Use of circuit configurations for testing circuit configurations that generate output DC voltage and electrical energy storage devices.

Abstract

The present invention relates to a circuit configuration (1) that generates at least one output DC voltage (2, 2a, 2b) based on an input AC voltage (3), and includes at least one input stage (4), at least one power converter (5), and at least one DC voltage converter (10, 10a, 10b). The input stage (4) is coupleable to the input AC voltage (3) and can generate an intermediate circuit voltage. The power converter (5) has at least one double resonant stage (8, 8a, 8b) that can generate at least one first DC voltage (6a, 6b) and at least one second DC voltage (7a, 7b) from the intermediate circuit voltage. The DC voltage converter (10, 10a, 10b) can generate output DC voltage (2, 2a, 2b) from the first DC voltage (6a, 6b) and the second DC voltage (7a, 7b). Furthermore, the first output of the DC voltage converter (10, 10a, 10b) is connected to the common ground point of the first DC voltage (6a, 6b) and the second DC voltage (7a, 7b).

Description

Technical Field

[0001] The present invention relates to a circuit arrangement for generating at least one output DC voltage based on an input AC voltage. This circuit arrangement has at least one input stage, at least one power converter, and at least one DC voltage converter. The input stage can be coupled to the input AC voltage and can generate at least one intermediate circuit voltage at the input stage. From the intermediate circuit voltage, at least one first DC voltage and at least one second DC voltage can be generated using the power converter. The power converter has at least one double resonance stage for generating the first DC voltage and the second DC voltage. The output DC voltage can be generated from the first DC voltage and the second DC voltage using the DC voltage converter.

[0002] Furthermore, the present invention also relates to the use of the circuit arrangement for testing an electrical energy storage device.

Background Art

[0003] Electronic circuits and assemblies often operate with DC voltages. Usually, multiple different potentials are required simultaneously. In order to enable supply from an AC voltage circuit, the provided AC voltage (input AC voltage) needs to be first converted to the corresponding output DC voltage using a circuit arrangement.

[0004] Known circuit arrangements usually have an input-side AC / DC converter that supplies a relatively high single-ended DC voltage (so-called bus voltage) to the output terminals, and from this AC / DC converter, a downstream DC / DC converter generates the DC voltages required for the individual assemblies. Such circuit arrangements can sometimes become very complex and include components that cause significant interference at the output. Furthermore, for special applications such as testing an electrical energy storage device, it is also necessary to generate a negative output voltage.

[0005] Many electronic devices, particularly test equipment for electrical energy storage devices, are subject to legal safety requirements, which necessitate galvanic isolation (electrical isolation) between the power supply and low-voltage circuits based on external connections (e.g., DIN EN61010 (issued March 2020): Safety requirements for electrical measurement, control, adjustment and experimental equipment).

[0006] Generally, galvanic isolation in input converters (AC / DC converters) is known to be achieved by integrated or upstream transformers. However, galvanic isolation can also be performed in DC / DC converters. For this purpose, output-side DC / DC converters are typically used, but they are very expensive due to the high power levels. It is also known that transformer-based galvanic isolation can be used when connecting to commercial power supplies. It is also possible to provide an additional independent transformer on the AC side.

[0007] German Patent Application Publication No. 102014013039 discloses an automotive device that uses, for example, a galvanically isolated DC voltage converter to galvanically decouple the voltage transfer between a high-voltage circuit and a low-voltage circuit, the galvanically isolated DC voltage converter converts the high-voltage DC voltage supplied by the high-voltage circuit into a first DC voltage, and the galvanically isolated DC voltage converter then converts the first DC voltage into a second DC voltage, thereby connecting the high-voltage circuit and the low-voltage circuit.

[0008] U.S. Patent Application Publication No. 2015 / 375628 discloses a galvanic isolation charging device for electric vehicles, comprising a reversible AC / DC converter capable of supplying power to two outputs of different voltages.

[0009] Charging devices with galvanic isolation for electric vehicles can also be found in U.S. Patent Publication No. 2013 / 162032, U.S. Patent Publication No. 2013 / 175990, and German Patent Publication No. 102017208360, each of which presents multiple converters.

[0010] German Patent Application Publication No. 102012212291 discloses an apparatus for electrical DC rapid charging or discharging of an energy storage device, comprising an AC / DC converter module coupled to a power supply circuit and a DC / DC controller module electrically coupled to the AC / DC converter module, wherein the DC / DC controller module comprises a DC / DC step-down controller module without galvanic isolation and a DC / DC resonant converter module for galvanic isolation.

[0011] As explained, test equipment and devices for electrical energy storage devices also operate on direct current (DC) voltage. Therefore, a circuit configuration that generates an output DC voltage based on an input AC voltage is particularly necessary.

[0012] An electrical energy storage device is a mobile or stationary device or electrical system that stores electrical energy and releases it as needed. Such energy storage devices are based on chemical or physical effects and are often implemented as batteries or capacitors. The characteristics of an electrical energy storage device are determined by test equipment. These tests essentially involve supplying electrical energy to the energy storage device and then removing that energy. The resulting measurements evaluate the characteristics of the energy storage device.

[0013] At this time, a test system is known that rapidly charges and discharges energy storage devices through cyclical supply and DC removal. The charging and discharging process is performed with high current and high dynamics to investigate the energy storage system, for example, to investigate its suitability for battery electric vehicles (BEVs).

[0014] Power electronics used for this purpose are typically installed in an integrated test apparatus that utilizes this measurement technique. The requirements for power electronics include high current and high dynamics, as well as very rapid changes in the direction of current (charging / discharging). Because the voltage under test is sometimes low, the test apparatus must also be able to supply negative output voltages to meet the required dynamic characteristics.

[0015] It is already known that high-frequency transformers controlled by active components are used. These active components generate a high-frequency AC voltage, which is then rectified on the other side of the high-frequency transformer, again using active components. [Prior art documents] [Patent Documents]

[0016] [Patent Document 1] German Patent Application Publication No. 102014013039 Specification [Patent Document 2] U.S. Patent Application Publication No. 2015 / 375628 [Patent Document 3] U.S. Patent Application Publication No. 2013 / 162032 [Patent Document 4] U.S. Patent Application Publication No. 2013 / 175990 [Patent Document 5] German Patent Application Publication No. 102017208360 Specification [Patent Document 6] German Patent Application Publication No. 102012212291 Specification [Non-patent literature]

[0017] [Non-Patent Document 1] Article on "Insulation (Electricity)", especially about "isolation", Wikipedia (Japanese version), [online], [searched on March 3, 2026], Internet <https: / / ja.wikipedia.org / wiki / 絶縁_(電気)> [Summary of the Invention] [Problems to be Solved by the Invention]

[0018] This circuit described as a "dual active bridge" in the literature operates a high-frequency transformer with galvanic isolation and changes the output voltage by active control of the rectifier circuits on its input and output sides. However, this circuit hardware-switchingly turns on and off the input current and output current by switching transistors. This switching operation causes undesirable interference due to strong switching pulses. This interference can be controlled by appropriate interference suppression measures in static processing at a fixed operating point. However, the test system does not operate at a fixed operating point. Due to the dynamic characteristics of the test, the operating point always changes. This is a major technical drawback of the "dual active bridge" circuit. This generated interference is not preferable regarding both the measurement accuracy and the problem of interference suppression. [Means for Solving the Problems]

[0019] Based on the above prior art, an object of the present invention is to provide a circuit configuration that can test an electrical energy storage device and generate at least one DC output voltage (especially a negative DC output voltage) from an input AC voltage.

[0020] According to the present invention, this problem is solved by a circuit configuration having the technical features of claim 1.

[0021] For this reason, a circuit configuration for generating at least one output DC voltage based on an input AC voltage includes at least one input stage, at least one power converter, and at least one DC voltage converter. The input stage can be coupled to the input AC voltage and generate an intermediate circuit voltage from the input stage. In the power converter, at least one first DC voltage and at least one second DC voltage can be generated from the intermediate circuit voltage. The power converter has at least one doubly resonant stage for generating the first DC voltage and the second DC voltage. In the DC voltage converter, an output DC voltage can be generated from the first DC voltage and the second DC voltage.

[0022] This circuit configuration is characterized in that the first and second DC voltages generated by the doubly resonant stage are each led to a common ground point, one output of the DC voltage converter is connected to this ground point, and the other output of the DC voltage converter is connected to the remaining output of the power converter or the doubly resonant stage, so that the DC voltage converter can generate an output DC voltage with a controllable output DC voltage in either polarity.

[0023] The intermediate circuit voltage refers to a voltage at an intermediate voltage level different from the AC input voltage before the power converter. The intermediate circuit voltage may be an AC voltage or a DC voltage. That is, the input stage is designed to convert the input AC voltage into an intermediate circuit AC voltage or an intermediate circuit DC voltage. In this circuit configuration, the voltage conversion from the input AC voltage to the output DC voltage is performed in a multi-stage process.

[0024] The power converter should preferably match the input stage or the intermediate circuit voltage that can be generated from the input stage. The power converter should preferably be designed as a rectifier circuit capable of additional voltage conversion, especially when the intermediate circuit voltage is AC, or as a DC voltage converter when the intermediate circuit voltage is DC. Alternatively, the power converter can be designed as a rectifier circuit capable of supplying DC voltage and can be used in combination with an arbitrarily designed input stage.

[0025] The advantage of the circuit configuration based on this invention is that it can generate either a single output DC voltage or several different output DC voltages, which are automatically set by the conversion ratio. The dual resonant stage ensures electromagnetic compatibility (EMC) and interference operation without voltage spikes due to switching at the zero point. Furthermore, the dual resonant stage enables a compact design for galvanic isolation, resulting in less space and mass.

[0026] Dynamic, full four-quadrant operation is effectively achieved through post-control via a common ground point using first and second DC voltages that can be generated in the resonant stage using at least one DC voltage converter, and individually controllable output DC voltages that can be generated with any polarity.

[0027] In the first embodiment of the circuit configuration, the power converter is designed as an LLC resonant converter. This means that a resonant circuit (inductance and additional capacitors) is connected in series with the transformer on the primary side of the transformer to generate a sine wave (rather than a square pulse). This series resonant circuit is also called a resonant tank.

[0028] An LLC resonant converter preferably has at least two resonant converters, which are well known in terms of circuitry. Each resonant converter stage has a resonant tank connected to the primary side of its respective transformer, and the two resonant converter stages are interconnected to generate a first DC voltage and a second DC voltage.

[0029] Each of the two resonant stages consists of two resonant converters, and therefore preferably comprises a first LLC stage and a second LLC stage in parallel therewith. Each of these LLC stages includes at least a resonant tank, a transformer, and a secondary converter circuit.

[0030] Preferably, there are at least two double resonance stages. Preferably, there are three to 64 double resonance stages. In particular, there are six double resonance stages. It is also suggested that 64 or more double resonance stages may be arranged.

[0031] In a more preferred embodiment, the first LLC stage includes a first capacitor, a first inductance, and a first transformer. The second LLC stage includes a second capacitor, a second inductance, and a second transformer. The basic principle of this resonant converter is based on the fact that the primary drive winding of the first converter transformer, together with the first capacitor and the first inductance, forms a first LC series resonant circuit, and the primary drive winding of the second converter transformer, together with the second capacitor and the second inductance, forms a second LC series resonant circuit.

[0032] The LLC resonant converter preferably has at least one double resonant stage in addition to at least one front-end H-bridge supplied with an intermediate circuit voltage to rectify the input AC voltage. The AC side of the H-bridge is connected to the primary side of the first transformer via a series connection of the first capacitor and first inductance of the first LLC stage, and to the primary side of the second transformer via a series connection of the second capacitor and second inductance of the second LLC stage. In this way, the rectified input AC voltage can be transmitted to the first and second transformers, respectively.

[0033] Furthermore, it is desirable that the secondary sides of the first transformer and the second transformer be connected so that the first DC voltage is generated in the first LLC stage and the second DC voltage is generated in the second LLC stage.

[0034] In particular, for each double resonant stage, the first DC voltage generated by the first LLC stage and the second DC voltage generated by the second LLC stage are coupled at a common ground point, and preferably, the negative terminal of the first DC voltage is coupled to the positive terminal of the second DC voltage. Each double resonant stage is connected to its respective downstream DC voltage converter.

[0035] According to a preferred embodiment of the power converter, the secondary side of the first transformer and the secondary side of the second transformer each have a full-bridge rectifier circuit. Preferably, each full-bridge rectifier circuit has four transistors as switching elements, which are connected to the secondary windings in a well-known manner to generate a first or second DC voltage.

[0036] According to another embodiment of the power converter, the first or second transformer has a plurality of windings on the secondary side, preferably a plurality of windings connected in series, in particular two windings. In this embodiment, it is presented that the secondary sides of the first transformer and the secondary sides of the second transformer each have a half-bridge rectifier circuit having two transistors, and these transistors are connected to the secondary windings in a well-known manner to generate a first or second DC voltage.

[0037] A second embodiment of the circuit configuration also presents a power converter having at least two resonant converter stages. Unlike the first embodiment described above, the series resonant circuit of the transformer, inductance, and capacitor is formed on the secondary side of the transformer, but not on the primary side.

[0038] Similar to the first embodiment, each resonant converter stage has a resonant tank connected to the secondary side of its respective transformer and a well-known converter circuit. Two resonant converter stages are interconnected to generate a first DC voltage and a second DC voltage. At least one double resonant stage of the second embodiment consists of two resonant converter stages, preferably a first LLC stage and a second LLC stage.

[0039] A third embodiment of the circuit configuration presents a power converter having at least two resonant converter stages. Unlike the second embodiment described above, there is only one transformer with multiple windings on the secondary side, and each series resonant circuit is coupled to the first or second secondary winding.

[0040] According to the present invention, it is proposed that at least one DC voltage converter is connected downstream of the power converter.

[0041] Preferably, the DC voltage converter is designed and configured such that the output DC voltage varies between a negative first DC voltage and a positive second DC voltage, for example, between -10V and 20V.

[0042] An advantage of this embodiment is that the polarity of the output voltage can be reversed, for example, to generate a negative output voltage of -10V, which allows for testing of energy storage cells with voltages ranging from 2V to 7V.

[0043] The DC voltage converter is preferably designed as a buck boost stage, a linearly regulated output stage, or a buck stage, where each double resonant stage preferably has at least one buck boost stage, at least one linearly regulated output stage, or at least one buck stage.

[0044] This allows the circuit configuration, and thus its galvanic isolation, to operate in both directions, resulting in high dynamic control operation not only for the dynamic characteristics of current and power, but also for both the direction of energy flow (charging / discharging).

[0045] Bidirectional means, for example, that the energy obtained from the test subject can be fed back into its power supply circuit in the form of regeneration. In this way, energy storage systems, especially large-scale ones, can be tested without releasing the extracted energy as waste energy.

[0046] In the case of a DC voltage converter designed as a buck boost stage, it is preferable that the buck boost stage is coupled to a first DC voltage via a first switching element (specifically, a first transistor) and to a second DC voltage via a second switching element (specifically, a second transistor). The output DC voltage is then supplied via at least one capacitor connected in series with at least one storage inductor. Preferably, the storage inductor is further connected in series with a current measuring shunt. This allows for effective control of the output current and output voltage. The storage inductor is a coil for storing energy. The current measuring shunt is a low-resistance electrical measuring resistor.

[0047] Preferably, the first DC voltage and the second DC voltage are each less than 100V, particularly less than 50V, preferably less than 20V, and especially preferably in the range of 10V to 20V.

[0048] Preferably, the input AC voltage is between 100V and 690V.

[0049] According to a preferred embodiment, the input stage is designed and configured to generate an intermediate circuit voltage of 300V to 1200V, preferably 800V.

[0050] Furthermore, the input stage is preferably designed as a power factor controller. This reduces the load on the power supply circuit and decreases reactive currents and power supply harmonics that cause unacceptable distortion of the power supply voltage.

[0051] Furthermore, an objective of the present invention is to enable testing of electrical energy storage devices.

[0052] According to the present invention, this problem is solved by the feature of claim 16, in that the circuit configuration based on the present invention is used for testing electrical energy storage devices.

[0053] The circuit configuration based on the present invention can be used for testing a single energy storage device, as well as for testing multiple energy storage devices connected in parallel to this circuit configuration.

[0054] Preferably, the energy storage device includes at least one primary battery, at least one secondary battery, at least one individual cell, at least one half-cell, or at least one electric double-layer capacitor (supercapacitor).

[0055] Further useful embodiments of the present invention can be obtained from the following drawings and the descriptions of the dependent claims. [Brief explanation of the drawing]

[0056] [Figure 1] This is a part of the circuit diagram of an embodiment of the circuit configuration according to the present invention. [Figure 2] This is a circuit diagram of an embodiment based on Figure 1 in which a DC voltage converter has been added. [Figure 3] This is a circuit diagram of an embodiment having multiple double resonant stages. [Figure 4] This is a circuit diagram of another embodiment using a half-bridge rectifier circuit. [Figure 5] This is a circuit diagram of another embodiment having a secondary resonant tank. [Figure 6] This is a circuit diagram of another embodiment having only one transformer and a secondary resonant tank. [Modes for carrying out the invention]

[0057] In each drawing, the same part is always assigned the same reference number.

[0058] With respect to the following description, the present invention is not limited to embodiments and is therefore not limited to all or some of the combinations of features described. Rather, each partial feature of an embodiment is important to the subject matter of the present invention, both in isolation from all other partial features described in connection therewith and in combination with features of other embodiments.

[0059] Figure 1 shows a portion of the circuit diagram of an embodiment of circuit configuration 1 according to the present invention, which generates at least one output DC voltage based on an input AC voltage 3. Circuit configuration 1 includes an input stage 4 and a power converter 5. According to the present invention, circuit configuration 1 further includes a DC voltage converter connected downstream of the power converter 5, but is not shown in Figure 1.

[0060] The input stage 4 is coupled to the input AC voltage 3 and provides an intermediate circuit voltage to the power converter 5. The input stage 4 is preferably a bidirectional AC / DC power supply, for example, a 10kW power factor correction stage (PFC stage) 12 having an output parallel capacitor, which provides an intermediate circuit voltage of about 800V.

[0061] The power converter 5 is connected to the output terminal or output capacitor of the input stage 4. The power converter 5 has a front-end H-bridge H1 and a dual-resonant converter stage 8.

[0062] The H-bridge H1 is connected at its input side to the output terminal of input stage 4. The H-bridge H1 is a common design. There are four transistors Q1 through Q4. The drain terminals of transistors Q1 and Q2 are connected to the first output terminal of input stage 4. The source terminals of transistors Q3 and Q4 are connected to the second output terminal of input stage 4. The source terminals of Q1 and Q2 are connected to the drain terminals of Q3 and Q4, respectively.

[0063] The dual resonant converter stage 8 has galvanically isolated first and second LLC stages 9a and 9b, and a first output H bridge H2 and a second output H bridge H3 on the secondary side.

[0064] The LLC stages 9a and 9b each have resonant tanks consisting of capacitors C1 and C2 and inductors L1 and L2 connected in series on the positive polarity of the primary side of transformers T1 and T2, respectively. The resonant tanks are connected to the input transistors Q1 and Q3 of the H bridge H1, respectively, and the negative polarities of transformers T1 and T2 are connected to transistors Q2 and Q4 of the H bridge H1, respectively.

[0065] On the secondary side of transformers T1 and T2, a first output H-bridge H2 or a second output H-bridge H3 is provided. Output H-bridges H2 and H3 are designed in a manner known as a full-bridge rectifier circuit. Each has four transistors Q1 through Q4. The positive polarity of transformers T1 and T2 is connected to the source of transistor Q1 and the drain of transistor Q3, respectively. Its negative polarity is connected to the source of transistor Q2 and the drain of transistor Q4. The drain terminals of Q1 and Q2 are connected to each other and are also connected to the output capacitors. The drain terminals of Q3 and Q4 are also connected to each other and are also connected to the second terminals of the output capacitors.

[0066] It should be understood that the transistors specified by Q1 to Q4 in the H1, H2, and H3 H-bridges may be designed identically or differently. Preferably, transistors Q1 to Q4 are selected according to the voltage level of each intermediate circuit. This enables efficient optimization of each H-bridge in H1, H2, and H3, which is beneficial in terms of thermal management and device size.

[0067] Figure 2 shows a circuit diagram of an embodiment of circuit configuration 1 based on Figure 1, in which a DC voltage converter 10 is additionally provided at the output of the rectifier circuit stage 5 in the form of a buck boost stage 11. For the structure of the input stage 4 and the power converter 5, please refer to the explanation in Figure 1.

[0068] The buck boost stage 11 includes a storage inductor L3, a measurement shunt R1, and an output capacitor C3, in addition to the transistor-designed switching elements Q7 and Q8.

[0069] Transistor Q7 is connected to the first output terminal of power converter 5 via its drain terminal. Transistor Q8 is connected to the second output terminal of power converter 5 via its source terminal. The source of transistor Q7 and the drain of transistor Q8 are connected to each other and are connected in series to the first output terminal of buck boost stage 11 via storage inductor L3 and measuring shunt R1. The second output terminal of buck boost stage 11 is connected between the two output capacitors of power converter 5. The negative terminal of the first output capacitor is connected to the positive terminal of the second output capacitor, so that the first DC voltage 6a and the second DC voltage 7a are led to a common ground point. Buck boost capacitor C3 is connected in parallel to the first and second output terminals of buck boost stage 11.

[0070] Figure 3 shows a circuit diagram of a further embodiment of circuit configuration 1, in which case the DC voltage converter is not shown. The DC voltage converter is designed, for example, according to Figure 2. Circuit configuration 1 according to Figure 3 is basically designed the same as Figure 2, but with two double resonant stages 8a and 8b. Therefore, circuit configuration 1 according to this embodiment also includes two buck boost stages 11, which are connected to the double resonant stages 8a and 8b, respectively. For details of the electrical connections, please refer to the description of the embodiment in Figure 2. The two double resonant stages 8a and 8b are configured in the same way and are connected to the H bridge H1 described in Figure 2 above.

[0071] The first double resonant stage 8a can generate the first and second DC voltages 6a and 7a. The second double resonant stage 8b can further independently generate the first and second DC voltages 6b and 7b. The subsequent buck-boost stage 11 can generate mutually independent output voltages 2a and 2b, as described above.

[0072] Figure 4 shows a circuit diagram of yet another embodiment of circuit configuration 1 according to the present invention, where again the DC voltage converter is not shown. The DC voltage converter is designed, for example, according to Figure 2. Circuit configuration 1 according to this other embodiment has an input stage 4 and a power converter 5 as shown in Figure 1. The input stage 4 corresponds to the input stage 4 in Figure 1.

[0073] Unlike the power converter 5 in the embodiment shown in Figure 1, power converter 5 has two half-bridge rectifier circuits on the secondary side of the transformer instead of two full-bridge rectifier circuits. The first transformer T3 and the second transformer T4 each have two windings connected in series on their secondary sides, and both are connected to the first and second transistors Q5 and Q6.

[0074] The half-bridge rectifier circuit is designed in a known manner, with the first terminals or positive terminals of the first windings of transformers T3 and T4 connected to the source terminals of the first transistor Q5, respectively. The second terminals or negative terminals of the second windings of transformers T3 and T4 are connected to the source terminals of the second transistor Q6, respectively. The drain of the first transistor Q5 is connected to the drain of the second transistor Q6 and to the output capacitor. The other terminal of the output capacitor is connected to transformer T3 or T4 between the first and second windings. This leads the first output DC voltage 6a and the second output DC voltage 7a to a common ground point. The first output DC voltage 6a and the second output DC voltage 7a are present in these output capacitors.

[0075] Figure 5 shows a circuit diagram of a further embodiment of circuit configuration 1 according to the present invention, in which the DC voltage converter is not shown. The DC voltage converter is designed, for example, according to Figure 2. This circuit configuration 1, like Figure 1, has an input stage 4 and a power converter 5 having a double resonant stage 8. This input stage 4 corresponds to the input stage 4 of Figure 1. The power converter 5 differs from the embodiment in Figure 1 only in that the resonant tanks 9a and 9b of the double resonant stage 8 are located on the secondary side of transformers T1 and T2, respectively.

[0076] The embodiment shown in Figure 5 can be combined with multiple double resonant stages, and can also be implemented as a half-bridge rectifier circuit as shown in Figure 4.

[0077] Figure 6 shows a circuit diagram of a further embodiment of circuit configuration 1 according to the present invention, in which case the DC voltage converter is not shown. The DC voltage converter is designed, for example, according to Figure 2. Unlike Figures 1 to 5, only one transformer T5 is provided here. The resonant tanks 9a and 9b are located on the secondary side as in Figure 5. Transformer T5 has two secondary windings for supplying power to the resonant tanks 9a and 9b. Otherwise, the circuit is designed similarly to Figure 5. The DC voltages 6a and 7a can be individually adjusted by the number of turns of the two secondary windings. [Explanation of Symbols]

[0078] 1. Circuit Configuration Output DC voltages of 2, 2a, and 2b 3. Input AC voltage 4 input stages 5 Power Converters 6a, 6b First DC voltage 7a, 7b Second DC voltage 8, 8a, 8b double resonant stage 9a 1st LLC stage 9b 2nd LLC stage 10, 10a, 10b DC voltage converter 11 Back Boost Stages 12 PFC input stage C Capacitor L Inductance HH Bridge Q Transistor R resistance T Transformer

Claims

1. A circuit configuration (1) that generates at least one output DC voltage (2, 2a, 2b) based on an input AC voltage (3), It comprises at least one input stage (4), at least one power converter (5), and at least one DC voltage converter (10, 10a, 10b), The above input stage (4) is capable of coupling to the above input AC voltage (3) and generating an intermediate circuit voltage. Using the power converter (5) described above, at least one first DC voltage (6a, 6b) and at least one second DC voltage (7a, 7b) can be generated from the intermediate circuit voltage. The power converter (5) has at least one double resonant stage (8, 8a, 8b) for generating the first DC voltage (6a, 6b) and the second DC voltage (7a, 7b), Using the above DC voltage converters (10, 10a, 10b), the above output DC voltages (2, 2a, 2b) can be generated from the above first DC voltages (6a, 6b) and the above second DC voltages (7a, 7b). The above circuit configuration (1), The first DC voltage (6a, 6b) and the second DC voltage (7a, 7b) are connected to a common ground point. The first output of the DC voltage converter (10, 10a, 10b) is coupled to the common ground point of the first DC voltage (6a, 6b) and the second DC voltage (7a, 7b), and the second output of the DC voltage converter (10, 10a, 10b) is coupled to the power converter (5) so that the output DC voltage (2, 2a, 2b) can be generated as a DC output voltage (2, 2a, 2b) that can be controlled to either polarity. Circuit configuration (1) characterized by the following:

2. The circuit configuration (1) according to claim 1 is characterized in that the power converter (5) described above is designed as a DC voltage converter or a rectifier circuit, particularly an LLC resonant converter.

3. The circuit configuration (1) according to 1 is characterized in that the above double resonant stage (8, 8a, 8b) has a first LLC stage (9a) and a second LLC stage (9b) in parallel therewith.

4. The circuit configuration (1) according to 3 is characterized in that the first LLC stage (9a) has a first capacitor (C1), a first inductance (L1), and a first transformer (T1, T3), and the second LLC stage (9b) has a second capacitor (C2), a second inductance (L2), and a second transformer (T2, T4).

5. The power converter (5), particularly the LLC converter, has at least one front-end H-bridge to which the intermediate circuit voltage is supplied, and at least one double resonant stage (8, 8a, 8b), and the AC side of the H-bridge is connected to the primary side of the first transformer (T1, T3) via the first capacitor (C1) and the first inductance (L1) connected in series with the first LLC stage (9a), and is also connected to the primary side of the second transformer (T2, T4) via the second capacitor (C2) and the second inductance (L2) connected in series with the second LLC stage (9b), characterized in that the circuit configuration (1) according to 4.

6. The power converter (5), particularly the LLC converter, has at least one front-end H-bridge to which the intermediate circuit voltage is supplied and which is connected to the first and second transformers (T1, T2), and the first capacitor (C1) and first inductance (L1) of the first LLC stage (9a) are provided on the secondary side of the first transformer (T1), and the second capacitor (C2) and second inductance (L2) of the second LLC stage (9b) are provided on the secondary side of the second transformer (T2), characterized in that the circuit configuration (1) is based on 4.

7. Circuit configuration (1) according to 5 or 6, characterized in that the secondary sides of the first transformer (T1, T3) and the secondary sides (T2, T4) of the second transformer are connected so that the first DC voltage (6a, 6b) can be generated by the first LLC stage (9a) and the second DC voltage (7a, 7b) can be generated by the second LLC stage (9b).

8. Circuit configuration (1) according to 7, characterized in that the secondary side of the first transformer (T1) and the secondary side of the second transformer (T2) each have a full-bridge rectifier circuit having preferably four transistors (Q1 to Q4), or the first transformer (T3) or the second transformer (T4) has a plurality of windings on its secondary side, preferably a plurality of windings connected in series, particularly two windings, and the secondary side of the first transformer (T3) and the secondary side of the second transformer (T4) each have a half-bridge rectifier circuit.

9. The power converter (5) has a transformer (T5) having multiple windings, particularly two windings, connected in series on the secondary side, and at least one front-end H-bridge to which the intermediate circuit voltage is supplied and which is connected to the transformer (T5). The first LLC stage (9a) has a first capacitor (C1) and a first inductance (L1) connected in series to the first secondary winding of the transformer (T5), The second LLC stage (9b) has a second capacitor (C2) and a second inductance (L2) connected in series to the second secondary winding of the transformer (T5). Preferably, the first and second secondary windings are connected such that the first LLC stage (9a) can generate the first DC voltage (6a) and the second LLC stage (9b) can generate the second DC voltage (7a), characterized in that the circuit configuration (1) according to 3.

10. The circuit configuration (1) according to 1 is characterized in that the output DC voltages (2, 2a, 2b) vary between the positive first DC voltage (6a, 6b) and the negative second DC voltage (7a, 7b).

11. The above DC voltage converters (10, 10a, 10b) are designed as a buck boost stage (11), a linear control output stage, or a buck stage, and preferably, each of the above double resonant stages (8, 8a, 8b) has a buck boost stage (11), a linear control output stage, or a buck stage, characterized in that the circuit configuration (1) according to 10.

12. The buck boost stage (11) is coupled to the first DC voltage (6a, 6b) via a first switching element (Q7), particularly a transistor, and is also coupled to the second DC voltage (7a, 7b) via a second switching element (Q8), particularly a transistor. The above output DC voltages (2, 2a, 2b) are supplied via at least one storage inductor (L3) and at least one capacitor (C3) connected in series with it. The storage inductor (L3) is preferably connected in series with the current measuring shunt (R1). Circuit configuration (1) based on characteristic 11.

13. A circuit configuration (1) based on 1, characterized in that there are at least two double resonant stages (8, 8a, 8b), preferably three to 64 double resonant stages (8, 8a, 8b), and particularly six double resonant stages (8, 8a, 8b).

14. Circuit configuration (1) according to 1, characterized in that the first and second DC voltages (6a, 6b, 7a, 7b) are less than 100V, particularly less than 50V, preferably less than 20V, and particularly preferably in the range of 10V to 20V, and the input AC voltage is in the range of 100V to 690V.

15. The above input stage (4) is designed and configured to generate the above intermediate circuit voltage from 300V to 1200V, preferably 800V, and the above input stage (4) is preferably designed as a power factor controller, characterized in that the circuit configuration (1) according to 1.

16. A method of using the circuit configuration (1) according to claim 1 to test at least one electrical energy storage device.

17. A method of use according to claim 16, wherein the electrical energy storage device includes at least one primary battery, at least one secondary battery, at least one individual cell, at least one half cell, or at least one electric double-layer capacitor.

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