CN116191576A - Network-structured three-phase converter and impedance and admittance model modeling method thereof - Google Patents
Network-structured three-phase converter and impedance and admittance model modeling method thereof Download PDFInfo
- Publication number
- CN116191576A CN116191576A CN202310340499.XA CN202310340499A CN116191576A CN 116191576 A CN116191576 A CN 116191576A CN 202310340499 A CN202310340499 A CN 202310340499A CN 116191576 A CN116191576 A CN 116191576A
- Authority
- CN
- China
- Prior art keywords
- model
- converter
- current
- axis
- voltage
- 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.)
- Withdrawn
Links
- 238000000034 method Methods 0.000 title claims abstract description 35
- 230000009466 transformation Effects 0.000 claims abstract description 26
- 238000004364 calculation method Methods 0.000 claims abstract description 20
- 238000005070 sampling Methods 0.000 claims abstract description 9
- 238000001914 filtration Methods 0.000 claims abstract description 5
- 238000010586 diagram Methods 0.000 claims description 32
- 238000006243 chemical reaction Methods 0.000 claims description 30
- 239000011159 matrix material Substances 0.000 claims description 19
- 239000003990 capacitor Substances 0.000 claims description 10
- 238000013016 damping Methods 0.000 claims description 8
- 238000002347 injection Methods 0.000 claims description 7
- 239000007924 injection Substances 0.000 claims description 7
- 230000008878 coupling Effects 0.000 claims description 6
- 238000010168 coupling process Methods 0.000 claims description 6
- 238000005859 coupling reaction Methods 0.000 claims description 6
- 230000001360 synchronised effect Effects 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 4
- 238000011217 control strategy Methods 0.000 claims description 3
- 230000001939 inductive effect Effects 0.000 claims description 3
- 230000003071 parasitic effect Effects 0.000 claims description 3
- 238000004458 analytical method Methods 0.000 abstract description 5
- 230000004044 response Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000013178 mathematical model Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Images
Classifications
-
- 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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/48—Controlling the sharing of the in-phase component
-
- 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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/50—Controlling the sharing of the out-of-phase component
-
- 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
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a network three-phase converter and an impedance and admittance model modeling method thereof, which adopts a calculation method for constructing a dq model step by step, adopts modularized analysis, accumulates layer by layer, integrates calculation, and forms the dq impedance and admittance model of the network three-phase converter, wherein the method comprises the following steps: constructing a small signal dq model of a main circuit of the converter; constructing a small signal dq impedance model of a converter control link, and sequentially constructing a voltage-current variable coordinate transformation dq model, an active power reactive power dq model, a sampling low-pass filtering dq model, a power control loop phase angle dq model, a voltage reference signal dq model, a voltage control outer loop dq model, a current control inner loop dq model and a PWM control delay dq model; and simplifying calculation to form a dq impedance model and an admittance model expression of the network three-phase converter. The network-structured three-phase current transformer impedance and admittance model calculated by the invention can be expanded to impedance admittance models of a plurality of current transformers connected in parallel, and provides a model foundation for analyzing the stability of the system in the off-grid and grid-connected states of the current transformers.
Description
Technical Field
The invention relates to the technical field of new energy power systems, in particular to a network three-phase converter and an impedance and admittance model modeling method thereof.
Background
Renewable energy sources (mainly wind energy and solar energy) are developed and utilized rapidly, a large amount of new energy sources are connected in grid, and a converter is widely used as a key component for new energy source grid connection. The high-proportion new energy determines high-proportion power electronic equipment, so that the economical efficiency and the flexibility of the operation of the power system are greatly enhanced, but the capacity ratio of the synchronous generator in the power system is gradually reduced, the integral inertia of the power system is greatly reduced, and the stability of the power system is reduced.
Currently, existing converters for connecting renewable energy sources mostly use grid-connected control, and phase information of a grid-connected Point (PCC) is measured by a phase-locked loop (PLL) to achieve synchronization with a power grid. The grid-connected converters, although having a fast power response capability, cannot operate normally in islanding situations, and at the same time cannot usually establish frequency and voltage in weak grids with widely distributed renewable energy sources, have stability problems, which inhibit their grid support functions and interactions with other generator sets. Therefore, there is an urgent need for a grid-connected three-phase converter, instead of a grid-connected converter, which can operate under off-grid and on-grid conditions, so as to reduce the influence of the grid-connected converter on the system stability.
The stability analysis of the system relies on an accurate, simple, flexible mathematical model. The main methods at present are state space methods and impedance analysis methods. However, the state space method often integrates a system power supply and a load, builds an overall model, and has to reconstruct a new system model when the load topology changes, thereby greatly increasing the complexity of building and analyzing the model. Meanwhile, the constructed state equation is often difficult to analyze due to the fact that the order is too high. According to the impedance analysis method, a single converter is regarded as a voltage source or a current source, an impedance model of the whole system can be calculated only by calculating output impedance, and a simple, convenient and flexible modeling thought is provided for researching parallel operation of different converters and parallel operation of multiple converters of the same type. Therefore, on the basis of providing a network three-phase converter, the network three-phase converter impedance and admittance model modeling method is provided, and a model foundation is laid for researching system stability and parallel operation of multiple converters.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a grid-structured three-phase converter and an impedance and admittance model modeling method thereof, which replace a grid-following converter, can operate under off-grid and grid-connected conditions, reduce the influence of the grid-following converter on system stability, and lay a model foundation for researching system stability and parallel operation of the multi-converter.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
a network three-phase converter comprises a main circuit link and a control link;
the main circuit link comprises a three-phase six-arm inverter and an LC filter electrically connected with the three-phase six-arm inverter; the LC filter comprises an inductance L f And filter capacitor C f The inductance L f One end of the inductor L is connected with the output end of the three-phase six-arm inverter f The other end of (a) is connected with a filter capacitor C f And a bus bar, a capacitor C f The other end of the first electrode is grounded;
the control link comprises a first abc/dq coordinate transformation module, a second abc/dq coordinate transformation module, a third abc/dq coordinate transformation module, a fourth abc/dq coordinate transformation module, a power calculation module, a low-pass filter, a power control loop, a voltage control outer loop, a current control inner loop and a PWM control module;
the inductance L f Is of the inductance current i of (2) L The power calculation module receives a d-axis component voltage value and a q-axis component voltage value output by the abc/dq coordinate conversion module II and a d-axis component current value and a q-axis component current value output by the abc/dq coordinate conversion module III, and outputs instantaneous active power P e And instantaneous reactive power Q e The low-pass filter filters the instantaneous active power P output by the calculation module e And instantaneous reactive power Q e And outputting the average active power and the average reactive power to the power control loop; the power control loop receives active power parameters based on a virtual synchronization control strategyTest value P ref And reactive power reference value Q ref Outputting synchronous phase angles theta of a main circuit to a first abc/dq coordinate conversion module, a second abc/dq coordinate conversion module, a third abc/dq coordinate conversion module and a fourth abc/dq coordinate conversion module, and outputting a dq axis voltage control reference value v ref To the voltage control outer loop; the voltage control outer ring outputs dq axis current control reference value i ref The coupling between the voltage and current dq axes of the main circuit is decoupled by adopting a feedforward decoupling method on the basis of a PI controller through the current control inner ring, the voltage control outer ring and the current control inner ring, and PWM modulation voltage e is output r And outputting a signal to a PWM control module by the abc/dq coordinate conversion module IV, wherein the PWM control module outputs a control signal for controlling the main circuit inverter.
The invention also provides a method for modeling the impedance admittance of the network-structured three-phase converter, which comprises the following steps:
s1: constructing a complex frequency domain small signal dq model of a main circuit link after grid connection of the converter, and drawing a transfer function structure block diagram of the LC main circuit small signal model;
s2: constructing a complex frequency domain small signal dq model of a control link of the converter, wherein the complex frequency domain small signal dq model of the control link comprises a filtered output voltage v and a PWM modulation voltage e of the converter r Voltage coordinate transformation dq model of (2), inductance current i L The system comprises a power grid current i, a current coordinate conversion dq model, an active power reactive power dq model, a sampling low-pass filter dq model, a power control loop phase angle dq model, a voltage reference value dq model, a voltage control outer loop dq model, a current control inner loop dq model and a PWM control delay dq model;
s3: drawing a transfer function structure block diagram of a control link on the basis of the transfer function structure block diagram of the LC main circuit small signal model to obtain a full-system small signal structure block diagram, integrating and summarizing a complex frequency domain small signal dq model of the main circuit link and a complex frequency domain small signal dq model of a converter control link into an output voltage v filtered by the converter, an injected power grid current i and an inductance current i L And small signal models related to all set reference powers, and drawingAnd (3) a simplified full-system small signal structure block diagram is obtained, and a network three-phase converter impedance model and a network three-phase converter admittance model are formed according to the simplified full-system small signal structure block diagram.
In order to optimize the technical scheme, the specific measures adopted further comprise:
further, in S1, the complex frequency domain small signal dq model of the main circuit link specifically includes:
wherein Δe d And Δe q The disturbance quantity of the component of the unfiltered output voltage e of the converter on the d axis and the disturbance quantity of the component on the q axis are s being complex frequency L f And R is R f Inductance and parasitic resistance of LC filter, w 0 For the rated angular frequency of the converter, deltai Ld And Δi Lq Respectively the inductance current i L Disturbance variable of component on d-axis and disturbance variable of component on q-axis, Δv d And Deltav q The disturbance quantity of the component of the output voltage v of the converter on the d axis and the disturbance quantity of the component on the q axis through the filter are respectively; Δi d And Δi q The disturbance quantity of the component of the injection grid current i on the d axis and the disturbance quantity of the component on the q axis are respectively C f For filtering capacitance, Z L Is a filter inductance impedance transfer function matrix expressed as
Y C Is a filter capacitance admittance transfer function matrix expressed as +.>
Further in S2, the filtered output voltage v and PWM modulated voltage e of the converter r Is transformed dq model of the voltage coordinate of (d) and the inductance current i L And the current coordinate conversion dq model of the injected grid current i is respectively as follows:
in the method, in the process of the invention,
the small signal disturbance component of the filtered output voltage v of the converter on the d axis under the dq rotation coordinate system of the converter; />
The small signal disturbance component of the filtered output voltage v of the converter on the q axis under the dq rotation coordinate system of the converter; />
For small signal disturbance component of the filtered output voltage v of the converter on d axis under the system dq rotation coordinate system,
the small signal disturbance component of the filtered output voltage v of the converter on the q axis under the system dq rotating coordinate system; delta theta is the rotation angle phase difference of two coordinate systems, D v Is the coordinate transformation coefficient of the filtered output voltage v of the converter, expressed as
For the component of the steady-state value of the filtered output voltage v of the converter on the q-axis in the system dq rotation coordinate system,/->
The component of the steady-state value of the filtered output voltage v of the converter on the d-axis under the system dq rotation coordinate system; />
Injecting power grid electricity into current transformer dq rotation coordinate systemSmall signal disturbance component of stream i on d-axis,/->
Injecting a small signal disturbance component of the power grid current i on the q axis into the current transformer dq rotation coordinate system; />
And->
Respectively injecting small signal disturbance components of the grid current i on d axis and q axis under the system dq rotating coordinate system; d (D) i Is the coordinate transformation coefficient of the current i of the converter injected into the grid, expressed as +.>
And->
Respectively injecting components of steady-state values of the power grid current i on d-axis and q-axis under the system dq rotating coordinate system; />
And->
Respectively, the inductive current i under the rotating coordinate system of the current transformer dq L Small signal disturbance component on d-axis and q-axis,/->
And->
Respectively, inductance current i under system dq rotating coordinate system L Small signal disturbance component on D-axis and q-axis, D iL Is the inductance current i L Coordinate transformation of (a)Coefficient, expressed as->
And->
Respectively, inductance current i under system dq rotating coordinate system L The components of the steady state values of (c) on the d-axis and q-axis; />
And->
PWM modulation voltage e under system dq rotation coordinate system r Small signal disturbance component on d-axis and q-axis,/->
And->
PWM modulation voltage e under the rotation coordinate system of current transformer dq respectively r Small signal disturbance component in D-axis and q-axis, D er Is PWM modulation voltage e r Is expressed as +.>
And->
PWM modulation voltage e under system dq rotation coordinate system r The components of the steady state values of (c) on the d-axis and q-axis.
Further, in S2, the active power reactive power dq model specifically includes:
in the formula DeltaS e Is a complex power matrix, expressed as
ΔP e And DeltaQ e Respectively calculating an instantaneous active power small signal value and an instantaneous reactive power small signal value by a power calculation module; g S-V Is the power voltage coefficient, expressed as
G S-I Is the power current coefficient, expressed as +.>
Further, in S2, the sampling low-pass filter dq model is specifically:
wherein G is LPF A dq model representing the sampled low pass filter; w (w) c Is the cut-off angular frequency of the low pass filter.
Further, in S2, the power control loop phase angle dq model is specifically:
the voltage reference value dq model is specifically:
wherein G is A Is the relation coefficient between the phase difference and the power and represents
w 0 The rated angular frequency of the current transformer operation; j is the virtual inertia of the active power loop; ΔS ref Representation->
ΔP ref And DeltaQ ref The active power input reference value small signal variable and the reactive power input reference value small signal variable are respectively represented; deltav dref And Deltav qref Respectively the reference voltage small signal value Deltav ref The component K on the dq axis is the reactive power loop integral coefficient; v ref Is the reference voltage; g B And G C Respectively indicate->
And->
The relation coefficient between the reference voltage and the power and the relation coefficient between the output voltage of the converter through the filter are respectively; d (D) p And D q The active damping coefficient and the reactive damping coefficient are respectively.
Further, in S2, the voltage control outer loop dq model specifically includes:
the current control inner ring dq model specifically comprises:
wherein Δi dref And Δi qref Reference current small signal values delta i respectively output by the voltage control outer ring ref Components on the d-axis and q-axis;
representation of/>
For the voltage PI control transfer function, < >>
And->
The proportional gain coefficient and the integral gain coefficient of the voltage control outer ring are respectively; />
Representation->
The decoupling coefficient of the outer ring is controlled by voltage; />
Representation->
For the current PI control transfer function, < >>
And->
The proportional gain coefficient and the integral gain coefficient of the current control inner loop are respectively; />
Representation->
The decoupling coefficient is controlled for the current.
Further, in S2, the dq model of the PWM control delay is specifically:
wherein G is d For PWM control of a matrix of delay transfer functions, the matrix is represented
K d For the transfer function of the delay element +.>
Approximation by second order Pade->
To delay period f s Is the switching frequency.
Further in S3, the filtered output voltage v of the and converter is injected into the grid current i and the inductance current i L The small signal model related to each set reference power is specifically:
wherein H is v The relation between PWM modulation voltage and the output voltage of the converter through the filter under the system coordinate system is obtained; h i The relation between PWM modulation voltage and grid current injected into the converter is adopted; h Sref Setting a relation between PWM modulation voltage and reference power of the converter; h iL The relation between PWM modulation voltage and main circuit inductance current is adopted;
the impedance model of the network-structured three-phase converter is as follows:
Δv s ＝M·ΔS ref -Z·Δi s
the admittance model of the network-structured three-phase converter is as follows:
Δi s ＝N·ΔS ref -Y·Δv s
wherein M is a small signal relation expression between the output voltage of the converter and a power reference value under a system coordinate system; z is the output impedance expression of the converter; n is a small signal relation expression between the output current of the converter and a power reference value under a system coordinate system; y is the output admittance expression of the converter.
The beneficial effects of the invention are as follows:
(1) Aiming at the technical problems existing in the prior art, the invention provides a grid-structured three-phase converter which can operate under off-grid and on-grid conditions and has stronger applicability compared with the grid-structured converter;
(2) According to the invention, dq modeling is carried out on the network-structured three-phase current transformer, the constructed impedance and admittance model adopts modularized calculation, the realization method is simple, the precision is higher, the calling application is flexible, the network-structured three-phase current transformer can be used for constructing the parallel impedance admittance model of a plurality of current transformers, and the network-structured three-phase current transformer is beneficial to providing model reference for researching the stability problem of the current transformer.
Drawings
Fig. 1 is a topological diagram of a network three-phase converter according to the present invention;
FIG. 2 is a power control loop control block diagram;
FIG. 3 is a diagram of dq decoupling relationships between the voltage control outer loop and the current control inner loop control block diagrams, and the control loop and the main circuit controlled object;
FIG. 4 is a schematic diagram of a flow chart of a modeling method for modeling impedance and admittance models of a network-structured three-phase current transformer;
FIG. 5 is a block diagram of the transfer function of the LC main circuit small signal model;
FIG. 6 is a block diagram of a full system small signal architecture including a main circuit and control links;
fig. 7 is a simplified block diagram of a full system small signal architecture.
Detailed Description
The invention will now be described in further detail with reference to the accompanying drawings.
In one embodiment, the invention provides a network three-phase converter, and a topological diagram of the three-phase converter is shown in fig. 1, and the network three-phase converter comprises a main circuit link and a control link;
the main circuit link comprises a three-phase six-arm inverter and an LC filter electrically connected with the three-phase six-arm inverter; the LC filter comprises an inductance L f And filter capacitor C f The inductance L f One end of the inductor L is connected with the output end of the three-phase six-arm inverter f The other end of (a) is connected with a filter capacitor C f And a bus bar, a capacitor C f The other end of the first electrode is grounded;
the control link comprises a first abc/dq coordinate transformation module, a second abc/dq coordinate transformation module, a third abc/dq coordinate transformation module, a fourth abc/dq coordinate transformation module, a power calculation module, a low-pass filter, a power control loop, a voltage control outer loop, a current control inner loop and a PWM control module;
the inductance L f Is of the inductance current i of (2) L The power calculation module receives a d-axis component voltage value and a q-axis component voltage value output by the abc/dq coordinate conversion module II and a d-axis component current value and a q-axis component current value output by the abc/dq coordinate conversion module III, and outputs instantaneous active power P e And instantaneous reactive power Q e The low-pass filter filters the instantaneous active power P output by the calculation module e And instantaneous reactive power Q e And outputting the average active power and the average reactive power to the power control loop; the power control loop is based on virtualQuasi-synchronous control strategy for receiving active power reference value P ref And reactive power reference value Q ref Outputting synchronous phase angles theta of a main circuit to a first abc/dq coordinate conversion module, a second abc/dq coordinate conversion module, a third abc/dq coordinate conversion module and a fourth abc/dq coordinate conversion module, and outputting a dq axis voltage control reference value v ref To the voltage control outer loop; as shown in fig. 2, a power control loop control block diagram; the voltage control outer ring outputs dq axis current control reference value i ref The coupling between the voltage and current dq axes of the main circuit is decoupled by adopting a feedforward decoupling method on the basis of a PI controller through the current control inner ring, the voltage control outer ring and the current control inner ring, and PWM modulation voltage e is output r And outputting a signal to a PWM control module by the abc/dq coordinate conversion module IV, wherein the PWM control module outputs a control signal for controlling the main circuit inverter. Fig. 3 shows the dq decoupling relationship between the voltage control outer loop and the current control inner loop, and the control loop and the main circuit controlled object.
In another embodiment, the invention provides a network three-phase converter impedance admittance modeling method, in order to construct dq impedance and admittance models of the network three-phase converter, the invention adopts a calculation method for constructing the dq models step by step, performs modular analysis, accumulates layer by layer, integrates calculation, and forms a network three-phase converter dq impedance model based on virtual synchronous power control, taking power sampling low-pass filtering into consideration and taking dq decoupling voltage and current PI double-loop control into consideration, and the process is shown in fig. 4, and specifically comprises the following steps:
s1: constructing a complex frequency domain small signal dq model of a main circuit link after grid connection of the converter, and drawing a transfer function structure block diagram of the LC main circuit small signal model;
s2: constructing a complex frequency domain small signal dq model of a control link of the converter, wherein the complex frequency domain small signal dq model of the control link comprises a filtered output voltage v and a PWM modulation voltage e of the converter r Voltage coordinate transformation dq model of (2), inductance current i L And a current coordinate conversion dq model, an active power reactive power dq model, a sampling low-pass filter dq model, a power control loop phase angle dq model of the injected grid current iA dq model of a voltage reference value, a dq model of a voltage control outer ring, a dq model of a current control inner ring and a dq model of PWM control delay;
s3: drawing a transfer function structure block diagram of a control link on the basis of the transfer function structure block diagram of the LC main circuit small signal model to obtain a full-system small signal structure block diagram, integrating and summarizing a complex frequency domain small signal dq model of the main circuit link and a complex frequency domain small signal dq model of a converter control link into an output voltage v filtered by the converter, an injected power grid current i and an inductance current i L And drawing a simplified full-system small signal structure block diagram according to each small signal model related to the set reference power, and arranging and forming a network three-phase converter impedance model and a network three-phase converter admittance model according to the simplified full-system small signal structure block diagram.
Specifically, a complex frequency domain small signal dq model of a main circuit link is firstly constructed according to the following formula:
wherein Δe d And Δe q The disturbance quantity of the component of the unfiltered output voltage e of the converter on the d axis and the disturbance quantity of the component on the q axis are s being complex frequency L f And R is R f Inductance and parasitic resistance of LC filter, w 0 For the rated angular frequency of the converter, deltai Ld And Δi Lq Respectively the inductance current i L Disturbance variable of component on d-axis and disturbance variable of component on q-axis, Δv d And Deltav q The disturbance quantity of the component of the output voltage v of the converter on the d axis and the disturbance quantity of the component on the q axis through the filter are respectively; Δi d And Δi q The disturbance quantity of the component of the injection grid current i on the d axis and the disturbance quantity of the component on the q axis are respectively C f For filtering capacitance, Z L Is a filter inductance impedance transfer function matrix expressed as
Y C Is a filter capacitance admittance transfer function matrix expressed as +.>
The main circuit equation is thus:
to draw a transfer function block diagram of the LC main circuit small signal model as shown in fig. 5.
And secondly, considering a complex frequency domain small signal impedance model of the control link. The whole system is divided into a system dq rotating coordinate system and a converter dq rotating coordinate system, and in a stable running state, the two coordinate systems are overlapped, and in an actual power grid, when the power grid voltage is slightly disturbed, a phase difference exists between the two coordinate systems. Each variable in the coordinate system of the system is x s The phase angle is theta, and each variable in the converter coordinate system is x c Phase angle of theta c The method comprises the steps of carrying out a first treatment on the surface of the The rotation angle phase difference of the two coordinate systems is delta theta, and the phase angle relation between the system coordinate system and the converter coordinate system is theta c =θ+Δθ. The Park transformation matrix can be used for obtaining a transformation matrix T for changing the system coordinates into the converter coordinates Δq The following is shown:
considering Δθ≡0, sin (Δθ) ≡Δθ, cos (Δθ) ≡1 may be approximated to obtain the conversion relation expression between small signal disturbance of voltage (or current) variable in two coordinate systems of the system and the controller as follows:
wherein,,
and +.>
The small signal disturbance components of the voltage (or current) variable on the dq axis under the coordinate system of the converter and the coordinate system of the system are respectively; />
And->
Is the steady-state value X of voltage (or current) under the system coordinate system s Components on the dq axis.
The output voltage v and the filter inductance current i of the converter are sequentially constructed according to the method L Current i, current of converter injection into grid and PWM modulation voltage e r The voltage-current variable coordinate conversion dq model of (2) is as follows:
in the method, in the process of the invention,
the small signal disturbance component of the filtered output voltage v of the converter on the d axis under the dq rotation coordinate system of the converter; />
The small signal disturbance component of the filtered output voltage v of the converter on the q axis under the dq rotation coordinate system of the converter; />
For small signal disturbance component of the filtered output voltage v of the converter on d axis under the system dq rotation coordinate system,
the small signal disturbance component of the filtered output voltage v of the converter on the q axis under the system dq rotating coordinate system; delta theta is twoRotational angle phase difference of coordinate system, D v Is the coordinate transformation coefficient of the filtered output voltage v of the converter, expressed as
For the component of the steady-state value of the filtered output voltage v of the converter on the q-axis in the system dq rotation coordinate system,/->
The component of the steady-state value of the filtered output voltage v of the converter on the d-axis under the system dq rotation coordinate system; />
Injecting a small signal disturbance component of a grid current i on a d axis into a dq rotating coordinate system of the converter, < >>
Injecting a small signal disturbance component of the power grid current i on the q axis into the current transformer dq rotation coordinate system; />
And->
Respectively injecting small signal disturbance components of the grid current i on d axis and q axis under the system dq rotating coordinate system; d (D) i Is the coordinate transformation coefficient of the current i of the converter injected into the grid, expressed as +.>
And->
Respectively, system dq rotating seatInjecting components of steady-state values of the power grid current i on d-axis and q-axis under the standard system; />
And->
Respectively, the inductive current i under the rotating coordinate system of the current transformer dq L Small signal disturbance component on d-axis and q-axis,/->
And->
Respectively, inductance current i under system dq rotating coordinate system L Small signal disturbance component on D-axis and q-axis, D iL Is the inductance current i L Is expressed as +.>
And->
Respectively, inductance current i under system dq rotating coordinate system L The components of the steady state values of (c) on the d-axis and q-axis; />
And->
PWM modulation voltage e under system dq rotation coordinate system r Small signal disturbance component on d-axis and q-axis,/->
And->
PWM modulation voltage e under the rotation coordinate system of current transformer dq respectively r Small signal disturbance component in D-axis and q-axis, D er Is PWM modulation voltage e r Is expressed as +.>
And->
PWM modulation voltage e under system dq rotation coordinate system r The components of the steady state values of (c) on the d-axis and q-axis.
The voltage-current variable coordinate conversion equation can be written as:
obviously the converter output voltage v, the filter inductor current i L Current i, current of converter injection into grid and PWM modulation voltage e r The small signal conversion relation of the three-phase converter is not separated from the rotation angle phase difference delta theta of the two coordinate systems, and the phase difference delta theta is found to be closely related to the output power of the main circuit of the converter according to the control strategy block diagram of the network-structured three-phase converter.
The active power and reactive power dq model of the network-structured three-phase converter is constructed according to the following steps:
in the formula DeltaS e Is a complex power matrix, expressed as
ΔP e And DeltaQ e The instantaneous active power small signal value and the instantaneous reactive power small signal value calculated by the power calculation module are respectively；G S-V Is the power voltage coefficient, expressed as
G S-I Is the power current coefficient, expressed as +.>
The power calculation equation for shorthand is obtained as follows:
ΔS e ＝G S-V ·Δv s +G S-I ·Δi s (8)
further, if the first order low pass filter calculated by taking the output power samples into account, the low pass filter transfer function is expressed as:
wherein K is LPF Is a low pass filter transfer function; w (w) c Is the cut-off angular frequency of the low pass filter.
Combining active power and reactive power into a complex power matrix for integral calculation, and constructing a sampling low-pass filter dq model according to the following steps:
wherein G is LPF Representing the dq model of the sampled low pass filter.
Further according to
And->
The described power control loop strategy, the column write power control loop small signal control equation set is:
wherein w and w 0 The actual angular frequency and the rated angular frequency of the current transformer are respectively operated; the Δw converter runs an actual angular frequency small signal variable; p (P) ref And Q ref Inputting a reference value for active power and reactive power; ΔP ref And DeltaQ ref Representing the input reference value small signal variable of the active power and the reactive power; j is the virtual inertia of the active power loop; k is the integral coefficient of the reactive power loop; d (D) p And D q The active damping coefficient and the reactive damping coefficient are respectively; v N And v is the actual capacitor voltage and the nominal voltage, respectively; v ref Is the reference voltage.
According to the described power control loop small signal equation set, the active power and the reactive power are regarded as the whole to be operated, so that the phase small signal variable of the converter is repeatedly listed as a matrix of 1*2, and a phase angle dq model of the power control loop is constructed as follows:
voltage reference dq model:
wherein G is A Is the relation coefficient between the phase difference and the power and represents
w 0 The rated angular frequency of the current transformer operation; j is the virtual inertia of the active power loop; ΔS ref Representation->
ΔP ref And DeltaQ ref The active power input reference value small signal variable and the reactive power input reference value small signal variable are respectively represented; deltav dref And Deltav qref Respectively are provided withIs the small signal value Deltav of the reference voltage ref The component K on the dq axis is the reactive power loop integral coefficient; v ref Is the reference voltage; g B And G C Respectively indicate->
And->
The relation coefficient between the reference voltage and the power and the relation coefficient between the output voltage of the converter through the filter are respectively; d (D) p And D q The active damping coefficient and the reactive damping coefficient are respectively.
The power control loop equation, abbreviated, is obtained as:
in this embodiment, the main circuit inductance current i in the dq coordinate system is found according to the main circuit equation L And coupling exists between dq axes of the grid-connected voltage v, so that in order to eliminate coupling interaction, control precision and dynamic response characteristics are improved, and the influence of a coupling term is reduced by adopting feedforward decoupling control. Meanwhile, in order to track the voltage reference signal output by the power control loop, zero steady-state error is realized, and the voltage control outer loop adopts PI control; in order to improve the dynamic response performance of the system and realize zero steady-state error, the current control inner loop also adopts PI control. The dq model of the voltage control outer loop is constructed as follows:
the dq model of the current control inner loop is constructed as follows:
wherein Δi dref And Δi qref Reference current small signal values delta i respectively output by the voltage control outer ring ref Components on the d-axis and q-axis;
representation->
For the voltage PI control transfer function, < >>
And->
The proportional gain coefficient and the integral gain coefficient of the voltage control outer ring are respectively; />
Representation->
The decoupling coefficient of the outer ring is controlled by voltage; />
Representation->
For the current PI control transfer function, < >>
And->
The proportional gain coefficient and the integral gain coefficient of the current control inner loop are respectively; />
Representation->
For controlling the inner loop decoupling coefficient for current。/>
The voltage-current double-loop control equation is:
further, in this embodiment, a 1.5 sampling period delay generated by PWM digital control is considered, and the transfer function expression of the delay link is:
wherein K is d Is a transfer function of a time delay link;
to delay period f s Is the switching frequency.
Due to K d As a nonlinear function, a new transfer function of the delay link can be obtained by second-order pad approximation according to the following formula:
the small signal model of PWM control delay is established according to the following steps:
wherein G is d For PWM control of a matrix of delay transfer functions, the matrix is represented
The PWM control delay equation is obtained by short:
Δe＝G d ·Δe r (21)
finally, a system-wide small signal block diagram including the main circuit and the control link is drawn as shown in fig. 6. Will be described in(6) (8) (10) (14) (17) integrating and summarizing to obtain output voltage v of the converter through a filter, injection grid current i and main circuit inductance current i L Setting a reference power related small signal model as follows:
wherein H is v The relation between PWM modulation voltage and the output voltage of the converter through the filter under the system coordinate system is obtained; h i The relation between PWM modulation voltage and grid current injected into the converter is adopted; h Sref Setting a relation between PWM modulation voltage and reference power of the converter; h iL Is the relationship between the PWM modulation voltage and the main circuit inductor current.
Drawing a simplified full-system small signal structure block diagram shown in fig. 7 according to formulas (2) (22) and (21), and arranging to obtain a network-structured three-phase converter impedance model as follows:
Δv s ＝M·ΔS ref -Z·Δi s
the admittance model of the net-structured three-phase converter is obtained by arrangement:
Δi s ＝N·ΔS ref -Y·Δv s
wherein M is a small signal relation expression between the output voltage of the converter and a power reference value under a system coordinate system; z is the output impedance expression of the converter; n is a small signal relation expression between the output current of the converter and a power reference value under a system coordinate system; y is the output admittance expression of the converter.
The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above examples, and all technical solutions belonging to the concept of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to the invention without departing from the principles thereof are intended to be within the scope of the invention as set forth in the following claims.
Claims (10)
1. The network-structured three-phase converter is characterized by comprising a main circuit link and a control link;
the main circuit link comprises a three-phase six-arm inverter and an LC filter electrically connected with the three-phase six-arm inverter; the LC filter comprises an inductance L f And filter capacitor C f The inductance L f One end of the inductor L is connected with the output end of the three-phase six-arm inverter f The other end of (a) is connected with a filter capacitor C f And a bus bar, a capacitor C f The other end of the first electrode is grounded;
the control link comprises a first abc/dq coordinate transformation module, a second abc/dq coordinate transformation module, a third abc/dq coordinate transformation module, a fourth abc/dq coordinate transformation module, a power calculation module, a low-pass filter, a power control loop, a voltage control outer loop, a current control inner loop and a PWM control module;
the inductance L f Is of the inductance current i of (2) L The power calculation module receives a d-axis component voltage value and a q-axis component voltage value output by the abc/dq coordinate conversion module II and a d-axis component current value and a q-axis component current value output by the abc/dq coordinate conversion module III, and outputs instantaneous active power P e And instantaneous reactive power Q e The low-pass filter filters the instantaneous active power P output by the calculation module e And instantaneous reactive power Q e And output averagePower and average reactive power to power control loop; the power control loop receives the active power reference value P based on a virtual synchronization control strategy ref And reactive power reference value Q ref Outputting synchronous phase angles theta of a main circuit to a first abc/dq coordinate conversion module, a second abc/dq coordinate conversion module, a third abc/dq coordinate conversion module and a fourth abc/dq coordinate conversion module, and outputting a dq axis voltage control reference value v ref To the voltage control outer loop; the voltage control outer ring outputs dq axis current control reference value i ref The coupling between the voltage and current dq axes of the main circuit is decoupled by adopting a feedforward decoupling method on the basis of a PI controller through the current control inner ring, the voltage control outer ring and the current control inner ring, and PWM modulation voltage e is output r And outputting a signal to a PWM control module by the abc/dq coordinate conversion module IV, wherein the PWM control module outputs a control signal for controlling the main circuit inverter.
2. The method for modeling the impedance admittance of the network-structured three-phase converter is characterized by comprising the following steps of:
s1: constructing a complex frequency domain small signal dq model of a main circuit link after grid connection of the converter to obtain a main circuit equation, and drawing a transfer function structure block diagram of the LC main circuit small signal model according to the main circuit equation;
s2: constructing a complex frequency domain small signal dq model of a control link of the converter, wherein the complex frequency domain small signal dq model of the control link comprises a filtered output voltage v and a PWM modulation voltage e of the converter r Voltage coordinate transformation dq model of (2), inductance current i L The system comprises a power grid current i, a current coordinate conversion dq model, an active power reactive power dq model, a sampling low-pass filter dq model, a power control loop phase angle dq model, a voltage reference value dq model, a voltage control outer loop dq model, a current control inner loop dq model and a PWM control delay dq model;
s3: drawing a transfer function structure block diagram of a control link on the basis of the transfer function structure block diagram of the LC main circuit small signal model to obtain a full-system small signal structure block diagram, and carrying out complex frequency domain small signal dq model and current transformation on the main circuit linkThe complex frequency domain small signal dq model of the controller control link is integrated and summarized into output voltage v, injection grid current i and inductance current i which are filtered by the converter L And drawing a simplified full-system small signal structure block diagram according to each small signal model related to the set reference power, and arranging and forming a network three-phase converter impedance model and a network three-phase converter admittance model according to the simplified full-system small signal structure block diagram.
3. The method for modeling the impedance admittance of the network-structured three-phase converter according to claim 2, wherein in S1, the complex frequency domain small signal dq model of the main circuit link is specifically:
wherein Δe d And Δe q The disturbance quantity of the component of the unfiltered output voltage e of the converter on the d axis and the disturbance quantity of the component on the q axis are s being complex frequency L f And R is R f Inductance and parasitic resistance of LC filter, w 0 For the rated angular frequency of the converter, deltai Ld And Δi Lq Respectively the inductance current i L Disturbance variable of component on d-axis and disturbance variable of component on q-axis, Δv d And Deltav q The disturbance quantity of the component of the output voltage v of the converter on the d axis and the disturbance quantity of the component on the q axis through the filter are respectively; Δi d And Δi q The disturbance quantity of the component of the injection grid current i on the d axis and the disturbance quantity of the component on the q axis are respectively C f For filtering capacitance, Z L Is a filter inductance impedance transfer function matrix expressed as
Y C Is a filter capacitance admittance transfer function matrix expressed as +.>
4. The method of modeling impedance admittance of a three-phase grid-structured converter according to claim 2, characterized in that in S2 the filtered output voltage v and PWM modulated voltage e of the converter r Is transformed dq model of the voltage coordinate of (d) and the inductance current i L And the current coordinate conversion dq model of the injected grid current i is respectively as follows:
in the method, in the process of the invention,
the small signal disturbance component of the filtered output voltage v of the converter on the d axis under the dq rotation coordinate system of the converter; />
The small signal disturbance component of the filtered output voltage v of the converter on the q axis under the dq rotation coordinate system of the converter;
for small signal disturbance component of the filtered output voltage v of the converter in the system dq rotation coordinate system on d-axis,/->
The small signal disturbance component of the filtered output voltage v of the converter on the q axis under the system dq rotating coordinate system; Δq is the rotation angle phase difference of two coordinate systems, D v Is the coordinate transformation coefficient of the filtered output voltage v of the converter, expressed as +.>
For the component of the steady-state value of the filtered output voltage v of the converter on the q-axis in the system dq rotation coordinate system,/->
The component of the steady-state value of the filtered output voltage v of the converter on the d-axis under the system dq rotation coordinate system; />
Injecting a small signal disturbance component of a grid current i on a d axis into a dq rotating coordinate system of the converter, < >>
Injecting a small signal disturbance component of the power grid current i on the q axis into the current transformer dq rotation coordinate system; />
And->
Respectively injecting small signal disturbance components of the grid current i on d axis and q axis under the system dq rotating coordinate system; d (D) i Is the coordinate transformation coefficient of the current i injected into the power grid by the converter, expressed as
And->
Respectively injecting components of steady-state values of the power grid current i on d-axis and q-axis under the system dq rotating coordinate system; />
And->
Respectively, the inductive current i under the rotating coordinate system of the current transformer dq L Small signal disturbance components on the d-axis and q-axis,
and->
Respectively, inductance current i under system dq rotating coordinate system L Small signal disturbance component on D-axis and q-axis, D iL Is the inductance current i L Is expressed as +.>
And->
Respectively, inductance current i under system dq rotating coordinate system L The components of the steady state values of (c) on the d-axis and q-axis; />
And->
PWM modulation voltage e under system dq rotation coordinate system r Small signal disturbance component on d-axis and q-axis,/->
And->
PWM modulation voltage e under the rotation coordinate system of current transformer dq respectively r Small signal disturbance components on the d-axis and q-axis,D er is PWM modulation voltage e r Is expressed as
And->
PWM modulation voltage e under system dq rotation coordinate system r The components of the steady state values of (c) on the d-axis and q-axis.
5. The method for modeling the impedance admittance of a three-phase network converter according to claim 2, wherein in S2, the active power reactive power dq model is specifically:
in the formula DeltaS e Is a complex power matrix, expressed as
ΔP e And DeltaQ e Respectively calculating an instantaneous active power small signal value and an instantaneous reactive power small signal value by a power calculation module; g S-V Is the power voltage coefficient, expressed as +.>
G S-I Is the power current coefficient, expressed as +.>
6. The method for modeling impedance admittance of a three-phase network converter according to claim 2, wherein in S2, the sampling low-pass filter dq model is specifically:
wherein G is LPF A dq model representing the sampled low pass filter; w (w) c Is the cut-off angular frequency of the low pass filter.
7. The method for modeling impedance admittance of a three-phase network converter according to claim 2, wherein in S2, the power control loop phase angle dq model is specifically:
the voltage reference value dq model is specifically:
wherein G is A Is the relation coefficient between the phase difference and the power and represents
w 0 The rated angular frequency of the current transformer operation; j is the virtual inertia of the active power loop; ΔS ref Representation->
ΔP ref And DeltaQ ref The active power input reference value small signal variable and the reactive power input reference value small signal variable are respectively represented; deltav dref And Deltav qref Respectively the reference voltage small signal value Deltav ref The component K on the dq axis is the reactive power loop integral coefficient; v ref Is the reference voltage; g B And G C Respectively indicate->
And->
The relation coefficient between the reference voltage and the power and the relation coefficient between the output voltage of the converter through the filter are respectively; d (D) p And D q The active damping coefficient and the reactive damping coefficient are respectively.
8. The method for modeling impedance admittance of a three-phase network converter according to claim 2, wherein in S2, the voltage control outer loop dq model is specifically:
the current control inner ring dq model specifically comprises:
wherein Δi dref And Δi qref Reference current small signal values delta i respectively output by the voltage control outer ring ref Components on the d-axis and q-axis;
representation->
For the voltage PI control transfer function, < >>
And->
Proportional gain for voltage controlled outer loopCoefficients and integral gain coefficients; />
Representation->
The decoupling coefficient of the outer ring is controlled by voltage; />
Representation->
For the current PI control transfer function, < >>
And->
The proportional gain coefficient and the integral gain coefficient of the current control inner loop are respectively; />
Representation->
The decoupling coefficient is controlled for the current.
9. The method for modeling impedance admittance of a three-phase network converter according to claim 2, wherein in S2, the dq model of the PWM control delay is specifically:
wherein G is d For PWM control of a matrix of delay transfer functions, the matrix is represented
K d As a transfer function of the delay element,
approximation by second order Pade->
To delay period f s Is the switching frequency.
10. The method of modeling impedance admittance of three-phase grid-connected converter according to claim 2, wherein in S3, the filtered output voltage v of said converter, the injected grid current i, the inductor current i L The small signal model related to each set reference power is specifically:
wherein H is v The relation between PWM modulation voltage and the output voltage of the converter through the filter under the system coordinate system is obtained; h i The relation between PWM modulation voltage and grid current injected into the converter is adopted; h Sref Setting a relation between PWM modulation voltage and reference power of the converter; h iL The relation between PWM modulation voltage and main circuit inductance current is adopted;
the impedance model of the network-structured three-phase converter is as follows:
Δv s ＝M·ΔS ref -Z·Δi s
the admittance model of the network-structured three-phase converter is as follows:
Δi s ＝N·ΔS ref -Y·Δv s
wherein M is a small signal relation expression between the output voltage of the converter and a power reference value under a system coordinate system; z is the output impedance expression of the converter; n is a small signal relation expression between the output current of the converter and a power reference value under a system coordinate system; y is the output admittance expression of the converter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310340499.XA CN116191576A (en) | 2023-03-31 | 2023-03-31 | Network-structured three-phase converter and impedance and admittance model modeling method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310340499.XA CN116191576A (en) | 2023-03-31 | 2023-03-31 | Network-structured three-phase converter and impedance and admittance model modeling method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116191576A true CN116191576A (en) | 2023-05-30 |
Family
ID=86440622
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310340499.XA Withdrawn CN116191576A (en) | 2023-03-31 | 2023-03-31 | Network-structured three-phase converter and impedance and admittance model modeling method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116191576A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116418049A (en) * | 2023-06-08 | 2023-07-11 | 四川大学 | Accurate admittance modeling method for sagging-controlled three-phase grid-connected inverter |
-
2023
- 2023-03-31 CN CN202310340499.XA patent/CN116191576A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116418049A (en) * | 2023-06-08 | 2023-07-11 | 四川大学 | Accurate admittance modeling method for sagging-controlled three-phase grid-connected inverter |
| CN116418049B (en) * | 2023-06-08 | 2023-08-11 | 四川大学 | Accurate admittance modeling method for sagging-controlled three-phase grid-connected inverter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108964118B (en) | Phase-locked loop-considered small-signal impedance modeling method for single-phase grid-connected inverter | |
| WO2021143319A1 (en) | Customized harmonic repetitive controller and control method | |
| CN105553304B (en) | A kind of modular multilevel type solid-state transformer and its internal model control method | |
| CN108988343B (en) | Global high-frequency oscillation suppression method for multi-inverter grid-connected system under weak grid | |
| CN110739678B (en) | Control method for series virtual impedance of grid-connected converter | |
| CN102801346B (en) | Three-phase inverter with no-signal interconnecting lines connected in parallel and control method of three-phase inverter | |
| CN108847669B (en) | Multi-synchronous rotation coordinate system-based multifunctional grid-connected inverter harmonic treatment method | |
| CN105743091B (en) | A kind of double close-loop decoupling control method of Active Power Filter-APF | |
| CN110086196B (en) | Control method of single-phase cascade H-bridge grid-connected inverter under weak grid | |
| CN105743123A (en) | LCL-LC based active damping parameter design method for grid-connected system | |
| CN113629763B (en) | Current control method and system for medium-voltage direct-hanging energy storage converter under non-ideal power grid | |
| CN112994100B (en) | Multi-mode control photovoltaic grid-connected inverter based on intelligent distribution transformer terminal | |
| CN111611696A (en) | Nonlinear modeling method of micro-grid system | |
| CN116191576A (en) | Network-structured three-phase converter and impedance and admittance model modeling method thereof | |
| WO2024093334A1 (en) | Control method, new energy converter, and grid-connected power system | |
| CN105490297B (en) | Micro-capacitance sensor supply voltage and grid current harmonic synchroballistic method based on twin inverter group's coordinated control | |
| CN109327048B (en) | Robust phase locking system and method for grid-connected converter | |
| CN115276445A (en) | VSG-based LCL grid-connected inverter resonance suppression and stability analysis method under weak network | |
| CN109830995B (en) | Island control strategy based on energy router | |
| CN110190741A (en) | High-power high step-up ratio photovoltaic DC current transformer starts control method | |
| CN107528587B (en) | High-precision quick broadband single-phase soft phase-locked loop based on PIR (passive infrared sensor) regulator | |
| CN117833275A (en) | Parameter setting method for grid-structured converter with synchronous resonance suppression function | |
| CN113258603A (en) | Second-order linear active disturbance rejection control system and control method based on VSG in island state | |
| Chen et al. | Nonlinear control for VSC based HVDC system | |
| CN111525567B (en) | Method and device for calculating fault current of photovoltaic grid-connected inverter |
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 | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20230530 |
|
| WW01 | Invention patent application withdrawn after publication |