CN110649829B

CN110649829B - Single-phase three-level power factor correction rectifier based on asymmetric four-port

Info

Publication number: CN110649829B
Application number: CN201910872348.2A
Authority: CN
Inventors: 马辉; 鲁海鹏
Original assignee: China Three Gorges University CTGU
Current assignee: China Three Gorges University CTGU
Priority date: 2019-09-16
Filing date: 2019-09-16
Publication date: 2021-03-23
Anticipated expiration: 2039-09-16
Also published as: CN110649829A

Abstract

Single-phase three electricity based on asymmetric four portsThe flat power factor correction rectifier comprises an AC power supply AC, an inductor L and a switching tube Q₁、Q₂、Q₃、Q₄(ii) a One side of the AC power supply is respectively connected with a diode D₁Anode, diode D₂A cathode, the connection node of which constitutes an end point b; the other side of the AC power supply is connected with one end of an inductor L, and the other end of the inductor L is respectively connected with a switching tube Q₃Source electrode, switch tube Q₄Drain electrode, diode D₁₀A cathode, the connection node of which constitutes an end a; switch tube Q₃The drain electrodes are respectively connected with a diode D₁Cathode, diode D₈An anode connected to the node to form an end c; closing tube Q₄The source electrodes are respectively connected with a diode D₂Anode, diode D₇A cathode, the connection node of which constitutes an end point d; diode D₈Cathode connection capacitor C_dc1One end, the connection node of which constitutes an endpoint p; capacitor C_dc1The other end is connected with a capacitor C_dc2One end, the connection node of which forms an endpoint n; capacitor C_dc2The other end is connected with a diode D₇And the anode is connected with the node to form the endpoint m. The rectifier reduces the harmonic content of the rectifier and reduces the loss of components in the rectifying process.

Description

Single-phase three-level power factor correction rectifier based on asymmetric four-port

Technical Field

The invention relates to the technical field of single-phase electric energy conversion, in particular to a single-phase three-level power factor correction rectifier based on four asymmetric ports.

Background

The development of industrial modernization urgently needs to search a new topological structure of the electric energy converter in the electric energy conversion so as to reduce the electric energy loss and reduce the hardware cost. In industrial application, the direct current is generally obtained by rectifying the alternating current of a power grid, the rectifying process needs to consider that the current cannot change along with the voltage, and in order to solve the problem, a Boost power factor correction circuit is introduced into a rectification post stage under the common condition so as to improve the power factor. The main disadvantages of such topologies are: the number of the adopted components is increased, and the loss of the components is increased, so that the topological structure is not suitable for occasions with larger power.

Disclosure of Invention

The invention provides an asymmetric four-port-based single-phase three-level power factor correction rectifier which has the characteristics of Boost boosting, rectification, three-level power factor correction and an asymmetric four-port network structure. The voltage stress at two ends of the switching tube is reduced, the harmonic content of the rectifier is reduced, and the loss of components in the rectifying process is reduced; meanwhile, the control mode of the rectifier is improved, and the control complexity is reduced.

The technical scheme adopted by the invention is as follows:

the single-phase three-level power factor correction rectifier based on the asymmetric four-port comprises an alternating current power supply AC, an inductor L and a switching tube Q₁、Q₂、Q₃、Q₄Diode D₁、D₂、D₇、D₈、D₉、D₁₀Capacitor C_dc1、C_dc2；

One side of the AC power supply is respectively connected with a diode D₁Anode, diode D₂A cathode, the connection node of which constitutes an end point b;

the other side of the AC power supply is connected with one end of an inductor L, and the other end of the inductor L is respectively connected with a switching tube Q₃Source electrode, switch tube Q₄Drain electrode, diode D₁₀A cathode, the connection node of which constitutes an end a;

switch tube Q₃The drain electrodes are respectively connected with a diode D₁Cathode, diode D₈An anode connected to the node to form an end c;

switch tube Q₄The source electrodes are respectively connected with a diode D₂Anode, diode D₇A cathode, the connection node of which constitutes an end point d;

diode D₈Cathode connection capacitor C_dc1One end, the connection node of which constitutes an endpoint p;

capacitor C_dc1The other end is connected with a capacitor C_dc2One end, the connection node of which forms an endpoint n;

capacitor C_dc2The other end is connected with a diode D₇An anode, the connection node of which forms an endpoint m;

switch tube Q₁Source electrode of (2) is connected with a diode D₁₀Anode, switching tube Q₁Are respectively connected with a diode D₉A cathode, an endpoint n;

switch tube Q₂Source electrode of (2) is connected with a diode D₉Anode, switching tube Q₂Is connected to terminal c;

switch tube Q₁、Q₂、Q₃、Q₄Respectively anti-parallel diode D₅、D₆、D₃、D₄。

The end point a, the end point c, the end point d and the end point n form an asymmetric four-port. The main reasons for adopting the asymmetric four-port network structure by the asymmetric four-port network structure are as follows: the four-port structure has a plurality of expansion structures, the four-port network structure can realize cascade connection of a plurality of units to form a cascade type converter structure, and the structure has a deformation mode that four ports can improve the structure.

The switch tube Q₁、Q₂、Q₃、Q₄Is an IGBT or a power MOSFET.

The capacitor C_dc1、C_dc2The split capacitor is formed by connecting two capacitors with the same capacitance in series, and the capacitors with the same capacitance in series are divided by the capacitors in series, so that the series voltage bears half of each capacitor, the voltage division and the splitting of the direct-current side voltage are mainly performed, a middle point of half of the bus voltage is constructed, and the purpose of completing the lifting of the level is achieved.

The invention discloses an asymmetric four-port based single-phase three-level power factor correction rectifier, which has the following technical effects:

1: the topological structure innovation point of the rectifier is as follows: on the basis of a bridgeless rectifier, a four-port network structure is adopted to finish three-level power factor correction, single-phase power circulation and power path selection are realized by using a mode that a switching tube is connected with a diode in series, and a diode D is used₇、D₈The power of the direct current bus is communicated in a single direction, so that the requirement of intrinsic safety is met. The topology has the structural characteristics of Boost, rectification, three-level power factor correction and an asymmetric four-port network structure, and the four ports of the topology mainly form the asymmetric four-port network structure by four end points of a, c, d and n.

2: the invention provides two completely upper and lower dual topological structures I and II, wherein all analysis is based on the topological structure I, and the analysis of the topological structure II and the modal process are completely similar to the topological structure I and are not repeated in the invention. The main control switch tube device is IGBT or power MOSFET. Such topology can also be generalized to three-phase rectifiers and it presents a four-port structure that can be used as a modular multi-level power cell.

3: three-level power factor correction is integrated into a rectifier topological structure; a Boost process is introduced into a rectifier topological structure, and compared with the prior power factor correction, the quantity of switching tubes and inductors is reduced; a four-port network structure is skillfully applied in the topological structure of the rectifier, so that the four-port network structure has expansibility and practicability in structure; the rectifier topological structure adopts an intrinsic safety structure, so that other components are protected under the condition of failure, and the failure loss is reduced to a certain degree.

Drawings

Fig. 1 shows a first circuit topology according to the present invention.

Fig. 2 shows a second circuit topology according to the present invention.

Fig. 3 is a switch mode flow diagram (topology one) of the present invention.

Fig. 4 is a switch mode two-flow diagram (topology one) of the present invention.

Fig. 5 is a switch mode three-flow diagram (topology one) of the present invention.

Fig. 6 is a switch mode four-flow diagram (topology one) of the present invention.

Fig. 7 is a switch mode five flow diagram (topology one) of the present invention.

Fig. 8 is a switch mode hexaflow diagram (topology one) of the present invention.

Fig. 9(1) is a switch mode flow diagram (topology two) according to the present invention.

Fig. 9(2) is a switch mode two-flow diagram (topology two) according to the present invention.

Fig. 9(3) is a switch mode three-flow diagram (topology two) of the present invention.

Fig. 9(4) is a switch mode four-flow diagram (topology two) of the present invention.

Fig. 9(5) is a switch mode five flow diagram (topology two) of the present invention.

Fig. 9(6) is a switch mode hexaflow diagram (topology two) of the present invention.

FIG. 10 shows the input voltage V of the topological rectifier of the present invention_abA voltage waveform diagram.

FIG. 11 is a waveform diagram of the input voltage and current of the topology of the present invention.

FIG. 12 is a waveform diagram of the voltage and current at the DC side of the topology output of the present invention.

FIG. 13 is a graph of the topological load halved rectifier input voltage V of the present invention_abA voltage waveform diagram.

FIG. 14 is a waveform of the input voltage and current halved by the topological load of the present invention.

FIG. 15 is a waveform diagram of the DC side voltage and current output by halving the topological load according to the present invention.

Detailed Description

As shown in fig. 1, the single-phase three-level power factor correction rectifier based on the asymmetric four-port has a first topology:

comprises an AC power supply AC, an inductor L and a switching tube Q₁、Q₂、Q₃、Q₄Diode D₁、D₂、D₇、D₈、D₉、D₁₀Capacitor C_dc1、C_dc2；

capacitor with a capacitor elementC_dc1The other end is connected with a capacitor C_dc2One end, the connection node of which forms an endpoint n;

The end point a, the end point c, the end point d and the end point n form an asymmetric four-port.

The switch tube Q₁、Q₂、Q₃、Q₄Is an IGBT or a power MOSFET.

The capacitor C_dc1、C_dc2Is a split capacitance.

Load R_LIs connected between the end point p and the end point m.

As shown in fig. 1, current i_lFor the inductor to output a current, i_dcFor the load current output value, V_dcIs a load R_LThe output voltage values at the two ends are selected by adopting an asymmetric structure as the first topological structure, the anti-parallel diode of the MOSFET of the switching tube is used as a conducting loop of the circuit for multiple times, the design cost is saved to a certain extent, the topology adopts an asymmetric four-port structural form, the topology is convenient to further deduce, and a second topological structure is deduced in the invention and has the structure shown in figure 2.

Taking the topology one as an example:

the rectifier topology is suitable for use in a three-phase rectifier and it presents a four-port structure for use as a modular multi-level power cell.

The single-phase three-level power factor correction rectifier based on the asymmetric four-port comprises the following switching modes:

a first switching mode: as shown in fig. 3, the switching tube Q is now the positive half cycle of the AC power source AC₄Conducting, current passing through inductor L and switching tube Q₄Finally via a diode D₂Flowing back, in the process, the inductor L stores energy and the load R_LBy a capacitor C_dc1、C_dc2Supplying power;

and a second switching mode: as shown in FIG. 4, the switching tube Q is the positive half cycle of the AC power supply AC₁Conducting current through inductor L and diode D₃、D₇、D₉、D₁₀And a capacitor C_dc2In the process, the AC power supply and the inductor L simultaneously couple the capacitor C_dc2Charging, load R_LBy a capacitor C_dc1The power supply is realized, and the conversion process of the first switch mode and the second switch mode is a Boost process;

and (3) switching mode III: as shown in FIG. 5, in this case, the positive half cycle of the AC power source AC, the current passes through the inductor L and the diode D₂、D₃、D₇、D₈And a capacitor C_dc1、C_dc2In the process, the AC power supply AC and the inductor L simultaneously supply the load R_LAnd a capacitor C_dc1、C_dc2Supply, capacitor C_dc1、C_dc2Charging;

and a fourth switching mode: as shown in FIG. 6, the switching tube Q is now the negative half cycle of the AC power supply AC₃On and current flows through the diode D₁Switching tube Q₃Finally, the AC power supply AC returns to the AC power supply through the inductor L, in the process, the inductor L stores energy, and the load R_LBy a capacitor C_dc1、C_dc2Supplying power;

a switching mode five: as shown in FIG. 7, the switching tube Q is now the negative half cycle of the AC power supply AC₂On and current flows through the diode D₁、D₈、D₁₀And a split capacitor C_dc1And finally, the current flows through the inductor L and returns to the alternating current power supply AC, and in the process, the alternating current power supply AC and the inductor L simultaneously supply the capacitor C_dc1Charging, wherein the conversion process from the switching mode four to the switching mode five is a Boost process;

a switching mode six: as shown in fig. 8, in this case, the negative half cycle of the AC power source AC, the current passes through the diode D₁、D₄、D₇、D₈And a capacitor C_dc1、C_dc2Returns to the AC power supply AC through the inductor L, and in the process, the AC power supply AC and the inductor L simultaneously supply the load R_LAnd a capacitor C_dc1、C_dc2Supply, capacitor C_dc1 C_dc2And (6) charging.

Experimental parameters:

the peak value of the AC power supply is 200V, and the DC voltage V is output_dc220V, 80 omega of resistance load, 2.5mH of filter inductance and a split capacitor C_dc1＝C_dc21000 muf, switching frequency 10 KHz.

Fig. 10-12 are simulated waveforms of the present invention at a medium load of 80 ohms.

FIG. 10 is a graph of the voltage waveforms in the series branch of the AC power source and the inductor, where V is clearly visible in FIG. 10_abThe voltage achieves three levels.

Fig. 11 is a waveform diagram of voltage and current at two sides of an ac power supply, and it can be seen that the voltage and the current are alternately positive and negative, and the voltage and the current are close to the same phase.

Fig. 12 is a waveform of the topology rectified output voltage and current, wherein the voltage and current change in the waveform is substantially consistent due to the load linearity.

Fig. 13-15 are waveforms illustrating the reduction of the load from 80 ohms to 40 ohms at 0.15s according to the present invention.

FIG. 13 is a graph of the rectified input voltage V_abThe relief waveform is unchanged.

Fig. 14 is a waveform of the process of load shedding change at two sides of an alternating current power supply, and the load shedding is only that the current waveform changes greatly.

Fig. 15 is a waveform of a load shedding change process on two sides of the dc power supply, the current value is doubled due to load shedding, and the fluctuation range of the current and voltage waveform is enlarged due to poor dc filtering effect of the rear stage.

Fig. 13 to fig. 15 can show that the present invention has good stability, strong robustness, and less components and lower cost in the circuit in the topology structure.

Single-phase three-level power factor correction rectifier based on asymmetric four-port, and the intrinsic safety of the rectifier is that a diode D is used₇、D₈The following circuit protection is performed:

one, two diodes D are adopted₇ D₈Ensuring one-way circulation of power and ensuring the capacitance C_dc1 C_dc2Will only flow to the load R_LFlow without flowing backward;

secondly, when the circuit is in fault, the circuit can well protect;

thirdly, in the mode switching process, the diode is used as a Boost voltage clamping diode;

fourthly, when the switch mode is I or IV, the voltage of the inductor L in the energy storage process is lower than that of the capacitor C_dc1 C_dc2When the voltage is applied, the voltage clamping function is realized.

Based on an asymmetric four-port single-phase three-level power factor correction rectifier,

a. in the working process of the circuit, four switching tubes work in six switching modes only in the four switching modes, only one switching tube in each switching mode works, and only one switching tube in each alternating current period works;

b. the four-port structure exists, and the topological structure can be improved to a modular multi-level direction to generate a novel direct current-direct current converter topology.

The invention provides two completely upper and lower dual topological structures I and II, wherein all analysis is based on the topological structure I, the topological structure II and the modal process are completely similar to the topological structure, redundant description is omitted in the invention, the topological structures I and II share the same right protection range, and the adopted main control switching tube device is an IGBT or a power MOSFET.

Claims

1. The single-phase three-level power factor correction rectifier based on the asymmetric four-port comprises an alternating current power supply AC, an inductor L and a switching tube Q₁、Q₂、Q₃、Q₄Diode D₁、D₂、D₇、D₈、D₉、D₁₀Capacitor C_dc1、C_dc2(ii) a The method is characterized in that:

switch tube Q₁、Q₂、Q₃、Q₄Respectively anti-parallel diode D₅、D₆、D₃、D₄；

The endpoint a, the endpoint c, the endpoint d and the endpoint n form an asymmetric four-port.

2. According to the rightThe asymmetric four-port based single-phase three-level power factor correction rectifier of claim 1, wherein: the switch tube Q₁、Q₂、Q₃、Q₄Is an IGBT or a power MOSFET.

3. The asymmetric four-port based single-phase three-level power factor correction rectifier of claim 1, wherein: the capacitor C_dc1、C_dc2Is a split capacitance.

4. The asymmetric four-port based single-phase three-level power factor correction rectifier of claim 1, wherein: the rectifier topology is suitable for use in a three-phase rectifier and it presents a four-port structure for use as a modular multi-level power cell.

5. The asymmetric four-port based single-phase three-level power factor correction rectifier of claim 1, wherein: comprising the following switching modes:

a first switching mode: at this time, the positive half cycle of the AC power supply, the switching tube Q₄Conducting, current passing through inductor L and switching tube Q₄Finally via a diode D₂Flowing back, in the process, the inductor L stores energy and the load R_LBy a capacitor C_dc1、C_dc2Supplying power;

and a second switching mode: at this time, the positive half cycle of the AC power supply, the switching tube Q₁Conducting current through inductor L and diode D₃、D₇、D₉、D₁₀And a capacitor C_dc2In the process, the AC power supply and the inductor L simultaneously couple the capacitor C_dc2Charging, load R_LBy a capacitor C_dc1The power supply is realized, and the conversion process of the first switch mode and the second switch mode is a Boost process;

and (3) switching mode III: in this case, the positive half cycle of the AC power supply AC, the current passes through the inductor L and the diode D₂、D₃、D₇、D₈And a capacitor C_dc1、C_dc2In the process, AC power supplySimultaneously with the inductor L to the load R_LAnd a capacitor C_dc1、C_dc2Supply, capacitor C_dc1、C_dc2Charging;

and a fourth switching mode: at this time, the negative half cycle of the AC power supply, the switch tube Q₃On and current flows through the diode D₁Switching tube Q₃Finally, the AC power supply AC returns to the AC power supply through the inductor L, in the process, the inductor L stores energy, and the load R_LBy a capacitor C_dc1、C_dc2Supplying power;

a switching mode five: at this time, the negative half cycle of the AC power supply, the switch tube Q₂On and current flows through the diode D₁、D₈、D₁₀And a split capacitor C_dc1And finally, the current flows through the inductor L and returns to the alternating current power supply AC, and in the process, the alternating current power supply AC and the inductor L simultaneously supply the capacitor C_dc1Charging, wherein the conversion process from the switching mode four to the switching mode five is a Boost process;

a switching mode six: in this case the negative half cycle of the AC source, current passes through diode D₁、D₄、D₇、D₈And a capacitor C_dc1、C_dc2Returns to the AC power supply AC through the inductor L, and in the process, the AC power supply AC and the inductor L simultaneously supply the load R_LAnd a capacitor C_dc1、C_dc2Supply, capacitor C_dc1 C_dc2And (6) charging.

6. The asymmetric four-port based single-phase three-level power factor correction rectifier of claim 5, wherein: the intrinsically safe nature of the rectifier consists in the use of a diode D₇、D₈The following circuit protection is performed:

secondly, when the circuit is in fault, the circuit can well protect;

7. The asymmetric four-port based single-phase three-level power factor correction rectifier of claim 5, wherein: a. in the working process of the circuit, four switching tubes work in six switching modes only in the four switching modes, only one switching tube in each switching mode works, and only one switching tube in each alternating current period works;