DE102015011654B4 - System for contactless energy transfer from a primary conductor to a secondary winding arranged on a vehicle - Google Patents

Abstract

System for contactless energy transmission from a primary conductor, which can be charged with alternating current from a stationary feed unit, to a secondary winding (2) arranged on a vehicle (1) for power transmission, a winding on the vehicle (1) for information transmission being designed to be acted upon by a voltage signal, the frequency of which is higher than the frequency of the alternating current, with a voltage induced by the voltage signal in a further winding being fed to the feed unit to control the alternating current, the feed unit having a means for detecting the level of modulation of an on-off sequence of the voltage signal, the feed unit having a Has means for applying alternating current to the primary conductor depending on the degree of modulation for the transmission of electrical power, with alternating current not being applied to the primary conductor for power transmission when the degree of modulation disappears, whereby i with full modulation of the primary conductor for power transmission with alternating current, whereby when the modulation is between vanishing and full modulation the primary conductor for power transmission is only conditionally supplied with alternating current, whereby the information is transmitted by near-field communication by inductive near-field coupling, whereby the range of the near-field communication is smaller than half the width of a primary-side field plate, i.e. a ferrite plate covering the primary winding (3), the ferrite plate being arranged on the side of the winding facing away from the vehicle (1), the information being transmitted in the form of a binary signal which is generated by the vehicle (1) and is evaluated by the feed unit, the information being encoded as the modulation level of an on-off sequence of a voltage signal and as the pulse width modulation ratio of a pulse width modulated voltage signal, where the vehicle (1) has a state machine that controls the generation of the voltage signal, the information having a component that indicates a conditional charge or a conditional charge request separately from a required, i.e. unconditional, charge or required, i.e. unconditional, charge request, With a conditional charging request, the stationary feed unit activates the energy transfer depending on external influences, the feed unit being fed from an electrical supply network, the supply voltage of which is generated from systems for generating electrical energy, with the feed unit only being fed into the primary conductor with alternating current when there is a conditional application of alternating current impresses when the total power generated by the systems exceeds a minimum value, with at least one of the systems using a regenerative energy source, namely a wind energy system.

Description

The invention relates to a system for contactless energy transmission from a primary conductor to a secondary winding arranged on a vehicle.

It is generally known that electrical energy can be transmitted via an inductive coupling.

From the US 2012/0 235 636 A1 inductive energy transmission is known.

From the US 2011/0187321 A1 inductive energy transmission for a vehicle is known.

From the DE 10 2011 115 092 A1 a system for contactless transmission of energy and data is known.

From the DE 10 2010 027 640 A1 an electrical charging system is known.

From the DE 10 2011 010 049 A1 a charging device for charging a battery of a vehicle is known.

From the U.S. 4,496,896 A a vehicle battery charging method is known.

From the JP 2013 - 251 946 A is known a communication method for contactless charging.

From the U.S. 4,347,472 A a method for charging a battery of a vehicle is known.

From the publication NOBIS, P. [et al.]: PV self-consumption with electric vehicles and home storage systems. In: 9th International Energy Industry Conference at the Vienna University of Technology (IEWT 2015), Vienna, Austria, February 2015, pp. 1-9 charging of electric vehicles from a PV system is known.

The invention is therefore based on the object of developing a system for contactless energy transmission, whereby the environment should be protected, that is to say the energy resources should be more effectively usable without significantly restricting the functionality of the system.

According to the invention, the object is achieved in the system according to the features specified in claim 1.

Important features of the invention in the system for contactless energy transfer from a primary conductor, which can be charged with alternating current from a feed unit, to a secondary winding arranged on a vehicle, in particular for power transmission, are that a winding on the vehicle for information transfer can be charged with a voltage signal whose frequency is higher is than the frequency of the alternating current,
wherein a voltage induced by the voltage signal in a further winding is fed to the feed unit, in particular to control the alternating current,
wherein the feed unit has a means for recognizing the level of modulation of an on-off sequence of the voltage signal,
wherein the feed unit has a means for applying alternating current to the primary conductor, depending on the degree of modulation, for the purpose of transmitting electrical power.

The advantage here is that there is signaling for the transmission of information, in particular a communication channel, from the mobile side to the stationary side. In this way, control or even regulation of the energy transfer via the inductive coupling is made possible. In particular, when there is a conditional power requirement, electrical power can only be transmitted if there is an oversupply of electrical power available in the electrical supply network, for example when regenerative energy sources can be used intensively. The vehicle's energy store is then only charged in those time segments in which there is an oversupply of electrical power generated from regenerative energy sources. The advantage of the invention is therefore that the environment is spared, since non-regenerative energy sources are spared, in particular energy sources based on the combustion of fossil fuels, whereby the carbon dioxide emission and accompanying substances that pollute the environment are reduced.

Furthermore, the coding of the information by means of the modulation level of an on-off sequence of a high-frequency signal is a simple and effective type of communication. Because the expenditure on electronic switching is low.

According to the invention, the primary conductor, in particular for power transmission, is not subjected to alternating current when the degree of modulation disappears,
and that at full modulation level, the primary conductor, in particular for power transmission, is supplied with alternating current,
and that if the level of modulation is between the vanishing and full modulation levels, the primary conductor, in particular for power transmission, is only subjected to a limited amount of alternating current. The advantage here is that conditional charging of the vehicle's energy store is made possible. Thus, from regenerative Excess power flows generated by energy sources are used for charging.

According to the invention, the feed unit is fed from an electrical supply network, the supply voltage of which is generated by systems for generating electrical energy, with the supply unit only impressing alternating current into the primary conductor when the power that can be generated, in particular generated, by the regenerative systems as a whole is conditionally applied exceeds a minimum value and / or is higher than the power consumption of non-controllable loads,
in particular wherein at least one of the systems uses at least one regenerative energy source, in particular a supply energy source, in particular being a solar energy system or a wind energy system. The advantage here is that as much renewable energy as possible is used.

Important features of a system, in particular according to the aforementioned type, for the transmission of electrical power from a stationary device, such as from a stationary feed unit with a connected primary conductor to a mobile device, such as a vehicle, are that the transmission is dependent on information that is provided by the mobile device is transmitted to the stationary device,
where the information includes an unconditional or conditional performance requirement,
whereby the stationary device activates the energy transfer depending on external influences when there is a conditional power requirement.

The advantage here is that it is possible to use energy that is inexpensive or that is generated from renewable energy sources.

In an advantageous embodiment, the information is transmitted by near-field communication, in particular by inductive near-field coupling,
in particular where the range of the near-field communication, in particular near-field coupling, is less than half the width of a primary-side field plate, in particular a ferrite plate covering the primary winding,
in particular wherein the ferrite plate is arranged on the side of the winding facing away from the vehicle. The advantage here is that no sources of interference can erroneously influence the data transmission, in particular none on other vehicles
provided transmitter, since the ferrite plate is less extensive than the underside of a respective vehicle and the vehicles can only be arranged side by side on the travel surface.

According to the invention, the information is transmitted in the form of a binary signal which is generated by the mobile device and evaluated by the stationary device. The advantage here is that a simple transfer of information, in particular data transfer, is sufficient.

According to the invention, the information is encoded as a modulation level, in particular an on-off sequence of a voltage signal, and / or a pulse width modulation ratio, in particular a pulse width modulated voltage signal
or alternatively
the information is encoded as a frequency value of a frequency-modulated voltage signal, in particular by means of correspondingly different carrier frequencies. The advantage here is that the data transmission can be carried out in a simple manner.

According to the invention, the mobile device has a state machine which controls the generation of the voltage signal,
wherein the information has a component that indicates a conditional charge or a conditional charge request separately from a required, in particular an unconditional charge or a necessary, in particular an unconditional charge request. The advantage here is that a simple sequence control can be carried out.

Further advantages result from the subclaims. The invention is not restricted to the combination of features of the claims. For the person skilled in the art, there are further meaningful possible combinations of claims and / or individual claim features and / or features of the description and / or the figures, in particular from the task and / or the task posed by comparison with the prior art.

• In der 1 ist ein erfindungsgemäßes System gezeigt, bei welchem ein Fahrzeug 1 an seiner Unterseite eine Sekundärwicklung 2 aufweist, die induktiv an eine bodenverlegte, also stationär angeordnete Primärwicklung 3, koppelbar ist.

The invention will now be explained in more detail with reference to figures:

• In the 1 a system according to the invention is shown in which a vehicle 1 a secondary winding on its underside 2 has, which inductively to a ground-laid, ie stationary primary winding 3 , can be coupled.

Electrical power can thus be transmitted inductively to the vehicle if it is fed into the primary winding by a stationary supply unit 3 a medium-frequency alternating current is impressed. In order to achieve a high level of efficiency that is as independent of deviations from the ideal position as possible, a capacitance is connected in series and / or in parallel to the secondary winding, so that the resonance frequency of the oscillating circuit thus created essentially corresponds to the frequency of the medium-frequency alternating current.

In addition, there is also a communication channel between vehicles 1 and stationary, with the primary conductor 3 connected feed unit provided.

The communication channel can be implemented either via magnetic fields or via radio waves, i.e. by means of an electromagnetic far field, or by means of infrared.

Alternatively, however, a near-field signal transmission by means of magnetic fields can also be carried out. In this case, a first winding is arranged on the vehicle, in particular this winding consisting of two partial windings which are electrically connected in series or in parallel and which are wound in opposite directions to one another. Likewise, a second winding consisting of two partial windings wound in opposite directions is provided in a stationary manner, preferably in the area of the primary conductor 3 covered floor area. Despite the strong from the primary conductor 3 With the medium-frequency alternating magnetic field generated, a signal transmission can be carried out with this near field. Because the winding in opposite directions does not generate any effective voltage in the winding from this quasi-homogeneous alternating magnetic field of the medium-frequency power transmission.

The first winding can therefore be acted upon by a higher frequency current than the frequency of the alternating current impressed in the primary conductor by the feed unit, and thus reliable communication can be provided in the area of the strong magnetic field. However, the first and second windings are only intended for near-field transmission. The frequency of the higher frequency current is preferably a high frequency.

In a simple embodiment of the invention, information is transmitted by means of frequency modulation.

In a further exemplary embodiment according to the invention, however, information can also be transmitted by means of a binary signal. The presence of a high-frequency signal voltage or the absence of the signal is detected here. A periodic on-off sequence with a certain degree of modulation a is used to signal the respective information.

With a vanishing level of modulation a, i.e. a = 0, i.e. no high-frequency signal voltage, the vehicle 1 no power requested via the inductive power transfer from the primary winding 3 to secondary winding 2 .

At a full modulation level a, i.e. a = 100%, i.e. permanently uninterrupted high-frequency signal voltage, the vehicle 1 Service requested.

With an average level of modulation a, for example a = 50%, that is to say, on average over time, the high-frequency signal voltage is present in the vehicle 1 Service requested only conditionally.

Upon receipt of the information that the vehicle 1 does not request any power, the primary conductor is not charged with the current intended for the power transmission.

Upon receipt of the information that the vehicle 1 Requests power, i.e. after receipt of an unconditional power request, the primary conductor is charged with the current provided for the power transmission.

Upon receipt of the information that the vehicle 1 Requires power only conditionally, the primary conductor is charged with the current provided for the power transmission if there is a high supply of regenerative producers of electrical power and / or the supply of the producers of electrical power exceeds a critical value. Because depending on the proportion of regenerative energy producers, i.e. systems for generating electrical energy, such as wind power plants and / or solar power plants, and depending on the presence of the respective associated energy source, such as solar radiation and / or wind, the feed unit can be controlled.

Thus, when there is a conditional power requirement, the feed unit is controlled in such a way that the feed unit applies the current provided for inductive power transmission to the primary conductor.

The primary winding formed from the primary conductor is preferably designed as a flat winding and covered by a ferrite plate on its side facing away from the vehicle. The projection of the ferrite plate perpendicular into the plane of movement thus includes the corresponding perpendicular projection of the primary winding into the plane of movement. The range of the post-field transmission between the windings is less than half the width of the ferrite plate. The width here is preferably the greatest extent of the perpendicular projection of the ferrite plate into the plane of travel.

As an alternative to the information transmission described above, where the information is transmitted as the modulation level of the on-off sequence of a high-frequency voltage signal, the information transmission can also be carried out with a frequency-modulated high-frequency voltage signal. Here, the information of an unconditional power requirement is assigned a first frequency value of the voltage signal and a conditional power requirement is assigned a second frequency value of the voltage signal.

In a further embodiment according to the invention, a communication channel is implemented between the vehicle and the feed unit, via which the information for unconditional or conditional charging can be transmitted. The communication channel can be implemented as a far-field connection, such as a WLAN connection, or as a near-field connection.

List of reference symbols

1

vehicle

2

Secondary winding

3

Primary winding

Claims (2)

System for contactless energy transmission from a primary conductor, which can be charged with alternating current from a stationary feed unit, to a secondary winding (2) arranged on a vehicle (1) for power transmission, a winding on the vehicle (1) for information transmission being able to be acted upon by a voltage signal, the frequency of which is higher than the frequency of the alternating current, a voltage induced by the voltage signal in a further winding is fed to the feed unit to control the alternating current, wherein the feed unit has a means for recognizing the level of modulation of an on-off sequence of the voltage signal, wherein the feed unit has a means for applying the primary conductor, depending on the degree of modulation, with the alternating current for the transmission of electrical power, With a vanishing degree of modulation, the primary conductor for power transmission is not charged with alternating current, with the primary conductor for power transmission being charged with alternating current when the degree of modulation is full, with an alternating current being applied to the primary conductor for power transmission only to a limited extent if the level of modulation is between zero and full, where the information is transmitted through near-field communication by inductive near-field coupling, the range of the near-field communication is less than half the width of a primary-side field plate, i.e. a ferrite plate covering the primary winding (3), wherein the ferrite plate is arranged on the side of the winding facing away from the vehicle (1), The information is transmitted in the form of a binary signal which is generated by the vehicle (1) and evaluated by the feed unit, wherein the information is encoded as the degree of modulation of an on-off sequence of a voltage signal and as a pulse width modulation ratio of a pulse width modulated voltage signal, wherein the vehicle (1) has a state machine which controls the generation of the voltage signal, wherein the information has a component that indicates a conditional charge or a conditional charge request separately from a required, i.e. unconditional, charge or required, i.e. unconditional, charge request, with a conditional charging request, the stationary feed unit activates the energy transfer depending on external influences, wherein the feed unit is fed from an electrical supply network, the supply voltage of which is generated from systems for generating electrical energy, with a conditional supply of alternating current, the feed unit only impresses alternating current in the primary conductor if the total power generated by the systems exceeds a minimum value, wherein at least one of the systems uses a regenerative energy source, namely a wind energy system. System according to Claim 1 , characterized in that the information is alternatively encoded as a frequency value of a frequency-modulated voltage signal.

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