WO2023165760A1 - Elektrisches antriebssystem - Google Patents
Elektrisches antriebssystem Download PDFInfo
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- WO2023165760A1 WO2023165760A1 PCT/EP2023/051459 EP2023051459W WO2023165760A1 WO 2023165760 A1 WO2023165760 A1 WO 2023165760A1 EP 2023051459 W EP2023051459 W EP 2023051459W WO 2023165760 A1 WO2023165760 A1 WO 2023165760A1
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- Prior art keywords
- drive system
- winding
- stator
- inverter
- designed
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/30—Structural association with control circuits or drive circuits
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- B60K7/00—Disposition of motor in, or adjacent to, traction wheel
- B60K7/0007—Disposition of motor in, or adjacent to, traction wheel the motor being electric
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60L50/00—Electric propulsion with power supplied within the vehicle
- B60L50/50—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells
- B60L50/60—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells using power supplied by batteries
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/12—Stationary parts of the magnetic circuit
- H02K1/16—Stator cores with slots for windings
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/12—Stationary parts of the magnetic circuit
- H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K16/00—Machines with more than one rotor or stator
- H02K16/02—Machines with one stator and two or more rotors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
- H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
- H02K3/12—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors arranged in slots
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/04—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
- H02K3/12—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors arranged in slots
- H02K3/14—Windings characterised by the conductor shape, form or construction, e.g. with bar conductors arranged in slots with transposed conductors, e.g. twisted conductors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/46—Fastening of windings on the stator or rotor structure
- H02K3/50—Fastening of winding heads, equalising connectors, or connections thereto
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/483—Converters with outputs that each can have more than two voltages levels
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P23/00—Arrangements or methods for the control of AC motors characterised by a control method other than vector control
- H02P23/0004—Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
- H02P23/0027—Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control using different modes of control depending on a parameter, e.g. the speed
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
- H02P25/02—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the kind of motor
- H02P25/022—Synchronous motors
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
- H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
- H02P27/14—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation with three or more levels of voltage
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/30—Structural association with control circuits or drive circuits
- H02K11/33—Drive circuits, e.g. power electronics
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
- H02K2201/06—Magnetic cores, or permanent magnets characterised by their skew
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K2213/00—Specific aspects, not otherwise provided for and not covered by codes H02K2201/00 - H02K2211/00
- H02K2213/03—Machines characterised by numerical values, ranges, mathematical expressions or similar information
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P2207/00—Indexing scheme relating to controlling arrangements characterised by the type of motor
- H02P2207/03—Double rotor motors or generators, i.e. electromagnetic transmissions having double rotor with motor and generator functions, e.g. for electrical variable transmission
Definitions
- the present invention relates to an electric drive system for or in a motor vehicle.
- TECHNICAL BACKGROUND Electric machines with a stator and two rotors connected to one another in a rotationally fixed manner so-called double-rotor machines (in addition to double-rotor also referred to as multiple rotor, dual-rotor, etc.) can increase both the torque density and the efficiency of electric drives compared to conventional electric machines increase with only one rotor. This can be explained by the fact that no magnetic yoke is required in the stator, particularly in the so-called “yokeless” design, which means that the core losses can be significantly reduced.
- stator winding only allow the use of single-tooth windings with the corresponding disadvantages in terms of noise excitation.
- established manufacturing processes suitable for large-scale production can be used in principle for the winding and laminated core in radial-flow double-rotor machines.
- EP 1879 283 B1 describes a possibility of designing the stator winding as a so-called yoke winding.
- the ring-shaped laminated core of the stator has grooves on the inner and outer diameters, between which there is a magnetic yoke that is effective in the tangential direction (also referred to as the stator yoke).
- the forward and return conductors of each phase winding are guided in slots that lie radially one above the other and are wound around the yoke.
- the stator yoke is axially accessible between the winding strands and can, for example, be screw connections on the housing (e.g. described in JP 2018082 600).
- the axial compression of the screws ensures both torsional rigidity of the laminated core and torque support at the axial end.
- the north and south poles of the rotor field face each other.
- the disadvantage of this concept is that the magnetic flux has to be routed completely via the return yoke located between the stator slots. On the one hand, this leads to an increased weight of the stator lamination stack and significantly increases the iron losses.
- the magnetic yoke in the stator can be omitted and a so-called "yokeless" double-rotor machine with distributed winding is created.
- the magnetic field lines close above the rotor.
- a magnetic yoke in the stator is not required, which means that the weight and iron losses in such machines are very low.
- the distributed winding does not allow direct mechanical contacting of the laminated core of the stator for torque support.
- WO 2004/004098 A1 describes a yokeless design with distributed winding. Even with a so-called “yokeless” design, it can still make sense to design a thin yoke for the mechanical connection of the stator teeth, but this is not necessary electromagnetically.
- the term "yokeless” thus refers to electromagnetic flux conduction in which there is no flux in the tangential direction in the stator.
- the winding cannot be designed as a yoke winding, since the outgoing and return conductors of the winding strands are distributed radially around the circumference and thus form a distributed winding. This results in winding overhangs of distributed windings, which make it difficult to access the laminated core in the axial direction.
- the purely radial flux guidance also prohibits the use of axial, metallic screw connections, as these form conductor loops with a large number of interlinked fluxes and high additional current heat losses.
- An inverter is provided for the operation of such a double-rotor machine for or in a motor vehicle due to the DC voltage present at the output of suitable energy storage devices.
- An inverter also known as an inverter or rotary converter, is an electrical device that converts direct current into alternating current.
- Such inverters are used, for example, in modern motor vehicles, in photovoltaics (solar inverters), as components in frequency converters and many other applications in which a suitable AC voltage is to be generated from a DC voltage.
- Inverters of this type and their areas of application are generally known in a wide variety of circuitry variants, so that there is no need to go into more detail about their circuitry design and mode of operation.
- Such drive systems include, for example, one or more electrical machines, such as synchronous machines or asynchronous machines, which are supplied with a multi-phase AC voltage.
- So-called two-level inverters also called 2-level inverters or 2L inverters for short
- 2-level inverters With two-stage inverters, an AC voltage with two voltage levels is generated from the DC voltage of a DC voltage source.
- Two-stage inverters have prevailed over other inverter topologies, particularly in the area of drive inverters for electric vehicles.
- IGBT switching elements are predominantly used in two-stage inverters.
- the object of the present invention is to improve the efficiency of an electric drive system equipped with a double rotor, while at the same time enabling simpler and more cost-effective manufacture. According to the invention, this object is achieved by an electric drive system having the features of patent claim 1 .
- an electric drive system for or in a motor vehicle with: at least one synchronous machine, which has a double rotor and a distributed winding placed in a stator core, the double rotor being made of flux-carrying material made of solid material, wherein the winding is designed to be self-supporting for torque support; and at least one three-stage or multi-stage inverter circuit, which is coupled to the synchronous machine at a load output and which is designed to convert a DC voltage taken up on the supply side into an AC voltage, via which the synchronous machine can be driven via the load output, the Inverter circuit has a controllable three- or multi-stage inverter.
- the core of the present invention consists in a combination of a special electrical synchronous machine with a double rotor, the stator of which is equipped with a distributed winding designed to be self-supporting and whose double rotor is made of solid rotor material, i.e. in full construction, and a three- or multi-stage inverter circuit.
- the torsionally stiff winding offers the possibility of constructing the winding of a synchronous machine with a double rotor, in particular a yokeless double rotor machine, as a distributed winding with a correspondingly low upper field spectrum.
- the causative harmonics in the input voltage can be significantly reduced by the inventive use of the combination of rotors made of flux-carrying solid material and a three-stage or multi-stage inverter, which leads to a reduction in losses by more than 75%. Since the harmonic losses in electrical machines in the prior art do not play a major role, de this does not justify the additional costs of a three-stage inverter. The combination of features according to the invention can only be rated as advantageous in this special case.
- One of the underlying findings here is that electrical machines with a double rotor made of solid material have high losses in the rotor when fed from a conventional 2L inverter. Structurally, the losses in the electrical machine cannot be reduced or can only be reduced to an insignificant extent.
- the basic mechanism for reducing the losses in the solid material of the double rotor is based on the fact that the amplitude of that magnetic flux density in the solid material of the double rotor which does not contribute to the generation of torque should be reduced.
- This component which is defined by harmonics in the flux density, is approximately directly proportional to the square of its amplitude to the change in the THD-induced losses. So changing the inverter switching frequency results in an indirect linear change in the losses and is therefore less effective.
- a reduction in losses in the solid material contributes significantly to reducing the overall losses of the electrical machine and to its economical use.
- the resulting knowledge which is part of the present invention, is that the losses in the electrical machine are compensated by an inverter circuit, which only reduces the amplitude of the harmonics in the flux density can be effectively reduced.
- the following measures and aspects were taken into account when designing and selecting the mode of operation of the inverter:
- the function of the 2L inverter is replaced by the function of a 3L inverter in order to reduce the harmonics at the phase outputs of the inverter to reduce. This reduces the harmonics in the flux density and in the stator current. A frequency change is not necessary for this.
- the 3L inverter used offers three voltage levels (3L) and is preferably (but not necessarily) three-phase. With three voltage levels and three phases, a relatively high level of cost efficiency can be achieved. However, the system can be expanded to any number of phases and any number of voltage levels with the same design of all phases. In contrast to known 2L inverters, the power losses in the electrical machine are greatly reduced when operating a 3L inverter according to the invention due to the lower harmonics.
- the switching losses of the 3L inverter are also reduced comparatively, while the conduction losses are increased.
- the prevailing loss mechanisms change depending on the load both in the electrical machine and in the 3L inverter.
- the harmonics are lower, so the machine losses are greatly reduced.
- Harmonic induced losses are dominant at low currents. With larger currents, the predominant loss mechanism changes and resistive line or copper losses dominate, whereas losses induced by harmonics are of secondary importance or are comparatively small.
- Inverter switching losses are reduced (approximately by 50%) in the 3L inverter compared to 2L inverters. With small loads (currents) these switching losses are dominant, whereas with larger currents conduction losses dominate and 2L operation is more efficient.
- One of the present The aspect on which the invention is based is therefore to design the winding arranged in the stator core to be self-supporting for torque support.
- a self-supporting design of the winding means that the winding is sufficiently rigid and strong against torsion around the machine axis to support the drive torque.
- the self-supporting winding is in particular embedded in a soft-magnetic stator core for magnetic flux guidance. This results in the particular advantage that the stator core itself does not require any inherent torsional rigidity with respect to the machine axis and no other auxiliary construction is required to fix the stator core. Rather, the torque is supported, in particular completely, via the winding.
- the winding is a so-called distributed winding.
- the selected pitch angle (also twisting angle) of the stator slots or the helixes described with it ensures that by connecting the inserted conductor bars, nested conductor loops are formed, which thus form a distributed winding.
- the angle covered by the conductor loops in the machine in relation to the central axis encloses one magnetic pole of the rotors.
- these are permanent-magnet-excited rotors with surface magnets and/or buried magnets, squirrel-cage rotors or electrically excited rotors.
- Hybrid variants with different rotor variants in the inner and outer rotor can also be provided.
- One A particularly advantageous embodiment results when the rotors are made of soft magnetic solid material and are made with surface-mounted permanent magnets.
- the low upper field spectrum of the winding variants described here and the distance between the solid material and the air gap guaranteed by the magnets prevent impermissibly large losses from occurring as a result of eddy currents in the rotors.
- comparatively high efficiencies can then advantageously be achieved and the rotors can nevertheless be manufactured very inexpensively.
- the synchronous machine can be integrated into a vehicle axle, for example, and can be provided to drive a drive wheel.
- the synchronous machine can be coupled to the drive wheel without a gear.
- an electric drive system according to the invention with a vehicle axle, in particular for a motor vehicle is also disclosed, wherein the synchronous machine with a double rotor is coupled to a drive wheel in a gearless manner.
- a motor vehicle with such an electric drive system is also disclosed.
- Advantageous refinements and developments result from the further dependent claims and from the description with reference to the figures of the drawing.
- the synchronous machine is designed as a radial flux double rotor machine.
- the mass of a radial flux double rotor machine can be reduced and the torque density can be increased due to the functional integration.
- the synchronous machine is designed for a wheel hub drive, in particular as a wheel hub motor for an electrically operated motor vehicle.
- a wheel hub motor is an electrical machine that is installed directly in a wheel and in particular in the hub of a vehicle and at the same time supports the wheel hub. A part of the hub motor transfers the generated torque directly to the wheel to be driven, with which it rotates.
- a comparatively short axial length can be realized with a comparatively large diameter, which is advantageous in particular in the wheel interior with regard to torque support and installation space.
- very high torques are also possible, which in particular are high enough to directly drive a wheel of a vehicle without a gear. drive. In this way, particularly advantageously, transmission losses are avoided, further weight is saved and particularly high efficiency advantages can be achieved.
- this high torque which is already possible in the four-digit range, in particular greater than 5000 Nm, for sizes within the dimensions of conventional motor vehicle rims, and thus already reaches the area of the adhesion limit of conventional road tires, even a rear axle Replace the wheel brake with the wheel hub motor.
- the winding protrudes beyond the stator core at at least one axial end.
- a support device is provided which is arranged offset axially with respect to the stator core and is designed for positive engagement with the winding at the at least one axial end for torque support.
- the self-supporting winding is positively engaged with the carrier device for torque support, which is arranged offset axially with respect to the stator core.
- the synchronous machine has a mechanically fixed base.
- the carrier device is in positive engagement with the at least one axial end of the winding and is supported on the base.
- the carrier device is firmly connected to the base as the stationary part of the synchronous machine by a suitable method.
- a possible embodiment provides recesses, for example through-holes, for non-positive fastening means, such as screws.
- form-fitting connecting means and/or a material-to-material connection would also be conceivable.
- the double rotor has a first rotor made of solid material arranged radially inside the stator core and a second rotor made of solid material arranged radially outside of the stator core.
- the rotors are preferably firmly coupled to one another, for example stamped, riveted or screwed.
- the flux-carrying material in the double rotor or in the first and second rotor consists of iron or an iron alloy.
- the magnetic flux is thus advantageously optimized.
- the synchronous machine is a three-phase synchronous machine.
- the inverter circuit is preferably designed at least as a three-phase inverter. Another finding of the present invention is that synchronous machines that use a three- or multi-stage inverter topology show a significantly improved overall efficiency of the drive system.
- the inverter circuit has an operating mode setting device which is designed to convert the inverter from three-stage or multi-stage operation to two-stage operation and vice versa, depending on the overall efficiency of the electric drive system.
- the inverter circuit has an operating mode setting device which is designed to convert the inverter from three-stage or multi-stage operation to two-stage operation and vice versa, depending on the overall efficiency of the electric drive system the overall efficiency is solely a function of the detected phase current of the synchronous machine or a function of at least one other property of the synchronous machine that influences the overall efficiency.
- the operating mode setting device has an evaluation device which is designed to optimize the overall efficiency on the basis of the phase current or the at least one further property.
- this has a special inverter circuit connected with an adaptation of the entire drive system, which makes it possible to increase the overall benefit without entailing an increase in costs.
- a novel controllable three- or multi-stage inverter is proposed, which can be operated in three- or multi-stage operation (hereinafter referred to as 3L operation) and in two-stage operation (hereinafter referred to as 2L operation).
- An operating mode setting device provided specifically for this purpose sets the respective operating mode in that the power switches of the inverter are controlled in a suitable manner.
- the operating mode is set according to the overall efficiency of the entire drive system - and thus not only on the basis of the synchronous machine and/or the inverter used.
- an overall efficiency consideration is therefore carried out here.
- One idea of the present invention consists in reducing the losses, above all in the case of small loads, by the inverter being operated in 3L operation in this case. The losses of the inverter at all operating points are at most insignificantly increased or even reduced.
- the overall efficiency of the drive system i.e. the inverter and the synchronous machine, increases significantly, especially when used in electrically powered vehicles.
- the inverter circuit has an operating mode setting device.
- the operating mode setting device does not necessarily switch over sharply from 2L operation to 3L operation and vice versa. Rather, it would also be conceivable if such a switchover instead takes place successively, for example by fading from the inner circuit breakers to the outer circuit breakers taking place. This fading can be carried out, for example, taking into account the average current values of the various circuit breakers, so that the operating times or the times in which the respective circuit breakers are switched on are taken into account. In addition or as an alternative, it would also be conceivable for the circuit breakers to be switched slowly and/or according to a predetermined range sequence.
- the operating mode setting device which for example is an evaluation device, a control device and/or measuring has devices can be designed, for example, as a program-controlled device, such as a microprocessor or microcontroller. However, a logic circuit such as an FPGA, PLD or the like would also be conceivable for this function. According to an advantageous development, the operating mode setting device has an evaluation device.
- the evaluation device is designed to optimize the overall efficiency of the electric drive system using the phase current and using the at least one additional parameter and/or the at least one property of the electric drive system. Typically, but not necessarily, the overall efficiency is calculated numerically by the evaluation circuit. In addition or as an alternative, the overall efficiency can be determined using a predefined family of characteristics, which is mapped in a lookup table, for example.
- the determination of the overall efficiency can be calculated or determined during operation or in advance.
- the optimal i.e. the most efficient operating strategy possible, is preferably calculated in a so-called offline mode before the operation of the electric drive system, for example numerically. This can be accomplished with comparatively little computer resources and is to be preferred above all when a large number of parameters are taken into account in the numerical precalculation of the optimum overall efficiency. In addition, more time is available for the calculation in offline mode.
- a very dynamic determination of the respective operating mode (2L operation or 3L operation) would also be conceivable and possible in a so-called real-time operation, for example via a lookup table. This is This is particularly advantageous and possible if a smaller number of parameters is used to calculate the overall efficiency.
- the evaluation device has an optimization module which is designed to initially determine the overall efficiency.
- the overall efficiency can then be optimized via an optimization function, taking into account the phase current and the at least one further parameter and/or property.
- the overall efficiency can be optimized analytically and/or using a suitable lookup table, which has been generated beforehand, for example.
- At least one of the following parameters is provided as a further parameter: temperature of the inverter circuit; - synchronous machine temperature; - intermediate circuit voltage of the inverter; - rotor speed or rotor speed; - torque of the synchronous machine; - degree of modulation; - Phase voltage or phase current.
- Other parameters would of course also be conceivable.
- the operating mode used in each case e.g. 2L operation or 3L operation
- a further property can be seen in the special configuration of the rotor of the synchronous machine, for example such that the rotor is a double rotor and/or that the double rotor is formed from flux-carrying material from solid material.
- the operating mode setting device has at least one measuring device:
- a first measuring device has at least one sensor input via which the first measuring device can be coupled to the synchronous machine.
- the first measuring device is designed to record the phase current, the temperature, the rotor speed and/or other measurable parameters.
- the temperature of the synchronous machine or its rotors can be recorded using appropriate thermocouples.
- the change in the temperature-dependent electrical resistance of certain conductors and semiconductors or special semiconductor circuits can be used to generate a voltage that is proportional to the absolute temperature (keyword: bandgap reference).
- the torque of the synchronous machine cannot be measured directly, it can be calculated, among other things, by measuring the phase current.
- the rotational speed of the rotor and from it the rotor speed can be determined in a variety of ways, for example using a Hall sensor attached to the rotor or an incremental encoder.
- a second measuring device which is arranged and designed in such a way that it detects the temperature and/or the intermediate circuit voltage of the inverter. The temperature can be recorded analogously to the above with regard to the first measuring device.
- the inverter includes a T-type neutral point clamped (TNPC) inverter architecture.
- a hybrid inverter topology can also be set up with TNPC in order to further increase efficiency and/or optimize manufacturing costs. For example, different switch technologies can be used for this in the zero-potential or middle bridge branch. Especially in the case of a TNPC inverter built entirely with IGBTs (Insulated Gate Bipolar Transistors), the losses can be drastically reduced using gallium nitride (GaN).
- the hybrid TNPC inverter topology can also be used in motor controls in electric vehicles, but is not found in practice.
- the 3-level converter is particularly advantageous to design the 3-level converter as a T-type converter, with the middle switches having a significantly lower current-carrying capacity than the outer switches.
- the converter In the low output torque range, the converter is then operated in 3L operation and in the high output torque range in 2L operation.
- the advantage of this design is that the harmonic losses are avoided in the area of low output torques, where they are of particular relevance.
- TNPC-based 3L inverters can operate in two modes to increase system efficiency. With 3L-TNPC inverters, the zero potential (middle) bridge arms can be switched off to operate in 2L operation and switched on to change to 3L operation. The two operating modes are switched in order to increase the system efficiency.
- TNPC-based 3L inverters can be designed asymmetrically to reduce the cost of the inverter.
- the asymmetry refers to the current-carrying capacity of the zero-potential (middle) bridge branches, which is lower than that of the outer bridge branches. This is possible because the zero-potential bridge arms are no longer used at higher loads in order to optimize overall efficiency.
- the outer bridge branches are designed for peak currents and the zero-potential bridge branches for small or continuous currents.
- the inverter has a first driver stage and at least one second driver stage.
- the second driver stage is designed to carry output load currents to the load output which are smaller than the output load currents provided by the first driver stage.
- the operating mode setting device is preferably designed to control the inverter in such a way that, depending on the overall efficiency, the first driver stage and the second driver stage are activated in three-stage or multi-stage operation and at least in two-stage operation. at least one of the driver stages is deactivated, preferably the inner, second driver stage.
- the first driver stage has at least one bridge circuit, in particular a half-bridge circuit, whose center tap forms the output load connection of the inverter circuit.
- Each bridge circuit has at least one first (semiconductor) power switch, which is connected to a first supply connection (to which a positive supply potential is applied, for example) and which is designed to provide a first voltage stage at the load output.
- Each bridge circuit also has at least one second (semiconductor) power switch, which is connected to a second supply connection (to which, for example, a negative supply potential or a reference potential is applied) and which are designed to generate a second voltage level at the load output to provide.
- the semiconductor-based power switches can be implemented with any number of different semiconductor materials.
- the second driver stage has at least one third power switch, the load paths of which are connected in series between an intermediate circuit circuit and the center tap of the first driver circuit.
- the power switches of the second driver stage are designed to provide a third voltage level, which lies between the first and the second voltage level, at the load output.
- all the power switches of the inverter ie the power switches of the first driver stage and/or the second driver stage, are designed as semiconductor switches of the same switch type and/or the same semiconductor technology.
- Switch types are, for example, bipolar transistors, field effect transistors (such as MOSFETs, JFETs, etc.), thyristors, IGBTs, etc.
- Semiconductor technology refers to the semiconductor technology on the basis of which the power switch is manufactured, such as on the basis of the Si, SiC, GaAs or GaN technology.
- the semiconductor switches are designed as GaN power switches, for example as GaN MOSFETs.
- the semiconductor switches are designed as SiC power switches, in particular as SiC MOSFETs.
- IGBT-based power switches for example silicon-based IGBTs with Si diodes or SiC diodes, would also be conceivable.
- hybrid inverter topology at least two different switch types and/or at least two different semiconductor technologies are provided for the semiconductor switches of the inverter, i.e. for the semiconductor switches of the first driver stage and/or for the semiconductor switches of the second driver stage.
- the hybrid inverter topology does not use the same semiconductor materials for all power switches within the inverter.
- a different technology (different switch types) is used for the power switches of the zero-potential bridge branch, ie for the second driver stage, than for the outer switches of the first driver stage.
- it is recommended to optimize the power switches in the zero-potential bridge branches (second driver stage) for low switching losses and the lowest possible reverse recovery losses. This makes sense since the zero-potential bridge arms (second driver stage) are activated at low currents and low reverse recovery losses also reduce the switching losses in the outer switches.
- a hybrid design is particularly recommended if the inverter is designed asymmetrically.
- the semiconductor switches of the first driver stage are in the form of IGBTs (silicon or SiC) with a freewheeling diode.
- the semiconductor switches of the second driver stage can preferably be designed as SiC power switches, in particular as SiC MOSFETs.
- the semiconductor switches of the first driver stage are designed as SiC MOSFETs.
- the semiconductor switches of the second driver stage can be designed as GaN-based MOSFETs.
- the semiconductor switches of the first driver stage are designed as IGBTs with a freewheeling diode.
- the semiconductor switches of the second driver stage can be designed as GaN power switches, in particular as GaN MOSFETs.
- the flux-carrying material in the rotor consists of iron or an iron alloy. Electrical induction machines - and here preferably synchronous machines with double rotors - can be designed in the rotor with flux-carrying material in solid construction, i.e. made of solid material. The reason for this is that, in an idealized view, there is no periodic relative movement between the directional vector of the rotating field generated by the stator winding and the double rotor in synchronous machines.
- the synchronous machine has a stator with a stator, the stator being designed to guide a primarily radial magnetic flux, in particular to avoid magnetic flux being guided in a tangential direction. It is therefore a so-called "yokeless" design of the stator, which in particular avoids a magnetic flux guidance in the circumferential direction.
- the stator of the stator has a radial yoke thickness which is less than 30%, preferably less than 20%, particularly preferably less than 10% of a total radial stator thickness.
- a mechanical connection of the stator teeth is still provided in this way. which would not be necessary electromagnetically and via which no functionally relevant magnetic flux takes place.
- the term “yokeless” thus refers to the electromagnetic design of the stator.
- the winding is designed to be torsionally stiff in such a way that a torque acting on the stator core during operation of a radial flux double-rotor machine can be supported, in particular completely, via the torsionally stiff winding on the carrier element.
- the stator core is designed to guide a primarily radial magnetic flux. It is therefore a so-called “yokeless" design of the stator core, which in particular avoids a magnetic flux guidance in the circumferential or tangential direction. A magnetic yoke in the stator core is not required, which reduces weight and iron losses.
- the stator core has a radial yoke thickness that is less than 30%, preferably less than 20%, particularly preferably less than 10% of a total radial stator core thickness.
- a mechanical connection of the stator teeth is nevertheless provided in this way, which is not necessary electromagnetically and via which no functionally relevant magnetic flux takes place.
- the term “yokeless” thus refers in particular to the electromagnetic flux guidance of the stator core.
- the winding is formed from conductor bars connected to one another, in particular in the manner of a truss.
- the conductor bars can be integrally bonded be connected, for example by welding or soldering.
- other connection techniques would also be conceivable.
- Two conductor bars are preferably connected at the ends of the conductor bars and all the conductor bars together form a framework.
- the framework formed with the conductor bars is advantageously designed to be torsionally rigid and designed for torque transmission around the central axis of the stator.
- the conductor bars are formed with a thickness sufficient for power transmission.
- the thickness of the conductor bars can be in the range of several millimeters, for example. In particular, it can be rods with a square profile with edge lengths of several millimeters.
- the winding has a radially inner layer of helically arranged conductor bars and a radially outer layer of oppositely helically arranged conductor bars.
- a framework is formed by the winding, which has a high torsional rigidity.
- the conductor bars of the inner layer and the conductor bars of the outer layer each describe a helical line whose winding directions or gradients are opposite to one another.
- a swept angle of the helical line between the beginning and end of a conductor bar in relation to the central axis of the stator is in particular designed in such a way that in a radial flux double-rotor machine, one conductor loop is formed per pole of the rotors.
- the swept angle to be provided can thus be calculated from the quotient of a complete revolution (2 ⁇ or 360°) and twice the number of pole pairs ⁇ .
- the radially inner layer and the radially outer layer of the winding each have the thickness of a single conductor bar. That is, a phase of wick- ment is formed with the cross section of a single conductor bar.
- a design of a winding according to the invention is made possible, among other things, by the special design of the radial flux double rotor machine, which suppresses the current displacement to the surface that is otherwise present in conductors by means of its magnetic symmetry. In this way, comparatively thick conductor cross sections are made possible and a relatively uniform current distribution over the cross section is nevertheless achieved.
- the thickness of the conductor bars can be in the range of several millimeters.
- the conductor bars are twisted in accordance with the helical course in such a way that a cross section of a conductor bar is the same at every point of the conductor in relation to a radial axis of the cross section.
- the conductor bars can also be bent.
- the inner and the outer layer are interlaced with one another, that is to say twisted, twisted and possibly bent in opposite directions.
- the alignment of a conductor bar from a mechanical point of view at every point of the stator core is ideally aligned for power transmission with the stator core, so that the respective conductor bar is loaded evenly over its length.
- the conductors when subjected to a tangential force, advantageously primarily absorb tensile and compressive stresses. In this way, peak loads and deformation of the conductor bars are avoided. the.
- the mechanical stresses can thus be significantly reduced, in particular compared to a design with axis-parallel, straight conductors.
- the conductor bars of the radially inner and outer layer belonging to the same phase of the winding are connected to one another at the ends of the conductor bars, in particular via a radially arranged conductor bar piece and/or by means of an integral connection.
- this also results in a torsionally rigid truss-like structure, so that when an axially accessible winding end is fixed, the winding can absorb a high torque without causing impermissibly large deformations and/or stress states.
- the self-supporting design of the winding is made possible only by the winding material, for example copper, without additional support means or elements.
- the stator core contains a stator core with stator slots running helically in accordance with the course of the winding, with a single conductor bar being arranged in each stator slot of the stator core.
- the winding or the self-supporting framework formed with it is thus embedded in the laminated core of the stator. Similar to the conductor bars of the winding, the stator slots therefore change their tangential position depending on the axial position, resulting in the helical shape.
- the direction of the change in position follows the conductor bars, i.e. the center line of the radially outer grooves and the radially inner grooves also each describe a helix whose winding directions are opposite.
- Stator core geometry according to the invention with the radially inner and outer stator slots running in opposite helical configurations is conceivable, in particular also additive production methods, such as sintering methods or the like.
- additive production methods such as sintering methods or the like.
- only a single conductor bar is placed in each stator slot of the stator core.
- the conductor bars of the inner and outer stator slots are helically twisted against one another by torsion around the central axis of the machine, so that the conductor ends of the inner and outer layers are guided towards one another.
- the conductor bars are conductively connected to one another at the conductor bar ends, in particular via a radially arranged conductor bar piece and/or by means of an integral connection, for example by welding or brazing.
- the conductively connected conductor bars of the inner and outer layers together form wave-shaped winding strands.
- the winding strands can be interconnected by appropriate connections known to those skilled in the art to form a rotating field-generating winding with a desired or adaptable number of strands.
- the voltage-carrying number of phase windings results directly from the quotient of the number of slots in the meter and a product of the number of phases and the number of parallel branches in the meter.
- the number of parallel branches is chosen to be 1.
- the stator laminations of the stator laminations are each of identical design with recesses provided for forming the stator slots.
- the helical course of the stator slots is provided by means of stacking of the stator laminations that are twisted relative to one another.
- the laminated stator core can be manufactured in a very economical manner, since the same stamping die can be used for all the stator laminates arranged or stacked in parallel. Accordingly, two adjacent stator laminations are rotated slightly relative to one another by a predetermined angle about the central axis, so that the recesses are arranged in an overlap relative to one another, which corresponds to the course of the helical line.
- the laminated core of the stator contains an inner sub-package with radially inner stator slots and an outer sub-package with radially outer stator slots.
- the stator laminations of the inner subpackage each have the same geometry and the stator laminations of the outer subpackage each have the same geometry.
- the stator laminations of the inner sub-package and the stator laminations of the outer sub-package are stacked in opposite directions to one another. In this way, the opposite helices of the stator slots can be realized with little manufacturing effort.
- stator laminations with recesses provided for forming the stator slots are each designed differently.
- the helical course of the stator slots is provided by means of different distances between the recesses in the individual stator laminations. In this respect, for each position of a stator lamination within the stack, an individually fitting stator lamination shape is produced, it also being possible for the individual geometries to be repeated within the stack.
- the production can be implemented, for example, by means of a beam cutting process, in particular a laser beam cutting process, which is more flexible in terms of shape compared to a stamping process.
- a beam cutting process in particular a laser beam cutting process
- flexible stamping dies with variable geometry or, in the case of very large quantities, of course, several individual stamping dies for each of the different stator sheet metal shapes.
- the recesses for radially inner and radially outer stator slots are each integrated into a common stator lamination, the opposite helical progression of the radially inner and radially outer stator slots being caused by a continuous displacement of the inner and outer stator slots relative to one another Stator lamination is provided to stator lamination.
- stator laminations have straight edges, in particular stamped edges.
- a width of the recesses provided for the stator slots is designed to be greater than the width of the conductor bars by an amount predetermined by the gradient of the helical shape of the course of the stator slots and by the sheet thickness of the stator sheets.
- a reduced clear width or continuous width of the stator slots due to the offset between the recesses of the stator laminations thus essentially corresponds to the width of a conductor bar.
- the continuous clear width of the stator slot is intended to be slightly larger than the width of the conductor bar in order to provide a clearance fit necessary for inserting the conductor bars.
- the edge of a stator slot thus describes a stair shape with the respective sheet thickness as steps, on which the conductor bar is evenly supported. In this way, the torque support is made possible uniformly over the entire thickness of the laminated stator core or over the entire length of the conductor bars accommodated in the laminated stator core.
- an angle swept by the stator slots is smaller than an angle swept by the conductor bars.
- the angle drawn relates to a rotation around the central axis of the stator.
- the difference in the swept angles comes about because the conductor bars protrude axially beyond the stator core and are therefore longer than the stator slots. Since the helical course also continues, the result is a larger swept angle.
- the said difference is intended to ensure sufficient accessibility of the winding ends for connecting, in particular welding, the conductor bar which is guaranteed after insertion into the stator slots. Furthermore, in this way, an axially offset engagement of the winding with the carrier device or its carrier element with respect to the stator core is made possible.
- a so-called degree of pole coverage for the stator core can be defined.
- a ratio of the angle swept by the stator slots to the angle swept by the conductor bars is in a range between 0.6 and 0.8, in particular between 0.6 and 0.75, preferably between 0.6 and 0.7. In this area, this ratio (degree of pole coverage) provides an optimum between losses caused by Joule heat and torque utilization.
- the carrier device has a carrier element in which carrier grooves are provided which correspond to the helical arrangement of the conductor bars and which engage with the conductor bars.
- the carrier element can be coupled to a mechanically fixed base of a radial-flow double-rotor machine.
- a possible design provides through-holes for non-positive fastenings. means such as screws, but of course form-fitting connection means or a bonded connection would also be conceivable.
- the carrier grooves follow the helical course of the twisted conductor bars at least in sections.
- the carrier grooves have a course that is twisted in the same way as the conductor bars.
- the support element is essentially ring-shaped and has recesses on the inner and/or outer circumference, which are aligned radially and correspond to the course of the conductor bars.
- the carrier device has a radially inner carrier element for engagement with the radially inner layer of the conductor bars and a radially outer carrier element for engagement with the radially outer layer of the conductor bars.
- the support elements can be ring-shaped, with the inner support element on its outer circumference corresponding to the course of the inner layer of the conductor bars grooves or teeth for positively receiving the radially inner conductor bars and the outer support element on its inner circumference the course of the outer layer of the conductor bars has corresponding grooves or teeth for positively locking reception of the radially outer conductor bars.
- the grooves or teeth follow in particular the respective helical course. Due to the arrangement on the inner or outer circumference, the recessed grooves are easily accessible for mechanical processing, which simplifies the production of the carrier elements.
- the support elements are fixed to the base and thus guide the torque to the fixed part of the electric machine.
- the carrier elements can be attached individually to the base, for example a housing, of the machine. Alternatively or additionally, the inner and outer support elements can also be fastened to one another.
- the carrier device contains a heat-conducting material, in particular a metal, preferably an aluminum alloy.
- both carrier elements can contain such a material. In this way, in addition to high mechanical strength, it is also possible to dissipate heat from the winding via the carrier device.
- the base also has a heat sink which is designed to absorb heat dissipated from the stator, in particular from the winding, via the carrier device.
- the carrier device has a high mechanical strength and at the same time ensures a good thermal connection of the winding to the heat sink.
- the housing of the machine can serve as a heat sink.
- the carrier device preferably the inner and outer carrier elements, can be in thermal contact with an actively cooled heat sink of the machine. In this way, the current heat losses occurring in the winding or in the conductor bars can be effectively dissipated.
- a predetermined number of pool pairs are provided on both the first rotor and the second rotor. An angle swept out by the conductor bars is used to form a conductor loop per pole of the rotors formed.
- the swept angle to be provided can thus be calculated from the quotient of a complete revolution (2 ⁇ or 360°) and twice the number of pole pairs ⁇ .
- FIG. 2 shows an electric drive system according to one embodiment based on a block diagram
- FIG. 3 shows an example of an electric machine of the electric drive system according to the invention according to FIG. 1 using a schematic cross-sectional illustration
- Fig. 4 based on a block diagram, a three- or multi-stage inverter circuit for an inventive the electric drive system according to the invention according to FIG.
- FIG. 1 shows a particularly preferred exemplary embodiment of an inverter circuit according to the invention using a circuit diagram; 6 uses a flowchart to show a method according to the invention for operating an electric drive system; 7 shows a schematic longitudinal sectional illustration of a stator; 8 shows a schematic longitudinal sectional view of a radial flow double rotor machine; 9 shows an exploded view of a stator according to an embodiment; 10 is an exploded view of a radial flux dual rotor machine according to one embodiment; 11 is an exploded view of a radial flux dual rotor machine according to another embodiment; FIG. 12 shows a perspective illustration of the radial flux double rotor machine according to FIG.
- FIG. 11 in the assembled state is a longitudinal cross-sectional perspective view of a radial flow twin rotor machine according to yet another embodiment
- 14 shows an exploded view of a stator lamination stack of a stator core
- 15 shows a schematic longitudinal sectional illustration of a stator slot
- 16 is a perspective view of a winding
- Fig. 17 is a plan view of a winding
- 18 shows a perspective view of an FEM simulation of a winding under load
- 19 shows a perspective representation of an FEM simulation of a comparison winding with a straight design of the conductor bars under load
- FIG. 20 shows a flow chart of a method for manufacturing a stator.
- the accompanying drawings are provided to provide a further understanding of embodiments of the invention.
- FIG. 1 uses a block diagram to show an electric drive system 10 according to the invention for a motor vehicle.
- the electric drive system identified here by reference numeral 10 is preferably—but not necessarily—provided for use in a motor vehicle.
- the drive system 10 comprises at least one polyphase electrical synchronous machine 11 and an inverter circuit 12.
- the synchronous machine 11 is shown symbolized in the block diagram with a section of a cross-sectional diagram. It is connected on the input side to the inverter circuit 12 which drives the machine 11 .
- the synchronous machine 11 is designed as a double rotor machine and accordingly has a double rotor with two rotors 21 , 22 .
- a stator with a stator core (2) and a distributed winding (3) placed in the stator core (2) is provided, which is designed to be self-supporting for torque support.
- the double rotor is or the rotors 21, 22 are made of flow-carrying material made of solid material.
- the inverter circuit 12 is designed as a three-stage or multi-stage inverter circuit 12 .
- the inverter circuit 12 has at least one inverter 13 .
- the inverter 13 is coupled to the electrical machine 11 via its load output 15 and to a supply voltage source 18 via supply connections 16 , 17 .
- the inverter 13 is designed to convert a direct voltage VDC received on the supply side into an alternating voltage VAC.
- the inverter 13 is designed as a multi-phase inverter 13, the number of phases of the inverter 13 typically corresponding to the number of phases of the electrical machine 11.
- the electrical machine 11 is driven via the phase currents provided by the inverter 13 at the load output 15 .
- the synchronous machine is preferably a yokeless double rotor machine.
- the torsionally stiff winding is designed as a distributed winding and has a correspondingly low upper field spectrum. Due to this design, the rotors can be made of solid or solid material, since the winding generates only small upper fields and the resulting eddy currents in the rotor. Induced current harmonics, which would cause eddy currents and additional losses in the rotors made of solid material with a conventional two-stage converter, can be reduced with the three-stage or multi-stage inverter circuit 12 . By operating the three-stage or multi-stage inverter circuit 12, the causative harmonics in the input voltage can be significantly reduced, which leads to a reduction in the losses by more than 75%. FIG.
- the operating mode of the inverter circuit 12 is set via an operating mode setting device 14 which, on the input side, has, among other things, is coupled to the electrical machine 11, adjustable.
- the operating mode setting device 14 can be used to set whether the inverter 13 is operating in two-stage operation, in three-stage or multi-stage operation or in mixed operation.
- Mixed operation designates an operating mode in which the inverter is operated both in two-stage operation and in three-stage or multi-stage operation, as can occur, for example, when changing from one operating mode to the next.
- the construction and functioning of the operating mode setting device 14 is explained in detail below with reference to the following FIGS. 4 to 6.
- the electrical machine 11 is a synchronous machine 11, preferably, but not necessarily, a three-phase synchronous machine 11.
- the inverter circuit 12 preferably includes a three-phase inverter 13. It is also preferred if the electrical machine 11 of the electrical drive system 10 is a Wheel hub motor for an electrically operated motor vehicle.
- the double rotor is also constructed from flux-carrying material made of solid material.
- the cross section of the double rotor synchronous machine 11 is shown in FIG.
- the double rotor machine 20 comprises the outer rotor 21 and the inner rotor gate 22.
- the stator 23 is arranged in a manner known per se.
- the stator 23 can preferably, but not necessarily, be a yokeless stator 23 .
- the outer rotor 21 and inner rotor 22 are preferably not laminated, but constructed from solid material.
- the inner rotor 22 is tubular. However, a massive, full-volume configuration of the inner rotor 22 would be conceivable. It would be conceivable and advantageous if the magnets 24, 25 were embedded in pocket-shaped recesses provided specifically for this purpose in the outer rotor 21. However, it would also be conceivable for the magnets 24, 25 to be spaced apart from the outer rotor 21, ie not attached directly to its inner surface.
- the flux lines 27 between the north and south poles of the opposite-pole magnets 24, 25 run here in the core material of the outer rotor 21.
- the magnets 28, 29 can be embedded in corresponding pockets of the inner rotor 22 or spaced apart from the inner rotor 22.
- the flux lines 31 between the north and south poles of the opposite-pole magnets 28, 29 run here in the core material of the inner rotor 22.
- the flux-carrying material in the outer and/or inner rotor 21, 22 preferably consists of solid iron or a corresponding solid iron alloy.
- the inverter circuit 12 includes—as already explained with reference to FIG. or multi-stage inverter 13 and an operating mode setting device 14.
- a first supply potential V11 for example a positive supply potential
- a second supply potential V12 for example a negative supply potential or a reference potential
- a multi-phase load current I1 can be tapped off at the load output 15, via which the various phases of the electrical machine 11 that can be connected via the load output 15 are operated.
- the controllable three-stage or multi-stage inverter 13 is arranged between the supply connections 16 , 17 and the load output 15 .
- the inverter 13 is designed to convert a direct current voltage VDC taken on the supply side into an alternating current voltage VAC in order to provide the multi-phase load current I1 at the load output.
- the inverter 13 has a first driver stage 40 and at least one second driver stage 41 .
- the second driver stage 41 is designed to output load currents to the To lead load output 15, which are smaller than the currents provided by the first driver stage 40 output load.
- the operating mode setting device 14 serves the purpose of setting and thus controlling the operating mode of the inverter 13 and thus of the entire inverter circuit 12 .
- the inverter 13 is designed to operate the inverter 13 either in a first operating mode in a three-stage or multi-stage operation or in a second operating mode in a two-stage operation.
- At least a third operating mode would also be conceivable, which includes a mixed form of two-stage operation and three-stage or multi-stage operation.
- the third operating mode would be conceivable and useful in particular in the case of a transition from the first operating mode to the second operating mode and vice versa.
- the operating mode setting device 14 controls the operating mode used for the inverter 13 depending on the overall efficiency of the entire electric drive system 10.
- the overall efficiency is a function of the detected phase current of the electric machine 11 and at least one other parameter influencing the overall efficiency and/or one further property of the electrical machine 11 that influences the overall efficiency.
- the operating mode setting device 14 comprises at least one of the following devices: an evaluation device 42; - a first measuring device 43; - a second measuring device 44; - a control device 45.
- Evaluation device 42 is designed to optimize the overall efficiency of electric drive system 10 based on the phase current and the at least one additional parameter and/or the at least one additional property. This can be done in situ, for example, that is to say during the operation of the electric drive system 10 .
- the relatively computationally intensive calculation is preferably carried out in advance, for example by means of a suitable calculation (e.g. numerically or analytically) and/or using a predefined family of characteristics.
- a suitable calculation e.g. numerically or analytically
- the numerical efficiency calculation for 2L operation and 3L operation as well as the mapping of the function with decision output is carried out in advance, i.e. offline.
- the choice of the better efficiency with the help of switching and the use of the lookup table to determine the efficiency can also—but not exclusively—be made more or less dynamically during operation.
- the evaluation device 42 has an optimization module 46 for the purpose of optimization. The optimization module 46 first calculates the overall efficiency.
- the operating mode setting device 14 also includes first and/or second measuring devices 43, 44.
- the first measuring device 43 has at least one sensor input 47, for example.
- the operating mode setting device 14 can be coupled to the electrical machine 11 via the sensor inputs 47 in order to record and record electrical or physical parameters of the electrical machine 11, such as the phase current, the temperature and/or the rotor speed of the electrical machine 11 to er- grasp.
- the second measuring device 44 is arranged in such a way as to detect the temperature and/or the intermediate circuit voltage of the inverter 13, for example.
- the supply voltage VDC can also be detected via the second measuring device 44 .
- the actual control of the inverter takes place via a control device 45 provided specifically for this purpose.
- the control device 45 sets the respective operating mode of the inverter 13, i.e. whether the inverter 13 is operated in three- or multi-stage operation or in two-stage operation.
- the control device 45 can, for example, control the inverter 13 in such a way that both driver stages 40, 41 are activated in three-stage or multi-stage operation and the second driver stage 40 is deactivated in two-stage operation.
- 5 uses a circuit diagram to show a particularly preferred exemplary embodiment of an inverter circuit according to the invention.
- a reference potential for example the potential of the reference ground GND
- An intermediate circuit 50 consisting of a series connection of two intermediate circuit capacitors 51, 52 is connected on the input side of the inverter 13.
- the intermediate circuit 50 acts as an energy store.
- the first, outer driver stage in the illustrated case of a 3-phase inverter has three half-bridge circuits 53a-53c, which are also connected on the load side between the supply connections 16, 17 with regard to their load paths.
- the respective center taps 54a-54c of the half-bridge circuits 53a-53c each form an output load connection 15a-15c of the inverter 13.
- Each of the half-bridge circuits 53a-53c has a first controllable power switch T1, T2, T3, which is High-side switches are formed. These first power switches T1, T2, T3 are connected to the first supply connection 16.
- the first power switches T1, T2, T3 are designed to provide a first voltage level at the load output 15.
- Each of the half-bridge circuits 53a-53c also has a second controllable power switch T4, T5, T6, which are designed as low-side switches. These second circuit breakers T4, T5, T6 are connected to the second supply connection 17.
- the second power switches T4, T5, T6 are designed to provide a second voltage stage at the load output 15.
- the second, inner driver stage 41 is connected between the center tap 55 of the intermediate circuit and the output load connections 15a-15c—and thus the respective center taps 54a-54c of the half-bridge circuits 53a-53c.
- the second driver stage 41 each includes three circuit branches 56a-56c.
- Each of the circuit branches 56a-56c comprises a series connection of two controllable circuit breakers T7/T8; T9/T10; T11/T12, which are arranged antiparallel with respect to their load paths.
- the controllable circuit breakers T7/T8; T9/T10; T11/T12 are designed to provide a third voltage level, which is between the first and the second voltage level, at the load output 15a-15c.
- the control device 45 has a first control unit 45a and a second control unit 45b.
- the first control unit 45a is designed to control the power switches T1-T6 of the first driver stage 40.
- the second control unit 45b is designed to control the power switches T7-T12 of the second driver stage 41.
- the inverter 13 has a hybrid design.
- the power switches of the inverter 13 are not manufactured using the same semiconductor technology and/or are not of the same switch type.
- the power switches T1-T6 are Si-IGBTs with Si freewheeling diodes.
- the power switches T7-T12 are in the form of SiC MOSFETs.
- the power switches T7-T12 can be in the form of SiC MOSFETs and the power switches T1-T6 can be in the form of GaN MOSFETs.
- the power switches T1-T6 can be in the form of GaN MOSFETs.
- the power switches T7-T12 can be in the form of IGBTs with a freewheeling diode and the power switches T1-T6 can be in the form of GaN power switches, in particular GaN MOSFETs.
- the power switches T1-T6 can be in the form of GaN power switches, in particular GaN MOSFETs.
- all power switches T1-T12 of the inverter 13 can be of the same switch type and/or with the same semiconductor technology. gie be made, for example as GaN power switches, SiC power switches, such as SiC MOSFETs designed.
- FIG. 6 uses a flow chart to show a method according to the invention for operating an electric drive system.
- the electrical drive system which can be a drive system according to FIG.
- a synchronous machine equipped with a double rotor.
- the double rotor is made of flux-carrying solid material.
- the overall efficiency of the electric drive system is determined, for example offline.
- the phase current of the electrical machine of the electrical drive system is first detected (S11).
- at least one further parameter (S12) influencing the overall efficiency and/or at least one further property (S13) influencing the overall efficiency of the electrical machine is determined.
- the synchronous machine is operated from all this information.
- a controllable three- or multi-stage inverter circuit is used for this purpose.
- the controllable three- or multi-stage inverter of the inverter circuit is operated either in the three- or multi-stage operating mode S21 or in the two-stage operating mode S22, depending on the overall efficiency of the electric drive system and the parameters and properties influencing it.
- a mixed form of three-stage or multi-stage operation and two-stage operation would also be conceivable.
- Such a mixed mode of operation would be conceivable, for example, in the case of a transition from three-stage or multi-stage operation to two-stage operation advantageous, for example, to avoid hard switching. The latter could be associated with losses and thus reduced efficiency.
- 7 shows a schematic longitudinal sectional illustration of a stator 101.
- FIG. 8 This is a basic sketch of a stator 101 for a synchronous machine 110 designed as a radial flux double rotor machine according to a further embodiment (see FIG. 8), in particular for a wheel hub motor.
- the stator has a stator core 102 , a winding 103 and a carrier device 105 .
- the stator core 102, the winding 103 and the carrier device 105 are rotationally symmetrical about the center axis M shown.
- the winding 103 is designed to be self-supporting to support the torque of the stator and protrudes beyond the stator core 102 at at least one axial end 104 .
- the carrier device 105 is arranged offset axially with respect to the stator core 102 and is positively connected to the winding 103 at at least one axial end 104 for torque support. In this way, a torque present at the stator core 102 during operation of a radial flux double-rotor machine 110 can be supported on the carrier device 105 by means of the self-supporting winding 103 .
- the winding 103 contains a low electrical resistance conductor material, preferably copper.
- the stator core 102 is preferably constructed from a soft-magnetic material for guiding the magnetic flux.
- the carrier device preferably contains a heat-conducting material, for example an aluminum alloy. Of course, the winding 103 is electrically isolated.
- FIG. 8 shows a schematic longitudinal sectional view of a radial flux double rotor machine.
- the synchronous machine 110 designed as a radial flux double rotor machine accordingly has a mechanically fixed base 111, a first rotor 112 and a second rotor 113 in addition to the stator 101 according to FIG.
- the stator core 102, the winding 103, the carrier device 105, the base 111, the first rotor 112 and the second rotor 113 are also constructed rotationally symmetrically about the central axis M shown.
- the winding 103 is designed to be self-supporting to support the torque of the stator 101 and projects beyond the stator core 102 at at least one axial end 104 and is supported on the base 111 via the carrier device 105 .
- the carrier device 105 is arranged offset axially with respect to the stator core 102 and is positively connected to the winding 103 at at least one axial end 104 for torque support.
- the carrier device 105 is in turn fastened to the base, so that the torque can be supported on the base 111 via the carrier device 105 .
- the first rotor 112 is arranged radially inside the stator core 102 and the second rotor 113 is arranged radially outside the stator core 102 .
- the base 111 can, for example, be designed as the housing of the machine and, purely by way of illustration, comprises an L-shaped structure which is shown with two legs 107, 108.
- the representation is not to be understood as conclusive, rather the base can have further components and/or structural sections.
- the first leg 107 runs essentially radially, the second leg 107 is essentially axial with the greatest distance from the center axis M.
- the carrier device 105 is shown running radially in one piece purely schematically, but it can also be provided in multiple pieces and/or with a different geometry designed for a form fit with the winding 103 be.
- the illustrated overlap of the winding 103 with the base 111 is purely due to the illustrative schematic representation and does not mean a direct connection.
- the winding 103 is preferably connected via the carrier element 105 to the base 111 for torque support.
- the radial flux double rotor machine 110 according to FIG. 8 can be used as a synchronous machine 11 in an electric drive system 10 according to one of FIGS. 1 or 2 and in connection with an inverter circuit 12 according to one of FIGS. 9 shows an exploded view of a stator 101 according to a further embodiment.
- the stator 101 has a winding 103, a stator core 102 and a carrier device 105, with an advantageous exemplary embodiment of these components being shown in more detail in perspective here.
- the winding 103 is made up of an inner and outer layer with a plurality of conductor bars 106 connected to one another in the manner of a framework.
- the conductor bars 106 in the inner and outer layers are arranged opposite one another in a helical manner and are cohesively coupled at the ends of the conductor bars to a radial conductor piece 117 connecting the inner and outer layers.
- the thickness of the inner and outer layer corresponds in each case to the thickness of a conductor bar 106.
- the winding 103 is formed by a single conductor layer forming the conductor loop and having a comparatively large cross section in the form of a conductor bar 106 in each case. Due to the truss structure formed with the conductor bars, the winding is torsionally rigid and thus designed to be self-supporting for torque support.
- stator bars 106 accordingly form wavy winding strands and can be connected to form a rotary field-generating winding with any number of strands by means of appropriate connections known to those skilled in the art and therefore not described further, such as delta connection, star connection or the like.
- the stator core 102 and the carrier device 105 are each constructed from two components, for example.
- the winding 103, the stator core 102 and the carrier device 105 are arranged in a nested manner. After assembly, the components are aligned coaxially with one another on the common central axis M.
- the two-part support device 105 here, for example, is arranged axially offset relative to the other components and forms the innermost and outermost component of the stator 101. It is an inner ring and an outer ring each formed with grooves for positive engagement with the conductor bars.
- the two-part stator core 102 shown here by way of example is formed with two stator lamination packets 118 twisted in a helical manner relative to one another, which will be discussed in more detail with reference to FIG.
- the stator core 102 and the carrier device 105 can each also be designed in one piece or with more than two parts.
- 10 shows an exploded view of a radial flux dual rotor machine 110 according to one embodiment.
- the radial flux dual rotor machine 110 includes, in addition to the stator 101 components, a first rotor 112, second rotor 113, and a base 111.
- the first rotor 112 is arranged radially inside and the second rotor 112 is arranged radially outside of the stator core 102 .
- the rotors 112, 113 are preferably made of a soft-magnetic solid material and have permanent magnets, so-called surface magnets, as poles on the respective surface facing the stator core.
- other rotors known to those skilled in the art can also be used, for example with buried magnets, squirrel-cage rotors or electrically excited rotors.
- the base 111 is only shown schematically here for the sake of clarity. As already described in the description of FIG. 8 , the base 111 is attached to the carrier device 105 in the assembled state.
- the base 111 is fixed mechanically in relation to a reference system, for example a carrier of a vehicle axle.
- the radial flux double rotor machine 110 according to FIG. 10 can be used as a synchronous machine 11 in an electric drive system 10 according to one of FIGS. 1 or 2 and in connection with an inverter circuit 12 according to one of FIGS. 4 to 6.
- 11 shows an exploded view of a radial flow twin rotor machine 110 according to a further embodiment.
- the radial flow twin rotor machine 110 here has essentially the same components as explained with reference to FIGS.
- the carrier device 105 shown on the right is also made in two parts and differs in the design of the respective annular inner carrier element 127 and outer carrier element 128 .
- the carrier elements 127 , 128 are equipped with carrier grooves 126 here. These are provided on the inner circumference of the outer carrier element 128 and on the outer circumference of the inner carrier element 127 for engagement with the conductor bars 106 of the winding 103 .
- FIG. 12 shows a perspective representation of a radial flow double rotor machine 110 according to FIG. 11 in the assembled state.
- the carrier device 105 is fastened via the bores 109, for example in a machine housing (not shown) as a base 111 and thus leads the torque to the mechanically fixed part of the radial flux double rotor machine 110. In this way, the radial flux double rotor machine 110 generated torque can be effectively supported.
- the attachment of the carrier device 105 is implemented using appropriate attachment means (not shown), for example screws.
- the conductor bars 106 of the winding 103 extend axially on both sides to the outside of the stator core 102 and the first and second rotors 112, 113.
- the helically arranged conductor bars 106 of the radially inner and outer layers are connected to one another outside the stator core 102, respectively.
- the carrier elements 127, 128 are shown engaged with the conductor bars 106 of the winding 103 here. It can be seen that a conductor bar 106 is placed in each carrier groove 126, so that all conductor bars are positively coupled to the carrier device.
- the radial flux double rotor machine 110 according to FIGS. 11 and 12 can also be used advantageously as a synchronous machine 11 in an electrical drive system 10 according to one of FIGS. 1 or 2 and in conjunction with an inverter circuit 12 according to one of FIGS. 13 shows a longitudinal cross-sectional perspective view of a radial flow twin rotor machine 110 according to yet another embodiment.
- This embodiment essentially corresponds to the assembly of a radial-flow double-rotor machine 110 according to FIG. 10, the components of which will be discussed in more detail below.
- the stator core 102 has an inner subpackage 123 and an outer subpackage 124 .
- the partial packages 123, 124 run annularly between the first and second rotors 112, 113. Due to the sectional view, it is also possible to see the inner and outer layers 114, 115 of the conductor bars 106 running within the partial packages 123, 124.
- the radial flux double rotor machine 110 shown is a so-called “yokeless” design in which the yoke between two teeth is not in the functionally relevant magnetic flux. Although a stator yoke 130 runs between the conductor bars 106, this only serves to mechanically hold the laminated stator core 118 together.
- a radial yoke thickness can be made correspondingly thin, which in the illustrated embodiment is, for example, about 10% of the total radial stator thickness. With the comparatively small yoke thickness, additionally undesired magnetic stray flux in the yoke is reduced. In further embodiments, the radial yoke thickness can be less than 30%, preferably less than 20%, particularly preferably less than 10% of the total radial stator thickness for this purpose.
- the carrier device 105 also has an inner carrier element 127 and an outer carrier element 128 here.
- the support elements 127, 128 are arranged here in an axially offset manner in relation to the stator 101 and the rotors 112, 113, as can be clearly seen.
- the positive engagement of the carrier elements 127, 128 with the conductor bars 106 of the inner and outer layers 114, 115 can be seen at least in sections. It is also easy to see here that the conductor bars 106 of the inner and outer layers 114, 115 are connected at the conductor bar ends 116 via a radially arranged conductor bar piece 117.
- the connection is preferably implemented as an integral connection, for example by laser beam welding.
- the surface magnets of the rotors 112, 113 can also be seen in section.
- the first rotor 112 has a plurality of permanent magnets mounted on its outer peripheral surface.
- the second rotor 113 has a plurality of permanent magnets mounted on its inner peripheral surface.
- stator slots 119 This serves to simplify production of the oppositely twisted stator slots 119 with the same inner and outer stator laminations 121, 122 which are stacked twisted relative to one another and are provided with recesses at the same points Stator laminations are provided with differently arranged recesses and are stacked in the order necessary to form the stator slots.
- completely one-piece stator cores 102 are also conceivable, which can be produced additively, for example.
- an inner diameter of the outer part package 124 is almost the same as the outer diameter of the inner part package 123. This makes it possible to arrange the inner part package 123 coaxially within the outer part package 124.
- the subpackages 123, 124 are made up of individual annular stator laminations 121, 122 stacked on top of one another.
- the stator laminations 121 of the outer partial assembly 124 are manufactured with recesses positioned distributed over the outer circumference for forming the outer stator slots 119 .
- the stator laminations 122 of the inner partial assembly 123 are manufactured with recesses positioned distributed over the inner circumference for forming the inner stator slots 120 .
- manufacturing such stator laminations by stamping is advantageous because of the quality of the edges and the very low manufacturing costs.
- the inner and outer stator slots 119, 120 describe helical lines which run in opposite directions to one another with the same pitch and which are characterized by the drawn-in angle of the stator slots ⁇ .
- the swept angle of the stator slots ⁇ can be defined from the angle between the position of the same stator slot on one axial side of the stator core 102 and on the other axial side of the stator core 102 with respect to the central axis M .
- the stator slots 119, 120 are designed here, for example, as T-slots with a rectangular recess with a tapered opening. These are intended in particular for the form-fitting reception of conductor bars with a rectangular cross section.
- the geometry of the recesses or stator slots can be adapted to the conductor geometry. Other cross-sectional shapes would also be conceivable.
- Fig. 15 shows a schematic longitudinal sectional view of a stator slot 119, 120.
- the usable or continuous clear width a of the stator slots 119, 120 within the stator laminated core 118 is essentially the same as the width of the conductor bars 106 accommodated within the stator core 102 educated.
- the stator laminations 121, 122 have straight edges, in particular stamped edges. Due to the offset of the sheets relative to one another, a width b of the recesses provided for the stator slots 119, 120 is greater than the width d of the conductor bars 106 by an amount predetermined by the pitch ⁇ of the helical shape of the course and the sheet thickness t .
- a conductor bar 106 is shown schematically with dashed lines in the stator slot 119, 120, the continuous clear width a of the stator slot 119, 120 being slightly larger than the width d of the conductor bar 106 and the width a of the recess to provide a loose fit in the stator lamination 121, 122 is in turn formed significantly larger than the clear width b.
- the sheet thickness t and the angle of attack ⁇ of the slope of the groove course represent a noticeable influencing factor for the difference between the width b of the recess and the clear width a of the usable passage within the groove in the case of straight, for example stamped, sheet metal edges.
- stator 15 is dimensioned such that a clear width a of the stator slots 119, 120 reduced by the offset between the recesses of the stator laminations has a predetermined loose fit with the width d of a conductor bar to be inserted into the stator slot 106 forms, but the contact is still close enough to serve for evenly distributed power transmission or torque support between the stator laminated core and the winding.
- a dimensioning is made possible, among other things, by the fact that on the one hand each stator lamination is designed with the same high edge quality and twisted with the same offset, and on the other hand only a single conductor bar 106 is placed in each stator slot 119, 120, the dimensions of which are constant.
- the conductor bar 106 is a rectangular bar with an edge length or width of several millimeters, for example in the range from 2 mm to 6 mm, in particular in the range from 3 mm to 5 mm. It can preferably be a rectangular profile of 5 mm ⁇ 3 mm.
- 16 shows a perspective view of a winding 103.
- the winding 103 is made up of said conductor bars 106, which run helically along the central axis M.
- the conductor bars 106 are not only arranged correspondingly crossed, but also twisted according to the course of the helical line.
- the swept angle ⁇ of the conductor bars 106 identifies the angle between the beginning and end of a conductor bar 106 relative to the central axis M. Since the pitch of the helix of the conductor bars 106 is equal to the pitch of the helix of the stator slots 119, 120, but the conductor bars 106 are longer than the stator slots are formed, a ratio of the respective swept angles ⁇ and ⁇ can be formed to characterize the geometric conditions, which is also referred to as the degree of pole coverage. to a To provide an optimum between magnetic losses and torque utilization of a radial flux double rotor machine, this ratio (degree of pole coverage) is preferably in a range between 0.6 and 0.75.
- the opposite twisting and torsion of the inner and outer radial layers 114, 115 of conductor bars 106 can also be seen here.
- the torsion is designed in such a way that the cross section in relation to a radial line through the center of the conductor bar is always the same at every point of the conductor bar, which is also referred to as 2.5 D geometry.
- the conductor bar ends of the inner and outer layers 114, 115 are superimposed in a like alignment.
- the conductor bars 106 of the radial inner and outer layers 114, 115 can thus be conductively connected in a simple manner, here for example via a radially running conductor bar piece 117, which is welded to the conductor bar 106.
- FIG. 17 shows a plan view of a winding 103.
- the conductor bar ends 116 each form the connection point between the inner and outer radial layers 114, 115.
- the winding has a total of twelve connection contacts 31, for example. At three-phase connection, a three-phase operation is preferably provided.
- FIG. 18 shows a perspective view of an FEM simulation of a winding 103 under load. This is essentially the winding geometry shown in FIG. 16, with minor simplifications for simulation purposes.
- the scale shown relates to the voltages within the winding, where, for example, in the case of a rectangular profile of the conductor bars 106 of 5 mm ⁇ 3 mm, it can be a scale from 0 MPa to 30 MPa.
- the conductor bar ends are defined by a swept angle of the conductor bars ⁇ >0, that is to say they are arranged and formed in a helical shape or formed in a correspondingly twisted manner.
- a maximum torque of the correspondingly dimensioned radial flux double rotor machine 110 is plotted than 1000 Nm, in particular more than 1500 Nm, in a specific example about 2000 Nm, in another specific example about 5000 Nm.
- the stresses within the winding are distributed very homogeneously due to the helix geometry. Hardly any deformation can be seen despite the strong superelevation that has been set.
- FIG. 19 shows a perspective view of a comparison model with a straight design and with the conductor bars 106 running axially under load. Compared to Fig.
- FIG. 18 shows a flow chart of a method for producing a stator 1.
- the method comprises a first step of providing S1 a stator core 102 with radially outer stator slots 119 each describing a helical line and radially inner stator slots 120 each describing a helical line with opposite winding direction individual conductor bars 106 following the helical lines through the inner and outer stator slots 119, 120.
- the conductor bars are inserted in particular in the axial direction.
- a step of connecting S3 of the conductor bars 106 introduced into the inner and outer stator slots at the conductor bar ends 116 to form conductor loops is provided.
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Abstract
Description
Claims
Priority Applications (3)
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KR1020247005354A KR20240033055A (ko) | 2022-03-02 | 2023-01-23 | 전기 구동 시스템 |
CN202380012863.8A CN117751508A (zh) | 2022-03-02 | 2023-01-23 | 电力驱动系统 |
EP23701884.1A EP4309264A1 (de) | 2022-03-02 | 2023-01-23 | Elektrisches antriebssystem |
Applications Claiming Priority (2)
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DE102022202123.1 | 2022-03-02 | ||
DE102022202123.1A DE102022202123B4 (de) | 2022-03-02 | 2022-03-02 | Elektrisches Antriebssystem |
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WO2023165760A1 true WO2023165760A1 (de) | 2023-09-07 |
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PCT/EP2023/051459 WO2023165760A1 (de) | 2022-03-02 | 2023-01-23 | Elektrisches antriebssystem |
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KR (1) | KR20240033055A (de) |
CN (1) | CN117751508A (de) |
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WO (1) | WO2023165760A1 (de) |
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- 2023-01-23 EP EP23701884.1A patent/EP4309264A1/de active Pending
- 2023-01-23 CN CN202380012863.8A patent/CN117751508A/zh active Pending
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DE102022202123A1 (de) | 2023-09-07 |
DE102022202123B4 (de) | 2023-09-28 |
KR20240033055A (ko) | 2024-03-12 |
CN117751508A (zh) | 2024-03-22 |
EP4309264A1 (de) | 2024-01-24 |
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