An improved npc three-level inverter
A technology of three-level inverters and power switching devices, which is applied in the direction of electrical components, AC motor control, and output power conversion devices, etc. Problems such as unbalanced heating can be achieved to enhance safety margins, solve unbalanced heating, and increase output power
Active Publication Date: 2022-08-02
TIANJIN POLYTECHNIC UNIV
View PDF6 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0004] There is a problem with the topology of the NPC three-level inverter. During operation, the duration of current flowing through each switching device and diode is different, and the switching times of each switching device are different, resulting in uneven heating of each switching device and a large difference in temperature rise. In particular, the switching loss of the medium-voltage switching device used in the medium-voltage high-power three-level inverter accounts for a large proportion of the total loss of the switching device. When the inverter outputs a high fundamental frequency, the switching frequency of the switching device is relatively high. Further, Exacerbating the problem of uneven heating of switching devices, because the output power of the entire device depends on the switching device with the highest temperature rise among all devices, many switching devices are not fully utilized
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0031] The invention aims at the problems in the topology structure of the NPC three-level inverter, that is, the duration of current flowing through each controllable power device and the diode during operation is different, and the switching times of each controllable power device are different, resulting in unbalanced heating of each power device, The temperature rise varies greatly, and many power devices are not fully utilized, which affects the output power of the entire device. The present invention proposes a novel three-level inverter topology structure. Each bridge arm consists of six switching devices, four freewheeling diodes and two clamping diodes, referred to as 6SNPC (6 Switch Device and Neutral Point Clamped, referred to as 6SNPC) three-level inverter topology.
[0032] The specific implementation is as follows, taking the switching device IGCT as an example, the anode of the first IGCT is defined as the first connection point, and the cathode is defined as th...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention relates to an improved NPC three-level inverter, each bridge arm comprises six switching power devices, four freewheeling diodes and two clamping diodes. The anode of the first switching power device is defined as the first connection point, the cathode thereof is defined as the second connection point, and the first switching power device is connected in parallel with the first freewheeling diode; the second switching power device to the fourth switching power device support The circuit is similar; the fifth switching power device has its anode connected to the first connection point and its cathode connected to the second connection point; the sixth switching power device has its anode connected to the fourth connection point and its cathode connected to the fifth connection point ; The first clamping diode, its cathode is connected to the second connection point, and its anode is defined as the sixth connection point; the second clamp diode, its cathode is connected to the sixth connection point, and its anode is connected to the fourth connection point.
Description
Technical field: [0001] The invention relates to an inverter topology, in particular to an improved NPC three-level inverter. Background technique: [0002] Most high-power motors use medium voltage, especially one of the development directions of high-performance medium-voltage inverters is to use a three-level inverter topology. The three-level structure has many advantages, such as: reducing the busbar that each switching device bears Therefore, low voltage withstand devices can be used to achieve high voltage and high power output; the increase in the number of levels improves the output voltage waveform and reduces harmonic distortion; a relatively good voltage waveform can be obtained with a lower switching frequency, so the switching loss is small , High efficiency; low output voltage change rate, improved electromagnetic compatibility performance of the device. [0003] At present, three-level inverters are usually clamped by diodes, that is, neutral point clamped (...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & AuthorityPatents(China)
IPC IPC(8): H02M7/487H02P27/14
CPCH02M7/487H02P27/14
Inventor金雪峰陈炜谷鑫王志强张国政李新旻
OwnerTIANJIN POLYTECHNIC UNIV