Modular cascade resonant DC-DC converter
By designing a modular cascaded resonant DC-DC converter, the capacity expansion and flexible control of medium and large-sized battery energy storage systems have been realized, solving the capacity expansion problem in existing technologies, improving system reliability and efficiency, and reducing switching losses.
Patent Information
- Application Number
- CN202423252983.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-12-27
AI Technical Summary
Existing isolated DC-DC converters are difficult to expand and flexibly control in medium and large-scale battery energy storage systems, and have large switching losses, as well as insufficient safety and reliability.
By adopting a modular cascaded resonant DC-DC converter and designing combined topology A and combined topology B, zero-voltage turn-on of fully controllable switching devices and zero-current turn-off of diodes are achieved. Combined with appropriate control methods, continuous adjustment of the output voltage across the entire range and soft-switching operation are realized.
This enables easy expansion and flexible control of medium and large-sized battery energy storage systems, improves system reliability and safety, reduces voltage stress on devices, and enhances the efficiency of the energy storage system.
Smart Images
Figure CN223666258U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of power electronics, especially relates to a modularization cascade resonant DC-DC converter. BACKGROUND
[0002] New energy power generation generally has the characteristics of volatility and intermittence, and when new energy power generation is connected to the grid, it will seriously affect the peak regulation and frequency regulation and stable operation of the power grid. By applying energy storage technology to the power system, the high power regulation flexibility and fast response speed of the energy storage device can be used to mitigate the adverse effects of new energy power generation on the power system. For medium and large battery energy storage systems, modularization technology can not only meet the needs of unified scheduling, but also easily realize voltage step-up and expansion, and can also realize flexible control through internal grouping, and has broad application prospects.
[0003] A battery energy storage system mainly consists of an energy storage battery and a power conversion system. The power conversion system is generally a power electronic converter, which undertakes the power conversion function of the entire energy storage system. In a direct-current microgrid, the power conversion system is composed of a DC-DC converter. Among them, the isolated DC-DC converter realizes electrical isolation between the input and output due to the presence of a transformer, effectively ensuring the safety of personnel and equipment. In existing isolated DC-DC converters, resonant converters have the ability to achieve soft switching, which can effectively reduce switching loss and have been widely valued and researched in the field of high-frequency power conversion. Among them, the LC series resonant converter can realize zero-voltage turn-on of all controlled switching devices and zero-current turn-off of all diodes through optimization of circuit parameters.
[0004] The utility model aims at providing a modularization cascade resonant DC-DC converter suitable for medium and large battery energy storage systems, which is easy to expand and realize flexible control through internal grouping, has the advantages of high reliability, high safety, and small voltage stress of devices, and through the use of appropriate control methods, the modularization cascade resonant DC-DC converter can realize full-range continuous regulation of output voltage and soft switching operation, all controlled switching devices have zero-voltage turn-on, all diodes have zero-current turn-off, and the energy storage system has high efficiency. UTILITY MODEL CONTENTS
[0005] The utility model provides a modularization cascade resonance DC-DC converter which comprises a main power circuit, the main power circuit includes an output capacitor C1, a load resistance R, N combination top A and a combination top B, wherein N is a positive integer, the combination top A includes a branch capacitor C0, two fully controlled switching devices S1, S2, a transformer TR, the first wiring terminal p of branch capacitor C0 is connected with the first wiring terminal p of fully controlled switching device S1, the second wiring terminal n of branch capacitor C0 is connected with the second wiring terminal n of fully controlled switching device S2, the second wiring terminal b of transformer TR primary winding side, fully controlled switching device S1 and fully controlled switching device S2 are located in the same bridge arm, the second wiring terminal n of fully controlled switching device S1 is connected with the first wiring terminal p of fully controlled switching device S2, the first wiring terminal a of transformer TR primary winding side, the secondary winding side of transformer TR includes the first wiring terminal c and the second wiring terminal d, the combination top B includes two ordinary diodes D1, D2, a resonance inductance L, two resonance capacitors C r , C r1 , C r2 , ordinary diode D1 and ordinary diode D2 are located in the same bridge arm, resonance capacitor C r1 And resonance capacitor C r2 Are located in the same bridge arm, the second wiring terminal n of resonance inductance L r Is connected with the first wiring terminal e of combination top B, the anode of ordinary diode D1, the cathode of ordinary diode D2, the cathode of ordinary diode D1 is connected with the first wiring terminal p of resonance capacitor C r1 , the first wiring terminal p of output capacitor C1, the first wiring terminal p of load resistance R, the second wiring terminal n of resonance capacitor C r1 Is connected with the first wiring terminal p of resonance capacitor C r2 , the second wiring terminal f of combination top B, the anode of ordinary diode D2 is connected with the second wiring terminal n of resonance capacitor C r2 , the second wiring terminal n of output capacitor C1, the second wiring terminal n of load resistance R, the main power circuit includes N combination top A, wherein the second wiring terminal n of branch capacitor C0 of each combination top A is connected with the first wiring terminal p of branch capacitor C0 of next combination top A in turn, the second wiring terminal d of transformer TR secondary winding side of each combination top A is connected with the first wiring terminal c of transformer TR secondary winding side of next combination top A in turn, the remaining four free ends of combination top A connected, namely the first wiring terminal p of branch capacitor C0 of first combination top A connects input voltage V inThe positive terminal, the second terminal n of the branch capacitor C0 of the Nth combined topology A, is connected to the input voltage V. in The negative terminal, the first terminal c on the secondary winding side of the transformer TR of the first combined topology A, and the resonant inductor L of the combined topology B. r The first terminal p is connected, and the second terminal d of the transformer TR secondary winding side of the Nth combined topology A is connected to the second terminal f of the combined topology B.
[0006] To achieve the above objectives, this utility model provides a modular cascaded resonant DC-DC converter, including a main power circuit. The main power circuit includes one output capacitor C1, one load resistor R, and N combined topologies C. Each combined topology C includes one branch capacitor C0, two fully controlled switching devices S1 and S2, one transformer TR, two ordinary diodes D1 and D2, and one resonant inductor L. r 2 resonant capacitors C r1 C r2 The first terminal p of the branch capacitor C0 is connected to the first terminal p of the fully controlled switching device S1. The second terminal n of the branch capacitor C0 is connected to the second terminal n of the fully controlled switching device S2 and the second terminal b of the primary winding side of the transformer TR. The fully controlled switching device S1 and the fully controlled switching device S2 are located in the same bridge arm. The second terminal n of the fully controlled switching device S1 is connected to the first terminal p of the fully controlled switching device S2 and the first terminal a of the primary winding side of the transformer TR. The ordinary diode D1 and the ordinary diode D2 are located in the same bridge arm. The resonant capacitor C... r1 With the resonant capacitor C r2 Located on the same bridge arm, the first terminal c of the secondary winding side of the transformer TR is connected to the resonant inductor L. r The first terminal p is connected, and the resonant inductor L r The second terminal n is connected to the anode of the ordinary diode D1 and the cathode of the ordinary diode D2, and the resonant capacitor C r1 The second terminal n is connected to the resonant capacitor C r2 The first terminal p of the transformer is connected to the second terminal d on the secondary winding side of the transformer TR. The cathode of the ordinary diode D1 is connected to the resonant capacitor C. r1 The first terminal p of the ordinary diode D2 is connected to the resonant capacitor C. r2 The second terminal n is connected; the main power circuit includes N combined topologies C, wherein the second terminal n of the branch capacitor C0 of each combined topology C is sequentially connected to the first terminal p of the branch capacitor C0 of the next combined topology C, and the resonant capacitor C of each combined topology C...r2 The second terminal n is connected to the resonant capacitor C of the next combined topology C. r1 The first terminal p of the combined topology C is connected in sequence, and the remaining four free terminals of the combined topology C are connected together. That is, the first terminal p of the branch capacitor C0 of the first combined topology C is connected to the input voltage V. in The positive terminal, the second terminal n of the branch capacitor C0 in the Nth combined topology C, is connected to the input voltage V. in Negative electrode, the first of the combined topologies C, the resonant capacitor C r1 The first terminal p is connected to the first terminal p of the output capacitor C1 and the first terminal p of the load resistor R. The Nth combined topology C contains the resonant capacitor C. r2 The second terminal n is connected to the second terminal n of the output capacitor C1 and the second terminal n of the load resistor R.
[0007] The advantages and positive effects of this modular cascaded resonant DC-DC converter are as follows: it is suitable for medium and large-scale battery energy storage systems. The proposed modular cascaded resonant DC-DC converter is easy to expand and can achieve flexible control through internal grouping. It has the advantages of high reliability, high safety, and low voltage stress on devices. Moreover, by adopting appropriate control methods, the proposed modular cascaded resonant DC-DC converter can achieve continuous adjustment of the output voltage across the entire range and soft-switching operation. All fully controlled switching devices can be turned on at zero voltage, and all diodes can be turned off at zero current, resulting in high efficiency of the energy storage system.
[0008] The present invention will now be described with reference to the accompanying drawings. Attached Figure Description
[0009] Figure 1 This is a circuit diagram of combined topology A in the modular cascaded resonant DC-DC converter of this utility model;
[0010] Figure 2 This is a circuit diagram of combined topology B in the modular cascaded resonant DC-DC converter of this utility model;
[0011] Figure 3 This is a circuit topology diagram of the first embodiment of the modular cascaded resonant DC-DC converter of this utility model;
[0012] Figure 4 This is a circuit diagram of the combined topology C in the modular cascaded resonant DC-DC converter of this utility model;
[0013] Figure 5 This is a circuit topology diagram of the second embodiment of the modular cascaded resonant DC-DC converter of this utility model. Detailed Implementation
[0014] The specific embodiments of the utility model are described in detail below with reference to the drawings to fully understand the purpose, features and effects of the utility model. The embodiments give detailed implementation and specific operation process, but the protection scope of the utility model is not limited to the embodiments.
[0015] Referring to Figure 1 , Figure 2 and Figure 3 , in the first embodiment of the modular cascaded resonant DC-DC converter of the utility model, the main power circuit comprises one output capacitor C1, one load resistor R, N combined topologies A and one combined topology B, wherein N is a positive integer, the combined topology A comprises one branch capacitor C0, two fully controlled switching devices S1 and S2, and one transformer TR; the first terminal p of the branch capacitor C0 is connected with the first terminal p of the fully controlled switching device S1, the second terminal n of the branch capacitor C0 is connected with the second terminal n of the fully controlled switching device S2 and the second terminal b of the primary winding side of the transformer TR, the fully controlled switching device S1 and the fully controlled switching device S2 are located in the same bridge arm, the second terminal n of the fully controlled switching device S1 is connected with the first terminal p of the fully controlled switching device S2 and the first terminal a of the primary winding side of the transformer TR, the secondary winding side of the transformer TR comprises the first terminal c and the second terminal d, the combined topology B comprises two ordinary diodes D1 and D2, one resonant inductor L r , two resonant capacitors C r1 , r2 , the ordinary diode D1 and the ordinary diode D2 are located in the same bridge arm, the resonant capacitor C r1 and the resonant capacitor C r2 are located in the same bridge arm, the second terminal n of the resonant inductor L r is connected with the first terminal e of the combined topology B, the anode of the ordinary diode D1 and the cathode of the ordinary diode D2, the cathode of the ordinary diode D1 is connected with the first terminal p of the resonant capacitor C r1 , the first terminal p of the output capacitor C1 and the first terminal p of the load resistor R, the second terminal n of the resonant capacitor C r1 is connected with the first terminal p of the resonant capacitor C r2 , the second terminal f of the combined topology B, and the anode of the ordinary diode D2 is connected with the resonant capacitor C r2the second terminal n of the output capacitor C1, the second terminal n of the load resistor R are connected; the main power circuit comprises N combined topologies A, the second terminal n of the branch capacitor C0 of each combined topology A is connected with the first terminal p of the branch capacitor C0 of the next combined topology A in turn, the second terminal d of the secondary winding side of the transformer TR of each combined topology A is connected with the first terminal c of the secondary winding side of the transformer TR of the next combined topology A in turn, the remaining four free terminals of the combined topologies A connected, namely the first terminal p of the branch capacitor C0 of the first combined topology A is connected with the input voltage V in the positive electrode, the second terminal n of the branch capacitor C0 of the Nth combined topology A is connected with the input voltage V in the negative electrode, the first terminal c of the secondary winding side of the transformer TR of the first combined topology A is connected with the first terminal p of the resonant inductor L r of the combined topology B, the second terminal d of the secondary winding side of the transformer TR of the Nth combined topology A is connected with the second terminal f of the combined topology B.
[0016] Referring to Figure 4 and Figure 5 , in the second embodiment of the modular cascaded resonant DC-DC converter, the main power circuit comprises one output capacitor C1, one load resistor R, N combined topologies C, the combined topology C comprises one branch capacitor C0, two fully-controlled switching devices S1, S2, one transformer TR, two ordinary diodes D1, D2, one resonant inductor L r , two resonant capacitors C r1 , C r2 ; the first terminal p of the branch capacitor C0 is connected with the first terminal p of the fully-controlled switching device S1, the second terminal n of the branch capacitor C0 is connected with the second terminal n of the fully-controlled switching device S2 and the second terminal b of the primary winding side of the transformer TR, the fully-controlled switching device S1 and the fully-controlled switching device S2 are located in the same bridge arm, the second terminal n of the fully-controlled switching device S1 is connected with the first terminal p of the fully-controlled switching device S2 and the first terminal a of the primary winding side of the transformer TR, the ordinary diode D1 and the ordinary diode D2 are located in the same bridge arm, the resonant capacitor C r1 and the resonant capacitor C r2 are located in the same bridge arm, the first terminal c of the secondary winding side of the transformer TR is connected with the first terminal p of the resonant inductor L r , the second terminal n of the resonant inductor L r is connected with the anode of the ordinary diode D1 and the cathode of the ordinary diode D2, the second terminal n of the resonant capacitor C r1 is connected with the second terminal n of the resonant capacitor C r2The first terminal p of the common diode D1 is connected with the second terminal d of the transformer TR secondary winding side, and the cathode of the common diode D1 is connected with the second terminal n of the resonant capacitor C r1 The anode of the common diode D2 is connected with the first terminal p of the resonant capacitor C r2 The second terminal n of the resonant capacitor C r2 The second terminal n of the resonant capacitor C r1 The first terminal p of the resonant capacitor C in The first terminal p of the resonant capacitor C in The first terminal p of the resonant capacitor C r1 The first terminal p of the resonant capacitor C r2 The second terminal n of the resonant capacitor C
[0017] The modular cascaded resonant DC-DC converter has the advantages that it is suitable for a medium / large battery energy storage system, is easy to expand, realizes flexible control through internal grouping, has the advantages of high reliability, high safety, and small voltage stress of devices, and through appropriate control methods, the modular cascaded resonant DC-DC converter can realize full-range continuous regulation of output voltage and soft switching operation, all the fully controlled switching devices are zero-voltage turned on, all the diodes are zero-current turned off, and the energy storage system has high efficiency.
[0018] The above-described embodiments are merely preferred embodiments of the utility model, and do not limit the concept and scope of the utility model, and various modifications and improvements of the technical scheme of the utility model made by engineering technicians in the field without departing from the design scheme of the utility model shall fall within the protection scope of the utility model, and the technical content of the utility model claimed for protection has been recorded in the claims.
Claims
1. A modular cascaded resonant DC-DC converter, characterized in that, The system includes a main power circuit, comprising one output capacitor C1, one load resistor R, N combined topologies A and one combined topology B, where N is a positive integer. Combined topology A includes one branch capacitor C0, two fully controlled switching devices S1 and S2, and one transformer TR. The first terminal p of the branch capacitor C0 is connected to the first terminal p of the fully controlled switching device S1. The second terminal n of the branch capacitor C0 is connected to the second terminal n of the fully controlled switching device S2 and the second terminal b of the primary winding side of the transformer TR. The fully controlled switching devices S1 and S2 are located in the same bridge arm. The second terminal n of the fully controlled switching device S1 is connected to the first terminal p of the fully controlled switching device S2 and the first terminal a of the primary winding side of the transformer TR. The secondary winding side of the transformer TR includes a first terminal c and a second terminal d. Combined topology B includes two ordinary diodes D1 and D2 and one resonant inductor L. r 2 resonant capacitors C r1 C r2 The ordinary diode D1 and the ordinary diode D2 are located in the same bridge arm, and the resonant capacitor C r1 With the resonant capacitor C r2 Located in the same bridge arm, the resonant inductor L r The second terminal n is connected to the first terminal e of the combined topology B, the anode of the ordinary diode D1, and the cathode of the ordinary diode D2. The cathode of the ordinary diode D1 is connected to the resonant capacitor C. r1 The first terminal p of the output capacitor C1 and the first terminal p of the load resistor R are connected together, and the resonant capacitor C r1 The second terminal n is connected to the resonant capacitor C r2 The first terminal p of the diode is connected to the second terminal f of the combined topology B, and the anode of the ordinary diode D2 is connected to the resonant capacitor C. r2 The second terminal n of the output capacitor C1 and the second terminal n of the load resistor R are connected; the main power circuit includes N combined topologies A, wherein the second terminal n of the branch capacitor C0 of each combined topology A is sequentially connected to the first terminal p of the branch capacitor C0 of the next combined topology A, and the second terminal d of the transformer TR secondary winding side of each combined topology A is sequentially connected to the first terminal c of the transformer TR secondary winding side of the next combined topology A. The remaining four free terminals of the combined topology A, i.e., the first terminal p of the branch capacitor C0 of the first combined topology A, are connected to the input voltage V. in The positive terminal, the second terminal n of the branch capacitor C0 of the Nth combined topology A, is connected to the input voltage V. in The negative terminal, the first terminal c on the secondary winding side of the transformer TR of the first combined topology A, and the resonant inductor L of the combined topology B. r The first terminal p is connected, and the second terminal d of the transformer TR secondary winding side of the Nth combined topology A is connected to the second terminal f of the combined topology B.
2. A modular cascaded resonant DC-DC converter, characterized in that, The circuit includes a main power circuit, which comprises one output capacitor C1, one load resistor R, and N combined topologies C. Each combined topology C includes one branch capacitor C0, two fully controlled switching devices S1 and S2, one transformer TR, two ordinary diodes D1 and D2, and one resonant inductor L. r 2 resonant capacitors C r1 C r2 The first terminal p of the branch capacitor C0 is connected to the first terminal p of the fully controlled switching device S1. The second terminal n of the branch capacitor C0 is connected to the second terminal n of the fully controlled switching device S2 and the second terminal b of the primary winding side of the transformer TR. The fully controlled switching device S1 and the fully controlled switching device S2 are located in the same bridge arm. The second terminal n of the fully controlled switching device S1 is connected to the first terminal p of the fully controlled switching device S2 and the first terminal a of the primary winding side of the transformer TR. The ordinary diode D1 and the ordinary diode D2 are located in the same bridge arm. The resonant capacitor C... r1 With the resonant capacitor C r2 Located on the same bridge arm, the first terminal c of the secondary winding side of the transformer TR is connected to the resonant inductor L. r The first terminal p is connected, and the resonant inductor L r The second terminal n is connected to the anode of the ordinary diode D1 and the cathode of the ordinary diode D2, and the resonant capacitor C r1 The second terminal n is connected to the resonant capacitor C r2 The first terminal p of the transformer is connected to the second terminal d on the secondary winding side of the transformer TR. The cathode of the ordinary diode D1 is connected to the resonant capacitor C. r1 The first terminal p of the ordinary diode D2 is connected to the resonant capacitor C. r2 The second terminal n is connected; the main power circuit includes N combined topologies C, wherein the second terminal n of the branch capacitor C0 of each combined topology C is sequentially connected to the first terminal p of the branch capacitor C0 of the next combined topology C, and the resonant capacitor C of each combined topology C... r2 The second terminal n is connected to the resonant capacitor C of the next combined topology C. r1 The first terminal p of the combined topology C is connected in sequence, and the remaining four free terminals of the combined topology C are connected together. That is, the first terminal p of the branch capacitor C0 of the first combined topology C is connected to the input voltage V. in The positive terminal, the second terminal n of the branch capacitor C0 in the Nth combined topology C, is connected to the input voltage V. in Negative electrode, the first of the combined topologies C, the resonant capacitor C r1 The first terminal p is connected to the first terminal p of the output capacitor C1 and the first terminal p of the load resistor R. The Nth combined topology C contains the resonant capacitor C. r2 The second terminal n is connected to the second terminal n of the output capacitor C1 and the second terminal n of the load resistor R.