Energy supply device having transitions between operation and stand-by that are dependent on the output current

Abstract

The present disclosure relates to an energy supply device for providing an output voltage and an output current. The device includes a first operating state, a second operating state, a measuring assembly, and a signal generator. The measuring assembly is configured to sense a current amplitude of the output current of the energy supply device. The signal generator is configured to produce the output voltage and the output current. The signal generator is further configured to reduce a voltage amplitude of the output voltage of the energy supply device in the first operating state to change to the second operating state if the sensed current amplitude falls below a first current threshold value and to increase a voltage amplitude of the output voltage of the energy supply device in the second operating to change to the first operating state if the sensed current amplitude exceeds a second current threshold value.

Claims

1. An energy supply device configured to provide an output voltage and an output current, the energy supply device having a first operating state and a second operating state, comprising: a measuring assembly configured to sense a current amplitude of the output current of the energy supply device; and a signal generator configured to produce the output voltage and the output current, wherein the signal generator is configured to: reduce a voltage amplitude of the output voltage of the energy supply device in the first operating state of the energy supply device after expiry of a settable or prestored first delay time interval to change to the second operating state if the sensed current amplitude falls below a first current threshold value; and increase a voltage amplitude of the output voltage of the energy supply device in the second operating state of the energy supply device to change to the first operating state if the sensed current amplitude exceeds a second current threshold value.

2. The energy supply device according to claim 1, wherein the first operating state is an active state, and the second operating state is an energy-saving state, wherein the energy-saving state comprises a stand-by mode or a sleep mode.

3. The energy supply device according to claim 1, wherein the second current threshold value is the first current threshold value or a further current threshold value.

4. The energy supply device according to claim 3, wherein the first current threshold value or the second current threshold value or the further current threshold value is configured to be settable or prestored.

5. The energy supply device according to claim 3, wherein the signal generator is configured to compare the sensed current amplitude with the first current threshold value or the second current threshold value or the further current threshold value.

6. The energy supply device according to claim 1, wherein the signal generator is configured to reduce the voltage amplitude of the output voltage of the energy supply device to a settable first or prestored first voltage amplitude value if the sensed current amplitude falls below the first current threshold value.

7. The energy supply device according to claim 1, wherein the signal generator comprises a transformer having a primary side, wherein an input voltage can be applied to the primary side, and the transformer with a secondary side configured to output the output voltage.

8. The energy supply device according to claim 1, wherein the signal generator is configured to increase the voltage amplitude of the output voltage of the energy supply device to a settable second or prestored second voltage amplitude value if the sensed current amplitude exceeds the second current threshold value.

9. The energy supply device according to claim 1, wherein the signal generator is configured to increase the voltage amplitude of the output voltage of the energy supply device immediately or after expiry of a prestored second delay time interval after detecting that the second current threshold value of the current amplitude has been exceeded.

10. The energy supply device according to claim 1, wherein the measuring assembly comprises a measuring resistor.

11. A method for operating an energy supply device, comprising: sensing, at a measuring assembly, a current amplitude of an output current of the energy supply device; controlling, with a signal generator, a voltage amplitude of an output voltage of the energy supply device, wherein controlling the voltage amplitude comprises: reducing the voltage amplitude of the output voltage of the energy supply device in a first operating state of the energy supply device after expiry of a settable or prestored first delay time interval to change to a second operating state if the sensed current amplitude falls below a first current threshold value; and increasing the voltage amplitude of the output voltage of the energy supply device in the second operating state of the energy supply device to change to the first operating state if the sensed current amplitude exceeds a second current threshold value.

12. The method according to claim 11, further comprising comparing the sensed current amplitude with the first current threshold value or the second current threshold value or a further current threshold value by the signal generator.

13. The method according to claim 12, wherein the signal generator increases the voltage amplitude of the output voltage of the energy supply device to a settable second or prestored second voltage amplitude value if the sensed current amplitude exceeds the second current threshold value or the further current threshold value.

14. The method according to claim 13, further comprising limiting the increase of the voltage amplitude of the output voltage to avoid exceeding a safety range.

15. The method according to claim 11, further comprising reducing, by the signal generator, the voltage amplitude of the output voltage of the energy supply device to a settable first or prestored first voltage amplitude value if the sensed current amplitude falls below the first current threshold value.

16. The method according to claim 11, wherein the sensing further comprises repeatedly recording the voltage drop across a measuring resistor at a time interval.

17. The method according to claim 16, wherein the time interval is regular.

18. The method according to claim 11, wherein the controlling further comprises applying an input voltage to a primary side of a transformer and outputting the output voltage from a secondary side of the transformer.

19. The method according to claim 18, further comprising converting the output voltage from the secondary side of the transformer from an AC voltage to a DC voltage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Examples of the principles of this disclosure are illustrated in the drawings and are described in more detail below.

(2) In the drawings:

(3) FIG. 1 shows a schematic illustration of an energy supply device;

(4) FIG. 2 shows a schematic illustration of a measuring assembly of the energy supply device;

(5) FIG. 3 shows a schematic illustration of a signal generator of the energy supply device;

(6) FIG. 4 shows a schematic illustration of the energy supply device with a connected consumer;

(7) FIG. 5 shows a schematic diagram for the sequence of the method for operating the energy supply device;

(8) FIG. 6 shows a schematic illustration of the time against the output voltage and the output current of the energy supply device; and

(9) FIG. 7 shows a flowchart of exemplary method for operating the energy supply device.

DETAILED DESCRIPTION

(10) FIG. 1 shows a schematic illustration of an energy supply device 100 having a measuring assembly 101 for sensing a current amplitude of the output current of the energy supply device 100 and having a signal generator 103 for producing the output voltage and the output current of the energy supply device 100.

(11) The measuring assembly 101 is schematically illustrated with further details in FIG. 2. The measuring assembly 101 has a measuring resistor 201 and repeatedly senses the current amplitude of the output current of the energy supply device 100 (see FIG. 1) at intervals of time. The measuring assembly 101 senses the current amplitude of the output current on the basis of a voltage drop UA-UM across the measuring resistor 201. UA denoting the output voltage of the energy supply device and the input to the measuring assembly 101, and UM denoting the voltage across the measuring resistor 201.

(12) The measuring resistor 201 is provided in the form of a measuring shunt, as illustrated in FIG. 2. The current which flows through a measuring resistor 201 causes a voltage drop UA-UM which is proportional to it and is measured. The measuring resistor 201 is connected in parallel with a measuring circuit 203, the voltage drop across the measuring resistor 201 being used to measure the current amplitude. The resistance value of the measuring resistor 201 is, for example, in the milli-ohm range or below at several tenths or hundredths of a milli-ohm.

(13) The signal generator 103 (see FIG. 1) is electrically connected to the measuring assembly 101. FIG. 3 shows a schematic illustration of the signal generator 103 which comprises a transformer 300. The transformer 300 has a primary side 301, to which an input voltage U.sub.ein is applied, and a secondary side 303 which then provides a nominal output voltage U.sub.nom.

(14) The transformer 300 of the signal generator 103 has, on its primary side 301, a primary winding 305 which is directly fed with the input voltage U.sub.ein, that is to say the AC voltage from the energy supply network and the network frequency of the energy supply network, and has, on its secondary side 303, a secondary winding 307 which provides the output voltage U.sub.nom. The transformer 300 of the signal generator 103 converts the input voltage U.sub.ein, that is to say the AC voltage from the energy supply network, to the required output voltage value(s) U.sub.nom and ensures galvanic separation from the mains. U.sub.nom is set at a U.sub.nom control block 309 on the basis of a comparison between the voltage drop UA-UM sensed by the measuring assembly 101 and multiple current threshold values, as discussed with reference to FIGS. 1 and 4-7. The current threshold values may be stored in a memory 311 of the signal generator 103.

(15) The secondary AC voltage on the secondary side 303 of the transformer 300 can be converted, by means of a rectifier 313 and a smoothing capacitor 315, to a DC output voltage which can be provided at the output of the signal generator 103. A downstream linear regulator 317 and a buffer capacitor 319 also possibly provide an output voltage U.sub.nom which can be kept constant.

(16) FIG. 4 shows a schematic illustration of the energy supply device 100, to the output 405 of which a consumer 401 is connected. A capacitor 403 is connected in parallel with the consumer 401. The capacitor 403 provides a backup capacitance which provides a predetermined minimum power with a minimum load current and a minimum load voltage. Interposing the backup capacitance ensures that a consumer 401 connected to the energy supply device 100 exceeds a current threshold value, in particular the second current threshold value, with the result that the energy supply device 100 changes to its active state in order to automatically supply the connected consumer 401 with energy.

(17) The connected consumer 401 may be an electrical device, a motor, a PLC consumer (programmable logic controller), an industrial installation, a device which can be mounted on top-hat rails, a control cabinet or another electrical consumer. The connected consumer can be operated with DC voltage or with AC voltage.

(18) FIG. 5 shows a schematic diagram for the sequence of the method 500 for operating an energy supply device 100. The method 500 for operating the energy supply device 100 first of all comprises sensing 501 a current amplitude of the output current 601 of the energy supply device 100 by means of the measuring assembly 101. The sensed current amplitude of the output current 601 is then compared with settable or prestored current threshold values. After comparing 503 with a first current threshold value I1 and a second current threshold value I2, either the output voltage 603 is reduced 505 or the output voltage 603 is increased 507 depending on the result of the comparison 503.

(19) If the energy supply device 100 is in its first operating state 605, its active state, in which the consumer(s) 401 connected to the energy supply device 100 are supplied with energy, the energy supply device 100 changes from its first operating state 605 to its second operating state 607 if a current threshold value which is below a first current threshold value I1 is sensed 501. This transition is effected by reducing 505 the voltage amplitude of the output voltage 603 of the energy supply device 100 to a settable or prestored output voltage value U.sub.low. The second operating state 607 is an energy-saving state which is operated with the reduced output voltage U.sub.low.

(20) If the energy supply device 100 is in its second operating state 607, the energy-saving state, the energy supply device 100 changes from its second operating state 607 to its first operating state 605 if a current threshold value which is above a second current threshold value I2 is sensed 501. This transition is effected by increasing 507 the voltage amplitude of the output voltage 603 of the energy supply device 100 to a settable or prestored output voltage value U.sub.nom. The first operating state 605 is the active state which is operated with the nominal output voltage U.sub.nom.

(21) FIG. 6 shows a schematic illustration of the output voltage and the output current of the energy supply device. In its first operating state 605, the energy supply device 100 provides an output voltage value U.sub.nom and an output current value I.sub.nom at its output or is increased to these values, with the result that connected consumers 401 can be supplied with energy. The temporal profile of the amplitude of the output current 601 and the temporal profile of the amplitude of the output voltage 603 are illustrated both in the first operating state 605 and in the second operating state 607 in FIG. 6.

(22) At a time t0, a consumer 401 connected to the energy supply device 100 is switched off, with the result that the amplitude of the output current 601 is reduced to a first current threshold value I1 or to a value below the latter until a time t1, while the amplitude of the output voltage 603 has remained constant at the output voltage value U.sub.nom. The energy supply device 100 changes over from its first operating state 605 to the second operating state 607 only after expiry of the first delay interval 609 which corresponds to a period t1-t0. This results in the amplitude of the output voltage being reduced to the output voltage value U.sub.low and the amplitude of the output current being reduced to the second current threshold value I2 between the times t1 and t2.

(23) For example, the amplitude of the output voltage is reduced from 24 V to 8 V to 16 V or 10-12 V, for example, while the amplitude of the output current is reduced by 5-20% below the amplitude of the rated current.

(24) The remaining output current I2 is repeatedly measured at equidistant intervals of time in the second operating state 607. As long as the amplitude of the output current does not exceed the second current threshold value I2, the energy supply device 100 remains in its second operating state 607. Only if a consumer 401 having a load is connected to the energy supply device 100 at a time t3 is the amplitude of the output current 601 through the consumer 401 increased until a time t4, whereas the amplitude of the output voltage 603 is kept constant at the output voltage value U.sub.low. Connecting the consumer 401 having a backup capacitance can also result in a current peak in the amplitude of the output current 601 (not illustrated). In both cases, the increase in the amplitude of the output current is evaluated as the end of the second operating state 607. Consequently, at the time t4, that is to say after expiry of a second delay interval 611 which comprises the period t4-t3, the amplitude of the output current 601 is increased to the output current I.sub.nom and the amplitude of the output voltage is increased to the nominal output voltage U.sub.nom 603 until the time t5.

(25) At the time t5, the energy supply device provides an output voltage U.sub.nom and an output current I.sub.nom which can be used to operate the connected consumer 401. The output voltage U.sub.nom is, for example, 24 V or more. For example, 60 V for the output voltage U.sub.nom are not exceeded in order to avoid exceeding a safety range. The output current I.sub.nom is in a range between 40 A and 80 A, for example.

(26) FIG. 7 shows a flowchart of exemplary process at the energy supply device. At block 701, in its first operating state 605, the energy supply device 100 provides an output voltage value U.sub.nom and an output current value I.sub.nom at its output or is increased to these values, with the result that connected consumers 401 can be supplied with energy. The temporal profile of the amplitude of the output current 601 and the temporal profile of the amplitude of the output voltage 603 are illustrated both in the first operating state 605 and in the second operating state 607 in FIG. 6.

(27) At block 703 at a time t0, a consumer 401 connected to the energy supply device 100 is switched off, with the result that the amplitude of the output current 601 is reduced to a first current threshold value I1 or to a value below the latter until a time t1, while the amplitude of the output voltage 603 has remained constant at the output voltage value U.sub.nom.

(28) At block 705, the first delay interval 609 expires. At block 707, the energy supply device 100 changes over from its first operating state 605 to the second operating state 607 only after expiry of the first delay interval 609 which corresponds to a period t1-t0. This results in the amplitude of the output voltage being reduced to the output voltage value U.sub.low and the amplitude of the output current being reduced to the second current threshold value I2 between the times t1 and t2.

(29) For example, the amplitude of the output voltage is reduced from 24 V to 8 V to 16 V or 10-12 V, for example, while the amplitude of the output current is reduced by 5-20% below the amplitude of the rated current.

(30) The remaining output current I2 is repeatedly measured at equidistant intervals of time in the second operating state 607. As long as the amplitude of the output current does not exceed the second current threshold value I2, the energy supply device 100 remains in its second operating state 607.

(31) At block 709, if a consumer 401 having a load is connected to the energy supply device 100 at a time t3 is the amplitude of the output current 601 through the consumer 401 increased until a time t4, whereas the amplitude of the output voltage 603 is kept constant at the output voltage value U.sub.low. Connecting the consumer 401 having a backup capacitance can also result in a current peak in the amplitude of the output current 601 (not illustrated). In both cases, the increase in the amplitude of the output current is evaluated as the end of the second operating state 607. At block 711, a second delay interval 611 expires. Consequently, at block 713 at the time t4, that is to say after expiry of a second delay interval 611 which comprises the period t4-t3, the amplitude of the output current 601 is increased to the output current I.sub.nom and the amplitude of the output voltage is increased to the nominal output voltage U.sub.nom 603 until the time t5.

(32) At the time t5, the energy supply device provides an output voltage U.sub.nom and an output current I.sub.nom which can be used to operate the connected consumer 401, and the energy supply device has returned to the first operating state at block 701. The output voltage U.sub.nom is, for example, 24 V or more. For example, 60 V for the output voltage U.sub.nom are not exceeded in order to avoid exceeding a safety range. The output current I.sub.nom is in a range between 40 A and 80 A, for example.

(33) All features explained and shown in connection with individual examples of the principles of this disclosure can be provided in a different combination in the subject matter according to the disclosure in order to simultaneously achieve their advantageous effects.

(34) The scope of protection of the present disclosure is given by the claims and is not restricted by the features explained in the description or shown in the Figures.

LIST OF REFERENCE NUMBERS

(35) 100 Energy supply device 101 Measuring assembly 103 Signal generator 201 Measuring resistor 203 Measuring circuit 300 Transformer 301 Primary side 303 Secondary side 305 Primary winding 307 Secondary winding 309 U.sub.nom Control 311 Memory 313 Rectifier 315 Smoothing capacitor 317 Linear regulator 319 Buffer capacitor 401 Consumer 403 Capacitor 405 Output 500 Method 501 Sensing 503 Comparing 505 Reducing U.sub.nom 507 Increasing U.sub.nom 601 Output current 603 Output voltage 605 First operating state 607 Second operating state 609 First delay interval 611 Second delay interval I1 First current threshold value I2 Second current threshold value I.sub.nom Amplitude of the output current in the first operating state U.sub.nom Amplitude of the output voltage in the first operating state U.sub.low Amplitude of the output voltage in the second operating state U.sub.A Output voltage at the output of the measuring assembly U.sub.M Voltage across the measuring resistor U.sub.A-U.sub.M Voltage drop U.sub.ein Input voltage t0 Time t1 Time t2 Time t3 Time t4 Time t5 Time