DE102009017087B4 - Method for loading an energy store - Google Patents

Abstract

A method for loading an energy storage device, in particular a battery, in particular a high-voltage battery, an electric motor driven vehicle, wherein the vehicle a first setpoint is determined, wherein the stationary control electronics impresses a current in a primary conductor to which a secondary winding of the vehicle is inductively coupled, in particular by inserting the primary conductor in a recess of the vehicle, around which the secondary winding is arranged, wherein the stationary control electronics comprises a control unit which controls the impressed in the primary conductor current to the first set point out of a arranged in the vehicle control electronics contactlessly to the control unit the stationary control electronics is transmitted, being specified by means for battery charging management, whether a current-controlled or a voltage-controlled charging is performed, wherein in current-controlled charging of the means a Stro msollwert is supplied as a first setpoint value or from the difference between the detected and desired charging current, a current setpoint is determined as the first setpoint value, and wherein in voltage controlled charging from the means a voltage setpoint is supplied to a control unit is supplied, which is also the corresponding detected voltage value on Energy storage, in particular charging voltage, is supplied and from a control value is determined, which is used as the first setpoint, wherein the first setpoint, the current setpoint and / or the voltage setpoint are limited to maintain a control limit, wherein the electric motor is operated in star point circuit, wherein the star point of the electric motor current is supplied from a rectifier, which is fed by a secondary winding, wherein the secondary winding is supplied from a primary winding without contact, wherein charging current for the energy storage is formed by an inverter through which the St atorwicklungen the electric motor can be fed with a three-phase voltage system, which is generated during power supply of the inverter from the energy storage, as long as the voltage occurring at the neutral point is below a first critical value, the charging current is supplied to the energy storage directly from the rectifier, as long as the at the ...

Description

The invention relates to a charging device and a method for loading an energy store.

It is known to feed electric motors from an inverter, which is supplied from an energy storage, such as DC link capacitor of an inverter. It is also obvious, for battery-powered vehicles with electric motor drive, to feed the electric motor from an inverter, which is powered by the battery.

It is also known to charge a battery, such as a rechargeable battery, out of a charger.

From the WO 94/10 004 A1 As the closest prior art, a method for contactless charging of an electric vehicle is known.

From the EP 0 834 977 A2 a device for charging at least one accumulator for an electric vehicle is known.

From the DE 10 2007 033 654 A1 is a system comprising a carriage and at least one base unit, the carriage comprising a secondary coil.

From the EP 2 034 607 A1 is a motorized vehicle known.

From the JP H11-98 713 A a charging device is known.

From the JP H08-165 986 A is a charge control known, being switched from constant current to constant voltage.

From the DD 1 14 729 A1 a circuit arrangement for a voltage-controlled power supply device is known.

The invention is therefore based on the object to provide a powerful cost-effective charging circuit for an energy storage.

According to the invention, the object is achieved in the method according to the features indicated in claim 1.

The advantage here is that for charging the power source, a charging method can be used, which uses the stator windings of the existing electric motor anyway. Thus, not only is a long voltage usable as a secondary voltage and thus as an energy source for the charging circuit, but also a very compact design, since the stator windings of the motor are used to operate a charging circuit.

According to the charging current is supplied to the energy storage directly from the rectifier, as long as the voltage occurring at the neutral point is above the first critical value. The advantage here is that no further losses occur.

According to the invention, at least one of the lower switches of the inverter is set in the conductive state, whereby current is dissipated from the rectifier via the associated stator winding to the lower potential of the energy storage, so in particular the energy storage is protected from current from the rectifier, as long as the occurring at the neutral point Voltage is above a second critical value, which is greater than the first critical value and beyond which the energy storage is endangered with a certain probability. The advantage here is that a high level of security is achievable.

In an advantageous embodiment, a further current path is released, via which current is dissipated from the rectifier directly or via the associated stator winding to the lower potential of the energy store, ie in particular the energy storage is protected from current from the rectifier, as long as the voltage occurring at the neutral point above a third critical value is greater than the second critical value and beyond which the energy storage is more likely to be at risk.

In particular, wherein the further current path is formed from a passive circuit arrangement, in particular wherein the further current path comprises a thyristor, in whose drive path a zener diode or a corresponding component which has a switching threshold-like behavior is provided. The advantage here is that a very high level of security can be achieved, since the current dissipation path is doubly executable.

In an advantageous embodiment, the stator windings can be fed with a three-phase voltage system that can be generated from the energy store. The advantage here is that a conventional inverter can be used, which consists of three half-bridges of one series circuit of two semiconductor switches and thus a pulse width modulated control to achieve the motor or generator operation of the semiconductor switch can be achieved.

In an advantageous embodiment of the inverter is pulse width modulated or Block-commutated controlled, in particular for motor or generator operation of the electric motor. The advantage here is that simple methods are applicable.

In an advantageous embodiment, the switches of the inverter are controlled pulse width modulated. The advantage here is that a simple and inexpensive operation is feasible, in particular, a regulation of the charging voltage is made possible to a target value by the pulse width modulation ratio is used as a manipulated variable.

In an advantageous embodiment of the inverter is designed multi-phase and the drive signals for the switches of the inverter synchronously, secondarily synchronously or asynchronously executed. The advantage here is that in synchronous operation, a particularly simple control is executable in asynchronous operation of a uniform and independent utilization of the half-bridges of the inverter and the stator windings is executed and synchronous operation with time offset a uniform utilization of the half-bridges and the stator windings in a simple manner is possible.

In an advantageous embodiment, the recharging of the energy storage is repeated cyclically, in particular the recharging is carried out alternately with the motor or generator operation of the electric motor. The advantage here is that the stator windings is only possible to the maximum of the current occurring in the modes. Alternatively, a simultaneous generation of charging current for motor and generator mode of operation of the electric motor is possible, although the stator windings must be dimensioned accordingly stronger.

In a charging device for charging an energy storage device, in particular a battery, in particular a high-voltage battery, a motor-driven vehicle for carrying out an aforementioned method is important that
in the vehicle an electronic control system is arranged with means for determining a desired value,
wherein data exchange means for non-contact data exchange between the control electronics and a stationary control electronics are provided,
wherein the stationary control electronics impresses a current in a primary conductor, to which a secondary winding of the vehicle is inductively coupled, in particular by inserting the primary conductor into a recess of the vehicle about which the secondary winding is arranged,
wherein the stationary control electronics comprises a control unit which regulates the impressed in the primary conductor current to a target value, which is transmitted from the arranged in the vehicle control electronics, in particular via the data exchange means.

The advantage here is that a current regulator is provided in the stationary part, which is thus close to the power electronics and can be operated quickly. The predetermined first set point, on the other hand, is determined in the vehicle, ie, close to the battery, and is thus trackable in a timely manner to the state changes of the battery. In particular, therefore, no large data flow between the vehicle and stationary electronics is necessary because only one setpoint is transmitted. In addition, in the vehicle, the determination of the desired value in accordance with the respectively activated by switching control method executable, so in a simple way with current-controlled charging method and by means of a voltage regulator in voltage-controlled charging method.

• – entweder den Sollwert von einem Stromsollwerterzeugungs-Mittel erhält, das mit Mitteln zum Batterielademanagement verbunden ist,
• – oder als Stellgröße erhält, die von einer Spannungsregelungseinheit bestimmt wird, die mit Mitteln zur Erfassung der Spannung am Energiespeicher und mit einem Mittel zur Erzeugung eines Spannungs-Sollwerts, das mit den Mitteln zum Batterielademanagement verbunden ist, verbunden ist.

Von Vorteil ist dabei, dass je nach Ladezustand ein schnelles Aufladen mit dem stromgeregelten Ladeverfahren erreichbar ist und ein die Batterie schonendes Aufladen mit dem spannungsgeregelten Verfahren.In an advantageous embodiment, the setpoint is transmitted by a switch, which is realized in the control electronics of the vehicle,
the switch

• Either receives the desired value from a current setpoint generation means, which is connected to means for battery charging management,
• - or receives as a manipulated variable, which is determined by a voltage regulation unit, which is connected to means for detecting the voltage at the energy storage and with a means for generating a voltage setpoint, which is connected to the means for battery charging management.

The advantage here is that depending on the state of charge a fast charging with the current-controlled charging method is achievable and the battery gentle charging with the voltage-controlled method.

Important features in the method for loading an energy store are that a first setpoint value is determined in the vehicle,
wherein the stationary control electronics impresses a current in a primary conductor, to which a secondary winding of the vehicle is inductively coupled, in particular by inserting the primary conductor into a recess of the vehicle about which the secondary winding is arranged,
wherein the stationary control electronics comprises a control unit which regulates the impressed in the primary conductor current to the first set value, which is transmitted by a control electronics arranged in the vehicle contactlessly to the control unit of the stationary control electronics.

The advantage here is that the stationary current regulator can be realized quickly working, ie has a high data flow. Likewise is in the Vehicle allows a high data stream to determine the first setpoint. But only a small data stream is necessary at the interface for data transmission, that is to say for the non-contact transmission of the first setpoint value to the stationary part.

In an advantageous embodiment, means for battery charging management specify whether a current-controlled or a voltage-controlled charging is carried out,
wherein, in the case of current-controlled charging, a current nominal value is supplied as the first nominal value by the means or a current nominal value is determined from the difference between the detected and desired charging current than the first nominal value,
and wherein in voltage-controlled charging by the means a voltage setpoint is supplied, which is supplied to a control unit, which also the corresponding detected voltage value at the energy storage, in particular charging voltage, is supplied and from a control value is determined, which is used as the first setpoint.

The advantage here is that adaptable to the state of the battery, the respective advantageous method is selectable.

In an advantageous embodiment, the first setpoint values, the current setpoint value and / or the voltage setpoint value are limited, in particular for maintaining an adjustment limit. The advantage here is that the setting limit is met and thus the controller has a controlled behavior.

In an advantageous embodiment, the charging device comprises a drive system which comprises an electric motor, an inverter and at least one energy store,
wherein the electric motor can be fed by the inverter, which can be supplied from the energy store,
wherein the electric motor is designed as a three-phase motor in star-point connection,
wherein the star point of the electric motor current from a rectifier can be supplied, which is fed by a secondary winding,
wherein the secondary winding can be supplied from a primary winding, which is provided inductively coupled to the secondary winding.

The advantage here is that a very compact charging circuit can be realized, even at the secondary winding may be a much lower voltage level than the voltage required to charge the energy storage. Because the fact that the stator winding is connected via the inverter to the energy storage and thus as an inductance for the charging circuit, for example in the manner of a buck converter, is usable, even a high setting of the voltage level of the secondary voltage to the required charging voltage is possible. In other words, so a long-voltage supplied charging circuit is possible. If the secondary voltage is sufficiently large, that is above a first critical value, a direct loading of the energy storage from the secondary winding is possible.

If the secondary voltage is too high, that is above a second critical value, from which the energy storage is endangered with a certain probability, a derivation of the current through the inverter is possible, so a routing of the current from the energy storage. Thus, a deterioration, premature aging or other hazards, such as overheating of the energy storage can be avoided.

If the secondary voltage is greater than a third critical value, in addition, a further current path can be released, which is executable without active control, then the current with high security can be derived to protect the energy storage safely, especially with a higher safety category.

If the secondary voltage is thus below the first critical value, it is advantageous that the stator windings also at least partially have the function of an additional energy store and, moreover, also contribute to the smoothing of the charging current.

So it is a wide voltage usable. Thus, a loading is possible even with a deterioration of the coupling or in a primary-side supply network with fluctuating or variable voltage. It is even wide-voltage operation allows, so the loading of different supply networks, which are different not only in their frequency but also effective voltage.

In an advantageous embodiment, the primary winding is supplied from a voltage-current converter, in particular a gyrator, which is fed by an inverter with an alternating voltage,
wherein the voltage-current converter comprises at least one capacitor and an inductance such that the associated resonant frequency substantially corresponds to the frequency of the AC voltage, in particular wherein capacitance and inductance are connected in series. The advantage here is that the voltage source-like behavior of the primary winding feeding single-phase inverter is converted into a power source-like behavior, whereby a substantially constant current is available. In this way, even with weak inductive coupling is a high Efficiency in the contactless energy transfer to the secondary coil achievable.

In an advantageous embodiment, when a first critical value of the voltage at the neutral point is exceeded, the charging current is carried out directly by the rectifier to or from the energy stores by means of a diode, in particular wherein the first critical value corresponds to the charging voltage for the energy store (s). The advantage here is that no further losses occur but the full contactless energy is available for charging the energy storage available.

In an advantageous embodiment, falls below the first critical value of the voltage at the neutral point of the charging current via at least one stator winding and the inverter is guided by the rectifier to or to the energy storage, in particular wherein the inverter is operable together with the stator windings as boost converter. The advantage here is that the low voltage at the secondary coil is hochsetzbar and thus charging is possible despite this low voltage.

In an advantageous embodiment, when a second critical value is exceeded, which is greater than the first critical value, a switch is closed, is derived via the current from the neutral point to the lower potential. The advantage here is that a protection of the energy storage against overcharging is providable.

In an advantageous embodiment, one or more energy stores is a capacitor, an ultracap capacitor or a battery. The advantage here is that, depending on requirements, a capacity is selectable, which ensures the operation of the planned application.

In an advantageous embodiment, the stator windings of the electric motor are connected in star point circuit. The advantage here is that all stator windings can be used in a simple manner as inductors of the charging circuit. In particular, when using the inverter connected to the stator windings as a boost converter, a distribution of the charging current to the stator windings allows. The ohmic heat losses can thus be reduced.

In an advantageous embodiment, an additional inductance is provided between the neutral point and the rectifier. The advantage here is that lower switching frequencies of the inverter can be used to generate equal in the individual stator windings current, which then the switching losses of the semiconductor switch covered by the inverter can be reduced. In addition, larger voltage differences between charging voltage and voltage level of the power source are possible. Another advantage is that a division of the current can be done on the stator windings and thus lower losses can be achieved.

In an advantageous embodiment of the RMS value or peak value of the rectifier supplying secondary voltage is smaller than the charging voltage for the energy storage, ie in particular smaller than the voltage required for charging the energy storage, in particular input voltage of the inverter. The advantage here is that a wide-voltage power source can be used as the switch supplying power source.

The invention will now be explained in more detail with reference to figures:
In the 1 a device with a schematic circuit diagram is shown. Here, a motor M for driving the vehicle is provided in a vehicle.

Here, from the parallel-connected energy storage B and C, which are preferably designed as a battery and / or capacitor, an inverter for feeding the electric motor M is provided. The stator windings of the electric motor M are designed as a three-phase winding in star point circuit. Thus, the electric motor with a determinable by the inverter feed frequency, that is a supply voltage rotating with this supply voltage supply and controllable in this way, the speed of the electric motor or alternatively when attaching a rotation angle or speed sensor adjustable to a desired speed or a desired torque.

In regenerative operation, the energy generated by the electric motor M can be supplied to the energy store via the inverter.

The inverter consists of three half-bridges, that is, pairs of branches, each comprising a series connection of an upper and lower controllable semiconductor switch, which in turn in each case a diode is connected in parallel. The semiconductor switches are preferably controlled pulse width modulated. The control electronics A generates the drive signals for the semiconductor switches. In motor operation, therefore, the motor M is supplied with a rotational tension system with a predefinable frequency, and thus the motor M is set in rotary motion.

Conversely, in regenerative operation, energy from the motor via the inverter to the Energy storage B and C can be fed and thus they are loaded.

However, the loading of the energy storage device can also be carried out when the motor M is not rotating. If, for example, the vehicle is in park position, a primary winding L2 can be brought into inductive coupling with a secondary winding L1 from the outside for this purpose. This secondary winding L1 is part of a charging unit 2 , which is plugged with the rest of the motor-inverter unit 1 ,

The primary winding is fed by a gyrator G, which in turn is supplied by a single-phase inverter which comprises the switches S1, S2, S3, S4 and which is fed by the DC voltage applied to the capacitor C2. Here, the gyrator G converts the voltage source-like behavior of the output side of the gyrator-feeding, single-phase inverter in a power source-like behavior towards the primary winding L2 out. Thus, therefore, the current in the primary winding L2 is regulated to a desired value by the output voltage of the gyrator-feeding, single-phase inverter is regulated out to a target voltage value. Since the secondary winding L1 is inductively coupled to the primary winding L2, the current source is translated, so to speak transformer. At the terminals of the secondary winding L1 so a source of power is essentially provided or at least there is a power source-like behavior.

For shutting off the supplied energy, a short-circuiter R is provided parallel to the secondary winding. If this short-circuiter R is open, the secondary alternating current de rectifier, comprising the diodes D2, D3, D4, D5 supplied and the rectified current through the diode D1 to the energy storage B and C, respectively.

In the case of an overvoltage or other protection of the energy storage B and C, for example, as protection against overcharge, the inverter is used to terminate the load by one or more lower switch of the inverter, so arranged at lower potential of the energy storage switch in the conductive Condition are derived, whereby the rectified AC across the neutral point SP of the motor M and the one or more stator windings of the motor M and the or the lower switch is derived.

When all the switches of the inverter are open, part of the rectified alternating current is supplied via the neutral point SP and the stator windings of the motor M to the diodes of the inverter, which rectify the alternating current and provide a unipolar current for charging the energy stores B and C. The stator windings reduce high-frequency components and contribute to smoothing.

A charging of the energy storage is also possible if the voltage applied to the neutral point SP is smaller than the required charging voltage. Then namely by means of the inductances of the stator winding Hochsetzstellerbetrieb enabled. For this purpose, the motor with inverter is not only used for the mere rectification but operated as a boost converter. For this purpose, the switches are controlled accordingly, so that a much higher voltage can be generated at the energy store than the peak voltage value of the unipolar voltage that can be generated by the rectifier. In this case, the inductances of the stator windings during switching operations of the semiconductor switch of the inverter together and make the amount of voltage to the energy storage controllable or adjustable when attaching a means for detecting the voltage at the energy storage. An important parameter here is the switching frequency of the switches of the inverter. Despite a mains voltage whose peak value and / or effective value is smaller than the charging voltage necessary for the energy store, charging of the energy store is therefore possible.

In motor and / or regenerative operation of the motor, the inverter is controlled such that a rotary voltage is applied to the motor. Thus, the drive signals are dependent on each other, so that the rotational voltage is applied to the stator windings. In the described charging operation and non-driving or driven motor M, the drive signals for the switches of the half-bridges may be generated independently of each other.

The control of the three half-bridges, ie branch pairs, of the inverter is synchronously executable. In an asynchronous execution of the drive signals, a further improved uniform utilization of the switch is possible. Asynchronous here means that the drive signals assigned to the respective half bridges have a different frequency and thus are not synchronous with one another.

By means of the unipolar current, which is generated when loading the energy storage and boost converter operation, a holding torque is generated in the electric motor, in particular when designed as a synchronous motor.

By closing the bottom switch of the inverter, the battery can be estimated against overcharging or overvoltage.

In a further embodiment of the invention, a further electronic switch is provided, which is provided between the neutral point and the lower potential or alternatively between one of the motor terminals and the lower potential, that is arranged parallel to one of the lower switch. In this way, the security can be further increased. In particular, when implementing this further switch as a thyristor, a passive circuit, for example comprising a Zener diode or the like, executable, with a derivation of the current from the neutral point to the lower potential of the energy storage B and C is enabled from exceeding a critical voltage, the greater than the critical voltage above which the lower switches of the inverter are closed.

In a further embodiment of the invention, the switches of the inverter instead of pulse width modulated block commutated driven by the in 1 shown control electronics A.

In a further embodiment of the invention, even with motor operation of the motor M can be supplied to the energy storage in the manner described, so that the capacity of the energy storage is used up more slowly, so the above charge current for at least partial power supply of the inverter is usable. However, for this purpose, the stator windings and the diodes of the rectifier must be dimensioned correspondingly robust.

In a further embodiment of the invention a plurality of inverters are supplied from the energy storage, each feeding an electric motor, wherein via a stator winding of a first or more electric motors of the energy storage in the above-described manner, each with a switch for the controlled supply of electricity to the respective stator winding.

In further embodiments of the invention, an additional inductance L between star point SP and the rectifier (D2, D3, D4, D5) is inserted, whose current can be influenced by a controllable switch. In this case, the switch essentially operates in accordance with a buck converter, wherein, however, at least the stator windings and the inductance L are provided at the star point of the stator windings as an inductance, and the inverter with energy storage is effective as the load.

The switch, preferably a semiconductor switch, a diode is connected in parallel, said parallel circuit is connected via the diode connected in series with the lower potential of the unipolar voltage.

In this way, it is now possible to supply an alternating current to the neutral point by means of the switch, so that via the diodes of the inverter 1 the energy storage a charging current can be supplied. Thus, a charging of the energy storage is possible.

During loading with charge current conducted via the stator windings, the stator windings have a smoothing effect on the current supplied via the switch and also constitute an additional energy store.

According to 1 On the secondary side, control electronics are provided and can also be supplied by the secondary winding, which includes the first microcontroller MC1 and also the control electronics A. This is via an infrared interface in the data exchange with a primary side arranged, that is stationary and thus not arranged in the vehicle control electronics, which includes the second microcontroller MC2.

At the energy storage B, so for example a high-voltage battery, sensors and other means for battery charging management are arranged. These detect state parameters of the energy store B, such as state of charge and / or temperature, and / or the means comprise an electronic circuit, which determine the state parameters of the energy store B from the course of state parameters, such as the course of the battery current or the course of the battery terminal voltage.

In this way, the means for battery charging management are able to determine a desired value for a charging current or a charging voltage for charging the energy storage device.

This setpoint is transmitted to the secondary-side control electronics and optionally forwarded to the primary-side control electronics.

If the desired value transmitted in this way is a current setpoint for charging current, the primary-side control electronics controls the single-phase inverter in such a way that it is regulated to the corresponding value by means of the gyrator circuit, the current impressed into the primary winding. For this purpose, the value of the output voltage of the single-phase inverter detected by a voltage sensor is regulated to a value corresponding to the desired value, or the current impressed into the primary winding is detected by means of a current sensor and then this detected current value is determined by appropriately setting the Output voltage of the single-phase inverter to the desired setpoint out regulated. Thus, a current-controlled charging of the energy storage is thus effected. In this case, limiting means are provided on the control unit, which keep the current, in particular the desired value, below a critical value. Thus, the energy storage is protected against overcurrent.

However, if the desired value transmitted by the means for battery charging management is a voltage setpoint, this is supplied to a control unit which is encompassed by the secondary-side control electronics and to which the detected voltage at the energy store B is also supplied. From the control deviation, a desired current control value is generated, which is then transmitted to the primary-side control electronics. In turn, this regulates the current, in particular first of all the current impressed into the primary winding, to the desired desired value. In this way, a corresponding charging current is supplied to the energy storage B on the secondary side. Since the desired current control value is changed in accordance with the aforementioned control deviation, the detected voltage value is then changed to the desired value in the described manner and thus a voltage-controlled charging of the energy accumulator is effected. In this case, limiting means are provided on the control unit, which keep the voltage, in particular the desired value, below a critical value. Thus, the energy storage is protected against overvoltage. Thus, although a current source is realized on the primary side, on the secondary side, however, a voltage-controlled charging of the energy store can be carried out.

It is also important that the means for battery charging management specify whether a current-controlled or a voltage-controlled charging of the energy storage device should be performed. In order to bring about particularly rapid charging, current-regulated charging is carried out, for example, in the case of an empty energy store until the energy store is charged approximately 80% or even 90%. Then it is switched to a voltage-controlled charging. The necessary switching means are thus controlled by the means for battery charging management.

The means for battery charging management also comprise monitoring means, such as sensors for detecting the current in or out of the energy store. When critical values are exceeded, a disconnect switch is controlled by the means in such a way that the energy store is disconnected and thus protected.

This is in 2 the embodiment shown schematically in more detail:
At the energy storage B are the means 20 provided for battery charging management, where the detected values of cell voltage U1 of the energy storage, so for example a cell of the high-voltage battery, and supplied to the terminals of the energy storage battery voltage U2 is supplied. In addition, the means of monitoring 21 recorded current values the means 20 fed, on the one hand the switch 22 trigger and thus cause a separation of the energy storage B when a critical value of voltage and / or current is exceeded.

The energy store B becomes a consumer 23 supplied, which are supplied via a buck converter only with a low voltage of, for example, 12 volts or 24 volts. The energy store has an operating voltage of more than 200 volts, in particular up to 400 volts or more.

The charging current for the energy storage is provided by the secondary-side control electronics 25 provided for data exchange 32 with a central higher-level control 24 connected and with the means 20 for battery charging management. The central higher-level control 24 Also controls a refrigeration unit, which is not only provided for cooling the engine of the vehicle and / or a cooling liquid for cooling the motor but also for cooling the energy storage in dependence on its temperature profile and / or power supply.

The secondary-side control electronics 25 receives over the data exchange connection 32 the current setpoint from the means 20 or values such as the sensed value of the energy storage current and the battery current setpoint.

From this, the block determines current setpoint generation 29 the secondary-side control electronics 25 the current setpoint, which is governed by the primary-side control electronics.

If, however, a voltage setpoint is supplied by the means for battery charging management, that is, a voltage-controlled charging method is to be executed, the actual value and setpoint value for voltage at the energy store of the control unit 28 supplied to the voltage control, which generates a current control value, which is transmitted as a current setpoint to the primary-side control electronics, so that they can regulate to this value.

Thus, therefore, of the means 20 specifiable whether a voltage-controlled or a current-controlled method is to be executed. The switching means then control according to this specification 26 for switching the control mode the switch 27 on, thus either the current control value, ie current setpoint, the control unit 28 for voltage-controlled regulation or alternatively that of the block current setpoint generation 29 generated current setpoint to the primary-side control electronics 33 transmitted. This is done via a galvanic isolation, in particular infrared or by radio waves.

There in the primary-side control electronics 33 then the setpoint is the current controller, so the charging current control 30 , supplied, which generates a control value, which the power part 31 which comprises the single-phase inverter and the subsequent gyrator circuit.

In this way, the current in the primary winding is set to the desired value.

LIST OF REFERENCE NUMBERS

1

Inverter-motor unit

2

Charging unit, secondary part

3

Charging unit, primary part

D1

diode

D2

diode

D3

diode

D4

diode

D5

diode

S1

switch

S2

switch

S3

switch

S4

switch

C2

capacitor

B

Energy storage, such as battery

C

Energy storage, for example, capacitor

S

connector

M

Electric motor in star point circuit

R

relay

G

gyrator

L1

secondary inductance

L2

primary inductance

MC1

first microcontroller

MC2

second microcontroller

A

control electronics

20

Means for battery charging management

21

Monitoring means, in particular current detection

22

switch

23

consumer

24

central higher-level control

25

Secondary control electronics

26

Switching means for switching the control mode

27

Switch for switching the control mode

28

Control unit for voltage regulation

29

Current setpoint generation

30

Charging current regulation

31

Power unit, in particular single-phase inverter

32

data exchange

33

primary-side control electronics

U1

cell voltage

U2

battery voltage

Claims (2)

A method for loading an energy storage device, in particular a battery, in particular a high-voltage battery, an electric motor driven vehicle, wherein the vehicle a first setpoint is determined, wherein the stationary control electronics impresses a current in a primary conductor to which a secondary winding of the vehicle is inductively coupled, in particular by inserting the primary conductor in a recess of the vehicle, around which the secondary winding is arranged, wherein the stationary control electronics comprises a control unit which controls the impressed in the primary conductor current to the first set point out of a arranged in the vehicle control electronics contactlessly to the control unit the stationary control electronics is transmitted, being specified by means for battery charging management, whether a current-controlled or a voltage-controlled charging is performed, wherein in current-controlled charging of the means a Stro msollwert is supplied as a first setpoint value or from the difference between the detected and desired charging current, a current setpoint is determined as the first setpoint value, and wherein in voltage controlled charging from the means a voltage setpoint is supplied to a control unit is supplied, which is also the corresponding detected voltage value on Energy storage, in particular charging voltage, is supplied and from a control value is determined, which is used as the first setpoint, wherein the first setpoint, the current setpoint and / or the voltage setpoint are limited to maintain a control limit, wherein the electric motor is operated in star point circuit, wherein the neutral point of the electric motor current is supplied from a rectifier, which is fed by a secondary winding, wherein the secondary winding is supplied from a primary winding without contact, charging current for the energy storage is formed by an inverter, via which the St atorwicklungen the electric motor can be fed with a three-phase voltage system, which is generated during power supply of the inverter from the energy storage, as long as the voltage occurring at the neutral point is below a first critical value, the charging current is supplied to the energy storage directly from the rectifier, as long as the at the Star point voltage occurring above the first critical value is at least one of the lower switch of the inverter is set in the conductive state, whereby current is dissipated from the rectifier via the associated stator winding to the lower potential of the energy storage, ie in particular the energy storage before electricity from the Rectifier is protected as long as the voltage occurring at the neutral point is above a second critical value which is greater than the first critical value and beyond which the energy storage is endangered with a certain probability. The method of claim 1, wherein a further current path is released, via which current is dissipated from the rectifier directly or via the associated stator winding to the lower potential of the energy store, ie in particular the energy storage is protected from current from the rectifier, as long as the voltage occurring at the neutral point above a third critical value which is greater than the second critical value and beyond which the energy storage is more likely to be at risk. in particular wherein the further current path is formed from a passive circuit arrangement, in particular wherein the further current path comprises a thyristor, in whose drive path a zener diode or a corresponding component which has a switching threshold-like behavior is provided, and / or that the inverter is controlled pulse width modulated or block commutated, in particular for motor or generator operation of the electric motor, and / or that the inverter is designed to be multiphase and when the energy store is being charged, the control signals for the switches of the inverter are executed synchronously, secondarily synchronously or asynchronously, and / or that the recharging of the energy storage is repeated cyclically, in particular the recharging is carried out alternately with the motor or generator operation of the electric motor.

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