A bidirectional DC power supply topology circuit

Abstract

The invention discloses a bidirectional direct current power supply topology circuit, which belongs to the technical field of power supply circuits, and specifically comprises a first primary filter capacitor, a second secondary filter capacitor, a first primary filter inductor, a second secondary filter inductor, a first primary filter inductor short-circuit device, a second primary filter inductor short-circuit device, a third secondary filter inductor short-circuit device, a fourth secondary filter inductor short-circuit device, a first primary full-bridge power tube, a second primary full-bridge power tube, a third primary full-bridge power tube, a fourth primary full-bridge power tube, a first primary resonant inductor, a second secondary resonant inductor, a first isolation transformer, a first secondary full-bridge power tube, a second secondary full-bridge power tube, a third secondary full-bridge power tube and a fourth secondary full-bridge power tube; the circuit has the characteristics of simple design, high efficiency, high power density and high dynamic response, so as to solve various problems existing in the current bidirectional direct current power supply topology.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supply circuits, and particularly relates to a bidirectional DC power supply topology circuit. Background Art

[0002] In recent years, DC power conversion technology has advanced by leaps and bounds. In particular, wide bandgap devices have greatly promoted the development of DC power supplies, which are moving towards bidirectional power flow, high efficiency, high power density, and high dynamic response. Although there are already many topologies for bidirectional DC power supplies, such as CLLC, CLLC+SR-BUCK, or DAB / DHB, the above three topologies all have some drawbacks. First of all, although the single-stage CLLC can achieve bidirectional power flow and ensure ZVS at the same time, it has the same drawbacks as the LLC topology, with limited wide-range operating ability, a sharp decline in efficiency after leaving the optimal operating point, and poor dynamic response, making it unable to adapt to high-dynamic loads. Secondly, the CLLC+SR-BUCK topology combines the ZVS CLLC with a synchronous rectifier BUCK, which can achieve high dynamic response. However, after all, it is a two-stage topology, and the synchronous rectifier BUCK cannot achieve ZVS, which limits the efficiency of this topology and the switching frequency cannot be increased either. Moreover, the DAB / DHB can achieve ZVS within a certain range and can also ensure high dynamic response. However, the DAB / DHB realizes power control based on the phase-shift angle, and there is a non-linear control relationship between the phase-shift angle and the power flow. In addition, the two full bridges / half bridges of the DAB / DHB are directly connected to the input and output DC sources, resulting in high-frequency ripple current operation states for both the two ends of the source and the load during bidirectional operation. Generally, the low-voltage side of the bidirectional DC power supply is connected to a battery-like energy storage load, and the high-voltage side is generally connected to the output of a bidirectional ACDC. Generally speaking, the output of the bidirectional ACDC can withstand a certain amount of high-frequency ripple current and has little impact on the system performance. However, the low-voltage side generally requires low ripple current to prevent some negative impacts on battery-like loads. Although there is also a type of current-mode DAB / DHB that can achieve low current ripple on the low-voltage side, generally isolated capacitors are used for voltage clamping, and these isolated capacitors are not directly connected to the source and the load. Such a configuration will reduce the power supply's tolerance to power fluctuations because the voltage of the isolated capacitor completely depends on the power transistors for regulation. At the same time, this type of DAB / DHB still has the problem of non-linear control, increasing the design complexity of the controller and also having certain difficulties in parameter design. From the above analysis, it can be seen that the existing several bidirectional DC power supply topologies all have certain drawbacks and cannot achieve high dynamic response, high efficiency, high power density, and simple design at the same time. Infineon has adopted a new idea in the latest bidirectional phase-shifted full-bridge reference design to implement a bidirectional power supply. Using the phase-shifted full-bridge topology, the normal operating state is the BUCK mode, and the BUCK mode is the traditional phase-shifted full-bridge soft-switching topology. At the same time, this reference design can also work in the BOOST mode. The BOOST mode uses a secondary synchronous rectifier tube to achieve the isolation BOOST operating mode, and the primary MOSFET is used as a synchronous rectifier tube to improve efficiency.However, in the BOOST mode, the low-voltage side is in a hard-switching BOOST state, resulting in a decrease in the efficiency of the BOOST mode, an increase in device stress, and a reduction in reliability. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to propose a brand-new bidirectional DC power supply topology circuit in view of the deficiencies of the background technology, which has the characteristics of simple design, high efficiency, high power density, and high dynamic response, so as to solve various problems existing in the current bidirectional DC power supply topology.

[0004] The present invention adopts the following technical solutions to solve the above technical problems: A bidirectional DC power supply topology circuit includes a first primary filter capacitor C1, a second secondary filter capacitor C2, a first primary filter inductor L1, a second secondary filter inductor L2, a first primary filter inductor short-circuit device SL1, a second primary filter inductor short-circuit device SL2, a third secondary filter inductor short-circuit device SL3, a fourth secondary filter inductor short-circuit device SL4, a first primary full-bridge power transistor SP1, a second primary full-bridge power transistor SP2, a third primary full-bridge power transistor SP3, a fourth primary full-bridge power transistor SP4, a first primary resonant inductor Lr1, a second secondary resonant inductor Lr2, a first isolation transformer T1, a first secondary full-bridge power transistor SS1, a second secondary full-bridge power transistor SS2, a third secondary full-bridge power transistor SS3, and a fourth secondary full-bridge power transistor SS4.

[0005] Among them, one end of the first primary filter capacitor C1 is respectively connected to one end of the first primary filter inductor L1, one end of the first primary filter inductor short-circuit device SL1, the other end of the first primary filter inductor short-circuit device SL1 is connected to one end of the second primary filter inductor short-circuit device SL2, and the other end of the first primary filter inductor L1 is respectively connected to the other end of the second primary filter inductor short-circuit device SL2, one end of the first primary full-bridge power transistor SP1, and one end of the third primary full-bridge power transistor SP3. The other end of one end of the first primary full-bridge power transistor SP1 is respectively connected to one end of the second primary full-bridge power transistor SP2 and one end of the first primary resonant inductor Lr1. The other end of the second primary full-bridge power transistor SP2 is respectively connected to the other end of the first primary filter capacitor C1 and one end of the fourth primary full-bridge power transistor SP4. The other end of the fourth primary full-bridge power transistor SP4 is respectively connected to the other end of the third primary full-bridge power transistor SP3 and the a end of the first isolation transformer T1. The other end of the first primary resonant inductor Lr1 is connected to the b end of the first isolation transformer T1. The c end of the first isolation transformer T1 is respectively connected to one end of the third secondary full-bridge power transistor SS3 and one end of the fourth secondary full-bridge power transistor SS4. The d end of the first isolation transformer T1 is connected to one end of the second secondary resonant inductor Lr2. The other end of the second secondary resonant inductor Lr2 is respectively connected to one end of the first secondary full-bridge power transistor SS1 and one end of the second secondary full-bridge power transistor SS2. The other end of the first secondary full-bridge power transistor SS1 is respectively connected to the other end of the third secondary full-bridge power transistor SS3, one end of the second secondary filter inductor L2, and one end of the third secondary filter inductor short-circuit device SL3. The other end of the third secondary filter inductor short-circuit device SL3 is connected to one end of the fourth secondary filter inductor short-circuit device SL4. The other end of the fourth secondary filter inductor short-circuit device SL4 is respectively connected to the other end of the second secondary filter inductor L2 and one end of the second secondary filter capacitor C2. The other end of the second secondary filter capacitor C2 is respectively connected to the other end of the fourth secondary full-bridge power transistor SS4 and the other end of the second secondary full-bridge power transistor SS2.

[0006] Compared with the prior art, the present invention adopts the above technical solutions and has the following technical effects:

[0007] The present invention patent for invention proposes a bidirectional DC power supply topology, which has a simple design and can achieve ZVS at the same time to ensure high efficiency and high power density. In addition, this topology is derived from the phase-shifted full-bridge, thus ensuring that this topology has excellent voltage regulation ability and fast dynamic response. Detailed implementation manners

[0008] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0009] The present invention provides a bidirectional DC power supply topology circuit, which includes a first primary filter capacitor C1, a second secondary filter capacitor C2, a first primary filter inductor L1, a second secondary filter inductor L2, a first primary filter inductor shorting device SL1, a second primary filter inductor shorting device SL2, a third secondary filter inductor shorting device SL3, a fourth secondary filter inductor shorting device SL4, a first primary full-bridge power transistor SP1, a second primary full-bridge power transistor SP2, a third primary full-bridge power transistor SP3, a fourth primary full-bridge power transistor SP4, a first primary resonant inductor Lr1, a second secondary resonant inductor Lr2, a first isolation transformer T1, a first secondary full-bridge power transistor SS1, a second secondary full-bridge power transistor SS2, a third secondary full-bridge power transistor SS3, and a fourth secondary full-bridge power transistor SS4.

[0010] Among them, one end of the first primary filter capacitor C1 is respectively connected to one end of the first primary filter inductor L1, one end of the first primary filter inductor short-circuit device SL1, and the other end of the first primary filter inductor short-circuit device SL1 is connected to one end of the second primary filter inductor short-circuit device SL2. The other end of the first primary filter inductor L1 is respectively connected to the other end of the second primary filter inductor short-circuit device SL2, one end of the first primary full-bridge power transistor SP1, and one end of the third primary full-bridge power transistor SP3. The other end of one end of the first primary full-bridge power transistor SP1 is respectively connected to one end of the second primary full-bridge power transistor SP2 and one end of the first primary resonant inductor Lr1. The other end of the second primary full-bridge power transistor SP2 is respectively connected to the other end of the first primary filter capacitor C1 and one end of the fourth primary full-bridge power transistor SP4. The other end of the fourth primary full-bridge power transistor SP4 is respectively connected to the other end of the third primary full-bridge power transistor SP3 and the a end of the first isolation transformer T1. The other end of the first primary resonant inductor Lr1 is connected to the b end of the first isolation transformer T1. The c end of the first isolation transformer T1 is respectively connected to one end of the third secondary full-bridge SS3 and one end of the fourth secondary full-bridge power transistor SS4. The d end of the first isolation transformer T1 is connected to one end of the second secondary resonant inductor Lr2. The other end of the second secondary resonant inductor Lr2 is respectively connected to one end of the first secondary full-bridge power transistor SS1 and one end of the second secondary full-bridge power transistor SS2. The other end of the first secondary full-bridge power transistor SS1 is respectively connected to the other end of the third secondary full-bridge power transistor SS3, one end of the second secondary filter inductor L2, and one end of the third secondary filter inductor short-circuit device SL3. The other end of the third secondary filter inductor short-circuit device SL3 is connected to one end of the fourth secondary filter inductor short-circuit device SL4. The other end of the fourth secondary filter inductor short-circuit device SL4 is respectively connected to the other end of the second secondary filter inductor L2 and one end of the second secondary filter capacitor C2. The other end of the second secondary filter capacitor C2 is respectively connected to the other end of the fourth secondary full-bridge power transistor SS4 and the other end of the second secondary full-bridge power transistor SS2.

[0011] When in the BUCK mode, that is, when power flows from the primary side to the secondary side, the first primary filter inductor shorting device SL1 and the second primary filter inductor shorting device SL2 are driven to turn on, thus shorting the first primary filter inductor L1. The third secondary filter inductor shorting device SL3 and the fourth secondary filter inductor shorting device SL4 are driven to turn off, and the second secondary filter inductor L2 remains in series in the secondary side loop. The power flows from the primary side to the secondary side in accordance with the traditional phase-shifted full-bridge mode, while achieving ZVS and fast dynamic response. The first primary full-bridge power transistor SP1, the second primary full-bridge power transistor SP2, the third primary full-bridge power transistor SP3, and the fourth primary full-bridge power transistor SP4 are in the traditional phase-shifted full-bridge mode, and the first secondary full-bridge power transistor SS1, the second secondary full-bridge power transistor SS2, the third secondary full-bridge power transistor SS3, and the fourth secondary full-bridge power transistor SS4 are in the synchronous rectification mode.

[0012] When in the BOOST mode, that is, when power flows from the secondary side to the primary side, the third secondary filter inductor shorting device SL3 and the fourth secondary filter inductor shorting device SL4 are driven to turn on, thus shorting the second secondary filter inductor L2. The first primary filter inductor shorting device SL1 and the second primary filter inductor shorting device SL2 are driven to turn off, and the first primary filter inductor L1 remains in series in the primary side loop. The power flows from the secondary side to the primary side in accordance with the traditional phase-shifted full-bridge mode, while achieving ZVS and fast dynamic response. The first secondary full-bridge power transistor SS1, the second secondary full-bridge power transistor SS2, the third secondary full-bridge power transistor SS3, and the fourth secondary full-bridge power transistor SS4 are in the traditional phase-shifted full-bridge mode, and the first primary full-bridge power transistor SP1, the second primary full-bridge power transistor SP2, the third primary full-bridge power transistor SP3, and the fourth primary full-bridge power transistor SP4 are in the synchronous rectification mode.

[0013] From the above analysis, it can be seen that due to the complete symmetry of the primary and secondary sides of the topology, it fully possesses the characteristics of a bidirectional phase-shifted full-bridge. The power flows bidirectionally, and the eight MOSFETs on the primary and secondary sides can achieve ZVS simultaneously under a certain power condition. At the same time, it inherits the characteristics of a simple phase-shifted full-bridge design, small output current ripple, and wide-range regulation ability, making it an ideal topology for a bidirectional DC power supply.

[0014] In some cases, if real-time bidirectional power flow is not required, the first primary filter inductor shorting device SL1, the second primary filter inductor shorting device SL2, the third secondary filter inductor shorting device SL3, and the fourth secondary filter inductor shorting device SL4 can be replaced by electromagnetic relays, solid-state relays, or thyristors to meet different requirements under different applications. In addition, the primary and secondary resonant inductors can be realized by using the leakage inductance of the transformer to achieve true primary and secondary side symmetry. Of course, discrete inductors can also be used to reduce the design difficulty of the transformer.

[0015] All MOSFETs in the above topology can be replaced by different power devices such as IGBTs, Si, or GaN, so as to meet the differentiated requirements of different efficiencies, different power densities, and different costs, and further improve the adaptability of the topology.

[0016] Using a digital controller such as DSP or FPGA, seamless switching between BUCK / BOOST states can be easily achieved, so as to provide fast dynamic response for the load and truly realize a high-efficiency, high-power-density, single-stage, high-dynamic-response bidirectional DC power supply.

[0017] The following variants are all obtained by simple modifications based on this patent and should fall within the scope of protection of this patent: capacitors are connected in series on one or both sides of the primary side and the secondary side, and the capacitors are in an equivalent series relationship with the resonant inductor. Regardless of the series order of the capacitors, the resonant inductor, and the transformer, they all fall within the scope of this modification; one or both of the first primary filter inductor L1 and the second secondary filter inductor L2 are short-circuited in other ways, including but not limited to the following methods: electromagnetic relays, solid-state relays, thyristors, power transistors, IGBTs, Si-MOSFETs, SiC / GaN MOSFETs, or possible hybrid combination schemes, etc.; one or both of the first primary filter inductor L1 and the second secondary filter inductor L2 are replaced by the primary / secondary side of a current sensor; the resonant inductor may be integrated into the isolation transformer, or may be realized by a discrete inductor, or by means of a PCB winding inductor, PCB parasitic inductor, etc., or a hybrid implementation of the above methods; all switching devices have various possible combinations, such as high-voltage-side IGBTs and low-voltage-side Si-MOSFETs, etc.; high-voltage-side SiC and low-voltage-side Si-MOSFETs; high-voltage-side GaN and low-voltage-side Si-MOSFETs, etc. All these combinations are simple modifications based on this patent and fall within the scope of protection of this patent; some capacitors are inserted between the first primary filter inductor L1, the second secondary filter inductor L2, and the corresponding full bridge; common-mode and differential-mode filters are added to the input or output; a multi-port converter implemented using the same design concept, mainly using a transformer to realize various numbers of primary and secondary winding turns, thereby realizing the multi-port converter; various possible modifications are made to the phase-shifted full bridge, such as diode clamping (two types: Tr-Lead and Tr-Lag), or replacing the current ZVS phase-shifted full bridge topology with a ZVZCS full bridge topology, etc.; other possible simple modifications.

[0018] Those skilled in the art can understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention pertains. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with their meaning in the context of the prior art, and will not be interpreted in an idealized or overly formal sense unless defined as such here.

[0019] The above embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the present invention. The above has made a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made without departing from the gist of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A bidirectional DC power supply topology circuit, characterized in that: It includes a first primary filter capacitor C1, a second secondary filter capacitor C2, a first primary filter inductor L1, a second secondary filter inductor L2, a first primary filter inductor short-circuit device SL1, a second primary filter inductor short-circuit device SL2, a third secondary filter inductor short-circuit device SL3, a fourth secondary filter inductor short-circuit device SL4, a first primary full-bridge power tube SP1, a second primary full-bridge power tube SP2, a third primary full-bridge power tube SP3, a fourth primary full-bridge power tube SP4, a first primary resonant inductor Lr1, a second secondary resonant inductor Lr2, a first isolation transformer T1, a first secondary full-bridge power tube SS1, a second secondary full-bridge power tube SS2, a third secondary full-bridge power tube SS3 and a fourth secondary full-bridge power tube SS4; Among them, one end of the first primary filter capacitor C1 is respectively connected to one end of the first primary filter inductor L1 and one end of the first primary filter inductor short-circuit device SL1, the other end of the first primary filter inductor short-circuit device SL1 is respectively connected to one end of the second primary filter inductor short-circuit device SL2, the other end of the first primary filter inductor L1 is respectively connected to the other end of the second primary filter inductor short-circuit device SL2, one end of the first primary full-bridge power tube SP1, and one end of the third primary full-bridge power tube SP3, the other end of one end of the first primary full-bridge power tube SP1 is respectively connected to one end of the second primary full-bridge power tube SP2 and one end of the first primary resonant inductor Lr1, the other end of the second primary full-bridge power tube SP2 is respectively connected to the other end of the first primary filter capacitor C1 and one end of the fourth primary full-bridge power tube SP4, the other end of the fourth primary full-bridge power tube SP4 is respectively connected to the other end of the third primary full-bridge power tube SP3 and the a end of the first isolation transformer T1, and the other end of the first primary resonant inductor Lr1 is connected to the b end of the first isolation transformer T1. The first isolation transformer T1 has a first end connected to the first secondary full-bridge power tube SS3 and a second end connected to the fourth secondary full-bridge power tube SS4. The first isolation transformer T1 has a second end connected to the first secondary full-bridge power tube SS1 and a second end connected to the second secondary full-bridge power tube SS2. The first secondary full-bridge power tube SS1 has a second end connected to the third secondary full-bridge power tube SS3, a second secondary filter inductor L2 and a third secondary filter inductor short-circuit device SL3. The third secondary filter inductor short-circuit device SL3 has a second end connected to the fourth secondary filter inductor short-circuit device SL4. The fourth secondary filter inductor short-circuit device SL4 has a second end connected to the second secondary filter inductor L2 and a second secondary filter capacitor C2. The second secondary filter capacitor C2 has a second end connected to the fourth secondary full-bridge power tube SS4 and a second secondary full-bridge power tube SS2. When in BUCK mode, that is, power flows from the primary side to the secondary side, the first primary side filter inductor short-circuit device SL1 and the second primary side filter inductor short-circuit device SL2 are driven to open, thereby short-circuiting the first primary side filter inductor L1, and the third secondary side filter inductor short-circuit device SL3 and the fourth secondary side filter inductor short-circuit device SL4 are driven to close, and the second secondary side filter inductor L2 is still connected in series in the secondary side loop; When in BOOST mode, that is, power flows from the secondary side to the primary side, the third secondary side filter inductor short-circuit device SL3 and the fourth secondary side filter inductor short-circuit device SL4 are driven to open, thereby short-circuiting the second secondary side filter inductor L2, and the first primary side filter inductor short-circuit device SL1 and the second primary side filter inductor short-circuit device SL2 are driven to close, and the first primary side filter inductor L1 is still connected in series in the primary side loop; Use digital controller DSP or FPGA to achieve seamless switching of BUCK / BOOST status.