ES2310960A1 - Heating device connection - Google Patents

Abstract

The circuit has a voltage converter unit (56) assigned to a heating unit (22). The voltage converter unit is assigned to a set of heating modules (24) for producing a heating signal (H). A control device (46) is provided to form a heating group of the heating modules depending on a position of an object (18) i.e. pot, to be heated relative to the heating modules for heating the object. The voltage converter unit exhibits a maximum power that is lesser than the power of the set of heating modules, where the voltage converter unit converts an input voltage (VN) into a small output voltage (V).

Description

Heating device circuit.

The invention relates to a circuit of heating device, especially a circuit induction cooking device, according to the general concept of claim 1

Circuits are known for a device heating, especially for a cooking device by induction. Such circuits have heating bodies, such as for example, induction coils, which are actuated in the operation under a power supply voltage of net.

The object of the invention is especially in the development of heating device circuits generic, which can provide the parameters of operation to drive the bodies of heating that are adapted to such a configuration heating bodies.

According to the invention, a solution is provided for that purpose through the characteristics of the claim 1, while of the dependent claims embodiments and refinements can be extracted advantageous of the invention.

The invention relates to a circuit of heating device, especially a circuit induction cooking device, with at least one unit of heating.

It is proposed that the device circuit of heating present a voltage transformer unit, the which is added to the heating unit. In this way, it can advantageously provide a voltage of operation of the heating unit that is adapted to a  true configuration of said heating unit. In special, the voltage transformer unit can serve to supply the heating unit with a voltage of operation that is adapted to the impedance of said unit of heating. In this context, it can be understood by a "aggregation" especially the provision of a connection with tension, especially in the form of a line electrical, between the heating unit and the unit voltage transformer Through this aggregation, the unit of  heating or, what is the same, functional components of the heating unit, may have an electrical signal that present a voltage provided by the transformer unit of tension. In this context, "aggregation" can be understood especially a preconnection. The voltage transformer unit can transform an input voltage into an output voltage, whose value remains predefined and constant. So alternatively, the output voltage may depend on a load connected next to the transformer unit of tension.

The heating device circuit according to the invention it is especially suitable for use in induction cooking devices, such as in a field induction cooking. The cooking devices by induction, in which the heating bodies are correspond to induction heating coils, can be differentiate especially in relation to the geometry of induction heating coils used. Can be use, for example, induction heating coils with different perimeter and / or a different number of windings. Through the voltage transformer unit can be provided a operating voltage for driving the coils of induction heating that is specially coordinated with the impedance of the same.

In a preferred embodiment of the invention it is proposed that the voltage transformer unit be added to at least one set of heating modules for the production of a heating signal. By employing the voltage transformer unit for a multiplicity of modules heating, can be advantageously saved space of construction, components, as well as time and effort to carry assembly out. A heating module presents preferably at least one heating body for the production of the heating signal, which is transmitted to an object to be heated. Also, the module heating may comprise command means to direct the heating body. If the heating signal shows a heating frequency, the control means are shaped preferably as a heating frequency unit for the heating frequency production. As an example, in a heating unit intended for operation by induction, the heating signal is set as a Alternate magnetic field with heating frequency. In this In this case, the heating frequency unit is formed by example, as an inverter.

The heating device circuit preferably shows a control unit, which is provided to form a heating group of heating modules formed for the heating of the object to be heated, depending on a position of the object with regarding heating modules. In this way, you can achieve great flexibility in the application of a device heating in which the device circuit is used heating

This is especially appropriate for employment. of the heating device circuit in a device cooking. In this case, the heating modules are preferably arranged under a hob. At case of a group operation for heating the object, a heating group of heating modules is preferably composed of assembly heating modules that are at least partially covered by the object being found on the hob, especially by an element of A kitchen battery The layout of the modules heating is preferably configured as a array layout In this case, heating modules of different rows and / or different columns of the arrangement of matrix can be covered at least partially by the object placed on the hob. Heating modules preferably have dimensions such that an element of a kitchen battery of conventional dimensions, as per example a pot with a diameter of at least 8 cm., cover at least partially heating modules of different rows and of different columns The set of heating modules determines a related cooking zone of the surface of the cooking plate, suitable for heating the object, the which covers at least a predominant part of the surface of the cooking plate, advantageously at least 60%, preferably at least 70% and, especially advantageously, at least 80% of the surface of the hob. To the move the object on the hob, it can be carried carry out heating of objects of this cooking zone flexibly and in any positions chosen from these objects. By doing this, the control unit is planned preferably to adapt the composition of the group of heating to a change in the position of the object with respect to the heating modules at least semi-automatically, of advantageously completely automatically. When placing another object, another heating group can be formed to lead to perform a group operation. A heating unit intended for group operation of the modules heating is preferably provided with a large number of heating modules, especially at least six modules heating In order to achieve great flexibility in object positioning for operation of heating, the heating unit is provided preferably of a set of at least ten, advantageously at least twenty and, especially preferably at least forty heating modules. The heating modules of a set of such characteristics present for its construction especially a small resistance as heating modules, which are used in a cooking device with areas of cooking of the predefined cooking plate. Through the unit voltage transformer, one can easily reach operating voltage that is adapted to a module heating planned for group operation.

The voltage transformer unit features advantageously a maximum power that is shaped less than the power of the set of heating modules. In this way, economical and conventional components can be used for voltage transformer unit. The "power of the whole" preferably equals the sum of all powers individual, especially the maximum powers of the modules heating. This is especially appropriate when the heating modules to heat an object by means of a operation in groups. In the case of operation by groups of heating modules, the set of modules heating is divided into groups of heating modules powered and not powered. In this way, during operation heating, the heating unit is operated normally with a power less than the sum of the powers individual of all heating modules in the set. The maximum power of the voltage transformer unit can be advantageously chosen less than 90%, so especially advantageous less than 70%, and especially preferred less than 50% of the power of the set. The expression "maximum power" of a unit can be understood in this context especially as the power of delivery or of maximum admission allowed. The value of it is fixed by the dimensions of internal components of the unit. Maximum power it can amount to the upper limit of a power range that is Appropriate for trouble-free operation of the unit. In special, you can understand "maximum power" as the term rated power

Advantageously, the device circuit heating is provided with a protection device, the which is planned to limit the power delivered or admitted by the voltage transformer unit. In this way, you can achieve a high level of security and a transformer unit of Long-lasting tension In this case, the transformer unit voltage may present the protection device as internal component, or the protection device may be configured as a component and / or as a program of a unit of external control to direct operation of the module set heating The protection device may have a sensor unit to detect the delivered power, as per example, a current transformer to detect a current delivered or admitted by the voltage transformer unit.

A configuration of the transformer unit of Low voltage cost and simple construction can be achieved If it has a DC voltage transformer. This is suitable for applications with high current intensity, such as especially in the application in a cooking device by induction. Advantageously, the DC voltage transformer is connected directly following a rectifier to the rectification of a power supply signal of net.

In a preferred embodiment of the invention it is proposed that the voltage transformer unit serve to transform an input voltage into an output voltage minor, through which operation can be achieved especially effective of a small heating unit impedance. This is especially appropriate for use in a  induction cooking device, which is intended for a operation by groups of heating modules. In this case, the impedance of a heating module rises conventionally less than one ohm. In this context, it implies a advantage if the voltage transformer unit is used for at least reduce the input voltage in half. The input voltage is  preferably configured as a current supply voltage Network

It is also proposed that the unit voltage transformer is added to a set of plates conductors, on each of which a group of functional components of the heating unit. This form, you can get a circuit configuration of compact and construction heating device simple.

In this context it is proposed that on each one of the conductive plates a group of units of heating frequency for the production of a frequency of heating. In this way, you can get a configuration especially simple of the device circuit of heating, especially in the supply of the units of heating frequency with the voltage provided by the voltage transformer unit. A unit of frequency of heating forms with a heating body preferably a heating module for the production of a signal of heating, which is transmitted to an object to be heated.

In another variety of embodiment, proposes that the voltage transformer unit has a set of voltage transformers, each of which is added to a phase of the network current, through which flexible use of several phases of the stream.

Other advantages are taken from the following Description of the illustrations. In the illustrations, they represent examples of embodiments of the invention. The illustrations, description and claims contain numerous features combined. The subject matter expert will consider the characteristics also individually and in a way advantageous, and will gather them in other convenient combinations.

The figures show:

Figure 1: An induction cooking field with a hob and a set of heating modules and two elements of a kitchen battery arranged on the plate cooking.

Figure 2: an internal circuit of the field of induction cooking of figure 1 with a transformer unit of tension and,

Figure 3: A detailed view of the unit voltage transformer of figure 2.

Figure 1 shows a device of heating 10 configured as a cooking field mode induction. The heating device 10 has a frame of fixing 12 for fixing to a work plate, a plate cooking 14 to place kitchen battery elements and a panel of controls 16 to start, stop and adjust operation of heating. On the cooking plate 14 there are two objects 18, 20 configured as a pot, each of which is schematically represented by plotting a circular line To carry out a cooking operation of the heating device 10, this is provided with a unit of heating 22. The heating unit 22 has a set of heating modules 24, each of which comprises a heating body 26 shaped as a coil induction The arrangement of the heating bodies 26, the which is schematically represented in the figure by a rectangle drawn in a dashed line is set to array layout. In said arrangement, there are bodies of heating 26 of different columns and of different rows covered by object 18.

In an operation of a heating module 24, the corresponding heating body 26 generates a heating signal H configured as an alternating magnetic field (see Figure 2), which has a heating frequency that amounts to, for example, 25 kHz. The heating signal H induces electrical currents in the metal base of objects 18, 20. These electrical currents heat a food that is found in objects 18, 20 through ohmic losses. With the corresponding heating module 24 in operation, a heating body 26 is supplied with an alternating electric current for the production of the heating signal H, said heating body oscillating with the heating frequency. For the production of this alternating current, the heating modules 24 are each provided with a heating frequency unit 28 configured as an inverter. These heating frequency units 28 are represented in the
figure 2.

The heating device 10 is provided for heating objects 18, 20 by means of a group operation of the heating modules 24. To the heating modules 24 are each provided with sensor means that are not represented in more detail, by means of which you can determine if a module heating 24 is at least partially covered by one of the objects 18, 20. With the help of a grouping process that does not described in more detail, heating groups of heating modules 24, each of which is awarded to one of the objects 18, 20. If a user starts an operation of  heating device 10 cooking by means of a panel of controls 16, this cooking operation is carried out by medium of the heating modules 24 of both groups of heating, while the other heating modules 24, which are not part of any of the groups of heating formed, remain un powered. If the user move one of the objects 18, 20 on the cooking plate 14 or place another kitchen battery element on the hob 14, heating groups are adapted or reformed corresponding heating modules 24 by means of the new arrangement of objects to be heated with with respect to the heating bodies 26.

In figure 2 it appears represented schematically a heating device circuit 30 of the heating device 10 of figure 1. The circuit of heating device 30 comprises the heating unit  22. This presents the set of heating bodies 26, each one of which is configured as an induction coil and which, in addition, can be observed in figure 1. The unit of heating 22 further comprises, as described previously, a set of frequency units of heating 28, which is added to the set of bodies of heating 26, where each heating frequency unit 28 and a heating body 26 form a module of heating 24.

The heating module assembly 24 is distributed in different groups 32. In this example, in the form of realization, the set is divided into groups 32 of six heating modules 24 each. To each group 32 of modules heating 24 a control unit 34 is added, which is intended to direct the heating frequency units 28 of group 32. Control units 34 may present a microprocessor or can be configured as a microprocessor. Each of the frequency units of heating 28 of a group 32 and the control unit 34 corresponding are mounted on a conductive plate 36. The heating unit 22 therefore has a number of plates conductors 36 different, which is equivalent to the number of group 32 of heating modules 24. In this example, in the form of embodiment, the heating unit 22 has eight groups 32. For clarity, only two were represented in the figure groups 32 with corresponding conductive plates 36. The lines of current represented by dashed lines indicate the arrangement of other groups 32 and conductive plates 36. The topology of heating unit 22 can also be changed flexibly during operation, so that for example the aggregation of the heating bodies 26 at heating frequency units 28 for the formation of a heating module 24 can be adapted during a heating unit operation 22. For supply of electrical energy to the control units 34, the circuit of heating device 30 is provided with a unit of power supply 38, which is connected by a part to a mains power supply 40 and, on the other hand, to each of the conductive plates 36. The power supply unit 38 makes available a power supply signal in a current lane 42, from which a current input is derived 44 for the supply of each of the control units 34.

To direct the operation by groups of heating modules 24 described above, the circuit of heating device 30 is further provided with a unit of control 46. The control unit 46 may have a microprocessor or it can be configured as a microprocessor. Said unit is connected to the control units 34 of the different groups 32 of heating modules 24 via a bus of data 47. The control unit 46 is specially configured for, depending on the position of the objects 18, 20 on the hob and through a communication with the control units 34, form the heating groups and to lead a warm-up process with the groups of heating. In another variant embodiment, the paper of the control unit 46 for the control of an operation by groups can be assumed by a command unit 34 or several control units 34 of groups 32 of heating modules 24, where the group operation of the modules heating 24 takes place by means of a self-organization to less partial of the control units 34. To do this, the units control 34 may be connected to each other for exchange of information, which is indicated in the figure of schematic form by means of the connection lines represented by dashed lines between the control units 34.

The heating frequency units 28 are provided for the production of the heating frequency of the heating signal H generated by the corresponding heating body 26. For this, each of the heating frequency units 28 is configured as an inverter. A heating frequency unit 28 preferably comprises at least one pair of connection elements 48, which are configured as semiconductor components. Regardless of the topology of the heating frequency unit 28, the connection elements 48 of the heating frequency units 28 are indicated schematically by a transistor symbol. In this example, the connection elements 48 are configured as an IGBT ( Insulated Gate Bipolar Transistor or bipolar transistor with insulated gate electrode). An alternative embodiment of the connection elements 48, such as Mosfet ( Metal Oxid Semiconductor Field Effect Transistor or field effect transistor of metal oxide semiconductor), or others that the person skilled in the art can consider as elements of Convenient connection, are considerable. The inverter can be constructed with different topologies, for example, with a pair of connection elements 48 in a half-bridge topology or with two pairs of connection elements 48, which are arranged in a complete bridge topology.

For the production of an alternating current, by means from which the heating bodies 26 generate the signal heating H configured as an alternating magnetic field mode, heating frequency units 28 are powered with an electrical signal 50, which has a continuous voltage V.  The heating frequency units 28 produce the alternating current by means of this electrical signal 50 by connection processes of connection elements 48, which are directed by the control unit 34 of group 32 correspondent. This principle is known and is not explained with more detail within the framework of this description. Electrical signal 50 is produced by rectifying a signal of mains power supply 52. To do this, the circuit of heating device 30 is provided with a rectifier 54, which is schematically represented by a symbol of diode. The rectifier 54 provides an electrical signal, which it has a continuous voltage that is equivalent to a voltage of mains power supply V_ {N} of 230 V. In this example of embodiment, the shaped heating bodies 26 as induction heating coils are configured with a set diameter less than 100 mm. The coils of induction heating in induction cooking fields Conventional with predefined cooking zones present normally a diameter of more than 200 mm. Due to configuration of the heating bodies 26, the impedance of the bodies of heating 26 has a value set below 1 \Omega. A usual impedance of a heating body in a conventional induction cooking field rises, on the other part, at approximately 3.5 \ Omega. Therefore, it is advantageous if the heating modules 24 are driven by the voltage continuous V, which is set lower than the voltage of network power supply V_ {N}. To do this, the circuit of heating device 30 has a transformer unit voltage 56, which is connected after the rectifier 54. The voltage transformer unit 56 is formed by a DC voltage transformer. Said transformer produces the electrical signal 50, with which the heating frequency units 28, and whose voltage continues V has a value between 30 V and 100 V. The transformer unit of voltage 56 is connected to the conductive plates 36 by means of a current lane 58. From this current lane 58 are derived input lines 60 for the conduction of the electrical signal 50 a each of the conductive plates 36 and the units of heating frequency 28 arranged on said plate conductive 36. In this configuration it can be achieved by aggregation of voltage transformer unit 56 for various groups 32 of heating modules 24 or, which is the same, for several conductive plates 36, a conformation especially simple heating circuit 30. This is You can achieve, in particular, by making available the electrical signal 50 for the frequency units of heating 28 by means of the current rail 58 set for the heating frequency units 28.

In this exemplary embodiment, the heating modules 24 have dimensions such that produce a maximum power of 500 W. The heating unit 22 thus presents a theoretical maximum power P_ {M} of 24 kW, which could be achieved if all heating modules 24 were operated simultaneously with their maximum power. Since this does not happen in a realistic application of heating device 10, it is advantageous if the maximum power of the voltage transformer unit 56 is set lower that the sum of the individual powers of the modules of heating 24. As an example, the maximum power of the unit voltage transformer 56 has a value between 10% and 50% of the maximum power P_ {M}. In this example, the unit voltage transformer 56 has a maximum power of 3600 W. In order to avoid deterioration of the transformer unit of voltage 56 in operation above its maximum power, the heating device circuit 30 is provided with a power limiter, which limits the power allowed by the heating unit 22 at the maximum power of the unit voltage transformer 56. In this example, the control unit 46 is programmed with software that monitors the power supported by the heating unit 22 and limits it so correspondent. Alternatively or additionally, the unit voltage transformer 56 may have a limiter of power, such as in the form of a limiter of stream.

Figure 3 shows a view Detailed of the voltage transformer unit 56. This is configured as a DC voltage transformer, which is made as a reducer of the type known as Buck. Unit voltage transformer 56 features a diode 62, an inductivity 64 and a connector 66. In period T the connector 66 is in a conductive state for a time t_ {on} less than T. The signal of input corresponds to the rectified signal through the rectifier 54 with the mains current supply voltage V_ {N}. The output voltage, which corresponds to the DC voltage V for powering the units of heating frequency 28, is lower compared to the input voltage V_ {N}, and can be varied by setting of the relation t_ {on} / T. The principle of a transformer of Continuous voltage of such characteristics is known, and is not describes in more detail within the framework of this description. The continuous voltage V has a value between 30 V and 100 V.

References

10

Heating device

12

Fixing frame

14

Cooking plate

16

Control panel

18

Object

twenty

Object

22

Heating unit

24

Heating module

26

Heating body

28

Heating frequency unit

30

Heating device circuit

32

Group

3. 4

Control unit

36

Conductive plate

38

Power supply unit

40

Mains power supply

42

Current rail

44

Current input

46

Control unit

47

Data bus

48

Connection elements

fifty

Signal

52

Mains power supply signal

54

Rectifier

56

Voltage transformer unit

58

Current rail

60

Input line

62

Diode

64

Inductivity

66

Connector

H

Heating signal

V

Continuous voltage

V_ {N}

Supply voltage of net.

Claims (9)

1. Heating device circuit, especially induction cooking device circuit, with at least one heating unit (22), characterized by a voltage transformer unit (56), which is added to the heating unit ( 22). 2. Heating device circuit according to claim 1, characterized in that the voltage transformer unit (56) is added to at least one set of heating modules (24) for the production of a heating signal (H). 3. Heating device circuit according to claim 2, characterized by a control unit (46), which is intended to form a heating group of heating modules (24) formed for heating the object (18, 20) , depending on a position of the object to be heated (18, 20) with respect to the heating modules (24). 4. Heating device circuit according to claim 2 or 3, characterized in that the voltage transformer unit (56) has a maximum power, which is formed less than the power of the set of heating modules (24). 5. Heating device circuit according to one of the preceding claims, characterized in that the voltage transformer unit (56) has a direct voltage transformer. 6. Heating device circuit according to one of the preceding claims, characterized in that the voltage transformer unit (56) serves to transform an input voltage (V N) into a lower output voltage (V). 7. Heating device circuit according to one of the preceding claims, characterized in that the voltage transformer unit (56) is added to a set of conductive plates (36), on each of which a group (32) is arranged of functional components of the heating unit (22). 8. Heating device circuit according to claim 7, characterized in that a group of heating frequency units (28) is arranged on each of the conductive plates (36) for the production of a heating frequency. 9. Heating device, especially a induction cooking device, with a circuit of heating device (30) according to one of the claims listed above.