Apparatus for inductively supplying power to a circuit breaker

Abstract

Apparatus (9, 1c, 1d, 1e) comprises: a power transmission coil (L2', L2) for supplying power by inductive coupling to a power reception coil (L1) of a circuit breaker (1c, 1d, 1e), and a frequency-controllable AC signal generator (17, T1'...T4', T1…T4) coupled 5 to provide an AC energising signal to the power transmission coil. The apparatus (9, 1c, 1d, 1e) is configured to control the frequency-controllable AC signal generator (17, T1'...T4', T1…T4) to adjust a frequency of the AC energising signal.

Description

[0001] Apparatus For Inductively Supplying Power to a Circuit Breaker

[0002] Field of the Invention

[0003] The invention relates to apparatus for inductively supplying power to a circuit breaker.

[0004] Background to the Invention

[0005] A circuit breaker invariably comprises a circuit breaker housing, a switching contact within the circuit breaker housing and metallic main power terminals, which are conductively connected to the switching contact and which protrude through the circuit breaker housing. Further on, the circuit breaker comprises a trigger unit acting on the switching contact, a circuit breaker microcontroller and a circuit breaker memory within the circuit breaker housing as well as a circuit breaker data interface, which is connected to a data input and / or output of the circuit breaker microcontroller and / or to a data input and / or output of the circuit breaker memory.

[0006] It is known from WO2023 / 179915 to provide a circuit breaker of the above kind and an interface unit designed to communicate with the circuit breaker microcontroller and / or the circuit breaker memory of the circuit breaker via the circuit breaker data interface or

[0007] a computer designed to communicate with the circuit breaker microcontroller and / or the circuit breaker memory of the circuit breaker via the circuit breaker data interface or

[0008] a computer with an interface unit designed to communicate with the circuit breaker microcontroller and / or the circuit breaker memory of the circuit breaker via the circuit breaker data interface.

[0009] The switching contact is provided to switch off a current path between the main power terminals. For example, the switching contact can disconnect the main power terminals or switch off the current path respectively by means of the trigger unit in case of overcurrent or upon manual actuation. Moreover, data and commands may be exchanged between the circuit breaker and an interface unit or a computer via the circuit breaker data interface. For example, measurement values for a current flowing over the switching contact or a voltage of the current path can be sent from the circuit breaker to the interface unit or the computer. Furthermore, tripping characteristics for setup of the tripping unit may be sent from the interface unit or the computer to the circuit breaker.Dangers caused by voltages are avoided in WO2013 / 179915 by using an optical interface for the circuit breaker data interface. In this way, a computer or interface unit connected to the circuit breaker is galvanically separated from parts of the circuit breaker under high voltage and is even save against dangerous creeping voltage. Hence, neither the equipment connected to the circuit breaker, nor the personnel operating said equipment is exposed to the risk or danger of an electric shock originating from the power grid connected to the main power terminals of the circuit breaker.

[0010] Beneficially, the optical circuit breaker data interface comprises

[0011] an optical circuit breaker output sender, which is connected to a data output or a combined data input / output of the circuit breaker microcontroller and / or the circuit breaker memory and which is arranged within the circuit breaker housing, and a circuit breaker output light guide, which is optically coupled to the optical circuit breaker output sender and which protrudes through the circuit breaker housing or is part of the same and / or

[0012] an optical circuit breaker input receiver, which is connected to a data input or a combined data input / output of the circuit breaker microcontroller and / or the circuit breaker memory and which is arranged within the circuit breaker housing, and a circuit breaker input light guide, which is optically coupled to the optical circuit breaker input receiver and which protrudes through the circuit breaker housing or is part of the same.

[0013] In this way, modulated light pulses representing the data to be transmitted can be guided from the optical circuit breaker output sender out of the circuit breaker housing or can be guided to the optical circuit breaker input receiver into the circuit breaker housing. By use of the proposed measures, a very good electrical insulation and safety against electrical shocks originating from the power grid connected to the main power terminals of the circuit breaker is obtained. In this embodiment, the modulated light pulses representing the data to be transmitted are received and / or sent by the interface unit or the computer. For this reason, an optical interface unit output receiver may optically be coupled to the optical circuit breaker output sender and / or an optical interface unit input sender may optically be coupled to the optical circuit breaker input receiver.

[0014] Accordingly it is beneficial if the interface unit comprises an optical interface unit data interface, metallic interface unit data terminals, an interface unit microcontroller and an interface unit memory, wherein the metallic interface unit data terminals areconnected to the interface unit microcontroller and wherein the optical interface unit data interface comprises

[0015] an optical interface unit input sender, which is connected to a data output or a combined data input / output of the interface unit microcontroller and / or the interface unit memory and which is designed to be optically coupled to the optical circuit breaker input receiver of the circuit breaker and / or

[0016] an optical interface unit output receiver, which is connected to a data input or a combined data input / output of the interface unit microcontroller and / or the interface unit memory and which is designed to be optically coupled to the optical circuit breaker output sender of the circuit breaker.

[0017] In this way, modulated light pulses representing transmitted data can be received in the optical interface unit output receiver and can be converted there into electric signals. The electric signals are then decoded in the interface unit microcontroller, and decoded data can be provided to a computer connected to the interface unit via the metallic interface unit data terminals. Similarly, data can be sent from the computer to the interface unit via the metallic interface unit data terminals, can be coded in the interface unit microcontroller and can be converted into modulated light pulses in the optical interface unit input sender.

[0018] It should be noted at this point that the terms "input" and "output" consistently relate to the circuit breaker's view (strictly speaking to the view of its circuit breaker microcontroller and / or the circuit breaker memory). That means, that data input to the circuit breaker is output from the optical interface unit input sender, and that data output from the circuit breaker is input to the optical interface unit output receiver. In other words, the terms "input" and "output" have a diametric meaning for the interface unit and the computer.

[0019] Alternatively, the circuit breaker can comprise a circuit breaker power interface, which is coupled to the power pins of the circuit breaker microcontroller and / or the circuit breaker memory. In this way, the circuit breaker microcontroller and / or the circuit breaker memory can be powered from outside of the circuit breaker. Accordingly, no measures have to be taken that a battery for powering the circuit breaker microcontroller and / or the circuit breaker memory has a certain power level.

[0020] Beneficially, the circuit breaker power interface can be a contactless interface. In this way, a galvanic separation can be provided between a power source for powering the circuit breaker microcontroller and / or the circuit breaker memory and the circuitbreaker microcontroller and / or the circuit breaker memory as such. Accordingly, a very good electrical insulation and safety against electrical shocks originating from the power grid connected to the main power terminals of the circuit breaker can be provided.

[0021] Advantageously, the circuit breaker power interface can comprise an electromagnetic receiver arranged within the circuit breaker housing. In this way, power can electromagnetically be transmitted to the circuit breaker microcontroller and / or the circuit breaker memory. No power terminals are necessary on or in the circuit breaker for powering the circuit breaker microcontroller and / or the circuit breaker memory. Accordingly, a very good electrical insulation and safety against electrical shocks originating from the power grid connected to the main power terminals of the circuit breaker can be provided.

[0022] In WO2013 / 179915, the circuit breaker power interface comprises an electromagnetic receiver and an electromagnetic circuit breaker sender electromagnetically coupled to each other, wherein both are arranged within the circuit breaker housing. Also, the circuit breaker comprises metallic circuit breaker auxiliary power terminals, which are provided to feed power to the electromagnetic circuit breaker sender and which protrude through the circuit breaker housing.

[0023] Alternatively, the electromagnetic circuit breaker sender and the electromagnetic receiver are part of the circuit breaker. Galvanic separation is provided by the circuit breaker power interface, which is fully integrated in the circuit breaker. Hence, the interface unit, the computer or a power unit for the circuit breaker does not need to have a contactless power interface but can be electrically connected to the circuit breaker.

[0024] The circuit breaker comprises a circuit breaker power stage with circuit breaker switching transistors, which is

[0025] connected to the circuit breaker power interface (in particular to its electromagnetic circuit breaker sender),

[0026] controlled by an interfacing microcontroller of the circuit breaker and powered via the metallic circuit breaker auxiliary power terminals.

[0027] By these measures, the interface unit, the computer or a power unit for the circuit breaker does not need to provide an AC voltage to the circuit breaker. Instead, provision of a DC voltage is sufficient. This DC voltage is provided to the circuitbreaker switching transistors and converted there into an AC voltage. For example, the circuit breaker switching transistors can form half bridges, which are connected to an electromagnetic circuit breaker sender of the circuit breaker. Control of the circuit breaker switching transistors or half bridges is done by the interfacing microcontroller.

[0028] Similar considerations can be made for the interface unit, which may comprise i) metallic auxiliary interface unit power terminals,

[0029] ii) an interface unit power interface with an electromagnetic interface unit sender, which is designed to be electromagnetically coupled to the electromagnetic receiver of the circuit breaker and

[0030] iii) an interface unit power stage with interface unit switching transistors, which is connected to the interface unit power interface (in particular to its electromagnetic interface unit sender),

[0031] controlled by an interface unit microcontroller of the interface unit and powered via the metallic auxiliary interface unit power terminals.

[0032] In this embodiment, the conversion from a DC voltage to an AC voltage is done in a dedicated interface unit. Accordingly, the computer does not need to provide an AC voltage to the circuit breaker. Instead, provision of a DC voltage to the interface unit is sufficient. This DC voltage is provided to the interface unit switching transistors and converted there into an AC voltage. For example, the interface unit switching transistors can form half bridges, which are connected to an electromagnetic interface unit sender of the interface unit. Control of the interface unit switching transistors or half bridges is done by the interface unit microcontroller.

[0033] Beneficially the metallic circuit breaker data terminals and / or the metallic auxiliary power terminals are part of an USB socket. In this way, the interface unit or the computer can be connected to the circuit breaker by commonly used means. The same counts for the metallic interface unit data terminals and / or the metallic auxiliary interface unit power terminals of the interface unit which may be part of an USB socket as well.

[0034] Beneficially, the circuit breaker microcontroller is functionally coupled to the trigger unit and is designed

[0035] to receive tripping characteristics or a choice of tripping characteristics for the tripping unit through the circuit breaker data interface (for example in form of tripping curves B, C, D) and / or

[0036] to receive a command for running a self-test and to send results of said self-test through the circuit breaker data interface.

[0037] In this way, data can be sent to the circuit breaker to set up the tripping unit. For example, data representing tripping characteristics in form of tripping curves B, C, D can be sent to the circuit breaker. If a plurality of tripping characteristics is stored in the circuit breaker microcontroller or the tripping unit, it is sufficient to send a choice to set up the tripping unit. In an alternative embodiment, a self-test can be run in the circuit breaker, for example testing internal functions of the circuit breaker. After the test, the results of the same can be sent back to the interface unit or computer.

[0038] In yet another beneficial embodiment, the circuit breaker comprises

[0039] a current sensor, which is connected to the circuit breaker microcontroller, wherein the circuit breaker microcontroller is designed to send a measurement value measured by the current sensor or a parameter derived from said measurement value (e.g. a harmonic distortion of a course of the current) via the circuit breaker data interface and / or

[0040] a voltage sensor, which is connected to the circuit breaker microcontroller, wherein the circuit breaker microcontroller is designed to send a measurement value measured by the voltage sensor or a parameter derived from said measurement value (e.g. a harmonic distortion of a course of the voltage) via the circuit breaker data interface.

[0041] In this embodiment, actual and also historic data related to a current flowing over the switching contact or the main power terminals and / or a voltage at the switching contact or at the main power terminals can be measured and can be read out by the interface unit or the computer. In addition, parameters derived from said current and / or voltage can be calculated in the circuit breaker microcontroller and can be sent to the interface unit or the computer, for example, a harmonic distortion of said current and / or voltage. The circuit breaker microcontroller may also be designed to calculate an electric power, an electric energy and / or a phase shift between voltage and current based on the measured values and to send the calculated value via the circuit breaker data interface.

[0042] It should be noted that the term "transmitter" may synonymously be used for the "sender" throughout this application. Accordingly, an "optical sender" may also be denoted as an "optical transmitter", and an "electromagnetic sender" may also be denoted as an "electromagnetic transmitter". The same counts for the verb "send", for which the term "transmit" may be used instead. This applies to both "data transmission" and "power transmission".Summary of the Invention

[0043] An aspect of the invention provides apparatus comprising:

[0044] a power transmission coil for supplying power by inductive coupling to a power reception coil of a circuit breaker; and

[0045] a frequency-controllable AC signal generator coupled to provide an AC energising signal to the power transmission coil,

[0046] wherein the apparatus is configured to control the frequency-controllable AC signal generator to adjust a frequency of the AC energising signal.

[0047] The apparatus may further comprise a power sensor configured to sense a magnitude of power supplied to the power transmission coil.

[0048] The apparatus may be configured to detect a resonant frequency of the arrangement comprising the power transmission coil and the power reception coil by controlling the frequency-controllable AC signal generator to sweep the AC energising signal across a frequency range and to detect a frequency at which the maximum current flows through the power transmission coil.

[0049] The apparatus may be configured to control the frequency-controllable AC signal generator to hold the energising signal at a frequency that is different to a resonant frequency of the arrangement comprising the power transmission coil and the power reception coil. This apparatus may be configured to control the frequency-controllable AC signal generator to hold the energising signal at a frequency that is higher than the resonant frequency of the arrangement comprising the power transmission coil and the power reception coil.

[0050] The frequency-controllable AC signal generator may be an H bridge.

[0051] The apparatus may further comprise the circuit breaker and the power receiving coil, wherein the circuit breaker includes a circuit breaker controller.

[0052] Further advantageous embodiments are disclosed in the claims and in the description as well as in the figures.

[0053] Brief Description of Drawings

[0054] The invention now is described in more detail hereinafter with reference to particular embodiments, to which the invention however is not limited.Figure 1 shows a schematic of a first example of a system with a circuit breaker, an optically coupled interface unit and a computer;

[0055] Figure 2 shows a schematic of a second example of a system with a circuit breaker with an optocoupler and a computer connected thereto;

[0056] Figure 3 shows a system similar to that of Figure 2 but which comprises an external power unit connected to the circuit breaker;

[0057] Figure 4 shows a plot of frequency versus voltage relating to power transfer.

[0058] Detailed Description

[0059] Generally, same parts or similar parts are denoted with the same / similar names and reference signs. The features disclosed in the description apply to parts with the same / similar names respectively reference signs. Indicating the orientation and relative position is related to the associated figure, and indication of the orientation and / or relative position has to be amended in different figures accordingly as the case may be.

[0060] Figure 1 shows a circuit breaker lc, which comprises a circuit breaker housing 2, switching contacts SI, S2 within the circuit breaker housing 2, metallic main power terminals M1..M4, which are conductively connected to the switching contacts SI, S2 and which protrude through the circuit breaker housing 2, and a trigger unit 3 acting on the switching contacts SI, S2. Moreover, the circuit breaker la comprises a circuit breaker microcontroller 4 and a circuit breaker memory 5, which form a circuit breaker control unit 6 and which are arranged within the circuit breaker housing 2. In addition, the circuit breaker la comprises an optional current sensor A and an optional voltage sensor V, which are connected to the circuit breaker microcontroller 4.

[0061] Further on, the circuit breaker la comprises an optical circuit breaker data interface Dll, which is connected both to a data input and to a data output of the circuit breaker microcontroller 4 and / or which is connected both to a data input and to a data output of the circuit breaker memory 5 respectively. In this example, the optical circuit breaker data interface Dll comprises an optical circuit breaker output sender DI, which is connected to a data output or a combined data input / output of the circuit breaker microcontroller 4 and / or the circuit breaker memory 5 and which is arranged within the circuit breaker housing 2. In addition, the optical circuit breaker data interface Dll in this example comprises an optional circuit breaker output light guide 7, which is optically coupled to the optical circuit breaker output sender DI and which protrudes through the circuit breaker housing 2 or is part of the same.

[0062] Moreover, the optical circuit breaker data interface Dll comprises an optical circuitbreaker input receiver Pl, which is connected to a data input or a combined data input / output of the circuit breaker microcontroller 4 and / or the circuit breaker memory 5 and which is arranged within the circuit breaker housing 2. In addition, the optical circuit breaker data interface Dll comprises an optional circuit breaker input light guide 8, which is optically coupled to the optical circuit breaker input receiver Pl and which protrudes through the circuit breaker housing 2 or is part of the same, too.

[0063] Furthermore, Figure 1 shows an interface unit 9, which comprises an interface unit housing 10, an optical interface unit data interface DI2 within the interface unit housing 10, metallic interface unit data terminals DT', an interface unit microcontroller 11' and an interface unit memory 12', which form an interface unit control unit 13' and which are arranged within the interface unit housing 10. The metallic interface unit data terminals DT' protrude through the interface unit housing 10 and are connected to the interface unit microcontroller 11'.

[0064] The optical interface unit data interface DI2 comprises an optical interface unit output receiver P2', which is connected to a data input or a combined data input / output of the interface unit microcontroller 11' and / or the interface unit memory 12' and which is designed to be optically coupled to the optical circuit breaker output sender DI of the circuit breaker la. For this reason, the optical interface unit data interface DI2 comprises an optional interface unit output light guide 14, which is optically coupled to the optical interface unit output receiver P2' and which protrudes through the interface unit housing 10 or is part of the same.

[0065] Moreover, the optical interface unit data interface DI2 comprises an optical interface unit input sender D2', which is connected to a data output or a combined data input / output of the interface unit microcontroller 11' and / or the interface unit memory 12' and which is designed to be optically coupled to the optical circuit breaker input receiver Pl of the circuit breaker la. For this reason, the optical interface unit data interface DI2 comprises an optional interface unit input light guide 15, which is optically coupled to the optical interface unit input sender D2' and which protrudes through the interface unit housing 10 or is part of the same as well.

[0066] Finally, Figure 1 shows a computer 16, which is connected to the interface unit 9 via its metallic interface unit data terminals DT'. Overall, Figure 1 shows a system, comprising the circuit breaker la, the interface unit 9 and the computer 16.Again, it is noted that the terms "input" and "output" consistently relate to the circuit breaker's view (strictly speaking to the view of its circuit breaker microcontroller 4 and / or the circuit breaker memory 5) and that the terms "input" and "output" have a diametric meaning for the interface unit 9 and the computer 16.

[0067] The function of the system shown in Figure 1 now is as follows:

[0068] The switching contacts SI, S2 are provided to disconnect the first main power terminal Ml from the second main power terminal M2 and to disconnect the third main power terminal M3 from the fourth main power terminal M4. In other words, the switching contacts SI, S2 are provided to switch off a first current path between the first main power terminal Ml and the second main power terminal M2 and to switch off a second current path between the third main power terminal M3 and the fourth main power terminal M4. In this example, the switching contacts SI, S2 are separated from each other by means of the trigger unit 3, for example, in case of overcurrent or upon manual actuation. It should be noted that although in Figure 1 a two-pole circuit breaker la with two switching contacts SI, S2 is shown, the technical teaching applies to any number of poles or switching contacts SI, S2 equivalently, for example, to one-pole circuit breakers, three-pole circuit breakers and four-pole circuit breakers. The switching function of a circuit breaker lc in principle is known per se and thus it is not explained in more detail at this point.

[0069] In addition, a current through the first current path between the first main power terminal Ml and the second main power terminal M2 is measured by the optional current sensor A, and a voltage is measured between the first main power terminal Ml and the third main power terminal M3 by the optional voltage sensor V. The circuit breaker microcontroller 4, which the current sensor A is connected to, can be designed to send a measurement value measured by the current sensor A or a parameter derived from said measurement value via the circuit breaker data interface Dll. A parameter derived from said measurement value for example can be a harmonic distortion of said current. Moreover, the circuit breaker microcontroller 4, which the voltage sensor V is connected to, can be designed to send a measurement value measured by the voltage sensor V or a parameter derived from said measurement value via the circuit breaker data interface Dll as well. A parameter derived from said measurement value for example can be a harmonic distortion of said voltage. In particular, the circuit breaker microcontroller 4 may be provided to code the measurement value or parameters before they are sent via the circuit breaker data interface Dll. Further parameters, which can be calculated by the circuit breakermicrocontroller 4 are an electric power, an electric energy and / or a phase shift between voltage and current based on the measured values.

[0070] In detail, said measurement values or parameters are transmitted to the interface unit 9 by means of the optical circuit breaker output sender DI. Here, the optical circuit breaker output sender DI is directly connected to the circuit breaker control unit 6. However, a driver stage may be arranged between the circuit breaker control unit 6 and the optical circuit breaker output sender DI as the case may be.

[0071] Modulated light pulses generated by the optical circuit breaker output sender DI and representing the data to be transmitted pass the circuit breaker output light guide 7 and the interface unit output light guide 14 before they reach the optical interface unit output receiver P2', where the modulated light pulses are converted back to electric signals again. These electric signals are received by the interface unit microcontroller 11', decoded there and provided to the computer 16 at the interface unit data terminals DT'. For example, the interface unit data terminals DT' may be part of an USB socket ("universal serial bus"). Accordingly, the measurement values or parameters measured by the current sensor A or the voltage sensor V may be provided to the computer 16 according to an USB standard.

[0072] In this example, the system in shown in Figure 1 is not only designed to transmit measurement values or parameters derived therefrom from the circuit breaker la to the computer 16 via the interface unit 9, but also to transmit data from the computer 16 to the circuit breaker la via the interface unit 9.

[0073] For example, the circuit breaker microcontroller 4 can be functionally coupled to the trigger unit 3 and can be designed to receive tripping characteristics or a choice of tripping characteristics for the tripping unit 3 through the circuit breaker data interface Dll and / or to receive a command for running a self test and to send results of said self test through the circuit breaker data interface Dll. For example, said tripping characteristics can be defined by tripping curves B, C and D providing a different (fast, medium, slow) time / current behavior of the circuit breaker la. A self test, for example, can be provided to test the proper function of the tripping unit 3.

[0074] If data or commands are to be transmitted to the circuit breaker la, said data or commands are sent from the computer 16 to the interface unit 9 via the interface unit data terminals DT' (which again may be part of an USB socket) and are received in the interface unit microcontroller 11'. Here the data or commands are prepared to be sentvia the circuit breaker data interface Dll. In detail, said data or commands are transmitted to the circuit breaker la by means of the optical interface unit input sender D2', which converts electric signal into modulated light pulses. Here, the optical interface unit input sender D2' is directly connected to the interface unit microcontroller 11'. However, a driver stage may be arranged between the interface unit microcontroller 11' and the optical interface unit input sender D2' as the case may be.

[0075] The modulated light pulses representing the data to be transmitted pass the interface unit input light guide 15 and the circuit breaker input light guide 8 before they reach the optical circuit breaker input receiver Pl, where the modulated light pulses are converted back to electric signals again. These electric signals are received by the circuit breaker microcontroller 4, decoded there and used to change tripping characteristics of the trigger unit 3 or for starting a self test there for example.

[0076] Of course, the function of the circuit breaker microcontroller 4 and the interface unit microcontroller 11' is not limited to the aforementioned functions, but the circuit breaker microcontroller 4 and the interface unit microcontroller 11' may take over further functions as well. The circuit breaker memory 5 and the interface unit memory 12' can be used for storing both data and executable code. In the example shown in Figure 1, the circuit breaker microcontroller 4 and the circuit breaker memory 5 are integral part of the circuit breaker control unit 6. This is no necessary condition and the circuit breaker microcontroller 4 and the circuit breaker memory 5 can be provided as separate devices as well. The same counts for the interface unit control unit 13', which the interface unit microcontroller 11' and the interface unit memory 12' are integral part of. The interface unit microcontroller 11' and the interface unit memory 12' can be provided as separate devices as well.

[0077] It should also be noted that data can be directed to the circuit breaker microcontroller 4 and / or to the circuit breaker memory 5 or can be read from the circuit breaker microcontroller 4 and / or to the circuit breaker memory 5. Similarly, data can be directed to the interface unit microcontroller 11' and / or to the interface unit memory 12' or can be read from the interface unit microcontroller 11' and / or to the interface unit memory 12'.

[0078] The optical circuit breaker output sender DI and the optical interface unit input sender D2' each are embodied as a light emitting diode. This is a beneficial solution, however, the use of other optional senders is possible as well. The same counts forthe optical circuit breaker input receiver Pl and the optical interface unit output receiver P2', which each are embodied as a phototransistor. Although this is a beneficial solution, the use of other optical receivers is possible as well.

[0079] A light guide (not shown) may be present between the light emitting diode I optical circuit breaker output sender DI and the phototransistor / optical interface unit output receiver P2'.

[0080] Another light guide (not shown) may be present between the light emitting diode I optical interface unit input sender D2' and the phototransistor / optical circuit breaker input receiver Pl.

[0081] The use of light guides is advantageous but not necessary because optical coupling of the optical circuit breaker data interface Dll and the optical interface unit data interface DI2 can be done in another way as well, e.g. using free space optical communications.

[0082] Further on, the optical circuit breaker data interface Dll and the optical interface unit data interface DI2 do not necessarily support bidirectional data transmission. Instead, it is possible that data can only be sent form the circuit breaker la to the interface unit 9 or from the interface unit 9 to the circuit breaker la.

[0083] A circuit breaker power interface PI1 is coupled to the power pins of the circuit breaker microcontroller 4 and / or the circuit breaker memory 5. In detail, the circuit breaker power interface PI1 is a contactless interface and comprises an electromagnetic receiver LI arranged within the circuit breaker housing 2. Here the electromagnetic receiver LI is embodied as a coil and is in series connection with a first circuit breaker capacitor Cl (although it may instead be in parallel). Downstream of this series connection there is a bridge rectifier BR, which powers the circuit breaker microcontroller 4 and the circuit breaker memory 5, wherein power fluctuations are damped by a third circuit breaker capacitor C3.

[0084] The interface unit 9 comprises:

[0085] i) metallic auxiliary interface unit power terminals PT',

[0086] ii) an interface unit power interface PI2 with an electromagnetic interface unit sender L2', which is designed to be electromagnetically coupled to the electromagnetic receiver LI of the circuit breaker lc, and

[0087] iii) an interface unit power stage PS' with interface unit switchingtransistors T1'...T4', which is connected to the interface unit power interface PI2 (in particular to the electromagnetic interface unit sender L2'), controlled by an interface unit microcontroller 11' of the interface unit 9 and powered via the metallic auxiliary interface unit power terminals PT'.

[0088] In detail, the electromagnetic interface unit sender L2' is embodied as a coil and is in series connection with an interface unit capacitor C2' (although the capacitor C2' may instead be in parallel). The interface unit switching transistors T1'...T4' form half bridges, wherein a first half bridge is formed by the first and second interface unit switching transistors Tl', T2' and wherein a second half bridge is formed by the third and fourth interface unit switching transistors T3', T4'. The first half bridge is connected to a first end of the series connection of the electromagnetic interface unit sender L2' and the interface unit capacitor Cl, and the second half bridge is connected to a second end of said series connection. Power is supplied from the computer 16 to the transistors T1'...T4' via the metallic auxiliary interface unit power terminals PT'. In particular, the metallic auxiliary interface unit power terminals PT' can be part of an USB socket.

[0089] However, the circuit breaker microcontroller 4 and the circuit breaker memory 5 are powered in a different way. In detail, the half bridges are controlled by the interface unit microcontroller 11' in a way that DC power originating from the computer 16 is converted into AC power, which is wirelessly transmitted from the electromagnetic interface unit sender L2' of the interface unit 9 to the electromagnetic receiver LI of the circuit breaker lc and converted back to DC power by the bridge rectifier BR before it is transmitted to the circuit breaker microcontroller 4 and the circuit breaker memory 5.

[0090] A current sense resistor R1 is connected in series with the electromagnetic interface unit sender L2'. This allows sensing by the interface unit microcontroller 11' of the current flowing through the electromagnetic interface unit sender L2', in particular by detecting the voltage across the sense resistor R1 and dividing the value by the resistance of the sense resistor Rl.

[0091] The current sense resistor Rl allows the interface unit microcontroller 11' to detect the power transmitted by the electromagnetic interface unit sender L2' at any given point in time, in particular by squaring the detected voltage across the sense resistor Rl and dividing the value by the resistance of the sense resistor Rl. The interface unitmicrocontroller 11' is configured to monitor the power transmitted by the electromagnetic interface unit sender L2' over time.

[0092] Another suitable means may alternatively allow the interface unit microcontroller 11' to detect the power transmitted by the electromagnetic interface unit sender L2' at any given point in time.

[0093] In Figure 1, the electromagnetic interface unit sender is an example of a power transmission coil L2'. This power transmission coil L2' is for inductive coupling to the electromagnetic receiver LI, which is an example of a power reception coil.

[0094] The interface unit transistors T1'..T4' generate an AC signal under control of the interface unit microcontroller 11'. The interface unit transistors T1'..T4' and the interface unit microcontroller 11' thus form a frequency-controllable AC signal generator, which is coupled to provide an AC energising signal to the power transmission coil L2'. The frequency of the AC energising signal is adjusted by adjusting the frequency of the signals from the interface unit microcontroller 11' to the control (e.g. gate) electrodes of the interface unit transistors T1'..T4'. The frequency of the signals from the interface unit microcontroller 11' to the control (e.g. gate) electrodes of the interface unit transistors T1'..T4' is known by the interface unit microcontroller 11' and is set by the interface unit microcontroller 11' as related to the frequency of the internal clock (not shown) of the interface unit microcontroller 11'. The interface unit microcontroller 11' is configured to adjust a frequency of the AC energising signal to control the power transmitted to the power reception coil LI and thus the circuit breaker control unit 6.

[0095] Specifically, the power transmitted to the power reception coil LI, and thus the circuit breaker control unit 6, is a function of the frequency of the AC energising signal and depends on characteristics of components of the circuit breaker lc. This will now be discussed with reference to Figure 4.

[0096] Figure 4 shows an example plot of voltage across the capacitor Cl for different frequencies of the AC energising signal. It can be seen from Figure 4 that the voltage across the capacity Cl increases as the frequency of the AC energising signal increases from 100 kHz. The voltage across the capacity Cl increases as the frequency of the AC energising signal increases to a peak at around 200 kHz.

[0097] Following this peak, the voltage decreases as the frequency continues to increase.The peak is at Point A. The frequency corresponding to Point A is the resonant frequency of the circuit including the power transmission coil L2' and the power reception coil LI. The resonant frequency will be different for different apparatus constructed from supposedly the same components because of differences in values of capacitance, inductance, resistance etc. and because of slightly different spacings between and alignment of, inter alia, the power transmission coil L2' and the power reception coil LI.

[0098] The interface unit microcontroller 11' is configured to determine the resonant frequency of the circuit including the power transmission coil L2' and the power reception coil LI. Specifically, the interface unit microcontroller 11' determines the resonant frequency by sweeping the frequency of the AC energising signal and monitoring the power at the power transmission coil L2' for different frequencies. Monitoring the power is performed by sensing the voltage across the resistor Rl, as discussed above. The frequency of the AC energising signal at which the maximum current flows through the power transmission coil is detected, and this is determined to be the resonant frequency of the circuit including the power transmission coil L2' and the power reception coil LI.

[0099] Determining the resonant frequency in this way is advantageous since it does not require any power measurement circuitry on the receive side, nor does it require any communication of measurements etc. from the receive side to the interface unit 9.

[0100] The resonant frequency can alternatively be determined by sweeping the frequency of the AC energising signal and using feedback signals, e.g. current / power measurements or estimates, from the circuit breaker lc and transmitted by the circuit breaker microcontroller 4 over the optical interfaces Dll, DI2 to the interface unit microcontroller 11'.

[0101] Once the resonant frequency is known, the interface unit microcontroller 11' can better control the power transmitted to the receive side.

[0102] At some times, the interface unit microcontroller 11' is configured to control the frequency-controllable AC signal generator to hold the AC energising signal at a frequency that is substantially equal to the resonant frequency of the arrangement comprising the power transmission coil L2' and the power reception coil LI. At the resonant frequency, maximum power is transmitted.The interface unit microcontroller 11' is configured to control the frequency-controllable AC signal generator not to hold the AC energising signal at the resonant frequency of the arrangement comprising the power transmission coil L2' and the power reception coil LI. In this way, maximum power is not ever transmitted to the receive side. Instead, the transmitted power is always less than the maximum power (except when the resonant frequency is being determined by sweeping the frequency of the AC energising signal).

[0103] At some times, the interface unit microcontroller 11' is configured to control the frequency-controllable AC signal generator to hold the AC energising signal at a frequency that is different to the resonant frequency of the arrangement comprising the power transmission coil L2' and the power reception coil LI. For instance, the interface unit microcontroller 11' is configured to hold the energising signal at a frequency that is higher than the resonant frequency of the arrangement comprising the power transmission coil L2' and the power reception coil LI. Providing an AC energising signal at a frequency that is higher than the resonant frequency causes the power transmitted to the receive side to be less than the maximum transmit power.

[0104] For instance, by causing the AC energising signal to be at a frequency that is around 10% higher than the resonant frequency, the transmit power can be reduced by around 20% from the maximum. This is shown at Point B in Figure 4. By causing the AC energising signal to be at a frequency that is around 20% higher than the resonant frequency, the transmit power can be reduced by around 40% from the maximum. This is shown at Point C in Figure 4. A similar effect can be provided by controlling the interface unit microcontroller 11' to provide the AC energising signal to be at a frequency that is lower than the resonant frequency. However, controlling the power transfer is advantageously provided by causing the AC energising signal to be at a frequency that is higher than the resonant frequency.

[0105] The plot of transmit power, as a proportion of the maximum transmit power, can be identified by the interface unit microcontroller 11' by supplying different frequencies of the AC energising signal and detecting the power that is transmitted at the different frequencies. The interface unit microcontroller 11' can then use the information to self-calibrate. The information can be used by the interface unit microcontroller 11' to identify the AC energizing signal frequencies that are needed in order to supply power levels that are required to be supplied.

[0106] Supplying less than full power is advantageous for three reasons.The first is that it reduces heating on the transmit side, i.e. on the interface unit 9. In many circumstances, generating heat on the interface unit 9 may not be problematic. However, generating heat for extended periods may negatively impact the interface unit microcontroller 11' or the interface unit 9 more generally, potentially causing it to shut down, enter a reduced operating mode, or malfunction.

[0107] The second is that it reduces heating on the receive side circuit breaker lc. In many circumstances, generating heat on the receive side circuit breaker lc may not be problematic. However, generating heat for extended periods may negatively impact the circuit breaker microcontroller 4 or the circuit breaker control unit 6 more generally, potentially causing it to shut down, enter a reduced operating mode, or malfunction.

[0108] The reduction in heating is more significant on the transmit side than on the receive side.

[0109] The third is power saving on the transmit side, i.e. at the interface unit 9. This may be particularly important if the interface unit 9 is powered by the computer 16 (e.g. over USB) and the computer 16 is a laptop or other battery-powered computer.

[0110] The magnitude of the power that is supplied by the interface unit 9 to the circuit breaker lc is controlled according to the power demand of the circuit breaker lc. For times when the circuit breaker lc is not switching and instead is merely monitoring conditions or taking no action, power is supplied at a lowest power value. The supplied power is sufficient to power the circuit breaker control unit 6 and the circuit breaker memory 5 and to drive the optical interface unit data interface DI2, which are the only components that require power in this state. This may correspond to Point C in Figure 4.

[0111] When it is determined that the circuit breaker lc is required to open or close the switches SI, S2, the interface unit 9 supplies power at a highest power value. This may correspond to Point A in Figure 4, or it may be at a frequency different (preferably higher than) the resonant frequency. The supplied power is sufficient to power the circuit breaker control unit 6 and the circuit breaker memory 5 and also to power the trigger unit and change the state of the switches SI, S2. Determination that the circuit breaker lc is required to open or close the switches SI, S2 can be made in a number of different ways.First, the computer 16 may issue a control signal to open or close the switches SI, S2, in response to a user input or in an automated way. Here, the interface unit 9 receives an indication from the computer 16, which causes the interface unit microcontroller 11' to alter the frequency of the AC energising signal such as to supply power at the highest power value. Secondly, the circuit breaker lc may determine, e.g. based on detected voltage and current values, to open the switches SI, S2. In this case, a control signal is transmitted by the circuit breaker microcontroller 4 via the diode DI to the interface unit microcontroller 11' of the interface unit 9. This causes the interface unit microcontroller 11' to alter the frequency of the AC energising signal such as to supply power at the highest power value.

[0112] When it is determined that the circuit breaker lc requires power to power other components, power is supplied at a further, appropriate power value. For instance, if it is determined that it is required to power a display (not shown) forming part of the circuit breaker lc, the interface unit 9 supplies power at an intermediate power value. This may correspond to Point B in Figure 4. The supplied power is sufficient to power the circuit breaker microcontroller 4 and the circuit breaker memory 5 and also to power the display. Determination that the circuit display is required to be powered can be made by the interface unit microcontroller 11' based on signals received from the computer 16, or it can be made by the circuit breaker microcontroller 4 and communicated to the interface unit microcontroller 11' via the data interfaces Dll, DI2.

[0113] In all cases, the interface unit microcontroller 11' may be configured to cause the magnitude of the transmitted power to exceed the expected power consumption. The excess power will result in heating in the circuit breaker lc, but ensures that there is not insufficient power for powering the various components of the circuit breaker lc.

[0114] Instead of the circuit breaker microcontroller 4 signalling to the interface unit microcontroller 11' a power requirement in terms of a desired power level, the signalling may be in terms of an increase or a decrease. For instance, the circuit breaker microcontroller 4 can be configured to monitor power draw and received power. The circuit breaker microcontroller 4 can send a request to increase transmit power if the required power exceeds the power received (or exceeds it by less than a threshold amount). The circuit breaker microcontroller 4 can send a request to decrease transmit power if the required power is less the power received (or is less than the power received plus a threshold amount).Upon receiving a request to increase transmit power, the interface unit microcontroller 11' causes the frequency of the AC energising signal to increase or decrease by an amount (e.g. a fixed step) such as to move further away from the resonant frequency, and vice versa.

[0115] The interface unit transistors Tl' ... T4' form an H bridge, and thus the frequency-controllable AC signal generator in Figure 1 is an H bridge. The frequency is controlled by the interface unit microcontroller 11', as discussed above.

[0116] Instead of an H bridge, the frequency-controllable AC signal generator may take the form of an LLC or another suitable circuit or device.

[0117] The power transmission coil L2' advantageously is formed on a printed circuit board. The power reception coil LI is formed on another printed circuit board. The coils L2', LI can then be placed in an overlapping arrangement, with electrical insulation between the coils. A ferrite core extends into both the power transmission coil L2' and the power reception coil LI, which increases coupling between the coils L2', LI. The power transmission coil L2' and the power reception coil LI may alternatively take another form, for instance wire coils.

[0118] Figure 2 shows a second embodiment of a system, which is similar to the system shown in Figure 1. In contrast, the system of Figure 2 does not comprise an interface unit 9. Instead, the computer 16 is directly connected to circuit breaker Id of Figure 2.

[0119] A further difference is that the circuit breaker data interface Dll basically forms an optocoupler and comprises both an optical circuit breaker output sender DI and an optical circuit breaker output receiver P2 optically coupled thereto as well as both an optical circuit breaker input sender D2 and an optical circuit breaker input receiver Pl optically coupled thereto. In detail, the optical circuit breaker output sender DI is connected to a data output or a combined data input / output of the circuit breaker microcontroller 4 and / or the circuit breaker memory 5. Both the optical circuit breaker output sender DI and the optical circuit breaker output receiver P2 are arranged within the circuit breaker housing 2, wherein the circuit breaker Id comprises metallic circuit breaker data output terminals DTI, which are connected to the optical circuit breaker output receiver P2 and which protrude through the circuit breaker housing 2. Moreover, the optical circuit breaker input receiver Pl is connected to a data input or a combined data input / output of the circuit breaker microcontroller 4 and / or the circuitbreaker memory 5. Both the optical circuit breaker input sender D2 and the optical circuit breaker input receiver Pl are arranged within the circuit breaker housing 2, wherein the circuit breaker Id comprises metallic circuit breaker data input terminals DT2, which are connected to the optical circuit breaker input sender D2 and which protrude through the circuit breaker housing 2. The optical circuit breaker input sender D2 may be embodied as a light emitting diode and the optical circuit breaker output receiver P2 may be embodied as phototransistor. The metallic circuit breaker data terminals DTI, DT2 may be part of an USB socket.

[0120] The function of the system shown in Figure 2 in parts equals the function of the system shown in Figure 1, in detail in view of the switching contacts SI, S2, the main power terminals M1..M4, the trigger unit 3, the optional current sensor A, the optional voltage sensor V, the circuit breaker microcontroller 4, the circuit breaker memory 5, the circuit breaker control unit 6, the optical circuit breaker output sender DI, the optical circuit breaker input receiver Pl and the data and commands exchanged between the circuit breaker Id and the computer 16.

[0121] Modulated light pulses representing the data to be transmitted reach the optical circuit breaker output receiver P2, where the modulated light pulses are converted back to electric signals again. These electric signals are received in the computer 16 and are decoded there. Data or commands which are to be transmitted to the circuit breaker la are coded by the computer 16 and converted into modulated light pulses in the optical circuit breaker input sender D2. These modulated light pulses reach the optical circuit breaker input receiver Pl, where the modulated light pulses are converted back to electric signals again. These electric signals are received by the circuit breaker microcontroller 4 and decoded there as already explained in view of the example shown in Figure 1.

[0122] The optical circuit breaker data interface Dll does not necessarily support bidirectional data transmission. Instead, it is possible that data can only be sent form the circuit breaker Id to the computer 16 or from the computer 16 to the circuit breaker Id.

[0123] The optical circuit breaker output receiver P2 and the optical circuit breaker input sender D2 are coupled to an interfacing microcontroller 11 and an interfacing memory 12, which form an interfacing control unit 13 and are part of the circuit breaker Id. A similar structure is shown in the embodiment of Figure 1 where the optical interface unit input sender D2' and the optical interface unit output receiver P2' are connected to the interface unit microcontroller 11' and an interface unitmemory 12'. In other words, the optical interface unit output receiver P2' of Figure 1 becomes the optical circuit breaker output receiver P2 of Figure 2, the optical interface unit input sender D2' becomes the optical circuit breaker input sender D2, the interface unit microcontroller 11' becomes the interfacing microcontroller 11 and an interface unit memory 12' becomes the interfacing memory 12. That is why the technical teaching related to the connection of the circuit breaker data interface Dll to the interface unit control unit 13' shown in Figure 1 similarly applies to the circuit breaker Id of Figure 2.

[0124] Further on, the power transfer from the computer 16 to the circuit breaker microcontroller 4 and / or the circuit breaker memory 5 shown in Figure 2 is similar to the power transfer from the computer 16 to the circuit breaker microcontroller 4 and / or the circuit breaker memory 5 shown in Figure 1. The only difference is that the parts and functions of the circuit breaker power interface PI1 and the interface unit power interface PI2 of Figure 1 are integrated into a single circuit breaker power interface PI1 in Figure 2. In other words, the electromagnetic interface unit sender L2' of Figure 2 becomes the electromagnetic circuit breaker sender L2 of Figure 1, the interface unit capacitor C2' becomes the second circuit breaker capacitor C2, the interface unit transistors T1'..T4' become the circuit breaker transistors T1..T4 and the interface unit power stage PS' becomes the circuit breaker power stage PS. That is why the technical teaching to the power transfer related to Figure 1 equally applies to the power transfer of Figure 2. In this embodiment, the electromagnetic receiver LI and the electromagnetic circuit breaker sender L2, which is electromagnetically coupled to the electromagnetic receiver LI, are both arranged within the circuit breaker housing 2.

[0125] Although not shown in Figure 2, a current sense resistor R.1 is connected in order to allow the transmit power to be sensed. Operation of the interfacing microcontroller 11 in controlling the frequency of the AC energising signal, detecting the resonant frequency and / or setting the frequency to achieve a desired transmit power is the same as described in relation to Figure 1 and the interface unit microcontroller 11'.

[0126] Figure 3 shows a third embodiment of a system, which is similar to the system shown in Figure 1. In contrast, the system of Figure 3 does not comprise an interface unit 9. Instead, the computer 16 is directly connected to circuit breaker le of Figure 2.

[0127] A further difference is that the circuit breaker data interface Dll basically forms an optocoupler and comprises both an optical circuit breaker output sender DI and anoptical circuit breaker output receiver P2 optically coupled thereto as well as both an optical circuit breaker input sender D2 and an optical circuit breaker input receiver Pl optically coupled thereto. In detail, the optical circuit breaker output sender DI is connected to a data output or a combined data input / output of the circuit breaker microcontroller 4 and / or the circuit breaker memory 5. Both the optical circuit breaker output sender DI and the optical circuit breaker output receiver P2 are arranged within the circuit breaker housing 2, wherein the circuit breaker lb comprises metallic circuit breaker data output terminals DTI, which are connected to the optical circuit breaker output receiver P2 and which protrude through the circuit breaker housing 2. Moreover, the optical circuit breaker input receiver Pl is connected to a data input or a combined data input / output of the circuit breaker microcontroller 4 and / or the circuit breaker memory 5. Both the optical circuit breaker input sender D2 and the optical circuit breaker input receiver Pl are arranged within the circuit breaker housing 2, wherein the circuit breaker lb comprises metallic circuit breaker data input terminals DT2, which are connected to the optical circuit breaker input sender D2 and which protrude through the circuit breaker housing 2. The optical circuit breaker input sender D2 may be embodied as a light emitting diode and the optical circuit breaker output receiver P2 may be embodied as phototransistor. The metallic circuit breaker data terminals DTI, DT2 may be part of an USB socket.

[0128] The function of the system shown in Figure 3 in parts equals the function of the system shown in Figure 1, in detail in view of the switching contacts SI, S2, the main power terminals M1..M4, the trigger unit 3, the optional current sensor A, the optional voltage sensor V, the circuit breaker microcontroller 4, the circuit breaker memory 5, the circuit breaker control unit 6, the optical circuit breaker output sender DI, the optical circuit breaker input receiver Pl and the data and commands exchanged between the circuit breaker lb and the computer 16.

[0129] Modulated light pulses representing the data to be transmitted reach the optical circuit breaker output receiver P2, where the modulated light pulses are converted back to electric signals again. These electric signals are received in the computer 16 and are decoded there. Data or commands which are to be transmitted to the circuit breaker la are coded by the computer 16 and converted into modulated light pulses in the optical circuit breaker input sender D2. These modulated light pulses reach the optical circuit breaker input receiver Pl, where the modulated light pulses are converted back to electric signals again. These electric signals are received by the circuit breaker microcontroller 4 and decoded there as already explained in view of the example shown in Figure 1.The optical circuit breaker data interface Dll does not necessarily support bidirectional data transmission. Instead, it is possible that data can only be sent form the circuit breaker lba to the computer 16 or from the computer 16 to the circuit breaker le.

[0130] The system of Figure 3 comprises a separate external power unit 17, which is electrically connected to a circuit breaker power interface PH, which is embodied like the circuit breaker power interface PI1 of Figure 2.

[0131] The power unit 17 of this embodiment is considered to provide an AC power, which is wirelessly transmitted to the circuit breaker microcontroller 4 and the circuit breaker memory 5 by use of the circuit breaker power interface PH. In detail, the power unit 17 is connected to the series connection of the electromagnetic circuit breaker sender L2 and the second circuit breaker capacitor C2 via the auxiliary circuit breaker power terminals PT1, PT2.

[0132] In the Figure 3 system, the power unit 17 includes a microcontroller 17', which provides some of the functions described in relation to the interface unit microcontroller 11' of Figure 1 and the interfacing microcontroller 11 of Figure 2. The microcontroller 17' of the power unit 17 is unable to communicate with the circuit breaker microcontroller 4.

[0133] Although not shown in Figure 3, a current sense resistor R.1 is connected in order to allow the transmit power to be sensed. Operation of the microcontroller 17' in controlling the frequency of the AC energising signal, detecting the resonant frequency and / or setting the frequency to achieve a desired transmit power is the same as described in relation to Figure 1 and the interface unit microcontroller 11', except that there is no feedback from the circuit breaker microcontroller 4.

[0134] By means of the isolation features described above, a computer 16 or interface unit 9 connected to the circuit breaker la..le is galvanically separated from parts of the circuit breaker la..le under high voltage and is even save against dangerous creeping voltage. Hence, neither the equipment connected to the circuit breaker la..le, nor the personnel operating said equipment is exposed to the risk or danger of an electric shock originating from the power grid connected to the main power terminals Ml ... M4 of the circuit breaker lc..le.The circuit breaker lc ... le may be a moulded case circuit breaker (MCCB), or another type of circuit breaker.

[0135] It is noted that the invention is not limited to the embodiments disclosed hereinbefore, but combinations of the different variants are possible. In reality, the system may have more or less parts than shown in the figures. Moreover, the description may comprise subject matter of further independent inventions.

[0136] It should also be noted that the term "comprising" does not exclude other elements and the use of articles "a" or "an" does not exclude a plurality. Also, elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

[0137] Key to the Figures

[0138] lc ... le circuit breaker

[0139] 2 circuit breaker housing

[0140] 3 trigger unit

[0141] 4 circuit breaker microcontroller

[0142] 5 circuit breaker memory

[0143] 6 circuit breaker control unit

[0144] 7 circuit breaker output light guide

[0145] 8 circuit breaker input light guide

[0146] 9 interface unit

[0147] 10 interface unit housing

[0148] 11 interfacing microcontroller

[0149] 12 interfacing memory

[0150] 13 interfacing control unit

[0151] 11' interface unit microcontroller

[0152] 12' interface unit memory

[0153] 13' interface unit control unit

[0154] 14 interface unit output light guide

[0155] 15 interface unit input light guide

[0156] 16 computer

[0157] 17 power unit

[0158] 17' power unit microcontrollerBR bridge rectifier

[0159] Cl ... C3 circuit breaker capacitor

[0160] C2' interface unit capacitor

[0161] DI light emitting diode I optical circuit breaker output sender D2 light emitting diode I optical circuit breaker input sender D2' light emitting diode I optical interface unit input sender Dll optical circuit breaker data interface

[0162] DI2 optical interface unit data interface

[0163] DTI circuit breaker data output terminal

[0164] DT2 circuit breaker data input terminal

[0165] DT combined circuit breaker data input / output terminal DT' combined interface unit data input / output terminal LI secondary coil I electromagnetic receiver

[0166] L2 primary coil I electromagnetic circuit breaker sender L2' primary coil I electromagnetic interface unit sender Ml ... M4 main power terminals

[0167] Pl phototransistor / optical circuit breaker input receiver R1 current sense resistor

[0168] P2 phototransistor / optical circuit breaker output receiver P2' phototransistor / optical interface unit output receiver PI1 circuit breaker power interface

[0169] PI2 interface unit power interface

[0170] PS circuit breaker power stage

[0171] PS' interface unit power stage

[0172] PT, PT1, PT2 auxiliary circuit breaker power terminal

[0173] PT' auxiliary interface unit power terminal

[0174] SI, S2 switching contact

[0175] T1 ... T4 circuit breaker transistor

[0176] Tl' ... T4' interface unit transistor

Claims

- 27 - Claims1. Apparatus (9, lc, Id, le) comprising:a power transmission coil (L2', L2) for supplying power by inductive coupling to a power reception coil (LI) of a circuit breaker (lc, Id, le); anda frequency-controllable AC signal generator (17, T1'...T4', T1...T4) coupled to provide an AC energising signal to the power transmission coil,wherein the apparatus (9, lc, Id, le) is configured to control the frequency-controllable AC signal generator (17, T1'...T4', T1...T4) to adjust a frequency of the AC energising signal.

2. Apparatus as claimed in claim 1, further comprising a power sensor (Rl, 11) configured to sense a magnitude of power supplied to the power transmission coil.

3. Apparatus as claimed in either preceding claim, configured to detect a resonant frequency of the arrangement comprising the power transmission coil and the power reception coil by controlling the frequency-controllable AC signal generator to sweep the AC energising signal across a frequency range and to detect a frequency at which the maximum current flows through the power transmission coil.

4. Apparatus as claimed in any preceding claim, configured to control the frequency-controllable AC signal generator to hold the energising signal at a frequency that is different to a resonant frequency of the arrangement comprising the power transmission coil and the power reception coil.

5. Apparatus as claimed in claim 4, configured to control the frequency-controllable AC signal generator to hold the energising signal at a frequency that is higher than the resonant frequency of the arrangement comprising the power transmission coil and the power reception coil.

6. Apparatus as claimed in any preceding claim, wherein the frequency-controllable AC signal generator is an H bridge.

7. Apparatus as claimed in any preceding claim, further comprising the circuit breaker (lc, Id, le) and the power receiving coil (LI), wherein the circuit breaker includes a circuit breaker controller (4).

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