Routing topology circuit based on partial power conversion circuit and TAB circuit

Abstract

The present invention discloses a routing topology circuit based on a partial power conversion circuit and a TAB circuit, and relates to the technical field of power electronic application, and specifically comprises a three-winding transformer, a partial power conversion circuit and a TAB circuit, wherein the TAB circuit comprises a first DC bus port structure, an energy storage battery port structure and a second DC bus port structure, wherein the energy storage battery port structure is used to connect the energy storage battery; the first DC bus port structure is connected to the medium voltage side winding of the three-winding transformer; the energy storage battery port structure is connected to the low voltage side winding of the three-winding transformer T; the second DC bus port structure is connected to the high voltage side winding of the three-winding transformer; a battery port for connecting a fuel cell is provided between the partial power conversion circuit and the first DC bus port structure; the first DC bus port structure is used to connect to a first DC bus, and the second DC bus port structure is used to connect to a second DC bus, and the present invention can ensure stable and multi-directional transmission of energy.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics applications, and in particular to a routing topology circuit based on a partial power conversion circuit and a TAB circuit. Background Art

[0002] Research background of multi-port converter:

[0003] 1) With the widespread application of new energy sources such as solar energy, wind energy and energy storage equipment, traditional distribution systems need to adapt to the access of these new energy sources and loads. This requires the distribution system to be able to quickly respond to changes in distributed energy output and loads, and to accurately adjust power flow;

[0004] 2) In order to cope with the access of new loads such as distributed renewable energy, energy storage equipment and electric vehicles in the power grid, it is important to build an AC / DC hybrid distribution system based on power electronic converters. Multi-port power electronic transformers (PETs) play a key hub role in this system, which can realize flexible control of power and voltage at each port, power quality management, energy interconnection and fault isolation between ports;

[0005] 3) Multi-port power electronic transformers are gaining more and more attention due to their ability to achieve bidirectional energy flow, flexible power flow regulation, harmonic and reactive power control, and fault isolation. They have broad application prospects in AC / DC hybrid power distribution systems, especially in situations where isolation and high-power AC / DC and DC / DC conversion are required;

[0006] 4) The multi-port power router based on power electronic transformers has attracted attention because it can improve the voltage and power level of the device through the series and parallel connection of module units, and achieve electrical isolation of each port through high-frequency transformers. This power router can better access various forms of new energy and energy storage equipment;

[0007] Due to the wide variety of traditional DC conversion equipment, the multi-port DC converter obtained by adding ports also has many different architectures. According to the degree of electrical isolation, it can be divided into: non-isolated multi-port DC / DC converter, semi-isolated multi-port DC / DC converter and isolated multi-port DC / DC converter. Most three-port DC / DC converters can realize bidirectional energy transfer between any two ports. The three-port DC / DC converter generally works in the following three working modes: single-port input and single-port output, single-port input and dual-port output, and dual-port input and single-port output. Among them, TAB is the most typical isolated DC / DC converter. The complete isolation of the three ports makes its power flow easy to analyze. At the same time, it has a high degree of freedom and flexible control. Different control methods have different control difficulties. Moreover, the output range can also be adjusted with the control amount. Its control amount is the phase shift angle between ports and the phase shift angle between bridge arms in the full bridge.

[0008] For systems with variable output demands, the traditional way of processing is to treat the required output as a whole. All the transmitted energy flows through the converter and is adjusted according to the real-time demand of the load. It is converted by switching devices and electrical isolation devices, including voltage and current processing, and then supplied to the load. This process of processing all the transmitted power is called full-power conversion, and the converter built based on this idea is called a full-power converter; partial power processing is a concept proposed relative to full-power processing. The specific idea is: the output is divided, a part of it is transmitted at a constant amount, without passing through the conversion equipment, and flows directly to the load only under the influence of the port parameters. The other non-constant part is converted and dynamically adjusted through the control amount to meet the load demand. Since there is only a part of the amount that changes with the output, this processing method is called partial power processing, and the converter built for partial power processing is a partial power converter.

[0009] The traditional TAB topology is a three-inductor model, which generally adopts a simple SPS control, and the control requires complex software decoupling. In the TAB topology of the full-bridge converter, the leakage inductance of the transformer, the eddy current generated in it, and the energy feeding are the primary factors causing losses, and there are problems such as low power conversion efficiency and low stability. Therefore, reducing losses needs to be considered from reducing the energy flowing through the transformer and switching devices. However, in addition to adjusting the voltage, the existence of the transformer also plays an important role in providing electrical isolation between ports. Therefore, it is necessary to start from reducing losses and reducing the energy flowing through the transformer and switching devices. Summary of the invention

[0010] The technical problem to be solved by the present invention is to address the deficiencies of the prior art and specifically provide the following technical solutions to replace the traditional TAB converter to obtain higher efficiency and better quality output energy. The specific technical solutions are as follows:

[0011] 1) In the first aspect, the present invention provides a routing topology circuit based on a partial power conversion circuit and a TAB circuit, and the specific technical solution is as follows:

[0012] It includes a three-winding transformer, a part of the power conversion circuit and a TAB circuit, wherein the TAB circuit includes a first DC bus port structure, an energy storage battery port structure and a second DC bus port structure, and the energy storage battery port structure is used to connect the energy storage battery;

[0013] The first DC bus port structure is connected to the medium voltage side winding of the three-winding transformer;

[0014] The energy storage battery port structure is connected to the low voltage side winding of the three-winding transformer;

[0015] The second DC bus port structure is connected to the high voltage side winding of the three-winding transformer;

[0016] A battery port for connecting to a fuel cell is provided between the partial power conversion circuit and the first DC bus port structure;

[0017] The first DC bus port structure is used to connect the first DC bus, and the second DC bus port structure is used to connect the second DC bus.

[0018] On the basis of the above solution, the routing topology circuit based on a partial power conversion circuit and a TAB circuit of the present invention can also be improved as follows.

[0019] Further, the first DC bus port structure includes a first port capacitor, a first inductor and a first power tube full-bridge circuit having four power tubes;

[0020] One end of the first inductor is connected to the same-name terminal on the medium voltage side of the three-winding transformer, and the other end of the first inductor is connected to the source of the first power tube of the first power tube full-bridge circuit and the drain of the second power tube of the first power tube full-bridge circuit;

[0021] The opposite-name end of the medium-voltage side of the three-winding transformer is connected to the source of the third power tube of the first power tube full-bridge circuit and the drain of the fourth power tube of the first power tube full-bridge circuit;

[0022] The drain of the first power tube of the first power tube full-bridge circuit, the drain of the third power tube of the first power tube full-bridge circuit and the positive electrode of the first port capacitor are all connected to the positive electrode of the first DC bus; the source of the second power tube of the first power tube full-bridge circuit, the source of the fourth power tube of the first power tube full-bridge circuit and the negative electrode of the first port capacitor are all connected to the negative electrode of the first DC bus.

[0023] Further, the energy storage battery port structure includes a second port capacitor, a second inductor and a second power tube full-bridge circuit having four power tubes;

[0024] One end of the second inductor is connected to the same-name end of the low-voltage side of the three-winding transformer, and the other end of the second inductor is connected to the source of the first power tube of the second power tube full-bridge circuit and the drain of the second power tube of the second power tube full-bridge circuit;

[0025] The low-voltage side opposite-name terminal of the three-winding transformer is connected to the source of the third power tube of the second power tube full-bridge circuit and the drain of the fourth power tube of the second power tube full-bridge circuit;

[0026] The drain of the first power tube of the second power tube full-bridge circuit, the drain of the third power tube of the second power tube full-bridge circuit, and the positive electrode of the second port capacitor are all connected to the positive electrode of the energy storage battery; the source of the second power tube of the second power tube full-bridge circuit, the source of the fourth power tube of the second power tube full-bridge circuit, and the negative electrode of the second port capacitor are all connected to the negative electrode of the energy storage battery.

[0027] Further, the second DC bus port structure includes a third port capacitor and a third power tube full-bridge circuit having four power tubes;

[0028] The high-voltage side like-name end of the three-winding transformer is connected to the source of the first power tube of the third power tube full-bridge circuit and the drain of the second power tube of the third power tube full-bridge circuit; the high-voltage side opposite-name end of the three-winding transformer is connected to the source of the third power tube of the third power tube full-bridge circuit and the drain of the fourth power tube of the third power tube full-bridge circuit;

[0029] The drain of the first power tube of the third power tube full-bridge circuit, the drain of the third power tube of the third power tube full-bridge circuit, and the positive electrode of the third port capacitor are all connected to the positive electrode of the second DC bus; the source of the second power tube of the third power tube full-bridge circuit, the source of the fourth power tube of the third power tube full-bridge circuit, and the negative electrode of the third port capacitor are all connected to the negative electrode of the second DC bus.

[0030] Further, the partial power conversion circuit includes a four-switch circuit, a fourth port capacitor and a fifth port capacitor, the four-switch circuit includes a first half-bridge circuit and a second half-bridge circuit, and a third inductor is connected between a midpoint of a bridge arm of the first half-bridge circuit and a midpoint of a bridge arm of the second half-bridge circuit;

[0031] The positive electrode of the fuel cell is connected to the positive electrode of the first DC bus, the negative electrode of the fuel cell is connected to the drain electrode of the first power tube of the first half-bridge circuit and the positive electrode of the fourth port capacitor, and the negative electrode of the fourth port capacitor and the negative electrode of the fifth port capacitor are connected to the source electrode of the second power tube of the first half-bridge circuit, the source electrode of the second power tube of the second half-bridge circuit, the negative electrode of the first DC bus and the negative electrode of the energy storage battery;

[0032] One end of the third inductor is connected to the source of the first power tube of the first half-bridge circuit and the drain of the second power tube of the first half-bridge circuit, the other end of the third inductor is connected to the source of the first power tube of the second half-bridge circuit and the drain of the second power tube of the second half-bridge circuit, and the drain of the first power tube of the second half-bridge circuit is connected to the positive electrode of the fifth port capacitor and the positive electrode of the energy storage battery.

[0033] Furthermore, the voltage of the first DC bus is 220V, and the voltage of the second DC bus is 750V.

[0034] 2) In the second aspect, the present invention also provides a method for using a routing topology circuit based on a partial power conversion circuit and a TAB circuit, and the specific technical solution is as follows:

[0035] The routing topology circuit based on the partial power conversion circuit and the TAB circuit includes: a three-winding transformer, a partial power conversion circuit and a TAB circuit, the TAB circuit includes a first DC bus port structure, an energy storage battery port structure, and a second DC bus port structure, and the energy storage battery port structure is used to connect the energy storage battery;

[0036] The first DC bus port structure is connected to the medium voltage side winding of the three-winding transformer;

[0037] The energy storage battery port structure is connected to the low voltage side winding of the three-winding transformer;

[0038] The second DC bus port structure is connected to the high voltage side winding of the three-winding transformer;

[0039] A battery port for connecting to a fuel cell is provided between the partial power conversion circuit and the first DC bus port structure;

[0040] The first DC bus port structure is used to connect the first DC bus, and the second DC bus port structure is used to connect the second DC bus;

[0041] The first DC bus port structure includes a first port capacitor, a first inductor and a first power tube full-bridge circuit having four power tubes;

[0042] One end of the first inductor is connected to the same-name terminal on the medium voltage side of the three-winding transformer, and the other end of the first inductor is connected to the source of the first power tube of the first power tube full-bridge circuit and the drain of the second power tube of the first power tube full-bridge circuit;

[0043] The opposite-name end of the medium-voltage side of the three-winding transformer is connected to the source of the third power tube of the first power tube full-bridge circuit and the drain of the fourth power tube of the first power tube full-bridge circuit;

[0044] The drain of the first power tube of the first power tube full-bridge circuit, the drain of the third power tube of the first power tube full-bridge circuit, and the positive electrode of the first port capacitor are all connected to the positive electrode of the first DC bus; the source of the second power tube of the first power tube full-bridge circuit, the source of the fourth power tube of the first power tube full-bridge circuit, and the negative electrode of the first port capacitor are all connected to the negative electrode of the first DC bus;

[0045] The energy storage battery port structure includes a second port capacitor, a second inductor and a second power tube full-bridge circuit having four power tubes;

[0046] One end of the second inductor is connected to the same-name end of the low-voltage side of the three-winding transformer, and the other end of the second inductor is connected to the source of the first power tube of the second power tube full-bridge circuit and the drain of the second power tube of the second power tube full-bridge circuit;

[0047] The low-voltage side opposite-name terminal of the three-winding transformer is connected to the source of the third power tube of the second power tube full-bridge circuit and the drain of the fourth power tube of the second power tube full-bridge circuit;

[0048] The drain of the first power tube of the second power tube full-bridge circuit, the drain of the third power tube of the second power tube full-bridge circuit, and the positive electrode of the second port capacitor are all connected to the positive electrode of the energy storage battery; the source of the second power tube of the second power tube full-bridge circuit, the source of the fourth power tube of the second power tube full-bridge circuit, and the negative electrode of the second port capacitor are all connected to the negative electrode of the energy storage battery;

[0049] The second DC bus port structure includes a third port capacitor and a third power tube full-bridge circuit having four power tubes;

[0050] The high-voltage side like-name end of the three-winding transformer is connected to the source of the first power tube of the third power tube full-bridge circuit and the drain of the second power tube of the third power tube full-bridge circuit; the high-voltage side opposite-name end of the three-winding transformer is connected to the source of the third power tube of the third power tube full-bridge circuit and the drain of the fourth power tube of the third power tube full-bridge circuit;

[0051] The drain of the first power tube of the third power tube full-bridge circuit, the drain of the third power tube of the third power tube full-bridge circuit, and the positive electrode of the third port capacitor are all connected to the positive electrode of the second DC bus; the source of the second power tube of the third power tube full-bridge circuit, the source of the fourth power tube of the third power tube full-bridge circuit, and the negative electrode of the third port capacitor are all connected to the negative electrode of the second DC bus;

[0052] The partial power conversion circuit includes a four-switch circuit, a fourth port capacitor and a fifth port capacitor, the four-switch circuit includes a first half-bridge circuit and a second half-bridge circuit, and a third inductor is connected between a midpoint of a bridge arm of the first half-bridge circuit and a midpoint of a bridge arm of the second half-bridge circuit;

[0053] The positive electrode of the fuel cell is connected to the positive electrode of the first DC bus, the negative electrode of the fuel cell is connected to the drain electrode of the first power tube of the first half-bridge circuit and the positive electrode of the fourth port capacitor, and the negative electrode of the fourth port capacitor and the negative electrode of the fifth port capacitor are connected to the source electrode of the second power tube of the first half-bridge circuit, the source electrode of the second power tube of the second half-bridge circuit, the negative electrode of the first DC bus and the negative electrode of the energy storage battery;

[0054] One end of the third inductor is connected to the source of the first power tube of the first half-bridge circuit and the drain of the second power tube of the first half-bridge circuit, the other end of the third inductor is connected to the source of the first power tube of the second half-bridge circuit and the drain of the second power tube of the second half-bridge circuit, and the drain of the first power tube of the second half-bridge circuit is connected to the positive electrode of the fifth port capacitor and the positive electrode of the energy storage battery;

[0055] Usage methods include:

[0056] When the actual voltage of the second DC bus and the actual voltage of the energy storage battery are both in a fluctuating state, the power of the fuel cell and the transmission power of each port are controlled by controlling the phase shift angles among the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the duty cycle of the four-switch circuit;

[0057] When the actual voltage of the second DC bus is in a stable state and the actual SOC value of the energy storage battery does not exceed the first preset SOC threshold, the energy storage battery is placed in a charging state by controlling the phase shift angles between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the duty cycle of the four-switch circuit;

[0058] When the actual voltage of the second DC bus is in a stable state and the actual SOC value of the energy storage battery is not less than the second preset SOC threshold, the energy storage battery is placed in a discharge state by controlling the phase shift angles between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell, wherein the second preset SOC threshold is not less than the first preset SOC threshold;

[0059] When the actual voltage of the second DC bus is lower than the preset voltage threshold, and the actual SOC value of the energy storage battery is not less than the second preset SOC threshold, the energy storage battery is placed in a discharge state by controlling the phase shift angle between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell;

[0060] When the actual voltage of the second DC bus is lower than the preset voltage threshold and the actual SOC value of the energy storage battery does not exceed the first preset SOC threshold, the energy storage battery is put into a charging state by controlling the phase shift angle between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell.

[0061] On the basis of the above solution, the method for using the routing topology circuit based on a partial power conversion circuit and a TAB circuit of the present invention can be further improved as follows.

[0062] Furthermore, when the energy storage battery is in a charging state or a discharging state, a voltage inner loop control is performed based on a potential difference between an actual output voltage of the energy storage battery and a rated voltage of the energy storage battery, and a current outer loop control is performed based on a difference between an actual SOC value of the energy storage battery and a minimum SOC value of the energy storage battery discharged experimentally obtained;

[0063] When the actual power of the first DC bus is less than a first preset power threshold, voltage control is performed based on a potential difference between an actual output voltage of the first DC bus and a rated voltage of the first DC bus;

[0064] When the power of the second DC bus is less than a second preset power threshold, an inner voltage loop control is performed based on a potential difference between an actual output voltage of the second DC bus and a rated voltage of the second DC bus, and an outer current loop control is performed based on a current difference between an actual output current of the second DC bus and a standard current reference value of the second DC bus;

[0065] When the actual power of the fuel cell is greater than the third preset power threshold, the voltage on the fourth port capacitor is reduced by adjusting the duty cycle of the four-switch circuit;

[0066] When the actual power of the fuel cell is less than the fourth preset power threshold, the voltage on the fourth port capacitor is increased by adjusting the duty cycle of the four switch circuits, and the fourth preset power threshold is not less than the third preset power threshold;

[0067] When the actual power of the first DC bus is greater than the actual power of the fuel cell, charging the fuel cell through the first DC bus;

[0068] When the actual power of the first DC bus is less than the actual power of the fuel cell, the fuel cell is charged through the second DC bus;

[0069] The current of the fuel cell is sampled and compared with the reference current of the fuel cell, and the duty cycle of the four-switch circuit is adjusted by the PI regulator to stabilize the voltage of the fourth port capacitor.

[0070] 3) In a third aspect, the present invention further provides an electrical device with a power conversion function, comprising any of the above-mentioned routing topology circuits based on a partial power conversion circuit and a TAB circuit.

[0071] 4) In a fourth aspect, the present invention further provides a power grid system, comprising any of the above-mentioned routing topology circuits based on a partial power conversion circuit and a TAB circuit.

[0072] The beneficial effects of the present invention are as follows:

[0073] By connecting two ports as output, although the original full isolation is eliminated, partial power processing is achieved, the power conversion efficiency is improved, and the charge and discharge range of the fuel cell is adjusted by transmitting a smaller power through the four-switch circuit. The energy storage fault troubleshooting and maintenance are easy, and the impact of the fault on the output is small. The fuel cell and the energy storage battery are integrated through the four-switch circuit to form a partial power conversion structure (i.e., partial power conversion circuit). By adding various distributed energy sources and partial power conversion technology, the power level required to be processed by the four-port converter is reduced; by hardware decoupling the TAB circuit, the complex control of the TAB circuit is solved, and the TAB circuit is converted into a cascade of two DABs (isolated bidirectional DC / DC converters). The electrical isolation of each port is achieved through the power tube full-bridge circuit and the three-winding transformer. Through the inductor (also called phase-shifting inductor), each port can achieve phase-shifting control, and jointly ensure the stability and multi-directional transmission of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments of the present invention:

[0075] Figure 1 A schematic diagram of the structure of a routing topology circuit based on a partial power conversion circuit and a TAB circuit according to an embodiment of the present invention;

[0076] Figure 2 This is the electrical structure diagram of the fuel cell port based on partial power conversion technology;

[0077] Figure 3 The electrical structure diagram of two ports in TAB circuit being equivalent to DAB;

[0078] Figure 4 This is the forward control waveform of DAB;

[0079] Figure 5 This is the forward control block diagram of DAB;

[0080] Figure 6 This is the reverse control waveform of DAB;

[0081] Figure 7 This is the reverse control block diagram of DAB;

[0082] Figure 8 For all TAB control block diagrams;

[0083] Fig. 9 The three-port voltage and current waveforms of the TAB circuit under working condition 1;

[0084] Fig.10 The three-port voltage and current waveforms of the TAB circuit under working condition 2;

[0085] Fig.11 The three-port voltage and current waveforms of the TAB circuit under working condition 3;

[0086] Fig.12 The three-port voltage and current waveforms of the TAB circuit under working condition 4;

[0087] Fig.13 The three-port voltage and current waveforms of the TAB circuit under working condition 5;

[0088] Fig.14 The three-port voltage and current waveforms of the TAB circuit under working condition 6;

[0089] Fig.15 is a schematic diagram of a control scheme for a partial power variation circuit;

[0090] Fig.16 The main voltage and current waveforms of some power change circuits. DETAILED DESCRIPTION

[0091] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0092] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0093] like Figure 1 As shown, a routing topology circuit based on a partial power conversion circuit and a TAB circuit according to an embodiment of the present invention includes a three-winding transformer T, a partial power conversion circuit and a TAB circuit, wherein the TAB circuit includes a first DC bus port structure, an energy storage battery port structure and a second DC bus port structure, wherein the energy storage battery port structure is used to connect an energy storage battery;

[0094] The first DC bus port structure is connected to the medium voltage side winding N1 of the three-winding transformer T;

[0095] The energy storage battery port structure is connected to the low voltage side winding N2 of the three-winding transformer T;

[0096] The second DC bus port structure is connected to the high voltage side winding N3 of the three-winding transformer T;

[0097] A battery port for connecting to a fuel cell is provided between the partial power conversion circuit and the first DC bus port structure;

[0098] The first DC bus port structure is used to connect the first DC bus, and the second DC bus port structure is used to connect the second DC bus.

[0099] Among them, the voltage of the first DC bus is 220V, and the first DC bus can be recorded as a 220V DC bus. The voltage of the second DC bus is 750V, and the second DC bus can be recorded as a 750V DC bus. The first DC bus and the second DC bus with other voltage values ​​can also be selected according to actual conditions.

[0100] The three-winding transformer T may be a high-frequency three-winding transformer T.

[0101] Among them, the fuel cell, energy storage battery and 220V DC bus are combined with four-switch circuits to form part of the power conversion circuit.

[0102] Optionally, in the above technical solution, the first DC bus port structure includes a first port capacitor C1, a first inductor L1 and a first power tube full-bridge circuit having four power tubes;

[0103] One end of the first inductor L1 is connected to the same-name end of the medium-voltage side winding N1 of the three-winding transformer T, and the other end of the first inductor L1 is connected to the source of the first power tube S1-1 of the first power tube full-bridge circuit and the drain of the second power tube S1-2 of the first power tube full-bridge circuit;

[0104] The opposite-name end of the medium-voltage side winding N1 of the three-winding transformer T is connected to the source of the third power tube S1-3 of the first power tube full-bridge circuit and the drain of the fourth power tube S1-4 of the first power tube full-bridge circuit;

[0105] The drain of the first power tube S1-1 of the first power tube full-bridge circuit, the drain of the third power tube S1-3 of the first power tube full-bridge circuit and the positive electrode of the first port capacitor C1 are all connected to the positive electrode of the first DC bus; the source of the second power tube S1-2 of the first power tube full-bridge circuit, the source of the fourth power tube S1-4 of the first power tube full-bridge circuit and the negative electrode of the first port capacitor C1 are all connected to the negative electrode of the first DC bus.

[0106] Optionally, in the above technical solution, the energy storage battery port structure includes a second port capacitor C2, a second inductor L2 and a second power tube full-bridge circuit having four power tubes;

[0107] One end of the second inductor L2 is connected to the same-name end of the low-voltage side winding N2 of the three-winding transformer T, and the other end of the second inductor L2 is connected to the source of the first power tube S2-1 of the second power tube full-bridge circuit and the drain of the second power tube S2-2 of the second power tube full-bridge circuit;

[0108] The opposite-name end of the low-voltage side winding N2 of the three-winding transformer T is connected to the source of the third power tube S2-3 of the second power tube full-bridge circuit and the drain of the fourth power tube S2-4 of the second power tube full-bridge circuit;

[0109] The drain of the first power tube S2-1 of the second power tube full-bridge circuit, the drain of the third power tube S2-3 of the second power tube full-bridge circuit, and the positive electrode of the second port capacitor C2 are all connected to the positive electrode of the energy storage battery; the source of the second power tube S2-2 of the second power tube full-bridge circuit, the source of the fourth power tube S2-4 of the second power tube full-bridge circuit, and the negative electrode of the second port capacitor C2 are all connected to the negative electrode of the energy storage battery.

[0110] Optionally, in the above technical solution, the second DC bus port structure includes a third port capacitor C3 and a third power tube full-bridge circuit having four power tubes;

[0111] The same-name end of the high-voltage side winding N3 of the three-winding transformer T is connected to the source of the first power tube S3-1 of the third power tube full-bridge circuit and the drain of the second power tube S3-2 of the third power tube full-bridge circuit; the opposite-name end of the high-voltage side winding N3 of the three-winding transformer T is connected to the source of the third power tube S3-3 of the third power tube full-bridge circuit and the drain of the fourth power tube S3-4 of the third power tube full-bridge circuit;

[0112] The drain of the first power tube S3-1 of the third power tube full-bridge circuit, the drain of the third power tube S3-3 of the third power tube full-bridge circuit, and the positive electrode of the third port capacitor C3 are all connected to the positive electrode of the second DC bus; the source of the second power tube S3-2 of the third power tube full-bridge circuit, the source of the fourth power tube S3-4 of the third power tube full-bridge circuit, and the negative electrode of the third port capacitor C3 are all connected to the negative electrode of the second DC bus.

[0113] Optionally, in the above technical solution, the partial power conversion circuit includes four switch circuits, a fourth port capacitor C4 and a fifth port capacitor C5, the four switch circuits include a first half-bridge circuit and a second half-bridge circuit, and a third inductor L3 is connected between the midpoint of the bridge arm of the first half-bridge circuit and the midpoint of the bridge arm of the second half-bridge circuit;

[0114] The positive electrode of the fuel cell is connected to the positive electrode of the first DC bus, the negative electrode of the fuel cell is connected to the drain electrode of the first power tube Q1 of the first half-bridge circuit and the positive electrode of the fourth port capacitor C4, the negative electrode of the fourth port capacitor C4 and the negative electrode of the fifth port capacitor C5 are connected to the source electrode of the second power tube Q2 of the first half-bridge circuit, the source electrode of the second power tube Q4 of the second half-bridge circuit, the negative electrode of the first DC bus and the negative electrode of the energy storage battery;

[0115] One end of the third inductor L3 is connected to the source of the first power tube Q1 of the first half-bridge circuit and the drain of the second power tube Q2 of the first half-bridge circuit, the other end of the third inductor L3 is connected to the source of the first power tube Q3 of the second half-bridge circuit and the drain of the second power tube Q4 of the second half-bridge circuit, and the drain of the first power tube Q3 of the second half-bridge circuit is connected to the positive electrode of the fifth port capacitor C5 and the positive electrode of the energy storage battery.

[0116] A method for using a routing topology circuit based on a partial power conversion circuit and a TAB circuit according to an embodiment of the present invention includes: a three-winding transformer T, a partial power conversion circuit and a TAB circuit, the TAB circuit includes a first DC bus port structure, an energy storage battery port structure, and a second DC bus port structure, and the energy storage battery port structure is used to connect an energy storage battery;

[0117] The first DC bus port structure is connected to the medium voltage side winding N1 of the three-winding transformer T;

[0118] The energy storage battery port structure is connected to the low voltage side winding N2 of the three-winding transformer T;

[0119] The second DC bus port structure is connected to the high voltage side winding N3 of the three-winding transformer T;

[0120] A battery port for connecting to a fuel cell is provided between the partial power conversion circuit and the first DC bus port structure;

[0121] The first DC bus port structure is used to connect the first DC bus, and the second DC bus port structure is used to connect the second DC bus;

[0122] The first DC bus port structure includes a first port capacitor C1, a first inductor L1 and a first power tube full-bridge circuit having four power tubes;

[0123] One end of the first inductor L1 is connected to the same-name end of the medium-voltage side winding N1 of the three-winding transformer T, and the other end of the first inductor L1 is connected to the source of the first power tube S1-1 of the first power tube full-bridge circuit and the drain of the second power tube S1-2 of the first power tube full-bridge circuit;

[0124] The opposite-name end of the medium-voltage side winding N1 of the three-winding transformer T is connected to the source of the third power tube S1-3 of the first power tube full-bridge circuit and the drain of the fourth power tube S1-4 of the first power tube full-bridge circuit;

[0125] The drain of the first power tube S1-1 of the first power tube full-bridge circuit, the drain of the third power tube S1-3 of the first power tube full-bridge circuit, and the positive electrode of the first port capacitor C1 are all connected to the positive electrode of the first DC bus; the source of the second power tube S1-2 of the first power tube full-bridge circuit, the source of the fourth power tube S1-4 of the first power tube full-bridge circuit, and the negative electrode of the first port capacitor C1 are all connected to the negative electrode of the first DC bus;

[0126] The energy storage battery port structure includes a second port capacitor C2, a second inductor L2 and a second power tube full-bridge circuit having four power tubes;

[0127] One end of the second inductor L2 is connected to the same-name end of the low-voltage side winding N2 of the three-winding transformer T, and the other end of the second inductor L2 is connected to the source of the first power tube S2-1 of the second power tube full-bridge circuit and the drain of the second power tube S2-2 of the second power tube full-bridge circuit;

[0128] The opposite-name end of the low-voltage side winding N2 of the three-winding transformer T is connected to the source of the third power tube S2-3 of the second power tube full-bridge circuit and the drain of the fourth power tube S2-4 of the second power tube full-bridge circuit;

[0129] The drain of the first power tube S2-1 of the second power tube full-bridge circuit, the drain of the third power tube S2-3 of the second power tube full-bridge circuit, and the positive electrode of the second port capacitor C2 are all connected to the positive electrode of the energy storage battery; the source of the second power tube S2-2 of the second power tube full-bridge circuit, the source of the fourth power tube S2-4 of the second power tube full-bridge circuit, and the negative electrode of the second port capacitor C2 are all connected to the negative electrode of the energy storage battery;

[0130] The second DC bus port structure includes a third port capacitor C3 and a third power tube full-bridge circuit having four power tubes;

[0131] The same-name end of the high-voltage side winding N3 of the three-winding transformer T is connected to the source of the first power tube S3-1 of the third power tube full-bridge circuit and the drain of the second power tube S3-2 of the third power tube full-bridge circuit; the opposite-name end of the high-voltage side winding N3 of the three-winding transformer T is connected to the source of the third power tube S3-3 of the third power tube full-bridge circuit and the drain of the fourth power tube S3-4 of the third power tube full-bridge circuit;

[0132] The drain of the first power tube S3-1 of the third power tube full-bridge circuit, the drain of the third power tube S3-3 of the third power tube full-bridge circuit, and the positive electrode of the third port capacitor C3 are all connected to the positive electrode of the second DC bus; the source of the second power tube S3-2 of the third power tube full-bridge circuit, the source of the fourth power tube S3-4 of the third power tube full-bridge circuit, and the negative electrode of the third port capacitor C3 are all connected to the negative electrode of the second DC bus;

[0133] The partial power conversion circuit includes a four-switch circuit, a fourth port capacitor C4 and a fifth port capacitor C5, the four-switch circuit includes a first half-bridge circuit and a second half-bridge circuit, and a third inductor L3 is connected between a midpoint of a bridge arm of the first half-bridge circuit and a midpoint of a bridge arm of the second half-bridge circuit;

[0134] The positive electrode of the fuel cell is connected to the positive electrode of the first DC bus, the negative electrode of the fuel cell is connected to the drain electrode of the first power tube Q1 of the first half-bridge circuit and the positive electrode of the fourth port capacitor C4, the negative electrode of the fourth port capacitor C4 and the negative electrode of the fifth port capacitor C5 are connected to the source electrode of the second power tube Q2 of the first half-bridge circuit, the source electrode of the second power tube Q4 of the second half-bridge circuit, the negative electrode of the first DC bus and the negative electrode of the energy storage battery;

[0135] One end of the third inductor L3 is connected to the source of the first power tube Q1 of the first half-bridge circuit and the drain of the second power tube Q2 of the first half-bridge circuit, the other end of the third inductor L3 is connected to the source of the first power tube Q3 of the second half-bridge circuit and the drain of the second power tube Q4 of the second half-bridge circuit, and the drain of the first power tube Q3 of the second half-bridge circuit is connected to the positive electrode of the fifth port capacitor C5 and the positive electrode of the energy storage battery;

[0136] Usage methods include:

[0137] 1) When the actual voltage of the second DC bus and the actual voltage of the energy storage battery are both in a fluctuating state, the power of the fuel cell and the transmission power of each port are controlled by controlling the phase shift angles between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the duty cycle of the four-switch circuit;

[0138] When the 750V DC bus and the energy storage battery voltage fluctuate, the power of the fuel cell and the transmission power of each port are controlled by controlling the phase shift angle between the three power tube full-bridge circuits in the TAB circuit and the duty cycle of the four-switch circuit, thereby controlling the power flow of the entire system (based on the routing topology circuit of the partial power conversion circuit and the TAB circuit).

[0139] 2) When the actual voltage of the second DC bus is in a stable state (i.e., the voltage on the 750V side is stable), and the actual SOC value of the energy storage battery does not exceed the first preset SOC threshold value (i.e., the actual SOC value of the energy storage battery is at a lower level), by controlling the phase shift angle between the first power tube full-bridge circuit, the second power tube full-bridge circuit, and the third power tube full-bridge circuit and the duty cycle of the four-switch circuit, the energy storage battery is in a charging state, the fuel cell is in a low-power operation level, the power of the 220V port on the low-voltage side is provided by the fuel cell and the 750V DC bus, and at the same time, the 750V DC bus releases power to charge the energy storage battery.

[0140] 3) When the actual voltage of the second DC bus is in a stable state (i.e., the voltage on the 750V side is stable), and the actual SOC value of the energy storage battery is not less than the second preset SOC threshold value (i.e., the actual SOC value of the energy storage battery is at a relatively high level), the energy storage battery is in a discharge state by controlling the phase shift angle between the first power tube full-bridge circuit, the second power tube full-bridge circuit, and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell, and the fuel cell is in a low-power operation level, and the power of the 220V port on the low-voltage side is mainly provided by the high-voltage bus and the energy storage battery, wherein the second preset SOC threshold value is not less than the first preset SOC threshold value;

[0141] 4) When the actual voltage of the second DC bus is lower than the preset voltage threshold (i.e., the voltage on the 750V side is lower), and the actual SOC value of the energy storage battery is not less than the second preset SOC threshold (i.e., the actual SOC value of the energy storage battery is at a higher level), the energy storage battery is put into a discharge state by controlling the phase shift angle between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell, and the fuel cell and the energy storage battery are put into a power release mode, and the power of the 220V port on the low-voltage side is mainly provided by the fuel cell and the energy storage battery.

[0142] 5) When the actual voltage of the second DC bus is lower than the preset voltage threshold (i.e., the voltage on the 750V side is lower), and the actual SOC value of the energy storage battery does not exceed the first preset SOC threshold (i.e., the actual SOC value of the energy storage battery is at a lower level), by controlling the phase shift angle between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell, the energy storage battery is in a charging state, the fuel cell is in a high-power operating level, the power of the 220V port on the low-voltage side is mainly provided by the high-voltage fuel cell, and at the same time the fuel cell releases power to charge the energy storage battery.

[0143] Optionally, in the above technical solution, it also includes:

[0144] 1) When the energy storage battery is in a charging state or a discharging state, the voltage inner loop control is performed based on the potential difference between the actual output voltage of the energy storage battery and the rated voltage of the energy storage battery, and the current outer loop control is performed based on the difference between the actual SOC value of the energy storage battery and the minimum SOC value of the energy storage battery discharged obtained in the experiment. Specifically:

[0145] For the energy storage battery, what is controlled is the constant voltage and current at the energy storage battery port; when the energy storage battery is in the state of charging or discharging, the potential difference between the actual output voltage of the energy storage battery (the voltage at the energy storage battery port) and the rated voltage of the energy storage battery is used as the target of the voltage inner loop control, and the difference between the SOC level of the energy storage battery and the minimum SOC of the energy storage battery discharge obtained in the experiment is used as the target of the current outer loop control, and then the PI regulator and EPS control output drive signals are sent to all power tubes on the high-voltage side and the energy storage battery side to construct a power conversion structure at the energy storage battery side port, so that the voltage at the energy storage battery port is constant at the rated voltage of the energy storage battery, and the current at the energy storage battery port is constant at the rated current of the energy storage battery.

[0146] 2) When the actual power of the first DC bus is less than the first preset power threshold, voltage control is performed based on the potential difference between the actual output voltage of the first DC bus and the rated voltage of the first DC bus, specifically:

[0147] For the 220V DC bus, the voltage at the 220V DC bus port is controlled to be constant; when the 750V DC bus power is too small, the potential difference between the 220V bus output voltage and the rated voltage is used as voltage control, and then the PI regulator and EPS control output drive signal are used to all power tubes on the 750V side and the 220V bus side to build a 220V DC bus port power conversion structure and keep the port voltage constant at 220V.

[0148] 3) When the power of the second DC bus is less than the second preset power threshold, the voltage inner loop control is performed based on the potential difference between the actual output voltage of the second DC bus and the rated voltage of the second DC bus, and the current outer loop control is performed based on the current difference between the actual output current of the second DC bus and the standard current reference value of the second DC bus, specifically:

[0149] For the 750V DC bus, the control is to keep the voltage and current of the 750V DC bus port constant; when the power of the 750V DC bus is too small, the potential difference between the 750V DC bus output voltage and the rated voltage is used as the voltage inner loop control, and the current difference between the 750V DC bus current and the standard reference value is used as the current outer loop control, and then the PI regulator and EPS control output drive signals are sent to all power tubes on the low-voltage side and the 750V DC bus side to build a 750V DC bus port power conversion structure to keep the port voltage constant at 750V.

[0150] 4) When the actual power of the fuel cell is greater than the third preset power threshold, the voltage on the fourth port capacitor C4 is reduced by adjusting the duty cycle of the four switch circuits;

[0151] 5) When the actual power of the fuel cell is less than the fourth preset power threshold, the voltage on the fourth port capacitor C4 is increased by adjusting the duty cycle of the four switch circuits, and the fourth preset power threshold is not less than the third preset power threshold;

[0152] 6) When the actual power of the first DC bus is greater than the actual power of the fuel cell, the fuel cell is charged through the first DC bus;

[0153] 7) When the actual power of the first DC bus is less than the actual power of the fuel cell, the fuel cell is charged through the second DC bus; the current of the fuel cell is sampled and compared with the reference current of the fuel cell, and the duty cycle of the four-switch circuit is adjusted through the PI regulator to stabilize the voltage of the fourth port capacitor C4.

[0154] like Figure 2 As shown in FIG. 1 , a partial power conversion structure (partial power conversion circuit) on the fuel cell side is established. When the fuel cell is converting power at work, the energy flow in the four-switch circuit is adjusted to ensure that the output voltage of the 220V DC bus is stably maintained at V DC220 , to achieve efficient use of fuel cells, V DC220 It is 220V.

[0155] like Figure 3As shown, the two ports in the TAB circuit are equivalent to DAB, where V1 represents the energy storage battery side, which can also be represented as the 220V DC bus side, V2 represents the 750V DC bus side, and the inductor L corresponds to the first inductor L1 or the second inductor L2. The power tubes S1, S3, S2, and S4 in the full-bridge power tube circuit on the left correspond to S1-1, S1-2, S1-3, and S1-4, or S2-1, S2-2, S2-3, and S2-4, respectively. The power tube Q11, power tube Q31, power tube Q21 and power tube Q41 in the power tube full-bridge circuit correspond to S3-1, S3-2, S3-3 and S3-4 respectively, the winding N4 of the transformer T1 corresponds to the medium voltage side winding N1 or the low voltage side winding N2 of the transformer T, the winding N5 of the transformer T1 corresponds to the high voltage side winding N3 of the transformer T, the sixth port capacitor C6 corresponds to the first port capacitor C1 or the second port capacitor C2, and the sixth port capacitor C7 corresponds to the third port capacitor C3, which plays a filtering role.

[0156] Among them, the positive electrode of the sixth port capacitor C6 is connected to the positive electrode of V1 and the drain electrodes of the power tubes S1 and S2, the negative electrode of the sixth port capacitor C6 is connected to the negative electrode of V1 and the source electrodes of the power tubes S3 and S4, the source electrode of the power tube S1 is connected to the drain electrode of the power tube S3, and the source electrode of the power tube S2 is connected to the drain electrode of the power tube S4.

[0157] Among them, the positive electrode of the seventh port capacitor C7 is connected to the positive electrode of V2 and the drain electrodes of the power tubes Q11 and Q21, the negative electrode of the seventh port capacitor C7 is connected to the negative electrode of V2 and the source electrodes of the power tubes Q21 and Q41, the source electrode of the power tube Q11 is connected to the drain electrode of the power tube Q31, and the source electrode of the power tube Q21 is connected to the drain electrode of the power tube Q41.

[0158] Among them, the same-name end of the winding N4 of the transformer T1 is connected to one end of the inductor L, the other end of the inductor L is connected to the source of the power tube S1 and the drain of the power tube S3, the opposite-name end of the winding N4 of the transformer T1 is connected to the source of the power tube S2 and the drain of the power tube S4; the same-name end of the winding N5 of the transformer T1 is connected to the source of the power tube Q11 and the drain of the power tube Q31, and the opposite-name end of the winding N5 of the transformer T1 is connected to the source of the power tube Q21 and the drain of the power tube Q41.

[0159] like Figure 4 As shown, the forward control waveform of DAB includes:

[0160] 1) Full bridge on the winding side of transformer N1: There is a phase shift angle D1T between power tube S1 and power tube S4 sThe control signals of the power tube S1 and the power tube S3 are complementary signals, and the control signals of the power tube S2 and the power tube S4 are complementary signals.

[0161] 2) Full bridge on the winding side of transformer N2: The control signals of power tubes Q11 and Q41 are the same, the control signals of power tubes Q21 and Q31 are the same, and the control signals of power tubes Q11 and Q31 are complementary signals. At the same time, the phase shift angle between the bridge of power tube S1 and power tube Q11 is D2T s , the control signal of power tube S4 is ahead of the control signal of power tube S1; the control signal of power tube S1 is ahead of the control signal of power tube Q11, T s It is expressed as the time required for half a switching cycle. The duty cycle corresponding to each driving waveform is 0.5. The value range of the phase shift duty cycle D1 within the bridge and the phase shift duty cycle D2 between the bridges is 0-0.5, and D1+D2<1. The phase shift angle is the ratio of the phase shift duty cycle and T s The product between .

[0162] like Figure 5 As shown, during forward operation, the voltage of V2 is sampled, and the voltage difference obtained based on the voltage sampling value V2 and the output reference value V2ref is limited by the PI controller to obtain the transmission power P, and then K is obtained by dividing the input reference value V1ref by the product of the output reference value V2ref and the transformer ratio n. P and K are substituted into the optimal controller to obtain the optimal bridge intra-phase shift duty ratio D1 and inter-bridge phase shift duty ratio D2, where: voltage regulation ratio K = V1 / nV2>1, transformer T1 ratio n is the turns ratio of N4 winding to N5 winding, and the phase shift angle is the ratio of the phase shift duty ratio and T s The product between them is passed through the driving circuit to obtain the driving voltage to control the on and off of the corresponding power tube, where: U S1 The voltage controls the on and off of the power tube S1; U S2 The voltage controls the on and off of the power tube S2; U S3 The voltage controls the on and off of the power tube S3; U S4 The voltage controls the on and off of the power tube S4; U Q11 The voltage controls the on and off of the power tube Q11; U Q21 The voltage controls the on and off of the power tube Q21; U Q31 The voltage controls the on and off of the power tube Q31; U Q41 The voltage controls the on and off of the power tube Q41.

[0163] like Figure 6 As shown, the reverse control waveform of DAB includes:

[0164] 1) Full bridge on the winding side of transformer N1: The phase shift angle within the bridge between power tube S1 and power tube S4 is D1T sThe control signals of the power tube S1 and the power tube S3 are complementary signals, and the control signals of the power tube S2 and the power tube S4 are complementary signals.

[0165] 2) Full bridge on the winding side of transformer N2: The control signals of power tube Q11 and power tube Q41 are the same, and the control signals of power tube Q21 and power tube Q31 are the same. The control signals of power tube Q11 and Q31 are complementary signals. At the same time, the inter-bridge phase shift angle between power tube S1 and power tube Q11 is D2T s , the control signal of power tube S1 leads the control signal of power tube S4, the control signal of power tube Q11 leads the control signal of power tube S1, T s It is expressed as the time required for half a switching cycle. The duty cycle corresponding to each driving waveform is 0.5. The value range of the phase shift duty cycle D1 within the bridge and the phase shift duty cycle D2 between the bridges is 0-0.5, and D1+D2<1. The phase shift angle is the ratio of the phase shift duty cycle and T s The product between .

[0166] like Figure 7 As shown, during reverse operation, the voltage of V1 is sampled, and the voltage difference between the voltage sampling value V1 and the input reference value V1ref is limited by the PI controller to obtain the transmission power P, and P is inverted (multiplied by -1), and then K is obtained by dividing the input reference value V1ref by the product of the output reference value V2ref and the transformer ratio n. P and K are substituted into the optimal controller to obtain the optimal bridge intra-phase shift duty ratio D1 and inter-bridge phase shift duty ratio D2, where: voltage regulation ratio K = V1 / nV2>1, transformer T1 ratio n is the turns ratio of N4 winding to N5 winding, and phase shift angle is the ratio of phase shift duty ratio to T s The product between them is passed through the driving circuit to obtain the driving voltage to control the on and off of the corresponding power tube, where: U S1 The voltage controls the on and off of the power tube S1; U S2 The voltage controls the on and off of the power tube S2; U S3 The voltage controls the on and off of the power tube S3; U S4 The voltage controls the on and off of the power tube S4; U Q11 The voltage controls the on and off of the power tube Q11; U Q21 The voltage controls the on and off of the power tube Q21; U Q31 The voltage controls the on and off of the power tube Q31; U Q41 The voltage controls the on and off of the power tube Q41.

[0167] according to Figure 3 and Figure 7 Get the closed-loop control block diagram of TAB, such as Figure 8 As shown, with 48V as the input voltage, the voltage of the 750V DC bus and the 220V DC bus are sampled. Specifically:

[0168] 1) The energy storage battery 48V to 750V DC bus is: the sampling value V750 of the 750V DC bus is compared with the reference value V750ref, and the voltage difference is limited by the PI controller to obtain the transmission power P 750 Then, K1 is obtained by dividing the input reference voltage V48ref by the product of the output reference voltage V750ref and the transformer ratio n1. 750 Substitute K1 into the optimal controller to obtain the optimal bridge duty cycle D1 750 , bridge duty cycle D2 750 .

[0169] Among them, the voltage regulation ratio K1=V48ref / (n1×V750ref)>1, and the transformer T transformation ratio n1 is: the turns ratio of the low-voltage side winding N2 to the high-voltage side winding N3.

[0170] 2) 750V DC bus to 220V DC bus: the sampled value V220 of the 220V DC bus is compared with the reference value V220ref, and the voltage difference is limited by the PI controller to obtain the transmission power P 220 , for P 220 Perform the inversion process (multiply by -1), and then obtain K2 by dividing the output reference value V220ref by the product of the input reference value V750ref and the transformer ratio n2. 220 Substitute K2 into the optimal controller to obtain the optimal bridge internal phase shift duty cycle D1 220 , inter-bridge phase shift duty ratio D2 220 , and obtain the final TAB control scheme.

[0171] Among them, the voltage regulation ratio K2=V220ref / (n2×V750)>1, the transformer T ratio n2 is: the turns ratio of the medium voltage side winding N1 and the high voltage side winding N3, the phase shift angle is the phase shift duty ratio and T s The product between s is the time required for half a switching cycle.

[0172] 3) There is an internal phase shift angle between the full bridge on the 48V side of the energy storage battery and the full bridge on the DC bus on the 220V side, that is, the internal phase shift angle between the power tube S1-1 and the power tube S1-4 is D1 220 T s The phase shift angle between power tube S2-1 and power tube S2-4 is D1. 750 T s; There is no inter-bridge phase shift angle between the 750V side DC bus full bridge, that is, the control signals between the power tube S3-1 and the power tube S3-4 are the same; There is an inter-bridge phase shift angle between the 48V side full bridge of the energy storage battery and the 750V side DC bus full bridge, that is, the inter-bridge phase shift angle between the power tube S2-1 and the power tube S3-1 is D2 750 T s ; There is an inter-bridge phase shift angle between the 220V side DC bus full bridge and the 750V side DC bus full bridge, that is, the inter-bridge phase shift angle between the power tube S1-1 and the power tube S3-1 is D2 220 T s ; The duty cycle of all control waveforms is 0.5; the control signals between the bridge arms of each half bridge are complementary, that is, the control signals between the power tube S1-1 and the power tube S1-2 are complementary, the control signals between the power tube S1-3 and the power tube S1-4 are complementary, the control signals between the power tube S2-1 and the power tube S2-2 are complementary; the control signals between the power tube S2-3 and the power tube S2-4 are complementary, the control signals between the power tube S3-1 and the power tube S3-2 are complementary, and the control signals between the power tube S3-3 and the power tube S3-4 are complementary.

[0173] 4) The driving voltage is obtained through the driving circuit to control the on and off of the corresponding power tube, where: U S1-1 The voltage controls the on and off of the power tube S1-1; U S1-2 The voltage controls the on and off of the power tube S1-2; U S1-3 The voltage controls the on and off of the power tube S1-3; U S1-4 The voltage controls the on and off of the power tube S1-4; U S2-1 The voltage controls the on and off of the power tube S2-1; U S2-2 The voltage controls the on and off of the power tube S2-2; U S2-3 The voltage controls the on and off of the power tube S2-3; U S2-4 The voltage controls the on and off of the power tube S2-4; U S3-1 The voltage controls the on and off of the power tube S3-1; U S3-2 The voltage controls the on and off of the power tube S3-2; U S3-3 The voltage controls the on and off of the power tube S3-3; U S3-4 The voltage controls the on and off of the power tube S3-4.

[0174] When the TAB circuit is in working condition 1, the voltages and currents of the three ports are as follows: Fig. 9As shown, 220-U represents the 220V port voltage, 220-I represents the 220V side current; 750-U represents the 750V port voltage, 750-I represents the 750V side current, and 48-I represents the current of the energy storage battery. The energy storage battery is regarded as a 48V constant voltage source, so the 48V side voltage waveform is not displayed. A positive current represents absorbed power, and a negative current represents emitted power. Working condition 1 is: energy storage battery discharge, 750V connected to load, and 220V connected to load.

[0175] When the TAB circuit is in working condition 2, the voltages and currents of the three ports are as follows: Fig.10 As shown, 220-U represents the 220V port voltage, 220-I represents the 220V side current; 750-U represents the 750V port voltage, 750-I represents the 750V side current, and 48-I represents the current of the energy storage battery. The energy storage battery is regarded as a 48V constant voltage source, so the 48V side voltage waveform is not displayed. A positive current represents absorbed power, and a negative current represents emitted power. Working condition 2 is: charging the energy storage battery, 750V connected to the load, and 220V connected to the bus.

[0176] When the TAB circuit is in working condition 3, the voltages and currents of the three ports are as follows: Fig.11 As shown, 220-U represents the 220V port voltage, 220-I represents the 220V side current; 750-U represents the 750V port voltage, 750-I represents the 750V side current, and 48-I represents the current of the energy storage battery. The energy storage battery is regarded as a 48V constant voltage source, so the 48V side voltage waveform is not displayed. A positive current represents absorbed power, and a negative current represents emitted power. Working condition 3 is charging the energy storage battery, connecting 750V to the bus, and connecting 220V to the load.

[0177] When the TAB circuit is in working condition 4, the voltages and currents of the three ports are as follows: Fig.12 As shown, 220-U represents the 220V port voltage, 220-I represents the 220V side current; 750-U represents the 750V port voltage, 750-I represents the 750V side current, 48-I represents the current of the energy storage battery, and the energy storage battery is regarded as a 48V constant voltage source, so the 48V side voltage waveform is not displayed. A positive current represents absorbed power, and a negative current represents emitted power. Working condition 4 is: the energy storage battery discharges, 750V is connected to the load, and 220V is connected to the bus.

[0178] When the TAB circuit is in working condition 5, the voltages and currents of the three ports are as follows: Fig.13As shown, 220-U represents the 220V port voltage, 220-I represents the 220V side current; 750-U represents the 750V port voltage, 750-I represents the 750V side current, and 48-I represents the current of the energy storage battery. The energy storage battery is regarded as a 48V constant voltage source, so the 48V side voltage waveform is not displayed. A positive current represents absorbed power, and a negative current represents emitted power. Working condition 5 is: the energy storage battery is discharged, 750V is connected to the bus, and 220V is connected to the load.

[0179] When the TAB circuit is in working condition 6, the voltages and currents of the three ports are as follows: Fig.14 As shown, 220-U represents the 220V port voltage, 220-I represents the 220V side current; 750-U represents the 750V port voltage, 750-I represents the 750V side current, and 48-I represents the current of the energy storage battery. The energy storage battery is regarded as a 48V constant voltage source, so the 48V side voltage waveform is not displayed. A positive current represents absorbed power, and a negative current represents emitted power. Working condition 6 is: energy storage battery charging, 750V connected to the bus, and 220V connected to the bus.

[0180] like Fig.15 As shown, the voltage and current sampling of the fuel cell can be understood as the voltage U on the fourth port capacitor C4. C4 Sampling, the voltage U on the fourth port capacitor C4 C4 Voltage difference ε with reference value Uref v , through the PI controller, the required duty cycle D2 is obtained by mode switching, and the voltage U of the fifth port capacitor C5 is C5 The voltage on the energy storage battery is the reference voltage value Uref and the current value i of the fourth terminal capacitor C4. C4 And the energy storage battery voltage U C5 Substituting into the optimal duty cycle scheme of the four switches, the phase shift angle D is calculated. φ And duty cycle D1; D1 is the duty cycle driven by power tube Q1, 1-D1 is the duty cycle driven by power tube Q21, D2 is the duty cycle driven by power tube Q31, 1-D2 is the duty cycle driven by power tube Q41, D φ is the phase shift angle between the power tube Q11 and the power tube Q31. The driving voltage is obtained through the driving circuit to control the on and off of the corresponding power tube. Q1 The voltage controls the on and off of the power tube Q1; U Q2 The voltage controls the on and off of the power tube Q2; U Q3 The voltage controls the on and off of the power tube Q3; U Q4 The voltage controls the on and off of the power tube Q4.

[0181] like Fig.16As shown, the voltage change of the four-switch circuit is related to the power generated by the fuel cell, where: V in It is represented by the voltage of the fifth terminal capacitor C5, I in Represented as the current of the fifth port capacitor C5; V out It is represented by the voltage of the fourth terminal capacitor C4, I out1 It is represented by the current of the fifth port capacitor C5; I L is the current on the inductor.

[0182] The present invention is based on partial power conversion technology and uses a TAB three-port routing topology circuit to design a four-port energy routing topology circuit, including a 750V side bus, a 220V side bus, three full-bridge structures on the energy storage battery side, and a four-switch circuit on the fuel cell side as the main parts, as well as two sets of DC buses of different voltage levels. Electrical isolation is achieved by a three-winding transformer, and the fuel cell, the energy storage battery and the four-switch circuit constitute their respective partial power conversion structures. Two sets of control methods are designed on the basis of phase shift control to achieve stable operation of each port. The present invention has higher efficiency and better output energy for the conversion of electric energy than the existing TAB circuit. Compared with the traditional TAB converter, the present invention is an alternative with broad development prospects. In terms of decoupling, it is achieved through hardware decoupling, avoiding complex decoupling in control; in the use scenario of high power transmission, the integration and direct output of the energy storage port reduces the power transmitted by the transformer, thereby reducing the rated value and loss of the transformer capacity.

[0183] The present invention connects two ports as outputs. Although the original full isolation is eliminated, partial power processing is achieved, the power conversion efficiency is improved, and the charge and discharge range of the fuel cell is adjusted by transmitting a smaller power through a four-switch circuit. The energy storage fault troubleshooting and maintenance are easy, and the impact of the fault on the output is small. The fuel cell and the energy storage battery are integrated through a four-switch circuit to form a partial power conversion structure (i.e., a partial power conversion circuit). By adding various distributed energy sources and partial power conversion technologies, the power level that the four-port converter needs to process is reduced. The hardware decoupling of the TAB circuit solves the problem of complex TAB circuit control. The TAB circuit is converted into a cascade of two DABs (isolated bidirectional DC / DC converters). The electrical isolation of each port is achieved through a power tube full-bridge circuit and a three-winding transformer. Through inductance (also called phase-shifting inductance), each port is guaranteed to be able to achieve phase-shifting control, thereby jointly ensuring the stability and multi-directional transmission of energy.

[0184] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the disclosure scope involved in the present invention is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) by each other.

[0185] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects and represent the definition of a specific order or sequence. The order of use of similar objects can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than the order shown or described.

[0186] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A routing topology circuit based on a partial power conversion circuit and a TAB circuit, characterized in that: It includes a three-winding transformer, a partial power conversion circuit and a TAB circuit, wherein the TAB circuit includes a first DC bus port structure, an energy storage battery port structure and a second DC bus port structure, and the energy storage battery port structure is used to connect the energy storage battery; The first DC bus port structure is connected to the medium voltage side winding of the three-winding transformer; The energy storage battery port structure is connected to the low-voltage side winding of the three-winding transformer; The second DC bus port structure is connected to the high voltage side winding of the three-winding transformer; A battery port for connecting to a fuel cell is provided between the partial power conversion circuit and the first DC bus port structure; The first DC bus port structure is used to connect a first DC bus, and the second DC bus port structure is used to connect a second DC bus.

2. A routing topology circuit based on a partial power conversion circuit and a TAB circuit according to claim 1, characterized in that: The first DC bus port structure includes a first port capacitor, a first inductor and a first power tube full-bridge circuit having four power tubes; One end of the first inductor is connected to the same-name terminal on the medium voltage side of the three-winding transformer, and the other end of the first inductor is connected to the source of the first power tube of the first power tube full-bridge circuit and the drain of the second power tube of the first power tube full-bridge circuit; The medium voltage side opposite-name end of the three-winding transformer is connected to the source of the third power tube of the first power tube full-bridge circuit and the drain of the fourth power tube of the first power tube full-bridge circuit; The drain of the first power tube of the first power tube full-bridge circuit, the drain of the third power tube of the first power tube full-bridge circuit and the positive electrode of the first port capacitor are all connected to the positive electrode of the first DC bus; the source of the second power tube of the first power tube full-bridge circuit, the source of the fourth power tube of the first power tube full-bridge circuit and the negative electrode of the first port capacitor are all connected to the negative electrode of the first DC bus.

3. The routing topology circuit based on a partial power conversion circuit and a TAB circuit according to claim 1, characterized in that: The energy storage battery port structure includes a second port capacitor, a second inductor and a second power tube full-bridge circuit having four power tubes; One end of the second inductor is connected to the same-name end of the low-voltage side of the three-winding transformer, and the other end of the second inductor is connected to the source of the first power tube of the second power tube full-bridge circuit and the drain of the second power tube of the second power tube full-bridge circuit; The low-voltage side opposite-name end of the three-winding transformer is connected to the source of the third power tube of the second power tube full-bridge circuit and the drain of the fourth power tube of the second power tube full-bridge circuit; The drain of the first power tube of the second power tube full-bridge circuit, the drain of the third power tube of the second power tube full-bridge circuit, and the positive electrode of the second port capacitor are all connected to the positive electrode of the energy storage battery; the source of the second power tube of the second power tube full-bridge circuit, the source of the fourth power tube of the second power tube full-bridge circuit, and the negative electrode of the second port capacitor are all connected to the negative electrode of the energy storage battery.

4. The routing topology circuit based on a partial power conversion circuit and a TAB circuit according to claim 1, characterized in that: The second DC bus port structure includes a third port capacitor and a third power tube full-bridge circuit having four power tubes; The high-voltage side like-name end of the three-winding transformer is connected to the source of the first power tube of the third power tube full-bridge circuit and the drain of the second power tube of the third power tube full-bridge circuit; the high-voltage side opposite-name end of the three-winding transformer is connected to the source of the third power tube of the third power tube full-bridge circuit and the drain of the fourth power tube of the third power tube full-bridge circuit; The drain of the first power tube of the third power tube full-bridge circuit, the drain of the third power tube of the third power tube full-bridge circuit, and the positive electrode of the third port capacitor are all connected to the positive electrode of the second DC bus; the source of the second power tube of the third power tube full-bridge circuit, the source of the fourth power tube of the third power tube full-bridge circuit, and the negative electrode of the third port capacitor are all connected to the negative electrode of the second DC bus.

5. The routing topology circuit based on a partial power conversion circuit and a TAB circuit according to claim 1, characterized in that: The partial power conversion circuit includes a four-switch circuit, a fourth port capacitor and a fifth port capacitor, the four-switch circuit includes a first half-bridge circuit and a second half-bridge circuit, and a third inductor is connected between a midpoint of a bridge arm of the first half-bridge circuit and a midpoint of a bridge arm of the second half-bridge circuit; The positive electrode of the fuel cell is connected to the positive electrode of the first DC bus, the negative electrode of the fuel cell is connected to the drain electrode of the first power tube of the first half-bridge circuit and the positive electrode of the fourth port capacitor, the negative electrode of the fourth port capacitor and the negative electrode of the fifth port capacitor are connected to the source electrode of the second power tube of the first half-bridge circuit, the source electrode of the second power tube of the second half-bridge circuit, the negative electrode of the first DC bus and the negative electrode of the energy storage battery; One end of the third inductor is connected to the source of the first power tube of the first half-bridge circuit and the drain of the second power tube of the first half-bridge circuit, the other end of the third inductor is connected to the source of the first power tube of the second half-bridge circuit and the drain of the second power tube of the second half-bridge circuit, and the drain of the first power tube of the second half-bridge circuit is connected to the positive electrode of the fifth port capacitor and the positive electrode of the energy storage battery.

6. A routing topology circuit based on a partial power conversion circuit and a TAB circuit according to any one of claims 1 to 5, characterized in that: The voltage of the first DC bus is 220V, and the voltage of the second DC bus is 750V.

7. A method for using a routing topology circuit based on a partial power conversion circuit and a TAB circuit, characterized in that: The routing topology circuit based on a partial power conversion circuit and a TAB circuit includes: a three-winding transformer, a partial power conversion circuit and a TAB circuit, wherein the TAB circuit includes a first DC bus port structure, an energy storage battery port structure and a second DC bus port structure, wherein the energy storage battery port structure is used to connect an energy storage battery; The first DC bus port structure is connected to the medium voltage side winding of the three-winding transformer; The energy storage battery port structure is connected to the low-voltage side winding of the three-winding transformer; The second DC bus port structure is connected to the high voltage side winding of the three-winding transformer; A battery port for connecting to a fuel cell is provided between the partial power conversion circuit and the first DC bus port structure; The first DC bus port structure is used to connect a first DC bus, and the second DC bus port structure is used to connect a second DC bus; The first DC bus port structure includes a first port capacitor, a first inductor and a first power tube full-bridge circuit having four power tubes; One end of the first inductor is connected to the same-name terminal on the medium voltage side of the three-winding transformer, and the other end of the first inductor is connected to the source of the first power tube of the first power tube full-bridge circuit and the drain of the second power tube of the first power tube full-bridge circuit; The medium voltage side opposite-name end of the three-winding transformer is connected to the source of the third power tube of the first power tube full-bridge circuit and the drain of the fourth power tube of the first power tube full-bridge circuit; The drain of the first power tube of the first power tube full-bridge circuit, the drain of the third power tube of the first power tube full-bridge circuit, and the positive electrode of the first port capacitor are all connected to the positive electrode of the first DC bus; the source of the second power tube of the first power tube full-bridge circuit, the source of the fourth power tube of the first power tube full-bridge circuit, and the negative electrode of the first port capacitor are all connected to the negative electrode of the first DC bus; The energy storage battery port structure includes a second port capacitor, a second inductor and a second power tube full-bridge circuit having four power tubes; One end of the second inductor is connected to the same-name end of the low-voltage side of the three-winding transformer, and the other end of the second inductor is connected to the source of the first power tube of the second power tube full-bridge circuit and the drain of the second power tube of the second power tube full-bridge circuit; The low-voltage side opposite-name end of the three-winding transformer is connected to the source of the third power tube of the second power tube full-bridge circuit and the drain of the fourth power tube of the second power tube full-bridge circuit; The drain of the first power tube of the second power tube full-bridge circuit, the drain of the third power tube of the second power tube full-bridge circuit, and the positive electrode of the second port capacitor are all connected to the positive electrode of the energy storage battery; the source of the second power tube of the second power tube full-bridge circuit, the source of the fourth power tube of the second power tube full-bridge circuit, and the negative electrode of the second port capacitor are all connected to the negative electrode of the energy storage battery; The second DC bus port structure includes a third port capacitor and a third power tube full-bridge circuit having four power tubes; The high-voltage side like-name end of the three-winding transformer is connected to the source of the first power tube of the third power tube full-bridge circuit and the drain of the second power tube of the third power tube full-bridge circuit; the high-voltage side opposite-name end of the three-winding transformer is connected to the source of the third power tube of the third power tube full-bridge circuit and the drain of the fourth power tube of the third power tube full-bridge circuit; The drain of the first power tube of the third power tube full-bridge circuit, the drain of the third power tube of the third power tube full-bridge circuit, and the positive electrode of the third port capacitor are all connected to the positive electrode of the second DC bus; the source of the second power tube of the third power tube full-bridge circuit, the source of the fourth power tube of the third power tube full-bridge circuit, and the negative electrode of the third port capacitor are all connected to the negative electrode of the second DC bus; The partial power conversion circuit includes a four-switch circuit, a fourth port capacitor and a fifth port capacitor, the four-switch circuit includes a first half-bridge circuit and a second half-bridge circuit, and a third inductor is connected between a midpoint of a bridge arm of the first half-bridge circuit and a midpoint of a bridge arm of the second half-bridge circuit; The positive electrode of the fuel cell is connected to the positive electrode of the first DC bus, the negative electrode of the fuel cell is connected to the drain electrode of the first power tube of the first half-bridge circuit and the positive electrode of the fourth port capacitor, the negative electrode of the fourth port capacitor and the negative electrode of the fifth port capacitor are connected to the source electrode of the second power tube of the first half-bridge circuit, the source electrode of the second power tube of the second half-bridge circuit, the negative electrode of the first DC bus and the negative electrode of the energy storage battery; One end of the third inductor is connected to the source of the first power tube of the first half-bridge circuit and the drain of the second power tube of the first half-bridge circuit, the other end of the third inductor is connected to the source of the first power tube of the second half-bridge circuit and the drain of the second power tube of the second half-bridge circuit, and the drain of the first power tube of the second half-bridge circuit is connected to the positive electrode of the fifth port capacitor and the positive electrode of the energy storage battery; Usage methods include: When the actual voltage of the second DC bus and the actual voltage of the energy storage battery are both in a fluctuating state, the power of the fuel cell and the transmission power of each port are controlled by controlling the phase shift angles among the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the duty cycle of the four-switch circuit; When the actual voltage of the second DC bus is in a stable state and the actual SOC value of the energy storage battery does not exceed the first preset SOC threshold, the energy storage battery is placed in a charging state by controlling the phase shift angles between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the duty cycle of the four-switch circuit; When the actual voltage of the second DC bus is in a stable state and the actual SOC value of the energy storage battery is not less than a second preset SOC threshold, the energy storage battery is placed in a discharge state by controlling the phase shift angles between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell, wherein the second preset SOC threshold is not less than the first preset SOC threshold; When the actual voltage of the second DC bus is lower than a preset voltage threshold, and the actual SOC value of the energy storage battery is not less than a second preset SOC threshold, the energy storage battery is placed in a discharge state by controlling the phase shift angles between the first power tube full-bridge circuit, the second power tube full-bridge circuit, and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell; When the actual voltage of the second DC bus is lower than the preset voltage threshold and the actual SOC value of the energy storage battery does not exceed the first preset SOC threshold, the energy storage battery is put into a charging state by controlling the phase shift angle between the first power tube full-bridge circuit, the second power tube full-bridge circuit and the third power tube full-bridge circuit and the fuel intake speed of the fuel cell.

8. The method for using the routing topology circuit based on a partial power conversion circuit and a TAB circuit according to claim 7, characterized in that: The usage also includes: When the energy storage battery is in a charging state or a discharging state, an inner voltage loop control is performed based on the potential difference between the actual output voltage of the energy storage battery and the rated voltage of the energy storage battery, and an outer current loop control is performed based on the difference between the actual SOC value of the energy storage battery and the minimum SOC value of the energy storage battery discharged obtained in an experiment; When the actual power of the first DC bus is less than a first preset power threshold, voltage control is performed based on a potential difference between an actual output voltage of the first DC bus and a rated voltage of the first DC bus; When the power of the second DC bus is less than a second preset power threshold, a voltage inner loop control is performed based on a potential difference between an actual output voltage of the second DC bus and a rated voltage of the second DC bus, and a current outer loop control is performed based on a current difference between an actual output current of the second DC bus and a standard current reference value of the second DC bus; When the actual power of the fuel cell is greater than a third preset power threshold, the voltage on the fourth port capacitor is reduced by adjusting the duty cycle of the four switch circuits; When the actual power of the fuel cell is less than the fourth preset power threshold, the voltage on the fourth port capacitor is increased by adjusting the duty cycle of the four switch circuits, and the fourth preset power threshold is not less than the third preset power threshold; When the actual power of the first DC bus is greater than the actual power of the fuel cell, charging the fuel cell through the first DC bus; When the actual power of the first DC bus is less than the actual power of the fuel cell, charging the fuel cell through the second DC bus; The current of the fuel cell is sampled and compared with the reference current of the fuel cell, and the duty cycle of the four-switch circuit is adjusted by a PI regulator to stabilize the voltage of the fourth port capacitor.

9. An electrical device with power conversion function, characterized in that: A routing topology circuit based on a partial power conversion circuit and a TAB circuit as described in any one of claims 1 to 6.

10. A power grid system, characterized in that: A routing topology circuit based on a partial power conversion circuit and a TAB circuit as described in any one of claims 1 to 6.

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