Energy supply device for electrolysis unit and electrolysis equipment
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-04-14
- Publication Date
- 2026-03-03
AI Technical Summary
The prior art increases energy conversion loss when solving the voltage increase problem caused by aging of electrolytic equipment, and traditional solutions are complex and costly.
The energy supply device that uses a combination of a multi-winding transformer and a multi-phase rectifier provides a stable voltage to the auxiliary unit through a multi-winding transformer, and provides an adaptive DC voltage to the electrolytic device through a multi-phase rectifier, avoiding the voltage increase problem due to aging.
It realizes that during the aging of the electrolytic equipment, keeping the energy conversion loss within an acceptable range, reducing the system complexity and cost, and ensuring the stable operation of the electrolytic equipment.
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Abstract
Description
[Technical field]
[0001] The present patent application relates to an energy supply device for an electrolysis unit and to an electrolysis installation comprising such an energy supply device. [Background technology]
[0002] Hydrogen can be produced from water by electrolysis by supplying it with electrical energy. Industrial hydrogen production is often performed using electrolyzers that are supplied from an energy supply grid (e.g., a medium voltage grid) via a rectifier. Electrolyzers are known to be sensitive to aging, which means that for a given DC input voltage, the hydrogen production rate of the electrolyzer decreases during aging. The hydrogen production rate depends directly on the current throughput of the electrolyzer and usually increases with increasing DC input voltage of the electrolyzer. Therefore, to ensure that the electrolyzer can achieve a specified hydrogen production rate even with aging, the DC input voltage must be increased.
[0003] The problem of an age-related increase in the supply voltage of the electrolyzer is solved in the prior art by providing a so-called tap changer in the transformer, through which the rectifier is connected to the energy supply grid. The tap changer, usually on the primary side of the transformer, can be used to change the transformation ratio of the transformer. In this way, the voltage amplitude of the AC voltage supplied to the AC side of the rectifier can be increased (or decreased) over time. By increasing the AC voltage amplitude, the effects of ageing of the electrolyzer can be at least partially compensated for, without the need to operate the rectifier under conditions in which the conversion losses due to ageing of the electrolyzer increase significantly.
[0004] In addition to the electrolyser, the electrolysis unit also contains auxiliary units, e.g. cooling devices, pumps, heating devices, etc., which supply and discharge the required medium to the electrolyser in the specified quality (pressure, temperature, etc.). The power supply to the auxiliary units is usually via a standardized AC voltage (e.g. 400V, 480V), which generally has a narrow tolerance range with regard to its voltage amplitude. Changing the transformation ratio of the transformer via the primary tap changer also affects the secondary AC voltage supplying the auxiliary units, which also increases and would fall outside the tolerance range if no further measures were taken.
[0005] In order to avoid an increase in the AC voltage used for the auxiliary units, a design of an electrolysis installation 150 with an energy supply device 100 and an electrolysis unit 120 according to Fig. 1 is known. The energy supply device 100 comprises two separate transformers 102, 104, each of which is connected on its primary side to the energy supply grid 40 via a grid connection 115 of the energy supply device 100. The electrolysis device 22 of the electrolysis unit 120 receives a DC input voltage U DC、ELis supplied. For this, the first transformer 104 is connected on the secondary side via an AC isolation unit 105, an AC / DC converter 106, a DC isolation unit 112 and a DC voltage output 116 of the energy supply device 100 to a DC voltage input (DC input) 21 of the electrolyzer 22, which is supplied to the electrolyzer 20 of the electrolysis unit 120. The second transformer 102 serves to supply a standardized alternating voltage to the auxiliary units 23, 24 of the electrolysis unit 120 and for this purpose is connected on the secondary side via an auxiliary power output 117 of the energy supply device 100 to the auxiliary units 23, 24 of the electrolysis unit 120. Only the first transformer 104, and not the second transformer 102, has a tap changer for compensating for ageing effects of the electrolyzer 22. Although the second transformer 102 does not require a tap changer and its nominal power is usually designed to be significantly lower than the nominal power of the first transformer 104, and the two transformers 102, 104 do not necessarily have to be designed as multi-winding transformers, the overall solution is nevertheless costly, especially if the energy supply grid 40 is a medium voltage grid and the second transformer 102 is designed as a separate medium voltage transformer.
[0006] Another conventional variant of an electrolysis installation 250 with an energy supply device 200 and an electrolysis unit 220 is shown in Fig. 2. Here, the supply unit 200 contains a transformer 202 designed as a multi-winding transformer with a first and a second secondary side, which is connected on its primary side to the energy supply grid 40 via a grid connection 215 of the energy supply device 200. The auxiliary units 23, 24 of the electrolysis unit are powered via the first secondary side of the transformer 202. The second secondary side supplies the electrolysis device 22 of the electrolysis unit 220 with a DC input voltage U DC、ELfor supplying the auxiliary power output 217 to the electrolyzer 22. For this purpose, it is connected via an AC isolation unit 205, an AC / DC converter 206, a DC isolation unit 212 and a DC voltage output 216 of the energy supply device 200 to the DC input 21 of the electrolyzer 22. In order to compensate for the ageing effects of the electrolyzer 22, the transformer 202 has a tap changer on the primary side, which increases the voltage amplitude of the AC voltage supplied to the AC / DC converter 206. In order that the change in the transformation ratio by the tap changer of the transformer 202 does not affect the AC voltage of the auxiliary units 23, 24 connected to the auxiliary power output 217, the second transformer 204 is also provided with a tap changer. Here, the tap changer of the second transformer 204 operates in the opposite direction to the tap changer of the transformer 202, which again reduces the AC voltage on the secondary side of the second transformer 204 facing the auxiliary units 23, 24. This allows the voltage rise of the transformer 202 when powering the auxiliary units 23, 24 to be compensated and reset to the standard value required for the auxiliary units. In this conventional variant, a low-voltage transformer can be used as the second transformer 204, which does not necessarily have to be designed as a multiple-winding transformer. However, an additional tap changer is still required. Such a transformer with a tap changer is generally more expensive than a transformer without a tap changer. In summary, the conventional solutions shown in Figures 1 and 2 are complex, costly and prone to errors during implementation.
[0007] Publication CN202930937U discloses an energy supply system for an electrolytic tank. The system includes an AC step-down station, a power conversion station for converting AC to DC, and an electrolytic tank. The power conversion station includes a sampling circuit for input AC current and input AC voltage, a load voltage regulator, a rectifier transformer, a rectifier, a controller, a filter and a power compensation device, and a sampling circuit for output DC current and output DC voltage. The power conversion station is designed so that the power loss of the rectifier transformer due to harmonics is greatly reduced.
[0008] WO2009 / 144266A1 discloses a three-phase rectifier circuit with two or more transformers, which are connected in parallel to each other on the primary side to the AC grid and each connected to at least one semiconductor rectifier bridge on the secondary side. The rectifier bridges connected to the different transformers are connected in series on the DC side to supply DC power to household appliances. One of the rectifier bridges is a thyristor rectifier bridge and the remaining rectifier bridges are diode rectifier bridges.
[0009] GB778989A discloses an electrolytic installation with multiple electrolytic loads, each of which is powered through its own multi-phase rectifier by a separate star-connected group of secondary windings of a transformer. The transformer has two groups of primary windings connected to a three-phase supply. In the event of an error, only the affected loads are switched off.
[0010] Document DE897696B discloses an electrolysis apparatus comprising an electric pump, a liquid container and an electrolysis cell fed with liquid from the container by the pump. The electrolysis apparatus includes a grid transformer, a rectifier and a voltage regulator for supplying power to the electrolysis cell, as well as an auxiliary transformer and rectifier for operating a motor that pumps brine to the cell. Summary of the Invention
[0011] It is an object of the present invention to provide an energy supply device for an electrolysis unit, which, when supplying energy to the electrolyzer, does not increase at all, or at least not significantly, the power losses associated with the conversion, despite the progressive ageing of the electrolyzer. The energy supply device should also be as cost-effective as possible. It is a further object of the present invention to provide an electrolysis installation having these characteristics. [Means for solving the problem]
[0012] An energy supply device for an electrolysis unit according to the invention comprises: a grid connection for connecting the energy supply device to an energy supply grid; a DC voltage output for connecting the electrolysis device of the electrolysis unit; and an auxiliary power output for connecting at least one auxiliary unit of the electrolysis unit.
[0013] The system further includes a first multi-winding transformer having a primary side connected to a grid connection of the energy supply device and a secondary side having a first secondary connection and a second secondary connection electrically isolated therefrom, the first secondary connection being connected to the auxiliary power output and having a first voltage amplitude. The second secondary connection is connected to the AC connection of the first AC / DC converter acting as a rectifier and is designed to supply an AC voltage having a second voltage amplitude. The first AC / DC converter is designed to supply an AC voltage having a third voltage amplitude. The DC connection of the first AC / DC converter is connected to a DC output of the energy supply device. The energy supply device also includes a second transformer having a primary side connected to the grid connection and a secondary side. The secondary side of the second transformer is designed to supply an AC voltage having a third voltage amplitude. TIFF2025514915000004.tif7170 and having a third secondary connection connected to the AC connection of the second AC / DC converter. The DC connection of the second AC / DC converter is connected to the DC output. The primary and first secondary connections of the first multi-winding transformer or the primary and secondary of the first multi-winding transformer, respectively, are not provided with tap changers.
[0014] In addition to the first multi-winding transformer and the second transformer, the energy supply device may also comprise one or possibly several additional transformers. The one or several further transformers may each be connected on the primary side to the grid connection and on the secondary side to the DC voltage output of the energy supply device, each connected via an AC / DC converter acting as a rectifier or, in the case of a transformer having two electrically isolated secondary connections each also connected via two AC / DC converters acting as rectifiers. Each of the further transformers may be designed as a multi-winding transformer. Each of the further transformers may, but does not necessarily have to, have a tap changer.
[0015] A multi-winding transformer is a transformer that includes multiple windings on its primary side and / or its secondary side for each phase of the AC voltage. For example, a three-winding transformer may comprise one winding on its primary side and two windings on its secondary side for each phase. A four-winding transformer may thus have two primary windings and two secondary windings per phase. In the multi-winding transformers referred to here, the two secondary windings for each phase are usually electrically isolated from each other. However, it is also possible instead for one or more multi-winding transformers each to have two secondary windings connected in parallel. In the case of two primary windings per phase, such as in a four-winding transformer, these may be electrically connected to each other, in particular connected in parallel to each other. A multi-winding transformer with two electrically isolated secondary windings for each phase allows the transformation of a primary AC voltage into two secondary AC voltages with different voltage amplitudes using two different transformation ratios.
[0016] For the electrolysis reaction, the electrolyzer requires a chemical medium of a certain chemical and / or physical quality. The medium is transformed into another medium by the electrolysis reaction, but once transformed, it also needs to be transported to be removed again. The auxiliary units of the electrolysis unit are those units that serve to supply the chemicals to the electrolyzer and are necessary to supply the chemical medium to the electrolyzer and / or transport the chemical medium to be removed from the electrolyzer. Alternatively or additionally, auxiliary units can also be used in the preparation of the chemical medium to achieve and / or maintain a certain chemical or physical quality. Thus, such auxiliary units, which are used, for example, in the electrolytic production of hydrogen from water, can in particular comprise a gas pump, a liquid pump, a gas compressor, a gas drying unit, a washing unit for water purification, a cooling unit or a heating unit. An electrolysis unit can usually include a plurality of identical and / or different auxiliary units.
[0017] In the energy supply device according to the invention, the first multi-winding transformer supplies a first voltage amplitude to the auxiliary unit of the electrolysis unit via its first secondary connection. The second secondary winding and the second voltage amplitude supplied to it serve to supply the AC voltage of TIFF2025514915000005.tif6170. The AC voltage of TIFF2025514915000006.tif6170 is rectified via a first AC / DC converter and supplied to a DC voltage output of the energy supply device and then to a DC input of the electrolytic device for supplying it. The second transformer can be, but does not necessarily have to be, a multi-winding transformer. A third voltage amplitude is supplied via it at a third secondary connection. The alternating voltage having the TIFF2025514915000007.tif6170 is rectified via a second AC / DC converter and also fed to the direct voltage output of the energy supply device and then to the DC input of the electrolyzer in order to supply it. The two AC / DC converters connected to the DC input of the electrolyzer do not have to be simultaneously activated to power the electrolyzer. Rather, in case of low hydrogen production rates, i.e. low power conversion relative to the nominal power, it is possible to initially power the electrolyzer from the second AC / DC converter rather than the first AC / DC converter. Furthermore, the first AC / DC converter can only be connected to the second AC / DC converter if the power conversion level of the electrolyzer is high and close to the nominal power rating of the electrolyzer. In particular, it is also possible to start up the electrolyzer and possibly operate it at partial load using the second AC / DC converter rather than the first AC / DC converter. The transformation ratios at the second and third secondary connections can be adjusted to a second voltage amplitude. TIFF2025514915000008.tif8170 is the third voltage amplitude By selecting it to be greater, and in particular always greater, than TIFF2025514915000009.tif7170, the power losses occurring during the operation of the electrolysis unit or energy supply device can be minimized and the entire operating range of the electrolyzer in its current-voltage diagram can be reached by at least one of the at least one AC / DC converter (and, if necessary, both AC / DC converters). This also applies to the ageing-related increase in the DC voltage supplied to the DC input of the electrolyzer.
[0018] Since there are no tap changers at the primary side and the first secondary side connection of the first multi-winding transformer, or at the primary side and the secondary side of the first multi-winding transformer, respectively, a first voltage amplitude of the AC voltage applied to the first secondary side connection TIFF2025514915000010.tif9170 is constant over time and invariant, especially with respect to aging of the electrolysis device. It can therefore always correspond to the standardized AC voltage required for the auxiliary units of the electrolysis unit. 11 The second voltage amplitude applied to the second secondary connection, if there is also no tap changer across the first multi-winding transformer This also applies in a similar manner to an AC voltage having a TIFF2025514915000011.tif7170. The first multi-winding transformer can thus be designed cost-effectively. The second transformer can also be designed cost-effectively, especially if it is not designed as a multi-winding transformer and does not have a tap changer. Nevertheless, in the energy supply device according to the invention, the first multi-winding transformer and the second transformer can be optimally utilized in terms of their energy supply. This applies in particular to the first multi-winding transformer, which supplies the auxiliary unit with its first secondary connection and the electrolyzer with its second secondary connection. In summary, this results in a cost-effective energy supply device for an electrolysis unit, in which the conversion losses do not increase significantly even with ageing of the electrolysis unit.
[0019] In an advantageous embodiment of the energy supply device, the second transformer can also be designed as a multi-winding transformer, which has a fourth secondary connection on its secondary side in addition to the third secondary connection. The fourth secondary connection provides a fourth voltage amplitude. TIFF2025514915000012.tif7170. It is connected to the AC connection of a third AC / DC converter, the DC connection of which is connected to the DC output of the energy supply device. Advantageously, a fourth voltage amplitude TIFF2025514915000013.tif7170 is the second voltage amplitude It is smaller than TIFF2025514915000014.tif7170. It is the third voltage amplitude. TIFF2025514915000015.tif6170, but advantageously different therefrom. In this way, the AC / DC converters can cover the operating range of the electrolyzer when generating the DC input voltage for the electrolyzer, such that during operation, each of the AC / DC converters covers a different voltage range in which it operates particularly efficiently and with low conversion losses. The voltage ranges of the different AC / DC converters can advantageously overlap. This does not mean that in each voltage range only the AC / DC converter assigned to that voltage range operates. Rather, several, in particular all, AC / DC converters can be operated in individual voltage ranges or simultaneously in each of the voltage ranges. However, the AC / DC converter assigned in particular to this voltage range operates with particularly low conversion losses compared to the other AC / DC converters. Regardless of whether the second transformer is a second multi-winding transformer or not, the second transformer can advantageously be provided with a tap changer on the primary or secondary side. Placing a tap changer on the secondary side allows changing the transformation ratio of only one of the secondary connections, the third and the fourth. The second transformer, having a tap changer, can further minimize the conversion losses that would otherwise increase as the electrolyzer ages during operation of the energy supply system.
[0020] In a further embodiment of the energy supply device, the first AC / DC converter can be designed as a transistor-based AC / DC converter. The transistor-based AC / DC converter has a bridge circuit with a plurality of bridge branches, each of which comprises a series connection of at least two transistors. Each of the transistors can have a separate or intrinsic diode connected in anti-parallel to the transistor. In particular, the transistors can each be designed as an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET). During operation, the transistor-based AC / DC converter generates only a small amount of unwanted reactive power at its AC connection, which is transferred as an interference signal to the energy supply grid via the grid connection and / or from the first secondary connection to the second secondary connection. In any case, the interference signal of the transistor-based AC / DC converter is significantly less noticeable than the interference signal of the thyristor-based AC / DC converter. Also, in contrast to thyristor-based AC / DC converters, transistor-based AC / DC converters are designed to generate bidirectional power flows, i.e. they can operate not only in rectification mode but also in inversion mode. In this way, a desired reactive power can also be generated in order to at least partially compensate for reactive powers generated elsewhere or present elsewhere. Since the first AC / DC converter is transistor-based, particularly low interference signals are generated at the second secondary connection. Thus, the crosstalk of interference signals to the first secondary connection, signals that may adversely affect the operation of the auxiliary units, is also relatively low. In addition to the first AC / DC converter, at least one further AC / DC converter (e.g. the second AC / DC converter and / or the third AC / DC converter) can also be optionally designed as a transistor-based AC / DC converter.In this manner, the second and / or third AC / DC converters can be operated to generate compensating reactive power that at least partially compensates for undesirable reactive power that would otherwise be present (e.g., undesirable reactive power at the grid connection).
[0021] In a further embodiment of the energy supply device, at least one of the AC / DC converters, and optionally each of the AC / DC converters, may be connected to its AC connection via an AC isolation unit with pre-charging means to its assigned transformer, consisting of a first multi-winding transformer and a second transformer. The pre-charging means are used to limit the current when switching on capacitors that are not yet charged or are not fully charged. Such pre-charging means can be actively or passively controlled (not controlled). For example, a passively designed pre-charging means can have a path with a series connection of a pre-charging resistor and a switch and a further switch connected in parallel to the series connection. An actively controlled pre-charging means can be, for example, a DC / DC converter designed to operate in step-down mode in the direction of power flow.
[0022] In a further embodiment of the energy supply device, a DC isolation unit can be arranged between each of the AC / DC converters and the DC voltage output. However, it is not necessary for each of the DC isolation units to also include pre-charging means. For example, one DC isolation unit, or possibly several DC isolation units, may be devoid of pre-charging means. Such pre-charging means in the DC isolation units are usually provided to limit the current when the electrolyzer is switched on, since the electrolyzer exhibits a capacitive behavior at its DC input, in particular during the start-up phase. In the energy supply device provided here, it is in principle sufficient to provide only one of the DC isolation units with pre-charging means, in particular the DC isolation unit that is active when the electrolyzer is switched on. Capacitors of the DC connections of AC / DC converters that have an open DC isolation unit and thus are not yet conductively connected to the electrolyzer, can be pre-charged via their assigned corresponding AC isolation unit with pre-charging means. In this case, each of the DC isolation units associated with these AC / DC converters can only be closed if the potentials of the two contacts of the corresponding DC isolation unit are very close to each other, so that a very low voltage is applied across the contacts, thereby avoiding high transient power flows when the corresponding DC isolation unit is closed. One or more of the corresponding DC isolation units can therefore each be designed without pre-charging means, whereby the energy supply device can be realised particularly cost-effectively.
[0023] In the energy supply system, the second transformer can also be designed as a multi-winding transformer. If the rated power of the first multi-winding transformer and the second transformer designed as a multi-winding transformer are the same, several identical transformers can be used in the energy supply system. However, the rated power levels of the first and second multi-winding transformers are often adjusted to the rated power of the electrolytic device and auxiliary units and therefore differ from each other. In particular, the rated power of the first multi-winding transformer may exceed the rated power of the second transformer.
[0024] The first multi-winding transformer of the energy supply device can be designed in such a way that the nominal power of the second secondary connection is higher than the nominal power of the first secondary connection. In particular, the nominal power of the second secondary connection differs by at least 10%, in particular is at least 10% higher. It is particularly advantageous if the nominal power P(2S2) of the second secondary connection is 1.5-2.5 times higher than the nominal power P(2S1) of the first secondary connection, i.e. 1.5 x P(2S1) ≦ P(2S2) ≦ 2.5 x P(2S1). This is especially the case if the nominal power of the electrolysis device significantly exceeds the nominal power of all auxiliary units of the electrolysis unit.
[0025] Advantageously, the nominal power P(2S2) of the second secondary connection can also be greater than the nominal power P(4S3) of the third secondary connection and, if present, the nominal power P(4S4) of the fourth secondary connection. In particular, for example, if the second transformer is designed as a second multi-winding transformer, the nominal power P(2S2) of the second secondary connection can be greater than half the total nominal power available on the secondary side of the further transformer, i.e. P(2S2)>0.5×[P(4S3)+P(4S4)]. This is particularly advantageous if the first AC / DC converter assigned to the second secondary connection is connected to the electrolyzer by closing the corresponding DC isolation unit only if the electrolyzer has a high consumption, i.e. if there is a high DC voltage at the DC input of the electrolyzer.
[0026] If the nominal power P(2S2) of the second secondary connection exceeds the nominal power P(4S3) of the third secondary connection and also exceeds the nominal power P(4S4) of the fourth secondary connection, then the second voltage amplitude at the second secondary connection TIFF2025514915000016.tif7170 is the third voltage amplitude TIFF2025514915000017.tif7170 can be larger than 7170, plus a fourth voltage amplitude if present TIFF2025514915000018.tif7170. This allows different nominal powers of the secondary connections to be at least partially predefined via different voltage amplitudes, thus compensating or at least reducing the use of material that would otherwise be required for an increased conductor cross section at higher nominal currents.
[0027] If the second transformer of the energy supply device is designed as a second multi-winding transformer, it is useful to design the secondary connections (here the third and fourth secondary connections) so that their nominal powers are as similar as possible, with the aim of manufacturing the multi-winding transformer as easily as possible. However, in order to operate the electrolysis installation with as low as possible conversion-related power losses of the energy supply device, it is advantageous not to design the nominal powers of the secondary connections to be the same, but to make them intentionally different, since this will generate different DC voltages within the operating range of the electrolysis device, so that at least one of the AC / DC converters connected to it will operate as efficiently as possible. It has been found that the nominal power P(4S3) of the third secondary connection is advantageously designed to be different from the nominal power P(4S4) of the fourth secondary connection, but should not differ from the nominal power P(4S4) of the fourth secondary connection by more than 40%. Specifically, therefore, it is preferable that the nominal power P(4S3) of the third secondary side connection part corresponds to 0.6 to 1.4 times the nominal power P(4S4) of the fourth secondary side connection part, that is, the following holds: 0.6×P(4S4)≦P(4S3)≦1.4×P(4S4).
[0028] The energy supply grid may be a low-voltage grid and the energy supply device is designed, in particular for the first multi-winding transformer and the second transformer, for connection to the low-voltage grid. However, if the nominal power of the electrolyzer is high, the energy supply grid may be a medium-voltage grid. In this case, the energy supply device may be designed for connection to the medium-voltage grid.
[0029] In one embodiment, the first multi-winding transformer can be designed as a three-winding transformer with a primary winding and two separate (i.e. electrically isolated) secondary windings, which allows the first multi-winding transformer and thus also the energy supply device to be implemented particularly cheaply. However, from a technical point of view, a four-winding transformer offers better isolation of its secondary connections. In particular, with a four-winding transformer, interference signals generated at the AC connection of the first AC / DC converter and present at the second secondary connection can crosstalk less into the first secondary connection. Suppression of interference signals from the second secondary connection to the first secondary connection and an interference-free power supply to the auxiliary unit are more feasible with a four-winding transformer than with a three-winding transformer. Therefore, alternatively, the first multi-winding transformer can be designed as a four-winding transformer with two primary windings and two separate (i.e. electrically isolated) secondary windings. The same applies to the second transformer.
[0030] The electrolysis installation according to the invention comprises an electrolysis unit with an electrolysis device and at least one auxiliary unit for the supply of chemicals to the electrolysis device. The electrolysis installation also comprises an energy supply device according to the invention, the DC voltage connection of which is connected to the electrolysis device and the auxiliary power output of which is connected to the at least one auxiliary unit of the electrolysis unit, thereby obtaining the advantages already enumerated in connection with the energy supply device. [Brief description of the drawings]
[0031] The invention will be explained below with the aid of the drawings.
[0032] [Figure 1] FIG. 1 shows a first variant of a conventional electrolysis installation. [Diagram 2] FIG. 2 shows a second variant of the conventional electrolysis installation. [Diagram 3] FIG. 3 shows an embodiment of an electrolysis installation according to the invention, comprising an energy supply device according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] 3 shows an electrolysis installation 50 according to the present invention, which includes an energy supply device 10 according to the present invention. The electrolysis installation 50 includes the energy supply device 10 according to the present invention, an electrolysis unit 20, and a control unit 30.
[0034] The energy supply device 10 will be described in detail below. The energy supply device 10 is connected to the energy supply grid 40 via a grid connection 15. An AC isolation unit 3 is arranged between the grid connection 15 and each of the transformers 2 and 4. The first transformer 2 is a multi-winding transformer and has a primary side 2P connected to the grid connection 15 and a secondary side 2S. The secondary side 2S has a first secondary side connection 2S1 and a second secondary side connection 2S2. The first secondary side connection 2S1 is connected to the electrolysis unit 20 via an auxiliary power output 17 and has a first voltage amplitude U 1 The second secondary connection 2S2 is connected to the AC connection 6.1 of the first AC / DC converter 6 via an AC isolation unit 5 with precharging means VL and supplies it with an AC voltage having a second AC voltage amplitude TIFF2025514915000019.tif8170. The first AC / DC converter 6 is connected with its DC connection 6.2 via an output capacitor 9 and a DC isolation unit 11 to a DC voltage output 16. The first AC / DC converter 6 operates in rectification mode during operation of the electrolysis installation 50 and is able to convert the AC voltage at its AC connection 6.1 into a DC voltage at its DC connection 6.2, which is also present at the DC voltage output 16 of the energy supply device 10 when the DC isolation unit 11 is closed.
[0035] By way of example, the second transformer 4 is also designed as a multi-winding transformer and has a primary side 4P and a secondary side 4S. The secondary side 4S has a third secondary connection 4S3 and a fourth secondary connection 4S4. The third secondary connection 4S3 is connected to the AC connection 7.1 of the second AC / DC converter 7 via an AC isolation unit 5 with precharging means and has a third AC voltage amplitude 4S4. TIFF2025514915000020.tif7170 to it. Furthermore, the second AC / DC converter 7 is connected with its DC connection 7.2 via an output capacitor 9 and a DC isolation unit 12 with precharging means VL to a DC voltage output 16. The second AC / DC converter 7 is able to convert the AC voltage at the AC connection 7.1 into a DC voltage at the DC connection 7.2, which it then applies to the DC voltage output 16.
[0036] The fourth secondary connection 4S4 is connected to the AC connection 8.1 of the third AC / DC converter 8 via an AC isolation unit 5 with pre-charging means and has a fourth voltage amplitude TIFF2025514915000021.tif7170 to it. Furthermore, the third AC / DC converter 8 is connected with its DC connection 8.2 via an output capacitor 9 and a DC isolation unit 12 to a DC voltage output 16. The third AC / DC converter 8 is able to convert the AC voltage at its AC connection 8.1 into a DC voltage at its DC connection 8.2, which it then applies to the DC voltage output 16. In other words, the AC / DC converters 6, 7, 8 each have a different voltage amplitude. TIFF2025514915000022.tif7170 can be converted to a DC voltage and connected to the DC voltage output 16 such that the DC voltage is present at the DC voltage output 16. The first AC / DC converter 6 and, if applicable, the further AC / DC converters 7, 8 can each be a transistor-based AC / DC converter. All AC isolation units 3, all AC isolation units 5 with pre-charging means, all DC isolation units 11 and the DC isolation unit 12 with pre-charging means as well as the AC / DC converters 6, 7, 8 are controlled by a control unit 13 of the energy supply device 10 and, if necessary, in combination with an overall control unit 30.
[0037] In Fig. 3 the output capacitors 9 are shown as separate components connected to the DC connections 6.2, 7.2, 8.2 of the AC / DC converters 6, 7, 8 respectively assigned to them. However, it is alternatively possible that the output capacitors 9 are at least partially, possibly completely, integrated into and thus part of the AC / DC converters 6, 7, 8 respectively assigned to them.
[0038] The electrolysis unit 20 is described in detail below. The electrolysis unit 20 comprises an electrolysis device 22, an auxiliary unit 23 (which may be a pump), an auxiliary unit 24 (which may be a heater) and a control unit 25 for the electrolysis unit 22. By way of example, only two auxiliary units are shown. However, it is also within the scope of the invention for the electrolysis unit 20 to have a different number of auxiliary units, in particular three or more auxiliary units, which are also powered via the auxiliary power output 17 of the energy supply device 10. A direct current input (DC input) of the electrolysis device 22 is connected to the DC output 16 of the energy supply device 10 and is supplied with direct current by this device. The auxiliary units 23, 24 are supplied with an alternating voltage by the energy supply device 10 via the auxiliary power output 17. A control unit 25 of the electrolysis unit controls the electrolysis device 22 and the auxiliary units 23, 24.
[0039] The control unit 30 of the electrolysis installation 50 issues control commands to both the energy supply device 10 and the electrolysis unit 20 and acts as a higher-level control unit during operation of the electrolysis installation 50. The control unit 30 thus enables controlling the energy supply device 10 and the electrolysis unit 20 in such a way that a smooth operation of the electrolysis unit 20 is ensured. The higher-level control unit 30 is shown as a separate component in Figure 3. However, it is alternatively possible for the higher-level control functions to be handled within the control unit 13 of the energy supply device 10 and / or the control unit 25 of the electrolysis unit 22. In this case, the higher-level control unit 30 can not be present as a separate component but rather be split into at least one of the control units 13, 25.
[0040] In the following, the operation of the electrolysis installation 50 is described using the example of start-up of the electrolysis installation 50. For this purpose, it is assumed that all AC isolation units 3, 5 and all DC isolation units 11, 12 are open. Furthermore, the transformation ratio of the transformers 2, 4 is, by way of example, given by the following formula for the voltage amplitude: The first voltage amplitude U 1 is set to the value required to supply the auxiliary units 23, 24 (for example 400 V or 480 V) via the transformation ratio assigned to the first secondary connection 2S1 of the first multi-winding transformer 2. It is usually 2 Optionally, it is a fourth voltage amplitude U 4 It can be made smaller or, in some cases, a third voltage amplitude U 3 First, the AC isolation unit 3 is closed, which reduces the voltage amplitude An AC voltage of TIFF2025514915000024.tif8170 is generated via the first secondary connection 2S1 and supplied to the auxiliary units 23, 24 of the electrolysis unit 22. These units are controlled via the control unit 25 of the electrolysis unit 20 and can thus take over the supply of chemicals to the electrolysis device 22, putting the electrolysis device 22 into operation. Furthermore, the AC isolation unit 5 assigned to the third secondary connection 4S3 and, if applicable, the other AC isolation units 5 still open are closed. Now, the pre-charging means VL included in the AC isolation unit 5 perform a current-limited pre-charging of the output capacitors 9 assigned to the second AC / DC converter 7 and, if applicable, also a current-limited pre-charging of the output capacitors 9 assigned to the further AC / DC converters 6, 8. Voltage amplitude Since the TIFF2025514915000025.tif8170 is different, the minimum possible voltage applied to the output capacitor 9 may also be different. The DC isolation unit 12 with the pre-charging means VL is then closed, whereby the DC input of the electrolyser 22 is pre-charged via the second AC / DC converter 7. The DC voltage U DC、EL is the open circuit voltage U of the electrolysis device 20 0 When the electrolysis reaction begins to occur within the electrolysis device 20, the electrolysis reaction begins to occur when the electrolysis reaction reaches or exceeds the threshold voltage Vcc.
[0041] Start-up and part-load operation of the electrolyser 22 can be performed solely by the second AC / DC converter 7. The increasing power consumption of the electrolyser 22 is regulated by the DC voltage U DC,EL The DC voltage U at the DC input of the electrolyzer 22 is controlled by the level of DC,ELbecomes sufficiently close to the DC voltage present at one of the further output capacitors 9, the remaining DC isolation units 11 respectively assigned to AC / DC converters 6, 8 not yet connected to the electrolyser 22 can be closed. Since there is a sufficient proximity between the DC voltage applied to the output capacitors 9 and the DC voltage applied to the DC input of the electrolyser 22, each corresponding DC isolation unit 11 can be designed without pre-charging means VL.
[0042] The above operation is illustrated using the example of starting up the electrolysis installation 50 and then increasing the power of the electrolyzer 22, where the AC / DC converters 6, 7, 8 are sequentially connected to the electrolyzer 22 by their assigned DC isolation units 11, 12. When the power of the electrolyzer 22 drops, the AC / DC converters 6, 7, 8 can be isolated again in the reverse order by opening the corresponding DC isolation units 11, 12. [Explanation of symbols]
[0043] 2 (First) Multi-winding Transformer 2P primary side 2S Secondary side 2S1 1st secondary connection 2S2 Secondary side connection 3 AC isolation units 4 (Second) Transformer 4P primary side 4S Secondary side 4S3 3rd secondary connection 4S4 4th secondary connection 5 AC isolated units (with pre-charging means VL) 6, 7, 8 AC / DC Converters 6.1, 7.1, 8.1 AC Connections 6.2, 7.2, 8.2 DC connections 9 Output Capacitor 10 Energy supply device 11 DC isolated unit (no pre-charging means) 12 DC isolated units (with pre-charging means) 13 (Supply device) control unit 15 Grid Connection 16 DC output section 17 Auxiliary power output section 20 Electrolysis Unit 21 DC inputs 22 Electrolyzer 23 Auxiliary unit (pump) 24 Auxiliary unit (heating) 25 Control unit (electrolysis unit) 30 Control unit (electrolysis equipment) 40 Energy Supply Grid 50 Electrolysis System 100, 200 Energy Supply Device 102, 104, 202 Transformers 103, 203 AC isolation unit 105, 205 AC isolated units (with pre-charging means) 106, 206 AC / DC Converters 106.1, 206.1 AC Connections 106.2, 206.2 DC Connections 112, 212 DC isolated units (with pre-charging means VL) 115, 215 Grid connection 116, 216 DC output section 117, 217 Auxiliary power output section
Claims
1. An energy supply device (10) for an electrolysis unit (20), comprising: a grid connection (15) for connection to an energy supply grid (40); a DC voltage output (16) for connecting the electrolysis device (22) of the electrolysis unit (20); an auxiliary power output (17) for connecting at least one auxiliary unit (23, 24) of the electrolysis unit (20); a first multi-winding transformer (2) having a primary side (2P) connected to the grid connection (15) and a secondary side (2S); a second transformer (4) having a primary side (4P) connected to the grid connection (15) and a secondary side (4S); An energy supply device (10) comprising: The secondary side (2S) of the first multi-winding transformer (2) has a first secondary side connection portion (2S1) and a second secondary side connection portion (2S2) electrically insulated from the first secondary side connection portion (2S1), The first secondary side connection (2S1) has a first voltage amplitude and connected to an auxiliary power output (17); The second secondary side connection (2S2) has a second voltage amplitude and connected to an AC connection (6.1) of a first AC / DC converter (6), the DC connection (6.2) of said first AC / DC converter (6) being connected to said DC voltage output (16), The secondary side (4S) of the second transformer (4) has a third secondary side connection (4S3), and the third secondary side connection (4S3) has a third voltage amplitude. and connected to an AC connection (7.1) of a second AC / DC converter (7), the DC connection (7.2) of said second AC / DC converter (7) being connected to said DC voltage output (16), The energy supply device (10) is characterized in that the primary side (2P) and the first secondary side connection (2S1) of the first multi-winding transformer (2), or the primary side (2P) and the secondary side (2S) of the first multi-winding transformer (2), are not provided with tap changers.
2. The secondary side (4S) of the second transformer (4) has a fourth secondary side connection (4S4), and the fourth secondary side connection (4S4) has a fourth voltage amplitude. and connected to an AC connection (8.1) of a third AC / DC converter (8), the DC connection (8.2) of which is connected to the DC voltage output (16).
3. 3. The energy supply device (10) according to claim 1 or 2, wherein the second transformer (4) comprises a tap changer on the primary side (4P) of the second transformer (4) or on the secondary side (4S) of the second transformer (4).
4. 3. The energy supply device (10) according to claim 1 or 2, wherein at least one AC / DC converter (6-8), optionally each AC / DC converter (6, 7, 8), is connected on the AC side to the respectively assigned transformer (2, 4) via an AC isolation unit (5) having pre-charging means (VL).
5. 3. The energy supply device (10) according to claim 1 or 2, characterized in that a DC isolation unit (11, 12) is arranged between each of the AC / DC converters (6-8) and the DC voltage output part (16), and one of the DC isolation units (11), or possibly even several of the DC isolation units (11), is not provided with pre-charging means (VL).
6. the second voltage amplitude is the third voltage amplitude and optionally said fourth voltage amplitude is greater than The energy supply device (10) according to claim 1 or 2, wherein the energy supply device (10) is greater than 1000 kJ / s.
7. 3. The energy supply device (10) according to claim 1 or 2, wherein the second transformer (4) is designed as a multi-winding transformer, and the first multi-winding transformer (2) and the second transformer (4) have the same nominal power.
8. 3. Energy supply device (10) according to claim 1 or 2, wherein the nominal power of the second secondary connection (2S2) differs from the nominal power of the first secondary connection (2S1) by at least 10%.
9. An energy supply device (10) as described in claim 3, insofar as it is dependent on claim 2, wherein the nominal power P(4S3) of the third secondary side connection is different from the nominal power P(4S4) of the fourth secondary side connection P(4S4).
10. 3. The energy supply device (10) according to claim 1 or 2, wherein the nominal power of the second secondary connection (2S2) is higher than half of the nominal power present on the secondary side (4S) of the second transformer (4), i.e. P(2S2)>0.5*P(4S).
11. 3. The energy supply device (10) according to claim 1 or 2, wherein the energy supply device (10) is configured to be connected to a medium voltage grid as an energy supply grid (40).
12. 3. The energy supply device (10) according to claim 1 or 2, wherein the first multi-winding transformer (2) is designed as a three-winding transformer with a primary winding and two independent secondary windings.
13. 3. The energy supply device (10) according to claim 1 or 2, wherein the first multi-winding transformer (2) is designed as a four-winding transformer with two primary windings and two independent secondary windings.
14. 3. The energy supply device (10) according to claim 1 or 2, wherein the first AC / DC converter (6), and optionally the second AC / DC converter (7) and / or the third AC / DC converter (8) are designed as transistor-based AC / DC converters.
15. an electrolysis unit (20) comprising an electrolysis device (22) and at least one auxiliary unit (23, 24) for supplying chemicals to said electrolysis device (22); An energy supply device (10) according to claim 1 or 2; wherein the DC voltage connection (16) of the energy supply device (10) is connected to the electrolysis device (22) and the auxiliary power output (17) of the energy supply device (10) is connected to the at least one auxiliary unit (23, 24) of the electrolysis unit (20).