CN102437768B - Single-phase half-bridge five-level inverter and application circuit thereof - Google Patents
Single-phase half-bridge five-level inverter and application circuit thereof Download PDFInfo
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- CN102437768B CN102437768B CN201110314755.5A CN201110314755A CN102437768B CN 102437768 B CN102437768 B CN 102437768B CN 201110314755 A CN201110314755 A CN 201110314755A CN 102437768 B CN102437768 B CN 102437768B
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Abstract
The invention provides a single-phase half-bridge five-level inverter and an application circuit thereof. The single-phase half-bridge five-level inverter comprises eight switching tubes, eight diodes and two clamping diodes. The number of the clamping diodes is smaller than that in the prior art. Moreover, flying capacitors are eliminated. In the five-level inverter of the prior art, the clamping diodes not only provide paths for current, but also have the function of preventing the capacitors from being short-circuited, so that the clamping diodes cannot be eliminated. However, by the five-level inverter provided by the invention, the paths can be provided for the current and the function of preventing the capacitors from being short-circuited can be ensured by the diodes which are reversely connected in parallel with the eight switching tubes and the two clamping diodes. Therefore, the number of semiconductor devices in the whole inverter is ensured to be small, and the inverter is relatively lower in loss, relatively higher in efficiency, small in volume and low in cost. The flying capacitors in the prior art are used for generating multiple levels, but are relatively higher in cost; while the multiple levels are not generated by the capacitors in the embodiment of the invention, so that the cost is low.
Description
Technical field
The present invention relates to electric and electronic technical field, particularly a kind of single-phase semi-bridge five-electrical level inverter and application circuit thereof.
Background technology
The large capacity occasion of middle pressure, multi-electrical level inverter is widely used, and current five-electrical level inverter is mainly diode-clamped and striding capacitance type structure.Introduced respectively below.
Referring to Fig. 1 a, this figure is the five-electrical level inverter topological diagram of the diode-clamped that provides in prior art.
Shown in Fig. 1 a is the topological structure of half-bridge five-electrical level inverter.Diode is used to each switching tube to carry out voltage clamp.For example, the first diode DB1 is for being positioned at the voltage clamp of switch transistor T 1 lower end the lower end of the first capacitor C 1; The second diode DB2 is for being positioned at the voltage clamp of switch transistor T 5 lower ends the lower end of the first capacitor C 1.Other diodes DB3, DB4, DB5 and DB6 are similar, do not repeat them here.
Because clamping diode need to be blocked many times of level voltages, conventionally need the diode series connection of multiple same nominal values, as shown in Figure 1 b, diode DB21, DB22 and DB23 series connection are equivalent to the diode DB2 in Fig. 1 a.These three diodes of DB21, DB22 and DB23 are together in series and jointly bear the voltage that in Fig. 1 a, DB2 bears.Due to the dispersiveness of diode and the impact of stray parameter, also difference to some extent of the pressure that the diode that nominal value is identical can bear, is together in series like this and may causes the diode two ends overvoltage having.Therefore, need to all press measure and very large RC absorbing circuit, but will cause like this systems bulky, cost increases.
Therefore, the problem existing in order to solve Fig. 1 b, has proposed a kind of corrective measure, as shown in Fig. 1 c.The same used with Fig. 1 a of this topology switching tube quantity used, within this topology can be clamped at single level voltage by each diode voltage, as shown in Fig. 1 c, all diodes do not have the situation of two series connection.In the more inverter of level number, there is larger superiority.But the shortcoming of sort circuit is that the quantity of clamping diode is too many.
Referring to Fig. 2, this figure is the striding capacitance type five-electrical level inverter topological diagram providing in prior art.
Electric capacity in topology shown in Fig. 2 can play all the effect of pressing, more but shortcoming is the electric capacity number that uses.
In sum, two kinds of five-electrical level inverter topologys of the prior art are all used more semiconductor device, cause volume larger, and loss is more, and efficiency is lower.
Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of single-phase semi-bridge five-electrical level inverter and application circuit thereof, and the semiconductor number of use is less, and loss is less, and efficiency is higher, and cost is low.
The embodiment of the present invention provides a kind of single-phase semi-bridge five-electrical level inverter, comprising: the first switching tube, second switch pipe, the 3rd switching tube, the 4th switching tube, the 5th switching tube, the 6th switching tube, the 7th switching tube, the 8th switching tube, the first clamping diode and the second clamping diode;
Diode of each described switching tube reverse parallel connection;
The anode of DC power supply is connected the negative terminal of DC power supply by the first electric capacity, the second electric capacity, the 3rd electric capacity and the 4th electric capacity of connecting successively;
The first end of the first switching tube connects the first end of the first electric capacity, and the second end of the first switching tube connects first node;
The first end of second switch pipe connects first node, and the second end of second switch pipe connects Section Point;
The first end of the 3rd switching tube connects the first end of the 4th switching tube, and the second end of the 4th switching tube connects the second end of the first electric capacity, and the second end of the 3rd switching tube connects Section Point;
The first end of the 5th switching tube connects Section Point, and the second end of the 5th switching tube connects the 3rd node;
The second end of the 6th switching tube connects Section Point, and the first end of the 6th switching tube connects the first end of the 7th switching tube, and the second end of the 7th switching tube connects the first end of the 4th electric capacity;
The first end of the 8th switching tube connects the 3rd node, and the second end of the 8th switching tube connects the second end of the 4th electric capacity;
Anodic bonding second electric capacity of the first clamping diode and the common port of the 3rd electric capacity, the negative electrode of the first clamping diode connects first node;
The anodic bonding of the second clamping diode the 3rd node, the negative electrode of the second clamping diode connects the anode of the first clamping diode;
Section Point is as an ac output end of this inverter, and the common port of the first clamping diode and the second clamping diode is as another ac output end of this inverter.
Preferably, described switching tube is IGBT pipe, and described first end is collector electrode, and the second end is emitter.
Preferably, also comprise the first inductance, the second inductance and electric capacity;
Described Section Point is connected the common port of the second electric capacity and the 3rd electric capacity by the first inductance, electric capacity and second inductance of connecting successively.
Preferably, five level operation modes that this single-phase semi-bridge five-electrical level inverter is corresponding are respectively:
First mode: the first switching tube and the conducting of second switch pipe; Rest switch pipe all ends;
Second mode: the 3rd switching tube and the 4th switching tube conducting, rest switch pipe all ends;
The 3rd mode: second switch pipe and the 5th switching tube conducting, rest switch pipe all ends;
The 4th mode: the 6th switching tube and the 7th switching tube conducting, rest switch pipe all ends;
The 5th mode: the 5th switching tube and the 8th switching tube conducting, rest switch pipe all ends.
Preferably,
The conducting sequential of described the first switching tube compares generation by sinusoidal wave and the first triangular wave, when described sine wave is greater than described the first triangular wave, and described the first switching tube conducting, otherwise cut-off;
The conducting sequential of described second switch pipe compares generation by described sine wave and the second triangular wave, when the backward-wave of described sine wave is less than described the second triangular wave, and the conducting of described second switch pipe, otherwise cut-off;
The conducting sequential of described the 3rd switching tube compares generation by described sine wave and described the second triangular wave, when described sine wave is greater than described the second triangular wave, and described the 3rd switching tube conducting, otherwise cut-off;
The conducting sequential of described the 4th switching tube compares generation by described sine wave and the first triangular wave, and described sine wave and described the first triangular wave be when non-intersect, described the 4th switching tube conducting, otherwise cut-off;
The conducting sequential of the 5th switching tube and the conducting sequential of second switch pipe are exchanged about positive half cycle and the negative half period of sine wave;
The conducting sequential of the conducting sequential of the 6th switching tube and the 4th switching tube is exchanged about positive half cycle and the negative half period of sine wave;
The conducting sequential of the conducting sequential of the 7th switching tube and the 3rd switching tube is exchanged about positive half cycle and the negative half period of sine wave;
The conducting sequential of the 8th switching tube and the conducting sequential of the first switching tube are exchanged about positive half cycle and the negative half period of sine wave.
The embodiment of the present invention also provides a kind of application circuit of described inverter, comprises two described single-phase semi-bridge five-electrical level inverters, is respectively the first single-phase semi-bridge five-electrical level inverter and the second single-phase semi-bridge five-electrical level inverter;
The first single-phase semi-bridge five-electrical level inverter links together and is all connected the anode of DC power supply with the first end of the first switching tube in the second single-phase semi-bridge five-electrical level inverter;
The first single-phase semi-bridge five-electrical level inverter links together and is all connected the negative terminal of direct voltage with the second end of the 8th switching tube in the second single-phase semi-bridge five-electrical level inverter;
The first single-phase semi-bridge five-electrical level inverter is with in the second single-phase semi-bridge five-electrical level inverter: the second end of the 4th switching tube all links together and is all connected the common port of the first electric capacity and the second electric capacity; The anode of the first clamping diode all connects the common port of the second electric capacity and the 3rd electric capacity; The second end of the 7th switching tube all links together and connects the common port of the 3rd electric capacity and the 4th electric capacity;
The Section Point of the Section Point of the first single-phase semi-bridge five-electrical level inverter and the second single-phase semi-bridge five-electrical level inverter is respectively as two ac output ends of this application circuit.
Preferably, described the first single-phase semi-bridge five-electrical level inverter is modulated by the primary sinusoid, and described the second single-phase semi-bridge five-electrical level inverter is modulated by the second sine wave;
The phase phasic difference 180 of the described primary sinusoid and the second sine wave is spent.
The embodiment of the present invention also provides a kind of application circuit of described inverter, comprising three described single-phase semi-bridge five-electrical level inverters, is respectively the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter;
The first end of the first switching tube in the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter links together and is all connected the anode of DC power supply;
The second end of the 8th switching tube in the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter links together and is all connected the negative terminal of direct voltage;
In the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter: the second end of the 4th switching tube all links together and is all connected the common port of the first electric capacity and the second electric capacity; The anode of the first clamping diode all connects the common port of the second electric capacity and the 3rd electric capacity; The second end of the 7th switching tube all links together and connects the common port of the 3rd electric capacity and the 4th electric capacity;
The Section Point of the Section Point of the first single-phase semi-bridge five-electrical level inverter, the Section Point of the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter is respectively as three ac output ends of this application circuit.
Preferably, described the first single-phase semi-bridge five-electrical level inverter is modulated by the primary sinusoid, and the second single-phase semi-bridge five-electrical level inverter is modulated by the second sine wave, and the 3rd single-phase semi-bridge five-electrical level inverter is modulated by the 3rd sine wave;
The primary sinusoid, the second phase place sinusoidal wave and the 3rd sine wave differ 120 degree successively.10, the application circuit of inverter described in a kind of claim 1, it is characterized in that, comprising four described single-phase semi-bridge five-electrical level inverters, is respectively the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter, the 3rd single-phase semi-bridge five-electrical level inverter and the 4th single-phase semi-bridge five-electrical level inverter;
The first end of the first switching tube in the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter, the 3rd single-phase semi-bridge five-electrical level inverter and the 4th single-phase semi-bridge five-electrical level inverter links together and is all connected the anode of DC power supply;
The second end of the 8th switching tube in the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter, the 3rd single-phase semi-bridge five-electrical level inverter and the 4th single-phase semi-bridge five-electrical level inverter links together and is all connected the negative terminal of direct voltage;
In the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter, the 3rd single-phase semi-bridge five-electrical level inverter and the 4th single-phase semi-bridge five-electrical level inverter: the second end of the 4th switching tube all links together and is all connected the common port of the first electric capacity and the second electric capacity; The anode of the first clamping diode all connects the common port of the second electric capacity and the 3rd electric capacity; The second end of the 7th switching tube all links together and connects the common port of the 3rd electric capacity and the 4th electric capacity;
The Section Point of the first single-phase semi-bridge five-electrical level inverter, the Section Point of the second single-phase semi-bridge five-electrical level inverter, the Section Point of the 3rd single-phase semi-bridge five-electrical level inverter and the Section Point of the 4th single-phase semi-bridge five-electrical level inverter are respectively as four ac output ends of this application circuit.
Compared with prior art, the present invention has the following advantages:
Single-phase semi-bridge five-electrical level inverter provided by the invention comprises eight switching tubes, eight diodes and two clamping diodes, than few a lot of clamping diodes in prior art, nor comprise striding capacitance, it is because these diodes are not only for electric current provides path that five-electrical level inverter of the prior art cannot remove clamping diode, and play electric capacity not by the effect of short circuit, and five-electrical level inverter provided by the invention utilizes the diode of eight switching tube self reverse parallel connections and two clamping diodes just can provide path for electric current, and ensure that electric capacity is not by the effect of short circuit.Ensure that like this semiconductor device in whole inverter is less, loss is less, and efficiency is higher, and volume is also little, and then cost is also low.Striding capacitance of the prior art is in order to generate many level, but because the cost of electric capacity own is higher; And the embodiment of the present invention gives up and become many level next life with electric capacity, cost is low.
Brief description of the drawings
Fig. 1 a is the five-electrical level inverter topological diagram of the diode-clamped that provides in prior art;
Fig. 1 b is the five-electrical level inverter topological diagram of the another kind of diode-clamped that provides in prior art;
Fig. 1 c is the five-electrical level inverter topological diagram of another diode-clamped of providing in prior art;
Fig. 2 is the striding capacitance type five-electrical level inverter topological diagram providing in prior art;
Fig. 3 is the single-phase semi-bridge five-electrical level inverter topological diagram that the embodiment of the present invention provides;
Fig. 4 is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to first mode;
Fig. 5 is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to second mode;
Fig. 6 is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to the 3rd mode;
Fig. 7 is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to the 4th mode;
Fig. 8 is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to the 5th mode;
Fig. 9 is the conducting sequential chart of eight switches in the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention;
Figure 10 is the single-phase semi-bridge five-electrical level inverter topology unit isoboles that the embodiment of the present invention provides;
Figure 11 is the single-phase full bridge five-electrical level inverter topological diagram that the embodiment of the present invention provides;
Figure 12 is the three-phase three-wire system five-electrical level inverter topological diagram that the embodiment of the present invention provides;
Figure 13 is the three-phase four-wire system five-electrical level inverter topological diagram that the embodiment of the present invention provides.
Embodiment
For above-mentioned purpose of the present invention, feature and advantage can be become apparent more, below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in detail.
Referring to Fig. 3, this figure is the single-phase semi-bridge five-electrical level inverter topological diagram that the embodiment of the present invention provides.
The single-phase semi-bridge five-electrical level inverter that the embodiment of the present invention provides, the first switch transistor T 1, second switch pipe T2, the 3rd switch transistor T 3, the 4th switch transistor T 4, the 5th switch transistor T 5, the 6th switch transistor T 6, the 7th switching tube T7, the 8th switching tube T8, the first clamping diode DF1 and the second clamping diode DF2;
Diode of each described switching tube reverse parallel connection, as shown in Figure 3, T1-T8 is D1-D8 in parallel respectively.
The anode of DC power supply is connected the negative terminal of DC power supply with the 4th capacitor C 4 by the first capacitor C 1, the second capacitor C 2, the 3rd capacitor C 3 of connecting successively;
The first end of the first switch transistor T 1 connects the first end (being the anode of DC power supply) of the first capacitor C 1, and the second end of the first switch transistor T 1 connects first node m;
The first end of second switch pipe T1 connects first node m, and the second end of second switch pipe T2 connects Section Point a;
The first end of the 3rd switch transistor T 3 connects the first end of the 4th switch transistor T 4, and the second end of the 4th switch transistor T 4 connects second end (being C1 and C2) of the first capacitor C 1, and the second end of the 3rd switch transistor T 3 connects Section Point a;
The first end of the 5th switch transistor T 5 connects Section Point a, and the second end of the 5th switch transistor T 5 connects the 3rd node p;
The second end of the 6th switch transistor T 6 connects Section Point a, and the first end of the 6th switch transistor T 6 connects the first end of the 7th switching tube T7, and the second end of the 7th switching tube T7 connects the first end (being the common port of C3 and C4) of the 4th capacitor C 4;
The first end of the 8th switching tube T8 connects the 3rd node p, and the second end of the 8th switching tube T8 connects second end (being the negative terminal of DC power supply) of the 4th capacitor C 4;
Anodic bonding the second capacitor C 2 of the first clamping diode DF1 and the common port of the 3rd capacitor C 3, the negative electrode of the first clamping diode DF1 connects first node m;
The anodic bonding of the second clamping diode DF2 the 3rd node p, the negative electrode of the second clamping diode DF2 connects the anode of the first clamping diode DF1.
Section Point a is as an ac output end of this inverter, and the common port of the first clamping diode DF1 and the second clamping diode DF2 is as another ac output end of this inverter.
It should be noted that, the inverter that the embodiment of the present invention provides is five-electrical level inverter, and five-electrical level inverter can provide five level, so need four identical capacitances in series of capacitance that five level are provided.N electrical level inverter needs the identical electric capacity of (N-1) individual capacitance that level is provided.As shown in the figure, four electric capacity in the present invention are respectively C1, C2, C3 and C4.
The single-phase semi-bridge five-electrical level inverter that the embodiment of the present invention provides comprises eight switching tubes, eight diodes and two clamping diodes, than few a lot of clamping diodes in prior art, nor comprise striding capacitance, it is because these diodes are not only for electric current provides path that five-electrical level inverter of the prior art cannot remove clamping diode, and play electric capacity not by the effect of short circuit, and the five-electrical level inverter that the embodiment of the present invention provides utilizes the diode of eight switching tube self reverse parallel connections and two clamping diodes just can provide path for electric current, and ensure that electric capacity is not by the effect of short circuit.Ensure that like this semiconductor device in whole inverter is less, loss is less, and efficiency is higher, and volume is also little, and then cost is also low.
For the advantage of the embodiment of the present invention is described better, the following describes in five-electrical level inverter of the prior art, to need to exist clamping diode why.Taking the circuit shown in Fig. 1 a as example, when the common port of C1 and C2 flows to electric current to a, pass through DB1, T2, T3 and T4 and arrive a.Being clamping diode DB1 provides path for electric current.In the time that a flows out electric current to the common port of C1 and C2, be through the common port of T5 and DB2 arrival C1 and C2.Being clamping diode DB2 provides path for electric current.Be understandable that, in order to provide path to replace with wire for electric current, suppose to remove DB1 and DB2, from circuit diagram, can find out, in the time of T1 conducting, the two ends of C1 will be by short circuit, and obviously this is irrational.Therefore, clamping diode of the prior art is essential.
And in the embodiment of the present invention, the diode of switching tube self reverse parallel connection can play the effect of clamping diode in prior art, for example, the diode D3 of T3 reverse parallel connection is both for electric current provides path, when the common port of C1 and C2 flows to electric current to a, can ensure T1 conducting again time, C1 is not by short circuit.
Although and the another kind that prior art provides topology has been removed clamping diode, the striding capacitance increasing is in order to generate many level, because the cost of electric capacity own is higher; And the embodiment of the present invention gives up and become many level next life with electric capacity, cost is low.
It should be noted that, preferably, above eight switching tubes can be IGBT pipe, MOSFET pipe, IGCT pipe or IEGT pipe.In the time that described switching tube is IGBT pipe, described first end is collector electrode, and the second end is emitter.Be understandable that, above eight switching tubes also can be selected the switching tube of other types.
It should be noted that, the diode of above switching tube reverse parallel connection can be diode independently, can be also the diode together with switching tube encapsulation and integration.
It should be noted that described single-phase semi-bridge five-electrical level inverter can also comprise the first inductance L 1, the second inductance L 2 and capacitor C;
Described Section Point a is connected the second end of the second capacitor C 2, i.e. node n by the first inductance L 1, capacitor C and second inductance L 2 of connecting successively.
The single-phase semi-bridge five-electrical level inverter that the embodiment of the present invention provides, every kind of operation mode only has two switching tube conductings.Below in conjunction with accompanying drawing, five kinds of operation modes are carried out to labor.
Referring to Fig. 4, this figure is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to first mode.
Five level operation modes that this single-phase semi-bridge five-electrical level inverter is corresponding are respectively:
First mode: the first switch transistor T 1 and second switch pipe T2 conducting; Rest switch pipe all ends; Wherein do not have the switching tube of pulsed drive to illustrate with fine line in the drawings, have the switching tube of pulsed drive and the path of conducting to illustrate with heavy line.Be that T3, T4, T5, T6, T7 and T8 in Fig. 4 is all not conductings, T4, T5, T7 and T8 do not have pulsed drive.And T3 and T6 have pulsed drive, this is that Pulse Design in order to make T3 and T6 is fairly simple, provides the pulse signal of high level in this mode for T3 and T6.
In the time that Section Point a flows out electric current, the path of electric current is: T1-T2-L1-V
g-L2-C2-C1-T1.In the time that Section Point a flows to electric current, the path of electric current is: D2-D1-C1-C2-L2-V
g-L1-D2.
Referring to Fig. 5, this figure is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to second mode.
Second mode: the 3rd switch transistor T 3 and the 4th switch transistor T 4 conductings, rest switch pipe all ends; Wherein do not have the switching tube of pulsed drive to illustrate with fine line in the drawings, have the switching tube of pulsed drive and the path of conducting to illustrate with heavy line.Be that T1, T2, T5, T6, T7 and T8 in Fig. 5 is all not conductings, T1, T5, T7 and T8 do not have pulsed drive.And T2 and T6 have pulsed drive, this is that Pulse Design in order to make T2 and T6 is fairly simple, provides the pulse signal of high level in this mode for T2 and T6.
In the time that Section Point a flows out electric current, the path of electric current is: D4-T3-L1-V
g-L2-C2-D4.In the time that Section Point a flows to electric current, the path of electric current is: D3-T4-C2-L2-V
g-L1-D3.
Referring to Fig. 6, this figure is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to the 3rd mode.
The 3rd mode: second switch pipe T2 and the 5th switch transistor T 5 conductings, rest switch pipe all ends; Wherein do not have the switching tube of pulsed drive to illustrate with fine line in the drawings, have the switching tube of pulsed drive and the path of conducting to illustrate with heavy line.Be that T1, T3, T4, T6, T7 and T8 in Fig. 6 is all not conductings, T1, T3, T7 and T8 do not have pulsed drive.And T4 and T6 have pulsed drive, this is that Pulse Design in order to make T4 and T6 is fairly simple, provides the pulse signal of high level in this mode for T4 and T6.
In the time that Section Point a flows out electric current, the path of electric current is: DF1-T2-L1-V
g-L2-DF1.In the time that Section Point a flows to electric current, the path of electric current is: T5-DF2-L2-V
g-L1-T5.
Referring to Fig. 7, this figure is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to the 4th mode.
The 4th mode: the 6th switch transistor T 6 and the 7th switching tube T7 conducting, rest switch pipe all ends; The switching tube of not conducting illustrates with fine line in the drawings, and the path of conducting illustrates with heavy line.Be that T1, T2, T3, T4, T5 and T8 in Fig. 7 is all not conductings, T1, T2, T3, T4 and T8 do not have pulsed drive.And T5 has pulsed drive, this is that Pulse Design in order to make T5 is fairly simple, provides the pulse signal of high level in this mode for T5.
In the time that Section Point a flows out electric current, the path of electric current is: D7-T6-L1-V
g-L2-C3-D7.In the time that Section Point a flows to electric current, the path of electric current is: D6-T7-C3-L2-V
g-L1-D6.
Referring to Fig. 8, this figure is that the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention is in topological diagram corresponding to the 5th mode.
The 5th mode: the 5th switch transistor T 5 and the 8th switching tube T8 conducting, rest switch pipe all ends.The switching tube of not conducting illustrates with fine line in the drawings, and the path of conducting illustrates with heavy line.Be that T1, T2, T3, T4, T6 and T7 in Fig. 8 is all not conductings, T1, T2, T3, T4 and T6 do not have pulsed drive.And T7 has pulsed drive, this is that Pulse Design in order to make T7 is fairly simple, provides the pulse signal of high level in this mode for T7.
In the time that Section Point a flows out electric current, the path of electric current is: D8-D5-L1-V
g-L2-C3-C4-D8.In the time that Section Point a flows to electric current, the path of electric current is: T5-T8-C4-C3-L2-V
g-L1-T5.
Known by above analysis, every kind of operation mode only has two switching tube conductings.
Referring to Fig. 9, this figure is the conducting sequential chart of eight switches in the single-phase semi-bridge five-electrical level inverter that provides of the embodiment of the present invention.
S1-S8 in Fig. 9 is respectively the gate drive signal of switch transistor T 1-T8.In the time that the driving signal of switching tube is high level, corresponding switching tube conducting, in the time that the driving signal of switching tube is low level, corresponding switching tube cut-off.
Van in Fig. 9 is the voltage between node a and node n in Fig. 3.
In Fig. 9, the waveform of upper end comprises two triangular waves (being respectively the first triangular wave A and the second triangular wave B) and a sinusoidal wave Z, and this sinusoidal wave Z and two triangular waves compare and produce S1-S8.
Described the first triangular wave A, the second triangular wave B have identical frequency and identical amplitude, and the trough of described the first triangular wave A equals the crest of the second triangular wave B.
The conducting sequential of described the first switch transistor T 1 compares generation by sinusoidal wave Z and the first triangular wave A, when described sinusoidal wave Z is greater than described the first triangular wave A, and described the first switch transistor T 1 conducting, otherwise cut-off;
The conducting sequential of described second switch pipe T2 compares generation by described sinusoidal wave Z and the second triangular wave B, when the backward-wave of described sinusoidal wave Z is less than described the second triangular wave B, and described second switch pipe T2 conducting, otherwise cut-off;
The conducting sequential of described the 3rd switch transistor T 3 compares generation by described sinusoidal wave Z and described the second triangular wave B, when described sinusoidal wave Z is greater than described the second triangular wave B, and described the 3rd switch transistor T 3 conductings, otherwise cut-off;
The conducting sequential of described the 4th switch transistor T 4 compares generation by described sinusoidal wave Z and the first triangular wave A, and described sinusoidal wave Z and described the first triangular wave A be when non-intersect, described the 4th switch transistor T 4 conductings, otherwise cut-off;
The conducting sequential of the conducting sequential of the 5th switch transistor T 5 and second switch pipe T2 is exchanged about positive half cycle and the negative half period of sinusoidal wave Z;
The conducting sequential of the conducting sequential of the 6th switch transistor T 6 and the 4th switch transistor T 4 is exchanged about positive half cycle and the negative half period of sinusoidal wave Z;
The conducting sequential of the conducting sequential of the 7th switching tube T7 and the 3rd switch transistor T 3 is exchanged about positive half cycle and the negative half period of sinusoidal wave Z;
The conducting sequential of the conducting sequential of the 8th switching tube T8 and the first switch transistor T 1 is exchanged about positive half cycle and the negative half period of sinusoidal wave Z.
What above embodiment provided is all single-phase semi-bridge five-electrical level inverters, is understandable that, can form single-phase full bridge, three-phase three-wire system and three-phase four-wire system topology by single-phase semi-bridge.Introduced respectively below.
Referring to Figure 10, this figure is the single-phase semi-bridge five-electrical level inverter topology unit isoboles that the embodiment of the present invention provides.
Section Point a in single-phase semi-bridge five-electrical level inverter in Fig. 3 is defined as to the AC exit of topology unit, the first end of T1 is defined as the DC+ exit of topology unit, the second end of T8 is defined as the DC-exit of topology unit, the second end of T4 is defined as the M1 exit of topology unit, the anode of DF1 is defined as the M2 exit of topology unit, and the second end of T7 is defined as the M3 exit of topology unit.
C1 in the M1 exit connection layout 3 of topology unit and the common port of C2, the C2 in M2 exit connection layout 3 and the common port of C3, the C3 in M3 exit connection layout 3 and the common port of C4.
Topology unit schematic diagram after single-phase semi-bridge five-electrical level inverter equivalence in Fig. 3 as shown in figure 10.
Referring to Figure 11, this figure is the single-phase full bridge five-electrical level inverter topological diagram that the embodiment of the present invention provides.
Single-phase full bridge five-electrical level inverter comprises two described single-phase semi-bridge five-electrical level inverters, is respectively the first single-phase semi-bridge five-electrical level inverter and the second single-phase semi-bridge five-electrical level inverter; These two single-phase semi-bridge five-electrical level inverters are equivalent to the topology unit shown in Figure 10.
As shown in figure 11, the DC+ end of two topology unit links together, and then connects the anode of DC power supply; DC-end links together, and then connects the negative terminal of DC power supply.
The M1 of two topology unit links together, and then connects the common port of C1 and C2; M2 links together, and then connects the common port of C2 and C3; M3 links together, and then connects the common port of C3 and C4.
The AC of two topology unit is two ac output ends of this single-phase full bridge five-electrical level inverter.
It should be noted that, described the first single-phase semi-bridge five-electrical level inverter is modulated by the primary sinusoid, and described the second single-phase semi-bridge five-electrical level inverter is modulated by the second sine wave;
The phase phasic difference 180 of the described primary sinusoid and the second sine wave is spent.
Referring to Figure 12, this figure is the three-phase three-wire system five-electrical level inverter topological diagram that the embodiment of the present invention provides.
The difference of this figure and Figure 11 is, comprises three topology unit shown in Figure 10, comprises three described single-phase semi-bridge five-electrical level inverters.The connection of these three single phase half bridge inverters is identical with the connected mode of two single phase half bridge inverters in Figure 11, as shown in figure 12, does not repeat them here.
It should be noted that, described the first single-phase semi-bridge five-electrical level inverter is modulated by the primary sinusoid, and the second single-phase semi-bridge five-electrical level inverter is modulated by the second sine wave, and the 3rd single-phase semi-bridge five-electrical level inverter is modulated by the 3rd sine wave;
The primary sinusoid, the second phase place sinusoidal wave and the 3rd sine wave differ 120 degree successively.
The AC of these three topology unit is three ac output ends of this three-phase three-phase system five-electrical level inverter.
Referring to Figure 13, this figure is the three-phase four-wire system five-electrical level inverter topological diagram that the embodiment of the present invention provides.
The difference of this figure and Figure 11 is, comprises four topology unit shown in Figure 10, comprises four described single-phase semi-bridge five-electrical level inverters.The connection of these four single phase half bridge inverters is identical with the connected mode of two single phase half bridge inverters in Figure 11, as shown in figure 13, does not repeat them here.
The AC of these four topology unit is four ac output ends of this three-phase four-wire system five-electrical level inverter.
It should be noted that, the semiconductor device that the single-phase semi-bridge five-electrical level inverter that the embodiment of the present invention provides uses is less, the power consumption causing is lower, therefore efficiency is higher, be understandable that, the single-phase full bridge, three-phase three-wire system and the three-phase four-wire system five-electrical level inverter that are made up of this single-phase semi-bridge five-electrical level inverter have this advantage equally.
It should be noted that, are all the processes that are later incorporated into the power networks as alternating current by inverter inversion taking DC power supply in above embodiment, V in figure
grepresent electrical network.Be understandable that, this inverter also can be applied to the process from network operation, V in figure
gpart to replace with load be situation from network operation.
The above, be only preferred embodiment of the present invention, not the present invention done to any pro forma restriction.Although the present invention discloses as above with preferred embodiment, but not in order to limit the present invention.Any those of ordinary skill in the art, do not departing from technical solution of the present invention scope situation, all can utilize method and the technology contents of above-mentioned announcement to make many possible variations and modification to technical solution of the present invention, or be revised as the equivalent embodiment of equivalent variations.Therefore, every content that does not depart from technical solution of the present invention,, all still belongs in the scope of technical solution of the present invention protection any simple modification made for any of the above embodiments, equivalent variations and modification according to technical spirit of the present invention.
Claims (9)
1. a single-phase semi-bridge five-electrical level inverter, it is characterized in that, comprising: the first switching tube, second switch pipe, the 3rd switching tube, the 4th switching tube, the 5th switching tube, the 6th switching tube, the 7th switching tube, the 8th switching tube, the first clamping diode and the second clamping diode;
Diode of each described switching tube reverse parallel connection;
The anode of DC power supply is connected the negative terminal of DC power supply by the first electric capacity, the second electric capacity, the 3rd electric capacity and the 4th electric capacity of connecting successively;
The first end of the first switching tube connects the first end of the first electric capacity, and the second end of the first switching tube connects first node;
The first end of second switch pipe connects first node, and the second end of second switch pipe connects Section Point;
The first end of the 3rd switching tube connects the first end of the 4th switching tube, and the second end of the 4th switching tube connects the second end of the first electric capacity, and the second end of the 3rd switching tube connects Section Point;
The first end of the 5th switching tube connects Section Point, and the second end of the 5th switching tube connects the 3rd node;
The second end of the 6th switching tube connects Section Point, and the first end of the 6th switching tube connects the first end of the 7th switching tube, and the second end of the 7th switching tube connects the first end of the 4th electric capacity;
The first end of the 8th switching tube connects the 3rd node, and the second end of the 8th switching tube connects the second end of the 4th electric capacity;
Anodic bonding second electric capacity of the first clamping diode and the common port of the 3rd electric capacity, the negative electrode of the first clamping diode connects first node;
The anodic bonding of the second clamping diode the 3rd node, the negative electrode of the second clamping diode connects the anode of the first clamping diode;
Section Point is as an ac output end of this inverter, and the common port of the first clamping diode and the second clamping diode is as another ac output end of this inverter;
Five level operation modes that described single-phase semi-bridge five-electrical level inverter is corresponding are respectively:
First mode: the first switching tube and the conducting of second switch pipe; Rest switch pipe all ends;
Second mode: the 3rd switching tube and the 4th switching tube conducting, rest switch pipe all ends;
The 3rd mode: second switch pipe and the 5th switching tube conducting, rest switch pipe all ends;
The 4th mode: the 6th switching tube and the 7th switching tube conducting, rest switch pipe all ends;
The 5th mode: the 5th switching tube and the 8th switching tube conducting, rest switch pipe all ends.
2. single-phase semi-bridge five-electrical level inverter according to claim 1, is characterized in that, described switching tube is IGBT pipe, and described first end is collector electrode, and the second end is emitter.
3. single-phase semi-bridge five-electrical level inverter according to claim 1 and 2, is characterized in that, also comprises the first inductance, the second inductance and electric capacity;
Described Section Point is connected the common port of the second electric capacity and the 3rd electric capacity by the first inductance, electric capacity and second inductance of connecting successively.
4. single-phase semi-bridge five-electrical level inverter according to claim 1, is characterized in that,
The conducting sequential of described the first switching tube compares generation by sinusoidal wave and the first triangular wave, when described sine wave is greater than described the first triangular wave, and described the first switching tube conducting, otherwise cut-off;
The conducting sequential of described second switch pipe compares generation by described sine wave and the second triangular wave, when the backward-wave of described sine wave is less than described the second triangular wave, and the conducting of described second switch pipe, otherwise cut-off;
The conducting sequential of described the 3rd switching tube compares generation by described sine wave and described the second triangular wave, when described sine wave is greater than described the second triangular wave, and described the 3rd switching tube conducting, otherwise cut-off;
The conducting sequential of described the 4th switching tube compares generation by described sine wave and the first triangular wave, and described sine wave and described the first triangular wave be when non-intersect, described the 4th switching tube conducting, otherwise cut-off;
The conducting sequential of the 5th switching tube and the conducting sequential of second switch pipe are exchanged about positive half cycle and the negative half period of sine wave;
The conducting sequential of the conducting sequential of the 6th switching tube and the 4th switching tube is exchanged about positive half cycle and the negative half period of sine wave;
The conducting sequential of the conducting sequential of the 7th switching tube and the 3rd switching tube is exchanged about positive half cycle and the negative half period of sine wave;
The conducting sequential of the 8th switching tube and the conducting sequential of the first switching tube are exchanged about positive half cycle and the negative half period of sine wave.
5. an application circuit for inverter described in claim 1, is characterized in that, comprises two described single-phase semi-bridge five-electrical level inverters, is respectively the first single-phase semi-bridge five-electrical level inverter and the second single-phase semi-bridge five-electrical level inverter;
The first single-phase semi-bridge five-electrical level inverter links together and is all connected the anode of DC power supply with the first end of the first switching tube in the second single-phase semi-bridge five-electrical level inverter;
The first single-phase semi-bridge five-electrical level inverter links together and is all connected the negative terminal of direct voltage with the second end of the 8th switching tube in the second single-phase semi-bridge five-electrical level inverter;
The first single-phase semi-bridge five-electrical level inverter is with in the second single-phase semi-bridge five-electrical level inverter: the second end of the 4th switching tube all links together and is all connected the common port of the first electric capacity and the second electric capacity; The anode of the first clamping diode all connects the common port of the second electric capacity and the 3rd electric capacity; The second end of the 7th switching tube all links together and connects the common port of the 3rd electric capacity and the 4th electric capacity;
The Section Point of the Section Point of the first single-phase semi-bridge five-electrical level inverter and the second single-phase semi-bridge five-electrical level inverter is respectively as two ac output ends of this application circuit.
6. the application circuit of inverter according to claim 5, is characterized in that, described the first single-phase semi-bridge five-electrical level inverter is modulated by the primary sinusoid, and described the second single-phase semi-bridge five-electrical level inverter is modulated by the second sine wave;
The phase phasic difference 180 of the described primary sinusoid and the second sine wave is spent.
7. the application circuit of inverter described in a claim 1, it is characterized in that, comprising three described single-phase semi-bridge five-electrical level inverters, is respectively the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter;
The first end of the first switching tube in the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter links together and is all connected the anode of DC power supply;
The second end of the 8th switching tube in the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter links together and is all connected the negative terminal of direct voltage;
In the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter: the second end of the 4th switching tube all links together and is all connected the common port of the first electric capacity and the second electric capacity; The anode of the first clamping diode all connects the common port of the second electric capacity and the 3rd electric capacity; The second end of the 7th switching tube all links together and connects the common port of the 3rd electric capacity and the 4th electric capacity;
The Section Point of the Section Point of the first single-phase semi-bridge five-electrical level inverter, the Section Point of the second single-phase semi-bridge five-electrical level inverter and the 3rd single-phase semi-bridge five-electrical level inverter is respectively as three ac output ends of this application circuit.
8. the application circuit of inverter according to claim 7, it is characterized in that, described the first single-phase semi-bridge five-electrical level inverter is modulated by the primary sinusoid, the second single-phase semi-bridge five-electrical level inverter is modulated by the second sine wave, and the 3rd single-phase semi-bridge five-electrical level inverter is modulated by the 3rd sine wave;
The primary sinusoid, the second phase place sinusoidal wave and the 3rd sine wave differ 120 degree successively.
9. the application circuit of inverter described in a claim 1, it is characterized in that, comprising four described single-phase semi-bridge five-electrical level inverters, is respectively the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter, the 3rd single-phase semi-bridge five-electrical level inverter and the 4th single-phase semi-bridge five-electrical level inverter;
The first end of the first switching tube in the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter, the 3rd single-phase semi-bridge five-electrical level inverter and the 4th single-phase semi-bridge five-electrical level inverter links together and is all connected the anode of DC power supply;
The second end of the 8th switching tube in the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter, the 3rd single-phase semi-bridge five-electrical level inverter and the 4th single-phase semi-bridge five-electrical level inverter links together and is all connected the negative terminal of direct voltage;
In the first single-phase semi-bridge five-electrical level inverter, the second single-phase semi-bridge five-electrical level inverter, the 3rd single-phase semi-bridge five-electrical level inverter and the 4th single-phase semi-bridge five-electrical level inverter: the second end of the 4th switching tube all links together and is all connected the common port of the first electric capacity and the second electric capacity; The anode of the first clamping diode all connects the common port of the second electric capacity and the 3rd electric capacity; The second end of the 7th switching tube all links together and connects the common port of the 3rd electric capacity and the 4th electric capacity;
The Section Point of the first single-phase semi-bridge five-electrical level inverter, the Section Point of the second single-phase semi-bridge five-electrical level inverter, the Section Point of the 3rd single-phase semi-bridge five-electrical level inverter and the Section Point of the 4th single-phase semi-bridge five-electrical level inverter are respectively as four ac output ends of this application circuit.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201118461Y (en) * | 2007-10-10 | 2008-09-17 | 山东新风光电子科技发展有限公司 | A dynamic voltage balance circuit for five-level commutator |
| CN101902142A (en) * | 2010-07-26 | 2010-12-01 | 南京航空航天大学 | Diode clamping five-level dual buck half-bridge inverter |
| CN102142784A (en) * | 2011-03-31 | 2011-08-03 | 华中科技大学 | Full digital five-level inverter sinusoidal pulse width modulation (SPWM) control method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4742229B2 (en) * | 2005-02-08 | 2011-08-10 | 富士電機株式会社 | 5-level inverter and driving method thereof |
-
2011
- 2011-10-17 CN CN201110314755.5A patent/CN102437768B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201118461Y (en) * | 2007-10-10 | 2008-09-17 | 山东新风光电子科技发展有限公司 | A dynamic voltage balance circuit for five-level commutator |
| CN101902142A (en) * | 2010-07-26 | 2010-12-01 | 南京航空航天大学 | Diode clamping five-level dual buck half-bridge inverter |
| CN102142784A (en) * | 2011-03-31 | 2011-08-03 | 华中科技大学 | Full digital five-level inverter sinusoidal pulse width modulation (SPWM) control method |
Non-Patent Citations (3)
| Title |
|---|
| JP特开2006-223009A 2006.08.24 |
| 一种新型单相不对称五电平逆变器;丁凯等;《中国电机工程学报》;20041130;第24卷(第11期);第116-120页 * |
| 丁凯等.一种新型单相不对称五电平逆变器.《中国电机工程学报》.2004,第24卷(第11期),第116-120页. |
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