CN208797827U - A kind of micro- inverter ac side power coupling circuit of six switches - Google Patents
A kind of micro- inverter ac side power coupling circuit of six switches Download PDFInfo
- Publication number
- CN208797827U CN208797827U CN201821733232.8U CN201821733232U CN208797827U CN 208797827 U CN208797827 U CN 208797827U CN 201821733232 U CN201821733232 U CN 201821733232U CN 208797827 U CN208797827 U CN 208797827U
- Authority
- CN
- China
- Prior art keywords
- switch
- switching tube
- coupling circuit
- inverter
- diode
- 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
Landscapes
- Inverter Devices (AREA)
Abstract
A kind of micro- inverter ac side power coupling circuit of six switches, is made of six switching tubes (T1-T6), six diodes (D1-D6), two coupled capacitors (Cd1, Cd2) and an inductance (L).It absorbs/releases energy according to inverter output voltage polarity and coupling circuit, power coupling circuit can be divided into four kinds of operating modes, and be operating mode 1 respectively: inverter output voltage is positive, and coupling circuit absorb energy；Operating mode 2: inverter output voltage is positive, and coupling circuit release energy；Operating mode 3: inverter output voltage is negative, and coupling circuit absorb energy；Operating mode 4: inverter output voltage is negative, and coupling circuit release energy.Power decoupling circuit is connected in parallel on the exchange outlet side of inverter by the utility model, and the circuit structure of inverter is simple, and decoupling circuit and inverter circuit can independent controls；Using the utility model proposes power coupling circuit realize power-balance, it can be achieved that no electrolytic capacitor, extends the service life of inverter.
Description
Technical field
The utility model relates to micro- inverter ac side power coupling circuits of six switch of one kind, belong to micro- inverter technology neck
Domain.
Background technique
The advantages of micro- inverter is because of its multiple electricity, easily extension, low cost, hot plug and modularized design, is increasingly becoming
The trend of the following distributed photovoltaic inverter.However, photovoltaic module generates permanent since MPPT is controlled in distributed generation system
Fixed input power, and the power of power grid is transferred to containing the power pulsations of twice of power frequency, the instantaneous value of the two is inconsistent.Therefore
The micro- inverter of tradition is all made of the balance that electrolytic capacitor realizes the instantaneous input-output power of inverter.In this way, opposite 5-10
For the semiconductor devices and passive element in ten thousand hour service life, the electrolytic capacitor service life less than 10,000 hours, becomes the micro- inversion of limitation
The key of device stability and service life.Therefore, the micro- inverter technology for studying no electrolytic capacitor, which becomes, improves micro- inverter
One of the optimal technical scheme and the important research direction of numerous scholars of energy and service life.
The so-called micro- inverter technology of no electrolytic capacitor, i.e., using the power electronics function being made of power switch and passive device
Rate coupling circuit replace traditional electrolytic capacitor to realize energy snubber function.It is big according to the difference of power coupling circuit access point
Cause is divided into direct current input side type, DC-link medial side type, exchange outlet side type and three port decoupling types, four seed type.
Direct current input side power coupling technique is commonly available to the grid-connected micro- inverter of single-stage.Tokyo, Japan founds university
Professor Shimizu etc. proposes the flyback photovoltaic combining inverter with power coupling circuit, when inverter input power is greater than defeated
Out when power, decoupling capacitance is charged by transformer primary side magnetizing inductance, when inverter input power is less than output power, solution
Coupling capacitor, which discharges, supplements energy to magnetizing inductance.Professor B.J.Pierquet etc. of Washington, DC university proposes a kind of by power
Coupling circuit are connected between photovoltaic permutation and micro- inverter, constitute the micro- inverter structure of two-stage, so convenient for individually control energy
Amount storage voltage and fluctuation, avoid using electrolytic capacitor, and maintain the idle transfer function of micro- inverter.Though however,
The right micro- inverter of single-stage only has primary structure, but the detection of the MPPT of system, isolated island and power coupling control complex, system
Step-up ratio it is low, photovoltaic DC output voltage is high, and coupling capacitance is still larger.
In multistage micro- inverter, since intermediate dc side voltage contains high voltage, therefore generally use among DC-link
The power coupling technique of side type allows DC voltage to fluctuate larger at this time in order to reduce coupling capacitance.Univ cambridge uk
G.A.J.Amaratunga etc. propose a kind of three-level knot being made of phase whole-bridging circuit, Buck circuit and full-bridge inverter
Structure miniature photovoltaic grid-connected inverter.Wherein phase whole-bridging circuit realizes boosting and MPPT function, and Buck circuit generates half-sinusoid
Electric current, afterbody circuit generate sinusoidal Injection Current.The topological structure passes through electricity different before and after synchronously control DC bus
Road, to guarantee the conservation of energy and stable busbar voltage, to realize the balance of input power and output power.
And exchanging side coupling technique is that coupled capacitor is attempted by exchange side, since its voltage is larger and is alternating voltage,
Therefore decoupling capacitance can effectively reduce.The B.S.Wang etc. that State of Arizona, US founds university proposes a kind of two-way AC/AC (alternating current) variable-frequency formula
Micro- inverter topology realizes the exchange grid-connected connection in side by the three-phase current source type current transformer that six two-way switch form, wherein two
It is mutually connect with power grid, in addition one communicates overcoupling capacitor and connect with power grid, realize two-way flow and the energy snubber of power, it can be big
It is big to reduce coupled capacitor.
It is a port in three Port Translation devices for realizing maximum power for three port power coupling techniques
Point tracking, another port realize that power decoupled, third port are realized grid-connected.Professor Hu Haibing etc. of Nanjing Aero-Space University
A kind of three port inverse-excitation type single-stage photovoltaic miniature inverters with power decoupled function are had studied, in traditional circuit of reversed excitation
On, the 3rd port constituted with one group of primary side winding is switched by increasing by one to realize power decoupled, power decoupled capacitor
It is used as power storage element simultaneously and leakage inductance energy absorbs buffer circuit, power loss can be reduced, improved efficiency.National Taiwan is big
Electric energy treatment research group it is also proposed that a kind of three port inverse-excitation type single-stage photovoltaic micro-inverters with active power coupling circuit,
The power decoupled port that bridge-type current transformer by increasing by one group of negative side winding and a four quadrant running is constituted, enormously simplifies
Exchange the Control System Design of grid-connected port.The Krein of University of Illinois, the U.S., professor P.T etc. propose a kind of exchange connection
The micro- inverter structure in three ports, one group of winding and bridge-type current transformer will be increased in transformer alternating side ports and constitute power coupling
Circuit.These three ports photovoltaic micro-inverters allow capacitance voltage and voltage ripple to have very big mention using transformer winding
Coupling capacitance can be greatly reduced in height.
Summary of the invention
The purpose of this utility model is, in order to realize the power coupling function of micro- inverter, this reality instead of electrolytic capacitor
With the novel micro- inverter ac side power coupling circuit for proposing six switch of one kind.
The technical scheme for implementing the utility model is as follows, a kind of micro- inverter ac side power coupling circuit of six switches,
It is made of six switch transistor T 1-T6, six diode D1-D6, two coupled capacitors Cd1, Cd1 and an inductance L.Wherein first
Switch transistor T 1 and first diode D1, second switch T2 and the second diode D2, third switch transistor T 3 and third diode D3,
4th switch transistor T 4 and the 4th diode D4, the 5th switch transistor T 5 and the 5th diode D5 and the 6th switch transistor T 6 and the six or two
Pole pipe D6 is inverse parallel connection；The first switch tube T1 is connected with the collector of second switch T2, third switch transistor T 3
It is connected with the emitter of the 4th switch transistor T 4, constitutes two series arms, respectively in first switch tube after this two branch circuit parallel connection
The emitter of T1 connects the second capacitor Cd2 between the collector with third switch transistor T 3；The emitter of first switch tube T1 connects
The negative terminal of second capacitor Cd2, the collector of third switch transistor T 3 connect the anode of the second capacitor Cd2；The hair of second switch T2
Emitter-base bandgap grading links together with the collector of the 4th switch transistor T 4 and connect with the upper end inductance L；The lower end connection inverter output of inductance L
Side；The parallel connection in the same direction of 5th switch transistor T 5 and the 6th switch transistor T 6；The collector of 5th switch transistor T 5 and the 6th switch transistor T 6 point
Not Lian Jie inductance upper and lower ends；The negative terminal of the emitter connection first capacitor Cd1 of 5th switch transistor T 5, the 6th switch transistor T 6
The anode of emitter connection first capacitor Cd1；
It absorbs/releases energy according to inverter output voltage polarity and coupling circuit, power coupling circuit can be divided into four
Kind operating mode, be operating mode 1 respectively: inverter output voltage is positive, and coupling circuit absorb energy；Operating mode 2: inversion
Device output voltage is positive, and coupling circuit release energy；Operating mode 3: inverter output voltage is negative, and coupling circuit absorb energy
Amount；Operating mode 4: inverter output voltage is negative, and coupling circuit release energy.
The operating mode 1, when power coupling circuit is in operating mode 1, input voltage is positive, and coupling circuit absorb energy
Amount, first capacitor Cd1 voltage increase；
First diode D1, the 5th diode D5 conducting, first switch tube T1, the shutdown of the 5th switch transistor T 5, the 4th switch
Pipe T4, third switch transistor T 3 turn off, and the 6th switch transistor T 6 conducting, second switch T2 is master switch；Adjust second switch
The energy size that coupling circuit absorb is adjusted in the drive signal duty cycle of T2, and first capacitor Cd1 voltage rises at this time；Second
When switch transistor T 2 is opened, electric current idCirculation path is negative for the n- first diode D1- second switch T2- inductance L- power supply of power supply；
When second switch T2 is disconnected, electric current idCirculation path is the 5th diode of the 6th switch transistor T 6- first capacitor Cd1- of inductance L-
D5- inductance L.
The operating mode 2, when power coupling circuit is in operating mode 2, input voltage is positive, and coupling circuit discharge energy
Amount, first capacitor Cd1 voltage reduce；
Second diode D2, the 6th diode D6 conducting, second switch T2, the shutdown of the 6th switch transistor T 6, the 4th switch
Pipe T4, third switch transistor T 3 turn off, and first switch tube T1 conducting, the 5th switch transistor T 5 is master switch；Adjust the 5th switching tube
The energy size of coupling circuit release is adjusted in the drive signal duty cycle of T5, and first capacitor Cd1 voltage declines at this time；5th opens
When pass pipe T5 is opened, electric current idCirculation path is n- 6th diode D6- inductance L-the, the five switch transistor T 5- of first capacitor Cd1 the
One capacitor Cd1 is negative；When second switch T2 is disconnected, electric current idCirculation path is the second diode of inductance L- D2- first switch tube
The n- power supply of T1- power supply bears-inductance L.
The operating mode 3, when power coupling circuit is in operating mode 3, input voltage is negative, and coupling circuit absorb energy
Amount, the second capacitor Cd2 voltage increase；
Second diode D2, third diode D3 conducting, second switch T2, third switch transistor T 3 turn off, the 5th switch
Pipe T5, the shutdown of the 6th switch transistor T 6, first switch tube T1 conducting, the 4th switch transistor T 4 are master switch；Adjust the 4th switching tube
The energy size that coupling circuit absorb is adjusted in the driving signal of T4, duty ratio, and the second capacitor Cd2 voltage increases at this time, polarity
It is consistent with input voltage, when the 4th switch transistor T 4 is opened, electric current idCirculation path is the n- 6th diode D6- of first capacitor Cd1
Four switch transistor T 4- capacitor Cd1 of inductance L-the is negative；When 4th switch transistor T 4 disconnects, electric current idCirculation path is inductance L- the two or two
The pole pipe D2- n- power supply of first switch tube T1- power supply bears-inductance L.
The operating mode 4, when power coupling circuit is in operating mode 4, input voltage is negative, and coupling circuit discharge energy
Amount, the second capacitor Cd2 voltage reduce；
First diode D1, the 4th diode D4 conducting, first switch tube T1, the shutdown of the 4th switch transistor T 4, the 5th switch
Pipe T5, the shutdown of the 6th switch transistor T 6, second switch T2 conducting, third switch transistor T 3 are master switch；Adjust third switching tube
The energy size of coupling circuit release is adjusted in the drive signal duty cycle of T3, and the second capacitor Cd2 voltage declines at this time, polarity with
Input voltage is consistent, when third switch transistor T 3 is opened, electric current idCirculation path is the n- third switch transistor T 3- of the second capacitor Cd2 the
Four diode D4- inductance L-the second capacitor Cd2 are negative, when third switch transistor T 3 disconnects, electric current idCirculation path is inductance L- power supply
Negative-n- first diode D1- second switch T2- inductance L of power supply.
The power coupling circuit parallel connection access realizes power coupling instead of electrolytic capacitor in the ac output end of inverter
Close function.
The utility model has the beneficial effects that the utility model exports the exchange that power decoupling circuit is connected in parallel on inverter
The circuit structure of side, inverter is simple, and decoupling circuit and inverter circuit can independent controls；Using the utility model proposes power
Coupling circuit realize power-balance, it can be achieved that no electrolytic capacitor, extends the service life of inverter.
Inversion unit and decoupling unit only need 10 switching tubes in total in the utility model, exchange side power decoupled with previous
Project plan comparison, power decoupled unit are integrated with inversion unit, need 6 two-way switch pipes in total, i.e., 12 are unidirectionally opened
It closes, the utility model reduces costs.
The utility model main circuit design is common two-stage type voltage-source type topology, since decoupling unit is independently of main electricity
Outside road, the circuit structure of transformation inverter is not needed.
Detailed description of the invention
Fig. 1 is six switch power decoupling circuits；
Fig. 2 is the micro- inverter structure of no electrolytic capacitor and power relation based on six switch power decoupling circuits；
Fig. 3 is that power coupling circuit absorbs energy diagram in operating mode 1；
Fig. 4 is that power coupling circuit releases energy schematic diagram in operating mode 2；
Fig. 5 is that power coupling circuit absorbs energy diagram in operating mode 3；
Fig. 6 is that power coupling circuit releases energy schematic diagram in operating mode 4；
Fig. 7 is the matlab simulation result schematic diagram of each switching pulse control；
Fig. 8 is bus capacitor voltage UdcWith input current IdcSimulation waveform；
Fig. 8 (a) is bus capacitor voltage U when decoupling circuit is not devoted oneself to workdcWith input current IdcSimulation waveform,
Bus capacitor voltage U when Fig. 8 (b) devotes oneself to work for decoupling circuitdcWith input current IdcSimulation waveform；
Fig. 9 is network voltage vg, electric current igSimulation waveform；
Fig. 9 (a) is network voltage v when decoupling circuit does not workg, electric current igSimulation waveform,
Fig. 9 (b) is network voltage v when decoupling circuit worksg, electric current igSimulation waveform；
Figure 10 is current on line side frequency analysis,
Figure 10 (a) is current on line side frequency analysis schematic diagram when decoupling circuit does not work,
Figure 10 (b) is current on line side frequency analysis schematic diagram when decoupling circuit works；
Figure 11 is decoupling circuit key waveforms；
Figure 11 (a) is decoupling capacitance voltage Ud1And Ud2Simulation waveform；
Figure 11 (b) is decoupling inductive current idWaveform；
Figure 12 is decoupling current and inverter bridge driving pulse；
In figure, T1 is first switch tube；T2 is second switch；T3 is third switching tube；T4 is the 4th switching tube；T5 is
5th switching tube；T6 is the 6th switching tube；D1 is first diode；D2 is the second diode；D3 is third diode；D4 is
Four diodes；D5 is the 5th diode；The 6th diode of D6；L is inductance；Cd1 is first capacitor；Cd1 is the second capacitor；PoFor
The output power of micro- inverter；PIFor DC side input power；PcFor the coupled power of power coupling circuit；UdcIt is straight for inverter
Flow side voltage；IdcFor inverter direct-flow side electric current；voFor inverter ac outlet side voltage；vgFor network voltage；igFor micro- inversion
To the Injection Current of power grid.
Specific embodiment
Specific embodiment of the present utility model is as shown in Figure 1.
This implements micro- inverter ac side power coupling circuits of six switch of one kind, by six switch transistor T 1-T6, six two
Pole pipe D1-D6, two coupled capacitors Cd1, Cd1 and an inductance L are constituted.Wherein first switch tube T1 and first diode D1,
Second switch T2 and the second diode D2, third switch transistor T 3 and third diode D3, the 4th switch transistor T 4 and the four or two pole
Pipe D4, the 5th switch transistor T 5 are that inverse parallel connects with the 5th diode D5 and the 6th switch transistor T 6 with the 6th diode D6；
The first switch tube T1 is connected with the collector of second switch T2, the emitter of third switch transistor T 3 and the 4th switch transistor T 4
It is connected, two series arms is constituted, respectively in the emitter of first switch tube T1 with third switching tube after this two branch circuit parallel connections
The second capacitor Cd2 is connected between the collector of T3；The emitter of first switch tube T1 connects the negative terminal of the second capacitor Cd2, third
The collector of switch transistor T 3 connects the anode of the second capacitor Cd2；The collection of the emitter of second switch T2 and the 4th switch transistor T 4
Electrode links together to be connect with the upper end inductance L；The lower end of inductance L connects inverter outlet side；5th switch transistor T 5 and the 6th
The parallel connection in the same direction of switch transistor T 6；The collector of 5th switch transistor T 5 and the 6th switch transistor T 6 is separately connected the upper and lower ends of inductance；
The negative terminal of the emitter connection first capacitor Cd1 of 5th switch transistor T 5, the emitter of the 6th switch transistor T 6 connect first capacitor Cd1
Anode.Only when concatenated two switching tubes are turned off, series arm is just fully disconnected.By to two series arms
Adjustable inductance L is controlled to the charging route of capacitor, to change the equivalent circuit of power coupling circuit, realizes the slow of energy
Punching.
The micro- inverter structure of no electrolytic capacitor and power relation based on six switch power decoupling circuits as shown in Fig. 2,
Micro- inverter is mainly made of inverter and power coupling circuit in figure.Inverter uses common voltage source inverter structure,
Power decoupling circuit uses the circuit structure of the utility model, and power decoupling circuit is connected in parallel with inverter ac outlet side,
Inductance L and capacitor C is filter inductance and capacitor.U in figuredcFor DC side voltage of converter, IdcFor inverter direct-flow side electric current, vo
For inverter ac outlet side voltage, vgFor network voltage, igIt is micro- inversion to the Injection Current of power grid.PIFor DC side input
Power is invariable；PoFor the output power of micro- inverter, average value and PIIt is equal in magnitude, but export instantaneous power
For sinusoidal variations, frequency is 2 times of mains frequency；PcFor the coupled power of power coupling circuit.Therefore, DC side input work
Rate is power coupling circuit realization power that is unbalanced, being proposed using the utility model benefit with inverter output power instantaneous value
Balance is, it can be achieved that no electrolytic capacitor, extends the service life of inverter.
It absorbs/releases energy according to inverter output voltage polarity and coupling circuit, power coupling circuit can be divided into four
Kind operating mode, be operating mode 1 respectively: inverter output voltage is positive, and coupling circuit absorb energy；Operating mode 2: inversion
Device output voltage is positive, and coupling circuit release energy；Operating mode 3: inverter output voltage is negative, and coupling circuit absorb energy
Amount；Operating mode 4: inverter output voltage is negative, and coupling circuit release energy.
The operating mode 1, when power coupling circuit is in operating mode 1, input voltage is positive, and coupling circuit absorb energy
Amount, first capacitor Cd1 voltage increase, and equivalent circuit and current flow paths are as shown in Figure 3.
As shown in figure 3, first diode D1, the 5th diode D5 are connected, first switch tube T1, the 5th switch transistor T 5 are closed
Disconnected, the 4th switch transistor T 4, third switch transistor T 3 turn off, and the 6th switch transistor T 6 conducting, second switch T2 is master switch；It adjusts
The energy size that coupling circuit absorb is adjusted, at this time first capacitor Cd1 voltage in the drive signal duty cycle of second switch T2
Rise；When second switch T2 is opened, electric current idCirculation path is the n- first diode D1- second switch T2- inductance of power supply
L- power supply is negative；When second switch T2 is disconnected, electric current idCirculation path is the 6th switch transistor T 6- first capacitor Cd1- of inductance L- the
Five diode D5- inductance L.Since input and output voltage is contrary, then its equivalent operation circuit is buck-boost circuit.
The operating mode 2, when power coupling circuit is in operating mode 2, input voltage is positive, and coupling circuit discharge energy
Amount, first capacitor Cd1 voltage reduce, and equivalent circuit and current flow paths are as shown in Figure 4.
As shown in figure 4, the second diode D2, the 6th diode D6 are connected, second switch T2, the 6th switch transistor T 6 are closed
Disconnected, the 4th switch transistor T 4, third switch transistor T 3 turn off, and first switch tube T1 conducting, the 5th switch transistor T 5 is master switch；It adjusts
The energy size of coupling circuit release is adjusted in the drive signal duty cycle of 5th switch transistor T 5, at this time first capacitor Cd1 voltage
Decline；When 5th switch transistor T 5 is opened, electric current idCirculation path is the n- 6th diode D6- inductance L-the five of first capacitor Cd1
Switch transistor T 5- first capacitor Cd1 is negative；When second switch T2 is disconnected, electric current idCirculation path is the second diode of inductance L- D2-
The n- power supply of first switch tube T1- power supply bears-inductance L.Since input and output voltage is contrary, then its equivalent operation circuit
For buck-boost circuit.
The operating mode 3, when power coupling circuit is in operating mode 3, input voltage is negative, and coupling circuit absorb energy
Amount, the second capacitor Cd2 voltage increase, and equivalent circuit and current flow paths are as shown in Figure 5.
As shown in figure 5, the second diode D2, third diode D3 are connected, second switch T2, third switch transistor T 3 are closed
Disconnected, the 5th switch transistor T 5, the shutdown of the 6th switch transistor T 6, first switch tube T1 conducting, the 4th switch transistor T 4 is master switch；It adjusts
The energy size that coupling circuit absorb is adjusted in the driving signal of 4th switch transistor T 4, duty ratio, at this time the second capacitor Cd2 voltage
It increases, polarity is consistent with input voltage, is equivalent to Boost circuit.When 4th switch transistor T 4 is opened, electric current idCirculation path is
N- 6th diode D6- inductance L-the, the four switch transistor T 4- capacitor Cd1 of first capacitor Cd1 is negative；When 4th switch transistor T 4 disconnects, electricity
Flow idCirculation path is that the second diode of inductance L- D2- n- power supply of first switch tube T1- power supply bears-inductance L.
The operating mode 4, when power coupling circuit is in operating mode 4, input voltage is negative, and coupling circuit discharge energy
Amount, the second capacitor Cd2 voltage reduce, and equivalent circuit and current flow paths are as shown in Figure 6.
As shown in fig. 6, first diode D1, the 4th diode D4 are connected, first switch tube T1, the 4th switch transistor T 4 are closed
Disconnected, the 5th switch transistor T 5, the shutdown of the 6th switch transistor T 6, second switch T2 conducting, third switch transistor T 3 is master switch；It adjusts
The energy size of coupling circuit release is adjusted in the drive signal duty cycle of third switch transistor T 3, at this time the second capacitor Cd2 voltage
Decline, polarity is consistent with input voltage, is equivalent to Buck circuit.When third switch transistor T 3 is opened, electric current idCirculation path is
N- the 4th diode D4- inductance L-the second capacitor Cd2 of third switch transistor T 3- of second capacitor Cd2 is negative, and third switch transistor T 3 disconnects
When, electric current idCirculation path is that inductance L- power supply bears the-n- first diode D1- second switch T2- inductance L of power supply.
In conclusion the state of each switch under every kind of operating mode is as shown in table 1.
The switch state table of each operating mode of table 1
| T1 | T2 | T3 | T4 | T5 | T6 | |
| Mode 1 | 0 | 1/0 | 0 | 0 | 0 | 1 |
| Mode 2 | 1 | 0 | 0 | 0 | 1/0 | 0 |
| Mode 3 | 1/0 | 0 | 0 | 1 | 0 | 0 |
| Mode 4 | 0 | 1 | 1/0 | 0 | 0 | 0 |
Illustrate under each operating mode in table, only one switch is in controllable state, and rest switch is then kept fixed
State.Each switch state is absorbed or is released energy related with network voltage polarity, decoupling circuit.
Fig. 7 show the control signal waveforms of the 6th switch transistor T 6 of first switch tube T1- in a grid cycle.
It for operating mode 1, is worked under Boost mode at this time, T2 is absorbed as master switch control decoupling circuit
Energy, T1, T3, T4, T5 are in an off state at this time, and T6 is in the conductive state.It is controlled by each switching pulse of Figure 11 imitative
True result can be seen that formula (1) switching logic formula meets the requirement of operating mode A.By the work of simulation result and circuit topology
Mode 2, operating mode 3, the switch state of operating mode 4 gradually check analysis it can be found that each operating mode lower switch pipe
Work is consistent with theory analysis.
For verifying above-mentioned theory analysis, emulation is carried out to circuit operation principle in the system of 500W with MATLAB software and is tested
Card designs rated output power 500W, DC input voitage 360V, decoupling capacitance average voltage 485V, amplitude 200V, according to formula
(1) can calculate required capacitor is 16uF
In formula (1), ω indicates electrical network angular frequency, UavIndicate decoupling capacitance average voltage, △ U=UH-UL, indicate decoupling
Capacitance voltage ripple amplitude.Other simulation parameters are as shown in table 2.
2 simulation parameter of table
| Circuit parameter | Symbol | Reference value | Circuit parameter | Symbol | Reference value | |
| Rated power | Pn | 500W | Decoupling capacitance 2 | Cd2 | 16uF | |
| Input voltage | Uin | 100V | Filter inductance | Lf | 20mF | |
| Busbar voltage | Udc | 360V | Output frequency | f | 50Hz | |
| Bus capacitor | Cb | 70uF | Boost switching frequency | fb | 50KHz | |
| Decoupling circuit inductance | Ld | 100uH | H bridge switch frequency | fH | 20KHz | |
| Decoupling capacitance 1 | Cd1 | 16uF | Decoupling circuit switching frequency | fd | 20KHz |
When Fig. 8 (a) is that decoupling circuit is not devoted oneself to work, inverter bus capacitor voltage UdcWith input current Idc, voltage
Secondary ripple wave is up to 130V, input current secondary ripple wave about 3A；Bus capacitor electricity when Fig. 8 (b) devotes oneself to work for decoupling circuit
Pressure and input current, voltage secondary ripple wave are only 20V, input current secondary ripple wave about 1.2A.Decoupling circuit is to two in this programme
Secondary Ripple Suppression significant effect, stable input current are conducive to improve the tracking performance of MPPT, promote photovoltaic utilization rate, stablize
Bus current advantageously reduce grid-connected current THD.
Fig. 9 is voltage on line side v when decoupling circuit does not work and works respectivelygWith current waveform ig, grid-connected electricity in two width figures
Stream and network voltage all keep same-phase.Slight distortion occurs for grid-connected current when decoupling circuit does not work in Fig. 9 (a)；Fig. 9 (b)
When middle decoupling circuit works, grid-connected current waveform is good.
Figure 10 is the THD of grid-connected current, and when Figure 10 (a) decoupling circuit does not work, grid-connected current THD is 9.86%；Figure 10
(b) grid-connected current THD is 4.04% in, less than 5%, meets Grid-connection standards.
Figure 11 (a) is decoupling capacitance voltage Ud1, Ud2Simulation waveform, decoupling capacitance Cd1, Cd2Half of power frequency week of each work
Phase；Figure 11 (b) is decoupling inductive current idSimulation waveform, black envelope indicate decoupling inductive current peak given value Idref,
Near voltage zero-crossing point of power grid moment (t=0.01K, K=0,1,2 ...), in remaining time, inductive current just reaches substantially
IdrefDecline again, because of the characteristics of being modulated according to SPWM, the pulsewidth of inverter bridge driving pulse presses sinusoidal variations, and inverter bridge is each
There is pulsewidth decision in the time be connected in switch periods, and the pulsewidth of the inverter bridge driving pulse near voltage over zero is
tpulse=maTssin(0.01ωK+τ) (2)
In formula (2), maIt is modulation degree, TsConverter bridge switching parts frequency, τ indicate voltage zero-cross point moment to it is neighbouring any when
The time difference at quarter, τ is minimum, so t near voltage over zeropulseVery small, decoupling circuit possibly can not during this period of time delay
Enough energy are rushed, but from Fig. 8,9 effect is seen, this influence to decoupling circuit performance is very small.Figure 12 display understands
Relationship between coupling inductive current and inverter driving moving pulse, when decoupling circuit realization is full decoupled, decoupling inductive current can be first
Drop to zero before the driving pulse of inverter bridge terminates.
Claims (6)
1. micro- inverter ac side power coupling circuit of six switch of one kind, which is characterized in that the power coupling circuit is by six
A switching tube, six diodes, two coupled capacitors and an inductance are constituted；The first switch tube and first diode, the
Two switching tubes and the second diode, third switching tube and third diode, the 4th switching tube and the 4th diode, the 5th switching tube
It is that inverse parallel connects with the 5th diode and the 6th switching tube and the 6th diode；The first switch tube and second switch
The collector of pipe is connected, and third switching tube is connected with the emitter of the 4th switching tube, constitutes two series arms, this two branches
The second capacitor is connected between the collector in the emitter of first switch tube with third switching tube respectively after parallel connection；First switch tube
Emitter connect the negative terminal of the second capacitor, the collector of third switching tube connects the anode of the second capacitor；Second switch
Emitter links together with the collector of the 4th switching tube and connect with inductance upper end；The lower end connection inverter output of inductance
Side；The parallel connection in the same direction of 5th switching tube and the 6th switching tube；The collector of 5th switching tube and the 6th switching tube is separately connected electricity
The upper and lower ends of sense；The negative terminal of the emitter connection first capacitor of 5th switching tube, the emitter connection first of the 6th switching tube
The anode of coupled capacitor；
It absorbs/releases energy according to inverter output voltage polarity and coupling circuit, power coupling circuit is divided into four kinds of work
Mode: being respectively operating mode 1, operating mode 2, operating mode 3 and operating mode 4.
2. a kind of micro- inverter ac side power coupling circuit of six switch according to claim 1, which is characterized in that institute
Operating mode 1 is stated, when power coupling circuit is in operating mode 1, input voltage is positive, and coupling circuit absorb energy, the first coupling
Capacitance voltage is closed to increase；
First diode, the 5th diode current flow, first switch tube, the shutdown of the 5th switching tube, the 4th switching tube, third switching tube
Shutdown, the conducting of the 6th switching tube, second switch is master switch；The drive signal duty cycle of second switch is adjusted, it is adjustable
The energy size that coupling circuit absorb is saved, the first coupled capacitor voltage rises at this time；When second switch is opened, current flowing road
Diameter is negative for the n- first diode-second switch-inductance-power supply of power supply；When second switch disconnects, current flow paths are
Six the-the five diodes of the-the first coupled capacitor of switching tube of inductance-the-inductance.
3. a kind of micro- inverter ac side power coupling circuit of six switch according to claim 1, which is characterized in that institute
Operating mode 2 is stated, when power coupling circuit is in operating mode 2, input voltage is positive, and coupling circuit release energy, the first coupling
Closing capacitance voltage reduces；
Second diode, the 6th diode current flow, second switch, the shutdown of the 6th switching tube, the 4th switching tube, third switching tube
Shutdown, first switch tube conducting, the 5th switching tube are master switch；The drive signal duty cycle for adjusting the 5th switching tube is adjustable
The energy size of coupling circuit release, the first coupled capacitor voltage declines at this time；When 5th switching tube is opened, current flow paths
It is negative for n- six diodes-inductance the-the first coupled capacitor of the-the five switching tube of the first coupled capacitor；When second switch disconnects,
Current flow paths are that the-the second diode of inductance-first switch tube-n- power supply of power supply bears-inductance.
4. a kind of micro- inverter ac side power coupling circuit of six switch according to claim 1, which is characterized in that institute
Operating mode 3 is stated, when power coupling circuit is in operating mode 3, input voltage is negative, and coupling circuit absorb energy, the second coupling
Capacitance voltage is closed to increase；
Two or two pole, third diode current flow, second switch, the shutdown of third switching tube, the 5th switching tube, the 6th switching tube close
Disconnected, first switch tube conducting, the 4th switching tube is master switch；The driving signal of the 4th switching tube is adjusted, duty ratio is adjustable
The energy size that coupling circuit absorb, the second coupled capacitor voltage increases at this time, and polarity is consistent with input voltage, the 4th switching tube
When opening, current flow paths are negative for n- the-the four switching tubes of the six diodes-inductance-coupled capacitor of the first coupled capacitor；The
When four switching tubes disconnect, current flow paths are that the-the second diode of inductance-first switch tube-n- power supply of power supply bears-inductance.
5. a kind of micro- inverter ac side power coupling circuit of six switch according to claim 1, which is characterized in that institute
Operating mode 4 is stated, when power coupling circuit is in operating mode 4, input voltage is negative, and coupling circuit release energy, the second coupling
Closing capacitance voltage reduces；
First diode, the 4th diode current flow, first switch tube, the shutdown of the 4th switching tube, the 5th switching tube, the 6th switching tube
Shutdown, second switch conducting, third switching tube are master switch；The drive signal duty cycle for adjusting third switching tube is adjustable
The energy size of coupling circuit release, the second coupled capacitor voltage declines at this time, and polarity is consistent with input voltage, third switching tube
When opening, current flow paths are n- the-the four diodes of third switching tube of the second coupled capacitor-the-the second coupled capacitor of inductance
Negative, when third switching tube disconnects, current flow paths are that inductance-power supply bears the-n- first diode-second switch-electricity of power supply
Sense.
6. a kind of micro- inverter ac side power coupling circuit of six switch according to claim 1, which is characterized in that institute
Power coupling circuit parallel connection access is stated in the ac output end of inverter, realizes that power couples function instead of electrolysis coupling capacitor
Energy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821733232.8U CN208797827U (en) | 2018-10-24 | 2018-10-24 | A kind of micro- inverter ac side power coupling circuit of six switches |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821733232.8U CN208797827U (en) | 2018-10-24 | 2018-10-24 | A kind of micro- inverter ac side power coupling circuit of six switches |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208797827U true CN208797827U (en) | 2019-04-26 |
Family
ID=66212186
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821733232.8U Active CN208797827U (en) | 2018-10-24 | 2018-10-24 | A kind of micro- inverter ac side power coupling circuit of six switches |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN208797827U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109450239A (en) * | 2018-10-24 | 2019-03-08 | 华东交通大学 | A kind of micro- inverter ac side power coupling circuit of six switches |
-
2018
- 2018-10-24 CN CN201821733232.8U patent/CN208797827U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109450239A (en) * | 2018-10-24 | 2019-03-08 | 华东交通大学 | A kind of micro- inverter ac side power coupling circuit of six switches |
| CN109450239B (en) * | 2018-10-24 | 2023-10-27 | 华东交通大学 | Six-switch micro-inverter alternating-current side power coupling circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106655853B (en) | A kind of three-level inverter | |
| CN102005958B (en) | Photovoltaic grid-connected three-level inverter | |
| CN106301042B (en) | A kind of seven electrical level inverters | |
| CN108702104A (en) | Five-electrical level inverter topological circuit and three-phase five-level inverter topological circuit | |
| CN106169885B (en) | A kind of switch of tandem type six multi-electrical level inverter | |
| CN110086360A (en) | A kind of five level high efficiency rectifiers | |
| Dreher et al. | Comparison of H-bridge single-phase transformerless PV string inverters | |
| CN102447396A (en) | Transformer with high set-up ratio, solar inverter and solar battery system | |
| Satyanarayana et al. | Analysis and design of solar photo voltaic grid connected inverter | |
| CN109194175A (en) | A kind of non-isolated grid-connected inverter circuit of type leakage current and control method altogether | |
| CN113328649A (en) | Conversion circuit and control method thereof | |
| CN208797827U (en) | A kind of micro- inverter ac side power coupling circuit of six switches | |
| CN105099248A (en) | Double-input single-phase inverter | |
| CN106208131B (en) | Multilevel Inverters topological structure for new energy access and active distribution network | |
| CN109450239A (en) | A kind of micro- inverter ac side power coupling circuit of six switches | |
| CN207460024U (en) | A kind of four switch AC side power decoupling circuits | |
| CN206564546U (en) | A kind of micro- inverter ac side power coupling circuit of six switches | |
| Lai | A single-stage grid-connected pv micro-inverter based on interleaved flyback converter topology | |
| CN107508479B (en) | Four-switch alternating-current side power decoupling circuit and decoupling control method | |
| CN110299861A (en) | Boost active neutral-point-clamped type five-level converter | |
| CN106961226B (en) | Six-switch micro-inverter alternating-current side power coupling circuit | |
| CN203119788U (en) | Three-level inversion unit and photovoltaic inverter | |
| CN202475260U (en) | High step-up ratio converter, solar energy inverter and solar energy cell system | |
| CN108988675A (en) | A kind of single-phase non-isolated MOSFET gird-connected inverter | |
| CN108964502A (en) | A kind of single-phase non-isolated active clamp MOSFET inverter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |