A dual active bridge dc converter of a switch reconfigurable network and a modulation method thereof
By designing a dual active bridge DC-DC converter with a switch-reconfigurable network, employing two operating modes and a bidirectional active switching circuit, the low efficiency and safety hazards of dual active bridge converters during wide voltage gain operation are solved, achieving efficient and safe power conversion.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FUZHOU UNIV
- Filing Date
- 2024-12-13
- Publication Date
- 2026-06-12
AI Technical Summary
Existing dual active bridge converters are inefficient and pose safety hazards when operating over a wide voltage gain range, and they also struggle to achieve bidirectional energy control and address issues such as excessive reactive power.
A dual active bridge DC-DC converter with a switch-reconfigurable network is designed, featuring two operating modes. The operation structure of the six-switch network is reconfigured by switching modes, and different gain modes are controlled to reduce reactive current. A bidirectional active switching loop and a filter circuit are used for current isolation and filtering.
It achieves efficient operation over a wide voltage range, reduces conduction losses, expands the operating area, and improves the efficiency and safety of the converter.
Smart Images
Figure CN119727403B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electronics, specifically relating to a dual active bridge DC-DC converter with a switch reconfigurable network and its modulation method. Background Technology
[0002] In recent years, with the development of the new energy industry, renewable energy power generation, characterized by high penetration, has become a major trend. However, the intermittency, volatility, and randomness of renewable energy pose challenges to the stable operation of the power grid. Therefore, developing energy storage systems to "shaving peaks and filling valleys" for the power grid has become a feasible solution. In energy storage systems, power electronic conversion devices need to charge and discharge battery packs. Because the voltage fluctuations of batteries during charging and discharging are significant, the corresponding power electronic charging and discharging devices need to have wide voltage gain characteristics. At the same time, in order to reduce system energy consumption, the power electronic charging and discharging devices also need to operate with high efficiency.
[0003] For wide-voltage-gain power electronic charging and discharging devices, there are currently two main types of solutions: non-isolated devices and isolated devices. Non-isolated devices primarily include topologies such as Buck converters and four-switch Buck-Boost converters. These converters can achieve wide voltage range operation by controlling the duty cycle, but due to the lack of isolation, they pose safety hazards in industrial applications. Isolated devices primarily include LLC resonant converters, phase-shifted full-bridge converters, and dual active bridge converters. LLC converters can achieve wide voltage range operation by controlling the switching frequency, but the voltage gain is limited in bidirectional operation. Phase-shifted full-bridge converters can regulate voltage by controlling the phase shift angle and can achieve a large voltage gain. However, this converter is difficult to implement bidirectional energy control. Dual active bridge converters can achieve bidirectional energy flow naturally and can implement soft switching. However, this converter generates significant reactive power during wide-voltage-gain operation, reducing operating efficiency. Summary of the Invention
[0004] To address the efficiency reduction caused by port voltage mismatch in dual active bridge DC-DC converters used in practical applications, this application proposes a dual active bridge DC-DC converter with reconfigurable switching network and its operating method. This converter has two modes, corresponding to two operating methods. This allows the converter to switch between the two modes according to specific operating conditions, thereby expanding the operating range of the dual active bridge converter. Switching between different operating modes reduces reactive power and circulating current, thus lowering the converter's conduction losses and improving efficiency. Using this scheme, the converter can operate in different modes according to specific conditions, thereby achieving a wider ZVS (Zero Voltage Switching) load range over a wider voltage range.
[0005] To achieve the above objectives, the technical solution of the present invention is: a dual active bridge DC-DC converter with a switch reconfigurable network and its modulation method. It includes a main circuit and operating modes for the converter under the specified operating method, wherein:
[0006] The converter's main circuit includes a bidirectional active switching loop, enabling bidirectional active operation. Furthermore, the converter can operate in different gain modes through switching network reconfiguration, thereby reducing reactive current.
[0007] The bidirectional energy storage and discharging module of the converter main circuit realizes current isolation during converter operation and stores and discharges energy through a bidirectional active switching circuit.
[0008] The main circuit of the converter also includes a filter circuit, the function of which is to filter the converter input port V in and output port V o Perform filtering.
[0009] In the converter's filter circuit, the filter circuit consists of the input filter capacitor C. in Output filter capacitor C o1 Output filter capacitor C o2 Together they form; input filter capacitor C in One end is connected to the converter input port V in The positive terminal is connected; the input filter capacitor C in The other end is connected to the converter input port V in The negative terminal is connected; the output filter capacitor C o1 One end and the output filter capacitor C o2 One end is connected to the output filter capacitor C. o1 The other end and the converter output port V o The positive terminal is connected to the output filter capacitor C. o2 The other end and the converter output port V o The negative terminal is connected.
[0010] The converter's bidirectional active switching circuit includes a first switching circuit and a second switching circuit. The first switching circuit is connected to the second switching circuit via a bidirectional energy storage and release module. The first switching circuit is connected to the bidirectional energy storage and release module at nodes a1, b1, a2, and b2. The second switching circuit is connected to the bidirectional energy storage and release module at nodes c1, d1, c2, and d2.
[0011] The first switching circuit includes switching transistors S1, S2, S3, S4, S5, and S6, and the drains of switching transistors S1 and S4 and the converter input terminal V. in The positive terminals are connected; the sources of switching transistors S3 and S6 are connected to the converter input terminal V. inThe negative terminal of the transistor is connected; the source of the transistor S1 is connected to the drain of the transistor S2; the source of the transistor S2 is connected to the drain of the transistor S3; the source of the transistor S4 is connected to the drain of the transistor S5; and the source of the transistor S5 is connected to the drain of the transistor S6.
[0012] Furthermore, the second switching circuit includes switching transistors S7, S8, S9, and S... 10 S 11 S 12 S 13 and S 14 The drains of switching transistors S7 and S8 are connected to the converter output terminal V. o The positive terminals are connected; the source of switch S7 is connected to the drain of switch S9; the source of switch S8 is connected to the drain of switch S9. 10 The drain of transistor S9 is connected to the source of transistor S1; the source of transistor S2 is connected to the drain of transistor S3. 10 The source of the switch is connected; the switch S 13 S 14 The source and converter output V o The negative terminal is connected; the switching transistor S 11 The source and the switch S 13 The drains of the transistors are connected; the switching transistor S 12 The source and the switch S 14 The drains of the transistors are connected; the switching transistor S 11 The drain and the switching transistor S 12 The drains are connected.
[0013] The bidirectional energy storage and release module includes two transformers, T1 and T2, and two inductors, L1 and L2. One end of the primary side of transformer T1 is connected to node a1; the other end of the primary side of transformer T1 is connected to node b1. One end of the primary side of transformer T2 is connected to node a2; the other end of the primary side of transformer T2 is connected to node b2. One end of the secondary side of transformer T1 is connected to one end of inductor L1; the other end of the secondary side of transformer T1 is connected to node d1; the other end of inductor L1 is connected to node c1. One end of the secondary side of transformer T2 is connected to one end of inductor L2; the other end of the secondary side of transformer T2 is connected to node d2; the other end of inductor L2 is connected to node c2.
[0014] In addition, the two inductors L1 and L2 of the bidirectional energy storage and dissipation module function as follows: absorbing the input V of the converter. in The energy absorbed by the converter output V o The energy; or the energy supplied to the converter input V in The inductor releases the energy stored within itself, which is then sent to the converter output V. o Release the energy stored in the inductor itself; inductors L1 and L2 are composed of an external inductor and the leakage inductance of the transformer.
[0015] The converter involved in this invention has a more advanced operating circuit mode, including operating mode one and operating mode two;
[0016] When the converter is in operating mode, the voltage v of inductor L1 in one cycle L1 and the voltage v of inductor L2 L2 The current i of inductor L1 L1 and the current i of inductor L2 L2 It is symmetrical; the primary windings of transformers T1 and T2 are essentially connected in series to the input terminal V of the converter. in At both ends, this modulation method can control the amplitude of the primary voltage of the transformer to V. in / 2; By adjusting switches S2, S4, S6 and switches S8, S9, S 11 S 14 The phase difference can change the transmission power.
[0017] In operating mode two, the voltage v of inductor L1 in one cycle L1 and the voltage v of inductor L2 L2 The current i of inductor L1 L1 and the current i of inductor L2 L2 They are exactly the same; the primary windings of transformers T1 and T2 are essentially connected in parallel to the input terminal V of the converter. in At both ends, this modulation method can control the amplitude of the primary voltage of the transformer to V. in By adjusting switches S3, S4 and S8, S9, S... 12 S 13 The phase difference can change the transmission power.
[0018] Compared with the prior art, the present invention has the following beneficial effects:
[0019] 1) The dual active bridge DC-DC converter of the switch reconfigurable network has two operating modes. By switching modes, the operating topology of the six-switch network can be reconfigured to achieve multi-gain point operation.
[0020] 2) The dual active bridge DC-DC converter of the switch reconfigurable network reduces reactive current by controlling different gain modes, thereby improving operating efficiency; Attached Figure Description
[0021] Figure 1 This invention relates to a dual active bridge DC-DC converter topology with reconfigurable switching network.
[0022] Figure 2 This is circuit state 1 of the dual active bridge DC-DC converter mode 1 with reconfigurable switching network of the present invention.
[0023] Figure 3This is circuit state 2 of the dual active bridge DC-DC converter mode 1 with reconfigurable switching network of the present invention.
[0024] Figure 4 This is circuit state 3 of the dual active bridge DC-DC converter mode 1 with reconfigurable switching network of the present invention.
[0025] Figure 5 This is circuit state 4 of the dual active bridge DC-DC converter mode 1 with reconfigurable switching network of the present invention.
[0026] Figure 6 This is circuit state 5 of the dual active bridge DC-DC converter mode one with reconfigurable switching network of the present invention.
[0027] Figure 7 This is circuit state 6 of the dual active bridge DC-DC converter mode one with reconfigurable switching network of the present invention.
[0028] Figure 8 The waveforms are the main operating waveforms of the dual active bridge DC-DC converter with reconfigurable switching network of the present invention in mode one.
[0029] Figure 9 This is circuit state 1 of mode two of the reconfigurable dual active bridge DC-DC converter with switch network of the present invention.
[0030] Figure 10 This is circuit state 2 of the mode two of the reconfigurable dual active bridge DC-DC converter with switch network of the present invention.
[0031] Figure 11 This is circuit state 3 of mode two of the reconfigurable dual active bridge DC-DC converter with switch network of the present invention.
[0032] Figure 12 This is circuit state 4 of the mode two circuit of the reconfigurable dual active bridge DC-DC converter with switch network of the present invention.
[0033] Figure 13 This is circuit state 5 of mode two of the reconfigurable dual active bridge DC-DC converter with switch network of the present invention.
[0034] Figure 14 This is circuit state 6 of mode two of the reconfigurable dual active bridge DC-DC converter with switch network of the present invention.
[0035] Figure 15 The waveforms are the main operating waveforms of the dual active bridge DC-DC converter with reconfigurable switching network in this invention, in mode two. Detailed Implementation
[0036] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings.
[0037] Figure 1 This is a dual active bridge DC-DC converter topology with reconfigurable switching networks. For example... Figure 1 As shown, the main circuit of the converter includes a converter input port V. in Converter output terminal V o The converter consists of two transformers, two inductors, and two switching circuits. The input port V of the converter... in and converter output V o One port can be selectively used as the power supply terminal, while the other port can be used as the load terminal. Input filter capacitor C in Connected to the input port V of the converter in Output filter capacitor C o1 and C o2 Connected to the output terminal V of the converter o The first switching circuit includes switches S1, S2, S3, S4, S5, and S6; the second switching circuit includes switches S7, S8, S9, and S6. 10 S 11 S 12 S 13 and S 14 The converter has two transformers, T1 and T2. The inductors L1 and L2 consist of an external inductor and the leakage inductance of the transformer.
[0038] The connection relationships of the components in the reconfigurable dual active bridge DC-DC converter topology using a switching network are as follows: Input filter capacitor C in One end is connected to the converter input terminal V in The positive terminal is connected; the input filter capacitor C in The other end is connected to the converter input terminal V. in The negative terminals are connected; the drains of switching transistors S1 and S4 are connected to the converter input terminal V. in The positive terminals are connected; the sources of switching transistors S3 and S6 are connected to the converter input terminal V. in The negative terminal of transistor S1 is connected to the negative terminal of transistor S2; the source of transistor S2 is connected to the drain of transistor S3; the source of transistor S4 is connected to the drain of transistor S5; the source of transistor S5 is connected to the drain of transistor S6; one end of the primary winding of transformer T1 is connected to the source of transistor S4; the other end of the primary winding of transformer T1 is connected to the source of transistor S1; one end of the secondary winding of transformer T1 is connected to one end of inductor L1; the other end of the secondary winding of transformer T1 is connected to the source of transistor S7; the other end of inductor L1 is connected to the source of transistor S8; one end of the primary winding of transformer T2 is connected to the source of transistor S5; the other end of the primary winding of transformer T2 is connected to the source of transistor S2; one end of the secondary winding of transformer T2 is connected to one end of inductor L2; the other end of the secondary winding of transformer T2 is connected to the source of transistor S3; the negative terminal of transistor S4 is connected to the drain of transistor S5; the source of transistor S4 is connected to the drain of transistor S5; the source of transistor S6 is connected to the drain of transistor S7; one end of the primary winding of transformer T2 is connected to the source of transistor S4; the other end of the primary winding of transformer T2 is connected to the source of transistor S2; one end of the secondary winding of transformer T2 is connected to the source of transistor S5; the other end of the secondary winding of transformer T2 is connected to the source of transistor S6; the negative terminal of transistor S7 is connected to the negative terminal of transistor S8; the negative terminal of transistor S4 is connected to the negative terminal of transistor S5; the negative terminal of transistor S6 is connected to the negative terminal of transistor S7; the negative terminal of transistor S7 is connected to the negative terminal of transistor S8 ... 11 The source terminal of inductor L2 is connected to the source terminal of transistor S; the other terminal of inductor L2 is connected to the source terminal of transistor S. 12The source terminals of the transistors S7 and S8 are connected to the source terminal of the converter; the drain terminals of the switching transistors S7 and S8 are connected to the output terminal V of the converter. o The positive terminals are connected; the source of switch S7 is connected to the drain of switch S9; the source of switch S8 is connected to the drain of switch S9. 10 The drain of transistor S9 is connected to the source of transistor S1; the source of transistor S2 is connected to the drain of transistor S3. 10 The source of the switch is connected; the switch S 10 The source and output filter capacitor C o1 One end is connected; output filter capacitor C o1 The other end is connected to the converter output terminal V. o The positive terminal is connected; the switching transistor S 13 S 14 The source and converter output V o The negative terminal is connected; the switching transistor S 11 The source and the switch S 13 The drains of the transistors are connected; the switching transistor S 12 The source and the switch S 14 The drains of the transistors are connected; the switching transistor S 11 The drain and the switching transistor S 12 The drains of the transistors are connected; the switching transistor S 12 The drain and output filter capacitor C o2 One end is connected; output filter capacitor C o2 The other end is connected to the converter output terminal V. o The negative terminal is connected.
[0039] The dual active bridge DC-DC converter of the switch-reconfigurable network has two modulation methods. In the first operating mode, the converter circuit is characterized by: the voltage v of inductor L1 within one cycle... L1 and the voltage v of inductor L2 L2 The current i of inductor L1 L1 and the current i of inductor L2 L2 It is symmetrical; the primary windings of transformers T1 and T2 are essentially connected in series to V. in At both ends, this modulation method can control the amplitude of the primary voltage of the transformer to V. in / 2; By adjusting switches S2, S4, S6 and switches S8, S9, S 11 S 14 The phase difference can change the transmitted power; for operating mode two, the converter circuit is characterized by: the voltage v of inductor L1 within one cycle. L1 and the voltage v of inductor L2 L2 The current i of inductor L1 L1 and the current i of inductor L2 L2 They are exactly the same; the primary windings of transformers T1 and T2 are essentially connected in parallel to V. inAt both ends, this modulation method can control the amplitude of the primary voltage of the transformer to V. in By adjusting switches S3, S4 and S8, S9, S... 12 S 13 The phase difference can change the transmission power.
[0040] In this embodiment, the converter state for operating mode one is described in detail below:
[0041] Operating mode 1, circuit state 1 [t0-t1]: corresponding to Figure 2 i in The current is negative, and the primary currents of transformer T1 and T2 flow through the reverse parallel diodes S2, S4, and S6. L1 i L2 From S7, S 10 S 12 S 13 The current flows through the reverse parallel diode, allowing the switching transistors S7 and S2 to be turned on with zero voltage. 10 S 12 S 13 .at this time, And v L1 =KV in / 2+V o / 2, therefore i L1 Linear increase; And v L2 =-KV in / 2-V o / 2, therefore i L2 Linear decrease. In this mode, the inductor releases energy to V. in and V o .
[0042] Operating mode 1, circuit state 2 [t1-t2]: corresponding to Figure 3 Starting from time t1, i in When the signal is positive, switches S2, S4, and S6 are turned on, and the primary currents of transformer T1 and T2 flow through switches S2, S4, and S6. L1 i L2 From the switching transistors S7 and S 10 S 12 S 13 It flows through the middle of the river. L1 Still equal to KV in / 2+V o / 2,i L1 Continue to rise linearly; v L2 Still equal to -KV in 2-V o / 2,i L2It continues to decrease linearly. In this mode, the power supply V... in and V o At the same time, it stores energy in the inductor.
[0043] Operating mode 1, circuit state 3 [t2-t3]: corresponding to Figure 4 At time t2, switches S7 and S... 10 S 12 S 13 Turn off. Then, i L1 i L2 From S8, S9, S 11 S 14 The current flows through the reverse parallel diode, allowing the switching transistors S8, S9, and S2 to be turned on with zero voltage. 11 S 14 .at this time, and Then v L1 =KV in 2-V o / 2,i L1 Continue to rise slowly and linearly; and Then v L2 =-KV in 2+V o / 2,i L2 It continues to decrease slowly and linearly. In this mode, the power supply V... in Output power, power supply V o Absorbed power.
[0044] Operating mode 1, circuit state 4 [t3-t4]: corresponding to Figure 5 i in The current is negative, and the primary currents of transformer T1 and T2 flow through the reverse parallel diodes S1, S3, and S5. L1 i L2 From S8, S9, S 11 S 14 The current flows through the reverse parallel diode, allowing the switching transistors S7 and S2 to be turned on with zero voltage. 10 S 12 S 13 .at this time, And v L1 =-KV in / 2-V o / 2, therefore i L1 Linear decrease; And v L2 =KV in / 2+V o / 2, therefore i L2 Linear increase. In this mode, the inductor releases energy to V. inand V o .
[0045] Operating mode 1, circuit state 5 [t4-t5]: corresponding to Figure 6 Starting from time t4, i in When the signal is positive, switches S1, S3, and S5 are turned on, and the primary currents of transformer T1 and T2 flow through switches S1, S3, and S5. L1 i L2 From the switching transistors S8, S9, S 11 S 14 It flows through the middle of the river. L1 Still equal to -KV in / 2-V o / 2,i L1 Continue to decrease linearly; v L2 Still equal to KV in / 2+V o / 2,i L2 It continues to rise linearly. In this mode, the power supply V... in and V o At the same time, it stores energy in the inductor.
[0046] Operating mode 1, circuit state 6 [t5-t6]: corresponding to Figure 7 At time t5, switches S8, S9, and S... 11 S 14 Turn off. Then, i L1 i L2 From S7, S 10 S 12 S 13 The current flows through the reverse parallel diode, allowing the switching transistors S8, S9, and S2 to be turned on with zero voltage. 11 S 14 .at this time, and Then v L1 =-KV in / 2+V o / 2,i L1 Continue to decline slowly and linearly; and Then v L2 =KV in / 2-V o / 2,i L2 It continues to rise slowly and linearly. In this mode, the power supply V... in Output power, power supply V o Absorbed power.
[0047] The above describes the operation of the converter in one switching cycle when its modulation method is in mode one. From the above analysis, it can be seen that the voltage v of inductor L1 within one cycle...L1 and the voltage v of inductor L2 L2 The current i of inductor L1 L1 and the current i of inductor L2 L2 It is symmetrical, so only v is drawn in its working waveform diagram. L1 i L1 The waveform. The primary windings of transformers T1 and T2 are essentially connected in series to V. in At both ends, this modulation method can control the amplitude of the primary voltage of the transformer to V. in / 2. By adjusting switches S2, S4, S6 and switches S8, S9, S... 11 S 14 The phase difference can change the transmission power.
[0048] The final operating waveform of the converter is as follows: Figure 8 As shown.
[0049] For operating mode two, the converter state is described in detail below:
[0050] First, throughout the entire process, switching transistors S2 and S5 are always kept at a high level to maintain their conduction state.
[0051] Operating mode two circuit state 1 [t0-t1]: corresponding Figure 9 i in The primary current of transformer T1 flows through the anti-parallel diodes S2, S3, and S4, while the primary current of transformer T2 flows through the anti-parallel diodes S3, S4, and S5. L1 i L2 From S7, S 10 S 11 S 14 The current flows through the reverse parallel diode, allowing the switching transistors S7 and S2 to be turned on with zero voltage. 10 S 11 S 14 .at this time, And v L1 =KV in +V o / 2, therefore i L1 Linear increase; And v L2 =KV in +V o / 2, therefore i L2 Linear increase. In this mode, the inductor releases energy to V. in and V o .
[0052] Operating mode two circuit state 2 [t1-t2]: corresponding Figure 10 Starting from time t1, iin When the signal is positive, switches S3 and S4 are turned on. The primary current of transformer T1 flows through switches S2, S3, and S4, while the primary current of transformer T2 flows through switches S3, S4, and S5. L1 i L2 From the switching transistors S7 and S 10 S 11 S 14 It flows through the middle of the river. L1 Still equal to KV in +V o / 2,i L1 Continue to rise linearly; v L2 Still equal to KV in +V o / 2,i L2 It continues to rise linearly. In this mode, the power supply V... in and V o At the same time, it stores energy in the inductor.
[0053] Operating mode 2, circuit state 3 [t2-t3]: corresponding to Figure 11 At time t2, switches S7 and S... 10 S 11 S 14 Turn off. Then, i L1 i L2 From S8, S9, S 12 S 13 The current flows through the reverse parallel diode, allowing the switching transistors S8, S9, and S2 to be turned on with zero voltage. 12 S 13 .at this time, and Then v L1 =KV in -V o / 2,i L1 Continue to rise slowly and linearly; and Then v L2 =KV in -V o / 2,i L2 It continues to rise slowly and linearly. In this mode, the power supply V... in Output power, power supply V o Absorbed power.
[0054] Operating mode 2, circuit state 4 [t3-t4]: corresponding to Figure 12 i in The primary current of transformer T1 flows through the reverse parallel diodes S1, S5, and S6, while the primary current of transformer T2 flows through the reverse parallel diodes S1, S2, and S6. L1 iL2 From S8, S9, S 12 S 13 The current flows through the reverse parallel diode, allowing the switching transistors S8, S9, and S2 to be turned on with zero voltage. 12 S 13 .at this time, And v L1 =-KV in -V o / 2, therefore i L1 Linear decrease; And v L2 =-KV in -V o / 2, therefore i L2 Linear decrease. In this mode, the inductor releases energy to V. in and V o .
[0055] Operating mode two circuit state 5 [t4-t5]: corresponding Figure 13 Starting from time t4, i in When the signal is positive, switches S1 and S6 are turned on. The primary current of transformer T1 flows through switches S1, S5, and S6, and the primary current of transformer T2 flows through switches S1, S2, and S6. L1 i L2 From the switching transistors S8, S9, S 12 S 13 It flows through the middle of the river. L1 Still equal to -KV in -V o / 2,i L1 Continue to decrease linearly; v L2 Still equal to -KV in -V o / 2,i L2 It continues to decrease linearly. In this mode, the power supply V... in and V o At the same time, it stores energy in the inductor.
[0056] Operating mode two circuit state 6 [t5-t6]: corresponding Figure 14 At time t5, switches S8, S9, and S... 12 S 13 Turn off. Then, i L1 i L2 From S7, S 10 S 11 S 14 The current flows through the reverse parallel diode, allowing the switching transistors S7 and S2 to be turned on with zero voltage. 10 S 11 S 14 .at this time, and Then v L1 =-KV in +V o / 2,i L1 Continue to decline slowly and linearly; and Then v L2 =-KV in +V o / 2,i L2 It continues to decrease slowly and linearly. In this mode, the power supply V... in Output power, power supply V o Absorbed power.
[0057] The above describes the operation process of the converter in mode two under its modulation method during one switching cycle. From the above analysis, it can be seen that the voltage v of inductor L1 within one cycle... L1 and the voltage v of inductor L2 L2 The current i of inductor L1 L1 and the current i of inductor L2 L2 They are exactly the same; the primary windings of transformers T1 and T2 are essentially connected in parallel to the input terminal V of the converter. in At both ends, this modulation method can control the amplitude of the primary voltage of the transformer to V. in By adjusting switches S3, S4 and S8, S9, S... 12 S 13 The phase difference can change the transmission power.
[0058] The final operating waveform of the converter is as follows: Figure 15 As shown.
[0059] Experimental demonstration
[0060] A 1000W converter prototype was built with an input voltage of 250V–450V and an output voltage of 800V. MOSFETs were used as switching devices in both switching loops. The drive signal for the main circuit was generated by a TI TMS320F280049 digital signal processor, and then isolated and amplified by the drive circuit to provide the drive voltage for the main circuit's switching transistors. Under these experimental conditions, the dual active bridge DC-DC converter with a switch reconfigurable network could operate normally in closed-loop mode. The converter prototype operated normally under different input voltages and loads.
[0061] The present invention has the following advantages:
[0062] 1) The dual active bridge DC-DC converter of the switch reconfigurable network has two operating modes. By switching modes, the operating topology of the six-switch network can be reconfigured to achieve multi-gain point operation.
[0063] 2) The dual active bridge DC-DC converter of the switch reconfigurable network reduces reactive current by controlling different gain modes, thereby improving operating efficiency;
[0064] 3) This converter can switch between two operating modes according to specific operating conditions, thereby expanding the operating range of the dual active bridge converter. Switching between different operating modes reduces reactive power and circulating current, thus lowering the converter's conduction losses and improving efficiency. Using this scheme, the converter can operate in different operating modes according to specific conditions, thus achieving a wider ZVS (Zero Voltage Suppressor) load range over a wider voltage range.
[0065] The above are preferred embodiments of the present invention. Any changes made to the technical solution of the present invention that do not exceed the scope of the technical solution of the present invention shall fall within the protection scope of the present invention.
Claims
1. A dual active bridge DC-DC converter with reconfigurable switching network, characterized in that, Includes a bidirectional active switching circuit and a bidirectional energy storage and discharging module; among which, The bidirectional active switching circuit enables bidirectional active operation and allows the converter to operate in different gain modes through switching network reconfiguration, thereby reducing reactive current. The bidirectional energy storage and dissipation module achieves current isolation during converter operation and stores and dissipates energy through a bidirectional active switching circuit. The bidirectional active switching circuit includes switching transistors S1, S2, S3, S4, S5, S6, S7, S8, S9, and S1. 10 S 11 S 12 S 13 and S 14 ; The bidirectional energy storage and release module includes two transformers T1 and T2, and two inductors L1 and L2. The relationships between the various components are as follows: The drains of switching transistors S1 and S4 and the input terminal of the converter The positive terminals are connected; the sources of switching transistors S3 and S6 are connected to the input terminals of the converter. The negative terminal of transistor S1 is connected to the negative terminal of transistor S2; the source of transistor S2 is connected to the drain of transistor S3; the source of transistor S4 is connected to the drain of transistor S5; the source of transistor S5 is connected to the drain of transistor S6; one end of the primary winding of transformer T1 is connected to the source of transistor S4; the other end of the primary winding of transformer T1 is connected to the source of transistor S1; one end of the secondary winding of transformer T1 is connected to one end of inductor L1; the other end of the secondary winding of transformer T1 is connected to the source of transistor S7; the other end of inductor L1 is connected to the source of transistor S8; one end of the primary winding of transformer T2 is connected to the source of transistor S5; the other end of the primary winding of transformer T2 is connected to the source of transistor S2; one end of the secondary winding of transformer T2 is connected to one end of inductor L2; the other end of the secondary winding of transformer T2 is connected to the source of transistor S3; the negative terminal of transistor S4 is connected to the drain of transistor S5; the source of transistor S4 is connected to the drain of transistor S5; the source of transistor S6 is connected to the drain of transistor S7; one end of the primary winding of transformer T2 is connected to the source of transistor S4; the other end of the primary winding of transformer T2 is connected to the source of transistor S2; one end of the secondary winding of transformer T2 is connected to the source of transistor S5; the other end of the secondary winding of transformer T2 is connected to the source of transistor S6; the negative terminal of transistor S7 is connected to the negative terminal of transistor S8; the negative terminal of transistor S4 is connected to the negative terminal of transistor S5; the negative terminal of transistor S6 is connected to the negative terminal of transistor S7; the negative terminal of transistor S7 is connected to the negative terminal of transistor S8 ... 11 The source terminal of inductor L2 is connected to the source terminal of transistor S; the other terminal of inductor L2 is connected to the source terminal of transistor S. 12 The sources of the transistors are connected; the drains of the switching transistors S7 and S8 are connected to the converter output. The positive terminals are connected; the source of switch S7 is connected to the drain of switch S9; the source of switch S8 is connected to the drain of switch S9. 10 The drain of transistor S9 is connected to the source of transistor S1; the source of transistor S2 is connected to the drain of transistor S3. 10 The source of the switch is connected; the switch S 13 S 14 The source and the converter output The negative terminal is connected; the switching transistor S 11 The source and the switch S 13 The drains of the transistors are connected; the switching transistor S 12 The source and the switch S 14 The drains of the transistors are connected; the switching transistor S 11 The drain and the switching transistor S 12 The drains are connected; The aforementioned switch network reconfigurable dual active bridge DC-DC converter includes operating mode one and operating mode two; In the operating mode of the converter, the voltage of inductor L1 within one cycle and the voltage of inductor L2 The current i of inductor L1 L1 and the current i of inductor L2 L2 It is symmetrical; the primary windings of transformers T1 and T2 are connected in series and then connected to the input terminal of the converter. At both ends, this modulation method can control the amplitude of the primary voltage of the transformer to be... By adjusting switches S2, S4, S6 and switches S8, S9, S... 11 S 14 The phase difference can change the transmission power; In operating mode two, the voltage of inductor L1 within one cycle of the converter... and the voltage of inductor L2 The current i of inductor L1 L1 and the current i of inductor L2 L2 Yes, they are the same. The primary windings of transformers T1 and T2 are connected in parallel and then connected to the input of the converter. At both ends, this modulation method can control the amplitude of the primary voltage of the transformer to be... By adjusting switches S3, S4 and S8, S9, S... 12 S 13 The phase difference can change the transmission power.
2. The dual active bridge DC-DC converter with reconfigurable switch network according to claim 1, characterized in that, It also includes a filter circuit, the function of which is to filter the converter input port. and output ports Perform filtering.
3. A dual active bridge DC-DC converter with reconfigurable switching network according to claim 2, characterized in that, The filter circuit consists of an input filter capacitor. Output filter capacitor C o1 Output filter capacitor C o2 Together they form; input filter capacitor One end is connected to the converter input port The positive terminal is connected; the input filter capacitor The other end is connected to the converter input port The negative terminal is connected; the output filter capacitor C o1 One end and the output filter capacitor C o2 One end is connected to the output filter capacitor C. o1 The other end and the converter output port The positive terminal is connected to the output filter capacitor C. o2 The other end and the converter output port The negative terminal is connected.