A power converter topology, control system and control method

Abstract

The application discloses a power converter topology, a control system and a control method. The topology comprises m matrix full-bridge circuits, a first bus and a second bus, m resonant cavities, a transformer and a matrix half-bridge circuit. Each matrix full-bridge circuit has an independent power port on one side, and the first end and the second end of the independent power port are selectively connected to the first bus and the second bus respectively. The first end of the independent power port is selectively connected to the second end of the next adjacent independent power port. Each matrix full-bridge circuit is connected to one side of the matrix half-bridge circuit through the corresponding resonant cavity and the transformer, and the other side of the matrix half-bridge circuit has a common power port. The above topology can realize bidirectional transmission of electric energy, can reconfigure the electrical connection relationship of multiple independent power ports, can widen the compatible range of different specifications of AC and DC power supplies and the voltage regulation capacity, and can switch between the resonant mode and the non-resonant mode, thereby effectively improving the working efficiency.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, and in particular to a power converter topology, control system, and control method. Background Technology

[0002] Currently, power electronic transformers, as core equipment for the interaction between distributed energy resources and the grid in microgrids, face challenges due to the traditional multi-stage architecture (such as cascaded H-bridges and modular multilevel converters) which requires multiple power units to be cascaded for voltage matching and power transmission, resulting in progressive efficiency degradation. Single-stage isolated converters, on the other hand, generally suffer from insufficient multi-port support and poor AC / DC input compatibility, making them unsuitable for the multi-source coordination requirements of AC / DC hybrid microgrids. Among existing isolated single-stage converters, resonant topologies (such as LLC resonant converters) have high peak efficiency, but the soft-switching window shrinks under wide-gain scenarios, leading to a sharp drop in efficiency. Non-resonant topologies (such as traditional dual active bridge converters) have a wide voltage regulation range but high switching losses, and most topologies only adapt to a single input type; multi-port integration requires stacking isolation units, further increasing losses and size. Single-stage micro-inverters (such as Cyclo converters), while supporting a wide range of DC inputs, are limited by frequency modulation, resulting in insufficient dynamic response and integration. Summary of the Invention

[0003] The purpose of this invention is to disclose a power converter topology, control method, and control system to solve the problems existing in the prior art.

[0004] First, this invention discloses a power converter topology, including m matrix full-bridge circuits, a first bus, a second bus, m resonant cavities, a transformer, and a matrix half-bridge circuit. Each matrix full-bridge circuit has an independent power port on one side, and the first and second ends of the independent power port are selectively connected to the first bus and the second bus, respectively. The first end of the independent power port is selectively connected to the second end of the next adjacent independent power port. The other side of each matrix full-bridge circuit is connected to the corresponding winding of the transformer through its respective resonant cavity. The other winding of the transformer is connected to one side of the matrix half-bridge circuit. The other side of the matrix half-bridge circuit has a common power port. Each matrix full-bridge circuit selectively operates in resonant mode or non-resonant mode. Wherein, m is an integer, and m≥2.

[0005] Furthermore, the first and second ends of the other winding of the transformer are respectively connected to the first and second ends of one side of the matrix half-bridge circuit.

[0006] Furthermore, the first and second ends of each independent power port are selectively connected to the first bus and the second bus via corresponding first and second switching switches, respectively, and the first end of the independent power port is selectively connected to the second end of the next adjacent independent power port via corresponding third switching switch.

[0007] Furthermore, the first end of the other side of each of the matrix full-bridge circuits is connected to the first end of the corresponding winding on one side of the transformer through its respective resonant cavity, and the second end of the other side of each of the matrix full-bridge circuits is connected to the second end of the corresponding winding on one side of the transformer.

[0008] Furthermore, it also includes a fourth switching switch, and the corresponding winding on one side of the transformer also has a center tap, and the second end on the other side of each of the matrix full-bridge circuits is selectively connected to the center tap through the fourth switching switch.

[0009] Furthermore, the resonant cavity includes an inductor, a second capacitor, a third capacitor, and a resonant switching switch. One end of the inductor and the other end of the third capacitor are respectively one end and the other end of the resonant cavity. The other end of the inductor is connected to one end of the third capacitor. The second capacitor and the resonant switching switch are connected in series to form a series bridge circuit. The two ends of the series bridge circuit are connected in parallel with the two ends of the third capacitor.

[0010] Furthermore, m=3.

[0011] Furthermore, when the resonant switching switch is open, the corresponding matrix full-bridge circuit operates in resonant mode; when the resonant switching switch is closed, the corresponding matrix full-bridge circuit operates in non-resonant mode.

[0012] Secondly, this invention discloses a control system for controlling the power converter topology, including a gain calculation module, a current setting module, a voltage control loop, a current selection module, a mode switching module, and a modulation quantity module; wherein,

[0013] The gain calculation module is used to calculate the real-time voltage gain, the current setting module is used to provide the current selection module with a first current reference value, the voltage control loop is used to provide the current selection module with a second current reference value and a third current reference value, the current selection module is used to output the final current command value, the mode switching module is used to control the switching between resonant and non-resonant operating modes, and the modulation quantity module is used to generate a PWM modulation signal.

[0014] Furthermore, this invention discloses a control method for controlling the power converter topology, comprising: when any of the matrix full-bridge circuits is configured to operate in resonant mode, the corresponding inner shift ratio and outer shift ratio are set to zero, and the drive signal of the switching transistor in the matrix full-bridge circuit is synchronized with the drive signal of the leading switching transistor in the matrix half-bridge circuit; when any of the matrix full-bridge circuits is configured to operate in non-resonant mode, based on the real-time acquired voltage of the independent power supply port, voltage of the common power supply port, and power requirements, dynamically adjusting the corresponding inner shift ratio and outer shift ratio; wherein, the side where the matrix half-bridge circuit is located is defined as the input side, and the matrix full-bridge circuit MB... x The side it is located on is the output side.

[0015] Compared with existing technologies, this invention realizes the switching of multiple connection modes of matrix full-bridge circuit through a power converter topology, control system and control method. It can broaden the compatibility range and voltage regulation capability of AC and DC power supplies of different specifications, and can select between resonant and non-resonant modes. It flexibly realizes the interconnection of multiple AC / DC ports of different specifications, which can effectively improve working efficiency. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a power converter topology according to Embodiment 1 of the present invention;

[0017] Figure 2 For the present invention Figure 1 A schematic diagram of a matrix-type full-bridge circuit in a topology;

[0018] Figure 3 For the present invention Figure 1 A schematic diagram of a resonant cavity in a topology;

[0019] Figure 4 For the present invention Figure 1 A schematic diagram of a matrix-type half-bridge circuit in a topology;

[0020] Figure 5 This is a schematic diagram of a power converter topology according to Embodiment 2 of the present invention;

[0021] Figure 6 This is a schematic diagram of a power converter topology in Embodiment 1 of the present invention when m=3;

[0022] Figure 7 For the present invention Figure 6 A schematic diagram of the topology in working mode 3;

[0023] Figure 8 For the present invention Figure 6 A schematic diagram of the topology in working mode 6;

[0024] Figure 9 For the present invention Figure 6 A schematic diagram of the topology in working mode 7;

[0025] Figure 10 This is a control system block diagram of a power converter topology according to an embodiment of the present invention;

[0026] Figure 11 This is a gain-based resonant and non-resonant hysteresis switching logic diagram according to an embodiment of the present invention;

[0027] Figure 12 This is a schematic diagram of the operating waveforms of a power converter topology according to an embodiment of the present invention;

[0028] Figure 13 For the present invention Figure 6 A schematic diagram of the steady-state operating waveform of the topology in operating mode 2;

[0029] Figure 14 for Figure 13 A magnified view of a portion of the image;

[0030] Figure 15 For the present invention Figure 6 A schematic diagram of the steady-state operating waveform of the topology in operating mode 3;

[0031] Figure 16 for Figure 15 A magnified view of a portion of the image.

[0032] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0033] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0034] Some terms in this invention are explained as follows:

[0035] Matrix Bridge (MB): A full-bridge topology composed of power semiconductor devices, characterized by replacing the single switch in the classic full-bridge topology with two anti-series power semiconductor switches.

[0036] Dual Active Bridge (DAB): A power electronic converter that can be connected to voltage sources on both sides. It is generally composed of a high-frequency transformer and bridge circuits on both sides. The bridge circuit of the DAB mentioned in this invention is a matrix full-bridge circuit, and the voltage source at both ends can be either an AC source or a DC source.

[0037] Isolated Matrix Reconfigurable Dual Active Bridge (IMRDAB): A DAB circuit that uses a matrix full-bridge circuit on at least one side, and whose circuit parameters or structure can be reconfigured by switching.

[0038] Example 1:

[0039] Reference Figure 1 This embodiment discloses a power converter topology, including m matrix full-bridge circuits MB1 to MB2. m First bus L1, second bus L2, m resonant cavities RT1~RT m A transformer T r and a matrix half-bridge circuit M h Each matrix full-bridge circuit MB x One side has an independent power port V x Independent power port V x The first end V x1 Selectively connect to the first bus L1, independent power supply port V x The second end V x2 Selectively connect to the second busbar L2; independent power supply port V x The first end V x1 Selectively connect to the next adjacent independent power supply port V x+1 The second end V (x+1)2 Each matrix full-bridge circuit MB x On the other side, through their respective resonant cavities RT x Connect to transformer T r The corresponding one-sided winding W x Transformer T r The other winding W h Connected to matrix half-bridge circuit M h On one side, the matrix half-bridge circuit M h The other side has a common power port V h Each matrix full-bridge circuit MB x It can selectively operate in resonant mode or non-resonant mode. Where x, m, and n are integers, m≥2, 1≤x≤m.

[0040] Understandably, the matrix full-bridge circuit MB x RT resonant cavity x Transformer T r One side winding W x and the other side winding W h Matrix half-bridge circuit M h Constructing a power conversion unit PR x .

[0041] In one embodiment, the common power port V h Having the first end V h1 Second end V h2 .

[0042] In one embodiment, transformer T r The other winding W h Connected to matrix half-bridge circuit M h One side, specifically referring to transformer T r The other winding W h The first end W h1 Connect to matrix half-bridge circuit M h The first end on one side, transformer T r The other winding W h The second end W h2 Connect to matrix half-bridge circuit M h The second end on one side.

[0043] In one embodiment, each independent power port V x The first end V x1 via the corresponding first switching switch S x1 Selectively connect to the first bus L1, each independent power port V x The second end V x2 via the corresponding second switching switch S x2 Selectively connect to the second bus L2, independent power supply port V x The first end V x1 via the corresponding third switching switch S x3 Selectively connect to the next adjacent independent power supply port V x+1 The second end V (x+1)2 .

[0044] In one embodiment, the second busbar L2 is grounded to the ground wire Gnd.

[0045] Understandably, in one embodiment, the first switching switch S x1 There are m in total, which is S 11 ~S m1 Second switch S x2 There are m in total, which is S 12 ~Sm2 The third switching switch has a total of m-1 switches, namely S 13 ~S (m-1)3 .

[0046] In one embodiment, transformer T r One side winding W x Having the first end W x1 Second end W x2 Each matrix full-bridge circuit MB x On the other side, through their respective resonant cavities RT x Connect to transformer T r One side winding W x , refers to each matrix full-bridge circuit MB x The first end on the other side passes through its respective resonant cavity RT x Connect to transformer T r The corresponding winding W on one side x The first end W x1 Each matrix full-bridge circuit MB x The second terminal on the other side is connected to transformer T r The corresponding winding W on one side x The second end W x2 .

[0047] In one embodiment, each matrix full-bridge circuit MB x The first end on the other side passes through its respective resonant cavity RT x Connect to transformer T r One side winding W x The first end W x1 Specifically, this refers to each matrix full-bridge circuit MB x The first end on the other side is connected to the corresponding resonant cavity RT x At one end, the corresponding resonant cavity RT x The other end is connected to transformer T r One side winding W x The first end W x1 .

[0048] In one embodiment, such as Figure 2 As shown, any matrix full-bridge circuit MB x Including 8 open tubes Q x1 -Q x8 In this configuration, four switching transistors are connected in series to form a group, which together constitute the first bridge arm Bg. x1 Second bridge arm Bg x2 First bridge arm Bg x1 The first end connects to the second bridge arm Bg x2 The first end constitutes an independent power supply port V x The first end Vx1 First bridge arm Bg x1 The second end connects to the second bridge arm Bg x2 The second end constitutes an independent power supply port V x The second end V x2 First bridge arm Bg x1 Midpoint M x1 That is, the second bridge arm Bg x2 Midpoint M x2 Matrix full-bridge circuit MB x The first end on the other side, the second bridge arm Bg x2 Midpoint M x2 That is, the matrix full-bridge circuit MB x The second end on the other side, M x1 M x2 The two are referred to as a matrix full-bridge circuit (MB). x V-shaped bridge entrance px .

[0049] In one embodiment, four switches are connected in series to form a group, which together constitute the first bridge arm Bg. x1 Second bridge arm Bg x2 Specifically, the four switching transistors Q x1 -Q x4 The first bridge arm Bg is formed by connecting them in series. x1 Four switching transistors Q x5 -Q x8 The second bridge arm Bg is formed by connecting them in series. x2 Among them, the first switching transistor Q x1 The current input terminal is the first bridge arm Bg x1 The first terminal, the fourth switch Q x4 The current input terminal is the first bridge arm Bg x1 The second terminal, the fifth switch Q x5 The current input terminal is the second bridge arm Bg. x2 The first terminal, the eighth switch Q x8 The current input terminal is the second bridge arm Bg. x2 The second terminal; the first switching transistor Q x1 The current output terminal is connected to the second switching transistor Q. x2 The current output terminal, the second switching transistor Q x2 The current input terminal is connected to the third switching transistor Q. x3 The current input terminal forms the first bridge arm Bg x1 Midpoint M x1 The third switch Q x3 The current output terminal is connected to the fourth switching transistor Q. x4 The current output terminal; the fifth switch Q x5 The current output terminal is connected to the sixth switching transistor Q.x6 The current output terminal, the sixth switch Q x6 The current input terminal is connected to the seventh switch transistor Q. x7 The current input terminal forms the second bridge arm Bg x2 Midpoint M x2 The seventh switch Q x7 The current output terminal is connected to the eighth switching transistor Q. x8 The current output terminal.

[0050] In one embodiment, any matrix full-bridge circuit MB x It also includes the first capacitor C x1 The first capacitor C x1 Both ends are connected across an independent power supply port V. x .

[0051] In one embodiment, such as Figure 3 As shown, any resonant cavity RT x Including an inductor L x Second capacitor C x2 Third capacitor C x3 and a resonant switching switch S rx Inductor L x One end, the third capacitor C x3 The other end is the resonant cavity RT x One end and the other end (the two can also be interchanged, i.e., inductor L) x One end, the third capacitor C x3 The other end is the resonant cavity RT x (the other end, one end), inductor L x The other end is connected to the third capacitor C x3 One end, the second capacitor C x2 With resonant switching switch S rx After being connected in series, it forms a series bridge circuit B. sx Connecting bridge B sx The two ends of the third capacitor C x3 The two ends are connected in parallel. A resonant switching switch S is used. rx The switching on and off of the second capacitor C can control the switching on and off of the second capacitor C. x2 Whether to connect or not, thus realizing two capacitors (the second capacitor C) x2 Third capacitor C x3 Parallel operation mode with a single capacitor (third capacitor C) x3 The independent working mode can be switched to achieve the switching between non-resonant mode and resonant mode.

[0052] In one embodiment, such as Figure 4 As shown, the matrix half-bridge circuit M h Including the fourth capacitor C4, the fifth capacitor C5, and the half-bridge arm Bgh Half-bridge arm Bg h The midpoint Pc1 is the matrix half-bridge circuit M. h The first end on one side; one end of the fourth capacitor C4 and one end of the fifth capacitor C5 are connected together to form the midpoint terminal Pc2, i.e., the matrix half-bridge circuit M. h The second end on one side.

[0053] In one embodiment, the half-bridge arm Bg h Including the ninth switch Q h9 The tenth switch Q h10 Eleventh switching transistor Q h11 and the twelfth switch Q h12 Among them, the ninth switch Q h9 The current output terminal is connected to the tenth switching transistor Q. h10 The current output terminal; the tenth switch Q h10 The current input terminal is connected to the eleventh switching transistor Q. h11 The current input terminals form the half-bridge arm Bg. h The midpoint terminal Pc1; the eleventh switch Q h11 The current output terminal is connected to the twelfth switching transistor Q. h12 The current output terminal; the ninth switch Q h9 The current input terminal is connected to the other end of the fourth capacitor C4 to form a common power supply port V. h The first end V h1 The twelfth switch Q h12 The current input terminal is connected to the other end of the fifth capacitor C5 to form a common power supply port V. h The second end V h2 .

[0054] Understandably, the matrix half-bridge circuit M h The first and second ends on one side form a matrix half-bridge circuit M. h V at the half-bridge entrance s .

[0055] In one embodiment, the aforementioned switching transistors are all MOSFETs, and correspondingly, the current input terminal refers to the drain of the MOSFET, and the current output terminal refers to the source of the MOSFET.

[0056] In one embodiment, the aforementioned switching transistors are all IGBTs, and correspondingly, the current input terminal refers to the collector of the IGBT, and the current output terminal refers to the emitter of the IGBT.

[0057] In one embodiment, the aforementioned switching transistors are all bipolar transistors. Accordingly, the current input terminal refers to the collector of the bipolar transistor, and the current output terminal refers to the emitter of the bipolar transistor.

[0058] In one embodiment, the aforementioned switching device can be any of a MOSFET, IGBT, transistor, or other types of switches.

[0059] In one embodiment, each of the aforementioned switching transistors is connected in antiparallel to a corresponding diode, forming an antiparallel diode.

[0060] In one embodiment, the matrix full-bridge circuit and the matrix half-bridge circuit can also be replaced by a full-bridge topology, a multi-level topology (such as a three-level NPC topology, a cascaded H-bridge topology, etc.) or a three-phase bridge topology.

[0061] Understandably, i x Indicates that the current flows through the independent power port V x The current, i px For flow through the matrix full-bridge circuit MB x V-shaped bridge entrance px The current, i h Indicates that the current flows through the common power port V h The current. Also, for simplicity, V x Also used to indicate an independent power port V x voltage, V h Also used to indicate the common power port V h voltage, V px Also used to represent matrix full-bridge circuit MB x V-shaped bridge entrance px voltage, V s Also used to represent matrix half-bridge circuit M h V at the half-bridge entrance s The voltage.

[0062] The power converter topology described above can be used to construct each independent power port V. x With common power port V h It has a bidirectional energy (electrical energy) transmission channel between the two sides, and the power supply port is compatible with AC power and DC power supply access. The electrical connection relationship of the independent power supply port can be reconfigured, so the matrix full bridge circuit can switch between independent mode, series mode or parallel mode.

[0063] Understandably, when electrical energy flows from the independent power supply port V... x Transmission to common power port V h At that time, the matrix full-bridge circuit MB x One side is its input side, a matrix full-bridge circuit MB x The other side is its output side; one winding W of transformer Tr x Its primary winding, transformer T r The other winding W h Its secondary winding; matrix half-bridge circuit Mh One side is its input side, matrix half-bridge circuit M h The other side is its output side; when electrical energy is drawn from the common power port V h When transmitting to an independent power port, the matrix half-bridge circuit M h The other side is its input side, the matrix half-bridge circuit M h One side is its output side; transformer T r The other winding W h Its primary winding, transformer T r One side winding W x Its secondary winding; matrix full-bridge circuit MB x The other side is its input side, the matrix full-bridge circuit MB x One side is its output side.

[0064] This power converter topology can achieve a variety of different operating modes, specifically through an independent power supply port V. x The first switch S on the side x1 Second switching switch S x2 Third switch S x3 The switching combinations reconstruct the independent power port V x The electrical connections are used to realize the matrix full-bridge circuit MB. x The ability to switch between independent, series, parallel, and common ground modes expands the compatibility range and voltage regulation capability with AC / DC power supplies of different specifications; this is achieved through the resonant switching switch S. rx The switching on and off of the resonant cavity enables different configurations, thereby switching between the resonant and non-resonant modes of the power converter; this is achieved through the fourth switching switch S. x4 The switching capability allows for flexible adjustment of the transformer ratio to accommodate different input voltage levels; furthermore, this power converter topology features an independent power supply port V... x Public power port V h It is compatible with the access of AC and DC power supplies of various specifications, and realizes the interconnection of AC and DC power sources and loads with multiple ports.

[0065] Understandably, the matrix full-bridge circuit MB x The circuits can be configured in various modes, including independent, series, parallel, and common-ground connections. Specifically, this can be represented by a matrix full-bridge circuit (MB). x The corresponding first switching switch S x1 Second switching switch S x2 Third switch S x3 All disconnected, a matrix full-bridge circuit (MB) can be implemented. x Independent of other matrix full-bridge circuits; specifically, when all first to third switches are open, each matrix full-bridge circuit operates independently. First switch S x1Second switching switch S x2 All are disconnected, third switch S x3 When the circuit is turned on, a matrix full-bridge circuit (MB) can be realized. x With the next adjacent matrix full-bridge circuit MB x+1 The series connection; specifically, when all first to second switching switches are off, all third switching switches are on, and all matrix full-bridge circuits are connected in series. Multiple first switching switches S x1 Multiple second switching switches S x2 All are on, multiple third switching switches S x3 Disconnection allows for the implementation of multiple matrix full-bridge circuits (MB). x Parallel connection between them; specifically, all first and second switching switches are turned on, and all third switching switches are turned off, enabling parallel connection of all matrix full-bridge circuits. Second switching switch S x2 Turn on, first switching switch S x1 Third switch S x3 All disconnected, a matrix full-bridge circuit (MB) can be implemented. x of common ground.

[0066] With any matrix full-bridge circuit MB x For example, whether it operates in resonant mode is achieved as follows: when the control matrix full-bridge circuit MB... x Resonant switching switch S rx When disconnected, the third capacitor C x3 With inductor L x When connected in series, they form a series resonant circuit, at which point the resonant cavity RT x The resonant frequency is the first resonant frequency fr1, and the matrix full-bridge circuit MB x The switching frequency f x Equal to the first resonant frequency f r1 At this time, it operates in resonant mode; when the resonant switching switch S rx When closed, the third capacitor C x3 With the second capacitor C x2 First connect in parallel, then connect with inductor L x When connected in series, a resonant circuit is formed, at which point the resonant cavity RT x The resonant frequency becomes the second resonant frequency f. r2 The matrix full-bridge circuit MB x The switching frequency f x It is still fixed at the first resonant frequency f r1 (usually f) r1 The design value is f r2 (2-3 times), therefore f x >f r2 At this time, the matrix full-bridge circuit MB xIt operates in non-resonant mode. In non-resonant mode, its circuit characteristics are similar to those of a non-resonant dual active bridge (DAB) converter.

[0067] Specifically, f r1 with f r2 The calculation formula is: .

[0068] In the above formula, L a For inductor L x The sensitivity value, C a2 For the second capacitor C x2 The capacitance value, Ca3 is the third capacitor C x3 The capacitance value.

[0069] In one embodiment, f x For MB x The switching frequency, Pa is MB. x Rated power, V x_min V h_min Two ports V x V h The lowest effective value of the voltage, n x This refers to the transformer turns ratio. (By MB) x Operating frequency f x Equal to the first resonant frequency f r1 Therefore, the third capacitor C can be deduced. x3 The capacitance value is: When S rx When closed, take the first resonant frequency f. r1 The two resonant frequencies are f r2 Three times that, we can obtain the second capacitor C. x2 The capacitance value is: .

[0070] Understandably, through the resonant switching switch S rx By flexibly switching between resonant and non-resonant operating states and utilizing the resonant mode to achieve partial power transmission, operating efficiency can be improved.

[0071] Example 2:

[0072] Please refer to Figure 5 ,and Figure 1 The difference in the embodiments is that, Figure 5 The power converter topology of Embodiment 2 also includes a fourth switching switch S. x4 Transformer T r The corresponding winding W on one side x It also has a center tap W x3 Each matrix full-bridge circuit MB x On the other side, through their respective resonant cavities RTx Fourth switch S x4 Connect to transformer T r One side winding W x .

[0073] In one embodiment, each matrix full-bridge circuit MB x On the other side, through their respective resonant cavities RT x Fourth switch S x4 Connect to transformer T r One side winding W x , refers to each matrix full-bridge circuit MB x The first end on the other side passes through its respective resonant cavity RT x Connect to transformer T r One side winding W x The first end W x1 Each matrix full-bridge circuit MB x The second end on the other side is connected to the fourth switching switch S x4 Selective connection transformer T r One side winding W x The second end W x2 Or the middle tap W x3 .

[0074] via the fourth switching switch S x4 Selective connection transformer T r One side winding W x The second end W x2 Or the middle tap W x3 By controlling the fourth switching switch S x4 The connected transformer T r One side winding W x The position can change the transformer T in the circuit. r One side winding W x The number of turns, thereby changing the transformer T r The ratio of change.

[0075] In one embodiment, each matrix full-bridge circuit MB x The second end on the other side is connected to the fourth switching switch S x4 Selective connection transformer T r One side winding W x The second end W x2 Or the middle tap W x3 Specifically, this refers to the matrix full-bridge circuit MB. x The second terminal on the other side is connected to the corresponding fourth switching switch S. x4 One end, the fourth switch S x4 The other end is selectively connected to transformer T rOne side winding W x The second end W x2 Or one side winding W x center tap W x3 By controlling the fourth switching switch S x4 The other end of the connection position changes the transformer T in the connection circuit. r One side winding W x The number of turns is adjusted to change the transformer's turns ratio. For example, in a matrix full-bridge circuit (MB) x The second end on the other side is connected to the fourth switching switch S x4 Connected to transformer T r One side winding W x The second end W x2 At that time, transformer T r One side winding W connected to the circuit x The number of turns is N x1 At this time, the transformer turns ratio n x1 =N h / N x1 (N) h (The number of turns in the other winding of the transformer); when the matrix full-bridge circuit MB x The second end on the other side is connected to the fourth switching switch S x4 Connected to transformer T r One side winding W x center tap W x3 At that time, transformer T r One side winding W connected to the circuit x The number of turns becomes N x2 N x2 < N x1 At this time, the transformer turns ratio n x2 =N h / N x2 Through the fourth switch S x4 The switching allows for flexible adjustment of the transformer ratio, for example, designing n... x1 =4,n x2 =8, etc., to accommodate different levels of input voltage. Understandably, N x1 N x2 Collectively referred to as N x This refers to the matrix full-bridge circuit MB. x Transformer T r One side winding W x Number of turns in the circuit; transformer turns ratio n x1 n x2 Collectively referred to as transformer turns ratio n x .

[0076] The following is an example of a power converter topology with m=3 (its topology diagram is shown below). Figure 6 This explains its main working principle / process.

[0077] Please refer to Table 1, which records nine typical operating modes (actually more than nine) of a power converter topology when m=3 according to the present invention. In these nine typical operating modes, the switching switch S... 11 S 12 S 13 S 21 S 22 S 23 S 31 S 32 S r1 S r2 S r3 Different combinations of switch states are possible, represented by the numbers 1 or 0, where 1 indicates the switch is on and 0 indicates the switch is off. Table 1 also shows the values ​​of V1, V2, V3, and V under different operating modes. h The power supply that can be connected, where AC represents alternating current source, DC represents direct current source, Ld represents load, and "" indicates "OR" relationship.

[0078] The nine typical working modes are as follows:

[0079] Understandably, in each typical operating mode, the four ports (i.e., V1, V2, V3, V4, V5, V6, V7, V8, V9, V1, V1, V2, V1, V2, V3, V4, V5, V6, V7, V8, V9, V1, V1, V1, V2, V1, V1, V2, V3, V4 ...2, V3, V4 h At least one of them is connected to a power source (AC or DC).

[0080] Operating Mode 1: The ports corresponding to V1, V2, and V3 operate independently. The matrix full-bridge circuit MB1-MB3 all operate in non-resonant mode, with all four ports (i.e., V1, V2, V3, V4, V5, V6, V7, V8, V9, V1, V2, V1, V2, V3, V4, V6, V7, V8, V9, V1, V2, V9, V1, V2, V3, h All four ports (i.e., V1, V2, V3, V4, V5, V6, V7, V8, V9, V1, V1, V2, V1, V2, V3, V4, V5, V6, V7, V8, V9, V1, V1, V2, V1, V1, V2, V3, V4, V1, V1, V2, V1, V1, V2, V3, V4, V1, V1, V2, V1, V2, V3, V1, V1, V2 ... h All of them can be connected to any one of the following: AC source, DC source, or load Ld.

[0081] Operating Mode 2: Ports corresponding to V1, V2, and V3 operate independently. Part of the matrix full-bridge circuit operates in non-resonant mode, while part operates in resonant mode. Specifically, matrix full-bridge circuits MB1 and MB2 operate in non-resonant mode, while matrix full-bridge circuit MB3 operates in resonant mode. In resonant mode, the AC / DC characteristics of the output voltage of MB3 are related to those of port V1. h Keep them consistent, and the voltage at port V3 is consistent with that at port V. h The voltages at ports V1, V2, and V2 maintain a constant proportional relationship. hAll can be connected to any one of an AC power source, a DC power source, or a load Ld; the voltage characteristic of port V3 follows that of port V. h V3 and V h You cannot connect an AC power source at the same time.

[0082] Operating Mode 3: Ports V1, V2, and V3 are connected to the same ground and operate independently. If port V... h When connected to a DC power source, ports V1, V2, and V3 can be connected to any of the following: AC power source, DC power source, or load Ld. Specifically, the low-voltage side ports V1, V2, and V3 can output three-phase AC power (including both grid-connected and off-grid states; for the equivalent topology diagram in grid-connected mode, please refer to...). Figure 7 Where A, B, and C refer to the three phases of a three-phase AC power grid; if port V h If connected to an AC source, ports V1, V2, and V3 can all be connected to a DC source and a load L. d Or with V h Any type of AC power supply with the same phase. The matrix full-bridge circuit MB1~MB3 operates in non-resonant mode, and can independently control the three-phase grid-connected current, or operate off-grid and output three-phase AC voltages with V1, V2 and V3 as targets. Among them, "grid" in "grid-connected" and "off-grid" both refer to "power grid".

[0083] Operating Mode 4: The ports corresponding to V1, V2, and V3 operate on a common ground. Part of the matrix full-bridge circuit, namely MB2 and MB3, operates in resonant mode (fixed gain, AC / DC characteristics of ports V2 and V3 are the same as those of port V). h (Consistent), the remaining matrix full-bridge circuit, namely MB1, operates in non-resonant mode. Ports V1, V... h All can be connected to any one of an AC power source, a DC power source, or a load Ld; the voltage characteristics of ports V2 and V3 follow those of port V. h But V2 and V h You cannot connect AC, V3 and V simultaneously. h You cannot connect an AC power source at the same time.

[0084] Operating Mode 5: Ports V1, V2, and V3 are all connected in parallel, and the matrix full-bridge circuit MB1-MB3 operates in non-resonant mode. Ports V1, V2, and V3 are connected in parallel to form a single port, called the parallel port. This parallel port is connected to port V... h At least one of them must be connected to a power source.

[0085] Working Mode 6: For equivalent topology graphs, please refer to [link / reference]. Figure 8 Ports V1, V2, and V3 are connected in series, and the matrix full-bridge circuit MB1-MB3 operates in non-resonant mode. Understandably, ports V1, V2, and V3 connected in series form a single port, called a series port. This series port is connected to V... h At least one of them must be connected to a power source.

[0086] Operating Mode 7: Ports V1, V2, and V3 are connected in series to form a single port, called a series port. Part of the matrix full-bridge circuit, namely MB2 and MB3, operates in resonant mode, while the remaining matrix full-bridge circuit, namely MB1, operates in non-resonant mode, forming a partial power converter. The AC / DC characteristics of the series port are related to the input side V... h Consistent, serial port and V h Do not connect loads simultaneously.

[0087] For the equivalent topology diagram of working mode 7, please refer to [link / reference]. Figure 9 Corresponding to working mode 6 Figure 8 In comparison, the only difference lies in the switching states of the resonant cavity: in operating mode 7, some matrix full-bridge circuits, namely MB2 and MB3, operate in resonant mode, while the remaining matrix full-bridge circuit, namely MB1, operates in non-resonant mode. The circuit operating in resonant mode is in fixed-gain mode, meaning that V2 and V3 are both in constant gain with respect to V... h For a fixed proportional relationship: In the formula, V2, N2, and V... h N h V3 and N3 represent the voltage at port V2 and the transformer T corresponding to port V2, respectively. r The number of turns of one winding W2, and the port V h Voltage, transformer T r The other winding W h Number of turns, voltage at port V3, and transformer T corresponding to port V3 r The number of turns of one winding W3.

[0088] Understandably, the topology of this invention lacks voltage regulation capability in the resonant mode portion. However, since the resonant circuit can naturally achieve soft switching of the power switch at the resonant point, its operating efficiency is relatively high. The portion operating in non-resonant mode, while possessing a wide range of voltage regulation capability, has reduced efficiency. Therefore, in mode 7, the magnitude of the total series voltage Vo on the output side can be adjusted by controlling V1. Since the low-voltage side (i.e., V1, V2, V3, defined as the output side) is a series structure, and the currents flowing through MB1, MB2, and MB3 are of equal magnitude, their power is proportional to their output voltage. Therefore, the overall circuit efficiency is: Where P1, P2, and P3 are the powers flowing into MB1, MB2, and MB3, respectively, and η1, η2, and η3 are the efficiencies of the corresponding circuit sections of MB1, MB2, and MB3, respectively. This refers to the current flowing through the series port on the output side. If the power flowing through the resonant section is designed to be greater than the power flowing through the non-resonant section (i.e., V2 + V3 > V1), then the circuit efficiency will be dominated by the efficiency η2 and η3 of the circuit operating in resonant mode. This achieves the goal of balancing voltage regulation capability and improving the overall circuit efficiency.

[0089] Operating Mode 8: Ports V1 and V2 are connected in series, thus MB1 and MB2 form a partial power converter in series, while the matrix full-bridge circuit MB3 operates independently. Understandably, the series connection of ports V1 and V2 creates a partially series-connected port, and the AC / DC characteristics of this partially series-connected port are different from those of port V1. h Consistent. Partial serial ports, port V h At least one of them must be connected to a power source.

[0090] Operating Mode 9: Ports V1 and V2 are connected in parallel, and the matrix full-bridge circuits MB1 and MB2 are connected in parallel. The matrix full-bridge circuit MB3 operates independently. The parallel connection of ports V1 and V2 forms a partially parallel port, and both the resulting parallel matrix full-bridge circuit and the matrix full-bridge circuit MB3 operate in non-resonant mode. (Partially parallel ports, port V...) h At least one of them must be connected to a power source.

[0091] Table 1

[0092] Working Mode 1 00000000 1 1 1 AC / DC AC / DC AC / DC AC / DC Working Mode 2 00000000 1 1 0 AC / DC AC / DC <![CDATA[same as V h > AC / DC Working Mode 3 10010010 1 1 1 AC / DC AC / DC AC / DC AC / DC Working Mode 4 10010010 1 0 0 AC / DC <![CDATA[Same V h > <![CDATA[same V h > AC / DC Working Mode 5 11011011 1 1 1 AC / DC AC / DC AC / DC AC / DC Working Mode 6 00100100 1 1 1 AC / DC Same as V1 Same as V1 AC / DC Working Mode 7 00100100 1 0 0 AC / DC Same as V1 Same as V1 AC / DC Working Mode 8 00100000 0 1 0 AC / DC Same as V1 AC / DC AC / DC Working Mode 9 11011000 1 1 1 AC / DC Same as V1 AC / DC AC / DC

[0093] Table 1

[0094] Please refer to Figure 10 The present invention also discloses a control system for the aforementioned power converter topology. The control system includes a gain calculation module 1, a current setting module 2, a voltage control loop 3, a current selection module 4, a mode switching module 5, and a modulation quantity module 6.

[0095] Among them, the gain calculation module 1 is used to calculate the real-time voltage gain M. That is, for the corresponding matrix full-bridge circuit MB... x With matrix half-bridge circuit M h For the circuit constructed, calculate the real-time voltage gain M = n x *V h / V x .

[0096] Current setting module 2 is used to provide an independent power supply port V for current selection module 4. x First current reference value I xref1 Specifically, the current setting module 2 sets the independent power supply port V in constant current operating mode. x The initial current reference value I xref0 After being processed by the limiting module, it becomes an independent power supply port V. xFirst current reference value I xref1 (referred to as the first current reference value I) xref1 ), and transmit to the current selection module 4.

[0097] Voltage control loop 3 is used to provide an independent power port V for current selection module 4. x Second current reference value I xref2 (referred to as the second current reference value I) xref2 Independent power port V x The third current reference value I xref3 (referred to as the third current reference value I) xref3 Specifically, voltage control loop 3 includes a common port voltage control loop (V... h Voltage loop) and independent power port voltage control loop (V x (Voltage loops), used to control the common power port voltage V. h and independent power supply port voltage V x For V h Voltage loop, V h Reference value V href With the sampled V h The difference between the two values ​​is taken as the error. After adjustment by the PI regulator and processing by the limiting module, the independent power supply port V is obtained. x Second current reference value I xref2 The current is fed into the current selection module 4 and compared with the current reference value output from other loops. Using V... x Taking a positive DC voltage as an example, i x >0 indicates that electrical energy comes from V x Lateral flow V h Side, when V h Below V href At that time, the error between the two is positive. The PI regulator increases the error, and when the modulation module 6 tracks the command, V... x Lateral V h Delivering more power prompts V h Rise to follow V href For V x Voltage loop, sampling V x Value and its reference value V xref The difference between the two is used as the error. After adjustment by a PI controller and upper and lower limit processing, an independent power supply port V is generated. x The third current reference value I xref3 And send it to current selection module 4. When V x Below V xref When the error is negative, the PI regulator output reduces the error. When the modulation module 6 tracks this command, V h From V xThe obtained power decreases, causing V x to rise to follow V xref . The voltage control loop 3 may select either one to act alone or both to act simultaneously according to the control requirements for the common power port voltage V h and the independent power port voltage V x .

[0098] The current selection module 4 is configured to output a final current command value I xref . More specifically, the current selection module 4 receives the aforementioned three current reference values I xref1 , I xref2 , I xref3 , and outputs the final current command value I xref according to the operating mode (constant voltage or constant current). It can be understood that for any independent circuit composed of the matrix full-bridge circuit MB x and the matrix half-bridge circuit M h , it can be configured as a constant current mode or a constant voltage mode according to practical applications. In the constant current mode, the final current command I xref is directly determined by the initial current reference value I xref0 of the current setting module 2, at this time I xref =I xref1 ; in the constant voltage mode, the final current command I xref is determined by the one with the smaller absolute value among the second current reference value I xref2 and the third current reference value I xref3 , at this time I xref =Min[I xref2 , I xref3 , so as to ensure the stability of voltage control.

[0099] The mode switching module 5 is configured to control switching between resonant and non-resonant operating modes. Specifically, the mode switching module 5 has a built-in hysteresis comparator, and controls the power converter topology to switch between the resonant and non-resonant operating modes according to the real-time voltage gain M; it can be understood that if it is intended to enter the resonant mode, S rx is controlled to be turned off; if it is intended to enter the non-resonant mode, S rx is controlled to be turned on. The specific implementation logic of the mode switching module 5 may refer to Figure 11 , when the real-time voltage gain M≤0.9 or M>1.1, the non-resonant mode is entered; when 0.95≤M≤1.05, the resonant mode is entered; when 0.9<M<0.95 or 1.05<M≤1.1, the current mode is maintained. It can be understood that the current mode may be the resonant mode or the non-resonant mode. It can be understood that Figure 11 the middle switching point is an exemplary configuration, and dynamic adjustment may be performed according to indicators such as efficiency in practical applications.

[0100] Modulation module 6 is used to generate PWM modulation signals for the power converter topology. Specifically, when the system is in resonant operating mode, the inward shift ratio D a1 Compared to outward movement, D a2 All values ​​are zero, and a fixed-frequency drive signal is used for control. The output of modulation module 6 is a fixed-frequency PWM modulation signal, ePWM1, used to drive the switching transistors in the matrix full-bridge and matrix half-bridge circuits. When the system operates in non-resonant mode, the final current command value I output by current selection module 4 is used. xref Compared to the real-time voltage gain M, the optimal inward shift is obtained by... a1 Compared to outward movement, D a2 After being processed by the limiting module, it is then sent to the PWM generation module, where it is connected to a frequency of f. x high-frequency carrier S fx The comparisons are then performed to generate the PWM modulation signal ePWM2, which is used to drive the switching transistors in the matrix full-bridge circuit and the matrix half-bridge circuit.

[0101] Among them, obtaining the optimal inward shift compared to D a1 Compared to outward movement, D a2 Built-in efficiency optimization algorithms, such as offline table lookup, can be used during the testing phase, based on I... xref And M, tested multiple groups of different inward shifts compared to D a1 Compared to outward movement, D a2 The system efficiency was calculated and presented in a table; during actual control, the real-time I / O was used as the basis for further analysis. xref By looking up M in a table, the optimal shift in system efficiency compared to D is obtained. a1 Compared to outward movement, D a2 This enables dynamic adjustment of the inward shift ratio and the outward shift ratio. In other embodiments, the efficiency optimization algorithm may also be other methods, which will not be elaborated here.

[0102] The control system, through the configuration of the aforementioned multiple modules, adopts a voltage and current dual closed-loop collaborative control architecture to ensure the rapid dynamic response of the power converter topology to voltage and current changes. Simultaneously, the control system, through a mode switching decision mechanism with a built-in hysteresis comparator, realizes the transition between resonant and non-resonant operating modes, avoiding current surges and voltage fluctuations caused by mode switching. Differentiated modulation schemes are formulated for the different resonant and non-resonant operating modes, improving the operating efficiency of the power converter topology.

[0103] This invention also discloses a control method applied to the power converter topology. A common power port V is defined. h For the input side, there is an independent power supply port V. x For the output side, this control method uses the first resonant frequency f r1The switching frequency of all transistors (correspondingly, the switching period T of all transistors is the first resonant frequency f) is the switching frequency of all transistors. r1 (the reciprocal of the common power port V) h The polarity of the matrix half-bridge circuit M h Switching its switching transistor Q h9 -Q h12 The conduction mode of the switching transistor Q h9 -Q h12 Partially continuous, partially continuous at frequency f r1 The moment when the switch that leads the other switch to turn on is defined as the start time t of the unified switching cycle of the entire system. Z =0 (i.e., the reference time t) Z =0). Based on the independent power supply port voltage V x The polarity of the output side matrix full-bridge circuit MB x Dynamically allocate its switching transistor Q x1 -Q x8 Forward or backward arm, and by inward shift compared to D a1 The transmission power is controlled by adjusting the conduction delay of the lagging arm relative to the leading arm. This is achieved by shifting the relative D... a2 Adjust the lead-arm conduction time of each circuit relative to the overall reference time t. Z The phase is 0, thus enabling power distribution among multiple output ports. The inward shift is compared to D. a1 This indicates the proportion of the delay conduction time of the lagging arm compared to the leading arm in half a switching cycle; the outward shift compared to D a2 MB represents a matrix full-bridge circuit x The lead time of the forearm conduction relative to the reference time t Z =0 represents the percentage of time that occurs in half a switching cycle. (Inward shift compared to D) a1 Compared to D, the external movement a2 The ranges are [0, 1] and [-1, 1], respectively.

[0104] Specifically, the matrix half-bridge circuit M h The control logic / method is as follows: when the common power port V h When the voltage is greater than 0, for the matrix half-bridge circuit M h The switching transistor Q h10 Q h12 Apply a normally-on drive signal to the switching transistor Q. h9 Q h11 Apply a complementary square wave drive signal with dead time, and switch Q h9 Leading Q h11 On; when the common power port V h When the voltage is less than 0, for the switching transistor Q h9 Q h11Apply a normally-on drive signal to the switching transistor Q. h10 Q h12 Apply a complementary square wave drive signal with dead time, and switch Q h10 Leading switching transistor Q h12 On; when the common power port V h When the voltage is 0, the matrix half-bridge circuit M is turned off. h All drive signals; with the leading switch Q being turned on. h9 Or Q h10 The conduction time is defined as the start time t of the switching cycle. Z =0.

[0105] Specifically, the matrix full-bridge circuit MB x The control logic / method is as follows: based on the independent power supply port V x The voltage polarity is controlled by a fixed-frequency phase-shift control. When the voltage V at the independent power supply port... x When greater than 0, for the matrix full-bridge circuit MB x The forearm (first bridge arm Bg) x1 Q in ) x2 Q x 4 and matrix full-bridge circuit MB x The lagging arm (second bridge arm Bg) x2 Q in ) x6 Q x8 Apply a constant drive signal to the Q in the forearm. x1 Q x3 Apply a complementary square wave drive signal with dead time and Q x1 Leading Q x3 Conduction, for Q in the hysteresis arm x5 Q x7 Applying each lags behind Q x1 Q x3 The square wave drive signal has a lag time shifted inward compared to D. a1 Control, with a lag time of D a1 *T hs T hs It is half of the switching cycle. When the independent power supply port voltage V x When it is less than 0, for the switching transistor Q x1 Q x3 Q x5 Q x7 Apply a constant drive signal to the forearm Q x2 Q x 4. Apply a complementary square wave drive signal with dead time and Q x2 Leading Q x4 Conduction, for the hysteresis arm Q x6 Q x8 Applying each lags behind Qx2 Q x The lag time of the square wave drive signal with a 4-bit delay is shifted from inward compared to D. a1 Control, with a lag time of D a1 *T hs When the independent power supply port voltage V x When the value is 0, the matrix full-bridge circuit MB is turned off. x All drive signals, introduced by external shift compared to D a2 The turn-on time of the leading switch in the control arm (referred to as the leading turn-on time of the leading arm) is relative to the start time t of each switching cycle. Z The phase. By shifting inward compared to D a1 Adjustable matrix full-bridge circuit MB x The conduction delay of the internal hysteresis arm relative to the leading arm controls the transmission power. This is achieved by shifting the external relative D... a2 Adjust each matrix full-bridge circuit MB x The lead time of the forearm conduction relative to the overall reference time t Z The phase of 0 makes the matrix full-bridge circuit MB x The leading-conduction switch in the forearm is at t Z D before =0 a2 *T hs The circuit is turned on, thereby adjusting the output power obtained by each independent power port and realizing power distribution among multiple independent power ports.

[0106] In one embodiment, the above control method further includes: when any matrix full-bridge circuit MB on the output side x When configured to operate in resonant mode, the corresponding inward shift is relative to D. a1 Compared to outward movement, D a2 Set to zero to enable the output-side matrix full-bridge circuit MB x The switching transistor drive signal and the input-side matrix half-bridge circuit M h The drive signal of the first conducting switch in the middle remains synchronized. When any matrix full-bridge circuit MB on the output side... x When configured to operate in non-resonant mode, based on the real-time acquired independent power supply port voltage V x Public power port V h Voltage and power requirements, dynamically adjust their corresponding inward shift relative to D a1 Compared to outward movement, D a2 This adaptive adjustment enables power regulation. Through this adaptive adjustment, the power converter topology can achieve an optimal balance between efficiency and regulation accuracy based on operating conditions.

[0107] The above control method simplifies the complexity of multi-port cooperative control and ensures the accuracy and stability of power distribution control.

[0108] To further illustrate the above control methods, please refer to [link / reference]. Figure 12 , Figure 12 Taking the matrix full-bridge circuits MB1 and MB2 as examples, we will explain the matrix full-bridge circuit MB. x The driving method and steady-state waveform under both non-resonant and resonant operating modes. Where V1>0, V2>0, V h >0.

[0109] Among them, the matrix full-bridge circuit MB1 operates in non-resonant mode, and the matrix full-bridge circuit MB2 operates in resonant mode. Ignoring the commutation process during the dead time, the circuit waveforms of the power converter topology during one switching cycle t1-t5 are described below.

[0110] First, the matrix full-bridge circuit MB1 operates in non-resonant mode. In non-resonant mode, fixed-frequency phase-shift control is used, based on the independent power supply port voltage V1 and the common power supply port voltage V. h The voltage and current power requirements are dynamically adjusted to adjust the corresponding inward shift relative to D. a1 Compared to outward movement, D a2 Because of V h >0, switch Q h10 and Q h12 Apply a normally-on drive signal, Q h9 and Q h11 Apply a square wave drive signal with dead time, and Q h9 The activation time is the start time t of the switching cycle. Z In Q h9 During conduction, the voltage V at the half-bridge port s =V h / 2; in Q h11 During conduction, the voltage V at the half-bridge port s = -V h / 2, therefore the voltage N1V on the transformer winding W1 on the MB1 side of the matrix full-bridge circuit s This refers to a square wave voltage with a duty cycle close to 50% (the theoretical duty cycle is 50%, but in practice there is a dead zone, hence the duty cycle is close to 50%). This applies to the matrix full-bridge circuit MB1 and the matrix half-bridge circuit M. h The specific circuit waveforms of the power converter topology during one switching cycle from t1 to t5 are described below:

[0111] From t1 to t2: at t1 = -D a2 T hs Moment, driving Q 11 The circuit is on. Because the resonant cavity current i is at this time... L1 <0, i.e., Q 11Before conduction, its body diode and / or anti-parallel diode are already in freewheeling conduction state, therefore Q 11 Zero-voltage turn-on can be achieved. During the time interval t1 to t2, Q in the matrix full-bridge circuit MB1... 11 and Q 15 When the matrix full-bridge circuit MB1 is turned on, it is in the freewheeling state of the inductor current, and the freewheeling path is: Q 15 →Q 16 →MB1 side transformer windings→L1 and C 13 C 12 The resonant cavity formed → Q 12 →Q 11 V at this stage p1 =0, the transformer winding voltage on the MB1 side is -N1V s The resonant cavity is subjected to a positive voltage, and the resonant cavity current i L1 It increases approximately linearly.

[0112] t2 to t Z Stage: at t2 = t1 + D a1 T hs =(D a1 - D a2 ) T hs Moment, driving Q 17 The circuit is on. Because the resonant cavity current i is at this time... L1 Still less than 0, i.e., Q 17 Before conduction, its body diode and / or anti-parallel diode are already conducting with freewheeling current, therefore Q 17 Zero-voltage turn-on can be achieved. From t2 to t Z During the time period, the current flow path is: V1 positive terminal → Q 11 →Q 12 →L1 and C 13 C 12 The resonant cavity formed → MB1 side transformer winding W1 → Q 17 →Q 18 → V1 negative terminal. During this stage, Vp1 = V1, and the voltage across transformer winding W1 on the MB1 side is -N1V. s The resonant cavity withstands a larger positive voltage, and the resonant cavity current i L1 After turning from negative to zero, it continues to grow positively.

[0113] t Z Up to stage t3: at t Z At any given moment, drive the matrix half-bridge circuit M h Q within h9 When the circuit is turned on, the voltage of transformer winding W1 on the MB1 side of the matrix full-bridge circuit becomes N1V. s Assume V1 <N1V s At this time, the resonant cavity is subjected to a negative voltage, and the resonant cavity current iL1 decline.

[0114] t3 to t4 phase: At time t3, Q is turned off. 11 Q will be activated after a brief dead zone delay. 13 Since the resonant cavity current is positive, Q 13 Before turn-on, the current has already flowed through its body diode and / or anti-parallel diode, therefore Q... 13 Zero-voltage turn-on can be achieved. During the time interval t3 to t4, Q in the matrix full-bridge circuit MB1... 13 and Q 17 When the matrix full-bridge circuit MB1 is turned on, it is in the freewheeling state of the inductor current, and the freewheeling path is: Q 14 →Q 13 →L1 and C 13 C 12 The resonant cavity formed → MB1 side transformer winding W1 → Q 17 →Q 18 V at this stage p1 =0, the transformer winding voltage on the MB1 side of the matrix full-bridge circuit is N1V. s The resonant cavity is subjected to a negative voltage, and the resonant cavity current i L1 It decreases approximately linearly.

[0115] t4-T hs At time t4, drive Q15 is turned on, because the resonant cavity current i L1 Still greater than 0, i.e., Q 15 Before conduction, its body diode and / or anti-parallel diode are already conducting with freewheeling current, therefore Q 15 Zero-voltage turn-on can be achieved. In t4-T hs During the time period, the current flow path is: V1 positive terminal → Q 15 →Q 16 →L1 and C 13 C 12 The resonant cavity formed → MB1 side transformer winding W1 → Q 13 →Q 14 →V1 negative electrode. During this stage, V... p1 =V1, the voltage of transformer winding W1 on the MB1 side is N1V s The resonant cavity withstands a larger negative voltage, and the resonant cavity current i L1 After changing from positive to zero, it continues to grow negatively.

[0116] T hs -t5, in t hs At any given moment, drive the matrix half-bridge circuit M h Q within h11When the circuit is turned on, the voltage of the transformer winding on the MB1 side of the matrix full-bridge circuit becomes -N1Vs. At this time, the resonant cavity is subjected to positive voltage, and the resonant cavity current i L1 The circuit rises, then Q13 is turned off, and after a brief dead zone, it enters the next switching cycle.

[0117] Secondly, regarding the matrix full-bridge circuit MB2 and the matrix half-bridge circuit M... h For explanation:

[0118] Please continue to refer to Figure 12 The matrix full-bridge circuit MB2 operates in resonant mode, controlled by a fixed-frequency drive signal. The polarity of the control port voltage V2 is related to V... h Keep it consistent, and D a1 =D a2 =0, matrix full-bridge circuit MB2, matrix half-bridge circuit M h A synchronous square wave drive is adopted; specifically, since V2>0, for Q... 22 Q 24 Q 26 and Q 28 Apply a normally-on drive signal to Q 21 Q 27 And Q 23 Q 25 Apply to Q respectively h9 Q h11 Synchronous square wave drive signal, i.e., Q 21 Q 27 The square wave drive signal and Q h9 Synchronization, Q 23 Q 25 The square wave drive signal and Q h11 Synchronization. Corresponding resonant cavity current i L2 It exhibits a sinusoidal wave shape. At this time, the device Q that leads the conduction in the upper arm is... 21 With Q h9 Simultaneous conduction, according to the definition of outward shift comparison, D b2 =0; Simultaneously, the lagging arm and the forearm are synchronously activated (Q 27 With Q 21 (Simultaneous conduction), according to the definition of inward shift, D b1 =0, which conforms to the modulation strategy in the resonant mode.

[0119] To better illustrate the present invention, Figure 13 and Figure 14 ( Figure 14 for Figure 13 The enlarged view shows a circuit signal waveform when m=3 and operating mode 2; where V p1 V p2 V p3These are the voltages at the full-bridge ports of MB1, MB2, and MB3, respectively. p1 i p2 i p3 V represents the current flowing through the respective full-bridge ports of MB1, MB2, and MB3. h For the voltage of the common power port, i h For the current flowing through the common power port V h The current, V s M is a matrix half-bridge circuit h The voltage at the half-bridge port. Figure 13 , Figure 14 In waveform-corresponding mode, independent power supply ports V1, V2, and V3 are connected to a DC source, a DC source, and a resistive load, respectively, while the common power supply port V... h When connected to an AC source (such as the mains), the half-bridge port voltage Vs is a square wave voltage with a fixed duty cycle close to 50%. Matrix full-bridge circuits MB1 and MB2 operate in non-resonant mode, while matrix full-bridge circuit MB3 operates in resonant mode. Under non-resonant mode control, the full-bridge port voltage Vs of matrix full-bridge circuits MB1 and MB2... p1 and V p2 The angles of the independent power supply ports V1 and V2 are adaptively adjusted to lead or lag the half-bridge voltage Vs according to power demand. At this time, independent power supply port V1 outputs power, independent power supply port V2 absorbs power, and independent power supply port V3 absorbs power. The matrix full-bridge circuit MB3 operates in resonant mode, V... p3 With V s With the same frequency and no phase shift, the independent power supply port V3 obtains the same voltage as V. h The AC voltage is proportional. Since the power at each independent power supply port V1, V2, and V3 is active, and each controls its own power supply to the common power supply port V... h Since the injected or absorbed current is a sinusoidal quantity, the resulting grid-connected current is the superposition of three sinusoidal quantities, i. h It is still a sinusoidal quantity and is related to V. h Same frequency and phase.

[0120] To better illustrate the present invention, Figure 15 and Figure 16 ( Figure 16 for Figure 15 The enlarged view shows a circuit signal waveform when m=3 and operating mode 3. V1, V2, and V3 are the voltages at the independent power supply ports of MB1, MB2, and MB3, respectively; i p1 i p2 i p3 i1, i2, and i3 are the currents flowing through the full bridge ports of MB1, MB2, and MB3, respectively, and i1, i2, and i3 are the currents flowing through the independent power supply ports of MB1, MB2, and MB3, respectively. Figure 15 , Figure 16 In the waveform-corresponding mode, MB1, MB2, and MB3 each have their own independent power supply ports V1, V2, and V3 connected to a three-phase AC voltage source (such as the power grid). The matrix full-bridge circuit MB1-MB3 all operate in non-resonant mode, and the common power supply port V... h Connecting to a DC power source converts the DC power into three-phase AC power to supply a three-phase AC voltage source. In non-resonant mode, independent control of the three-phase grid-connected current can be achieved through MB1, MB, and MB3. Since the AC power supplies connected to the independent power ports V1, V2, and V3 are themselves three-phase symmetrical (voltage symmetry is an objective external condition), the corresponding voltages V1, V2, and V3 of the independent power ports are AC voltages with equal amplitudes and a phase difference of 120 degrees. To demonstrate the independence of power or current control of the three independent power ports, the currents i1, i2, and i3 of each independent power port of MB1, MB2, and MB3 are AC currents with unequal amplitudes (of course, the currents i1, i2, and i3 can also be controlled to be three-phase symmetrical currents).

[0121] Through the above-mentioned technical solution of the present invention, the switching of multiple connection methods of matrix full-bridge circuit and the selection of resonant and non-resonant modes are realized, and the interconnection of multiple AC / DC ports of different specifications is flexibly realized, further meeting the energy interaction needs of AC / DC source, load and storage units of different specifications in AC / DC hybrid microgrids.

[0122] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A power converter topology, characterized in that, The system includes m matrix full-bridge circuits, a first bus, a second bus, m resonant cavities, a transformer, and a matrix half-bridge circuit. Each matrix full-bridge circuit has an independent power supply port on one side. The first and second ends of each independent power supply port are selectively connected to the first bus and the second bus, respectively. The first end of each independent power supply port is selectively connected to the second end of the next adjacent independent power supply port. The other side of each matrix full-bridge circuit is connected to the corresponding winding of the transformer through its respective resonant cavity. The other winding of the transformer is connected to one side of the matrix half-bridge circuit. The other side of each matrix half-bridge circuit has a common power supply port. Each matrix full-bridge circuit selectively operates in resonant mode or non-resonant mode. Wherein, m is an integer, and m≥2.

2. The power converter topology according to claim 1, characterized in that, The first and second ends of the other winding of the transformer are respectively connected to the first and second ends of one side of the matrix half-bridge circuit.

3. A power converter topology according to claim 1, characterized in that, The first and second ends of each independent power port are selectively connected to the first bus and the second bus via corresponding first and second switching switches, respectively. The first end of the independent power port is selectively connected to the second end of the next adjacent independent power port via corresponding third switching switch.

4. A power converter topology according to claim 1, characterized in that, The first end of the other side of each of the matrix full-bridge circuits is connected to the first end of the corresponding winding on one side of the transformer through its respective resonant cavity, and the second end of the other side of each of the matrix full-bridge circuits is connected to the second end of the corresponding winding on one side of the transformer.

5. A power converter topology according to claim 4, characterized in that, It also includes a fourth switching switch, and the corresponding winding on one side of the transformer also has a center tap. The second end on the other side of each matrix full-bridge circuit is selectively connected to the center tap through the fourth switching switch.

6. A power converter topology according to claim 4 or 5, characterized in that, The resonant cavity includes an inductor, a second capacitor, a third capacitor, and a resonant switching switch. One end of the inductor and the other end of the third capacitor are respectively one end and the other end of the resonant cavity. The other end of the inductor is connected to one end of the third capacitor. The second capacitor and the resonant switching switch are connected in series to form a series bridge circuit. The two ends of the series bridge circuit are connected in parallel with the two ends of the third capacitor.

7. A power converter topology according to claim 1, characterized in that, The value of m is 3.

8. A power converter topology according to claim 6, characterized in that, When the resonant switching switch is open, the corresponding matrix full-bridge circuit operates in resonant mode; when the resonant switching switch is closed, the corresponding matrix full-bridge circuit operates in non-resonant mode.

9. A control system for controlling the power converter topology according to any one of claims 1-8, characterized in that, It includes a gain calculation module, a current setting module, a voltage control loop, a current selection module, a mode switching module, and a modulation quantity module; among which, The gain calculation module is used to calculate the real-time voltage gain, the current setting module is used to provide the current selection module with a first current reference value, the voltage control loop is used to provide the current selection module with a second current reference value and a third current reference value, the current selection module is used to output the final current command value, the mode switching module is used to control the switching between resonant and non-resonant operating modes, and the modulation quantity module is used to generate a PWM modulation signal.

10. A control method for controlling the power converter topology according to any one of claims 1-8, characterized in that, include: When any of the matrix full-bridge circuits is configured to operate in resonant mode, the corresponding inner shift ratio and outer shift ratio are set to zero, and the drive signal of the switching transistor in the matrix full-bridge circuit is synchronized with the drive signal of the leading switching transistor in the matrix half-bridge circuit. When any of the matrix full-bridge circuits is configured to operate in non-resonant mode, the corresponding inner shift ratio and outer shift ratio are dynamically adjusted based on the real-time collected voltage of the independent power supply port, the voltage of the common power supply port, and the power requirements.

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