Multi-power control method

Abstract

A method for controlling a plurality of power sources includes configuring the plurality of power sources to supply power to corresponding loads coupled to the plurality of power sources, where inputs of the plurality of power sources are coupled to an input voltage bus, and coordinating the plurality of power sources during a start-up process such that the plurality of power sources are powered on in a controllable manner, where the plurality of power sources are powered on in a controllable manner. The plurality of power supplies are coordinated to reduce inrush current flowing through the input voltage bus.

Description

Technical Field

[0001] The present invention relates to a method for controlling multiple power supplies, and in particular to a method for controlling multiple power supplies to start up in sequence. Background Art

[0002] As technology has further developed, high performance computers have become one of the most computationally demanding activities. High performance computers can be implemented as graphics processing units (GPUs) or application specific integrated circuits (ASICs).

[0003] A plurality of power supplies are connected in parallel to power a plurality of high-performance computers. In particular, each high-performance computer is powered by a power supply. The power supply is connected between a power grid and the high-performance computer. The power supply is configured to convert an AC voltage of the power grid into a voltage suitable for driving the high-performance computer.

[0004] The power supply is capable of maintaining the output voltage within a specified range for a given period of time after the input power, i.e., the grid power supply, is interrupted. During this period of time, the energy required to support the output power comes from the energy storage capacitor. In order to have a long period of time after the input power is interrupted, the capacitance value of the energy storage capacitor needs to be relatively large. For such a relatively large capacitance value, the inrush current when charging the energy storage capacitor during the startup process can be very large.

[0005] During operation, if multiple power supplies are started at the same time and have the same startup conversion rate, the startup currents of the multiple power supplies will be added together to form an excessive inrush current. Such an excessive inrush current may damage the fuses, circuit breakers, and system connectors of the power system. In addition, nearby electrical equipment may be disturbed by the excessive inrush current. Therefore, a reliable and cost-effective method is needed to control the startup process of multiple power supplies to reduce the inrush current. Summary of the invention

[0006] The above problems can generally be solved or circumvented, and technical advantages can generally be achieved, through the preferred embodiments of the present application, which provide a method for controlling multiple power supplies to start up in a sequential manner.

[0007] According to one embodiment, a multi-power supply control method includes: configuring multiple power supplies to supply power to corresponding loads coupled to the multiple power supplies, wherein input terminals of the multiple power supplies are coupled to an input voltage bus, and coordinating the multiple power supplies during a startup process so that the multiple power supplies are powered on in a controllable manner; wherein the function of coordinating the multiple power supplies is to reduce surge current flowing through the input voltage bus.

[0008] According to another embodiment, a system includes multiple power supplies coupled between a power supply and multiple loads, wherein each of the multiple power supplies is configured to provide power to a corresponding load, and a system control device configured to coordinate the multiple power supplies during a startup process so that the multiple power supplies are powered on in a sequential manner.

[0009] The foregoing has been a fairly extensive overview of the features and technical advantages of the present disclosure so that the subsequent detailed description of the present application may be better understood. Additional features and advantages that form the subject matter of the claims of the present application will be described hereinafter. It will be appreciated by those skilled in the art that the disclosed concepts and specific embodiments may be readily used as a basis for modifying or designing other structures or processes to achieve the same purpose of the present application. It will also be appreciated by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the present disclosure set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to better understand the technical solutions and effects of the present application, the following description and the accompanying drawings are now used as references, wherein:

[0011] Figure 1 A block diagram of a power conversion system including multiple power sources according to various embodiments of the present application is shown;

[0012] Figure 2 Various embodiments of the present application are shown for controlling Figure 1 A flowchart of a first method of multiple power supplies shown;

[0013] Figure 3 Various embodiments of the present application are shown for controlling Figure 1 A flowchart of a second method of multiple power supplies shown;

[0014] Figure 4 The control of various embodiments of the present application is shown Figure 1 A flowchart of multiple power supplies being powered on in a first operating mode;

[0015] Figure 5 The control of various embodiments of the present application is shown Figure 1 A flowchart of multiple power supplies being powered on in a second operating mode;

[0016] Figure 6 The control of various embodiments of the present application is shown Figure 1 A flowchart of multiple power supplies being powered on in a third operating mode;

[0017] Figure 7 Various embodiments of the present application are shown Figure 1 A schematic diagram of a first embodiment of the power supply shown;

[0018] Figure 8 Various embodiments of the present application are shown Figure 1 A schematic diagram of a second embodiment of the power supply shown;

[0019] Fig. 9 Various embodiments of the present application are shown Figure 1 A schematic diagram of a third embodiment of the power supply shown;

[0020] Fig.10 Various embodiments of the present application are shown Figure 1 A schematic diagram of a fourth embodiment of a power supply is shown.

[0021] Fig.11 Various embodiments of the present application are shown Figure 1 A schematic diagram of a fifth embodiment of a power supply shown;

[0022] Fig.12 The control of various embodiments of the present application is shown Fig.11 A flow chart of a method of supplying power as shown;

[0023] Fig.13 Various embodiments of the present application are shown Figure 1 Multiple startup waveforms of multiple power supplies shown;

[0024] Fig.14 The control of various embodiments of the present application is shown Figure 1 A flowchart of a method for a soft start process of a power supply shown in;

[0025] Fig.15 Various embodiments of the present application are shown Figure 1 Another plurality of startup waveforms of the plurality of power supplies shown; and

[0026] Fig.16 The control of various embodiments of the present application is shown Figure 1 Flowchart of another method of the soft start process of a power supply is shown in FIG.

[0027] Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated.The figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION

[0028] The manufacture and use of the preferred embodiments of the present application are discussed in detail below. However, it should be understood that the present disclosure provides many applicable inventive concepts that can be embodied in a variety of specific contexts. The specific embodiments discussed only illustrate specific ways to manufacture and use the present application and do not limit the scope of the present application.

[0029] In this application, the method for controlling the sequential startup of multiple power supplies will be described in a specific context for a preferred embodiment. However, the present invention can also be applied to various power conversion systems. In the following, various embodiments will be explained in detail with reference to the accompanying drawings.

[0030] Figure 1 1 shows a block diagram of a power conversion system including multiple power supplies in various embodiments of the present application. The power conversion system includes multiple power supplies 101, 102 and 103, which are coupled between an input voltage bus VS and corresponding loads 111, 112 and 113. Figure 1 As shown, the input terminal of each power supply (eg, power supply 101) is connected to an input voltage bus VS. The output terminal of each power supply (eg, power supply 101) is connected to a corresponding load (eg, load 111).

[0031] In some implementations, the load (eg, load 111) is a plurality of computers, such as a plurality of high-performance computers, each of which may include a plurality of graphics processing units (GPUs), a plurality of application-specific integrated circuits (ASICs), or a combination thereof.

[0032] In some embodiments, the input voltage bus VS is coupled to an AC power source. The AC power source may be generated by a power substation of a power grid. It should be noted that the input voltage bus VS may not be directly coupled to the AC power source. Some power conversion components, such as rectifiers and filters, may be coupled between the input voltage bus VS and the AC power source.

[0033] In some embodiments, each power supply (e.g., power supply 101) includes a power factor correction stage and a DC / DC power conversion stage. The power factor correction stage is implemented as a boost converter. The DC / DC power conversion stage can be implemented as an isolated power converter, such as a forward converter, a flying converter, a flying-forward converter, a full-bridge converter, a half-bridge converter, an inductor-inductor-capacitor (LLC) resonant converter, a combination thereof, etc. Alternatively, the power factor correction stage is an isolated power converter with a forward topology, a flying-forward topology, a flying-back converter topology, etc. The DC / DC power conversion stage can be implemented as an isolated DC / DC converter, such as a forward converter, a flying converter, a flying-forward converter, a full-bridge converter, a half-bridge converter, an LLC resonant converter, a combination thereof, etc. Alternatively, the DC / DC power conversion stage can be implemented as a non-isolated DC / DC converter, such as a buck converter, a boost converter, a buck-boost converter, any combination thereof, etc.

[0034] In operation, a system controller (not shown) is configured to determine a startup sequence of the multiple power supplies. In particular, the multiple power supplies are not started simultaneously. The multiple power supplies are started in a sequential manner to reduce inrush current during startup of the power conversion system.

[0035] Figure 1 One advantage of the illustrated power conversion system is that the multiple power supplies 101 , 102 , and 103 can be started up in a sequential manner, thereby reducing the magnitude of inrush current.

[0036] In operation, each power supply includes an LLC resonant power converter. The initial switching frequency of each power supply is higher than the resonant frequency of the LLC resonant power converter. During startup, each power supply has a different frequency conversion time (from the initial switching frequency to the resonant frequency). The different frequency conversion times help reduce the inrush current when the power conversion system starts. The detailed implementation of this control method will be described below. Figure 11-12 discussed in.

[0037] In operation, each power supply has a different soft start time. Different soft start times help reduce the inrush current when the power conversion system starts. The detailed implementation of this control method will be described in the following Figure 13-14 discussed in.

[0038] In operation, the soft start time of the multiple power supplies is divided into multiple time periods. In each of the multiple time periods, the multiple power supplies 101, 102 and 103 have different conversion rates. Different conversion rates help reduce the inrush current when the power conversion system starts. The detailed implementation of this control method will be described in the following Figure 15-16 discussed in.

[0039] Figure 2 The various embodiments of the present application are shown. Figure 1 A flow chart of a first method of controlling multiple power supplies is shown. Figure 2 The flowcharts shown in are only examples and should not unduly limit the scope of the claims. A person of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, Figure 2 The various steps shown in may be added, removed, substituted, rearranged and repeated.

[0040] Please return to Figure 1 , multiple power supplies 101, 102, and 103 are coupled to the same voltage bus. In order to reduce the inrush current through the voltage bus, the output voltages of the multiple power supplies cannot be established at the same time. In other words, the startup time of the system is configured so that the multiple power supplies 101, 102, and 103 are powered on in a sequential manner.

[0041] In step 202, multiple power supplies are configured to provide power to respective loads coupled thereto, wherein input terminals of the multiple power supplies are connected to an input voltage bus.

[0042] In step 204, during the startup process, multiple power supplies are coordinated so that the multiple power supplies are powered on in a controllable manner. The coordination of the multiple power supplies is used to reduce the inrush current flowing through the input voltage bus.

[0043] In some embodiments, each of the plurality of power supplies includes a non-isolated power factor correction device and an isolated DC / DC converter cascade-connected between the power supply and the load. The non-isolated power factor correction device is a boost converter. The isolated DC / DC converter is a forward converter. The load is a computer, such as a high-performance computer.

[0044] In another embodiment, each of the plurality of power supplies includes an isolated power factor correction device and a DC / DC converter cascade-connected between the power supply and the load. The isolated power factor correction device is a forward converter.

[0045] Figure 3 Various embodiments of the present application are shown Figure 1 FIG. 1 is a flow chart of a second method for controlling multiple power supplies. Figure 3 The flowcharts shown in are only examples and should not unduly limit the scope of the claims. A person of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, Figure 3 The various steps shown in may be added, removed, substituted, rearranged and repeated.

[0046] In step 302, when the input voltage is detected, the auxiliary power supply starts to operate while the multiple power supplies are kept in a closed state.

[0047] In step 304, a startup control unit is configured to operate. More specifically, the startup control unit is used to control the startup sequence of the plurality of power supplies.

[0048] In step 306, an operating mode is selected based on different operating conditions. According to different operating conditions, there may be three different operating modes during the startup process of the power conversion system. The first operating mode is described in step 308. The second operating mode is described in step 310. The third operating mode is described in step 312.

[0049] In step 308, the plurality of power supplies are configured to communicate with each other to arrange a startup sequence. Figure 4 The detailed working principle of the first operation mode is described.

[0050] In step 310, the system controller is configured to generate a plurality of startup instructions to arrange the startup sequence of the plurality of power supplies. Figure 5 The detailed working principle of the second operation mode is described.

[0051] In step 312, the startup sequence of the multiple power supplies is determined according to the multiple random numbers. Figure 6 The detailed working principle of the third operating mode is described.

[0052] Figure 4 The control of various embodiments of the present application is shown Figure 1 A flow chart of powering up multiple power supplies in a first operating mode is shown. Figure 4 The flowcharts shown in are only examples and should not unduly limit the scope of the claims. A person of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, Figure 4 The various steps described in the description may be added, removed, substituted, rearranged and repeated.

[0053] In step 402, prior to a startup process, a plurality of power supplies are configured to communicate with each other to arrange a startup sequence.

[0054] In step 404, a startup sequence of the plurality of power supplies is determined based on the communication between the plurality of power supplies.

[0055] In some embodiments, multiple power supplies communicate with each other by sending and receiving radio signals. These radio signals can be transmitted through appropriate wireless networks, such as WIFI, ZigBee, Bluetooth, etc. In another embodiment, multiple power supplies communicate with each other by transmitting data over existing power lines.

[0056] Figure 5 The control of various embodiments of the present application is shown Figure 1 A flow chart of powering up multiple power supplies in a second operating mode is shown. Figure 5 The flowcharts shown in are only examples and should not unduly limit the scope of the claims. A person skilled in the art will recognize many variations, substitutions, and modifications. For example, Figure 5 The various steps described in the description may be added, removed, substituted, rearranged and repeated.

[0057] In step 502, prior to the startup process, the system controller generates a plurality of startup instructions.

[0058] In step 504, multiple start-up instructions are sent to corresponding communication ports of multiple power supplies. Each start-up instruction is used to determine a start-up time point of a corresponding power supply, that is, a start-up moment of the corresponding power supply.

[0059] In operation, the startup time points of the multiple power supplies are different, which helps to reduce the inrush current when the power conversion system starts.

[0060] Figure 6 The control of various embodiments of the present application is shown Figure 1 A flow chart of powering up multiple power supplies in a third operating mode is shown. Figure 6 The flowcharts shown in are only examples and should not unduly limit the scope of the claims. A person skilled in the art will recognize many variations, substitutions, and modifications. For example, Figure 6 The various steps shown in may be added, removed, substituted, rearranged and repeated.

[0061] In step 602, a plurality of random start-up time points are generated for a plurality of power supplies.

[0062] In step 604, multiple startup time points are generated based on multiple random numbers. Each startup time point is used to determine a startup time point of a corresponding power source, that is, a startup moment.

[0063] In operation, the startup time points of the multiple power supplies are different because the startup time points are generated based on multiple random numbers. The different startup time points of the multiple power supplies help reduce the inrush current when the power conversion system starts.

[0064] Figure 7 The configuration according to various embodiments of the present application is shown Figure 1 The schematic diagram of the first embodiment of the power supply shown in FIG. 101 has two input terminals. One input terminal (VIN) is connected to Figure 1 The other input terminal is connected to ground. Figure 7 As shown, the power supply 101 includes a non-isolated power converter and an isolated power converter connected in cascade. Figure 7 As shown, the non-isolated power converter is a boost converter. The boost converter is configured as a power factor correction stage of the power supply 101. The output capacitor of the boost converter serves as an energy storage capacitor. The isolated power converter is a forward converter. The forward converter is configured to convert the voltage on the output capacitor of the boost converter into a voltage suitable for a load connected to the output terminal Vo of the power supply 101.

[0065] It should be noted that Figure 7 The forward converter shown in is only an example and should not unduly limit the scope of the claims. A person skilled in the art will recognize many variations, substitutions, and modifications. For example, other related circuits (such as an active clamp) may be included to achieve better efficiency depending on different applications and design requirements.

[0066] like Figure 7 As shown, the boost converter includes an input capacitor C1, an inductor L1, a switch Q1, a diode D1 and an output capacitor C2. Figure 7As shown, the first end of the inductor L1 is connected to the input terminal VIN of the boost converter. The second end of the inductor L1 is connected to the anode of the diode D1. The switch Q1 is connected between the common node of the inductor L1 and the diode D1 and is connected to the ground. The output capacitor C2 is connected between the cathode of the diode D1 and the ground.

[0067] The primary circuit of the forward converter includes a primary switch Q2 and a primary winding NP connected in series therewith. The secondary circuit of the forward converter includes a rectifier and a filter connected in cascade between the secondary winding NS of the transformer and the load. Figure 7 As shown, the rectifier includes a first rectifier diode D2 and a second rectifier diode D3. The filter includes an output inductor L2 and an output capacitor C3. Figure 7 As shown, the anode of the first rectifier diode D2 is connected to the first end of the secondary winding NS of the transformer. The anode of the second rectifier diode D3 is connected to the second end of the secondary winding NS of the transformer. The cathodes of the first rectifier diode D2 and the second rectifier diode D3 are connected, and are further connected to the first end of the output inductor L2. The second end of the output inductor L2 is connected to the first end of the output capacitor C3. The second end of the output capacitor C3 is connected to the second end of the secondary winding NS of the transformer.

[0068] It should be noted that Figure 7 The illustrated diagrams are only examples and should not unduly limit the scope of the claims. Those skilled in the art will recognize many variations, substitutions, and modifications. For example, the non-isolated power converter can be implemented as any other applicable power factor correction device. In addition, diodes D1, D2, and D3 can be replaced by high-efficiency switching elements.

[0069] In one embodiment, Figure 7 The switches in the circuit (e.g., switches Q1-Q2) may be metal oxide semiconductor field effect transistor (MOSFET) devices, bipolar transistor (BJT) devices, super junction transistor (SJT) devices, insulated gate bipolar transistor (IGBT) devices, gallium nitride (GaN)-based power devices, etc.

[0070] It should be noted that although Figure 7 The switches Q1-Q2 are shown implemented as a single N-type transistor, but those skilled in the art will recognize that there are many variations, modifications, and alternatives. For example, at least a portion of the switches may be implemented as P-type transistors, depending on the application and design requirements. In addition, Figure 7 Each switch shown in the figure can be implemented as multiple switches connected in parallel. In addition, a capacitor can be connected in parallel with a switch to achieve zero voltage switching (ZVS) / zero current switching (ZCS)

[0071] Figure 8The configuration according to various embodiments of the present application is shown Figure 1 A schematic diagram of a second embodiment of a power supply is shown. Figure 8 The second embodiment of the power supply shown is similar to Figure 7 The first embodiment of the power supply shown is similar, except that the first rectifier diode and the second rectifier diode are replaced by two rectifier switches respectively. It should be noted that Figure 8 The replacements shown in are only examples. Those skilled in the art will appreciate that there are many variations. For example, the first rectifier diode and the second rectifier diode may be replaced by two MOSFET switches, a combination of a MOSFET switch and a diode, any of these combinations, etc.

[0072] like Figure 8 As shown, the rectifier includes a first rectifier switch Q3 and a second rectifier switch Q4. The filter includes an output inductor L2 and an output capacitor C3. The drain of the first rectifier switch Q3 is connected to the first end of the secondary winding NS of the transformer. The drain of the second rectifier switch Q4 is connected to the second end of the secondary winding NS of the transformer. The source of the first rectifier switch Q3 and the source of the second rectifier switch Q4 are connected together and further connected to the second end of the output capacitor C3. The first end of the output inductor L2 is connected to the first end of the secondary winding NS of the transformer. The first end of the output capacitor C3 is connected to the second end of the output inductor L2.

[0073] Fig. 9 The configuration according to various embodiments of the present application is shown Figure 1 A schematic diagram of a third embodiment of a power supply is shown in FIG. 101 . The power supply 101 includes an isolated power converter and a downstream converter 150 connected in cascade.

[0074] The primary side power supply network of the isolated power converter includes an input capacitor C1 and a switch Q1 connected in series, and the switch is connected to the primary winding NP of the transformer. The secondary side power supply network of the isolated power converter is coupled between the secondary side of the transformer and the downstream converter 150. Specifically, the secondary side power supply network includes a rectifier and a filter connected in series, and the rectifier and the filter are located between the secondary side of the transformer and the downstream converter 150.

[0075] The rectifier includes a first rectifier diode D1 and a second rectifier diode D2. The filter includes an output inductor L1 and an output capacitor C2. Fig. 9As shown, the anode of the first rectifier diode D1 is connected to the first end of the secondary winding NS of the transformer. The anode of the second rectifier diode D2 is connected to the second end of the secondary winding NS of the transformer. The cathode of the first rectifier diode D1 and the cathode of the second rectifier diode D2 are connected together and further connected to the first end of the output inductor L1. The second end of the output inductor L1 is connected to the first end of the output capacitor C2. The second end of the output capacitor C2 is connected to the second end of the secondary winding NS of the transformer.

[0076] like Fig. 9 As shown, the switch Q1 and the primary winding NP form a primary circuit of the forward converter. The first rectifier diode D1, the second rectifier diode D2, the output inductor L1 and the output capacitor C2 form a secondary circuit of the forward converter. The forward converter is configured to operate as a power factor correction stage of the power supply 101.

[0077] The downstream converter 150 is configured to convert the voltage across the capacitor C2 into a voltage suitable for a load connected to the output terminal Vo of the power supply 101 .

[0078] Fig.10 The configuration according to various embodiments of the present application is shown Figure 1 A schematic diagram of a fourth embodiment of a power supply is shown. Fig.10 The fourth embodiment of the power supply shown is similar to Fig. 9 The third embodiment of the power supply shown is similar, except that the first rectifier diode and the second rectifier diode are replaced by two rectifier switches respectively. It should be noted that Fig.10 The replacements shown in are only examples. Those skilled in the art will appreciate that there are many variations. For example, the first rectifier diode and the second rectifier diode can be replaced by two MOSFET switches, a combination of a MOSFET switch and a diode, any of these combinations, etc.

[0079] like Fig.10 As shown, the rectifier includes a first rectifier switch Q2 and a second rectifier switch Q3. The filter includes an output inductor L1 and an output capacitor C2. The drain of the first rectifier switch Q2 is connected to the first end of the secondary winding NS of the transformer. The drain of the second rectifier switch Q3 is connected to the second end of the secondary winding NS of the transformer. The source of the first rectifier switch Q2 and the source of the second rectifier switch Q3 are connected together and further connected to the second end of the output capacitor C2. The first end of the output inductor L1 is connected to the first end of the secondary winding NS of the transformer. The first end of the output capacitor C2 is connected to the second end of the output inductor L1.

[0080] Fig.11 The configuration according to various embodiments of the present application is shown Figure 11 is a schematic diagram of a fifth embodiment of a power supply as shown. The power supply includes an inductor-inductor-capacitor (LLC) resonant converter. The LLC resonant converter includes a switch network 1102, a resonant tank 1104, a transformer 1112, a rectifier 1114, and an output filter 1116. Fig.11 As shown, the switch network 1102, the resonant tank 1104, the transformer 1112, the rectifier 1114 and the output filter 1116 are coupled to each other and connected in cascade between the input DC power source VIN and a load (not shown) coupled to the output end of the LLC resonant converter.

[0081] The switch network 1102 includes four switch elements, namely, switch elements Q11, Q12, Q13 and Q14. Fig.11 As shown, the first pair of switch elements Q11 and Q12 are connected in series. The second pair of switch elements Q13 and Q14 are connected in series. The common node of the switch elements Q11 and Q12 is coupled to the first input terminal T1 of the resonant tank 1104. Similarly, the common node of the switch elements Q13 and Q14 is coupled to the second input terminal T2 of the resonant tank 1104.

[0082] Fig.11 It is further shown that the resonant circuit 1104 is coupled between the switch network 1102 and the transformer 1112. The resonant circuit 1104 is composed of a series resonant inductor Lr, a series resonant capacitor Cr and a parallel inductor Lm. Fig.11 As shown, the series resonant inductor Lr and the series resonant capacitor Cr are connected in series and further coupled to the primary side 1112 of the transformer.

[0083] It should be noted that Fig.11 The series resonant inductor Lr shown is an independent component, wherein the series resonant inductor Lr can be replaced by the leakage inductance of the transformer 1112. In other words, the leakage inductance of the transformer (not shown) can be used as the series resonant inductor Lr.

[0084] It should be further pointed out that although Fig.11 The resonant tank 1104 is shown to be located on the primary side of the LLC resonant converter, but this figure is only an example. Those skilled in the art will recognize many variations, substitutions, and modifications. For example, the resonant tank 1104 can be placed on the secondary side. Alternatively, the resonant tank 1104 can also be placed on both sides of the transformer 1112.

[0085] The transformer 1112 may have a primary winding NP and a secondary winding NS. The primary winding is coupled to the terminals T3 and T4 of the resonant tank 1104, such as Fig.11The secondary winding NS is coupled to the output end of the LLC resonant converter through a rectifier 1114 , which is a full-bridge rectifier including switches Q21 , Q22 , Q23 and Q24 .

[0086] like Fig.11 As shown, switches Q21 and Q22 are connected in series and further coupled between two ends of the output capacitor Co. Switches Q23 and Q24 are connected in series and further coupled between two ends of the output capacitor Co. A common node T5 of switches Q21 and Q22 is coupled to a first end of the secondary winding of the transformer 1112. Similarly, a common node T6 of switches Q23 and Q24 is coupled to a second end of the secondary winding of the transformer 1112.

[0087] It should be noted that Fig.11 The transformer structure shown is only an example. Those skilled in the art will recognize many alternatives, variations and modifications. For example, the secondary side of the transformer 1112 can be a center-tapped transformer winding. Therefore, a synchronous rectifier consisting of two switching elements can be used on the secondary side. The working principle of a synchronous rectifier coupled to a center-tapped transformer winding is well known, so it will not be discussed in further detail here to avoid redundancy.

[0088] It should be further noted that the LLC resonant converter power topology can be applied not only to Fig.11 The rectifier shown may also be applied to other secondary configurations, such as a voltage doubler rectifier, a current doubler rectifier, any combination thereof, and / or the like.

[0089] In operation, when the switching frequency of the LLC resonant converter is equal to the resonant frequency of the resonant tank of the LLC resonant converter, the LLC resonant converter can have a unity system gain. On the other hand, when the switching frequency of the LLC resonant converter is higher than the resonant frequency, the system gain of the LLC resonant converter is low.

[0090] During the startup process of the LLC resonant converter, the LLC resonant converter is configured to operate at an initial switching frequency (e.g., a higher switching frequency) so as to have a lower system gain. During the startup process, the switching frequency is gradually reduced. Once the startup process is completed, the LLC resonant converter operates at the resonant frequency.

[0091] Please return to Figure 1 , Figure 1 The multiple power supplies shown can have different frequency transition times (from the initial switching frequency to the resonant frequency). The different frequency transition times help reduce inrush current during startup.

[0092] Fig.12 A method for controlling the Fig.11 A flow chart of a method of power supply is shown in FIG. Fig.12 The flowchart shown is only an example, which should not unduly limit the scope of the claims. A person of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, Fig.12 The various steps shown in may be added, deleted, substituted, rearranged and repeated.

[0093] Please return to Figure 1 , multiple power supplies 101, 102, and 103 are coupled to the same voltage bus. In order to reduce the surge current flowing through the voltage bus, the voltages of the multiple power output terminals cannot be established at the same time. In other words, the startup time of the system is configured so that the multiple power supplies 101, 102, and 103 are powered on in sequence. By controlling the switching frequency of each of the multiple power supplies, the sequential power-on of the multiple power supplies can be achieved. In particular, Figure 1 Each power supply in can be implemented as Fig.11 By controlling the switching frequency of the LLC resonant converter, the startup of each power supply can be controlled so that the multiple power supplies 101, 102, 103 are powered on in sequence.

[0094] In step 1202, a plurality of different switching frequency transition times are generated for a plurality of power supplies.

[0095] In step 1204, each of the plurality of power supplies is configured to change a switching frequency from an initial frequency setting value to a predetermined resonant frequency within a corresponding switching frequency transition time.

[0096] In operation, the initial switching frequency, ie, the initial frequency setting, of each power supply is set at a frequency away from the resonant frequency of the power supply. In some embodiments, the initial switching frequency is at least ten times greater than the resonant frequency.

[0097] During startup, the switching frequency is dynamically adjusted from an initial switching frequency to a final switching frequency approximately equal to the resonant frequency within a predetermined transition time.

[0098] In operation, in order to reduce the inrush current flowing through the voltage bus, each power supply has a different switching frequency transition time. Due to the different switching frequency transition times, the inrush current flowing through the voltage bus can be reduced accordingly.

[0099] Fig.13 Various embodiments of the present application are shown Figure 1 Multiple startup waveforms of multiple power supplies are shown in . Fig.13 The horizontal axis represents the time interval. Fig.13There may be three rows in the diagram. The first row represents the output voltage V1 of power supply 101. The second row represents the output voltage V2 of power supply 102. The third row represents the output voltage V3 of power supply 103.

[0100] The first power supply 101 has a first soft start time from t0 to t1. The second power supply 102 has a second soft start time ranging from t0 to t2. The third power supply 103 has a third soft start time ranging from t0 to t3. Since the power supplies have different soft start times, the surge current flowing through the voltage bus can be reduced accordingly.

[0101] ] Fig.14 The control of various embodiments of the present application is shown Figure 1 A flow chart of a method for a soft start process of a power supply is shown in FIG. Fig.14 The flowchart shown is only an example, which should not unduly limit the scope of the claims. A person of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, Fig.14 The various steps shown in may be added, deleted, substituted, rearranged and repeated.

[0102] Reference Fig.13 , multiple power supplies 101, 102, and 103 are coupled to the same voltage bus. In order to reduce the surge current flowing through the voltage bus, the voltages at the output terminals of the multiple power supplies can be fully established at different time points, i.e., at different moments (such as t1, t2, and t3). In other words, the startup time of the power conversion system is configured to enable the multiple power supplies 101, 102, and 103 to be powered on in sequence.

[0103] In step 1402, a plurality of different soft start times are generated for a plurality of power supplies.

[0104] At step 1404, each of the plurality of power supplies is configured to establish an output voltage within a corresponding soft start time.

[0105] Fig.15 Various embodiments of the present application are shown Figure 1 Another plurality of startup waveforms of the plurality of power supplies shown in . Fig.15 The horizontal axis represents the time interval. Fig.15 There may be three rows in the diagram. The first row represents the output voltage V1 of power supply 101. The second row represents the output voltage V2 of power supply 102. The third row represents the output voltage V3 of power supply 103.

[0106] Multiple power supplies have the same soft start time. The soft start process can be divided into multiple stages. The first stage of the soft start process is from t0 to t1. The second stage of the soft start process is from t1 to t2. The third stage of the soft start process is from t2 to t3. Fig.15As shown in Figure 1, multiple power supplies have different conversion rates during each startup phase. Due to the different conversion rates, the surge current flowing through the voltage bus can be reduced accordingly. Fig.15 As shown in the above figures, the conversion rate of the power supply or the voltage of the power supply in the present application can specifically be the rate of change of the voltage of the power supply.

[0107] Fig.16 The control according to various embodiments of the present application is shown Figure 1 A flow chart of another method of the soft start process of a power supply is shown in FIG. Fig.16 The flowchart shown is only an example, which should not unduly limit the scope of the claims. A person of ordinary skill in the art will recognize many variations, substitutions, and modifications. For example, Fig.16 The various steps shown in may be added, deleted, substituted, rearranged and repeated.

[0108] Please return to Figure 1 , multiple power supplies 101, 102, and 103 are coupled to the same voltage bus. In order to reduce the inrush current flowing through the voltage bus, the conversion rates of the output voltages of the multiple power supplies 101, 102, and 103 are different at various stages of the startup process. Different conversion rates help reduce the inrush current flowing through the voltage bus.

[0109] In step 1602, the soft start time of the plurality of power supplies is divided into a plurality of time periods.

[0110] In step 1604, a plurality of power supplies are configured to have different slew rates during each of a plurality of time periods.

[0111] Although the embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0112] In addition, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, material compositions, means, methods, and steps described in the specification. It will be readily understood by those of ordinary skill in the art from the disclosure of this disclosure that processes, machines, manufactures, material compositions, means, methods, or steps that currently exist or will be developed in the future and perform substantially the same functions may use the embodiments described in the embodiments associated with this application or substantially the same results as the corresponding embodiments described herein. Therefore, the appended claims are intended to include such processes, machines, manufactures, material compositions, means, methods, or steps within their scope.

Claims

1. A method comprising: A plurality of power supplies are configured to provide power to corresponding loads coupled to the plurality of power supplies, wherein: Input terminals of the plurality of power supplies are coupled to an input voltage bus; as well as During the startup process, the multiple power supplies are coordinated so that the multiple power supplies are powered on in a controllable manner, wherein the coordination of the multiple power supplies serves to reduce the surge current flowing through the input voltage bus.

2. The method according to claim 1, characterized in that The load is a plurality of computers.

3. The method according to claim 1, characterized in that The method further comprises: Before initiating the process, generating a number of random numbers; and A plurality of startup time points are generated based on the plurality of random numbers, wherein each of the plurality of startup time points is used to determine a startup time point of a corresponding power source.

4. The method according to claim 3, characterized in that Each power supply includes a startup control program configured to generate a random number, and the startup control programs of the plurality of power supplies are configured to generate a plurality of random numbers.

5. The method according to claim 1, characterized in that Each of the plurality of power supplies includes a non-isolated power factor correction device and an isolated DC / DC converter connected in cascade between an AC power source and a load.

6. The method according to claim 5, characterized in that The non-isolated power factor correction device is a boost converter; and the isolated DC / DC converter is a forward converter; wherein, The boost converter comprises an inductor, a switch, a diode and an output capacitor, wherein: The first end of the inductor is coupled to the first input end of the boost converter; The second end of the inductor is coupled to the anode of the diode; The switch is coupled between a common node of the inductor and the diode and a second input terminal of the boost converter; and The output capacitor is coupled between the cathode of the diode and the second input terminal of the boost converter; and The forward converter includes a primary switch connected in series with a primary winding of a transformer, a rectifier connected with a secondary winding of the transformer, and an output filter connected with the rectifier.

7. The method according to claim 1, characterized in that Each of the plurality of power supplies includes an isolated power factor correction device and a DC / DC converter connected in cascade between an AC power source and a load.

8. The method according to claim 7, characterized in that The isolated power factor correction device is a forward converter; and the DC / DC converter is a non-isolated DC / DC converter, and the forward converter includes: a primary switch connected in series with the primary winding of the transformer; and A rectifier and a filter are connected in series between the secondary winding of the transformer and the input terminal of the DC / DC converter, wherein: The rectifier comprises a first rectifier diode and a second rectifier diode; The filter comprises an output inductor and an output capacitor, wherein: The anode of the first rectifier diode is connected to the first end of the secondary winding of the transformer; The anode of the second rectifier diode is connected to the second end of the secondary winding of the transformer; The cathode of the first rectifier diode is connected to the cathode of the second rectifier diode, and is further connected to the first end of the output inductor; The second end of the output inductor is connected to the first end of the output capacitor; and The second end of the output capacitor is connected to the second end of the secondary winding of the transformer.

9. The method according to claim 7, characterized in that The isolated power factor correction device is a forward converter; and the DC / DC converter is a non-isolated DC / DC converter, and the forward converter includes: a primary switch connected in series with the primary winding of the transformer; A rectifier and a filter are connected in series between the secondary winding of the transformer and the input terminal of the DC-DC converter, wherein: The rectifier includes a first rectifier switch and a second rectifier switch; and The filter comprises an output inductor and an output capacitor, wherein: The drain of the first rectifier switch is connected to the first end of the secondary winding of the transformer; The drain of the second rectifier switch is connected to the second end of the secondary winding of the transformer; The source of the first rectifier switch and the source of the second rectifier switch are connected and connected together to the second end of the output capacitor; A first end of the output inductor is connected to a first end of the secondary winding of the transformer; and The first terminal of the output capacitor is connected to the second terminal of the output inductor.

10. The method according to claim 1, characterized in that The method further comprises: Prior to the startup process, a plurality of startup instructions are generated by the system controller; and A plurality of start-up instructions are sent to communication ports corresponding to the plurality of power supplies, wherein each of the plurality of start-up instructions is used to determine a start-up time point of a corresponding power supply.

11. The method according to claim 1, characterized in that The method further comprises: Prior to the boot process, multiple power supplies communicate with each other to arrange the boot sequence.

12. The method according to claim 1, characterized in that Each of the plurality of power supplies includes an LLC resonant power converter having a predetermined resonant frequency determined by a resonant tank of the LLC resonant power converter.

13. The method according to claim 12, characterized in that The method further comprises: Generate multiple different switching frequency transition times for multiple power supplies; and Each of the plurality of power supplies is configured to change a switching frequency from an initial frequency setting value to a predetermined resonant frequency within a corresponding switching frequency transition time.

14. The method according to claim 13, characterized in that The initial frequency setting value is at least ten times the predetermined resonant frequency.

15. The method according to claim 1, wherein: The method further comprises: Generates multiple different soft-start times for multiple power supplies; and Each of the plurality of power supplies is configured to establish an output voltage within a corresponding soft start time.

16. The method according to claim 1, wherein: The method further comprises: Dividing the soft start time of multiple power supplies into multiple time periods; and The plurality of power supplies are configured to have different slew rates during each of the plurality of time periods.

17. A system comprising: a plurality of power supplies coupled between a power source and a plurality of loads, wherein each of the plurality of power supplies is configured to provide power to a corresponding load; and A system control device is configured to coordinate multiple power supplies during startup so that the multiple power supplies are powered on in a sequential manner.

18. The system of claim 17, wherein: The system control device includes a plurality of startup control programs, each of which is located on a corresponding power supply, wherein: The plurality of startup control programs are configured to generate a plurality of random numbers; as well as A plurality of startup time points are generated based on the plurality of random numbers, wherein each of the plurality of startup time points is used to determine a startup time point of a corresponding power source.

19. The system of claim 17, wherein: The system control device is configured to generate a plurality of startup instructions, which are sent to a communication port of the plurality of power supplies, and each of the plurality of startup instructions is used to determine a startup time point of a corresponding power supply.

20. The system of claim 17, wherein: The system control device includes a plurality of communication channels, each of which is coupled between two power supplies, and the power supplies communicate with each other through the plurality of communication channels to arrange a startup sequence.

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