A three-level NPC-I topology layout and energy storage inverter

Abstract

The utility model discloses a three-level NPC-I topology layout and an energy storage inverter. The three-level NPC-I topology layout includes: a circuit board, a conductive bar, an IGBT unit, and a diode unit; the IGBT unit, the diode unit, and the conductive bar are all fixedly connected to the circuit board; the IGBT unit is electrically connected to a positive voltage input terminal and a negative voltage input terminal respectively; the IGBT unit is electrically connected to a voltage output terminal; the IGBT unit is also electrically connected to a neutral point voltage input terminal through a diode unit and a conductive bar in sequence; in summary, the utility model can adjust the layout of the NPC-I topology structure from a horizontal layout to a vertical layout under the premise of using a six-layer PCB by arranging a conductive bar.

Description

Technical Field

[0001] The utility model relates to the technical field of NPC-I, and in particular to a three-level NPC-I topology layout and an energy storage inverter. Background Art

[0002] At present, high-power energy storage converters on the market are all implemented with IGBT modules, and single-tube IGBTs are rarely used to implement high-power energy storage converters. IGBT is the abbreviation of insulated gate bipolar transistor, which is a three-terminal semiconductor switching device that can be used for efficient and fast switching in a variety of electronic devices. The use of IGBT modules is convenient and relatively small in size, but the cost of purchasing IGBT modules is high, the delivery time is long, and most importantly, the substitutability is very poor. Single-tube IGBTs have low costs, short delivery times, and strong substitutability, but the use of single-tube IGBTs will bring another problem, that is, the power circuit loop is long. If the layout is unreasonable, it will lead to poor reliability and poor dynamic response consistency.

[0003] The NPC topology (Neutral Point Clamped) is a multi-level inverter topology that can reduce losses and electromagnetic interference (EMI) caused by switching frequency. NPC-I is one of the specific implementations, usually used in three-level inverters. In the NPC-I topology, IGBT modules are usually used as switching elements.

[0004] The NPC-I topology requires multiple switching elements and diodes to achieve voltage midpoint clamping. Each switch unit is usually composed of an IGBT module, which is responsible for controlling the on and off of the current. In the NPC-I structure, the voltage borne by the IGBT module is part of the total voltage, which can reduce the voltage stress of a single IGBT and improve the reliability of the system. Since the NPC-I structure can generate an output voltage that is closer to a sine wave, the switching frequency of the IGBT module can be reduced, reducing switching losses. This configuration helps to improve the efficiency of the entire power electronic system, especially in high-voltage and high-power applications.

[0005] The Chinese utility model patent (application number: 202220918760.0) proposes an optimized circuit of an NPC-I three-level converter and a three-phase NPC-I three-level converter, including an N module, a P module and an O module, each of which includes two power switches. And the utility model patent further provides a structural layout of an optimized circuit of an NPC-I three-level converter such as Figure 2As shown, the P module, O module, and N module are arranged from top to bottom, and the connection terminals connected to the first connection line or the second connection line are arranged on the same side, and the AC output terminal and the connection terminals connected to the DC negative pole, DC positive pole, and DC neutral line are arranged on the same side. In this structural layout, the modules are placed very compactly, the distance between the first connection line and the second connection line is short, and if absorption capacitors are needed between the positive and negative terminals of the P module and the N module, they are also very easy to place. The overall layout is conducive to reducing the radiator area, reducing the current loop, and reducing the turn-off spike of the semiconductor device.

[0006] However, this product still has some defects. The connection lines of the NPC-I module are located on the two longer sides (i.e. the left and right sides), so when multiple modules are used in parallel, Figure 2 As shown, only the short sides (i.e., the upper and lower sides) of the module without connecting wires can be connected side by side, which will result in a larger lateral width and make it difficult to meet certain design requirements for a relatively compact width. However, if the connection position of the device is set at the short side position, the production cost will be significantly increased. The specific reasons are as follows: If the NPC-I three-level converter is used in a high-current scenario, in order to ensure the stability of the level converter, the current of each switch tube needs to be designed on a layer of PCB. Then, two layers of circuit boards are required for the two directions of the current, one going and one returning. Taking the copper foil at Q1A as an example, two layers are required from BUS+ to Q1A, two layers are required from Q1A to Q2A, and two layers are required for the drive of Q1A and other weak current signals, for a total of six layers, so a high-power PCB is at least a six-layer board. If the circuit layout is converted into a vertical layout and the circuit connection position is set at the short side, the current of each switch tube uses two layers of copper routing. Taking the copper at Q1A as an example, BUS+ to Q1A requires two layers, Q1A to Q2A requires two layers, Q1A drive and other weak current signals require two layers, and the connection from N+ to D5 and D6 requires an extra layer of PCB, resulting in a significant increase in the production cost of the module.

[0007] Therefore, in order to solve the above problems, the present application proposes a three-level NPC-I topology layout and energy storage inverter, which can reduce the width of the NPC-I module without affecting the cost of the module. Utility Model Content

[0008] The utility model aims to disclose a three-level NPC-I topology layout and an energy storage inverter, which solves the problem that an additional layer of PCB is required in the existing three-level NPC-I layout when the layout is switched.

[0009] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0010] A three-level NPC-I topology layout includes: a circuit board, a conductive bar, an IGBT unit, and a diode unit; the IGBT unit, the diode unit, and the conductive bar are all fixedly connected to the circuit board; the IGBT unit is electrically connected to a positive voltage input terminal and a negative voltage input terminal respectively; the IGBT unit is electrically connected to a voltage output terminal; the IGBT unit is also electrically connected to a neutral point voltage input terminal through the diode unit and the conductive bar in sequence.

[0011] Optionally, the diode unit includes: a first diode and a second diode; the anode of the first diode and the cathode of the second diode are both electrically connected to the other end of the conductive row; the cathode of the first diode and the anode of the second diode are both electrically connected to the IGBT unit.

[0012] Optionally, the IGBT unit includes: a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; the control end of the first switch tube, the control end of the second switch tube, the control end of the third switch tube and the control end of the fourth switch tube are all communicatively connected to a control module for outputting a control signal; the collector of the first switch tube is electrically connected to the positive voltage input end; the collector of the second switch tube is electrically connected to the emitter of the first switch tube; the collector of the third switch tube is electrically connected to the emitter of the second switch tube; the collector of the fourth switch tube is electrically connected to the emitter of the third switch tube; the emitter of the fourth switch tube is electrically connected to the negative voltage input end; the collector of the second switch tube is electrically connected to the voltage output end.

[0013] Optionally, the first diode is located between the first switching tube and the second switching tube; the second diode is located between the third switching tube and the fourth switching tube; one end of the conductive bar is fixedly connected to the neutral point voltage input terminal on the circuit board; and the other end of the conductive bar is located between the first diode and the second diode.

[0014] An energy storage inverter includes the above-mentioned three-level NPC-I topology layout.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] The utility model provides a three-level NPC-I topology layout, comprising: a circuit board, a conductive bar, an IGBT unit, and a diode unit; the IGBT unit, the diode unit, and the conductive bar are all fixedly connected to the circuit board; the IGBT unit is electrically connected to a positive voltage input terminal and a negative voltage input terminal respectively; the IGBT unit is electrically connected to a voltage output terminal; the IGBT unit is also electrically connected to a neutral point voltage input terminal through the diode unit and the conductive bar in sequence; in summary, the utility model can adjust the layout of the NPC-I topology structure from a horizontal layout to a vertical layout under the premise of using a six-layer PCB by arranging a conductive bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is the circuit schematic diagram of the three-level NPC-I topology layout;

[0019] Figure 2 It is the NPC-I circuit layout of the prior art;

[0020] Figure 3 It is a schematic diagram of the horizontal layout of NPC-I components in the prior art;

[0021] Figure 4 It is a schematic diagram of the vertical layout of the NPC-I components of the present application;

[0022] Figure 5 It is a vertical layout stereogram of the NPC-I components of the present application;

[0023] Figure 6 This is the first layer PCB layout diagram of this application;

[0024] Figure 7 It is the second layer PCB layout diagram of this application;

[0025] Figure 8 It is the third layer PCB layout diagram of this application;

[0026] Fig. 9 It is the fourth layer PCB layout diagram of this application;

[0027] Fig.10 It is the fifth layer PCB layout diagram of this application;

[0028] Fig.11It is the sixth layer PCB layout diagram of this application;

[0029] In the figure, 1, circuit board; 2, conductive bar; 3, first switch tube; 4, first diode; 5, second switch tube; 6, third switch tube; 7, second diode; 8, fourth switch tube. DETAILED DESCRIPTION

[0030] In the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0031] In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact not directly but through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. The terms "vertical", "horizontal", "left", "right", "above", "below" and similar expressions are for illustrative purposes only, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0033] Embodiment 1

[0034] like Figure 1A three-level NPC-I topology layout is shown, comprising: a circuit board, a conductive bus, an IGBT unit, and a diode unit; the IGBT unit, the diode unit, and the conductive bus are all fixedly connected to the circuit board; the IGBT unit is electrically connected to the positive voltage input terminal and the negative voltage input terminal respectively; the IGBT unit is electrically connected to the voltage output terminal; the IGBT unit is also electrically connected to the neutral point voltage input terminal through the diode unit and the conductive bus in sequence.

[0035] In the prior art, during the circuit board processing, each additional layer of PCB board will significantly increase the circuit cost. In the traditional NPC-I layout, Figure 3 As shown, the first diode and the second diode are arranged vertically, and the IGBT units are set at both ends of the two diodes. In this arrangement, the IGBT tubes in the first vertical row correspond to the BUS+ connection point, the diodes in the second vertical row correspond to the N point position, and the IGBT tubes in the third vertical row correspond to the BUS- connection point. In actual use, the NPC-I layout usually uses multiple phases at the same time to improve the current load capacity of the inverter. When the multi-phase NPC-I topology layout is used in parallel, it will be like Figure 2 As shown in the figure, each individual NPC-I is arranged side by side, so that the NPC-I topology layouts are connected in series. However, since the switches and diodes in the NPC-I topology layout are arranged in three vertical rows, a large horizontal space will be occupied. In order to save the horizontal space of a single NPC-I topology layout, the present application proposes a new NPC-I topology layout without increasing the number of PCB layers, such as Figure 4 As shown, the first vertical row is composed of the second switch tube, the first diode and the first switch tube from top to bottom, and the first vertical row corresponds to the BUS+ connection point; the second vertical row is composed of the third switch tube, the second diode and the fourth switch tube from top to bottom, and the second vertical row corresponds to the BUS- connection point. The N connection point is still located between BUS+ and BUS-. In order to interconnect the N connection point with the two diodes without increasing the number of PCB layers, the present application sets an additional connection row, one end of which is interconnected with the N connection point, and the other end is interconnected with the connection point at the diode position. The number of PCB layers is replaced by a conductive row, which can satisfy the NPC-I topology layout to be arranged vertically without increasing the number of PCB layers. The demand for horizontal space of the NPC-I topology layout is effectively reduced, and more NPC-I circuits can be accommodated in the same space.

[0036] Furthermore, the diode unit includes: a first diode D1A and a second diode D2A; the anode of the first diode D1A and the cathode of the second diode D2A are both electrically connected to the other end of the conductive bar; the cathode of the first diode D1A and the anode of the second diode D2A are both electrically connected to the IGBT unit.

[0037] Furthermore, the IGBT unit includes: a first switch tube Q1A, a second switch tube Q2A, a third switch tube Q3A and a fourth switch tube Q4A; the control end of the first switch tube Q1A (that is, the gate of the IGBT tube), the control end of the second switch tube Q2A, the control end of the third switch tube Q3A and the control end of the fourth switch tube Q4A are all communicatively connected to a control module for outputting a control signal; the collector of the first switch tube Q1A is electrically connected to the positive voltage input end BUS+; the collector of the second switch tube Q2A is electrically connected to the emitter of the first switch tube Q1A; the collector of the third switch tube Q3A is electrically connected to the emitter of the second switch tube Q2A; the collector of the fourth switch tube Q4A is electrically connected to the emitter of the third switch tube Q3A; the emitter of the fourth switch tube Q4A is electrically connected to the negative voltage input end BUS-; the collector of the second switch tube Q2A is electrically connected to the voltage output end.

[0038] Furthermore, the first diode is located between the first switch tube and the second switch tube; the second diode is located between the third switch tube and the fourth switch tube; one end of the conductive bar is fixedly connected to the neutral point voltage input terminal on the circuit board; and the other end of the conductive bar is located between the first diode and the second diode.

[0039] Further, such as Figure 5 As shown, it is a schematic diagram of the three-dimensional structure of the NPC-I topology layout of the present application on the circuit board, wherein the conductive bar 2 is a copper bar, which is connected from the N connection point at one end of the circuit board 1 to the connection point between the first diode 4 and the second diode 7, so as to replace a layer of PCB and realize the purpose of the vertical layout of the circuit.

[0040] For other structures of the first embodiment, refer to the prior art.

[0041] Embodiment 2

[0042] This embodiment further provides a PCB layout method, such as Figure 6-Figure 11 As shown, they are the PCB layout diagrams corresponding to the 6-layer circuit boards.

[0043] Taking the copper foil at Q1 as an example, the top PCB is used to route the drive signal, the 2nd and 3rd layers connect BUS+ to the C pole of Q1, the 4th and 5th layers connect the E pole of Q1 to the cathode of D1 and the C pole of Q2, and the 6th layer is the copper plating of the C pole of Q1. Figure 5 By using the copper busbar jumper method, the original horizontal layout can be converted into a vertical layout while still using a 6-layer PCB, and the width of the PCB can be reduced by adjusting the layout, which is convenient for the horizontal layout of the PCB.

[0044] Embodiment 3

[0045] This embodiment further provides an energy storage inverter, including the three-level NPC-I topology layout as described in any one of the first embodiment or the second embodiment.

[0046] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the claims of the present invention and the scope of equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A three-level NPC-I topology layout, characterized in that: include: Circuit board, conductive bar, IGBT unit, and diode unit; The IGBT unit, the diode unit and the conductive bar are all fixedly connected to the circuit board; The IGBT unit is electrically connected to the positive voltage input terminal and the negative voltage input terminal respectively; The IGBT unit is electrically connected to the voltage output terminal; The IGBT unit is also electrically connected to the neutral point voltage input terminal through the diode unit and the conductive bar in sequence.

2. A three-level NPC-I topology layout according to claim 1, characterized in that: The diode unit comprises: a first diode and a second diode; The anode of the first diode and the cathode of the second diode are both electrically connected to the other end of the conductive bar; The cathode of the first diode and the anode of the second diode are both electrically connected to the IGBT unit.

3. A three-level NPC-I topology layout according to claim 2, characterized in that: The IGBT unit includes: a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; The control end of the first switch tube, the control end of the second switch tube, the control end of the third switch tube and the control end of the fourth switch tube are all communicatively connected to a control module for outputting a control signal; The collector of the first switch tube is electrically connected to the positive voltage input terminal; The collector of the second switch tube is electrically connected to the emitter of the first switch tube; The collector of the third switch tube is electrically connected to the emitter of the second switch tube; The collector of the fourth switch tube is electrically connected to the emitter of the third switch tube; The emitter of the fourth switch tube is electrically connected to the negative voltage input terminal; The collector of the second switch tube is electrically connected to the voltage output terminal.

4. A three-level NPC-I topology layout according to claim 3, characterized in that: The first diode is located between the first switch tube and the second switch tube; The second diode is located between the third switch tube and the fourth switch tube; One end of the conductive bar is fixedly connected to a neutral point voltage input terminal on the circuit board; The other end of the conductive bar is located between the first diode and the second diode.

5. An energy storage inverter, characterized in that: It comprises a three-level NPC-I topology layout as described in any one of claims 1 to 4.

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