阅读说明：本技术 一种中压变流器三电平功率模块拓扑模块及装置 (Medium voltage converter three-level power module topology module and device ) 是由 杨飞 毛江 雷肖 张斯翔 过亮 周敏 于彬 王�琦 罗维 于 2020-03-23 设计创作，主要内容包括：本发明公开了一种中压变流器三电平功率模块拓扑模块及装置,包括二极管钳位型三电平拓扑结构,所述二极管钳位型三电平拓扑结构包括两个吸收电容Cs1、Cs2、四个功率开关管T1-T4、两个钳位二极管D5、D6,在所述二极管钳位型三电平拓扑结构中的两个钳位点之间加入钳位电阻。优点：本发明具有电气拓扑先进,器件选型合理,机械结构紧凑,稳定可靠,整体性能处于国内先进水平。(The invention discloses a medium-voltage converter three-level power module topology module and a device, which comprise a diode-clamped three-level topology structure, wherein the diode-clamped three-level topology structure comprises two absorption capacitors Cs1 and Cs2, four power switch tubes T1-T4, two clamping diodes D5 and D6, and a clamping resistor is added between two clamping points in the diode-clamped three-level topology structure. The advantages are that: the invention has the advantages of advanced electrical topology, reasonable device type selection, compact mechanical structure, stability and reliability, and the overall performance of the invention is at the domestic advanced level.)

1. A medium-voltage converter three-level power module topology module comprises a diode-clamped three-level topology structure, wherein the diode-clamped three-level topology structure comprises two absorption capacitors Cs1 and Cs2, four power switch tubes T1-T4, two clamping diodes D5 and D6, and the topology module is characterized in that: and adding a clamping resistor between two clamping points in the diode clamping type three-level topological structure.

2. The medium voltage converter three-level power module topology module of claim 1, characterized in that: the clamping resistor is connected in parallel with two clamping diodes which are connected in series in the diode clamping type three-level topological structure.

3. The medium voltage converter three-level power module topology module of claim 1, characterized in that: the power switch tube is a crimping type IGBT power module or a crimping type IEGT power module.

4. A medium voltage converter three-level power module topology device is characterized in that: a medium voltage converter tri-level power module topology module as claimed in any of claims 1-3 comprising a housing and said medium voltage converter tri-level power module topology module being provided in said housing.

5. The medium voltage converter three-level power module topology arrangement according to claim 4, characterized in that: the water-cooled heat sink further comprises a neutral point copper bar (21), an AC copper bar (19), a laminated bus bar (9), eight water-cooled heat sinks (10-17), a third water-cooled heat sink (11), a first direct current supporting capacitor (7) and a second direct current supporting capacitor (8);

the power switch tube T1 (1) is in pressure joint between the first water-cooled radiator (10) and the second water-cooled radiator (11), the power switch tube T2 (2) is in pressure joint between the second water-cooled radiator (11) and the third water-cooled radiator (12), the power switch tube T3 (3) is in pressure joint between the sixth water-cooled radiator (15) and the seventh water-cooled radiator (16), and the power switch tube T4 (4) is in pressure joint between the seventh water-cooled radiator (16) and the eighth water-cooled radiator (17);

the clamping diode D5(5) is in compression joint between the fourth water-cooled radiator (13) and the neutral point copper bar (21), and the clamping diode D6(6) is in compression joint between the fifth water-cooled radiator (14) and the neutral point copper bar (21);

the third water-cooled radiator (12) and the sixth water-cooled radiator (15) are connected on an AC copper bar (19) through a wiring copper bar;

a neutral point copper bar (21) is connected to the laminated busbar (9), a first water-cooling radiator (10) is connected to the laminated busbar (9) through a first output copper bar (22), an eighth water-cooling radiator (17) is connected to the laminated busbar (9) through a second output copper bar (23), the laminated busbar (9) outputs a neutral point through a first busbar (92), outputs + DC through a second busbar (91) and outputs-DC through a third busbar (93);

the second direct current supporting capacitor (8) is connected to the laminated busbar (9) through a first terminal (81) and a second terminal (82), the first supporting capacitor (7) is connected to the laminated busbar (9) through a terminal, the absorbing capacitor Cs1(24) and the absorbing capacitor Cs2(25) are connected to the laminated busbar (9) through a cable, and the clamping resistor (20) is connected to the laminated busbar (9) through a cable.

6. The medium voltage converter three-level power module topology arrangement according to claim 5, characterized in that: the AC copper bar (19) collects AC current through the Hall current sensor (18).

7. The medium voltage converter three-level power module topology arrangement according to claim 5, characterized in that: the power switch tube (1-4), the clamping diodes (5, 6) and the water-cooling radiator (10-17) are fixed in a mechanical frame (26) through fasteners.

Technical Field

The invention relates to a medium-voltage converter three-level power module topology module and a device, and belongs to the technical field of medium-voltage converter systems.

Background

In recent years, due to the restriction of various land resources, the development of wind power begins to develop to the sea with better wind resources, and the sea wind power has rapidly developed in the world. In order to adapt to the development of offshore wind power, all international large-fan manufacturing companies have introduced 5MW and above-grade fan water-cooled converters on the basis of respective fans. The medium-voltage converter serving as a key device for connecting wind power into a power system is an optimal technical scheme, and the mainstream of the future offshore wind power converter market is certainly a medium-voltage full-power large-capacity converter.

Due to the high technical threshold and the high capital threshold, the medium-voltage current transformer of the offshore wind turbine generator set built and built in China currently adopts ABB and GE imported products, is still in the prototype stage in China, and is one of the key electrical components with low localization rate. The power level of the whole machine is more than 3MW, 3.6MW and 4MW, and more than 5MW is in a prototype stage and is not in batch. Basically, the scheme is a 690V low-voltage scheme in China, and a 3300V medium-voltage class medium-voltage converter is still in a pre-research stage.

Disclosure of Invention

The invention aims to provide a three-level power module topology module and a device of a medium voltage converter aiming at the technical requirement of a 3300V medium voltage converter.

In order to solve the technical problem, the invention provides a medium-voltage converter three-level power module topology module which comprises a diode-clamped three-level topology structure, wherein the diode-clamped three-level topology structure comprises two absorption capacitors Cs1 and Cs2, four power switch tubes T1-T4, two clamping diodes D5 and D6, and a clamping resistor is added between two clamping points in the diode-clamped three-level topology structure.

Further: the clamping resistor is connected in parallel with two clamping diodes which are connected in series in the diode clamping type three-level topological structure.

Further: the power switch tube is a crimping type IGBT power module or a crimping type IEGT power module.

A medium voltage converter tri-level power module topology arrangement comprising a housing and a medium voltage converter tri-level power module topology module according to any of claims 1-3, said medium voltage converter tri-level power module topology module being provided in said housing.

Further: the device also comprises a neutral point copper bar, an AC copper bar, a laminated bus bar, eight water-cooled radiators, a third water-cooled radiator, a first direct current support capacitor and a second direct current support capacitor;

the power switch tube T1 is in pressure joint between the first water-cooled radiator and the second water-cooled radiator, the power switch tube T2 is in pressure joint between the second water-cooled radiator and the third water-cooled radiator, the power switch tube T3 is in pressure joint between the sixth water-cooled radiator and the seventh water-cooled radiator, and the power switch tube T4 is in pressure joint between the seventh water-cooled radiator and the eighth water-cooled radiator;

the clamping diode D5 is in pressure joint between the fourth water-cooled radiator and the neutral point copper bar, and the clamping diode D6 is in pressure joint between the fifth water-cooled radiator and the neutral point copper bar;

the third water-cooled radiator and the sixth water-cooled radiator are connected to the AC copper bar through a wiring copper bar;

the neutral point copper bar is connected to the laminated busbar, the first water-cooling radiator is connected to the laminated busbar through a first output copper bar, the eighth water-cooling radiator is connected to the laminated busbar through a second output copper bar, the laminated busbar outputs the neutral point through the first busbar, outputs the + DC through the second busbar and outputs the-DC through the third busbar;

the second direct current supports the electric capacity and connects on the female row of range upon range of row through first terminal and second terminal, and same first support electric capacity passes through the terminal connection on the female row of range upon range of, and absorption electric capacity Cs1 and absorption electric capacity Cs2 pass through the cable connection on the female row of range upon range of, and the clamp resistance passes through the cable connection on the female row of range upon range of.

Further: the AC copper bar collects AC current through the Hall current sensor.

Further: the power switch tube, the clamping diode and the water-cooling radiator are fixed in the mechanical frame through fasteners.

The invention achieves the following beneficial effects:

the invention has the advantages of advanced electrical topology, reasonable device type selection, compact mechanical structure, stability and reliability, and the overall performance of the invention is at the domestic advanced level.

Drawings

Fig. 1 is a circuit schematic diagram of a three-level power module topology module of the medium voltage converter of the present invention;

FIG. 2 is a topology diagram of an absorption capacitor tri-level half-bridge arm of the tri-level power module topology and apparatus of the present invention;

FIG. 3 is a clamp resistor topology diagram of a three-level power module topology and apparatus of the present invention;

FIG. 4 is a state topology diagram of a clamp diode "0" of the three-level power module topology and apparatus of the present invention;

FIG. 5 is a perspective front view of a three-level power module topology and apparatus of the present invention;

FIG. 6 is a perspective rear view of a three-level power module topology and apparatus of the present invention;

fig. 7 is a perspective view of a crimping mechanism of the three-level power module topology and device of the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

Hair brushThe electric topology adopts a double-bridge back diode clamping three-level topological structure and comprises an IGBT/IEGT power module, a clamping diode, a direct current supporting capacitor, an absorption capacitor, a clamping resistor and the like. The direct-current voltage 2600V in the double-bridge back electrical topology is according to a formula U_m＝(k₁U_Max+U_sp)·k₂The rated voltage of the pressure-welding type IEGT power module is calculated to be 4032V. Wherein k is₁-an overvoltage coefficient; k is a radical of₂-a safety factor; u shape_Max-a dc voltage maximum; u shape_sp-switching off the spike overvoltage. Get k₁Is 1.1, k₂Is 1.2, U_spIs 500V. According to technical parameters provided by a power module manufacturer, when the switching frequency is 750HZ, the Zema T1800GB45A type IGBT meets the design requirements of a system.

As shown in fig. 1, a specific circuit of an electrical topology structure of a medium voltage converter three-level power module is as follows:

the three-level topological structure comprises a plurality of parallel double-bridge back diode clamping structures and two direct-current supporting capacitors C1 and C2;

the double-bridge back diode clamping three-level topological structure comprises two absorption capacitors Cs1, Cs2, a clamping resistor R1, four power switch tubes T1-T4, two clamping diodes D5 and D6. Four freewheeling diodes D1-D4;

the collector of the power switch tube T1 is respectively connected with one end of an absorption capacitor Cs1, one end of a direct current support capacitor C1, a first level output end and the negative electrode of a fly-wheel diode D1;

an emitter of the power switch tube T1 is respectively connected with a collector of the power switch tube T2, one end of a clamping resistor R1, the cathode of a clamping diode D5, the anode of a freewheeling diode D1 and the cathode of a freewheeling diode D2;

the emitter of the power switch tube T2 is respectively connected with the anode of the current diode D2, the collector of the power switch tube T3, the cathode of the fly-wheel diode D3 and the alternating current input end;

the emitter of the power switch tube T3 is respectively connected with the anode of a clamping diode D6, the other end of a clamping resistor R1, the collector of the power switch tube T4, the anode of a freewheeling diode D3 and the cathode of a freewheeling diode D4;

the emitter of the power switch tube T3 is respectively connected with the anode of the current diode D4, one end of the absorption capacitor Cs2, one end of the current support capacitor C2 and a second level output end;

the other end of the direct current supporting capacitor C1 is connected with a third level output end (NP), the other end of the direct current supporting capacitor C2, the other end of the absorption capacitor Cs1, the other end of the absorption capacitor Cs2, the anode of the clamping diode D5 and the cathode of the clamping diode D6.

As shown in fig. 2 to 4, the topology design diagrams of the absorption capacitor tri-level half-bridge arm, the clamp resistor topology design diagram, and the clamp diode "0" state topology design diagram correspond to each other.

The absorption capacitor is directly connected in parallel at two ends of the IGBT, and the method has the advantages of simple circuit structure, low cost and reliable application, and is shown in figure 2. According to the formula:

wherein L is_sParasitic inductance of the absorption circuit; l is_PIs a DC bus stray inductance; l is_CIs a parasitic inductance of a direct current capacitor; i.e. i₀Is the working current; delta U_P2Is the peak voltage; c_sIs the capacitance value of the absorption capacitor.

Wherein (L)_C+L_P+L_s) Referring to a double-pulse simulation report of a Xima IGBT manufacturer, taking a minimum value of 300Nh, i₀Is composed ofΔU_P2Obtaining C by taking 1000V_sThe value is more than or equal to 1.86 muF, 2 muF is taken, a clamping resistor is added between two clamping points shown in figure 3, and the one-way clamping effect of the diode is compensated through a path provided by the clamping resistor. Theoretically, the larger the clamping resistance value is, the better the clamping effect is, but when the voltage is constant, the resistance is large, and the heat is also serious, and it is considered that the auxiliary clamping resistance is 20k omega.

The clamping diode "0" state topology is shown in fig. 4. For the diode-clamped three-level topology, 4 main pipes of each bridge arm oil are connected in series, and each phase is formed by connecting 2 clamping diodes in anti-parallel and in the middle of an upper bridge arm and a lower bridge arm. According to the three-level working principle, each bridge arm has three switching states of positive, negative and zero, and two current flowing modes of flowing in and flowing out exist in each switching state according to the direction of load current. In the invention, a clamping diode of a Simma E2400EC45E type is selected, the reverse peak voltage is 4500V, and the forward current is 2400A.

Please further refer to fig. 5 to 7, which are respectively corresponding to a front perspective view, a back perspective view and a crimping mechanical device of a three-level power module topology and device.

Fig. 5-6 illustrate electrical connections for a three-level power module topology. The crimping type IGBT/IEGT power module 1 is crimped between the water-cooled radiators 10 and 11, the IGBT/IEGT power module 2 is crimped between the water-cooled radiators 11 and 12, the IGBT/IEGT power module 3 is crimped between the water-cooled radiators 15 and 16, and the IGBT/IEGT power module 4 is crimped between the water-cooled radiators 16 and 17; the clamping diode 5 is in pressure joint between the water-cooling radiator 13 and the neutral point copper bar 21, and the clamping diode 6 is in pressure joint between the water-cooling radiator 14 and the neutral point copper bar 21. The water-cooled radiators 12 and 15 are connected to the module AC copper bar 7 through copper bars, and the AC copper bar 19 collects AC current through the current sampling Hall 18. The neutral point copper bar 21 is connected on the laminated busbar 9, the water-cooling radiator 1 is connected on the laminated busbar 9 through the + DC copper bar 22, the water-cooling radiator 4 is connected on the laminated busbar 9 through the-DC copper bar 23, the laminated busbar 9 outputs the neutral point through 92, outputs the + DC through 91 and outputs the-DC through 93. The dc support capacitor 8 is connected to the laminated busbar 9 via the terminals 81 and 82, the support capacitor 7 is connected to the laminated busbar 9 via the terminals, the absorption capacitors 24 and 25 are connected to the laminated busbar 9 via cables, and the clamp resistor 20 is connected to the laminated busbar 9 via the cables.

Fig. 7 shows a three-level power module topology crimping mechanism. The crimping type IGBT/IEGT power module 1, 2, 3, 4, the clamping diodes 5, 6, the water cooling radiators 10, 11, 12, 13, 14, 15, 16, 17 are limited in position by a mechanical frame 26 and fixing bolts 27, 28, 29, and 20MP pre-tightening force is provided by disc-shaped gaskets 30, 31 and fastening nuts 32, 33. The crimping mechanical device forms the three-level power module into an organic whole, and the structure is compact, reliable and stable.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.