CN104852603A - Multi-link-tower structure modularized multi-level voltage source current converter - Google Patents

Abstract

The invention relates to a combined structure of a multi-level voltage source converter valve tower, in particular to a modular multi-level voltage source converter with a multi-connected tower structure. The modular multilevel converter is composed of three-phase six bridge arms, and it is characterized in that each bridge arm is composed of multi-connected towers, and the multi-connected towers are composed of at least two valve towers, at least two The valve towers are connected by a common support; each valve tower is composed of vertically arranged, at least two-layer modular units arranged back-to-back. The present invention adopts a multi-connected tower structure and expands along the plane direction to reduce the floor area and engineering cost of the converter, facilitate the design, manufacture, installation and expansion of the converter equipment, and provide flexibility for the design of the valve hall. options.

Description

A Modular Multilevel Voltage Source Converter with Multi-tower Structure

technical field

The invention relates to a combined structure of a multi-level voltage source converter valve tower, in particular to a modular multi-level voltage source converter with a multi-connected tower structure. the

Background technique

The core component of the converter, the IGBT, has a voltage level of thousands of volts, and the voltage level of the power grid is much higher than that of the IGBT. In order to realize the commutation, a low-voltage, low-power The basic independent converter module, and then several basic independent converter modules constitute a higher voltage level module unit, and the module unit is expanded to meet the high voltage and high power power transmission occasions. the

In the application of power electronics engineering, the realization of the modular multi-level voltage source converter is to use the basic independent converter modules manufactured by several low-voltage power devices, and connect each other in a certain way to obtain higher Voltage level and higher power output. When the voltage level reaches tens of kilovolts or even hundreds of kilovolts or more, the original module unit must not only be expanded in the plane, but also expanded in the height direction to form a tower structure. the

At present, foreign converter valves generally adopt a simple one-line arrangement, and all the modular units of a bridge arm are connected together to form a tall and narrow "wall". However, such an arrangement is not the best choice when the equipment is required to be compact and the footprint is reduced, and its stability and shock resistance also limit the height of the equipment. the

Contents of the invention

Aiming at the deficiencies of the prior art, the object of the present invention is to provide a modular multi-level voltage source converter with a multi-tower structure. The present invention adopts a multi-tower structure and extends along the plane direction to reduce the The floor area and engineering cost of the inverter are reduced, which facilitates the design, manufacture, installation and expansion of the inverter equipment, and provides flexible options for the design of the valve hall. the

The purpose of the present invention is to adopt the following technical solutions to achieve:

The present invention provides a modular multi-level voltage source converter with multi-connected tower structure. The modular multi-level converter is composed of three-phase six bridge arms. The improvement is that each bridge arm It is composed of multi-connected towers, the multi-connected towers are composed of at least two valve towers, at least two valve towers form a whole through a common support, and are electrically connected through busbars; each The valve tower is composed of at least two layers of modular units arranged vertically and arranged back to back; one or both ends of the beam at the bottom of each layer of modular units are supported on a common support;

The module unit is composed of cascaded several sub-modules, the sub-modules include insulated gate bipolar power transistors IGBT1 and IGBT2, thyristor V, energy storage capacitor C, vacuum switch, resistor R1 and resistor R2; the resistor R1 connected in series with resistor R2 to form a R1-R2 branch; the vacuum switch, thyristor V and IGBT2 are sequentially connected in parallel; the IGBT1 and IGBT2 are up and down structures and the emitter of IGBT1 is connected to the collector of IGBT2; the IGBT1, R1-R2 The branch circuit and the energy storage capacitor C are connected in parallel in sequence. the

Further, both ends of the valve tower are provided with support members, and a length-adjustable diagonal tie rod is arranged between the two support members. the

Further, after multi-layer modular units form a multi-connected valve tower, two back-to-back modular units on the same floor at one end are connected through flat busbars between the same floors, and the modular units at the other end are connected to the same end on the upper floor. The modular units on the back are connected through the oblique busbars between the upper and lower layers, forming a complete circuit from the incoming line to the outgoing line. the

Compared with prior art, the beneficial effect that the present invention reaches is:

1. The multi-connected tower structure provided by the present invention can increase the number of stacked modular units, increase the height of the valve tower itself, and reduce the occupied area;

2. The multi-connected tower structure provided by the present invention can further reduce the occupied area due to the elimination of the gap between the towers;

3. The multi-connected tower structure provided by the present invention can increase stability and improve seismic performance;

4. The present invention adopts a multi-connected tower structure and expands along the plane direction to reduce the floor area and engineering cost of the converter, facilitate the design, manufacture, installation and expansion of the converter equipment, and facilitate the design of the valve hall. Flexible options are provided. the

Description of drawings

Fig. 1 is the standard three views of the modularized multilevel voltage source converter of the multi-connected tower structure provided by the present invention, that is, the schematic diagram of the multi-connected valve tower (the figure is a triple valve tower, which can be made into two or more valve towers as required. quadruple or multiple). the

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings. the

The present invention provides a modular multi-level voltage source converter with multi-connected tower structure. A bridge arm is composed of multi-group towers, the multi-group towers are composed of at least two valve towers, at least two valve towers are connected by a common support to form a whole, and the electrical connection is realized through the busbar Connection; each valve tower is composed of vertically arranged modular units with at least two layers and arranged back to back, and the modular units are composed of several cascaded sub-modules. the

That is to say, multiple modular units are stacked and arranged back to back to form an independent converter valve tower, and then several such valve towers are arranged together along the side to form a multi-connected tower. According to the needs of the project, a bridge arm may be composed of several or dozens of such multiple valve towers. After multi-layer modular units form a multi-connected valve tower, two back-to-back modular units between the same layer at one end are connected through flat busbars between the same layers, and the module unit at the other end is connected to the module at the same end on the upper layer. The units are connected through the inclined busbars between the upper and lower floors, forming a complete circuit from the incoming line to the outgoing line. the

The module unit is composed of several cascaded sub-modules, the sub-modules include insulated gate bipolar power transistors IGBT1 and IGBT2, thyristor V, energy storage capacitor C, vacuum switch, resistor R1 and resistor R2; the resistor R1 and resistor R2 is connected in series to form the R1-R2 branch; the vacuum switch, thyristor V and IGBT2 are connected in parallel in sequence; the IGBT1 and IGBT2 are up and down structures and the emitter of IGBT1 is connected to the collector of IGBT2; the IGBT1, R1-R2 branch It is connected in parallel with the energy storage capacitor C in turn. In order to simplify the structure, adjacent valve towers can share the middle support;

In order to increase the stability and shock resistance of the multi-valve tower, an adjustable-length diagonal tie rod is added to the lower support. the

Such a structure can reduce the footprint of the equipment and facilitate further expansion in the height direction. the

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention. the

Claims (3)

1. the modular multi-electrical-level voltage source current converter of a multi-joint group of tower structure, described modularization multi-level converter is made up of three-phase six brachium pontis, it is characterized in that, each brachium pontis is made up of multi-joint group of tower, described multi-joint group of tower is made up of at least two connection valve towers, the valve tower of at least two connection is integrally formed by common support part between any two, and realizes the connection electrically by busbar; Each valve tower is made up of modular unit that is that vertically arrange, at least two-layer and back-to-back layout; The one or both ends of the beam bottom every layer of modular unit are supported on common support part;

Described modular unit is made up of several submodules of cascade, and described submodule comprises insulated gate bipolar translator power tube IGBT1 and IGBT2, thyristor V, storage capacitor C, vacuum switch, resistance R1 and resistance R2; Described resistance R1 and resistance R2 connects, composition R1-R2 branch road; Described vacuum switch, thyristor V and IGBT2 are in parallel successively; Described IGBT1 with IGBT2 is up-down structure and the emitter of IGBT1 is connected the collector electrode of IGBT2; Described IGBT1, R1-R2 branch road and storage capacitor C in parallel successively.

2. the modular multi-electrical-level voltage source current converter of multi-joint group of tower structure as claimed in claim 1, is characterized in that, the two ends of described valve tower are provided with strutting piece, is provided with the brace of adjustable length between two strutting pieces.

3. the modular multi-electrical-level voltage source current converter of multi-joint group of tower structure as claimed in claim 1, it is characterized in that, after multilayer module unit composition Multigang valve tower, two back-to-back modular units of the same interlayer of one end, connected by flat busbar between same layer, modular unit that the modular unit of the other end is opposing with the same end of last layer is connected by busbar oblique between levels, from inlet wire to outlet, form a complete loop.