CN101599708B - Method for controlling power balance of DC side of cascaded multilevel inverter - Google Patents
Method for controlling power balance of DC side of cascaded multilevel inverter Download PDFInfo
- Publication number
- CN101599708B CN101599708B CN2009100628838A CN200910062883A CN101599708B CN 101599708 B CN101599708 B CN 101599708B CN 2009100628838 A CN2009100628838 A CN 2009100628838A CN 200910062883 A CN200910062883 A CN 200910062883A CN 101599708 B CN101599708 B CN 101599708B
- Authority
- CN
- China
- Prior art keywords
- control
- full
- inverting unit
- bridge inverting
- power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The invention discloses a method for controlling the power balance of the DC side of a cascaded multilevel inverter. The power control of the cascaded multilevel inverter is divided into two layers, an upper layer control and a lower layer control,wherein, the upper layer control realizes the total power control, and the lower layer control carries out the operation of active power redistribution on each full-bridge conversion unit by overlapping a pure active power vector which is parallel to the current direction on the basis of the upper layer control, thereby enabling the input power on the DC side of each full-bridge conversion unit of the cascaded multilevel inverter to tend to be balanced. The invention does not need to be provided with an extra power circuit, and can effectively realize the power balance of the DC side of the inverter, thereby reducing the cost fo the system and improving the reliability of the system.
Description
Technical field:
The invention belongs to the control technology field of power electronics and Electric Power Automation Equipment, relate to cascaded multilevel inverter, particularly relate to the method for controlling power balance of DC side of cascaded multilevel inverter.
Background technology:
The cascade connection multi-level technology is a kind of effective means that solves high-power transformation of electrical energy problem.Compared with transformer multiple technology commonly used, cascaded multilevel inverter has that floor space is little, cost is low, is easy to modularization, is easy to realize advantages such as redundant, that the asymmetric ability of anti-AC side is strong, is used to occasions such as generation of electricity by new energy, large-capacity power drag, STATCOM, active filter.Yet the cascaded multilevel inverter DC side is independent separately, because that each inversion unit characteristic can't be accomplished is in full accord, if do not add control, is easy to cause the imbalance of each inversion unit DC side power.This imbalance not only influences the utilance of place capacity, and also easy stability to the DC side power supply causes harmful effect.Particularly in occasions such as STATCOM, active filters, device is as pure reactive power source work, and each inversion unit DC side does not have DC power supply, only and be connected to electric capacity.The imbalance of each inversion unit DC side power will cause the imbalance of capacitance voltage, thereby influence device output voltage quality, also will cause device to move when serious.Therefore, the Balance Control technology of DC side power is one of key issue of cascaded multilevel inverter.
Power balance of DC side method commonly used at present often needs extra power circuit, and in big capacity, high voltage occasion that cascaded multilevel inverter is used, these class methods have increased the cost of system greatly, have reduced the reliability of system.
Summary of the invention:
The objective of the invention is to propose a kind of cascaded multilevel inverter method for controlling power balance of DC side, need not to set up the excess power circuit and can effectively realize the inverter direct-flow side power-balance, reduced system cost, improved system reliability.
The cascaded multilevel inverter method for controlling power balance of DC side, comprise upper strata control and lower floor's control to whenever being linked, the upper strata is controlled to be each full-bridge inverting unit and distributes identical modulating wave, lower floor's control is adjusted the modulating wave that each full-bridge inverting unit distributes, it is characterized in that lower floor's control is carried out according to following steps:
(1) measure be linked in the dc capacitor voltage of each full-bridge inverting unit, and it is made mean filter;
(2) summation is averaged the dc-voltage balance reference value that obtains being linked to the dc capacitor voltage behind each full-bridge inverting unit filtering;
(3) be instruction with the dc-voltage balance reference value respectively, dc capacitor voltage behind each full-bridge inverting unit filtering is feedback, carry out proportional control, the result of proportional control and the transient current that is linked are multiplied each other, obtain the modulating wave amount trimmed of each full-bridge inverting unit;
(4) respectively the modulating wave amount trimmed of each full-bridge inverting unit and the modulating wave of upper strata Control Allocation are superposeed, generate the actual modulated ripple of each full-bridge inverting unit.
Technique effect of the present invention is embodied in: the present invention is vector parallel with the sense of current of stack on the basis of upper strata control, i.e. pure meritorious vector, when the voltage of link is on the low side, the vector identical that superposes with the sense of current, on the contrary when link voltage is higher the vector of one of stack and current opposite in direction.The institute's control method levels of carrying control is full decoupled, and control characteristic is good, and parameter designing is simple, does not influence owing to only change the meritorious of each link units in addition that it is idle, thus the dc capacitor voltage high conformity, output waveform quality height.The present invention is simple to operate, therefore realize that device of the present invention does not need to comprise expensive power device, only need adopt that signal acquisition device and control chip can be realized cheaply, can adopt analog circuit also can adopt digital circuit during specific implementation, features simple structure, control effectively, have higher utility.
Description of drawings
Fig. 1 is the related cascaded multilevel inverter circuit theory diagrams of the present invention.
Fig. 2 is a cascaded multilevel inverter hierarchical control method schematic diagram of the present invention.
Fig. 3 is a cascaded multilevel inverter method for controlling power balance of DC side schematic diagram of the present invention.
Fig. 4 is each link units dc voltage waveform schematic diagram of cascaded multilevel inverter of the present invention, and Fig. 4 (a) is not for using the result schematic diagram of method for controlling power balance of the present invention, and Fig. 4 (b) is for using the result schematic diagram of method for controlling power balance of the present invention.
Embodiment
The present invention can be used for Electric Drive, electric power system compensation arrangement etc. and needs high voltage, powerful occasion.Be example now, the present invention is described with electric power system reactive-load compensation equipment in parallel.The static synchronous compensator plant schematic diagram such as Fig. 1 (A that constitute by cascaded multilevel inverter, B, C represents the A phase respectively, the B phase, the C phase), because this device dc bus capacitor is independent separately, if do not add control, can there be imbalance in each inversion unit dc capacitor voltage, thereby influences device output voltage quality, causes device to move when serious.The control method that the present invention proposes at first will be divided into two-layer (as shown in Figure 2) to the power control algorithm of cascaded multilevel inverter, the upper strata algorithm is that each full-bridge inverting unit distributes identical modulating wave with the total power control of implement device, and upper strata control can be adopted decoupling zero control, nonlinear Control, transient current tracking Control etc.; Lower floor is controlled on the basis of upper strata control output and modulates (as shown in Figure 3) again, promptly adjusts the distribution between each full-bridge converter unit of active power, finishes power balance of DC side.
Appoint and to get one and be linked and be that research object, link units number are N, its specific implementation step is as follows:
(1) each link units is provided with voltage hall sensor in link, gathers dc capacitor voltage.
(2) direct voltage that will gather each link units is delivered to the upper strata controller, does mean filter, obtains filtered each inversion unit magnitude of voltage V
Cn, n=1,2...N.
(3) every mutually filtered magnitude of voltage summation is averaged, obtains the dc-voltage balance control reference value of each phase, V
Ref=(V
C1+ V
C2+ ... V
CN)/N.
(4) with above-mentioned reference value V
RefBe instruction, each inversion unit magnitude of voltage V
CnFor feedback, carry out proportional control, controller can adopt control with changed scale control, when actual phase current hour, controller parameter is constant, when actual phase current was big, controller parameter was relevant with given reactive current size.The transient current i that output and every phase current mutual inductor of proportional controller collected
sMultiply each other, obtain the amount trimmed Δ v of each link units modulating wave
Fn
Each full-bridge inverting cells modulate ripple amount trimmed Δ v that (5) will obtain
FnWith the modulating wave v that obtains by upper strata control
fCarry out the instantaneous value stack, generate the new modulating wave v in each full-bridge inverting unit
Fn
(6) with the modulating wave v that obtains
FnSend as the PWM ripple S of the generation of the PWM generating unit among Fig. 2 at each full-bridge inverting unit
n
In the above-mentioned control method, step (1) realizes in DSP to step (5), step (6) realizes in FPGA, Fig. 4 one adds Balance Control and does not add Balance Control dc voltage effect contrast figure in being linked, for not adding the dc capacitor voltage waveform of balance control method, Fig. 4 (b) is for adopting the dc capacitor voltage waveform of the control method of carrying among Fig. 4 (a).As seen from the figure, when not adding Balance Control, each chain link dc capacitor voltage is very inconsistent; After adding Balance Control, the chain link dc capacitor voltage reaches unanimity, and has verified the validity and the feasibility of the balanced algorithm of putting forward thus.
Claims (1)
1. the method for controlling power balance of DC side of cascaded multilevel inverter, comprise each upper strata that is linked control and lower floor's control, the upper strata is controlled to be each full-bridge inverting unit and distributes identical modulating wave, lower floor's control is adjusted the modulating wave that each full-bridge inverting unit is assigned with, it is characterized in that lower floor's control is carried out according to following steps:
(1) measure be linked in the dc capacitor voltage of each full-bridge inverting unit, and it is made mean filter;
(2) summation is averaged the dc-voltage balance reference value that obtains being linked to the dc capacitor voltage behind each full-bridge inverting unit filtering;
(3) be instruction with the dc-voltage balance reference value respectively, dc capacitor voltage behind each full-bridge inverting unit filtering is feedback, carry out proportional control, the result of proportional control and the transient current that is linked are multiplied each other, obtain the modulating wave amount trimmed of each full-bridge inverting unit;
(4) respectively the modulating wave amount trimmed of each full-bridge inverting unit and the modulating wave of upper strata Control Allocation are superposeed, generate the actual modulated ripple of each full-bridge inverting unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100628838A CN101599708B (en) | 2009-06-26 | 2009-06-26 | Method for controlling power balance of DC side of cascaded multilevel inverter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100628838A CN101599708B (en) | 2009-06-26 | 2009-06-26 | Method for controlling power balance of DC side of cascaded multilevel inverter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101599708A CN101599708A (en) | 2009-12-09 |
| CN101599708B true CN101599708B (en) | 2011-01-26 |
Family
ID=41421000
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009100628838A Active CN101599708B (en) | 2009-06-26 | 2009-06-26 | Method for controlling power balance of DC side of cascaded multilevel inverter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101599708B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101950960B (en) * | 2010-09-19 | 2012-05-23 | 西安交通大学 | Control method of DC bus voltage of cascading multi-level power quality conditioners |
| CN102215004B (en) * | 2011-03-16 | 2014-07-30 | 中国电力科学研究院 | Valve current control method based on modular multi-level converter |
| CN102185331B (en) * | 2011-04-28 | 2014-01-29 | 中国电力科学研究院 | Zero-sequence-voltage-based current conversion chain average DC voltage control method |
| CN102291030A (en) * | 2011-08-16 | 2011-12-21 | 南京国睿新能电子有限公司 | Method for controlling balance of three-level photovoltaic grid-connected inverter direct current voltage |
| CN102522906B (en) * | 2011-12-22 | 2014-01-08 | 东南大学 | Voltage balance and power balance control method of cascaded H bridge converter |
| CN102638038B (en) * | 2012-03-20 | 2014-03-05 | 华中科技大学 | Parallel charging and discharging power conversion system |
| US10199823B2 (en) * | 2012-08-07 | 2019-02-05 | Abb Schweiz Ag | Chain-link converter system with different DC-sources and method for operation |
| CN102931864B (en) * | 2012-11-26 | 2015-05-13 | 国电南京自动化股份有限公司 | Method for voltage balance control of DC (direct current) buses of power units of cascade static var generator |
| CN103036238B (en) * | 2012-12-24 | 2015-02-04 | 珠海万力达电气自动化有限公司 | Control structure and method of chain-type active power filter (FAPF) linkage unit bypass |
| WO2014154290A1 (en) | 2013-03-28 | 2014-10-02 | Abb Technology Ltd | Method for controlling a chain-link converter |
| CN103595285A (en) * | 2013-11-29 | 2014-02-19 | 哈尔滨工业大学 | Method and device for controlling energy balance between bridge arms of modularized multi-level converter |
| CN103762856B (en) * | 2014-01-13 | 2016-07-27 | 叶宗彬 | A kind of transless hands over orthogonal cascade multilevel converter |
| CN104065062B (en) * | 2014-06-23 | 2016-08-24 | 许继电气股份有限公司 | The properly functioning modulation control method of STATCOM |
| CN104810835B (en) * | 2015-04-23 | 2017-09-22 | 许继电气股份有限公司 | STATCOM unbalance controls method and its zero-sequence component generation method |
| CN108631628B (en) * | 2018-05-18 | 2020-10-16 | 南京铁道职业技术学院 | Capacitor voltage balance control method for H-bridge cascade rectifier |
| CN109039129B (en) * | 2018-09-04 | 2019-05-07 | 中国矿业大学(北京) | Unidirectional cascade multi-level electronic power convertor voltage balance control strategy |
| CN114362561A (en) * | 2021-12-30 | 2022-04-15 | 中车永济电机有限公司 | Locomotive traction converter and control method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5642275A (en) * | 1995-09-14 | 1997-06-24 | Lockheed Martin Energy System, Inc. | Multilevel cascade voltage source inverter with seperate DC sources |
| US6075350A (en) * | 1998-04-24 | 2000-06-13 | Lockheed Martin Energy Research Corporation | Power line conditioner using cascade multilevel inverters for voltage regulation, reactive power correction, and harmonic filtering |
| CN1933274A (en) * | 2006-09-30 | 2007-03-21 | 中国科学院电工研究所 | H bridge cascade active electric filter DC side capacitance-voltage equalizing controlling maethod |
| US7230837B1 (en) * | 2006-03-27 | 2007-06-12 | North Carolina State University | Method and circuit for cascaded pulse width modulation |
| CN101170259A (en) * | 2007-11-26 | 2008-04-30 | 天津理工大学 | DC voltage balance control system for mixed multi-level static synchronization compensator |
-
2009
- 2009-06-26 CN CN2009100628838A patent/CN101599708B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5642275A (en) * | 1995-09-14 | 1997-06-24 | Lockheed Martin Energy System, Inc. | Multilevel cascade voltage source inverter with seperate DC sources |
| US6075350A (en) * | 1998-04-24 | 2000-06-13 | Lockheed Martin Energy Research Corporation | Power line conditioner using cascade multilevel inverters for voltage regulation, reactive power correction, and harmonic filtering |
| US7230837B1 (en) * | 2006-03-27 | 2007-06-12 | North Carolina State University | Method and circuit for cascaded pulse width modulation |
| CN1933274A (en) * | 2006-09-30 | 2007-03-21 | 中国科学院电工研究所 | H bridge cascade active electric filter DC side capacitance-voltage equalizing controlling maethod |
| CN101170259A (en) * | 2007-11-26 | 2008-04-30 | 天津理工大学 | DC voltage balance control system for mixed multi-level static synchronization compensator |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101599708A (en) | 2009-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101599708B (en) | Method for controlling power balance of DC side of cascaded multilevel inverter | |
| Basu et al. | Investigation on the performance of UPQC-Q for voltage sag mitigation and power quality improvement at a critical load point | |
| Kannan et al. | Photovoltaic based distribution static compensator for power quality improvement | |
| Verma et al. | Grid interfaced solar photovoltaic power generating system with power quality improvement at AC mains | |
| Thrimawithana et al. | A novel matrix converter based bi-directional IPT power interface for V2G applications | |
| CN104821607A (en) | Photovoltaic microgrid power equalization control method based on three-end cooperative control | |
| CN104158211B (en) | Based on many power grids system control method of Modular multilevel converter | |
| Shen et al. | Transformer-less three-port grid-connected power converter for distribution power generation system with dual renewable energy sources | |
| Meng et al. | Optimal input and output power quality control of single-phase AC–DC–DC converter with significant DC-link voltage ripple | |
| Rastogi et al. | Performance investigation of two-level reduced-switch D-STATCOM in grid-tied solar-PV array with stepped P&O MPPT algorithm and modified SRF strategy | |
| Li et al. | Realization of UPQC H∞ coordinated control in Microgrid | |
| CN110535192A (en) | A kind of alternating current-direct current mixing micro-capacitance sensor system and its control method based on parallel-connection network side converter | |
| CN101741275B (en) | Control method of modular full-bridge grid-connected inverters capable of parallel operation | |
| Savaghebi et al. | A new control strategy for distributed generation interface converters to compensate microgrid harmonics | |
| CN104852388B (en) | A kind of chain type SVG device with active power filtering function | |
| Balamurugan et al. | Solar PV Based Shunt Active Filter with p-q Theory Control for Improvement of Power Quality | |
| CN113098013A (en) | Electrolytic capacitor-free parallel active power filter system and control method | |
| Chakraborty et al. | Advanced active filtering in a single phase high frequency AC microgrid | |
| Alotaibi et al. | Three-phase inverter based on isolated SEPIC/CUK converters for large-scale PV applications | |
| Vijayakumar et al. | PV based three-level NPC shunt active power filter with extended reference current generation method | |
| Huang et al. | PR controller for grid-connected inverter control using direct pole placement strategy | |
| Azhagesan et al. | Predictive current control of FL-shunt active power filter for dynamic and heterogeneous load compensation | |
| Wen et al. | Reactive power compensation and harmonics elimination at medium-voltage using hexagram converter | |
| CN114336660A (en) | UPQC direct current prediction control method based on power angle | |
| CN102969735A (en) | Photovoltaic flexibility grid-connection device and control method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |