CN107134938B - Single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing - Google Patents
Single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing Download PDFInfo
- Publication number
- CN107134938B CN107134938B CN201710555080.0A CN201710555080A CN107134938B CN 107134938 B CN107134938 B CN 107134938B CN 201710555080 A CN201710555080 A CN 201710555080A CN 107134938 B CN107134938 B CN 107134938B
- Authority
- CN
- China
- Prior art keywords
- diode
- switching tube
- capacitor
- cathode
- 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.)
- Active
Links
- 239000003990 capacitor Substances 0.000 title claims abstract description 62
- 238000000034 method Methods 0.000 claims abstract description 4
- 230000002035 prolonged effect Effects 0.000 abstract description 2
- 230000002349 favourable effect Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 7
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
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
-
- H02J3/385—
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
-
- 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
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses a single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing, which comprises a boost circuit and a three-level half-bridge inverter circuit, wherein the boost circuit comprises a flyback bus voltage balancing circuit. The invention has the advantages that: the voltage balance of the two capacitors at the direct current side is balanced through the compensation of the flyback bus voltage balance circuit, so that the direct current voltage utilization rate is greatly improved; electromagnetic compatibility is improved; the characteristic of small harmonic content of the output voltage of the traditional three-level inverter is enhanced through the balance of the voltage of the bus capacitor, and the service life of the capacitor is prolonged; the method is favorable for realizing the tracking of the maximum power point and fully playing the maximum efficiency of the solar photovoltaic array; thereby improving the reliability of the system.
Description
Technical Field
The invention relates to a three-level inverter, in particular to a single-phase three-level half-bridge inverter capable of balancing direct-current side capacitor voltage.
Background
At present, the increasing energy demands are increasingly important to develop new energy and improve the energy utilization rate, and the photovoltaic solar energy is a clean and environment-friendly energy in the development of various new energy, so the photovoltaic solar energy has very important significance in the development. However, the single-phase three-level half-bridge inverter is the core of photovoltaic solar energy conversion, plays a role in converting solar direct current into alternating current required by loads of people, and realizes maximum power tracking.
Multilevel inverters have long become a hot spot for research in high-power, medium-voltage applications. The three-level half-bridge inverter is one of the multi-level inverters, and the output characteristics of the three-level half-bridge inverter are that bridge arms of the three-level half-bridge inverter have three output levels of +vin/2, -Vin/2 and 0, so that the equivalent switching frequency can be reduced under the condition of the same output voltage harmonic standard, thereby reducing the switching loss and improving the efficiency and the electromagnetic compatibility. On the other hand, due to the existence of the midpoint of the direct-current voltage-dividing capacitor, the voltage stress born by the switching device is only half of that of the two levels, so that the application of the low-voltage-resistant switching device in a high-voltage occasion is possible, the economic cost of the inverter design is greatly reduced, and the reliability of the system is improved.
However, under the condition of load or grid connection, the single-phase three-level half-bridge inverter can enable the voltage on two capacitors in the direct-current side bus to generate larger oscillation, so that output waveform distortion is caused. Shortens the life of electric capacity, and unstable voltage can influence MPPT's precision. Therefore, the method aims at solving the problem of unbalanced voltage on the direct-current side capacitor of the single-phase three-level half-bridge inverter, and has great significance on the increase of the reliability of the system, the reduction of harmonic waves and the service life extension of the capacitor and related devices.
Disclosure of Invention
The invention aims to solve the problem of unbalanced voltage on a half-bridge three-level direct-current side capacitor.
In order to solve the problems, the invention adopts a flyback bus voltage balance circuit to realize the balance of the half-bridge three-level direct-current side capacitor voltage.
A single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing comprises a flyback transformer T, switching tubes S1-S10, diodes D1-D10 and D01, D11-D15, capacitors C1-C3 and inductors L1 and L2; the method is characterized in that:
The right end of the inductor L1, the upper end of the switch tube S1, the cathode of the diode D1 and the anode of the diode D01 are connected with each other,
The lower end of the switch tube S1, the anode of the diode D1, the upper end of the switch tube S2, the cathode of the diode D2 and the upper end of the primary side of the flyback transformer T are mutually connected,
The lower end of the primary side of the flyback transformer T, the lower end of the switching tube S2, the anode of the diode D11, the lower end of the capacitor C2, the lower end of the switching tube S6 and the anode of the diode D6 are mutually connected,
The upper end of the negative side of the flyback transformer T is connected with the anode of a diode D13,
The cathode of the diode D13, the left end of the switching tube S7, the left end of the switching tube S8, the cathode of the diode D7 and the cathode of the diode D8 are connected to each other,
The right end of the switching tube S7, the anode of the diode D7 and the anode of the diode D12 are connected to each other,
The right end of the switch tube S8, the anode of the diode D8, the lower end of the capacitor C1, the upper end of the capacitor C2, the right end of the switch tube S9, the cathode of the diode D9, the anode of the diode D14 and the cathode of the diode D15 are connected with each other and grounded,
The lower end of the negative side of the flyback transformer T, the left end of the switching tube S9, the left end of the switching tube S10, the anode of the diode D9 and the anode of the diode D10 are connected with each other,
The right end of the switching tube S10, the cathode of the diode D10 and the cathode of the diode D11 are connected to each other,
The upper end of the capacitor C1, the cathode of the diode D12, the cathode of the diode D01, the upper end of the switching tube S3 and the cathode of the diode D3 are connected to each other,
The lower end of the switching tube S3, the anode of the diode D3, the cathode of the diode D14, the upper end of the switching tube S4 and the cathode of the diode D4 are connected to each other,
The lower end of the switch tube S4, the anode of the diode D4, the left end of the inductor L2, the upper end of the switch tube S5 and the cathode of the diode D5 are connected with each other,
The lower end of the switching tube S5, the anode of the diode D15, the upper end of the switching tube S6 and the cathode of the diode D6 are connected to each other,
The right end of the inductor L2 is connected to the upper end of the capacitor C3,
The lower end of the capacitor C3 is grounded.
The switching tubes S3-S6, the diodes D3-D6, the diodes D14 and D15, the inductor L2 and the capacitor C3 are connected in the way described above to form a half-bridge inverter circuit; the switching tubes S1 and S2 and S7-S10, the diodes D1 and D2 and D7-D10, the diodes D01 and D11-D13, the inductor L1 and the flyback transformer T form a boost circuit together, and in the boost circuit, the switching tubes S2 and S7-S10, the diodes D2 and D7-D10, the diodes D01 and D11-D13 and the flyback transformer T form a flyback bus voltage balance circuit.
When the photovoltaic power generation device is used, the left end of the inductor L1 and the lower end of the primary side of the flyback transformer T are respectively connected with the anode and the cathode of the photovoltaic panel, and the right end of the inductor L2 and the lower end of the capacitor C3 are respectively connected with the anode and the cathode of a load.
The single-phase three-level half-bridge inverter comprises a flyback bus voltage balance circuit and a half-bridge inverter circuit, wherein the input side of the half-bridge inverter is connected with a photovoltaic solar cell array, and the output side of the half-bridge inverter is connected with a load. Four switching tubes S7-S10 in the flyback bus voltage balancing circuit are switched by zero crossing of power frequency power grid voltage, direct current side capacitor voltage is alternately balanced at Vin/2, the service lives of the capacitors and the switching tubes are prolonged, and the reliability of the system is improved.
The invention has the beneficial effects that: (1) Four switching tubes in the flyback bus voltage balance circuit work in a low-frequency environment, so that the electromagnetic interference is small, and the switching loss is small; (2) Through the alternate work of the switch, the direct-current side capacitor voltage is balanced, and the direct-current voltage utilization rate and the service life of the capacitor and the switch tube are greatly improved; (3) The stable voltage on the bus capacitor is beneficial to the realization of Maximum Power Point Tracking (MPPT), so that the power generation efficiency of solar energy is maximized; and (4) the circuit structure is simple and easy to realize.
Drawings
Fig. 1 is a circuit topology schematic of a single-phase three-level half-bridge inverter of the present invention.
Fig. 2 is a schematic diagram showing the compensation loop of the flyback bus voltage balancing circuit when the voltage of the capacitor C1 is pulled down.
Fig. 3 is a schematic diagram showing the compensation loop of the flyback bus voltage balancing circuit when the voltages of the capacitor C1 and the capacitor C2 are not pulled down.
Fig. 4 is a schematic diagram showing the compensation loop of the flyback bus voltage balancing circuit when the voltage of the capacitor C2 is pulled down.
In the figure, 1 is a photovoltaic panel, 2 is a booster circuit, 3 is a half-bridge inverter circuit, and 4 is a load; wherein S1-S10 are switching tubes, D01, D11-D15 are diodes, L1, L2 are inductors, C1-C3 are capacitors, D1-D10 are diodes, rload is a load, and T is a flyback transformer.
Detailed Description
According to the connection circuit shown in fig. 1, the inverter in the scheme comprises a flyback bus voltage balance circuit and a half-bridge inverter circuit, in the flyback bus voltage balance circuit, two ends of a switching tube S2 are connected with two ends of a primary side of a flyback transformer T, one end of a switching tube S8 is connected with a bridge arm midpoint formed by a first capacitor C1 and a second capacitor C2, and one end of a switching tube S9 is connected with a bridge arm midpoint formed by the first capacitor C1 and the second capacitor C2; the upper end of the negative side of the flyback transformer T is connected with the anode of a diode D13, the cathode of the diode D13 is connected with a switching tube S7 and a switching tube S8, the switching tube S7 is connected with the anode of a diode D12, the cathode of the diode D12 is connected with the upper end of a capacitor C1, and the lower end of the negative side of the flyback transformer T is connected with a switching tube S9 and a switching tube S10.
Working principle analysis:
(1) FIG. 2 is a schematic diagram showing a compensation loop of a flyback bus voltage balance circuit when the voltage of the capacitor C1 is pulled down, namely V c1 is smaller than E/2-delta, and meanwhile, a switching tube S1 in the flyback bus voltage balance circuit normally works according to the boosting principle and also serves as a primary side main switching tube for flyback; the switching tube S2 is disconnected, the switching tube S7 and the switching tube S9 are conducted, the switching tube S8 and the switching tube S10 are disconnected, and the capacitor C1 is charged.
(2) FIG. 3 is a schematic diagram showing a compensation loop of the flyback bus voltage balancing circuit when the voltages of the capacitor C1 and the capacitor C2 are not pulled down, namely V c1 is larger than E/2-delta, at this time, a switching tube S2 in the flyback bus voltage balancing circuit is conducted, and the switching tube S1 only works normally according to the boosting principle; the switching tubes S7, S8, S9, S10 are all turned off.
(3) FIG. 4 is a schematic diagram showing a compensation loop of the flyback bus voltage balancing circuit when the voltage of the capacitor C2 is pulled down, namely V c2 is smaller than E/2-delta, meanwhile, a switching tube S2 in the flyback bus voltage balancing circuit is disconnected, a switching tube S1 works normally according to the boosting principle, and also serves as a primary side main switching tube for flyback; the switching tube S8 and the switching tube S10 are conducted, the switching tube S7 and the switching tube S9 are disconnected, and the capacitor C2 is charged.
(4) Fig. 3 is a schematic diagram showing a compensation loop of the flyback bus voltage balancing circuit when the voltage across the capacitor C2 is greater than E/2- Δ, i.e., V c2 > E/2- Δ, at this time, the switching tube S2 in the flyback bus voltage balancing circuit is turned on, the switching tubes S7, S8, S9, S10 are all turned off, and the switching tube S1 only works normally according to the boosting principle.
(5) As the diode D11 and the diode D12 in fig. 1 play a role in preventing short circuit, firstly, when the diode D11 charges the capacitor C1 to raise its voltage when the switching tube S7 and the switching tube S9 are turned on, a closed loop formed by the upper end of the capacitor C2, the switching tube S9, the diode D10 and the lower end of the capacitor C2 is prevented from being short-circuited, so that the diode D11 is designed to avoid forming a loop short circuit; secondly, the diode D12 also plays a role of preventing short circuit, and firstly, when the diode D12 charges the capacitor C2 to raise the voltage when the switching tube S8 and the switching tube S10 are turned on, a closed loop formed by the lower end of the capacitor C1, the switching tube S8, the diode D7 and the upper end of the capacitor C1 is prevented from being short-circuited, so that the diode D11 is designed to avoid forming a loop short circuit.
Claims (2)
1. A single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing comprises a flyback transformer T, a switching tube S1, a switching tube S2, a switching tube S3, a switching tube S4, a switching tube S5, a switching tube S6, a switching tube S7, a switching tube S8, a switching tube S9, a switching tube S10, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a diode D6, a diode D7, a diode D8, a diode D9, a diode D10, a diode D01, a diode D11, a diode D12, a diode D13, a diode D14, a diode D15, a capacitor C1, a capacitor C2, a capacitor C3, an inductor L1 and an inductor L2; the method is characterized in that:
The right end of the inductor L1, the upper end of the switch tube S1, the cathode of the diode D1 and the anode of the diode D01 are connected with each other,
The lower end of the switch tube S1, the anode of the diode D1, the upper end of the switch tube S2, the cathode of the diode D2 and the upper end of the primary side of the flyback transformer T are mutually connected,
The lower end of the primary side of the flyback transformer T, the lower end of the switching tube S2, the anode of the diode D11, the lower end of the capacitor C2, the lower end of the switching tube S6 and the anode of the diode D6 are mutually connected,
The upper end of the negative side of the flyback transformer T is connected with the anode of a diode D13,
The cathode of the diode D13, the left end of the switching tube S7, the left end of the switching tube S8, the cathode of the diode D7 and the cathode of the diode D8 are connected to each other,
The right end of the switching tube S7, the anode of the diode D7 and the anode of the diode D12 are connected to each other,
The right end of the switch tube S8, the anode of the diode D8, the lower end of the capacitor C1, the upper end of the capacitor C2, the right end of the switch tube S9, the cathode of the diode D9, the anode of the diode D14 and the cathode of the diode D15 are connected with each other and grounded,
The lower end of the negative side of the flyback transformer T, the left end of the switching tube S9, the left end of the switching tube S10, the anode of the diode D9 and the anode of the diode D10 are connected with each other,
The right end of the switching tube S10, the cathode of the diode D10 and the cathode of the diode D11 are connected to each other,
The upper end of the capacitor C1, the cathode of the diode D12, the cathode of the diode D01, the upper end of the switching tube S3 and the cathode of the diode D3 are connected to each other,
The lower end of the switching tube S3, the anode of the diode D3, the cathode of the diode D14, the upper end of the switching tube S4 and the cathode of the diode D4 are connected to each other,
The lower end of the switch tube S4, the anode of the diode D4, the left end of the inductor L2, the upper end of the switch tube S5 and the cathode of the diode D5 are connected with each other,
The lower end of the switching tube S5, the anode of the diode D15, the upper end of the switching tube S6 and the cathode of the diode D6 are connected to each other,
The right end of the inductor L2 is connected to the upper end of the capacitor C3,
The lower end of the capacitor C3 is grounded.
2. The single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing according to claim 1, wherein: the connection is wire connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710555080.0A CN107134938B (en) | 2017-07-10 | 2017-07-10 | Single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710555080.0A CN107134938B (en) | 2017-07-10 | 2017-07-10 | Single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107134938A CN107134938A (en) | 2017-09-05 |
| CN107134938B true CN107134938B (en) | 2024-05-10 |
Family
ID=59737426
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710555080.0A Active CN107134938B (en) | 2017-07-10 | 2017-07-10 | Single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107134938B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111769756B (en) * | 2020-07-10 | 2023-11-07 | 上海交通大学 | Single-phase half-bridge type multi-level inverter with double alternating current ports and construction and debugging method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102403920A (en) * | 2011-11-16 | 2012-04-04 | 广东易事特电源股份有限公司 | Three-level half-bridge photovoltaic grid connected inverter |
| CN103701355A (en) * | 2013-12-18 | 2014-04-02 | 南京航空航天大学 | Control system of NPC (Neutral Point Clamped) tri-level half-bridge inverter and voltage sharing control method |
| CN207200598U (en) * | 2017-07-10 | 2018-04-06 | 南昌航空大学 | A kind of single-phase tri-level half-bridge inverter that can realize capacitor voltage equalizing |
-
2017
- 2017-07-10 CN CN201710555080.0A patent/CN107134938B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102403920A (en) * | 2011-11-16 | 2012-04-04 | 广东易事特电源股份有限公司 | Three-level half-bridge photovoltaic grid connected inverter |
| CN103701355A (en) * | 2013-12-18 | 2014-04-02 | 南京航空航天大学 | Control system of NPC (Neutral Point Clamped) tri-level half-bridge inverter and voltage sharing control method |
| CN207200598U (en) * | 2017-07-10 | 2018-04-06 | 南昌航空大学 | A kind of single-phase tri-level half-bridge inverter that can realize capacitor voltage equalizing |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107134938A (en) | 2017-09-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7440300B2 (en) | Transformerless power conversion circuit for grid-connected power generation systems | |
| CN107370392B (en) | Electric power electric transformer towards mesohigh intelligent distribution network | |
| WO2012010053A1 (en) | Transformer-less static synchronous compensator (statcom) topological structure based on modular multilevel converter (mmc) | |
| US20130038130A1 (en) | Dc-to-ac converter system and dc-to-ac converter circuit | |
| CN102005957A (en) | Single-power supply cascade multi-level converter | |
| WO2018171767A1 (en) | Five-level low-common-mode leakage current single-phase photovoltaic grid-connected inverter and photovoltaic grid-connected system | |
| CN101394091B (en) | Voltage feedback single-stage power factor calibrating circuit | |
| CN105978376A (en) | Grid-connected inverter circuit and control method thereof | |
| CN105119516A (en) | Quasi Z-source inverter with high boost gain | |
| CN110350816B (en) | Single-stage single-phase current type inverter with energy storage inductor connected with active buffer circuit in parallel | |
| CN102496932A (en) | Parallel voltage sag compensation device | |
| CN201966811U (en) | Buck power electronics transformer used for network distribution | |
| CN113726136B (en) | conversion device | |
| CN210405078U (en) | Three-phase multiple power frequency isolation type photovoltaic grid-connected inverter | |
| CN105186900A (en) | Five-level transformerless inverter circuit | |
| CN107134938B (en) | Single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing | |
| CN110061645B (en) | High-voltage flexible direct-current device with reduced capacitance | |
| CN204696953U (en) | A kind of Z-source inverter being applicable to photovoltaic generation | |
| CN101895205A (en) | Transducer | |
| CN105429452A (en) | Common-mode rejection dual-Boost bridgeless PFC converter | |
| CN207200598U (en) | A kind of single-phase tri-level half-bridge inverter that can realize capacitor voltage equalizing | |
| CN104539180A (en) | Single-phase transformer-free inverter capable of reducing system leak current | |
| Chandra et al. | A Review on Single-Phase Transformerless Inverter Topologies for PV Applications | |
| CN209250496U (en) | Bidirectional, dc conversion circuit | |
| CN112994500A (en) | Single-stage single-phase asymmetric full-bridge 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |