CN111751635B - Alternating current network voltage mutation simulation system - Google Patents
Alternating current network voltage mutation simulation system Download PDFInfo
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- CN111751635B CN111751635B CN201910243888.4A CN201910243888A CN111751635B CN 111751635 B CN111751635 B CN 111751635B CN 201910243888 A CN201910243888 A CN 201910243888A CN 111751635 B CN111751635 B CN 111751635B
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Abstract
An alternating current network voltage sudden change simulation system, comprising: a primary winding of the traction transformer is used for being connected with an alternating current contact network; the reactor voltage division circuit is connected with a secondary winding of the traction transformer and used for simulating the switching of the voltage division state of the reactor voltage division circuit according to the sudden change of the network voltage; and an alternating current input end of the traction converter is connected with the reactor voltage division circuit, and an alternating current output end of the traction converter is used for being connected with the traction motor. The voltage sudden change degree of this system can not receive the influence of tested article electric current size, consequently to different products, operating mode not used, this system need not just like prior art recalculate the resistance value when carrying out the voltage sudden change simulation, just so can reduce testing personnel's work load greatly, and then improve test efficiency to can also avoid the potential safety hazard of testing personnel in the process of the test.
Description
Technical Field
The invention relates to the technical field of electric locomotives, in particular to an alternating current network voltage sudden change simulation system.
Background
In the running process of the locomotive, various complex conditions such as sudden voltage change of an actual power grid and the like necessarily exist. In order to simulate the actual operating environment of a locomotive and detect the reliability of tested equipment, according to series standard requirements such as IEC 61377, GB/T25117 and GB/T25122, a rail transit electric transmission system and a traction converter need to be examined by a supply voltage sudden change test.
Disclosure of Invention
In order to solve the above problems, the present invention provides an alternating current network voltage mutation simulation system, including:
a primary winding of the traction transformer is used for being connected with an alternating current contact network;
the reactor voltage division circuit is connected with a secondary winding of the traction transformer and used for simulating the switching of the voltage division state of the reactor voltage division circuit according to the sudden change of the network voltage;
and an alternating current input end of the traction converter is connected with the reactor voltage division circuit, and an alternating current output end of the traction converter is used for being connected with a traction motor.
According to an embodiment of the present invention, the reactor voltage-dividing circuit further includes:
and the analog controller is connected with the reactor voltage division circuit and used for generating a corresponding control instruction according to the network voltage sudden change simulation requirement so as to control the reactor voltage division circuit to switch the voltage division state of the reactor voltage division circuit.
According to one embodiment of the invention, the reactor voltage division circuit comprises a plurality of reactor voltage division branches with the same structure, and each reactor voltage division branch is connected between corresponding ports of the traction transformer and the traction converter.
According to an embodiment of the present invention, the reactor voltage dividing branch includes:
a first end of the first change-over switch is connected with the secondary winding of the traction transformer;
a first end of the second change-over switch forms a first external port of the reactor voltage division branch and is connected with the traction converter, and a second end of the second change-over switch is connected with a second end of the first change-over switch;
a first reactor and a first controllable switch which are connected in parallel, wherein a first end of the first reactor is connected with a third end of the first change-over switch, and a second end of the first reactor is connected with a third end of the second change-over switch;
one end of a circuit formed by connecting the second reactor and the second controllable switch in series is connected with the second end of the first reactor, and the other end of the circuit forms a second external port of the reactor voltage division branch circuit and is connected with the traction converter;
the first change-over switch and the second change-over switch are configured to synchronously conduct the electrical connection between the first end and the second end or conduct the electrical connection between the first end and the third end respectively according to the requirement of sudden change of the network voltage.
According to an embodiment of the present invention, when the network voltage sudden change simulation requirement is a voltage reduction sudden change simulation, the simulation controller is configured to perform the following steps:
step a, after receiving a voltage reduction mutation simulation instruction, controlling the first controllable switch to be closed and simultaneously controlling the second controllable switch to be opened;
b, controlling a main breaker connected with the traction transformer and an alternating current contact network to be closed, respectively conducting the electric connection between the first ports and the third ports of the first change-over switch and the second change-over switch, and operating the tested system to a preset working condition;
and c, controlling the first controllable switch to be switched off and simultaneously controlling the second controllable switch to be switched on.
According to an embodiment of the invention, in the step a, after the first controllable switch is controlled to be closed and the second controllable switch is controlled to be opened, whether the reactor voltage division branch is in a voltage reduction sudden change preparation state is judged, if yes, the step b is executed, otherwise, the step a is executed again.
According to an embodiment of the present invention, when the reactor voltage-dividing circuit includes a reactor voltage-dividing branch, the analog controller is configured to determine whether the reactor voltage-dividing branch is in a voltage-reducing abrupt-change preparation state according to the following steps:
acquiring a sudden drop enabling signal and a sudden rise enabling signal, wherein when the network voltage sudden change simulation requirement is voltage reduction sudden change simulation, the sudden drop enabling signal is a high level signal, and the sudden rise enabling signal is a low level signal;
after the sudden rising enabling signal is inverted, carrying out AND gate logical operation on the sudden rising enabling signal and the sudden falling enabling signal to obtain a first AND gate signal;
acquiring a closed state signal of a first controllable switch and an open state signal of a second controllable switch in a voltage division branch of the reactor, wherein the closed state signal represents that the first controllable switch is normally closed when the closed state signal is at a high level, and the open state signal represents that the second controllable switch is normally open when the open state signal is at the high level;
performing AND gate logic operation on the first AND gate signal, the closing state signal of the first controllable switch and the closing state signal of the second controllable switch to obtain a second AND gate signal;
and if the second AND gate signal is a high level signal, the reactor voltage division branch is determined to be in a voltage reduction sudden change preparation state.
According to an embodiment of the present invention, when the reactor voltage-dividing circuit includes two reactor voltage-dividing branches, the analog controller is configured to determine whether the reactor voltage-dividing branch is ready for voltage-reducing sudden-change according to the following steps:
acquiring a sudden drop enabling signal and a sudden rise enabling signal, wherein when the network voltage sudden change simulation requirement is voltage reduction sudden change simulation, the sudden drop enabling signal is a high level signal, and the sudden rise enabling signal is a low level signal;
after the sudden rising enabling signal is inverted, carrying out AND gate logical operation on the sudden rising enabling signal and the sudden falling enabling signal to obtain a first AND gate signal;
obtaining reactor voltage division branch selection signals, wherein when one reactor voltage division branch is selected, the sudden change enabling signal of the reactor voltage division branch is a high level signal, and the sudden change enabling signal of the other reactor voltage division branch is a low level signal;
acquiring a closed state signal of a first controllable switch and an open state signal of a second controllable switch in a selected reactor voltage division branch, wherein the closed state signal represents that the first controllable switch is normally closed when the closed state signal is at a high level, and the open state signal represents that the second controllable switch is normally open when the open state signal is at a high level;
performing AND gate logic operation on the first AND gate signal, a sudden change enabling signal of the first reactor voltage division branch, a closed state signal of a first controllable switch of the first reactor voltage division branch and an open state signal of a second controllable switch to obtain a third AND gate signal;
performing AND gate logic operation on the first AND gate signal, a sudden change enabling signal of the second reactor voltage division branch, a closed state signal of a first controllable switch of the second reactor voltage division branch and an open state signal of a second controllable switch to obtain a fourth AND gate signal;
inverting the mutation enabling signal of the first reactor voltage division branch circuit, and performing OR gate logical operation on the mutation enabling signal and the third AND gate signal to obtain a first OR gate signal, and inverting the mutation enabling signal of the second reactor voltage division branch circuit, and performing OR gate logical operation on the mutation enabling signal and the fourth AND gate signal to obtain a second OR gate signal;
performing NAND gate logic operation on the inverted mutation enabling signal of the first reactor voltage division branch and the inverted mutation enabling signal of the second reactor voltage division branch to obtain a first NAND gate signal;
performing AND gate logic operation on the first OR gate signal, the second OR gate signal and the first NAND gate signal to obtain a fifth AND gate signal,
and if the fifth AND gate signal is a high level signal, the reactor voltage division branch is determined to be in a voltage reduction sudden change preparation state.
According to an embodiment of the present invention, in the step c, after the first controllable switch is controlled to be turned off and the second controllable switch is controlled to be turned on, whether a timed duration reaches a preset duration is further determined by timing, and if the timed duration reaches the preset duration, the first controllable switch is controlled to be turned on and the second controllable switch is controlled to be turned off.
According to an embodiment of the present invention, when the network voltage sudden change simulation requirement is a voltage boost sudden change simulation, the simulation controller is configured to perform the following steps:
d, after receiving a boosting sudden change simulation instruction, controlling the first controllable switch to be switched off and simultaneously controlling the second controllable switch to be switched on;
step e, controlling a main breaker connected with the traction transformer and an alternating current contact network to be closed, conducting the electric connection between the first ports and the third ports of the first change-over switch and the second change-over switch, and operating the tested system to a preset working condition;
and f, controlling the first controllable switch to be closed and controlling the second controllable switch to be opened at the same time.
Compared with the prior art, the voltage mutation degree of the alternating current network voltage mutation simulation system provided by the invention is not influenced by the current of the tested object, so that the resistance value does not need to be recalculated when the system is used for voltage mutation simulation as in the prior art according to different products and different working conditions, the workload of testers can be greatly reduced, the test efficiency is improved, and the potential safety hazard of the testers in the test process can be avoided.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required in the description of the embodiments or the prior art:
FIG. 1 is a schematic structural diagram of a conventional network pressure mutation simulation device;
FIG. 2 is a schematic diagram of an AC voltage network mutation simulation system according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a circuit configuration of a first reactor voltage-dividing branch according to an embodiment of the present invention;
fig. 4 is an equivalent circuit diagram of a first reactor voltage-dividing branch according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an implementation flow of a simulation of a grid voltage step-down jump simulation according to an embodiment of the present invention;
FIG. 6 is a schematic flow chart illustrating an implementation of a simulation of a sudden step-up voltage change of a simulated grid according to an embodiment of the present invention;
fig. 7 is a schematic flow chart of a specific implementation of the simulation controller controlling the reactor voltage-dividing circuit to simulate the sudden change of the grid voltage according to an embodiment of the invention;
FIGS. 8 and 9 are schematic diagrams of the control logic for the status indicator lights according to one embodiment of the present invention;
fig. 10 and 11 are schematic diagrams of control logic for status indicator lights according to one embodiment of the present invention.
Detailed Description
The following detailed description of the embodiments of the present invention will be provided with reference to the drawings and examples, so that how to apply the technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented. It should be noted that, as long as there is no conflict, the embodiments and the features of the embodiments of the present invention may be combined with each other, and the technical solutions formed are within the scope of the present invention.
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details or with other methods described herein.
Additionally, the steps illustrated in the flow charts of the figures may be performed in a computer system such as a set of computer-executable instructions and, although a logical order is illustrated in the flow charts, in some cases, the steps illustrated or described may be performed in an order different than here.
Fig. 1 shows a schematic structural diagram of a conventional network pressure sudden change simulation device.
As shown in fig. 1, a conventional network voltage sudden change simulation apparatus includes: a traction transformer 101, a resistance voltage-dividing circuit 102, a traction converter 103, a traction motor 104, and the like. In a normal working mode, both the switch QS1 and the switch QS2 are turned to the A position, the switch QF0, the switch QF3, the switch QF4, the switch QF5 and the switch QF6 are sequentially closed, a test of a required working condition is carried out, and the process does not involve network voltage sudden change.
And in the network voltage mutation mode, both the switch QS1 and the switch QS2 are switched to the B position, and at the moment, the size of the voltage dividing resistor R needs to be calculated according to the current value corresponding to the test working condition and the voltage mutation amplitude.
When the network voltage sudden drop simulation is required, the switch QF1, the switch QF0, the switch QF3, the switch QF4, the switch QF5 and the switch QF6 are required to be closed in sequence, and after the tested traction converter 103 is operated to a working condition required by a test, the switch QF2 is closed and the switch QF1 is opened. At this time, due to the voltage division effect of the resistor R, the network voltage reduction sudden change test can be completed.
When network voltage sudden rise simulation is required, the switch QF2, the switch QF0, the switch QF3, the switch QF4, the switch QF5 and the switch QF6 are required to be closed in sequence, and after the converter 103 to be tested is operated to the working condition required by the test, the switch QF1 is closed and the switch QF2 is opened. At this time, the voltage is not divided any more because the resistor R is bypassed, so that the network voltage boosting sudden change test can be completed.
However, the inventor discovers that the conventional network pressure sudden change simulation device has many defects through analyzing the principle, the structure and the working process of the conventional network pressure sudden change simulation device.
For example, for an existing network voltage sudden change simulation device, the voltage sudden change degree is strongly related to the current passing through the resistor, the resistance value of the voltage dividing resistor needs to be adjusted according to different products and different working conditions, and multiple tests are needed to meet test requirements. Meanwhile, the existing network voltage sudden change simulation device needs to be reconnected in each test, so that the working strength of the whole test process is high, the efficiency is low, and the whole test process has large potential safety hazards due to the reconnection.
Aiming at the defects in the prior art, the invention provides a novel alternating current network voltage sudden change simulation system which is a voltage sudden change test system based on a full-coupling reactor and can eliminate the influence of a current value on the voltage sudden change amplitude.
Fig. 2 shows a schematic structural diagram of the alternating-current network voltage sudden change simulation system provided by this embodiment.
As shown in fig. 2, the alternating current network voltage mutation simulation system provided in this embodiment preferably includes: a traction transformer 201, a reactor voltage divider circuit 202 and a traction converter 203. The primary winding of the traction transformer 201 is used for connecting with an ac contact system. Specifically, in the present embodiment, the primary winding of the traction transformer 201 is preferably connected to the ac catenary through the main breaker QF 0. Wherein the ac contactor may provide an ac current of e.g. 25 kV.
The reactor voltage dividing circuit 202 is connected to the secondary winding of the traction transformer 201, and can switch its own voltage dividing state according to the network voltage abrupt change simulation requirement. An ac input end of the traction converter 203 is connected to the reactor voltage dividing circuit 202, and an ac output end thereof is used for being connected to the traction motor. The traction converter 203 can convert the frequency of the ac power transmitted from the reactor voltage-dividing circuit 202 to obtain the ac power with a specific frequency required and drive the traction motor to operate by using the ac power.
The reactor voltage-dividing circuit 202 includes a plurality of reactor voltage-dividing branches having the same structure. For example, in the present embodiment, the reactor voltage-dividing circuit 202 includes two reactor voltage-dividing branches (i.e., a first reactor voltage-dividing branch 202a and a second reactor voltage-dividing branch 202 b).
As shown in fig. 2, in the present embodiment, the first reactor voltage-dividing branch 202a preferably includes: a first changeover switch QS1, a second changeover switch QS2, a first reactor L1, a second reactor L2, a first controllable switch QF1 and a second controllable switch QF2, a third changeover switch QS3 and a fourth changeover switch QS 4.
In this embodiment, the reactor used in the system includes a plurality of taps, and the reactors formed by the different taps are all coupled. In the test, the first reactor L1 and the second reactor L2 were composed by using three of the taps. For example, assume that three taps 1, 2, and 3 are selected in sequence, and reactance values between them are L1 and L2, respectively.
In this embodiment, a first terminal of a first switch QS1 is connected to the secondary winding of the traction transformer 201, a second terminal (i.e., terminal a) is connected to a second terminal (i.e., terminal a) of a second switch QS2, and a third terminal (i.e., terminal B) of the first switch QS3 is connected to a first terminal of a first reactor L1.
A first end of the second switch QS2 forms a first external port of the first reactor voltage dividing branch 202a to be connected with the traction converter 203, and a third end (i.e., end B) is connected with a second end of the first reactor L1. The first controllable switch QF1 is connected in parallel across the first reactor L1.
One end of a circuit formed by the second reactor L2 and the second controllable switch QF2 in series is connected to the second end of the first reactor L1, and the other end is connected to the third end (i.e., the B end) of the fourth switch QS 4. As shown in fig. 2, in the embodiment, the first end of the second reactor L2 is connected to the second end of the first reactor L2, and the second end is connected to the second controllable switch QF 2.
Of course, in other embodiments of the present invention, the positions of the second reactor L2 and the second controllable switch QF2 may be exchanged according to actual needs, and the present invention is not limited thereto.
A first terminal of the third switch QS3 is connected to the secondary winding of the traction transformer 201, a second terminal (i.e., terminal a) is connected to a second terminal (i.e., terminal a) of the fourth switch QS4, and a third terminal is connected to a third terminal of the fourth switch QS 4. A first end of the fourth switch QS4 forms a second external port of the first reactor voltage dividing branch 202a to connect with the traction converter 203.
In this embodiment, the first switch QS1, the second switch QS2, the third switch QS3 and the fourth switch QS4 are implemented by single-pole double-throw switches. Of course, in other embodiments of the present invention, the switch may be implemented by other reasonable circuits or devices, which is not limited in the present invention.
In this embodiment, the first switch QS1, the second switch QS2, the third switch QS3 and the fourth switch QS4 are preferably configured to respectively conduct the electrical connection between the first port and the second terminal (i.e., the a terminal) or the electrical connection between the first port and the third terminal (i.e., the B terminal) synchronously according to the requirement of sudden network voltage change.
Meanwhile, it should be further noted that in other embodiments of the present invention, the third switch QS3 and/or the fourth switch QS4 may not be configured in the first reactor voltage dividing branch 202 a. For example, when the third switch QS3 and the fourth switch QS4 are not disposed in the first reactor voltage-dividing branch 202a, one end of a circuit formed by the second reactor L2 and the second controllable switch QF2 in series is connected to the second end of the first reactor L1, and the other end of the circuit forms a second external port of the reactor voltage-dividing branch 202a to be connected to the traction converter 203.
In this embodiment, since the structures of the reactor voltage-dividing branches included in the reactor voltage division are the same, the content of the second reactor voltage-dividing branch 202b is not described herein again. For convenience of description, the first reactor voltage-dividing branch 202a is taken as an example for further analysis and explanation.
Fig. 3 shows a schematic circuit diagram of the first reactor voltage-dividing branch 202a in this embodiment, and the equivalent circuit diagram shown in fig. 4 can be obtained by decoupling and equivalent the reactor voltage-dividing branch.
From fig. 4, it can be found that:
wherein R isdRepresenting the equivalent resistance, L, of the griddRepresenting the equivalent inductance, L, of the network1Denotes a reactance value, L, of the first reactor2A reactance value of the second reactor is represented,
which is indicative of the first loop current,
representing the second loop current, M representing the coupled inductance,
representing the grid voltage.
From expression (1), one can obtain:
therefore, it is possible to further obtain:
wherein the content of the first and second substances,
representing the voltage across the second reactor.
In expression (3), there is:
Z＝Rd+jwLd (4)
where Z represents the short-circuit impedance of the transformer.
The short-circuit impedance of the transformer can be obtained by considering the parameters (such as 860V/1700A) of the traction transformer for the test of the traction converter of the electric locomotive and a certain short-circuit impedance (such as 8 percent). While
And
of the same order of magnitude, L2+ M and L2Are of the same order of magnitude and are therefore
The effect of the change in (c) on the result of expression (3) is negligible. Thus, the expression (3) can be simplified as follows:
the voltage droop ratio τ at this time is:
as can be seen from expression (5), the voltage drop ratio τ (which represents the voltage drop degree) is independent of the magnitude of the current of the tested product, or can be ignored. Because the voltage mutation degree is irrelevant to the current size of the tested product, the reactance value does not need to be recalculated according to different products and different working conditions during voltage mutation, so that the workload of testers is greatly reduced, the test efficiency is improved, and the potential safety hazard of the testers can be effectively avoided.
In this embodiment, the ac grid voltage sudden change simulation system preferably further includes a simulation controller (not shown in the figure). The analog controller is connected with the reactor voltage dividing circuit 202, and can generate a corresponding control instruction according to the network voltage sudden change simulation requirement to control the reactor voltage dividing circuit 202 to switch the voltage dividing state of the reactor voltage dividing circuit.
Fig. 5 shows a schematic flow chart of implementing the simulation of the voltage drop sudden change of the power grid by controlling the reactor voltage-dividing circuit by the simulation controller in the embodiment. It is assumed that the selected reactor voltage-dividing branch is the first reactor voltage-dividing branch 202 a.
As shown in fig. 5, when the network voltage jump simulation to be performed is a voltage drop jump simulation, after receiving a voltage drop jump simulation command, the analog controller first controls the first controllable switch QF1 in the selected first reactor voltage-dividing branch 202a to be closed and the second controllable switch QF2 to be opened in step S501. Subsequently, in step S502, the analog controller controls the main breaker QF0 connecting the traction transformer 201 and the ac catenary to close, and electrically connects the first port and the third port (i.e., the B port) of each of the first switch QS1, the second switch QS2, the third switch QS3, and the fourth switch QS4, so as to operate the system under test to a preset working condition. Subsequently, the analog controller will control the first controllable switch QF1 to be open and the second controllable switch to be closed in step S503. Thus, the simulation of the net pressure drop is realized.
Similarly, when the network voltage jump simulation requirement is a boost jump (i.e. jump) simulation, as shown in fig. 6, in the embodiment, after receiving the boost jump simulation command, the simulation controller firstly controls the first controllable switch QF1 in the selected first reactor voltage-dividing branch 202a to be turned off and the second controllable switch QF2 to be turned on in step S601. Subsequently, in step S602, the analog controller controls the main breaker QF0 connecting the traction transformer 201 and the ac catenary to close, and electrically connects the first port and the third port (i.e., the B port) of each of the first switch QS1, the second switch QS2, the third switch QS3, and the fourth switch QS4, so as to operate the system under test to a preset working condition. Subsequently, the analog controller controls the first controllable switch QF1 to be closed and controls the second controllable switch to be opened in step S603. Thus, the simulation of the sudden net pressure rise is realized.
Fig. 7 shows a specific implementation flow diagram of the simulation controller controlling the reactor voltage dividing circuit to simulate the sudden change of the grid voltage in this embodiment.
As shown in fig. 7, in this embodiment, the analog controller first determines the reactor voltage dividing branch to be used in step S701. Specifically, the analog controller may obtain the reactor voltage-dividing branch selected by the user through a coherent key on the control interface, so as to obtain the reactor voltage-dividing branch required to be used.
In this embodiment, after a certain reactor voltage division branch is selected, the sudden change enable signal of the reactor voltage division branch is preferably a high level signal (i.e., "1" in the digital signal); and when the reactor voltage-dividing branch is not selected, the abrupt change enable signal of the reactor voltage-dividing branch is preferably configured as a low level signal (i.e., "0" in the digital signal).
The analog controller also determines the type of mutation in step S702. In this embodiment, similarly, the simulation controller may obtain the abrupt change desired to be simulated by the user through a coherent key on the control interface, so that the abrupt change type may be determined. Specifically, in the present embodiment, the mutation type may preferably be a step-up mutation (i.e., a step-up) or a step-down mutation (i.e., a step-down).
It should be noted that, in other embodiments of the present invention, the specific execution sequence of the above steps S701 and S702 may be determined according to actual needs, and the present invention is not limited thereto.
Subsequently, the analog controller controls the on/off states of the respective switching devices in the reactor voltage dividing branch determined in step S701 according to the abrupt change type determined in step S702 in step S703, and determines whether the status indicator lamp is normal or not in step S704. The state indicator lamp can represent whether the reactor voltage division branch is in a preparation state for carrying out voltage mutation or not.
Fig. 8 and 9 are schematic diagrams illustrating the control logic of the status indicator lamp in the present embodiment.
As shown in fig. 8, in the present embodiment, when the reactor voltage-dividing circuit includes two reactor voltage-dividing branches, the analog controller is configured to first obtain the falling enable signal and the rising enable signal. When the network voltage sudden change analog requirement is a voltage reduction sudden change analog requirement, the sudden reduction enable signal is at a high level (namely '1' in the digital signal), and the sudden increase enable signal is at a low level (namely '0' in the digital signal).
Then, the analog controller uses the first not gate 801 to invert the kick enable signal, and uses the first and gate to perform an and gate logic operation on the inverted signal and the kick enable signal, thereby obtaining a first and gate signal.
Specifically, when the voltage dip simulation is required, the kick enable signal is "0" at a low level, and the kick enable signal is "1" at a high level, so that the first and gate signal is "1" at a high level.
After obtaining the first and gate signal, as shown in fig. 8, in this embodiment, the analog controller may obtain a reactor voltage-dividing branch selection signal. When one of the reactor voltage division branches is selected, the sudden change enable signal of the reactor voltage division branch is a high level signal (i.e., "1" in the digital signal), and the sudden change enable signal of the other reactor voltage division branch is a low level signal (i.e., "0" in the digital signal).
Meanwhile, the analog controller can also obtain a closed state signal of the first controllable switch and an open state signal of the second controllable switch in the selected reactor voltage division branch. In the step-down sudden change simulation test, when the closed state signal is at a high level, the first controllable switch is normally closed, and when the open state signal is at a high level, the second controllable switch is normally open.
And then, the analog controller performs and gate logical operation on the first and gate signal, the sudden change enabling signal of the first reactor voltage division branch, the closed state signal of the first controllable switch in the first reactor voltage division branch and the open state signal of the second controllable switch to obtain a third and gate signal.
And the analog controller also carries out AND gate logical operation on the first AND gate signal, the sudden change enabling signal of the second reactor voltage division branch, the closed state signal of the first controllable switch in the second reactor voltage division branch and the open state signal of the second controllable switch to obtain a fourth AND gate signal.
Specifically, as shown in fig. 8, in the present embodiment, the analog controller performs an and gate logic operation on the winding-one sudden change enable signal (i.e., the sudden change enable signal of the first reactor voltage-dividing branch) and the first and gate signal by using the second and gate 803, and inputs a signal obtained by the second and gate 803 into the third and gate 804, so that the signal obtained by the second and gate 802 and the closing state signal of the first controllable switch QF1 are subjected to an and gate logic operation by using the third and gate 804.
The analog controller also uses the fourth and gate 805 to logically budget the signal obtained by the third and gate 804 and the off-state signal of the second controllable switch QF2, so as to obtain the third and gate signal.
Similarly, the analog controller further performs an and gate logic operation on the winding two sudden change enable signal (i.e. the sudden change enable signal of the second reactor voltage-dividing branch) and the first and gate signal by using the fifth and gate 809, and inputs a signal obtained by the fifth and gate 809 into the sixth and gate 810, so that the signal obtained by the fifth and gate 809 and the closed state signal of the first controllable switch QF3 in the second reactor voltage-dividing branch are subjected to the and gate logic operation by using the sixth and gate 810.
The analog controller also uses the seventh and gate 811 to perform and gate logic budgeting on the signal obtained by the sixth and gate 810 and the off-state signal of the second controllable switch QF4 in the second reactor voltage-dividing branch, so as to obtain the fourth and gate signal.
Then, the analog controller inverts the sudden change enable signal of the first reactor voltage-dividing branch by using the second not gate 807, and inputs the inverted signal into the first or gate 806, so that the first or gate 806 performs an or gate logic operation on the signal obtained by the second not gate 807 and the third and gate signal, thereby obtaining the first or gate signal.
Similarly, the analog controller also uses the third not gate 808 to invert the sudden change enable signal of the second reactor voltage division branch and inputs the inverted signal into the second or gate 812, so that the second or gate 812 is used to perform an or gate logical operation on the signal obtained by the third not gate 808 and the fourth and gate signal, thereby obtaining the second or gate signal.
The analog controller also uses the first nand gate 813 to perform nand gate logic budget on the signal obtained by the second not gate 807 and the signal obtained by the third not gate 808, so as to obtain a first nand gate signal.
Then, the analog controller uses the eighth and gate 814 to perform an and gate logic operation on the first or gate signal, the second or gate signal, and the first nand gate signal, so as to obtain a fifth and gate signal. If the fifth and-gate signal is a high-level signal (i.e., "1" in the digital signal), the analog controller may determine that the selected reactor voltage-dividing branch is in the voltage-reducing abrupt-change preparation state, and the state indicator light may display a green color representing normal at this time; otherwise, the selected reactor voltage division branch is judged not to be in a voltage reduction preparation state, and the state indicator lamp displays red representing abnormity.
Similarly, fig. 9 shows a schematic diagram of a control logic of the status indicator lamp when the reactor voltage-dividing circuit includes two reactor voltage-dividing branches in this embodiment, and the principle and the process are similar to those shown in fig. 8, so that details of this part are not repeated here.
As shown in fig. 7 again, in this embodiment, if the status indicator light is not normal, the analog controller will re-execute step S703 at this time. If the status indicator light is normal, the analog controller closes the main breaker QF0 in step S705, and then operates the system under test to the corresponding operating condition (e.g., the operating condition to be tested, etc.) in step S706.
Subsequently, the analog controller issues a sudden change command in step S707, and then controls the on/off state of the switching device in the reactor voltage dividing branch in step S708, so that the voltage sudden change is realized. After controlling the switching device in the reactor voltage-dividing branch circuit to switch the corresponding switching state, the analog controller preferably starts timing, and determines whether the timing duration reaches the preset duration in step S709.
If the preset time length is reached, the analog controller quits the voltage sudden change by controlling the on-off state of a switch device in the reactor voltage division branch in step S710; if the preset time period is not reached, the analog controller continues to execute step S708.
Taking the voltage dip simulation as an example, if the first reactor voltage-dividing branch 202a is selected, in step S703, the analog controller controls the first controllable switch QF1 in the first reactor voltage-dividing branch 202a to be in a closed state, and controls the second controllable switch QF2 to be in an open state. At this time, if the switching states of the first controllable switch QF1 and the second controllable switch QF2 are normal, the sudden drop state indicator lamp will present a green color representing normal, which indicates that the reactor voltage dividing circuit can perform the voltage sudden drop simulation normally at this time.
Subsequently, the analog controller controls the main breaker QF0 to close, so that the first end and the third end of each of the first switch QS1, the second switch QS2, the third switch QS3 and the fourth switch QS4 are all in a conducting state, so that the electrical connection between the traction converter 203 and the ac power grid is also conducted, and the system to be tested can normally work at this time.
After the operation condition of the system to be tested is adjusted to a required condition (i.e., the condition of the traction motor when the network voltage suddenly changes), the analog controller issues a control command, so as to control the first controllable switch QF1 in the first reactor voltage-dividing branch 202a to be switched off and control the second controllable switch QF2 to be switched on. At this time, due to the voltage division of the first reactor L1 and the second reactor L2, the input voltage of the traction converter 203 will suddenly drop.
After the preset time period, the analog controller controls the first controllable switch QF1 to be closed and controls the second controllable switch QF2 to be opened, so that the analog controller can exit the ramp-down analog state.
Taking the voltage spike simulation as an example, if the first reactor voltage-dividing branch 202a is selected, in step S503, the analog controller controls the first controllable switch QF1 in the first reactor voltage-dividing branch 202a to be in the open state, and simultaneously controls the second controllable switch QF2 to be in the closed state. At this time, if the switching states of the first controllable switch QF1 and the second controllable switch QF2 are normal, the light of the sudden rising state indicator will present a green color indicating normal, which indicates that the reactor voltage dividing circuit can perform the voltage sudden rising simulation normally at this time.
Subsequently, the analog controller controls the main breaker QF0 to close, so that the first end and the third end of each of the first switch QS1, the second switch QS2, the third switch QS3 and the fourth switch QS4 are all in a conducting state, so that the electrical connection between the traction converter 203 and the ac power grid is also conducted, and the system to be tested can normally work at this time.
After the operation condition of the system to be tested is adjusted to a required condition (i.e., the condition of the traction motor when the network voltage suddenly changes), the analog controller issues a control instruction, so as to control the first controllable switch QF1 in the first reactor voltage-dividing branch 202a to be closed, and control the second controllable switch QF2 to be opened. At this time, the first reactor L1 and the second reactor L2 are no longer connected to the conductive loop, so the input voltage of the traction converter 203 will suddenly rise.
After the preset time period, the analog controller will control the first controllable switch QF1 to be turned off and the second controllable switch QF2 to be turned on, so as to exit the snap-up analog state.
It should be noted that, if the second reactor voltage-dividing branch is selected to perform voltage mutation simulation, the principle and process thereof are similar to the principle and process of selecting the first reactor voltage-dividing to perform voltage mutation simulation, and therefore, the details of this part are not repeated herein.
Meanwhile, it should be noted that, in other embodiments of the present invention, the number of branches included in the reactor voltage dividing circuit may be configured to be different reasonable values (for example, one or three or more branches, etc.) according to actual needs, and the present invention does not limit this.
If the reactor voltage-dividing branch comprises one reactor voltage-dividing branch, fig. 8 and 9 can be simplified as shown in fig. 10 and 11, respectively.
As shown in fig. 10, taking the voltage dip simulation as an example, when determining whether the reactor voltage-dividing branch is in the voltage-dropping sudden-change preparation state, the analog controller performs an and gate logical operation on the obtained first and gate signal, the closed state signal of the first controllable switch, and the off state signal of the second controllable switch, so as to obtain a second and gate signal. If the second and gate signal is a high level signal, the analog controller determines that the reactor voltage division branch is in a voltage reduction abrupt change preparation state.
Similarly, the principle and process for determining whether the voltage dividing branch of the reactor is in the voltage boosting sudden change equipment state in the voltage sudden rise simulation process are similar to those described above, and therefore, the details are not repeated herein.
It can be seen from the above description that, compared with the existing method, the voltage mutation degree of the alternating current network voltage mutation simulation system provided by the present invention is not affected by the current magnitude of the tested object, so that for different products and different working conditions, the system does not need to recalculate the resistance value as in the prior art when performing voltage mutation simulation, and thus, the workload of the testing personnel can be greatly reduced, the testing efficiency can be improved, and the potential safety hazard of the testing personnel in the testing process can be avoided.
It is to be understood that the disclosed embodiments of the invention are not limited to the particular structures or process steps disclosed herein, but extend to equivalents thereof as would be understood by those skilled in the relevant art. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.
Reference in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrase "one embodiment" or "an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment.
While the above examples are illustrative of the principles of the present invention in one or more applications, it will be apparent to those of ordinary skill in the art that various changes in form, usage and details of implementation can be made without departing from the principles and concepts of the invention. Accordingly, the invention is defined by the appended claims.
Claims (4)
1. An alternating current network voltage jump simulation system, the system comprising:
a primary winding of the traction transformer is used for being connected with an alternating current contact network;
reactor bleeder circuit, it includes a plurality of reactor partial pressure branch roads that the structure is the same, and each reactor partial pressure branch road is connected between traction transformer's secondary winding and traction converter's corresponding port for the partial pressure state that needs switch over self according to net voltage sudden change simulation, wherein, reactor partial pressure branch road includes:
a first end of the first change-over switch is connected with the secondary winding of the traction transformer;
a first end of the second change-over switch forms a first external port of the reactor voltage division branch and is connected with the traction converter, and a second end of the second change-over switch is connected with a second end of the first change-over switch;
a first reactor and a first controllable switch which are connected in parallel, wherein a first end of the first reactor is connected with a third end of the first change-over switch, and a second end of the first reactor is connected with a third end of the second change-over switch;
the first converter is connected with the first end of the first reactor, the second converter is connected with the second end of the first reactor, the other end of the first converter is connected with the second external port of the reactor voltage-dividing branch circuit, and the first converter is connected with the traction converter;
the alternating current input end of the traction converter is connected with the reactor voltage division circuit, and the alternating current output end of the traction converter is used for being connected with a traction motor;
the analog controller is connected with the reactor voltage division circuit and used for generating a corresponding control instruction according to the network voltage sudden change simulation requirement so as to control the reactor voltage division circuit to switch the voltage division state of the reactor voltage division circuit,
when the network voltage sudden change simulation requirement is voltage reduction sudden change simulation, the simulation controller is configured to execute the following steps: step a, after receiving a voltage reduction mutation simulation instruction, controlling the first controllable switch to be closed and simultaneously controlling the second controllable switch to be opened; b, controlling a main breaker connected with the traction transformer and an alternating current contact network to be closed, respectively conducting the electric connection between the first ports and the third ports of the first change-over switch and the second change-over switch, and operating the tested system to a preset working condition; c, controlling the first controllable switch to be opened and the second controllable switch to be closed, in the step a, after controlling the first controllable switch to be closed and the second controllable switch to be opened, judging whether the reactor voltage division branch is in a voltage reduction mutation preparation state, if so, executing the step b, otherwise, executing the step a again;
when the reactor voltage division circuit comprises one reactor voltage division branch, the analog controller is configured to judge whether the reactor voltage division branch is in a voltage reduction sudden change preparation state according to the following steps:
acquiring a sudden drop enabling signal and a sudden rise enabling signal, wherein when the network voltage sudden change simulation requirement is voltage reduction sudden change simulation, the sudden drop enabling signal is a high level signal, and the sudden rise enabling signal is a low level signal;
after the sudden rising enabling signal is inverted, carrying out AND gate logical operation on the sudden rising enabling signal and the sudden falling enabling signal to obtain a first AND gate signal;
acquiring a closed state signal of a first controllable switch and an open state signal of a second controllable switch in a voltage division branch of the reactor, wherein the closed state signal represents that the first controllable switch is normally closed when the closed state signal is at a high level, and the open state signal represents that the second controllable switch is normally open when the open state signal is at the high level;
and performing AND gate logical operation on the first AND gate signal, the closed state signal of the first controllable switch and the off state signal of the second controllable switch to obtain a second AND gate signal, wherein if the second AND gate signal is a high level signal, it is determined that the reactor voltage division branch is in a voltage reduction mutation preparation state.
2. The system of claim 1, wherein when the reactor voltage dividing circuit comprises two reactor voltage dividing branches, the analog controller is configured to determine whether the reactor voltage dividing branches are ready for a step-down jump according to the following steps:
acquiring a sudden drop enabling signal and a sudden rise enabling signal, wherein when the network voltage sudden change simulation requirement is voltage reduction sudden change simulation, the sudden drop enabling signal is a high level signal, and the sudden rise enabling signal is a low level signal;
after the sudden rising enabling signal is inverted, carrying out AND gate logical operation on the sudden rising enabling signal and the sudden falling enabling signal to obtain a first AND gate signal;
obtaining reactor voltage division branch selection signals, wherein when one reactor voltage division branch is selected, the sudden change enabling signal of the reactor voltage division branch is a high level signal, and the sudden change enabling signal of the other reactor voltage division branch is a low level signal;
acquiring a closed state signal of a first controllable switch and an open state signal of a second controllable switch in a selected reactor voltage division branch, wherein the closed state signal represents that the first controllable switch is normally closed when the closed state signal is at a high level, and the open state signal represents that the second controllable switch is normally open when the open state signal is at a high level;
performing AND gate logic operation on the first AND gate signal, a sudden change enabling signal of the first reactor voltage division branch, a closed state signal of a first controllable switch of the first reactor voltage division branch and an open state signal of a second controllable switch to obtain a third AND gate signal;
performing AND gate logic operation on the first AND gate signal, a sudden change enabling signal of the second reactor voltage division branch, a closed state signal of a first controllable switch of the second reactor voltage division branch and an open state signal of a second controllable switch to obtain a fourth AND gate signal;
inverting the mutation enabling signal of the first reactor voltage division branch circuit, and performing OR gate logical operation on the mutation enabling signal and the third AND gate signal to obtain a first OR gate signal, and inverting the mutation enabling signal of the second reactor voltage division branch circuit, and performing OR gate logical operation on the mutation enabling signal and the fourth AND gate signal to obtain a second OR gate signal;
performing NAND gate logic operation on the inverted mutation enabling signal of the first reactor voltage division branch and the inverted mutation enabling signal of the second reactor voltage division branch to obtain a first NAND gate signal;
performing AND gate logic operation on the first OR gate signal, the second OR gate signal and the first NAND gate signal to obtain a fifth AND gate signal,
and if the fifth AND gate signal is a high level signal, the reactor voltage division branch is determined to be in a voltage reduction sudden change preparation state.
3. The system according to claim 1 or 2, wherein in the step c, after the first controllable switch is controlled to be opened and the second controllable switch is controlled to be closed, whether a timed duration reaches a preset duration is further determined by timing, and if the timed duration reaches the preset duration, the first controllable switch is controlled to be closed and the second controllable switch is controlled to be opened.
4. The system of claim 1 or 2, wherein when the grid voltage flare simulation demand is a boost flare simulation, the simulation controller is configured to perform the steps of:
d, after receiving a boosting sudden change simulation instruction, controlling the first controllable switch to be switched off and simultaneously controlling the second controllable switch to be switched on;
step e, controlling a main breaker connected with the traction transformer and an alternating current contact network to be closed, conducting the electric connection between the first ports and the third ports of the first change-over switch and the second change-over switch, and operating the tested system to a preset working condition;
and f, controlling the first controllable switch to be closed and controlling the second controllable switch to be opened at the same time.
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10282171A (en) * | 1997-04-02 | 1998-10-23 | Toshiba Eng Co Ltd | Tester for protective relay |
| CN102237687A (en) * | 2011-03-31 | 2011-11-09 | 中电普瑞科技有限公司 | Multi-column independent control compound switch type stepped controlled shunt reactor device |
| CN102507224A (en) * | 2011-11-01 | 2012-06-20 | 株洲南车时代电气股份有限公司 | Alternating-current grid voltage saltation simulator |
| CN203204129U (en) * | 2013-02-01 | 2013-09-18 | 江苏有能新能源有限公司 | Low voltage ride-through test system for wind turbine generator system |
| CN203218090U (en) * | 2013-02-01 | 2013-09-25 | 江苏有能新能源有限公司 | Multi-gear adjustable reactor |
| CN104124916A (en) * | 2014-06-30 | 2014-10-29 | 国网青海省电力公司电力科学研究院 | Power grid fault simulation test system movement detection device for high-altitude photovoltaic power station |
| EP2801239A1 (en) * | 2012-01-06 | 2014-11-12 | OSRAM GmbH | Power factor controller based single-stage flyback driver and light-emitting system |
| CN104578827A (en) * | 2015-01-27 | 2015-04-29 | 南车株洲电力机车研究所有限公司 | Transformer |
| CN106597872A (en) * | 2016-12-26 | 2017-04-26 | 中国铁道科学研究院 | Subway traction system net voltage interruption, mutation and fluctuation testing system and method |
| CN109030909A (en) * | 2018-07-13 | 2018-12-18 | 北京和信瑞通电力技术股份有限公司 | A kind of distribution one or two times fusions three-phase resistance reactance divided voltage sensor |
| CN208452808U (en) * | 2018-04-28 | 2019-02-01 | 西安中车永电电气有限公司 | A kind of novel high-power locomotive trailer system |
-
2019
- 2019-03-28 CN CN201910243888.4A patent/CN111751635B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10282171A (en) * | 1997-04-02 | 1998-10-23 | Toshiba Eng Co Ltd | Tester for protective relay |
| CN102237687A (en) * | 2011-03-31 | 2011-11-09 | 中电普瑞科技有限公司 | Multi-column independent control compound switch type stepped controlled shunt reactor device |
| CN102507224A (en) * | 2011-11-01 | 2012-06-20 | 株洲南车时代电气股份有限公司 | Alternating-current grid voltage saltation simulator |
| EP2801239A1 (en) * | 2012-01-06 | 2014-11-12 | OSRAM GmbH | Power factor controller based single-stage flyback driver and light-emitting system |
| CN203204129U (en) * | 2013-02-01 | 2013-09-18 | 江苏有能新能源有限公司 | Low voltage ride-through test system for wind turbine generator system |
| CN203218090U (en) * | 2013-02-01 | 2013-09-25 | 江苏有能新能源有限公司 | Multi-gear adjustable reactor |
| CN104124916A (en) * | 2014-06-30 | 2014-10-29 | 国网青海省电力公司电力科学研究院 | Power grid fault simulation test system movement detection device for high-altitude photovoltaic power station |
| CN104578827A (en) * | 2015-01-27 | 2015-04-29 | 南车株洲电力机车研究所有限公司 | Transformer |
| CN106597872A (en) * | 2016-12-26 | 2017-04-26 | 中国铁道科学研究院 | Subway traction system net voltage interruption, mutation and fluctuation testing system and method |
| CN208452808U (en) * | 2018-04-28 | 2019-02-01 | 西安中车永电电气有限公司 | A kind of novel high-power locomotive trailer system |
| CN109030909A (en) * | 2018-07-13 | 2018-12-18 | 北京和信瑞通电力技术股份有限公司 | A kind of distribution one or two times fusions three-phase resistance reactance divided voltage sensor |
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