Regulation of an effective electrical quantity on the basis of a provided ac power grid

Abstract

The present invention relates to a device having at least one electrical consumer, wherein the device is configured to be connected to a first AC power grid with a first line voltage and to a second AC power grid with a second line voltage, wherein the second line voltage is greater than the first line voltage, wherein the device comprises a controller, the controller is configured to provide, in a first state, the line voltage applied to an input of the controller at an output of the controller, and not to provide any voltage at the output in a second state. The controller is configured to switch between the first state and the second state according to different switching patterns and, depending on the line voltage that is connected, to select a switching pattern of such a kind that an effective electrical quantity provided at the output of the controller substantially corresponds to a target value for which it does not matter whether the device is connected to the first AC power grid or the second AC power grid, wherein the at least one electrical consumer is electrically connected to the output of the controller. Furthermore, a method is disclosed for regulating an effective electrical quantity on the basis of an AC power grid provided for a device.

Description

REGULATION OF AN EFFECTIVE ELECTRICAL QUANTITY ON THE BASIS OF A PROVIDED AC POWER GRID

[0001] The present invention relates to the field of regulation, e.g., open-loop or closed-loop control, of an effective electrical quantity on the basis of a provided AC power grid. More particularly, the present invention relates to the regulation of an effective electrical quantity, e.g., an effective voltage, for a device on the basis of a line voltage of the provided AC power grid.

[0002] Line voltages and frequencies sometimes differ greatly among different power grids. For example, the European power grid operates with a line voltage of 230 V and a line frequency of 50 Hz, whereas the power grid in the USA operates with a line voltage of 120 V and a line frequency of 60 Hz. The differing line voltage of power grids leads to greatly varying current and energy or power consumption for devices with a corresponding internal resistance.

[0003] This disadvantageously results in devices operated within a power grid typically having to be adapted to the corresponding line voltage and / or frequency in order to ensure a desired power consumption or desired currents. For example, an ohmic heating element that is intended to provide a specified maximum power must be adapted to the corresponding line voltage.

[0004] It is known to control, using open-loop control, the effective value of the voltage for closed-loop power control by open-loop leading-edge phase control or open-loop trailing-edge phase control. However, corresponding open-loop control is not compatible with all technical apparatuses, since current and voltage have a non-sinusoidal waveform and are switched under load. A non-sinusoidal voltage can lead to damage to electronic components, e.g., due to high frequency peaks. These can arise because the steep leading or trailing edges can produce a wide spectrum of harmonics. Overall, there may therefore be problems with electromagnetic compatibility, as the high frequency peaks or harmonics can leadto radio interference voltages. A non-sinusoidal current can also lead to reactive power because a phase shift occurs between the voltage and current.

[0005] In this light, it is an object of the present invention to overcome or at least mitigate the shortcomings and disadvantages of the prior art. In general, it may be an object of the present invention to regulate an effective electrical quantity, e.g., the effective voltage, for a device, preferably without causing a phase shift.

[0006] The object is achieved by the subjects of the independent claims. Advantageous developments of the invention are described by the dependent claims, the following description and the drawings.

[0007] In a first aspect, the present invention relates to a device having at least one electrical consumer, wherein the device is configured to be connected to a first AC power grid having a first line voltage and to a second AC power grid having a second line voltage, wherein the second line voltage is greater than the first line voltage. Furthermore, the device comprises a controller, the controller is configured to provide, in a first state, the line voltage applied to an input of the controller at an output of the controller and not to provide any voltage at the output in a second state. Furthermore, the controller is configured to switch between the first state and the second state according to different switching patterns and, depending on the line voltage that is connected, to select a switching pattern that an effective electrical quantity provided at the output of the controller substantially corresponds to a target value which is not dependent on whether the device is connected to the first AC power grid or the second AC power grid, wherein the at least one electrical consumer is electrically connected to the output of the controller.

[0008] In other words, the device comprises a controller to which a line voltage is applied during operation of the device, which voltage is then provided to at least one consumer, which is electrically connected to the output of the controller, by the controller in accordance with a switching pattern. Theswitching pattern is selected by the controller in such a way that an effective electrical quantity is provided at the output that substantially corresponds to an associated target value, namely regardless of which AC power grid the device is connected to. This allows the device to be advantageously operated independently of the connected AC power grid, in particular without any hardware adjustments. For example, an effective voltage can be provided that substantially corresponds to a target voltage, and therefore the at least one electrical consumer only “sees” the effective voltage and not the line voltage. Alternatively, for example, an effective power can be provided at the output of the controller such that the power consumption of the at least one consumer corresponds to the effective power. It goes without saying that in the latter case an effective voltage is of course also provided, but the target value would be a target power.

[0009] It goes without saying that the controller can include both open-loop control and closed-loop control means and that “regulate” can accordingly include “open-loop control” and / or “closed-loop control.” Regulation can therefore in particular be open-loop and / or closed-loop control.

[0010] In embodiments of the invention, it can be provided that the device is configured to be operated at most with a maximum voltage at the output of the controller. In particular, it can be provided that the voltage applied to the at least one consumer is limited. For example, in order to limit the power and / or current consumption of the at least one consumer.

[0011] In embodiments of the invention, it can be provided that the maximum voltage corresponds at most to the first line voltage. Additionally or alternatively, it may be provided that the maximum voltage is not more than 127 V, preferably not more than 120 V.

[0012] In embodiments of the invention, it can be provided that the device is configured to be operated at most with a predetermined maximum powerconsumption and / or a predetermined maximum current consumption at the output of the controller. In particular, the at least one consumer may be configured at most for a maximum power consumption and / or a maximum current consumption. The specified maximum power and / or current consumption may result from safety regulations for operating the device and / or desired device parameters. For example, it may be desirable that the device can heat up with a power of up to 180 W, resulting in a desired and thus predetermined power consumption for the device.

[0013] In embodiments of the invention, it can be provided that the device comprises an internal resistance. The internal resistance can preferably be largely (e.g., at least 90%, preferably at least 99%, e.g., approximately 100%) determined by the at least one consumer. Furthermore, it can be provided that the internal resistance of the device is configured for the first line voltage and the specified maximum power and / or current consumption of the device. In other words, the internal resistance can be selected with regard to the first line voltage and the specified maximum power and / or current consumption of the device. For example, it may be specified that a heating element of the device is intended to have a maximum power consumption of 180 W. Furthermore, it can be provided that the device is to be operated at a first line voltage of 120 V; accordingly, the internal resistance can then be 80 Q.

[0014] In embodiments of the invention, it can be provided that the device has the predetermined maximum power and / or current consumption when the maximum voltage is applied.

[0015] In embodiments of the invention, it can be provided that the device is configured to be operated at most with a maximum power at the output of the controller. Furthermore, it can be provided that the maximum power is provided when the maximum voltage is provided at the output of the controller. Additionally or alternatively, it may be provided that the maximum power corresponds to the specified maximum power consumption.

[0016] In embodiments of the invention, it can be provided that the controller is configured to switch between the first state and the second state only at the zerocrossing of the line voltage of the connected AC power grid. Furthermore, it can be provided that switching at the zero crossing comprises switching when an applied voltage is no more than 20% of an amplitude of the connected line voltage, preferably no more than 10% of the amplitude, more preferably no more than 5% of the amplitude. Additionally or alternatively, it can be provided that switching at the zero crossing comprises switching within 500 ps, preferably 250 ps, more preferably 100 ps, of the applied voltage being 0 V.

[0017] In embodiments of the invention, it can be provided that the effective electrical quantity substantially corresponds to the target value if a deviation of the effective electrical quantity is no more than ± 20%, preferably no more than ± 10%.

[0018] In embodiments of the invention, it can be provided that the device is configured to determine the line voltage of a connected AC power grid. In other words, when the device is connected to an AC power grid, the device can be configured to detect the line voltage of the connected AC power grid. In particular, the device can thus be configured to determine the line voltage of the first AC power grid when the device is connected to the first AC power grid and to determine the line voltage of the second AC power grid when the device is connected to the second AC power grid.

[0019] In embodiments of the invention, it can be provided that the device is configured to sample an applied alternating voltage and thus to determine the maximum amplitude and the resulting line voltage. It goes without saying that the line voltage corresponds to the effective value of the corresponding alternating voltage, which value can be calculated on the basis of the maximum amplitude.

[0020] In embodiments of the invention, it can be provided that the first AC power grid comprises a first line frequency and the second AC power grid comprises a second line frequency.

[0021] In embodiments of the invention, it can be provided that the device is configured to determine the line frequency of a connected AC power grid. In other words, when the device is connected to an AC power grid, the device can be configured to detect the line frequency of the connected AC power grid. In particular, the device can thus be configured to determine the line frequency of the first AC power grid when the device is connected to the first AC power grid and to determine the line frequency of the second AC power grid when the device is connected to the second AC power grid.

[0022] In embodiments of the invention, it can be provided that the device comprises a memory, a plurality of switching patterns being stored in the memory. In other words, a plurality of predetermined switching patterns can be stored in a corresponding memory in the device so that the switching patterns do not have to be recalculated each time.

[0023] In embodiments of the invention, it can be provided that the device is configured to, when the device is connected to an AC power grid, automatically select a switching pattern to be used on the basis of the line voltage of the connected AC power grid. It goes without saying that the corresponding switching pattern can be selected in particular from the plurality of predetermined switching patterns saved in the memory.

[0024] In embodiments of the invention, it can be provided that the device is configured to determine an adjustment factor on the basis of the connected line voltage. The adjustment factor can fundamentally characterize a desired adjustment of the line voltage. Furthermore, it can be provided that the switching pattern is selected on the basis of the adjustment factor.

[0025] In embodiments of the invention, it can be provided that each switching pattern is characterized by a duty cycle. It goes without saying that the duty cycle refers to the ratio of the on-duration tE to the switching pattern duration to.

[0026] In embodiments of the invention, it can be provided that the device is a laboratory device. In particular, the device can be at least one of: an incubator, a climatic cabinet, an oven, a heating cabinet, a refrigerator, and / or a freezer.

[0027] In embodiments of the invention, it can be provided that the device comprises at least one processing unit, preferably wherein the controller comprises at least one processing unit. Furthermore, it can be provided that the at least one processing unit is configured to initiate switching between the first state and the second state on the basis of the different switching patterns. Additionally or alternatively, it can be provided that the at least one processing unit is configured to automatically select a switching pattern to be used on the basis of the line voltage of a connected AC power grid. Additionally or alternatively, it can be provided that the at least one processing unit is configured to determine the adjustment factor and to select the switching pattern on the basis of the adjustment factor.

[0028] In embodiments of the invention, it can be provided that the different switching patterns are each configured such that an energy consumption of the device never deviates from a predetermined, uniform energy consumption by more than the energy of a full sine wave. It goes without saying that the energy consumption and power consumption of the device are directly related.

[0029] In embodiments of the invention, it can be provided that the predetermined, uniform energy consumption is determined from the duty cycle of the switching pattern.

[0030] In embodiments of the invention, it can be provided that the electrical consumer is an ohmic consumer.

[0031] In embodiments of the invention, it can be provided that the effective electrical quantity is an effective voltage. Additionally or alternatively, the controller can be an open-loop voltage control means.

[0032] In embodiments of the invention, it may be provided that the controller is configured to use a first switching pattern when the device is connected to the first AC power grid and to use a second switching pattern when the device is connected to the second AC power grid. Furthermore, it can be provided that the target value is a target voltage. In other words, the first switching pattern and the second switching pattern are of such a kind that the effective voltage provided by the controller substantially corresponds to a target voltage which is not dependent on whether the device is connected to the first AC power grid or the second AC power grid.

[0033] In embodiments of the invention, it can be provided that the target voltage corresponds at most to the maximum voltage. Additionally or alternatively, it can be provided that the effective voltage substantially corresponds to the target voltage if a deviation of the effective voltage is substantially no more than ± 15%, preferably no more than ± 10%.

[0034] In embodiments of the invention, it can be provided that the first switching pattern and the second switching pattern are stored in the device memory. Additionally or alternatively, the adjustment factor can be determined as (target voltage I line voltage)2.

[0035] In embodiments of the invention, it can be provided that the switching patterns are selected such that the duty cycle corresponds to the adjustment factor.

[0036] In embodiments of the invention, it can be provided that the controller is a closed-loop power control means, the effective electrical quantity is aneffective power, and the target value is a target power. In other embodiments, the controller may be a closed-loop power control means which is configured to select a switching pattern on the basis of the connected line voltage, which pattern is of such a kind that the effective power provided to the at least one consumer at the output of the closed-loop power control means substantially corresponds to a target power which is not dependent on whether the device is connected to the first AC power grid or the second AC power grid.

[0037] It goes without saying that the provision of effective power is achieved by appropriately influencing the voltage and / or current. In particular, by switching between the first state and the second state, an effective voltage and, in conjunction with the at least one electrical consumer, effective power is thus provided. In other words, the provision of the effective power means that the power consumption (averaged over time) of the at least one consumer connected to the output of the closed-loop power control means corresponds to the provided effective power.

[0038] Furthermore, it can be provided that the target power corresponds at most to the maximum power. Additionally or alternatively, it may be provided that the effective power substantially corresponds to the target power if a deviation of the effective power is substantially no more than ± 30%, preferably no more than ± 20%.

[0039] In embodiments of the invention, it can be provided that the closed- loop power control means is a closed-loop controller. The closed-loop power control means can, for example, comprise a closed-loop PID controller.

[0040] Furthermore, the closed-loop controller can be configured to determine a closed-loop control factor for the power. Furthermore, it can be provided that the closed-loop control factor lies in the range from 0 to 1 and the target power corresponds to the product of the maximum power and the closed-loop control factor. Additionally or alternatively, it can be provided that the closed-loopcontrol factor is determined on the basis of an input quantity. The input quantity can also generally be referred to as a closed-loop control deviation.

[0041] In embodiments of the invention in which the controller is a closed-loop power control means, it can be provided that the adjustment factor is determined as (maximum voltage I line voltage)2. Furthermore, it can be provided that the switching patterns are selected such that the duty cycle corresponds to the product of the adjustment factor and the closed-loop control factor.

[0042] In a further aspect, the present invention relates to a method for regulating an effective electrical quantity on the basis of an AC power grid provided for a device. The method comprises determining a line voltage Uv of the provided AC power grid, selecting a switching pattern on the basis of the line voltage Uv, and providing the effective electrical quantity on the basis of the selected switching pattern, wherein the switching pattern is selected such that the effective electrical quantity substantially corresponds to a target value.

[0043] It goes without saying that the controller can include both open-loop control and closed-loop control means and that “regulate” can accordingly include “open-loop control” and / or “closed-loop control.”

[0044] In embodiments of the invention, it can be provided that the provision of the effective electrical quantity by means of open-loop multi-cycle control using the selected switching pattern comprises.

[0045] In embodiments of the invention, it can be provided that the device comprises at least one electrical consumer and wherein the effective electrical quantity is provided by switching a voltage supply to the at least one consumer on and off on the basis of the selected switching pattern.

[0046] In embodiments of the invention, it can be provided that the device comprises at least one electrical consumer and a controller, wherein the atleast one electrical consumer is electrically connected to an output of the controller, and wherein the controller is configured to provide, in a first state, the line voltage applied to an input of the controller at the output of the controller, and not to provide any voltage at the output in a second state current; and wherein the provision of the effective electrical quantity comprises switching the controller between the first state and the second state on the basis of the selected switching pattern such that the effective electrical quantity is provided at the output of the controller.

[0047] In embodiments of the invention, it can be provided that the device is configured to be operated at most with a maximum voltage at the output of the controller.

[0048] In embodiments of the invention, it can be provided that the voltage supply is switched at the zero crossing. Additionally or alternatively, it can be provided that the controller is switched at the zero crossing.

[0049] In embodiments of the invention, it can be provided that switching at the zero crossing comprises switching when an applied voltage is no more than 20% of an amplitude of the connected line voltage, preferably no more than 10% of the amplitude, more preferably no more than 5% of the maximum voltage. Additionally or alternatively, it can be provided that switching at the zero crossing comprises switching within 500 ps, preferably 250 ps, more preferably 100 ps of the applied voltage being 0 V.

[0050] In embodiments of the invention, it can be provided that the switching pattern is selected from a plurality of predetermined switching patterns. Furthermore, it can be provided that each one of the plurality of predetermined switching patterns comprises an on-duration tE and a switching pattern duration to. The on-duration and switching pattern duration can be quantized into units of full sine waves.

[0051] Each one of the plurality of predetermined switching patterns can be characterized by a duty cycle, i.e. , a ratio of the on-duration tE to the switching pattern duration to. In other words, each one of the plurality of predetermined switching patterns is predetermined for a different duty cycle. Furthermore, it can be provided that the switching pattern is selected on the basis of the duty cycle.

[0052] In embodiments of the invention, it can be provided that selecting the switching pattern comprises determining an adjustment factor that is dependent on the line voltage.

[0053] In embodiments of the invention, it can be provided that the method comprises predetermining at least one switching pattern of the plurality of predetermined switching patterns.

[0054] In embodiments of the invention, it can be provided that predetermining at least one switching pattern comprises uniformly distributing the on-duration over the switching pattern duration. It goes without saying that the uniform distribution of the on-duration refers in particular to the most uniform distribution of the on- duration over the switching pattern duration possible, since these are quantized into full sine waves and, in addition, the switching pattern duration can be limited.

[0055] The at least one switching pattern can be predetermined in such a way that the energy consumption of the device deviates from a uniform energy consumption by no more than the energy of a full sine wave. Additionally or alternatively, the at least one switching pattern can be predetermined such that each full sine wave, during the duration of which an ideal uniform energy consumption exceeds the actual energy consumption of the device by at least the energy unit of a full sine wave, is switched on.

[0056] In embodiments of the invention, it can be provided that the determination of the line voltage, the selection of a switching pattern and the provision of the effective electrical quantity are carried out automatically.

[0057] In embodiments of the invention, it can be provided that the device is a laboratory apparatus. In particular, the device can be at least one of: an incubator, a climatic cabinet, an oven, a heating cabinet, a refrigerator, and / or a freezer.

[0058] In embodiments of the invention, it can be provided that the device is a device as described above.

[0059] In embodiments of the invention, it can be provided that the effective electrical quantity substantially corresponds to the target value if a deviation of the effective electrical quantity is substantially no more than ± 20%, preferably no more than ± 10%.

[0060] In embodiments of the invention, it can be provided that the effective electrical quantity is an effective voltage. Furthermore, it can be provided that the method is a method for the open-loop control of the effective voltage.

[0061] In embodiments of the invention, it can be provided that the target value is a target voltage. Furthermore, it can be provided that the adjustment factor is determined as the square of the ratio of the target voltage to the line voltage.

[0062] In embodiments of the invention, it can be provided that the switching pattern is selected such that the associated duty cycle is closest to the adjustment factor. Additionally or alternatively, it may be provided that the switching pattern is selected such that the associated duty cycle corresponds to the adjustment factor rounded to 2 decimal places.

[0063] In embodiments of the invention, it can be provided that the target voltage corresponds at most to the maximum voltage.

[0064] In embodiments of the invention, it can be provided that the method is a method for the closed-loop control of an effective electrical quantity.Furthermore, it can be provided that the adjustment factor is determined as the square of the ratio of the maximum voltage to the line voltage. Additionally or alternatively, the method may comprise determining a closed-loop control factor. Furthermore, it can be provided that the switching pattern is selected such that the associated duty cycle is closest to the product of the adjustment factor and the closed-loop control factor. Additionally or alternatively, it may be provided that the switching pattern is selected such that the associated duty cycle corresponds to the product of the adjustment factor and the closed-loop control factor rounded to two decimal places. The effective electrical quantity can be an effective power and the target value can be a target power.

[0065] Furthermore, it can be provided that a maximum power is provided when the maximum voltage is provided at the output of the controller. The closed-loop control factor can establish the target power in relation to the maximum power.

[0066] It can be provided that, in embodiments of the invention, the device according to the invention is configured to determine the line voltage, select a switching pattern and provide the effective electrical quantity according to the method described above.

[0067] It can be provided that, in embodiments of the invention, the device according to the invention is configured such that the processing unit is configured to determine the line voltage, select a switching pattern and provide the effective electrical quantity according to the method described above.

[0068] It can be provided that, in embodiments of the invention, the device according to the invention is configured such that the device is configured to carry out the method disclosed above.

[0069] In embodiments of the invention, it can be provided that the processing unit is configured to carry out the method according to any one of the above method embodiments.

[0070] The invention is also defined by the following numbered embodiments.

[0071] Reference is made below to device embodiments. These embodiments are designated by a D, followed by a number. Where reference is made below to device embodiments or D embodiments, these embodiments are meant.

[0072] D1 . A device having at least one electrical consumer, wherein the device is configured to be connected to a first AC power grid with a first line voltage and to a second AC power grid with a second line voltage, wherein the second line voltage is greater than the first line voltage, wherein the device comprises a controller, wherein the controller is configured to provide, in a first state, the line voltage applied to an input of the controller at an output of the controller, not to provide any voltage at the output in a second state, wherein the controller is configured to switch between the first state and the second state according to different switching patterns, wherein the controller is configured to select a switching pattern on the basis of the connected line voltage that is of such a kind that an effective electrical quantity provided at the output of the controller substantially corresponds to a target value which does not depend on whether the device is connected to the first AC power grid or the second AC power grid, wherein the at least one electrical consumer is electrically connected to the output of the controller.

[0073] D2. The device according to the preceding device embodiment, wherein the device is configured to be operated at most with a maximum voltage at the output of the controller.

[0074] D3. The device according to the preceding device embodiment, wherein the maximum voltage at most corresponds to the first line voltage.

[0075] D4. The device according to any one of the two preceding device embodiments, wherein the maximum voltage is at most 127 V, preferably at most 120 V.

[0076] D5. The device according to any one of the preceding device embodiments, wherein the device is configured to be operated at most with a predetermined maximum power consumption and / or a predetermined maximum current consumption at the output of the controller.

[0077] D6. The device according to any one of the preceding device embodiments, wherein the device comprises an internal resistance.

[0078] D7. The device according to the preceding device embodiment and having the features of D5, wherein the internal resistance of the device is configured for the first line voltage and the predetermined maximum power and / or current consumption of the device.

[0079] D8. The device according to any one of the three preceding device embodiments and having the features of D2, wherein the device has the predetermined maximum power and / or current consumption when the maximum voltage is applied.

[0080] D9. The device according to any one of the preceding device embodiments, wherein the device is configured to be operated at most with a maximum power at the output of the controller.

[0081] D10. The device according to the preceding device embodiment and having the features of D2, wherein the maximum power is provided when the maximum voltage is provided at the output of the controller.

[0082] D11. The device according to any one of the two preceding device embodiments and having the features of D5, wherein the maximum power corresponds to the predetermined maximum power consumption.

[0083] D12. The device according to any one of the preceding device embodiments, wherein the controller is configured to switch between the first state and the second state only when the line voltage of the connected AC power grid passes through zero.

[0084] D13. The device according to the preceding device embodiment, wherein switching at the zero crossing comprises switching when an applied voltage is at most 20% of an amplitude of the connected line voltage, preferably at most 10% of the amplitude, more preferably at most 5% of the amplitude.

[0085] D14. The device according to any one of the two preceding device embodiments, wherein switching at the zero crossing comprises switching within 500 ps, preferably 250 ps, more preferably 100 ps of the applied voltage being 0 V.

[0086] D15. The device according to any one of the preceding device embodiments, wherein the effective electrical quantity substantially corresponds to the target value when a deviation of the effective electrical quantity is a maximum of ± 20%, preferably a maximum of ± 10%.

[0087] D16. The device according to any one of the preceding device embodiments, wherein the device is configured to determine the line voltage of a connected AC power grid.

[0088] D17. The device according to the preceding device embodiment, wherein the device is configured to sample an applied alternating voltage and thus determine the maximum amplitude and the resulting line voltage.

[0089] D18. The device according to any one of the preceding device embodiments, wherein the first AC power grid comprises a first line frequency and the second AC power grid comprises a second line frequency.

[0090] D19. The device according to any one of the preceding device embodiments, wherein the device is configured to determine the line frequency of a connected AC power grid.

[0091] D20. The device according to any one of the preceding device embodiments, wherein the device comprises a memory, wherein a plurality of switching patterns is stored in the memory.

[0092] D21. The device according to any one of the preceding device embodiment, wherein, when the device is connected to an AC power grid, the device is configured to automatically select a switching pattern to be used on the basis of the line voltage of the connected AC power grid.

[0093] D22. The device according to any one of the preceding device embodiments, wherein the device is configured to determine an adjustment factor on the basis of the connected line voltage.

[0094] D23. The device according to the preceding device embodiment, wherein the switching pattern is selected on the basis of the adaptation factor.

[0095] D24. The device according to any one of the preceding device embodiments, wherein each switching pattern is characterized by a duty cycle.

[0096] It goes without saying that the duty cycle refers to the ratio of the on- duration tE to the switching pattern duration to.

[0097] D25. The device according to any one of the preceding device embodiments, wherein the device is a laboratory apparatus.

[0098] D26. The device according to the preceding device embodiment, wherein the device is at least one of: an incubator, a climate cabinet, an oven, a heating cabinet, a refrigerator, and / or a freezer.

[0099] D27. The device according to any one of the preceding device embodiment, wherein the device comprises at least one processing unit, preferably wherein the controller comprises at least one processing unit.

[0100] D28. The device according to the preceding device embodiment, wherein the at least one processing unit is configured to initiate switching between the first state and the second state on the basis of the different switching patterns.

[0101] D29. The device according to any one of the two preceding device embodiments, wherein the at least one processing unit is configured to automatically select a switching pattern to be used on the basis of the line voltage of a connected AC power grid.

[0102] D30. The device according to any one of the three preceding device embodiments and having the features of D22, wherein the at least one processing unit is configured to determine the adjustment factor and to select the switching pattern on the basis of the adjustment factor.

[0103] D31. The device according to any one of the preceding device embodiments, wherein the different switching patterns are each configured such that an energy consumption of the device never deviates from a predetermined, uniform energy consumption by more than the energy of a full sine wave.

[0104] D32. The device according to the preceding device embodiment and having the features of D24, wherein the predetermined, uniform energy consumption is determined from the duty cycle of the switching pattern.

[0105] D33. The device according to any one of the preceding device embodiments, wherein the electrical consumer is an ohmic consumer.

[0106] D34. The device according to any one of the preceding device embodiments, wherein the effective electrical quantity is an effective voltage.

[0107] D35. The device according to any one of the preceding device embodiments, wherein the controller is an open-loop voltage control means.

[0108] D36. The device according to any one of the two preceding device embodiments, wherein the controller is configured to use a first switching pattern when the device is connected to the first AC power grid, and wherein the controller is configured to use a second switching pattern when the device is connected to the second AC power grid; wherein the target value is a target voltage.

[0109] D37. The device according to the preceding device embodiment and having the features of D2, wherein the target voltage at most corresponds to the maximum voltage.

[0110] D38. The device according to any one of the two preceding device embodiments, wherein the effective voltage substantially corresponds to the target voltage when a deviation of the effective voltage is substantially at most ± 15%, preferably at most ± 10%.

[0111] D39. The device according to any one of the three preceding device embodiments and having the features of D20, wherein the first switching pattern and the second switching pattern are stored in the device memory.

[0112] D40. The device according to any one of the four preceding device embodiments and having the features of D22, wherein the adjustment factor is determined as (target voltage I line voltage)2.

[0113] D41. The device according to any one of the five preceding device embodiments and having the features of D22 and D24, wherein the switching patterns are selected such that the duty cycle corresponds to the adjustment factor.

[0114] D42. The device according to device embodiments D1 -D33, wherein the controller is a closed-loop power control means, the effective electrical quantity is an effective power, and the target value is a target power.

[0115] D43. The device according to the preceding device embodiment and having the features of D9, wherein the target power corresponds at most to the maximum power.

[0116] D44. The device according to any one of the two preceding device embodiments, wherein the effective power substantially corresponds to the target power when a deviation of the effective power is substantially at most ± 30%, preferably at most ± 20%.

[0117] D45. The device according to any one of the three preceding device embodiments, wherein the closed-loop power control means is a closed-loop controller.

[0118] D46. The device according to the preceding device embodiment, wherein the closed-loop controller is configured to determine a closed-loop control factor for the power.

[0119] D47. The device according to the preceding device embodiment and having the features of D9, wherein the closed-loop control factor is in the range from 0 to 1 and the target power corresponds to the product of the maximum power and the closed-loop control factor.

[0120] D48. The device according to the two preceding device embodiments, wherein the closed-loop control factor is determined on the basis of an input quantity.

[0121] D49. The device according to any one of the seven preceding device embodiments and having the features of D22 and D2, wherein the adjustment factor is determined as (maximum voltage / line voltage)2.

[0122] D50. The device according to the preceding device embodiment and having the features of D46 and D24, wherein the switching patterns are selected such that the duty cycle corresponds to the product of the adjustment factor and the closed-loop control factor.

[0123] Reference is made below to method embodiments. These embodiments are indicated with an M followed by a number. Whenever the term “method embodiments” or “M embodiments” is used below, these embodiments are meant.

[0124] M1. A method for regulating an effective electrical quantity on the basis of an AC power grid provided for a device, the method comprising: determining a line voltage Uv of the provided AC power grid; selecting a switching pattern on the basis of the line voltage Uv, andproviding the effective electrical quantity on the basis of the selected switching pattern, wherein the switching pattern is selected such that the effective electrical quantity substantially corresponds to a target value.

[0125] M2. The method according to the above method embodiment, wherein the provision of the effective electrical quantity comprises by means of open-loop multi-cycle control on the basis of the selected switching pattern.

[0126] M3. The method according to any one of the preceding method embodiments, wherein the device comprises at least one electrical consumer and wherein the effective electrical quantity is provided by switching the voltage supply to the at least one consumer on and off on the basis of the selected switching pattern.

[0127] M4. The method according to any one of the preceding method embodiments, wherein the device comprises at least one electrical consumer and a controller, wherein the at least one electrical consumer is electrically connected to an output of the controller, and wherein the controller is configured to provide, in a first state, the line voltage applied to an input of the controller at the output of the controller, andNot to provide any voltage at the output in a second state; and wherein the provision of the effective electrical quantity comprises switching the controller between the first state and the second state on the basis of the selected switching pattern such that the effective electrical quantity is provided at the output of the controller.

[0128] M5. The method according to the preceding method embodiments, wherein the device is configured to be operated at most with a maximum voltage at the output of the controller.

[0129] M6. The method according to any one of the preceding method embodiments and having the features of M3, wherein the voltage supply is switched at the zero crossing.

[0130] M7. The method according to any one of the preceding method embodiments and having the features of M4, wherein the controller is switched at the zero crossing.

[0131] M8. The method according to any one of the two preceding method embodiments, wherein switching at the zero crossing comprises switching when an applied voltage is no more than 20% of an amplitude of the connected line voltage, preferably no more than 10% of the amplitude, more preferably no more than 5% of the maximum voltage.

[0132] M9. The method according to any one of the three preceding method embodiments, wherein switching at the zero crossing comprises switching within 500 ps, preferably 250 ps, more preferably 100 ps of the applied voltage being 0V.

[0133] M10. The method according to any one of the preceding method embodiments, wherein the switching pattern is selected from a plurality of predetermined switching patterns.

[0134] M11. The method according to the preceding method embodiments, wherein each one of the plurality of predetermined switching patterns comprises an on-duration tE and a switching pattern duration to.

[0135] M12. The method according to the preceding method embodiment, wherein the on-duration and the switching pattern duration are quantized into units of full sine waves.

[0136] M13. The method according to any one of the three preceding method embodiments, wherein each one of the plurality of predetermined switching patterns is characterized by a duty cycle, i.e. , a ratio of the on-duration tE to the switching pattern duration to.

[0137] In other words, each one of the plurality of predetermined switching patterns is predetermined for a different duty cycle.

[0138] M14. The method according to the above method embodiment, wherein the switching pattern is selected on the basis of the duty cycle.

[0139] M15. The method according to any one of the preceding method embodiments, wherein selecting the switching pattern comprises determining an adjustment factor which is dependent on the line voltage.

[0140] M16. The method according to any one of the preceding method embodiments and having the features of M10, wherein the method comprises predetermining at least one switching pattern of the plurality of predetermined switching patterns.

[0141] M17. The method according to the preceding method embodiment and having the features of M11 , wherein predetermining at least one switching pattern comprises uniformly distributing the on-duration over the switching pattern duration.

[0142] M18. The method according to any one of the two preceding method embodiments, wherein the at least one switching pattern is predeterminedsuch that the energy consumption of the device deviates from a uniform energy consumption by a maximum of the energy of a full sine wave.

[0143] M19. The method according to any one of the two preceding method embodiments, wherein the at least one switching pattern is predetermined in such a way that each full sine wave, during the duration of which an ideal uniform energy consumption exceeds the actual energy consumption of the device by at least the energy unit of a full sine wave, is switched on.

[0144] M20. The method according to any one of the preceding method embodiments, wherein the determination of the line voltage, the selection of a switching pattern and the provision of the effective electrical quantity are carried out automatically.

[0145] M21 . The method according to any one of the preceding method embodiments, wherein the device is a laboratory apparatus.

[0146] M22. The method according to any one of the preceding method embodiments, wherein the device is at least one of: an incubator, a climatic cabinet, an oven, a heating cabinet, a refrigerator, and / or a freezer.

[0147] M23. The method according to any one of the preceding method embodiment, wherein the device is a device according to any one of the preceding device embodiments.

[0148] M24. The method according to any one of the preceding method embodiment, wherein the effective electrical quantity substantially corresponds to the target value when a deviation of the effective electrical quantity is substantially no more than ± 20%, preferably no more than ± 10%.

[0149] M25. The method according to any one of the preceding method embodiments, wherein the effective electrical quantity is an effective voltage.

[0150] M26. The method according to the preceding method embodiment, wherein the method is a method for controlling the effective voltage using open-loop control.

[0151] M27. The method according to any one of the preceding method embodiments, wherein the target value is a target voltage.

[0152] M28. The method according to the preceding method embodiment and having the features of M15, wherein the adjustment factor is determined as the square of the ratio of the target voltage to the line voltage.

[0153] M29. The method according to any one of the two preceding method embodiments and to the features of M14 and M15, wherein the switching pattern is selected such that the associated duty cycle is closest to the adjustment factor.

[0154] M30. The method according to any one of the three preceding method embodiments and to the features of M14 and M15, wherein the switching pattern is selected such that the associated duty cycle corresponds to the adjustment factor rounded to 2 decimal places.

[0155] M31. The method according to any one of the four preceding method embodiments and to the features of M5, wherein the target voltage at most corresponds to the maximum voltage.

[0156] M32. The method according to any one of method embodiments M1 to M25, wherein the method is a method for controlling an effective electrical quantity using closed-loop control.

[0157] M33. The method according to the preceding method embodiment and having the features of M5 and M15, wherein the adjustment factor is determined as the square of the ratio of the maximum voltage to the line voltage.

[0158] M34. The method according to any one of the two preceding method embodiments, wherein the method comprises determining a closed-loop control factor.

[0159] M35. The method according to the preceding method embodiment and having the features of M14 and M15, wherein the switching pattern is selected such that the associated duty cycle is closest to the product of the adjustment factor and the closed-loop control factor.

[0160] M36. The method according to any one of the two preceding method embodiments and having the features of M14 and M15, wherein the switching pattern is selected such that the associated duty cycle corresponds to the product of the adjustment factor and the closed-loop control factor rounded to two decimal places.

[0161] M37. The method according to any one of the three preceding method embodiments, wherein the effective electrical quantity is an effective power and the target value is a target power.

[0162] M38. The method according to the preceding method embodiment and having the features of M5, wherein a maximum power is provided when the maximum voltage is provided at the output of the controller.

[0163] M39. The method according to the preceding method embodiment and having the features of M34, wherein the closed-loop control factor establishes the target power in relation to the maximum power.

[0164] A51. The device according to any one of the preceding device embodiments, wherein the device is configured to determine the line voltage, to select a switching pattern and to provide the effective electrical quantity in accordance with any one of the preceding method embodiments.

[0165] A52. The device according to any one of the preceding device embodiments and having the features of D27, wherein the processing unit is configured to determine the line voltage, select a switching pattern and provide the effective electrical quantity in accordance with any one of the preceding method embodiments.

[0166] A53. The device according to any one of the preceding device embodiments, wherein the device is configured to carry out the method according to any one of the preceding method embodiments.

[0167] A54. The device according to any one of the preceding device embodiments and having the features of D27, wherein the processing unit is configured to carry out the method according to any one of the preceding method embodiments.

[0168] Embodiments of the present invention are now described with reference to the accompanying drawings. These embodiments are intended to be exemplary and not limitative of the present invention.

[0169] Fig. 1a and billustrate a device comprising a controller;Fig. 2a illustrates the effective value of an alternating voltage;Fig. 2b illustrates the reduction of the effective voltage by means of an openloop multi-cycle control;Fig. 3a and b illustrate an exemplary open-loop multi-cycle control;Fig. 4 illustrates a uniform distribution of the on-duration;Fig. 5 illustrates a method according to the invention;Fig. 6 illustrates a method for determining a switching pattern with the most uniformly distributed on-duration possible; andFig. 7 illustrates, by way of example, switching patterns for duty cycles of 0- 72% with an on-duration that is as uniformly distributed as possible.

[0170] It is noted that not all drawings bear all reference signs. Instead, in some of the drawings, some of the reference signs have been omitted for brevity and ease of presentation. Embodiments of the present invention are now described with reference to the accompanying drawings.

[0171] The present invention is directed to a device 1 having at least one electrical consumer 14 and a controller 12, wherein the controller 12 is configured in principle to determine an effective electrical quantity which is substantially independent of a supplied line voltage Uv.

[0172] A corresponding device 1 having a controller 12 and two electrical consumers 14 is shown in Fig. 1a and 1 b. The device 1 is configured to be connected to an AC power grid with an associated supply voltage Uv, the supply voltage also being referred to as line voltage. The voltage or current supply to the device is therefore provided by means of an AC power grid connected thereto. In particular, the device 1 is configured to be connected to a first AC power grid with a first line voltage and to a second AC power grid with a second line voltage, wherein the second line voltage is greater than the first line voltage. It goes without saying that the device can also be configured to be connected to other AC power grids. In any case, however, the device is configured to be connected to at least two AC power grids with different line voltages. It also goes without saying that “supply voltage” and “line voltage” each refer to the effective value of an underlying alternating voltage. For example, the European AC power grid comprises a line voltage of 230 V, i.e., the effective value of the alternating voltage supplied to households is essentially 230 V.

[0173] The controller 12 of the device 1 is configured to provide an effective electrical quantity, e.g., an effective voltage Ueff, on the basis of an applied line voltage Uv.

[0174] The controller 12 is configured to provide, in a first state, the line voltage applied to an input of the controller at an output of the controller (Fig.1 a) and not to provide any voltage at the output in a second state (Fig. 1 b). In other words, the controller 12 is configured to supply current to the at least one electrical consumer 14 (Fig. 1 a) and, in a second state, to block current to the at least one electrical consumer 14 (Fig. 1 b). The controller 12 can therefore targetedly interrupt the voltage supply to the at least one electrical consumer 14, i.e. , switch it off and back on again, and thus allow or interrupt the resulting current. It goes without saying that this also makes it possible to provide electrical power at the output of the controller which results from the voltage provided and the resulting current and thus the corresponding power consumption of the at least one electrical consumer 14. In particular, the controller 12 is electrically conductively connected to the at least one electrical consumer 14. The at least one electrical consumer is preferably an ohmic consumer.

[0175] Furthermore, the controller 12 is configured to switch between the first state and the second state according to different switching patterns, wherein the switching pattern used depends on the line voltage and a desired target value for the provided electrical quantity. In particular, the controller 12 is configured to select a switching pattern on the basis of the connected line voltage of such a kind that an effective electrical quantity provided at the output of the controller 12 substantially corresponds to the target value for which it does not matter whether the device is connected to the first AC power grid or the second AC power grid. In other words, the effective electrical quantity is substantially the same when the device is connected to the first AC power grid or the second AC power grid. The wording “substantially” includes deviations from the target value of ± 15%, preferably ± 10%. These deviations may be caused, for example, by the fact that the smallest possible adjustment by means of the controller may depend on the connected AC power grid and / or the at least one electrical consumer of the device. These can, for example, limit the duration of the switching pattern. Corresponding deviations can also be caused by the line voltage, which can be subject to voltage variations. For example, the line voltage in the European power grid can already vary by up to ± 10%. It goes withoutsaying that the corresponding switching pattern is repeated cyclically, i.e., always starting from the beginning. The corresponding switching patterns can be redetermined in a regular or irregular fashion, for example to adapt the target value to a requirement of the device.

[0176] The controller 12 is advantageously configured to switch between the first and the second state only when the line voltage of the AC power grid connected to the device passes through zero. Switching at the zero crossing advantageously avoids steep leading or trailing edges and / or reactive power. In particular, the controller 12 can thus be configured to switch between the first and the second state only when the applied voltage is approximately 0 V. The wording “approximately” here includes deviations with regard to the applied voltage of at most 20% of a maximum voltage of the connected AC power grid, preferably at most 10% of the maximum voltage, more preferably at most 5% of the maximum voltage. Switching at the zero crossing can occur within 500 ps, preferably 250 ps, more preferably 100 ps of the applied voltage being 0 V.

[0177] It goes without saying that the controller can include both open-loop control and closed-loop control means and that “regulate” can accordingly include “open-loop control” and / or “closed-loop control.”

[0178] The device can be configured to be operated at most with the maximum voltage at the output of the controller 12. In other words, the maximum voltage corresponds to a maximum voltage at which the device may be operated, independently of the controller. The maximum voltage can therefore correspond to the voltage for which the electrical components connected downstream of the controller are configured, in particular the at least one electrical consumer 14. However, the maximum voltage can also be deliberately set so as to be lower in order to limit power consumption, for example. The maximum voltage can advantageously correspond to the first line voltage at most. The maximum voltage may be no more than 127 V, preferably no more than 120 V, and in some cases no more than 110 V.

[0179] In general, the device can be configured to be operated at most with a predetermined maximum power consumption and / or a predetermined maximum current consumption at the output of the controller. More particularly, the at least one consumer may be configured at most for a maximum power consumption and / or a maximum current consumption. The specified maximum power and / or current consumption may result from safety regulations for operating the device and / or desired device parameters. For example, it may be desirable that the device can heat up with a power of up to 180 W, resulting in a desired and thus predetermined power consumption for the device.

[0180] Furthermore, the device can have an internal resistance which is preferably largely (e.g., 90%, preferably at least 99%, e.g., approximately 100%) determined by the at least one consumer. The internal resistance preferably refers to the resistance of the device at the output of the controller. The internal resistance and preferably the at least one consumer can be configured for the first line voltage and the predetermined maximum power and / or current consumption of the device. In other words, the internal resistance and preferably the at least one consumer can be selected with regard to the first line voltage and the predetermined maximum power and / or current consumption of the device. For example, it may be specified that a heating element of the device is intended to have a maximum power consumption of 180 W. Furthermore, it can be provided that the device is to be operated at a first line voltage of 120 V; accordingly, the internal resistance can then be 80 Q. In particular, it can be provided that the device has the predetermined maximum power and / or current consumption when the maximum voltage is applied.

[0181] In other words, the device can be configured to be operated with a maximum power at the output of the controller. It goes without saying that the maximum power at the output of the controller results from the power consumption of the at least one electrical consumer and in particular from the internal resistance. The maximum power preferably corresponds to thespecified maximum power consumption and is provided when the maximum voltage is provided at the output of the controller.

[0182] The switching patterns define when the controller 12 switches between the first state and the second state, i.e. , when voltage is provided by the controller 12 and when it is not, and thus also when a current is supplied to the at least one electrical consumer 14, and when it is not. In other words, the controller 12 switches the voltage supply of the device, more precisely of the at least one electrical consumer 14, on and off. In simple terms, the switching pattern determines when the open-loop voltage controller switches the line voltage on and off. The “when” can be defined here in time intervals between switching or, preferably, in the number of (half) periods between switching, the latter having the advantage that it is not dependent on the line frequency. The controller can therefore in particular comprise or be an openloop voltage controller.

[0183] The controller 12 can therefore be configured in principle to switch one or more whole or half periods of the line voltage on or off in order to provide an effective voltage, an effective current and / or an effective power, with the maximum in each case being limited by the line voltage. The controller 12 can in particular be configured to provide the corresponding effective electrical quantity by means of open-loop multi-cycle control on the basis of the corresponding switching pattern. The open-loop multi-cycle control can also be referred to as open-loop wave packet control.

[0184] The device can be configured to determine an adjustment factor on the basis of the connected line voltage. This adjustment factor can preferably be in the range of 0-1 and describe a percentage of the line voltage, e.g., a proportion of the line voltage that is to be provided at the output of the controller. More generally, the adjustment factor can refer to the percentage of a line voltage required to provide a target voltage, e.g., the maximum voltage, at the output of the controller. The device can in particular be configured to select a switchingpattern on the basis of the adjustment factor. For this purpose, the device can, for example, comprise a memory in which a plurality of switching patterns is stored. The switching patterns can be characterized by a duty cycle, which can refer to the ratio of an on-duration tE (i.e., the duration during which the controller assumes the first state) and a switching pattern duration to (i.e., the total duration of the switching pattern).

[0185] In principle, an effective voltage is given by the effective value for the alternating voltage, which corresponds to the root mean square of the voltage over time. With reference to Fig. 2a), the effective value of a continuous, sinusoidal alternating voltage-^ corresponds to the maximum voltage; in the European power grid, the line voltage and thus the effective value of the voltage or the effective voltage is Ueff = Uv = 230 V. The effective value of the alternating voltage in principle indicates how large a direct voltage would be to convert the same electrical energy as the alternating voltage at an ohmic consumer within a representative period of time.

[0186] With reference to Fig. 2b), by means of targeted switching between the first state and the second state at zero crossings of the voltage or during openloop multi-cycle control, one or more half or preferably whole sine waves can be switched off and thus be cut out. This reduces the effective voltage Ueff. The effective voltage can be determined from the line voltage Uv and on the basis of the ratio of the on-duration tE to the switching pattern duration to, where

[0187] In relation to a switching pattern, the on-duration tE here refers to the period of time for which the voltage is applied to the at least one electrical consumer, i.e., the controller is in the first state. The switching pattern duration to refers to the total length of the switching pattern and is also referred to as the oscillation packet duration within the context of open-loop multi-cycle control. Since thecorresponding switching pattern is repeated cyclically (possibly until the switching pattern is changed), the switching pattern duration accordingly refers to the length of a (switching pattern) period. The t to ratio thus analogously indicates the on- portion, i.e. , the portion of the total duration of the switching pattern for which the controller is in the first state, in which current is supplied to the electrical consumer or a corresponding voltage is supplied to the electrical consumer. Therefore, the ratio can also be referred to as the duty cycle.

[0188] It goes without saying that the on-duration in principle at most corresponds to the switching pattern duration, i.e., tE to. In particular, the on-duration can also correspond to the switching pattern duration. In this case, the effective voltage provided by the controller 12 would correspond to the line voltage. In other words, the controller 12 would permanently remain in the first state and would not switch to the second state. A switching pattern can therefore also mean that switching does not occur between the first state and the second state, i.e., that the controller always remains in the first state during the switching method.

[0189] At a line voltage of Uv = 230 V and a ratio of tE / to of 1 / 2, for example, an effective voltage Ueff of 163 V is thus obtained. This means that if half of all the sine waves are switched off in a periodic switching pattern each time, the line voltage can be reduced by a factor of about 0.71 . Accordingly, on the basis of the line voltage and optionally the line frequency, a switching pattern can be selected, for example, in which the ratio of the on-duration to the switching pattern duration (i.e., the duty cycle) at least substantially corresponds to the square of the ratio of the line voltage to a target voltage or the maximum voltage. More generally, a switching pattern can be chosen to include a desired duty cycle. With unlimited switching pattern duration, a desired effective electrical quantity, e.g., a target voltage, can thus be provided with virtually any desired degree of accuracy. However, if a switching pattern only comprises a switch-on and switch-off phase, the switching pattern duration can often be limited and depend in particular on the electrical consumers. Highly integratingconsumers, such as ohmic heating elements, can advantageously allow longer switch-on and switch-off phases. For less integrating consumers, the fluctuations can be reduced by using a switching pattern that comprises a plurality of switch-on and switch-off phases, if necessary. In this case too, the switching pattern duration refers to the total length of the cyclically repeated switching pattern. In principle, restrictions may also be imposed by a grid operator on the switching pattern duration and optionally the on-duration.

[0190] It goes without saying that the on-duration tE and switching pattern duration to can be specified in actual time units, e.g., ps, or as the number of zero crossings or half or full sine waves. The latter is preferable because it is not dependent on the line frequency.

[0191] Fig. 3 shows an example of an open-loop multi-cycle control for an alternating voltage with a line frequency of 50 Hz. Fig. 3a shows an implementation for a manipulated variable of 25% on-duration. In other words, a duty cycle of 0.25 or 25% is used. Here, the on-duration tE is 250 ms with a switching pattern duration to of 1 s. In other words, 25 half sine waves are allowed through first and then the following 75 half sine waves are switched off. The switching pattern is then repeated. This switching pattern can thus halve the effective voltage. Since switching of full sine waves is preferred and may be necessary in some applications, a corresponding reduction can also be achieved by a switching pattern duration to of 2 s and an on-duration tE of 500 ms.

[0192] Fig. 3b shows an implementation for a manipulated variable of 75% on-duration, or a duty cycle of 0.75 or 75%. Here, the on-duration tE is 750 ms with a switching pattern duration to of 1 s. In other words, 75 half sine waves are allowed through first and then the following 25 half sine waves are switched off. The pattern is then repeated. This switching pattern allows the effective voltage to thus be reduced to approximately 87%. Here too, by doubling the switching pattern duration and an on-duration tE of 1.5 s, it is of course possible to accordingly switch to full sine waves.

[0193] It goes without saying that, as a result of the electrical connection to the at least one electrical consumer, corresponding switching patterns also provide an effective current and an effective power. There is a connection between the effective voltage, the effective current and the effective power. Assuming that at a line voltage Uv, a current lv and a power Pv are provided and the switching pattern comprises a duty cycle t / to, the effective current is given by leff= Iv(tE / to) and the effective power byPeff= Pv(tE / to). The effective quantity provided by the controller may depend in particular on the quantity for which the target value is specified. For example, a desired power can be specified so that effective power is provided by the controller. It goes without saying that this inevitably also provides an effective voltage and an effective current.

[0194] Preferably, the device can be configured to determine the line voltage of an applied AC power grid. That is, the device may be configured to determine the corresponding line voltage of the AC power grid when the device is connected to an AC power grid. For example, the line voltage can be measured. This may include sampling the alternating voltage applied, which allows conclusions to be drawn about the maximum voltage and thus also the line voltage (i.e., the effective value). When determining the line voltage, for example, it can be taken into account that the line voltage is typically 100 V, 110 V, 115 V, 120 V, 127 V, 220 V, 230 V, or 240 V, with 110 V and 230 V being particularly widely used. That is, determining the line voltage may be sufficient if the device can distinguish between these voltages.

[0195] In addition to the line voltage, AC power grids also have a line frequency. The line frequency can be relevant for the switching pattern, since the line frequency specifies the time intervals between the zero crossings and thus also the possible switching times. In particular, the first AC power grid can have a first line frequency and the second AC power grid can have a second line frequency. The device can be configured to determine the line frequency. That is, the devicemay be configured to determine the corresponding line frequency of the AC power grid when the device is connected to an AC power grid. The line frequency can be determined, for example, using a frequency meter, preferably with a digital frequency counter. When determining the line frequency, it is possible to consider that only two different line frequencies are used worldwide — 50 Hz and 60 Hz — and therefore it may be sufficient if the device can distinguish between these two frequencies in order to determine the line frequency.

[0196] Preferably, however, a measurement of the line frequency is neither required nor provided. Rather, the switching patterns can preferably be based solely on the number of zero crossings and thus the number of (half) sine waves so that detection of the line frequency is not necessary. In particular, the same switching pattern can be used for AC power grids with the same line voltage but different line frequency, for example. This would then lead to different absolute on-durations tE and switching pattern durations to (i.e., measured in seconds), since a full wave corresponds to a different duration depending on the line frequency, but the ratio of the on-duration tE to the switching pattern duration to (and thus the duty cycle) remains unaffected thereby, so that the same effective voltage is provided in both cases.

[0197] The device can be configured to automatically select a suitable switching pattern on the basis of the line voltage and optionally also the line frequency in order to provide a desired target value for an effective electrical quantity. In addition, the instantaneous requirement of the device can also be taken into account. In particular, the device may comprise a memory in which a plurality of switching patterns is stored. The device can be configured to automatically select the corresponding switching pattern from the stored switching patterns on the basis of the target value and the determined line voltage and / or line frequency. For example, if the device is only used in Europe and the USA, determining the line voltage is sufficient, since the frequency results directly from the determined line voltage. Thus, the correspondingswitching pattern can be selected on the basis of the line voltage alone. The same applies if the switching patterns are defined on the basis of the number of zero crossings between the switching operations. In this case, each switching pattern can be characterized by the associated duty cycle and the selection of the switching pattern can be based on the duty cycle, which in some embodiments corresponds to the adjustment factor determined from the line voltage.

[0198] The device may comprise at least one processing unit, for example the controller may comprise at least one processing unit. The at least one processing unit can be configured to determine the line voltage and / or line frequency, for example on the basis of data captured by means of corresponding sensors. The at least one processing unit may be configured to control switching between the first state and the second state of the controller using open-loop control according to a switching pattern, i.e., to accordingly initiate switching according to the switching pattern. The at least one processing unit can also be configured to automatically select a switching pattern to be used from the stored switching patterns on the basis of the line voltage of the connected AC power grid. For example, the device may comprise a micro-controller configured to sample the incoming voltage and thus detect and possibly even anticipate zero crossings. Switching between the first state and the second state at the zero crossing can then be realized, for example, by means of triacs (e.g., optotriacs) or thyristors.

[0199] The device can be a laboratory apparatus, e.g., an incubator, a climatic cabinet, an oven, a heating cabinet, or the like. For example, the device may be an incubator with an ohmic heater, i.e., at least one ohmic heating element. Depending on the application of the incubator, the heater in the form of an electrical consumer can, for example, have a calculated maximum power requirement of 180 W. If the line voltage is supplied to the electrical consumers of the device without being changed, an electrical resistance of 80 O is therefore required for the ohmic heater, for example at a line voltage of 120 V, since R = U2 / P = (120 V)2 / 180 W = 80 Q. However, with a line voltage of 230 V, withoutadjusting the voltage, an electrical resistance of 294 0 would be required (R = U2 / P = (230 V)2 / 180 W = 294 0). Different heaters would therefore be necessary to adjust the power at different input voltages. Accordingly, the incubator would usually have to be equipped with a suitable heater depending on the application. This disadvantageously leads to more complex production of the corresponding devices, which requires various components.

[0200] With reference to this example, the present invention makes it possible to advantageously equip all incubators with the same heater and, more generally, with the same hardware. This means that the incubator, which is to be operated with 230 V, will also be equipped with a heater that comprises an electrical resistance of 80 Q. If no further adjustments were made, the power consumption of the incubator operated at 230 V would be significantly higher than 180 W. This is already clear from the above calculation of the required resistances, but is also clear when considering the following theoretical currents. At 120 V, a corresponding resistance leads to a current of I = U / R = 120 V / 80 Q = 1.5 A, whereas at 230 V, a corresponding resistance would lead to a current of I = U / R = 230 V / 80 Q = 2.9 A. The current would therefore be almost twice as high. However, if the controller is used with a switching pattern that only allows 14 out of 50 full sine waves through, the current is reduced from 2.9 A to 1.53 A, which substantially corresponds to the current consumption at 120 V. An even better result could be achieved, for example, with a switching pattern that selects 27 full sine waves from 100 full sine waves. In order to reduce voltage and current fluctuations, a corresponding switching pattern could, for example, be configured so that the controller is initially in the first state for 14 full sine waves, i.e. , these full sine waves are allowed through, then in the second state for 36 full sine waves, i.e. , these full sine waves are blocked, then again in the first state for 13 full sine waves and finally in the second state for 37 full sine waves. After that, the switching pattern would be repeated, as already described. Accordingly, an even better result could be achieved by selecting 268 full sine waves from 1000 full sine waves. In principle, theswitching pattern duration determines the maximum resolution with regard to adjusting the line voltage.

[0201] Since the present invention provides a line-dependent controller that provides an effective electrical quantity that substantially corresponds to a target value, the power consumption or current consumption and thus the energy consumption of a device can be substantially independent of the connected AC power grid. This allows the device to operate safely in the corresponding AC power grids without having to make any changes to the device (in particular changes to the device's hardware). The controller is configured for at least 2 different AC power grids, but can also be configured for more, possibly all, AC power grids known.

[0202] As the above example illustrates, the present invention also makes it possible to adapt the maximum current consumption of a device, e.g., with regard to country-specific requirements. Adaptation to country-specific requirements may require user input, if necessary, as corresponding countries cannot be reliably identified based on the line voltage. For example, the plugs used in Great Britain can be protected and operated up to a maximum of 13 amps, and so the power consumption can be adjusted accordingly. On the one hand, this can be done on a country-specific basis or, alternatively, an adaptation can be selected that meets all country-specific requirements for a corresponding line voltage.

[0203] If, for example, the known open-loop multi-cycle control is used in conjunction with an ohmic heating element, as shown in Fig. 3, this can (at least theoretically) disadvantageously lead to overloads, in particular the heater can overheat due to a long on- durations. Therefore, the on-duration tE can be distributed over the switching pattern duration to (preferably uniformly). In other words, the switching patterns can be accordingly determined so that the on-duration is distributed as uniformly as possible over the switching pattern duration. For example, the controller of the device can be configured to (pre)determine the switching patterns accordingly.

[0204] Fig. 4 shows a corresponding switching pattern for a manipulated variable of 25% on-duration (cf. Fig. 3a). The switched-on full sine waves are distributed over the switching pattern duration of, for example, 2 s (at 50 Hz). The switching patterns can be accordingly pre-calculated and saved for different line voltages and optionally line frequencies. It goes without saying that the energy cannot be released entirely uniformly, but only ever in multiples of a half-wave, preferably a full wave. A method for determining corresponding switching patterns will be explained below in connection with Fig. 6.

[0205] In some embodiments, the effective electrical quantity provided by the controller 12 at the output may be an effective voltage Ueff. In particular, the controller 12 can be an open-loop voltage controller. The open-loop voltage controller may be configured to use a first switching pattern when the device is connected to the first AC power grid and to use a second switching pattern when the device is connected to a second AC power grid. The target value can be a target voltage. The target voltage can preferably at most correspond to the first line voltage.

[0206] The switching patterns, i.e., in particular the first switching pattern and the second switching pattern, can be of such a kind that the effective voltage provided by the open-loop voltage controller substantially corresponds to the target voltage, which is not dependent on whether the device is connected to the first AC power grid or the second AC power grid. In other words, the effective voltage stays substantially the same when the device is connected to the first AC power grid or the second AC power grid. The wording “substantially” includes deviations from the target voltage of ± 15%, preferably ± 10%. These deviations may be caused, for example, by the fact that the smallest possible adjustment of the voltage by means of the open-loop voltage controller may depend on the connected AC power grid and / or the at least one electrical consumer of the device. These can, for example, limit the duration of the switching pattern. Corresponding deviations can also be caused by the linevoltage, which can be subject to voltage variations. For example, the line voltage in the European power grid can already vary by up to ± 10%.

[0207] The target voltage is therefore not dependent on the AC power grid to which the device is connected and can be limited by the maximum voltage. The maximum voltage is typically adapted to an internal resistance and / or a maximum power consumption or current consumption of the device. The internal resistance can be selected, for example, on the basis of a minimum line voltage at which the device is to be operated, e.g., 110 V or 120 V. The maximum voltage corresponds at most to the minimum line voltage. The provision of a corresponding open-loop voltage controller according to the invention advantageously allows the use of the device in AC power grids with a voltage that exceeds the maximum voltage.

[0208] The first switching pattern and the second switching pattern can therefore be predetermined. This means that the switching patterns can be predetermined on the basis of a target voltage for the corresponding line voltage and, if applicable, line frequency. The switching patterns are predetermined so that, for a given line voltage (and optionally line frequency), an effective voltage is provided that substantially corresponds to the desired target voltage. The desired target voltage is limited by the maximum voltage that is adapted to an internal resistance of the device and to a power and / or current requirement of the device, wherein the internal resistance is selected such that the maximum voltage corresponds at most to the minimum line voltage.

[0209] Accordingly, with open-loop voltage control, the duty cycle of the switching pattern used may preferably correspond to the adjustment factor, wherein the adjustment factor corresponds to the square of the ratio of the target voltage to the line voltage.

[0210] In other words, the adjustment factor can be determined on the basis of the line voltage and a target voltage, which corresponds, for example, to the maximum voltage or a fraction of the maximum voltage, which adjustmentfactor corresponds, in the case of open-loop voltage control (i.e., without active feedback), to the duty cycle of the desired switching pattern, so that only a corresponding switching pattern with a duty cycle corresponding to the adjustment factor is selected. For open-loop voltage control, the target value is preferably constant such that the corresponding switching pattern only needs to be changed when the line voltage changes. For this purpose, the line voltage can be checked at regular intervals if necessary, i.e., it can be re-determined by the device. Alternatively, the line voltage can only be determined after restarting the device, for example, since the line voltage typically does not change during operation.

[0211] However, for some applications it may be desirable to control, for example, the power consumption of the at least one consumer using closed- loop control. For example, the at least one consumer may be a heating element and the power consumption of the heating element can be controlled using closed-loop control on the basis of a temperature in order to provide, for example, a desired target temperature.

[0212] Accordingly, in some embodiments, the controller may be a closed- loop power control means. The effective electrical quantity is then the effective power and the target value is a target power. As previously explained, the effective power is provided by switching between the first state and the second state according to a corresponding switching pattern. In principle, closed-loop power control can therefore include open-loop voltage control, which, however, no longer depends solely on the line voltage but also on a closed-loop control factor. Using the line voltage, a corresponding adjustment factor can also be determined, which then, in combination with the closed-loop control factor, determines the duty cycle for the switching pattern. The target power is then given by the product of the maximum power and duty cycle, since the line is scaled linearly with the duty cycle.

[0213] In general, the closed-loop power control means may in particular comprise a closed-loop controller, e.g., a closed-loop PID controller, which is configured to determine a closed-loop control factor for the power. For this purpose, the closed-loop controller receives an input quantity, which can typically represent a measure of a deviation between the actual and target quantity and can also be referred to as a closed-loop control deviation. Based on this input quantity, the closed-loop controller then determines a closed-loop control factor, which is output accordingly and lies in the range from 0 to 1 . The closed-loop control factor is determined such that the target power corresponds to the product of the maximum power and closed-loop control factor.

[0214] The device can then be configured to determine the adjustment factor on the basis of the maximum voltage such that, when the adjustment factor alone (closed-loop control factor = 1 ) is used, the maximum voltage is provided at the output of the closed-loop power control means and the power consumption of the at least one consumer corresponds to the maximum power.

[0215] The duty cycle for the desired switching pattern then corresponds to the product of the adjustment factor and the closed-loop control factor. A corresponding switching pattern then leads to the provision of the desired effective power at the output of the power controller. In other words, the switching pattern adjusts the voltage and the corresponding current so that an effective power consumption of the at least one electrical consumer corresponds to the desired target power resulting from the closed-loop control factor and the maximum voltage.

[0216] For example, a temperature can be controlled using closed-loop control by the power controller: For example, the device can be an incubator and the electrical consumer a heating element. In order to bring the interior of the incubator to a desired temperature and then maintain it, the closed-loop power control means can advantageously control the power consumption of the heating element using closed-loop control by means of a temperature sensorand a predetermined temperature by selecting the switching patterns such that a certain proportion of the maximum power is provided by the closed-loop power control means. The adjustment factor based on the line voltage advantageously allows the incubator to be operated at different line voltages without having to adjust the hardware and in particular the electrical resistance of the heating element. In particular, the adjustment factor ensures that the maximum power is provided for a closed-loop control factor of 1 , regardless of the line voltage. This allows the closed-loop control factor to be advantageously determined independently of the line voltage.

[0217] The present invention accordingly also relates to a method for regulating an effective electrical quantity on the basis of an AC power grid provided for a device, wherein the effective electrical quantity is substantially independent of the line voltage. It goes without saying that the effective electrical quantity (e.g., effective voltage) corresponds to the effective value of the electrical quantity (e.g., voltage) provided over the length of the switching pattern.

[0218] With reference to Fig. 5, the method comprises determining the line voltage Uv (step 220) provided by the AC power grid. According to the method, a line voltage is thus determined, which is provided, for example, by a grid operator. For example, the line voltage provided can be measured. It goes without saying that the line voltage is in principle characterized by the effective value of the alternating voltage of the AC power grid. Determining the line voltage therefore means, in particular, determining the effective value of a provided alternating voltage. Accordingly, the term “line voltage” or “supply voltage” can be used synonymously for the effective value of the provided AC power grid. For example, by sampling the line voltage, the maximum amplitude can be recorded and then used as a basis for determining the effective voltage. This is possible because it is known that the alternating voltage is sinusoidal, and therefore the effective value corresponds to approximately 70.71 % (more precisely-^)) of the maximum amplitude.V2

[0219] The method further comprises the step of selecting a switching pattern depending on the line voltage (step 240) and then providing the effective electrical quantity on the basis of the selected switching pattern (step 260). The effective electrical quantity can be provided by means of open-loop multi-cycle control on the basis of the selected switching pattern or by switching a voltage supply to the at least one electrical consumer of the device on and off on the basis of the selected switching pattern. The effective electrical quantity can in particular be an effective voltage or an effective power. It goes without saying that additionally when providing effective power by means of open-loop multi-cycle control or by switching a voltage supply on and off, an effective voltage is provided and blocked (at least insofar as the effective voltage is provided to the at least one consumer). What is relevant, however, is for which quantity regulation is carried out and thus for which effective quantity the switching pattern is selected.

[0220] In other words, depending on the line voltage provided, a corresponding switching pattern is selected and the effective electrical quantity is provided by switching the voltage supply to the at least one consumer having voltage that is provided by the AC power grid on and off on the basis of the switching pattern, or by carrying out open-loop multi-cycle control that is based on the selected switching pattern. In particular, switching only occurs when the alternating voltage provided within the AC power grid passes through zero. In other words, full- or, if necessary, half-sine waveforms of the line voltage are switched on or off based on the switching pattern so that the effective electrical quantity can be provided. The switching pattern is selected such that the effective electrical quantity substantially corresponds to a target value. It goes without saying that switching full sine shorts is preferred.

[0221] As a result, the method according to the invention makes it possible to provide an effective electrical quantity which essentially corresponds to a target value, specifically independently of a provided line voltage. This makes it possible to use a device independently of the line voltage each time withouthaving to adjust an internal resistance of the device. In this context, “substantially” means a deviation of the effective electrical quantity from the target value of no more than ± 15%, preferably no more than ± 10%.

[0222] Preferably, the switching pattern is selected from a plurality of predetermined switching patterns. For example, appropriate switching patterns can be predetermined and saved for the common line voltages (and, if applicable, line frequencies). This has the advantage that the switching patterns do not have to be redetermined each time, especially since the number of line voltages is limited.

[0223] More generally, different switching patterns can preferably be predetermined for different duty cycles of the switching patterns. The duty cycle is determined by the ratio of the on-duration tE to the switching pattern duration to of the switching pattern. The duty cycle can thus characterize the corresponding switching pattern and, in particular, establishes the extent to which the effective voltage or the effective power is reduced in comparison with operation at line voltage. Preferably, each predetermined switching pattern can therefore be determined for a corresponding duty cycle. The switching pattern to be used can then be selected based on a desired duty cycle.

[0224] The on-duration and switching pattern duration can preferably be determined by the number of zero crossings or half or full sine waves. This advantageously allows these durations to be determined in a manner that is not dependent of the line frequency. The total number of full sine waves or zero crossings and thus the switching pattern duration can in principle be specified such that the on-duration is accordingly selected to provide the desired duty cycle.

[0225] In general, selecting a switching pattern on the basis of the line voltage may comprise determining the adjustment factor. As already explained, the adjustment factor can preferably be in the range of 0-1 and describes a percentage of the line voltage that is required to reduce the line voltage tothe target voltage or the maximum voltage. The switching pattern can then be selected depending on the adjustment factor.

[0226] In order to in principle determine a manipulated variable of 0-100% on- duration (in other words a duty cycle in the range of 0-1 ) with respect to the switching pattern duration by means of full waves that are distributed as uniformly as possible (i.e. , power that is distributed as uniformly as possible), a uniform distribution method can be applied.

[0227] In principle, the smallest possible energy output is limited, i.e., discretized, since switching only occurs at the zero crossing. The smallest possible amount of energy is therefore given by the energy of a half sine wave, preferably a full sine wave. In other words, the energy can only be output in units of a half sine wave or a full sine wave. Likewise, the temporal component is discretized by the duration of a half sine wave or a full sine wave. Fig. 6 illustrates one possibility for determining the switching pattern for full sine waves. The grid lines show the discretization of energy and time given by a full sine waveform, i.e., the distances between two horizontal grid lines correspond to the energy of a full sine wave and the distances between two vertical grid lines correspond to the duration of a full sine wave.

[0228] The dashed line shows the desired energy output over time. Accordingly, the slope of the dashed line corresponds to the power that is output. In principle, it is desirable to have as uniform an energy output as possible and thus as uniform a power consumption as possible in order to avoid temporary overloads of an electrical consumer. Therefore, the desired energy output over time preferably increases linearly. The solid (dark-gray) squares represent the energy specified by switching on a single full wave. The solid line corresponds to the actual energy that is output, which in principle follows the dashed line. The determination of the switching pattern follows the following principle: Whenever the dashed line, i.e., the desired energy output, intersects with one of the horizontal grid lines, the associated full sine wave isswitched on. This means that a full sine wave is always switched on when the actual energy that is output falls too far short of the desired amount of energy.

[0229] In other words, a full sine wave is switched on when, during the duration of the full sine wave, the desired amount of energy exceeds the actual amount of energy by at least the energy unit of a full sine wave.

[0230] This procedure ensures that the error with respect to the energy actually output, or the deviation of the energy actually output, is always smaller than the energy of a full sine wave. It goes without saying that the energy and time of a half sine wave can instead also be chosen as the smallest unit.

[0231] Overall, the on-duration tE, i.e., the time at which the line voltage is applied to the at least one electrical consumer, can thus advantageously be distributed as uniformly as possible over the switching pattern duration to. This can advantageously prevent temporary overloads of the at least one consumer, e.g., overheating of a heating element.

[0232] Fig. 7 shows, by way of example, corresponding switching patterns for a manipulated variable of 0-72% on-duration with respect to the switching pattern duration (i.e., a duty cycle of 0-0.72). To achieve an accuracy of 1 %, the switching pattern duration is accordingly 100-times that of a full sine wave. In other words, the switching pattern duration corresponds to 100 full sine waves. For a line frequency of 50 Hz, for example, this is thus 2 s. Each line in Fig. 7 corresponds to a different duty cycle, accordingly indicated on the left. The duty cycle ranges from 0% (top line) to 72% (bottom line). An “X” corresponds to a full sine wave that is switched on, and a space corresponds to a full sine wave that is switched off. The figure illustrates the uniform and often symmetrical distribution of the switched-on full sine waves over the switching pattern duration.

[0233] In some embodiments, the method may be directed in particular to controlling an effective voltage using open-loop control on the basis of an ACpower grid provided for the device. In other words, the controller can be openloop control means and the effective electrical quantity can be an effective voltage. The switching pattern can then be selected so that the effective voltage corresponds to a predetermined target voltage, which can be determined, for example, on the basis of the maximum voltage. The target voltage can be fixed and correspond, for example, to the maximum voltage or a predefined fraction of the maximum voltage. In other words, in corresponding embodiments, a predefined target voltage is provided independently of the line voltage. The target voltage is predetermined and constant, i.e., it does not change during operation of the device.

[0234] In particular, the target voltage is typically limited by the maximum voltage specified by the device, i.e., the device and in particular the hardware of the device is configured to operate up to the maximum voltage. The maximum voltage can be determined taking into account the internal resistance of the device as well as a desired, i.e., predetermined, maximum power consumption or maximum current consumption. In general, the device can be configured with respect to a certain maximum voltage, i.e., maximum operating voltage. It goes without saying that the present invention advantageously also allows the device to be used where the applied line voltage exceeds the maximum voltage. What is relevant is that at most the maximum voltage is provided following appropriate regulation.

[0235] For example, the device and in particular its electrical consumers may be configured for operation at a voltage of 120 V. In particular, the device can be configured so that it can be operated at a predetermined minimum line voltage without having to be adjusted by means of regulation. This minimum line voltage can, for example, be specified by the planned application locations of the device and correspond to the lowest line voltage provided by the corresponding AC power grid at the intended application locations. This means that, proceeding from the minimum line voltage, the internal resistance of the device can be selected such that, for the specified maximum power and / or current consumption, the maximum voltage corresponds at most to theminimum line voltage. The maximum voltage then preferably corresponds to the minimum line voltage or can be determined on the basis of the internal resistance and the specified maximum power and / or current consumption (if the maximum voltage is lower than the minimum line voltage). By means of the method according to the invention, the device can then be operated at line voltages of 120 V and higher as a result of appropriate regulation.

[0236] The target voltage can be fixed and correspond, for example, to the maximum voltage or to a predefined fraction of the maximum voltage. In other words, in corresponding embodiments, a predefined target voltage is provided independently of the line voltage. The target voltage is predetermined and constant, i.e. , it does not change during operation of the device.

[0237] The adjustment factor can then be determined on the basis of the line voltage and the target voltage and corresponds to the square of the ratio of the line voltage to the target voltage. When the voltage is controlled in an open-loop manner with respect to a target voltage Uz, the duty cycle of the switching pattern can advantageously correspond to the adjustment factor.

[0238] In other words, the switching pattern can be selected on the basis of the line voltage by determining the adjustment factor on the basis of the line voltage and the desired target voltage and selecting the switching pattern so that the duty cycle of the switching pattern corresponds to the adjustment factor. It goes without saying that, for example, the adjustment factor can be rounded to two decimal places (e.g., if the predetermined switching patterns are predetermined in 1 % steps). This allows the appropriate switching pattern to be selected on the basis of the line voltage so as to provide an effective voltage that substantially corresponds to the target voltage.

[0239] The target voltage can be fixed and correspond, for example, to the maximum voltage or to a predefined fraction of the maximum voltage. In other words, in corresponding embodiments, a predefined target voltage is provided independently of the line voltage. The target voltage is predetermined and constant, i.e. , it does not change during operation of the device.

[0240] Alternatively, in some embodiments, the method may be directed in particular to the closed-loop control of an effective electrical quantity, preferably an effective power, on the basis of an AC power grid provided for the device. In other words, the controller can be a closed-loop control means and the effective electrical quantity can preferably be an effective power. However, it goes without saying that the effective electrical quantity can also be an effective voltage. The preferred example of closed-loop power control will be discussed below.

[0241] The switching pattern can be selected such that the effective power corresponds to a predetermined target power, which can be determined, for example, on the basis of the maximum power. The target power can be specified in relation to the maximum power, for example, by a closed-loop controller. That is, the method may comprise determining a closed-loop control factor that establishes the target power in relation to the maximum power. The closed-loop control factor can be determined on the basis of an input quantity and can be in the range of 0-1. The adjustment factor is then determined so that, for a closed-loop control factor of 1 , the maximum power is provided. The maximum power is typically provided when the maximum voltage is provided such that the adjustment factor is given by the ratio between the maximum voltage and the line voltage. The desired duty cycle is then the product of the adjustment factor and the closed-loop control factor.

[0242] As a result, the method makes it possible, for example, to control the power of a heating element using closed-loop control on the basis of a temperature, namely independently of the line voltage with which the device is supplied, since the adjustment factor is determined in such a way thatsubstantially the maximum voltage and thus substantially the maximum power is provided, which is then accordingly modified by means of the closed- loop control factor, if necessary, in order to provide the desired power or to induce the desired power consumption at the at least one consumer.

[0243] Overall, the present invention thus allows for the regulation (i.e. , openloop or closed-loop control) of an effective electrical quantity such that said quantity corresponds to a target value that is not dependent on the line voltage to which the device is connected. Thus, the present invention advantageously allows a device to be operated in a plurality of different AC power grids without having to make changes to the hardware and / or without exceeding maximum power and / or current consumptions of integrated electrical consumers. This can advantageously simplify the manufacture of corresponding devices, since they do not have to be configured specifically for the future location of use.

[0244] Whenever a relative term such as "approximately," "substantially," or "essentially" is used in this description or the claims, such a term should be construed to include the exact term as well. That is to say, e.g., "substantially straight" should be construed to also include "(exactly) straight."

[0245] Whenever steps are mentioned in the above and / or in the appended claims, it should be noted that the order in which the steps are mentioned in this text may be random. That is, the order in which the steps are presented may be random unless otherwise specified or obvious to a person skilled in the art. That is, if in the present document, for example, it is stated that a method comprises steps (A) and (B), this does not necessarily mean that step (A) occurs before step (B), but it is also possible that step (A) (at least in part) is carried out simultaneously with step (B) or that step (B) occurs before step (A). Furthermore, if it is stated that a step (X) precedes another step (Z), this does not mean that there is no step between steps (X) and (Z). That is, step (X) before step (Z) comprises the situation that step (X) is performed directly before step (Z), but also the situation that (X) is performedbefore one or more steps (Y1 followed by step (Z). Corresponding considerations apply when terms such as "after" or "before" are used.

[0246] While a preferred embodiment has been described above with reference to the accompanying drawings, a person skilled in the art will understand that this embodiment has been provided for illustrative purposes only and should in no way be construed as limiting the scope of the present invention which is defined by the claims.

Claims

Claims1 . A device comprising at least one electrical consumer, wherein the device is configured to be connected to a first AC power grid with a first line voltage and to a second AC power grid with a second line voltage, wherein the second line voltage is greater than the first line voltage, wherein the device comprises a controller, wherein the controller is configured to provide, in a first state, the line voltage applied to an input of the controller at an output of the controller, not to provide any voltage at the output in a second state, wherein the controller is configured to switch between the first state and the second state according to different switching patterns, wherein the controller is configured to select a switching pattern on the basis of the connected line voltage that is of such a kind that an effective electrical quantity provided at the output of the controller substantially corresponds to a target value which does not depend on whether the device is connected to the first AC power grid or the second AC power grid, wherein the at least one electrical consumer is electrically connected to the output of the controller.

2. The device according to the preceding claim, wherein the controller is configured to switch between the first state and the second state only at the zerocrossing of the line voltage of the connected AC power grid.

3. The device according to any one of the preceding claims, wherein the effective electrical quantity substantially corresponds to the target value when a deviation of the effective electrical quantity is at most ± 20%, preferably at most ± 10%.

4. The device according to any one of the preceding claims, wherein the device is configured to determine the line voltage of a connected AC power grid.

5. The device according to any one of the preceding claims, wherein the device is configured to, when the device is connected to an AC power grid, automatically select a switching pattern to be used on the basis of the line voltage of the connected AC power grid.

6. The device according to any one of the preceding claims, wherein the effective electrical quantity is an effective voltage; wherein the controller is an open-loop voltage control; wherein the controller is configured to use a first switching pattern when the device is connected to the first AC power grid, and wherein the controller is configured to use a second switching pattern when the device is connected to the second AC power grid; and wherein the target value is a target voltage.

7. The device according to any one of claims 1 to 5, wherein the controller is a closed-loop power control, the effective electrical quantity is an effective power, and the target value is a target power.

8. A method for regulating an effective electrical quantity on the basis of an AC power grid provided for a device, the method comprising: determining a line voltage Uv of the provided AC power grid; selecting a switching pattern on the basis of the line voltage Uv, and providing the effective electrical quantity on the basis of the selected switching pattern, wherein the switching pattern is selected such that the effective electrical quantity substantially corresponds to a target value.

9. The method according to the preceding claim, wherein the device comprises at least one electrical consumer and a controller,wherein the at least one electrical consumer is electrically connected to an output of the controller, and wherein the controller is configured to provide, in a first state, the line voltage applied to an input of the controller at the output of the controller, and not to provide any voltage at the output in a second state; and wherein the provision of the effective electrical quantity comprises switching the controller between the first state and the second state on the basis of the selected switching pattern such that the effective electrical quantity is provided at the output of the controller.

10. The method according to any one of claims 8 and 9, wherein the switching pattern is selected from a plurality of predetermined switching patterns, wherein each one of the plurality of predetermined switching patterns comprises an on-duration tE and a switching pattern duration to, and wherein predetermining at least one switching pattern comprises uniformly distributing the on-duration over the switching pattern duration.

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