CN214014124U - Non-overlap-time six-switch symmetrical inductor configuration current type grid-connected inverter - Google Patents

Non-overlap-time six-switch symmetrical inductor configuration current type grid-connected inverter Download PDF

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CN214014124U
CN214014124U CN202120023896.0U CN202120023896U CN214014124U CN 214014124 U CN214014124 U CN 214014124U CN 202120023896 U CN202120023896 U CN 202120023896U CN 214014124 U CN214014124 U CN 214014124U
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diode
power switch
switch tube
current
grid
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代云中
罗钟雨
代艳霞
林弘宇
刘健洋
刘勇
李泓廷
游元庆
鲁庆东
屈珣
冷云松
林虹宇
张鑫坤
彭宇峰
程健钊
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Yibin Vocational and Technical College
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Abstract

The utility model discloses a six switch symmetrical inductance configuration current type grid-connected inverter of no overlap time, the utility model discloses an inverter includes photovoltaic cell array PV, power switch pipe S1Power switch tube S2Power switch tube S3Power switch tube S4Power switch tube S5Power switch tube S6Two, twoPolar tube D1Diode D2Diode D3Diode D4Diode D5Diode D6Energy storage inductor L1Energy storage inductor L2AC filter capacitor CfAC filter inductor Lf1AC filter inductor Lf2And the electric network ug. The utility model provides a six switch symmetrical inductance configuration current type of non-overlap time are incorporated into power networks inverter topology can effectively restrain high frequency common mode and leak current.

Description

Non-overlap-time six-switch symmetrical inductor configuration current type grid-connected inverter
Technical Field
The utility model belongs to the technical field of electronic power, concretely relates to six switch symmetrical inductance configuration current type grid-connected inverter of no overlap time.
Background
The Current Source Grid-connected Inverter (CSGCI) outputs Current independent of impedance and only related to output voltage and impedance due to the constant Current characteristic of a Current Source, achieves the purpose of controlling the voltage by changing the impedance value, and has good boosting performance. In addition, the CSGCI output current can directly flow into a power grid through the filter, other additional devices are not needed for signal conversion, and the CSGCI output current has the advantages of high response speed and high power factor. The existing bridge-type symmetrical inductor configuration CSGCI circuit topology is shown in figure 1, and the inverter has a simple structure and has the characteristics of unipolar modulation, three-level output and the like, so that the inverter is widely applied. However, when the switches connected across the current source are turned off at the same time, the charging path of the current will be blocked, and a large voltage peak will be applied between the switch tubes. Therefore, in practical engineering, when the switching tubes are switched on the same bridge arm, overlapping time needs to be added between the switches. The introduction of the overlap time increases the harmonic content of the Grid-connected current, and reduces the power quality of a Grid-connected Inverter (GCI). Meanwhile, the German VDE-0126-1-1 standard specifies that the photovoltaic GCI must be cut off from the power grid within 0.3s when the leakage current amplitude is higher than 300 mA. In addition, the topology does not realize the isolation of the photovoltaic cell panel from the power grid in the follow current stage, and when unipolar modulation is adopted, common-mode voltage changes at high frequency, and leakage current is large. If the inverter is to be incorporated into a power grid, an isolation transformer needs to be added, the size and the cost of the inverter are increased, and the power density of the system is reduced.
SUMMERY OF THE UTILITY MODEL
In order to solve the great technical problem of current mode grid-connected inverter common mode leakage current, the utility model provides a six switch symmetrical inductance configuration current mode grid-connected inverter of non-overlap time. The utility model discloses can effectively restrain the high frequency common mode leakage current of dc-to-ac converter, and the leakage current satisfies VDE-0126-1-1's standard.
The utility model discloses a following technical scheme realizes:
there is not six switch symmetrical inductance configuration current type grid-connected inverter of overlap time, the utility model discloses an inverter includes photovoltaic cell array PV, power switch pipe S1Power switch tube S2Power switch tube S3Power switch tube S4Power switch tube S5Power switch tube S6Diode D1Diode D2Diode D3Diode D4Diode D5Diode D6Energy storage inductor L1Energy storage inductor L2AC filter capacitor CfAC filter inductor Lf1AC filter inductor Lf2And the electric network ug；
The positive end of the direct-current voltage of the photovoltaic cell array PV is connected with the energy storage inductor L1The one end of the energy storage inductor L1And the other end of the power switch tube S1One end of (1), power switch tube S2Is connected with one end of the power switch tube S1And the other end of the diode D1Is connected with one end of the power switch tube S2And the other end of the diode D2Is connected to one end of the diode D1And the other end of the power switch tube S3One terminal of, the said AC filter capacitor CfOne terminal of said AC filter inductor Lf1Is connected to one end of the diode D2And the other end of the diode D4One terminal of, the said AC filter capacitor CfAnother end of (1), the alternating current filter inductance Lf2Is connected with one end of the power switch tube S3And the other end of the diode D3Is connected to one end of the diode D4And the other end of the power switch tube S4Is connected with one end of the connecting rod; the AC filter inductor Lf1Is connected to the grid ugIs connected to the grid ugAnd the other end of the same and the AC filter inductor Lf2The other end of the first and second connecting rods is connected; the negative end of the direct-current voltage of the photovoltaic cell array PV is connected with the energy storage inductor L2The one end of the energy storage inductor L2And the other end of the diode D3Another end of the power switch tube S4The other end of the first and second connecting rods is connected;
the power switch tube S connected in series5And diode D5And the energy storage inductor L1Parallel connection; the power switch tube S connected in series6And diode D6And the energy storage inductor L2And (4) connecting in parallel.
The current type grid-connected inverter needs to set up the overlap time in order to prevent the problem of opening a way that appears during the change of current, and does not realize the isolation of direct current side and alternating current side during the afterflow, to this problem, the utility model discloses still through introduced two filter capacitance between two bridge arms of inverter for in the mode conversion process, need not to set up under the overlap time condition, the afterflow can be accomplished smoothly to current source inductive current, will not appear great voltage peak on the switch tube.
Specifically, the utility model discloses an inverter still includes filter capacitor C1And a filter capacitor C2；
The filter capacitor C1And the power switch tube S2Are connected in parallel;
the filter capacitor C2And the power switch tube S4Are connected in parallel.
Preferably, the utility model discloses a photovoltaic cell array PV direct current voltage positive terminal is to ground distributed capacitance is Cpv1The photovoltaic cell array PV direct-current voltage negative end-to-ground distributed capacitance is Cpv2Wherein, Cpv1＝Cpv2. The utility model discloses a photovoltaic cell array PV direct current voltage both ends have the effect of keeping apart DC power supply to ground distributed capacitance.
Preferably, the utility model discloses an energy storage inductance L1And an energy storage inductor L2The inductance values of the two capacitors are the same so as to eliminate differential mode leakage current.
Preferably, the inverter of the present invention operates in mode 1, ig>0，S1And S4Conduction, S2、S3、S5And S6Turn-off, PV-L1-S1-D1-Cf-D4-S4-L2Form a forward charging closed loop, and simultaneously Lf1-ug-Lf2-CfForm positive charging to the grid ugSupplying power; i.e. igIs the grid-connected current.
Preferably, the inverter of the present invention operates in mode 2, ig>0，S5And S6Conduction, S1、S2、S3And S4Off, L1-S5Form a follow current loop L of the positive end of the photovoltaic cell array2-S6Form a negative end follow current loop of the photovoltaic cell array, and simultaneously Lf1-ug-Lf2-CfForm a positive discharge to the grid ugSupplying power; i.e. igIs the grid-connected current.
Preferably, the inverter of the present invention operates in mode 3, ig<0，S2And S3Conduction, S1、S4、S5And S6Turn-off, PV-L1-S2-D2-Cf-S3-D3-L2Form a forward charging closed loop, and simultaneously Lf1-ug-Lf2-CfForm reverse charging to the grid ugSupplying power; i.e. igIs the grid-connected current.
Preferably, the inverter of the present invention operates in mode 4, ig<0，S5And S6Conduction, S1、S2、S3And S4Turn-off, PV-L1-S5Form a negative DC side follow current loop, and simultaneously Lf1-ug-Lf2-CfForm a positive discharge to the grid ugNegative power supply; i.e. igIs the grid-connected current.
Preferably, when the inverter of the present invention is switched between operating modes, the PV-L1-C1-D3-D4-C2-L2And forming an inductive current follow current loop in the overlapped time period.
The utility model discloses have following advantage and beneficial effect:
1. the utility model provides a six switch symmetrical inductance configuration current type of non-overlap time are incorporated into power networks inverter topology can effectively restrain high frequency common mode and leak current.
2. The utility model discloses introduced the filter capacitance who prevents that current type grid-connected inverter from opening a way between two switch tubes of two bridge arms of six switch symmetrical inductance configuration current type grid-connected inverter topological structure of non-overlap time, had and need not to set up the overlap time, advantage that grid-connected current total harmonic distortion is little.
3. The utility model discloses a high performance diode D1-D6The current flow direction can be ensured, and the current can not pass through the body diode with poorer IGBT performance, thereby improving the reliability of the inverter.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
fig. 1 is a diagram of a topology of a conventional current grid-connected inverter.
Fig. 2 is the topology structure diagram of the current source grid-connected inverter of the present invention.
Fig. 3 is a schematic diagram of the half-cycle modulation method of the present invention.
Fig. 4 is the utility model discloses a common mode equivalent circuit is simplified to current mode grid-connected inverter.
Fig. 5 shows the working mode of the current-mode grid-connected inverter of the present invention. Wherein (a) is a working mode 1; (b) working mode 2; (c) working mode 3; (d) working mode 4.
Fig. 6 is a schematic diagram of an actual driving waveform of the current-mode grid-connected inverter according to the present invention.
Fig. 7 shows the mode transition mode of the current-mode grid-connected inverter of the present invention.
FIG. 8(a) shows the dc-to-ac converter side energy storage inductor current idcA waveform diagram of (a).
Fig. 8(b) is a waveform diagram of the inverter grid-connected voltage and the grid-connected current according to the present invention.
Fig. 9 is a waveform diagram of the common mode leakage current of the inverter according to the present invention.
Detailed Description
Hereinafter, the terms "include" or "may include" used in various embodiments of the present invention indicate the existence of the functions, operations or elements of the present invention, and do not limit the addition of one or more functions, operations or elements. Furthermore, as used in various embodiments of the present invention, the terms "comprises," "comprising," "includes," "including," "has," "having" and their derivatives are intended to refer only to the particular feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combination of the foregoing.
In various embodiments of the present invention, the expression "or" at least one of a or/and B "includes any or all combinations of the words listed simultaneously. For example, the expression "a or B" or "at least one of a or/and B" may include a, may include B, or may include both a and B.
Expressions (such as "first", "second", and the like) used in various embodiments of the present invention may modify various constituent elements in various embodiments, but may not limit the respective constituent elements. For example, the above description does not limit the order and/or importance of the elements described. The foregoing description is for the purpose of distinguishing one element from another. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of various embodiments of the present invention.
It should be noted that: if it is described that one constituent element is "connected" to another constituent element, the first constituent element may be directly connected to the second constituent element, and a third constituent element may be "connected" between the first constituent element and the second constituent element. In contrast, when one constituent element is "directly connected" to another constituent element, it is understood that there is no third constituent element between the first constituent element and the second constituent element.
The terminology used in the various embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the various embodiments of the invention. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the present invention belong. The terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning that is consistent with their contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in various embodiments of the present invention.
To make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the following examples and drawings, and the exemplary embodiments and descriptions thereof of the present invention are only used for explaining the present invention, and are not intended as limitations of the present invention.
Example 1
Aiming at the technical problem that the common-mode leakage current of the topological structure of the existing current type grid-connected inverter is large, the embodiment provides a current type grid-connected inverter with six-switch symmetrical inductor configuration and without overlapping time.
Specifically, as shown in fig. 2, the inverter of the present embodiment mainly includes a photovoltaic cell array PV and a power switch tube S1Power switch tube S2Power switch tube S3Power switch tube S4Power switch tube S5Power switch tube S6Diode D1Diode D2Diode D3Diode D4Diode D5Diode D6Energy storage inductor L1Energy storage inductor L2AC filter capacitor CfAC filter inductor Lf1AC filter inductor Lf2And the electric network ugAnd (4) forming.
The positive end of the direct-current voltage of the photovoltaic cell array PV is connected with an energy storage inductor L1One end of (1), energy storage inductor L1The other end of the power switch tube S1One end of (1), power switch tube S2Is connected to a power switch tube S1Another terminal of (1) and a diode D1Is connected to a power switch tube S2Another terminal of (1) and a diode D2Is connected to one end of a diode D1The other end of the power switch tube S3One terminal of (1), AC filter capacitor CfOne terminal of (1), AC filter inductance Lf1Is connected to one end of a diode D2Another terminal of (1) and a diode D4One terminal of (1), AC filter capacitor CfAnother end of (1), AC filter inductance Lf2Is connected to a power switch tube S3Another terminal of (1) and a diode D3Is connected to one end of a diode D4The other end of the power switch tube S4Is connected with one end of the connecting rod; AC filter inductance Lf1Another end of (d) and the grid ugIs connected to the grid ugAnd the other end of the inductor L is connected with an AC filter inductor Lf2The other end of the first and second connecting rods is connected; the negative end of the direct-current voltage of the photovoltaic cell array PV is connected with an energy storage inductor L2One end of (1), energy storage inductor L2Another terminal of (1) and a diode D3Another end of (S), a power switch tube (S)4The other end of the first and second connecting rods is connected; series-connected power switching tubes S5And diode D5Is connected with the energy storage inductor L1 in parallel; series-connected power switching tubes S6And diode D6In parallel with the energy storage inductor L2.
Wherein C ispv1And Cpv2Respectively distributing capacitors to the ground for the positive terminal P and the negative terminal N of the DC voltage of the photovoltaic cell array, wherein Cpv1＝Cpv2＝Cpv；S1～S6Is a main circuit power switch tube. D1～D6Is a high performance diode. L isf1And Lf2Is a filter inductance of the AC side, L1And L2An inductor on the DC side, the function of which can be used for energy storage, CfIs a filter capacitor; u. ofgAnd igRespectively grid-connected voltage and grid-connected current; i.e. ioFor bridge arm output current；IdcIs the average current on the direct current side.
Using a half-cycle modulation method (the principle of the half-cycle modulation method is shown in fig. 3, S)1、S4、S5、S6Conducting in the positive half period, S2、S3、S5、S6Conducting in the negative half cycle. Wherein u isrBeing a unipolar triangular carrier wave, ucFor modulating the wave, f is the grid voltage frequency. At ucPositive half period of (d), urAnd ucComparison to produce S1、S4Driving signal of S2And S3Remains off, S1＝S4，
Figure BDA0002885902190000071
At ucNegative half period of (u)rAnd ucComparison to produce S2、S3Driving signal of S1And S4Remains off, S2＝S3，
Figure BDA0002885902190000072
That is, as can be seen from fig. 3, the current grid-connected inverter using half-cycle modulation has only four switching tubes for high-frequency switching in a half power cycle. During the positive half period S2And S3Remains off for a negative half period S1And S4Keeping off, which can effectively reduce the switching loss of the inverter) to analyze the working mode of the current-mode grid-connected inverter provided by the embodiment:
let igThe current from the bridge arm midpoint a to B is positive. Because two parasitic capacitances are in parallel connection, the equivalent capacitance is 2Cpv。CpvHas the function of isolating the DC power supply, so that the common-mode leakage current itcmOnly with ac sources. For eliminating differential mode leakage current1＝L2＝L。uPOAnd uNOThe voltages of the P terminal and the N terminal to the ground O point are respectively. When the DC current source pair i is not consideredtcmFig. 4 shows an equivalent model of the common mode loop of the current grid-connected inverter according to the present embodiment.
CSGCI simplified common mode equivalent circuit
Figure BDA0002885902190000081
In the formula ucmvIs the common mode voltage. As can be seen from FIG. 4 and equation (1), i in the looptcmIs a change of u from high frequencycmvAnd (4) causing.
Let igPositive from a to B. According to S in FIGS. 2 and 31～S6The current-mode grid-connected inverter of the present embodiment can be divided into the following four modes as shown in fig. 5:
mode 1:
when i isg>0，S1，S4Conduction, S2，S3，S5，S6When the current source grid-connected inverter of the present embodiment is turned off, the current source grid-connected inverter operates in mode 1, and an equivalent circuit thereof is shown in fig. 5 (a). As can be seen from FIG. 5(a), the photovoltaic cells PV, L1、S1、D1、Cf、D4、S4And L2Forming a forward charging closed loop; at the same time Lf1、ug、Lf2And CfPositive charging is formed, and power is supplied to a power grid. i.e. ig＝IdcAs can be seen from FIG. 5(a), uPO＝uAO＝ug，uNO＝u BO0. Therefore, according to the formula (1), the common mode voltage u of the mode 1 can be obtainedcmvComprises the following steps:
Figure BDA0002885902190000082
mode 2:
when i isg>0，S5，S6Conduction, S1，S2，S3，S4When the current source grid-connected inverter of the present embodiment is turned off, the current source grid-connected inverter operates in mode 2, and an equivalent circuit thereof is shown in fig. 5 (b). As can be seen from FIG. 5(b), L1、S5Forming a follow current loop at the positive end of the photovoltaic cell;L2、S6forming a negative end follow current loop of the photovoltaic cell. At the same time Lf1、ug、Lf2And CfForming positive discharge to supply power to the power grid. i.e. igAs 0, from KVL law and fig. 5 (b):
Figure BDA0002885902190000091
Figure BDA0002885902190000092
uAO＝ug uBO＝0 (5)
wherein u iss1，us2，us3And us4Respectively being a switching tube S1，S2，S3，S4Voltage stress of (d). Further, from fig. 5(b) and KVL law, it can be derived:
us1+us3+us2+us4＝0 (6)
the united type (1) and (3) to (6) can be obtained:
Figure BDA0002885902190000093
modality 3:
when i isg<0，S2，S3Conduction, S1，S4，S5，S6When the current-mode grid-connected inverter of the present embodiment is turned off, the current-mode grid-connected inverter operates in mode 3, and an equivalent circuit thereof is shown in fig. 5 (c). As can be seen from FIG. 5(c), photovoltaic cells PV and L1、S2、D2、Cf、S3、D3And L2Forming a forward charging closed loop; at the same time Lf1、ug、Lf2And CfAnd the reverse charging is formed, and power is supplied to a power grid. i.e. ig＝-IdcAs can be seen from FIG. 5(c), uPO＝uBO＝0，uNO＝uAO＝ug. Thus, according to the formula (1), u of the mode 3 can be obtainedcmvComprises the following steps:
Figure BDA0002885902190000094
modality 4:
when i isg<0，S5，S6Conduction, S1，S2，S3，S4When the current-mode grid-connected inverter of the present embodiment is turned off, the current-mode grid-connected inverter operates in the mode 4, and the equivalent circuit thereof is shown in fig. 5 (d). As can be seen from FIG. 5(d), photovoltaic cells PV and L1、S5Form a negative DC side follow current loop, and simultaneously Lf1、ug、Lf2And CfPositive discharge is formed, and negative power supply is performed to the power grid. Similar to mode 2, u of mode 4 can be obtainedcmvComprises the following steps:
Figure BDA0002885902190000101
the switching states and common mode voltages of the current-mode grid-connected inverter of the present embodiment obtained from the above are shown in table 1.
Table 1 switching state of current source grid-connected inverter of the present embodiment and u thereofcmv
Figure BDA0002885902190000102
As can be seen from Table 1, the modes 1, 2, 3, and 4 have the same ucmv＝0.5ugThe common mode voltage only contains a power grid component, and no high-frequency component exists. Therefore, the current-mode grid-connected inverter provided by the embodiment can effectively suppress the high-frequency common-mode leakage current of the inverter system while realizing three levels of output current.
Example 2
Ideally, the inverter circuit complements the drive signal S during the positive half cycle5And S1And S3Do not switch off at the same time, i.e. switch on and off at the control signalThe action has no delay after the number is sent out. In practical situations, however, the switching on and off of the switching tube cannot be accomplished instantaneously, as shown in fig. 6.
In the conversion of modality 1 to modality 2, S5And S6And S1And S3The working condition of simultaneous turn-off can appear, and the afterflow can't be accomplished to current source inductive current, can appear huge voltage peak value on the switch tube, causes the contravariant to fail and the device is burnt out. Therefore, S is to be5And S6Is delayed by a time period, i.e. the overlap time TeEnsure S1And S3After reliable opening, S5And S6Then the power is cut off, so that the commutation process is smoothly completed. The addition of the overlapping time can introduce low-order harmonic components which are difficult to filter into the grid-connected current of the current mode GCI. In addition, if the overlap time is improperly set, even the output current of the GCI is severely distorted, which makes it difficult to meet the requirement of the photovoltaic power generation on the voltage and power quality, in view of the problem, the present embodiment further introduces a filter capacitor between the two switch tubes of the two bridge arms of the topology structure of the current grid-connected inverter proposed in the above embodiment 1, so that the current source inductive current of the current grid-connected inverter can smoothly complete the follow current without setting the overlap time, and a large voltage peak will not occur on the switch tubes.
Specifically, as shown in fig. 2, the current-mode grid-connected inverter of the present embodiment further includes a filter capacitor C1And a filter capacitor C2(ii) a Filter capacitor C1And a power switch tube S2Are connected in parallel; filter capacitor C2And a power switch tube S4Are connected in parallel.
When S is5And S6Has been turned off, S2And S3When the current source grid-connected inverter is not turned on, that is, in a time period in which the overlap time needs to be set, the equivalent circuit of the current source grid-connected inverter of the present embodiment is as shown in fig. 7. The photovoltaic current source PV, L now1，C1，D3，D4，C2，L2Form an inductive current follow current loop in the overlapped time period to smoothly complete the continuation of the inductive current of the current sourceNo large voltage peaks will occur on the switching tube. High performance diode D1～D6The flow direction of the current can be ensured. Therefore, in the mode conversion process, under the condition of not setting the overlapping time, the symmetrical inductor configuration CSGCI without the overlapping time and the transformer can smoothly complete the current conversion.
Similarly, it can be seen that in the commutation process of the current-mode grid-connected inverter of the present embodiment in the negative half-cycle mode 3 and the mode 4, the commutation equivalent circuit is shown in fig. 7, and the analysis is the same as that in the positive half-cycle. Furthermore, a high performance diode D1～D6The flow direction of the current can be ensured, so that the current cannot pass through the body diode with poorer performance of the IGBT.
Therefore, the current type grid-connected inverter has the advantages of no need of setting overlapping time, small grid-connected current total harmonic distortion, high grid-connected electric energy quality and the like, and can be widely applied to application occasions with high requirements on electric energy quality and reliability, such as photovoltaic grid-connected power generation, fuel cell grid-connected power generation, uninterruptible power supplies, aerospace power supplies and the like.
Example 3
The embodiment verifies the current-mode grid-connected inverter provided by the embodiment, and specifically includes:
a circuit simulation model based on MATLAB/simulink is set up, and the output power P iswThe circuit parameters are shown in table 2, 1.7 kW.
TABLE 2 Main Circuit parameters
Parameter(s) Numerical value Parameter(s) Numerical value
Idc 8.5A CPV 75nF
Um 220V L 20mH
Cf 80uF Lf1＝Lf2 25uH
fs 5kHz Im 9A
FIG. 8(a) shows the DC side energy storage inductor current idcThe waveform of (2), is maintained at 9.2A. FIG. 8(b) shows ugAnd igCan be seen from the figure, ugAnd igKeeping the same phase ugIs about 220V, igIs about 12.5A. Therefore, the overlapping-time-free transformer-free symmetrical inductor configuration CSGCI and the controller thereof can realize stable inversion, and the system has high power factor.
FIG. 9 shows the common mode leakage current itcmCan be seen from the figure, itcmIs about 250 mA. Therefore, the analysis shows that the leakage current of the inverter can be effectively inhibited, and the VDE-0126-1-1 standard is satisfied.
The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above description is only the embodiments of the present invention, and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (4)

1. A non-overlap-time six-switch symmetrical inductance configuration current type grid-connected inverter is characterized by comprising a photovoltaic cell array PV and a power switch tube S1Power switch tube S2Power switch tube S3Power switch tube S4Power switch tube S5Power switch tube S6Diode D1Diode D2Diode D3Diode D4Diode D5Diode D6Energy storage inductor L1Energy storage inductor L2AC filter capacitor CfAC filter inductor Lf1AC filter inductor Lf2And the electric network ug；
The positive end of the direct-current voltage of the photovoltaic cell array PV is connected with the energy storage inductor L1The one end of the energy storage inductor L1And the other end of the power switch tube S1One end of (1), power switch tube S2Is connected with one end of the power switch tube S1And the other end of the diode D1Is connected with one end of the power switch tube S2And the other end of the diode D2Is connected to one end of the diode D1And the other end of the power switch tube S3One terminal of, the said AC filter capacitor CfOne terminal of said AC filter inductor Lf1Is connected to one end of the diode D2And the other end of the diode D4One terminal of, the said AC filter capacitor CfAnother end of (1), the alternating current filter inductance Lf2Is connected with one end of the power switch tube S3And the other end of the diode D3Is connected to one end of the diode D4And the other end of the power switch tube S4Is connected with one end of the connecting rod; the AC filter inductor Lf1Is connected to the grid ugIs connected to the grid ugAnd the other end of the same and the AC filter inductor Lf2The other end of the first and second connecting rods is connected; the negative end of the direct-current voltage of the photovoltaic cell array PV is connected with the energy storage inductor L2The one end of the energy storage inductor L2And the other end of the diode D3Another end of the power switch tube S4The other end of the first and second connecting rods is connected;
the power switch tube S connected in series5And diode D5The energy storage inductor L1 is connected in parallel; the power switch tube S connected in series6And diode D6And is connected with the energy storage inductor L2 in parallel.
2. The non-overlap time six-switch symmetrical inductor current grid-connected inverter as claimed in claim 1, further comprising a filter capacitor C1 and a filter capacitor C2;
the filter capacitor C1 is connected in parallel with the power switch tube S2;
the filter capacitor C2 is connected in parallel with the power switch tube S4.
3. The non-overlap time six-switch symmetrical inductor configuration current grid-connected inverter as claimed in claim 1, wherein the positive end-to-ground distributed capacitance of the PV dc voltage of the PV cell array is Cpv1The photovoltaic cell array PV direct-current voltage negative end-to-ground distributed capacitance is Cpv2Wherein, Cpv1＝Cpv2。
4. The non-overlap time six-switch symmetrical inductor configuration current grid-connected inverter as claimed in claim 1, wherein the energy storage inductor L1And an energy storage inductor L2The sensitivity values are the same.
CN202120023896.0U 2021-01-06 2021-01-06 Non-overlap-time six-switch symmetrical inductor configuration current type grid-connected inverter Expired - Fee Related CN214014124U (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114285307A (en) * 2021-12-31 2022-04-05 麦田能源有限公司 DC-AC converter and system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114285307A (en) * 2021-12-31 2022-04-05 麦田能源有限公司 DC-AC converter and system
CN114285307B (en) * 2021-12-31 2022-09-02 麦田能源有限公司 DC-AC converter and system

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