CN108880286A - High pressure direct current valve pile structure design method based on chip and the unified optimization of system - Google Patents

Abstract

The invention belongs to the technical field of high-voltage DC valve stack heat dissipation, and in particular relates to a high-voltage DC valve stack structure design method based on unified optimization of chips and systems, including: reversely connecting two chip modules to form a small rectifier module, and the two chips share the same A heat sink, and multiple small rectifier modules connected in series to form a large rectifier structure. The present invention aims at the characteristic that the structure of the rectifier arm is the reverse of the upper and lower arms, combined with the characteristics of one-way heat dissipation of the chip, and without affecting the normal operation of the components, the conventional connection method is changed, and the two chips share the same heat sink, which is different from the original Compared with the connection method, the number of heat sinks is reduced by half, and the structure of components is simplified.

Description

High-voltage DC valve stack structure design method based on unified optimization of chip and system

technical field

The invention belongs to the technical field of high-voltage direct-current valve stack heat dissipation, and in particular relates to a high-voltage direct-current valve stack structure design method based on unified optimization of chips and systems.

Background technique

With the development of HVDC power grids, HVDC valve stacks have been widely used. The AC/DC rectifier is taken as an example for description below (the same is true for rectifier inverters such as DC/AC, DC/DC, and AC/AC). In the three-phase full-bridge rectifier circuit, the high-voltage DC valve stack on each rectifier arm is composed of several thyristors or IGBTs connected in series in the same direction. Take the disc spring crimping type IGBT as an example. When connected normally, all chip modules are connected in series in the same direction, and their electrical connections meet the specifications. However, through experiments, it can be found that under normal working conditions, when the module passes current, the main part of the heat is the chip in the module, and the temperature of the chip is the highest. The chip has two ways of dissipating heat, upward and downward through the upper contact sheet, upper conductive sheet, disc spring, upper cover plate and upper heat sink, and downward through the lower contact sheet, lower cover plate and heat sink. As shown in Figure 1 and Figure 2. Figure 1 from top to bottom: upper cover plate (aluminum material), butterfly spring (copper material), upper conductive sheet (silver material), upper contact sheet (molybdenum material), chip (silicon material), outer sheath ( engineering plastic material), lower contact sheet (molybdenum material). For easy observation, the internal structure of the chip has been lifted out of the outer sheath. It can be seen from Figure 2 that the area where the chip is located is a high temperature area, and the two ends are low temperature areas. The distance from the chip to the lower contact plate is so close that almost all heat is conducted away from this side. Through observation, it can be found that the upward heat dissipation path is long, the heat dissipation efficiency is low, and the heat is mainly dissipated through downward conduction, which can be roughly considered as one-way heat dissipation.

At present, in the high-voltage DC valve stack, each valve plate needs to be equipped with a heat sink, so the heat dissipation of each device requires a large number of heat sinks to meet the heat dissipation requirements, and the overall mechanism is relatively complicated, but in fact the disc spring crimping The heat dissipation of the type IGBT is basically one-way heat dissipation, and the heat of the upper cover actually mainly comes from the heat sink, and the utilization efficiency of the heat sink is low. Each valve plate needs to install a heat sink, and the usage is also relatively large.

Contents of the invention

In view of the above problems, the present invention proposes a high-voltage DC valve stack structure design method based on the unified optimization of the chip and the system, which includes: reversely connecting the chip modules in pairs to form a small rectifier module, and the two chips share the same heat sink. Multiple small rectifier modules are connected in series to form a large rectifier structure.

Described method specifically comprises:

Step 1. According to the design needs, determine that the number of chips is even. If the number of chips is odd, add one to form a redundant design;

Step 2. Taking the three-phase full-bridge rectifier circuit as an example, connect the three-phase 12 chip modules in reverse to form a small rectifier module;

Step 3, using the small rectifier module as the basic unit, and connecting them step by step in series to form a large rectifier structure;

Step 4. Calculate all voltage and current margins to meet system design requirements.

Beneficial effects of the present invention:

In view of the fact that the structure of the rectifier arm is the reverse of the upper and lower arms, combined with the characteristics of one-way heat dissipation of the chip, without affecting the normal operation of the components, the conventional connection method is changed. The two chips share the same heat sink, which is different from the original connection method. In comparison, the number of heat sinks is reduced by half, and the structure of components is simplified.

Description of drawings

Figure 1 shows the internal structure of the crimp-type IGBT chip module.

Fig. 2 Temperature distribution of crimp-type IGBT chip module under rated working conditions.

Detailed ways

In view of the fact that the structure of the rectifier arm is the reverse of the upper and lower arms, combined with the characteristics of one-way heat dissipation of the chip, and without affecting the normal operation of the components, the present invention proposes a high-voltage DC valve stack structure based on the unified optimization of the chip and the system The design method includes: two chip modules are reversely connected to form a small rectifier module, the two chips share the same heat sink, and then a plurality of small rectifier modules are connected in series to form a large rectifier structure.

Described method specifically comprises:

Step 1. According to the design needs, determine that the number of chips is even. If the number of chips is odd, add one to form a redundant design;

Step 2. Taking the three-phase full-bridge rectifier circuit as an example, connect the three-phase 12 chip modules in reverse to form a small rectifier module;

Step 3, using the small rectifier module as the basic unit, and connecting them step by step in series to form a large rectifier structure;

Step 4. Calculate all voltage and current margins to meet system design requirements.

This embodiment is only a preferred specific implementation of the present invention, but the scope of protection of the present invention is not limited thereto, any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention , should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (2)

1. A high-voltage DC valve stack structure design method based on the unified optimization of the chip and the system, characterized in that it includes: reversely connecting the chip modules in pairs to form a small rectifier module, the two chips share the same heat sink, and then multiple Several small rectifier modules are connected in series to form a large rectifier structure. 2. The method according to claim 1, wherein the method specifically comprises: Step 1. According to the design needs, determine that the number of chips is even. If the number of chips is odd, add one to form a redundant design; Step 2. Taking the three-phase full-bridge rectifier circuit as an example, connect the three-phase 12 chip modules in reverse to form a small rectifier module; Step 3, using the small rectifier module as the basic unit, and connecting them step by step in series to form a large rectifier structure; Step 4. Calculate all voltage and current margins to meet system design requirements.