CN117148009A - Low-frequency power transmission valve section operation test circuit and control method - Google Patents
Low-frequency power transmission valve section operation test circuit and control method Download PDFInfo
- Publication number
- CN117148009A CN117148009A CN202311123484.4A CN202311123484A CN117148009A CN 117148009 A CN117148009 A CN 117148009A CN 202311123484 A CN202311123484 A CN 202311123484A CN 117148009 A CN117148009 A CN 117148009A
- Authority
- CN
- China
- Prior art keywords
- frequency
- low
- voltage
- valve section
- power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000012360 testing method Methods 0.000 title claims abstract description 103
- 238000000034 method Methods 0.000 title claims abstract description 33
- 230000005540 biological transmission Effects 0.000 title claims abstract description 31
- 239000003990 capacitor Substances 0.000 claims abstract description 18
- 230000001502 supplementing effect Effects 0.000 claims description 13
- 238000004364 calculation method Methods 0.000 claims description 8
- 238000001514 detection method Methods 0.000 claims description 6
- 238000012163 sequencing technique Methods 0.000 claims description 6
- 239000011159 matrix material Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Classifications
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Electric Properties And Detecting Electric Faults (AREA)
Abstract
The application discloses a low-frequency transmission valve section operation test circuit and a control method, wherein the test circuit comprises: the device comprises a sample valve section 1, a sample valve section 2, a low-frequency valve section, a power frequency alternating current adjustable power supply, a current limiting reactance, a load reactance, a low-frequency resonant circuit and a filter capacitor. The test sample valve section is started to charge and the power loss in operation is provided by a single power frequency alternating current power supply, the single-phase alternating current is directly output by the commercial power through the voltage regulator to supply power to the test circuit, no additional power supply control is needed, and the power supply is simple and reliable. The alternating current power supply and the low-frequency valve section which are connected with the two ends of the test sample valve section provide power frequency and low-frequency end voltage for the test sample, and can accurately simulate the voltage characteristic between the low-frequency power transmission engineering converter valve ends. In the test circuit control method, voltage balance between the low-frequency valve section and the test sample valve section can be realized by controlling the low-frequency resonant circuit current, and the total capacitance voltage of the test sample valve section and the low-frequency valve section can be kept stable by controlling the power frequency current output by the alternating current power supply.
Description
Technical Field
The application relates to the technical field of low-frequency power transmission, in particular to a low-frequency power transmission valve section operation test circuit and a control method.
Background
With the development of open sea wind power, modular multilevel matrix converters have recently been called one of the research hotspots in the engineering field. The low-frequency wind power station can be used for low-frequency output of open sea wind power, is connected with a low-frequency running offshore wind power station, and omits an offshore converter station. The single bridge arm of the modularized matrix converter adopts a full-bridge power module cascading structure, 9 bridge arms are provided, and an alternating-current low-frequency port and an alternating-current power frequency port are provided, so that alternating-current and alternating-current conversion is realized. In the back-to-back topology of the three-phase bridge structure, 12 bridge arms are needed to realize the alternating-current conversion, and the number of the bridge arms is relatively large. Therefore, the method can greatly reduce the cost of the offshore wind power delivery in the aspect of the construction of the convertor station, and has better development prospect. For a large-scale offshore wind power plant, the stable operation of the matrix converter directly influences the reliability of wind power grid connection, so that the matrix converter in a low-frequency power transmission system also needs to be subjected to a converter valve operation test before operation, a short-time overload and long-time maximum load operation test is carried out on the converter valve by taking a valve section as a unit according to the existing flexible-direct engineering, and each valve section is usually formed by connecting more than 4 power modules in series as a test sample valve section according to the converter valve operation test standard of IEC.
The voltage and current stress born by the bridge arm of the matrix converter in the operation process are greatly different from those of the flexible direct system, the two ends of the bridge arm are connected with the alternating system, and the voltage of the bridge arm is about the voltage difference of the alternating system at the two ends, so that the voltage between the bridge arm ends mainly comprises a low-frequency component and a power frequency component. Bridge arm current is also the synthesis of low frequency component and high frequency component, and the stack of direct current component and alternating current component is between the test article valve section end in current gentle direct current valve operation test circuit, for example the chinese patent "cascade module test circuit, method and system" of publication No. CN115407147a provides a modularization cascade multi-level operation test circuit, and test circuit is to gentle direct current valve design, and the test circuit is output voltage and matrix converter difference between the test article valve section end is great, and test circuit needs two sets of direct current power of charging power supply and operation test power supply, and the power supply part is more complicated. And the operation test power supply provides loss power for the valve section operation test through the two test sample power modules, when the number of the test sample units connected in series is large, the operation loss can exceed the rated power limit of the power units, so that the number of the tested modules in a single test is limited by the rated power of the test sample power units.
Disclosure of Invention
The application provides a low-frequency transmission valve section operation test circuit and a control method. Only one power frequency alternating current power supply is needed to realize the charging of a test loop and the operation test power supply, and a direct current power supply and a rectifying device are not needed to be configured; and the required alternating current power supply can be a low-power voltage regulator which is connected with a power grid, and the main loop is simple and reliable.
In view of this, a first aspect of the present application provides a low frequency transmission valve section operation test circuit, the circuit comprising:
the device comprises a sample valve section 1, a sample valve section 2, a low-frequency valve section, a power frequency alternating current adjustable power supply, a current limiting reactance, a load reactance, a low-frequency resonant circuit and a filter capacitor;
the test article valve section 1 and the test article valve section 2 are connected in parallel through the load reactance, the high-voltage end of the test article valve section after being connected in parallel is connected with the low-voltage end of the low-frequency valve section, the low-voltage end of the test article valve section after being connected in parallel is connected with the positive pole of the power frequency alternating current adjustable power supply through the current limiting reactance, the grounding pole of the power frequency alternating current adjustable power supply is connected with the high-voltage end of the low-frequency valve section, the two ends of the low-frequency resonant circuit are respectively connected with the positive pole of the power frequency alternating current voltage adjustable power supply and the high-voltage end of the low-frequency valve section, and the two ends of the filter capacitor are respectively connected with the negative pole of the power frequency alternating current voltage adjustable power supply and the high-voltage end of the low-frequency valve section.
Optionally, the sample valve section 1, the sample valve section 2 and the low-frequency valve section are formed by connecting a plurality of full-bridge power modules in series.
Optionally, the power frequency ac adjustable power supply specifically includes: the low-voltage commercial power outputs 0-rated voltage adjustable single-phase alternating current through a single-phase voltage regulator, wherein the output end of the single-phase voltage regulator is the output end of the power frequency alternating current adjustable power supply.
Optionally, the low frequency resonant tank includes: a resonant inductance and a resonant capacitance;
the resonance inductor and the resonance capacitor are connected in series, and the resonance frequency of the resonance inductor is the same as the low-frequency component frequency of the voltage between the ends of the test sample valve section.
The second aspect of the present application provides a control method for a low-frequency transmission valve segment operation test circuit, which is applied to the low-frequency transmission valve segment operation test circuit described in the first aspect, and the method includes:
after the mains supply is connected, the voltage regulator of the power frequency alternating current adjustable power supply is adjusted, so that the output voltage of the power supply is gradually increased to the rated voltage, and the single-phase alternating current forms a charging loop through the current limiting reactance, the sample valve section 1, the sample valve section 2, the low-frequency valve section and the filter capacitor to charge the power unit;
calculating the phase of an alternating current power supply, and enabling a phase-locked loop module to calculate the phase of the output voltage of the alternating current power supply;
charging a power unit in the low-frequency valve section to the working voltage of the power unit, unlocking the low-frequency valve section, and enabling the low-frequency valve section control module;
lifting the test sample current, and simultaneously unlocking the test sample valve section 1 and the test sample valve section 2, so that a current control module of the test sample valve section enables test sample valve section 1 and the test sample valve section 2 to generate test current according to a current set value; and gradually increasing the magnitude of the current set point to a predetermined test current value.
Optionally, the phase-locked loop module is specifically configured to:
based on a conventional phase-locked loop calculation method, according to a voltage detection value output by a power frequency alternating current voltage regulation power supply and a delay signal of 1/4 power frequency period, calculating to obtain the voltage phase of the alternating current power supply, wherein the voltage detection value and the delay signal are in an orthogonal relationship.
Optionally, the low-frequency valve segment control module is specifically configured to:
integrating a given low-frequency signal to obtain a low-frequency phase, and performing sine operation on the low-frequency phase to obtain a low-frequency sine signal;
multiplying the low-frequency sinusoidal signal with a steady-state voltage amplitude signal of a low-frequency valve section to obtain a low-frequency steady-state voltage signal;
adding the low-frequency steady-state voltage signal with a voltage average value control signal and a voltage balance control signal to obtain a low-frequency valve segment modulation signal, wherein the low-frequency valve segment modulation signal is subjected to a recent level approximation and voltage sequencing method to obtain a low-frequency valve segment trigger pulse;
wherein, the voltage average value control signal is: the voltage average value control module is used for calculating; the voltage balance control signal is: calculated by a voltage balance control module.
Optionally, the voltage balance control module is specifically configured to:
the average voltage of the low-frequency valve section and the average voltage of the sample valve section 1 and the sample valve section 2 are subjected to difference, the difference value is input into a first PI regulator, and the output signal is multiplied by a low-frequency sinusoidal signal to obtain a low-frequency resonance current given signal;
and the given low-frequency resonance current signal and the feedback low-frequency resonance current signal are subjected to difference, and the difference value is subjected to a first proportional-resonance regulator, so that the voltage balance control signal is output.
Optionally, the voltage average value control module is specifically configured to:
the total capacitance voltage given value and the total capacitance voltage feedback value are subjected to difference, the difference value is input to a second PI regulator, and the output signal is multiplied with the sine calculation result of the power grid phase to obtain a power frequency energy supplementing current given signal;
and the power frequency energy supplementing current given signal and the power supply current feedback signal are subjected to difference, and the difference value passes through a second proportion-resonance regulator, so that the voltage average value control signal is output.
Optionally, the resonance frequency of the first proportional-resonance regulator is low frequency, and the resonance frequency of the second proportional-resonance regulator is power frequency.
From the above technical scheme, the application has the following advantages:
1) According to the low-frequency transmission valve section operation test topology and control method, only a single alternating current power supply and a voltage regulator are adopted to realize the charging and energy supplementing of the test sample valve section, a rectifying device and an additional power supply control system are not needed, and the power supply part of the test system is relatively simple and high in reliability;
2) According to the topology and the control method for the operation test of the low-frequency power transmission valve section, two ends of the test piece valve section are respectively connected with the low-frequency valve section and the power frequency power supply, and voltage stress between converter valve ends in the low-frequency power transmission engineering can be accurately equivalent.
3) According to the topology and the control method for the operation test of the low-frequency power transmission valve section, the low-frequency resonant current passage is arranged to realize the voltage balance control of the low-frequency valve section and the test sample valve section, the filter capacitor is arranged to provide a passage for the power frequency energy supplementing current output by the alternating-current power supply, the mutual independence of the low-frequency voltage balance control current and the power frequency energy supplementing current is realized, the energy supplementing current output by the alternating-current power supply only contains the power frequency component, and the fluctuation of the output power of the alternating-current power supply can be effectively reduced.
Drawings
Fig. 1 is a schematic structural diagram of a low-frequency transmission valve section operation test circuit provided in an embodiment of the present application;
fig. 2 is a schematic diagram of a phase-locked loop module according to an embodiment of the present application;
FIG. 3 is a schematic diagram of a low frequency valve segment control module provided in an embodiment of the present application;
FIG. 4 is a schematic diagram of a sample valve segment current control module provided in an embodiment of the present application;
fig. 5 is a schematic flow chart of a control method of a low-frequency transmission valve section operation test circuit provided in an embodiment of the application.
Detailed Description
In order to make the present application better understood by those skilled in the art, the following description will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Referring to fig. 1, a low-frequency transmission valve section operation test circuit provided in an embodiment of the present application includes: the device comprises a sample valve section 1, a sample valve section 2, a low-frequency valve section, a power frequency alternating current adjustable power supply S, a current limiting reactance Ls, a load reactance L1, a low-frequency resonant circuit and a filter capacitor C1;
the test article valve section 1 and the test article valve section 2 are connected in parallel through a load reactance L1, the high-voltage end of the parallel test article valve section is connected with the low-voltage end of the low-frequency valve section, the low-voltage end of the parallel test article valve section is connected with the positive pole of the power frequency alternating current adjustable power supply S through a current limiting reactance Ls, the grounding pole of the power frequency alternating current adjustable power supply is connected with the high-voltage end of the low-frequency valve section, the two ends of the low-frequency resonance loop are respectively connected with the positive pole of the power frequency alternating current adjustable power supply and the high-voltage end of the low-frequency valve section, and the two ends of the filter capacitor C1 are respectively connected with the negative pole of the power frequency alternating current adjustable power supply S and the high-voltage end of the low-frequency valve section.
The low-frequency resonant circuit is used for controlling the voltage balance between the low-frequency valve section and the sample valve section; the branch of the filter capacitor C1 is an energy supplementing current path with operation loss, and mainly flows through power frequency current.
In one embodiment, the sample valve section 1, the sample valve section 2 and the low-frequency valve section are formed by connecting a plurality of full-bridge power modules in series.
It should be noted that, the sample valve section 1, the sample valve section 2 and the low-frequency valve section are each formed by connecting a plurality of (e.g. 5) full-bridge power modules in series.
In one embodiment, the power frequency ac adjustable power source S specifically includes: the low-voltage commercial power outputs 0-rated voltage adjustable single-phase alternating current through a single-phase voltage regulator, wherein the output end of the single-phase voltage regulator is the output end of a power frequency alternating current adjustable power supply, and the single-phase voltage regulator is connected in series in a test loop.
In one embodiment, a low frequency resonant tank comprises: a resonance inductance L2 and a resonance capacitance C2;
the resonant inductor L2 and the resonant capacitor C2 are connected in series, the resonant frequency of the resonant inductor is the same as the low-frequency component frequency of the voltage between the ends of the valve section of the sample, and the resonant frequency is 20Hz.
The control method of the low-frequency transmission valve section operation test circuit provided by the embodiment of the application is as follows.
Referring to fig. 5, a control method for a low-frequency transmission valve segment operation test circuit provided in an embodiment of the present application includes:
step 201, after the mains supply is connected, a voltage regulator of the power frequency alternating current adjustable power supply is adjusted, so that the output voltage of the power supply is gradually increased to the rated value, and a charging loop is formed by single-phase alternating current through a current limiting reactance, a sample valve section 1, a sample valve section 2, a low-frequency valve section and a filter capacitor, so that a power unit is charged;
it should be noted that, the capacitor voltage of the power unit in the sample valve section 1, the sample valve section 2 and the low-frequency valve section in the initial stage of precharge is 0, after the mains supply is connected, the power frequency ac adjustable power supply voltage regulator is adjusted to gradually raise the output voltage of the power supply to the rated value, and the single-phase ac forms a charging loop through the current limiting reactance, the sample valve section 1, the sample valve section 2, the low-frequency valve section and the filter capacitor C1 to charge the power unit.
Step 202, calculating the phase of an alternating current power supply, and enabling a phase-locked loop module to calculate the phase of the output voltage of the alternating current power supply;
it should be noted that, calculating the phase of the ac power supply enables the phase-locked loop module to calculate the phase θs of the output voltage of the ac power supply s 。
Step 203, charging the power unit in the low-frequency valve section to the working voltage of the power unit, unlocking the low-frequency valve section, and enabling the low-frequency valve section control module;
it should be noted that, the power unit in the low-frequency valve section is charged to the working voltage of the power unit first, the low-frequency valve section is unlocked, and the low-frequency valve section control module is enabled, so that the average voltage of the sample valve section 1 and the sample valve section 2 is consistent with the average voltage of the low-frequency valve section, and the total average voltage of the three valve sections tracks the given value of the capacitor voltage.
Step 204, lifting the sample current, and simultaneously unlocking the sample valve section 1 and the sample valve section 2, so that a current control module of the sample valve section can generate test current between the sample valve section 1 and the sample valve section 2 according to a current set value; and gradually increasing the magnitude of the current set point to a predetermined test current value.
It should be noted that, as shown in fig. 4, in one embodiment, the current control module of the test sample valve section will test the current set point I at low frequency L1 Current I of industrial frequency test L2 Adding the given value and the sample voltage balance control signal to obtain the final sample current given value I Lt ，I Lt The difference is made with the current feedback value between the test samples, then the current feedback value is connected with the input ends of the proportion, resonance 3 and resonance 4 regulators which are connected in parallel, the outputs of the proportion, resonance 3 and resonance 4 regulators are added, and then the current feedback value is connected with the steady-state voltage signal M of the test sample valve section 1 t1 Adding to obtain steady-state voltage signal M of test sample valve section 2 t2 ，M t2 And obtaining the trigger pulse of the test sample valve section 2 through a latest level approximation and voltage sequencing method. Modulation voltage M of test sample valve section 1 t1 The trigger pulse of the test sample valve section 1 is obtained directly through a nearest level approximation and voltage sequencing method.
Further, as shown in FIG. 4, the sample voltage balance control signal is calculated by a sample voltage balance control module, in which the steady-state voltage M of the sample valve section 1 is first calculated t1 Dividing the sum by the rated module voltage of the valve section of the sample to obtain the per unit value of the steady-state voltage of the valve section of the sample. And secondly, the average voltage of the valve section 1 of the sample and the average voltage of the valve section 2 of the sample are subjected to difference, the difference is connected with the input end of a PI3 of a third PI regulator, and the PI3 output signal is multiplied by the per unit value of the steady-state voltage of the valve section of the sample to obtain a sample voltage balance control signal.
In one embodiment, the phase-locked loop module is specifically configured to:
based on a conventional phase-locked loop calculation method, according to a voltage detection value output by a power frequency alternating current voltage-regulating power supply and a delay signal of 1/4 power frequency period, calculating to obtain the alternating current power supply voltage phase, wherein the voltage detection value and the delay signal are in an orthogonal relationship.
It should be noted that, as shown in fig. 2, the input of the phase-locked loop module includes the detected value of the output voltage of the power frequency ac voltage regulating power supply and the delay signal of 1/4 of the power frequency period "delay T/4". The two input signals are in quadrature relation, and then obtained by a conventional phase-locked loop calculation methodTo the phase theta of the AC power supply voltage s
In one embodiment, the low frequency valve segment control module is specifically configured to:
integrating a given low-frequency signal to obtain a low-frequency phase, and performing sine operation on the low-frequency phase to obtain a low-frequency sine signal;
multiplying the low-frequency sinusoidal signal with a steady-state voltage amplitude signal of the low-frequency valve section to obtain a low-frequency steady-state voltage signal;
adding the low-frequency steady-state voltage signal with the voltage average value control signal and the voltage balance control signal to obtain a low-frequency valve segment modulation signal, and obtaining a low-frequency valve segment trigger pulse by the low-frequency valve segment modulation signal through a nearest level approximation and voltage sequencing method;
wherein, the voltage average value control signal is: the voltage average value control module is used for calculating; the voltage balance control signal is: calculated by a voltage balance control module.
It should be noted that, as shown in fig. 3, the low-frequency valve segment control module first outputs a given low-frequency signal f L Integrating to obtain low-frequency phase theta L ，θ L And obtaining a low-frequency sinusoidal signal through sinusoidal operation. Low-frequency sinusoidal signal and low-frequency valve segment steady-state voltage amplitude signal U L0 Multiplying to obtain a low-frequency steady-state voltage signal. The low-frequency steady-state voltage signal is added with the voltage average value control signal and the voltage balance control signal to obtain a low-frequency valve segment modulation signal, and the low-frequency valve segment modulation signal is subjected to a nearest level approximation NLM and a voltage sequencing method to obtain a low-frequency valve segment trigger pulse.
In one embodiment, the voltage balance control module is specifically configured to:
the average voltage of the low-frequency valve section and the average voltage of the sample valve section 1 and the sample valve section 2 are subjected to difference, the difference value is input into a first PI regulator, and the output signal is multiplied by a low-frequency sinusoidal signal to obtain a low-frequency resonance current given signal;
the given low frequency resonant current signal is differenced from the feedback low frequency resonant current signal by a first proportional-resonant regulator to output a voltage balance control signal.
It should be noted that, as shown in fig. 3, the voltage balance control signal is calculated by a voltage balance control module, which averages the low-frequency valve segment average voltage U L And average voltage U of valve sections of two samples t And the difference is connected with a first PI regulator PI1, and the PI1 output is multiplied by the low-frequency sinusoidal signal to obtain a low-frequency resonant current given signal. The low frequency resonant current given signal is further differenced from the low frequency resonant current feedback signal, and the difference is outputted as a voltage balance control signal through the first proportional-resonant regulator PR 1.
The low-frequency resonant current feedback signal is obtained by arranging a current sensor in the low-frequency resonant circuit L2-C2.
In one embodiment, the voltage average control module is specifically configured to:
the total capacitance voltage given value and the total capacitance voltage feedback value are subjected to difference, the difference value is input to a second PI regulator, and the output signal is multiplied with the sine calculation result of the power grid phase to obtain a power frequency energy supplementing current given signal;
the power frequency energy supplementing current given signal and the power supply current feedback signal are subjected to difference, and the difference value passes through the second proportion-resonance regulator, so that a voltage average value control signal is output.
It should be noted that, as shown in fig. 3, the voltage average control signal is calculated by a voltage average control module, in which the total capacitance voltage is given a value U c_ref And a total capacitance voltage feedback value U c_avg The difference is connected with a second PI regulator PI2, and the PI2 output is connected with the power grid phase theta s The sine sin calculation results are multiplied to obtain a power frequency energy supplementing current given signal. Further, the power frequency energy supplementing current given signal and the power supply current feedback signal are subjected to difference, and the difference value is subjected to second proportion-resonance regulator PR2 to output a voltage average value control signal.
In one embodiment, the resonant frequency of the first proportional-resonant regulator is low frequency and the resonant frequency of the second proportional-resonant regulator is power frequency.
As shown in fig. 3, the resonance frequency of the first proportional-resonance regulator PR1 should be set to be low frequency, for example, 20Hz, which is the same as the low frequency voltage component frequency of the valve section of the sample. The second proportional-resonant regulator PR2 should have a resonant frequency set at power frequency, for example 50Hz.
Further, as shown in fig. 4, the resonance 3 regulator is a second-order resonance link, and the resonance frequency is the same as the frequency of the low-frequency voltage component of the valve section of the sample, for example, 20Hz; the resonance 4 regulator is a second-order resonance link, and the resonance frequency is power frequency, for example, 50Hz; steady-state voltage M of test sample valve section 1 t1 The low-frequency power supply comprises a low-frequency component 20Hz and a power frequency component 50Hz, and is obtained by adding the low-frequency steady-state voltage signal and the output voltage of a power frequency alternating-current voltage regulating power supply S and then inverting.
It will be clear to those skilled in the art that, for convenience and brevity of description, the specific working procedures of the above-described system and unit may refer to the corresponding procedures in the foregoing method embodiments, which are not repeated here.
The terms "first," "second," "third," "fourth," and the like in the description of the application and in the above figures, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented, for example, in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.
In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: u disk, mobile hard disk, read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic disk or optical disk, etc.
The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims (10)
1. A low frequency transmission valve segment operation test circuit, comprising: the device comprises a sample valve section 1, a sample valve section 2, a low-frequency valve section, a power frequency alternating current adjustable power supply, a current limiting reactance, a load reactance, a low-frequency resonant circuit and a filter capacitor;
the test article valve section 1 and the test article valve section 2 are connected in parallel through the load reactance, the high-voltage end of the test article valve section after being connected in parallel is connected with the low-voltage end of the low-frequency valve section, the low-voltage end of the test article valve section after being connected in parallel is connected with the positive pole of the power frequency alternating current adjustable power supply through the current limiting reactance, the grounding pole of the power frequency alternating current adjustable power supply is connected with the high-voltage end of the low-frequency valve section, the two ends of the low-frequency resonant circuit are respectively connected with the positive pole of the power frequency alternating current voltage adjustable power supply and the high-voltage end of the low-frequency valve section, and the two ends of the filter capacitor are respectively connected with the negative pole of the power frequency alternating current voltage adjustable power supply and the high-voltage end of the low-frequency valve section.
2. The low frequency transmission valve section operation test circuit according to claim 1, wherein the sample valve section 1, the sample valve section 2 and the low frequency valve section are each formed by connecting a plurality of full bridge power modules in series.
3. The low-frequency transmission valve section operation test circuit according to claim 1, wherein the power frequency alternating current adjustable power supply specifically comprises: the low-voltage commercial power outputs 0-rated voltage adjustable single-phase alternating current through a single-phase voltage regulator, wherein the output end of the single-phase voltage regulator is the output end of the power frequency alternating current adjustable power supply.
4. The low frequency transmission valve segment operation test circuit of claim 1, wherein the low frequency resonant tank comprises: a resonant inductance and a resonant capacitance;
the resonance inductor and the resonance capacitor are connected in series, and the resonance frequency of the resonance inductor is the same as the low-frequency component frequency of the voltage between the ends of the test sample valve section.
5. A control method of a low-frequency transmission valve section operation test circuit, characterized by being applied to the low-frequency transmission valve section operation test circuit as claimed in any one of claims 1 to 4, the method comprising:
after the mains supply is connected, the voltage regulator of the power frequency alternating current adjustable power supply is adjusted, so that the output voltage of the power supply is gradually increased to the rated voltage, and the single-phase alternating current forms a charging loop through the current limiting reactance, the sample valve section 1, the sample valve section 2, the low-frequency valve section and the filter capacitor to charge the power unit;
calculating the phase of an alternating current power supply, and enabling a phase-locked loop module to calculate the phase of the output voltage of the alternating current power supply;
charging a power unit in the low-frequency valve section to the working voltage of the power unit, unlocking the low-frequency valve section, and enabling the low-frequency valve section control module;
lifting the test sample current, and simultaneously unlocking the test sample valve section 1 and the test sample valve section 2, so that a current control module of the test sample valve section enables test sample valve section 1 and the test sample valve section 2 to generate test current according to a current set value; and gradually increasing the magnitude of the current set point to a predetermined test current value.
6. The control method of a low frequency transmission valve segment operation test circuit according to claim 5, wherein the phase-locked loop module is specifically configured to:
based on a conventional phase-locked loop calculation method, according to a voltage detection value output by a power frequency alternating current voltage regulation power supply and a delay signal of 1/4 power frequency period, calculating to obtain the voltage phase of the alternating current power supply, wherein the voltage detection value and the delay signal are in an orthogonal relationship.
7. The control method of the low-frequency transmission valve segment operation test circuit according to claim 5, wherein the low-frequency valve segment control module is specifically configured to:
integrating a given low-frequency signal to obtain a low-frequency phase, and performing sine operation on the low-frequency phase to obtain a low-frequency sine signal;
multiplying the low-frequency sinusoidal signal with a steady-state voltage amplitude signal of a low-frequency valve section to obtain a low-frequency steady-state voltage signal;
adding the low-frequency steady-state voltage signal with a voltage average value control signal and a voltage balance control signal to obtain a low-frequency valve segment modulation signal, wherein the low-frequency valve segment modulation signal is subjected to a recent level approximation and voltage sequencing method to obtain a low-frequency valve segment trigger pulse;
wherein, the voltage average value control signal is: the voltage average value control module is used for calculating; the voltage balance control signal is: calculated by a voltage balance control module.
8. The control method of a low frequency transmission valve segment operation test circuit according to claim 7, wherein the voltage balance control module is specifically configured to:
the average voltage of the low-frequency valve section and the average voltage of the sample valve section 1 and the sample valve section 2 are subjected to difference, the difference value is input into a first PI regulator, and the output signal is multiplied by a low-frequency sinusoidal signal to obtain a low-frequency resonance current given signal;
and the given low-frequency resonance current signal and the feedback low-frequency resonance current signal are subjected to difference, and the difference value is subjected to a first proportional-resonance regulator, so that the voltage balance control signal is output.
9. The control method of the low-frequency transmission valve segment operation test circuit according to claim 8, wherein the voltage average value control module is specifically configured to:
the total capacitance voltage given value and the total capacitance voltage feedback value are subjected to difference, the difference value is input to a second PI regulator, and the output signal is multiplied with the sine calculation result of the power grid phase to obtain a power frequency energy supplementing current given signal;
and the power frequency energy supplementing current given signal and the power supply current feedback signal are subjected to difference, and the difference value passes through a second proportion-resonance regulator, so that the voltage average value control signal is output.
10. The method for controlling a low frequency transmission valve segment operation test circuit according to claim 9, wherein the resonance frequency of the first proportional-resonance regulator is a low frequency, and the resonance frequency of the second proportional-resonance regulator is a power frequency.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311123484.4A CN117148009A (en) | 2023-08-31 | 2023-08-31 | Low-frequency power transmission valve section operation test circuit and control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311123484.4A CN117148009A (en) | 2023-08-31 | 2023-08-31 | Low-frequency power transmission valve section operation test circuit and control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117148009A true CN117148009A (en) | 2023-12-01 |
Family
ID=88898243
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311123484.4A Pending CN117148009A (en) | 2023-08-31 | 2023-08-31 | Low-frequency power transmission valve section operation test circuit and control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117148009A (en) |
-
2023
- 2023-08-31 CN CN202311123484.4A patent/CN117148009A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Dasgupta et al. | A plug and play operational approach for implementation of an autonomous-micro-grid system | |
| CN110556871B (en) | Aggregation equivalence method for large-scale photovoltaic power generation system based on structure keeping method | |
| CN103441526B (en) | Grid-connected off-grid small photovoltaic power generation system and control method | |
| CN108879775B (en) | Power grid unbalanced photovoltaic inverter coordination control method considering current limit value | |
| CN112421690B (en) | Droop control method for improving running stability of hybrid micro-grid | |
| Song et al. | Current harmonic minimization of a grid-connected photovoltaic 500kW three-phase inverter using PR control | |
| CN106130062B (en) | A kind of two-stage type grid-connected photovoltaic system and intermediate dc side voltage stabilizing method | |
| Sepehrzad et al. | Islanded micro-grid frequency control based on the optimal-intelligent lyapunov algorithm considering power dynamic and communication uncertainties | |
| Dai et al. | A novel method for voltage support control under unbalanced grid faults and grid harmonic voltage disturbances | |
| Gao et al. | An active and reactive power controller for battery energy storage system in microgrids | |
| CN111611696A (en) | Nonlinear modeling method of micro-grid system | |
| Tan et al. | Modeling of single phase off-grid inverter for small standalone system applications | |
| CN113852120A (en) | Method and system for determining maximum grid-connected capacity of new energy power generation | |
| Wang et al. | Combined control strategy for proportional current sharing in dc microgrid clusters | |
| Kakkattil Narayanan et al. | Integration of solar PV into grid using a new UPQC with differential inverter control | |
| CN110190741A (en) | High-power high step-up ratio photovoltaic DC current transformer starts control method | |
| CN116819201B (en) | Device and method for testing composite function of energy storage converter in distributed new energy | |
| CN104578883A (en) | Inverter and control method thereof | |
| Božiček et al. | Performance evaluation of the DSP-based improved time-optimal current controller for STATCOM | |
| CN117148009A (en) | Low-frequency power transmission valve section operation test circuit and control method | |
| Sefa et al. | dSPACE based control of voltage source utility interactive inverter | |
| CN113742907B (en) | Unified calculation method for short-circuit current of photovoltaic power station | |
| Long et al. | Data-driven hybrid equivalent dynamic modeling of multiple photovoltaic power stations based on ensemble gated recurrent unit | |
| Chishti et al. | FLL unified AVF and NAAP filter for performance investigation of renewable based AC microgrid under grid to standalone transition mode | |
| CN108448595B (en) | Photovoltaic-series compensation system time domain simulation small disturbance analysis method and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |