Solid-state transformer and system

Abstract

A solid-state transformer (1) is specified, comprising - at least two modules (2) having a first side (3) and a second side (4), wherein each module (2) comprises - at least two sub-modules (22), each comprising a first converter (5) at the first side (3) and a second converter (6) at the second side (4), wherein - the first converter (5) is connected to the second converter (6) by a transformer, and - the at least two sub-modules (22) are connected i n parallel at the first side (3), and wherein - the at least two modules (2) are connected in series at the first side (3). Furthermore, a system is specified. Significant

Description

[0001] P2024,0661 WO N / P240059WO01 September18,2025 -1 - Description SOLID-STATE TRANSFORMER AND SYSTEMThe present disclosure relates to a solid-state tra nsformerand a system.For typical high-power electric applications such a s electricvehicle charging, batteries, hydrogen, wind and sol ar powerrequire actively controlled bi-directional galvanic allyinsulated conversion atmedium voltage,MV,level.Embodiments of the disclosure relate to a solid-sta tetransformerwhich isparticularlyefficient.This is achieved by the subject-matter of the indep endentclaim. Further embodiments are evident from the dep endentclaimsand the following description.The solid-state transformer is described. Exemplari ly, thesolid-state transformerisconfigured to transform electricalenergy from a first voltage level to a second volta ge level.In particular, the solid-state transformer is a bid irectionaltransformer. This means that the solid-state transf ormer isadditionally configured to transform electrical ene rgy fromthe second voltage levelthe firstvoltage level.The solid-state transformer comprises, for example, powersemiconductor devices. This means that the solid-st atetransformer is a power electronic transformer. At l east someof the power semiconductor devices particularly are based ona semiconductormaterial.Each powersemiconductor device cancomprise insulated gate bipolar transistors, IGBTs, metal P2024,0661 WO N / P240059WO01 September18,2025 -2 -oxide semiconductor field-effect transistors, MOSFE Ts, and / orgallium nitride,GaN,transistors. The term “power”here and in the following refers, forexample, to power semiconductor devices particularl ycomprised by the solid-state transformer adapted fo rprocessing voltages and currents of more than 100 V and / ormore than 5 A,exemplarilyvoltagesofup to 10 kV and electricalcurrentsofup to 10 kA.According to an embodiment, the solid-state transfo rmercomprisesatleasttwo moduleshaving a firstside and a second side.Exemplarily,each module hasan input side whichis characteristic of the first side, and each modul e has anoutput side which is characteristic of the second s ide. Inparticular,the firstside and the second side are located opposite to one another. Asthe modulescan workbidirectionally,the input side canbe the output side and the output side can be the i nput side.Thus, the term “output” and “input” are used herein inparticular for referencing different sides, e.g. th e firstside and the second side,ofthe modules.Preferably, the first side is a medium voltage side and thesecond side is a low voltage side of the solid-stat etransformer. Exemplarily, elements of the solid-sta tetransformer at the medium voltage side are configur ed toprocess electric energy of a medium voltage range a ndelementsofthe solid-state transformeratthe low voltageside are configured to process electric energy of a lowvoltage range. Therefore, the indication of the fir st sideand the second side can be characteristic for a geo metrical P2024,0661 WO N / P240059WO01 September18,2025 -3 -relationship of the elements and / or a functional re lationshipofthe elements.According to the embodiment of the solid-state tran sformer,each module comprises at least two sub-modules, eac hcomprising a firstconverteratthe firstside and a secondconverter at the second side. Exemplarily, the firs tconverter is of a first type and the second convert er is of asecond type,wherein the firsttype and the second type aredifferent from one another. The type is, for exampl e,characteristic of a voltage conversion from an alte rnatingcurrent, AC, to a direct current, DC, or vice versa . Thismeans that, if the first type is indicative of a DC to ACconversion,the second type isindicative ofan AC to DC conversion,and vice versa.According to the embodiment of the solid-state tran sformer,the first converter is connected to the second conv erter by atransformer. The transformer has, for example, a fi rst side,to which the first converter is connected, and a se cond side,to which the second converter is connected. The fir st side ofeach module particularly faces the first side of th etransformer, and the second side of each module par ticularlyfacesthe second side ofthe transformer.Exemplarily, the transformer comprises a primary wi nding anda secondary winding and a core. The primary winding ismagnetically connected to the core, and the seconda ry windingis magnetically connected to the core. In particul ar, thefirst winding and the second winding are each wound aroundthe core. Each of the primary winding and the secon darywinding has a number of turns. The transformation o f theelectrical energy from the first voltage level to t he second P2024,0661 WO N / P240059WO01 September18,2025 -4 -voltage level and vice versa is dependent on a rati o betweenthe number of turns, particularly between the numbe r of turnsof the primary winding and the number of turns of t hesecondarywinding.Exemplarily, each module has an input port and at l east one,particularlyatleasttwo,outputports.The input portofthe module is located at the first side, and the ou tput portofthe module islocated atthe second side. Exemplarily,the firstconverterhasan inputport and an outputport.The inputportofthe firstconverter facesawayfrom the transformer, and the output port of the fi rstconverter is connected to the transformer. Exemplar ily, theinputportofthe module isconnected to the input portofthe respective first converter. Exemplarily, the se condconverter has an input port and an output port. The inputport of the second converter is connected to the tr ansformer,and the output port of the second converter faces a way fromthe transformer. Exemplarily, the output port of th e firstconverterisconnected to the primarywinding,and the inputport of the second converter is connected to the se condarywinding. Exemplarily, the output port of the module isconnected to the output port of the respective seco ndconverter.As the modules and converters can work bidirectiona lly, therespective inputportscan be the outputportsand therespective output ports can be the input ports. Par ticularly,the terms “output”and “input”are used herein for referencing differentsides. P2024,0661 WO N / P240059WO01 September18,2025 -5 -According to the embodiment of the solid-state tran sformer,the at least two sub-modules are connected in paral lel at thefirst side. In particular, the sub-modules of one m odule areconnected in parallel via the input ports of the re spectivefirst converters and thus the input ports of the mo dules.According to the embodiment of the solid-state tran sformer,the at least two modules are connected in series at the firstside.The inputportsofthe modulesare connectedexemplarily in series. In particular, the modules a reconnected in series via the input ports of the resp ectivefirst converters and thus the input ports of the mo dules.According to the embodiment of the solid-state tran sformer,at least one of the sub-modules is not connected in parallelat the second side to the other sub-modules. In par ticular,at least one sub-module from all the sub-modules of all themodules, is not connected at the second side to the othersubmodules.Ifatleasttwo ofthe sub-modulesare notconnected in parallel at the second side to the oth er sub-modules, the at least two of the sub-modules not co nnected inparallel at the second side to the other sub-module s can beconnected in parallel, in series or can be not conn ected toone another. If at least three of the sub-modules a re notconnected in parallel at the second side to the oth er sub-modules, at least two of the at least three sub-mod ules ofthe sub-modules not connected in parallel at the se cond sideto the other sub-modules can be connected in parall el, inseriesorcan be notconnected to one another. Exemplarily,atleasttwo sub-modulesofdifferent modules and / oratleasttwo sub-modulesofthe same module are connected atthe second side,and wherein atleast one ofthe P2024,0661 WO N / P240059WO01 September18,2025 -6 -sub-modules is not connected in parallel to the oth er sub-modules.Advantageously, such a topology provides at least t wo,particularly several, independent outputs at the se cond side.This advantageously provides flexibility to reroute and / orbalance the power flow throughout all the serialize d modulesconnected at the first side, which is an enabler fo r havingseparate outputsatthe second side.In particular, having such galvanically separated o utputs atthe second side, both EV charging and H2 applicatio ns can beachieved.Exemplarily, all the modules comprise the same sub- modules.Advantageously,a voltage scaling isachieved byserialization of appropriate number of modules on t he firstside. The solid-state transformerhaving severalmodules beingconnected in series with parallel connected sub-mod ulesadvantageously provides a power flow equalization w ithin themodules, e.g. by connecting the submodules at the s econdside,based on the topologyofthe sub-modules,as wellasbyusing always the same basic building blocks for the modules,i.e. the sub-modules. Such a solid-state transforme r isadvantageouslyfullymodular,scalable,and allows for standardization ofthe basicbuilding blocks,e.g. the sub-modules. Advantageously, a simple change of how the sub-modules and / or modules are stacked allows for maxim umflexibilityin termsofcontrol. P2024,0661 WO N / P240059WO01 September18,2025 -7 -According to a further embodiment of the solid-stat etransformer,the firstconvertercomprisesa first directcurrent / alternating current, DC / AC, converter. Exem plarily,the firstDC / AC converterisconfigured to convert an inputDC voltage into an output AC voltage and vice versa . A DCside of the first DC / AC converter faces away from t hetransformer and an AC side of the first DC / AC conve rter isconnected to the transformer, e.g. the primary wind ing. TheDC side of the first DC / AC converter comprises, for example,the inputportofthe firstconverter.According to a further embodiment of the solid-stat etransformer, the second converter comprises a secon d AC / DCconverter.Exemplarily,the second AC / DC converter isconfigured to convert an input AC voltage into an o utput DCvoltage and vice versa. An AC side of the second AC / DCconverter is connected to the transformer, e.g. the secondarywinding, and a DC side of the second AC / DC converte r facesaway from the transformer. The DC side of the secon d AC / DCconverter comprises, for example, the output port o f thesecond converter.According to a further embodiment of the solid-stat etransformer,atleastone sub-module comprisesthe firstconverter comprising a first AC / DC converter and th e firstDC / AC converter.Thismeansin particularthatthe firstconverter is a first AC / DC / DC / AC converter comprisi ng thefirst AC / DC converter and the first DC / AC converter .Exemplarily, an AC side of the first AC / DC converte r facesaway from the first DC / AC converter. In particular, the ACside of the first AC / DC converter comprises the inp ut port of P2024,0661 WO N / P240059WO01 September18,2025 -8 -the first converter. A DC side of the first AC / DC c onverteris connected to the DC side of the first DC / AC conv erter.According to a further embodiment of the solid-stat etransformer, the first DC / AC converter is connected to thetransformer.Forexample,the AC side ofthe first DC / ACconverter is connected to the transformer, particul arly theprimarywinding.In particular,the AC side ofthe firstDC / AC converter comprises the output port of the fi rstconverter.According to a further embodiment of the solid-stat etransformer,atleastone sub-module comprisesthe secondconverter comprising the second AC / DC converter and a secondDC / AC converter.Thismeansin particularthatthe secondconverter is a second AC / DC / DC / AC converter compris ing thesecond AC / DC converter and the second DC / AC convert er.In particular, an AC side of the second DC / AC conve rtercomprisesthe outputportofthe second converter. The DC side ofthe second AC / DC converterisconnected to a DC side ofthe second DC / AC converter.According to a further embodiment of the solid-stat etransformer, the second AC / DC converter is connecte d to thetransformer. For example, the AC side of the second AC / DCconverter is connected to the transformer, particul arly thesecondary winding. In particular, the AC side of th e secondAC / DC converter comprises the input port of the sec ondconverter.Exemplarily, a first type of the sub-module compris es thefirst DC / AC converter as the first converter and th e second P2024,0661 WO N / P240059WO01 September18,2025 -9 -AC / DC converter as the second converter, wherein th erespective AC sides are connected to the transforme r.Exemplarily, a second type of the sub-module compri ses thefirstAC / DC / DC / AC converterasthe firstconverter and thesecond AC / DC converter as the second converter, whe rein therespective AC sides are connected to the transforme r.Exemplarily, a third type of the sub-module compris es thefirstAC / DC / DC / AC converterasthe firstconverter and thesecond AC / DC / DC / AC converter as the second converte r, whereinthe respective AC sides are connected to the transf ormer.For example, all modules comprise the same sub-modu les,wherein each module can comprise the same or differ ent typesofsub-modules.According to a further embodiment of the solid-stat etransformer,atleasttwo sub-modulesofdifferent modulesare connected at the second side in series or in pa rallel. Inparticular, in this further embodiment, it is possi ble thatat least two sub-modules of different modules are c onnectedatthe second side in seriesand thatatleasttwo differentsub-modules of different modules are connected at t he secondside in parallel.Exemplarily,the outputportsof the secondconverters of the at least two sub-modules of diffe rentmodulesare connected in seriesorin parallel. Advantageously,powerbalancing and / oran exchange ofelectrical energy between different modules is thus achieved.Due to the serial connection of at least two sub-mo dules atthe second side of different modules, this topology can beadvantageously used to adapt a voltage at the outpu t port of P2024,0661 WO N / P240059WO01 September18,2025 -10 -the corresponding module. Due to parallel connectio n of atleast two sub-modules at the second side of differe ntmodules, it is advantageously possible to circulate powerfrom one module to another module to correct any lo adingdisbalances.According to a further embodiment of the solid-stat etransformer, at least two sub-modules of the same m odule areconnected at the second side in series or in parall el. Inparticular, in this further embodiment, it is possi ble thatat least two sub-modules of the same module are con nected atthe second side in series and that at least two dif ferentsub-modules of the same module are connected at the secondside in parallel.Exemplarily,the outputportsof the secondconverters of the at least two sub-modules of the s ame moduleare connected in seriesorin parallel. Due to such connection topologies,powerbalancing and / oranexchange of electrical energy between different sub -modulesis thus advantageously achieved. In particular, the parallelconnection ofsubmoduleson the second side allows forpowerbalancing between different modules when submodules belong todifferent modules. Connection of submodules in para lleladvantageously additionally achieves an increased p ower.Connection ofsubmodulesin series,advantageously achievesapredetermined low voltage level on the respective o utputport.According to a further embodiment of the solid-stat etransformer, a matrix switch is connected to the su b-modulesat the second side. Exemplarily, the output ports o f thesecond converters are connected to the matrix switc h. P2024,0661 WO N / P240059WO01 September18,2025 -11 -Advantageously, a serial and / or parallel connection of theoutputs of at least some of the second converters w ithin amodule and / orofdifferentmodulescan be achieved with the matrixswitch.According to a further embodiment of the solid-stat etransformer, the solid-state transformer is a bidir ectionalsolid-state transformer.According to a further embodiment of the solid-stat etransformer, elements of the modules at the first s ide areconfigured to process electric energy of a medium v oltagerange,while elementsofthe modulesatthe second side areconfigured to process electric energy of a low volt age range.The elements comprise, inter alia, the first conver ters andthe respective ports.The medium voltage range is, forexample, at least 1 kV or at least 2kV and / or at mo st 50 kV.The low voltage range is, for example, smaller than 2 kV orsmallerthan 1 kV.According to a further embodiment of the solid-stat etransformer, the modules are configured to be conne ctable toa power grid at the first side. The power grid is c onfigured,for example, to provide electric energy of the medi um voltagerange to the solid-state transformer.Exemplarily, the powergrid is connected to the input ports of the modules .According to a further embodiment of the solid-stat etransformer, the modules are configured to be conne ctable toat least one energy dispenser at the second side. T he energydispenser is, for example, characteristic of a char gingstation of an electric vehicle. Exemplarily, the en ergy P2024,0661 WO N / P240059WO01 September18,2025 -12 - dispenserisconnected to a respective outputport ofa respective module.According to a further embodiment of the solid-stat etransformer, the modules are configured to be furth erconnectable to at least one energy storage and / or a t leastone energy generator at the second side. Exemplaril y, theenergy storage and / or the energy generator is / are c onnectedto a respective output port of a respective module.Advantageously, by using also energy storages and / o r energygenerators, electric energy can be provided also at thesecond side – forproviding electricenergyto the energy dispenserorthe powergrid.A further embodiment relates to a system, in partic ularcomprising a solid-state transformer as described h ereinabove. Therefore, the features as described in conn ectionwith the system are also applicable for the solid-s tatetransformerand vice versa.According to an embodiment, the system comprises th e solid-state transformerasdescribed herein before.According to the embodiment, the solid-state transf ormer isconnected to a power grid at the first side, and th e solid-state transformer is connected to at least one ener gydispenseratthe second side.Exemplarily, the power grid comprises three phases. Inparticular,the three phasesare formed ofa first phase,a second phase and a third phase. P2024,0661 WO N / P240059WO01 September18,2025 -13 -For example, each of the three solid state transfor mers isconnected between one of the three phases and a ref erencepotential.Forexample,the reference potentialis a groundpotential. Exemplarily, the three solid-state trans formersare formed of a first solid-state transformer, a se condsolid-state transformer and a third solid-state tra nsformer.The firstsolid-state transformerisin particular connectedbetween the first phase and the reference potential . Thesecond solid-state transformer is in particular con nectedbetween the second phase and the reference potentia l. Thethird solid-state transformer is in particular conn ectedbetween the third phase and the reference potential .For example, each of the three solid state transfor mers isconnected between two of the three phases. The firs t solid-state transformer is in particular connected betwee n thefirst phase and the second phase. The second solid- statetransformerisin particularconnected between the secondphase and the third phase. The third solid-state tr ansformerisin particularconnected between the third phase and the firstphase.Advantageously, due to such arrangements of the sol id-statetransformers with respect to the phases, the solid- statetransformerisconnectable to a 3-phase AC grid.According to a further embodiment of the system, th e solid-state transformerisfurtherconnected to atleast one energystorage and / or at least one energy generator at the secondside. The accompanying Figuresare included to provide a furtherunderstanding. In the Figures, elements of the same structure P2024,0661 WO N / P240059WO01 September18,2025 -14 - and / orfunctionalitymaybe referenced bythe same reference signs.Itisto be understood thatthe embodiments shown inthe Figures are illustrative representations and ar e notnecessarilydrawn to scale.Figure 1 shows a schematic view of a solid-state tr ansformeraccording to an exemplaryembodiment. Figures2,3 and 4 each show a schematicview ofa sub-moduleof a solid-state transformer according to an exempl aryembodiment.Figure 5 shows a detailed schematic view of a solid -statetransformeraccording to an exemplaryembodiment.Figure 6 shows a schematic diagram of an efficiency of asolid-state transformer according to an exemplary e mbodiment.Figures 7 and 8 each shows a detailed schematic vie w of asolid-state transformer according to an exemplary e mbodiment.The solid-state transformer 1 according to the exem plaryembodiment of Figure 1 comprises n modules 2, where in eachmodule has a first side 3 and a second side 4, arra ngedopposite to one another. The modules 2 are equal to oneanother,and each module 2 comprisesm sub-modules 22,whichare described in more detail in connection with Fig ures 2, 3,4 and 5. n and m are natural numbers bigger than or equal to2. n and m can be different or equal to one another .The solid-state transformer 1 is configured to be c onnectedto a powergrid atthe firstside 3,in particular an AC powergrid. P2024,0661 WO N / P240059WO01 September18,2025 -15 - The modules2 are connected in seriesatthe first side 3.Each module 2 has an input port 11, comprising a fi rst sub-port 17 and a second sub-port 18. The first sub-por t 17 ischaracteristic of a first polarity type and the sec ond sub-port 18 is characteristic of a second polarity type . Theinput port 11 of the module 2 is located at the fir st side 3.The power grid is configured to be connected to the inputport 11 of the first module 2 and to the input port 11 of thelast module 2. The first module 2 is the module 2 c onnectedto a first terminal with a first polarity of the po wer grid,and the lastmodule 2 isthe module 2 connected to a second terminalwith a second polaritydifferentfrom the firstpolarity of the power grid. In particular, the powe r grid isconfigured to be connected to the first sub-port 17 of thefirst module 2, and the power grid is configured to beconnected to the second sub-port 18 of the last mod ule 2.Directlyneighbouring modules2 are connected with oneanother by the second sub-port 18 and the first sub -port 17,respectively, for achieving the serial connection o f themodules2.The sub-modules 22 are connected in parallel at the firstside 3. Each sub-module 22 has an input port 11, co mprising afirst sub-port 17 and a second sub-port 18. The inp ut port 11of the module 2 is connected to the input port 11 o f thefirst sub-module 22 and to the input port 11 of the last sub-module 22. The first sub-module 22 is the sub-modul e 22closest to the first sub-port 17 of the module 2, a nd thelastsub-module 22 isthe sub-module 22 closestto the secondsub-port 18 of the module 2. In particular, the inp ut port11, particularly the first sub-port 17, of the modu le 2 isconnected to all sub-ports 17 of the sub-modules 22 of the P2024,0661 WO N / P240059WO01 September18,2025 -16 -module 2. Particularly, the input port 11, particul arly thesecond sub-port 18, of the module 2 is connected to allsecond sub-ports 18 of the sub-modules 22 of the mo dule 2.The first sub-module 22, in particular the first su b-port 17thereof, is connected to all neighbouring sub-modul es 22, inparticular to all respective first sub-ports 17 the reof. Thefirst sub-module 22, in particular the second sub-p ort 18thereof, is connected to all neighbouring sub-modul es 22, inparticular to all respective second sub-ports 18 th ereof.Such a connection enables the parallel connection o f the sub-modules22 atthe firstside 3.The solid-state transformer 1 is configured to be c onnectedto energydispensersatthe second side 4.Each module 2 has at least one, according to Figure 1 inparticularthree,outputports12,each comprising a firstsub-port 17 and a sub-second port 18. The output po rts 12 ofthe module 2 are located at the second side 4. Each outputport 12 is configured to be connected to one of the energydispensers.In particular, the first side 3 is configured to pr ocesselectricenergyofa medium voltage range,and the second side 4 isconfigured to processelectricenergyof a low voltage range. The sub-modules22 according to Figures2,3 and 4 eachcomprise a first converter 5 at the first side 3 an d a secondconverter 6 at the second side 4, wherein the first converter5 is connected to the second converter 6 by a trans former 7.The transformer 7 comprises a primary winding 9 and a P2024,0661 WO N / P240059WO01 September18,2025 -17 -secondary winding 10 and a core 8. In particular, e ach sub-module 22 comprisesone single transformer7.The first converter 5 has an input port 11, compris ing afirst sub-port 17 and a second sub-port 18. The inp ut port 11of the respective sub-module 22 is connected to the inputport 11 of the first converter 5. The first convert er 5 hasan output port 12, comprising a first sub-port 17 a nd asecond sub-port 18. The output port 12 of the first converter5 isconnected to the primarywinding 9.The second converter 6 has an input port 11, compri sing afirst sub-port 17 and a second sub-port 18, wherein the inputport 11 of the second converter 6 is connected to t hesecondary winding 10. The second converter 6 has an outputport 12, comprising a first sub-port 17 and a secon d sub-port18, wherein the output port 12 of the second conver ter 6 isconfigured to be connected to one of the energy dis pensers.The sub-module 22 according to Figure 2 comprises a firstDC / AC converter 14 as the first converter 5. A DC s ide of thefirst DC / AC converter 14 comprises the input port 1 1 of thefirst converter 5 and an AC side of the first DC / AC converter14 comprises the output port 12 of the first conver ter 5,which isconnected to the primarywinding 9.In particular, the sub-module 22 according to Figur e 2 is asub-module 22 ofa firsttype comprising the first DC / ACconverter 14 as the first converter 5 and the secon d AC / DCconverter 15 as the second converter 6, wherein therespective AC sides are connected to the transforme r 6. P2024,0661 WO N / P240059WO01 September18,2025 -18 -The sub-module 22 according to Figure 3 comprises a firstAC / DC converter 13 and a first DC / AC converter 14 a s thefirst converter 5. An AC side of the first AC / DC co nverter 13comprisesthe inputport11 ofthe firstconverter 5,and aDC side of the first AC / DC converter 13 is connecte d to a DCside of the first DC / AC converter 14. An AC side of the firstDC / AC converter14 comprisesthe outputport12 of the firstconverter 5, which is connected to the primary wind ing 9.The second converter 6 according to Figure 3 is equ al to thesecond converter6 according to Figure 2.In particular, the sub-module 22 according to Figur e 3 is asub-module 22 of a second type comprising a first A C / DC / DC / ACconverter as the first converter 5 and the second A C / DCconverter 15 as the second converter 6, wherein therespective AC sides are connected to the transforme r 7.The first converter 5 according to Figure 4 is equa l to thesecond converter6 according to Figure 3.The sub-module 22 according to Figure 4 comprises a secondAC / DC converter15 and a second DC / AC converter16 asthe second converter6.An AC side ofthe second AC / DC converter15 comprises the input port 11 of the second conver ter 6,which is connected to the secondary winding 10, and a DC sideofthe second AC / DC converter15 isconnected to a DC side ofthe second DC / AC converter 16. An AC side of the se cond DC / ACconverter 16 comprises the output port 12 of the fi rstconverter5.In particular, the sub-module 22 according to Figur e 4 is asub-module 22 ofa third type comprising the first P2024,0661 WO N / P240059WO01 September18,2025 -19 - AC / DC / DC / AC converterasthe firstconverter5 and the secondAC / DC / DC / AC converter as the second converter 6, wh erein therespective AC sides are connected to the transforme r 7.The solid-state transformer 1 according to the exem plaryembodiment of Figure 5 comprises n modules 2, where in eachmodule 2 comprises three sub-modules 22, particular ly a firstsub-module, a second sub-module and a third sub-mod ule, ofthe firsttype,asdescribed in Figure 2.The second converters 6, in particular the output p orts 12thereof, of the first sub-module and the second sub -moduleare connected in series. The second converters 6, i nparticular the output ports 12 thereof, of the firs t sub-module and the second sub-module are connected to a n energydispenser. The first sub-port 17 of the output port 12 of thefirst sub-module is connected to the energy dispens er, andthe energy dispenser is connected to the second sub -port 18of the output port 12 of the second sub-module. The secondsub-port 18 of the output port 12 of the first sub- module isconnected to the first sub-port 17 of the output po rt 12 ofthe second sub-module, thereby establishing a seria lconnection. Between the first and the second sub-po rts 17, 18of the first sub-module, a first switch is arranged , forelectrically connecting the first sub-port 17 to th e secondsub-port 18 when closed and electrically disconnect ing thefirstsub-port17 from the second sub-port18 when opened.Between the first and the second sub-ports 17, 18 o f thesecond sub-module, a second switch is arranged, sim ilar tothe firstswitch.With such a serial connection of the output ports 1 2 of thesub-modules 22, an output voltage range trimming is P2024,0661 WO N / P240059WO01 September18,2025 -20 -advantageously achieved. Exemplarily, electric vehi clesoperate at different voltages in a very wide range, roughly200 V to 1200 V. The serial topology can advantageo usly beused to match the output voltage of the module 2 to therespective energy dispenser, particularly to the el ectricvehicle. This is advantageously achieved by the con nection ofoutput ports 12 of two or more sub-modules 22 in se ries, e.g.O11 and O 12. Depending on the voltage of the electric vehicleconnected to the respective output port 12 of the m odule 2,one or more serialized output ports 12 of the respe ctive sub-modules 22 can simply be shorted to decrease the no minalvoltage at optimal conversion ratio. For example, i f thevoltage on each output port 12 of the sub-modules 2 2 inFigure 5 is 400 V, both O 11 and O 12 in series would provide800 V at a nominal conversion ratio and a control r ange from600-1000 V, whereas, if one of them was shorted, th is wouldyield 400 V and a 200-600 V range, respectively, as shown inconnection with Figure 6. This advantageously enabl esefficientwide voltage coverage. Note thatthe sub-module 22 thatisshorted byone oftheswitches is not converting electrical energy, and i n thatmode ofoperation a maximum powerofthe converter isdecreased for that amount. Also, an application pow er isalways proportional to the voltage, so a matching i sadvantageouslyachieved.The second converters 6, in particular the output p orts 12thereof, of the third sub-module of the first modul e 2 andthe third sub-module of the nth module 2, and parti cularlyall other modules 2, are connected in parallel. The secondconverters 6, in particular the output ports 12 the reof, ofthe third sub-module ofthe firstmodule 2 and the third sub- P2024,0661 WO N / P240059WO01 September18,2025 -21 -module of the nth module 2, and particularly all ot hermodules i, where i is from 1 to n, are connected to an energystorage. The first sub-port 17 of the output port 1 2 of thethird sub-module of the first module 2 is connected to theenergy storage, and the first sub-port 17 of the ou tput port12 of the third sub-module of the first module 2 is connectedto the first sub-port 17 of the output port 12 of t he thirdsub-module of the nth module 2. The second sub-port 18 of theoutput port 12 of the third sub-module of the first module 2isconnected to the energystorage,and the second sub-port18 of the output port 12 of the third sub-module of the firstmodule 2 isconnected to the second sub-port18 of the outputport 12 of the third sub-module of the nth module 2 , andparticularly all other modules i, where i is from 1 to n-1,thereby establishing a parallel connection. Each mo dule 2particularly needs to have at least one submodule t hat isconnected in parallel together with submodules 22 f rom othermodules2 to achieve the powerbalancing.Such a parallel connection advantageously enables b alancingand / or an exchange of electrical energy between dif ferentmodules 2. Due to parallel connection of output por ts 12 ofdifferent sub-modules 22 of different modules 2, in this caseOi3 , where i is a natural number between 1 and n, it i spossible to circulate electric energy from one modu le 2 i toanother module 2 j to correct any loading disbalanc e.By using the energy storage, advantageously, an ene rgybuffering is achieved. In particular, this allows m ultipleseparate outputs of the sub-modules 22 being used f or localbattery storage by the respective energy storage to provideenergy buffering, i.e. peak power shaving, function ality.This is advantageously important for remote electri c vehicle P2024,0661 WO N / P240059WO01 September18,2025 -22 - charging via the respective energydispenserswith high-power where grid capacityisnotsufficient.The outputs oftherespective sub-modules 22 used for balancing electr ic energy,i.e. load balancing, can be also directly connected to anenergystorage to provide thisfeature.For the sake of simplicity, in the exemplarily embo diment ofFigure 5, each energy dispenser is connected to sev eraloutput ports 12 of one module 2. It is possible tha t at leastsome or each energy dispenser is connected to diffe rentoutput ports 12 of different sub-modules 22 of diff erentmodules 2. This advantageously allows to better equ alize theelectric energy, i.e. the load, of each module 2 an d minimizethe power circulation needed for balancing electric energyamongstthe modules2. In the diagram according to Figure 6,an outputDC voltage onthe second side 4, V LVDC, is indicated on the y-axis in theupperpart,and an efficiency η isindicated on the y-axisin the lowerpart.The efficiencydropsexponentially whenmoving away from a nominal voltage, e.g. a conversi on ratio,of the respective module 2. The nominal voltages ar eindicated by dashed dotted lines in the upper part. In thelower part the left dashed curve indicates an effic iency whenall sub-modules 22 are connected, and the right das hed dottedcurve indicates an efficiency when half of the sub- modules 22are shorted,asexplained in Figure 5.The solid-state transformer 1 according to the exem plaryembodiment of Figure 7 has in contrast to the solid -statetransformer 1 of Figure 5 no interconnections of th e outputports 12 of the second converters 6 between differe nt modules2. P2024,0661 WO N / P240059WO01 September18,2025 -23 -The solid-state transformer 1 according to the exem plaryembodiment of Figure 8 has in contrast to the solid -statetransformer 1 of Figure 7 interconnections of the o utputports 12 of the second converters 6 between differe nt modules2.In contrastto the solid-state transformer1 of Figure 5,energy dispensers are connected to the serial conne ctions ofsub-modules22 ofdifferentmodules2.The exemplary embodiments, in particular features o f theexemplary embodiments, of the Figures can be combin ed withone another. Thispatentapplication claimsthe priorityofthe European patentapplication EP 24201313.4,the disclosure ofwhich isherebyincorporated byreference.

[0002] P2024,0661 WO N / P240059WO01 September18,2025 -24 - Reference Signs 1 solid-state transformer 2 module 3 firstside 4 second side 5 firstconverter 6 second converter 7 transformer 8 core 9 primarywinding 10 secondarywinding 11 inputport 12 outputport 13 firstAC / DC converter 14 firstDC / AC converter 15 second AC / DC converter 16 second DC / AC converter 17 firstsub-port 18 second sub-port 22 sub-module

Claims

P2024,0661 WO N / P240059WO01 September18,2025 -25 - Claims 1.Solid-state transformer(1),comprising -atleasttwo modules(2)having a firstside (3) and a second side (4),wherein each module (2)comprises -atleasttwo sub-modules(22),each comprising a first converter(5)atthe firstside (3)and a second converter(6)atthe second side (4),wherein -the first converter (5) is connected to the secon dconverter(6)bya transformer(6),and -the at least two sub-modules (22) are connected i nparallelatthe firstside (3),and wherein- the at least two modules (2) are connected in ser ies at thefirstside (3),- at least one of the sub-modules (22) is not conne cted inparallel at the second side (4) to the other sub-mo dules(22).

2. Solid-state transformer (1) according to claim 1 , wherein-the firstconverter(5)comprisesa firstdirect current / alternating current,DC / AC,converter,and- the second converter (6) comprises a second AC / DC converter(15). 3.Solid-state transformer(1)according to one of claims1 or2,wherein -atleastone sub-module (22)comprisesthe first converter(5) comprising a first AC / DC converter (13) and the firstDC / AC converter(14),and- the first DC / AC converter (14) is connected to th etransformer(7).P2024,0661 WO N / P240059WO01 September18,2025 -26 - 4.Solid-state transformer(1)according to one of claims1 to 3,wherein- at least one sub-module (22) comprises the second converter(6)comprising the second AC / DC converter(15)and a second DC / AC converter(16),and- the second AC / DC converter (15) is connected to t hetransformer(7). 5.Solid-state transformer(1)according to one of claims1 to 4,wherein- at least two sub-modules (22) of different module s (2) areconnected at the second side (4) in series or in pa rallel.6.Solid-state transformer(1)according to one of claims1 to 5,wherein -atleasttwo sub-modules(22)ofthe same module (2)areconnected at the second side (4) in series or in pa rallel.7.Solid-state transformer(1)according to one of claims1 to 6,wherein- a matrix switch is connected to the sub-modules ( 22) at thesecond side (4). 8.Solid-state transformer(1)according to one of claims1 to 7,wherein- the solid-state transformer (1) is a bidirectiona l solid-state transformer. 9.Solid-state transformer(1)according to one of claims1 to 8,wherein- elements of the modules (2) at the first side (3) areconfigured to process electric energy of a medium v oltagerange,andP2024,0661 WO N / P240059WO01 September18,2025 -27 -- elements of the modules (2) at the second side (4 ) areconfigured to process electric energy of a low volt age range.

10. Solid-state transformer (1) according to one of claims 1to 9,wherein -the modules(2)are configured to be connectable to a power grid atthe firstside (3).

11. Solid-state transformer (1) according to one of claims 1to 10,wherein -the modules(2)are configured to be connectable to at leastone energydispenseratthe second side (4). 12.Solid-state transformer(1)according to claim 11, wherein- the modules (2) are configured to be further conn ectable toat least one energy storage and / or at least one ene rgygeneratoratthe second side (4). 13.System,comprising -the solid-state transformer(1)according to one ofclaims 1 to 12,wherein- the solid-state transformer (1) is connected to a powergrid atthe firstside (3),and- the solid-state transformer (1) is connected to a t leastone energydispenseratthe second side (4). 14.System according to claim 13,wherein- the solid-state transformer (1) is further connec ted to atleast one energy storage and / or at least one energy generatoratthe second side (4).

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