CN109980627A - The oscillation suppression method and device of DC distribution net - Google Patents
The oscillation suppression method and device of DC distribution net Download PDFInfo
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- CN109980627A CN109980627A CN201910255353.9A CN201910255353A CN109980627A CN 109980627 A CN109980627 A CN 109980627A CN 201910255353 A CN201910255353 A CN 201910255353A CN 109980627 A CN109980627 A CN 109980627A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/102—Parallel operation of dc sources being switching converters
Abstract
The present invention relates to the oscillation suppression methods and device of a kind of DC distribution net, and wherein method is the following steps are included: obtain the operating parameter of each converter in DC distribution net, wherein operating parameter includes output voltage, output electric current, impedance operator and harmonic characterisitic；The converter set that resonance is easy to produce in DC distribution net is obtained according to operating parameter；Corresponding parameter adjustment mode is selected according to the number of converter in converter set, and it is adjusted according to parameter of the parameter adjustment mode of selection to each converter in converter set, inhibited with the oscillation to DC distribution net, to realize the dynamic inhibition to system oscillation, and system power dissipation and cost are not will increase.
Description
Technical field
The present invention relates to DC distribution network technology field, a kind of oscillation suppression method more particularly to DC distribution net and
Device.
Background technique
In DC distribution net, most of equipment are to be realized by DC/DC converter or AC/DC converter and direct current mother
The electrical connection of line, thus on DC bus not only have DC component, but also due to by power electronic devices switching characteristic and
The influence of load characteristic etc., so that inevitably there is certain harmonic component on DC bus, such DC bus is posted
Raw inductance and parasitic capacitance just have the possibility of resonance under certain condition.Meanwhile often there are more DC/ in DC distribution net
DC converter or AC/DC converter, and different converters are due to by its power grade, topological structure and control parameter etc.
The influence of factor, impedance operator and the oscillation injected to DC bus are also different, when the frequency of oscillation and direct current of converter
When natural mode shape on bus is consistent, DC bus will vibrate, and break down so as to cause DC distribution net, because
This needs to inhibit the oscillation of DC bus.
In the related technology, mainly the oscillation of DC distribution net is inhibited in the following manner:
1) method based on the passive damping of installation, for example, the resistance in series or in parallel on the filter element of converter, and
Keep the control strategy of converter constant, to realize the purpose for inhibiting system oscillation, but this method is actual due to increasing
Resistance, therefore the power loss of system, cost and volume increase, and due to circuit connection complexity be easy to appear it is biggish
Risk, thus it is not very practical.
2) active damping method, for example, equivalent damping is generated in controlled system by increasing control ring, to reach
To inhibit system oscillation purpose, but due to resonance frequency can with electric network impedance, element loss and environmental change etc. because
Element changes, therefore when carrying out oscillation inhibition using traditional active damping method, can not be according to resonance frequency dynamic regulation
The impedance operator of itself, to be difficult to obtain ideal inhibitory effect.
3) based on the method for installing harmonic compensation and vibration suppression device additional, for example, installing active power filtering additional in systems
Device filters out multiple and higher hamonic wave by Active Power Filter-APF, thus achieve the purpose that inhibit system oscillation, but due to electricity
Network capacity amount is larger, relatively high to the capacity requirement of Active Power Filter-APF, therefore will increase the cost and cost of system.
Although above method is able to solve system oscillation problem to a certain extent, still remaining oscillation can not dynamic
Inhibit and big, the at high cost problem of system power dissipation.
Summary of the invention
Based on this, it is necessary to for when carrying out oscillation inhibition to DC distribution net, existing oscillation can not in the related technology
The problem that dynamic inhibits and system power dissipation is big, at high cost, provides the oscillation suppression method and device of a kind of DC distribution net.
A kind of oscillation suppression method of DC distribution net, comprising the following steps:
Obtain the operating parameter of each converter in DC distribution net, wherein operating parameter includes output voltage, output electricity
Stream, impedance operator and harmonic characterisitic；
The converter set that resonance is easy to produce in DC distribution net is obtained according to operating parameter；
Corresponding parameter adjustment mode is selected according to the number of converter in converter set, and according to the parameter tune of selection
Perfect square formula is adjusted the parameter of each converter in converter set, is inhibited with the oscillation to DC distribution net.
The converter collection that resonance is easy to produce in DC distribution net is obtained according to operating parameter in one of the embodiments,
It closes, comprising:
The resonance frequency of DC distribution net is obtained according to operating parameter；
Obtain the participation factor of each converter in the corresponding DC distribution net of resonance frequency；
The converter set for being easy to produce resonance is determined according to the size relation for participating in the factor.
Include: according to the resonance frequency that operating parameter obtains DC distribution net in one of the embodiments,
The node admittance matrix of DC distribution net under different predeterminated frequencies is established, according to operating parameter to obtain multiple nodes
Admittance matrix；
The mode impedance of each node admittance matrix is obtained, to obtain multiple mode impedances；
The resonance frequency of DC distribution net is obtained according to the size relation of multiple mode impedances.
Obtain in one of the embodiments, the participation of each converter in the corresponding DC distribution net of resonance frequency because
Son, comprising:
The node admittance matrix for obtaining the corresponding dc distribution network of resonance frequency, is denoted as first node admittance matrix, and
Obtain the node voltage matrix and injection current matrix of corresponding DC distribution net；
Mode voltage vector and mode are obtained according to first node admittance matrix, node voltage matrix and injection current matrix
Current vector；
The participation factor of each converter is obtained according to mode voltage vector and mode current vector.
The converter collection for being easy to produce resonance is determined according to the size relation for participating in the factor in one of the embodiments,
It closes, comprising:
Obtain the maximum value for participating in the factor；
Judge whether the remaining absolute value for participating in the difference between the factor and maximum value is less than preset threshold；
If it is, the corresponding converter of the participation factor is included in converter set.
Corresponding parameter adjustment side is selected according to the number of converter in converter set in one of the embodiments,
Formula, comprising:
If number is one, parameter adjustment mode is active damping parameter adjustment mode；
If number is two or more, parameter adjustment mode is that active damping parameter and virtual electrical network parameter combine
Adjustment mode.
Active damping parameter adjustment mode is expressed by following formula in one of the embodiments:
Z=1-RaIo,
Wherein, Z is active damping parameter, RaFor adjustment factor, IoFor the output electric current of converter to be adjusted.
In one embodiment, the adjustment mode that active damping parameter and virtual electrical network parameter combine includes:
The active damping parameter of each converter to be adjusted is adjusted, and virtual to each converter injection to be adjusted
Electrical network parameter, so that the resonance frequency of all converters to be adjusted is same fixed resonant frequency, and to same fixed resonance frequency
Rate is inhibited.
A kind of vibration suppression device of DC distribution net, comprising:
Parameter acquisition module, for obtaining the operating parameter of each converter in DC distribution net, wherein operating parameter packet
Include output voltage, output electric current, impedance operator and harmonic characterisitic；
Resonance, which generates, obtains module, for obtaining the converter for being easy to produce resonance in DC distribution net according to operating parameter
Set；
Suppression module is vibrated, for selecting corresponding parameter adjustment mode according to the number of converter in converter set,
And be adjusted according to parameter of the parameter adjustment mode of selection to each converter in converter set, to DC distribution net
Carry out oscillation inhibition.
Oscillation suppression module selects to correspond in the number according to converter in converter set in one of the embodiments,
Parameter adjustment mode when, wherein
If number is one, parameter adjustment mode is active damping parameter adjustment mode；
If number is two or more, parameter adjustment mode is that active damping parameter and virtual electrical network parameter combine
Adjustment mode.
The oscillation suppression method and device of above-mentioned DC distribution net, by the fortune for obtaining each converter in DC distribution net
Row parameter, including output voltage, output electric current, impedance operator and harmonic characterisitic, and DC distribution net is obtained according to operating parameter
In be easy to produce the converter set of resonance, and select corresponding parameter to adjust according to the number of converter in converter set
Mode, and be adjusted according to parameter of the parameter adjustment mode of selection to each converter in converter set, to direct current
The oscillation of power distribution network is inhibited, to can realize to the inhibition of the dynamic of system oscillation, and not will increase system power dissipation and at
This.
Detailed description of the invention
Fig. 1 is the flow chart of the oscillation suppression method of DC distribution net in one embodiment；
Fig. 2 is the topology diagram of DC distribution net in one embodiment；
Fig. 3 is that the flow chart that the converter set of resonance is easy to produce in DC distribution net is obtained in one embodiment；
Fig. 4 is shadow when power grid equivalent impedance is respectively 1mH, 2mH and 3mH in one embodiment to DC distribution net resonance
Ring schematic diagram；
Fig. 5 is the schematic diagram that self-adaptive damping and conventional damper influence output voltage in one embodiment；
Fig. 6 is the flow chart of the oscillation suppression method of DC distribution net in a specific example；
Fig. 7 is the block diagram of the vibration suppression device of DC distribution net in one embodiment；
Fig. 8 is the system diagram that the oscillation of DC distribution net in a specific embodiment inhibits.
Specific embodiment
In order to make the foregoing objectives, features and advantages of the present invention clearer and more comprehensible, with reference to the accompanying drawing to the present invention
Specific embodiment be described in detail.Many details are explained in the following description in order to fully understand this hair
It is bright.But the invention can be embodied in many other ways as described herein, those skilled in the art can be not
Similar improvement is done in the case where violating intension of the present invention, therefore the present invention is not limited to the specific embodiments disclosed below.
Unless otherwise defined, all technical and scientific terms used herein and belong to technical field of the invention
The normally understood meaning of technical staff is identical.Term as used herein in the specification of the present invention is intended merely to description tool
The purpose of the embodiment of body, it is not intended that in the limitation present invention.Each technical characteristic of above embodiments can carry out arbitrary group
It closes, for simplicity of description, combination not all possible to each technical characteristic in above-described embodiment is all described, however,
As long as there is no contradiction in the combination of these technical features, all should be considered as described in this specification.
Fig. 1 is the flow chart of the oscillation suppression method of DC distribution net in one embodiment, as shown in Figure 1, DC distribution
The oscillation suppression method of net the following steps are included:
Step 102, the operating parameter of each converter in DC distribution net is obtained, wherein operating parameter includes output electricity
Pressure, output electric current, impedance operator and harmonic characterisitic.
Specifically, refering to what is shown in Fig. 2, usually in DC distribution net containing a large amount of distributed generation resource (such as photovoltaic power generation,
Wind-power electricity generation), energy storage device (such as energy-storage system) and alternating current-direct current load (such as electric car, AC load, DC load), and
And these equipment pass through DC/DC converter or AC/DC converter is connected on DC bus, and in the process of running,
Due to the power swing of distributed generation resource, the switching of large capacity load and the failure for exchanging side etc., lead to direct current system
Fluctuation, and these fluctuate generated harmonic wave and can adversely affect to DC distribution net, it is therefore desirable to DC distribution net
Oscillation inhibited.
When the oscillation to DC distribution net inhibits, each converter in DC distribution net can be first passed through to itself
Operating parameter obtained, for example, detecting the output voltage and output electric current of itself, and the impedance operator for analyzing itself is harmonious
Then the output voltage of itself, output electric current, impedance operator and harmonic characterisitic etc. are uploaded to overlayer monitors center by wave property.
Step 104, the converter set that resonance is easy to produce in DC distribution net is obtained according to operating parameter.
Specifically, such as exporting electricity in the operating parameter that overlayer monitors center receives each converter in DC distribution net
After pressure, output electric current, impedance operator and harmonic characterisitic, beginning determines in DC distribution net according to these operating parameters to be easy to produce
All converters of resonance, and as a converter set.
In one embodiment, resonance is easy to produce refering to what is shown in Fig. 3, obtaining in DC distribution net according to operating parameter
Converter set, comprising:
Step 302, the resonance frequency of DC distribution net is obtained according to operating parameter.
In one embodiment, obtaining the resonance frequency of DC distribution net according to operating parameter includes: according to operating parameter
The node admittance matrix of DC distribution net under different predeterminated frequencies is established, to obtain multiple node admittance matrixes；Obtain each section
The mode impedance of point admittance matrix, to obtain multiple mode impedances；Direct current is obtained according to the size relation of multiple mode impedances to match
The resonance frequency of power grid.Wherein, the frequency that resonance can may occur according to DC distribution net for different predeterminated frequencies determines.
Specifically, electricity is such as exported in the operating parameter that overlayer monitors center receives each converter in DC distribution net
After pressure, output electric current, impedance operator and harmonic characterisitic, converter network in DC distribution net can be first established under predeterminated frequency f1
Node admittance matrix Y1, and Eigenvalues Decomposition is carried out to node admittance matrix Y1, to obtain eigenvalue λ 1, and record characteristic value
The absolute value or modulus value of 1/ λ 1 of inverse of λ 1 | 1/ λ 1 |, and it is defined as mode impedance.Then, direct current under predeterminated frequency f2 is established
The node admittance matrix Y2 of converter network in power distribution network, and Eigenvalues Decomposition is carried out to node admittance matrix Y2, to obtain
Eigenvalue λ 2, and record the absolute value or modulus value of 1/ λ 2 of inverse of eigenvalue λ 2 | 1/ λ 2 |, and it is defined as mode impedance.It connects
, switch next predeterminated frequency and repeat the above steps, frequency can be ascending, until the frequency of resonance may all occur for traversal
Rate, it is assumed that such frequency has n, then the finally absolute value or modulus value reciprocal of the available corresponding characteristic value of n mode
The distribution situation of (i.e. mode impedance).
Then, the maximum value of the absolute value or modulus value (i.e. mode impedance) reciprocal of the corresponding characteristic value of n mode is obtained,
To obtain maximum mode impedance.It, can be using situation corresponding to the maximum mode impedance as system after obtaining maximum mode impedance
Crucial parallel resonance, and using its corresponding characteristic value as crucial mode, the corresponding frequency of peak value is parallel resonance at this time
Resonance frequency namely DC distribution net resonance frequency.
Step 304, the participation factor of each converter in the corresponding DC distribution net of resonance frequency is obtained.
In one embodiment, the participation factor of each converter in the corresponding DC distribution net of resonance frequency, packet are obtained
It includes: obtaining the node admittance matrix of the corresponding dc distribution network of resonance frequency, be denoted as first node admittance matrix, and obtain phase
The node voltage matrix and injection current matrix for the DC distribution net answered；According to first node admittance matrix, node voltage matrix
Mode voltage vector and mode current vector are obtained with injection current matrix；It is obtained according to mode voltage vector and mode current vector
Take the participation factor of each converter.
Specifically, after the resonance frequency for obtaining DC distribution net, the corresponding DC distribution of the resonance frequency can first be obtained
The node admittance matrix Y of net, and then available left and right eigen vector matrix can get each by left and right eigenvectors matrix
The participation factor of the converter for current mode.
Specifically, it is assumed that the corresponding mode impedance of predeterminated frequency f2 is maximum mode impedance, then predeterminated frequency f2 is
For the resonance frequency of DC distribution net, converter net in DC distribution net is first established under predeterminated frequency f2 at overlayer monitors center at this time
The node admittance matrix Y of network, and the node voltage matrix V and injection current matrix I of DC distribution net under predeterminated frequency f2 are obtained,
And there are following relationships by node admittance matrix Y, node voltage matrix V and injection current matrix I:
V=Y-1*I (1)
Meanwhile following formula (2) can get according to matrix decomposition node admittance matrix Y:
Y=L Λ T (2)
Wherein, Λ is the eigenvalue matrix of node admittance matrix Y, and matrix L is left eigenvector matrix, and matrix T is right spy
Levy vector matrix.Then, above-mentioned formula (2) substitution formula (1) be can get into following formula:
V=L Λ-1TI TV=Λ-1TI (3)
Wherein, defining U=TV is mode voltage vector, and J=TI is mode current vector, then by each transformation of acquisition
The output voltage matrix and output current matrix of device substitute into above-mentioned formula (3), can be obtained mode voltage vector and mode electric current
Vector.
Then, the relationship of mode voltage vector and mode current vector is established, can further obtain following formula:
U=Λ-1J or
By above-mentioned formula (4) it is found that the participation factor of each converter of current mode (resonance frequency f2) is respectively as follows:..., it so far completes to match the corresponding direct current of resonance frequency
The acquisition of the participation factor of each converter in power grid.
Step 306, the converter set for being easy to produce resonance is determined according to the size relation for participating in the factor.
In one embodiment, the converter set for being easy to produce resonance, packet are determined according to the size relation for participating in the factor
It includes: obtaining the maximum value for participating in the factor；It is pre- to judge whether the remaining absolute value for participating in the difference between the factor and maximum value is less than
If threshold value；If it is, the corresponding converter of the participation factor is included in converter set.Wherein, preset threshold can be according to reality
Border situation is demarcated.
Specifically, in obtaining the corresponding DC distribution net of resonance frequency after the participation factor of each converter, it can root
Judge which converter is easier to cause oscillation according to the size relation for participating in the factor, to determine the transformation for being easy to produce resonance
Device set.For example, can first from it is all participation the factors in obtain participate in the factor maximum values, then to residue participate in the factor carry out by
Whether one judgement is less than preset threshold with each remaining absolute value for participating in the difference between the factor and maximum value of determination, that is, sentences
Each remaining factor that participates in break whether close to maximum value, if it is, thinking that the corresponding converter of the participation factor is easy to produce
Raw resonance, is included in converter set at this time；Otherwise, give up the corresponding converter of the participation factor.
Step 106, corresponding parameter adjustment mode is selected according to the number of converter in converter set, and according to selection
Parameter adjustment mode the parameter of each converter in converter set is adjusted, with to DC distribution net oscillation carry out
Inhibit.
In one embodiment, corresponding parameter adjustment mode, packet are selected according to the number of converter in converter set
Include: if number is one, parameter adjustment mode is active damping parameter adjustment mode；If number is two or more,
Then parameter adjustment mode is active damping parameter and the adjustment mode that virtual electrical network parameter combines.
Specifically, when in all participation factors only have a participations factor it is larger when, illustrate currently only the participation because
The corresponding converter of son is easy to cause oscillation, is adjusted at this time using active damping parameter adjustment mode to the parameter of the converter
It is whole, the inhibition to the oscillation of DC distribution net can be realized.For example, by taking above-mentioned formula (4) as an example.It is assumed that participating in factor P1
For all maximum values for participating in the factors, and it participates in the factor much larger than remaining, then the converter for being easy to produce resonance only has one
It is a, i.e. participation factor P1Corresponding converter, active damping parameter adjustment mode may be selected to the change in overlayer monitors center at this time
The parameter of parallel operation is adjusted, to inhibit to the oscillation of DC distribution net.
In one embodiment, active damping parameter adjustment mode is expressed by following formula:
Z=1-RaIo (5)
Wherein, Z is active damping parameter, RaFor adjustment factor, IoFor the output electric current of converter to be adjusted.
Specifically, when the active damping parameter to converter is adjusted, although being conducive to inhibit converter may
The resonance of generation, but will cause the decline of converter output voltage, therefore the resonance in order to inhibit converter that may occur,
Reduce the influence to converter output voltage simultaneously, adaptive active damping adjusting method can be used, i.e., by single active damping
Parameter is set as one can make active damping parameter as shown in above-mentioned formula (5) with current related function is exported in this way
The automatic adjusument with the variation of electric current, and then reduce the pressure drop of output voltage, it is specific as shown in Figure 5.Match as a result, in direct current
When only having converter in power grid and being easy to cause oscillation, by the adaptive adjustment to active damping parameter, it can be realized pair
Effective inhibition of DC distribution net oscillation.
Further, it when there is multiple participation factors larger and close in all participation factors, is easy at this time to these ginsengs
Converter corresponding with the factor influences the resonance of system to generate erroneous judgement, therefore inhibits the humorous of DC distribution net to be further accurate
Vibration, introduces virtual electrical network parameter at this time, is inhibited by virtual electrical network parameter to the oscillation of DC distribution net.It is specific next
It says, when more converters access DC distribution net, since the power grade and filtering parameter of converter itself immobilize, institute
It is held essentially constant with the resonance frequency of converter itself, and the grid-connected resonance frequency of converter is with the increasing of power grid equivalent impedance
Reduce greatly, as shown in figure 4, can make therefore by injecting for example virtual electric network impedance of different virtual electrical network parameters to converter
The resonance frequency for participating in the larger and close converter of the factor is moved to a certain fixed resonant frequency, then by humorous to the fixation
Vibration frequency is inhibited that the inhibition to the oscillation of DC distribution net can be realized (as being filtered).
In practical applications, to reach better inhibitory effect, active damping parameter and virtual electrical network parameter phase can be used
In conjunction with adjustment mode the oscillation of DC distribution net inhibited.In one embodiment, active damping parameter and virtual
The adjustment mode that electrical network parameter combines includes: to be adjusted to the active damping parameter of each converter to be adjusted, and to every
A converter to be adjusted injects virtual electrical network parameter, so that the resonance frequency of all converters to be adjusted is same fixed resonance frequency
Rate, and same fixed resonant frequency is inhibited.
Specifically, still taking the above example as an example.If participating in factor P2Close to maximum value P1, and much larger than remaining ginseng
With the factor, i.e. P2≈P1> > P3..., then can not determine which converter is easier excited target and generates resonance at this time, therefore
The adjustment mode that the optional active damping parameter in overlayer monitors center and virtual electrical network parameter combine at this time is to participation factor P1
And P2The parameter of corresponding converter is adjusted.For example, can be first respectively to P1And P2The active damping parameter of corresponding converter
It is adjusted, adjustment mode can damp adjustment side for single active damping parameter regulation means or above-mentioned adaptive active
Method, then, respectively to P1And P2Corresponding converter injects the virtual for example virtual electric network impedance of electrical network parameter, to P1And P2It is corresponding
Converter output impedance and power grid equivalent impedance carry out dynamic regulation, to destroy DC distribution net resonant network, will point
Scattered multiple spot resonance frequency is unified for a certain fixed resonant frequency, then by being inhibited to the fixed resonant frequency (as filtered
Wave processing) i.e. the oscillation that may occur of suppressor system.There are two or more converters to be easy in DC distribution net as a result,
When causing oscillation, by the adjustment to active damping parameter and virtual electrical network parameter, it can be realized to the oscillation of DC distribution net
Effectively inhibit.
Fig. 6 is the flow chart of the oscillation suppression method of DC distribution net in a specific example, as shown in fig. 6, the direct current
The oscillation suppression method of power distribution network can comprise the following steps that
Step 602, overlayer monitors center obtains the output voltage of each converter in DC distribution net, output electric current, resistance
Anti- characteristic and harmonic characterisitic.
Step 604, the node admittance matrix of DC distribution net under predeterminated frequency is established.
Step 606, the characteristic value of calculate node admittance matrix, and record the absolute value or modulus value reciprocal of characteristic value.
Step 608, the frequency of resonance may all be occurred until traversing, it is corresponding to be obtained n mode by small and big for frequency
The distribution situation of the absolute value or modulus value reciprocal of characteristic value.
Step 610, according to the size of the absolute value or modulus value reciprocal of the corresponding characteristic value of n mode, judge and obtain
The resonance frequency of dc distribution network.
Step 612, the node admittance matrix of DC distribution net at this time is found out according to resonance frequency, and then obtains left and right spy
Vector matrix is levied, each converter is found out for the participation factor of current mode by left and right eigenvectors matrix, and obtain participation
The biggish converter of the factor.
Step 614, overlayer monitors center sends for example active damping parameter of adjusting parameter to the biggish converter of the factor is participated in
Or active damping parameter and virtual electrical network parameter, to change the impedance operator of converter, to inhibit the generation of system oscillation.
In the present embodiment, each converter uploads the voltage and current information of itself to upper layer monitoring center in DC distribution net
And impedance operator and harmonic characterisitic information, overlayer monitors center obtain the harmonic characterisitic point of entire DC distribution net by analysis
Cloth and the resonance frequency that resonance may occur, and then calculate active damping parameter and virtual electricity that each converter needs to adjust
Network parameters, and active damping parameter and virtual electrical network parameter are issued to each converter in system, thus dynamic regulation system
The impedance operator of each converter in system, the resonance that inhibition system may occur ensure that the safety of whole system.
To sum up, the oscillation suppression method of above-mentioned DC distribution net, based on the harmonic wave to each converter in DC distribution net
It measures, the impedance operator of each converter in dynamic adjusting system, so that the harmonic frequency off-resonance frequency of each converter
Point so that the oscillation for inhibiting system that may occur, improves the overall security of DC distribution net, and not will increase system power dissipation
And cost.
Fig. 7 is the block diagram of the vibration suppression device of DC distribution net in one embodiment, as shown in fig. 7, direct current
The vibration suppression device of power distribution network includes: parameter acquisition module 10, resonance generation acquisition module 20 and oscillation suppression module 30.
Wherein, parameter acquisition module 10 is used to obtain the operating parameter of each converter in DC distribution net, wherein operation
Parameter includes output voltage, output electric current, impedance operator and harmonic characterisitic；Resonance, which generates, obtains module 20 for joining according to operation
Number obtains the converter set that resonance is easy to produce in DC distribution net；Suppression module 30 is vibrated to be used for according in converter set
The number of converter selects corresponding parameter adjustment mode, and according to the parameter adjustment mode of selection to each in converter set
The parameter of converter is adjusted, to carry out oscillation inhibition to DC distribution net.It in practical applications, refering to what is shown in Fig. 8, can be right
Answer each converter that one parameter acquisition module 10 is set, while resonance generates and obtains module 20 and vibrate suppression module 30 and can collect
At being arranged in overlayer monitors center, specifically here with no restrictions.
In one embodiment, oscillation suppression module 30 is corresponding in the number selection according to converter in converter set
When parameter adjustment mode, wherein if number is one, parameter adjustment mode is active damping parameter adjustment mode；If
Number is two or more, then parameter adjustment mode is active damping parameter and the adjustment mode that virtual electrical network parameter combines.
It should be noted that the description of the vibration suppression device about DC distribution net, can refer to about DC distribution net
Oscillation suppression method description, which is not described herein again.
The vibration suppression device of above-mentioned DC distribution net, the operation by obtaining each converter in DC distribution net are joined
Number, and the converter set that resonance is easy to produce in DC distribution net is obtained according to operating parameter, and according to converter set
The number of middle converter selects corresponding parameter adjustment mode, and according to the parameter adjustment mode of selection to every in converter set
The parameter of a converter is adjusted, and is inhibited with the oscillation to DC distribution net, is moved to can realize to system oscillation
State inhibits, and not will increase system power dissipation and cost.
Each technical characteristic of embodiment described above can be combined arbitrarily, for simplicity of description, not to above-mentioned reality
It applies all possible combination of each technical characteristic in example to be all described, as long as however, the combination of these technical characteristics is not deposited
In contradiction, all should be considered as described in this specification.
The embodiments described above only express several embodiments of the present invention, and the description thereof is more specific and detailed, but simultaneously
It cannot therefore be construed as limiting the scope of the patent.It should be pointed out that coming for those of ordinary skill in the art
It says, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to protection of the invention
Range.Therefore, the scope of protection of the patent of the invention shall be subject to the appended claims.
Claims (10)
1. a kind of oscillation suppression method of DC distribution net, which comprises the following steps:
Obtain the operating parameter of each converter in DC distribution net, wherein the operating parameter includes output voltage, output electricity
Stream, impedance operator and harmonic characterisitic；
The converter set that resonance is easy to produce in the DC distribution net is obtained according to the operating parameter；
Corresponding parameter adjustment mode is selected according to the number of converter in the converter set, and according to the ginseng of selection
Number adjustment mode is adjusted the parameter of each converter in the converter set, with the oscillation to the DC distribution net
Inhibited.
2. the method according to claim 1, wherein described obtain the DC distribution according to the operating parameter
The converter set of resonance is easy to produce in net, comprising:
The resonance frequency of the DC distribution net is obtained according to the operating parameter；
Obtain the participation factor of each converter in the corresponding DC distribution net of the resonance frequency；
The converter set for being easy to produce resonance is determined according to the size relation for participating in the factor.
3. according to the method described in claim 2, it is characterized in that, described obtain the DC distribution according to the operating parameter
The resonance frequency of net includes:
The node admittance matrix of the DC distribution net under different predeterminated frequencies is established according to the operating parameter, it is multiple to obtain
The node admittance matrix；
The mode impedance of each node admittance matrix is obtained, to obtain multiple mode impedances；
The resonance frequency of the DC distribution net is obtained according to the size relation of multiple mode impedances.
4. according to the method described in claim 2, it is characterized in that, the corresponding direct current of the resonance frequency that obtains is matched
The participation factor of each converter in power grid, comprising:
The node admittance matrix for obtaining the corresponding dc distribution network of the resonance frequency is denoted as first node admittance square
Battle array, and obtain the node voltage matrix and injection current matrix of the corresponding DC distribution net；
According to the first node admittance matrix, the node voltage matrix and the injection current matrix obtain mode voltage to
Amount and mode current vector；
The participation factor of each converter is obtained according to the mode voltage vector and mode current vector.
5. according to the method described in claim 2, it is characterized in that, described determined according to the size relation for participating in the factor is held
It is also easy to produce the converter set of resonance, comprising:
Obtain the maximum value for participating in the factor；
Judge whether the remaining absolute value for participating in the difference between the factor and the maximum value is less than preset threshold；
If it is, the corresponding converter of the participation factor is included in the converter set.
6. method according to any one of claims 1-5, which is characterized in that described to become according in the converter set
The number of parallel operation selects corresponding parameter adjustment mode, comprising:
If the number is one, the parameter adjustment mode is active damping parameter adjustment mode；
If the number is two or more, the parameter adjustment mode is active damping parameter and virtual electrical network parameter phase
In conjunction with adjustment mode.
7. according to the method described in claim 6, it is characterized in that, the active damping parameter adjustment mode passes through following formula
It is expressed:
Z=1-RaIo,
Wherein, Z is active damping parameter, RaFor adjustment factor, IoFor the output electric current of converter to be adjusted.
8. according to the method described in claim 6, it is characterized in that, the active damping parameter and virtual electrical network parameter combine
Adjustment mode include:
The active damping parameter of each converter to be adjusted is adjusted, and virtual to each converter injection to be adjusted
Electrical network parameter, so that the resonance frequency of all converters to be adjusted is same fixed resonant frequency, and to described same solid
Determine resonance frequency to be inhibited.
9. a kind of vibration suppression device of DC distribution net characterized by comprising
Parameter acquisition module, for obtaining the operating parameter of each converter in DC distribution net, wherein the operating parameter packet
Include output voltage, output electric current, impedance operator and harmonic characterisitic；
Resonance, which generates, obtains module, for obtaining the change for being easy to produce resonance in the DC distribution net according to the operating parameter
Parallel operation set；
Suppression module is vibrated, for selecting corresponding parameter adjustment mode according to the number of converter in the converter set,
And be adjusted according to parameter of the parameter adjustment mode of selection to each converter in the converter set, to institute
It states DC distribution net and carries out oscillation inhibition.
10. device according to claim 9, which is characterized in that the oscillation suppression module is according to the converter collection
When the number of converter selects corresponding parameter adjustment mode in conjunction, wherein
If the number is one, the parameter adjustment mode is active damping parameter adjustment mode；
If the number is two or more, the parameter adjustment mode is active damping parameter and virtual electrical network parameter phase
In conjunction with adjustment mode.
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