Interleaved half-bridge bidirectional conversion circuit based on inductors with same direction coupling

Abstract

The utility model belongs to the technical field of direct current non - isolation converter, concretely relates to based on the same direction coupling inductance staggered parallel half -bridge bidirectional conversion circuit, including high -voltage end direct current voltage source U1, two half -bridge circuits, same direction coupling inductance, low -voltage end direct current voltage source U2 and control circuit, high -voltage end direct current voltage source U1 with two half -bridge circuits electric connection, two half -bridge circuits with same direction coupling inductance electric connection, same direction coupling inductance with low -voltage end direct current voltage source U2 electric connection, the pulse drive signal in control circuit with power MOSFET pipe in two half -bridge circuits electric connection, same direction coupling inductance output current with the current feedback signal in control circuit electric connection, the utility model energy flow direction changes and the impact is small, avoids the possible through -going problem, conversion circuit efficiency is high, and control method is simple and easy to realize.

Description

Technical Field

[0001] This utility model belongs to the field of DC non-isolated conversion technology, specifically relating to a bidirectional conversion circuit based on alternating parallel half-bridge of co-coupled inductors. Background Technology

[0002] Bidirectional DC-DC converters have been widely used in applications such as battery charging and discharging, electric vehicles, UPS systems, and new energy power generation systems.

[0003] Currently, the half-bridge bidirectional DC-DC converter circuit and its control are simple and widely used. However, it suffers from problems such as potential shoot-through of the switching transistors, hard switching of power devices, reverse recovery of the body diode, and low efficiency under light load. Chinese patent application number 201010102548.9 discloses a bidirectional DC-DC converter with a reverse-coupled inductor, which solves the problems of potential shoot-through and low efficiency under light load during the switching of the half-bridge structure, but suffers from problems such as resonance of the reverse-coupled inductor, internal circulating current causing additional losses, and hard switching of power devices. Chinese patent application number 201811307506.1 discloses a combined bidirectional DC-DC converter circuit, which solves the problems of potential shoot-through and low efficiency under light load of the half-bridge structure, but its power devices are still hard-switched. At the same time, analysis of these circuits reveals that they use additional independent freewheeling loops, do not fully utilize the body diode of the switching transistors, and require at least two independent inductors, which will increase the cost and size of the converter; and the control circuit becomes more complex when they are interleaved in parallel. Meanwhile, the inductor current is triangular, and the large peak value and the large rate of change of current at the peak value also have adverse effects. Therefore, the above problems urgently need to be solved. To this end, this utility model proposes a bidirectional converter circuit based on alternating parallel half-bridge with co-coupled inductors. Utility Model Content

[0004] The purpose of this invention is to provide a bidirectional converter circuit based on alternating parallel half-bridge with co-coupled inductors, which minimizes the impact when the energy flow direction changes, avoids potential shoot-through problems, has high conversion circuit efficiency, and features a simple and easy-to-implement control method.

[0005] The specific technical solution adopted by this utility model is as follows:

[0006] The bidirectional converter circuit based on alternating parallel half-bridge with co-coupled inductors includes a high-voltage DC voltage source U1, two half-bridge circuits, a co-coupled inductor, a low-voltage DC voltage source U2, and a control circuit. The high-voltage DC voltage source U1 is electrically connected to the two half-bridge circuits. The two half-bridge circuits are electrically connected to the co-coupled inductor. The co-coupled inductor is electrically connected to the low-voltage DC voltage source U2. The pulse drive signal in the control circuit is electrically connected to the power MOSFETs in the two half-bridge circuits. The output current of the co-coupled inductor is electrically connected to the current feedback signal in the control circuit.

[0007] Preferably, the two half-bridge circuits include power switches S1, S2, S3, and S4, freewheeling diodes D1, D2, D3, and D4; the positive terminal of the high-voltage DC voltage source U1 is connected to the drain of power switch S1 and the drain of power switch S3, respectively, and the negative terminal of the high-voltage DC voltage source U1 is connected to the source of power switch S2 and the source of power switch S4, respectively; the drain and source of power switch S1 are respectively... The drain and source of the power switch S2 are connected to the anode and cathode of the freewheeling diode D1, respectively; the drain and source of the power switch S3 are connected to the anode and cathode of the freewheeling diode D3, respectively; and the drain and source of the power switch S4 are connected to the anode and cathode of the freewheeling diode D4, respectively. The source of the power switch S1 is connected to the drain of the power switch S2; and the source of the power switch S3 is connected to the drain of the power switch S4.

[0008] Preferably, the co-coupled inductor includes a self-inductance L1 and a self-inductance L2; one end of the self-inductance L1 is connected to the source of the power switch S1, and one end of the self-inductance L2 is connected to the source of the power switch S3.

[0009] Preferably, the positive terminal of the low-voltage DC voltage source U2 is connected to the other end of the same-direction coupled inductor, including the self-inductance L1 and the self-inductance L2, respectively, and the negative terminal of the low-voltage DC voltage source U2 is connected to the source of the power switch S2 and the source of the power switch S4 respectively.

[0010] Preferably, the control circuit includes a current regulator, a PWM generator 1, a PWM generator 2, a frequency divider 1, a frequency divider 2, and a circuit with a DC bias voltage u. bias carrier u tr ; and the current i of the self-inductance L1 L1 With the current i of self-inductance L2L2 The sum of i L and current reference value i ref Each is connected to the input terminal of the current regulator, and the current reference value i in the current regulator is... ref The current i of self-inductance L1 and self-inductance L2 L1 i L2 The sum of i L The difference is used to obtain the output control signal u through the current regulator. e And output control signal u e After inversion, another control signal -u is obtained. e ; and the control signal u output by the current regulator e And another control -u e It is connected to the non-inverting input terminal of PWM generator 1 and the non-inverting input terminal of PWM generator 2 respectively; and the DC bias voltage u bias carrier u tr The inverting input terminals of PWM generator 1 and PWM generator 2 are connected respectively; the output of PWM generator 1 is divided by two frequency dividers 1 to obtain two drive signals u with a phase difference of 180°. gs1 and u gs2 The gates of the power switching transistors S1 and S3 are connected respectively; and the output of the PWM generator 2 obtains two drive signals u with a 180° phase difference via a frequency divider 2. gs2 and u gs4 It is connected to the gate of the power switch S2 and the gate of the power switch S4, respectively.

[0011] The technical effects achieved by this utility model are as follows:

[0012] (1) This utility model realizes zero-current turn-on of power switching transistor and zero-current turn-off of freewheeling diode, thereby reducing the switching loss of power devices;

[0013] (2) This utility model utilizes a carrier signal biased by DC voltage to achieve a “soft switching” process when the energy transfer direction, i.e. the inductor current direction, is switched, thus avoiding the impact of sudden changes in the operating state of the power switch and the shoot-through problem that may exist when the operating state of the power switch is switched.

[0014] (3) The present invention achieves an effective duty cycle that is twice that of the actual switching transistor, thus extending the duty cycle and providing a higher voltage gain.

[0015] (4) This utility model utilizes the same discontinuous self-induced current to achieve a better current sharing effect; compared with the "triangle" inductor current in the traditional bidirectional half-bridge converter circuit, the self-induced current waveform in the circuit of this utility model is beneficial to reduce inductor loss and the more serious electromagnetic interference problem caused by the large current conversion rate at the peak of the "triangle" inductor current.

[0016] (5) This utility model utilizes one in-phase coupled inductor and four power switching MOSFETs to realize the bidirectional energy flow function;

[0017] (6) The control method of the conversion circuit of this utility model is simple and easy to implement because the duty cycle is extended;

[0018] (7) This utility model is applicable to occasions where bidirectional flow of electrical energy is required. Attached Figure Description

[0019] Figure 1 This is an electrical schematic diagram of a bidirectional converter circuit and control method based on alternating parallel half-bridge with co-coupled inductors according to this utility model.

[0020] Figure 2 This is a diagram showing the main waveforms of a bidirectional converter circuit and control method based on alternating parallel half-bridge with co-coupled inductors, as described in this utility model, when energy flows from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2.

[0021] Figure 3 This is a diagram showing the main waveforms of a bidirectional converter circuit and control method based on alternating parallel half-bridge with co-coupled inductors, as described in this utility model, when energy flows from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1.

[0022] Figure 4 is an equivalent circuit diagram of the present invention based on a bidirectional half-bridge converter circuit and control method with alternating parallel half-bridges of co-coupled inductors, when energy flows from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2.

[0023] Figure 4(a) is the equivalent circuit diagram of the working mode of the present invention based on the bidirectional half-bridge converter circuit and control method with alternating parallel half-bridge of the same-direction coupled inductors when energy flows from the DC voltage source U1 at the high-voltage end to the DC voltage source U2 at the low-voltage end.

[0024] Figure 4(b) is the equivalent circuit diagram of the working mode two of the present invention based on the bidirectional half-bridge converter circuit and control method of alternating parallel half-bridge with co-coupled inductors when energy flows from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2.

[0025] Figure 4(c) is a three-equivalent circuit diagram of the working mode of the present invention based on the bidirectional half-bridge converter circuit and control method with alternating parallel half-bridge of the same-direction coupled inductors when energy flows from the DC voltage source U1 at the high-voltage end to the DC voltage source U2 at the low-voltage end.

[0026] Figure 4(d) is the equivalent circuit diagram of the working mode four of the present invention based on the bidirectional half-bridge converter circuit and control method of alternating parallel half-bridge with co-coupled inductors when energy flows from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2.

[0027] Figure 4(e) is the equivalent circuit diagram of the working mode five of the present invention based on the bidirectional half-bridge converter circuit and control method of alternating parallel half-bridge with co-coupled inductors when energy flows from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2.

[0028] Figure 4(f) is the equivalent circuit diagram of the working mode six of the present invention based on the bidirectional converter circuit and control method of the interleaved parallel half-bridge with co-coupled inductors when energy flows from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2.

[0029] Figure 5 is an equivalent circuit diagram of the present invention, which describes a bidirectional converter circuit and control method based on alternating parallel half-bridge with co-coupled inductors, when the DC voltage flows from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1.

[0030] Figure 5(a) is an equivalent circuit diagram of the working mode of the present invention based on the bidirectional half-bridge converter circuit and control method with alternating parallel half-bridge of the same-direction coupled inductors when energy flows from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1.

[0031] Figure 5(b) is the equivalent circuit diagram of the working mode two of the present invention based on the bidirectional half-bridge converter circuit and control method with alternating parallel half-bridge of the same-direction coupled inductors when energy flows from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1.

[0032] Figure 5(c) is a three-equivalent circuit diagram of the working mode of the present invention based on the bidirectional half-bridge converter circuit and control method with alternating parallel half-bridge of the same-direction coupled inductors when energy flows from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1.

[0033] Figure 5(d) is the equivalent circuit diagram of the working mode four of the present invention based on the bidirectional half-bridge converter circuit and control method of alternating parallel half-bridge with co-coupled inductors when energy flows from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1.

[0034] Figure 5(e) is the equivalent circuit diagram of the working mode five of the present invention based on the bidirectional half-bridge converter circuit and control method of alternating parallel half-bridge with co-coupled inductors when energy flows from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1.

[0035] Figure 5(f) is the equivalent circuit diagram of the working mode six of the present invention based on the bidirectional half-bridge converter circuit and control method with alternating parallel half-bridge of the same-direction coupled inductors when energy flows from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1.

[0036] Figure 6 shows the control signal u of the bidirectional converter circuit and control method based on alternating parallel half-bridge with co-coupled inductors according to this invention when the energy flow direction changes. e -u e And a schematic diagram showing the changes in the operating state of the power switch.

[0037] Figure 6(a) shows the control signal u when switching from the flow of energy from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2 to the flow of energy from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1 according to the present invention and the control method. e -u e And a schematic diagram showing the changes in the operating state of the power switch.

[0038] Figure 6(b) shows the control signal u when switching from the flow of energy from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1 to the flow of energy from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2 according to the present invention and the control method. e -u e And a schematic diagram showing the changes in the operating state of the power switch.

[0039] Figure 7 This invention relates to a bidirectional converter circuit and control method based on an alternating parallel half-bridge with co-coupled inductors, and addresses the corresponding co-coupled inductor current i when the energy flow direction switches. L (i L =i L1 +i L2 The two inductor (self-inductance) currents iL1 and iL2 in the co-coupled inductor and the driving signal U gs1 U gs2 U gs3 and U gs4 Simulation waveform diagram.

[0040] Figure 8 This invention relates to a bidirectional converter circuit and control method based on an alternating parallel half-bridge with co-coupled inductors, where the self-induced current i flows from the high-voltage DC voltage source U1 to the low-voltage DC voltage source U2. L1 and i L2 Drive signal U gs1 U gs2 U gs3 and Ugs4 and the power MOSFET body diode current i D1 i D2 i D3 i D4 Simulated waveform unfolded diagram.

[0041] Figure 9 This invention relates to a bidirectional converter circuit and control method based on an alternating parallel half-bridge with co-coupled inductors. When energy is transferred from the low-voltage DC voltage source U2 to the high-voltage DC voltage source U1, the self-induced current i should be... L1 and i L2 Drive signal U gs1 U gs2 U gs3 and U gs4 and the power MOSFET body diode current i D1 i D2 i D3 i D4 Simulated waveform unfolded diagram.

[0042] The attached diagram lists the components represented by each number as follows:

[0043] 1. High-voltage DC voltage source U1; 2. Two half-bridge circuits; 3. Coupling inductor; 4. Low-voltage DC voltage source U2; 5. Control circuit. Detailed Implementation

[0044] To make the objectives and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of this utility model and does not strictly limit the scope of protection specifically claimed by this utility model.

[0045] like Figure 1 As shown, a bidirectional converter circuit based on alternating parallel half-bridges with co-coupled inductors includes a high-voltage DC voltage source U11, two half-bridge circuits 2, a co-coupled inductor 3, a low-voltage DC voltage source U24, and a control circuit 5. The high-voltage DC voltage source U11 is electrically connected to the two half-bridge circuits 2; the two half-bridge circuits 2 are electrically connected to the co-coupled inductor 3; the co-coupled inductor 3 is electrically connected to the low-voltage DC voltage source U24; the pulse drive signal in the control circuit 5 is electrically connected to the power MOSFETs in the two half-bridge circuits 2; and the output current of the co-coupled inductor 3 is electrically connected to the current feedback signal in the control circuit 5.

[0046] Preferably, the two half-bridge circuits 2 include power switches S1, S2, S3, and S4, freewheeling diodes D1, D2, D3, and D4; the positive terminal of the high-voltage DC voltage source U11 is connected to the drain of power switch S1 and the drain of power switch S3, respectively, and the negative terminal of the high-voltage DC voltage source U11 is connected to the source of power switch S2 and the source of power switch S4, respectively; the drain and source of power switch S1 are... The drain and source of the power switch S2 are connected to the anode and cathode of the freewheeling diode D1, respectively; the drain and source of the power switch S3 are connected to the anode and cathode of the freewheeling diode D3, respectively; and the drain and source of the power switch S4 are connected to the anode and cathode of the freewheeling diode D4, respectively. The source of the power switch S1 is connected to the drain of the power switch S2; and the source of the power switch S3 is connected to the drain of the power switch S4.

[0047] Preferably, the co-coupled inductor 3 includes a self-inductance L1 and a self-inductance L2; one end of the self-inductance L1 is connected to the source of the power switch S1, and one end of the self-inductance L2 is connected to the source of the power switch S3.

[0048] Preferably, the positive terminal of the low-voltage DC voltage source U24 is connected to the other end of the self-inductance L1 and self-inductance L2 included in the same-direction coupling inductor 3, and the negative terminal of the low-voltage DC voltage source U24 is connected to the source of the power switch S2 and the source of the power switch S4, respectively.

[0049] Preferably, the control circuit 5 includes a current regulator, a PWM generator 1, a PWM generator 2, a frequency divider 1, a frequency divider 2, and a circuit with a DC bias voltage u. bias carrier u tr ; and the current i of the self-inductance L1 L1 With the current i of self-inductance L2 L2 The sum of i L and current reference value i ref Each is connected to the input terminal of the current regulator, and the current reference value i in the current regulator is... ref The current i of self-inductance L1 and self-inductance L2 L1 i L2 The sum of i L The difference is used to obtain the output control signal u through the current regulator. e And output control signal u e After inversion, another control signal -u is obtained. e; and the control signal u output by the current regulator e And another control -u e It is connected to the non-inverting input terminal of PWM generator 1 and the non-inverting input terminal of PWM generator 2 respectively; and the DC bias voltage u bias carrier u tr The inverting input terminals of PWM generator 1 and PWM generator 2 are connected respectively; the output of PWM generator 1 is divided by two frequency dividers 1 to obtain two drive signals u with a phase difference of 180°. gs1 and u gs2 The gates of the power switching transistors S1 and S3 are connected respectively; and the output of the PWM generator 2 obtains two drive signals u with a 180° phase difference via a frequency divider 2. gs2 and u gs4 It is connected to the gate of the power switch S2 and the gate of the power switch S4, respectively.

[0050] The working principle of this utility model is as follows:

[0051] Since the boost mode of energy transfer from low-voltage DC voltage source U24 to high-voltage DC voltage source U11 and the buck mode of energy transfer from high-voltage DC voltage source U11 to low-voltage DC voltage source U24 are similar, we will only analyze the working principle when energy is transferred from high-voltage DC voltage source U11 to low-voltage DC voltage source U24.

[0052] Working Mode 1: Time period t1-t2

[0053] like Figure 2 As shown in Figure 4(a), before time t1, the current i in the same-direction coupled inductor 3 is... L The current is freewheeled through the freewheeling diode D4, and the equivalent leakage inductance (L2-L) in the same-direction coupled inductor 3 is used for freewheeling. M Current i L2 (i.e., the self-inductance L2 current) is equal to the mutual inductance L M current i L At time t1, power switch S1 is turned on. Because freewheeling diode D4 is conducting, the high-voltage DC voltage source U11 acts on the equivalent leakage inductance (L1-L). M ) and equivalent leakage inductance (L2-L) M Therefore, the equivalent leakage inductance (L1-L) in the same-direction coupled inductor 3 is calculated as follows: M Current i L1 Linear rise, equivalent leakage inductance in the same-direction coupled inductor 3 (L2-L) M Current i L2 The current decreases linearly until time t2. L2 Drops to zero, current iL1 Equal to current i L This completes the commutation of two self-induced currents. Due to the equivalent leakage inductance (L1-L) in the same-direction coupled inductor 3. M Current i L1 When power switch S1 is turned on, the current is zero, so power switch S1 turns on with zero current; at time t2, due to the equivalent leakage inductance (L2-L) in the same-direction coupling inductor 3... M Current i L2 The current drops to zero, so the freewheeling diode D4 is turned off with zero current and there is no reverse recovery.

[0054] Working Mode 2: t2-t3 time period

[0055] like Figure 2 As shown in Figure 4(b). The equivalent leakage inductance (L2-L) in the same-direction coupled inductor 3. M Current i L2 The voltage is zero. The high-voltage side DC voltage source U11 and the low-voltage side DC voltage source U24 act together on the self-inductance L1 in the co-coupled inductor 3, and the current i in the self-inductance L1 of the co-coupled inductor 3 is zero. L1 The linear increase continues until power switch S1 is turned off at time t3.

[0056] Working Mode 3: t3-t4 time period

[0057] like Figure 2 As shown in Figure 4(c), starting from time t3, the low-voltage DC voltage source U24 acts on the self-inductance L1 in the co-coupled inductor 3, and the current i in the self-inductance L1 of the co-coupled inductor 3... L1 The current decreases linearly through diode D2 until power switch S3 is turned on at time t4.

[0058] Working Mode 4: t4-t5 time period

[0059] like Figure 2 As shown in Figure 4(d), at time t4, power switch S3 is turned on. Due to the freewheeling diode D2 conducting, the high-voltage DC voltage source U11 acts on the equivalent leakage inductance (L1-L). M ) and equivalent leakage inductance (L2-L) M Therefore, the equivalent leakage inductance (L2-L) in the same-direction coupled inductor 3 is calculated as follows: M Current i L2 Linear rise, equivalent leakage inductance in the same-direction coupled inductor 3 (L1-L) M Current i L1 The current decreases linearly until time t5. L1 Drops to zero, current i L2 Equal to current i L This completes the commutation of two self-induced currents. Due to the equivalent leakage inductance (L2-L... MThe current i L2 The current is zero when power switch S3 is turned on, so power switch S3 turns on with zero current; at time t5, due to the equivalent leakage inductance (L1-L... M Current i L1 The current drops linearly to zero, so the freewheeling diode D2 is turned off with zero current and there is no reverse recovery.

[0060] Working Mode 5: t5-t6 time period

[0061] like Figure 2 As shown in Figure 4(e), the equivalent leakage inductance (L1-L) of the same-direction coupled inductor 3 M Current i L1 The voltage is zero. The high-voltage DC voltage source U11 and the low-voltage DC voltage source U24 act together on the self-inductance L2 in the co-coupled inductor 3. The current i in the self-inductance L2 of the co-coupled inductor 3 is zero. L2 The linear increase continues until power switch S3 is turned off at time t6.

[0062] Working Mode 6: Time Period t6-t7

[0063] like Figure 2 As shown in Figure 4(f), starting from time t6, the DC voltage source U24 at the low-voltage end acts on the self-inductance L2 in the same-direction coupled inductor 3, and the current i in the self-inductance L2 of the same-direction coupled inductor 3... L2 The freewheeling current decreases linearly through the freewheeling diode D4 until the power switch S1 is turned on at time t7.

[0064] The next cycle begins at time t7.

[0065] If we assume the duty cycle is D, we can deduce the voltage relationship between the two terminals when energy is transferred from the high-voltage DC voltage source U11 to the low-voltage DC voltage source U24 (step-down mode): Similarly, by analyzing the energy transfer process from the low-voltage DC voltage source U24 to the high-voltage DC voltage source U11 (boost mode), the relationship between the two terminal voltages in this case can also be derived as follows: Therefore, this circuit and its control method also achieve duty cycle extension functionality.

[0066] The simulation parameters for the simulation experiment are as follows: the voltage U1 of the high-voltage DC voltage source U11 is 48V, the voltage U2 of the low-voltage DC voltage source U24 is 24V, the switching frequency of power switches S1, S2, S3 and S4 is 50kHz, the self-inductance of the co-current coupling inductor 3, i.e., inductances L1 and L2, is 50μH, and the coupling coefficient is 0.9.

[0067] Figure 7 It is a two-way energy transfer (buck mode current reference value i)ref Equal to 10A; Boost mode current reference value i ref When the self-induced current i is equal to -10A, L1 i L2 And the sum of these two currents, i L (i L =i L1 +i L2 ), drive signal u gs1 u gs2 u gs3 and u gs4 Simulation waveform diagram.

[0068] It can be seen that when energy is transferred from the high-voltage DC voltage source U11 to the low-voltage DC voltage source U24 (buck mode), i L i L1 and i L2 Both are greater than zero; and Figure 2 The reference directions are the same, and the driving signal u gs1 and u gs3 It exists, and the driving signal u gs2 and u gs4 This does not exist, meaning power switches S1 and S3 are working, while power switches S2 and S4 are not working; conversely, when energy is transferred from the low-voltage DC voltage source U24 to the high-voltage DC voltage source U11 (boost mode), i L i L1 and i L2 Both are less than zero; and Figure 3 The reference direction is opposite, and the driving signal u gs2 and u gs4 It exists, and the driving signal u gs1 and u gs3 This does not mean that power switches S2 and S4 are working, while power switches S1 and S3 are not working. This is clearly consistent with the previous analysis.

[0069] Figure 8 yes Figure 7 Medium energy is transferred from the high-voltage DC voltage source U11 to the low-voltage DC voltage source U24 (i L >0, i L1 >0, i L2 The diagram shows the unfolded state when the current i is greater than 0. It can be seen that before power switches S1 and S3 are turned on, the current i... L1 and i L2 The currents of power switches S1 and S3 are zero, achieving zero-current turn-on; after power switches S1 and S3 are turned off, the currents i of freewheeling diodes D2 and D4 are zero. D2 and i D4After freewheeling, the current gradually decreases to zero, achieving zero-current turn-off for freewheeling diodes D2 and D4, thus eliminating the reverse recovery problem.

[0070] Figure 9 yes Figure 7 Medium energy is transferred from the low-voltage DC voltage source U24 to the high-voltage DC voltage source U11 (i L <0, i L1 <0, i L2 The diagram shows the unfolded state when the current i is less than 0. It can be seen that before power switches S2 and S4 are turned on, the current i... L1 and i L2 The currents are also zero, achieving zero-current turn-on for power switches S2 and S4; after power switches S2 and S4 are turned off, the currents i in freewheeling diodes D1 and D3 are... D1 and i D3 After freewheeling, the current gradually decreases to zero, achieving zero-current turn-off of freewheeling diodes D1 and D3, thus eliminating the reverse recovery problem.

[0071] Simulation results show that this invention can effectively achieve bidirectional energy flow, zero-current turn-on of the power switch, and zero-current turn-off of the freewheeling diode under this control circuit 5.

[0072] The above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. Structures, devices, and operating methods not specifically described or explained in this utility model, unless otherwise specified or limited, shall be implemented using conventional methods in the field.

Claims

1. A bidirectional converter circuit based on alternating parallel half-bridge with co-coupled inductors, characterized in that: The system includes a high-voltage DC voltage source U1, two half-bridge circuits, a co-inverting inductor, a low-voltage DC voltage source U2, and a control circuit. The high-voltage DC voltage source U1 is electrically connected to the two half-bridge circuits. The two half-bridge circuits are electrically connected to the co-inverting inductor. The co-inverting inductor is electrically connected to the low-voltage DC voltage source U2. The pulse drive signal in the control circuit is electrically connected to the power MOSFETs in the two half-bridge circuits. The output current of the co-inverting inductor is electrically connected to the current feedback signal in the control circuit.

2. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 1, characterized in that: The two half-bridge circuits include power switches S1, S2, S3, and S4, freewheeling diodes D1, D2, D3, and D4; the positive terminal of the high-voltage DC voltage source U1 is connected to the drain of power switch S1 and the drain of power switch S3, respectively, and the negative terminal of the high-voltage DC voltage source U1 is connected to the source of power switch S2 and the source of power switch S4, respectively.

3. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 2, characterized in that: The drain and source of the power switch S1 are connected to the anode and cathode of the freewheeling diode D1, respectively; the drain and source of the power switch S2 are connected to the anode and cathode of the freewheeling diode D2, respectively; the drain and source of the power switch S3 are connected to the anode and cathode of the freewheeling diode D3, respectively; and the drain and source of the power switch S4 are connected to the anode and cathode of the freewheeling diode D4, respectively. The source of the power switch S1 is connected to the drain of the power switch S2; and the source of the power switch S3 is connected to the drain of the power switch S4.

4. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 3, characterized in that: The co-coupled inductor includes self-inductance L1 and self-inductance L2; one end of self-inductance L1 is connected to the source of the power switch S1, and one end of self-inductance L2 is connected to the source of the power switch S3.

5. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 4, characterized in that: The positive terminal of the low-voltage DC voltage source U2 is connected to the other end of the self-inductance L1 and self-inductance L2 included in the same-direction coupling inductor, and the negative terminal of the low-voltage DC voltage source U2 is connected to the source of the power switch S2 and the source of the power switch S4.

6. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 5, characterized in that: The control circuit includes a current regulator, PWM generator 1, PWM generator 2, frequency divider 1, frequency divider 2, and a circuit with a DC bias voltage u. bias carrier u tr .

7. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 6, characterized in that: The current i of the self-inductance L1 L1 With the current i of self-inductance L2 L2 The sum of i L and current reference value i ref Each is connected to the input terminal of the current regulator, and the current reference value i in the current regulator is... ref The current i of self-inductance L1 and self-inductance L2 L1 i L2 The sum of i L The difference is used to obtain the output control signal u through the current regulator. e And output control signal u e After inversion, another control signal -u is obtained. e .

8. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 7, characterized in that: The control signal u output by the current regulator e And another control control -u e It is connected to the non-inverting input terminal of PWM generator 1 and the non-inverting input terminal of PWM generator 2, respectively.

9. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 8, characterized in that: The DC bias voltage u bias carrier u tr It is connected to the inverting input terminal of PWM generator 1 and the inverting input terminal of PWM generator 2, respectively.

10. The bidirectional converter circuit based on interleaved parallel half-bridge with co-coupled inductors according to claim 9, characterized in that: The output of the PWM generator 1 is divided by a frequency divider 1 to obtain two drive signals with a 180° phase difference. gs1 and u gs2 The gates of the power switching transistors S1 and S3 are connected respectively; and the output of the PWM generator 2 obtains two drive signals u with a 180° phase difference via a frequency divider 2. gs2 and u gs4 It is connected to the gate of the power switch S2 and the gate of the power switch S4, respectively.

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