power supply

Abstract

Power supply (1) with a converter unit (3) for providing output power at the output (2) of the power supply (1) by converting input power at the input of the power supply (1) and with a detection unit (6) for detecting an event, wherein the power supply (1) is configured to change the output power to a boost output power for the duration of a boost interval when an event triggering the change is detected in order to provide the boost output power at the output of the power supply (1), and wherein the power supply (1) is configured to reduce the output power of the power supply (1) to the rated power or below the rated power after the change of the output power to the boost output power for the boost interval, characterized in thatthat the power supply (1) is designed to vary the variably adjustable boost output power during the boost interval after the detection of an event triggering the change and before the output power is reduced to or below the rated power.

Description

[0001] The invention relates to a power supply, such as a switching power supply, with a converter unit for providing output power at the output of the power supply by converting input power at the input of the power supply and with a detection unit for detecting an event, wherein the power supply is configured to change the output power to a boost output power for the duration of a boost interval when an event triggering the change is detected in order to provide the boost output power at the output of the power supply, and wherein the power supply is configured to reduce the output power of the power supply to the rated power or below the rated power after the change of the output power to the boost output power for the boost interval.

[0002] Power supplies are devices that provide energy by delivering an output voltage and / or current that differs from the input voltage. The output voltage can be fixed, and the output current can be limited to a maximum value. Such power supplies, particularly switching power supplies, can be designed to deliver a regulated DC voltage or current and to regulate the output power in the event of a fault, such as a short circuit.

[0003] Passive transformer power supplies provide an output current far exceeding the rated current in the event of a fault, such as a short circuit, which can reliably trip a downstream circuit breaker. However, with switched-mode power supplies, the output current is limited to a value close to the rated current. This means that a downstream circuit breaker can no longer be reliably tripped, as it typically requires a short-circuit current significantly higher than the rated current for a sufficient tripping time. This creates the risk of thermal overload in a faulty load circuit.

[0004] Therefore, power supplies are available that feature a short-term overcurrent capability to provide a predetermined higher boost output current than the actual rated current for a fixed boost interval in the event of a fault. The boost interval and boost output current are designed to ensure that a circuit breaker trips reliably and disconnects a faulty load circuit.

[0005] The switching power supplies must then be regulated to the higher specified boost output current to ensure that the power supply still has sufficient thermal reserve to deliver a time-limited overcurrent (boost) without thermal shutdown, even at a maximum ambient temperature, continuous rated operation, and when supplying a specified minimum value for the input voltage.

[0006] DE 10 2005 031 833 B4 discloses such an electronic power supply device for supplying energy to a low-voltage load, comprising a transformer, a device for detecting an electrical fault, and a device associated with the detection device for limiting the output current of the device to a first predetermined value. Upon detection of an electrical fault, the output current is set to a second predetermined value, which is greater than the first predetermined value, for a predetermined time. This second predetermined value for the output current is set such that a protective device associated with the device can be reliably tripped. After a predetermined time has elapsed, the output current is limited to the first predetermined value by the limiting device.

[0007] DE 10 2015 105 476 A1 discloses a method and a device for supplying power to a low-voltage load using an electronic power supply device. The power supply device is configured to provide an output current to the low-voltage load up to a predetermined peak current value when needed. The output current provided by the electronic power supply device to the low-voltage load is monitored to detect an increase in the output current above a threshold value that is lower than the peak current value. If an increase in the output current to an elevated output current value higher than the threshold value is detected, the elevated output current value is recorded, and an output current pulse duration is determined as a function of the elevated current value. The output current is provided at the level of the elevated current value for the duration of the determined output current pulse duration.After the output current pulse duration has elapsed, the output current is provided at the threshold value.

[0008] DE 35 19 151 C1 discloses a static inverter with controllable semiconductor switching elements and antiparallel diodes, as well as a circuit for briefly increasing the current above the rated current in the event of a short circuit. Antiparallel thyristors are connected across the inverter output. A control circuit is provided which, in the event of a short circuit, overrides the normal control of the inverter and switches the semiconductor switching elements between two currents in the load circuit. The higher current corresponds to the current limit for the semiconductor switching elements, and the lower current is significantly above the rated current. Upon reaching the current limit, the control circuit blocks the semiconductor switching elements and triggers at least the thyristor conducting in the forward direction of the current.

[0009] DE 10 2013 113 648 A1 discloses a power supply device for converting an input voltage into an output voltage, comprising at least one switching stage that is clocked by a pulse-width modulation circuit, wherein a control circuit is provided that influences the pulse-width modulation circuit to change the level of the output voltage, and wherein a current-limiting circuit is provided. After a threshold is exceeded, the current-limiting circuit first limits the output current of the power supply to an increased maximum current for a certain period of time and then to a regular maximum current. The control circuit is designed such that the duration for which the output current is limited to the increased maximum current depends on the level of the output current.

[0010] Based on this, the object of the present invention is to create an improved power supply, in particular a switching power supply.

[0011] The problem is solved by the power supply unit having the features of claim 1. Advantageous embodiments are described in the dependent claims.

[0012] It is proposed that the power supply be designed to vary the variably adjustable boost output power during the boost interval after the detection of an event triggering the change and before the output power is reduced to the rated power and / or below the rated power.

[0013] The level of boost output power, such as the output current, output voltage, and / or its timing (e.g., by adjusting the output power curve), is therefore not fixed but variably adjustable. This ensures that the power supply is not overloaded by the boost output power and can still be optimally utilized depending on the operating conditions.

[0014] The power supply can be configured to detect an influencing factor in order to control the boost output power and / or boost interval based on this factor. This allows for variable adjustment of the boost output power and / or boost interval depending on the at least one detected influencing factor. The boost output power can thus be adapted, for example, to the specific operating point of the power supply at the time an event triggering the change in output power is detected. In this way, the power supply's power reserves can be utilized to their fullest potential.

[0015] The power supply may have a temperature sensor to detect the temperature of the power supply itself and / or the ambient temperature at the power supply. It may be configured to adjust the boost output power and / or the boost interval based on the detected operating and / or ambient temperature.

[0016] This ensures that the boost output power is adjusted to the current operating point of the power supply, which is determined by the temperature. Thermal stress on the power supply can be counteracted by reducing the boost output power and / or boost duration at higher temperatures compared to lower temperatures.

[0017] The power supply can be configured to detect the electrical load at its output and to adjust the boost output power and / or boost interval based on this detected load. The electrical load at the power supply output can be determined, for example, by the output current. Alternatively, the output voltage can be measured to detect an overload, which, despite constant voltage regulation, would lead to a reduction in output voltage if the power supply can no longer provide the required constant voltage.

[0018] The measured electrical load is then a measure of the current operating point of the power supply, which is used to determine the boost output power and / or the boost interval.

[0019] The power supply can be configured to detect the input voltage and use it to adjust the boost output power and / or boost delay as a factor. The input voltage is also a characteristic that determines the power supply's operating point and can be used to set the boost output power and / or boost delay.

[0020] The power supply can be configured to monitor the operating parameters of its electronic components and to adjust the boost output power and / or boost interval based on these parameters. Monitoring the operating parameters of at least one electronic component can also determine the operating point of the power supply, which can then be used to set the boost output power and / or boost interval.

[0021] By taking such characteristics into account for the current operating point of the power supply, it can be ensured that the power supply delivers sufficient boost output power for a sufficient time without overloading the power supply.

[0022] In particular, the power supply's output power can be increased above the nominal output power during the boost period, for example to ensure a higher output current than the nominal current for a short time to trip a circuit breaker that interacts with the power supply.

[0023] The power supply is designed to vary the boost output power during the boost interval after detecting an event that triggers the change. The boost output power is therefore not set to a constant value during the boost interval, but can vary. For example, the boost output power can decrease linearly or non-linearly, such as by reducing the boot output current. The boost output power can fall from a maximum value to a nominal value, or to a value above or below the nominal value. The change pattern for varying the boost output power can be a parameter preset within the power supply or one applied externally.

[0024] The power supply can be configured to randomly adjust the boost output power and / or boost interval. A random number generator, for example, is used as the influencing factor for this.

[0025] It is conceivable that the power supply has a signal generator to provide an alternating signal. In this case, the random adjustment of the boost output power and / or the boost interval depends on the time of detection of the event triggering the throttle, the signal state of the alternating signal at that detection time, and the subsequent signal waveform. The boost output power can then be varied depending on this subsequent waveform of the alternating signal. The boost interval can also depend on the alternating signal and end when a predetermined signal level of the alternating signal is reached.

[0026] The power supply can be configured to adjust the output current and / or output voltage and / or the current-time curve and / or the voltage-time curve of the boost output power. One or more of the aforementioned parameters can be set individually or in combination. Parameters that are not set can be kept constant. For example, with a constant current source, it is advantageous if the output current is regulated to a variable boost output current during the boost period, depending on an influencing factor. However, it is also conceivable that the current and / or voltage-time curve of the boost output power can be adjusted, for example, by temporarily blanking a signal or changing the frequency in the power supply.

[0027] The power supply may be configured to regulate the output power back to the rated power or even to a value below the rated power after regulating the output power to the boost output power for the boost period, which may include completely shutting down the power supply.

[0028] The variable setting of the boost output power and / or the boost interval time can run automatically, i.e., without user intervention.

[0029] The boost output power and / or boost interval setting can be controlled by a central power management system. When multiple power supplies are connected, it's conceivable that several might activate the boost function simultaneously, potentially leading to power shortages and / or tripping a central fuse. To prevent undesirable effects from simultaneous boost events involving multiple power supplies, the variable boost output power and / or boost interval setting can be coordinated by a central power management system. For example, the central power management system can limit the boost function to a selected power supply if it is requested by multiple power supplies.It is conceivable that the variable setting of the boost output power and / or the boost interval in a power supply unit only takes place once the power supply unit has transmitted a release request to the higher-level energy management control center and has received a release from the higher-level energy management control center.

[0030] The invention is explained in more detail below with reference to an exemplary embodiment and the accompanying drawings. These show: Fig. 1 - Block diagram of a power supply with a control unit for variable adjustment of a boost output power; Fig. 2 - Time course of the power supply output current with variably set boost output current during a boost interval; Fig. 3 - Time course of the power supply output current for a different boost output current course during a boost interval; Fig. 4 - Diagram of the power supply output current with variable boost output current during two different boost intervals depending on an alternating signal.

[0031] Fig. Figure 1 shows a block diagram of a power supply 1, which can, for example, be implemented as a switched-mode power supply. A switched-mode power supply has an input rectifier, optionally with a mains filter and smoothing capacitors for interference suppression and filtering of the input power, and a subsequent switching unit with power transistors to generate a switched voltage at an intermediate frequency, which is fed into a subsequent power transformer. The output power of the power transformer is then fed to a rectifier for rectification and filtering in order to provide a DC voltage at the output of the power supply, preferably with a constant output voltage and a limit on a maximum output current. However, a constant current source providing a constant output current and a variable output voltage limited to a maximum voltage value, or the like, is also conceivable.

[0032] Such a switched-mode power supply also has a control unit to control the switching unit in order to keep the output power within predetermined limits.

[0033] For example, with such a known circuit arrangement, output power is provided at the output of power supply 1 by converting input power at input 2 of power supply 1.

[0034] Such electronics are used in the Fig. 1 is summarized as converter unit 3. The specific circuit design is not important here. Other configurations of converter unit 3 are conceivable, besides the previously described basic, exemplary setup for a switched-mode power supply.

[0035] Power supply 1 also has a control unit 4, which is connected downstream of, for example, the converter unit 3 and is designed to variably adjust a boost output power for a boost interval at the output of power supply 1. A load 5 is connected to the output of power supply 1. A temporary or continuous overload, or a short circuit, can cause the power demanded by power supply 1 to become overloaded. For example, such an overload could result in thermal overload of power supply 1. Alternatively, an overload caused by a short circuit at the output of power supply 1 could necessitate a reduction in the power supply's output.

[0036] The converter unit 3 is regularly set up to react to such load changes at the load 5 connected to the output of the power supply 1 or to fluctuations at the input 2 of the power supply 1.

[0037] The power supply 1 has a detection unit 6 for detecting an event that should trigger a change in the output power of the power supply 1. For this purpose, the detection unit 6 is connected to the control unit 4 in order to transmit a detected event to the control unit 4 and cause the control unit 4 to change the output power of the power supply 1.

[0038] In this illustrated embodiment, the power supply is configured, for example, by the control unit 4 to variably adjust the output power of the power supply 1. After an event is detected by the detection unit 6, the output power of the power supply 1 is briefly increased to a boost output power for a boost interval, in order to provide sufficient current to trip downstream power protection devices connected to the power supply 1, a current that exceeds the rated current of the power supply 1. However, other boost output power settings are also conceivable.

[0039] The boost output power and / or the boost interval time are not fixed, but are variably set by the control unit 4 depending on an influencing factor.

[0040] For this purpose, the control unit 4 can, for example, be connected to a temperature sensor 7 that measures the operating temperature of the power supply and / or the ambient temperature in the vicinity of the power supply 1. It is also conceivable that several temperature sensors 7 are present, for example, to measure the operating temperature inside the power supply and to measure the ambient temperature outside the power supply 1. The at least one measured temperature value then serves as an influencing factor for determining the boost output power and / or the boost interval. Thus, at a higher temperature, the boost output power or the boost interval can be set lower than at a lower temperature. A high temperature signals an operating point of the power supply 1 at which there is very little heat capacity remaining before the power supply 1 is overloaded.To avoid overloading power supply 1, the additional power required by power supply 1 due to changes in output power is set to a level that is adapted to the current operating point of power supply 1.

[0041] An important factor determining the operating point of power supply 1 is its temperature. Other factors can include the load on power supply 1, the input voltage, and the ambient temperature. These factors ultimately result in the operating temperature of power supply 1 itself, so that measuring the operating temperature of power supply 1 with a single temperature sensor 7 is sufficient to adjust the boost output power and / or the boost interval variably according to the operating point of power supply 1.

[0042] The power supply unit 1 can optionally be equipped with a signal generator 8 for generating an alternating or random signal. With this configuration, it is conceivable that the boost output power and / or boost interval could be set randomly. This statistically ensures that overloading of the power supply unit 1 is largely prevented. The alternating signal then serves as the input for the variable adjustment of the boost output power and / or boost interval.

[0043] Fig. Figure 2 shows a diagram of the output current I in the unit amperes A over time t in seconds. It can be seen that the output current I initially reduces to the nominal current I. NENN This is regulated. After detection of a change in the output current triggering event, a boost interval t is initiated. BOOSTDuring this period, the boost output current I, and thus the boost output power, is changed. In the illustrated embodiment, the output current I initially rises to a maximum value I. MAX on and then becomes linear until the end of the boost interval t BOOST to nominal value I NENN reduced. The boost output power is therefore not set to a fixed value, but is variable by regulating the output current. This prevents overloading of power supply unit 1.

[0044] Fig. Figure 3 shows a diagram of the output current I of power supply 1 over time t. The boost output current during the boost interval t is also shown. BOOST from a defined maximum value I MAX linearly reduced during the boost interval to a value that results from the boost interval and the slope of the boost output current characteristic curve. In contrast to the variant on Fig. 2. The output power of the power supply 1 must not return to the range of the nominal current I at the end of the boost interval. NENN The output current I is not necessarily higher, but can be higher or possibly lower. After the boost output power has elapsed, the output current I of power supply 1 can return to the nominal current I. NENN be regulated.

[0045] Fig. Figure 4 shows a diagram of the output current I of power supply 1 in amperes A over time t in seconds, with two successively detected events representing changes in the output power I. It is evident that a signal S(t) is present, alternating over time t. This signal S(t) could, for example, have the form of a sawtooth curve. However, other regular, irregular, or even random waveforms are also conceivable.

[0046] It becomes clear that after the detection of an event, there is always a boost interval t. BOOST_1 , t BOOST_2The output current I of power supply 1 is then adapted according to the following waveforms of the alternating signal S(t) until the alternating signal S(t) assumes a characteristic value, which marks the end of the boost interval t. BOOST This can be signaled, for example, in the case of a sawtooth curve, by the falling edge back to the starting point, which serves as the value for the nominal current I. NENN is assumed.

[0047] It is evident that for the second event, the start of the boost interval t BOOST2 falls into a time point of the alternating signal S(t) where the alternating signal S(t) has risen more sharply than in the first event and is closer to the falling edge than at the first event with the boost interval t BOOST_1 This results in the boost interval being t BOOST2The second event is shorter than the first event as outlined. The amplitude of the output current I follows from the output value at the beginning of the boost interval t. BOOST the curve's shape, without being dependent on its amplitude.

[0048] It is also conceivable that the output current I depends on the amplitude of the alternating signal S(t) during the boost interval t. BOOST is set. Then the output current I for the first event in the boost interval t would be BOOST_1 starting from the nominal current I NENN First, make a small jump upwards. For the second event, for the boost interval t BOOST_2 The amplitude of the output current I would show a significantly larger increase at the beginning of the boost interval. This would not only increase the boost interval t. BOOSTThe boost output power, such as the boost output current in this case, is determined variably and randomly depending on the time of detection of an event and the corresponding time in the curve of the alternating signal S(t). Rather, the boost output power is also determined variably and randomly depending on the curve of the alternating signal S(t) and the time of detection of an event in that curve.

Claims

[1] Power supply (1) comprising a converter unit (3) for providing output power at the output (2) of the power supply (1) by converting input power at the input of the power supply (1) and comprising a detection unit (6) for detecting an event, wherein the power supply (1) is configured to change the output power to a boost output power for the duration of a boost interval when an event triggering the change is detected in order to provide the boost output power at the output of the power supply (1), and wherein the power supply (1) is configured to reduce the output power of the power supply (1) to the rated power or below the rated power after the change of the output power to the boost output power for the boost interval. characterized by, that the power supply (1) is designed to vary the variably adjustable boost output power during the boost intermediate time after the detection of an event triggering the change and before the output power is regulated down to the rated power or below the rated power. [2] Power supply (1) according to claim 1, characterized by , that the power supply (1) has a temperature sensor (7) for detecting the temperature of the power supply (1) or the ambient temperature at the power supply (1) and is set up to adjust the boost output power and / or boost intermediate time depending on the detected operating and / or ambient temperature as an influencing factor for variable adjustment. [3] Power supply (1) according to claim 1 or 2, characterized by, that the power supply (1) is configured to detect the electrical load at the output of the power supply (1) and to adjust the boost output power and / or boost intermediate time as a variable influencing factor based on the detected electrical load. [4] Power supply (1) according to any one of the preceding claims, characterized by , that the power supply (1) is set up to detect the level of the input voltage at the input of the power supply (1) and to adjust the boost output power and / or the boost intermediate time as a variable influencing factor based on the detected input voltage. [5] Power supply (1) according to any one of the preceding claims, characterized by, that the power supply is set up to record operating parameters of electronic components of the power supply (1) and to adjust the boost output power and / or boost intermediate time as an influencing factor for variable adjustment depending on the recorded operating parameters. [6] Power supply (1) according to any one of the preceding claims, characterized by , that the power supply (1) is set up to randomly adjust the boost output power and / or boost intermediate time. [7] Power supply (1) according to claim 6, characterized by , that the power supply has a signal generator (8) for generating an alternating signal (S(t)) and is set up for random adjustment of the boost output power and / or boost intermediate time depending on the alternating signal generated by the signal generator and the time of detection of the event triggering the curtailment as an influencing factor for variable adjustment. [8] Power supply (1) according to any one of the preceding claims, characterized by , that the power supply (1) is configured to adjust the current and / or voltage and / or current time profile and / or voltage time profile of the boost output power. [9] Power supply (1) according to any one of the preceding claims, characterized by , that the variable setting of the boost output power and / or the boost interval occurs automatically. [10] Power supply (1) according to any one of the preceding claims, characterized by , that the setting of the boost output power and / or the boost interval is dependent on a higher-level energy management control center.

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