CN-115912960-B - Single-phase three-level heterogeneous mixed bridge arm type energy storage inverter

CN115912960BCN 115912960 BCN115912960 BCN 115912960BCN-115912960-B

Abstract

A single-phase three-level heterogeneous hybrid bridge arm type energy storage inverter comprises a switching tube S 1 、S 2 、S 3 、S 4 、S 5 、S 6 、S 7 , a diode D 1 、D 2 、D 3 , inductors L 1 and L 2 , and capacitors C 1 and C 2 . The inverter adopts a heterogeneous mixed bridge arm structure, so that the power flow path is increased, and meanwhile, the utilization rate of components is improved. Compared with the traditional bridge type inverter, the single-phase three-level heterogeneous mixed bridge arm type energy storage inverter has the advantages that the bridge arm power switch tube direct-connection risk and the power switch tube diode reverse recovery problem are avoided, the working reliability is improved, meanwhile, compared with the traditional two-level inverter, the inverter has the advantages that the output level number is increased, the voltage and current stress of a switch tube is reduced, the switching loss is reduced, and the electric energy conversion efficiency is improved.

Inventors

MA HUI
HUANG YUEHUA
PAN YU
FAN LIPING
YAO JUNWEI
WANG HAILIANG
XIE QIONGYAO
HE QI
LI ZHENHUA
CHENG JIANGZHOU

Assignees

三峡大学

Dates

Publication Date: 20260508
Application Date: 20221109

Claims (5)

1. The single-phase three-level heterogeneous hybrid bridge arm type energy storage inverter comprises a switching tube S 1 、S 2 、S 3 、S 4 、S 5 、S 6 、S 7 , a diode D 1 、D 2 、D 3 , an inductor L 1 、L 2 and a capacitor C 1 、C 2 , and is characterized in that: The anode of the capacitor C 1 is connected with the drain electrode of the switching tube S 1 , and the connecting node of the capacitor C 1 forms an endpoint p; The cathode of the capacitor C 2 is connected with the source electrode of the switching tube S 7 , and the connecting node of the capacitor C 2 forms an endpoint m; The negative electrode of the capacitor C 1 is respectively connected with the positive electrode of the capacitor C 2 and the drain electrode of the switching tube S 4 , and the connecting nodes of the capacitor C 1 form an endpoint n; The source electrode of the switching tube S 4 is respectively connected with the anode of the diode D 1 and the cathode of the diode D 2 , and the connection nodes of the switching tube S 4 form an endpoint e; The drain electrode of the switching tube S 7 is respectively connected with the source electrode of the switching tube S 5 , the source electrode of the switching tube S 6 , the anode of the diode D 2 and the anode of the diode D 3 , and the connection nodes form an endpoint D; The source electrode of the switching tube S 1 is respectively connected with the drain electrode of the switching tube S 2 and the drain electrode of the switching tube S 3 , and the connection nodes of the drain electrodes form an endpoint c; The source electrode of the switching tube S 2 is respectively connected with one end of the inductor L 1 and the cathode of the diode D 1 , and the connecting nodes of the switching tube S 2 form an endpoint a; The source electrode of the switching tube S 3 is respectively connected with the other end of the inductor L 2 and the cathode of the diode D 3 , and the connecting nodes of the switching tube S 3 form an endpoint b; The drain electrode of the switching tube S 5 is respectively connected with one end of the load R L and the other end of the inductor L 1 ; The drain electrode of the switch tube S 6 is respectively connected with the other end of the load R L and one end of the inductor L 2 .
2. The single-phase three-level heterogeneous hybrid arm energy storage inverter of claim 1, wherein the switching tube S 2 , the diode D 1 and the diode D 2 are connected to form a heterogeneous hybrid arm, and the diode D 1 、D 2 in the heterogeneous hybrid arm is connected to the switching tube S 4 to provide an additional power flow path.
3. The single-phase three-level heterogeneous hybrid bridge arm energy storage inverter of claim 1, wherein an endpoint p and an endpoint m of the energy storage inverter are connected with an output side of a bidirectional DC-DC converter, and an input side of the bidirectional DC-DC converter is connected with an energy storage battery.
4. The three-level heterogeneous mixed bridge arm type single-phase energy storage inverter of claim 1, wherein the capacitor C 1 、C 2 is an electrolytic capacitor with equal capacitance values, and each capacitor bears half of the direct current voltage U s at the output side of the bidirectional DC-DC converter.
5. The single-phase three-level heterogeneous hybrid bridge arm energy storage inverter of any one of claims 1-4, wherein the energy storage inverter is characterized by comprising the following six working modes when working normally: The first working mode is that the circuit works in a positive half period of output voltage u o , switching tubes S 1 、S 2 、S 6 and S 7 are conducted, and other switching tubes are turned off, an energy storage battery supplies power to an inductor L 1 and a load R L , an inductor L 1 current i L1 rises linearly, and output current i o =i L1 , and in the first working mode, voltage u ab =+U s between an endpoint a and an endpoint b is generated; The second working mode is that the circuit works in the positive half period of the output voltage u o , the switching tubes S 4 、S 6 and S 7 are conducted, and the other switching tubes are turned off, the energy storage battery charges the capacitor C 1 , the voltage of the capacitor C 1 rises, the capacitor C 2 supplies power to the inductor L 1 and the load R L , the voltage of the capacitor C 2 drops, the current i L1 of the inductor L 1 rises linearly to output the current i o =i L1 , and the voltage u ab =+1/2U s between the endpoint a and the endpoint b in the second working mode; The third working mode is that the circuit works in the positive half period of the output voltage u o , the switching tube S 6 is conducted, and the other switching tubes are turned off, the energy storage battery charges the capacitor C 1 and the capacitor C 2 , the voltage of the capacitor C 1 and the capacitor C 2 rises, the current i L1 of the inductor L 1 flows through the diode D 2 and the diode D 1 and supplies power to the load R L , the current i L1 of the inductor L 1 linearly drops, and the current i o =i L1 is output, and under the mode, the voltage u ab =0 between the terminal a and the terminal b; The circuit works in the negative half period of the output voltage u o , the switching tube S 5 is conducted, and the other switching tubes are turned off, so that the energy storage battery charges the capacitor C 1 and the capacitor C 2 , the voltages of the capacitor C 1 and the capacitor C 2 rise, the current i L2 of the inductor L 2 flows through the diode D 3 and supplies power to the load R L , the current i L2 of the inductor L 2 linearly drops, and the current i o =-i L2 is output, and in the mode, the voltage u ab =0 between the terminal a and the terminal b; The circuit works in a negative half period of output voltage u o , switching tubes S 1 、S 3 and S 5 are conducted, and other switching tubes are turned off, an energy storage battery charges a capacitor C 2 , the voltage of the capacitor C 2 rises, a capacitor C 1 supplies power to an inductor L 2 and a load R L , the voltage of the capacitor C 1 drops, the current i L2 of the inductor L 2 rises linearly to output current i o =-i L2 , and the voltage u ab =-1/2U s between a terminal a and a terminal b in the mode; The working mode six is that the circuit works in a negative half period of output voltage u o , switching tubes S 1 、S 3 、S 5 and S 7 are conducted, other switching tubes are turned off, an energy storage battery supplies power to an inductor L 2 and a load R L , current i L2 of the inductor L 2 rises linearly to output current i o =-i L2 , and voltage u ab =-U s between an endpoint a and an endpoint b is generated in the mode.

Description

Single-phase three-level heterogeneous mixed bridge arm type energy storage inverter Technical Field The invention relates to the field of power electronic and electric energy conversion, in particular to a single-phase three-level heterogeneous hybrid bridge arm type energy storage inverter. Background Along with the increasing severity of the conventional fossil energy crisis and environmental problems, the country is continuously increasing the investment and support of new energy industry, and new energy power generation technology is rapidly developing. However, the power generated and output by the new energy source has larger randomness and fluctuation under the influence of natural conditions, and the energy storage inversion technology can effectively solve the problem of unstable power generated by the new energy source, thereby playing an important role in the effective utilization of the new energy source. Compared with the traditional two-level inverter, the three-level inverter has the advantages of small voltage stress of a switching tube, convenience in switching tube selection and prolonged service life of the switching tube, small output harmonic content, capability of using a filter inductor with small inductance, low overall cost and loss, low switching loss and high electric energy conversion efficiency. Disclosure of Invention The invention provides a single-phase three-level heterogeneous hybrid bridge arm type energy storage inverter which adopts a heterogeneous hybrid bridge arm structure, so that a power circulation path is increased, and the stability of a topological circuit is improved. Compared with a two-level inverter, the energy storage inverter increases the output level number, reduces the voltage and current stress of a switching tube, reduces the switching loss and improves the electric energy conversion efficiency. The technical scheme adopted by the invention is as follows: A single-phase three-level heterogeneous hybrid bridge arm type energy storage inverter comprises a switching tube S 1、S2、S3、S4、S5、S6、S7, a diode D 1、D2、D3, an inductor L 1、L2 and a capacitor C 1、C2; The anode of the capacitor C 1 is connected with the drain electrode of the switching tube S 1, and the connecting node of the capacitor C 1 forms an endpoint p; The cathode of the capacitor C 2 is connected with the source electrode of the switching tube S 7, and the connecting node of the capacitor C 2 forms an endpoint m; The negative electrode of the capacitor C 1 is respectively connected with the positive electrode of the capacitor C 2 and the drain electrode of the switching tube S 4, and the connecting nodes of the capacitor C 1 form an endpoint n; The source electrode of the switching tube S 4 is respectively connected with the anode of the diode D 1 and the cathode of the diode D 2, and the connection nodes of the switching tube S 4 form an endpoint e; The drain electrode of the switching tube S 7 is respectively connected with the source electrode of the switching tube S 5, the source electrode of the switching tube S 6, the anode of the diode D 2 and the anode of the diode D 3, and the connection nodes form an endpoint D; The source electrode of the switching tube S 1 is respectively connected with the drain electrode of the switching tube S 2 and the drain electrode of the switching tube S 3, and the connection nodes of the drain electrodes form an endpoint c; The source electrode of the switching tube S 2 is respectively connected with one end of the inductor L 1 and the cathode of the diode D 1, and the connecting nodes of the switching tube S 2 form an endpoint a; The source electrode of the switching tube S 3 is respectively connected with the other end of the inductor L 2 and the cathode of the diode D 3, and the connecting nodes of the switching tube S 3 form an endpoint b; The drain electrode of the switching tube S 5 is respectively connected with one end of the load R L and the other end of the inductor L 1; The drain electrode of the switch tube S 6 is respectively connected with the other end of the load R L and one end of the inductor L 2. In the energy storage inverter, a switching tube S 2, a diode D 1 and a diode D 2 are connected to form a heterogeneous hybrid bridge arm, and a diode D 1、D2 in the heterogeneous hybrid bridge arm is connected with a switching tube S 4 to provide an additional power flow path. In the energy storage inverter, an endpoint p and an endpoint m are connected with an output side of a bidirectional DC-DC converter, and an input side of the bidirectional DC-DC converter is connected with an energy storage battery. In the energy storage inverter, the capacitor C 1、C2 is an electrolytic capacitor with equal capacitance values, and each capacitor bears half of the direct current voltage U s at the output side of the bidirectional DC-DC converter, so that conditions are provided for realizing the level + -1/2U s. When the energy storage inverter works nor