NL2019772B1

NL2019772B1 - An electrical converter, a method and a computer program product

Info

Publication number: NL2019772B1
Application number: NL2019772A
Authority: NL
Inventors: Anatol’Evic Guzyeyev Valeriy
Original assignee: Dutch Infinity Energy D I E B V
Priority date: 2017-10-20
Filing date: 2017-10-20
Publication date: 2019-04-29

Abstract

The invention relates to an electrical converter, comprising a DC-AC converter provided With a DC input port, an AC output port and a controller controlling a frequency of an electric signal provided at the AC output port. Further, the electrical converter comprises a source coil connected to the AC output port, and a reversely oriented load coil positioned in proximity to the source coil such that the source coil and the load coil are coupled via a resonance capacitor.

Description

Title: An electrical converter, a method and a computer program product

The invention relates to an electrical converter.

Electrical converters are generally known for a wide area of applicants, e.g. for converting electrical DC energy towards electrical AC energy or vice versa. Further, AC to AC converters are known, also known as transformers, for increasing or reducing AC levels.

It is an object of the invention to provide an electrical converter that may generate a specific electrical output signal, e.g. an electrical AC signal having a desired frequency. Thereto, an electrical converter is provided, comprising a DC-AC converter provided with a DC input port, an AC output port and a controller controlling a frequency of an electric signal provided at the AC output port, further comprising a source coil connected to the AC output port, and a reversely oriented load coil positioned in proximity to the source coil such that the source coil and the load coil are coupled via a resonance capacitor.

By including a DC-AC converter generating an AC signal that is transferred from a source coil to a reversely oriented load coil positioned in proximity to the source coil such that the source coil and the load coil are coupled via a resonance capacitor, a desired electrical output signal can be provided.

The invention also relates to a method.

Further, the invention relates to a computer program product. A computer program product may comprise a set of computer executable instructions stored on a data carrier, such as but not limited to a flash memory, a CD or a DVD. The set of computer executable instructions, which allow a programmable computer to carry out the method as defined above, may also be available for downloading from a remote server, for example via the Internet, e.g. as an app.

Other advantageous embodiments according to the invention are described in the following claims.

By way of example only, embodiments of the present invention will now be described with reference to the accompanying figures in which

Fig. 1 shows a system view of a first embodiment of an electrical converter according to the invention;

Fig. 2 a shows a system view of a second embodiment of an electrical converter according to the invention;

Fig. 2b shows a system view of a third embodiment of an electrical converter according to the invention;

Fig. 3 shows a schematic view of a source coil and a load coil of an electrical converter according to the invention,

Fig. 4 shows a schematic view of a fourth embodiment of an electrical converter according to the invention;

Fig. 5a shows a schematic cross sectional view of a source coil and a multiple number of load coils of the electrical converter shown in Fig. 4;

Fig. 5b shows a diagram illustrating pitch angles of load coils of the electrical converter shown in Fig. 4;

Fig. 6a shows a schematic view of a first load coil configuration in the electrical converter shown in Fig. 4;

Fig. 6b shows a schematic view of a second load coil configuration in the electrical converter shown in Fig. 4;

Fig. 6c shows a schematic view of a third load coil configuration in the electrical converter shown in Fig. 4;

Fig. 6d shows a schematic view of a fourth load coil configuration in the electrical converter shown in Fig. 4;

Fig. 6e shows a schematic view of a fifth load coil configuration in the electrical converter shown in Fig. 4, and

Fig. 6f shows a schematic view of a sixth load coil configuration in the electrical converter shown in Fig. 4.The figures merely illustrate a preferred embodiments according to the invention. In the figures, the same reference numbers refer to equal or corresponding parts.

Figure 1 shows a system view of a first embodiment of an electrical converter 1 according to the invention. The converter 1 includes a DC-AC converter 2, a source coil 3 and a load coil 4.

The DC-AC converter 2 has a DC input port 5, an AC output port 6 and a controller 7 controlling a frequency of an electric signal that is generated at the AC output port 6. In the shown embodiment, the DC input port 5 has a first input terminal 5a and a second input terminal 5b. Similarly, the AC output port 6 has a first output terminal 6a and a second output terminal 6b.

The source coil 3 is connected to the AC output port 6. In the shown embodiment, the source coil 3 has a first terminal 3a and a second terminal 3b. The first source coil terminal 3a is connected to the first output terminal 6a of the DC-AC converter 2 and the second source coil terminal 3b is connected to the second output terminal 6b of the DC-AC converter 2.

The load coil 4 is reversely oriented relative to the orientation of the source coil 3. Further, the load coil 4 is positioned in proximity to the source coil such that the source coil 3 and the load coil 4 are coupled via a resonance capacitor 8. The load coil 4 has a first terminal 4a and a second terminal 4b.

The capacitor 8 forms with the coils a resonance circuit, and is therefore also called inductive capacitor.

The source coil 3, the load coil 4 and the resonance capacitor 8 form a resonance circuit. During operation, voltage and current signals in the resonance spectrum of said resonance circuit are dominant over signals in a spectrum outside said resonance spectrum. Then, the electrical signal that is generated by the DC-AC converter 2 is controlled such that its frequency is within the resonance spectrum of the resonance circuit, and preferably matches a resonance frequency of the resonance circuit. In practice, the frequency of the electric signal can be automatically controlled by generating a signal having a broad spectrum including said resonance spectrum determined by the resonance circuit. Then, the resonance circuit acts as a bandpass filter so that electric signals within the resonance spectrum dominate signals having a frequency outside said resonance spectrum. The combination of the DC-AC converter 2 and the resonance circuit then control the frequency of the generated signal.

In the shown embodiment, the load coil 4 is implemented as a first load coil Lxl that is connected with a load 9 having a low impedance such as a heater, e.g. an immersion heater or cooker. The impedance can be mainly resistive. In the shown embodiment, the first terminal 4a of the load coil 4 is connected to a first terminal 9a of the load 9, while the second terminal 4b of the load coil 4 is connected to a second terminal 9b of the load 9.

In Fig. 1 it is also shown that the load coil 4 can be implemented as a second load coil Lx2, also connected with a load, similar to the load connected to the first load coil Lxi. Here, the load is implemented as a fight source 10.

It is noted that, in principle, multiple loads can be applied, e.g. by connected multiple loads to the load coil 4, in series and/or in parallel. Further, multiple load coils could be used, each load coil being connected to a single or multiple number of loads.

The resonance capacitor has a capacitance value in a range from circa 1000 pF to circa 10.000 pF, preferably in a range from circa 1000 pF to circa 4700 pF.

During operation of the electrical converter 1 an electrical DC signal is provided to the DC-AC converter 2, e.g. using a 12 V or 24 V, 10 A signal. Generally, the electrical DC signal is variable. In particular, the voltage of the electrical DC signal can then be set to a desired voltage level. The DC-AC converter 2 converts the DC signal into an electrical AC signal having a controlled frequency, and feeds said AC signal towards the source coil 3 that interacts with the load coil 4. Then, an electrical signal is provided to a load 9, 10.

Generally, the capacitance value of the resonance capacitor 8 may depend on the mutual position and orientation of the source coil 3 and the load coil 4, the frequency of the electrical AC signal that is generated by the DC-AC converter 2, a frequency of the electrical AC signal at the load 8 and/or a type of load 8.

Generally, the resonance capacitor 8 may have a capacitance value in a range from circa 1000 pF to circa 10.000 pF. Further, the controller of 7 the DC-AC converter 2 may be arranged for setting the frequency of the electric signal provided at the AC output port 6 in a range from circa 10 kHz to circa 200 kHz.

Figure 2 a shows a system view of a second embodiment of an electrical converter 1 according to the invention. Here, the converter 1 includes an AC-DC converter 11 for converting electrical AC mains energy into electrical DC energy for feeding the DC-AC converter 2. The AC-DC converter 11 includes an input port 12 and an output port 13. In the shown embodiment, the input port 12 includes a first input terminal 12a and a second input terminal 12b. Similarly, the output port 13 includes a first output terminal 13a and a second input terminal 13b. The first output terminal 13a is connected to the first input terminal 5a of the DC-AC converter 2, and the second output terminal 13b is connected to the second input terminal 5b of the DC-AC converter 2. The input terminal 12a,b can be connected to mains terminals of an AC electrical energy source e.g. 230 VAC.

It is noted that the embodiment shown in Fig. 1 can also be provided with an AC-DC converter 11 as shown in Fig. 2a.

Further, the embodiment shown in Fig. 2 a has another load configuration. Here, the converter 1 comprises a load transformer 14 and a mains transformer 15. Both the load transformer 14 and the mains transformer 15 have an input port 16; 18 and an output port 17; 19. The input port 16 of the load transformer 14 has a first and second input terminal 16a,b, while the output port 17 of the load transformer 14 also has a first and a second terminal 17a,b.

In the shown embodiment, the first input terminal 16a of the load transformer 14 is connected to the first terminal 4a of the load coil 4, and the second input terminal 16b of the load transformer 14 is connected to the second terminal 4b of the load coil 4. Then, the input port 16 of the load coil 4 is connected to the load coil 4. Further, in the shown embodiment, the first output terminal 17a of the load transformer 14 is connected to the first output terminal 19a of the main transformer 15. Then, the output port 17 of the load transformer 14 is connected to the output port 19 of the mains transformer 15 for setting a frequency of an electrical signal at the output port 17 of the load transformer 14.

The input terminals 18a,b of the mains transformer 15 can be connected to mains terminals of an AC electrical energy source e.g. 230 VAC. Further, the mains transformer 15 can be arranged for transforming the input voltage and current to a same level, i.e. also to 230 VAC.

In the shown embodiment, the second output terminal 17b of the load transformer 17 forms a first AC output terminal 22b of the electrical converter 1, while the second output terminal 19b of the mains transformer 15 forms a second AC output terminal 22a of the electrical converter 1.

Further, in the shown embodiment, the converter 1 further includes a load capacitor 20 arranged parallel to the first and second AC output terminals 17b, 19b. As an example, the load capacitor 20 has a capacitance value of circa 22 microF arranged for being subjected to a voltage of circa 400 VAC. It is noted that the load capacitor 20 may have other characteristics, e.g. depending on a desired load type.

Figure 2b shows a system view of a third embodiment of an electrical converter 1 according to the invention. Again, the DC-AC converter 2 is fed by a DC source, at the first and second input terminals 5a,b. Further, the system 1 includes a DC-AC converter 21 having a first input terminal 5e and a second input terminal 5f, and a first output terminal 19a and a second output terminal 19b. The DC-AC converter 21 is fed by the DC source, at its first and second input terminals 5e,f, and generates an AC signal, at its first and second output terminals 19a,b that replace the output terminals 19a,b of the mains transformer 15 in the embodiment shown in Fig. 2a.

Figure 3 shows a schematic view of a source coil 3 and a load coil 4 of an electrical converter 1 according to the invention. As shown, the orientation of the source coil 3 and the load coil 4 is opposite. Further, the resonance capacitor 8 between the coils 3, 4 may have a parasitic character. Then, there is no discrete or integrated capacitor element included in the structure of the converter 1. However, in principle, a discrete resonance capacitor may be added to contribute to the capacitance between the coils 3, 4. Generally, the source coil 3 and the load coil 4 are located such that they are coupled via said resonance capacitor 8. The capacitance value of the capacitor 8 can be influenced by setting a specific location of the coils 3, 4 relative to each other. In the shown embodiment, the source coil 3 and the load coil 4 have substantially coinciding rotational symmetry axes.

However, the load coil 4 might have another position and/or orientation, e.g. shifted along the symmetry axis of the source coil 3 or shifted in a direction transverse to said source coil symmetry axis. The source coil 3 and the load coil 4 may have a specific inductance, preferably less than circa 200 micro Henry.

Figure 4 shows a schematic view of a fourth embodiment of an electrical converter 1 according to the invention. The electrical converter 1 is similar to the converter shown in Fig. 1 provided that a multiple number of load coils 4’, 4”, 4”’, 4””, 4”’” are provided instead of a single load coil. Further, the circuit connected to the load coils 4’, 4”, 4”’, 4””, 4’”” differs, as explained in more detail below.

Generally, a load coil has a capacitive coupling to other load coils, especially with adjacent load coils. The capacitance between load coils generally depends on a distance between the coils and the thickness and type of isolation material surrounding the coils.

In the embodiment shown in Fig. 4, a first load coil 4’ surrounds the source coil 3, in reverse order with respect to the orientation of the source coil 3 such that the orientation of the source coil 3 and the first load coil 4’ is opposite. Further, a second load coil 4” surrounds the first load coil 4’, a third load coil 4”’ surrounds the second load coil 4”, a fourth load coil 4”” surrounds the third load coil 4”’, and a fifth load coil 4””’ surrounds the fourth load coil 4””. The orientation of two subsequent load coils is mutually opposite. Further, the thickness of subsequent load coils may increase. Also, the load coils are preferable concentric, wound around a shared winding axis.

Each load coil has a first and second end, the first ends being located adjacent the first source coil terminal 3a and the second ends being located adjacent the second source coil terminal 3b. The second ends of the first and second load coil 4’, 4” are connected via a first connection terminal 4b. Similarly, the second ends of the third and fourth load coil 4”’, 4”” are connected via a second connection terminal 4c. The first and second end 4e, 4d of the fifth load coil 4’”” is connected to a load circuit including a load 110 such as a fight unit or an electric appliance.

In the shown embodiment, the load 110 is arranged in parallel with a rechargeable energy source 105 such as a rechargeable battery cell e.g. a lithium battery. Further, a capacitor 103 is arranged in parallel with the load 110 and the rechargeable energy source 105. Here, a first end 4g of the capacitor 103 is connected to the first end 4e of the fifth load coil 4’”” via the diode 102. The first end 4g of the capacitor 103 is further connected to the first end 4f of the load 110 and the rechargeable energy source 105 via a resistor 104 such as a temperature dependent resistor. A second end of the capacitor 103, the rechargeable energy source 105 and the load 110 is connected to the second end 4d of the fifth load coil 4””’. Further, the first and second end 4f, 4d of the rechargeable energy source 105 are connected to the first and second input terminals 5a, 5b, respectively of the DC-AC converter 2. When an electrical current flows through the fifth load coil 4”’” the load 110 may be energized and the rechargeable energy source 105 can be charged. Then, electrical energy is converted are transmitted in a static or quasi static way from the DC-AC converter to the load side.

It will apparent that many variations are possible. As an example, the first and second end 4f, 4d of the rechargeable energy source 105 can be connected to the first and second input terminals 5a, 5b, respectively of the DC-AC converter 2, via switching elements. Further, the invertor may include more or less load coils, such that subsequent coils have a mutually reverse orientation. In the embodiment shown in Fig. 4, the invertor includes five load coils 4.

Figure 5a shows a schematic cross sectional view of a source coil 3 and a multiple number of load coils 4 of the electrical converter 1 shown in Fig. 4. As shown, each subsequent load coil surrounds the previous load coil. Between each subsequent load coil, an isolation layer is provided for counteracting any electric breakdown thus forming a sandwiched structure. Here, a first isolation layer 11Γ is located between the first and second load coil 4’, 4”, a second isolation layer 111” is located between the second and third load coil 4”, 4”’, a third isolation layer 111” is located between the third and fourth load coil 4’”, 4””, and a fourth isolation layer 111”” is located between the fourth and fifth load coil 4””, 4’””.

Fig. 5b shows a diagram illustrating pitch angles of the load coils 4 of the electrical converter shown in Fig. 4. The coils 4’, 4”, 4”’, 4””, 4”’” are wound around a shared winding axis W such that subsequent load coils are wound in mutually reverse order. In the diagram, the pitch angle is defined relative to a cross sectional plane P that is transverse to the winding axis W. Each load coil 4 has its own pitch angle a, 6, also called winding angle or tilting angle, such that the pitch angle of subsequent load coils switches sign, since they have a mutually different orientation. Further, the amphtude of the pitch angles a, 6, of the individual load coils 4 may be mutually different. In the shown diagram, the amplitude of the pitch angle 6 of the second load coil 4” is slightly greater than the amplitude of the pitch a of the first load coil 4’, thereby increasing the number of crossing points CP where the first load coil 4’ and the second load coil 4” cross each other. Preferably, the amplitude of the pitch angle of subsequent load coils increases, preferably with a fixed angle step Δα. Said fixed angle step Δα can e.g. be selected from a range between circa 4° and circa 7°, preferably in a range between circa 5° and circa 6°, e.g. circa 5°. Then, as an example, the pitch angles of the load coils 4 can be set as follows: ai of first load coil 4’ is 30°, 6j of second load coil 4” is -35°, a-2 of third load coil 4’” is 40°, 62 of fourth load coil 4” is -45°, and aa of fifth load coil 4”’ is 50°. Apparently, other pitch angles can be selected. As an example, the pitch angle ai of first load coil 4’ may shift a number of degrees, e.g. 2°. Then, the pitch angle of the first load coil 4’ is circa 28° such that the selected pitch angles of the second to fifth load coil also shift 2°.

Figures 6a-f show schematic views of a first load coil configuration, a second load coil configuration, a third load coil configuration, a fourth load coil configuration, a fifth load coil configuration, and a sixth load coil configuration, respectively.

Generally, a terminal of a load coil can be connected directly or via a capacitor to a terminal of another load coil.

In the first load coil configuration 44, shown in Fig. 6a, the second terminals 4c of the first and second load coil 4’, 4” are directly connected.

Similarly, the second terminals of the third and fourth coil 4”’, 4”” are directly connected. In a similar way, the first terminals 4a of the first, and second coil 4’, 4” are directly connected, and the first terminals of the third and second coil 4’”, 4”” are directly connected. Further, the first terminals of the first and second coil 4’, 4” are connected to the first terminals of the third and fourth coil 4’”, 4”” via a coupling capacitor Cc.

In the second load coil configuration 44, shown in Fig. 6b, the second terminals 4c of the first and second load coil 4’, 4” are directly connected, and the second terminals of the third and fourth coil 4”’, 4”” are directly connected. Further, the first terminals 4a of the first and second coil 4’, 4” are directly connected. Said first terminals of the first and second coil 4’, 4” are connected to the first terminal of the third coil 4’” via a first coupling capacitor Cel. Said first terminals of the first and second coil 4’, 4” are also connected to the first terminal of the fourth coil 4””, via a second coupling capacitor Cc2.

In the third load coil configuration 44, shown in Fig. 6c, the second terminals 4c of the first and second load coil 4’, 4” are directly connected, and the second terminals of the third and fourth coil 4’”, 4”” are directly connected. Further, the first terminal 4a of the first coil 4’ is coupled to the first terminal of the fourth coil 4”” via a first couphng capacitor Cel and the first terminal of the second coil 4” is coupled to the first terminal of the fourth coil 4”” via a second couphng capacitor Cc2. The first terminals of the third and fourth coil 4”’, 4”” are directly connected.

In the fourth load coil configuration 44, shown in Fig. 6d, the second terminals 4c of the first, second, third and fourth coil 4’, 4”, 4’”, 4”” are open, disconnected from other terminals. Further, the first terminal 4a of the first coil 4‘ is coupled to the first terminal of the second coil 4” via a first coupling capacitor Cel, while the first terminal of the third coil 4”’is coupled to the first terminal of the fourth coil 4”” via a second couphng capacitor Cc2.

In the fifth load coil configuration 44, shown in Fig. 6e, the second terminals 4c of the second load coil 4” and the third load coil 4 ” are directly connected, while the second terminal of the first load coil 4’ and the second terminal of the fourth load coil 4”” are open. Further, the first terminal 4a of the first coil 4‘ is coupled to the first terminal of the second coil 4” via a first coupling capacitor Cel, while the first terminal of the third coil 4”’is coupled to the first terminal of the fourth coil 4”” via a second coupling capacitor Cc2. The first terminal of the second coil 4” and the first terminal of the third coil 4’” are directly coupled.

In the sixth load coil configuration 44, shown in Fig. 6f, the second terminals of the first load coil 4’ and the fourth load coil 4”” are directly connected, while the second terminal of the second load coil 4” and the third terminal of the third load coil 4”’ are open. Further, the first terminal 4a of the first coil 4‘ is coupled to the first terminal of the second coil 4” via a first coupling capacitor Cel, while the first terminal of the third coil 4”is coupled to the first terminal of the fourth coil 4”” via a second couphng capacitor Cc2.

According to an aspect of the invention, a method is provided for controlling operation of an electrical converter comprising a DC-AC converter provided with a DC input port, an AC output port, a source coil connected to the AC output port, and a reversely oriented load coil positioned in proximity to the source coil such that the source coil and the load coil are coupled via a resonance capacitor. The method comprises a step of controlling a frequency of an electric signal provided at the AC output port.

The method for controlling operation of an electrical converter can be performed using dedicated hardware structures, such as FPGA and/or ASIC components. Otherwise, the method can also at least partially be performed using a computer program product comprising instructions for causing a controller, a processor of a computer system or a control unit to perform the above described step of the method according to the invention, or at least a sub-step of receiving feedback data from a measured resonance capacitor voltage.

All steps can in principle be performed on a single processor. However, it is noted that at least one sub-step can be performed on a separate processor. A processor can be loaded with a specific software module. Dedicated software modules can be provided.

The invention is not restricted to the embodiments described herein. It will be understood that many variants are possible.

These and other embodiments will be apparent for the person skilled in the art and are considered to fall within the scope of the invention as defined in the following claims. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments. However, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

Claims

An electrical converter, comprising a DC to AC converter provided with a DC input terminal, an AC output terminal and a controller which controls a frequency of an electrical signal provided at the AC output terminal, further comprising a source coil connected to the AC output terminal and a inversely oriented load coil disposed in the vicinity of the source coil such that the source coil and the load coil are coupled via a resonance capacitor.

The electrical converter of claim 1, wherein the load coil is connected to a low impedance load.

An electrical converter according to claim 1 or 2, comprising a multiple number of load coils.

An electrical converter according to claim 3, wherein a first load coil surrounds the source coil, in reverse position, and wherein a subsequent load coil surrounds previous load coil, in an inverted position relative to the orientation of the previous load coil .

The electric converter according to claim 4, wherein the amplitude of a pitch angle of successive load coils increases, preferably with a fixed angular step.

The electrical converter of claim 1, further comprising a load transformer and a power transformer, wherein each transformer is provided with an input terminal and an output terminal, the input terminal of the load transformer being connected to the load coil and the output terminal. of the load transformer is connected to the output terminal of the power transformer for setting a frequency of an electrical signal at the output terminal of the load transformer.

The electrical converter of claim 6, wherein the output terminal of the load transformer and the output terminal of the power transformer each have a first output terminal and a second output terminal, the first output terminal of the load transformer being connected to a first terminal of the output terminal of the load transformer and the second output terminal of the load transformer, a first alternating current output terminal of the electrical converter, and wherein the second output terminal of the power transformer forms a second alternating current output terminal of the electrical converter.

An electrical converter according to any one of the preceding claims, wherein the resonance capacitor has a capacitance value in a range of about 1000 pF to about 10,000 pF.

9. An electrical converter as claimed in any one of the preceding claims, further comprising a direct current to alternating current converter for converting alternating current electric power supply energy into direct current electrical energy for supplying the direct current to alternating current converter.

10. An electrical converter according to any one of the preceding claims, wherein the source coil, the load coil and the resonance capacitor form a resonance circuit.

An electrical converter according to any one of the preceding claims, wherein the DC-to-AC converter controller is adapted to adjust the frequency of the electrical signal provided at the AC output terminal in a range of about 10 kHz to about 200 kHz.

12. A method for controlling the operation of an electric converter comprising a direct current to alternating current converter provided with a direct current input terminal, an alternating current output terminal, a source coil connected to the alternating current output terminal, and a reverse-oriented load coil located in the vicinity of the source coil is arranged such that the source coil and the load coil are coupled via a resonance capacitor, the method comprising the step of controlling a frequency of an electrical signal provided at the alternating current output terminal.

The method of claim 12, wherein the frequency is controlled by using a voltage on the resonance capacitor as input.

A computer program product for controlling the operation of an electrical converter comprising a direct current to alternating current converter provided with a direct current input terminal, an alternating current output terminal, a source coil connected to the alternating current output terminal, and a reverse-oriented load coil which the proximity of the source coil is arranged such that the source coil and the load coil are coupled via a resonance capacitor, the computer program comprising a product for a computer readable code that enables a processor to perform a step of controlling a frequency of an electrical signal provided at the alternating current output terminal.