A pulse charging circuit, pulse charging device
By combining a full-bridge rectifier circuit and a full-bridge resonant converter with a main controller, and adjusting the switching frequency and duty cycle, fast and accurate charging of the pulse capacitor is achieved. This solves the problem of difficult control of output fluctuation range in existing technologies and is suitable for high-precision charging requirements.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI YANFU TECHNOLOGY CO LTD
- Filing Date
- 2025-05-23
- Publication Date
- 2026-06-12
AI Technical Summary
Existing pulse charging circuits have difficulty precisely controlling the output fluctuation range and cannot meet the load capacitance requirements for high charging accuracy.
By employing a full-bridge rectifier circuit and a full-bridge resonant converter, combined with the main controller to adjust the switching frequency and duty cycle, cross-charging of large and small pulses is achieved. Through fast charging with large pulse width pulses and precise charging with small pulse width pulses, the voltage is controlled to regulate at different stages.
It achieves a balance between pulse capacitor charging speed and charging accuracy, with a simple topology and clear control logic, making it suitable for high-precision charging requirements.
Smart Images
Figure CN224355875U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pulse charging technology, and in particular to a pulse charging circuit and a pulse charging device. Background Technology
[0002] Pulse charging power supplies are charging devices for pulse capacitors and are widely used in modulators, pulsed lasers, and other fields requiring high pulse energy output. The main topology of pulse charging power supplies typically includes series resonant, parallel resonant, or a combination of series and parallel resonant structures. Among these, charging power supplies based on series resonant topologies are more widely used in pulse capacitor charging applications because they possess constant current charging characteristics, can adapt to different load impedance variations, and also feature high charging efficiency, high power density, and soft-switching capabilities, reducing switching losses and improving device reliability and lifespan.
[0003] like Figure 1 As shown, this is a charging power supply for an existing LC series resonant converter, which is the most widely used charging power supply topology in the field. However, the existing pulse charging circuit is affected by the resonant parameters and the target voltage requirements of the load capacitor, resulting in the inability to precisely control the fluctuation range of its output, making it difficult to meet the needs of load capacitors with high charging accuracy requirements. Utility Model Content
[0004] To address the technical problems existing in the prior art, the purpose of this utility model is to provide a pulse charging circuit and a pulse charging device. The pulse charging circuit can effectively balance the charging speed and charging accuracy of the pulse capacitor, has a simple topology and simple control logic, and is more promising for application.
[0005] The objective of this utility model is achieved through the following technical solution:
[0006] In a first aspect, this utility model provides a pulse charging circuit, the pulse charging circuit comprising:
[0007] A full-bridge rectifier circuit, wherein the full-bridge rectifier circuit is connected to the load;
[0008] A full-bridge resonant converter, wherein the full-bridge resonant converter is connected to the full-bridge rectifier circuit, and the full-bridge resonant converter has a full-bridge converter function;
[0009] A main controller is connected to the full-bridge resonant converter and is configured to adjust the switching frequency and switching duty cycle of the full-bridge converter to switch the operating state of the full-bridge converter.
[0010] In conjunction with the first aspect, this utility model also provides a first specific embodiment of the first aspect, wherein the full-bridge resonant converter includes a full-bridge converter, a resonant circuit, and an isolation transformer connected in sequence, the full-bridge converter is connected to an external power supply, and the isolation transformer is connected to the full-bridge resonant circuit.
[0011] In conjunction with the first aspect, this utility model also provides a second specific embodiment of the first aspect, wherein the full-bridge converter has a first operating state and a second operating state:
[0012] In the first operating state, the switching frequency of the full-bridge converter is lower than the resonant frequency setting of the resonant circuit;
[0013] In the second operating state, the full-bridge converter maintains the switching frequency of the first operating state, and the switching duty cycle of the full-bridge converter in the second operating state is lower than the switching duty cycle setting in the first operating state.
[0014] In conjunction with the first aspect, this utility model also provides a third specific embodiment of the first aspect, wherein the full-bridge converter has four insulated-gate bipolar transistors, each insulated-gate bipolar transistor is connected in parallel with a diode, the anode of the diode is connected to the emitter of the insulated-gate bipolar transistor, and the cathode of the diode is connected to the collector of the insulated-gate bipolar transistor.
[0015] In conjunction with the first aspect, this utility model also provides a fourth specific embodiment of the first aspect, wherein the resonant circuit includes a resonant inductor and a resonant capacitor, the resonant inductor is connected to a full-bridge converter, and the resonant inductor is connected to one end of the primary winding of an isolation transformer;
[0016] The resonant capacitor is connected to the full-bridge converter, and the resonant capacitor is connected to the other end of the primary winding of the isolation transformer.
[0017] In conjunction with the first aspect, this utility model also provides a fifth specific embodiment of the first aspect, wherein the full-bridge rectifier circuit adopts a bridge rectifier circuit consisting of four diodes, and the full-bridge rectifier circuit is connected to the secondary winding of the isolation transformer of the full-bridge resonant converter.
[0018] In conjunction with the first aspect, this utility model also provides a sixth specific embodiment of the first aspect, wherein the pulse charging circuit further includes a DC power supply, which is connected to the full-bridge resonant converter and the main controller respectively.
[0019] In conjunction with the first aspect, this utility model also provides a seventh specific embodiment of the first aspect, wherein the DC power supply includes a three-phase totem pole bridgeless PFC circuit, a synchronous BUCK circuit and an LC filter circuit connected in sequence, and the LC filter circuit is connected to the full-bridge resonant converter.
[0020] Secondly, this utility model also provides a pulse charging device, which includes the pulse charging circuit described in the first aspect and the first to seventh specific embodiments of the first aspect.
[0021] Compared with the prior art, the present invention has at least the following beneficial effects:
[0022] This utility model provides a pulse charging circuit, which includes a full-bridge rectifier circuit, a full-bridge resonant converter, and a main controller. The full-bridge rectifier circuit is connected to the load; the full-bridge resonant converter is connected to the full-bridge rectifier circuit and has the function of a full-bridge converter; the main controller is connected to the full-bridge resonant converter and is configured to adjust the switching frequency and switching duty cycle of the full-bridge converter to switch the operating state of the full-bridge converter.
[0023] This invention utilizes an LC resonant circuit to achieve alternating large and small pulse charging. The main controller regulates the charging process by adjusting the switching frequency and duty cycle of the full-bridge converter, enabling fast charging with large pulse widths and precise charging with small pulse widths, thus allowing for voltage regulation at different charging stages. This pulse charging circuit effectively balances charging speed and accuracy, features a simple topology and control logic, and shows promising application prospects.
[0024] This utility model also provides a pulse charging device, which includes the above-mentioned pulse charging circuit, and the pulse charging device has the same technical effect as the pulse charging circuit. Attached Figure Description
[0025] Figure 1 A circuit topology diagram of an existing pulse charging circuit;
[0026] Figure 2 This is a circuit topology diagram of the full-bridge resonant converter of this utility model;
[0027] Figure 3 This is a circuit topology diagram of the DC power supply and full-bridge resonant converter of this utility model. Detailed Implementation
[0028] To facilitate understanding of this utility model, the technical solutions and advantages of the utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Any mechanisms or methods not elaborated in this utility model can be referred to in the prior art. The specific structure and features of this utility model are illustrated below by way of example and should not constitute any limitation on this utility model. Furthermore, any technical feature mentioned below (including implicit or disclosed features), as well as any technical feature directly shown or implied in the figures, can be arbitrarily combined or deleted among these technical features to form more other embodiments that may not be directly or indirectly mentioned in this utility model. The accompanying drawings show preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.
[0029] like Figures 2-3 As shown, this embodiment provides a preferred structure for pulse charging current / pulse charging power supply.
[0030] like Figure 2 As shown, the pulse charging circuit of this utility model includes a full-bridge rectifier circuit, a full-bridge resonant converter, and a main controller. The full-bridge rectifier circuit is connected to the load; the full-bridge resonant converter is connected to the full-bridge rectifier circuit and has the function of a full-bridge converter; the main controller is connected to the full-bridge resonant converter and is configured to adjust the switching frequency and switching duty cycle of the full-bridge converter to switch the operating state of the full-bridge converter.
[0031] like Figure 2 As shown, to address the challenge of balancing target voltage accuracy and charging speed, this invention utilizes an LC resonant circuit to achieve alternating large and small pulse charging. The main controller regulates the charging process by adjusting the switching frequency and duty cycle of the full-bridge converter, enabling rapid charging with large pulse widths and precise charging with small pulse widths, thus allowing for voltage regulation at different charging stages. This invention's pulse charging circuit effectively balances charging speed and accuracy, featuring a simple topology and control logic.
[0032] like Figure 3 As shown, the full-bridge resonant converter includes a full-bridge converter, a resonant circuit, and an isolation transformer connected in sequence. The full-bridge converter is connected to an external power supply, and the isolation transformer is connected to the full-bridge resonant circuit.
[0033] Specifically, the full-bridge converter has four insulated-gate bipolar transistors (IGBTs), each with a diode connected in parallel. The anode of the diode is connected to the emitter of the IGBT, and the cathode of the diode is connected to the collector of the IGBT.
[0034] Combination Figure 3 The circuit topology and its operation are as follows: Channel 1 shows the driving voltage waveform of the insulated-gate bipolar transistor (IGBT) Q9. Channel 2 shows the source-drain voltage of the IGBT Q9. Channel 3 shows the primary-side resonant current Is, and Channel 4 shows the output charging current Io. It can be seen that the switching frequency of the IGBT Q9 is lower than the resonant frequency, operating in discontinuous current mode. The IGBT turns on with zero current and turns off with zero current and zero voltage, operating in a soft-switching state. During the charging process, the IGBT has no switching losses, only conduction losses, making it particularly suitable for high-power charging applications.
[0035] On the other hand, the resonant circuit includes a resonant inductor and a resonant capacitor. The resonant inductor is connected to the full-bridge converter, and one end of the primary winding of the isolation transformer is connected to the resonant inductor. The resonant capacitor is connected to the full-bridge converter, and the other end of the primary winding of the isolation transformer is connected to the resonant capacitor.
[0036] like Figure 3 As shown, the full-bridge rectifier circuit adopts a bridge rectifier circuit consisting of four diodes, and the full-bridge rectifier circuit is connected to the secondary winding of the isolation transformer of the full-bridge resonant converter.
[0037] In this technology, the full-bridge rectifier circuit consists of four silicon carbide diodes. Silicon carbide diodes have no reverse recovery time, which can significantly reduce diode losses. (SiS diodes have no reverse recovery time, resulting in lower losses compared to conventional diodes. This also leads to lower voltage spikes caused by reverse recovery time, which is more conducive to the safe and reliable operation of the power supply.)
[0038] In practical implementation, the full-bridge converter has a first operating state and a second operating state. In the first operating state, the switching frequency of the full-bridge converter is lower than the resonant frequency of the resonant circuit. In the second operating state, the full-bridge converter maintains the switching frequency of the first operating state, but the switching duty cycle of the full-bridge converter in the second operating state is lower than the switching duty cycle of the first operating state.
[0039] The main controller of this invention controls the charging process by adjusting the switching frequency and duty cycle of the full-bridge converter. The switching frequency of the full-bridge converter is lower than the resonant frequency of the resonant circuit, while the duty cycle of the full-bridge converter is large in the early stage and small in the later stage, further ensuring precise voltage control at different charging stages and improving charging accuracy.
[0040] Switching frequency refers to the frequency at which the switching transistors (such as MOSFETs and IGBTs) in a full-bridge converter are turned on and off, and is determined by the frequency of the PWM signal output by the main controller.
[0041] The resonant frequency is the natural frequency of the LC resonant network formed by the resonant inductor and resonant capacitor in the full-bridge converter.
[0042] As can be seen from the accompanying drawings, this invention employs a single pulse charging circuit (incremental ΔU). e In one control method (relatively large), before the load pulse capacitor voltage reaches the target voltage, the full-bridge converter with a full-bridge resonant circuit uses a soft-switching mode to quickly charge the load. When the load pulse capacitor voltage reaches the charging switching point, the main controller controls the full-bridge converter to exit the soft-switching mode, and the full-bridge converter uses small pulses to charge the load (small pulses are narrow pulses, because narrow pulses have a very low duty cycle, and the equivalent pulse increment ΔU is small). e (smaller)
[0043] The charging working principle of this utility model is as follows: through the alternating large and small pulse charging control method, a large pulse width pulse is used for fast charging in the early stage of charging, so that the pulse capacitor voltage rises rapidly to approach the target voltage; when it approaches the target voltage, it switches to a small pulse width pulse for precise charging. The voltage increment brought by each pulse is small, which can precisely control the voltage to reach the target value and achieve high-precision charging.
[0044] In one specific implementation, during the charging process, the main controller can monitor the pulse capacitor voltage value of the load in real time through the output voltage sensor. Before the pulse capacitor voltage of the load reaches the first target voltage, the main controller controls the switching frequency of the full-bridge converter to be lower than the resonant frequency of the resonant circuit. The full-bridge converter operates in discontinuous current mode (i.e., soft switching mode, first working state). During this process, the charging current is the largest and the voltage increment on the pulse capacitor is the largest.
[0045] When the load's pulse capacitor voltage reaches or approaches the second target voltage, the main controller controls the full-bridge converter to switch to the second operating state. The switching frequency of the full-bridge converter remains unchanged (i.e., it maintains the switching frequency of the first operating state), but the switching duty cycle gradually decreases from the duty cycle of the first operating state to a minimum value. After reaching the minimum value, the duty cycle remains unchanged, and charging continues until the final target voltage is reached. At this time, the switching transistors of the full-bridge converter are in hard-switching mode and hard-turn-off mode. Compared to the soft-switching state, although the small-pulse mode of the full-bridge converter is a hard-switching mode (with switching losses, zero-current turn-on, and hard turn-off), the small-pulse duration of the full-bridge converter is short, and the switching losses of the entire full-bridge converter are limited.
[0046] like Figure 3 As shown, the pulse charging circuit also includes a DC power supply, which is connected to both the full-bridge resonant converter and the main controller. The DC power supply includes a three-phase totem-pole bridgeless PFC circuit, a synchronous BUCK circuit, and an LC filter circuit connected in sequence, with the LC filter circuit connected to the full-bridge resonant converter.
[0047] In the design of this DC power supply, a three-phase totem pole bridgeless PFC is adopted to stabilize the PFC output voltage at 800V. A synchronous BUCK circuit and an LC filter circuit are then connected. The LC filter circuit effectively reduces the ripple on the DC bus, which is beneficial to the small pulse charging accuracy of the full-bridge resonant converter.
[0048] The above embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of protection of the present utility model. For those skilled in the art, it will be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.
Claims
1. A pulse charging circuit, characterized in that, The pulse charging circuit includes: A full-bridge rectifier circuit, wherein the full-bridge rectifier circuit is connected to the load; A full-bridge resonant converter, wherein the full-bridge resonant converter is connected to the full-bridge rectifier circuit, and the full-bridge resonant converter has a full-bridge converter function; A main controller is connected to the full-bridge resonant converter and is configured to adjust the switching frequency and switching duty cycle of the full-bridge converter to switch the operating state of the full-bridge converter.
2. The pulse charging circuit as described in claim 1, characterized in that: The full-bridge resonant converter includes a full-bridge converter, a resonant circuit, and an isolation transformer connected in sequence. The full-bridge converter is connected to an external power supply, and the isolation transformer is connected to the full-bridge rectifier circuit.
3. The pulse charging circuit as described in claim 2, characterized in that: The full-bridge converter has a first operating state and a second operating state; In the first operating state, the switching frequency of the full-bridge converter is lower than the resonant frequency setting of the resonant circuit; In the second operating state, the full-bridge converter maintains the switching frequency of the first operating state, and the switching duty cycle of the full-bridge converter in the second operating state is lower than the switching duty cycle setting in the first operating state.
4. The pulse charging circuit as described in claim 3, characterized in that: The full-bridge converter has four insulated-gate bipolar transistors (IGBTs), each with a diode connected in parallel. The anode of the diode is connected to the emitter of the IGBT, and the cathode of the diode is connected to the collector of the IGBT.
5. The pulse charging circuit as described in claim 3, characterized in that: The resonant circuit includes a resonant inductor and a resonant capacitor. The resonant inductor is connected to a full-bridge converter and to one end of the primary winding of an isolation transformer. The resonant capacitor is connected to the full-bridge converter, and the resonant capacitor is connected to the other end of the primary winding of the isolation transformer.
6. The pulse charging circuit as described in claim 3, characterized in that: The full-bridge rectifier circuit adopts a bridge rectifier circuit consisting of four diodes, and the full-bridge rectifier circuit is connected to the secondary winding of the isolation transformer of the full-bridge resonant converter.
7. The pulse charging circuit as described in claim 1, characterized in that: The pulse charging circuit also includes a DC power supply, which is connected to the full-bridge resonant converter and the main controller.
8. The pulse charging circuit as described in claim 7, characterized in that: The DC power supply includes a three-phase totem pole bridgeless PFC circuit, a synchronous BUCK circuit, and an LC filter circuit connected in sequence, and the LC filter circuit is connected to the full-bridge resonant converter.
9. A pulse charging device, characterized in that, The pulse charging device includes the pulse charging circuit according to any one of claims 1 to 8.