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 device for inductively transmitting electrical energy between a DC voltage source and an electrical load, in particular to an inductively excited synchronous machine. Furthermore, the present invention relates to an inductively excited synchronous machine comprising such a transformer device. In addition, the present invention relates to a data transmission method between a secondary side of a transformer device for inductively transmitting electrical energy from a DC voltage source to a load and a primary side of the transformer device.

Background Art

[0002] A synchronous machine is a rotating electrical machine in which, during operation, the rotor rotates in synchronization with the rotating magnetic field of the stator. Generally, a synchronous machine can operate as a motor or a generator. In the case of a wound-field synchronous machine or separately excited synchronous machine, the magnetic field is further generated electrically on the rotor. For this purpose, at least one rotor coil is used, and in order to generate the magnetic field on the rotor side, electrical energy needs to be supplied to the rotor coil, particularly in the form of direct current. In the case of an inductively excited wound-field synchronous machine, the electrical energy supply to each rotor coil occurs by induction without the need for brushes, i.e., it corresponds to a separately excited electrical synchronous machine that does not require brushes.

[0003] Such a synchronous machine is known, for example, from EP 2 869 316 A1 and includes a rotor comprising a rotor coil for generating a rotor magnetic field and a secondary transformer coil for supplying electrical energy to the rotor coil. In addition, the synchronous machine comprises a stator in which the rotor is fixedly mounted rotatably about a rotation axis and which comprises a stator coil for generating a stator magnetic field and a primary transformer coil for inductively transmitting electrical energy to the secondary transformer coil. The primary and secondary transformer coils form a rotary transformer and are part of a transformer device for inductively transmitting 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 adjust the excitation of the rotor coils. For this purpose, a communication channel is provided in the synchronous machine known as EP 2 869 316 A1, thereby enabling the transmission of desired data from the stator to the rotor. Here, an additional rotary transformer is used, with the primary coil of the rotary transformer on the stator side coupled to a modulator or driver, and the secondary coil of the rotary transformer on the rotor side coupled to a demodulator. Thus, inductive signal transmission or data transmission from the stator to the rotor becomes possible. Providing such an additional rotary transformer involves a relatively large expense. Separately, signal transmission by such an additional rotary transformer near an inductive wound-field synchronous machine is exposed to a relatively large amount of interference. The same applies to other methods of wireless communication, such as radial interconnects. This is even more true for synchronous machines with higher output power.

[0005] In addition, modern inductive wound-field synchronous machines are still needed for reverse data transmission, i.e., data transmission from rotor to stator. For example, the importance of the actual current flowing through the rotor coils is increasing in the stator-side control system in order to control the synchronous machine. As shown in the example above, conventional communication channels are expensive and susceptible to interference.

[0006] Communication between the primary and secondary sides is of increasing interest not only in rotary transformers, such as those found in inductive wound-field synchronous machines, but also in any transformer device for transmitting electrical energy between a DC voltage source and an electrical load. Examples of such transformer devices include rotary transformers and static transformers. For example, an inductive charging device can be provided in such a transformer device.

[0007] This invention addresses the problem of providing a path toward a transformer device for inductively transmitting electrical energy between a DC voltage source and a load, particularly an inductive wound-field synchronous machine equipped with such an inductive charging device, which enables data transmission from the secondary side to the primary side, can be implemented at a relatively low cost, is particularly characterized by reduced susceptibility to interference, and in addition, can avoid energy transmission failures between the primary and secondary sides.

[0008] According to the present invention, this problem is solved by the subject matter of the independent claim. A favorable embodiment is the subject matter of the dependent claim.

[0009] This invention is based on the general idea of ​​transmitting secondary-side data by frequency modulation, and for this purpose, the secondary-side resonant frequency is modulated. Within a transformer device, the primary and secondary sides form an electromagnetically coupled vibration system, so changes in the secondary resonant frequency affect the entire vibration system and, therefore, the primary side as well. Accordingly, there exists at least one primary-side parameter that correlates with the secondary-side resonant frequency. According to this invention, this primary parameter is monitored on the primary side, thereby allowing the data modulated to the secondary resonant frequency on the primary side to be demodulated from the primary parameter correlated with the secondary resonant frequency.

[0010] More specifically, the present invention presents a transformer device comprising a primary side and a secondary side. The primary side comprises a DC voltage source, an inverter, a primary compensator, and a primary transformer coil. The secondary side comprises a secondary transformer coil, a secondary compensator, a rectifier, and an electrical load. In this context, the indefinite articles "a" and "an" should be understood collectively, that is, "at least one." Therefore, multiple DC voltage sources can be present, for example, on the primary side. Similarly, multiple loads can also be present, for example, on the secondary side. The terms "primary" and "primary side" should be understood to be identical, as should the terms "secondary" and "secondary side."

[0011] An electrical load connected to a rectifier is, in practice, configured to be operable by a DC current or DC voltage.

[0012] The inverter's input is connected to a DC voltage source, and its output is connected to a primary transformer coil via a primary compensator. The primary compensator is matched to the primary transformer coil in a conventional manner, thus compensating for the reactive component in the primary AC current. Furthermore, the primary compensator and primary transformer coil form a primary resonant circuit with a primary resonant frequency. The inverter is pulse-modulated for optimal energy transmission at this primary resonant frequency; therefore, the AC voltage generated by the inverter has this primary resonant frequency.

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

[0014] According to the present invention, it is presented that the secondary compensation device is variably configured so that the compensation for the secondary resonant frequency can be changed. As described 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 side parameter, which correlates with the secondary resonant frequency.

[0015] For desired communication between the secondary and primary sides, the secondary side may be equipped with a secondary communication device, which encodes secondary side data according to a predetermined code, couples with a secondary compensator, and controls the secondary compensator according to the encoded data to change the secondary resonant frequency. The control occurs such that the temporal order of the changed secondary resonant frequencies corresponds to the encoded data. Thus, data as frequency modulation is modulated on or within the secondary resonant frequency, or encoded to the secondary resonant frequency. Here, the primary side is equipped with a primary communication device that monitors measurable primary side parameters, which correlate with the secondary side resonant frequency, and recognizes the encoded data in the process and decodes them according to the code. Due to the correlation between the secondary side resonant frequency and the primary side parameters, the frequency modulation of the secondary resonant frequency is transmitted from the secondary side to the primary side via a transformer coil, and on the secondary side, the secondary resonant frequency is detectable as frequency modulation in the primary side parameters, and can then be demodulated or decoded in the usual manner.

[0016] By introducing the transformer device according to the present invention, the secondary side communicates with the primary side via an energy transmission path, i.e., through the vibration system from the primary and secondary transformer coils, thus eliminating the need for an additional transmission path, for example, in the form of an additional transformer. It has been shown that even relatively small changes in the secondary resonant frequency are sufficient to significantly alter the primary parameters, thereby enabling safe signal transmission. Furthermore, it has been shown that such small detuning of the vibration system does not cause any substantial disruption to energy transmission between the primary and secondary sides. Moreover, in particular, within the electromagnetic vibrations of the transformer device's vibration system, this frequency modulation is largely unaffected by other normal interference effects to which the transformer device is exposed.

[0017] In an advantageous embodiment, the primary side may be equipped with a phase measuring device that measures the phase difference between AC current and AC voltage on the primary side, for example, in an inverter. The primary communication device is connected to the phase measuring device and monitors the phase difference as a primary-side parameter, which correlates with the secondary-side resonant frequency. This embodiment is based on the understanding that a change in the secondary-side resonant frequency on the primary side results in a phase difference between voltage and current. The measurable phase difference generally correlates with the deviation between the inverter's control frequency and the natural resonant frequency in the system, thereby being obtained from the primary-side and secondary-side resonant frequencies. Thus, since this phase difference ultimately correlates with the secondary resonant frequency, frequency modulation of the secondary resonant frequency results in frequency modulation of the primary-side phase difference that correlates with the secondary resonant frequency. Therefore, data modulated in the vibrating system by the secondary resonant frequency can be demodulated from the phase difference on the primary side. According to a preferred embodiment, the primary communication device specifically monitors the temporal sequence of the phase differences, recognizes and decodes the data encoded by the phase differences according to the code.

[0018] In another embodiment, the primary side may include a frequency control device that corrects the phase difference between the primary current and voltage by adjusting the frequency of the primary AC voltage or primary AC current. The frequency of the primary AC voltage or primary AC current is predetermined by the inverter. By coupling the frequency control device to the inverter, the inverter becomes controllable to adjust the frequency to correct the measured phase difference, and as a result, the current and voltage oscillate synchronously again on the primary side. For example, such a frequency control device may be provided to adapt the vibration system to changes in operating conditions, such as temperature, and to the aging of electronic components.

[0019] The primary communication device can be coupled to a frequency control device and / or inverter and can monitor frequency adjustments in the primary AC voltage or primary AC current as primary-side parameters that correlate with the secondary resonant frequency. As described above, a change in the secondary resonant frequency results in a phase shift between current and voltage on the primary side. Therefore, the phase shift correlates with the secondary resonant frequency. Such a phase shift is corrected by the frequency control device. Such adjustments of the frequency in the primary AC voltage or primary AC current therefore correlate with the phase shift and, consequently, with the secondary resonant frequency. According to an advantageous embodiment, the primary communication device specifically monitors the temporal sequence of the frequency adjustments mentioned, recognizes and decodes the data encoded by the frequency adjustments according to the code.

[0020] The adjustment of the frequency in the primary AC voltage or primary AC current can be expressed by control commands from a frequency control device to an inverter, or by pulse modulation changed by the inverter based on control commands, and also by the ultimately measurable frequency in the primary AC voltage or primary AC current. The frequency adjustment, associated control signals, and pulse modulation or control frequency represent measurable parameters on the primary side that correlate with the secondary resonant frequency. Therefore, the primary communication device can be coupled to a frequency control device to monitor the control signals, or to an 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 the above frequency in the primary AC current. According to an advantageous embodiment, the primary communication device thus monitors the temporal sequence of the aforementioned control signals, or the aforementioned pulse modulation or frequency, and recognizes and decodes the data encoded in the control signals, or in the pulse modulation or frequency, according to the code.

[0021] The secondary transformer coil has impedance. A secondary compensator matched to the secondary transformer coil has capacitance that matches the secondary transformer coil. Thus, the secondary transformer coil and the secondary compensator form a resonant circuit having a resonant frequency, which is hereby called the secondary resonant frequency. According to a preferred embodiment, the secondary compensator can be provided to comprise a variable capacitor with at least two different capacitances that can be electronically adjusted. Alternatively, the secondary compensator can comprise at least two invariant capacitors connected in parallel, one of which is electronically activatable and deactivatable, while the other is permanently active. For example, the secondary compensator may comprise an electronic switch, such as a transistor, which is coupled to a secondary communication device, thereby activating and deactivating the switchable capacitor via the switch in order to change the secondary resonant frequency. By changing the capacitance of the secondary compensator, the resonant frequency of the resonant circuit of the compensator 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 the "0" in the binary code, while the other resonant frequency forms the "1" in the binary code. By binary modulation, the desired data can be transmitted securely.

[0023] Another advantageous embodiment proposes that the secondary compensation device is configured such that the secondary resonant frequency can be varied only within a range of less than 1%. Similarly, it is conceivable that the secondary resonant frequency can be varied only within a range of less than 1%. Thus, the detuning of the vibrating system is so small that signal transmission has no or substantially no effect on energy transmission.

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

[0025] In another advantageous embodiment, the secondary side may be equipped with a secondary frequency capture device for capturing the current frequency in the secondary AC voltage or the secondary AC current. For the sake of illustration, only current frequency will be considered below, but it is clear that the same applies to voltage frequency. Here, the primary side communication device may be configured to encode primary side data according to a predetermined code. Furthermore, the primary side communication device may be coupled to an inverter and can control the inverter according to the encoded data for changing pulse modulation or the inverter's control frequency, and therefore the frequency of the primary side AC voltage, so that the temporal order of the changed frequencies in the primary side AC voltage represents the encoded data. The secondary side communication device may here be coupled to a secondary frequency detection device and can monitor the frequency in the secondary side AC voltage, and therefore 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 properly controlling the inverter, when pulse modulation and therefore the frequency of the primary side AC voltage change, the corresponding frequency change in the secondary side AC voltage occurs almost simultaneously. Typically, the pulse modulation of an inverter occurs in accordance with the resonant frequency of the vibration system, and since this is well known to the secondary communication device, the secondary communication device can recognize and evaluate the deviation from this resonant frequency.

[0026] This embodiment enables a communication path in the opposite direction, i.e., from the primary side to the secondary side. Therefore, it is possible to transmit control commands, for example. Here, the vibration system of the transformer device, which is installed for energy transmission, is also used for data transmission. The expenditure on equipment to realize such communication is correspondingly low.

[0027] The induction winding field magnetic synchronous machine according to the present invention comprises a stator, a rotor, and a transformer device of the above-described type. The stator comprises a stator control device. The rotor is rotatably fixed about the rotation axis of the stator and comprises a rotor control device arranged on the rotor. The primary side of the transformer device is arranged on the stator, while the secondary side of the transformer device is arranged on the rotor. Furthermore, the primary side communication device is electrically connected to the stator control device, while the secondary side communication device is electrically connected to the rotor control device. The transformer device enables communication between the rotor control device and the stator control device. Thus, the rotor control device can transmit, for example, the active current of the rotor or other relevant data to the stator control device via the transformer device and then utilize these, particularly for controlling and regulating the synchronous machine. The synchronous machine is preferably configured as a drive motor or traction motor for an automobile and can consume, in particular, from 100 kW to 240 kW, preferably from 120 kW to 160 kW, and particularly preferably approximately 140 kW of power.

[0028] According to an advantageous embodiment, the load of the transformer device can comprise a rotor coil for generating a rotor magnetic field. In this case, the transformer device serves to supply electrical energy to the rotor coil and can also supply electrical energy to the rotor control device at the same time.

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

[0030] The data transmission method according to the invention between the secondary side and the primary side of a transformer device, which serves to inductively transmit electrical energy from a DC voltage source to a load, is characterized in that data intended to be transmitted from the secondary side to the primary side is encoded on the secondary side by modulation of the secondary side resonance frequency and a primary side parameter correlated with the secondary side resonance frequency is monitored and decoded on the primary side. Modulation of the secondary side resonance frequency results in detuning of the oscillating system and, on the primary side, in a phase shift between the current and the voltage. Thus, this phase shift has the same modulation as the secondary side resonance frequency and can therefore be utilized for demodulation of the data. If a frequency control device is present on the primary side for correcting the phase shift between the voltage and the current by adjusting the pulse modulation or the frequency in the AC voltage on the primary side, this control activity of the frequency control device can also be utilized for recognizing the encoded signal, similar to the change in the pulse modulation of the inverter and the change in the frequency itself in the AC voltage on the primary side.

[0031] Further advantageous developments can provide a method in which data to be transmitted from the primary to the secondary is encoded on the primary side by modulation of the frequency of the primary AC voltage or primary AC current, and on the secondary side, the frequency of the secondary AC voltage or secondary AC current is monitored and decoded. For simplicity of explanation, only current frequency will be discussed below, but it is clear that the same applies to voltage frequency. Here again, communication is in the opposite direction, i.e., from the primary to the secondary. In this case, the assumption is made that the AC voltage on the secondary side oscillates at the same frequency as the AC voltage on the primary side. For example, modulation of the frequency of the primary AC voltage, which can be brought about by the corresponding modulation of pulse modulation in an inverter, results in a corresponding modulation of the frequency of the secondary AC voltage, and this modulation can be detected and evaluated in a suitable manner for decoding the data.

[0032] The various embodiments relating to transformer devices and synchronous machines introduced above can also be realized correspondingly by the methods introduced herein, and the features of the related devices are realized by the features of the corresponding methods.

[0033] Further important features and advantages of the present invention are derived from the dependent claims, the drawings, and the associated description of the drawings, and through the drawings.

[0034] The features described above, and those to be further described below, should be understood to be usable not only in the corresponding combinations described, but also in other combinations, or by themselves, without departing from the scope of the present invention. Higher-order units, for example, separately designed equipment, devices, or configurations, the parts named above and those to be named below, may constitute separate components of this unit, or they may be integral regions or parts of this unit, even if they are shown differently in the drawings. [Brief explanation of the drawing]

[0035] Preferred exemplary embodiments of the present invention are shown in the drawings and described in more detail below. The same reference numerals relate to the same, similar, or functionally identical components. [Figure 1] Figure 1 shows a very simplified schematic diagram of the transformer device as a circuit diagram. [Modes for carrying out the invention]

[0036] According to Figure 1, the transformer device 1 includes a primary side 2 and a secondary side 3. The primary side 2 comprises a DC voltage source 4, an inverter 5, a primary compensator 6, and a primary transformer coil 7. The secondary side 3 comprises a secondary transformer coil 8, a secondary compensator 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 static transformer 12. Preferably, the transformer 12 is a rotary transformer 12 or a rotary 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 isolated from each other. A suitable DC isolation is shown in Figure 1 by a dashed line and represented by 13.

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

[0038] For data communication between the primary side 2 and the secondary side 3, particularly from the secondary side 3 to the primary side 2, the secondary compensator 9 is configured to be variable. Thus, the secondary resonant frequency can be changed via the secondary compensator 9. For this purpose, the capacitance of the secondary compensator 9, which has an effect corresponding to the resonant frequency of the secondary resonant circuit, can be changed, and this is formed by the secondary transformer coil 8 and the secondary compensator 9. The secondary side 3 is further provided with a secondary communication device 18, which may also include at least one transmitter and preferably a receiver, thereby forming or including a transceiver in particular. The secondary communication device 18 is configured to encode secondary side data according to a predetermined code. For example, the secondary communication device 18 is part of a secondary side control device that, for example, knows the active current of the secondary side 3 and attempts to transmit the active current to the primary side 2. The secondary communication device 18 is coupled to the secondary compensator 9 so that the secondary communication device 18 can control the secondary compensator 9 to change the secondary resonant frequency. Therefore, the secondary communication device 18 can control the secondary communication device 9 to change the secondary resonant frequency according to the encoded data, so that the temporal order of the changed secondary resonant frequencies indicates the encoded data. In this way, the data to be transmitted is supplied to the vibration system as frequency modulation on the secondary side 3.

[0039] The primary side 2 is equipped with a primary communication device 19, which monitors primary side parameters correlated with the secondary side resonant frequency. In this way, the primary communication device 19 can recognize and decode encoded data coupled to the vibration system according to a 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 the data to control the entire system, including the transformer device 1. Such an entire system could be, for example, a synchronous machine, which will be described in more detail below.

[0040] In the example shown herein, the primary side 2 further includes a phase measuring device 20, which is coupled to the current conduction line at the output side 15 of the inverter 5. The phase measuring device 20 is configured to measure the phase difference 21 between the primary side current and voltage, i.e., in the primary side AC current or the primary side AC voltage. Optionally, the primary side 2 may further include a frequency control device 22, which is coupled to the phase measuring device 20 and the inverter 5 and serves to correct the phase difference 21. For this purpose, the frequency control device 22 appropriately adapts to its pulse modulation to change the frequency in the primary side AC current or the primary side AC voltage in order to reduce, and preferably eliminate, the phase difference 21.

[0041] The primary-side communication device 19 can be coupled to the phase measuring device 20 via a signal line 23, so that the primary-side communication device 19 monitors the phase shift 21 as a primary-side parameter correlated with the secondary-side resonant frequency. Alternatively, the primary-side communication device 19 can be coupled to the frequency control device 22 via a signal line 24, so that the primary-side communication device 19 monitors the frequency adjustment in the primary-side AC voltage or primary-side AC current as a primary-side parameter, and the primary-side parameter correlates with the secondary-side resonant frequency. Alternatively, the primary-side communication device 19 can be coupled to the inverter 5 via a signal line 25, so that it monitors the pulse modulation or frequency adjustment in the primary-side AC current or primary-side AC voltage as a primary-side signal corresponding to the secondary-side resonant frequency. Similarly, it is conceivable that the primary side 2 may be provided with a primary-side frequency measuring device (not shown), so that the primary-side frequency can be directly monitored as a primary-side parameter correlated with the secondary resonant frequency. To measure the current profile and voltage profile, the phase measuring device 20 is coupled to the corresponding current tap 26 and the corresponding voltage tap 27.

[0042] In the example shown here, the secondary side 3 may include a secondary frequency detection device 28, which is coupled, for example, to a voltage tap 29. The secondary frequency detection device 28 can measure the current frequency in the AC voltage or AC current of the secondary side. The secondary frequency detection device 28 is further coupled to a secondary communication device 18.

[0043] The primary-side communication device 19 can be configured to encode primary-side data, in particular control commands, according to a predetermined code. By appropriately coupling with the inverter 25, the primary-side communication device 19 can control the inverter 25 in accordance with the encoded data for changing the pulse modulation of the inverter 5, and therefore for changing the frequency of the primary-side AC current or primary-side AC voltage. Consequently, the temporal sequence of the changed frequencies in the primary-side AC current or primary-side AC voltage represents the encoded data. In other words, the primary-side data is modulated to the primary-side frequency of the AC current or AC voltage. The transformer 12 ensures that the frequencies in the secondary-side AC current and secondary-side AC voltage are equal to the frequencies in the primary-side AC current or primary-side AC voltage. This means that, by frequency modulation, the data modulated in the primary-side AC current or primary-side AC voltage is also modulated in the secondary-side AC current or secondary-side AC voltage. The secondary communication device 18, coupled to the secondary frequency detection device 28, can monitor the frequency in the secondary AC current or the secondary AC voltage, and therefore can also identify frequency modulation, thus detecting encoded data and decoding it according to the code.

[0044] In a preferred embodiment, the transformer device 1 introduced herein may be part of an inductive wound-field synchronous machine 30, which is only partially shown herein, comprising 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 positioned on the rotor 33 and rotates with the rotor 33. The primary side 2 of the transformer device 1 is positioned on the stator 31, while the secondary side 3 of the transformer device 1 is positioned on the rotor 33. A primary side communication device 19 is coupled to the stator control device 32, and a secondary side communication device 18 is coupled to the rotor control device 34. The rotor 33 comprises rotor coils 35 for generating a rotor magnetic field. In a simple embodiment, the transformer device 1 may serve to supply electrical energy to these rotor coils 35. In this case, the load 11 comprises the rotor coils 35.

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

[0046] The transformer device 1 introduced here enables data transmission between the primary side 2 and the secondary side 3 via the transformer 12, and the transformer 12 plays the role of transmitting energy from the DC voltage source 4 to the load 11. For this purpose, the data to be transmitted from the secondary side 3 to the primary side 2 is encoded on the secondary side 3 by modulation of the secondary side resonant frequency. Since the secondary side 3 is coupled with the primary side 2 via the transformer 12, a phase difference 21 between current and voltage is obtained on the primary side 2 of the primary side AC current. This phase difference 21, or parameters correlated with the phase difference 21, such as the pulse modulation of the inverter 5, or the frequency of the primary side AC current, or the adjustment of the primary side AC voltage, forms a primary side signal correlated with the secondary side resonant frequency, and the primary side signal can be easily monitored and decoded on the primary side 2.

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

Claims

1. A transformer device (1) for inductively transmitting electrical energy between a DC voltage source (4) and a load (11) of an induction-type wound-field synchronous machine (30), The primary side (2) comprises a DC voltage source (4), an inverter (5), a primary compensator (6), and a primary transformer coil (7). The secondary side (3) comprises a secondary transformer coil (8), a secondary compensator (9), a rectifier (10), and a load (11). 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 compensator (6). 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). The secondary compensation device (9) is configured to be variable so that the secondary resonant frequency can be changed. The secondary side (3) comprises a secondary communication device (18), which encodes secondary side data according to a predetermined code, and 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 to change the secondary side resonant frequency, and the temporal order of the changed secondary side resonant frequencies represents the encoded data. The primary side (2) comprises a primary communication device (19), the primary communication device (19) monitors primary side parameters, the primary side parameters correlate with the secondary side resonant frequency, recognizes the encoded data, and decodes the encoded data according to the code. The secondary side (3) is equipped with a secondary side frequency detection device (28) for detecting the current frequency in the AC current and / or AC voltage of 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 to change the frequency of the primary side AC current and / or the primary side AC voltage, wherein the temporal order of the changed frequencies in the primary side AC current represents the encoded data. The secondary communication device (18) is coupled to the secondary frequency detection device (28) and monitors the frequency of the AC current on the secondary side and / or the AC voltage on the primary side, recognizes the encoded data, and decodes the encoded data according to the code. Transformer device (1).

2. The primary side (2) is equipped with a phase measuring device (20), and the phase measuring device (20) measures the phase difference (21) between the current and voltage in the AC current of the primary side and / or the AC voltage of the primary side. The primary communication device (19) is coupled to the phase measuring device (20), and monitors the phase shift (21) as a primary-side parameter, and the primary-side parameter correlates with the secondary-side resonant frequency. A transformer device (1) according to claim 1, characterized in that...

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

4. The primary side (19) is equipped with a frequency control device (22), and the frequency control device (22) corrects the phase difference (21) between the current and voltage in the AC current and / or AC voltage of the primary side by adjusting the frequency in the AC current and / or AC voltage of the primary side. The primary communication device (19) is coupled to the frequency control device (22) and / or the inverter (5), and monitors the adjustment of the frequency of the AC current on the primary side and / or the AC voltage on the primary side as primary side parameters, and the primary side parameters correlate with the secondary side resonant frequency. A 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 temporal sequence of frequency adjustments in the AC current on the primary side and / or the AC voltage on the primary side.

6. The adjustment of the frequency in the primary AC voltage and / or the primary AC current is expressed by a control command from the frequency control device (22) to the inverter (5), or by pulse modulation changed by the inverter (5) based on the control command, or by the frequency in the primary AC voltage and / or the primary AC current. The primary communication device (19) decodes the data of the temporal sequence of the control commands to the inverter (5) from the frequency control device (22), or the temporal sequence of the pulse modulation of the inverter (5), or the temporal sequence of the frequencies in the AC voltage on the primary side and / or the AC current on the primary side. A transformer device (1) according to claim 4 or 5, characterized in that it is the same as the one described in claim 4 or 5.

7. The transformer device (1) according to claim 1, characterized in that the secondary compensator (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 is activatable and the other is deactivatable, while the other is always active.

9. The aforementioned code is a binary code, The secondary compensation device (9) is therefore configured such that two different secondary resonance frequencies can be adjusted. A 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 resonant frequency changes and / or can change only within a range of less than 1%.

11. The stator (31) is equipped with a stator control device (32), The rotor (33) on which the rotor control device (34) is located, A transformer device (1) according to claim 1, An induction-type wound-field synchronous machine (30), The primary side (2) of the transformer device (1) is located on the stator (31), The secondary side (3) of the transformer device (1) is located on the rotor (33), The primary side communication device (19) is coupled to the stator control device (32), The secondary communication device (18) is coupled to the rotor control device (34). Induction-type wound-field synchronous machine (30).

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

13. The rotor (33) is equipped with a rotor coil (35) for generating a rotor magnetic field. The wound-field synchronous machine (30) is equipped with a main power supply (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), the auxiliary power supply (37) inductively transmits the electrical energy to the rotor control device (34), and the load (11) is equipped with the rotor control device (34). A wound-field synchronous machine (30) according to claim 11, characterized in that...

14. 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), The data to be transmitted from the secondary side (3) to the primary side (2) is encoded on the secondary side (3) by modulation of the secondary side resonance frequency. The primary-side parameters that correlate with the secondary-side resonance frequency are monitored and decoded on the primary side (2). The primary side (2) comprises a DC voltage source (4), an inverter (5), a primary compensator (6), and a primary transformer coil (7). The secondary side (3) comprises a secondary transformer coil (8), a secondary compensator (9), a rectifier (10), and a load (11). 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 compensator (6). 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). The secondary compensation device (9) is configured to be variable so that the secondary resonant frequency can be changed. The secondary side (3) comprises a secondary communication device (18), which encodes the data of the secondary side according to a predetermined code, and 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 to change the secondary side resonant frequency, and the temporal order of the changed secondary side resonant frequencies represents the encoded data. The primary side (2) comprises a primary communication device (19), the primary communication device (19) monitors primary side parameters, the primary side parameters correlate with the secondary side resonant frequency, recognizes the encoded data, and decodes the encoded data according to the code. The secondary side (3) is equipped with a secondary side frequency detection device (28) for detecting the current frequency in the AC current and / or AC voltage of 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 to change the frequency of the primary side AC current and / or the primary side AC voltage, wherein the temporal order of the changed frequencies in the primary side AC current represents the encoded data. The secondary communication device (18) is coupled to the secondary frequency detection device (28) and monitors the frequency of the AC current on the secondary side and / or the AC voltage on the primary side, recognizes the encoded data, and decodes the encoded data according to the code. Data transmission method.

15. The data to be transmitted from the primary side (2) to the secondary side (3) is encoded on the primary side (2) by modulating the frequency of the AC current and / or AC voltage on the primary side. On the secondary side (3), the resonant frequencies of the AC current and / or AC voltage on the secondary side are monitored and decoded. The method according to claim 14, characterized in that

16. The primary side (2) is equipped with a phase measuring device (20), and the phase measuring device (20) measures the phase difference (21) between the current and voltage in the AC current of the primary side and / or the AC voltage of the primary side. The primary communication device (19) is coupled to the phase measuring device (20), and monitors the phase shift (21) as a primary-side parameter, and the primary-side parameter correlates with the secondary-side resonant frequency. The method according to claim 14, characterized in that

17. The method according to claim 16, characterized in that the primary communication device (19) decodes data from the phase shift (21).

18. The primary side (19) is equipped with a frequency control device (22), and the frequency control device (22) corrects the phase difference (21) between the current and voltage in the AC current and / or AC voltage of the primary side by adjusting the frequency in the AC current and / or AC voltage of the primary side. The primary communication device (19) is coupled to the frequency control device (22) and / or the inverter (5), and monitors the adjustment of the frequency of the AC current on the primary side and / or the AC voltage on the primary side as primary side parameters, and the primary side parameters correlate with the secondary side resonant frequency. The method according to claim 14, characterized in that

19. The primary communication device (19) decodes data from the temporal sequence of frequency adjustments in the AC current on the primary side and / or the AC voltage on the primary side. The method according to claim 18, characterized in that

20. The adjustment of the frequency in the primary AC voltage and / or the primary AC current is expressed by a control command from the frequency control device (22) to the inverter (5), or by pulse modulation changed by the inverter (5) based on the control command, or by the frequency in the primary AC voltage and / or the primary AC current. The primary communication device (19) decodes data of the temporal sequence of control commands from the frequency control device (22) to the inverter (5), or the temporal sequence of pulse modulation of the inverter (5), or the temporal sequence of frequencies in the AC voltage on the primary side and / or the AC current on the primary side. The method according to claim 18, characterized in that

21. The method according to claim 14, characterized in that the secondary compensation device (9) comprises a variable capacitor.

22. The method according to claim 14, characterized in that the secondary compensation device (9) comprises two capacitors connected in parallel, one of which is activatable and the other is deactivatable, while the other is always active.

23. The aforementioned code is a binary code, The secondary compensation device (9) is configured such that two different secondary resonance frequencies can be adjusted in this manner. The method according to claim 14, characterized in that

24. The method according to claim 14, characterized in that the secondary compensation device (9) is configured such that the secondary resonant frequency changes and / or can change only within a range of less than 1%.

25. The transformer device (1) forms part of an induction-type wound-field synchronous machine (30), The aforementioned wound-field synchronous machine (30) includes a stator (31), and the stator (31) includes a stator control device (32). The wound-field synchronous machine (30) is equipped with a rotor (33), and a rotor control device (34) is positioned on the rotor (33). The primary side (2) of the transformer device (1) is located on the stator (31), The secondary side (3) of the transformer device (1) is located on the rotor (33), The primary side 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 14, characterized in that

26. The method according to claim 25, characterized in that the load (11) comprises a rotor coil (35) for generating a rotor magnetic field.

27. The rotor (33) is equipped with a rotor coil (35) for generating a rotor magnetic field. The wound-field synchronous machine (30) is equipped with a main power supply (36) for inductively transmitting electrical energy to the rotor coil (35), The transformer device (1) forms an auxiliary power supply (37) within the wound-field synchronous machine (30), and the auxiliary power supply (37) inductively transmits the electrical energy to the rotor control device (34). Therefore, the load (11) is equipped with the rotor control device (34). The method according to claim 25, characterized in that

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