A two-stage power supply architecture and its cooperative control method

Abstract

This invention discloses a two-stage power supply architecture and its coordinated control method, including a first-stage converter, a second-stage converter, a first-stage controller, and a second-stage controller. The first-stage converter receives the voltage input from an external input bus and outputs an intermediate bus voltage to the second-stage converter. The second-stage converter outputs the transformed voltage to the second-stage controller and the external load device. The second-stage controller also receives an externally input reference voltage and controls the operating state of the second-stage converter based on the transformed voltage and the reference voltage, and outputs the current local operating state to the first-stage controller. The first-stage controller also receives an externally input reference operating state and controls the operating state of the first-stage converter based on the reference operating state and the current local operating state, ensuring that the two-stage power supply architecture operates at its optimal efficiency point. The power supply described in this invention features high efficiency and high transient response.

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology, specifically relating to a two-stage power supply architecture and its collaborative control method. Background Technology

[0002] With the ever-increasing demand for computing power in data centers, high computing power and high power consumption have become the development trend of data center processors. As power consumption demands continue to rise, how to provide processors with efficient and high transient response power is of great significance for improving the energy efficiency of data centers.

[0003] Advanced data center power supplies utilize a 48V bus input to increase rack capacity. To power processor loads operating at low voltages, a high step-down ratio of 48V to below 1V is required. To ensure power supply performance, a two-stage power supply structure is typically employed, consisting of a fixed-ratio DCX converter and a regulated converter. The fixed-ratio converter usually operates in an open-loop manner, efficiently achieving DC voltage scaling through resonant and soft-switching operations; it is also known as a DC transformer (DCX). The regulated converter, on the other hand, adjusts the output voltage in a closed loop based on a reference voltage to supply the processor load.

[0004] Currently, the mainstream power supply solutions include: 1) Cascading a fixed conversion ratio converter with a voltage-regulating converter, such as cascading an STC converter with a synchronous Buck converter. However, the voltage-regulating converter still has high voltage stress, large load current stress, low operating frequency, and requires large passive components, which limits its efficiency and power density; 2) Cascading a voltage-regulating topology converter with a fixed conversion ratio converter, such as cascading an FSBB converter with an LLC converter. However, this solution relies on the preceding stage to achieve voltage regulation, and is limited by the bandwidth of the preceding stage, resulting in a slow transient response.

[0005] Therefore, current mainstream power supply solutions cannot effectively balance efficiency, power density, and transient response. Summary of the Invention

[0006] To address the problems in the prior art, this invention provides a two-stage power supply architecture and its collaborative control method.

[0007] The technical solution adopted in this invention is as follows:

[0008] In a first aspect, the present invention discloses a two-stage power supply architecture, including a first-stage converter, a second-stage converter, a first-stage controller, and a second-stage controller;

[0009] The first-stage converter is connected to an external input bus. The first-stage converter is a voltage-regulating topology converter. The first-stage converter receives the voltage input from the input bus and performs voltage transformation on the voltage, outputting the intermediate bus voltage to the second-stage converter.

[0010] The second-stage converter is a fixed conversion ratio converter with voltage regulation function. The second-stage converter performs voltage transformation on the input intermediate bus voltage and outputs the transformed voltage to the second-stage controller and external load devices.

[0011] The second-stage controller also receives an externally input reference voltage. Based on the transformed voltage and the reference voltage, the second-stage controller controls the operating state of the second-stage converter and outputs the current local operating state to the first-stage controller. The first-stage controller also receives an externally input reference operating state. Based on the reference operating state and the current local operating state, the first-stage controller controls the operating state of the first-stage converter to ensure that the two-stage power architecture operates at the optimal efficiency point.

[0012] Secondly, the present invention discloses a cooperative control method for the aforementioned two-stage power supply architecture, comprising the following steps:

[0013] The first-stage converter receives the input bus voltage and performs voltage transformation on it. It outputs the intermediate bus voltage to the intermediate bus capacitor to ensure the stability of the intermediate bus voltage. The first-stage converter also outputs the intermediate bus voltage to the second-stage converter. The second-stage converter performs voltage transformation on the intermediate bus voltage and outputs the transformed voltage to the output voltage capacitor to ensure the stability of the output voltage of the second-stage converter. The second-stage converter also outputs the transformed voltage to the second-stage controller and external load devices.

[0014] The second-stage controller also receives an externally input reference voltage. Based on the transformed voltage and the reference voltage, the second-stage controller controls the operating state of the second-stage converter and outputs the current local operating state to the first-stage controller. The first-stage controller also receives an externally input reference operating state. Based on the reference operating state and the current local operating state, the first-stage controller controls the operating state of the first-stage converter and adjusts the intermediate bus voltage output by the first-stage converter. Ultimately, this ensures that the two-stage power supply architecture operates at its optimal efficiency point.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] (1) In the collaborative control method described in this invention, the working mode of the traditional fixed conversion ratio converter is changed by adopting a closed-loop voltage regulation control method. By utilizing its ability to work at high switching frequency and having high bandwidth, it can achieve high transient response when working under dynamic load switching.

[0017] (2) The second-level controller monitors and outputs the current local operating status. The first-level controller controls the operating status of the first-level converter based on this status and the reference operating status, thereby adjusting the intermediate bus voltage so that the second-level converter can still operate at the optimal efficiency point in steady state and has the characteristics of high conversion efficiency. Attached Figure Description

[0018] Figure 1 This is a system block diagram of a two-stage power supply architecture according to an embodiment of the present invention;

[0019] Figure 2 This is a flowchart of a collaborative control method for a two-stage power architecture according to an embodiment of the present invention;

[0020] Figure 3 This is a topology diagram of a first-stage converter and a second-stage converter according to an embodiment of the present invention, where N=1 and M=1;

[0021] Figure 4 This is a diagram showing alternative primary and secondary topologies for a second-stage converter according to an embodiment of the present invention.

[0022] Figure 5 This is a block diagram of a control unit according to an embodiment of the present invention;

[0023] Figure 6 for Figure 3 The diagram shows the waveforms of the resonant inductor and magnetizing inductor currents in the LLC resonant cavity under light and heavy loads, respectively, when the second-stage converter is operating in steady state in one embodiment.

[0024] Figure 7 for Figure 3 The diagram shows the waveforms of the resonant inductor and magnetizing inductor currents in the LLC resonant cavity during buck and boost cycles, respectively, when the second-stage converter is operating under voltage regulation in one embodiment.

[0025] Figure 8 for Figure 3 A schematic diagram of key waveforms during a sudden load increase in one embodiment is shown;

[0026] Figure 9 for Figure 3 A schematic diagram of key waveforms during a sudden load reduction in one embodiment is shown;

[0027] Figure 10 for Figure 3 The figure shows a simulation diagram of the key waveforms during a sudden load increase in one embodiment.

[0028] Figure 11 for Figure 3 The figure shows a simulation diagram of the key waveforms when the load suddenly decreases in one embodiment. Detailed Implementation

[0029] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0030] Given the inherent contradiction between efficiency and dynamic response in existing two-stage power supply schemes, which cannot simultaneously achieve high efficiency and high transient response, this invention discloses a two-stage power supply architecture and its collaborative control method, including a first-stage converter, a second-stage converter, a first-stage controller, and a second-stage controller; the first-stage converter is a voltage-regulating topology converter, which can consist of N four-switch Buck-Boost converters (i.e., FSBB converters); the second-stage converter is a fixed conversion ratio converter with voltage regulation function, which can consist of M four-switch Buck-Boost converters (i.e., FSBB converters).

[0031] The first-stage converter transforms the input bus voltage into an intermediate bus voltage, and the second-stage converter transforms the intermediate bus voltage into the output voltage. When the two-stage power supply architecture is in steady state, the first-stage converter maintains steady-state voltage regulation operation, while the second-stage converter operates in a first operating state, achieving high efficiency and stable output; the first operating state of the second-stage converter is a high-efficiency open-loop operating state.

[0032] When the two-stage power architecture is in a transient state, the second-stage controller controls the second-stage converter to quickly enter the second operating state, achieving high transient response and stable output. The second operating state is a high transient closed-loop voltage regulation operating state. The first-stage controller compares the reference operating state with the current operating state of the second-stage controller, and controls the operating state of the first-stage converter based on the comparison result, adjusts the intermediate bus voltage, and makes the second-stage converter operate in the first operating state, achieving high efficiency and stable output.

[0033] Figure 1 This is a system block diagram of the two-stage power supply architecture of the present invention. The overall architecture of the present invention employs a two-stage converter, wherein the first-stage converter is used to provide efficient voltage transformation to generate an adjustable intermediate bus voltage, and the second-stage converter is used to provide high-efficiency transformation and fast transient response.

[0034] The two-stage power architecture of the present invention includes a first-stage converter, a second-stage converter, a first-stage controller, and a second-stage controller; the first-stage controller and the second-stage controller constitute a control unit;

[0035] The first-stage converter is connected to an external input bus. The first-stage converter is a voltage-regulating topology converter. The first-stage converter receives the voltage input from the input bus and performs voltage transformation on the voltage. The first-stage converter outputs the intermediate bus voltage to the second-stage converter.

[0036] The second-stage converter steps down the intermediate bus voltage and outputs the processed voltage to the external processor load and the second-stage controller. The second-stage controller controls the operating state of the second-stage converter based on the output voltage and the reference voltage, forming a local loop to stabilize the output voltage of the second-stage converter and output the current local operating state to the first-stage controller. Based on the reference operating state and the current local operating state, the first-stage converter is controlled to form a global loop to stabilize the intermediate bus voltage.

[0037] like Figure 2 As shown, this invention discloses a cooperative control method for a two-stage power supply architecture. The second-stage controller generates the current local operating state and transmits relevant information to the first-stage controller, which can adjust the intermediate bus voltage so that the second-stage converter operates at the optimal operating point.

[0038] The specific process of the collaborative control method includes the following steps:

[0039] Based on the output reference operating state and the current local operating state, when no transient operating condition switching occurs and the optimal operating state is in place, the first-stage converter remains in the steady-state voltage regulation operating state, and the second-stage converter operates in the first operating state, thereby achieving high efficiency and stable output.

[0040] Based on the output bus voltage and reference voltage, when a transient operating condition switch occurs, the second-stage controller controls the second-stage converter to quickly enter the second operating state through the local loop, achieving high transient response. After internal processing, the second-stage controller outputs the current local operating state, which indicates that the second-stage converter has deviated from the optimal operating state. In the global loop, the first-stage controller compares the current local operating state with the reference operating state and controls the first-stage converter based on the comparison result, adjusting the intermediate bus voltage output by the first-stage converter and returning the second-stage converter to the first operating state (i.e., returning the second-stage converter to the optimal operating state), achieving high efficiency and stable output.

[0041] like Figure 3 As shown, an embodiment of the present invention is provided. The first-stage converter uses an adjustable FSBB converter (four-switch Buck-Boost converter) to output a controllable intermediate bus voltage, which has the advantages of high conversion ratio and high-efficiency voltage conversion. The second-stage converter uses a voltage-regulating LLC resonant converter to realize the output voltage, achieving high bandwidth and high transient response voltage conversion.

[0042] The first-stage converter can be composed of N FSBB converter structures (i.e. Figure 3 The FSBB converter consists of N ≥ 1, and the FSBB converter includes a first switching device S. BB-1 Second switchgear S BB-2 Third switchgear S BB-3 Fourth switchgear S BB-4 Inductor L1 and intermediate bus capacitor C MID The switching devices are MOSFETs, transistors, or IGBTs.

[0043] First switching device S BB-1 The source and the third switching device S BB-3 The drain of the circuit is connected to one end of the inductor L1, and the third switching device S is connected to the drain of the circuit. BB-3 The source and the fourth switching device S BB-4 The source terminal is connected, and then connected to the power ground. The second switching device S... BB-2 The source and the fourth switching device S BB-4 The drain of the first switching device S is connected to the other end of the inductor L1. BB-1 The drain of the second switching device S serves as the input terminal of the FSBB converter structure. BB-2 The drain of the capacitor serves as the output terminal of the FSBB converter structure, and the intermediate bus capacitor C MID One end is connected to the output of the FSBB converter structure, and the other end is connected to the power ground. The intermediate bus capacitor is used to ensure the stability of the intermediate bus voltage. The inputs of N FSBB converter structures are connected as the input of the first-stage converter, and the outputs of N FSBB converter structures are connected as the output of the first-stage converter. The gates of all switching devices are connected to the external drive circuit, and the switching devices are driven by the drive circuit.

[0044] The second-stage converter consists of M LLC converter structures (i.e., ... Figure 3 The LLC converter is composed of M ≥ 1, wherein the LLC converter structure includes a first switching device S. LLC-1 Second switchgear S LLC-2 Transformer, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r Third switchgear S LLC-3 Fourth switchgear S LLC-4 and output bus capacitor C OUT The switching devices are MOSFETs, transistors, or IGBTs.

[0045] First switching device S LLC-1The source and the second switching device S LLC-2 The drain is connected to the resonant inductor L. r One end is connected to the resonant inductor L. r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and resonant capacitor C r One end is connected, and then connected to the power ground; the resonant capacitor C r At the other end, the magnetizing inductor L m The other end is connected to the opposite end of the primary winding of the transformer in pairs; the secondary winding of the transformer includes the same-name end, the opposite-name end, and the intermediate tap, and the same-name end of the secondary winding of the transformer is connected to the third switchgear S. LLC-3 The source terminal is connected, and the opposite terminal of the transformer secondary winding is connected to the fourth switchgear S. LLC-4 The source is connected, and the third switching device S LLC-3 The drain and the fourth switching device S LLC-4 The drains are connected together, and this connection serves as the output terminal of the LLC converter structure, with the output bus capacitor C. OUT One end is connected to the output terminal of the LLC converter structure, and the other end is connected to power ground. The output bus capacitor is used to ensure the stability of the output voltage of the second-stage converter; the center tap of the transformer secondary winding is connected to power ground; the first switching device S LLC-1 The drain of the M LLC converter is used as the input terminal of the LLC converter structure. The input terminals of the M LLC converter structures are connected together as the input terminals of the second-stage converter. The output terminals of the M LLC converter structures are connected together as the output terminals of the second-stage converter. The gates of all switching devices are connected to an external driving circuit, and the switching devices are driven by the driving circuit.

[0046] like Figure 4 As shown, the LLC converter structure can also be selected with similar primary and secondary side structures according to power level, application scenario, etc., including but not limited to: primary side: asymmetric half bridge, symmetric half bridge, full bridge; secondary side: full bridge rectification, half bridge rectification.

[0047] The primary-side asymmetric half-bridge includes a first switching device S. LLC-1 Second switchgear S LLC-2 Primary winding, magnetizing inductor L m Resonant inductor L r and resonant capacitor C r First switchgear S LLC-1 The drain of the first switching device S serves as the input terminal of the primary-side asymmetric half-bridge. LLC-1 The source and the second switching device S LLC-2 The drain is connected to the resonant inductor L. rOne end is connected to the resonant inductor L. r At the other end, the magnetizing inductor L m One end of the primary winding is connected to the corresponding end of the secondary winding in pairs; the second switching device S LLC-2 The source and resonant capacitor C r One end is connected, and then connected to the power ground; the resonant capacitor C r At the other end, the magnetizing inductor L m The other end is connected to the opposite end of the primary winding of the transformer.

[0048] The primary-side symmetrical half-bridge includes a first switching device S. LLC-1 Second switchgear S LLC-2 Primary winding, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r1 and resonant capacitor C r2 First switchgear S LLC-1 The source and the second switching device S LLC-2 The drain is connected to the resonant inductor L. r One end is connected to the resonant inductor L. r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and resonant capacitor C r2 One end is connected, and then connected to the power ground; the resonant capacitor C r2 At the other end, the magnetizing inductor L m The other end, resonant capacitor C r1 One end is connected to the opposite end of the primary winding of the transformer, and the resonant capacitor C is connected to it. r1 The other end is connected to the first switching device S LLC-1 The drains are connected together, and the connection serves as the input of the primary-side symmetrical half-bridge.

[0049] The primary side full bridge includes the first switchgear S LLC-1 Second switchgear S LLC-2 Primary winding, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r Third switchgear S LLC-3 and the fourth switchgear S LLC-4 First switchgear S LLC-1 The drain and the third switching device S LLC-3 The drains of the two terminals are connected together, and the connection serves as the input terminal of the primary-side full bridge; the first switching device S LLC-1 The source electrode, the second switching device S LLC-2 Drain and resonant inductor L rOne end is connected in pairs, and the resonant inductor L r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and the fourth switching device S LLC-4 The source terminal is connected, and then connected to the power ground; the third switching device S LLC-3 The source electrode, the fourth switching device S LLC-4 Drain and resonant capacitor C r One end is connected in pairs, and the resonant capacitor C r At the other end, the magnetizing inductor L m The other end is connected to the opposite end of the primary winding of the transformer.

[0050] The secondary-side full-bridge rectifier includes switching devices S3, S4, S5, and S6, and a secondary winding. The same-name terminals of the secondary winding, the source of switching device S3, and the drain of switching device S5 are connected in pairs. The drain of switching device S3 and the drain of switching device S4 are connected, and the connection serves as the output terminal of the secondary-side full-bridge. The source of switching device S5 and the source of switching device S6 are connected, and the connection is then connected to power ground. The drain of switching device S6, the source of switching device S4, and the opposite-name terminals of the transformer secondary winding are connected in pairs.

[0051] The secondary half-bridge rectifier includes switching device S3, switching device S4, and a secondary winding. The secondary winding includes a same-name terminal, a different-name terminal, and a center tap. The same-name terminal of the secondary winding is connected to the drain of switching device S3, the different-name terminal of the secondary winding is connected to the drain of switching device S4, and the source of switching device S3 is connected to the source of switching device S4. The connection serves as the output terminal of the secondary half-bridge rectifier. The center tap of the secondary winding is connected to power ground.

[0052] In one specific embodiment of the present invention, the second-stage converter is composed of M LLC converter structures, each LLC converter structure including a first switching device S. LLC-1 Second switchgear S LLC-2 Transformer, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r1 Resonant capacitor C r2 The third switchgear S3, the fourth switchgear S4, and the output bus capacitor C OUT The switching device is a MOSFET, transistor, or IGBT; where N ≥ 1;

[0053] First switching device S LLC-1 The source and the second switching device S LLC-2 The drain is connected to the resonant inductor L. rOne end is connected to the resonant inductor L. r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and resonant capacitor C r2 One end is connected, and then connected to the power ground; the resonant capacitor C r2 At the other end, the magnetizing inductor L m The other end, resonant capacitor C r1 One end is connected to the opposite end of the primary winding of the transformer, and the resonant capacitor C is connected to it. r1 The other end is connected to the first switching device S LLC-1 The drains of the two terminals are connected together, and the connection is used as the input terminal of the LLC converter structure.

[0054] The secondary winding of the transformer includes a same-name terminal, a different-name terminal, and a center tap. The same-name terminal of the secondary winding is connected to the drain of the third switching device S3, and the different-name terminal is connected to the drain of the fourth switching device S4. The source of the third switching device S3 is connected to the source of the fourth switching device S4. This connection serves as the output terminal of the LLC converter structure, with the output bus capacitor C... OUT One end is connected to the output terminal, and the other end is connected to the power ground. The middle tap of the secondary winding of the transformer is connected to the power ground. All the gates of the switching devices are connected to the external drive circuit, and the switching devices are driven by the drive circuit.

[0055] The input terminals of M LLC converter structures are connected together as the input terminals of the second-stage converter, and the output terminals of the M LLC converter structures are connected together as the output terminals of the second-stage converter.

[0056] In one specific embodiment of the present invention, the second-stage converter is composed of M LLC converter structures, each LLC converter structure including a first switching device S. LLC-1 Second switchgear S LLC-2 Third switchgear S LLC-3 Fourth switchgear S LLC-4 Transformer, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r The fifth switchgear S5, the sixth switchgear S6, the seventh switchgear S7, the eighth switchgear S8, and the output bus capacitor C OUT The switching device is a MOSFET, transistor, or IGBT; where N ≥ 1;

[0057] First switching device S LLC-1 The drain and the third switching device S LLC-3The drains are connected, and the connection serves as the input terminal of the LLC converter structure; the first switching device S LLC-1 The source electrode, the second switching device S LLC-2 Drain and resonant inductor L r One end is connected in pairs, and the resonant inductor L r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and the fourth switching device S LLC-4 The source terminal is connected, and then connected to the power ground; the third switching device S LLC-3 The source electrode, the fourth switching device S LLC-4 Drain and resonant capacitor C r One end is connected in pairs, and the resonant capacitor C r At the other end, the magnetizing inductor L m The other end is connected to the opposite end of the primary winding of the transformer in pairs;

[0058] The same-name terminals of the transformer secondary winding, the source of the fifth switching device S5, and the drain of the seventh switching device S7 are connected in pairs. The opposite-name terminals of the transformer secondary winding, the source of the sixth switching device S6, and the drain of the eighth switching device S8 are connected in pairs. The drains of the fifth switching device S5 and the sixth switching device S6 are connected. This connection serves as the output terminal of the LLC converter structure, with the output bus capacitor C. OUT One end is connected to the output terminal, and the other end is connected to the power ground. The source of the seventh switching device S7 is connected to the source of the eighth switching device S8, and after connection, it is connected to the power ground. Among them, the gate of all switching devices is connected to the external driving circuit, and the switching devices are driven by the driving circuit.

[0059] The input terminals of M LLC converter structures are connected together as the input terminals of the second-stage converter, and the output terminals of the M LLC converter structures are connected together as the output terminals of the second-stage converter.

[0060] In one specific embodiment of the present invention, the second-stage converter is composed of M LLC converter structures, each LLC converter structure including a first switching device S. LLC-1 Second switchgear S LLC-2 Third switchgear S LLC-3 Fourth switchgear S LLC-4 Transformer, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r The fifth switchgear, the sixth switchgear, and the output bus capacitor C OUT The switching device is a MOSFET, transistor, or IGBT; where N ≥ 1;

[0061] First switching device S LLC-1 The drain and the third switching device S LLC-3 The drains are connected, and the connection serves as the input terminal of the LLC converter structure; the first switching device S LLC-1 The source electrode, the second switching device S LLC-2 Drain and resonant inductor L r One end is connected in pairs, and the resonant inductor L r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and the fourth switching device S LLC-4 The source terminal is connected, and after connection, it is connected to the signal power ground; the third switching device S LLC-3 The source electrode, the fourth switching device S LLC-4 Drain and resonant capacitor C r One end is connected in pairs, and the resonant capacitor C r At the other end, the magnetizing inductor L m The other end is connected to the opposite end of the primary winding of the transformer in pairs;

[0062] The secondary winding of the transformer includes a same-name terminal, a different-name terminal, and a center tap. The same-name terminal of the secondary winding is connected to the drain of the fifth switching device, and the different-name terminal is connected to the drain of the sixth switching device. The source of the fifth switching device is connected to the source of the sixth switching device. This connection serves as the output terminal of the LLC converter structure, with the output bus capacitor C. OUT One end is connected to the output terminal, and the other end is connected to the power ground. The middle tap of the secondary winding of the transformer is connected to the power ground. All the gates of the switching devices are connected to the external drive circuit, and the switching devices are driven by the drive circuit.

[0063] The input terminals of M LLC converter structures are connected together as the input terminals of the second-stage converter, and the output terminals of the M LLC converter structures are connected together as the output terminals of the second-stage converter.

[0064] like Figure 5 As shown, this is an embodiment of two controllers of the present invention. The second-level controller of the control unit includes a second compensator and M second units, and the M second units are connected one-to-one with M LLC converter structures; the second unit includes a voltage-controlled oscillator and a modulator.

[0065] The second-stage controller operates as follows: the second compensator receives the voltage V output from the second-stage converter. o and the external input reference voltage V REFThe second compensator performs compensation, generating and outputting a voltage-controlled oscillator (VCO) control voltage. Specifically, the second compensator, based on PID control, outputs the VCO control voltage to the VCO. The VCO outputs a clock signal to the modulator, which in turn outputs a switching signal to the LLC converter structure connected to this second unit. This controls the switching devices of the LLC converter structure, thereby controlling the switching devices to generate an appropriate switching frequency. Finally, the modulator generates a 50% duty cycle for the four switching devices S of the second-stage converter. LLC-1～4 The control signal enables the high-bandwidth, high-response-speed regulated output of the second-stage converter. Furthermore, the voltage-controlled oscillator control voltage will serve as the current local operating state. Local The output is sent to the first-stage controller (i.e., the second compensator will simultaneously output the voltage-controlled oscillator control voltage to the first-stage controller, and the voltage-controlled oscillator control voltage is the current local operating state), thereby controlling the switching state of the switching equipment of the first-stage converter through the first-stage controller to achieve high-efficiency voltage conversion with controllable turns ratio, and finally realizing feedback regulation of the first-stage converter.

[0066] The first-level controller of the control unit includes a first compensator and N first units, each of which is connected to one of the N FSBB converters; each first unit includes a clock reference unit and a modulator.

[0067] The first-level controller operates as follows: the first compensator receives the current local operating state (State). Local and the given external reference working state. REF The system outputs a control voltage to the modulator based on PID control. Simultaneously, the clock reference unit outputs a clock signal to the modulator. The modulator generates a switching signal using PWM modulation based on the control voltage and clock signal, and outputs this switching signal to the FSBB converter connected to the first unit. This controls the on / off state of the FSBB converter's switching devices, thereby controlling the switching state of the first-stage converter to achieve high-efficiency voltage conversion. Ultimately, this regulates the intermediate bus voltage, ensuring the second-stage converter operates at its optimal point. The reference operating state is described in the original text. REF This is the reference control voltage for the voltage-controlled oscillator.

[0068] like Figures 6-8 As shown, the switching device S of the second-stage converter LLC-1 With S LLC-2 The circuit is sequentially switched on, generating a square wave excitation with a 50% duty cycle, which is applied to the resonant cavity. The magnetizing inductor L with a relatively large inductance... m The current waveform exhibits linear operating characteristics and a fixed slope; the resonant inductor current I... Lr With the excitation inductor current I LmThe difference is transmitted to the secondary side of the transformer for rectification and output. For example... Figure 6 As shown, when the second-stage converter operates in the first operating state, the converter operates at or slightly above the resonant frequency, and the resonant inductor current I... Lr At the end of each half-switching cycle, it is equal to or slightly greater than the magnetizing inductor current I. Lm And under light load, the resonant inductor current I Lr The amplitude is small, and I is under heavy load. Lr The amplitude is relatively large;

[0069] like Figure 7 As shown, when the second-stage converter operates in the second operating state, according to the voltage regulation characteristics of the LLC converter, the second-stage converter can be made to operate in either boost or buck mode by adjusting the switching frequency: when the switching frequency is increased, the converter exhibits buck characteristics, and at this time the resonant inductor current I... Lr At the end of each half-switching cycle, it is greater than the excitation inductor current I. Lm (Right now Figure 7 In (a), the switching frequency F sw The resonant frequency is 3MHz, F r (2MHz); when the switching frequency is reduced, the converter exhibits boost characteristics, and the resonant inductor current I Lr The magnetizing inductor current I will be reached before the end of each half-switching cycle. Lm Same value (i.e.) Figure 7 In (b), the switching frequency F sw The resonant frequency is 1.5MHz, F. r (2MHz).

[0070] When the system load suddenly increases, the output voltage V out A momentary voltage drop occurs, and the second-stage converter, controlled by the local loop, enters a second operating state for voltage regulation. The voltage-controlled oscillator controls the voltage V. VCO Rapidly decreasing, controlling the second-stage converter to operate in boost mode; V VCO As a change in the current local operating state, under the regulation of the global loop, the first-stage converter adjusts the intermediate bus voltage to increase, causing the second-stage converter to return to the first operating state for efficient operation. Key waveforms are as follows: Figure 8 As shown; when the system load suddenly decreases, the system response is similar. The local loop controls the second-stage converter to quickly respond to the load voltage change, and the global loop controls the first-stage converter to adjust the intermediate bus voltage to the optimal operating point. Key waveforms are shown below. Figure 9 As shown, the system achieves optimal efficiency and optimal transient response.

[0071] The following will combine Figure 3The specific embodiment shown illustrates the advantages of the present invention through simulation analysis. In the simulation, the system input voltage is 60V, the output voltage is 1.5V, and the output capacitor is 22uF. The first-stage converter operates at 500kHz with a rated intermediate bus voltage of 48V; the second-stage adjustable LLC resonant converter uses a resonant inductor of 1uH, a magnetizing inductor of 10uH, a resonant capacitor of 7.5nF, and a resonant frequency of 1.85MHz. The operating frequency range is approximately 1.2–2.8MHz. The high switching frequency enables it to provide a fast transient response while also ensuring its high power density.

[0072] like Figure 10 As shown, at 5ms, the external load generates a 9A current jump within 4.5us, resulting in an output voltage drop. The second-stage controller of the second-stage converter detects that the output voltage is lower than the reference voltage and generates a control voltage through the second compensator to enable the second-stage converter to quickly adjust the output voltage back to the reference voltage. This is evident from the resonant cavity current waveform and the oscillator control voltage, indicating that the second-stage converter operates in its second operating mode, effectively regulating the voltage. Simulation results show that the system output voltage drop is 90mV. Under the same simulation conditions, using a traditional two-stage architecture control method (open-loop for the second-stage converter and closed-loop for the entire system), the system output voltage drop is 140mV, and the system recovery time is relatively long.

[0073] like Figure 11 As shown, when the load suddenly decreases, the controller responds similarly, with the local loop controlling the second-stage converter to respond quickly. Results show that the system output voltage overshoot is 90mV. Under the same simulation conditions, using a traditional two-stage architecture control method (open-loop for the second-stage converter and closed-loop for the entire system), the system output voltage overshoot is 140mV, and the system recovery time is relatively long. Therefore, the two-stage power converter described in this invention has a high transient response characteristic.

[0074] Furthermore, in this embodiment, the oscillator control voltage is provided as a second reference voltage to the first-stage controller, corresponding to the oscillator reference control voltage State of the reference operating state. REF After differential calculation, the modulator control voltage is obtained through PID control of the first compensator, which in turn controls the first-stage converter to adjust the intermediate bus, causing the intermediate bus voltage to rise. Ultimately, this allows the converter to operate at its optimal operating point for high efficiency. When the load suddenly decreases, the controller responds similarly; the second reference voltage will be compared with the State. REF After compensation, the intermediate bus voltage is reduced, ultimately allowing the converter to operate at its optimal operating point. Therefore, the two-stage power supply control method described in this invention, in addition to having high transient response, also has the advantage of high efficiency in steady state.

[0075] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A two-stage power supply architecture, characterized in that, It includes a first-stage converter, a second-stage converter, a first-stage controller, and a second-stage controller; The first-stage converter is connected to an external input bus. The first-stage converter is a voltage-regulating topology converter. The first-stage converter receives the voltage input from the input bus and performs voltage transformation on the voltage, outputting the intermediate bus voltage to the second-stage converter. The second-stage converter is a fixed conversion ratio converter with voltage regulation function. The second-stage converter performs voltage transformation on the input intermediate bus voltage and outputs the transformed voltage to the second-stage controller and external load devices. The second-stage controller also receives an externally input reference voltage. Based on the transformed voltage and the reference voltage, the second-stage controller controls the operating state of the second-stage converter and outputs the current local operating state to the first-stage controller. The first-stage controller also receives an externally input reference operating state. Based on the reference operating state and the current local operating state, the first-stage controller controls the operating state of the first-stage converter to ensure that the two-stage power architecture operates at the optimal efficiency point. The first-stage converter consists of N FSBB converter structures, each FSBB converter structure including a first switching device S. BB-1 Second switchgear S BB-2 Third switchgear S BB-3 Fourth switchgear S BB-4 Inductor L1 and intermediate bus capacitor C MID The switching device is a MOSFET, transistor, or IGBT; where N ≥ 1; the first switching device S BB-1 The source and the third switching device S BB-3 The drain of the circuit is connected to one end of the inductor L1, and the third switching device S is connected to the drain of the circuit. BB-3 The source and the fourth switching device S BB-4 The source terminal is connected, and then connected to the power ground. The second switching device S... BB-2 The source and the fourth switching device S BB-4 The drain of the first switching device S is connected to the other end of the inductor L1. BB-1 The drain of the second switching device S serves as the input terminal of the FSBB converter structure. BB-2 The drain of the capacitor serves as the output terminal of the FSBB converter structure, and the intermediate bus capacitor C MID One end is connected to the output terminal of the FSBB converter structure, and the other end is connected to power ground; The second-stage converter consists of M LLC converter structures; The second-level controller includes a second compensator and M second units, each of which is connected to one of the M LLC converter structures. Each second unit includes a voltage-controlled oscillator (VCO) and a modulator. The second compensator receives the error voltage from the output voltage of the second-level converter and an externally input reference voltage, and outputs a VCO control voltage to the VCO based on PID control. The VCO outputs a clock signal to the modulator, which in turn outputs a switching signal to the LLC converter structure connected to the second unit, controlling the switching on and off of the LLC converter structure's switching devices. The second compensator also outputs a VCO control voltage to the first-level controller, which represents the current local operating state. The first-level controller includes a first compensator and N first units, each of which is connected to one of the N FSBB converter structures. Each first unit includes a clock reference unit and a modulator. The first compensator receives the current local operating state and an externally input reference operating state. REF The error voltage is calculated, and a control voltage is output to the modulator based on PID control. Simultaneously, the clock reference unit outputs a clock signal to the modulator. The modulator generates a switching signal based on the control voltage and clock signal using PWM modulation, and outputs the switching signal to the FSBB converter connected to the first unit to control the on / off state of the FSBB converter. REF This is the reference control voltage for the voltage-controlled oscillator.

2. The two-stage power supply architecture according to claim 1, characterized in that, The intermediate bus capacitor is used to ensure the stability of the intermediate bus voltage; the input terminals of N FSBB converter structures are connected as the input terminals of the first-stage converter, and the output terminals of N FSBB converter structures are connected as the output terminals of the first-stage converter; wherein, the gates of all switching devices are connected to the external drive circuit, and the switching devices are driven by the drive circuit.

3. The two-stage power supply architecture according to claim 2, characterized in that, The LLC converter structure includes a first switching device S LLC-1 Second switchgear S LLC-2 Transformer, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r Third switchgear S LLC-3 Fourth switchgear S LLC-4 and output bus capacitor C OUT The switching device is a MOSFET, transistor, or IGBT; where M ≥ 1; First switching device S LLC-1 The source and the second switching device S LLC-2 The drain is connected to the resonant inductor L. r One end is connected to the resonant inductor L. r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and resonant capacitor C r One end is connected, and then connected to the power ground; the resonant capacitor C r At the other end, the magnetizing inductor L m The other end is connected to the opposite end of the primary winding of the transformer in pairs; the secondary winding of the transformer includes the same-name end, the opposite-name end, and the intermediate tap, and the same-name end of the secondary winding of the transformer is connected to the third switchgear S. LLC-3 The source terminal is connected, and the opposite terminal of the transformer secondary winding is connected to the fourth switchgear S. LLC-4 The source is connected, and the third switching device S LLC-3 The drain and the fourth switching device S LLC-4 The drains are connected together, and this connection serves as the output terminal of the LLC converter structure, with the output bus capacitor C. OUT One end is connected to the output terminal of the LLC converter structure, and the other end is connected to power ground. The output bus capacitor is used to ensure the stability of the output voltage of the second-stage converter; the center tap of the transformer secondary winding is connected to power ground; the first switching device S LLC-1 The drain of the M LLC converter is used as the input terminal of the LLC converter structure. The input terminals of the M LLC converter structures are connected together as the input terminals of the second-stage converter. The output terminals of the M LLC converter structures are connected together as the output terminals of the second-stage converter. The gates of all switching devices are connected to an external driving circuit, and the switching devices are driven by the driving circuit.

4. The two-stage power supply architecture according to claim 1, characterized in that, The LLC converter structure includes a first switching device S LLC-1 Second switchgear S LLC-2 Transformer, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r1 Resonant capacitor C r2 The third switchgear S3, the fourth switchgear S4, and the output bus capacitor C OUT The switching device is a MOSFET, transistor, or IGBT; where N ≥ 1; First switching device S LLC-1 The source and the second switching device S LLC-2 The drain is connected to the resonant inductor L. r One end is connected to the resonant inductor L. r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and resonant capacitor C r2 One end is connected, and then connected to the power ground; the resonant capacitor C r2 At the other end, the magnetizing inductor L m The other end, resonant capacitor C r1 One end is connected to the opposite end of the primary winding of the transformer, and the resonant capacitor C is connected to it. r1 The other end is connected to the first switching device S LLC-1 The drains of the two terminals are connected together, and the connection is used as the input terminal of the LLC converter structure. The secondary winding of the transformer includes a same-name terminal, a different-name terminal, and a center tap. The same-name terminal of the secondary winding is connected to the drain of the third switching device S3, and the different-name terminal is connected to the drain of the fourth switching device S4. The source of the third switching device S3 is connected to the source of the fourth switching device S4. This connection serves as the output terminal of the LLC converter structure, with the output bus capacitor C... OUT One end is connected to the output terminal, and the other end is connected to the power ground. The middle tap of the secondary winding of the transformer is connected to the power ground. All the gates of the switching devices are connected to the external drive circuit, and the switching devices are driven by the drive circuit. The input terminals of M LLC converter structures are connected together as the input terminals of the second-stage converter, and the output terminals of the M LLC converter structures are connected together as the output terminals of the second-stage converter.

5. The two-stage power supply architecture according to claim 1, characterized in that, The LLC converter structure includes a first switching device S LLC-1 Second switchgear S LLC-2 Third switchgear S LLC-3 Fourth switchgear S LLC-4 Transformer, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r The fifth switchgear S5, the sixth switchgear S6, the seventh switchgear S7, the eighth switchgear S8, and the output bus capacitor C OUT The switching device is a MOSFET, transistor, or IGBT; where N ≥ 1; First switching device S LLC-1 The drain and the third switching device S LLC-3 The drains are connected, and the connection serves as the input terminal of the LLC converter structure; the first switching device S LLC-1 The source electrode, the second switching device S LLC-2 Drain and resonant inductor L r One end is connected in pairs, and the resonant inductor L r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and the fourth switching device S LLC-4 The source terminal is connected, and then connected to power ground; the third switching device S LLC-3 The source electrode, the fourth switching device S LLC-4 Drain and resonant capacitor C r One end is connected in pairs, and the resonant capacitor C r At the other end, the magnetizing inductor L m The other end is connected to the opposite end of the primary winding of the transformer in pairs; The same-name terminals of the transformer secondary winding, the source of the fifth switching device S5, and the drain of the seventh switching device S7 are connected in pairs. The opposite-name terminals of the transformer secondary winding, the source of the sixth switching device S6, and the drain of the eighth switching device S8 are connected in pairs. The drains of the fifth switching device S5 and the sixth switching device S6 are connected. This connection serves as the output terminal of the LLC converter structure, with the output bus capacitor C. OUT One end is connected to the output terminal, and the other end is connected to the power ground. The source of the seventh switching device S7 is connected to the source of the eighth switching device S8, and after connection, it is connected to the power ground. Among them, the gate of all switching devices is connected to the external driving circuit, and the switching devices are driven by the driving circuit. The input terminals of M LLC converter structures are connected together as the input terminals of the second-stage converter, and the output terminals of the M LLC converter structures are connected together as the output terminals of the second-stage converter.

6. The two-stage power supply architecture according to claim 1, characterized in that, The LLC converter structure includes a first switching device S LLC-1 Second switchgear S LLC-2 Third switchgear S LLC-3 Fourth switchgear S LLC-4 Transformer, magnetizing inductor L m Resonant inductor L r Resonant capacitor C r The fifth switchgear, the sixth switchgear, and the output bus capacitor C OUT The switching device is a MOSFET, transistor, or IGBT; where N ≥ 1; First switching device S LLC-1 The drain and the third switching device S LLC-3 The drains are connected, and the connection serves as the input terminal of the LLC converter structure; the first switching device S LLC-1 The source electrode, the second switching device S LLC-2 Drain and resonant inductor L r One end is connected in pairs, and the resonant inductor L r At the other end, the magnetizing inductor L m One end of the second switchgear is connected to the corresponding end of the primary winding of the transformer in pairs; LLC-2 The source and the fourth switching device S LLC-4 The source terminal is connected, and after connection, it is connected to the signal power ground; the third switching device S LLC-3 The source electrode, the fourth switching device S LLC-4 Drain and resonant capacitor C r One end is connected in pairs, and the resonant capacitor C r At the other end, the magnetizing inductor L m The other end is connected to the opposite end of the primary winding of the transformer in pairs; The secondary winding of the transformer includes a same-name terminal, a different-name terminal, and a center tap. The same-name terminal of the secondary winding is connected to the drain of the fifth switching device, and the different-name terminal is connected to the drain of the sixth switching device. The source of the fifth switching device is connected to the source of the sixth switching device. This connection serves as the output terminal of the LLC converter structure, with the output bus capacitor C. OUT One end is connected to the output terminal, and the other end is connected to the power ground. The middle tap of the secondary winding of the transformer is connected to the power ground. All the gates of the switching devices are connected to the external drive circuit, and the switching devices are driven by the drive circuit. The input terminals of M LLC converter structures are connected together as the input terminals of the second-stage converter, and the output terminals of the M LLC converter structures are connected together as the output terminals of the second-stage converter.

7. A cooperative control method for the two-stage power supply architecture as described in claim 1, characterized in that, Includes the following steps: The first-stage converter receives the input bus voltage and performs voltage transformation on it. It outputs the intermediate bus voltage to the intermediate bus capacitor to ensure the stability of the intermediate bus voltage. The first-stage converter also outputs the intermediate bus voltage to the second-stage converter. The second-stage converter performs voltage transformation on the intermediate bus voltage and outputs the transformed voltage to the output voltage capacitor to ensure the stability of the output voltage of the second-stage converter. The second-stage converter also outputs the transformed voltage to the second-stage controller and external load devices. The second-stage controller also receives an externally input reference voltage. Based on the transformed voltage and the reference voltage, the second-stage controller controls the operating state of the second-stage converter and outputs the current local operating state to the first-stage controller. The first-stage controller also receives an externally input reference operating state. Based on the reference operating state and the current local operating state, the first-stage controller controls the operating state of the first-stage converter and adjusts the intermediate bus voltage output by the first-stage converter. Ultimately, this ensures that the two-stage power architecture operates at its optimal efficiency point.

Images