CN-115987122-B - Inverter and control method thereof

CN115987122BCN 115987122 BCN115987122 BCN 115987122BCN-115987122-B

Abstract

The invention discloses an inverter which comprises a switch capacitor circuit and a bridge type switch circuit, wherein the switch capacitor circuit and the bridge type switch circuit are connected with each other, the bridge type switch circuit comprises a left half-bridge type switch circuit and a right half-bridge type switch circuit, and the left half-bridge type switch circuit and the right half-bridge type switch circuit are respectively connected with the switch capacitor circuit. The inverter comprises an independent direct current input source, 6 switching tubes, 1 capacitor and 1 inductor, wherein the self-balancing of capacitor voltage is realized in the process of charging and discharging in a capacitor period, and each capacitor keeps the same working state, so that the stable output of the inverter is realized.

Inventors

NIE CHENHAO
JIN SHIMING
CHEN HAO
WANG XINFENG
HAO XI
WANG KAI
DENG YUNBO
MA WEIGANG
CHEN JUAN
SONG ZHENGHAN

Assignees

国网天津静海供电有限公司
国家电网有限公司

Dates

Publication Date: 20260508
Application Date: 20221130

Claims (10)

1. The inverter is characterized by comprising a switch capacitor circuit and a bridge type switch circuit, wherein the switch capacitor circuit and the bridge type switch circuit are connected with each other; The switch capacitor circuit comprises a power supply V in , a switch tube S 3 , a switch tube S 4 , a capacitor C 1 and an inductor L 1 , wherein the positive electrode of the power supply V in is connected with the drain electrode of the switch tube S 3 and the drain electrode of the switch tube S 4 through a first circuit node, the source electrode of the switch tube S 3 is connected with the positive electrode of the capacitor C 1 through a second circuit node, the negative electrode of the capacitor C 1 is connected with the source electrode of the switch tube S 4 and one end of the inductor L 1 through a third circuit node, and the other end of the inductor L 1 is connected with the negative electrode of the power supply V in through a fourth circuit node; The bridge type switch circuit comprises a left half-bridge type switch circuit and a right half-bridge type switch circuit, wherein the left half-bridge type switch circuit and the right half-bridge type switch circuit are respectively connected with the switch capacitor circuit; The left half-bridge type switching circuit comprises a switching tube S 1 and a switching tube S 2 , wherein the drain electrode of the switching tube S 1 is connected with the positive electrode of a power supply V in , the drain electrode of the switching tube S 3 and the drain electrode of the switching tube S 4 through a first circuit node, the source electrode of the switching tube S 2 is connected with the other end of an inductor L 1 and the negative electrode of a power supply V in through a fourth circuit node, and the drain electrode of the switching tube S 2 is connected with the source electrode of the switching tube S 1 through a fifth circuit node; The right half-bridge type switching circuit comprises a switching tube S 5 and a switching tube S 6 , wherein the drain electrode of the switching tube S 5 is connected with the source electrode of the switching tube S 3 and the anode electrode of a capacitor C 1 through a second circuit node, the source electrode of the switching tube S 6 is connected with the other end of an inductor L 1 and the cathode electrode of a power supply V in through a fourth circuit node, and the source electrode of the switching tube S 5 is connected with the drain electrode of the switching tube S 6 through a sixth circuit node.
2. The inverter of claim 1, further comprising an inductive impedance Z 1 , wherein the inductive impedance Z 1 is connected to the left half-bridge switching circuit via a fifth circuit node, and wherein the inductive impedance Z 1 is also connected to the right half-bridge switching circuit via a sixth circuit node.
3. The inverter of claim 1, wherein the power source V in is a stand-alone dc power source.
4. The inverter of claim 1, wherein the power source V in charges the capacitor C 1 through the switching tube S 3 and the inductor L 1 with the switching tube S 3 on.
5. The inverter of claim 4, wherein the capacitor C 1 is charged fully and has a voltage across it equal to the voltage of the power supply V in .
6. A cascaded inverter, characterized in that the cascaded inverter is formed by a plurality of cascaded inverters as claimed in claim 1; the sixth circuit node of the previous inverter is connected with the fifth circuit node of the next inverter to form a cascade.
7. The cascaded inverter of claim 6 further comprising an inductive impedance Z formed by a plurality of inductive impedances Z 1 in series; one end of the inductive impedance Z is connected with a fifth circuit node of the first inverter of the cascade, and the other end of the inductive impedance Z is connected with a sixth circuit node of the last inverter of the cascade.
8. A control method of an inverter is characterized in that the method comprises the steps of generating a driving signal, controlling the on or off of a switching tube of the inverter according to claim 1 through the driving signal so as to enable the inverter to work in five working states and output five levels; The method comprises the steps of generating driving signals, namely comparing triangular carrier waves with four same amplitude values with sine modulation waves to obtain square waves with different forms, and logically combining the square waves with different forms to generate the driving signals of the switching tubes.
9. An inverter system comprising an inverter as claimed in claim 1 and a controller for generating a drive signal to control the inverter.
10. An inverter control system comprising an inverter and a controller, wherein the controller is a controller that executes the inverter control method according to claim 8 to control the inverter.

Description

Inverter and control method thereof Technical Field The invention belongs to the technical field of inverters, and particularly relates to an inverter and a control method thereof. Background The traditional inverter is formed by connecting a front-stage switch unit and a rear-stage H bridge in parallel, wherein the front-stage switch unit is used for controlling the output quantity of the level, and the rear-stage circuit realizes the conversion of the positive and negative poles of the level. The traditional inverter adopts a complex control mode, has higher voltage change rate and higher harmonic distortion rate, and controls and outputs stable positive and negative ladder waves according to a switching tube operation sequence, but a later-stage H bridge is required to be subjected to a front-stage accumulation level, so that the switching tube bears larger anti-peak voltage, and the circuit bears over-high total voltage stress, thereby being applied to high-voltage class output limitation. Disclosure of Invention In order to solve the above problems, the present invention provides an inverter and a control method thereof. The inverter consists of a switch capacitor circuit and a bridge type switch circuit, wherein the switch capacitor circuit and the bridge type switch circuit are connected with each other; The switch capacitor circuit comprises a power supply V in, a switch tube S 3, a switch tube S 4, a capacitor C 1 and an inductor L 1, wherein the positive electrode of the power supply V in is connected with the drain electrode of the switch tube S 3 and the drain electrode of the switch tube S 4 through a first circuit node, the source electrode of the switch tube S 3 is connected with the positive electrode of the capacitor C 1 through a second circuit node, the negative electrode of the capacitor C 1 is connected with the source electrode of the switch tube S 4 and one end of the inductor L 1 through a third circuit node, and the other end of the inductor L 1 is connected with the negative electrode of the power supply V in through a fourth circuit node; The bridge type switch circuit comprises a left half-bridge type switch circuit and a right half-bridge type switch circuit, wherein the left half-bridge type switch circuit and the right half-bridge type switch circuit are respectively connected with the switch capacitor circuit; The left half-bridge type switching circuit comprises a switching tube S 1 and a switching tube S 2, wherein the drain electrode of the switching tube S 1 is connected with the positive electrode of a power supply V in, the drain electrode of the switching tube S 3 and the drain electrode of the switching tube S 4 through a first circuit node, the source electrode of the switching tube S 2 is connected with the negative electrode of the power supply V in through a fourth circuit node, and the drain electrode of the switching tube S 2 is connected with the source electrode of the switching tube S 1 through a fifth circuit node; The right half-bridge type switching circuit comprises a switching tube S 5 and a switching tube S 6, wherein the drain electrode of the switching tube S 5 is connected with the source electrode of the switching tube S 3 and the anode electrode of a capacitor C 1 through a second circuit node, the source electrode of the switching tube S 6 is connected with the inductor and the cathode electrode of a power supply V in through a fourth circuit node, and the source electrode of the switching tube S 5 is connected with the drain electrode of the switching tube S 6 through a sixth circuit node. The inductive impedance Z 1 is connected with the left half-bridge type switch circuit through a fifth circuit node, and the inductive impedance Z 1 is also connected with the right half-bridge type switch circuit through a sixth circuit node. The power supply V in is an independent direct current power supply. With the switching tube S 3 on, the power supply V in charges the capacitor C 1 through the switching tube S 3 and the inductor L 1. When the capacitor C 1 is fully charged, the voltage across the capacitor C 1 is equal to the voltage of the power supply V in. The invention also proposes a cascade inverter formed by cascading a plurality of inverters as described above; the sixth circuit node of the previous inverter is connected with the fifth circuit node of the next inverter to form a cascade. The cascading inverter further comprises an inductive impedance Z, wherein the inductive impedance Z is formed by connecting a plurality of inductive impedances Z 1 in series; one end of the inductive impedance Z is connected with a fifth circuit node of the first inverter of the cascade, and the other end of the inductive impedance Z is connected with a sixth circuit node of the last inverter of the cascade. The invention also provides a control method of the inverter, which comprises the steps of generating a driving signal, controlling the on or off of a swit