Multiple input power supply and control method

Abstract

A dual-input power conversion system comprising: a first primary-side power network comprising a first hold-up capacitor, wherein the first primary-side power network has an input configured to be coupled to a first power source and an output coupled to a transformer; a second primary-side power network comprising a second hold-up capacitor, wherein the second primary-side power network has an input configured to be coupled to a second power source and an output coupled to the transformer; and a secondary-side power network having an input coupled to a secondary-side of the transformer and an output coupled to a load, wherein the first primary-side power network and the second primary-side power network are configured such that a voltage across one of the first hold-up capacitor and the second hold-up capacitor is maintained by a voltage reflected from the secondary-side to the corresponding primary-side.

Description

Technical Field

[0001] The present invention relates to multi-input power supplies and control methods, and in a particular embodiment, to a dual-input power supply for efficiently supplying power for information technology (IT) power applications. Background Technology

[0002] With the further development of technology, various internet-based information processing services (such as media streaming and cloud computing) have become popular. Internet-based information processing services require information sharing over networks. This information sharing over networks necessitates multiple data centers to collect, store, process, and distribute the large amounts of data used in these services.

[0003] A data center is a facility (e.g., a building) configured to house a large number of computer servers and associated components. These computer servers are configured to process and respond to information service requests (e.g., multimedia streams) from individual users connected to the data center via the Internet.

[0004] Data center power is a fundamental element in designing and operating efficient and reliable data centers. Most data centers draw their primary power from the power grid. To ensure that data centers always operate smoothly and reliably, redundant or backup power supplies are used to provide a stable supply of clean, uninterrupted power. For example, a data center can be connected to the power grid through two independent power paths (e.g., two separate substations). Additionally, at least one fuel generator is connected to the data center. The fuel generator acts as a backup power supply. In the event of a power outage from the power grid, the fuel generator activates to supply power to the data center. Due to the long start-up time of fuel generators, there is a time delay in the delivery of full power. To maintain continuous and uninterrupted operation of the data center, at least one uninterruptible power supply (UPS) is connected to the data center. The UPS includes batteries, which can provide instantaneous power in the event of a power loss from the power grid.

[0005] To achieve reliable IT power, IT equipment with redundant power supplies (e.g., dual power supplies) is a common practice for reliably operating critical loads. For example, a data center power conversion system connects a power source (e.g., AC power from the grid) to a load (e.g., servers in the data center). The power source can be implemented as two power supplies. The first power supply is connected to a first AC power source. The second power supply is connected to a second AC power source. These two AC power sources are independent of each other. The power conversion system provides two power delivery paths from the two AC power sources to the load (e.g., servers). Therefore, the power conversion system enables input redundancy. A switch can be used to select which power delivery path is used to deliver power from the AC power source to the load. This switch can be implemented as a high-voltage switch with contacts that open and close in oil. Alternatively, the switch can be implemented as a mechanical relay.

[0006] In operation, if an AC power source fails, a switch can redirect power delivery from the failed path to another. The two most common types of switches mentioned above are mechanical switches. Mechanical switches cannot achieve rapid switching. Therefore, power conversion systems must have large holding capacitors to maintain power during failures. A reliable, cost-effective, and long-life power conversion system is desirable to continuously supply power to data centers under various operating conditions. Summary of the Invention

[0007] These and other problems are generally solved or circumvented by providing preferred embodiments of the present disclosure of multi-input power supplies and control methods, and often achieve technical advantages.

[0008] According to one embodiment, a power conversion system includes: a first primary-side power network including a first holding capacitor, wherein the first primary-side power network has an input terminal configured to be connected to a first power source and an output terminal connected to a transformer; a second primary-side power network including a second holding capacitor, wherein the second primary-side power network has an input terminal configured to be connected to a second power source and an output terminal connected to a transformer; and a secondary-side power network having an input terminal connected to the secondary side of the transformer and an output terminal connected to a load, wherein the first primary-side power network and the second primary-side power network are configured such that the voltage across one of the holding capacitors is maintained by a voltage reflected from the secondary side to the corresponding primary side.

[0009] According to another embodiment, a method includes: providing a dual-input power conversion system having two input terminals respectively connected to a first AC power source and a second AC power source, wherein the dual-input power conversion system includes: a first primary-side power network including a first power converter, a first holding capacitor, and a first primary switch connected between the first AC power source and a first primary winding of a transformer; a second primary-side power network including a second power converter, a second holding capacitor, and a second primary switch connected between the second AC power source and a second primary winding of the transformer; and a secondary-side power network connected between the secondary side of the transformer and a load; detecting whether both the first AC power source and the second AC power source are available; and in response to two available AC power sources, disabling one of the first power converter and the second power converter, and configuring the first primary switch and the second primary switch to operate synchronously such that the voltage across one of the holding capacitors is maintained by a voltage reflected from the secondary side to the corresponding primary side.

[0010] The features and technical advantages of this disclosure have been outlined quite extensively above to facilitate a better understanding of the detailed description that follows. Additional features and advantages of this disclosure, which form the subject matter of the claims, will be described below. Those skilled in the art will understand that the disclosed concepts and specific embodiments can be readily used as the basis for modifying or designing other structures or processes for achieving the same purpose as this disclosure. Those skilled in the art will also recognize that such equivalent structures do not depart from the spirit and scope of this disclosure as set forth in the appended claims. Attached Figure Description

[0011] To gain a more complete understanding of this disclosure and its advantages, reference is now made to the following description in conjunction with the accompanying drawings, wherein:

[0012] Figure 1 The illustration shows a block diagram of a dual-input power conversion system according to various embodiments of the present disclosure;

[0013] Figure 2 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of a first embodiment of the dual-input power conversion system shown;

[0014] Figure 3 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of a second embodiment of the dual-input power conversion system shown;

[0015] Figure 4 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the third embodiment of the dual-input power conversion system shown;

[0016] Figure 5 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the fourth embodiment of the dual-input power conversion system shown;

[0017] Figure 6 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the fifth embodiment of the dual-input power conversion system shown;

[0018] Figure 7 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the sixth embodiment of the dual-input power conversion system shown;

[0019] Figure 8 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the seventh embodiment of the dual-input power conversion system shown;

[0020] Figure 9 The diagram illustrates control according to various embodiments of the present disclosure. Figure 1 The flowchart of the dual-input power conversion system is shown; and

[0021] Figure 10 A block diagram of a multi-input power conversion system according to various embodiments of the present disclosure is illustrated.

[0022] Unless otherwise stated, corresponding numbers and symbols in the different figures generally refer to corresponding parts. These figures are drawn to clearly illustrate relevant aspects of the various embodiments and are not necessarily drawn to scale. Specific Implementation

[0023] The following discusses in detail the making and use of the presently preferred embodiments. However, it should be understood that this disclosure provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways of making and using this disclosure and do not limit its scope.

[0024] This disclosure will be described with reference to preferred embodiments in a specific context (i.e., a dual-input power conversion system and control method). However, this disclosure can also be applied to various power conversion systems. Various embodiments will be explained in detail below with reference to the accompanying drawings.

[0025] Figure 1 A block diagram of a dual-input power conversion system according to various embodiments of the present disclosure is illustrated. The dual-input power conversion system 100 includes a first primary-side power network 110, a second primary-side power network 120, a magnetic coupling device 130, and a secondary-side power network 140. As... Figure 1As shown, the input terminal of the first primary-side power network 110 is connected to the first AC power source VS1. The output terminal of the first primary-side power network 110 is connected to the primary side of the magnetic coupling device 130. The input terminal of the second primary-side power network 120 is connected to the second AC power source VS2. The output terminal of the second primary-side power network 120 is connected to the primary side of the magnetic coupling device 130. The secondary side of the magnetic coupling device 130 is connected to the load 150 through the secondary-side power network 140.

[0026] In some embodiments, load 150 is IT equipment in a data center. The first AC power source VS1 and the second AC power source VS2 are independent of each other. For example, VS1 is generated by a first substation of the power grid. VS2 is generated by a second substation of the power grid. Alternatively, VS1 and VS2 originate from the same power source. The power delivery path of VS1 is different from that of VS2. It should be noted that the dual-input power conversion system 100 is not directly connected to VS1 and VS2. Some power conversion components (such as rectifiers and filters) may be connected between the AC power sources VS1 and VS2 and the dual-input power conversion system 100.

[0027] In some embodiments, the magnetic coupling device 130 is implemented as a transformer. Throughout the description, the magnetic coupling device 130 may alternatively be referred to as a transformer. In some embodiments, the transformer 130 has two primary windings and one secondary winding. The first primary winding is connected to a first primary-side power network 110. The second primary winding is connected to a second primary-side power network 120. The secondary winding is connected to a secondary-side power network 140.

[0028] In some embodiments, the first primary-side power network 110 includes a first power converter (e.g., Figure 2 The first boost converter shown is formed by Ql, Dl and the first winding Ll), and the first holding capacitor (e.g., Figure 2 The holding capacitor C1 shown) and the isolation power converter (e.g., Figure 2 The primary-side circuit of the isolated converter (such as a forward converter, a fly-through converter, a fly-through forward converter, a full-bridge converter, a half-bridge converter, an inductor-inductor-capacitor (LLC) resonant converter, any combination thereof, etc.) formed by Q3, NP1, and NS shown is (e.g., Figure 2 Q3 and NP1 are shown. The second primary-side power network 120 includes a second power converter (e.g., Q3 and NP1). Figure 2 The second boost converter shown is formed by Q2, D2 and the second winding L1, and the second holding capacitor (e.g., Figure 2 The holding capacitor C2 shown) and another isolated power converter (e.g., Figure 2The primary-side circuit of the isolated converter (such as a forward converter, a fly-through converter, a fly-through forward converter, a full-bridge converter, a half-bridge converter, an LLC resonant converter, any combination thereof, etc.) formed by Q4, NP2, and NS shown is (e.g., Figure 2 (Q4 and NP2 shown).

[0029] In some embodiments, the first power converter is implemented as a first boost converter. The second power converter is implemented as a second boost converter. To obtain better system performance, the inductors of the first boost converter and the second boost converter are magnetically coupled to each other to form a connection inductor.

[0030] The secondary-side power network 140 may include a rectifier and a filter. The rectifier converts the alternating polarity waveform received from the transformer 130 into a unipolar waveform. The rectifier may be formed from a pair of switching elements, such as an n-type metal-oxide-semiconductor (NMOS) transistor. Alternatively, the rectifier may be formed from a pair of diodes. The filter is used to generate a stable and smooth output voltage at the output Vo of the dual-input power conversion system 100.

[0031] In operation, a system controller (not shown) is configured to determine whether both AC sources VS1 and VS2 are available. Once both AC sources are available, the system controller disables one power converter (e.g., the first converter in 110) and enables the other power converter (e.g., the second converter in 120). Simultaneously, the two primary circuits are turned on and off synchronously. Although the first power converter is disabled, the voltage on the first holding capacitor is maintained by the voltage reflected from the secondary side to the primary side where the first holding capacitor is located. In other words, both the first and second holding capacitors function as energy storage elements. When a fault occurs in the second power source VS2, both the first and second holding capacitors effectively function as a single large holding capacitor, supplying power to the load 150 through transformer 130. In response to a fault in the second power source VS2, the second power converter is disabled, and the first power converter is enabled. With the first power converter enabled, the first power source VS1 is able to supply power to the load 150.

[0032] have Figure 1 An advantageous feature of the illustrated dual-input power conversion system 100 is its ability to switch rapidly in response to system faults. Furthermore, when only one power converter is activated, both the first and second holding capacitors function as energy storage elements. These two holding capacitors function as a single holding capacitor, thereby increasing the effective holding time in the event of a system fault.

[0033] Figure 2 Various embodiments according to this disclosure are illustrated. Figure 1 The diagram shows a first embodiment of a dual-input power conversion system. The dual-input power conversion system has two input terminals respectively connected to a first AC power source VS1 and a second AC power source VS2. Figure 2 As shown, the dual-input power conversion system includes a first primary-side power network 110, a second primary-side power network 120, a transformer, and a secondary-side power network 140.

[0034] The first primary-side power network 110 includes a first power converter, a first holding capacitor C1, and a first primary switch Q3 connected between the first AC power source VS1 and the first primary winding NP1 of the transformer. The second primary-side power network 120 includes a second power converter, a second holding capacitor C2, and a second primary switch Q4 connected between the second AC power source VS2 and the second primary winding NP2 of the transformer. The secondary-side power network 140 is connected to the secondary side of the transformer and the load (not shown, but...). Figure 1 (as shown in the diagram).

[0035] In some embodiments, holding capacitors C1 and C2 are electrolytic capacitors. In alternative embodiments, holding capacitors C1 and C2 may be implemented as other suitable capacitors, such as ceramic capacitors, polymer capacitors, any combination thereof, etc.

[0036] like Figure 2 As shown, the first power converter is a first boost converter. The first boost converter is configured to operate as a power factor correction stage of a dual-input power conversion system. Q3 and NP1 form the primary-side circuitry of the first forward converter. The first forward converter is configured to convert the voltage across the first holding capacitor C1 to a voltage suitable for a load connected at the output Vo of the dual-input power conversion system. Similarly, the second power converter is a second boost converter. The second boost converter is configured to operate as a power factor correction stage of a dual-input power conversion system. Q4 and NP2 form the primary-side circuitry of the second forward converter. The second forward converter is configured to convert the voltage across the second holding capacitor C2 to a voltage suitable for a load connected at the output Vo of the dual-input power conversion system. In some embodiments, NP1 is equal to NP2. The voltage across C1 is equal to the voltage across C2. In alternative embodiments, NP1 is not equal to NP2. The voltage across C1 is not equal to the voltage across C2. Figure 2 The system shown can be operated correctly by applying appropriate control algorithms.

[0037] It should be noted that Figure 2The primary-side circuitry of the illustrated forward converter (e.g., Q3 and NP1) is merely an example and should not unduly limit the scope of the claims. Those skilled in the art will recognize many variations, substitutions, and modifications. For example, depending on different application and design requirements, other related circuitry (such as active clamping) may be included to achieve better efficiency.

[0038] like Figure 2 As shown, the first boost converter includes a first magnetic element, a first switch Q1, and a first diode D1. A first holding capacitor C1 serves as the output capacitor of the first boost converter. The first magnetic element is an inductor, formed by a first winding L1. Figure 2 As shown, the first terminal of the first magnetic element is connected to the first input terminal of the first primary-side power network 110. The second terminal of the first magnetic element is connected to the anode of the first diode D1. The first switch Q1 is connected between the common node of the first magnetic element and the first diode D1 and the second input terminal of the first primary-side power network 110. The first holding capacitor C1 is connected between the cathode of the first diode D1 and the second input terminal of the first primary-side power network 110.

[0039] like Figure 2 As shown, the second boost converter includes a second magnetic element, a second switch Q2, and a second diode D2. A second holding capacitor C2 serves as the output capacitor of the second boost converter. The second magnetic element is an inductor with a second winding L1 formed therein. Figure 2 As shown, the first terminal of the second magnetic element is connected to the first input terminal of the second primary-side power network 120. The second terminal of the first magnetic element is connected to the anode of the second diode D2. The second switch Q2 is connected between the common node of the second magnetic element and the second diode D2 and the second input terminal of the second primary-side power network 120. The second holding capacitor C2 is connected between the cathode of the second diode D2 and the second input terminal of the second primary-side power network 120.

[0040] like Figure 2 As shown, the first magnetic element of the first boost converter and the second magnetic element of the second boost converter are magnetically coupled to each other to form a connecting inductor L1. The controller 101 is configured to generate gate drive signals for the first switch Q1 and the second switch Q2. In some embodiments, the controller 101 is a power management integrated circuit. Alternatively, the controller 101 may be a microcontroller, a digital signal processor (DSP), etc.

[0041] The primary-side circuit of the first forward converter includes a first primary switch Q3 and a first primary winding NP1 of a transformer connected in series. Similarly, the primary-side circuit of the second forward converter includes a second primary switch Q4 connected in series with a second primary winding NP2 of a transformer. The controller 103 is configured to generate gate drive signals for the first primary switch Q3 and the second primary switch Q4.

[0042] The secondary-side power network 140 includes rectifiers and filters cascaded between the secondary side of the transformer and the load. For example... Figure 2 As shown, the rectifier includes a first rectifier diode D3 and a second rectifier diode D4. The filter includes an output inductor L2 and an output capacitor C3. Figure 2 As shown, the anode of the first rectifier diode D3 is connected to the first terminal of the secondary winding NS of the transformer. The anode of the second rectifier diode D4 is connected to the second terminal of the secondary winding NS of the transformer. The cathodes of the first rectifier diode D3 and the second rectifier diode D4 are connected together and further connected to the first terminal of the output inductor L2. The second terminal of the output inductor L2 is connected to the first terminal of the output capacitor C3. The second terminal of the output capacitor C3 is connected to the second terminal of the secondary winding NS of the transformer.

[0043] In some embodiments, Q3 of the first primary-side power network 110, Q4 of the second primary-side power network 120, the transformer, the secondary-side power network 140, and the filter form a converter with a forward topology. In operation, one of the power converters (e.g., the second power converter) can be disabled in response to two available AC power sources. Q3 and Q4 are both turned on and off synchronously. After the second power converter is disabled, the conduction of Q4 helps maintain the voltage across holding capacitor C2. The voltage across holding capacitor C2 is maintained at a level equal to the voltage reflected from the secondary side (NS) to the primary side (NP2). In other words, the voltage across holding capacitor C2 is equal to (Vo × NP2) / NS. Similarly, when the first power converter is disabled, Q3 and Q4 are both turned on and off synchronously. After the first power converter is disabled, the conduction of Q3 helps maintain the voltage across holding capacitor C1. The voltage across holding capacitor C1 is maintained at a level equal to the voltage reflected from the secondary side (NS) to the primary side (NP1). In other words, the voltage across capacitor C1 is equal to (Vo × NP1) / NS. In some embodiments, NP1 equals NP2. The voltage across capacitor C1 is approximately equal to the voltage across capacitor C2.

[0044] It should be noted that Figure 2The schematic diagrams shown are merely 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 first power converter can be implemented as any other suitable power factor correction device. Furthermore, both D1 and D2 can be replaced with high-efficiency switching elements.

[0045] According to one embodiment, Figure 2 The switches (e.g., switches Q1-Q4) can be metal-oxide-semiconductor field-effect transistor (MOSFET) devices, bipolar junction transistor (BJT) devices, superjunction transistor (SJT) devices, insulated gate bipolar transistor (IGBT) devices, gallium nitride (GaN) based power devices, etc.

[0046] It should be noted that, although Figure 2 The diagram shows switches Q1-Q4 implemented as a single n-type transistor, but those skilled in the art will recognize that many variations, modifications, and substitutions are possible. For example, depending on different applications and design requirements, at least some switches may be implemented as p-type transistors. Furthermore, Figure 2 Each switch shown can be implemented as multiple switches connected in parallel. Furthermore, a capacitor can be connected in parallel with one switch to achieve zero-voltage switching (ZVS) / zero-current switching (ZCS).

[0047] During operation, Q1 of the first converter and Q2 of the second converter are simultaneously turned on and off. Due to various mismatches, the voltage across one holding capacitor (e.g., C1) may be higher than the voltage across the other holding capacitor (e.g., C2). Due to magnetic coupling, the converter connected to the holding capacitor with the lower voltage can supply less power to the load.

[0048] During operation, a system controller (not shown) is configured to determine whether both AC power sources are available. Once both AC power sources are available, the system controller shuts off the switch of one power converter (e.g., Q1) while maintaining normal operation of the switch of the other power converter (e.g., Q2). Simultaneously, Q3 and Q4 are switched on and off synchronously. Although Q1 is disabled, the voltage across the first holding capacitor C1 is maintained by the voltage reflected from the secondary side to the primary side.

[0049] In operation, there are two ways to disable one of the power converters. In some embodiments, during the startup process of the dual-input power conversion system, both power converters are configured to operate simultaneously. Voltages are established across C1 and C2 during the startup process. A bias voltage for the system controller is also established during the startup process. This bias voltage can be generated from the voltages across C1 and C2. Once the bias voltage is established, the system controller detects whether both AC power sources are available. Once both AC power sources are available, the system controller can disable one power converter. In an alternative embodiment, the bias voltage for the system controller is generated by a dedicated bias power supply (e.g., an AC / DC converter) before enabling both power converters. Once the bias voltage is established, the system controller detects whether both AC power sources are available. Once both AC power sources are available, the system controller can enable only one power converter.

[0050] Figure 3 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of a second embodiment of the dual-input power conversion system shown. Figure 3 The second embodiment of the dual-input power conversion system shown is similar to Figure 2 The first embodiment of the dual-input power conversion system shown is similar, except that two controllers are used to control Q1 and Q2. For example... Figure 3 As shown, a first controller 101 is configured to generate a gate drive signal for a first switch Q1. A second controller 102 is configured to generate a gate drive signal for a second switch Q2. In some embodiments, Q1 and Q2 are not simultaneously turned on and off. In an alternative embodiment, Q1 and Q2 are in opposite states, one of which is on and the other is off.

[0051] It should be noted that Figure 3 The system configuration shown (two controllers for controlling two switches) applies to all other embodiments in this disclosure. In other words, Figure 3 The system configuration changes shown can be combined with other embodiments of this disclosure.

[0052] Figure 4 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the third embodiment of the dual-input power conversion system shown. Figure 4 The third embodiment of the dual-input power conversion system shown is Figure 2 The first embodiment of the dual-input power conversion system shown is similar, except that the connecting inductor L1 is replaced by two separate inductors L11 and L12. Figure 4 As shown, L11 and L12 are not magnetically coupled to each other.

[0053] It should be noted that Figure 4 The system configuration shown (replacing the connected inductor with two separate inductors) applies to all other embodiments in this disclosure.

[0054] Figure 5 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the fourth embodiment of the dual-input power conversion system shown. Figure 5 The fourth embodiment of the dual-input power conversion system shown is... Figure 2 The first embodiment of the dual-input power conversion system shown is similar, except that the first and second rectifier diodes are replaced by two rectifier switches, respectively. It should be noted that... Figure 5 The substitutions shown are merely examples. Those skilled in the art will understand that many variations exist. For example, the first and second rectifier diodes can be replaced by two MOSFET switches, a combination of a MOSFET switch and a diode, or any combination thereof.

[0055] like Figure 5 As shown, the rectifier includes a first rectifier switch Q5 and a second rectifier switch Q6. The filter includes an output inductor L2 and an output capacitor C3. The drain of the first rectifier switch Q5 is connected to the first terminal of the secondary winding NS of the transformer. The drain of the second rectifier switch Q6 is connected to the second terminal of the secondary winding NS of the transformer. The sources of the first rectifier switch Q5 and the second rectifier switch Q6 are connected together and further connected to the second terminal of the output capacitor C3. The first terminal of the output inductor L2 is connected to the first terminal of the secondary winding NS of the transformer. The first terminal of the output capacitor C3 is connected to the second terminal of the output inductor L2.

[0056] In some embodiments, Q3 of the first primary-side power network 110, Q4 of the second primary-side power network 120, the transformer, Q5 and Q6 of the secondary-side power network 140, and the filter form a converter with a forward topology. The operating principle of this forward topology has been explained above regarding... Figure 2 It has already been described, so it will not be discussed further here.

[0057] Figure 6 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the fifth embodiment of the dual-input power conversion system shown. Figure 6 The fifth embodiment of the dual-input power conversion system shown is... Figure 2 The first embodiment of the dual-input power conversion system shown is similar, except that diodes D1 and D2 are replaced by two switches respectively. It should be noted that... Figure 6The substitutions shown are merely examples. Those skilled in the art will understand that many variations exist. For example, diodes D1 and D2 can be replaced by two MOSFET switches, a combination of a MOSFET switch and a diode, or any combination thereof.

[0058] like Figure 6 As shown, D1 is replaced by the third switch Q11. D2 is replaced by the fourth switch Q21. The first boost converter includes a first magnetic element (first winding L1), a first switch Q1, and a third switch Q11. The first terminal of the first magnetic element is connected to the first input terminal of the first primary-side power network. The second terminal of the first magnetic element is connected to the source of the third switch Q11. The first switch Q1 is connected between the common node of the first magnetic element and the third switch Q11 and the second input terminal of the first primary-side power network. A first holding capacitor C1 is connected between the drain of the third switch Q11 and the second input terminal of the first primary-side power network. The second boost converter includes a second magnetic element (second winding L1), a second switch Q2, and a fourth switch Q21. The first terminal of the second magnetic element is connected to the first input terminal of the second primary-side power network. The second terminal of the first magnetic element is connected to the source of the fourth switch Q21. The second switch Q2 is connected between the common node of the second magnetic element and the fourth switch Q21 and the second input terminal of the second primary-side power network. The second holding capacitor C2 is connected between the drain of the fourth switch Q21 and the second input terminal of the second primary-side power network.

[0059] It should be noted that Figure 6 The system configuration shown (diodes D1 and D2 replaced by two switches) applies to all other embodiments of this disclosure. In other words, Figure 6 The system configuration changes shown can be combined with other embodiments in this disclosure.

[0060] Figure 7 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the sixth embodiment of the dual-input power conversion system shown. Figure 7 The sixth embodiment of the dual-input power conversion system shown is... Figure 2 The first embodiment of the dual-input power conversion system shown is similar, except that... Figure 2 The forward topology shown is replaced by the flying forward topology.

[0061] like Figure 7As shown, the rectifier includes a first rectifier diode D3 and a second rectifier diode D4. The filter includes an output capacitor C3. The anode of the first rectifier diode D3 is connected to the first terminal of the primary winding NS1 of the transformer. The anode of the second rectifier diode D4 is connected to the second terminal of the secondary winding NS2 of the transformer. The cathodes of the first rectifier diode D3 and the second rectifier diode D4 are connected together and further connected to the first terminal of the output capacitor C3. The second terminal of the primary winding NS1 of the transformer is connected to the first terminal of the secondary winding NS2 of the transformer and further connected to the second terminal of the output capacitor C3.

[0062] In some embodiments, Q3 of the first primary-side power network 110, Q4 of the second primary-side power network 120, the transformer, D3 and D4 of the secondary-side power network 140, and the filter form a converter with a flying forward topology.

[0063] Figure 8 Various embodiments according to this disclosure are illustrated. Figure 1 A schematic diagram of the seventh embodiment of the dual-input power conversion system shown. Figure 8 The seventh embodiment of the dual-input power conversion system shown is Figure 2 The first embodiment of the dual-input power conversion system shown is similar, except that... Figure 2 The forward topology shown is replaced by the flyback topology.

[0064] like Figure 8 As shown, the rectifier includes a rectifier diode D3. The filter includes an output capacitor C3. The anode of the rectifier diode D3 is connected to the first terminal of the secondary winding NS of the transformer. The cathode of the rectifier diode D3 is connected to the first terminal of the output capacitor C3. The second terminal of the output capacitor C3 is connected to the second terminal of the secondary winding NS of the transformer.

[0065] In some embodiments, Q3 of the first primary-side power network 110, Q4 of the second primary-side power network 120, the transformer, D3 of the secondary-side power network 140, and the filter form a converter with a flyback topology.

[0066] Figure 9 The diagram illustrates control according to various embodiments of the present disclosure. Figure 1 The flowchart shown is for a dual-input power conversion system. Figure 9 The flowchart shown is merely an example and should not unduly limit the scope of the claims. Those skilled in the art will recognize many variations, substitutions, and modifications. For example, additions, removals, substitutions, rearrangements, and repetitions may be made. Figure 9 The various steps are illustrated in the diagram.

[0067] Return to reference Figure 1 The dual-input power conversion system includes a first primary-side power network (e.g., Figure 1 The first primary-side power network 110 and the second primary-side power network (e.g., shown) are illustrated. Figure 1 The second primary-side power network 120 shown), and the transformer (e.g., Figure 1 Transformer 130 shown) and secondary power network (e.g., Figure 1 The secondary power network 140 shown.

[0068] The first primary-side power network includes connections to the first AC power source (e.g., ...). Figure 2 VS1 as shown) and the first primary winding of the transformer (e.g., Figure 2 The first power converter between NP1 (as shown) and (e.g., Figure 2 The first power converter shown is formed by Ql, Dl and the first winding of the connecting inductor Ll), and the first holding capacitor (e.g., Figure 2 The holding capacitor C1 and the first primary switch (e.g., shown) are shown. Figure 2 Q3 shown).

[0069] The second primary-side power network includes connections to the second AC power source (e.g., ...). Figure 2 The VS2 shown) and the second primary winding of the transformer (e.g., Figure 2 The second power converter between NP2 (as shown) and (e.g., Figure 2 The second power converter shown is formed by Q2, D2 and the second winding of the connecting inductor L1, and the second holding capacitor (e.g., Figure 2 The holding capacitor C2 shown) and the second primary switch (e.g., Figure 2 Q4 is shown. Secondary power network (e.g., Figure 2 D3, D4, L2 and C3 (shown) are connected between the secondary side of the transformer and the load.

[0070] At step 902, a dual-input power conversion system is provided. The dual-input power conversion system has two input terminals respectively connected to a first AC power source and a second AC power source.

[0071] The dual-input power conversion system includes: a first primary-side power network comprising a first power converter, a first holding capacitor, and a first primary switch connected between a first AC power source and a first primary winding of a transformer; a second primary-side power network comprising a second power converter, a second holding capacitor, and a second primary switch connected between a second AC power source and a second primary winding of a transformer; and a secondary-side power network connected between the secondary side of the transformer and the load.

[0072] At step 904, the system controller checks whether both the first AC power source and the second AC power source are available.

[0073] At step 906, in response to two available AC power sources, the system controller disables one of the first power converter and the second power converter, and configures the first primary switch and the second primary switch to operate synchronously, such that the voltage across one of the first holding capacitors is maintained by the voltage reflected from the secondary side to the corresponding primary side.

[0074] It should be noted that when the inductor of the first power converter is magnetically coupled to the inductor of the second power converter (e.g., Figure 2 When the inductor of the first power converter (as shown in inductor L1) is not magnetically coupled to the inductor of the second power converter (e.g., ...), the system controller must disable one power converter. Alternatively, when the inductor of the first power converter is not magnetically coupled to the inductor of the second power converter (e.g., ...), Figure 4 When inductors L11 and L12 are shown, both power converters can operate simultaneously. The power converter with the higher output voltage (PFC circuit) provides more power to the load.

[0075] The method further includes: during the startup process of the dual-input power conversion system, enabling both the first power converter and the second power converter to establish a first voltage across the first holding capacitor and a second voltage across the second holding capacitor; establishing a bias voltage based on the first voltage across the first holding capacitor and the second voltage across the second holding capacitor; and once the bias voltage has been established, detecting whether both the first AC power source and the second AC power source are available.

[0076] The method further includes: establishing a bias voltage using an independent AC / DC power converter during the startup process of the dual-input power conversion system; once the bias voltage has been established, detecting whether both the first AC power source and the second AC power source are available; and enabling one of the first power converter and the second power converter to establish a first voltage across the first holding capacitor and a second voltage across the second holding capacitor.

[0077] The method further includes: disabling a second power converter in response to two available AC power sources and configuring a first AC power source to provide power to a load; and disabling the first power converter in response to a fault occurring in the first AC power source, configuring a first holding capacitor and a second holding capacitor to provide power to a load, and enabling a second power converter to supplement the first holding capacitor and the second holding capacitor and provide power to the load.

[0078] Return to reference Figure 2The first power converter is a first boost converter, and the second power converter is a second boost converter. The inductors of the first boost converter and the second boost converter are magnetically coupled to each other to form a connecting inductor.

[0079] The method further includes: configuring the first boost converter as a first power factor correction circuit when the first boost converter is enabled; and configuring the second boost converter as a second power factor correction circuit when the second boost converter is enabled.

[0080] The method also includes configuring a first primary switch, a second primary switch, a transformer, and a secondary-side power network to form a converter with a forward topology.

[0081] The method also includes configuring a first primary switch, a second primary switch, a transformer, and a secondary-side power network to form a converter with a flying forward topology.

[0082] The method also includes configuring a first primary switch, a second primary switch, a transformer, and a secondary-side power network to form a converter with a flyback topology.

[0083] Figure 10 The figure illustrates a block diagram of a multi-input power conversion system according to various embodiments of the present disclosure. The multi-input power conversion system 1000 is similar to... Figure 1 The dual-input power conversion system 100 shown is an alternative to the multi-input power conversion system 1000, which has more than two input terminals. The aforementioned system and associated control methods are applicable to the multi-input power conversion system 1000. During operation, at least one input terminal and its associated power conversion circuit are disabled. The voltage across the holding capacitor of the disabled power conversion circuit is maintained by a reflected voltage.

[0084] In some embodiments, Figure 10 The power sources VS1 and VSN shown are multiple AC power sources. In this system configuration, each AC power source is connected to a boost converter (e.g., Figure 2 The first boost converter shown, formed by the first windings L1, Q1, and D1, is connected to a holding capacitor (e.g., Figure 2 The holding capacitor C1 is shown. In an alternative embodiment, Figure 10 The power sources VS1 and VSN shown are multiple DC power sources. In this system configuration, each DC power source is connected in parallel with a holding capacitor. Furthermore, Figure 10 The power sources VS1 and VSN shown can be implemented as multiple power sources, including both AC and DC power sources. In this system configuration, each DC power source is connected in parallel with a holding capacitor. Each AC power source is connected to the holding capacitor via a boost converter.

[0085] Although embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications may be made herein without departing from the spirit and scope of the present disclosure as defined by the appended claims.

[0086] Furthermore, the scope of this application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, means, methods, and steps described in the specification. As will be readily understood by those skilled in the art from the disclosure of this publication, existing or future processes, machines, manufactures, compositions of matter, means, methods, or steps that perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein can be utilized according to this disclosure. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, means, methods, or steps within their scope.

Claims

1. A power conversion system, comprising: A first primary-side power network includes a first holding capacitor, wherein the first primary-side power network has an input terminal configured to be connected to a first power source and an output terminal configured to be connected to a transformer. A second primary-side power network includes a second holding capacitor, wherein the second primary-side power network has an input terminal configured to be connected to a second power source and an output terminal configured to be connected to the transformer; as well as The secondary power network has an input terminal connected to the secondary side of the transformer and an output terminal connected to the load. A first primary switch of the first primary power network and a second primary switch of the second primary power network are configured to turn on and off synchronously, such that the voltage across one of the first and second holding capacitors is maintained by a voltage reflected from the secondary side to the corresponding primary side. Since the first and second primary switches are configured to turn on and off synchronously, both the first and second holding capacitors function as energy storage elements. When the first power source is disabled and the second power source fails, or when the second power source is disabled and the first power source fails, both the first and second holding capacitors effectively function as a single large holding capacitor, supplying power to the load through the transformer.

2. The power conversion system according to claim 1, wherein: The first power source is a first AC power source; The second power source is a second AC power source; The first primary-side power network includes the primary-side circuitry of the first boost converter and the first forward converter; and The second primary-side power network includes the primary-side circuitry of the second boost converter and the second forward converter.

3. The power conversion system according to claim 2, wherein: The first boost converter includes a first magnetic element, a first switch, and a first diode, wherein: The first terminal of the first magnetic element is connected to the first input terminal of the first primary-side power network; The second terminal of the first magnetic element is connected to the anode of the first diode; The first switch is connected between the common node of the first magnetic element and the first diode and the second input terminal of the first primary-side power network; and The first holding capacitor is connected between the cathode of the first diode and the second input terminal of the first primary-side power network; and The second boost converter includes a second magnetic element, a second switch, and a second diode, wherein: The first terminal of the second magnetic element is connected to the first input terminal of the second primary-side power network; The second terminal of the first magnetic element is connected to the anode of the second diode; The second switch is connected between the common node of the second magnetic element and the second diode and the second input terminal of the second primary-side power network; and The second holding capacitor is connected between the cathode of the second diode and the second input terminal of the second primary-side power network.

4. The power conversion system according to claim 3, wherein: The first input terminal and the second input terminal of the first primary-side power network are configured to be connected to the first AC power source; and The first and second input terminals of the second primary-side power network are configured to be connected to the second AC power source.

5. The power conversion system according to claim 3, wherein: The first magnetic element and the second magnetic element are magnetically coupled to each other to form a coupling inductor.

6. The power conversion system according to claim 3, wherein: The first magnetic element and the second magnetic element are two separate inductors.

7. The power conversion system according to claim 3, further comprising: A controller configured to generate gate drive signals for the first switch and the second switch.

8. The power conversion system according to claim 3, further comprising: A first controller is configured to generate a first gate drive signal for the first switch; as well as A second controller is configured to generate a second gate drive signal for the second switch.

9. The power conversion system according to claim 3, wherein: The primary-side circuit of the first forward converter includes a first primary switch connected in series with the first primary winding of the transformer; and The primary-side circuit of the second forward converter includes a second primary switch connected in series with the second primary winding of the transformer.

10. The power conversion system according to claim 9, wherein: After the first boost converter is disabled, the first primary switch and the second primary switch are configured to turn on and off synchronously, such that the voltage reflected from the secondary side is used to maintain the voltage across the first holding capacitor.

11. The power conversion system according to claim 1, wherein: The secondary power network includes a rectifier and a filter cascaded between the secondary side of the transformer and the load.

12. The power conversion system according to claim 11, wherein: The rectifier includes a first rectifier diode and a second rectifier diode; The filter includes an output inductor and an output capacitor, wherein: The anode of the first rectifier diode is connected to the first terminal of the secondary winding of the transformer; The anode of the second rectifier diode is connected to the second terminal of the secondary winding of the transformer; The cathodes of the first rectifier diode and the second rectifier diode are connected together and further connected to the first terminal of the output inductor; The second terminal of the output inductor is connected to the first terminal of the output capacitor; and The second terminal of the output capacitor is connected to the second terminal of the secondary winding of the transformer, and wherein the first primary-side power network, the second primary-side power network, the transformer, and the secondary-side power network form a converter with a forward topology.

13. The power conversion system according to claim 11, wherein: The rectifier includes a first rectifier switch and a second rectifier switch; The filter includes an output inductor and an output capacitor, wherein: The drain of the first rectifier switch is connected to the first terminal of the secondary winding of the transformer; The drain of the second rectifier switch is connected to the second terminal of the secondary winding of the transformer; The source of the first rectifier switch and the source of the second rectifier switch are connected together, and further connected to the second terminal of the output capacitor; The first terminal of the output inductor is connected to the first terminal 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, and the first primary-side power network, the second primary-side power network, the transformer, and the secondary-side power network form a converter with a forward topology.

14. The power conversion system according to claim 11, wherein: The rectifier includes a first rectifier diode and a second rectifier diode; The filter includes an output capacitor, and wherein: The anode of the first rectifier diode is connected to the first terminal of the primary winding of the transformer; The anode of the second rectifier diode is connected to the second terminal of the second stage winding of the transformer; The cathodes of the first rectifier diode and the second rectifier diode are connected together and further connected to the first terminal of the output capacitor; and The second terminal of the first primary winding of the transformer is connected to the first terminal of the second secondary winding of the transformer, and further connected to the second terminal of the output capacitor, wherein the first primary power network, the second primary power network, the transformer and the secondary power network form a converter with a flying forward topology.

15. The power conversion system according to claim 11, wherein: The rectifier includes rectifier diodes; The filter includes an output capacitor, and wherein: The anode of the rectifier diode is connected to the first terminal of the secondary winding of the transformer; The cathode of the rectifier diode is connected to the first terminal of the output capacitor; and The second terminal of the output capacitor is connected to the second terminal of the secondary winding of the transformer, and wherein the first primary-side power network, the primary-side power network, the transformer, and the secondary-side power network form a converter with a flyback topology.

16. The power conversion system according to claim 1, wherein: The first primary-side power network includes the primary-side circuitry of the first boost converter and the first forward converter; and The second primary-side power network includes the primary-side circuitry of the second boost converter and the second forward converter, wherein: The first boost converter includes a first magnetic element, a first switch, and a third switch, wherein: The first terminal of the first magnetic element is connected to the first input terminal of the first primary-side power network; The second terminal of the first magnetic element is connected to the source of the third switch; The first switch is connected between the common node of the first magnetic element and the third switch and the second input terminal of the first primary-side power network; and The first holding capacitor is connected between the drain of the third switch and the second input terminal of the first primary-side power network; and The second boost converter includes a second magnetic element, a second switch, and a fourth switch, wherein: The first terminal of the second magnetic element is connected to the first input terminal of the second primary-side power network; The second terminal of the second magnetic element is connected to the source of the fourth switch; The second switch is connected between the common node of the second magnetic element and the fourth switch and the second input terminal of the second primary-side power network; and The second holding capacitor is connected between the drain of the fourth switch and the second input terminal of the second primary-side power network.

17. A power conversion method, comprising: A dual-input power conversion system is provided, having two input terminals respectively connected to a first AC power source and a second AC power source, wherein the dual-input power conversion system includes; A first primary-side power network includes a first power converter, a first holding capacitor, and a first primary switch connected between the first AC power source and the first primary winding of the transformer. The second primary-side power network includes a second power converter, a second holding capacitor, and a second primary switch connected between the second AC power source and the second primary winding of the transformer; as well as The secondary power network is connected between the secondary side of the transformer and the load; Check whether both the first AC power source and the second AC power source are available; as well as In response to two available AC power sources, the second power converter is disabled, the first AC power source is configured to supply power to the load, and the first primary switch and the second primary switch are configured to operate synchronously such that the voltage across one of the first and second holding capacitors is maintained by the voltage reflected from the secondary side to the corresponding primary side. In response to a failure of the first AC power source, the first power converter is disabled, the first holding capacitor and the second holding capacitor are configured to supply power to the load, and the second power converter is enabled to supplement the first holding capacitor and the second holding capacitor and supply power to the load.

18. The method of claim 17, further comprising: During the startup process of the dual-input power conversion system, both the first power converter and the second power converter are activated to establish a first voltage across the first holding capacitor and a second voltage across the second holding capacitor. A bias voltage is established based on the first voltage across the first holding capacitor and the second voltage across the second holding capacitor; as well as Once the bias voltage has been established, it is determined whether both the first AC power source and the second AC power source are available.

19. The method of claim 17, further comprising: During the startup process of the dual-input power conversion system, a bias voltage is established using an independent AC / DC power converter; Once the bias voltage has been established, it is determined whether both the first AC power source and the second AC power source are available. as well as Enable one of the first power converter and the second power converter to establish a first voltage across the first holding capacitor and a second voltage across the second holding capacitor.

20. The method of claim 17, further comprising: In response to the two available AC power sources, the second power converter is disabled, and the first AC power source is configured to provide power to the load; as well as In response to a fault occurring in the first AC power source, the first power converter is disabled, the first holding capacitor and the second holding capacitor are configured to provide power to the load, and the second power converter is enabled to supplement the first holding capacitor and the second holding capacitor and provide power to the load.

21. The method of claim 17, wherein: The first power converter is a first boost converter; and The second power converter is a second boost converter.

22. The method according to claim 21, wherein: The inductors of the first boost converter and the second boost converter are magnetically coupled to each other to form a connecting inductor.

23. The method of claim 21, further comprising: When the first boost converter is enabled, the first boost converter is configured as a first power factor correction circuit; as well as When the second boost converter is enabled, the second boost converter is configured as a second power factor correction circuit.

24. The method of claim 17, wherein: The first AC power source is independent of the second AC power source.

25. The method of claim 17, further comprising: The first primary switch, the second primary switch, the transformer, and the secondary power network are configured to form a converter with a forward topology.

26. The method of claim 17, further comprising: The first primary switch, the second primary switch, the transformer, and the secondary power network are configured to form a converter with a flying forward topology.

27. The method of claim 17, further comprising: The first primary switch, the second primary switch, the transformer, and the secondary power network are configured to form a converter with a flyback topology.

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