Protective order
The protective arrangement optimizes tripping current settings using a current sensor and feedback signals to ensure reliable protection against overcurrent without unnecessary shutdowns.
Patent Information
- Application Number
- DE102015104623
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2015-03-26
- Publication Date
- 2026-05-13
- Estimated Expiration
- 2035-03-26
AI Technical Summary
Existing protective devices struggle to set optimal tripping currents for electrical devices, leading to inadequate protection against overcurrent or unnecessary shutdowns due to mismatched tripping current settings.
A protective arrangement with a current sensor and evaluation unit that adjusts the tripping current based on measured current, allowing manual adjustment with feedback signals to optimize the tripping current setting.
Ensures reliable protection against overcurrent while minimizing false tripping by adapting the tripping current to the device's current consumption, providing visual and auditory feedback for precise adjustment.
Smart Images
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Abstract
Description
[0001] The invention relates to a protective arrangement for protecting electrical devices against overcurrent according to the preamble of claim 1.
[0002] A protective device of this type has an input where current is supplied to the device from a power supply, and an output through which the current is passed as output current to the electrical device to be protected. The protective device includes a fuse in the current line between the input and the output, which interrupts the current line from the input to the output to protect the device from overcurrent when a preset tripping current is exceeded.
[0003] DE 10 2007 013 551 A1 relates to a method for automatically adjusting a protective device with an overcurrent release.
[0004] WO 2004 / 109 885 A2 concerns a self-learning electronic fuse.
[0005] AT 506 092 B1 concerns an electrical installation with a consumer which is protected by a protective device.
[0006] DE 10 2004 046 810 A1 relates to an electronic circuit breaker with adjustable tripping characteristic.
[0007] DE 196 20 575 A1 relates to a circuit arrangement for setting the parameters of electronic devices.
[0008] US Patent 2013 / 0066478A1 discloses a method for setting and adjusting trip settings for a circuit breaker by monitoring short-circuit current availability.
[0009] Setting the tripping characteristics, especially the tripping current, to the varying supply currents of the electrical devices to be connected is often problematic. If the set value for the tripping current is too high, a connected device cannot be reliably protected against overload, because even if the actual current significantly exceeds the typical current draw (rated current) of the connected device, the fuse will not trip.
[0010] The object of the invention is therefore to create a protective arrangement that allows for optimal adjustment of the tripping current, so that the protective arrangement is on the one hand sufficiently sensitive to safely protect the connected device and on the other hand not too sensitive to avoid false shutdowns in non-critical cases.
[0011] This problem is solved by the features of claim 1. Advantageous further developments can be found in the dependent claims.
[0012] The protective arrangement includes a current sensor that measures the current in the power line when the device is connected, whereby the tripping current for the circuit breaker can be adjusted to a value that is greater than the measured current by a difference.
[0013] For this purpose, the protective arrangement preferably has an evaluation and control unit to which the measured current is supplied, wherein the evaluation and control unit automatically sets the value for the tripping current based on the measured current.
[0014] In this way, the tripping current is optimally adapted to the current consumption of the connected device by setting a value for the tripping current that corresponds to the current device current plus a difference, where, for example, a value of 25% of the current device current is used for the difference.
[0015] In an advantageous embodiment, a solution is provided for the further development of existing protective arrangements that have a manual adjustment option for the tripping current of the circuit breaker, and which retains this manual adjustment option as an integral part of the protective arrangement. In this embodiment, the protective arrangement, in addition to the manual adjustment means with which the tripping current can be decreased or increased stepwise or continuously between an upper and a lower value in an adjustment mode, has an optical and / or acoustic feedback signaling device.The feedback signal provides the user with a first signal waveform indicating whether a threshold value, determined based on the currently set value for the trip current, is greater than the current measured by the current sensor. A second signal waveform, different from the first, indicates whether the threshold value, determined based on the currently set value for the trip current, is less than the measured current. In this way, the user can iteratively select an optimal trip current using the manual setting and taking the feedback signals into account. The selected trip current can then preferably be confirmed by the user for use in operating mode via a confirmation device, such as a push button. The threshold value can correspond to the trip current multiplied by a factor, preferably less than 1.The threshold value can also correspond directly to the currently set trigger current.
[0016] The underlying concept of the invention will be explained in more detail below with reference to the exemplary embodiments shown in the figures. The figures show: Fig. 1 a schematic representation of the protective arrangement with upstream power supply and device to be protected, Fig. 2 a block diagram of the protective arrangement, Fig. 3 a block diagram of the protection arrangement in the embodiment with setting means, feedback signal means and confirmation means, Fig. 4 an embodiment of the protective arrangement according to Fig. 3, Fig. 5+ Fig. 6 diagrams illustrating the manual, step-by-step adjustment of the trip current, Fig. 7 a diagram to illustrate the manual, stepless adjustment of the trigger current, Fig. 8. A flowchart to illustrate the setting of the trigger current. Fig. 9 a top view of a front panel of a protective arrangement according to the invention, Fig. 10 the distribution of a collective flow to 8 different channels designed according to the invention.
[0017] Fig. Figure 1 shows a schematic representation of a protective device (1) with an upstream power supply (3) and a connected device (2) to be protected. The protective device (1) receives the current supplied by the power supply (3) at an input (E). After passing through the protective device (2), this current exits the protective device (2) at output (A) and is forwarded to the device (2) to be supplied and protected. The electrical device can be any type of electrical load, e.g., a motor, etc.
[0018] The power supply (3) and the protective device (1) can be designed as separate units, each with its own housing, which can be snapped onto a mounting rail, in particular a DIN rail, within a control cabinet, for example. However, it is also possible to integrate the power supply (3) and the protective device (1) into a single unit (10), which in turn can be mounted on a mounting rail.
[0019] Fig. Figure 2 shows a block diagram of a protective arrangement (1) which includes a current sensor (5) in the current line between the input (E) and the output (A). When the device (2) is connected, the current sensor (5) measures the current. in the power line. Furthermore, the protective arrangement (1) includes a circuit breaker (4). The tripping current for the circuit breaker (4) is determined as a function of the measured current. set to a value that is greater than the measured current by a difference:
[0020] For this purpose, the protective arrangement (1) preferably includes an evaluation and control unit (9) to which the measured current is supplied, whereby the evaluation and control unit (9) is based on the measured current The value for the trip current is automatically calculated, and then, when the measured current If the tripping current is exceeded, a tripping signal is sent to the circuit breaker (4).
[0021] Fig. Figure 3 shows a block diagram of the protective device (1) in the embodiment with a manually operated adjusting device (6), an optical and / or acoustic feedback signaling device (7), and a manually operated confirmation device (8). Using the adjusting device (6), the user can, in an adjusting mode, decrease or increase the tripping current in steps or continuously between an upper and a lower value. The feedback signaling device (7) provides the user with a first signal waveform indicating whether the threshold value determined based on the set value for the tripping current is greater than the measured current. while it provides the user with feedback via a second signal waveform, different from the first, indicating whether the threshold value determined based on the set value for the trigger current is smaller than the measured current. The confirmation device (8) allows the user to confirm a selected value for the trip current for use in operating mode. The confirmation device (8) is not mandatory, but advantageous.
[0022] The optimal trip current is set based on Fig. 5 explained. The feedback signaling device (7) provides feedback with a first signal waveform when the measured current smaller than, for example, 80% of the set trip current, i.e., the trip current is at least 25% greater than the measured current. Furthermore, the feedback signal device (7) provides feedback via a second signal waveform when the measured current greater than 80% of the set trip current. In the present example, the difference is This represents 25% of the current electricity flow.
[0023] In this example, an adjustment device (6) is used that allows for stepless adjustment of the tripping current. The current currently flowing and measured by the current sensor (5) is 3 A. To start the setpoint adjustment for the tripping current, an upper value of 10 A is set, for example. To start the actual adjustment according to the invention, it is preferably provided to activate an adjustment mode. This can also be done, for example, by actuating the aforementioned confirmation device (8). The feedback signal device (7) can then signal to the user via a third signal form that the adjustment mode is activated. In the adjustment mode, the previously set maximum value for the tripping current for the tripping of the circuit breaker (4) is used until the newly selected, optimized tripping current is confirmed as the setpoint for the tripping current for use in operating mode.Upon confirmation of the selected tripping current, the feedback signal (7) indicates the operating mode again via the third signal waveform. In setting mode, the currently set tripping current is compared with the current flowing, and feedback (7) provides the user with feedback on the comparison for selecting the optimal tripping current. However, in the background, the tripping current set before the start of setting mode remains relevant for tripping the circuit breaker (4) until the new tripping current is confirmed.
[0024] Since the measured current of 3 A is less than 80% of the set trip current of 10 A, i.e., 3 A < 0.8 x 10 A, the feedback signal device (7) provides feedback with the first signal waveform. The user then reduces the trip current to the next lower level (6 A) using the setting device (6). The signal waveform of the feedback signal device (7) will not change because the measured current is still less than 80% of the now set trip current. The user then reduces the trip current again to the next lower level (4 A). This also does not result in a change in the signal waveform, since 3 A < 0.8 x 4 A. Only the next reduction of the trip current to 2A leads to a change in the signal shape, namely from the first signal shape to the second signal shape, since now the measured current of 3A is greater than 80% of the set trip current, i.e. 3 A > 0.8 x 2A.This change in the signal shape indicates to the user that the previously set value (4A) is the optimal value for the tripping current in the operating mode of the protective device (1). To select this value as the setpoint for the operating mode, the user will increase the tripping current from level 2A to the next level (4A) using the setting device (6), with the result again indicated by a change in the signal shape.
[0025] Thus, the tripping of the circuit breaker (4) is sufficiently sensitive to reliably protect the connected device (2) and not too sensitive to prevent false tripping in non-critical situations. The current flowing and measured during the setting process (here 3 A) typically corresponds at least approximately to the rated current of the device (2). Using the setting device (6) and the displayed signal waveform change, the user can easily approximate the rated current of the device (2) to be protected and set the tripping current to a value within a tolerance range. is greater than the rated current. In a preferred embodiment, the user also has the option of confirming the optimal tripping current by means of a confirmation means (8) for further use in the operating mode of the protective arrangement (1).
[0026] In the present case, a tripping current of 6A or even 10A would be far too high to reliably protect the device (2) with a rated current of 3A, whereas with the tripping current value of 4A set according to the invention, on the one hand reliable protection against overcurrent is given, while on the other hand relatively minor fluctuations in the current consumption of the device (2) do not lead to undesirable false tripping of the circuit breaker (4).
[0027] As in Fig. As shown in Figure 3, the protective arrangement has an evaluation and control unit (9) which measures the current and a signal is supplied to the adjusting device (6), whereby the evaluation and control unit (9) is used based on the measured current and the signal of the setting device (6), i.e. by comparing the measured current with the respective set trigger current, controls the feedback signal device (7).
[0028] Preferably, an optical feedback signaling device (7) is used as the feedback signaling device (7). The first and / or second signal form is defined by a) a flashing or continuous light, and / or b) a color, and / or c) a brightness characterized, wherein the first or the second signal form differs in at least one of the aforementioned characteristics.
[0029] Preferably an LED is used as an optical feedback signaling device (7), which, when controlled accordingly, can flash as well as light continuously and in at least two different colors.
[0030] As in Fig. As illustrated in Figure 7, the LED lights up in a first color 1 to indicate the first signal shape, where the measured current is less than the trigger current (possibly less than the trigger current multiplied by a factor less than 1), while the LED lights up in a second color to indicate the second signal shape, where the measured current is greater than the trigger current (possibly greater than the trigger current multiplied by a factor less than 1).
[0031] The characteristics “flashing” or “continuous illumination” are used as a third signal form to indicate whether the protective device is in setting mode.
[0032] The first and second signal forms can also differ in the blinking mode of the LED (7) in that the LED (7) only blinks in color 1 in the first signal form, while in the second signal form it blinks alternately in color 1 and color 2.
[0033] As an alternative to the optical signal, an acoustic feedback signaling device (7) is also provided. The first and / or second signal form is defined by a) a recurring sequence of tone pulses or a continuous tone, and / or b) a pitch, and / or c) a volume characterized.
[0034] In Fig. Figure 4 shows a protective arrangement (1) in which a microcontroller is used as the evaluation and control unit (9), an LED as the optical feedback signal (7), and a potentiometer as the setting means (6) for the trip current. In particular, an electronic switch (4B), preferably a transistor in the form of a MOSFET, is used as the protective switch (4), which is controlled via a comparator (4A). A step-adjustable potentiometer (see Figure 4) can be used as the potentiometer (6). Fig. 6 and Fig. 7) or a continuously adjustable potentiometer (see Fig. 8) can be used.
[0035] The analog measurement signal from the current sensor (5) is converted into a digital signal via an analog-to-digital converter (ADC) and then fed to the microcontroller (9). Similarly, the analog signal from the potentiometer (6) is also converted into a digital signal via an ADC and fed to the microcontroller. Within the microcontroller (9), the measured current is then compared to the signal from the potentiometer (6). with the trigger current set via the potentiometer (6). Based on the comparison result, the microcontroller (9) then controls the LED (7) to provide feedback to the user via the different signal forms ("flashing in color 1", flashing in color 2", "continuous illumination in color 1").
[0036] If the optimal trip current has been determined via manual adjustment and visual feedback, it is confirmed by the user using an actuating device (8) designed as a push button. This can be done, for example, by pressing the push button (8) for a predetermined time (e.g., 1 s). The signal from the push button (8) is then fed to the microcontroller (9), which, when the push button (8) is pressed, determines the setpoint for the trip current based on the current value of the potentiometer (6).
[0037] The comparator (4A) receives the measured current on the input side. The actual current and the setpoint current are supplied as the actual value, with the setpoint being generated by a signal from the microcontroller and fed to the comparator (4A) via a digital-to-analog converter. On the output side, the comparator (4A) controls the switch (4B) such that if the measured current exceeds the setpoint current, the switch (4B) opens and interrupts the power supply.
[0038] Fig. Figure 8 illustrates the setpoint adjustment for the trip current – similar to that in Fig. 7 - however, using an adjusting device (6) for the tripping current which allows stepless adjustment, i.e., lowering and increasing.
[0039] Fig. Figure 9 shows a flowchart to illustrate the setting of the trigger current.
[0040] Fig. Figure 10 shows a top view of a front panel of a protective arrangement (1) according to the invention. This protective arrangement (1) is designed to supply and protect several, for example 8, devices, for which purpose the protective arrangement (1) has 8 channels with 8 current outputs (A1, ..., A8). Each channel is assigned a current sensor, a potentiometer (61, ..., 68) for adjusting the trip current, an LED (7), and a push button (8), wherein the LED (7) and push button (8) are each designed as a single unit. The push button (8) is actuated by pressing the LED (7). Preferably, the 8 channels share an evaluation and control unit. A common current is supplied to the protective arrangement (1) at a central input (E), which is then distributed to the inputs (E1, ..., E8) for the individual channels (see Figure 10). Fig. 11). Reference symbol list 1. Protective order 2 electrical devices to be protected 3 Power supply 4 circuit breakers 4A comparator 4B MOSFET 5 Current sensor 6, 61, ..., 68 Adjustment devices 7 Feedback signaling devices 8 Confirmation Means 9 Evaluation and control unit 10 Component unit consisting of protective arrangement and power supply 11 Component unit consisting of feedback signaling means and confirmation means E, E1,..., E8 Inputs A, A1,..., A8 Exits
Claims
Protective arrangement (1) for protecting electrical devices (2) against overcurrent, wherein: - the protective arrangement (1) has an input (E, E1, ..., E8) to which a current (I) is supplied from a power supply to the protective arrangement (1); - the protective arrangement (1) has an output (A, A1, ..., A8) through which the current (I) is passed as output current to the electrical device (2); - the protective arrangement (1) has a circuit breaker (4) in the current line between the input (E, E1, ..., E8) and the output (A, A1, ..., A8), which interrupts the current line when a measured current exceeds a set trip current; characterized in that the protective arrangement (1) has a current sensor (5) which measures the current in the power line with the device (2) connected, the tripping current depending on the currently measured current is adjustable to a value that is adjusted by a predetermined difference is greater than the currently measured current wherein the protective arrangement (1) includes an evaluation and control unit (9) which receives the currently measured current is supplied, whereby the evaluation and control unit (9) uses the currently measured current to automatically resets the value for the current trip current. Protective arrangement according to claim 1, characterized in that the protective arrangement (1) has a manual adjustment means (6) for stepwise or stepless reduction or increase of the tripping current between an upper and a lower value, and the protective arrangement (1) has an optical and / or acoustic feedback signal means (7) which provides the user with a first signal form as to whether a threshold value determined on the basis of the respective set value for the tripping current is greater than the measured current. while it gives the user feedback with a second signal shape, different from the first, as to whether the threshold value determined based on the respective set value for the trigger current is smaller than the measured current. Protective arrangement according to claim 2, characterized in that the protective arrangement (1) has an actuating means (8) to activate an adjustment mode for the trip current. Protective arrangement according to claim 2 or 3, characterized in that the protective arrangement (1) includes a confirmation means (8) by which a selected value for the trip current for use in operating mode can be confirmed by the user. Protective arrangement according to claims 2 to 4, wherein the same has an optical feedback signal means (7), characterized in that the first and / or the second signal form is characterized by a) a flashing or a continuous light, and / or b) a color, and / or c) a brightness, wherein the first or the second signal form differs in at least one of the aforementioned characteristics. Protective arrangement according to claims 2 to 4, wherein the same has an acoustic feedback signal means (7), characterized in that the first and / or the second signal form is characterized by a) a recurring sequence of tone pulses or a continuous tone, and / or b) a pitch, and / or c) a volume, wherein the first or the second signal form differs in at least one of the aforementioned characteristics. Protective arrangement according to one of claims 2 to 6, characterized in that the feedback signal means (7) provides feedback with a third signal form as to whether the protective arrangement (1) is in setting mode or in operating mode. Protective arrangement according to one of the preceding claims 2 to 7, characterized in that it has an evaluation and control unit (9) to which the measured current and a signal is supplied to the adjusting device (6), whereby the evaluation and control unit (9) based on the measured current and the signal of the adjusting device (6) controls the feedback signal device (7). Protective arrangement according to claim 8, characterized in that a signal from the confirmation means (8) is supplied to the evaluation and control unit (9), wherein, upon receipt of the confirmation signal, the selected value for the trigger current is stored in the evaluation and control unit (9) for use in the operating mode. Protective arrangement according to one of the preceding claims, characterized in that the protective switch (4) has a transistor (4B) which is controlled by a comparator (4A), wherein the comparator (4A) receives as an input signal the measured current on the one hand as actual value and on the other hand the set trip current is supplied as target value, whereby the output of the comparator (4A) controls the switch (4B) in such a way that it interrupts the current line when the actual value is greater than the target value. Protective arrangement according to one of the preceding claims 2 to 10, characterized in that the adjusting means (6) is a potentiometer. Protective arrangement according to one of the preceding claims 2 to 11, characterized in that the feedback signal means (7) is an LED. Protective arrangement according to one of the preceding claims 3 to 12, characterized in that the confirmation means (8) is a push button. Protective arrangement according to claims 12 and 13, characterized in that the LED (7) and the button (8) are integrated in a single unit.