Matrix converter and AC-DC converter

Abstract

The utility model provides a matrix converter and AC-DC converter, and the matrix converter comprises a plurality of bridge arms, each bridge arm comprises a first active switch device, a second active switch device, a third active switch device and a fourth active switch device which are connected in series, the first end of the first active switch device is used for being electrically connected with an external load, and the first end of the fourth active switch device is used for being electrically connected with the load; the first ends of the second active switch device and the third active switch device are connected with each other and are used for being electrically connected with an external alternating current power grid, the plurality of first active switch devices share one isolation power supply, the plurality of fourth active switch devices share one isolation power supply, and the second active switch device and the third active switch device of each bridge arm share one isolation power supply. For the N-phase matrix converter, N + 2 paths of power supplies are needed, and compared with 2N paths of power supplies needed in the related technology, the design cost of the converter can be effectively saved, the design complexity is reduced, the size of the converter is reduced, and the integrated design of the system is facilitated.

Description

Technical Field

[0001] This utility model relates to the field of circuit technology, and in particular to a matrix converter and an AC-DC converter. Background Technology

[0002] Matrix circuits can efficiently and directly perform AC-AC conversion, offering advantages such as bidirectional energy flow, four-quadrant operation, flexible input power factor control, and no DC energy storage stage. They are well-suited for use as AC-side circuits in medium-to-high power applications and have gained widespread attention in academia and industry in recent years. Matrix circuits typically consist of multiple bidirectional switches, with the two switching transistors often connected in a common-source configuration. For an N-phase (N≥3) matrix circuit, this common-source layout requires 2N isolated drive power supply circuits. Therefore, in medium-to-high power applications with a high number of phases and parallel groups, higher drive circuit costs and board area are often required, hindering cost reduction and size / weight minimization. Utility Model Content

[0003] This invention provides a matrix converter and an AC-DC converter, aiming to solve the problem that the matrix circuit requires a large number of power supply circuits, resulting in a large space occupation and hindering the integrated design of the system.

[0004] To address the aforementioned technical problems, the present invention provides a matrix converter, comprising: multiple bridge arms, a first active switching device, a second active switching device, a third active switching device, and a fourth active switching device; a first terminal of the first active switching device is used for electrical connection to an external load, a first terminal of the fourth active switching device is used for electrical connection to the load, the first terminals of the second and third active switching devices are interconnected and used for electrical connection to an external AC power grid, the second terminals of the first and second active switching devices are interconnected, the second terminals of the third and fourth active switching devices are interconnected, the first active switching devices of the multiple bridge arms share a common isolated power supply, the fourth active switching devices of the multiple bridge arms share a common isolated power supply, and the second and third active switching devices of each bridge arm share a common isolated power supply.

[0005] Furthermore, the matrix converter includes three bridge arms, each including a first MOSFET, a second MOSFET, a third MOSFET, and a fourth MOSFET; the sources of all the first MOSFETs are electrically connected to the load, the sources of all the fourth MOSFETs are electrically connected to the load, the drains of the first MOSFETs and the second MOSFETs in each bridge arm are interconnected, the sources of the second MOSFETs and the third MOSFETs in each bridge arm are interconnected and used for electrical connection to the AC power grid, the drains of the third MOSFETs and the fourth MOSFETs in each bridge arm are interconnected, the gates of each MOSFET are electrically connected to an external control signal generator, all the first MOSFETs share a common isolation power supply, all the fourth MOSFETs share a common isolation power supply, and the second MOSFETs and the third MOSFETs in each bridge arm share a common isolation power supply.

[0006] Furthermore, the matrix converter includes three bridge arms, each including a first IGBT, a second IGBT, a third IGBT, and a fourth IGBT. The emitters of all the first IGBTs are electrically connected to the load, and the emitters of all the fourth IGBTs are electrically connected to the load. The collectors of the first and second IGBTs in each bridge arm are interconnected. The emitters of the second and third IGBTs in each bridge arm are interconnected and electrically connected to the AC power grid. The collectors of the third and fourth IGBTs in each bridge arm are interconnected. The base of each IGBT is electrically connected to an external control signal generator. All the first IGBTs share a common isolated power supply, all the fourth IGBTs share a common isolated power supply, and the second and third IGBTs in each bridge arm share a common isolated power supply.

[0007] The second aspect of this utility model provides an AC-DC converter, including an input filter circuit, a matrix converter as described in the first aspect of this utility model, a transformer, a rectifier circuit, and an output filter circuit; the input filter circuit is electrically connected to the matrix converter and is used for electrical connection to an external AC power grid, the transformer is electrically connected to the matrix converter and the rectifier circuit respectively, and the output filter circuit is electrically connected to the rectifier and the load respectively.

[0008] Furthermore, the output filter circuit includes a second filter capacitor, which is electrically connected to the rectifier circuit.

[0009] As can be seen from the above description, this utility model uses a shared isolated power supply for each active switching device at both ends of each bridge arm, and a shared isolated power supply for the other two adjacent active switching devices of each bridge arm. Thus, for a three-phase matrix converter, the number of power supplies is 5, while for an N-phase matrix converter, a total of N+2 power supplies are required. Compared with the 2N power supplies required in related technologies, this effectively saves converter design costs, reduces design complexity, and decreases converter size, which is beneficial for system integration design. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of a matrix converter according to an embodiment of the present invention;

[0011] Figure 2 This is a circuit diagram of the first matrix converter according to an embodiment of the present invention;

[0012] Figure 3 This is a circuit diagram of the second type of matrix converter according to an embodiment of the present invention;

[0013] Figure 4 This is a schematic diagram of the structure of an AC-DC converter according to an embodiment of the present invention;

[0014] Figure 5 This is a circuit diagram of the first AC-DC converter according to an embodiment of this utility model;

[0015] Figure 6 This is a circuit diagram of the second type of AC-DC converter according to an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Throughout the description, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0017] In related technologies, the matrix circuit requires a large number of power supply circuits, resulting in a large space occupation and hindering the integrated design of the system. Therefore, this utility model embodiment provides a matrix converter.

[0018] like Figure 1 The diagram shown is a structural schematic of a matrix converter provided in an embodiment of this utility model. Please refer to [link / reference]. Figure 1The matrix converter includes multiple bridge arms, each including a first active switching device, a second active switching device, a third active switching device, and a fourth active switching device. The first terminal of the first active switching device is electrically connected to an external load, the first terminal of the fourth active switching device is electrically connected to the load, the first terminals of the second and third active switching devices are interconnected and used for electrical connection to an external AC power grid, the second terminals of the first and second active switching devices are interconnected, the second terminals of the third and fourth active switching devices are interconnected, the first active switching devices of the multiple bridge arms share a common isolated power supply, the fourth active switching devices of the multiple bridge arms share a common isolated power supply, and the second and third active switching devices of each bridge arm share a common isolated power supply.

[0019] Specifically, in this embodiment, the matrix circuit includes multiple bridge arms, each with multiple active switching devices. The active switching devices at both ends of each bridge arm share a common isolated power supply for driving the active switching devices. That is, the first active switching device in each bridge arm is connected to the same isolated power supply, and the last active device in each bridge arm is connected to the same isolated power supply. The midpoints of the remaining active switching devices in each bridge arm share a common isolated drive circuit. Thus, when the matrix converter is a three-phase matrix circuit, a total of 5 power supplies are required. When the matrix converter is an N-phase matrix circuit, a total of N+2 power supplies are required. Compared with the common-source connection method of related technologies, which requires a power supply for each bidirectional switch and a total of 2N power supplies, the matrix converter in this embodiment only requires N+2 power supplies. Therefore, it can effectively reduce the number of isolated drive circuits in the matrix converter, save converter costs, reduce design complexity, reduce the size and weight of the converter, and facilitate the integrated design of the entire functional circuit.

[0020] like Figure 2 The diagram shown is the circuit schematic of the first type of matrix converter provided in this embodiment. Please refer to [link / reference]. Figure 2 The matrix converter includes three bridge arms, and the active switching devices include MOSFETs. The first terminal of each active switching device is the source, and the second terminal is the drain. Each bridge arm includes a first MOSFET. ap1 / S bp1 / S cp1 Second MOSFET S ap2 / S bp2 / S cp2 Third MOSFET S an1 / S bn1 / S cn1 and the fourth MOSFET S an2 / S bn2 / S cn2 All the first MOSFETs (i.e., S)ap1 S bp1 S cp1 The sources of all fourth MOSFETs (i.e., S) are used for electrical connection to the load. an2 S bn2 S cn2 The sources of all MOSFETs are used for electrical connection to the load. The first MOSFET in each bridge arm is S... ap1 / S bp1 / S cp1 Second MOSFET S ap2 / S bp2 / S cp2 The drain interconnection, the second MOSFET in each bridge arm ap2 / S bp2 / S cp2 Third MOSFET S an1 / S bn1 / S cn1 The source terminals are interconnected and all are used for electrical connection to the AC power grid. The third MOSFET in each bridge arm is S an1 / S bn1 / S cn1 Fourth MOSFET an2 / S bn2 / S cn2 The drains of the transistors are interconnected, and the gates of each MOSFET are used for electrical connection to an external control signal generator. All the first MOSFETs (i.e., S...) ap1 S bp1 S cp1 They share a common isolated power supply, and all the fourth MOSFETs (i.e., S) ap1 S bp1 S cp1 They share a common isolated power supply, and the second MOSFET in each bridge arm is S ap2 / S bp2 / S cp2 With the third MOSFET S an1 / S bn1 / S cn1 They share a single isolated power supply.

[0021] Specifically, in this embodiment, taking MOSFETs as the active switching device, each bridge arm of the matrix converter includes two bidirectional switches, each bidirectional switch contains two MOSFETs, the two MOSFETs are connected by a common drain, and the two bidirectional switches are connected by a common source. The first MOSFET of each bridge arm is S... ap1 / S bp1 / S cp1 For common-source connection, the fourth MOSFET of each bridge arm... an2 / S bn2 / S cn2The matrix converter requires N+2 power supplies due to the common source connection. Furthermore, the change in the bidirectional switch connection does not affect the working principle of the matrix converter. Therefore, the relevant scheme can still be used at the control or modulation level without any modifications.

[0022] like Figure 3 The diagram shown is the circuit schematic of the second type of matrix converter provided in this embodiment. Please refer to [link / reference]. Figure 3 The matrix converter includes three bridge arms, and the active switching devices include IGBT transistors. The first terminal of each active switching device is the emitter, and the second terminal is the collector. Each bridge arm includes a first IGBT transistor Q. ap1 / Q bp1 / Q cp1 The second IGBT tube Q ap2 / Q bp2 / Q cp2 The third IGBT tube Q an1 / Q bn1 / Q cn1 and the fourth IGBT Q an2 / Q bn2 / Q cn2 All the first IGBT transistors (i.e., Q) ap1 Q bp1 Q cp1 The emitters of all fourth IGBTs (i.e., Q) are used for electrical connection to the load. an2 Q bn2 Q cn2 The emitters of all IGBTs are used for electrical connection to the load. The first IGBT Q in each bridge arm... ap1 / Q bp1 / Q cp1 The second IGBT tube Q ap2 / Q bp2 / Q cp2 The collector interconnection, the second IGBT in each bridge arm Q ap2 / Q bp2 / Q cp2 The third IGBT tube Q an1 / Q bn1 / Q cn1 The emitters are interconnected and used for electrical connection to the AC power grid. The third IGBT in each arm is Q. an1 / Q bn1 / Q cn1 The fourth IGBT tube Q an2 / Q bn2 / Q cn2 The collectors of the IGBTs are interconnected, and the bases of each IGBT are used for electrical connection to an external control signal generator. All the first IGBTs (i.e., Q) ap1 Q bp1 Qcp1 They share a single isolated power supply, and all the fourth IGBT transistors (i.e., Q) an2 Q bn2 Q cn2 They share a common isolated power supply, and the second IGBT transistor Q in each bridge arm... ap2 / Q bp2 / Q cp2 With the third IGBT Q an1 / Q bn1 / Q cn1 They share a single isolated power supply.

[0023] Specifically, in this embodiment, taking a three-phase three-bridge-arm matrix converter with IGBTs as the active switching devices as an example, the two IGBTs of the bidirectional switch in the matrix converter are connected with a common collector, the first IGBT of each bridge arm is connected with a common emitter, and the fourth IGBT of each bridge arm is also connected with a common emitter. Therefore, the IGBT Q ap1 Q bp1 Q cp1 Common emitter, can share a single power supply, IGBT Q an2 Q bn2 Q cn2 Common emitter, can share a single power supply, IGBT Q ap2 Q an1 Common emitter, can share a single power supply, IGBT Q bp2 Q bn1 Common emitter, can share a single power supply, IGBT Q bp2 Q bn1 With a common emitter design, all power supplies can be shared, thus reducing the number of power supply circuits in a three-phase matrix converter from 6 to 5. Similarly, when the converter is expanded to N phases, the required number of power supply circuits is N+2.

[0024] This utility model embodiment also provides an AC-DC converter; please refer to [link / reference]. Figure 4 The schematic diagram of the AC-DC converter shown includes an input filter circuit 100, the aforementioned matrix converter 200, a transformer 300, a rectifier circuit 400, and an output filter circuit 500. The input filter circuit 100 is electrically connected to the matrix converter 200 and is used for electrical connection to an external AC power grid. The transformer 300 is electrically connected to the matrix converter 200 and the rectifier circuit 400, respectively. The output filter circuit 500 is electrically connected to the rectifier circuit 400 and an external load 600, respectively.

[0025] Specifically, in this embodiment, the input filter circuit 100 filters the AC power input to the AC-DC converter and outputs it to the matrix converter 200. The matrix converter 200 is responsible for converting the N-phase power frequency AC input into a volt-second balanced high-frequency AC square wave and transmitting it to the primary side of the transformer 300. The transformer 300 then couples the signal to the secondary side of the transformer, where it works with the rectifier circuit 400 on the secondary side to perform DC-DC phase shift control, achieving output voltage regulation and input power factor correction. The stable DC voltage obtained after processing by the rectifier circuit 400 and the output filter circuit 500 on the secondary side of the transformer is used to drive the load 600. In this embodiment, the output filter circuit 500 can be a filter capacitor, which is electrically connected to the rectifier circuit 400, which can be a bridge rectifier circuit. By using the above-mentioned matrix converter, the design complexity and cost of the AC-DC converter can be effectively reduced, and there is no need to change the original control strategy of the AC-DC converter, which is beneficial to the integrated design of the AC-DC converter.

[0026] Further, please see Figure 4 and Figure 5 The circuit schematic of the first type of AC-DC converter shown includes an input filter circuit 100 comprising multiple filter inductors (e.g., Figure 5 L in a L b L c One end of the filter inductor is connected to the AC mains, and the other end is connected to the corresponding bridge arm in the matrix converter 200. Furthermore, the input filter circuit 100 also includes multiple first filter capacitors (e.g., Figure 5 C in fa C fb C fc One end of each first filter capacitor is electrically connected to the other end of the corresponding filter inductor, and the other ends of each first filter capacitor are interconnected.

[0027] Specifically, in this embodiment, the input filtering circuit 100 may include multiple filter inductors and / or filter capacitors. The filter inductors can block high-frequency current, preventing high-frequency noise from passing through, thereby improving the purity of the input signal and reducing interference to other components and loads. The filter capacitors can short-circuit high-frequency signals, thereby reducing high-frequency noise interference, while providing sufficient impedance at low frequencies to ensure normal circuit operation.

[0028] Further, please see Figure 4 and Figure 5The bridge rectifier circuit includes a fifth MOSFET S1, a sixth MOSFET S2, a seventh MOSFET S3, and an eighth MOSFET S4. The drains of the fifth MOSFET S1 and the seventh MOSFET S3 are electrically connected to the output filter circuit 500. The sources of the sixth MOSFET S2 and the eighth MOSFET S4 are electrically connected to the output filter circuit 500. The source of the fifth MOSFET S1 and the drain of the sixth MOSFET S2 are electrically connected to the positive output terminal of the transformer 300. The source of the seventh MOSFET S3 and the drain of the eighth MOSFET S4 are electrically connected to the negative output terminal of the transformer 300. The gate of each MOSFET is used to connect to an external control signal generator.

[0029] Furthermore, please see Figure 4 and Figure 6 The circuit diagram of the second type of AC-DC converter shown includes a bridge rectifier circuit comprising a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The cathodes of the first diode D1 and the third diode D3 are electrically connected to the output filter circuit 500, and the anodes of the second diode D2 and the fourth diode D4 are electrically connected to the output filter circuit 500. The anode of the first diode D1 and the cathode of the second diode D2 are electrically connected to the positive output terminal of the transformer 300, and the anode of the third diode D3 and the cathode of the fourth diode D4 are electrically connected to the negative output terminal of the transformer 300.

[0030] Specifically, in this embodiment, the bridge rectifier circuit can be a controlled rectifier bridge composed of MOSFETs or an uncontrolled rectifier bridge composed of diodes, used to convert AC power transmitted by the transformer into DC power. Among them, the MOSFETs in the controlled rectifier bridge have better controllability and adjustment characteristics. The rectifier bridge can be precisely controlled by controlling its gate voltage, and has advantages such as lower power consumption, faster switching speed, better controllability, and suitability for high-frequency applications.

[0031] The matrix converter provided in this embodiment connects the active switching devices at both ends of each bridge arm to a separate power supply, and the other two adjacent active switching devices of each bridge arm are also connected to separate power supplies. Therefore, for a three-bridge-arm matrix converter, the number of power supplies is 5, while for an N-bridge-arm matrix converter, a total of N+2 power supplies are required. Compared to the 2N power supplies required in related technologies, this effectively saves converter design costs, reduces design complexity, and decreases converter size, which is beneficial for system integration design. Furthermore, this change in power connection method does not affect the working principle of the matrix converter; therefore, related solutions can still be used at the control or modulation level without any modifications. When this matrix converter is applied to an AC-DC converter, there is no need to change the original control strategy of the AC-DC converter, which reduces the design complexity of the AC-DC converter, saves space resources, and is beneficial for the integrated design of the AC-DC converter.

[0032] It should be noted that the various embodiments in this utility model are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0033] It should also be noted that, in the present invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0034] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in the present invention may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A matrix converter, characterized by, include: Multiple bridge arms, the bridge arms including a first active switching device, a second active switching device, a third active switching device and a fourth active switching device; The first terminal of the first active switching device is used for electrical connection with an external load, the first terminal of the fourth active switching device is used for electrical connection with the load, the first terminals of the second and third active switching devices are interconnected and used for electrical connection with an external AC power grid, the second terminals of the first and second active switching devices are interconnected, the second terminals of the third and fourth active switching devices are interconnected, the first active switching devices of multiple bridge arms share a common isolation power supply, the fourth active switching devices of multiple bridge arms share a common isolation power supply, and the second and third active switching devices of each bridge arm share a common isolation power supply.

2. The matrix converter of claim 1, wherein, It includes three bridge arms, each of which includes a first MOSFET, a second MOSFET, a third MOSFET, and a fourth MOSFET; The sources of all first MOSFETs are electrically connected to the load, the sources of all fourth MOSFETs are electrically connected to the load, the drains of the first and second MOSFETs in each bridge arm are interconnected, the sources of the second and third MOSFETs in each bridge arm are interconnected and connected to the AC power grid, the drains of the third and fourth MOSFETs in each bridge arm are interconnected, the gates of each MOSFET are electrically connected to an external control signal generator, all first MOSFETs share a common isolation power supply, all fourth MOSFETs share a common isolation power supply, and the second and third MOSFETs in each bridge arm share a common isolation power supply.

3. The matrix converter of claim 1, wherein, It includes three bridge arms, each of which includes a first IGBT, a second IGBT, a third IGBT, and a fourth IGBT. The emitters of all the first IGBT transistors are electrically connected to the load, the emitters of all the fourth IGBT transistors are electrically connected to the load, the collectors of the first and second IGBT transistors in each bridge arm are interconnected, the emitters of the second and third IGBT transistors in each bridge arm are interconnected and electrically connected to the AC power grid, the collectors of the third and fourth IGBT transistors in each bridge arm are interconnected, the base of each IGBT transistor is electrically connected to an external control signal generator, all the first IGBT transistors share a common isolation power supply, all the fourth IGBT transistors share a common isolation power supply, and the second and third IGBT transistors in each bridge arm share a common isolation power supply.

4. An AC-DC converter, characterized by, It includes an input filter circuit, a matrix converter as described in any one of claims 1 to 3, a transformer, a rectifier circuit, and an output filter circuit; the input filter circuit is electrically connected to the matrix converter and is used for electrical connection to an external AC power grid, the transformer is electrically connected to the matrix converter and the rectifier circuit respectively, and the output filter circuit is electrically connected to the rectifier circuit and an external load respectively.

5. The AC-DC converter of claim 4, wherein, The input filtering circuit includes multiple filtering inductors, one end of which is electrically connected to the AC mains, and the other end of which is electrically connected to the corresponding bridge arm in the matrix converter.

6. The AC-DC converter of claim 5, wherein, The input filtering circuit further includes a plurality of first filtering capacitors, one end of each first filtering capacitor being electrically connected to the other end of the corresponding filtering inductor, and the other ends of each first filtering capacitor being interconnected.

7. The AC-DC converter of claim 4, wherein, The rectifier circuit includes a bridge rectifier circuit.

8. The AC-DC converter according to claim 7, characterized in that, The bridge rectifier circuit includes a fifth MOSFET, a sixth MOSFET, a seventh MOSFET, and an eighth MOSFET. The drains of the fifth MOSFET and the seventh MOSFET are electrically connected to the output filter circuit. The sources of the sixth MOSFET and the eighth MOSFET are also electrically connected to the output filter circuit. The source of the fifth MOSFET and the drain of the sixth MOSFET are both electrically connected to the positive output terminal of the transformer. The source of the seventh MOSFET and the drain of the eighth MOSFET are both electrically connected to the negative output terminal of the transformer. The gate of each MOSFET is used to connect to an external control signal generator.

9. The AC-DC converter of claim 7, wherein, The bridge rectifier circuit includes a first diode, a second diode, a third diode, and a fourth diode. The cathodes of the first diode and the third diode are electrically connected to the output filter circuit. The anodes of the second diode and the fourth diode are electrically connected to the output filter circuit. The anodes of the first diode and the cathodes of the second diode are electrically connected to the positive output terminal of the transformer. The anodes of the third diode and the cathodes of the fourth diode are electrically connected to the negative output terminal of the transformer.

10. The AC-DC converter of claim 4, wherein, The output filter circuit includes a second filter capacitor, which is electrically connected to the rectifier circuit.

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