Transformer equipment and synchronous machines

Abstract

The present invention relates to data transmission between a secondary side (3) of a transformer arrangement (1) used for inductively transferring electrical energy from a DC voltage source (4) to a load (11) and a primary side (2) of the transformer arrangement (1). Data to be transmitted from the secondary side (3) to the primary side (2) is encoded on the secondary side (3) by modulating the secondary resonant frequency, and a primary side parameter correlated to the secondary resonant frequency is monitored and decoded on the primary side (2).

Description

[Technical field]

[0001] The present invention relates to a transformer arrangement for inductively transmitting electrical energy between a direct current voltage source and an electrical load, in particular an inductive wound-field synchronous machine. Furthermore, the present invention relates to an inductive wound-field synchronous machine comprising such a transformer arrangement. In addition, the present invention relates to a method for transmitting data between a secondary side of a transformer arrangement for inductively transmitting electrical energy from a direct current voltage source to a load and a primary side of the transformer arrangement. [Background technology]

[0002] A synchronous machine is a rotating electric machine, in which during operation the rotor rotates synchronously with the rotating magnetic field of the stator. In general, a synchronous machine can be operated as a motor or as a generator. In the case of wound-field synchronous machines or separately excited synchronous machines, a magnetic field is additionally generated electrically on the rotor. For this purpose, at least one rotor coil is used, which must be supplied with electrical energy, in particular in the form of direct current, in order to generate the magnetic field on the rotor side. In the case of inductive wound-field synchronous machines, the supply of electrical energy to each rotor coil occurs without the need for brushes, i.e. by induction. Inductive wound-field synchronous machines correspond to separately excited electric synchronous machines, which do not require brushes.

[0003] Such a synchronous machine is known, for example, from EP 2 869 316 A1 and comprises a rotor with a rotor coil for generating a rotor magnetic field and a secondary transformer coil for supplying the rotor coil with electrical energy. In addition, the synchronous machine comprises a rotor rotatably fixed about a rotation axis and a stator with a stator coil for generating a stator magnetic field and a primary transformer coil for inductively transferring electrical energy to the secondary transformer coil. The primary and secondary transformer coils form a rotary transformer, which are part of a transformer arrangement for inductively transferring electrical energy. Summary of the Invention

[0004] In such inductive wound-field synchronous machines, it is necessary to transmit data, such as control commands, from the stator to the rotor, for example, to control or regulate the excitation of the rotor coils. For this purpose, the synchronous machine known from the abovementioned EP 2 869 316 A1 is provided with a communication path, which allows the desired data transmission from the stator to the rotor. Here, by means of a further additional rotary transformer, the primary coil of the rotary transformer on the stator side is coupled to a modulator or driver and the secondary coil of the rotary transformer on the rotor side is coupled to a demodulator. Thus, an inductive signal or data transmission from the stator to the rotor is possible. The provision of such an additional rotary transformer entails a relatively large expenditure. Apart from this, the signal transmission by such an additional rotary transformer in the vicinity of the inductive wound-field synchronous machine is subject to a relatively large amount of interference. The same applies to other methods of wireless communication, such as, for example, radial interconnection. This applies even more to synchronous machines with more power.

[0005] In addition, there is still a need for modern inductive wound-field synchronous machines for reverse data transmission, i.e. from rotor to stator. For example, the actual current flowing through the rotor coils is becoming increasingly important in the stator-side control device to be able to control the synchronous machine. As shown in the above examples, traditional communication paths are expensive and susceptible to interference.

[0006] The communication between the primary side and the secondary side is not only of increasing interest in rotary or rotating transformers, such as those present in inductive wound-field synchronous machines, but is also fundamental in any transformer arrangement for transmitting electrical energy between a direct current voltage source and an electrical load. Such transformer arrangements can include rotary as well as stationary transformers. For example, an inductive charging device can be included in such a transformer arrangement.

[0007] The present invention deals with the problem of showing the way with a transformer arrangement for inductive transmission of electrical energy between a DC voltage source and a load, in particular an inductive wound-field synchronous machine with such an inductive charging arrangement, which allows at least data transmission from the secondary side to the primary side, can be realized at a relatively low outlay, is characterized in particular by a reduced susceptibility to interference, and in addition makes it possible to avoid energy transmission disturbances between the primary side and the secondary side.

[0008] According to the invention, this problem is solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0009] The invention is based on the general idea of ​​transmitting data on the secondary side by frequency modulation, for which purpose the resonant frequency of the secondary side is modulated. Since in a transformer arrangement the primary side and the secondary side form an electromagnetically coupled oscillating system, a change in the secondary resonant frequency affects the entire oscillating system and therefore also the primary side. There is therefore at least one primary side parameter which is correlated with the resonant frequency of the secondary side. According to the invention, this primary parameter is now monitored on the primary side, so that the data modulated to the secondary resonant frequency on the primary side can be demodulated from the primary parameter which is correlated with the secondary resonant frequency.

[0010] In particular, the present invention presents a transformer arrangement including a primary side and a secondary side. The primary side comprises a DC voltage source, an inverter, a primary compensation device, and a primary transformer coil. The secondary side comprises a secondary transformer coil, a secondary compensation device, a rectifier, and an electrical load. In this context, the indefinite article "a, an" should be understood generically, i.e. as "at least one". Thus, multiple DC voltage sources can be present, for example, on the primary side. Similarly, multiple loads can be present, for example, on the secondary side. The terms "primary" and "primary side", which are different from this, should be understood as identical, as are the terms "secondary" and "secondary side".

[0011] The electrical load connected to the rectifier is in practice arranged to be operable with a direct current or a direct voltage.

[0012] The inverter has an input connected to a DC voltage source and an output connected to a primary transformer coil via a primary compensation device. The primary compensation device is matched to the primary transformer coil in the usual way, so that the reactive component in the AC current on the primary side is compensated. Furthermore, the primary compensation device and the primary transformer coil form a primary resonant circuit having a primary resonant frequency. The inverter is pulse modulated for optimal energy transfer at the primary resonant frequency, so that the AC voltage generated by the inverter has this primary resonant frequency.

[0013] Furthermore, the rectifier has an input side connected to the secondary transformer coil via a secondary compensation device, and an output side connected to a load. Here, the secondary compensation device and the secondary transformer coil are matched to each other to compensate for reactive components in the secondary AC current. Similarly, the secondary compensation device and the secondary transformer coil form a secondary resonant circuit, which has a secondary resonant frequency. For optimal energy transmission, the secondary resonant frequency is usually selected to be equal to the primary resonant frequency. The primary and secondary resonant frequencies define the natural resonant frequency of the oscillating system formed by the transformer device.

[0014] According to the invention, it is now proposed to variably configure the secondary compensation device so that the compensation for the secondary resonant frequency can be changed. As explained above, the vibration system can be detuned by changing the secondary resonant frequency, which has an effect on the primary side and can be detected on the primary side by at least one primary parameter, which is correspondingly correlated with the secondary resonant frequency.

[0015] For the desired communication between the secondary side and the primary side, the secondary side may comprise a secondary communication device, which encodes secondary side data according to a predefined code and is coupled to the secondary compensation device, which controls the secondary compensation device according to the encoded data in order to vary the secondary resonant frequency. The control occurs such that the time sequence of the varied secondary resonant frequency indicates the encoded data. Thus, data as a frequency modulation is modulated onto or into the secondary resonant frequency or encoded into the secondary resonant frequency. Here, the primary side is provided with a primary communication device, which monitors measurable primary side parameters, which are correlated with the secondary resonant frequency, and in the process recognizes the encoded data and decodes them according to the code. Due to the correlation between the secondary resonant frequency and the primary side parameters, a frequency modulation of the secondary resonant frequency is transmitted from the secondary side to the primary side via the transformer coil, where the secondary resonant frequency is detectable as a frequency modulation in the primary side parameters, which can then be demodulated or decoded in the usual way.

[0016] By introducing the transformer arrangement according to the invention here, no additional transmission path, for example in the form of an additional transformer, is required, since the secondary side communicates with the primary side via the energy transmission path, i.e. by the vibration system from the primary and secondary transformer coils. It has been shown that even a relatively small change in the secondary resonant frequency is sufficient to significantly change the primary parameters, thus allowing a safe signal transmission. Moreover, it has been shown that such a small detuning of the vibration system does not result in any substantial disturbance of the energy transmission between the primary and secondary sides. Moreover, this frequency modulation is almost completely free of other usual interference influences to which the transformer arrangement is exposed, especially in the electromagnetic vibrations of the vibration system of the transformer arrangement.

[0017] In an advantageous embodiment, the primary side can comprise a phase measurement device, which measures the phase shift between the AC current and the AC voltage on the primary side, for example in an inverter, and the primary communication device is connected to the phase measurement device and monitors the phase shift as a primary side parameter, which is correlated with the secondary side resonant frequency. This embodiment is based on the recognition that a change in the secondary side resonant frequency on the primary side results in a phase shift between the voltage and the current. The measurable phase shift generally correlates with the deviation between the control frequency of the inverter and the natural resonant frequency of the system, and is thus obtained by the primary side resonant frequency and the secondary side resonant frequency. Thereby, finally, since this phase shift is correlated with the secondary resonant frequency, a frequency modulation of the secondary resonant frequency results in a frequency modulation of the phase shift on the primary side, which is correlated with the secondary resonant frequency. Thus, the data modulated by the secondary resonant frequency onto the oscillating system can be demodulated from the phase shift on the primary side. According to a preferred embodiment, the primary communication device in particular monitors the temporal sequence of the phase shifts and recognizes and decodes the data encoded in the phase shifts according to a code.

[0018] In another embodiment, the primary side can be equipped with a frequency control device, which adjusts the frequency of the primary side AC voltage or of the primary side AC current to correct the phase shift between the primary side current and voltage. The frequency of the primary side AC voltage or of the primary side AC current is predetermined by the inverter. By coupling the frequency control device to the inverter, the inverter can be controlled to adjust the frequency to correct the measured phase shift, so that the current and voltage oscillate again synchronously on the primary side. For example, such a frequency control device can be provided to adapt the oscillation system to changing operating conditions, for example temperature, and to aging symptoms of electronic components.

[0019] The primary communication device can now be coupled to the frequency control device and / or the inverter and can monitor the adjustment of the frequency in the primary side AC voltage or in the primary side AC current as a primary side parameter that correlates with the secondary resonant frequency. As explained above, a change in the secondary resonant frequency is brought about, which realizes a phase shift between current and voltage on the primary side. The phase shift thus correlates with the secondary resonant frequency. Such a phase shift is corrected by the frequency control device. Such an adjustment of the frequency in the primary side AC voltage or in the primary side AC current thus correlates with the phase shift and thus with the secondary resonant frequency. According to an advantageous embodiment, the primary communication device in particular monitors the temporal sequence of the mentioned frequency adjustments and recognizes and decodes the data encoded in the frequency adjustments according to the code.

[0020] The adjustment of the frequency in the primary AC voltage or in the primary AC current can be represented by a control command of the frequency control device to the inverter or by a pulse modulation changed by the inverter based on the control command, and also by a finally measurable frequency in the primary AC voltage or in the primary AC current. The frequency adjustment, the associated control signal and the pulse modulation or the control frequency represent measurable parameters of the primary that correlate with the secondary resonant frequency. The primary communication device can therefore be coupled to the frequency control device to monitor the control signal or to the inverter to monitor the pulse modulation, or alternatively to a frequency measuring device to measure the frequency in the primary AC voltage or to monitor said frequency in the primary AC current. According to an advantageous embodiment, the primary communication device therefore monitors the temporal sequence of the mentioned control signals or the mentioned pulse modulation or the mentioned frequencies and recognizes and decodes the data encoded in the control signals or in the pulse modulation or in the frequency according to the code.

[0021] The secondary transformer coil has an impedance. The secondary compensation device, matched to the secondary transformer coil, has a capacitance that matches the secondary transformer coil. The secondary transformer coil and the secondary compensation device therefore form a resonant circuit with a resonant frequency, referred to herein as the secondary resonant frequency. According to a preferred embodiment, it can now be provided that the secondary compensation device comprises a variable capacitor, the capacitance of which can be electronically adjusted to at least two different capacitances. Alternatively, the secondary compensation device can comprise at least two invariant capacitors connected in parallel, one of which can be electronically activated and deactivated, while the other is permanently active. For example, the secondary compensation device can comprise an electronic switch, for example a transistor, which is coupled to the secondary communication device, whereby the secondary communication device activates and deactivates the switchable capacitor via said switch in order to thus vary the secondary resonant frequency. By varying the capacitance of the secondary compensation device, the resonant frequency of the resonant circuit of the compensation device and the transformer coil is changed.

[0022] According to an advantageous embodiment, the code is a binary code. The secondary compensation device is then configured such that two different secondary resonant frequencies are adjustable. The binary code is formed by "0" and "1". One resonant frequency defines a "0" of the binary code, while the other resonant frequency forms a "1" of the binary code. By means of the binary modulation the desired data can be transmitted safely.

[0023] Another advantageous embodiment proposes that the secondary compensation device is configured such that the secondary resonant frequency can be changed only within a range of less than 1%. It is also conceivable that the secondary resonant frequency can be changed only within a range of less than 1%. This ensures that the detuning of the oscillatory system is so small that the signal transmission has no or practically no effect on the energy transmission.

[0024] The secondary side data may, for example, contain or represent values ​​relating to a current on the secondary side, and / or relating to a voltage on the secondary side, and / or relating to a temperature of at least one secondary side component.

[0025] In another advantageous embodiment, the secondary side can comprise a secondary side frequency acquisition device for acquiring the current frequency in the secondary side AC voltage or in the secondary side AC current. In the following, for ease of illustration, only the current frequency is considered, but it is clear that the same applies to the voltage frequency. Here, the primary side communication device can be configured to encode the primary side data according to a predefined code. Furthermore, the primary side communication device can be coupled to an inverter and can control the inverter according to the encoded data for pulse modulation or for varying the control frequency of the inverter and thus the frequency of the primary side AC voltage, so that the time sequence of the changed frequencies in the primary side AC voltage represents the encoded data. The secondary side communication device can now be coupled to a secondary side frequency detection device and can monitor the frequency in the secondary side AC voltage and thus recognize the encoded data and decode them according to the code. The frequency in the secondary side AC voltage always corresponds to the frequency in the primary side AC voltage. By appropriately controlling the inverter, if the pulse modulation and thus the frequency of the primary side AC voltage is changed, a corresponding change in frequency therefore occurs almost simultaneously in the secondary side AC voltage. Typically, the inverter pulse modulation occurs at a frequency that corresponds to the resonant frequency of the vibration system, which is known to the secondary communication device, so that the secondary communication device can recognize and evaluate deviations from this resonant frequency.

[0026] This embodiment provides a communication path in the opposite direction, i.e. from the primary side to the secondary side. It is thus possible to transmit, for example, control commands etc. Here, the vibration system of the transformer arrangement provided for the energy transmission is also utilized for the data transmission. The expenditure of the arrangement for realizing such communication is correspondingly low.

[0027] The inductive wound-field synchronous machine according to the invention comprises a stator, a rotor and a transformer arrangement of the above-mentioned kind. The stator comprises a stator control device. The rotor comprises a rotor control device rotatably fixed about the axis of rotation of the stator and arranged on the rotor. The primary side of the transformer arrangement is arranged on the stator, while the secondary side of the transformer arrangement is arranged on the rotor. Furthermore, the communication device on the primary side is electrically connected to the stator control device, while the communication device on the secondary side is electrically connected to the rotor control device. The transformer arrangement allows communication between the rotor control device and the stator control device. Thus, the rotor control device can transmit, for example, the rotor active current or other relevant data via the transformer arrangement to the stator control device, which can then be used, inter alia, for controlling and regulating the synchronous machine. The synchronous machine is preferably configured as a drive motor or traction motor for a motor vehicle and is capable of consuming in particular an electric power of 100 kW to 240 kW, preferably 120 kW to 160 kW, particularly preferably approximately 140 kW.

[0028] According to an advantageous embodiment, the load of the transformer arrangement can comprise a rotor coil for generating a rotor magnetic field, the transformer arrangement then serving for supplying the rotor coil with electrical energy and can simultaneously also supply electrical energy to the rotor control device.

[0029] In an alternative embodiment, the rotor comprises a rotor coil and the synchronous machine comprises a main power supply for inductively transmitting electrical energy to the rotor coil. In this case, a transformer arrangement of the above-mentioned kind forms an auxiliary power supply in the synchronous machine, which inductively transmits electrical energy to the rotor control device. In this case, the load comprises or is formed by the rotor control device. In this embodiment of the synchronous machine, the auxiliary energy transmission path, which supplies electrical energy to the rotor control device, is utilized for data transmission. The main energy transmission path, which supplies electrical energy to the rotor coil, remains unaffected by the auxiliary energy transmission path. Due to the main difference between the voltage level at the rotor coil on the one hand and the voltage level at the rotor control device on the other hand, it may be practical and more cost-effective to provide the rotor control device with a separate auxiliary power supply, which is formed by a transformer arrangement of the above-mentioned kind and which can be utilized at the same time for reliable or secure data transmission.

[0030] The method of data transmission according to the invention between the secondary side of a transformer arrangement, which serves for the inductive transmission of electrical energy from a DC voltage source to a load, and the primary side of the transformer arrangement, is characterized in that the data to be transmitted from the secondary side to the primary side are encoded on the secondary side by modulation of the secondary resonant frequency, and that a primary side parameter, which correlates with the secondary resonant frequency, is monitored and decoded on the primary side. The modulation of the secondary resonant frequency leads to a detuning of the oscillating system, which leads to a phase shift between current and voltage on the primary side. This phase shift therefore has the same modulation as the secondary resonant frequency and can therefore be used for demodulating the data. If there is a frequency control device on the primary side, which corrects the phase shift between voltage and current by adjusting the pulse modulation or frequency on the primary side, this control action of the frequency control device can also be used to recognize the encoded signal, as well as the change in the pulse modulation of the inverter and the change in frequency itself on the primary side AC voltage.

[0031] According to an advantageous further development, a method can be further provided in which data to be transmitted from the primary side to the secondary side is encoded on the primary side by modulation of the frequency of the primary side AC voltage or of the primary side AC current, and on the secondary side the frequency of the secondary side AC voltage or of the secondary side AC current is monitored and decoded. In the following, for the sake of simplicity, only the current frequency is also discussed, but it is clear that the same also applies to the voltage frequency. Here again, the communication takes place in the opposite direction, i.e. from the primary side to the secondary side. In this case, the recognition is used that the AC voltage on the secondary side oscillates with the same frequency as the AC voltage on the primary side. A modulation of the frequency of the primary AC voltage, which can be brought about for example by a corresponding modulation of the pulse modulation of the inverter, leads to a corresponding modulation of the frequency in the secondary side AC voltage, which can be detected and evaluated in a suitable manner in order to decode the data.

[0032] The various embodiments introduced above relating to the transformer arrangement and to the synchronous machine can also be correspondingly realized by the methods introduced herein, the relevant apparatus features being realized by the corresponding method features.

[0033] Further important features and advantages of the invention emerge from the dependent claims, the drawings and the associated figure description via the drawings.

[0034] It is to be understood that the features mentioned above and those to be further described below can be used not only in the corresponding combinations described, but also in other combinations or by themselves, without departing from the scope of the invention. The above-named and below-named parts of a higher-order unit, e.g. a separately designed installation, device or arrangement, can constitute separate components of this unit, or can be integral regions or parts of this unit, even if shown differently in the drawings. [Brief description of the drawings]

[0035] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred exemplary embodiments of the present invention are illustrated in the drawings and will be explained in more detail in the following description, in which like reference numbers refer to identical, similar or functionally identical components. [Figure 1] FIG. 1 shows a highly simplified schematic diagram of a transformer arrangement as a circuit diagram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] According to Fig. 1, the transformer arrangement 1 comprises a primary side 2 and a secondary side 3. The primary side 2 comprises a DC voltage source 4, an inverter 5, a primary compensation device 6 and a primary transformer coil 7. The secondary side 3 comprises a secondary transformer coil 8, a secondary compensation device 9, a rectifier 10 and a load 11. The primary transformer coil 7 and the secondary transformer coil 8 form a transformer 12. The transformer 12 can be a stationary transformer 12. Preferably, the transformer 12 is a rotary transformer 12 or a rotating transformer 12, in which the primary transformer coil 7 is stationary while the secondary transformer coil 8 rotates. In practice, the primary transformer coil 7 and the secondary transformer coil 8 are electrically separated from each other. A suitable galvanic separation is indicated in Fig. 1 by a dashed line and designated 13.

[0037] The transformer arrangement 1 serves for the inductive transmission of electrical energy between the primary side 2 and the secondary side 3, and in particular between a DC voltage source 4 and a load 11. For this purpose, an input side 14 of an inverter 5 is connected on the primary side 2 to the DC voltage source 4, and an output side 15 is connected via a primary compensation device 6 to a primary transformer coil 7. On the secondary side 3, an input side 16 of a rectifier 10 is connected via a secondary compensation device 9 to a secondary transformer coil 8, and an output side 17 is connected to the load 11.

[0038] For data communication between the primary side 2 and the secondary side 3, in particular from the secondary side 3 to the primary side 2, the secondary compensation device 9 is configured to be variable. The secondary resonant frequency can therefore be changed via the secondary compensation device 9. For this purpose, the capacitance of the secondary compensation device 9 can be changed, which has a corresponding effect on the resonant frequency of the secondary resonant circuit, which is formed by the secondary transformer coil 8 and the secondary compensation device 9. The secondary side 3 is further equipped with a secondary communication device 18, which can comprise at least one transmitter or transmitter and preferably also a receiver, thereby in particular forming or including a transceiver. The secondary communication device 18 is configured to encode the data of the secondary side according to a predefined code. For example, the secondary communication device 18 is part of a control device of the secondary side, which for example wants to know the active current of the secondary side 3 and to transmit the active current to the primary side 2. The secondary communication device 18 is coupled to the secondary compensation device 9 so that the secondary communication device 18 can control the secondary compensation device 9 to vary the secondary resonant frequency. Thus, the secondary communication device 18 can control the secondary communication device 9 to vary the secondary resonant frequencies in response to the encoded data, so that the temporal sequence of the varied secondary resonant frequencies is indicative of the encoded data. In this way, the data to be transmitted is fed to the oscillatory system at the secondary side 3 as frequency modulation.

[0039] The primary side 2 comprises a primary communication device 19, which monitors a primary side parameter that correlates with the secondary side resonant frequency. In this way, the primary communication device 19 can recognize and decode the encoded data coupled to the vibration system according to the code. For example, the primary communication device 19 can be coupled to a primary side control device, which can then receive the decoded data and use it to control the entire system including the transformer device 1. Such an entire system can be, for example, a synchronous machine, which will be described in more detail below.

[0040] In the example shown here, the primary side 2 further comprises a phase measurement device 20, which is coupled to the current conducting line at the output side 15 of the inverter 5. The phase measurement device 20 is configured to measure a phase shift 21 between the current and voltage of the primary side, i.e. in the primary side AC current or in the primary side AC voltage. Optionally, the primary side 2 can further comprise a frequency control device 22, which is coupled to the phase measurement device 20 and to the inverter 5 and serves to correct the phase shift 21. For this purpose, the frequency control device 22 suitably adapts its pulse modulation to vary the frequency in the primary side AC current or in the primary side AC voltage in order to reduce, and preferably eliminate, the phase shift 21.

[0041] The primary communication device 19 can now be coupled to the phase measurement device 20 by a signal line 23, so that the primary communication device 19 monitors the phase shift 21 as a primary side parameter correlated with the secondary side resonant frequency. Alternatively, the primary communication device 19 can be coupled to the frequency control device 22 by a signal line 24, so that the primary communication device 19 monitors the adjustment of the frequency in the primary side AC voltage or in the primary side AC current as a primary side parameter, which primary side parameter correlates with the secondary side resonant frequency. Alternatively, the primary communication device 19 can be coupled to the inverter 5 by a signal line 25, so that the primary communication device 19 monitors the adjustment of the pulse modulation or frequency in the primary side AC current or in the primary side AC voltage as a primary side signal corresponding to the secondary side resonant frequency. It is also conceivable that the primary side 2 can be equipped with a primary side frequency measurement device (not shown), so that the primary side frequency can be directly monitored as a primary side parameter correlated with the secondary side resonant frequency. To measure the current and voltage profiles, the phase measurement device 20 is coupled to a corresponding current tap 26 and to a corresponding voltage tap 27.

[0042] In the example shown here, the secondary side 3 may comprise a secondary side frequency detector 28, which is for example coupled to a voltage tap 29. By means of the secondary side frequency detector 28, the current frequency in the secondary side AC voltage or in the secondary side AC current may be measured. The secondary side frequency detector 28 is further coupled to the secondary side communication device 18.

[0043] The primary side communication device 19 can now be configured to encode the primary side data, in particular the control commands, according to a predefined code. By being appropriately coupled to the inverter 25, the primary side communication device 19 can now control the inverter 25 according to the encoded data for varying the pulse modulation of the inverter 5 and thus the frequency of the primary side AC current or of the primary side AC voltage. As a result, the time sequence of the changed frequency in the primary side AC current or in the primary side AC voltage represents the encoded data. In other words, the primary side data is modulated onto the primary side frequency of the AC current or of the AC voltage. Due to the transformer 12, the frequency in the secondary side AC current and in the secondary side AC voltage corresponds equally to the frequency in the primary side AC current or in the primary side AC voltage. This means that the data modulated onto the primary side AC current or on the primary side AC voltage by frequency modulation is also modulated onto the secondary side AC current or on the secondary side AC voltage. The secondary side communication device 18, by being coupled to the secondary side frequency detection device 28, can monitor the frequency in the secondary side AC current or in the secondary side AC voltage and can therefore also identify frequency modulation and therefore detect encoded data and decode them according to the code.

[0044] According to a preferred embodiment, the transformer arrangement 1 introduced here can be part of an inductive wound field synchronous machine 30, shown here only incompletely, which comprises a stator 31 including a stator control device 32 and a rotor 33 including a rotor control device 34. The rotor control device 34 is arranged on the rotor 33 and thus rotates together with the rotor 33. The primary side 2 of the transformer arrangement 1 is arranged on the stator 31, while the secondary side 3 of the transformer arrangement 1 is arranged on the rotor 33. The primary communication device 19 is coupled to the stator control device 32 and the secondary communication device 18 is coupled to the rotor control device 34. The rotor 33 comprises a rotor coil 35 for generating a rotor magnetic field. In a simple embodiment, the transformer arrangement 1 can serve to supply this rotor coil 35 with electrical energy. In this case, the load 11 comprises the rotor coil 35.

[0045] In another preferred embodiment, the synchronous machine 30 comprises a main power supply 36, which supplies electrical energy to the rotor coils 35. In this case, the transformer arrangement 1 then forms in the synchronous machine 30 an auxiliary energy supply 37, which serves to supply electrical energy to the rotor control device 34. In this case, the load 11 comprises the rotor control device 34. It is clear that the individual components of the transformer arrangement 1 or of the synchronous machine 30, shown here separately, can be structurally integrated with one another.

[0046] The transformer arrangement 1 introduced here allows data transmission between a primary side 2 and a secondary side 3 via a transformer 12, which serves for energy transmission from a DC voltage source 4 to a load 11. For this purpose, data to be transmitted from the secondary side 3 to the primary side 2 are encoded at the secondary side 3 by modulation of the secondary resonant frequency. Since the secondary side 3 is coupled to the primary side 2 via the transformer 12, a phase shift 21 between current and voltage is obtained at the primary side 2 of the primary side AC current. This phase shift 21 or a parameter correlated with the phase shift 21, such as, for example, an adjustment at the primary side of the pulse modulation of the inverter 5 or of the frequency of the primary side AC current or of the primary side AC voltage, forms a primary side signal correlated with the secondary side resonant frequency, which can be easily monitored and decoded at the primary side 2.

[0047] In the reverse case, where data are to be transmitted from the primary side 2 to the secondary side 3, these data can be encoded on the primary side 2 by modulating the frequency of the primary side AC current or of the primary side AC voltage. Since the frequencies of the AC current or of the AC voltage on the primary side 2 and on the secondary side 3 are the same, a frequency modulation on the AC current or of the AC voltage on the primary side 2 produces the same frequency modulation on the AC current or of the AC voltage on the secondary side 3 as on the primary side. This frequency modulation can therefore be decoded on the secondary side by monitoring the frequency of the secondary side AC current or of the AC voltage on the secondary side 3.

Claims

1. In particular, a transformer device (1) for inductively transmitting electrical energy between a DC voltage source (4) and a load (11) of an induction winding field magnetic synchronous machine (30), having a primary side (2) comprising a DC voltage source (4), an inverter (5), a primary compensation device (6), and a primary transformer coil (7), having a secondary side (3) comprising a secondary transformer coil (8), a secondary compensation device (9), a rectifier (10), and a load (11), wherein the inverter (5) has an input side (14) connected to the DC voltage source (4) and an output side (15) connected to the primary transformer coil (7) via the primary compensation device (6), wherein the rectifier (10) has an input side (16) connected to the secondary transformer coil (8) via the secondary compensation device (9) and an output side (17) connected to the load (11), wherein the secondary compensation device (9) is variably configured such that the secondary side resonance frequency can be changed, wherein the secondary side (3) comprises a secondary communication device (18), the secondary communication device (18) encodes secondary side data according to a predetermined code, the secondary communication device (18) is coupled to the secondary compensation device (9), and controls the secondary compensation device (9) according to the encoded data for changing the secondary side resonance frequency, and the time sequence of the changed secondary side resonance frequency represents the encoded data, wherein the primary side (2) comprises a primary communication device (19), the primary communication device (19) monitors primary side parameters, the primary side parameters are correlated with the secondary side resonance frequency, recognizes the encoded data, and decodes the encoded data according to the code, transformer device (1).

2. The primary side (2) comprises a phase measurement device (20), and the phase measurement device (20) measures a phase shift (21) between current and voltage in the alternating current of the primary side and / or in the alternating voltage of the primary side, wherein the primary communication device (19) is coupled to the phase measurement device (20), monitors the phase shift (21) as a primary side parameter, and the primary side parameter is correlated with the secondary side resonance frequency The transformer device (1) according to claim 1, characterized in that.

3. The transformer device (1) according to claim 2, characterized in that the primary communication device (19) decodes data from the phase shift (21).

4. The primary side (19) is provided with a frequency control device (22), and the frequency control device (22) corrects the phase shift (21) between the current and the voltage in the alternating current of the primary side and / or in the alternating voltage of the primary side by adjusting the frequency in the alternating current of the primary side and / or in the alternating voltage of the primary side. The primary communication device (19) is coupled to the frequency control device (22) and / or the inverter (5), monitors the adjustment of the frequency in the alternating current of the primary side and / or in the alternating voltage of the primary side as a primary side parameter, and the primary side parameter correlates with the secondary side resonance frequency. The transformer device (1) according to claim 1, characterized in that.

5. The transformer device (1) according to claim 4, characterized in that the primary communication device (19) decodes data from the time sequence of the adjustment of the frequency in the alternating current of the primary side and / or in the alternating voltage of the primary side.

6. The adjustment of the frequency in the alternating voltage of the primary side and / or in the alternating current of the primary side is represented by the control command of the frequency control device (22) to the inverter (5), or by the pulse modulation changed by the inverter (5) based on the control command, or by the frequency in the alternating voltage of the primary side and / or in the alternating current of the primary side. The primary communication device (19) decodes the time sequence data of the control command of the frequency control device (22) to the inverter (5), or the time sequence of the pulse modulation of the inverter (5), or the time sequence of the frequency in the alternating voltage of the primary side and / or in the alternating current of the primary side. The transformer device (1) according to claim 4 or 5, characterized in that.

7. The transformer device (1) according to claim 1, characterized in that the secondary compensation device (9) comprises a variable capacitor.

8. The transformer device (1) according to claim 1, characterized in that the secondary compensation device (9) comprises two capacitors connected in parallel, one of which can be activated and deactivated, while the other is always active.

9. The code is a binary code, and thus the secondary compensation device (9) is configured such that two different secondary side resonance frequencies can be adjusted. The transformer device (1) according to claim 1, characterized in that...

10. The transformer device (1) according to claim 1, characterized in that the secondary compensation device (9) is configured such that the secondary resonance frequency changes and / or can be changed only within a range of less than 1%.

11. The secondary side (3) is provided with a secondary side frequency detection device (28) for detecting the current frequency in the alternating current on the secondary side and / or in the alternating voltage on the secondary side. The primary side communication device (19) encodes primary side data according to a predetermined code, is coupled to the inverter (5), and controls the inverter (5) according to the encoded data for changing the frequency of the alternating current on the primary side and / or the alternating voltage on the primary side. The temporal order of the changed frequency in the alternating current on the primary side represents the encoded data. The secondary side communication device (18) is coupled to the secondary side frequency detection device (28), monitors the frequency in the alternating current on the secondary side and / or in the alternating voltage on the primary side, recognizes the encoded data, and decodes the encoded data according to the code. The transformer device (1) according to claim 1, characterized in that...

12. Having a stator (31) provided with a stator control device (32). Having a rotor (33) in which a rotor control device (34) is arranged. Having the transformer device (1) according to claim 1. An induction-wound field-excited synchronous machine (30), wherein... The primary side (2) of the transformer device (1) is arranged on the stator (31). The secondary side (3) of the transformer device (1) is arranged on the rotor (33). The primary side communication device (19) is coupled to the stator control device (32). The secondary side communication device (18) is coupled to the rotor control device (34). An induction-wound field-excited synchronous machine (30).

13. The wound field-excited synchronous machine (30) according to claim 12, characterized in that the load (11) is provided with a rotor coil (35) for generating a rotor magnetic field.

14. The rotor (33) is provided with a rotor coil (35) for generating a rotor magnetic field. The wound field-excited synchronous machine (30) is provided with a main power source (36) for inductively transmitting electrical energy to the rotor coil (35). The transformer device (1) within the wound-field synchronous machine (30) forms an auxiliary power supply (37), and the auxiliary power supply (37) inductively transmits the electrical energy to the rotor control device (34), and the load (11) includes the rotor control device (34). The wound-field synchronous machine (30) according to claim 12, characterized in that.

15. A data transmission method between the secondary side (3) of a transformer device (1) for inductively transmitting electrical energy from a DC voltage source (4) to a load (11) and the primary side (2) of the transformer device (1), comprising:[[]] Data scheduled to be transmitted from the secondary side (3) to the primary side (2) is encoded at the secondary side (3) by modulation of the secondary-side resonance frequency. The primary-side parameter correlated with the secondary-side resonance frequency is monitored and decoded at the primary side (2). Data transmission method.

16. Data scheduled to be transmitted from the primary side (2) to the secondary side (3) is encoded at the primary side (2) by modulation of the AC current on the primary side and / or the frequency of the AC voltage on the primary side. At the secondary side (3), the resonance frequency of the AC current on the secondary side and / or the AC voltage on the secondary side is monitored and decoded. The method according to claim 15, characterized in that.

17. The primary side (2) includes a DC voltage source (4), an inverter (5), a primary compensation device (6), and a primary transformer coil (7). The secondary side (3) includes a secondary transformer coil (8), a secondary compensation device (9), a rectifier (10), and a load (11). The inverter (5) has its input side (14) connected to the DC voltage source (4) and its output side (15) connected to the primary transformer coil (7) via the primary compensation device (6). The rectifier (10) has its input side (16) connected to the secondary transformer coil (8) via the secondary compensation device (9) and its output side (17) connected to the load (11). The secondary compensation device (9) is variably configured such that the secondary-side resonance frequency can be changed. The secondary side (3) is provided with a secondary communication device (18), the secondary communication device (18) encodes the data on the secondary side according to a predetermined code, the secondary communication device (18) is coupled to the secondary compensation device (9), and controls the secondary compensation device (9) according to the encoded data for changing the secondary side resonance frequency. The time sequence of the changed secondary side resonance frequency represents the encoded data. The primary side (2) is provided with a primary communication device (19), the primary communication device (19) monitors primary side parameters, the primary side parameters are correlated with the secondary side resonance frequency, recognizes the encoded data, and decodes the encoded data according to the code. The method according to claim 15 or 16, characterized in that.

18. The primary side (2) is provided with a phase measurement device (20), the phase measurement device (20) measures a phase shift (21) between a current and a voltage in the alternating current on the primary side and / or in the alternating voltage on the primary side. The primary communication device (19) is coupled to the phase measurement device (20), monitors the phase shift (21) as a primary side parameter, and the primary side parameter is correlated with the secondary side resonance frequency. The method according to claim 17, characterized in that.

19. The method according to claim 18, characterized in that the primary communication device (19) decodes data from the phase shift (21).

20. The primary side (19) is provided with a frequency control device (22), the frequency control device (22) corrects a phase shift (21) between a current and a voltage in the alternating current on the primary side and / or in the alternating voltage on the primary side by adjusting the frequency in the alternating current on the primary side and / or in the alternating voltage on the primary side. The primary communication device (19) is coupled to the frequency control device (22) and / or the inverter (5), monitors an adjustment of the frequency in the alternating current on the primary side and / or in the alternating voltage on the primary side as a primary side parameter, and the primary side parameter is correlated with the secondary side resonance frequency. The method according to claim 17, characterized in that.

21. The primary communication device (19) decodes data from the time sequence of the adjustment of the frequency in the alternating current on the primary side and / or in the alternating voltage on the primary side. The method according to claim 20, characterized in that.

22. The adjustment of the frequency in the AC voltage on the primary side and / or in the AC current on the primary side is by means of a control command of the frequency control device (22) to the inverter (5), or by a pulse modulation changed by the inverter (5) based on the control command, or is represented by the frequency in the AC voltage on the primary side and / or in the AC current on the primary side, The primary communication device (19) decodes the time sequence of the control commands of the frequency control device (22) to the inverter (5), or the time sequence of the pulse modulation of the inverter (5), or the time sequence data of the frequency in the AC voltage on the primary side and / or in the AC current on the primary side The method according to claim 20, characterized in that.

23. The method according to claim 17, characterized in that the secondary compensation device (9) comprises a variable capacitor.

24. The method according to claim 17, characterized in that the secondary compensation device (9) comprises two capacitors connected in parallel, one of which is activatable and non-activatable, while the other is always active.

25. The code is a binary code, The secondary compensation device (9) is configured such that two different secondary-side resonance frequencies can be adjusted in this way The method according to claim 17, characterized in that.

26. The method according to claim 17, characterized in that the secondary compensation device (9) is configured such that the secondary-side resonance frequency changes and / or is changeable only within a range of less than 1%.

27. The secondary side (3) comprises a secondary-side frequency detection device (28) for detecting the current frequency in the AC current on the secondary side and / or in the AC voltage on the secondary side, The primary-side communication device (19) encodes primary-side data according to a predetermined code, is coupled to the inverter (5), and controls the inverter (5) according to the encoded data for changing the frequency of the AC current on the primary side and / or the AC voltage on the primary side. The time sequence of the changed frequency in the AC current on the primary side represents the encoded data. The secondary communication device (18) is coupled to the secondary frequency detection device (28), monitors the frequency in the secondary alternating current and / or in the primary alternating voltage, recognizes the encoded data, and decodes the encoded data according to the code. The method according to claim 17, characterized in that.

28. The transformer device (1) forms part of an induction winding field magnetic synchronous machine (30). The winding field magnetic synchronous machine (30) comprises a stator (31), and the stator (31) comprises a stator control device (32). The winding field magnetic synchronous machine (30) comprises a rotor (33), and a rotor control device (34) is arranged on the rotor (33). The primary side (2) of the transformer device (1) is arranged on the stator (31). The secondary side (3) of the transformer device (1) is arranged on the rotor (33). The primary communication device (19) is coupled to the stator control device (32). The secondary communication device (18) is coupled to the rotor control device (34). The method according to claim 17, characterized in that.

29. The method according to claim 28, characterized in that the load (11) comprises a rotor coil (35) for generating a rotor magnetic field.

30. The rotor (33) comprises a rotor coil (35) for generating a rotor magnetic field. The winding field magnetic synchronous machine (30) comprises a main power source (36) for inductively transmitting electrical energy to the rotor coil (35). The transformer device (1) forms an auxiliary power source (37) within the winding field magnetic synchronous machine (30). The auxiliary power source (37) inductively transmits the electrical energy to the rotor control device (34). The load (11) comprises the rotor control device (34). The method according to claim 28, characterized in that.

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