Improved generation with inverter

Abstract

The present invention provides, inter alia, a device concerning a control module comprising: a processor; one or more data interfaces, for realising a data connection to an AC source module with an adjustable power level comprising an AC source contact and an energy source, a DC buffer module with a variable charge level comprising a DC buffer and a DC power interface, and an AC output module comprising an AC output and configured to produce current based on both current received from the AC source module via its AC source contact and current exchanged with the DC buffer module via its DC power interface, wherein the produced current is continuously supplied regardless of a reversal of a current sense when exchanging with the DC buffer module; wherein the processor is configured to repeatedly perform: receiving, from the AC source module, source data comprising a value of the power level; receiving, from the DC buffer module, buffer data comprising a value of the charge level; receiving, from the AC output module, load data comprising a value of an electrical load; adjusting, at least based on the values of the power level, the charge level and the electrical load, the power level of the AC source module.

Description

[0001] IMPROVED GENERATION WITH INVERTER

[0002] TECHNICAL DOMAIN

[0003] The invention relates to a device, system, and method for producing AC current at an AC output, using DC buffering. The generation is related to an energy source based, for example, on diesel or hydrogen.

[0004] STATE OF THE ART

[0005] From the state of the art, power supply systems are known to be used particularly in areas where no power supply is guaranteed through the grid. These include, for example, construction sites, remote areas, or locations where a "grid -like" alternative is desirable in case the regular power grid should temporarily fail, or no power grid is available. In all these cases, it is desirable to be able to power various devices independently of the grid, with a separate power source, which supplies AC power via appropriate conversion.

[0006] In the state of the art, a common energy source is provided as part of a power group, typically an alternator driven by a combustion engine, in particular a petrol or diesel engine.

[0007] A disadvantage of the known power supply systems is that, in the case of the combustion engines used, the energy value present in fossil fuels is only converted into electrical energy to a limited extent. Much of the energy generated remains unused, and is lost. One of the reasons is that power groups are often sized based on the peak power required for a particular application, even if this power is reached only for a short period of time.

[0008] CN102738836B, EP1959535A2, and W02022090432A1 disclose related concepts. However, with these systems, much of the converted energy remains unused, resulting in low efficiency for many applications, particularly when the load is not constant over time.

[0009] US2021075252A1 discloses a related concept, but offers the user only limited flexibility, compromising its practicality.

[0010] There is a need for methods, devices and systems that can supply AC power more efficiently, even when the load varies over time. The invention thereby aims to solve the above-mentioned problems. SUMMARY OF THE INVENTION

[0011] The invention relates to a device, system, process, and computer program product for generating AC current at an AC output. This preferably involves "grid-like" current.

[0012] In a first aspect, the invention provides a device, preferably a control module, comprising: a processor; one or more data interfaces, for realising a data connection to an AC source module with an adjustable power level comprising an AC source contact and an energy source with preferably a maximum power of at least 2 kW, a DC buffer module with a variable charge level comprising a DC buffer and a DC power interface, the DC buffer preferably being a rechargeable battery, the DC buffer preferably comprising a capacity of at least 10 kWh, and an AC output module comprising an AC output and configured to produce current based on both current received from the AC source module via its AC source contact and current exchanged with the DC buffer module via its DC power interface, wherein the produced current is continuously supplied regardless of a reversal of a current sense when exchanging with the DC buffer module; wherein the processor is configured to repeatedly perform: receiving, from the AC source module, source data comprising a value of the power level; receiving, from the DC buffer module, buffer data comprising a value of the charge level; receiving, from the AC output module, load data comprising a value of an electrical load; adjusting, at least based on the values of the power level, the charge level and the electric load, the power level of the AC source module.

[0013] In variants of the invention, the adjustment is not made based on each of the values of the power level, the charge level and the electric load, but only based on two of these values, e.g. only the power level and the electric load, or only the power level and the charge level, or only the charge level and the electric load.

[0014] In variants of the invention, the adjustment is not made based on each of the values of the power level, the charge level and the electric load, but only based on one of these values, for example only the charge level, or only the electric load. In embodiments, the adjustment is made based on two or each of the values of the power level, the charge level and the electric load, but only based on a single function value of these values, e.g. a ratio of the charge level and the electric load, wherein a high charge level and a low electric load both contribute to an increase in this ratio, which may then be an indicator for reducing the power level of the AC source module.

[0015] In embodiments, the adjustment is related to controlling an AVR belonging to the AC source module.

[0016] Here, the AC output module is of a type with functionality for inversion (AC / DC and DC / AC). This therefore involves power generation of the "hybrid" type. In embodiments, the AC output module thereto comprises an inverter. The AC output module here also comprises the functionality that the produced current is continuously supplied regardless of a reversal of a current sense when exchanging with the DC buffer module, in other words regardless of whether the battery is charged or discharged. Such continuous supply is known to the skilled person as on-grid emergency supply, in the form of a UPS (uninterruptible power supply). However, employing such functionality in off-grid power supply is much less common.

[0017] In preferred embodiments, the device is configured to allow the AC output module to draw power at least partially from both the AC source module and the DC buffer module when supplying power at peak loads. In related preferred embodiments, said peak load relates to a regime near a higher part of an operating area, or the highest quartile. It may also relate to an operating point near or at the maximum of the operating area. In exemplary embodiments, it relates to an interval covering the upper half of the operating area. In related preferred embodiments, the AC output module is configured to draw power at least partially from both the AC source module and the DC buffer module when supplying power at peak loads. In preferred embodiments, this thus relates to an AC output module that can simultaneously draw power from both. This can result in a more compact system, as energy available in both modules can be drawn simultaneously, allowing for smaller dimensions of these modules.

[0018] A device according to the invention may advantageously improve energy conversion efficiency, with reduced energy losses. The invention thereby advantageously allows the production of excess electricity to be prevented, in particular when the load at the AC output varies over time. The invention allows this by making the production of electricity at the AC source module dependent on both the load and the accumulated charge in a DC buffer, and, if appropriate, limiting it. Another possible advantage of the invention is the integrated approach offered by the invention. By considering both data from the AC source module and data from the AC output module, problems between the electronics of the AC source module and the electronics of the AC output module are avoided. In examples according to the state of the art, it happens that the logic of an AVR present on the AC source module (e.g. a power group) starts "fighting" with the logic of an inverter present on the AC output module. Because these two parties are not aligned, it is possible that they will perform corrections on each other's corrections in a kind of loop, which is undesirable, and leads to a risk of instability.

[0019] In examples according to the state of the art, an AC output is set up on construction sites, where, although large installations (such as tower cranes) only need to be powered at certain times, a power group still generates electricity continuously. There is often a complete lack of coordination between electricity generation and final consumption at the AC output. This is particularly problematic when the consumption is associated with high, short-term peak loads. In practice, the latter often leads to large- dimensioned power sources, such as large diesel engines, which can supply sufficient energy when demand peaks, but at other times generate electricity or dissipate energy that remains unused, and is therefore lost. The invention addresses this issue by providing a device that can adjust the power level of the AC source module, and prevent unused energy from being made available.

[0020] It also considers the presence of a DC buffer module, which allows to accumulate electrical energy, thereby allowing a smaller energy source to be used. However, such a DC buffer module does not in itself guarantee efficient conversion, as undesirable situations can still occur in which unused energy is made available and lost whenever the DC buffer module approaches the maximum charge level and the effective load at the AC output is low.

[0021] The device is hereby designed for both receiving data from the AC source module and adjusting at least the power level of the AC source module. In exemplary embodiments, the AC source module is a power group consisting of an assembly of a diesel generator or petrol generator and an alternator, and the power level is adjusted by a data channel between the device and the power group, whereby the power group is, for example, informed that a higher or lower current should be generated. This data channel may, for example, be related to the CAN bus on the power group and / or a separate data channel. The device further provides at least for receiving data from the AC output module and the DC buffer module. This may include a separate connection to these modules, but also a data channel running to one of these modules, and from there, with or without intermediate processing of this data, continuing to the other of these modules.

[0022] In embodiments, the device also provides for partial or complete control of the AC output module and / or the DC buffer module. In doing so, the device fulfils one or more functionalities of an EMS. In embodiments, in addition to adjusting the power level of the AC source module, the device also adjusts or controls a functionality related to inversion (AC / DC and / or DC / AC) at the AC output module, for example by controlling an inverter present in the AC output module. In addition, the EMS may be related to the adjustment of an AVR present in the AC source module.

[0023] In embodiments, adjusting the power level of the AC source module comprises adjusting the power level of the energy source, for example, the diesel engine or hydrogen engine. In still further examples, adjusting the power level of the AC source module comprises adjusting the deliverable power supplied at the AC output, by externally diverting part of the energy from the energy source, whether or not after conversion into electricity, to a further output different from the AC output, so that this energy can be used externally.

[0024] In a second aspect, the invention relates to a system comprising: an AC source module with an adjustable power level comprising an AC source contact and an energy source, a DC buffer module with a variable charge level comprising a DC buffer and a DC power interface, an AC output module connected to the AC source module by an AC connection and to the DC buffer module by a DC connection, and the device according to the invention, being the control module, connected to said AC source module, the DC buffer module and the AC output module by one or more data connections, wherein the AC output module comprises an AC output and is configured to produce current based on both current received from the AC source module via its AC source contact and current exchanged with the DC buffer module via its DC power interface, wherein the produced current is continuously supplied regardless of a reversal of a current sense when exchanging with the DC buffer module. In a third aspect, the invention provides for a method for controlling a system for generating a current at an AC output, comprising the steps: receiving, from an AC source module comprising an energy source with a maximum power of at least 2 kW, source data comprising a value of the power level; receiving, from a DC buffer module comprising a DC buffer with a capacity of at least 2 kWh, buffer data comprising a value of the charge level; receiving, from an AC output module comprising the AC output, load data comprising a value of an electrical load; adjusting, at least based on the values of the power level, the charge level and the electric load, the power level of the AC source module; wherein: said adjusting relates to an algorithm which, upon detection of the charge level exceeding a preset threshold, switches off the energy source and / or reduces the power level of the AC source module and / or said adjustment relates to an algorithm which, upon detection of the charge level falling below a preset threshold, turns on the energy source and / or increases the power level of the AC source module.

[0025] In a fourth aspect, the invention provides for a computer program product comprising memory comprising instructions which, when executed on a processor, said processor preferably belonging to a PLC, perform the steps of the method according to the invention.

[0026] The second, third and fourth aspects may offer advantages similar to those of the device according to the invention. Embodiments according to the dependent claims and their respective potential advantages are explained in the detailed description.

[0027] DESCRIPTION OF THE FIGURES

[0028] Figure 1 is a schematic representation of an exemplary embodiment of the device and system according to the invention.

[0029] DETAILED DESCRIPTION

[0030] Unless otherwise defined, all terms used in the description of the invention, including technical and scientific terms, have the meaning as generally understood by those skilled in the technical field of the invention. For better assessment of the description of the invention, the following terms are explicitly explained. "A", "an" and "the" refer to both singular and plural in this document unless the context clearly assumes otherwise. For example, "a segment" means one or more than one segment. Citing numeric intervals by its endpoints includes all integers, fractions and / or real numbers between the endpoints, these endpoints included.

[0031] In this document, "AC" refers to alternating current and "DC" to direct current, two terms as known to the skilled person.

[0032] In this document, "EMS" refers to energy management system. In the context of the invention, this is a non-limiting generic term for any type of control module or related module capable of electronically controlling one or more elements of a system for supplying an AC output. In embodiments, the device according to the invention is thereby an EMS. In embodiments, the device according to the invention is a component of an EMS which realises further functionality. In embodiments, the device realises all functionality of an EMS, such as adjusting the power level of the AC source module, and all functionality related to inversion (AC / DC and / or DC / AC) at the AC output module.

[0033] In this document, the terms "battery" and "accumulator" are interchangeable.

[0034] In this document, the term "PLC" refers to programmable logic controller, and the term "AVR" refers to automatic voltage regulator.

[0035] In this document, "lead-carbon" refers to a battery technology that is related to lead- acid battery technology, but with the addition of carbon. This may be related to a buildup of negative plates from lead and carbon. Possible advantages include reduced sensitivity to sulphation and / or longer lifetime and / or more charge / discharge cycles and / or deeper discharge capability and / or faster chargeability.

[0036] In this document, the term "electrical load" refers to a power to be supplied to the AC output. This can be either a real number expressed in Watts (or kW) or a complex number (e.g. considering the capacitive or inductive nature of load, e.g. based on cos <p). The electrical load is considered to potentially vary over time within a given operating range, with the invention in its preferred embodiments taking these variations into account. Here, the term "peak load" refers to a regime near the upper part of the operating range. For example, it may be an interval covering the upper half of the operating range, or the highest quartile. It may also be an operating point near or at the maximum of the operating range. In this document, the term "capacity" refers to the maximum amount of charge that can be stored in the DC buffer, preferably one or more batteries, and is expressed in kWh. This is related to the term "charge level", which can never exceed the capacity of the DC buffer and is preferably also expressed in kWh. In examples, the maximum charge level is equal to the capacity, but this value may also be lower, e.g. as a function of certain production characteristics of the DC buffer and / or as a function of an ageing of the DC buffer, whereby the maximum charge level decreases after prolonged use. In some cases, the charge level is also expressed relative to the maximum charge level, either as a fraction (between 0 and 1) or as a percentage (between 0 and 100%).

[0037] In this document, the term "hybrid" is a generic term for systems and devices in which a combination of two or more energy sources participates in power generation. In exemplary embodiments, both AC and DC participate in power generation. Exemplary embodiments involve a combination of a first AC energy source and a second AC energy source, extended with a DC battery. This could, for example, be a first AC energy source with diesel-based power generation, and a second energy source with hydrogen-based power generation. In preferred embodiments, it involves a combination of energy sources of which at least one energy source is a renewable energy source, such as an energy source with hydrogen-based energy generation from a renewable source. In embodiments, this involves a simple concatenation of AC and DC, wherein the generator is connected to a DC intermediate circuit via a rectifier and thereby supplies a DC buffer module with power. Such arrangements are called hybrid because they combine a traditional power group-based power supply system and an energy storage system. Such hybrid systems allow the energy source and / or the entire AC source module (e.g. a power group) to operate at a better operating point. A disadvantage of these systems is the limitation of the maximum load due to the capacity of the energy storage. The electrical energy storage must therefore be dimensioned relatively large. Moreover, especially at peak loads, significant conversion losses can occur due to the intervention of a DC buffer between the generator and the load. Preferred embodiments therefore involve true mixing of AC and DC, wherein the AC output module simultaneously draws power from both the power group and the DC buffer module at peak loads. Such arrangements allow for better dimensioning, with the energy source and the DC buffer working together in synergy.

[0038] In this document, the term "C-value" or, equivalently, "C-rate", refers to a charging or discharging rate, expressed in h'1("per hour"), of the DC buffer. Here, the C-value is a measure of the rate at which the DC buffer, e.g. a battery, is charged or discharged in relation to the capacity of the battery. The C-rate is defined as the charging or discharging current divided by the capacity of the DC buffer. The C-value is never negative; it is always indicated whether it is a charging or discharging process. In exemplary embodiments with a DC buffer with a capacity of 70 kWh and a charging capacity of 25 kWh for charging and a discharging capacity of 150 kWh, this corresponds to a C-value for charging of about 0.36 and a C-value for discharging of 2.14. The latter corresponds to a ratio of C-value for discharging to C-value for charging of 6.

[0039] In embodiments, "grid-like" AC is supplied at the output. In exemplary embodiments, this involves three-phase mains power at 50 Hz, with a voltage between phases of 400 volts, and a voltage between phase and neutral of 230 volts. In examples, this involves three-phase current at 50 Hz or 60 Hz. In still other examples, it involves single-phase current at 50 Hz or 60 Hz.

[0040] W02022090432A1 describes a mobile hybrid generator system for supplying "grid-like" AC power output to a load at off-grid locations. However, this system does not include any means to automatically adjust the power level of the energy source according to demand and / or charge level, which still leads to a loss of efficiency.

[0041] In embodiments, said adjustment relates to an algorithm which, upon detection of the charge level exceeding a preset threshold, switches off the energy source and / or reduces the power level of the AC source module. This can have the advantage that no excess energy is lost when there is sufficient energy in the DC buffer. In embodiments, said energy source is thereby switched on, with the algorithm reducing the power level of the AC source module without switching off the energy source. This can have the advantage that the energy source can return to higher power levels in a very short time, if it is detected that the load at the AC output is increasing. Indeed, delays caused by starting up the energy source can be avoided this way, while the power level can still be set low. In embodiments, detection includes checking that a preset threshold for the electrical load has not been exceeded during the last T seconds, with T preferably being greater than 1 second, more preferably greater than 10 seconds. This may have the advantage that the power level is, for example, only reduced when a low load is detected at the AC output for a sufficiently long time. In still other embodiments, the power level is reduced instantaneously, with T preferably being less than 10 ms, for example, more preferably less than 1 ms.

[0042] In embodiments, said adjustment relates to an algorithm which, upon detection of the charge level falling below a preset threshold, switches on the energy source and / or increases the power level of the AC source module. This may have the advantage that additional energy is made available only when the need arises, for example when it can be assumed that any surpluses will be routed through the AC output module to the DC buffer module. In embodiments, said energy source is already switched on, with the algorithm increasing the power level of the AC source module. This may have the advantage of avoiding the delay for starting the energy source. In embodiments, said detection includes checking that the electrical load has not dropped below a preset threshold during the last T seconds, with T preferably being greater than 1 second, more preferably greater than 10 seconds. This may have the advantage that the power level is, for example, only increased when there is actually a significant load at the AC output, which may improve energy efficiency, particularly if the fuel of the energy source is limited. In yet other embodiments, the power level is increased instantaneously, with T for example being less than 10 ms, more preferably less than 1 ms.

[0043] In embodiments, the adjustment is made based on the values of the power level, the charge level, the electric load, and the fuel level of the energy source. In preferred embodiments, when the fuel level drops below a certain preset threshold, the algorithm is triggered to adjust the power level according to an energy-efficient mode which differs from normal mode.

[0044] In embodiments, the AC source module relates to at least an assembly comprising an energy generating element for generating a rotation and an electrical power element comprising an alternator for converting the rotation into AC current at the AC source contact.

[0045] In embodiments, the energy generating element comprises a diesel engine and / or a hydrogen engine. In embodiments, the energy generating element relates to a diesel engine or a hydrogen engine. In embodiments, the energy generating element additionally or alternatively comprises a petrol engine and / or a further battery.

[0046] In embodiments, the energy generating element comprises, or alternatively relates to, a fuel cell. It involves, for example, a fuel cell with a metallic stack, for example with a proton exchange membrane (PEM). It involves, for example, a PEM fuel cell. In exemplary embodiments, the fuel is hydrogen. In exemplary embodiments, the number of cells is at least 100 or at least 200, for example 100 or 200 or 300. In exemplary embodiments, the rated power is at least 20 or 40 kW, for example 20 or 40 or 60 or 80 kW. In exemplary embodiments, the maximum output voltage is at least 100 volts or 200 volts. In exemplary embodiments, the maximum output current is at least 100 amps or 200 amps, for example 100 or 150 or 200 amps.

[0047] In embodiments, in addition to the power generating element, a further energy source is present, such as externally supplied mains voltage.

[0048] In embodiments, at least the AC output module and the device are provided in the same housing. In embodiments, the device thereby comprises a PLC.

[0049] In embodiments, the DC buffer comprises, or relates to, a lead-carbon type battery. Such technology may thereby be more advantageous than what is offered by the prior art. For example, W02022090432A1 describes a system also aimed at supplying a gridlike AC output, with a high C-value for discharging. Yet, W02022090432A1 does not describe lead-carbon technology for the battery. In still other embodiments, the DC buffer comprises, or relates to, a lithium-titanate (LTO) type battery, being a particular kind of lithium-ion battery. LTO allows higher C-values when discharging than typical lithium technology, and, related thereto, a higher ratio of C-value when discharging versus C-value when charging compared to lithium technology. In embodiments, the DC buffer comprises a lead-acid battery instead of a lead-carbon battery. In embodiments, the DC buffer comprises both a lead-carbon and a lead-acid type battery. Both lead-carbon and lead-acid can be advantageous because they are largely recyclable, whereas lithium batteries are generally more difficult to recycle and / or have more limited recyclability, and are therefore more harmful to the environment.

[0050] In embodiments, the capacity of the lead-carbon battery is at least 1 or 2 or 3 or 4 or 5 or 10 kWh. In exemplary embodiments, the battery has an operating voltage of at least 12 volts, for example 12 volts or 24 volts. In exemplary embodiments, the capacity is at least 100 Ah, for example 100 or 120 or 150 or 170 or 200 Ah. In exemplary embodiments

[0051] In embodiments, a ratio of C-value when discharging and C-value when charging the battery is at least 2, preferably at least 4, more preferably at least 8, wherein the capacity is preferably at least 10 kWh, regardless of the technology of the battery. Such a ratio may have the advantage that the battery is effectively optimised for rapid discharge at peak loads. The slower charging does not necessarily have to be a problem, and may be advantageous as it may allow the energy source of the AC source module, e.g. a diesel engine or a hydrogen engine, to operate at a lower power level, with, for example, less noise pollution and / or a more advantageous operating point. In embodiments, during at least one period of the power supply, power from the AC source module is integrally converted from AC to DC and then back to AC, before being routed to the AC output. In embodiments, during at least one period of the power supply, current from the AC source module is partially converted from AC to DC and then back to AC, with a portion of the current being routed directly to the AC output. The portion, which is converted to DC can be used, for example, to charge a battery which is present in the DC buffer module, and / or can be converted back to AC to be routed to the AC output. In embodiments, during at least one period of the power supply, power from the AC source module is integrally routed to the AC output, without being converted to DC. Thereby, the AC output may or may not be boosted with energy, after conversion from DC to AC, coming from a battery which is present in the DC buffer module.

[0052] In embodiments, the control module comprises a further interface for controlling one or more switching connections that regulate access to an AC bus which is situated between one or more external power sources and the AC output, said AC bus and the one or more switching connections preferably belonging to the AC output module. A possible advantage of this is the modular design, wherein one or more external power sources can be controlled without being involved in the DC conversion, which can simplify the design and / or reduce the technical requirements of the DC conversion (and associated cost) and / or increase the total power available to the AC output without impacting the technical requirements of the DC conversion.

[0053] In exemplary implementations, the AC bus is a unidirectional bus. In exemplary embodiments, the AC bus is bi-directional and / or the AC bus does not comprise any special provisions for controlling the current sense, and the current sense is, for example, completely controlled based only on the one or more switching connections.

[0054] Below, the invention will be described using non-limiting examples that illustrate the invention and are not intended or to be interpreted to limit the scope of the invention.

[0055] EXAMPLE 1

[0056] Figure 1 shows a schematic representation of a first exemplary embodiment of the device and system according to the invention.

[0057] The system comprises a device 1, being a control module, an AC source module 5, a DC buffer module 7, and an AC output module 6. The system is intended to supply 'grid-like' current to the AC output 10 of the AC output module 6, which is a three-phase grid current at 50 Hz, with a voltage between phases of 400 volts, and a voltage between phase and neutral of 230 volts, with an operating area for the working load between 0 and 25 kW.

[0058] The AC source module 5 and the AC output module 6 are connected by an AC cable 8, which allows, through the AC source contact present on the AC source module, AC power to be supplied from the AC source module 5 to the AC output module 8. The DC buffer module 7 and the AC output module 6 are connected by a DC cable 9. The AC output module comprises an inverter which is electronically controlled.

[0059] The control module 1 comprises a processor and the necessary data interfaces to connect to the AC source module 5, the DC buffer module 7 with a variable charge level comprising a DC buffer and a DC power interface for connection to the DC cable. The DC buffer is a lead-carbon type rechargeable battery with a capacity of 20 kWh, a C- value when charging of 0.3 h'1and a C-value when discharging of 3 h’1.

[0060] The control module comprises a PLC which is provided within the housing of the AC output module 6, and which communicates with the electronic control of the inverter using a certain defined set of parameters and ports. In variants of this example, this is a controller that does not comprise a PLC, but provides equivalent functionality.

[0061] The AC source module 5 has an adjustable power level, and an energy source with a maximum power of 50 kW. It is a power group, i.e. an assembly of a power generating element (in this example, a hydrogen engine) for generating a rotation and an electrical power element comprising an alternator for converting the rotation into AC current at the AC source contact.

[0062] The control module 1 and the AC output module 6 are configured to produce current based on both current received from the AC source module 5 and current exchanged with the DC buffer module 7. The produced current is supplied continuously according to UPS functionality, and regardless of a reversal of a current sense when exchanging with the DC buffer module.

[0063] During operation, the control module conducts the following steps, performed in real time: receiving, from the AC source module 5, source data comprising a value of the power level; receiving, from the DC buffer module 7, buffer data comprising a value of the charge level; receiving, from the AC output module 6, load data comprising a value of an electrical load.

[0064] Based on these data, i.e., each of the values of the power level, the charge level and the electric load, the control module adjusts the power level of the AC source module.

[0065] The adjustment is made with an algorithm that works according to certain thresholds.

[0066] Upon detection of the charge level exceeding a preset upper threshold, the algorithm decides to switch off the energy source (typically in the absence or negligibility of a load) OR to reduce the power level of the AC source module without switching off (typically in the case of a non-negligible load). In order to determine whether the load is low / negligible or not, and to determine the extent to which adjustment is required, the algorithm determines whether a preset threshold for the electrical load has not been exceeded during the last 10 seconds. In variants of this example, the adjustment is instantaneous, with T being less than 1 ms.

[0067] In addition, upon detection of the charge level falling below a preset lower threshold, the algorithm decides to switch on the energy source (if the energy source was switched off) OR to increase the power level of the AC source module (if the energy source was on). In order to check to what extent adjustment is required, the algorithm determines whether the electrical load has not fallen below a preset lower threshold during the last 10 seconds, which may indicate a negligible load. In variants of this example, the adjustment is instantaneous, with T being less than 1 ms.

[0068] In variants of this example, the battery technology is not lead-carbon but lead-acid or lithium. In still other variants, the AC source module comprises not one power group, but two power groups connected in parallel.

[0069] In still other variants, the AC source module 5 comprises a combination of a fuel cell, for example a PEM fuel cell, and a DC-AC inverter, so that AC is available at the output of the AC source module. This is illustrated by Figure 1, with the AC symbol at this output. In still other variants (not illustrated), instead of the AC source module 5, a DC source module is provided which comprises a fuel cell but not an inverter. In such a case, direct current is routed to the AC output module. EXAMPLE 2

[0070] Figure 2 shows a schematic representation of a second exemplary embodiment of the device and system according to the invention. This is substantially similar to what is explained in EXAMPLE 1, wherein the AC output module is additionally powered by an external power source 11 which, during at least a period of the power supply, supplies AC mains power. This may be, for example, periods when the battery is being charged, before the assembly is installed at an off-grid location. Additionally, or instead, it may involve additional power generation during regular periods of power supply.

[0071] In variants of this example (not shown), the AC output module 6 comprises an AC bus (not shown) which is situated between the AC output 10 and other parts of the AC output module. The external power source 11 thereby couples to this AC bus via a switching connection (not shown) which is controlled by the control module 1. Thus, the control module can switch between modes in which the AC output 10 is supplied with either only current coming from the external current source 11, or a mix comprising current coming from the external current source 11 and current coming from the AC source module 5 and / or the DC buffer module 7, or only current coming from the AC source module 5 and / or the DC buffer module 7 (without current coming from the external current source 11).

[0072] EXAMPLE 3

[0073] Figure 3 shows a schematic representation of a third exemplary embodiment of the device and system according to the invention. This exemplary embodiment comprises corresponding elements as Example 2. Thereby, the control module is provided in the combination of a PLC controller 1' and a system controller 1".

[0074] The control module (1', 1") comprises a further interface for controlling several switching connections 15-20 which control access to an AC bus 14 which is situated between several external power sources 11-13 and the AC output 10. Thereby, the AC bus 14 and the switching connections 15-20 are shown separately in this example, but may, in variants of this example, be part of the AC output module 6.

[0075] The AC bus is a power line that allows various AC power sources to be connected by means of the various switching connections 15-20. In addition, the AC bus 14 also receives power from the AC output module. All the incoming current on the AC bus 14 is then routed to the AC output 10.

[0076] In this example, the switching connections 15-20 are shown separately from the AC output module; in variants of this example (not shown), these connections 15-20 are part of the AC output module 6.

[0077] In summary, the AC output module may comprise only module 6, as shown, wherein the AC output module is indirectly connected to the AC output 10. In addition, the AC output module may comprise both module 6 and the AC bus 14, wherein the AC output module is connected, via the AC bus, directly to the AC output 10. In yet further examples, the AC output module comprises both module 6 and the assembly 21 of AC bus and switching connections, wherein the AC output module is connected, via the AC bus, directly to the AC output 10.

[0078] The various switching connections 15-20 are controllable by the control module, preferably by the PLC controller. This may be electronic data control, but also purely electrical control, wherein one or more, or all switching connections, are realised by a relay.

[0079] The combinations of 15 and 16, on the one hand, and 17 and 18, on the other hand, allow switching between charging mode and boosting mode, respectively. In charging mode, as shown for connection 15 but not for connection 17, current is routed from the external power source 11 to the AC output module 6. In boosting mode (as not shown for connection 16, but for connection 18), current is routed to the AC bus, and is thus routed to the AC output without DC conversion. The combination of 15 and 16 is thus switching between either charging (15 active) or boosting (16 active). Similarly, the combination of 17 and 18 is switching between either charging (17 active) or boosting (18 active). In variants of this example, there is thereby switching between both charging (15 and 17 active) and both boosting (16 and 18 active). In still other variants, there is alternating switching between charging from either one source or the other source (15 active or 17 active). With reference to Example 2, in variants of Example 2, switching connections and an AC bus may also be present as part of the AC output module, and in these variants, switching may also occur according to both charging and / or both boosting and / or alternating with charging from either one source or the other source.

[0080] The switching connections 19 and 20 allow a respective second 12 and third 13 external power source to supply AC power on the AC bus 14 or not. With this second and external power source, no possibility of DC conversion is provided. Hence, there is also no distinction between boosting or charging mode, it is only "on" (or, equivalently, boosting) or "off". In "on" mode, as shown for connections 19 and 20, current is routed from the second and third external power sources to the AC output module 6. In "off" mode (not shown), no current is routed from the second or third power sources. In variants of this example, this involves switching between both "on" (19 and 20 active) and both "off". In still other variants, there is alternating switching between one source or the other source (19 active or 20 active). With reference to Example 2, in variants of Example 2, a switching connection and an AC bus may also be present as part of the AC output module, and in these variants, switching may also occur according to the external power source 11 being "on" and "off".

[0081] In this example, the control of the various switching connections is done by the PLC controller 1'. In doing so, it operates according to various working modes, whether preprogrammed or not. These working modes correspond, for example, to maximum uptime, or minimum fuel consumption or minimum overall cost. The separate system controller 1" reads data, and optionally also receives instructions via an external data connection (e.g., via the Internet). Based on this, the system controller chooses from the existing working modes, or defines new working modes itself, whether self-learning or not.

[0082] In this example, the AC bus does not comprise any special provisions for controlling the power sense, and the power sense is, for example, completely controlled based only on the switching connections 15-20. It is assumed that the power and direction of all power sources 5, 11-13 are known, and / or controlled for proper mutual operation. In variants of this example, logic is provided, preferably belonging to the control module, which allows communication and automatic adjustment between sources 5, 11-13 and the AC bus. This may include, for example, synchronisation between a current source 5, 11-13 with respect to the bus, or vice versa, or among themselves. In still other variants, bidirectionality is provided between two or more of the power sources 5, 11-13, wherein a power source / drain is provided to enable this.

[0083] In variants of this example, all parts belonging to the assembly 21 are provided in a separate housing, as a standalone distribution module. In still other variants, all parts belonging to the assembly 21 and the assembly 22 are provided in a joint housing, as a standalone power system, for example corresponding to an example of the system according to the invention.

[0084] (END OF EXAMPLE 3)

[0085] It will be clear that the present invention is not limited to the embodiments described above and that some modifications or changes can be added to the described examples without revaluing the added claims. For example, the present invention was mainly described with a non-electric energy source, but it is possible that the energy source at least partially comprises an electric source, since electricity can also be employed for rotation. DC buffering also mainly referred to DC buffers based on lead-carbon batteries or lead-acid batteries. However, other battery technologies can equally be employed in the invention, regardless of whether they are of the starter battery type or the semitraction type. The use of lithium batteries as DC buffers is also possible, and is equally part of the disclosure of the present invention.

Claims

CLAIMS1. A device (1, 1', 1") relating to a control module, comprising: a processor; one or more data interfaces, for realising a data connection with an AC source module (5) with an adjustable power level comprising an AC source contact and an energy source with preferably a maximum power of at least 2 kW, a DC buffer module (7) with a variable charge level comprising a DC buffer and a DC power interface, the DC buffer preferably being a rechargeable battery, the DC buffer preferably comprising a capacity of at least 10 kWh, and an AC output module (6) comprising an AC output (10) and configured to produce current based on both current received from the AC source module (5) via its AC source contact and current exchanged with the DC buffer module (7) via its DC power interface, wherein the produced current is continuously supplied regardless of a reversal of a current sense when exchanging with the DC buffer module; wherein the processor is configured to repeatedly perform: receiving, from the AC source module (5), source data comprising a value of the power level; receiving, from the DC buffer module (7), buffer data comprising a value of the charge level; receiving, from the AC output module (6), load data comprising a value of an electrical load; adjusting, at least based on the values of the power level, the charge level and the electrical load, the power level of the AC source module; wherein the device (1, 1', 1") is configured to cause the AC output module (6) to draw power at least partially from both the AC source module (5) and the DC buffer module (7) when supplying power at peak load; wherein said peak load is related to a regime near the upper part of an operating area, for example, an interval covering the upper half of the operational area.

2. The device (1, 1', 1") according to claim 1, wherein said adjusting relates to an algorithm which, upon detection of the charge level exceeding a preset upper threshold, switches off energy power source and / or reduces the power level of the AC source module.

3. The device (1, 1', 1") according to claim 2, wherein said energy source is switched on and wherein the algorithm reduces the power level of the AC source module without switching off the energy source.

4. The device (1, 1', 1") according to claims 2 and 3, wherein the detection comprises checking whether a preset upper threshold for the electrical load has not been exceeded during the last T seconds, with T preferably being greater than 1 second, more preferably greater than 10 seconds.

5. The device (1, 1', 1") according to claims 1-4, wherein said adjusting relates to an algorithm which, upon detection of the charge level falling below a preset lower threshold, turns on the energy source and / or increases the power level of the AC source module.

6. The device (1, 1', 1") according to claim 5, wherein said energy source is already switched on and wherein the algorithm increases the power level of the AC source module.

7. The device (1, 1', 1") according to claims 1-6, further comprising a further interface for controlling one or more switching connections (15-20) which control access to an AC bus (14) which is situated between one or more external power sources (11- 13) and the AC output (10), said AC bus and the one or more switching connections preferably being part of the AC output module.

8. A system comprising: an AC source module (5) with an adjustable power level comprising an AC source contact and a power source, a DC buffer module (7) with a variable charge level comprising a DC buffer and a DC power interface, an AC output module (6) connected to the AC source module by an AC connection (8) and to the DC buffer module by a DC connection (9), and the device (1, 1', 1") according to claims 1-7 being the control module, connected to said AC source module (5), the DC buffer module (7) and the AC output module (6) by one or more data connections (2-4), wherein the AC output module (6) comprises an AC output (10) and is configured to produce current based on both current received from the AC source module (5) via its AC source contact and current exchanged with the DC buffer module (7) via its DCpower interface, wherein the produced current is continuously supplied regardless of a reversal of a current sense when exchanging with the DC buffer module; wherein the AC output module (6) is configured to draw power at least partially from both the AC source module (5) and the DC buffer module (7) when supplying power at peak load; wherein said peak load is related to a regime near the upper part of an operating area, for example an interval covering the upper half of the operating area.

9. The system according to claim 8, wherein the AC source module (5) relates to at least an assembly comprising a power generating element for generating a rotation and an electrical power element comprising an alternator for converting the rotation into AC current at the AC source contact.

10. The system according to claim 9, wherein the power generating element comprises a diesel engine and / or a hydrogen engine.

11. The system according to claims 9 and 10, wherein at least the AC output module (6) and the device (1, 1', 1") are provided in the same housing, preferably wherein the device comprises a PLC, more preferably is a PLC.

12. The system according to claims 8-11, wherein the DC buffer comprises a lead-carbon type battery.

13. The system according to claim 12, wherein the capacity of the lead-carbon battery is at least 1 kWh, and wherein a ratio of C-value when discharging and C- value when charging the battery is at least 2, preferably at least 4, more preferably at least 8.

14. A method for controlling a system for generating a current at an AC output, comprising the steps: receiving, from an AC source module (5) comprising an energy source with a maximum power of at least 2 kW, source data comprising a value of the power level; receiving, from a DC buffer module (7) comprising a DC buffer with a capacity of at least 2 kWh, buffer data comprising a value of the charge level receiving, from an AC output module (6) comprising the AC output, load data comprising a value of an electrical load; adjusting, at least based on the values of the power level, the charge level and the electrical load, the power level of the AC source module;wherein: said adjusting relates to an algorithm which, upon detection of the charge level exceeding a preset threshold, switches off the energy source and / or reduces the power level of the AC source module and / or said adjusting relates to an algorithm which, upon detection of the charge level falling below a pre-set threshold, switches on the energy source and / or increases the power level of the AC source module; wherein the AC output module (6) is configured to draw power at least partially from both the AC source module (5) and the DC buffer module (7) when supplying power at peak load; wherein said peak load is related to a regime near the upper part of an operating area, for example, an interval covering the upper half of the operating area.

15. A computer program product comprising memory comprising instructions which, when executed on a processor, said processor preferably belonging to a PLC, perform the steps of the method according to claim 14.

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