Modular static transfer switch with wide bandgap transistors

Abstract

A modular static transfer switch (STS) assembly includes a semiconductor power system constructed from wide-bandgap transistors. A first input terminal of the STS assembly is electrically coupled to a first power supply, and a second input terminal is electrically coupled to a second power supply. The output terminal of the STS assembly is electrically coupled to a load. The load is powered by the first power supply via the STS modular assembly. A current isolator, such as a relay, contactor, circuit breaker, or fuse, disconnects any faulty semiconductor power system. The STS also includes a controller for performing the conversion of power supplied to the load from the first power supply to the second power supply by: electrically decoupling the first power supply from the load, verifying that the first power supply has been disconnected from the load, and providing a command to electrically couple the second power supply to the load.

Description

Cross-references to related applications

[0001] This patent application claims priority to U.S. Patent Application No. 18 / 530,778, filed December 6, 2023, which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a modular static switching switch. Specifically, this disclosure relates to a modular static switching switch implemented using a wide-bandgap semiconductor transistor. Background Technology

[0003] Existing static transfer switches (STSs) lack modularity. Manufacturing STS products with different current ratings (e.g., 200A / 250A, 400A, and 600A) requires entirely different thyristor power modules and heatsink assemblies. Different STS designs necessitate a large number of components to be stocked at production and maintenance sites, creating a significant logistical and supply chain burden. Furthermore, the thyristors, the primary semiconductor device used in existing STSs, are unsuitable for parallel connections. Due to their negative temperature coefficient, thyristors are prone to thermal runaway, meaning their on-state voltage drop decreases as junction temperature increases. When two thyristors are connected in parallel, the hotter thyristor carries more current, becoming hotter and ultimately failing. Additionally, thyristors are semi-controlled semiconductor devices and cannot be turned off until an external current reverses. This turn-off delay is undesirable in next-generation mission-critical systems. Summary of the Invention

[0004] A first aspect of this disclosure provides a modular static transfer switch (STS) assembly. The modular STS assembly includes: at least one semiconductor power assembly, the at least one semiconductor power assembly being constructed using wide-bandgap transistors; a first input terminal of the modular STS assembly electrically coupled to a first power source; a second input terminal of the modular STS assembly electrically coupled to a second power source; an output terminal of the modular STS assembly electrically coupled to a load, wherein the load is powered via the modular STS assembly using the first power source; a current isolator for disconnecting any faulty semiconductor power system; and a controller for performing a conversion of power supplied to the load from the first power source to the second power source. The controller is configured to: provide instructions to electrically decouple the first power source from the load, verify the disconnection of the first power source from the load, and provide instructions to electrically connect the second power source to the load.

[0005] According to the implementation of the first aspect, at least one semiconductor power assembly includes two wide-bandgap transistors connected in reverse series, and the wide-bandgap transistors include at least one of the following: MOSFET, JFET, IGBT, GIT, HEMT, FinFET.

[0006] According to the implementation of the first aspect, a first power supply is connected to a first terminal of a first wide-bandgap transistor via a first input terminal, a second power supply is connected to a first terminal of a second wide-bandgap transistor via a second input terminal, and the output terminal of the modular STS component is connected to a second terminal of the first wide-bandgap transistor and a second terminal of the second wide-bandgap transistor.

[0007] According to the implementation of the first aspect, the modular static switching assembly further includes a second semiconductor power assembly composed of wide-bandgap transistors, wherein the second semiconductor power assembly includes two wide-bandgap transistors connected in reverse series.

[0008] According to the implementation of the first aspect, at least one semiconductor power assembly and a second semiconductor power assembly are connected in parallel.

[0009] According to the implementation of the first aspect, at least one semiconductor power assembly is connected to a first power source, and a second semiconductor power assembly is connected to a second power source.

[0010] According to the implementation of the first aspect, at least one semiconductor power assembly connected in parallel with the second semiconductor power assembly is a first STS unit, and further includes: a second STS unit, the second STS unit including a third semiconductor power assembly and a fourth semiconductor power assembly, wherein the third semiconductor power assembly is connected to at least one semiconductor power assembly, and the fourth semiconductor power assembly is connected to the second semiconductor power assembly.

[0011] According to the implementation of the first aspect, at least one semiconductor power assembly connected in parallel with the second semiconductor power assembly is a first STS unit, and further includes: a second STS unit, the second STS unit including a third semiconductor power assembly and a fourth semiconductor power assembly, wherein the third semiconductor power assembly is connected to the second phase of the first power supply, and the fourth semiconductor power assembly is connected to the second phase of the second power supply.

[0012] According to the implementation of the first aspect, at least one semiconductor power assembly and a second semiconductor power assembly are connected in series.

[0013] According to the implementation of the first aspect, at least one semiconductor power assembly includes one or more bidirectional or four-quadrant wide-bandgap transistors, and the wide-bandgap transistors include at least one of the following: MOSFET, JFET, IGBT, GIT, HEMT, FinFET.

[0014] According to the implementation method of the first aspect, the modular STS has N+1 parallel branches in structure, and the N+1th branch is used to maintain the operation of the modular STS in the event that one of the branches in the first N branches is disconnected and the circuit cannot be disconnected.

[0015] A second aspect of this disclosure provides a method for switching power supplied to a load from a first power source to a second power source. The method includes: providing instructions to electrically decouple the first power source from the load, verifying the disconnection of the first power source from the load, and providing instructions to electrically connect the second power source to the load.

[0016] A third aspect of this disclosure provides a non-transitory computer-readable medium having processor-executable instructions stored thereon, wherein the processor-executable instructions, when executed by one or more processors, are configured to: provide instructions to electrically decouple a first power supply from a load, verify that the first power supply is disconnected from the load, and provide instructions to electrically connect a second power supply to the load. Attached Figure Description

[0017] The subject matter of this disclosure will now be described in more detail with reference to the exemplary accompanying drawings. All features described and / or illustrated herein may be used alone or in different combinations. The features and advantages of various embodiments will be understood by referring to the following detailed description and in conjunction with the accompanying drawings, wherein:

[0018] Figure 1 A simplified circuit diagram of a modular static changeover switch according to one or more examples of this disclosure is shown;

[0019] Figure 2 The diagram shows the operating waveforms of a modular static changeover switch according to one or more examples of this disclosure;

[0020] Figure 3 The topology of a modular static changeover switch according to one or more examples of this disclosure is shown;

[0021] Figure 4 Another topology of a modular static changeover switch according to one or more examples of this disclosure is shown;

[0022] Figure 5 Another topology of a modular static changeover switch according to one or more examples of this disclosure is shown;

[0023] Figures 6A to 6D The diagram shows the current commutation waveforms of a modular static transfer switch according to one or more examples of this disclosure;

[0024] Figure 7 Circuit diagrams of thyristor-based and MOSFET-based static switching switches for calculating power consumption are shown according to one or more examples of this disclosure;

[0025] Figure 8 A schematic diagram of the mechanical structure of a modular static changeover switch according to one or more examples of this disclosure is shown;

[0026] Figure 9A block diagram of a controller for implementing a modular static transfer switch according to one or more examples of this disclosure is shown;

[0027] Figure 10 A flowchart illustrating a method for operating a modular static changeover switch according to one or more examples of this disclosure is shown; and

[0028] Figure 11 The process performed by a controller, which is part of a modular static toggle switch, is shown according to one or more examples of this disclosure. Detailed Implementation

[0029] Existing static transfer switches (STS) utilize thyristor power modules and heat sink modules. Manufacturing STSs with various rated currents (200A / 250A, 400A, or 600A) using thyristor modules requires a large number of components in production and maintenance, creating logistical and supply chain issues. Furthermore, thyristor power modules are prone to thermal runaway due to their negative temperature coefficient. Thyristors also cannot be used in parallel to achieve modular STS designs because when two thyristors are connected in parallel, the hotter thyristor will carry a larger current, causing its temperature to rise further and eventually leading to damage. In addition, thyristors are semi-controlled semiconductor devices and cannot be turned off before the external current reverses. In fact, in 60Hz systems adapted to thyristor-based STS solutions, devices typically exhibit a turn-off delay of up to 8 milliseconds. This turn-off delay is unacceptable in next-generation mission-critical systems.

[0030] This disclosure proposes a modular static switching (STS) topology for mission-critical systems, utilizing wide-bandgap transistor devices. The scalable STS, employing modular building blocks, improves efficiency in product design, manufacturing, and maintenance. Ultra-high-speed STS can rapidly switch between power sources during power outages, better meeting user needs. This disclosure utilizes high-power transistor devices in the modular STS design, including but not limited to various wide-bandgap transistors: field-effect transistors (FETs), such as metal-oxide-semiconductor field-effect transistors (MOSFETs), junction field-effect transistors (JFETs), insulated-gate bipolar transistors (IGBTs), gate-injected transistors (GITs), and high-electron-mobility transistors (HEMTs). In some embodiments, the wide-bandgap transistors can be fabricated using various semiconductor materials, including but not limited to silicon, silicon carbide (SiC), gallium nitride (GaN), and diamond (C). To achieve modular design, transistor modules are assembled into independent components, and multiple groups of components can be connected in parallel to obtain higher rated current; to achieve ultra-fast switching, transistor modules can complete active shutdown within 500 microseconds after receiving a shutdown command.

[0031] In some embodiments, the static transfer switch of this disclosure includes a semiconductor power circuit constructed from wide-bandgap transistors. In each STS modular component, wide-bandgap transistors are connected in parallel, and multiple STS modular components can also be connected in parallel to increase the rated current of each static transfer switch. The wide-bandgap transistors can be instantaneously turned off upon receiving a switching command, thereby achieving ultra-fast switching. In some embodiments, each STS modular component has at least two input terminals, connected to a preferred power supply and a backup power supply, respectively. In some embodiments, the cooling system of each STS modular component is shared by multiple input sources to improve utilization and reduce overall size. In other embodiments, the cooling system can be shared among different STS modules to improve the utilization of the cooling system. In some schemes, electrical isolation devices such as relays and contactors are connected in series with transistors in each STS modular component, allowing faulty components to be disconnected and the system to operate continuously using N+1 redundancy. As is well known, N+1 redundancy is achieved by adding a single additional STS module to the existing architecture consisting of N STS modules, thereby providing a minimum level of fault tolerance to support failures or allow a single STS module to be repaired without interrupting the overall function of the STS system.

[0032] Figure 1 A simplified circuit diagram of a modular static changeover switch according to one or more examples of this disclosure is shown. Figure 1The circuit diagram 100 includes a first power module input (S1) 102 and a second power module input (S2) 104. The two power module inputs 102 and 104 are connected to two input terminals of the STS building block 108. The first power module input 102 is connected to the first power module 112 of the STS building block 108 via a first fuse or contactor 110. Similarly, the second power module input 104 is connected to the second power module 114 of the STS building block 108 via a second fuse or contactor 116. The first power module 112 and the second power module 114 of the STS building block 108 are connected to the STS output terminal 106. In some embodiments, the first power module 112 and the second power module 114 include power modules containing wide-bandgap transistors. In some embodiments, the first power module input 102 is connected to the STS output terminal 106 via the first power module 112 and can be used to provide power to a load connected to the STS output terminal 106. Upon receiving a command from the controller, STS building block 108 can switch from the first power module input 102 to the second power module input 104. In some cases, when switching from the first power module input 102 to the second power module input 104, the first STS building block 108 shuts down the first power module 112 and turns on the second power module 114. This disconnects the first power module input 102 from the STS output 106 and connects the second power module input 104 to the STS output 106. In some embodiments, a switching algorithm can be used to complete the switching. STS blocks 118, 120, and 122 are similar to STS block 108.

[0033] In some embodiments, the voltage clamping circuit is connected in parallel with the semiconductor powertrain of the STS building block 108. During the process of switching the power supplied to the load from the first power module input 102 to the second power module input 104, when the semiconductor switch associated with the first power module 112 is turned off, the current is switched to the voltage clamping circuit, which reduces the current to zero.

[0034] The purpose of a voltage clamping circuit is to reduce the current to zero while preventing the voltage across the semiconductor power device from exceeding the maximum rated voltage of the semiconductor device used in the power device.

[0035] Without voltage clamping circuitry, the voltage across a semiconductor power device could rise to dangerous levels and damage the device.

[0036] For the purposes of this disclosure, STS building block 108 can be considered to have a rated current of 200A. In some embodiments, the capacity of the modular STS can be easily increased by connecting STS building blocks 108, 118, 120, and 122 in parallel, such as Figure 1As shown. In some embodiments, two STS blocks 108 and 118 can be connected in parallel to achieve a rated current of 400A, three STS blocks 108, 118, and 120 can be connected in parallel to achieve a rated current of 600A, and four STS blocks 108, 118, 120, and 122 can be connected in parallel to achieve a rated current of 800A. It is understood that STS blocks 108 and 118-122 can be constructed using wide-bandgap transistors to achieve any desired rated current. The peripheral gate driver and the control circuitry of the STS architecture will be modified accordingly to accommodate the operation of the wide-bandgap transistors in the STS blocks.

[0037] In the STS architecture, the wide-bandgap transistors used in STS block 108 can be connected in parallel because wide-bandgap transistors such as MOSFETs have a positive temperature coefficient, which is beneficial for parallel connection. In some embodiments, using wide-bandgap semiconductor transistors (e.g., silicon carbide (SiC) MOSFETs) in the first power module 112 and the second power module 114 enables low conduction losses, making them comparable to thyristors. The parallel MOSFETs operate in a manner similar to parallel resistors to automatically balance current sharing. MOSFETs are fully controllable devices with the ability to turn on and off instantly. The turn-off delay of the STS using MOSFETs is less than 0.5 milliseconds, which reduces the total transmission time when switching from the first power input 102 to the second power input 104. Thus, the MOSFET-based STS enables modularity and ultra-fast transmission. In each STS building block 108, 118, 120, and 122, SiC MOSFETs can be connected in parallel to reduce power losses and enhance overload withstand capability. In some embodiments, SiC MOSFETs can also be connected in series to achieve higher voltage levels.

[0038] Figure 2 Graphs relating to modular static transfer switches according to one or more examples of this disclosure are shown. Circuit diagram 200 shows two thyristors connected in parallel. Graph 201 plots the current shared between the two parallel thyristors over time. From circuit diagram 200 and graph 201, it is understood that thyristors are susceptible to thermal runaway due to their negative temperature coefficient. Furthermore, when two thyristors are connected in parallel, the heated thyristor will draw more current and become hotter, eventually failing.

[0039] Figure 2 Circuit diagram 200 shows two MOSFETs connected in parallel, and graph 203 plots the current shared between the two MOSFETs over time. From graph 203, it can be seen that the MOSFETs always have a positive temperature coefficient. Because MOSFETs have a positive temperature coefficient, they can be connected in parallel, and the parallel MOSFETs operate in a manner similar to parallel resistors to automatically balance the current sharing.

[0040] Figure 3 The topology of a single-phase circuit consisting of two parallel branches of MOSFET devices according to one or more embodiments of the present disclosure is shown. Figure 3 A circuit diagram 300 is shown, comprising four solid-state switches (e.g., MOSFET devices) 302, 304, 306, and 308. The first-level modularity of the STS, composed of switches, is as follows: Figure 3 As shown. Switches or MOSFETs 302 and 304 are connected in a source-to-source anti-series connection. Switches 306 and 308 are also connected in a source-to-source anti-series connection. In some embodiments, the connection of switches 302 and 304 or 306 and 308 corresponds to one phase of a multiphase current. In some other cases, the connection of 304 and 304 or 306 and 308 may correspond to the primary and secondary power supplies, respectively, as shown below. The source-to-source anti-series connection allows bidirectional current conduction when both MOSFETs (e.g., 302 and 304 or 306 and 308) are both on, and bidirectional voltage blocking when both MOSFETs (e.g., 302 and 304 or 306 and 308) are both off. The parallel connection of the two branches is used to reduce the total conduction losses of all MOSFETs. In some embodiments, using two branches of four anti-series MOSFETs (e.g., 302, 304, 306, and 308) can reduce total power loss by 50% compared to using only one branch of two anti-series MOSFETs (e.g., 302 and 304). Similarly, adding more parallel branches can further reduce the total conduction loss of the MOSFETs, subsequently making the MOSFET power loss comparable to that of a conventional thyristor under equivalent current conduction.

[0041] Figure 4 Components of an STS with different phase configurations of SiC MOSFETs according to one or more embodiments of the present disclosure are shown. Figure 450 shows a power system component of an STS building block having six SiC MOSFET modules for three phases of a primary power supply on one side of a heat sink and another three phases of a secondary power supply on the other side of the heat sink.

[0042] Figure 5 The parallel connection of two SiCSTS building blocks is shown in an exemplary component and circuit topology according to one or more embodiments of the present disclosure. Figure 5 Figure 500 shows a power system component illustrating two STS SiC building blocks. Figure 5 The diagram also shows circuit diagram 550 corresponding to the STS building block of the power system component.

[0043] A second level of modularity is introduced into the STS design by paralleling each STS building block, which can connect two phases. Circuit diagram 550 shows a first STS SiC block 552 and a second STS SiC block 554, each with six phases. In STS SiC block 552, three phases (A / B / C) are used for the main power supply, and another three phases (A / B / C) are used for the auxiliary power supply. Similarly, in STS SiC block 554, three phases (A' / B / C') are used for the main power supply, and another three phases (A' / b' / c') are used for the auxiliary power supply. When STS building blocks 552 and 554 are connected in parallel, phase A of the first building block 552 is short-circuited to phase A' of the second STS block 554. The other phases are also connected together accordingly. By paralleling the two STS building blocks 552 and 554, the total current capacity of the STS increases by 100%. Furthermore, the STS current capacity can be further increased by paralleling more building blocks made of SiC MOSFETs. The buses used for parallel STS building blocks are carefully designed to balance the inductance and resistance across all parallel paths, thereby balancing current sharing. In some embodiments, the STS building block design can be adapted to accommodate different phases of multiphase current. For example, for single-phase current, the number of phases in STS building block 552 can be reduced to one, having, for example, Figure 3 The four solid-state switches shown

[0044] Figure 5 circuit Figure 5-5 The design of the STS building block shown in 0 introduces three benefits: ultra-fast transmission, improved efficiency under light loads, and mechanical integration.

[0045] Figures 6A-6D A comparison of current interruption waveforms between a thyristor-based power system and a MOSFET-based power system according to one or more embodiments of the present disclosure is shown. Figure 6 illustrates the benefits of ultrafast transfer introduced by the MOSFET-based STS building block. Figure 6A Includes a first circuit diagram 600 for a thyristor-based power system, and Figure 6B Circuit diagram 625 is shown for a MOSFET-based power system. Figure 6C Includes a first diagram 650 corresponding to the thyristor-based power system shown in circuit diagram 600, and Figure 6D Figure 675 shows the MOSFET-based power system shown in circuit diagram 625.

[0046] First circuit diagram 600 shows a voltage source 602 for supplying power to two thyristors 604 and 606 connected in parallel. The parallel connection of the two thyristors 604 and 606 is connected in series with a current sensor 610 and a resistor 612. A step signal is provided to the thyristors 604 and 606 via 608, and an oscilloscope 614 measures the current through the current sensor 610 and the step signal provided by 608. In some embodiments, the step signal provided to the thyristors by 608 controls the operation of the thyristors. For example, if a step value of 1 is provided to one or both of the thyristors 604 and 606, one or both thyristors are turned on. Alternatively, if a step value of 0 is provided to one or both of the thyristors 604 and 606, one or both thyristors are turned off.

[0047] The different signals measured by oscilloscope 614 in circuit diagram 600 are plotted in graph 650. In graph 650, curve 654 plots the current sensed by current sensor 610, and curve 656 plots the step signal supplied to thyristors 604 and 606 and provided by 608. As can be seen from graph 650, the step signal 656 changes from 1 to 0 at time 652, which means that thyristors 604 and 606 are turned off at time 652. In response to thyristors 604 and 606 being turned off, current signal 654 does not turn off immediately at time 652. Instead, current signal 654 continues until it reaches zero and only turns off at zero. This is because the thyristors are only partially controlled and can only be turned off when the current direction is reversed, as previously described.

[0048] The second circuit diagram 625 is similar to circuit diagram 600, except that thyristors 604 and 606 are replaced by MOSFETs 626 and 628 connected in series. The remaining components of circuit 625 are similar to those in circuit diagram 600. As in circuit diagram 600, 608 provides a step signal to MOSFETs 626 and 628. Oscilloscope 614 measures the current from current sensor 610 and the step signal provided by 608. Similar to circuit diagram 600, the step signal provided by 608 to the MOSFETs controls the operating state of the MOSFETs. For example, if a step value of 1 is provided to one or both MOSFETs 626 and 628, one or both MOSFETs are turned on. Or, if a step value of 0 is provided to one or both MOSFETs 626 and 628, one or both MOSFETs are turned off.

[0049] In circuit diagram 625, the different signals measured by oscilloscope 614 are plotted in graph 675. In graph 675, curve 678 plots the current signal from current sensor 610, and curve 676 plots the step signal provided by 608 to MOSFETs 626 and 628. As can be seen from graph 675, the step signal 676 changes from 1 to 0 at time 680, which means that MOSFETs 626 and 628 are turned off at time 680. In response to the turn-off of MOSFETs 626 and 628, current signal 678 is turned off almost immediately at time 680. This is because MOSFETs are fully controllable devices that can be turned off and on upon receiving a command, as previously described.

[0050] In some embodiments, the turn-off time of a thyristor-based STS is approximately 8 milliseconds, while the turn-off time of a MOSFET-based STS is approximately 0.5 milliseconds. This saves valuable time when operating high-speed circuits.

[0051] The second advantage of MOSFET-based STS is the improved efficiency under light load. The power loss of thyristor-based STS and MOSFET-based STS under 50% light load (i.e., an STS rated at 250A carrying 125A of current) is calculated below with an example. Figure 7 Circuit diagram 700 in the document shows the circuit diagram of a thyristor-based STS, while the circuit diagram of a MOSFET-based STS is shown below. Figure 7 As shown. The power loss of the thyristor-based STS is calculated as follows: Table 1: Key parameters of STS based on thyristors

[0052] Using the parameters listed in Table 1, the thyristor-based STS phase voltage drop is calculated by adding the fixed voltage drop (VT0) to the voltage drop generated when a 125 A current passes through the thyristor, as described above under the operating conditions. Using the above formula, the voltage drop per phase is calculated as 0.83 V + 0.25 mΩ × 125 A = 0.83 V. After calculating the forward voltage drop per phase, the power loss per phase is calculated using the following formula: Using the above formula, the power loss per phase is calculated to be 125 A × 0.83 V = 104 W.

[0053] The circuit diagram of the MOSFET-based STS is as follows: Figure 7The circuit diagram 750 is shown in Figure 750. As shown in Figure 750, current can flow through MOSFETs 758 and 760 (as indicated by arrow 756) or through MOSFETs 762 and 764 (as indicated by arrow 766). An exemplary MOSFET-based STS has the following parameters: Table 2: Key parameters of MOSFET-based STS

[0054] Using the parameters in Table 2, the current through the MOSFET is 62.5 A, which is half of the total current of 125 A. Using the current through the MOSFET, the power loss of the MOSFET can be calculated using the following formula: Using the above formula, the power loss of each MOSFET is calculated to be 62.5. 2 A x 0.0038 Ω = 14.8 W. Using the power loss of each MOSFET, the total power loss of the MOSFET-based STS is calculated by multiplying the power loss of each MOSFET (14.8 W) by the number of MOSFETs in the STS (4). The total power loss of the MOSFET-based STS is 14.8 x 4 = 59 W. As can be seen from the calculation, at 50% load, the power loss of the MOSFET-based STS is nearly 40% lower than that of the thyristor-based STS.

[0055] The third benefit of MOSFET-based STS highlights the innovation of mechanical integration. Instead of having a separate heatsink and fan for each component, this design shares the same fan airflow between the two components, reducing the overall heatsink volume by 50%. This reduction takes into account that during STS operation, only one semiconductor component is turned on at a specific time, while the other semiconductor component is turned off. Figure 8 This highlights the mechanical integration mentioned above. Figure 9 Figures 802 and 804 illustrate an STS system with a separate pair of heatsinks and fans, as used in a thyristor-based STS. Figure 806 illustrates a MOSFET-based STS that shares the same fan flow between the two components and reduces the overall heatsink volume by 50%. In some embodiments, Figures 802 and 804 show two separate components connected to two different sources. For example, the thyristor-based STS shown in 802 can be configured to be connected to a preferred source, and the thyristor-based STS shown in 804 can be configured to be connected to a secondary backup source. On the other hand, the MOSFET-based STS shown in Figure 806 is configured to be connected to both the preferred source and the secondary backup source simultaneously.

[0056] Therefore, modular STSs are constructed using MOSFET power systems by combining multiple building blocks in series or parallel. For example, as described above, different building blocks are connected in series to increase the rated voltage of the STS architecture. Different STS building blocks can be connected in parallel to increase the current capacity of the STS architecture.

[0057] Each STS building block has an individually controlled semiconductor power system. In some embodiments, a first semiconductor in the semiconductor power system connects the primary power source to the load, and a second semiconductor in the semiconductor power system is also connected to the load. The power system connects an auxiliary power source to the load. The semiconductors in the semiconductor power system use high-power transistors to conduct line current when turned on and to isolate line voltage when turned off. In some embodiments, the semiconductor power system can actively interrupt the line current upon command before an external current reverses.

[0058] In some examples, high-power transistors include, but are not limited to, MOSFETs, JFETs, IGBTs, GITs, HEMTs, and FinFETs. High-power transistors are made of silicon and wide-bandgap semiconductor materials, including but not limited to SiC and GaN. Relays or contactors may be connected in series with the semiconductors to facilitate current isolation of the faulty (short-circuited) semiconductors and maintain STS operation with N+1 redundancy. In some cases, a properly designed power system allows for equal sharing of line current across all parallel branches of each phase of the STS.

[0059] In some embodiments, the STS building blocks can use discrete power semiconductor devices, custom bidirectional power modules, standard half-bridge modules, or standard full-bridge modules. In some embodiments, the STS building blocks can have heatsink assemblies with one phase per heatsink, three phases per heatsink, or six phases per heatsink. When multiple STS building blocks are connected in parallel, it may be appropriate to place all parallel branches of the STS on the same heatsink to provide better isolation from other phases and reduce bus inductance.

[0060] Figure 9This is a block diagram of an exemplary system or device 900 (such as controller 1004) within system 1000. System 900 includes a processor 904, such as a central processing unit (CPU) and / or logic, which executes computer-executable instructions for performing the functions, processes, and / or methods described herein. In some examples, the computer-executable instructions are locally stored and accessed from a non-transitory computer-readable medium (such as memory 910), which may be a hard disk drive or a flash drive. Read-only memory (ROM) 906 includes computer-executable instructions for initializing processor 904, while random access memory (RAM) 908 is main memory for loading and processing the instructions executed by processor 904. Network interface 912 can be connected to a wired or cellular network and a local area network or wide area network. System 900 may also include a bus 902 connecting processor 904, ROM 906, RAM 908, memory 910, and / or network interface 912. Components within system 900 can communicate with each other using bus 902. The components within system 900 are merely exemplary and may not include every component within controller 904. Additionally and / or alternatively, system 900 may also include components that may not be included in each entity of system 900. For example, in some examples, controller 1004 may not include network interface 912.

[0061] Figure 10 A simplified block diagram of a system for a modular static changeover switch, illustrating one or more examples according to this disclosure, is shown. Figure 10 The system 1000 includes a preferred source STS module 1002 and a backup source STS module 1006. The system 1000 also includes a central STS controller 1004 for controlling the operation of the STSs. In some embodiments, the central STS controller 1004 provides instructions to the preferred source STS module 1002 and the backup source STS module 1006. The controller 1004 can be configured to operate the preferred source STS module 1002 and the backup source STS module 1006.

[0062] In some embodiments, the preferred source STS module 1002 can be connected to the preferred power input, and the alternative source STS module 1006 can be connected to the alternative power input. The central controller 1004 can be used to power a load using either the preferred power input or the alternative power input. For example, to power a load using the preferred STS module 1002, the central controller 1004 can instruct the preferred source STS module 1002 to activate and connect the preferred power input to the load. Upon receiving a signal from the preferred power input, the central controller 1004 can initiate a switching process from the preferred power input to the alternative power input. In some embodiments, the switching between the preferred power input and the alternative power input can be controlled by a switching or transfer algorithm. Figure 11 The process of switching between the preferred power input and the alternative power input is described in more detail.

[0063] Figure 11 The present disclosure illustrates a process performed by a controller as part of a modular static transfer switch, according to one or more examples. Process 1100 can be performed by... Figure 10 The system 1000 shown is executed by controller 1004. However, it will be appreciated that any of the boxes below can be executed in any suitable order, and process 1100 can be executed in any environment and by any suitable computing device and / or controller.

[0064] At 1102, the central controller 1004 issues a shutdown command to all preferred source STS modules. In some embodiments, the shutdown command may be issued based on a signal received by the central controller 1004 from the preferred power input. For example, the central controller 1004 may receive a signal indicating a fault in the preferred power input. In response to receiving a fault indication signal, the central controller 1004 may initiate a transfer from the preferred power input 1002 to the alternative power input 1006. To initiate the transfer from the preferred power input to the alternative power input, the central controller 1004 instructs the preferred STS module to shut down. By turning around, the STS disconnects the load from the main power input.

[0065] At point 1104, upon receiving an instruction from the central controller 1004, the preferred source module is shut down. Once the central controller 1004 provides an instruction, the preferred STS source STS module is shut down.

[0066] At 1106, controller 1004 checks to ensure that all preferred source modules are shut down and that the preferred source is disconnected from the STS. In some embodiments, the check to ensure that all modules are shut down is performed using module-based feedback or system measurement-based feedback.

[0067] At 1108, controller 1004 issues a switch-on command to the alternating source module based on a transfer algorithm. The transfer algorithm calculates the transformer flux before and after the transfer to find the first moment when the flux change is minimal. In some embodiments, many transfer algorithms can be used. In one case, the transfer algorithm disconnects from the preferred source and then simultaneously reconnects all three phases of the alternative source. In another case, where the transformer may be connected downstream, the transfer algorithm uses measured voltages from the preferred and alternative sources to estimate the transformer flux and performs the transfer to minimize inrush current during the transfer.

[0068] In some embodiments, the activation of the backup power supply STS module 1006 connects the backup power input to the load via STS 1000.

[0069] While embodiments of the invention have been detailed and described in the accompanying drawings and the foregoing description, such description should be considered illustrative or exemplary, not restrictive. It should be understood that changes and modifications can be made by those skilled in the art within the scope of the appended claims. In particular, the invention covers other embodiments having any combination of features from the different embodiments described above and below. For example, various embodiments of kinematic, control, electrical, mounting, and user interface subsystems can be used interchangeably without departing from the scope of the invention. Furthermore, statements characterizing the invention herein refer to one embodiment of the invention, and not necessarily all embodiments.

[0070] The terminology used in the claims should be interpreted as having the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the articles "a" or "the" when introducing an element should not be interpreted as excluding the existence of multiple elements. Similarly, references to "or" should be interpreted as inclusive, meaning that the expression "A or B" does not exclude "A and B" unless it is clearly apparent from the context or the foregoing description that it is intended to refer only to one of A and B. Furthermore, the expression "at least one of A, B, and C" should be interpreted as one or more elements selected from the group consisting of A, B, and C, and should not be interpreted as requiring at least one of each of the listed elements A, B, and C, regardless of whether A, B, and C are associated by category or otherwise. Moreover, the expressions "A, B, and / or C" or "at least one of A, B, or C" should be interpreted as including any single entity of the listed elements, such as A; any subset of the listed elements, such as A and B; or the complete list of elements A, B, and C.

Claims

1. A modular static transfer switch (STS) assembly, wherein the modular STS assembly comprises: At least one semiconductor power system, said at least one semiconductor power system being constructed using a wide bandgap transistor; The first input terminal of the modular STS component electrically coupled to the first power source, and the second input terminal of the modular STS component electrically coupled to the second power source; The modular STS component is electrically coupled to the output of the load, wherein the load is powered via the modular STS component using the first power source; as well as Current isolators used to disconnect any faulty semiconductor power system, such as relays, contactors, circuit breakers, or fuses; A controller for performing the conversion of power supplied to the load from the first power source to the second power source, wherein the controller is configured to: Provide instructions to electrically decouple the first power source from the load; Verify that the first power supply is disconnected from the load; and Instructions are provided to electrically couple the second power source to the load.

2. The modular static switching assembly of claim 1, wherein the at least one semiconductor power system comprises two wide-bandgap transistors connected in reverse series, and wherein the wide-bandgap transistor comprises at least one of the following: MOSFET, JFET, IGBT, GIT, HEMT, FinFET.

3. The modular static transfer switch assembly according to claim 2, wherein: The first power supply is connected via the first input terminal to the first terminal of the first wide-bandgap transistor in the at least one power system. The second power supply is connected via the second input terminal to the first terminal of the second wide-bandgap transistor in the at least one power system, and The output terminal of the modular STS component is connected to the second terminal of the first wide-bandgap transistor and the second terminal of the second wide-bandgap transistor.

4. The modular static transfer switch assembly according to claim 1 further includes: The second semiconductor power system is constructed using wide-bandgap transistors, wherein the second semiconductor power system comprises two wide-bandgap transistors connected in reverse series.

5. The modular static transfer switch assembly according to claim 3, wherein the at least one semiconductor power system and the second semiconductor power system are connected in parallel.

6. The modular static switch assembly of claim 4, wherein the at least one semiconductor power system is connected to the first power supply, and the second semiconductor power system is connected to the second power supply.

7. The modular static switch assembly of claim 5, wherein the at least one semiconductor power system connected in parallel with the second semiconductor power system is a first STS unit, and the modular static switch assembly further comprises: The second STS unit includes a third semiconductor power system and a fourth semiconductor power system, wherein the third semiconductor power system is connected to the at least one semiconductor power system and the fourth semiconductor power system is connected to the second semiconductor power system.

8. The modular static switch assembly of claim 5, wherein the at least one semiconductor power system connected in parallel with the second semiconductor power system is a first STS unit, and the modular static switch assembly further comprises: The second STS unit includes a third semiconductor power system and a fourth semiconductor power system, wherein the third semiconductor power system is connected to the second phase of the first power supply, and the fourth semiconductor power system is connected to the second phase of the second power supply.

9. The modular static transfer switch assembly according to claim 3, wherein the at least one semiconductor power system and the second semiconductor power system are connected in series.

10. The modular static switching assembly of claim 1, wherein the at least one semiconductor power system comprises one or more four-quadrant or bidirectional wide-bandgap transistors, and wherein the wide-bandgap transistor comprises at least one of the following: MOSFET, JFET, IGBT, GIT, HEMT, FinFET.

11. The modular static transfer switch assembly according to claim 1, wherein the modular STS has N+1 parallel branches in structure, and wherein the N+1th branch is used to maintain the operation of the modular STS in the event that one of the first N branches is disconnected and the circuit cannot be disconnected.

12. The modular static transfer switch according to claim 1 further includes a voltage clamping circuit connected in parallel with at least one semiconductor power system.

13. A method for converting power supplied to a load from a first power source to a second power source, the method comprising: Provide instructions to electrically decouple the first power source from the load; Verify that the first power supply is disconnected from the load; as well as Instructions are provided to electrically couple the second power source to the load.

14. A non-transitory computer-readable medium having processor-executable instructions stored thereon, wherein the processor-executable instructions, when executed by one or more processors, cause: Provide instructions to electrically decouple the first power source from the load; Verify that the first power supply is disconnected from the load; and Instructions are provided to electrically couple the second power source to the load.

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