CN110943635A - MMC alternating-current side fault energy balance control method based on feedforward control - Google Patents
MMC alternating-current side fault energy balance control method based on feedforward control Download PDFInfo
- Publication number
- CN110943635A CN110943635A CN201911078925.7A CN201911078925A CN110943635A CN 110943635 A CN110943635 A CN 110943635A CN 201911078925 A CN201911078925 A CN 201911078925A CN 110943635 A CN110943635 A CN 110943635A
- Authority
- CN
- China
- Prior art keywords
- current
- energy
- bridge arm
- control
- mmc
- 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
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/483—Converters with outputs that each can have more than two voltages levels
-
- 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
- H02J3/24—Arrangements for preventing or reducing oscillations of power in 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
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
- H02M7/53871—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
-
- 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
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
-
- 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
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses an MMC alternating current side fault energy balance control method based on feedforward control, and provides a feedforward control strategy to improve the voltage balance of a modular multilevel converter under the condition of an unbalanced power grid, analyze the coupling relation between bridge arm energy and each electrical signal and solve the problem that the prior method is not suitable for the condition of the unbalanced power grid
Description
The invention discloses an MMC alternating current side fault energy balance control method based on feedforward control, which is applied to the field of flexible direct current power transmission.
Background
A high-voltage flexible direct-current power transmission technology based on a Modular Multilevel Converter (MMC) is a new generation direct-current power transmission technology taking a voltage source Converter as a core, and as an emerging technology, related fault protection and control strategies are not mature. Therefore, the research on the protection and ride-through capability of the flexible direct current transmission system during the fault is of great significance.
The MMC converter control system comprises a direct current side, an alternating current side and a circulating current control, wherein the most challenging part is the balance control of capacitance and voltage of the sub-modules, and the balance control aims to realize the balance of internal energy flow of the converter and comprises the control of total energy of all bridge arms, the balance control of interphase energy and the balance control of energy of upper and lower bridge arms. The energy-based control scheme can control the energy between arms in a closed loop manner, so that the convergence speed of voltage balance can be selected, and the balance is realized by acting on internal circulating current, so that the waveform of alternating current and direct current output current is not influenced, therefore, the control scheme based on the energy of the bridge arms is more and more concerned, the existing research mainly improves the voltage-sharing effect of capacitance of sub-modules by carrying out balance control on the total energy of each bridge arm, analyzes the total energy change rule of each bridge arm sub-module in the fault process of the converter, but is mostly only suitable for the condition of steady-state operation, based on the analysis, the MMC alternating current side fault energy balance control method based on feedforward control improves the capacitance-voltage balance of the modular multilevel converter under the condition of an unbalanced power grid, and improves the capacity of the alternating current grid for resisting asymmetrical faults and unbalanced burst voltage, the fault ride-through capability of the alternating current side can be effectively improved.
Disclosure of Invention
In order to improve transient response of the MMC under a power grid fault, improve balance performance of internal and external energy of a current converter, effectively inhibit power fluctuation and improve fault ride-through capability of the MMC at the alternating current side, the invention provides a feed-forward control-based MMC alternating current side fault energy balance control method, which analyzes energy rules inside the MMC in detail, can realize total energy balance among bridge arms and effectively improve voltage-sharing effect of sub-module capacitors among the bridge arms and fault ride-through capability at the alternating current side.
The invention provides an MMC alternating current side fault energy balance control method based on feedforward control, which comprises the following steps:
the invention has the beneficial effects that:
go deep into analyzing inside the inverterThe transient energy flow rule of the part researches the coupling relation between the bridge arm energy and each electric signal, and establishesAccording to the mathematical model of the bridge arm energy under the coordinate system, the disturbance of the bridge arm energy can be effectively inhibited through the design of a feedforward component in a bridge arm energy control link, the response performance of a controller is greatly improved, a discretization state space expression of a current signal inside a current converter is obtained at the same time, independent decoupling control is carried out on the current signal, a phase-locking link is not required to be designed for the control strategy provided by the text, and the step S1 of the current converter can be realized: analyzing the transient energy flow rule in the MMC converter in detail, solving a single-phase power expression, and providing a common-mode component of bridge arm energySum and difference mode components
Step S2: analyzing the coupling relation between the energy of the bridge arm and each electric signalA mathematical model of bridge arm energy is established under a coordinate system, a feedforward component is added in the links of interphase energy exchange and upper and lower bridge arm energy exchange control, the disturbance of the bridge arm energy is effectively inhibited, and the flexible and rapid control of the bridge arm energy is realized through an internal current signal of a current converter.
Step S3: because the energy of the upper bridge arm and the lower bridge arm may have difference, a fundamental frequency current can be introduced to balance the energy of the upper bridge arm and the lower bridge arm, the fundamental frequency current is asymmetric among the three-phase bridge arms, and a zero sequence component exists, and the zero sequence component can flow into a direct current bus to cause direct current bus fluctuation, so that a zero sequence current inhibition link is added for inhibiting the fundamental frequency zero sequence current.
Step S4: obtaining a discretization state space representation of an MMC internal current signal in a continuous time domain, independently decoupling and controlling the obtained current signal, realizing non-static tracking control on a direct current side current signal of an alternating current side through a PIR controller, and filtering 2 frequency multiplication components in a circulating current and a direct current side current through a PR controller.
The current component signals are subjected to reference non-static tracking, so that the steady-state error is reduced, the fault ride-through capability of the MMC alternating current side is improved, and the transient response speed is increased.
Drawings
FIG. 1 is a schematic view of MMC structure
FIG. 2 is a block diagram of an energy balance control strategy as described herein
FIG. 3 is a flow chart of MMC alternating current side fault energy balance control strategy design based on feedforward control
Detailed Description
The invention is further described below with reference to the figures and examples.
As shown in FIG. 1, the MMC structure is a schematic diagram, each phase is composed of three phases and has an upper bridge arm and a lower bridge arm, each bridge arm is provided with N sub-modules which are simultaneously connected with a reactor L in series0The port voltages of the upper and lower bridge arms of the current converter areThe current of the upper and lower bridge arms of the current converter isRepresentative of AC measured voltage and current, VDC、Vl DCThe high-voltage direct current side voltage and the upper and lower voltage are shown, wherein k is a, b and c.
From kirchhoff's voltage law:
in the above formula: l is0For bridge arm inductance,The voltage of the upper and lower bridge arms of K (a, b, c) phase,is K-phase upper and lower bridge arm current, udcThe direct current side voltage is obtained through (1) and (2), the physical relation between the current and the voltage of the upper and lower bridge arms can be obtained, and the expression of the bridge arm current is as follows:
in the formula (I), the compound is shown in the specification,is the component of the dc bus current,is a k-phase ac circulating current component, defined by:
vsum、vdifthe common mode component and the differential mode component of the upper and lower bridge arm voltages are respectively.
As shown in fig. 2, which is a block diagram of an energy balance control strategy provided herein, the analysis of the transient energy flow law inside the converter can show that the upper and lower bridge arm powers can be expressed as:
neglecting the MMC transverter internal loss can obtain:
in an actual system, an alternating current side transformer adopts Y-delta wiring to block the circulation of zero-sequence current, so that the zero-sequence component is not considered.
Based on the above analysis, the power of each phase of the MMC can be obtained according to the three-phase voltage and current signals, taking the phase a as an example:
in the above formula, the voltage and current signals are respectively expanded into positive sequence, negative sequence and direct current components, w is fundamental frequency, and V, theta (I, theta) are respectively expressed as corresponding amplitude and phase angle, so that p can be obtaineda=vaiaAs shown in equation (18), it can be seen that the first five terms are dc power terms, the average value of which is not 0, and if these power terms are not compensated in equations (7) and (8), the average value of the bridge arm energy will rise or fall outside the acceptable range, and these dc power terms are greatly affected by the negative sequence component of the voltage or current, so that these negative sequence components must be considered in both the design of the current controller and the balancing process of the bridge arm energy in order to achieve accurate control of the MMC. The last 8 terms in the formula (11) are alternating current power terms, and fundamental frequency and double frequency ripple waves are introduced into the bridge arm energy, but the average value of the bridge arm energy is not influenced.
In order to realize the internal interphase energy balance and the energy balance between the upper bridge arm and the lower bridge arm of the converter, the internal energy flow mechanism of the converter is researched, and the common-mode component of the energy of each phase of bridge arm is defined asA differential mode component ofThe expressions given by the equations (7) and (8) are as follows:
whereinRepresenting the multiplication of individual elements in each term, the common-mode voltage v being present when the network is in an unbalanced conditiondifWith alternating side current component igBoth contain positive and negative sequence components, i.e.The controller may be at vdifAdding a negative sequence component for regulating the negative sequence current
In order to realize the balance control of total energy and energy of each phase of the bridge arm, the formula (12) is converted intoThe coordinate system is expanded as shown in formula (11):
as can be seen from the formula (13),proportional relation with total energy stored by bridge arm, and can pass through DC side powerOr positive-sequence active power at AC sideRealizing dynamic balance control on total energy of the bridge arm, and on the other hand, realizing dynamic balance control on the total energy of the bridge arm by circulating direct current component of current of the bridge armThe balance of energy flow between phases can be realized by controlling, and the bridge arm energy e can be influenced by the change of current or voltage in the MMC current convertersumProducing disturbances by defining auxiliary control inputAndall direct current power items in the bridge arm energy are compensated in a feed-forward mode, and then a feedback control loop based on PI control is designed for achieving control over MMC interphase energy balance.
Thus, the reference value of the bridge arm current circulation direct current component can be obtained:
in order to obtain the direct current reference value, the negative sequence current of the alternating-current side power grid is injectedSet to 0, assist in controlling the inputThe introduction of the feed-forward phase can realize the rapid suppression of the energy disturbance measured by an energy feedback control loop.
Similarly, in order to realize the balance control of the energy between the upper and lower arms, equation (13) is switched toThe coordinate system is expanded as shown in formula (11):
from the above formula, the energy edifPositive and negative sequence components capable of circulating current through bridge armControl is performed, and similarly, an auxiliary input control amount is definedRespectively to the bridge arm energy The dc power term in (1) is dynamically compensated, wherein,the reactive power set to 0 is derived from the feedback control loop, i.e.:
in order to realize the energy balance of the upper and lower bridge arms, the AC circulating positive and negative sequence reference values can be obtained by the formula (18) - (20) as follows:
FIG. 3 is a schematic diagram of a design flow chart of a fault energy balance control strategy for an MMC AC side based on feedforward control, which analyzes the flowing rule of the internal energy of a converter and obtains a corresponding current reference, and makes the internal energy of the MMC converter balanced under the fault condition by flexibly and quickly controlling the current signal, and simultaneously realizes error-free tracking of the current references of the AC side and the DC side by combining with a PIR controller after obtaining a discretization state expression of the current signal, and filters 2 frequency multiplication components in the circulating current and the DC side current by combining with a PR controller, thereby greatly inhibiting fluctuation, ensuring the balance of the internal energy of the converter under the fault of the AC side, effectively inhibiting disturbance, and realizing fault ride-through.
Claims (2)
1. A novel MMC alternating current side fault energy balance control method based on feedforward control is characterized by comprising the following steps:
step S1: analyzing the transient energy flow rule in the MMC converter in detail, solving a single-phase power expression, and providing a common-mode component of bridge arm energySum and difference mode components
Step S2: analyzing the coupling relation between the energy of the bridge arm and each electric signalA mathematical model of bridge arm energy is established under a coordinate system, a feedforward component is added in the links of interphase energy exchange and upper and lower bridge arm energy exchange control, the disturbance of the bridge arm energy is effectively inhibited, and the flexible and rapid control of the bridge arm energy is realized through an internal current signal of a current converter.
Step S3: step S3: because the energy of the upper bridge arm and the lower bridge arm may have difference, a fundamental frequency current can be introduced to balance the energy of the upper bridge arm and the lower bridge arm, the fundamental frequency current is asymmetric among the three-phase bridge arms, and a zero sequence component exists, and the zero sequence component can flow into a direct current bus to cause direct current bus fluctuation, so that a zero sequence current inhibition link is added for inhibiting the fundamental frequency zero sequence current.
Step S4: obtaining a discretization state space representation of an MMC internal current signal in a continuous time domain, independently decoupling and controlling the obtained current signal, realizing non-static tracking control on a direct current side current signal of an alternating current side through a PIR controller, and filtering 2 frequency multiplication components in a circulating current and a direct current side current through a PR controller.
2. Method according to claim 1, characterized in that a non-static tracking control of the ac side dc side current signal is achieved by a PIR controller and a 2 x frequency component in the dc side current is filtered out by a PR controller.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201911078925.7A CN110943635A (en) | 2019-11-07 | 2019-11-07 | MMC alternating-current side fault energy balance control method based on feedforward control |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201911078925.7A CN110943635A (en) | 2019-11-07 | 2019-11-07 | MMC alternating-current side fault energy balance control method based on feedforward control |
Publications (1)
Publication Number | Publication Date |
---|---|
CN110943635A true CN110943635A (en) | 2020-03-31 |
Family
ID=69907287
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201911078925.7A Pending CN110943635A (en) | 2019-11-07 | 2019-11-07 | MMC alternating-current side fault energy balance control method based on feedforward control |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN110943635A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111654051A (en) * | 2020-05-21 | 2020-09-11 | 东南大学 | Direct current fault ride-through control method suitable for mixed MMC |
CN112986703A (en) * | 2021-04-30 | 2021-06-18 | 重庆大学 | Three-phase bridge arm direct current unbalance analysis method based on cyclic coupling relation |
CN113328643A (en) * | 2021-02-02 | 2021-08-31 | 长沙理工大学 | MMC novel control method based on self-adaptive backstepping method |
CN113644677A (en) * | 2020-05-11 | 2021-11-12 | 中国能源建设集团江苏省电力设计院有限公司 | Offshore wind power flexible-direct control method under receiving-end power grid fault |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104993533A (en) * | 2015-06-30 | 2015-10-21 | 上海交通大学 | Modular multilevel converter inter-bridge-arm energy balance control method |
CN106877365A (en) * | 2017-03-21 | 2017-06-20 | 合肥工业大学 | The alternate unbalanced power control method of modular multi-level converter |
WO2018059672A1 (en) * | 2016-09-28 | 2018-04-05 | Abb Schweiz Ag | Power unbalance compensation in ac/ac mmc |
CN108233403A (en) * | 2018-02-02 | 2018-06-29 | 山东大学 | MMC double loops circulation inhibition method based on quasi- ratio resonant regulator |
CN108306318A (en) * | 2018-01-11 | 2018-07-20 | 北京交通大学 | Symmetrical energy-storage system based on Modular multilevel converter |
CN108471226A (en) * | 2018-04-04 | 2018-08-31 | 长沙理工大学 | Novel energy cooperative control method and device for modular multilevel converter |
CN109660133A (en) * | 2018-12-12 | 2019-04-19 | 长沙理工大学 | Circulation inhibition method under MMC exchange side asymmetrical state based on energy balance |
CN110350571A (en) * | 2019-07-15 | 2019-10-18 | 贵州电网有限责任公司 | A kind of control method promoting flexible DC transmission exchange side fault ride-through capacity |
-
2019
- 2019-11-07 CN CN201911078925.7A patent/CN110943635A/en active Pending
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104993533A (en) * | 2015-06-30 | 2015-10-21 | 上海交通大学 | Modular multilevel converter inter-bridge-arm energy balance control method |
WO2018059672A1 (en) * | 2016-09-28 | 2018-04-05 | Abb Schweiz Ag | Power unbalance compensation in ac/ac mmc |
CN106877365A (en) * | 2017-03-21 | 2017-06-20 | 合肥工业大学 | The alternate unbalanced power control method of modular multi-level converter |
CN108306318A (en) * | 2018-01-11 | 2018-07-20 | 北京交通大学 | Symmetrical energy-storage system based on Modular multilevel converter |
CN108233403A (en) * | 2018-02-02 | 2018-06-29 | 山东大学 | MMC double loops circulation inhibition method based on quasi- ratio resonant regulator |
CN108471226A (en) * | 2018-04-04 | 2018-08-31 | 长沙理工大学 | Novel energy cooperative control method and device for modular multilevel converter |
CN109660133A (en) * | 2018-12-12 | 2019-04-19 | 长沙理工大学 | Circulation inhibition method under MMC exchange side asymmetrical state based on energy balance |
CN110350571A (en) * | 2019-07-15 | 2019-10-18 | 贵州电网有限责任公司 | A kind of control method promoting flexible DC transmission exchange side fault ride-through capacity |
Non-Patent Citations (1)
Title |
---|
董鹏等: ""不对称交流电网下MMC-HVDC系统的控制策略"", 《中国电机工程学报》 * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113644677A (en) * | 2020-05-11 | 2021-11-12 | 中国能源建设集团江苏省电力设计院有限公司 | Offshore wind power flexible-direct control method under receiving-end power grid fault |
CN113644677B (en) * | 2020-05-11 | 2024-04-16 | 中国能源建设集团江苏省电力设计院有限公司 | Offshore wind power flexible direct control method under fault of receiving end power grid |
CN111654051A (en) * | 2020-05-21 | 2020-09-11 | 东南大学 | Direct current fault ride-through control method suitable for mixed MMC |
CN111654051B (en) * | 2020-05-21 | 2021-09-07 | 东南大学 | Direct current fault ride-through control method suitable for mixed MMC |
CN113328643A (en) * | 2021-02-02 | 2021-08-31 | 长沙理工大学 | MMC novel control method based on self-adaptive backstepping method |
CN112986703A (en) * | 2021-04-30 | 2021-06-18 | 重庆大学 | Three-phase bridge arm direct current unbalance analysis method based on cyclic coupling relation |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN110943635A (en) | MMC alternating-current side fault energy balance control method based on feedforward control | |
CN106602916B (en) | A kind of mixing level three-phase four-bridge arm converter device and control method | |
CN107611991B (en) | Parameter design method of LC coupling type SVG under unbalanced power grid and control method and system thereof | |
CN111030152A (en) | Energy storage converter system and control method thereof | |
CN102324746A (en) | A kind of high-voltage chain type STATCOM power unit module DC bus-bar voltage control method based on Auto Disturbances Rejection Control Technique | |
CN105071403A (en) | Reactive compensation device based on double H-bridge modular multilevel topology and control method | |
CN109950916B (en) | UPFC fault transition method based on mixed impedance | |
CN112737388B (en) | Common-mode active damping resonant circulating current suppression system and method for inverter parallel system | |
Li et al. | Control strategy of a cross-phase-connected unified power quality conditioner | |
CN111864785A (en) | Alternating current-direct current fault-resistant alternating current side cascade type hybrid MMC topology and control method thereof | |
CN111244980A (en) | Power electronic transformer nonlinear control method based on MMC structure | |
Jung et al. | A cell capacitor energy balancing control of MMC-HVDC under the AC grid faults | |
CN111030131B (en) | MMC-STATCOM circulating current suppression device based on negative sequence virtual impedance | |
CN105790253A (en) | Double-loop control method | |
Arcuri et al. | Stability analysis of grid inverter LCL-filter resonance in wind or photovoltaic parks | |
CN204858577U (en) | Reactive power compensator based on two many level of H bridge modularization transverters | |
Zhang et al. | Unbalance loads compensation with STATCOM based on PR controller and notch filter | |
CN112398361B (en) | Method for inhibiting interphase circulating current of MMC interconnection converter | |
CN113890061A (en) | Method for stabilizing impulse current in active island grid-connected process of multi-source distribution network | |
CN111092446B (en) | Decoupling control-based electric energy router high-voltage alternating-current port multifunctional form implementation method | |
Sharma et al. | A brief review regarding sensor reduction and faults in shunt active power filter | |
CN111800028A (en) | Novel method for restraining power fluctuation and circulation of railway traction power supply system | |
CN112653346A (en) | Inverter feed-forward control method and system under three-phase load unbalance condition | |
Daramukkala et al. | Normalized sigmoid function LMS adaptive filter based shunt hybrid active power filter for power quality improvement | |
Zheng et al. | High Performance of Three-Phase Four-Leg Inverter Based on Repetitive Control Strategy |
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 | ||
WD01 | Invention patent application deemed withdrawn after publication | ||
WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200331 |