CN109004661A - The closed loop control method of three-phase imbalance equipment based on internal model principle and error iteration PI - Google Patents
The closed loop control method of three-phase imbalance equipment based on internal model principle and error iteration PI Download PDFInfo
- Publication number
- CN109004661A CN109004661A CN201810873309.XA CN201810873309A CN109004661A CN 109004661 A CN109004661 A CN 109004661A CN 201810873309 A CN201810873309 A CN 201810873309A CN 109004661 A CN109004661 A CN 109004661A
- Authority
- CN
- China
- Prior art keywords
- phase
- closed loop
- loop control
- error
- control method
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
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
- H02J3/26—Arrangements for eliminating or reducing asymmetry in polyphase networks
-
- 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
- H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
- H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
- H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
- H02J3/1842—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/30—Reactive power compensation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/50—Arrangements for eliminating or reducing asymmetry in polyphase networks
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The present invention relates to a kind of closed loop control methods of three-phase imbalance equipment based on internal model principle and error iteration PI, sample current on line side and carry out closed-loop control, directly control control target, realize good compensation effect;Possess current inner loop simultaneously, separation harmonic current control outer ring and busbar voltage control outer ring, it is ensured that busbar voltage it is constant, enhance the use scope of equipment;Harmonic current controls the controller that outer ring uses internal model principle, introduces DC component and removes link, the introducing of internal mode controller greatly improves the tracking effect of harmonic wave;Busbar voltage ring introduces error iteration PI controller, reduce the error of busbar voltage stable state control, while improving the response speed of busbar voltage ring in the case of fundamental active load sudden change, it ensures the safety of the voltage of bus and the stability of compensation effect, reaches and change violent occasion in fundamental wave load and still with stable operation and can ensure good compensation effect.
Description
Technical field
The present invention relates to power electronics control fields, more particularly to a kind of three based on internal model principle and error iteration PI
The mutually closed loop control method of uneven equipment.
Background technique
With the development of economy, the load of distribution becomes to become increasingly complex, especially as the continuous development of rural economy, agriculture
The three-phase imbalance situation of village's power distribution network is more next serious, certain serious normal lifves for affecting rural resident in place.
The abatement equipment of three-phase imbalance gradually obtained the concern of society in recent years, and the presence or absence of conventional source capacitance compensation is set
It is standby, active three-phase imbalance compensation equipment etc..It is passive and active in fact similar with APF with the TSC of power quality industry, have same
The respective advantage and disadvantage of the characteristic of sample.But for the scene of three-phase imbalance, the compensation effect of TSC equipment is very limited, it is main
If because it is the three-phase electricity because the three-phase investment of single-phase load is unbalanced caused that the three-phase imbalance of power distribution network is in the majority
Unbalanced characteristics exhibit is flowed in the imbalance (fundamental wave negative sequence and fundamental wave zero sequence composition) of fundamental current, 3-13 low-order harmonic
The imbalance of the electric current of (harmonic wave includes positive-negative sequence and zero sequence composition).
So occur many three-phase imbalance equipment being transformed using APF or SVG in the market, these equipment it is universal
Control method is the open loop control mode that detection load carries out uneven composition and Resonance Wave Composition, this mode there are compensation effect compared with
Difference, scene are not easy to the problem of debugging, and especially three-phase imbalance equipment is typically installed on utility poles, is not easy to very much
Installation.
So the demand of the three-phase imbalance equipment based on closed loop control method is more more and more urgent, closed loop control method is not only
It can perfectly solve the problems, such as to be not easy to debugging on electric pole, while may insure extraordinary compensation effect.
Summary of the invention
The present invention provides a kind of closed loop control method of three-phase imbalance equipment based on internal model principle and error iteration PI,
It can be readily appreciated that it is easy to accomplish, still with stable operation and it can ensure good compensation effect in the violent occasion of fundamental wave load variation
Fruit.
Its technical solution is as follows: a kind of closed-loop control of the three-phase imbalance equipment based on internal model principle and error iteration PI
Method, exchange side is directly connected to by three pole reactor and power grid in the topological diagram of three-phase imbalance equipment, and DC side is using two groups
The capacitor of division is connected, and the midpoint of two groups of capacitors is connect as middle line with power grid N line, as zero sequence access, passes through following step
It is rapid to realize control:
Step S1: sampling three-phase network voltage obtains the angle wt of network voltage using phaselocked loop, as control transformation
Phase angle foundation;
Step S2: acquisition power network current isa, isb, isc obtain the electric current of two axis of D, Q using ABC/DQ coordinate transform
Ingredient id, iq, and DC component removal is carried out to id, iq and is calculated, other current components without containing fundamental positive sequence are obtained,
And converted using DQ/ABC coordinate system, obtain three phase harmonic instruction ∑ iabc;
Step S3:0 makes the difference as given with three phase harmonic instruction ∑ iabc, error signal e rr is obtained, by internal model control
Device controls to obtain three-phase compensation electric current ira、irb、irc;
Step S4: sampling busbar voltage Udc, with Udc*It makes the difference, obtains error signal e rr, obtained by error iteration PI
The watt current Q axis instruction for stablizing busbar voltage, obtains three-phase pressure stabilizing active command i by DQ/ABC coordinate system transformationwa、iwb、
iwc;
Step S5: three-phase obtained above is compensated into electric current ira、irb、ircWith three-phase pressure stabilizing active command iwa、iwb、iwcIt asks
With as the given of inductive current control ring, make the difference to obtain error signal, error signal warp with three-phase output electric current ia, ib, ic
P adjuster is crossed to control to obtain modulating wave;
Step S6: modulating wave and carrier phase angle obtain SPWM, and the pipe movement of driving power main circuit realizes three-phase not
The control of balancing equipment.
In the above-mentioned technical solutions, ABC/DQ transformation uses positive sequence phase angle wt in the step S2, in DQ coordinate system, fundamental wave
Positive sequence composition is DC component, and fundamental wave negative sequence, zero sequence and Resonance Wave Composition are entirely Alternating Component.
In the above-mentioned technical solutions, the three phase harmonic instruction ∑ iabc in the step S2 includes fundamental wave negative sequence composition, base
Wave zero sequence composition and higher hamonic wave composition.
In the above-mentioned technical solutions, DC component removal calculates in the step S2, by the way of cumulative integral, extracts
Then DC component out makes the difference with id, iq, obtain the Alternating Component in DQ axis, the specific implementation of cumulative integral:
Difference expression are as follows:
Wherein, N is sample frequency points corresponding with respect to fundamental wave, and x (i) is the instantaneous value of active axis or idle axis.
In the above-mentioned technical solutions, the internal mode controller control in the step S3 is as follows:
Wherein, GrIt (z) is internal mode controller, speciallykrFor amplitude rectification, zkFor phasing, S
It (z) is low-pass filter.
In the above-mentioned technical solutions, in the step S4 error iteration PI algorithm iterative formula are as follows:
Wherein, ir(τ) is the output valve of the τ moment algorithm;E (τ) is the error sampled value at τ moment, and M is the rounding of τ/N
Value.
This closed loop control method, it can be readily appreciated that easy to accomplish, changing violent occasion in fundamental wave load can still stablize
It runs and ensures good compensation effect.
Detailed description of the invention
Fig. 1 is that the topological diagram of three-phase imbalance equipment in the present invention is intended to;
Fig. 2 is closed loop control method circuit diagram of the present invention.
Specific embodiment
To make the objectives, technical solutions, and advantages of the present invention more comprehensible, below in conjunction with attached drawing and specific embodiment party
Formula, the present invention is further described in detail.It should be understood that the specific embodiments described herein are only to solve
The present invention is released, and the scope of protection of the present invention is not limited.
It please refers to shown in Fig. 1 and Fig. 2, a kind of closed loop of the three-phase imbalance equipment based on internal model principle and error iteration PI
Control method, wherein three-phase imbalance equipment topological diagram: using two traditional level voltage type converter topologies, and exchange side is logical
It crosses three pole reactor to be directly connected to power grid, DC side is using the capacitor series connection of two groups of divisions, and the midpoint of two groups of capacitors is as middle line
It is connect with power grid N line, as zero sequence access.Wherein is is power network current, and ic is that equipment exports electric current, and Udc is DC bus electricity
Pressure.
Implement to control by following steps:
Step S1, sampling three-phase network voltage obtains the angle wt of network voltage using phaselocked loop, as control transformation
Phase angle foundation.
Step S2, acquisition power network current isa, isb, isc obtains the electric current of two axis of D, Q using ABC/DQ coordinate transform
Ingredient id, iq.
Because of the fundamental wave and Resonance Wave Composition in addition to fundamental positive sequence electric current of three-phase imbalance equipment replacement, at this time
ABC/DQ transformation need to use positive sequence phase angle wt, and in this way in DQ coordinate system, fundamental positive sequence composition is DC component, fundamental wave negative sequence, zero
Sequence and Resonance Wave Composition are entirely Alternating Component.
And DC component removal is carried out to output id, iq of b and is calculated, obtain other electric currents without containing fundamental positive sequence
Composition is converted using DQ/ABC coordinate system, obtains three phase harmonic instruction ∑ iabc, wherein including fundamental wave negative sequence composition, base
Wave zero sequence composition and higher hamonic wave composition.
The composition of id, iq are described, so expecting that fundamental wave negative sequence, zero sequence and Resonance Wave Composition just need to reject
Fall the DC component i.e. fundamental positive sequence composition in id, iq, DC component removal is calculated, by the way of cumulative integral, mentioned
Take out DC component, then made the difference with id, iq, obtain Alternating Component in DQ axis namely fundamental wave negative sequence composition, fundamental wave zero sequence at
Part and higher hamonic wave composition.
The specific implementation of cumulative integral:
Its difference expression are as follows:
Wherein N is sample frequency points corresponding with respect to fundamental wave, and x (i) is the instantaneous value of active axis or idle axis.
Step S3, it 0 is made the difference as given with three phase harmonic instruction ∑ iabc, error signal e rr is obtained, by internal model control
Device controls to obtain three-phase compensation electric current ira、irb、irc。
Because being closed loop networking electric current, after compensation occurs, networking electric current can be gradually reduced, so necessary in closed-loop control
There is the presence of internal mode controller, internal mode controller can guarantee still to keep the output of controller when input is 0.Internal model control
Device processed and integral are similar to the effect of DC component, are the emphasis for realizing closed-loop control.
Internal model control is as follows:
Wherein Gr(z) it is internal mode controller, is speciallyTherein 0.98 is for internal mode controller
Stablize.krFor amplitude rectification, zkFor phasing, S (z) is low-pass filter, and the main function of low-pass filter is to filter out height
Subharmonic, the size that number can be compensated according to three-phase imbalance equipment highest determine the cutoff frequency of low-pass filter, low pass
The form of filter is unlimited.For example the compensation of most high order is 13 subharmonic, then the cutoff frequency of low-pass filter may be selected by
For the frequency more slightly higher than 13 times, such as 750Hz.This low-pass filter may insure that internal mode controller does not remove response excessively high frequency
Harmonic wave or noise information.
Step S4, busbar voltage Udc is sampled, with Udc*It makes the difference, obtains error signal e rr, obtained by error iteration PI
The watt current Q axis instruction for stablizing busbar voltage, obtains three-phase pressure stabilizing active command i by DQ/ABC coordinate system transformationwa、iwb、
iwc。
Error iteration PI can greatly enhance the dynamic and steady-state characteristic of busbar voltage control ring.
The iterative formula of error iteration PI algorithm are as follows:
Wherein, ir(τ) is the output valve of the τ moment algorithm;E (τ) is the error sampled value at τ moment, and M is the rounding of τ/N
Value.
Step S5, the resulting three-phase of step S3 is compensated into electric current ira、irb、ircIt is active with the resulting three-phase pressure stabilizing of step S4
Instruct iwa、iwb、iwcIt sums as the given of inductive current control ring, makes the difference to obtain error with three-phase output electric current ia, ib, ic
Signal, error signal control to obtain modulating wave by P adjuster.
Step S6, modulating wave and carrier phase angle, obtain SPWM, and the pipe movement of driving power main circuit realizes three-phase not
The control of balancing equipment.
To sum up, the invention has the following advantages:
1. sampling current on line side carries out closed-loop control, control target is directly controlled, may be implemented to compensate well
Effect;Possess current inner loop simultaneously, separation harmonic current control outer ring and busbar voltage control outer ring, it is ensured that the perseverance of busbar voltage
It is fixed, greatly enhance the use scope of equipment.
2. harmonic current controls the controller that outer ring uses internal model principle, introduces DC component and remove link, it is ensured that 50Hz
Fundamental active does not influence busbar voltage, while introducing the height that low-pass filter flexibly adjusts compensation number, internal mode controller
Introducing greatly improve the tracking effect of harmonic wave.
3. busbar voltage ring introduces error iteration PI controller, the mistake of busbar voltage stable state control is greatly reduced
Difference, while improving the response speed of busbar voltage ring in the case of fundamental active load sudden change, it is ensured that the peace of the voltage of bus
Complete and compensation effect stability.This closed loop control method, it can be readily appreciated that it is easy to accomplish, change violent field in fundamental wave load
Conjunction still with stable operation and can ensure good compensation effect.
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.
Claims (6)
1. a kind of closed loop control method of the three-phase imbalance equipment based on internal model principle and error iteration PI, which is characterized in that
It exchanges side in the topological diagram of three-phase imbalance equipment to be directly connected to by three pole reactor and power grid, DC side uses two groups of divisions
Capacitor series connection, the midpoint of two groups of capacitors are connect as middle line with power grid N line, as zero sequence access, are realized by following steps
Control:
Step S1: sampling three-phase network voltage obtains the angle wt of network voltage using phaselocked loop, the phase angle as control transformation
Foundation;
Step S2: acquisition power network current isa, isb, isc obtain the current component of two axis of D, Q using ABC/DQ coordinate transform
Id, iq, and DC component removal is carried out to id, iq and is calculated, obtain other current components without containing fundamental positive sequence, and benefit
It is converted with DQ/ABC coordinate system, obtains three phase harmonic instruction ∑ iabc;
Step S3:0 makes the difference as given with three phase harmonic instruction ∑ iabc, error signal e rr is obtained, by internal mode controller control
Three-phase compensation electric current i is madera、irb、irc;
Step S4: sampling busbar voltage Udc, with Udc*It makes the difference, obtains error signal e rr, obtain stablizing mother by error iteration PI
The watt current Q axis of line voltage instructs, and obtains three-phase pressure stabilizing active command i by DQ/ABC coordinate system transformationwa、iwb、iwc;
Step S5: three-phase obtained above is compensated into electric current ira、irb、ircWith three-phase pressure stabilizing active command iwa、iwb、iwcSummation is made
For the given of inductive current control ring, make the difference to obtain error signal with three-phase output electric current ia, ib, ic, error signal passes through P tune
Section device controls to obtain modulating wave;
Step S6: modulating wave and carrier phase angle obtain SPWM, and three-phase imbalance is realized in the pipe movement of driving power main circuit
The control of equipment.
2. closed loop control method according to claim 1, which is characterized in that ABC/DQ transformation is using just in the step S2
Sequence phase angle wt, in DQ coordinate system, fundamental positive sequence composition is DC component, and fundamental wave negative sequence, zero sequence and Resonance Wave Composition are entirely to hand over
Flow composition.
3. closed loop control method according to claim 2, which is characterized in that the three phase harmonic in the step S2 instructs ∑
Iabc includes fundamental wave negative sequence composition, fundamental wave zero sequence composition and higher hamonic wave composition.
4. closed loop control method according to claim 3, which is characterized in that DC component removal meter in the step S2
It calculates, by the way of cumulative integral, extracts DC component, then made the difference with id, iq, obtain the Alternating Component in DQ axis, tire out
The specific implementation of product integral:
Difference expression are as follows:
Wherein, N is sample frequency points corresponding with respect to fundamental wave, and x (i) is the instantaneous value of active axis or idle axis.
5. closed loop control method according to claim 1, which is characterized in that the internal mode controller control in the step S3
It is as follows:
Wherein, GrIt (z) is internal mode controller, speciallykrFor amplitude rectification, zkFor phasing, S (z) is
Low-pass filter.
6. closed loop control method according to claim 1, which is characterized in that error iteration PI algorithm in the step S4
Iterative formula are as follows:
Wherein, ir(τ) is the output valve of the τ moment algorithm;E (τ) is the error sampled value at τ moment, and M is the rounding value of τ/N.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201810873309.XA CN109004661A (en) | 2018-08-03 | 2018-08-03 | The closed loop control method of three-phase imbalance equipment based on internal model principle and error iteration PI |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201810873309.XA CN109004661A (en) | 2018-08-03 | 2018-08-03 | The closed loop control method of three-phase imbalance equipment based on internal model principle and error iteration PI |
Publications (1)
Publication Number | Publication Date |
---|---|
CN109004661A true CN109004661A (en) | 2018-12-14 |
Family
ID=64594938
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201810873309.XA Pending CN109004661A (en) | 2018-08-03 | 2018-08-03 | The closed loop control method of three-phase imbalance equipment based on internal model principle and error iteration PI |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN109004661A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109802397A (en) * | 2019-01-03 | 2019-05-24 | 广州供电局有限公司 | The adaptive PI double-closed-loop control method of static reactive generator |
CN110829808A (en) * | 2019-11-01 | 2020-02-21 | 中车永济电机有限公司 | Current low-order harmonic suppression method for four-quadrant converter of electric locomotive |
CN113852290A (en) * | 2021-10-19 | 2021-12-28 | 山东华天电气有限公司 | Real-time voltage steady-state error recovery control method and system |
-
2018
- 2018-08-03 CN CN201810873309.XA patent/CN109004661A/en active Pending
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109802397A (en) * | 2019-01-03 | 2019-05-24 | 广州供电局有限公司 | The adaptive PI double-closed-loop control method of static reactive generator |
CN109802397B (en) * | 2019-01-03 | 2020-11-27 | 广东电网有限责任公司广州供电局 | Self-adaptive PI double closed-loop control method of static var generator |
CN110829808A (en) * | 2019-11-01 | 2020-02-21 | 中车永济电机有限公司 | Current low-order harmonic suppression method for four-quadrant converter of electric locomotive |
CN113852290A (en) * | 2021-10-19 | 2021-12-28 | 山东华天电气有限公司 | Real-time voltage steady-state error recovery control method and system |
CN113852290B (en) * | 2021-10-19 | 2023-08-08 | 山东华天电气有限公司 | Real-time voltage steady-state error recovery control method and system |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN106451466B (en) | Grid power quality control system and method based on Research on Unified Power Quality Conditioner | |
CN105553304B (en) | A kind of modular multilevel type solid-state transformer and its internal model control method | |
CN103532156B (en) | A kind of STATCOM imbalance compensation control method based on modularization multi-level converter | |
CN110707958B (en) | Modulation wave interval division-based midpoint voltage control method | |
CN105743091B (en) | A kind of double close-loop decoupling control method of Active Power Filter-APF | |
CN107611991B (en) | Parameter design method of LC coupling type SVG under unbalanced power grid and control method and system thereof | |
CN106602916B (en) | A kind of mixing level three-phase four-bridge arm converter device and control method | |
CN109347354B (en) | Midpoint voltage ripple suppression device and method based on third harmonic injection | |
CN108879775B (en) | Power grid unbalanced photovoltaic inverter coordination control method considering current limit value | |
CN106357143A (en) | Loop current inhibition method suitable for modular multilevel converter | |
CN109327036B (en) | Cascade type energy storage system for improving power quality of power grid and control method | |
CN204886199U (en) | Adapt to power electronic transformer uneven and non - linear load | |
CN103475250A (en) | General loop current control method for modular multi-level converter considering low frequency oscillation | |
CN112332426B (en) | Unified power quality regulator system based on MMC technology and control method | |
CN104410256A (en) | Active filter system containing modular multilevel converter and control method thereof | |
Das et al. | Improvement in power quality using hybrid power filters based on RLS algorithm | |
CN104393598A (en) | Frequency-adaptation improved resonant control method for active power filter | |
CN109004661A (en) | The closed loop control method of three-phase imbalance equipment based on internal model principle and error iteration PI | |
CN110429603B (en) | Six-switch seven-level active power filter and compensation method | |
CN104882886A (en) | LLCL filtering-based active power filter compound control method | |
CN106787880B (en) | A kind of low order circulation inhibition method of Modular multilevel converter | |
CN110266008A (en) | Based on the improved more level active power filters of neutral-point-clamped type | |
Salim et al. | Simplified control scheme of unified power quality conditioner based on three-phase three-level (NPC) inverter to mitigate current source harmonics and compensate all voltage disturbances | |
CN105071390A (en) | Control method of H-bridge three-level active power filter and system | |
CN107437818B (en) | Inhibit the control method of the small signal disturbance of three-phase LCL type grid-connection converter phaselocked loop under weak grid |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
WD01 | Invention patent application deemed withdrawn after publication | ||
WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20181214 |