Energy supply circuit for an x-ray generating system and x-ray generating system

Abstract

An energy supply circuit (1) for an X-ray generating system, the X-ray generating system having an inverter circuit (3) with an output for connecting the inverter circuit (3) to an X-ray source of the X-ray generating system, the energy supply circuit (1) comprising a rectifier circuit (5) with inputs (6a, 6b, 6c) for connecting the rectifier circuit (5) to an energy supply network (2), wherein an output (7a) of the rectifier circuit (5) can be connected to an input (4a) of the inverter circuit (3). The energy supply circuit (1) has a buffer circuit (8) with a plurality of energy storage cells (9) connected in series with one another, wherein the plurality of energy storage cells (9) can be connected in series between the input (4a) of the inverter circuit (3) and the output (7a) of the rectifier circuit (5).

Description

TECHNICAL FIELD

[0001] The present application relates to an energy supply circuit for an X-ray generating system and to an X-ray generating system having such an energy supply circuit. BACKGROUND

[0002] X-ray generating systems, for example for computed tomography systems, can be operated three- phase, for example with a desired voltage of several hundred volts and a relatively large tolerance range. One example is for example a desired voltage of 400 V with a tolerance range of +10 % / -20 %. Such X-ray generating systems, due to their short-time high power consumption, place very high demands on the infrastructure, for example on the building in which the X-ray generating system is installed, on the fuse devices, on the cable cross sections, etc. The grid internal resistance at the connection point here in particular only allows a high such that voltage dips during X-ray recording do not cause an under-voltage to other connected devices.

[0003] In order to match to a large operating voltage range, on the one hand matching transformers can be used. This results in high additional costs. Alternatively, X-ray generating systems with a wide-range input can be used. Here, a considerable part of the possible generator power must remain largely unused for the possible operating voltages. In the case of an X-ray generating system with two X-ray emitters, the second grid terminal must be guided through the entire power chain, including rectification, slip ring, grid filter and building connection, such that the requirements for the site installation correspondingly increase considerably. SUMMARY

[0004] It is an object of the present application to reduce the power consumption from the energy supply grid by means of an X-ray generating system.

[0005] The object is achieved by the subject matter of the embodiments of the present application. Advantageous refinements and preferred embodiments are the subject matter of the embodiments described below.

[0006] The present application is based on the idea that a buffer circuit, which has a plurality of energy storage cells connected in series with one another as such, is connected in series between a rectifier circuit and an inverter circuit for an X-ray generating system. Thus, an energy supply circuit for an X-ray generating system is provided, which reduces the maximum power consumption from the energy supply grid in the case of a given output power of the X-ray generating system or, in other words, increases the output power of the X-ray generating system in the case of a given maximum power consumption from the energy supply grid.

[0007] According to one aspect of the present application, an energy supply circuit for an X-ray generating system is described. The X-ray generating system has an inverter circuit having an output for connecting the inverter circuit with an X-ray source of the X-ray generating system. The energy supply circuit has a rectifier circuit having an input for connecting the rectifier circuit with an energy supply network, wherein an output of the rectifier circuit can be connected with an input of the inverter circuit. Furthermore, the energy supply circuit has a buffer circuit having a plurality of energy storage cells connected in series with each other. The plurality of energy storage cells can here be connected in series between the input of the inverter circuit and the output of the rectifier circuit.

[0008] In different embodiments of the energy supply circuit, the energy supply circuit also comprises the inverter circuit. The output of the rectifier circuit is then in particular connected with the input of the inverter circuit, and the plurality of energy storage cells is in particular connected in series between the input of the inverter circuit and the output of the rectifier circuit.

[0009] In different embodiments, the buffer can have two or more lines of the respectively series-connected energy storage cells connected in parallel with each other. Thus, not only a pure series connection is possible.

[0010] As far as not otherwise specified, an electrical connection here and in the following can be a direct electrical connection or an indirect electrical connection.

[0011] The energy supply network, which is not part of the energy supply circuit or of the X-ray generating system, is in particular designed as an alternating current network or as an alternating voltage network. An alternating voltage or an alternating current at the input of the rectifier circuit is converted by the rectifier circuit into a direct voltage or a direct current at the output of the rectifier circuit. The output of the rectifier circuit and the input of the inverter circuit correspond here to terminals of the same polarity between which the plurality of energy storage cells is connected in series.

[0012] The energy supply network can in particular be a multiphase, for example a three-phase, energy supply network. Correspondingly, the rectifier circuit is then designed as a multiphase, for example a three-phase, rectifier circuit. In other words, the rectifier circuit then converts a three-phase alternating voltage or alternating current provided by the energy supply network into a common direct voltage or a common direct current at the output of the rectifier circuit, in particular between the output and a reference potential terminal, for example a ground terminal.

[0013] The inverter circuit can then in turn convert the direct voltage thus generated into an alternating voltage or an alternating current, in particular a single-phase alternating current or a single-phase alternating voltage, for supplying the X-ray source.

[0014] Before the use of the X-ray generating system, i.e. in the case of a computed tomography system, for example, before the start of a scan, a plurality of energy storage cells can be charged to a preset voltage. The energy storage cells are arranged in series between the rectifier circuit and the inverter circuit, such that the energy storage cells provide an additional contribution to the voltage supply of the inverter circuit and thus of the X-ray source in addition to the voltage provided via the rectifier circuit from the energy supply network. For example, the voltage of the energy storage cells can be selected such that the total voltage applied to the inverter circuit corresponds to the maximum permissible voltage.

[0015] After the start of X-ray generation, the mains voltage provided by the energy supply network can drop sharply as a result of the high power consumption of the X-ray generating system. The voltage required for operating the X-ray generating system can still be provided by the buffer circuit and the energy stored in the energy storage cells of the plurality of energy storage cells.

[0016] The maximum power consumption of the X-ray generating system from the energy supply network is thus reduced to the extent to which the input voltage for the inverter circuit is increased by the buffer circuit. Alternatively or additionally to reducing the power consumption of the X-ray generating system, the energy supply circuit can also be used by the buffer circuit to increase the output power of the X-ray generating system in the case of a given mains terminal.

[0017] According to the application, it is thus possible to provide the X-ray generating system with a supply voltage which is largely independent of the energy supply network. An X-ray generating system designed for a wide range of outputs can achieve significantly more power by a correspondingly adjusted winding ratio of the high-voltage transformer. The X-ray generating system is thus also significantly less dependent on the mains impedance of the energy supply network at the connection point.

[0018] According to at least one embodiment, the energy supply circuit has a direct-voltage intermediate circuit which can be connected between the input of the inverter circuit and the buffer circuit or which is connected between the input of the inverter circuit and the buffer circuit.

[0019] Correspondingly, the direct-voltage intermediate circuit can stabilize the direct voltage provided to the inverter circuit. For example, the direct-voltage intermediate circuit can have one or a plurality of buffer capacitors connected in series and / or in parallel with one another, in particular in parallel with the input of the inverter circuit and the output of the rectifier circuit.

[0020] Alternatively, the direct-voltage intermediate circuit can also be understood as part of the inverter circuit.

[0021] According to at least one embodiment, the buffer circuit has a plurality of further energy storage cells which are connected in series with one another. Furthermore, the buffer circuit has a switching element, for example comprising a transistor, and which is provided and designed for selectively establishing and interrupting the series connection of the plurality of further energy storage cells between the input of the inverter circuit and the output of the rectifier circuit.

[0022] In other words, the plurality of further energy storage cells is connected in series between the input of the inverter circuit and the output of the rectifier circuit, wherein the series connection can be selectively interrupted and established by means of the switching element.

[0023] In other words, if the switching element is in a closed state, i.e. in a conductive state, the plurality of further energy storage cells is connected in series between the input of the inverter circuit and the output of the rectifier circuit. Thus, the energy storage cells of the plurality of energy storage cells and the further energy storage cells of the plurality of further energy storage cells are in particular all connected in series with one another and between the output of the rectifier circuit and the input of the inverter circuit. If the switching element is in an open state, i.e. in a non-conductive or substantially non-conductive state, the further energy storage cells are no longer connected in series between the rectifier circuit and the inverter circuit. However, in the case of an open switching element, the energy storage cells of the plurality of energy storage cells are still connected in series with one another and between the output of the rectifier circuit and the input of the inverter circuit.

[0024] Thus, in the described manner, in the buffer circuit, a fixed part of the energy buffer is formed by the plurality of energy storage cells, and a variable, i.e. switchable, part of the energy buffer is formed by the plurality of further energy storage cells.

[0025] In the described manner, it is possible to react dynamically or flexibly to fluctuations in the grid voltage or fluctuations in the power consumption of the X-ray generating system in such a way that the further energy storage cells are correspondingly switched on or switched off.

[0026] The further energy storage cells can also be correspondingly charged as described with regard to the energy storage cells before the start of operation of the X-ray generating system.

[0027] The plurality of further energy storage cells can in particular only be switched on after a certain time after the start of the scan and after the supply voltage or intermediate circuit voltage of the inverter circuit correspondingly drops below a predetermined threshold value. After being switched on, the further energy storage cells can remain switched on permanently in the case of systems with a sufficiently good grid internal resistance. In other cases, the further energy storage cells can also be disconnected again via the switching element when they are no longer needed.

[0028] According to at least one embodiment, the energy supply circuit, in particular the buffer circuit, has a control circuit which is designed to determine an input voltage of the inverter circuit, in particular an intermediate circuit voltage of a direct voltage intermediate circuit. The control circuit is coupled to the switching element in order to actuate the switching element depending on the input voltage of the inverter circuit. The control circuit can actuate the switching element in order to selectively establish or interrupt a series connection of the further energy storage cells between the input of the inverter circuit and the output of the rectifier circuit.

[0029] If the energy supply circuit has a direct voltage intermediate circuit and in particular one buffer capacitor or a plurality of buffer capacitors connected in parallel to one another, the input voltage of the inverter circuit corresponds to the intermediate circuit voltage of the direct voltage intermediate circuit, i.e. the voltage on the buffer capacitor or the plurality of buffer capacitors.

[0030] According to at least one embodiment, the control circuit is designed to actuate the switching element for establishing a series connection of the further energy storage cells between the input of the inverter circuit and the output of the rectifier circuit when, in particular exactly when, the input voltage of the inverter circuit does not exceed a predefined threshold value.

[0031] The input voltage not exceeding the threshold value can in particular be understood as meaning that the value of the input voltage is first greater than the threshold value and subsequently less than the threshold value.

[0032] In this way, the series connection can in particular be established when the input voltage first does not exceed the threshold value after the start of operation of the X-ray generating system.

[0033] According to at least one embodiment, the energy supply circuit, for example the buffer circuit, has a charging device which can be connected to or is connectable to the energy storage cells for charging the energy storage cells.

[0034] In a corresponding embodiment, the charging device can also be connected to or be connectable to the further energy storage cells in order to also charge the further energy storage cells. Alternatively, a further charging device for charging the further energy storage cells can be provided.

[0035] The energy storage cells of the energy storage cells and, in a corresponding embodiment, the further energy storage cells of the further energy storage cells can in different embodiments be embodied as capacitors, in particular double-layer capacitors.

[0036] By connecting the energy storage cells and, if necessary, the further energy storage cells in series with respect to one another and with respect to the rectifier circuit and the inverter circuit, it is possible, especially in the case of the use of double-layer capacitors, to provide very high power densities on very small construction spaces. Instead of capacitors, accumulators, especially lithium-ion accumulators, can also be used as energy storage cells or further energy storage cells of the buffer circuit.

[0037] Depending on the specific design of the X-ray generating system and depending on the required power consumption, the plurality of energy storage cells can consist of, for example, 30 to 70, for example 40 to 60, energy storage cells. The plurality of further energy storage cells can, if necessary, comprise fewer energy storage cells, for example consist of 10 to 50, especially 20 to 40, further energy storage cells.

[0038] According to a further aspect of the present application, an X-ray generating system is also given, which has an energy supply circuit according to the present application and an X-ray source connected to the output of the inverter circuit for supplying electrical energy.

[0039] According to at least one embodiment of the X-ray generating system, the X-ray generating system has a further X-ray source connected in parallel with the X-ray source.

[0040] The present application comes into particular advantage especially in the case of such double-beam or multi-beam X-ray generating systems, since the requirements on the energy supply network are correspondingly significantly increased here.

[0041] According to a further aspect of the present application, a computed tomography system is given, which has an X-ray generating system according to the present application. Alternatively, the X-ray generating system can be designed as a computed tomography system.

[0042] Further features of the present application result from the figures and the figure description. The features and feature combinations mentioned in the description previously and in the following figure description and / or shown in the figures can not only be included in the respective explicitly stated combinations, but also in other combinations of the present application. In particular, the present application also comprises embodiments and feature combinations which do not have all the features of the originally presented claims. Furthermore, the present application also comprises embodiments and feature combinations which go beyond or deviate from the feature combinations shown in the reference relationship of the claims. BRIEF DESCRIPTION OF DRAWINGS

[0043] The present application is explained in detail in the following on the basis of specific embodiments and associated schematic drawings. In the drawings, identical or functionally identical elements can be provided with the same reference signs. If necessary, the description of identical or functionally identical elements need not be repeated for different figures.

[0044] In the drawings, it is shown:

[0045] Figure 1 a schematic circuit diagram showing an exemplary embodiment of an energy supply circuit for an X-ray generating system according to the present application; and

[0046] Figure 2 a schematic circuit diagram showing another exemplary embodiment of an energy supply circuit for an X-ray generating system according to the present application. DETAILED DESCRIPTION

[0047] In Figure 1 a circuit diagram of an energy supply circuit 1 for an X-ray generating system according to the present application is shown, as well as an energy supply network 2, which is designed, for example, as a three-phase alternating current electrical network, is schematically shown.

[0048] Each phase of the energy supply network 2 is connected to a corresponding input terminal 6a, 6b, 6c of a rectifier circuit 5 of the energy supply circuit 1. Furthermore, the energy supply circuit 1 has an inverter circuit 3 as well as a direct current voltage intermediate circuit 13 and a buffer circuit 8.

[0049] The rectifier circuit 5 can convert an alternating voltage provided by the energy supply network 2 into a direct current voltage and provide the direct current voltage to two corresponding output terminals 7a, 7b of the rectifier circuit 5. The first output terminal 7a of the rectifier circuit 5 is connected to an input terminal 11 of the buffer circuit 8, and an output terminal 12 of the buffer circuit 8 is connected to a first input terminal 4a of the inverter circuit 3. The second output terminal 7b of the rectifier circuit 5 is connected to a second input terminal 4b of the inverter circuit 3.

[0050] The direct current voltage intermediate circuit 13 has a temporary storage capacitor 14, which is connected between the input terminals 4a, 4b and thus also between the output terminal 12 of the buffer circuit 8 and the second output terminal 7b of the rectifier circuit 5.

[0051] The buffer circuit 8 comprises a plurality of energy storage cells 9, which are connected to one another in series, the energy storage cells 9 being connected between Figure 1 are schematically shown in

[0052] The plurality of energy storage cells 9 is connected in series between the input terminal 11 and the output terminal 12 of the buffer circuit 8. Correspondingly, the buffer circuit 8 and the plurality of energy storage cells 9 are also connected in series between the output terminal 7a of the rectifier circuit 5 and the input terminal 4a of the inverter circuit 3 or the direct current voltage intermediate circuit 13.

[0053] Furthermore, the buffer circuit 8 can comprise a diode 10 which is connected in parallel to the plurality of energy storage cells 9. The cathode of the diode 10 is here connected to the output 12 of the buffer circuit 8, for example, and the anode of the diode 10 is connected to the input 11 of the buffer circuit 8.

[0054] Furthermore, the energy supply circuit 1 has a charging device (not shown in Figure 1 ) by means of which the plurality of energy storage cells 9 can be charged before the start of operation.

[0055] In the example shown in Figure 2 , the DC voltage intermediate circuit 13 comprises a further intermediate capacitor 15 which is connected in parallel to the intermediate capacitor 14. Furthermore, the buffer circuit 8 comprises a plurality of further energy storage cells 16 which are connected to one another in series and are likewise shown by means of a circuit symbol of a single capacitor for reasons of simplification. The plurality of further energy storage cells 16 are connected on one side to the plurality of energy storage cells 9 and on the other side can be connected to the input 11 of the buffer circuit 8. To this end, the buffer circuit 8 has, in particular, a switching element 18. Figure 2 Figure 1 The embodiment of the energy supply circuit 1 according to the application shown in

[0056] In the example shown in Figure 2 , the DC voltage intermediate circuit 13 comprises a further intermediate capacitor 15 which is connected in parallel to the intermediate capacitor 14. Furthermore, the buffer circuit 8 comprises a plurality of further energy storage cells 16 which are connected to one another in series and are likewise shown by means of a circuit symbol of a single capacitor for reasons of simplification. The plurality of further energy storage cells 16 are connected on one side to the plurality of energy storage cells 9 and on the other side can be connected to the input 11 of the buffer circuit 8. To this end, the buffer circuit 8 has, in particular, a switching element 18.

[0057] Thus, if the switching element 18 is in the closed state, the energy storage cells 9 and the further energy storage cells 16 are all connected to one another in series and also between the input 11 and the output 12 of the buffer circuit 8. If the switching element 18 is in the open state, the further energy storage cells 16 are separated from the series connection, and the energy storage cells 9 are still connected in series between the input 11 and the output 12 of the buffer circuit 8.

[0058] To actuate the switching element 18, the energy supply circuit 1 comprises a control unit 19, which can also be referred to as a control circuit. The control unit 19 can switch the switching element 18, in particular, from the open state to the closed state or vice versa. The control unit 19 can determine, in particular, the intermediate circuit voltage of the DC voltage intermediate circuit 13, i.e. the voltage which drops over the intermediate capacitor 14, 15 or between the input terminals 4a, 4b of the AC voltage circuit 3. The control unit 19 can compare the intermediate circuit voltage with a preset threshold value and, in the case of the switching element 18 being initially open, close the switching element 18 when the intermediate circuit voltage falls below the preset threshold value.

[0059] The charging device 20 is also shown in Figure 2 Furthermore, the charging device 20 is shown in Figure 2 ​In the example of Fig. 1, the energy supply circuit 1 has a further charging device 21 in order to charge the further energy storage 16 correspondingly. In alternative embodiments, the charging device 20, 21 can also be replaced by a common charging device for charging the energy storage 9 and the further energy storage 16.

[0060] Finally, the buffer circuit 8 can have a further diode 17, which is connected in parallel to the further energy storage 16 and in series to the diode 10.

[0061] Further details of the application are set out below in accordance with Figure 1 and Figure 2 The explanations are by no means limiting for the application. Depending on the given requirements, the specific design can be different.

[0062] Figure 1 and Figure 2 The X-ray generating system 1 operates three- phase, for example with a voltage of 400 V + 10% / - 20%, and due to its short-time high power consumption, very high requirements are placed on the infrastructure, for example the insurance devices of the building in which the X-ray generating system is installed, the cable cross-section, etc. The grid impedance of the energy supply network at the connection point only allows a high voltage drop during the X-ray recording which does not cause an under-voltage of simultaneously connected devices.

[0063] This not only leads to high requirements for the building installation, but can also limit the possible scan power per connection point. For example, if the rotational speed of the scan unit, also called gantry, is increased in a computed tomography system, for example corresponding to an increase in the rotational frequency from 4 Hz to 5 Hz, the scan power must be increased from, for example, 120 kW to 150 kW in order to keep the same dose per image. With the minimum permissible grid voltage, a grid impedance of 60 mΩ would be required, which is extremely high technically.

[0064] Thereby, according to the prior art, it is not feasible to use a common grid terminal for a dual-radiation system or to operate a high-power computed tomography system at a weak grid terminal.

[0065] According to the application, the energy supply circuit 1 has a further energy storage 16, which is connected in parallel to the energy storage 9 and is connected in series to the diode 10. Figure 1 and Figure 2The X-ray generating system 1 should cope with the restrictions in such a way that a buffer circuit 8 is connected between the rectifier circuit 5 and the direct voltage intermediate circuit 13, which can be charged to a variable voltage before the start of the scan according to a charging device 16, 21, for example, designed as a double-layer capacitor or a two-layer capacitor connected in series, by means of an energy store 9 and optionally a further energy store 16. The intermediate circuit voltage can thereby be raised to a constant value in the maximum permissible intermediate circuit voltage range, which can be, for example, 750 V.

[0066] The buffer circuit 8 can be installed together with the rectifier circuit 5, the direct voltage intermediate circuit 13 and the inverter circuit 3, or the buffer circuit 8 can be installed separately. The resulting reduction in power consumption results from the design of the energy store 9, 16, in particular the maximum voltage, the capacitance and the internal resistance.

[0067] In a design example, the intermediate circuit voltage should move in the range from 650 V to 720 V in a manner independent of the energy supply network 2 in order to reduce the current consumption of the X-ray generating system. The available range can be divided into a voltage drop of the energy store due to the discharge and a network voltage dip corresponding to the network impedance.

[0068] The total voltage of the buffer circuit 8 should therefore be sufficient to still be able to achieve an intermediate circuit voltage of, for example, 720 V in the event of a network voltage dip. The total voltage can therefore be designed to, for example, 220 V.

[0069] The dip, which can be compensated for by means of a switchable part of the buffer circuit 8 in the form of a further energy store 16, can be caused by the network impedance and the storage impedance, by means of contact resistance, etc. The further energy store 16 can be switched on, for example, a certain time after the start of the scan and after the intermediate circuit voltage has dropped below a certain value. In the case of a current consumption of 250 A, which refers to the effective value according to the root mean square, and a network internal resistance of 150 mΩ, the dip is, for example, approximately 90 V, and the voltage of the switchable part of the energy buffer can therefore be designed to, for example, 75 V. The further energy store 16 can be switched on by means of a control unit 19 via a switching element 18 depending on the current intermediate circuit voltage. The switching element 18 can have a pulsed current consumption here and be switched in the currentless state.

[0070] The further energy store 16 can remain permanently switched on in systems with a sufficiently good network internal resistance. If the further energy store 16 is required to compensate for a network voltage dip, the energy store 9 and the further energy store 16 can be charged to, for example, 750 V together.

[0071] In a corresponding embodiment, the required capacitance of the double-layer capacitor depends essentially on the limit load curve of an X-ray source or of a plurality of X-ray sources. For example, when two 90 kW X-ray sources are used at a single grid terminal of a 120 kW system designed with a generally varying curve of the limit load curve, a double-layer capacitor with a capacitance of 1800 F is sufficient.

[0072] The number of energy storage cells 9 can be designed, for example, to 45 to 55, and the number of the alternative energy storage cells 16 can be designed, for example, to 25 to 30, wherein the individual cell voltage can be charged, for example, to 2.7 V shortly before the scan. Otherwise, the cell voltage can be adjusted to a low value in order to prolong the service life.

[0073] At the minimum possible grid voltage and the minimum possible power, approximately 40% of the output power can be obtained from the buffer circuit. Thus, in the case of a maximum average power of, for example, 6 kW for a double-radiator system, the charging device 20, 21 can be designed, for example, such that it can provide 2.4 kW. The power is required only in the upper voltage range, so that an exemplary design of 250 V and 15 A provides sufficient reserve. Shorter time intervals can cause the charging power to be increased to 6 kW for a short time, if necessary. In the standby state and at the lowest scan power, the charging device 20, 21 can also contribute to improving the power factor of the X-ray generating system by appropriate adjustment.

[0074] As described, the application can be used to reduce the power consumption. The maximum current consumption is reduced, in particular, to the extent that the intermediate circuit voltage is increased by the buffer circuit 8. In the case of a buffer voltage of 200 V and an intermediate circuit voltage without storage of 450 V, the power consumption can be reduced by approximately 30%.

[0075] In addition to reducing the power consumption of the X-ray generating system, the buffer circuit 8 can also be used to increase the output power of the X-ray generating system in the case of a given grid terminal. In combination with the buffer circuit 8, the X-ray generating system is operated at a higher intermediate circuit voltage, which leads to an increase in the output power at constant internal current. In the case of the same input current, the possible output power increase in the above example is approximately 44%.

[0076] For example, in the current system, the reduction of the maximum current consumption of the X-ray generating system can be up to 40%. By this, a 90 kW computed tomography system with two X-ray radiators and only one grid input terminal can be realized.

[0077] Furthermore, the power consumption of the computed tomography system can be reduced, so that, for example, a 90 kW device can be replaced by a 120 kW device while keeping the same grid terminal power and implementation.

[0078] By the present application, the X-ray generating system can be provided with a supply voltage which is largely independent of the grid. An X-ray generating system designed for a wide range of input can achieve significantly more power by an adjusted winding ratio of the high-voltage transformer. The X-ray generating system is significantly less dependent on the grid impedance at the connection point.

[0079] In different embodiments, the power factor of the X-ray generating system, especially in standby state, can be improved by appropriate adjustment of the charging device.

Claims

1. An energy supply circuit (1) for an X-ray generating system, the X-ray generating system having an inverter circuit (3) with an output for connecting the inverter circuit (3) with an X-ray source of the X-ray generating system, the energy supply circuit (1) having: - a rectifier circuit (5) with inputs (6a, 6b, 6c) for connecting the rectifier circuit (5) with an energy supply network (2), wherein an output (7a) of the rectifier circuit (5) is connectable with an input (4a) of the inverter circuit (3); characterized in that - the energy supply circuit (1) has a buffer circuit (8) with a plurality of energy storage cells (9) connected in series with each other; and - the plurality of energy storage cells (9) is connectable in series between the input (4a) of the inverter circuit (3) and the output (7a) of the rectifier circuit (5), wherein the energy supply circuit has a DC voltage intermediate circuit (13) connectable between the input (4a) of the inverter circuit (3) and the buffer circuit (8), and wherein a maximum power consumption from the energy supply network is reduced to an extent by which the intermediate circuit voltage of the DC voltage intermediate circuit is increased by the buffer circuit.

2. The energy supply circuit (1) according to claim 1, wherein the DC voltage intermediate circuit (13) comprises a temporary storage capacitor (14, 15).

3. The energy supply circuit (1) according to claim 1 or 2, the buffer circuit (8) having: - a plurality of further energy storage cells (16) connected in series with each other; and - a switching element (18) arranged and designed for selectively establishing and interrupting a series connection of the plurality of further energy storage cells (16) between the input (4a) of the inverter circuit (3) and the output (7a) of the rectifier circuit (5).

4. The energy supply circuit according to claim 3, the energy supply circuit having a control circuit (19) which: - is designed for determining an input voltage of the inverter circuit (3); - is coupled with the switching element (18) in order to operate the switching element (18) depending on the input voltage of the inverter circuit (3) for selectively establishing and interrupting a series connection of the plurality of further energy storage cells (16) between the input (4a) of the inverter circuit (3) and the output (7a) of the rectifier circuit (5). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5. The energy supply circuit (1) according to claim 4, wherein the control circuit (19) is designed to operate the switching element (18) to establish a series connection of a plurality of the further energy storage cells (16) between the input (4a) of the inverter circuit (3) and the output (7a) of the rectifier circuit (5) when the input voltage of the inverter circuit (3) does not exceed a predetermined threshold value.

6. The energy supply circuit (1) according to claim 1 or 2, having a charging device which can be connected to or is connected to a plurality of the energy storage cells (9) for charging a plurality of the energy storage cells (9).

7. The energy supply circuit (1) according to claim 1 or 2, wherein the energy storage cells (9) of a plurality of the energy storage cells (9) are designed as double-layer capacitors.

8. The energy supply circuit (1) according to claim 1 or 2, wherein the energy storage cells (9) of a plurality of the energy storage cells (9) are designed as accumulators.

9. The energy supply circuit (1) according to claim 1 or 2, wherein a plurality of the energy storage cells (9) consists of 30 to 70 energy storage cells (9).

10. The energy supply circuit (1) according to claim 1 or 2, wherein the energy storage cells (9) of a plurality of the energy storage cells (9) are designed as lithium-ion accumulators.

11. The energy supply circuit (1) according to claim 1 or 2, wherein a plurality of the energy storage cells (9) consists of 40 to 60 energy storage cells (9).

12. An X-ray generating system having an energy supply circuit (1) according to any one of claims 1 to 11, an inverter circuit (4) and an X-ray source connected to the output of the inverter circuit (3) for supplying electrical energy.

13. The X-ray generating system according to claim 12, having a further X-ray source connected in parallel to the X-ray source.

14. The X-ray generating system according to claim 12 or 13, wherein the X-ray generating system is designed as a computed tomography system.

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