is a 380V three-phase power supply, and the output of the voltage regulator is 0-380V three-phase power.
The booster is required to boost the voltage to the voltage value required by the tested electric equipment test, the input of the booster is the output of the voltage regulator, the compensation capacitor is connected in series with the booster and the tested electric equipment, and the booster is used for connecting the output high voltage to the tested transformer through the 4 series compensation capacitor.
Generally speaking, the compensation capacitor is connected to the high-voltage side of the tested electric equipment, and the tested electric equipment is generally provided with a short-circuit point on the low-voltage side to short-circuit three phases of three-phase electricity, so that a current loop can be formed when test voltage is applied to the high-voltage side of the tested electric equipment.
The pressure regulator can manually adjust the proper output pressure value and also can automatically adjust the output pressure value, and the invention is not limited.
During manual adjustment, a set output pressure value needs to be preset manually, and then the whole current supply device is operated.
In a preferred embodiment, the invention can perform automatic regulation of the voltage regulator, and the current supply device further comprises a controller for regulating the voltage value output by the voltage regulator. The controller is coupled with the voltage regulator, and then outputs a control signal to the voltage regulator to regulate the output parameter, and when the controller is used specifically, a tester can input the magnitude of the test current required to be output in the controller, and the controller controls the output current to reach the target value. The control signal may be preset according to certain conditions, for example certain conditions matching time parameters, or certain conditions matching state parameters of the current supply device itself.
In a more preferred embodiment, the current supply device of the present invention further comprises: the current transformer is coupled with one end of the controller, and the other end of the controller is coupled with the voltage regulator. In this embodiment, the controller is coupled to the current transformer, and the current transformer can detect the current value of the line in real time and output the current value to the controller, so that the controller outputs a control signal of the voltage regulator in real time or at regular time according to the current value, and the current output by the current providing device is always stabilized within a target value interval, thereby improving the stability of the current providing device, or the voltage regulator is stopped adjusting until the current is stabilized at the target value through the detected current regulation voltage regulator, thereby realizing the function of automatic voltage regulation.
As can be seen from the above description, the current providing apparatus provided by the present invention changes the existing parallel connection compensation capacitor into the series connection compensation capacitor in the current providing apparatus, because the resistance of the transformer is very small, the presented impedance is mainly reactance, and after the capacitor is connected in series in the test loop, the reactance of the test loop can be reduced, so that the purpose that a larger test current can be obtained by applying the same test voltage during the test can be achieved, and the impedance of the compensation capacitor is different from the impedance of the tested electrical equipment, thereby avoiding the resonance caused by the same impedance during the series connection, and further, by skillful combination of the above measures, the present invention can be applied to a high-impedance transformer.
In a second aspect of the present invention, a vector testing apparatus for electrical equipment is provided, as shown in fig. 3, and includes the above current providing apparatus and at least one secondary device 9, where the at least one secondary device 9 is coupled to two ends of the electrical equipment 5 to be tested, and is used for detecting the electrical equipment 5 to be tested; the other end of the tested power device 5 is provided with a short contact 8, and the impedance of the compensation capacitor 4 is different from that of the tested power device 5.
It can be understood that the current supply device portion of the power device to the measurement test device in the present invention is the same as the previous embodiment, and is not described herein again.
The secondary equipment is auxiliary equipment for monitoring, measuring, controlling, protecting and adjusting the primary equipment in the power system, namely equipment which is not directly connected with electric energy. Specifically, the secondary device may include a voltage transformer, a current transformer, a relay protection device, a metering device (or referred to as an electric energy metering device), a fault recording device, and a measurement and control device (also referred to as a control and signal device).
More specifically, a voltage transformer detects the voltage of a branch where the detected electric equipment is located; the current transformer detects the current of a branch where the tested electric equipment is located; the relay protection device judges the fault state by utilizing the voltage and the current of the branch circuit of the tested power equipment; the metering device counts the electric quantity consumption of the tested electric equipment; and the fault recording device records the voltage and the current of the branch circuit of the tested power equipment when the power grid has a fault. The measuring and controlling device is used for inputting signals and controlling the circuit device.
It can be understood that, based on the inventive concept of the above embodiment, the vector testing apparatus for electrical equipment provided by the present invention changes the existing parallel connection compensation capacitance into the series connection compensation capacitance in the current providing apparatus, because the resistance of the transformer is very small, the presented impedance is mainly reactance, and after the capacitor is connected in series in the test loop, the reactance of the test loop can be reduced, so that the purpose of applying the same test voltage during the test to obtain a larger test current can be achieved, and the impedance of the compensation capacitor is different from the impedance of the electrical equipment to be tested, thereby avoiding the resonance caused by the same impedance in series connection, and further, by the ingenious combination of the above means, the vector testing apparatus can be applied to a high impedance transformer.
An embodiment of the third aspect of the present invention provides a vector testing system for power equipment, please continue to refer to fig. 3, including: tested electric equipment, 5 and the vector testing device of the electric equipment. The system comprises the tested electric equipment, namely the tested electric equipment is integrated with the vector testing device, and the system can be used for testing research, performance test and the like.
Based on the same inventive concept of the above embodiment, it can be understood that the vector test system for electrical equipment provided by the present invention changes the existing parallel connection compensation capacitance into the series connection compensation capacitance in the current providing device, because the resistance of the transformer is very small, the presented impedance is mainly reactance, and after the capacitor is connected in series in the test loop, the reactance of the test loop can be reduced, so that the purpose that a larger test current can be obtained by applying the same test voltage during the test period can be achieved, and the impedance of the compensation capacitor is different from the impedance of the electrical equipment to be tested, thereby avoiding the resonance caused by the same impedance in the series connection, and further, by the ingenious combination of the above means, the vector test system for electrical equipment can be applied to a high-impedance transformer.
An embodiment of a fourth aspect of the present invention provides a vector testing system for power equipment, please continue to refer to fig. 3, including: the test power supply 1 is coupled with the power equipment vector testing device.
In the embodiment, the test power supply, the vector testing device and the tested electric equipment are integrated together, the existing parallel connection compensation capacitor is changed into the series connection compensation capacitor in the current providing device, the impedance is mainly reactance due to the fact that the resistance of the transformer is very small, and the reactance of the test loop can be reduced after the capacitor is connected in series in the test loop, so that the purpose that the same test voltage is applied during the test period to obtain larger test current can be achieved, the impedance of the compensation capacitor is different from that of the tested electric equipment, resonance caused by the same impedance in series connection is avoided, and the high-impedance transformer can be suitable for the high-impedance transformer through ingenious combination of the measures.
In some embodiments, the test power supply is a three-phase grid, and in some embodiments, the test power supply is 380V three-phase, and the test power supply is typically taken from a substation in-situ service power box.
The following describes the use of the present invention by taking the measured electrical device as a high impedance transformer.
As shown in fig. 3, the test power supply 1 is generally taken from a transformer substation on-site maintenance power box and is 380V three-phase power; the test system consists of a voltage regulator 2, a booster 3 and a series compensation capacitor 4, wherein the input of the voltage regulator 1 is a 380V three-phase power supply, and the output is 0-380V three-phase power; the input of the booster 2 is the output of the regulator, which connects the output high voltage to the transformer under test 5, typically to the high side of the high impedance transformer under test, through a series compensation capacitor 4; the tested transformer is generally provided with a short-circuit point at the low-voltage side to short-circuit the A phase, the B phase and the C phase, so that a current loop can be formed when test voltage is applied to the high-voltage side of the transformer. Secondary equipment such as a relay protection device, a measurement and control device, a metering device, a fault recording device and the like collects voltage applied to a primary loop through a voltage transformer and collects current passing through a tested high-impedance transformer through a current transformer. The vector test is to test whether the secondary current loop passing through the secondary devices is correct or not, and whether the operation requirements including phase relation, amplitude value, transformation ratio and the like are met or not. In the test process, the controller is used for controlling the output voltage of the voltage regulator so as to control the test current; the tester can input the magnitude of the test current required to be output in the controller, and the controller controls the output current to reach the target value. The controller collects primary loop current through the current transformer, adjusts the output voltage of the voltage regulator according to the collected current, and when the output current is stabilized at a target value, the voltage regulator stops outputting. Since the resistance of the transformer is very small, the presented impedance is mainly reactive. After the capacitor is connected in series in the test loop, the reactance of the test loop can be reduced, so that the aim of obtaining larger test current by applying the same test voltage in the test period can be fulfilled.
The effects of the present invention will be described below with reference to specific test scenarios.
Fig. 4 shows a schematic structural diagram of a test power supply, the opening and closing positions of corresponding circuit breakers are shown in the figure, and the circuit breakers which are not marked are in separate positions. In the figure, 500kVI A, 500kVI B, 500kVII A and 500kVII B are 500kV buses, and 5011, 5012, 5013, 511, 522 and 5021 are circuit breakers. The station variable parameter is 525kV/10.5 kV; 40MVA, YN, d 11; uk 11.83%, calculated impedance Xd 815.2 Ω.
From this test power supply, three different schemes are shown below:
1. the first scheme is as follows: uncompensated scheme for 3kV boosting transformer
1) High side current
When a line voltage of 3000V is applied to the station high-voltage side, the high-voltage side primary phase current is
3000/(815.2×1.73)＝2.12A
CT transformation ratio:
a) the high-pressure side casing CT transformation ratio is as follows: 300-600/1, 2000-4000/1 and 150-300/1.
b) The CT transformation ratio of the 500kV circuit breaker is 800/1, 150-300/1, 2500-4000/1 and 200/1.
When the CT transformation ratio of the high-voltage side is 2000/1, the secondary current is 1.06 mA; when the high-side CT transformation ratio is 2500/1, the secondary current is 0.85 mA.
2) Low side current
The first value of the low-voltage side current is:
2.12A×525/10.5＝106A
CT transformation ratio:
a) the low-pressure side casing CT transformation ratio is as follows: 800/1.
b) The CT transformation ratio of the 10kV breaker is as follows: 2500/1, 800/1.
When the low-voltage side CT transformation ratio is 800/1, the secondary current is 133mA, and when the CT transformation ratio is 2500/1, the secondary current is 42.5mA, and table 1 shows the calculated data of the 3kV step-up transformation uncompensated scheme.
Table 13 kV boosting transformer uncompensated scheme calculation data
| Impedance of transformer | 815.2Ω |
| Primary line voltage/phase voltage | 3000V/1732V |
| Secondary value of phase voltage | 330mV |
| First order value of high-voltage side phase current | 2.12A |
| High side phase current secondary 800/1 | 2.6mA |
| High side phase current secondary 2000/1 | 1.06mA |
| High side phase current secondary 2500/1 | 0.85mA |
| First order value of low-voltage side phase current | 106A |
| Low side phase current secondary 800/1 | 133mA |
| Low side phase current secondary 2500/1 | 42.5mA |
| 220V power supply(photo) | 3.67kW |
| 220V supply current (phase) | 16.7A |
2. Scheme II: 3kV boosting transformer series compensation capacitor scheme
1) Series compensation capacitance calculation
The capacitance value of 8 groups of 40uF capacitors after being connected in series is 5uF, and the impedance value is:
1/(2π×5uF)＝637Ω
the comprehensive impedance after being connected in series with the station transformer is as follows:
815.2-637≈177.2Ω
2) high side current calculation
When a line voltage of 3000V is applied to the station high-voltage side, the high-voltage side primary phase current is
3000/(177.2×1.73)＝9.77A
When the CT transformation ratio of the high-voltage side is 2000/1, the secondary current is 4.9 mA; when the high-side CT transformation ratio is 2500/1, the secondary current is 3.9 mA.
3) Low side current
The first value of the low-voltage side current is:
9.11A×525/10.5＝488.7A
when the low-voltage side CT transformation ratio is 800/1, the secondary current is 611mA, and when the CT transformation ratio is 2500/1, the secondary current is 195mA, and the calculated data of the 3kV boosting transformer series compensation capacitance scheme are shown in Table 2.
Table 23 kV boosting transformer series compensation capacitance scheme calculation data
| Impedance of transformer | 815.2Ω |
| Primary line voltage/phase voltage | 3000V/1732V |
| Secondary value of phase voltage | 330mV |
| First order value of high-voltage side phase current | 9.77A |
| High side phase current secondary 800/1 | 12.2mA |
| High side phase current secondary 2000/1 | 4.9mA |
| High side phase current secondary 2500/1 | 3.9mA |
| First order value of low-voltage side phase current | 488.7A |
| Low side phase current secondary 800/1 | 611mA |
| Low side phase current secondary 2500/1 | 195mA |
| 220V power supply (phase) | 16.9kW |
| 220V supply current (phase) | 76.9A |
3. The third scheme is as follows: 10kV boosting transformer series compensation capacitor scheme
1) High side current calculation
If a line voltage of 10kV is applied to the station high voltage side, the high voltage side primary phase current is:
10000/(826.875×1.73)＝7.08A
at this time, the power (phase) of the 220V power supply is: 7.08 × 10000/1.732 ═ 40.9kVA
The 220V supply current (phase) at this time is: 40.3kVA ÷ 0.22kV ═ 186A > 120A
186A exceed the supply cable limit 120A, a capacitive compensation method or a voltage reduction should be taken.
a) If a parallel compensation capacitance method is adopted, the capacitance needing compensation is as follows:
in the above formula, "+" indicates a symbol of multiplication operation.
Calculated as C being 3.13-3.71 uF
When 8 sets of 40uF capacitors, 2 sets of 75uF capacitors are connected in series:
c ═ 4.41uF, the condition was still not satisfied.
When 8 sets of 40uF capacitors, 9 sets of 90uF capacitors are connected in series:
c-3.33 uF, the condition is met, but all capacitors are used for one-phase compensation only.
The solution of parallel capacitors is not satisfactory.
b) The scheme of reducing the booster voltage is that when the power current is 110A:
in the above formula, "+" indicates a symbol of multiplication operation.
The impedance of the transformer is 815.2 omega, so the maximum applied phase voltage is U-4442V
The primary phase current at this time is 4442 ÷ 815.2 ═ 5.45A
When the CT transformation ratio of the high-voltage side is 2000/1, the secondary current is 2.7 mA; when the high-side CT transformation ratio is 2500/1, the secondary current is 2.12 mA.
The first value of the low-voltage side current is:
5.45A×525/10.5＝272.4A
when the low-voltage side CT transformation ratio is 800/1, the secondary current is 340mA, and when the CT transformation ratio is 2500/1, the secondary current is 109mA, and table 3 shows the calculated data of the 10kV step-up transformation uncompensated scheme.
Table 310 kV boosting transformer uncompensated scheme calculation data
In summary, either scheme two or scheme three may be employed. However, the 10kV power transformer is large in size, heavy in weight and inconvenient to transport, so that the second scheme (i.e. the invention) is better under the same condition.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment. In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of an embodiment of the specification. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction. The above description is only an example of the embodiments of the present disclosure, and is not intended to limit the embodiments of the present disclosure. Various modifications and variations to the embodiments described herein will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present specification should be included in the scope of claims of the embodiments of the present specification.
Claims (13)
1. A current providing apparatus for vector testing of power devices, comprising:
the input end of the voltage regulator is coupled with the output end of the test power supply;
a booster having an input coupled to an output of the voltage regulator;
a compensation capacitor having an input coupled to the output of the booster; wherein the content of the first and second substances,
the output end of the compensation capacitor is coupled with one end of a tested electric device, the other end of the tested electric device is provided with a short-circuit point, and at least one end of the tested electric device is coupled with at least one secondary device for detecting the tested electric device;
the impedance of the compensation capacitor is different from the impedance of the electrical device under test.
2. The current providing apparatus of claim 1 wherein the impedance of the compensation capacitor is less than the impedance of the electrical device under test.
3. The current providing apparatus of claim 1 further comprising:
and the controller is used for adjusting the voltage value output by the voltage regulator.
4. The current providing apparatus of claim 3 further comprising:
the current transformer is coupled with one end of the controller, and the other end of the controller is coupled with the voltage regulator.
5. The current supply apparatus of claim 1, wherein the output terminal of the compensation capacitor is coupled to the high voltage terminal of the electrical device under test, and the low voltage terminal of the electrical device under test is provided with a shorting point.
6. A power equipment vector test device, comprising:
the input end of the voltage regulator is coupled with the output end of the test power supply;
a booster having an input coupled to an output of the voltage regulator;
the input end of the compensation capacitor is coupled with the output end of the booster, and the output end of the compensation capacitor is coupled with one end of a tested electric device; and the number of the first and second groups,
the secondary device is coupled to at least one end of the tested electric device and used for detecting the tested electric device; wherein the content of the first and second substances,
the other end of the tested electric equipment is provided with a short contact, and the impedance of the compensation capacitor is different from that of the tested electric equipment.
7. The power device vector test apparatus of claim 6, wherein the impedance of the compensation capacitor is less than the impedance of the tested power device.
8. The power equipment vector test apparatus of claim 6, further comprising:
and the controller is used for adjusting the voltage value output by the voltage regulator.
9. The power equipment vector test apparatus of claim 8, further comprising: the current transformer is coupled with one end of the controller, and the other end of the controller is coupled with the voltage regulator.
10. The power equipment vector testing device according to claim 6, wherein the output end of the compensation capacitor is coupled with the high-voltage end of the tested power equipment, and the low-voltage end of the tested power equipment is provided with a short-circuit point.
11. The power equipment vector testing apparatus of claim 6, wherein the secondary equipment comprises at least one of:
the voltage transformer is used for detecting the voltage of a branch where the tested electric equipment is located;
the current transformer is used for detecting the current of a branch where the tested electric equipment is located;
the relay protection device judges the fault state by utilizing the voltage and the current of the branch circuit where the tested power equipment is located;
the metering device is used for counting the electric quantity consumption of the tested electric equipment;
and the fault recording device records the voltage and the current of the branch circuit of the tested power equipment when the power grid has a fault.
12. A power equipment vector test system, comprising: a power device under test and a power device vector test apparatus according to any one of claims 6 to 11.
13. A power equipment vector test system, comprising: a test power supply, a power device under test and a power device vector test apparatus according to any one of claims 6 to 11, the test power supply being coupled to the power device vector test apparatus.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113933648A (en) * | 2021-09-27 | 2022-01-14 | 国网河北省电力有限公司电力科学研究院 | Power distribution network relay protection vector checking and action logic checking test device and method |
| CN115902480A (en) * | 2022-11-29 | 2023-04-04 | 西安西电电力电容器有限责任公司 | Integrated power capacitor test loop and tuning method thereof |
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2019
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113933648A (en) * | 2021-09-27 | 2022-01-14 | 国网河北省电力有限公司电力科学研究院 | Power distribution network relay protection vector checking and action logic checking test device and method |
| CN115902480A (en) * | 2022-11-29 | 2023-04-04 | 西安西电电力电容器有限责任公司 | Integrated power capacitor test loop and tuning method thereof |
| CN115902480B (en) * | 2022-11-29 | 2023-11-03 | 西安西电电力电容器有限责任公司 | Integrated power capacitor test loop and tuning method thereof |
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