Controllable power switching device, power switching method, socket, consumer installation

Abstract

A controllable power switching device (10) has a power switch (11) for switching a power supply line (2i), a control input (12) for receiving a control command (Sb) and for generating a control switching signal (Rss) according to the control command, a power monitoring device (13) for monitoring the power transported via the power supply line (2i) and generating a monitoring switching signal (Uess) according to the monitoring result, and a switch control device (14) for controlling the power switch (11) with a switch control signal (Sss) according to the control switching signal (Rss) and the monitoring switching signal (Uess).

Description

[0001] Description

[0002] Controllable circuit-breaker, circuit-breaker method, socket, consumer installation

[0003] The invention relates to a controllable power switching device, a power switching method, a socket and a consumer installation, such as a power switch, e.g. for blinds, according to the independent claims.

[0004] There is an increasing desire to be able to switch electrical loads with extended functionality, especially those not initially integrated into the device itself. Examples include remote controls (either wirelessly or via a network connection), extension control connections, actuation via motion detectors or gesture recognition devices, environment-dependent control (e.g., based on temperature and / or brightness), or even the switching of all power lines, i.e., L and N. To meet such requirements, additional switches are increasingly being integrated into the device supply line, which can then switch the electrical load according to the desired additional functionality.

[0005] The general topology within which this occurs is shown in Fig. 6, as long as it is understood without the boxes 10, 10', 10", and 5b. 69 denotes an electrical power-consuming device, for example a washing machine. It has an electric motor, for example, as a consumer 61. It has a main switch 62 that can be operated by the operator. In addition, other regular switches and control elements that are not shown in Fig. 6 can be provided. 64 indicates an electrical cable, and 63 a plug. The plug 63 can be plugged into a socket 65, which can be provided, for example, as a wall installation. This socket 65, in turn, is connected - usually flush-mounted - to a power source via cables 1, 2, 3, L, N, whereby the cable is protected by a circuit breaker 4.The miniature circuit breaker 4 has specific tripping characteristics, either with regard to short-term overloads, such as due to a short circuit, or with regard to long-term overloads. The miniature circuit breaker has a specific nominal value, for example, 16 A in domestic installations. If the nominal value is significantly exceeded, such as in the event of a short circuit, it must trip quickly (within a few milliseconds). If the overload occurs less severely, such as due to a motor that is blocked and therefore drawing more current than usual, it must also trip, although this can occur more slowly. These requirements are specified by standards. Rapid tripping can be implemented electromagnetically. Tripping due to overheating can be achieved using a bimetal strip. At least one of the power lines passes through the miniature circuit breaker 4, preferably the phase conductor L, and can be interrupted there if necessary.

[0006] If, in this scenario, an additional switch is installed in the supply line according to the desired additional functionalities described above, this switch is tested with the maximum electrical values ​​passed by the miniature circuit breaker in order to cope with any load that may occur without thermal or electrical faults. However, designing such an additional switch to pass this test is complex, as it necessarily leads to a comparatively large installation, which, especially in retrofits, cannot be made "smaller." In contrast, known protection mechanisms for the additional switch include current monitoring, which, in the event of current peaks or certain current integrals over time, serves as overload detection for the additional switch.The goal of this additional protection is to eliminate the additional switch and its associated circuitry as a source of danger. They must not overheat, catch fire, or melt during brief, large overloads. The same applies to less severe, long-term overloads.

[0007] The disadvantage of the known monitoring algorithms is that they are poorly adapted to real-life conditions, therefore they have to be designed to be comparatively sensitive and therefore often lead to false alarms.

[0008] The object of the invention is to provide a controllable power switching device, a power switching method, a socket and a consumer installation which can be switched with extended functionalities and the switch is protected in a realistic manner.

[0009] This problem is solved with the features of the independent patent claims.

[0010] A controllable power switching device has a power switch for switching a power supply line, a control input for receiving a control command and for generating a control switching signal in accordance with the control command, a power monitoring device for observing a power-relevant variable on the power supply line and generating a monitoring switching signal in accordance with the observation result, and a switch control device for controlling the power switch with a switch control signal in accordance with the control switching signal and the monitoring switching signal.

[0011] According to the invention, current amplitudes are not primarily evaluated, but rather power-relevant variables are considered. Their evaluation can be carried out with regard to one or more characteristic values ​​of the circuit breaker itself, such as its internal resistance, its thermal insulation (possibly provided by its installation), and similar variables. This results in a measure of the power loss generated and accumulated in the power switching device itself. The observation can be such that values ​​that are characteristic of the energy input into the power switching device are determined and evaluated. This can be done by considering, for example, the internal resistance of the power switching device and other relevant variables.

[0012] The power monitoring device may comprise a current measuring device for measuring a current flowing in the power supply line, which can continuously generate individual current measurement values ​​In according to a sampling. These individual current measurement values ​​In can be taken directly as current signals Im, or short-term averages of several, preferably consecutive, measurement results can be continuously determined from them, which are taken as the current signal Im, which is used to determine a monitoring signal.

[0013] In a consumer's power supply system, the current is the variable relevant to the power loss in the supply system, especially in the power switching device. The current can be measured by sampling a suitable analog signal. It can be digitized and then further processed digitally or in another suitable way.

[0014] To determine the effective power values ​​Im2 from the current signal Im, the current values ​​Im can be squared and then integrated over a suitable period, particularly a full wave or a multiple thereof. This can be done digitally to determine the effective power signal Im2. The sampling frequency can be selected according to the Nyquist criterion as at least twice the highest harmonic to be detected. Calibration values ​​can be taken into account. The effective value determination can also be performed using filtering.

[0015] Sampling, current signal determination, or power RMS measurement need not be performed continuously. It can be performed "occasionally," such as every second or once per minute. The current result is then stored and used until updated.

[0016] The power monitoring device can have a squaring device for squaring the current signal Im, which is then integrated. The squaring result, integrated with the effective power signal Im2, is used to determine the monitoring signal. The current signals are instantaneous values ​​of the AC mains current, which change according to the mains frequency. The squares of these are therefore also instantaneous values, but due to the squaring, they are no longer signed.

[0017] If the integral of the squares of the current signal Im is used as the effective power signal Im2, this is a good representation of the instantaneous power input in the power switching device. As is well known, the power consumption across a resistor is generally given by the formula

[0018] P = l 2*R can be calculated, where P is generally the power, I is the effective value of the applied current, and R is the resistance of the device or device component in question, in this case, for example, the internal resistance of the power switching device. The power loss in the power switching device is converted into heat. If, on the one hand, more power loss is permanently added than dissipated, the power switching device initially becomes warm and later hot, and can then be destroyed or catch fire. However, this does not occur instantly. Opposing effects are cooling through heat diffusion. This is more pronounced the higher the temperature gradient between the heat source and the environment.

[0019] The power monitoring device may therefore comprise an autoregressive averaging device that calculates the current monitoring signal from the most recent power RMS signal Im2 according to the following formula:

[0020] Uesa = k*lm2 + (lk)*Uesv where Uesa is the current monitoring signal, Uesv is the previous monitoring signal, Im2 is the most recent power RMS signal Im2 and k is a predetermined weighting factor between 0 and 1.

[0021] As explained, the effective power signal Im2 is a measure of the current power input. In contrast, the previous monitoring signal Uesv is a representation of the power input and outflow history. The two values ​​are correlated with each other, specifically summed, using the weighting factor k. The value k can be comparatively small, such as 0.01 or 0.005 or even smaller. However, it is greater than 0. The formula presented is sufficiently well suited to simulating real processes. If steady conditions prevail, such as a stable effective power signal Im2, equilibrium will sooner or later be established mathematically at a subcritical or possibly even critical or supercritical level. The formula reflects this. It also leads to a limit value if constant conditions exist.

[0022] The limit value is determined not only from the measured values ​​or the effective power signal Im2, but also from the selectable parameter k and the calculation frequency. The calculation frequency and the parameter k can thus be used to adapt the resulting curve to reality. Due to the weighted calculation against the historical data, short overcurrents do not lead to false shutdowns, unlike when considering current alone.

[0023] The power monitoring device may comprise a factor setting device that sets the weighting factor k, in particular such that it is set to a predetermined first factor value if the current power effective value signal Im2 is greater than the current monitoring signal Uesa, and otherwise to another predetermined second factor value, which may be smaller than the first factor value. If the two are equal, the currently valid factor value can be retained. Instead of the current monitoring signal Uesa, the previous monitoring signal Uesv can also be used for the comparison.

[0024] By setting the value of factor k on a case-by-case basis, the varying physical conditions during heating or cooling of the power switching device can be accounted for. The power input, based on the power loss as explained above, is primarily decisive for the inflow. The degree of insulation of the circuit, which is predictable to a certain extent, and the temperature gradient relative to the environment are primarily decisive for the heat dissipation. By setting different factors k on a case-by-case basis, a relatively realistic calculation or simulation is obtained based on the temperature in the power monitoring device. This can be compared with suitable threshold values. If these are exceeded, the device can be shut down.

[0025] Accordingly, the power monitoring device may comprise a comparison device configured to generate the monitoring switching signal based on the comparison of the current monitoring signal with a threshold value. The switch control device may comprise a threshold value generating device for generating the threshold value based on a previously input and stored parameter, in particular an internal resistance of the power switching device or a relevant component therein. The threshold value generating device provides a further parameter with which the shutdown characteristic can be determined.

[0026] Although the device parameter is described above as being used to generate a threshold, it should be noted that it can be used instead or also for determining the monitoring signal. It is essential that the power-correlated calculated signal and the threshold are appropriately calibrated relative to each other.

[0027] The power switching device may comprise a setting device for inputting or determining and storing the sampling frequency of the current measuring device, wherein the current measuring device is designed to sample the current flowing in the power supply line, in particular its effective value or a signal correlated therewith, in accordance with the set sampling frequency for measurement and, if necessary, to form an average value from several sample values ​​in order to form the current signal.

[0028] The sampling frequency for current measurement is a relevant parameter that, among other things, determines the required computing power. It can be set based on the expected temperature dynamics. The sampling frequency can be less than 10 Hz, 5 Hz, or 2 Hz.

[0029] The power switching device can comprise an A / D converter for A / D conversion of the measured current value, in particular the measured effective value or correlated signal, and a digitally operating circuit for digitally processing the digital output of the A / D converter. The current measuring device can comprise a series measuring resistor or an inductive tap. The power switch can comprise a relay, and the switch control device can comprise a driver circuit for the relay, which is designed to generate a relay control signal in accordance with the switch control signal.

[0030] In general, the required signal evaluation and processing can be performed in a suitable electronic circuit. This can be a fully or partially integrated circuit. It can operate largely digitally and be located between the analog / digital converter (A / D converter) at the input and the driver at the output. The circuit can be or contain an ASIC. It can be a small microcomputer with standard computer components such as RAM, ROM, CPU, registers, input and output interfaces, and a bus. A measuring resistor, also called a "shunt," can be connected in series with the switched line. It is comparatively small, thus generating a small voltage drop and correspondingly small power input. The voltage drop across the measuring resistor is proportional to the current flowing through it, i.e., proportional to the current through the power switching device, and is thus a precise representation of the current that determines the power input.The current can also be tapped inductively. The electrical voltage on the power supply line is usually alternating voltage, which can be tapped inductively or via magnetic effects. The advantage of inductive or magnetic tapping is that it generates virtually no voltage drop. The disadvantage is that the sensor technology and, if necessary, further processing into an analyzable signal are more complex.

[0031] If the current is alternating current, a measuring resistor or inductive pickup will also generate an alternating signal as the measurement signal. This can be rectified and smoothed using analog technology before being sampled.

[0032] The power switch itself can be a relay, in particular an electromechanical relay, and / or a power semiconductor. In each case, a suitable driver circuit is provided. The power semiconductor can be or comprise a FET, a MOSFET, an IGBT, a TRIAC, or a combination thereof, e.g., a TRIAC combined with a MOSFET.

[0033] The described power switching device can be installed in a load or in a line component. It can be incorporated into a socket, which can be installed in a building wall. Accordingly, a socket has at least one supply connection for connection to a power supply line, plug contacts for inserting a plug of a load, and a power switching device as described between the supply connection and at least one of the plug contacts.

[0034] It may be a normal-looking socket which, in addition to the conventional components, has the power switching device as described and then allows additional switching of the power transported via the socket, for example via a remote control connection or motion detector or similar.

[0035] The circuit breaker can also be installed directly in a consumer installation, such as in a washing machine or similar, whereby the provision of the circuit breaker in the respective plug of the device or machine is included. This installation then also allows additional functionalities, such as remote control of the respective device. Accordingly, a consumer installation has an electrical consumer, a connection to an electrical power network, a user switch between the electrical consumer and the connection for switching electrical power for the consumer, and between the electrical consumer and the connection of a circuit breaker as described. The circuit breaker is provided in addition to the conventional appliance switch.

[0036] The circuit breaker can also be separately housed. It can be dimensioned for installation in a recess, for example in a standardized flush-mounted box. It can be dimensioned for installation in a flush-mounted box beneath another component, such as a socket, switch, push-button, or dimmer, and can be dimensioned accordingly. It can also be designed and housed for series installation. It can be designed for DIN rail mounting in a distribution board or sub-distribution board. It can also be designed as an adapter plug. The adapter plug can be designed as a plug-in device for a normal socket, i.e., wireless.

[0037] The invention also relates to a power switching method comprising the steps of monitoring a power-relevant variable on a power supply line with a power switch therein and generating a monitoring switching signal based on the monitoring result, and controlling the power switch to switch a power supply line based on the monitoring switching signal. The control of the power switch can be based on a characteristic value of the power switch, in particular its internal resistance. In addition, in the power switching method, the control of the power switch can also be based on a further criterion, which corresponds to the primary function of the power switching device.

[0038] The method may generally comprise those steps described above as implemented by certain devices, in particular the calculation of the current monitoring signal as described above, the threshold value comparison, the determination of the respective system parameters, the sampling and A / D conversion and more.

[0039] Embodiments of the invention are described below with reference to the drawings, in which

[0040] Fig. 1 shows a power switching device in a possible installation environment,

[0041] Fig. 2 a current measuring device, Fig. 3 an averaging device,

[0042] Fig. 4 a switching control device,

[0043] Fig. 5A to 5F various timing diagrams,

[0044] Fig. 6 further installation options for the power switching device, and

[0045] Fig. 7 shows the image of a real device.

[0046] Fig. 1 shows a power switching device 10 installed at an abstractly depicted installation location 50. To the right of this, an electrical load 9 is shown schematically. For example, this could be lighting or an electrical device. To the left of the power switching device 10 is the electrical power grid. Typically, this will be an alternating current grid, such as an alternating voltage grid with 230 V rms and 50 Hz in Germany. The power is applied between a neutral line N, 3 and a phase conductor L, 2 and is tapped from there via spur lines 2a, 3a.

[0047] Typically, the power tap is protected by a miniature circuit breaker (MCB) 4, the characteristics of which are regulated by standards. It was described above. At least one of the power lines passes through the MCB 4, preferably the phase conductor L, and can be interrupted there if necessary, as described.

[0048] At least one of the power conductors 2, 3 passes through the power switching device 10, preferably the phase conductor L, 2, 2a, 2b. Inside the power switching device 10, it is symbolized by reference numeral 2i. 11 symbolizes a power switch designed to carry the expected power, in particular the expected current. It can be a relay or a power semiconductor. In any case, however, it also has an internal resistance, such as a contact resistance in a relay, or the thresholds typical for semiconductors in a semiconductor, so that heat is generated in accordance with this voltage drop when current flows.

[0049] The circuit breaker 11 primarily serves to implement an additional switching function, such as the described remote control or motion- or gesture-sensitive control, or similar. A control input 12 is provided for this purpose, which performs this primary function and can ultimately also influence the circuit breaker 11. Graphically indicated is a remote control that sends a control command Sb, which is received at the control input 12 and appropriately processed, resulting in a control switching signal Rss.

[0050] To protect the power switching device 10 against device faults, in particular heating of the internal resistance of the power switching device 10, a power monitoring device 13 is also provided. It monitors the transmitted power and generates suitable switching signals from this, which can also act on the power switch 11. If, in particular, it is determined that the power switching device 10 is overheating, this can lead to the opening of the switch 11, so that the power flow is interrupted and the device cools down. The power monitoring device 13 thus generates a monitoring switching signal Uess. The control input 12 generates a control switching signal Rss.Reference numeral 14 indicates a switch control device which, according to its primary function, receives the control switching signal Rss from the control input 12 and, according to a monitoring function or secondary function, the monitoring switching signal Uess from the power monitoring device 13. From this, it determines a switch control signal Sss, which is used overall to control the circuit breaker 11. Resetting the shutdown, i.e., reconnecting after shutdown based on power monitoring, can be carried out according to several strategies. For example, the monitoring algorithm can simply continue running but use a different, lower threshold value for reconnection in a hysteresis-like manner. Normal switching activities for the required power and / or switching operations on the circuit breaker, here, for example, a short off-on pattern, can also be monitored and, upon detection, used to initiate reconnection.A switch or button may also be provided on the power switching device itself, which enables manual re-connection, possibly after entering a predetermined switching or keying pattern, such as several keying operations in quick succession.

[0051] Since the observation-related shutdown is ultimately a serious error, a warning mechanism or alarm device can be provided that is activated when the observation-related shutdown occurs.

[0052] The switch control device 14 may comprise a driver circuit which, if necessary, generates the necessary analog signals from digital signals in order to control the power switch 11.

[0053] Fig. 1 shows an embodiment in which both power conductors L, 2 and N, 3 are passed through the power switching device 10. Accordingly, the power switching device 10 itself has terminals 18a, 18b, 19a, 19b, or the installation environment 50 has terminals 58a, 58b, 59a, 59b. However, it is not necessary for both power conductors 2, 3 to be passed through the power switching device 10. Only one of the two can be passed through the power switching device 10 to switch the power. In Fig. 1, the stub line away from the neutral conductor N, 3 would then not run through the power switching device 10.

[0054] Fig. 2 shows features of the power monitoring device 13. It can perform a current measurement. Shown is a measuring resistor 21, often referred to as a "shunt," connected to the power line 2i, L. When current flows through the line 2i, L, a voltage drop occurs across the measuring resistor 21, which can be detected and preprocessed in a measuring circuit 22. The measuring circuit can comprise a sample-and-hold amplifier with subsequent analog / digital conversion (A / D conversion), collectively symbolized by reference numeral 22a. The sample-and-hold amplifier 22a can perform sampling according to a predetermined sampling frequency or sampling rate. The setting can come from a setting device 25. This results in time-serially measured current values ​​that can be digitally tapped off at the output of an A / D converter with the desired resolution, for example, 8 bits.A first short-term averaging 22b can also be performed here by calculating an average from several time-series measured values. This averages over less than a half-wave, e.g., less than 20 or 10 or 5 consecutive measured values. The sampling frequency can be above 1 or 2 or 5 or 10 kHz. It can be below 20 or 10 kHz. The averaging can capture values, in particular unsigned values, over a half-wave or full wave, or multiples thereof.

[0055] This creates a preprocessed current signal Im, which represents the instantaneous value of the current. For an ideally sinusoidal supply voltage, the current signal Im is approximately

[0056] Im = Io * sin(cnt) where Io is the current amplitude, in is 2 n times the mains frequency, and t is the time. However, it should be noted that loads can affect the supply, so that waveforms at the supply input can deviate significantly from the ideal curve.

[0057] The current signal can be used to determine power. As an example, a squaring and integrating device 23 is shown, which receives the current signal Im, squares it, and integrates it over a reasonable period of time, in particular over a half-wave or full-wave or a multiple thereof, thus generating and outputting a power RMS signal Im2. The term "integration" can also refer to averaging or filtering (especially low-pass).

[0058] The device 23 can operate or calculate digitally. Based on the squared current value, the effective power signal Im2 is a measure of the power loss occurring in the power switching device 10. The latter is composed of the individual power losses at the measuring resistor 21, at the power switch 11, at the internal lines, and at the terminals.

[0059] Instead of a measuring resistor 21, an inductive or magnetic tap can also be used to measure the current flowing in the power line 2i, L. For example, Hall sensors can be used for a magnetic tap. An alternating signal is generated when alternating current flows, both along a measuring resistor 21 and with an inductive or magnetic tap.

[0060] The effective power signal Im2 from the squaring and integrating unit 23 is a representation of the instantaneous power loss input into the power switching device 10. However, it does not represent the overall prevailing conditions, as these also depend on the previous history, in particular on how long and how high the power input was previously. A brief power loss input can be harmless and does not necessarily lead to the device being shut down due to impending overheating. Therefore, additional devices are provided to generate a monitoring signal that meaningfully represents real conditions. An averaging device 24 is provided for this purpose. In particular, an autoregressive average can be formed here by adding the new effective power signal in a weighted manner to the previous signal according to the formula

[0061] Uesa = K • Im2 + (1 - k) • Uesv (Formula 1) where Uesa is the current monitoring signal, Uesv is the previous monitoring signal, Im2 is the most recent power RMS signal and K is a predetermined weighting factor between 0 and 1.

[0062] The effective power signal Im can be determined as described above or in another way. The factor k can be comparatively small. It can be less than 0.5, 0.2, 0.1, 0.05, 0.02, 0.01, or 0.005. During continuous compensating, the effective power signal "slowly" influences the current monitoring signal, which, similar to compensation processes, slowly follows the effective power signal. Formula 1 above can be used for this purpose because it is easy to implement, requires only basic arithmetic, and requires a few registers for processing.

[0063] Fig. 3 schematically shows a circuit for implementing Formula 1 above. The structure shown represents the averaging device 24 in Fig. 2. It receives the effective power signal Im2 on the left and outputs the current monitoring signal Uesa on the right. Clocked in discrete digital signal processing, an addition is performed at summing point 32: the effective power signal Im2 weighted by the factor K and the fed-back current monitoring signal weighted by the factor 1 - K. This then logically represents the previous monitoring signal Uesv.

[0064] 35 symbolizes a factor setting device which sets the factor k used in the multipliers 31 and 34. Simple embodiments in which the factor is fixed are conceivable. Fig. 3, on the other hand, shows a more complex embodiment in which the factor k can and should be set to values ​​kl or k2 depending on whether the temperature is rising or falling. This takes into account the idea that these physical effects are determined by different circumstances and are therefore advantageously not calculated in the same way. The heating rate is determined by the power input, while the cooling rate is adjusted by compensating processes with respect to the environment. This can be determined empirically in advance and can then be entered into the device during manufacture in the form of two factors kl and k2, which are used for one or the other case.

[0065] The factor setting device 35 can be configured to detect whether a temperature increase or decrease is occurring. This can be determined by comparing the magnitudes of the effective power signal Im2 and the current monitoring signal Uesa. If the former exceeds the latter, a temperature increase is present, and one of the factors k can be used. Otherwise, the other can be used. The previous monitoring signal Uesv can also be used to compare the effective power signal. In summary, the signal processing in one embodiment can be enumerated as follows:

[0066] (1) Digitization and single current measurement via S / H amplifier 22a

[0067] (2) Optional: In 22b Digital short-term averaging (over e.g. less than 20 or 10 or 5 consecutive single current measurements) to compensate for measurement errors and noise that would be harmful during squaring.

[0068] (3) In squarer / integrator 23, square the signal from 22a or 22b to obtain instantaneous power values

[0069] (4) Still in 23 averaging / integration / filtering over full wave to obtain power rms signal Im2

[0070] (5) Im2 from (4) or an otherwise generated power RMS signal Im2 goes into the autoregression 24.

[0071] The determination of the effective power value Im for use in autoregression can be performed using a specialized IC. For example, the ADE9153A chip from Analog Devices and the method implemented therein can be used.

[0072] Fig. 4 schematically shows the switch control device 14. It generates and outputs a switch control signal Sss. On the one hand, it receives the control switching signal Rss for controlling the circuit breaker according to the desired primary function. On the other hand, it receives the monitoring switching signal lass, which reflects the monitoring result of the internal temperature. The two signals are suitably combined and then fed to a driver circuit 42. The combination can be an OR operation such that, for example, a shutdown signal (interrupting the power line 2i by opening the switch) is generated as the switch control signal Sss when either the control switching signal Rss or the monitoring switching signal lass requires it.

[0073] To easily adapt the power switching device to different installation situations or electrical environments, it can have several parameter sets (e.g., sampling frequency and / or values ​​k, k1, k2 and / or threshold value Sw and / or calibration values) stored in a selectable manner and feature a selection device for this purpose. The parameter sets can each contain one or more or all of the parameters explained in this description and, if necessary, additional parameters. When one of them is selected via the selection device, its parameters are set and used for the operation of the power switching device.

[0074] The circuit-breaker device and, in particular, its parameter set used during operation, e.g., previously entered, permanently stored, or selected, can be adapted to typical installation situations or electrical operating environments of the circuit-breaker device, e.g., to the properties of a circuit breaker and / or an intended load. Several selectable, stored parameter sets can then map several such installation situations or electrical operating environments.

[0075] Figs. 5A to 5F each show, by way of example, time courses of various quantities. The abscissa denotes the time course in measuring points, assuming two measurements per second. The displayed 3,500 billing points therefore correspond to a time of 1,750 seconds, or just under half an hour. 53 denotes the measured current value, for which the ordinate 52 is indicated on the right of the graph. 54 denotes the mathematically determined current monitoring signal Uesa, for which the ordinate 51 is indicated on the left. 55 denotes a maximum permissible continuous current of the power switching device, for which the ordinate is again indicated on the right as 52. 56 denotes the threshold value Sw from device 26, for which the ordinate 51 on the left applies.

[0076] In Fig. 5A, a continuous overload of 25 A is assumed. This leads to an increase in the monitoring signal Uesa according to curve 54. The maximum permissible continuous current is assumed to be 18 A. The threshold value Sw is assumed to be 324 = 18*18. It is exceeded at approximately the measurement time 1800, i.e., after approximately 900 seconds, corresponding to 15 minutes. This would then lead to a monitoring switching signal lass, which causes the shutdown of the power switching device 10 by opening (interrupting) the power breaker 11, because the power switching device 10 is mathematically determined to be overheating, which can be prevented by interrupting the power supply.

[0077] In Fig. 5B, curve 53 assumes a current of just under 18 A, which is just below the permissible continuous current of 18 A according to curve 55. Stable conditions are then also established in the described calculation. 56 again shows the threshold value corresponding to the permissible 18 A continuous current. The stable calculated value according to the current monitoring signal Uesa in curve 54 is just below the threshold value of curve 56, so that the device, i.e., the power switching device 10, can operate continuously without interruption.

[0078] Fig. 5C shows an example in which a load, as shown in curve 53, has a current peak upon turn-on, with the current then dropping to significantly lower values. The permissible continuous current is again 18 A according to curve 55. This is initially significantly exceeded. Calculations according to curve 54 and monitoring signal Uesa result in curve 54, which does not exceed the threshold value Sw of 324 = 18*18.

[0079] Fig. 5D shows an example with a longer current peak at the beginning of the operation of a device, as indicated by curve 53. Accordingly, the calculated value Uesa of the current monitoring signal climbs to values ​​above the threshold according to curve 56, so that at the calculation time 300, corresponding to 150 seconds or 2 1 / 2 minutes, a shutdown would occur and the current would drop instantly to 0. However, the experimentally assumed case is shown in which the invention is not applied and the current is not switched off, but instead drops automatically to significantly lower values. Accordingly, the calculated value also decreases, falling below the calculation threshold value 56 at approximately calculation time 1200. After a shutdown according to the invention at calculation time 300, the restart can occur using one of the previously mentioned strategies.

[0080] Fig. 5E shows the same current waveform 53 as Fig. 5C. However, it is assumed that a different device history already existed beforehand, so that the calculated value of the current monitoring signal according to curve 54 begins at a higher value than in Fig. 5C and therefore also exceeds the threshold value 56, unlike in Fig. 5C.

[0081] Fig. 5F shows the current waveform of a pulsating appliance. For example, it could be a washing machine that heats continuously (base current of approximately 8 A) and occasionally, but not always, rotates the drum, resulting in current peaks of 20 A as shown in curve 53. The calculated value of the current monitoring signal Uesa 54 pulsates accordingly, but does not exceed the relevant threshold 56. Therefore, the appliance does not shut down.

[0082] Fig. 6 shows further installation options for the power switching device 10. On the far right, it is shown as part of an electrical device 69, for example, a washing machine. This can be, for example, a household appliance or an industrial device or a machine. 62 symbolizes the conventional switch of the device. 10 is the power switching device 10 as described, which is provided in addition to the conventional switch 62. 61 is the actual load, such as a motor. For the primary function of the power switching device 10, the control command is indicated, which can be supplied wirelessly to the power switching device 10.

[0083] As an alternative to providing the power switching device 10 in the device 69 itself, it can be provided in its plug 63, which is indicated by reference numeral 10', or in an intermediate plug. The plug can then be bulkier than usual, but can then provide the extended switching functionalities. Here, too, the primary function is symbolized by the dashed line indicating a supplied control command.

[0084] Another alternative to the installation options for the power switching device 10 described so far in Figure 6 is to provide it in a socket 65. This is indicated by reference number 10" in Figure 6. It would also be supplied with a control command Sb, for example, according to the desired primary function and would otherwise operate as described above. The power switching device 10 can, however, also be housed in a switch cabinet or cable or another suitable location. Figure 7 shows a prototype. An installation according to reference number 10" in Figure 6 is assumed, i.e. integrated in or with a socket that can be installed in a building wall, for example in a flush-mounted box. This can correspond to the installation environment 50 in Figure 1. The socket 65 has the contacts 71 for a suitable plug. Figure 7 shows the front view on the left and the rear view on the right.On the rear, the usual power line connections 72L for the phase conductor 2, L, 72N for the neutral conductor 3, and 72S for the protective conductor can be seen. 73 is the power switching device 10 permanently installed in the socket, whereby Fig. 7 particularly shows the relay that forms the power switch 11. 74 is a receiver structure on the front of the socket 65, with which a control command can be wirelessly received for the desired primary function of the power switching device 10, which can then be used to control the relay 73, as described. The receiver structure can also provide an input option for users, for example, to command switching back on after switching off. This can be done manually, mechanically, or wirelessly.

[0085] The values ​​required for calibration, such as factor k, kl, k2, threshold value Sw, calculation frequency, proportionality constants, internal resistances, contact resistances and the like, can be determined empirically and stored electronically in the device in a usable manner.

[0086] The features described in this description and the claims or illustrated in an illustration are to be considered as combinable with each other, even if their combination is not expressly described, as long as the combination is technically possible. Features described in a particular context, embodiment, figure, or claim are also to be considered as separable from that claim, context, embodiment, or figure and as combinable with any other figure, claim, embodiment, or context, as long as this is technically possible. Embodiments and figures are not to be understood as necessarily exclusive of each other.Descriptions of a method or a process or a process step or a process step are also to be understood as a description of devices and / or possibly program instructions of executable code on a data carrier that are suitable for implementing the method or the process or the process step or the process step, and vice versa.

[0087] List of reference symbols

[0088] 1 power supply network

[0089] 2 phase conductors

[0090] 3 neutral conductors

[0091] 4 circuit breakers

[0092] 9 electrical consumers

[0093] 10 Power switching device

[0094] 11 circuit breakers

[0095] 12 Control input

[0096] 13 Performance monitoring device

[0097] 14 Switch control device

[0098] 18, 19 connections

[0099] 21 Measuring resistor

[0100] 22 Preprocessing

[0101] 22a Sample-and-Hold Amplifier

[0102] 22b Average formation

[0103] 23 Squarers and integrators

[0104] 24 Averaging device 25 Setting device

[0105] 26 threshold memory

[0106] TI comparison device

[0107] 31, 34 multipliers

[0108] 32 adders

[0109] 33 registers

[0110] 35 Factor setting device

[0111] 41 link

[0112] 42 driver circuit

[0113] 50 Installation location

[0114] 51 Calculation value ordinate

[0115] 52 current coordinates

[0116] 53 Current flow

[0117] 54 Calculated value history

[0118] 55 Current threshold

[0119] 56 Calculation value threshold

[0120] 60 consumer installation

[0121] 61 consumers

[0122] 62 user switches

[0123] 63 plugs

[0124] 64 Line

[0125] 65 socket

[0126] 69 electrical device

[0127] 71 contacts

[0128] 72 connections

[0129] 73 installed power switching device

[0130] 74 recipients

Claims

Patent claims:

1. Controllable power switching device (10) with a power switch (11) for switching a power supply line (2i), a control input (12) for receiving a control command (Sb) and for generating a control switching signal (Rss) in accordance with the control command, a power monitoring device (13) for monitoring a power-relevant variable on the power supply line (2i) and for generating a monitoring switching signal (liess) in accordance with the monitoring result, a switch control device (14) for controlling the power switch (11) with a switch control signal (Sss) in accordance with the control switching signal (Rss) and the monitoring switching signal (liess).

2. Power switching device (10) according to claim 1, wherein the power monitoring device (13) comprises a current measuring device (21, 22) for measuring a current flowing in the power supply line (2i) and for generating a current signal (Im) in accordance with the measurement result, wherein the current signal (Im) can be an average value of several current measurement results and is used to determine the monitoring switching signal (liess).

3. Power switching device (10) according to claim 2, wherein the power monitoring device (13) has a squaring and integrating device (23) for squaring the current signal (Im) and integrating the squares, the integration result being used as the power effective value signal (Im2) for determining the monitoring switching signal (liess).

4. Power switching device (10) according to claim 3, wherein the power monitoring device (13) has an averaging device (24) which calculates a current monitoring signal (Uesa) from the most recent power effective value signal (Im2) according to the following formula: Uesa = k*lm2 + (lk)*Uesv where Uesa is the current monitoring signal, Uesv is the previous monitoring signal, Im2 is the most recent effective power signal (Im2) and k is a predetermined weighting factor between exclusively 0 and 1, and wherein the power monitoring device is designed to determine the monitoring switching signal (Uess) according to the current monitoring signal (Uesa), in particular based on a threshold value comparison.

5. Power switching device (10) according to claim 4, wherein the power monitoring device (13) has a factor setting device (35) which sets the weighting factor k, in particular such that it is set to a predetermined first factor value if the current power effective value signal (Im2) is greater than the current monitoring signal (Uesa), and otherwise to another predetermined second factor value, which may be smaller than the first factor value.

6. Power switching device (10) according to one of the preceding claims, wherein the power monitoring device (13) has a comparison device (27) which is designed to generate the monitoring switching signal (Uess) in accordance with the comparison of the current monitoring signal (Uesa) with a threshold value (Sw 26).

7. Power switching device (10) according to claim 6, wherein the switch control device (14) comprises a threshold value generating device for Generating the threshold value in accordance with a previously entered and stored parameter, in particular a resistance in the power switching device (10).

8. Power switching device (10) according to one of the preceding claims and claim 2, with a setting device (25) for inputting or determining and storing the sampling frequency of the current measuring device (21, 22), wherein the current measuring device (21, 22) is designed to sample the current flowing in the power supply line (2i) according to the set sampling frequency for measurement and, if necessary, to form an average value from several sample values ​​in order to form the current signal (Im).

9. Power switching device (10) according to one of the preceding claims and claim 2, with an A / D converter in the current measuring device (21, 22) for A / D conversion of the current measured value, and with a digitally operating circuit for digitally processing the digital output of the A / D converter.

10. Power switching device (10) according to one of the preceding claims and claim 2, wherein the current measuring device (21, 22) comprises a series measuring resistor or an inductive tap or a Hall sensor.

11. Power switching device (10) according to one of the preceding claims and claim 2, wherein the power switch (11) comprises a relay or a power transistor and the switch control device (14) comprises a driver circuit for the relay or the power transistor, which is designed to generate a relay drive signal or transistor drive signal in accordance with the switch control signal.

12. Socket with a supply connection for connection to a power supply line (2i), Plug contacts for inserting a plug of a consumer, and between the supply connection and at least one of the plug contacts a power switching device (10) according to one of the preceding claims.

13. Consumer installation (60), comprising an electrical consumer (61), a connection (63) to a network (1, L, N) of electrical power, between the electrical consumer (61) and the connection (63) a user switch (62) for switching electrical power for the consumer (61), and between the electrical consumer (61) and the connection (63) a power switching device (10) according to one of claims 1 to 11.

14. Power switching procedure (10) with the steps Observing a power-relevant quantity on a power supply line (2i) with a power switch (11) therein and generating a monitoring switching signal (lies) in accordance with the observation result, and Controlling the circuit breaker (11) to switch a power supply line (2i) in accordance with the monitoring switching signal (lies).

15. Power switching method (10) according to claim 13, wherein the control of the power switch (11) takes place in accordance with a characteristic value of the power switch, in particular its internal resistance.

16. Power switching method (10) according to claim 13 or 14, wherein the control of the power switch (11) also takes place in accordance with a further criterion.

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