CN105305862A - Capacitance self-voltage-sharing multi-level high-frequency inverter - Google Patents

Abstract

The invention discloses a capacitance self-voltage-sharing multi-level high-frequency inverter. The capacitance self-voltage-sharing multi-level high-frequency inverter comprises a switch capacitor cell and a full-bridge cell, wherein the switch capacitor cell comprises a first electrolytic capacitor, a second electrolytic capacitor, a first diode, a second diode, a third diode, a fourth diode, a ninth diode, a tenth diode, an eleventh diode, a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; and the full-bridge cell comprises a fifth diode, a sixth diode, a seventh diode, an eighth diode, a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube. The first diode, the second diode and the first switch tube are connected to the second switch tube; the first diode and the ninth diode are connected to the first switch tube; the third diode, the tenth diode and the third switch tube are connected to the first electrolytic capacitor; the third diode, the eleventh diode and the third switch tube are connected to the second electrolytic capacitor; the second diode, the fourth diode, the tenth diode, the second switch tube and the fourth switch tube are connected to the second electrolytic capacitor, the ninth diode, the eleventh diode and the first electrolytic capacitor are connected to the fifth diode, the seventh diode, the fifth switch tube and the seventh switch tube; and the fourth diode and the fourth switch tube are connected to the sixth diode, the eighth diode, the sixth switch tube and the eighth switch tube. The capacitance self-voltage-sharing multi-level high-frequency inverter has the advantages of low switching frequency, high transmission efficiency, capacitance self-voltage-sharing and the like.

Description

A kind of electric capacity is from all pressing many level high-frequencies inverter

Technical field

The present invention relates to high-frequency ac distribution system (HighFrequencyACPowerDistributionSystem, HFACPDS) field, referring in particular to a kind of electric capacity from all pressing many level high-frequencies inverter.

Background technology

Traditional direct-flow distribution system (DCPDS) is because of shortcomings such as its reliability are low, efficiency of transmission is low, dynamic response is slow, no longer applicable in many occasions higher to power reguirements.High-frequency alternating current (HFACPDS) is because having high reliability, high efficiency, high power density, can realizing the advantages such as wireless transmission and be subject to paying close attention to more and more widely, and correlative study also progressively applies to the fields such as computer, communication, electric automobile, regenerative resource microgrid.Meanwhile, high-frequency inverter is as the prime of high-frequency ac distribution system, and its research also achieves breakthrough progress.High-frequency inverter is used for direct current to be converted to high-frequency alternating current, and be fed to high frequency AC-bus (HFACBUS) for the reallocation of rear class HFAC/DC converter, be that the harmonic content of output waveform is little to the requirement of high-frequency inverter, the efficiency of transmission of inverter is high.Harmonic content is relevant with the level number that inverter can export, and usual output level number is more, and harmonic content is less; Efficiency of transmission high request loss is little, and the loss of inverter mainly comprises switching loss and conduction loss, and usual switching frequency is lower, and the device of inverters is fewer, and loss is less, and efficiency is higher.

Summary of the invention

The object of the invention is to the character utilizing capacitance energy storage, DC source is replaced with electric capacity, realize more level with a small amount of device to export, propose a kind of novel electric capacity from all pressing many level high-frequencies inverter, this electric capacity is from all pressing many level high-frequencies inverter to be applicable to high-frequency ac field of power distribution; The present invention only needs single input direct-current source, capacitance energy storage adds the level quantity of output, significantly reduces the harmonic distortion of output AC electricity, decreases the quantity using device, improve the efficiency of inverter, also effectively reduce the drive circuit needed for inverter and installing space simultaneously; The present invention is by making serial connection charge, the serial or parallel connection electric discharge simultaneously of two electric capacity, and realize electric capacity from all pressing, the generation of the capacitance voltage imbalance problem effectively avoided, simplifies modulation system.

For achieving the above object, technical scheme provided by the present invention is: a kind of electric capacity is from all pressing many level high-frequencies inverter, comprise the switching capacity unit and full bridge unit that are connected in parallel, wherein, described switching capacity unit comprises the first electrochemical capacitor, second electrochemical capacitor, first diode, second diode, 3rd diode, 4th diode, 9th diode, tenth diode, 11 diode, first switching tube, second switch pipe, 3rd switching tube and the 4th switching tube, described full bridge unit comprises the 5th diode, 6th diode, 7th diode, 8th diode, 5th switching tube, 6th switching tube, 7th switching tube and the 8th switching tube, the capacitance of described first electrochemical capacitor and the second electrochemical capacitor is equal, the negative electrode of described first diode, the negative electrode of the second diode, the leakage level of the first switching tube is connected with the leakage level of second switch pipe respectively, the anode of described first diode, the anode of the 9th diode is connected with the source class of the first switching tube respectively, the anode of described 3rd diode, the negative electrode of the tenth diode, the source class of the 3rd switching tube is connected with the negative pole of the first electrochemical capacitor respectively, the negative electrode of described 3rd diode, the anode of the 11 diode, the leakage level of the 3rd switching tube is connected with the positive pole of the second electrochemical capacitor respectively, the anode of described second diode, the negative electrode of the 4th diode, the anode of the tenth diode, the source class of second switch pipe, the leakage level of the 4th switching tube is connected with the negative pole of the second electrochemical capacitor respectively, the anode of described 5th diode, the negative electrode of the 6th diode, the source class of the 5th switching tube is connected with the leakage level of the 6th switching tube respectively, the anode of described 7th diode, the negative electrode of the 8th diode, the source class of the 7th switching tube is connected with the leakage level of the 8th switching tube respectively, described 9th diode cathode, the negative electrode of the 11 diode, the positive pole of the first electrochemical capacitor respectively with the negative electrode of the 5th diode, the negative electrode of the 7th diode, the leakage level of the 5th switching tube is connected with the leakage level of the 7th switching tube, the anode of described 4th diode and the source class of the 4th switching tube respectively with the anode of the 6th diode, the anode of the 8th diode, the source class of the 6th switching tube is connected with the source class of the 8th switching tube.

Compared with prior art, tool has the following advantages and beneficial effect in the present invention:

1, compared with existing three level, five level or seven electrical level inverters, the present invention achieves more level by electric capacity and exports, and the increase of level quantity effectively reduces the harmonic content of output voltage.

2, compared with existing nine electrical level inverters, the device that the present invention uses is less, while reducing conduction loss, also saves installing space.

3, existing multi-electrical level inverter needs two or more power supply to export to realize more level usually, and the present invention uses electric capacity to substitute the effect of independent source, and only need single power supply just can realize more level and export, the scope of application is more extensive.

4, electric capacity of the present invention is from all pressing many level high-frequencies inverter, switching frequency is only the twice exporting staircase waveform, when output frequency is 25kHz, switching frequency is only 50kHz, compared with existing multi-electrical level inverter, reduce switching frequency and switching loss, be therefore specially adapted to HFACPDS.

5, electric capacity of the present invention is from all pressing many level high-frequencies inverter, realize more level by the character of capacitance energy storage to export, two capacitances in series chargings, serial or parallel connections discharge, and efficiently avoid the generation of capacitance voltage imbalance problem, simplify the design of drive circuit.

6, electric capacity of the present invention is from all pressing many level high-frequencies inverter, reduces switching loss and conduction loss simultaneously, improves the efficiency of transmission of inverter.

Accompanying drawing explanation

Fig. 1 is that electric capacity of the present invention is from the structural representation of all pressing many level high-frequencies inverter.

Fig. 2 is that electric capacity of the present invention is from drive singal and the output voltage waveforms schematic diagram of all pressing many level high-frequencies inverter breaker in middle pipe.

Embodiment

Below in conjunction with specific embodiment, the invention will be further described.

As shown in Figure 1, the electric capacity described in the present embodiment is from all pressing many level high-frequencies inverter, and comprise the switching capacity unit X and full bridge unit Y that are connected in parallel, wherein, described switching capacity unit X comprises the first electrochemical capacitor C ₁, the second electrochemical capacitor C ₂, the first diode D ₁, the second diode D ₂, the 3rd diode D ₃, the 4th diode D ₄, the 9th diode D ₉, the tenth diode D ₁₀, the 11 diode D ₁₁, the first switching tube S ₁, second switch pipe S ₂, the 3rd switching tube S ₃with the 4th switching tube S ₄, described full bridge unit Y comprises the 5th diode D ₅, the 6th diode D ₆, the 7th diode D ₇, the 8th diode D ₈, the 5th switching tube S ₅, the 6th switching tube S ₆, the 7th switching tube S ₇with the 8th switching tube S ₈; Described first electrochemical capacitor C ₁with the second electrochemical capacitor C ₂capacitance equal, described first diode D ₁negative electrode, the second diode D ₂negative electrode, the first switching tube S ₁leakage level respectively with second switch pipe S ₂leakage level be connected, described first diode D ₁anode, the 9th diode D ₉anode respectively with the first switching tube S ₁source class be connected, described 3rd diode D ₃anode, the tenth diode D ₁₀negative electrode, the 3rd switching tube S ₃source class respectively with the first electrochemical capacitor C ₁negative pole be connected, described 3rd diode D ₃negative electrode, the 11 diode D ₁₁anode, the 3rd switching tube S ₃leakage level respectively with the second electrochemical capacitor C ₂positive pole be connected, described second diode D ₂anode, the 4th diode D ₄negative electrode, the tenth diode D ₁₀anode, second switch pipe S ₂source class, the 4th switching tube S ₄leakage level respectively with the second electrochemical capacitor C ₂negative pole be connected, described 5th diode D ₅anode, the 6th diode D ₆negative electrode, the 5th switching tube S ₅source class respectively with the 6th switching tube S ₆leakage level be connected, described 7th diode D ₇anode, the 8th diode D ₈negative electrode, the 7th switching tube S ₇source class respectively with the 8th switching tube S ₈leakage level be connected, described 9th diode D ₉negative electrode, the 11 diode D ₁₁negative electrode, the first electrochemical capacitor C ₁positive pole respectively with the 5th diode D ₅negative electrode, the 7th diode D ₇negative electrode, the 5th switching tube S ₅leakage level and the 7th switching tube S ₇leakage level be connected, described 4th diode D ₄anode and the 4th switching tube S ₄source class respectively with the 6th diode D ₆anode, the 8th diode D ₈anode, the 6th switching tube S ₆source class and the 8th switching tube S ₈source class be connected.

As shown in Figure 2, described first switching tube S ₁, second switch pipe S ₂, the 3rd switching tube S ₃, the 4th switching tube S ₄, the 5th switching tube S ₅, the 6th switching tube S ₆, the 7th switching tube S ₇with the 8th switching tube S ₈the first drive singal G ₁, the second drive singal G ₂, the 3rd drive singal G ₃, four-wheel drive signal G ₄, the 5th drive singal G ₅, the 6th drive singal G ₆, the 7th drive singal G ₇with the 8th drive singal G ₈by basic PWM ripple directly or obtain through basic logic operations, basic PWM ripple is by triangular carrier V _cwith direct voltage V _m1, V _m2, V _m3, V _m4relatively obtain; The above-mentioned electric capacity of the present embodiment is from all pressing many level high-frequencies inverter by output level grade analysis, and a work period has nine kinds of operating states:

State I: second switch pipe S ₂, the 3rd switching tube S ₃, the 5th switching tube S ₅with the 8th switching tube S ₈conducting, the 9th diode D ₉, the tenth diode D ₁₀with the 11 diode D ₁₁all oppositely end, the first electrochemical capacitor C ₁, the second electrochemical capacitor C ₂with power supply V _dcseries connection, inverter exports as 2V _dc.

State I I: second switch pipe S ₂, the 5th switching tube S ₅with the 8th switching tube S ₈conducting, the 9th diode D ₉reverse cut-off, the tenth diode D ₁₀with the 11 diode D ₁₁conducting, the first electrochemical capacitor C ₁with the second electrochemical capacitor C ₂rear and power supply V in parallel _dcseries connection, the output of inverter is 3/2V _dc.

State I II: the first switching tube S ₁, the 5th switching tube S ₅with the 8th switching tube S ₈conducting, the 9th diode D ₉conducting, power supply V _dcdirectly be added to load both sides, export as V _dc; Meanwhile, the tenth diode D ₁₀with the 11 diode D ₁₁cut-off, the 4th diode S ₄conducting, the first electrochemical capacitor C ₁with the second electrochemical capacitor C ₂serial connection charge is to 1/2V _dc.

State I V: the five switching tube S ₅, the 8th switching tube S ₈conducting, the first electrochemical capacitor C ₁with the second electrochemical capacitor C ₂by the 4th diode D after in parallel ₄electric discharge, inverter output voltage is 1/2V _dc.

State V: the five switching tube S ₅with the 7th switching tube S ₇conducting, electric current flows through the 5th switching tube S ₅with the 7th diode D ₇, it is 0 that inverter exports; As the 6th switching tube S ₆with the 8th switching tube S ₈during conducting, the output of inverter is also 0.

State VI: the six switching tube S ₆, the 7th switching tube S ₇conducting, the first electrochemical capacitor C ₁with the second electrochemical capacitor C ₂by the 4th diode D after in parallel ₄electric discharge, full bridge unit Y changes the polarity of output voltage, and inverter output voltage is-1/2V _dc.

State VII: the first switching tube S ₁, the 6th switching tube S ₆with the 7th switching tube S ₇conducting, the 9th diode D ₉conducting, power supply V _dcdirectly be added to load both sides, full bridge unit Y changes the polarity of output voltage, exports as-V _dc; Meanwhile, the tenth diode D ₁₀with the 11 diode D ₁₁cut-off, the 4th switching tube S ₄conducting, the first electrochemical capacitor C ₁with the second electrochemical capacitor C ₂serial connection charge is to 1/2V _dc.

State VIII: second switch pipe S ₂, the 6th switching tube S ₆with the 7th switching tube S ₇conducting, the 9th diode D ₉reverse cut-off, the tenth diode D ₁₀with the 11 diode D ₁₁conducting, the first electrochemical capacitor C ₁with the second electrochemical capacitor C ₂rear and power supply V in parallel _dcseries connection, full bridge unit Y changes the polarity of output voltage, and the output of inverter is-3/2V _dc.

State I X: second switch pipe S ₂, the 3rd switching tube S ₃, the 6th switching tube S ₆with the 7th switching tube S ₇conducting, the 9th diode D ₉, the tenth diode D ₁₀with the 11 diode D ₁₁all oppositely end, the first electrochemical capacitor C ₁, the second electrochemical capacitor C ₂with power supply V _dcseries connection, full bridge unit Y changes the polarity of output voltage, and inverter exports as-2V _dc.

Described electric capacity, from all pressing the output of many level high-frequencies inverter to be made up of above-mentioned nine kinds of level states, can obtain from all pressing the output of many level high-frequencies inverter to carry out Fourier analysis described electric capacity:

$v_{out}=\frac{2V_{dc}}{\mathrm{\π}}\underset{n=1,3,\mathrm{5...}}{\Σ}\[\cos \left({\mathrm{n\θ}}_1\right)+\cos \left({\mathrm{n\θ}}_2\right)+\cos \left({\mathrm{n\θ}}_3\right)+\cos \left({\mathrm{n\θ}}_4\right)\]\×\frac{\sin n\mathrm{\ω}t}{n}---\left(1\right)$

In formula: ω is output angle frequency, and 0 < V _m1< V _m2< V _m3< V _m4< V _c.

Can be obtained by formula (1), described electric capacity from all pressing the fundamental voltage output of voltage of many level high-frequencies inverter is:

$v_{out\_1}=\frac{2V_{dc}}{\mathrm{\&pi;}}\&lsqb;\cos \left({\mathrm{n\&theta;}}_1\right)+\cos \left({\mathrm{n\&theta;}}_2\right)+\cos \left({\mathrm{n\&theta;}}_3\right)+\cos \left({\mathrm{n\&theta;}}_4\right)\&rsqb;\&times;\sin n\mathrm{\&omega;}t---\left(2\right)$

Described electric capacity from all pressing the expression formula of the total harmonic distortion THD of the output voltage of many level high-frequencies inverter is:

$THD=\sqrt{\frac{\underset{n=3,5,\mathrm{7...}}{\&Sigma;}{\&lsqb;\frac{\cos \left({\mathrm{n\&theta;}}_1\right)+\cos \left({\mathrm{n\&theta;}}_2\right)+\cos \left({\mathrm{n\&theta;}}_3\right)+\cos \left({\mathrm{n\&theta;}}_4\right)}{n}\&rsqb;}^2}{\cos \left({\mathrm{\&theta;}}_1\right)+\cos \left({\mathrm{\&theta;}}_2\right)+\cos \left({\mathrm{\&theta;}}_3\right)+\cos \left({\mathrm{\&theta;}}_4\right)}}---\left(3\right)$

Described electric capacity, from all pressing many level high-frequencies inverter, when selecting modulation parameter, need meet 0<V _m1<V _m2<V _m3<V _m4<V _c, according to formula (2) and the fundamental voltage amplitude of (3) output voltage and the expression formula Selection parameter V of total harmonic distortion THD _m1, parameter V _m2, parameter V _m3, parameter V _m4, parameter V _cmeet the demands with the amplitude and total harmonic distortion THD of guaranteeing the voltage exported.

The examples of implementation of the above are only the preferred embodiment of the present invention, not limit practical range of the present invention with this, therefore the change that all shapes according to the present invention, principle are done, all should be encompassed in protection scope of the present invention.

Claims (1)

1. an electric capacity is from all pressing many level high-frequencies inverter, it is characterized in that: comprise the switching capacity unit (X) and full bridge unit (Y) that are connected in parallel, wherein, described switching capacity unit (X) comprises the first electrochemical capacitor (C ₁), the second electrochemical capacitor (C ₂), the first diode (D ₁), the second diode (D ₂), the 3rd diode (D ₃), the 4th diode (D ₄), the 9th diode (D ₉), the tenth diode (D ₁₀), the 11 diode (D ₁₁), the first switching tube (S ₁), second switch pipe (S ₂), the 3rd switching tube (S ₃) and the 4th switching tube (S ₄), described full bridge unit (Y) comprises the 5th diode (D ₅), the 6th diode (D ₆), the 7th diode (D ₇), the 8th diode (D ₈), the 5th switching tube (S ₅), the 6th switching tube (S ₆), the 7th switching tube (S ₇) and the 8th switching tube (S ₈); Described first electrochemical capacitor (C ₁) and the second electrochemical capacitor (C ₂) capacitance equal, described first diode (D ₁) negative electrode, the second diode (D ₂) negative electrode, the first switching tube (S ₁) leakage level respectively with second switch pipe (S ₂) leakage level be connected, described first diode (D ₁) anode, the 9th diode (D ₉) anode respectively with the first switching tube (S ₁) source class be connected, described 3rd diode (D ₃) anode, the tenth diode (D ₁₀) negative electrode, the 3rd switching tube (S ₃) source class respectively with the first electrochemical capacitor (C ₁) negative pole be connected, described 3rd diode (D ₃) negative electrode, the 11 diode (D ₁₁) anode, the 3rd switching tube (S ₃) leakage level respectively with the second electrochemical capacitor (C ₂) positive pole be connected, described second diode (D ₂) anode, the 4th diode (D ₄) negative electrode, the tenth diode (D ₁₀) anode, second switch pipe (S ₂) source class, the 4th switching tube (S ₄) leakage level respectively with the second electrochemical capacitor (C ₂) negative pole be connected, described 5th diode (D ₅) anode, the 6th diode (D ₆) negative electrode, the 5th switching tube (S ₅) source class respectively with the 6th switching tube (S ₆) leakage level be connected, described 7th diode (D ₇) anode, the 8th diode (D ₈) negative electrode, the 7th switching tube (S ₇) source class respectively with the 8th switching tube (S ₈) leakage level be connected, described 9th diode (D ₉) negative electrode, the 11 diode (D ₁₁) negative electrode, the first electrochemical capacitor (C ₁) positive pole respectively with the 5th diode (D ₅) negative electrode, the 7th diode (D ₇) negative electrode, the 5th switching tube (S ₅) leakage level and the 7th switching tube (S ₇) leakage level be connected, described 4th diode (D ₄) anode and the 4th switching tube (S ₄) source class respectively with the 6th diode (D ₆) anode, the 8th diode (D ₈) anode, the 6th switching tube (S ₆) source class and the 8th switching tube (S ₈) source class be connected.