Method for controlling reactive power flow in hybrid energy storage system

Abstract

It is proposed a method for actively controlling an output voltage of a first energy storage system connected in parallel to a second energy storage system for controlling reactive or active power flow from or into any one of the energy storage systems; the method comprises the following steps: providing (S1) at least one reactive or active power flow demand value of at least one phase load and / or phase network; providing (S2) an output voltage measurement and a current measurement of the second energy storage system; calculating (S3) a reactive or active power flow demand current value for the second energy storage system on the basis of the at least one reactive or active power flow demand value and the output voltage measurement value; calculating (S4) a control output voltage value of the first energy storage system based on the reactive or active power flow demand current value and the current measurement value of the second energy storage system; modulating (S5) the control output voltage value into at least one control signal; and controlling (S6) an output voltage of the first energy storage system based on the at least one control signal.

Description

Technical Field

[0001] The present application relates to a method for actively controlling the output voltage of a first energy storage system connected in parallel to a second energy storage system for controlling reactive or active power flow from or into either of the energy storage systems. Furthermore, the present application relates to a powertrain and / or a grid system. Background Art

[0002] In the field of energy systems and power applications, several interesting challenges arise when it comes to optimizing life, performance, and efficiency. In this context, three notable areas of focus are regenerative braking, field weakening of traction motors, and providing reactive power in grid applications through periodic micro-cycling. However, it is important to understand the potential drawbacks associated with these processes.

[0003] The concept of regenerative braking involves harnessing kinetic energy during vehicle deceleration or braking and converting it into electrical energy. While this is a valuable method for energy recovery, it introduces additional cycles into the battery, which ultimately reduces the overall life of the battery.

[0004] In conventional electric vehicles, electric motors with permanent magnets are applied. Such electric motors may require field weakening techniques to increase the achievable speed of the electric motor. However, such field weakening processes require reactive power, which microcirculates the traction battery, thereby increasing heat generation and shortening the life of the traction battery.

[0005] In the context of grid applications, periodic micro-cycling plays a role in providing reactive power. However, this introduces additional stress on the battery, causing a reduction in its overall lifespan.

[0006] Hybrid battery packs typically employ bidirectional DC-DC converters that are used to control the DC link voltage to improve the efficiency of the inverter. While these converters provide a standard solution, they typically lack the required dynamic characteristics to effectively control the power flow of high-frequency components (ripples) and mitigate microcirculation. Therefore, active control of ripples and mitigation of microcirculations remain unaddressed. As a result, alternative power conversion methods are often employed, which results in a reduction in overall system efficiency.

[0007] In this context, the term "ripple" refers to an undesirable fluctuation or oscillation in the output voltage or current of an electrical system, and a reactive power flow from or into an energy storage system. Undesirable fluctuations or oscillations in the output voltage and / or current of an electrical system represent residual AC components remaining after the conversion of a DC voltage level to another DC voltage level, a DC voltage to an AC voltage, an AC voltage to a DC voltage, or an AC voltage to another AC voltage. Ripples may occur in various electrical systems, such as power supplies, DC-DC converters, and inverters. This may be caused by imperfect filtering or smoothing of the input or output signal, which causes the residual AC component to be superimposed on the desired DC signal. Such ripples are usually characterized by their frequency and magnitude. For example, in power supply applications, the input voltage is usually rectified to obtain a DC voltage, but due to imperfect filtering, some residual AC voltages referred to as ripple voltages still exist. Similarly, in a DC-DC converter, when converting from one voltage level to another, a ripple current or voltage may appear in the output due to the switching action of the converter. The presence of ripples may have an adverse effect on electronic systems (such as energy storage systems). Thus, the ripples may cause fluctuations in the output energy of the system and / or may cause micro-circulations in the energy storage of the system. Summary of the invention

[0008] In this context, the object of the present invention is to provide an improved method for actively controlling power flow (in particular reactive power flow) of a hybrid energy storage system, the hybrid energy storage system comprising a first energy storage system connected in parallel to a second energy storage system. Furthermore, the object of the present application is to provide an improved powertrain and / or grid system.

[0009] This object is achieved by a method for actively controlling the output voltage of a first energy storage system, which is connected in parallel with a second energy storage system, for controlling the reactive or active power flow from or into the energy storage system, the method having the features of claim 1. Furthermore, the object is achieved by a power train and / or a grid system having the features of claim 8.

[0010] Advantageous embodiments of the disclosure are subject of the dependent claims. Any and all combinations of at least two features disclosed in the description, the claims and / or the drawings fall within the scope of the disclosure. Naturally, the description given in conjunction with the method equally relates to the power train and / or the power grid system according to the disclosure, without redundant mention in its context. In particular, within the scope of common language practice, linguistically common reformulations and / or analogical substitutions of corresponding terms, in particular the use of synonyms based on recognized language literature, are of course included in the content of the present disclosure without the need to explicitly mention each and every variation.

[0011] According to a first aspect, a method for actively controlling the output voltage of a first energy storage system, wherein the first energy storage system is connected in parallel to a second energy storage system for controlling reactive or active power flow from or into any one of the energy storage systems. The method comprises the following steps: providing at least one reactive or active power flow demand value of at least one phase load and / or phase power grid; providing an output voltage measurement value and a current measurement value of the second energy storage system; calculating a reactive or active power flow demand current value of the second energy storage system based on at least one reactive or active power flow demand value and an output voltage measurement value; calculating a control output voltage value of the first energy storage system based on the reactive or active power flow demand current value and the current measurement value of the second energy storage system; modulating the control output voltage value into at least one control signal; and controlling the output voltage of the first energy storage system based on the at least one control signal. Preferably, the control output voltage value is modulated into at least one control signal. The control signal can be used to control and / or adjust the output voltage of the first energy storage system, thereby preferably ensuring that it is consistent with the desired power flow demand.

[0012] Throughout the specification and claims, the expression "at least one phase load and / or phase grid" may be replaced by the term "phase system", wherein the "phase system" preferably includes at least one phase load or at least one phase grid or at least one phase load and at least one phase grid. Therefore, following this wording, the method includes the following steps: providing at least one reactive or active power flow demand value of at least one phase system; providing output voltage measurement values ​​and current measurement values ​​of the second energy storage system; calculating the reactive or active power flow demand current value of the second energy storage system based on at least one reactive or active power flow demand value and the output voltage measurement value; calculating the control output voltage value of the first energy storage system based on the reactive or active power flow demand current value and the current measurement value of the second energy storage system; modulating the control output voltage value into at least one control signal; and controlling the output voltage of the first energy storage system based on the at least one control signal.

[0013] "Output voltage" preferably refers to the voltage of an electrical signal generated or delivered by a device or system such as the first energy storage system as its final or generated. It preferably represents the voltage level and / or magnitude of the electrical signal generated at the output of a device or system such as the first energy storage system.

[0014] "Parallel connection" preferably refers to a configuration in which two or more electrical or electronic devices or systems are interconnected in such a way that they share a common electrical connection. In this configuration, the devices or systems are preferably connected side by side to allow current to be divided and distributed between them. When two energy storage systems are connected in parallel, this means that their positive terminals are connected to each other and their negative terminals are also connected to each other. This parallel connection preferably enables them to operate together as a single combined system, preferably with the ability to share loads and / or exchange power between them.

[0015] "Power flow demand value" preferably refers to a value representing the expected power flow from or into the corresponding first and / or second energy storage system, and is determined based on the requirements of the phase load or phase grid. Active power flow, also known as real power flow, preferably represents the actual power transfer that does useful work or generates energy within the electrical system. Preferably, it is measured in watts (W) and represents the rate at which energy is transferred from the power source to the load. Reactive power flow preferably represents the exchange of reactive energy between the power source and the load in the electrical system. Unlike active power flow, reactive power preferably does not do useful work, but is necessary to maintain voltage levels and / or support the operation of reactive components such as inductors and / or capacitors. Reactive power flow is preferably measured in units of volt-amperes reactive (VAR).

[0016] An "output voltage measurement" and a "current measurement" of the second energy storage system are provided / obtained. This preferably means that these measurements provide information about the current operating conditions of the second energy storage system.

[0017] According to the proposed method, a way of at least partially mitigating reactive power in an energy storage system such as a hybrid battery system can be provided. The energy storage system may include a hard-wired battery and / or a reconfigurable battery or a plurality of energy storage units in parallel, each of which may include a plurality of battery cells. The load condition may be actively controlled by the first and / or second energy storage system, for example, to provide continuous load conditions on either of the first or second energy storage system. In addition, the life of at least one of the energy storage unit and / or the energy storage system may be increased. Therefore, appropriate control of the power flow requires relatively high-power electronics and significantly higher dynamic characteristics compared to the use of an inverter. These requirements can be achieved by a first energy storage system, which preferably uses a low-voltage switch with high dynamic characteristics and / or with low switching losses. This allows a significant increase in the switching frequency.

[0018] The proposed method can be used to mitigate reactive power flows into the first or second energy storage system, in particular to reduce the stress on the respective energy storage system and / or to increase the life of the respective energy storage system. The first energy storage system can be configured as a reconfigurable, preferably modular energy storage system. The phase grid and / or the phase load may include at least one phase, preferably at least two phases, and more preferably at least three phases. Of course, without departing from the scope of the present invention, the phase grid may also include more than three phases. The phase grid may be understood as any kind of grid or an N-phase grid.

[0019] In an embodiment, providing at least one reactive or active power flow demand value includes at least one of the following steps: using a power calculation algorithm to calculate at least one reactive or active power flow demand value based on phase voltage measurements and phase current measurements; and / or calculating at least one reactive or active power flow demand value based on two dq transformed values ​​of phase voltage measurements, preferably of each phase, of at least one phase load and / or phase grid and two dq transformed values ​​of phase current measurements, preferably of each phase; and / or calculating and / or receiving at least one reactive or active power flow demand value based on an accelerator input value provided by an accelerator of the vehicle; and / or calculating and / or receiving at least one reactive or active power flow demand value of the phase grid based on the active power flow demand and / or reactive power flow demand of the phase grid; and / or measuring at least one reactive or active power flow demand value on the phase grid and / or at least one phase load.

[0020] The dq transformation is a mathematical transformation technique for converting three-phase electrical quantities into a rotating reference frame. The dq transformation preferably simplifies the analysis and control of the three-phase system by transforming the three-phase system into a two-dimensional coordinate system. This is achieved by aligning the reference frame with the rotating magnetic field of an AC machine such as an induction motor or a permanent magnet synchronous motor. The dq transformation preferably consists of two orthogonal transformations, namely, the d transformation and the q transformation. The d transformation preferably produces a direct axis component of a two-dimensional representation. It is aligned with the magnetic field vector of the AC machine, which is generally associated with the torque generating component of the system. The q transformation complements the d transformation by generating an orthogonal axis component. It is orthogonal to the direct axis component and represents the magnetizing component or flux generating component of the system. Together, the d and q transformations convert the three-phase quantity into a two-dimensional representation in a rotating reference frame, which is generally referred to as a dq reference frame.

[0021] Of course, any kind of suitable power calculation algorithm can be used. As a further exemplary power calculation algorithm, an α-β transformation algorithm can be used to calculate at least one reactive or active power flow demand value. The α-β transformation, also known as the Clarke transformation, is a mathematical transformation technique that is preferably used to convert a preferred three-phase coordinate system into a two-phase coordinate system. The α-β transformation can allow a set of three-phase quantities to be represented in a two-dimensional coordinate system. The α transformation preferably converts the three-phase quantity into a two-phase system, in which one phase represents the average value of the three-phase system. The α transformation output is preferably referred to as a "direct axis" or "in-phase" component. The β transformation preferably complements the α transformation by generating a second component of the two-phase system, which is orthogonal to the direct axis component. It preferably represents a "quadrature axis" or "90 degrees out of phase" component. Therefore, calculating at least one reactive or active power flow demand value can be performed based on two α-β transformation values ​​of phase voltage measurements of preferably each phase of at least one phase load and / or phase power grid and two α-β transformation values ​​of phase current measurements of preferably each phase.

[0022] In another embodiment, at least one reactive or active power flow demand value may be calculated based on the provided apparent power demand values ​​of the phase loads and / or phase grids. Apparent power depends on active power and reactive power. Apparent power may be a measure of the total power flow in an electrical system taking into account both active power (real power) and reactive power components. It is preferably represented by the symbol "S" and is measured in volt-amperes (VA). Taking into account the combination of active power (P) and reactive power (Q), the apparent power preferably represents the total amount of power in the AC circuit. Taking into account the magnitude and phase relationship of the active power and reactive power, the apparent power is preferably the vector sum of the active power and the reactive power.

[0023] In another embodiment, based on two dq transformed values ​​of phase voltage measurement values ​​of at least one phase load and / or phase grid, preferably of each phase, and two dq transformed values ​​of phase current measurement values ​​of preferably each phase, calculating at least one reactive or active power flow demand value comprises: providing at least one position and / or phase signal of at least one phase load and / or phase grid; providing at least one phase measured voltage value of the phase load and / or phase grid, preferably by measuring the phase voltage measurement value using at least one voltage sensor; transforming the phase voltage measurement value into a dq system to provide two dq transformed values ​​of the phase voltage measurement value of at least one phase load and / or phase grid; and providing two dq transformed values ​​of the phase current measurement value of at least one phase load and / or phase grid by a control circuit of at least one phase load and / or phase grid. Of course, alternatively or additionally, an alpha-beta transformation algorithm can be used.

[0024] The voltage can be measured by any kind of suitable voltage sensor. A position signal can be provided for a rotating load such as a motor. A phase signal can be provided for a power grid. For position measurement, a Hall sensor can be used. For phase sensing, a voltage transformer (VT), a current transformer (CT), a Hall sensor, a digital phase meter and / or a synchronizer / resolver sensor can be applied. The control circuit of at least one phase load and / or a phase power grid preferably refers to a system or circuit responsible for monitoring and / or regulating the operation of an electrical load or power grid in a specific phase / setting or setting. The control circuit may include at least one sensor for measuring various electrical parameters such as voltage, current, power, frequency or phase angle. The control circuit may include at least one controller for processing sensor feedback signals and / or for comparing them with set points and / or thresholds and / or control parameters. The control circuit may include at least one actuator for receiving a control signal from a controller and for performing the necessary actions to regulate the operation of the load or power grid. Such an actuator may include a switch and / or a power electronic device capable of controlling voltage, current or power flow. The control circuit may contain a specific algorithm or control strategy that determines how the system responds to different operating conditions. These strategies may include various control techniques, such as proportional-integral-derivative (PID) control, adaptive control, feedback control, or advanced control algorithms. The control circuit may include protection and / or safety features, for example, to prevent damage to the load, the grid, or the control components.

[0025] In another embodiment, providing two dq transformed values ​​of the phase current measurement value of at least one phase load and / or phase power grid by the control circuit of the at least one phase load and / or phase power grid includes the following steps performed by the control circuit: providing at least one position and / or phase signal of at least one phase load and / or phase power grid by measuring at least one position and / or phase signal using a position sensor and / or a position identification algorithm; providing at least one phase current measurement value of at least one phase load and / or phase power grid by measuring the phase current measurement value of at least one phase load and / or phase power grid; and transforming the phase current measurement value into a dq system to provide two dq transformed values ​​of the phase current measurement value of at least one phase load and / or phase power grid.

[0026] In order to provide at least one position and / or phase signal of at least one phase load and / or phase network, at least one position sensor commonly used for rotating loads (such as electric motors of vehicles) can be used. Alternatively or additionally, a position recognition algorithm can be applied. As such a position recognition algorithm, a phase locked loop can be combined, preferably for power grid applications. Such a phase locked loop preferably refers to an algorithm that calculates a phase signal from voltage measurements, preferably from each phase of an N-phase power network.

[0027] In another embodiment, providing the output voltage measurement value and the current measurement value of the second energy storage system includes: monitoring the output voltage measurement value and the current measurement value of the second energy storage system through an energy storage management system of the second energy storage system. Preferably, the output voltage measurement value and / or the current measurement value of the second energy storage system are monitored at regular time intervals.

[0028] In another embodiment, control of the output voltage of the first energy storage system results in active control of reactive or active power flow from or into the second energy storage system.

[0029] Thus, controlling and / or regulating the output voltage of the first energy storage system can be achieved by this embodiment. Thus, a mechanism can be applied to adjust and / or manipulate the voltage level generated by the first energy storage system. In addition, according to the provided method, this capability can be used to influence and / or manage the direction and / or magnitude of the power flow between the first and second energy storage systems. Preferably, reactive power represents the exchange of reactive energy that supports voltage stability and / or operation of reactive components. Active power preferably represents a power flow that does useful work and / or transfers energy.

[0030] In another embodiment, providing at least one reactive or active power flow demand value comprises: providing multiple reactive or active power flow demand values ​​of multiple phase loads and / or phase grids, and summing the multiple reactive or active power flow demand values ​​of the multiple phase loads and / or phase grids. Therefore, the method can also be applied when more than one phase load can be connected to the first and second energy storage systems.

[0031] According to a second aspect, a power transmission system and / or a power grid system is provided. The power transmission system and / or the power grid system at least comprises: a second energy storage system; a first energy storage system connected in parallel to the second energy storage system; an inverter unit connected in parallel to the first energy storage system and the second energy storage system; and a battery controller for actively controlling the output voltage of the first energy storage system for controlling the reactive or active power flow from or into any one of the energy storage systems; the battery controller is configured to perform at least the following steps: provide at least one reactive or active power flow demand value of at least one phase load and / or phase grid; provide an output voltage measurement value and a current measurement value of the second energy storage system; based on at least one reactive or active power flow demand value and an output voltage measurement value, calculate a reactive or active power flow demand current value of the second energy storage system; based on the active power flow demand current value and the current measurement value of the second energy storage system, calculate a control output voltage value of the first energy storage system; modulate the control output voltage value into at least one control signal; and control the output voltage of the first energy storage system based on at least one control signal.

[0032] Of course, all features and embodiments described for the method are applicable to the powertrain and / or grid system. In particular, all provided definitions and / or explanations of features or parts of features are mutually applicable to the system claimed herein. The battery controller can be configured as part of a battery management system (BMS) of the first and / or second energy storage system. In an alternative configuration, the battery controller can be a separate component.

[0033] In an embodiment, the first energy storage system is configured to receive the reactive power flow to at least partially mitigate the reactive power flow to the second energy storage system.

[0034] The first energy storage system may preferably be constructed and / or set to receive or provide reactive power flow. This may imply that the first energy storage system has the ability to periodically absorb or provide reactive energy. The purpose of configuring the first energy storage system to receive reactive power flow is preferably to mitigate and / or reduce the amount of reactive power that would otherwise flow to the second energy storage system. In this context, mitigation preferably means reducing or lowering the magnitude of the reactive power flow. The second energy storage system can generally be regarded as a target or recipient of reactive power flow. By at least partially mitigating the reactive power flow toward the second energy storage system, this may mean that the first energy storage system acts as a buffer and / or stabilizer, absorbing and / or suppressing the reactive power before the reactive power reaches the second system. Due to the use of the first energy storage system, the negative impact of the reactive power flow accompanying the second energy storage system can be omitted, thereby extending the life of the second energy storage system. Therefore, the first energy storage system is configured to receive reactive power flow, thereby protecting and / or optimizing the operation of the second energy storage system. The first energy storage system can also be configured in a manner that provides reactive power to cause less damage in the first energy storage system. This configuration ensures that the second energy storage system is not overwhelmed by excessive reactive power and can operate more efficiently or reliably. Moreover, the lifetime and / or life of the second energy storage system can be increased by this setting and / or configuration.

[0035] In another embodiment, the method and / or power transmission system and / or power grid system may further include: at least one phase load, preferably at least one motor, and / or phase grid, connected to the inverter unit; a current measurement sensor for measuring a phase current measurement value of at least one phase load and / or phase grid; an energy storage system voltage and energy storage system current sensor for measuring an output voltage measurement value and a current measurement value of a second energy storage system; at least one position sensor and / or a position identification algorithm for measuring at least one position and / or phase signal; and an inverter controller configured to control the inverter unit based on the phase current measurement value, the position and / or phase signal, the output voltage measurement value and the current measurement value of the second energy storage system.

[0036] In other words, the method and / or the powertrain and / or the grid system includes at least one phase load and / or a phase grid, all of which are connected to the inverter unit. This indicates that the inverter unit can be responsible for converting and / or controlling the electrical power supplied to the phase load or the phase grid. The inverter controller can utilize inputs from various sources, including phase current measurements, position and / or phase signals, and output voltage measurements and current measurements of the second energy storage system. It can process these inputs to determine appropriate control signals for the inverter unit, thereby providing effective and / or precise control of the entire powertrain and / or grid system.

[0037] In another embodiment, at least one capacitor connected in parallel with the first energy storage system is provided.

[0038] The capacitor is configured to receive a reactive power flow to at least partially mitigate the reactive power flow to the second energy storage system and / or the first energy storage system. Such a capacitor can provide the ability to quickly store and / or release electrical energy, making it very suitable for reactive power compensation. By connecting the capacitor in parallel to the first and second energy storage systems, it can at least partially absorb and release reactive power to mitigate the reactive power flow toward the first and / or second energy storage systems. This helps to stabilize the voltage level and improve the power factor. Moreover, such a capacitor can help maintain voltage stability within the electrical system. By connecting the capacitor in parallel, it can provide reactive power support, especially during periods of high demand and / or voltage drop within the entire system. This voltage support ensures that the second energy storage system operates within acceptable voltage limits, thereby enhancing system performance and reliability. Moreover, such a capacitor can help optimize power flow and / or improve overall system efficiency. By absorbing reactive power from the system, at least one capacitor can reduce the burden on the energy storage system to allow them to operate more efficiently. This causes reduced losses, lower energy consumption and improved utilization of the energy storage system. Moreover, the use of such capacitors can provide the effect of fast response time, making their use effective in compensating reactive power fluctuations and / or maintaining system stability. The ability of capacitors to quickly absorb and / or release energy helps to quickly respond to changes in reactive power flow to ensure efficient power transfer and minimize voltage changes. Moreover, capacitors are generally relatively inexpensive compared to other power compensation solutions.

[0039] In another embodiment, the method and / or the powertrain and / or the grid system further comprises at least a first filter unit connected to the first energy storage system; and / or at least a second filter unit connected to the second energy storage system.

[0040] The filter is preferably designed to reduce and / or eliminate undesirable harmonics in the electrical system. At least one first and / or second filter may preferably be configured to stabilize the power flow from or into the first and / or second energy storage system. In addition, at least one first and / or second filter may be configured to allow preferably stepless and / or smooth current control of the first and / or second energy storage system. By connecting the filter unit to the first energy storage system and / or the second energy storage system, harmonic distortion caused by nonlinear loads or other sources can be effectively mitigated. This helps to maintain a cleaner and more stable power supply, reduce equipment failures and improve overall system performance. Moreover, the filter unit can help regulate the voltage level within the electrical system. The filter can smooth voltage fluctuations and / or transients to provide a more stable and consistent voltage supply to the energy storage system. This can enhance the performance and / or reliability of the energy storage system to ensure that they operate within their specified voltage range. Further, the filter can improve power quality by reducing voltage sags, surges and transients. They can help minimize voltage distortion, flicker and / or other power anomalies that may negatively affect the performance of electrical equipment. This causes an increase in power factor, a decrease in power losses and an increase in overall system efficiency. Particularly preferably, at least one of the first and / or the second filter can be an inductor.

[0041] In another embodiment, the method and / or power train and / or grid system also includes: a phase grid capable of at least temporarily connecting to an inverter unit for performing charging operations of the first and / or second energy storage system and / or for performing grid support operations; a power controller configured to control the inverter unit based on an active power flow demand and a reactive power flow demand; and / or a power measurement sensor for measuring at least one active power flow value on the phase grid; and / or a battery controller configured to control the output voltage of the first energy storage system based on the active power flow demand of the phase grid and / or based on a measured active power flow demand value of the grid.

[0042] The power controller may be a grid power controller. In alternative embodiments, the power controller may be a powertrain power controller and / or a phase load power controller.

[0043] In another embodiment, the first energy storage system includes at least one switching device; wherein the first energy storage system also includes at least two energy sources, and the switching device is configured to selectively switch the at least two energy sources relative to each other at least temporarily in positive series, negative series or parallel connection to generate controllable alternating current or direct current at the output of the first energy storage system, or wherein the first energy storage system includes a battery and a DC / DC converter, and the DC / DC converter is configured to at least temporarily connect or disconnect the first energy storage system (preferably its output) in parallel with the second energy storage system. In the case where the first energy storage system includes a battery and a DC / DC converter, the DC / DC converter itself can be considered as a switching device.

[0044] "Switching device" preferably refers to an electronic device used in the first energy storage system to control the flow of current, such as a transistor or a thyristor. These switching devices can be selectively turned on or off to enable or interrupt the current path and facilitate the desired energy transfer or conversion.

[0045] In another embodiment, the second energy storage system comprises a battery, preferably hardwired. The battery may be a traction battery of a vehicle. The battery may be a buffer battery for a power application. Alternatively or additionally, the second energy storage system may comprise an energy storage, such as at least one fuel cell and / or at least one capacitor and / or at least one supercapacitor and / or at least one flywheel, preferably with at least one DC / DC converter.

[0046] In another embodiment, the second energy storage system includes a single energy storage unit or multiple energy storage units. In other words, in one embodiment, the second energy storage system consists of a single energy storage unit. A single energy storage unit may include multiple energy storage battery cells. This may suggest that there is only one storage device or unit for storing electrical energy. In another embodiment, the second energy storage system includes multiple energy storage units. This may suggest that there are multiple separate energy storage devices that are connected to form the second energy storage system.

[0047] It should be understood that the term "energy storage system" should not be understood as limited to energy storage, and any type of energy source may also fall under the term. Moreover, it should be understood that the term "energy storage unit" should not be understood as limited to energy storage, and any type of energy source may also fall under the term.

[0048] In another embodiment, each of the at least two energy sources comprises at least one battery cell and / or at least one capacitor and / or at least one photovoltaic panel and / or at least one fuel cell and / or at least one alternative electrical energy source. In general, other energy sources may be implemented. Therefore, the provided enumeration is not meant to be limiting.

[0049] In another embodiment, the first energy storage system comprises a high power density compared to the second energy storage system; and wherein the second energy storage system comprises a high energy density compared to the first energy storage system. Since the first energy storage system is configured as a high power density system, damage caused by microcirculation can be minimized, thereby reducing the negative impact of microcirculation on the life of the first energy storage system.

[0050] In this embodiment, the first energy storage system is characterized by high power density. This means that it can transmit or absorb electricity at a relatively high rate compared to its size or weight. The focus is on the power handling capability of the system, enabling it to provide high power output or accept high power input. In contrast, the second energy storage system is described as having a high energy density. This indicates that it has the capacity to store and / or hold a large amount of electrical energy relative to its size or weight. The focus is on the energy storage capacity of the system to allow it to store a large amount of energy in a relatively small volume or mass. By combining these different power / energy characteristics into energy storage systems, it becomes possible to adapt their functions to specific needs. For example, the high power density of the first system can be suitable for applications that require fast power delivery or absorption, such as electric vehicle acceleration or regenerative braking. On the other hand, the high energy density of the second system may be advantageous for long driving range applications. In other words, using the present invention, an energy storage solution for electric vehicles can be provided, whereby a high power density energy storage system can produce enhanced acceleration performance, while a high energy density energy storage system can produce an enhanced driving range of electric vehicles. By combining the two energy storage systems, both beneficial effects can be achieved by a single energy storage package including at least the first and second energy storage systems. Furthermore, in addition to the above advantages, with the present invention, reactive power mitigation can be provided, which results in an increase in the life of at least one of the first and second energy storage systems.

[0051] In an alternative embodiment, the first energy storage system comprises a high energy density compared to the second energy storage system; and wherein the second energy storage system comprises a high power density compared to the first energy storage system. In this configuration, the second energy storage system has a high power density system, and thus damage caused by microcirculation can be minimized, thereby reducing the negative impact of microcirculation on the life of the second energy storage system.

[0052] In this embodiment, the first energy storage system is characterized by a high energy density. This preferably means that it has the capacity to store or hold a large amount of electrical energy relative to its size or weight. The focus is on the energy storage capacity of the system to allow it to store a large amount of energy in a relatively small volume or mass. In contrast, the second energy storage system is described as having a high power density. This preferably indicates that it has the ability to deliver and / or absorb electricity at a relatively high rate compared to its size or weight. The focus is on the power handling capability of the system, enabling it to provide high power output and / or accept high power input. By combining these different characteristics into energy storage systems, their functionality can be adapted to specific needs. For example, the high energy density of the first system may be advantageous for applications where electric vehicles require long-distance energy storage. On the other hand, the high power density of the second system may be suitable for acceleration and / or regeneration applications provided in electric vehicles that require fast power delivery and / or absorption.

[0053] In another aspect, there is provided a data processing device, preferably a battery controller, comprising means for performing, preferably at least partially, the method provided herein according to any one of its embodiments.

[0054] On the other hand, an electric vehicle is provided comprising a data processing device comprising a device for executing a method provided herein according to any one of its embodiments and / or at least one of a powertrain and / or a grid system provided herein according to any one of its embodiments.

[0055] All aspects and embodiments described above may be combined as the skilled person sees fit.

[0056] In this case, "one" or "an" should not be understood as being strictly limited to one element. Instead, multiple elements, such as two, three or more elements, may also be provided. Any other numbers used herein should also not be understood as having a limiting effect on the exact stated number of elements. Rather, unless otherwise indicated, upward and downward numerical deviations are possible.

[0057] Other possible implementations of the present invention also include any feature or the combination of the embodiments described above or below about the exemplary embodiment that are not explicitly mentioned. In this case, those skilled in the art will also add various aspects as improvements or supplements to each basic form of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 Exemplary improvements of the proposed powertrain and / or grid system are shown;

[0059] Figure 2Exemplary improvements of the proposed powertrain and / or grid system are shown;

[0060] Figure 3 A schematic block diagram showing an exemplary powertrain and / or grid system control circuit improvement;

[0061] Figure 4 A further schematic block diagram showing an exemplary powertrain and / or grid system control circuit improvement;

[0062] Figure 5 Exemplary improvements of the proposed powertrain and / or grid system are shown;

[0063] Figure 6 An exemplary improvement to the first energy storage system is shown; and

[0064] Figure 7 A schematic flow chart showing an improvement of the proposed method is shown.

[0065] Unless indicated to the contrary, identical or functionally identical elements are given the same reference numerals in the figures. It should also be noted that the illustrations in the figures are not necessarily true to scale. DETAILED DESCRIPTION

[0066] Figure 1 An improvement of a powertrain and / or grid system 1000 is shown. The powertrain and / or grid system 1000 includes a first energy storage system 510 connected in parallel to a second energy storage system 110 for controlling reactive or active power flow from or into either of the energy storage systems 510, 110. In the improvement shown, the first energy storage system 510 is configured as a reconfigurable battery. In the improvement shown, the second energy storage system 110 includes a hard-wired battery. Merely by way of example, an inverter unit 300 is connected to the first and second energy storage systems 510, 110. At least one phase load and / or phase grid 410 is connected to the inverter unit 300. Herein, reference numeral 410 refers to at least one phase load and / or phase grid or both. According to Figure 1 , the phase load and / or the phase grid 410 is configured as a three-phase load and / or a three-phase grid.

[0067] Preferably, the first and second energy storage systems 510, 110 jointly power the DC (direct current) load of the at least one phase load 410. Therefore, the inverter unit 300 preferably converts the AC power of the phase load 410 into DC power (DC load) processed by the first and / or second energy storage systems 510, 110, and vice versa. In addition, the first energy storage system 510 can be configured to actively control its output voltage 511, also referred to as the terminal voltage. Therefore, the first energy storage system 510 is configured to control its power supply to the DC load, wherein the power supply of the second energy storage system 110 can be considered as a supplement to the DC load, which is preferably indirectly controlled by the first energy storage system 510. Each energy storage system 110, 510 may include energy storage battery cells of different qualities, such as high power and / or high energy and / or new battery cells and / or reused (second life) battery cells. Moreover, the chemical properties of each battery cell may be different, wherein each energy storage system 110, 510 may operate under different load conditions. The load conditions can be actively controlled by the first energy storage system 510, for example, to adapt the first energy storage system 510 to absorb ripples and provide continuous load conditions on the second energy storage system 110. In other configurations of the system 1000, the situation may be the opposite. Alternatively, the first energy storage system 510 can be configured so that the second energy storage system 110 absorbs ripples and provides preferably continuous load conditions on the first energy storage system 510. In the context of the present application, ripples have reactive characteristics, and therefore, the term reactive power is used herein as an alternative expression of the term ripple. Further, alternatively, for example, when entering a field weakening region of a phase load operation such as a motor operation, or during regenerative braking, the first energy storage system 510 can be controlled in a manner that covers reactive power. This can be performed to minimize additional cycling of the battery cells in the second energy storage system 110. In other configurations of the system 1000, the situation may be the opposite.

[0068] The present invention describes a way to mitigate reactive power in a hybrid battery system that integrates a reconfigurable battery to improve load conditions in the battery system.

[0069] according to Figure 2, a further improvement of the powertrain and / or grid system 1000 is shown. In this embodiment, the three-phase load 410 can be represented by an electric motor, which can be included in the powertrain 1500 of the electric vehicle 2000. The powertrain and / or grid system 1000 includes an inverter unit 300 configured as a traction inverter 300. In addition to the first and second energy storage systems 510, 110, the powertrain and / or grid system 1000 also includes a capacitor 200 configured as a DC link capacitor. In the improvement shown, the first and second energy storage systems 510, 110 are equipped with optional filtering units 130 and 520 to improve functionality.

[0070] The powertrain and / or grid system 1000 includes an inverter controller 600 configured to control the inverter unit 300. The inverter controller 600 can be more generally described as a control circuit for the at least one phase load and / or phase grid 410. Therefore, the inverter controller 600 can be equipped with a device suitable for executing a control loop. The execution of the control loop may require sensing phase current measurements. These measurements can be performed by current measurement sensors 421. The execution of the control loop may require sensing and / or providing position signals when the phase load is applied to the system 1000, and / or sensing and / or providing phase signals when the phase grid is applied to the system 1000. The position measurement can be performed by a position sensor 422. In an alternative, the position signal can be provided by a position identification algorithm.

[0071] The powertrain and / or grid system 1000 includes a battery controller 700 configured to control the output voltage 511 of the first energy storage system 510. The battery controller 700 may be configured to monitor and / or measure output voltage measurements and current measurements of the second energy storage system 110. To perform the measurements, the battery controller 700 and / or the system 1000 may include energy storage system voltage and energy storage system current sensors 120.

[0072] according to Figure 3, a schematic block diagram of a control circuit improvement of an exemplary powertrain and / or grid system 1000 is shown. The control circuit improvement can be implemented in an inverter controller 600 as a control algorithm 601. The inverter controller 600 can be implemented in the inverter unit 300, or can be configured as a separate, preferably spaced and / or independent unit. The at least one phase load 410, such as an electric motor 411, can be controlled by means of an input voltage 301 provided by the inverter unit 300. For motor control, the control algorithm 601 can use a field-oriented control method. The control algorithm 601 can be configured as a control loop to control the respective motor current of each phase of the preferably three-phase load 410 of each phase with respect to at least one reference and / or demand value. Therefore, as shown in box 412, the phase current measurement value 611 of the at least one phase load 410 can be provided by measuring the phase current measurement value of the at least one phase load 410.

[0073] The control algorithm 601 may be configured to transform the phase current measurement values ​​611 preferably measured and / or provided from the abc reference frame to the dq reference frame by performing a dq transformation operation. The dq operation is indicated by a control box 610. In order to perform the dq transformation operation 610, preferably, at least one position signal 612 may be measured by a position sensor 422 and / or provided by a position identification algorithm already indicated above. As a result of the dq transformation operation, two dq transformation values ​​613 of the phase current measurement values ​​611 of the at least one phase load 410, particularly preferably the electric motor 411, are provided. The dq transformation values ​​613 are provided as dq transformation current values. The control algorithm 601 may further be configured to adjust the provided dq transformation values ​​613 based on at least one current demand value 614 of at least one phase load 410. The adjustment operation is indicated by a control box 620. The at least one current demand value 614 may be an accelerator pedal request value of an electric vehicle. As an output of the regulation operation 620, the control algorithm 601 may be provided and / or calculate a corresponding desired output voltage value 621 in the dq reference frame. The control algorithm 601 may be configured to transform the dq output voltage value 621 back to the abc reference frame by an inverse transformation operation indicated by box 630. The inverse transformation operation 630 may be performed based on at least one position signal 612, which is preferably provided as an input for the inverse transformation operation 630. The abc output voltage value is indicated by reference numeral 631. In the modulation operation, the abc output voltage value 631 may be further modulated based on at least one output voltage measurement 632 of the second energy storage system 110, as indicated by the control box 640. Of course, in alternative embodiments, such modulation may be performed based on other values ​​based on current, voltage, power, etc. Such a value may be a variable value or a fixed value. As an output of the modulation operation 640, a switching signal 641 for the inverter unit 300 may be provided. Based on these switching signals 641 , the inverter unit 300 is controlled, thereby controlling the electric motor 411 . The output voltage measurement value 632 of the second energy storage system 110 may be monitored by an energy storage management system 643 of the second energy storage system 110 .

[0074] The battery controller 700 is preferably configured to perform control of the first energy storage system 510. By controlling the output of the first energy storage system 510, the second energy storage system 110 is indirectly controlled. Therefore, through the battery controller 700, the control of the separate power supply of the first and second energy storage systems 510, 110 is performed. Therefore, the battery controller 700 may include at least one battery control algorithm 701, which may include at least one control loop for actively controlling the output voltage 511 of the first energy storage system 510 for controlling the reactive or active power flow from or into any one of the energy storage systems 510, 110. In an embodiment of the battery control algorithm 701, the battery control algorithm 701 may be configured to perform a dq transformation operation 710 for transforming the provided and / or measured phase voltage measurement values ​​711 into corresponding dq transformation values ​​712. The two dq transformation values ​​712 are provided as dq transformation voltage values. Preferably, the dq transformation operation 710 is performed based on the at least one position signal 612, so the at least one position signal can be provided as an input to the dq transformation operation 710. The transformed dq transformed value 712 of the phase voltage measurement value 711 can be used together with the provided dq transformed value 613 of the phase current measurement value 611, in particular the provided dq transformed value from the regulation operation 620, to calculate the reactive or active power flow demand value 721. In other words, the battery control algorithm 701 can be configured to calculate the at least one reactive or active power flow demand value 721 based on the two dq transformed values ​​712 of the phase voltage measurement value 711 and the two dq transformed values ​​613 of the phase current measurement value 611 of the at least one phase load and / or phase grid 410 by performing the calculation operation 720. The battery control algorithm 701 can be configured to perform a division operation 730 by dividing the reactive or active power flow demand value 721 by the provided output voltage measurement value 632 of the second energy storage unit 110. As an output of the division operation 730, a reactive or active power flow demand current value 731 of the second energy storage system 110 is provided. Through a further calculation operation 740, the battery control algorithm 701 can be configured to calculate a control output voltage value 741 of the first energy storage system 510 based on the active power flow demand current value 731 and the current measurement value 742 of the second energy storage system 110. The battery control algorithm 701 can be configured to modulate the control output voltage value 741 into at least one control signal 751 in a modulation operation 750. Based on these control signals 751, the output voltage 511 of the first energy storage system 510 can be controlled. The control signal 751 can be provided as a switching signal. It should be understood that blocks 710 and 720 can be replaced by any algorithm configured to calculate at least one reactive or active power flow demand value 721. The current measurement value 742 of the second energy storage system 110 can be monitored by the energy storage management system 643 of the second energy storage system 110.

[0075] according to Figure 4 , a schematic block diagram of an improvement in the control circuit of an exemplary powertrain and / or grid system 1000 is shown. In this control circuit improvement, the powertrain and / or grid system 1000 may be equipped with more than one phase load 410. In particular, the powertrain and / or grid system 1000 may include more than one electric motor 411 and corresponding inverter 300. In this configuration, the control circuits for controlling the energy storage systems 110, 510 may be combined. A plurality of reactive or active power flow demand values ​​721 of a plurality of phase loads and / or phase grids 410 are provided. The battery control algorithm 701 may be configured to sum these reactive or active power flow demand values ​​721 in a summation operation 800 provided before performing operations 730, 740, 750. Figure 4 is expanded by a summation operation 800. However, Figure 3 The remaining figure descriptions provided also apply to Figure 4 , so there is no need to repeat at this point.

[0076] It should be noted that in order to mitigate the reactive power flow in the second energy storage system 110, the output voltage of the first energy storage system 510 can be actively controlled. In this way, the reactive power flow can be absorbed by the first energy storage system 510. In principle, the second energy storage system 110 can be used to cover the active power of the phase load 410, while the reactive power is at least partially covered by the first energy storage system 510. In some configurations, the reactive power can also be at least partially covered by the DC link capacitor 200. Therefore, the battery control algorithm 701 can be configured to set the output voltage 511 of the first energy storage system 510 to actively control the active power flow from the second energy storage system 110, while the reactive power can be "naturally" exchanged from other sources of the DC link.

[0077] Alternatively, the current demand (discharge rate) can be controlled externally instead of using instantaneous power. In this way, the second energy storage system 110 can remain protected from regenerative power flow from braking or any other reactive power source, such as field weakening, etc. Thereby, load conditions and / or life can be improved.

[0078] Figure 5An exemplary improvement of the presented powertrain and / or grid system 1000 in a grid connection configuration is shown. The three-phase grid 410, 900 is at least temporarily connectable to the inverter unit 300 for performing charging operations of the first and / or second energy storage system 510, 110 and / or for performing grid support operations. The system 1000 includes a power controller 901, which is configured to control the inverter unit 300 based on an active power flow demand 902 and a reactive power flow demand 903. The system 1000 also includes a power measurement sensor 904 for measuring the at least one active power flow value 905 on the three-phase grid 410, 900. The battery controller 700 is configured to control the output voltage 511 of the first energy storage system 510 based on the active power flow demand 902 of the three-phase grid 410, 900 and / or based on the measured active power flow value 905 of the three-phase grid 410, 900.

[0079] Figure 6 A schematic modification of the first energy storage system 510 is shown. It is to be specifically mentioned that this is only one possible configuration. There are a number of other topologies of the first energy storage system 510 that can be used. In particular, Figure 6 Potential switching settings for the first energy storage system 510 are shown. The first energy storage system 510 exemplarily includes at least two switching devices 2500, each of which forms a module. Moreover, the first energy storage system 510 also includes at least two energy sources 2600, wherein at least one of the energy sources 2600 is included in each of the switching devices 2500. Each of the at least two energy sources 2600 includes at least one battery cell and / or at least one capacitor and / or at least one photovoltaic panel. The switching device 2500 is configured to selectively switch at least one energy source 2600 of each module in positive series, negative series or parallel connection relative to other energy sources 2600 at least temporarily to generate controllable alternating current or direct current at the output of the first energy storage system 510. The switching device 2500 exemplarily includes four switching elements 2800. In other topologies, a different number of switching elements 2800 may be used. Two corresponding switching elements 2800 are provided to each module string 2802, 2804 of the exemplary first energy storage system 510. Between each of the two switching elements 2800 of each string 2802, 2804, a respective further terminal connection 2806, 2808 is provided. The terminal connections 2806, 2808 may be used to modularly connect a plurality of switching devices 2500 and / or respective modules and / or respective first energy storage systems 510 together.

[0080] In an alternative refinement, the first energy storage system 510 may include a battery and a DC / DC converter configured to at least temporarily connect and / or disconnect the first energy storage system 510 in parallel with the second energy storage system 110. In this refinement, the DC / DC converter serves as a switching device.

[0081] Figure 7 A schematic flow chart of an improvement of the proposed method is shown. Step S1 includes providing at least one reactive or active power flow demand value 721 of at least one phase load and / or phase grid 410. Step S2 includes providing an output voltage measurement value 632 and a current measurement value 742 of the second energy storage system 110. Step S3 includes calculating a reactive or active power flow demand current value 731 of the second energy storage system 110 based on the at least one reactive or active power flow demand value 721 and the output voltage measurement value 632. Step S4 includes calculating a control output voltage value 741 of the first energy storage system 510 based on the reactive or active power flow demand current value 731 and the current measurement value 742 of the second energy storage system 110. Step S5 includes modulating the control output voltage value 741 into at least one control signal 751. Step S6 includes controlling the output voltage 511 of the first energy storage system 510 based on the at least one control signal 751. The method may be performed at least in part by a data processing device 3000 comprising means for performing the method. Reference numerals list 110 Second Energy Storage System 120 Energy storage system voltage and energy storage system current sensor 130 filter unit 300 Inverter Units 301 Input voltage 410-phase load and / or phase grid 411 Electric Motor 421 Current Measurement Sensor 422 Position Sensor 510 First Energy Storage System 511 Output voltage 520 filter unit 600 Inverter Controller 601 Control Algorithm 610d-q conversion operation 611 Phase current measurement value 612 Position signal 613d-q transformation value 614 Current demand value 620 Adjustment Operation 621d-q output voltage value 630 Inverse transformation operation 631a-bc output voltage value 632 Output voltage measurement value 640 Modulation Operation 641 Switching signal 643 Energy Storage Management System 700 Battery Controller 701 Battery Control Algorithm 710d-q conversion operation 711 phase voltage measurement value 712d-q transformation value 720 calculation operations 721 Reactive or active power flow demand value 730 Division operation 731 Reactive or active power flow demand current value 740 calculation operations 741 Control output voltage value 742 Current measurement value 750 modulation operations 751 Control signal 900 Three-phase power grid 901 Power Controller 902 Active power flow demand 903 Reactive power flow demand 904 Power Measurement Sensor 905 Active power flow value 1000 Power train and / or grid system 1500 Powertrain 2000 Electric Vehicles 2500 Switching Device 2600 Energy Source 2800 Switching elements 2802 module string 2804 module string 2806 Terminal Connection 2808 Terminal connection 3000 Data Processing Device

Claims

1. A method for actively controlling an output voltage (511) of a first energy storage system (510), the first energy storage system (510) being connected in parallel to a second energy storage system (110) for controlling reactive or active power flow from or into either of the energy storage systems (510, 110); The method comprises the following steps: Providing (S1) at least one reactive or active power flow demand value (721) of at least one phase load and / or phase grid (410); Providing (S2) an output voltage measurement value (632) and a current measurement value (742) of the second energy storage system (110); Calculating (S3) a reactive or active power flow demand current value (731) of the second energy storage system (110) based on the at least one reactive or active power flow demand value (721) and the output voltage measurement value (632); Calculating (S4) a control output voltage value (741) of the first energy storage system (510) based on the reactive or active power flow demand current value (731) of the second energy storage system (110) and the current measurement value (742); modulating (S5) the control output voltage value (741) into at least one control signal (751); and Based on the at least one control signal (751), the output voltage (511) of the first energy storage system (510) is controlled (S6).

2. The method according to claim 1, wherein: Providing the at least one reactive or active power flow demand value (721) comprises at least one of the following steps: Calculating the at least one reactive or active power flow demand value (721) based on the phase voltage measurements (711) and the phase current measurements (611) using a power calculation algorithm; and / or Calculating the at least one reactive or active power flow demand value (721) based on two dq transformed values ​​(712) of a phase voltage measurement value (711) and two dq transformed values ​​(613) of a phase current measurement value (611) of the at least one phase load and / or the phase power grid (410); and / or calculating and / or receiving the at least one reactive or active power flow demand value based on an accelerator input value provided by an accelerator of the vehicle (721); and / or Calculating and / or receiving at least one reactive or active power flow demand value (721) of the phase power grid (410) based on the active power flow demand and / or reactive power flow demand of the phase power grid (410); and / or The at least one reactive or active power flow demand value (721) on the phase grid and / or the at least one phase load (410) is measured.

3. The method according to claim 2, wherein: Calculating the at least one reactive or active power flow demand value (721) based on the two dq transformed values ​​(712) of the phase voltage measurement value (711) of the at least one phase load and / or the phase power grid (410) and the two dq transformed values ​​of the phase current measurement value (611) comprises: Providing at least one position signal (612) and / or phase signal of the at least one phase load and / or phase grid (410); Providing the phase voltage measurement value (711) of the at least one phase load and / or the phase power grid (410); transforming the phase voltage measurement value (711) into a dq system to provide the two dq transformed values ​​(712) of the phase voltage measurement value (711) of the at least one phase load and / or the phase grid (410); and The two dq transformed values ​​(613) of the phase current measurement value (611) of the at least one phase load and / or the phase grid (410) are provided by a control circuit of the at least one phase load and / or the phase grid (410).

4. The method according to claim 3, wherein: Providing the two dq transformed values ​​(613) of the phase current measurement value (611) of the at least one phase load and / or the phase network (410) by the control circuit of the at least one phase load and / or the phase network (410) comprises the following steps performed by the control circuit: Providing the at least one position signal (612) and / or phase signal of the at least one phase load and / or the phase grid (410) by measuring the at least one position signal (612) and / or phase signal using a position sensor (422) and / or a position identification algorithm; Providing the phase current measurement value (611) of the at least one phase load and / or the phase grid (410) by measuring the phase current measurement value (611) of the at least one phase load and / or the phase grid (410); and The phase current measurement value (611) is transformed into the dq system to provide the two dq transformed values ​​(613) of the phase current measurement value (611) of the at least one phase load and / or the phase grid (410).

5. A method according to any one of the preceding claims, wherein: Providing the output voltage measurement value (632) and the current measurement value (742) of the second energy storage system (110) includes: The output voltage measurement value (632) and the current measurement value (742) of the second energy storage system (110) are monitored by an energy storage management system (642) of the second energy storage system (110).

6. A method according to any one of the preceding claims, wherein: Control of the output voltage (511) of the first energy storage system (510) results in active control of the reactive or active power flow from or into the second energy storage system (110).

7. A method according to any one of the preceding claims, wherein: Providing at least one reactive or active power flow demand value (721) includes: Providing a plurality of reactive or active power flow demand values ​​(721) of a plurality of phase loads and / or the phase power grid (410); and The plurality of reactive or active power flow demand values ​​(721) of the plurality of phase loads and / or the phase power grid (410) are summed.

8. A power transmission system and / or power grid system (1000), comprising at least: A second energy storage system (110); A first energy storage system (510) connected in parallel to the second energy storage system (110); An inverter unit (300) connected in parallel to the first energy storage system (510) and the second energy storage system (110); as well as A battery controller (700) for actively controlling an output voltage (511) of the first energy storage system (510) for controlling reactive or active power flow from or into any one of the energy storage systems (510, 110); The battery controller (700) is configured to at least perform the following steps: Providing at least one reactive or active power flow demand value (721) of at least one phase load and / or phase grid (410); Providing an output voltage measurement value (632) and a current measurement value (742) of the second energy storage system (110); Calculating a reactive or active power flow demand current value (731) of the second energy storage system (110) based on the at least one reactive or active power flow demand value (721) and the output voltage measurement value (632); Calculating a control output voltage value (741) of the first energy storage system (510) based on the active power flow demand current value and the current measurement value (742) of the second energy storage system (110); modulating the control output voltage value (741) into at least one control signal (751); as well as The output voltage (511) of the first energy storage system (510) is controlled based on the at least one control signal (751).

9. The power transmission system and / or grid system according to claim 8, wherein: The first energy storage system (510) is configured to receive the reactive power flow to at least partially mitigate the reactive power flow to the second energy storage system (110).

10. The power transmission system and / or grid system according to claim 8 or 9, further comprising: The at least one phase load and / or the phase grid (410) is connected to the inverter unit (300); A current measurement sensor (421) for measuring a phase current measurement value (611) of the at least one phase load and / or the phase power grid (410); An energy storage system voltage and energy storage system current sensor (120) for measuring the output voltage measurement value (632) and the current measurement value (742) of the second energy storage system (110); at least one position sensor (422) and / or a position identification algorithm for measuring at least one position signal (612) and / or phase signal; as well as An inverter controller (600) is configured to control the inverter unit (300) based on the phase current measurement value (611), the position signal (612) and / or the phase signal, the output voltage measurement value (632) of the second energy storage system (110), and the current measurement value (742).

11. The power transmission system and / or grid system according to any one of claims 8 to 10, further comprising: A capacitor (200) connected in parallel to the first energy storage system (510), The capacitor (200) is configured to receive the reactive power flow to at least partially mitigate the reactive power flow to the second energy storage system (110).

12. The power transmission system and / or grid system according to any one of claims 8 to 11, further comprising: At least a first filtering unit (520), connected to the first energy storage system (510); and / or At least a second filtering unit (130) is connected to the second energy storage system (110).

13. The power transmission system and / or grid system according to claim 8 or 9, further comprising: A phase grid (410, 900) capable of being at least temporarily connected to the inverter unit (300) for performing a charging operation of the first and / or second energy storage system (510, 110) and / or for performing a grid support operation; A power controller (901) configured to control the inverter unit (300) based on an active power flow demand (902) and a reactive power flow demand (903); and / or a power measurement sensor (904) for measuring said at least one active power flow value (905) on said phase power grid (410, 900); and / or The battery controller (700) is configured to control the output voltage (511) of the first energy storage system (510) based on the active power flow demand (902) of the phase grid (410) and / or based on the measured active power flow value (905) of the phase grid (410, 900).

14. The method according to any one of claims 1 to 7 and / or the power train and / or the grid system according to any one of claims 8 to 13, wherein: The first energy storage system (510) includes at least one switching device (2500); wherein the first energy storage system (510) further comprises at least two energy sources (2600), and the switching device (2500) is configured to selectively switch the at least two energy sources (2600) at least temporarily in positive series, negative series or parallel connection relative to each other to generate controllable alternating current or direct current at the output of the first energy storage system (510), or The first energy storage system (510) includes a battery and a DC / DC converter, and the DC / DC converter is configured to at least temporarily connect and / or disconnect the first energy storage system (510) and the second energy storage system (110) in parallel.

15. The method and / or the power train and / or the grid system according to claim 14, wherein: The second energy storage system (110) comprises a battery; and / or wherein the second energy storage system (110) comprises a single energy storage unit or a plurality of energy storage units.

16. The method and / or power train and / or grid system according to claim 14, wherein: Each of the at least two energy sources (2600) comprises at least one battery cell and / or at least one capacitor and / or at least one photovoltaic panel and / or at least one fuel cell and / or at least one alternative electrical energy source.

17. The method according to any one of claims 1 to 7 and / or the power train and / or grid system according to any one of claims 8 to 13; in, The first energy storage system (510) comprises a high power density compared to the second energy storage system (110); and wherein the second energy storage system (110) comprises a high energy density compared to the first energy storage system (510), or wherein the first energy storage system (510) comprises a high energy density compared to the second energy storage system (110); and wherein the second energy storage system (110) comprises a high power density compared to the first energy storage system (510).

18. A data processing device (3000) comprising means for executing the method according to any one of claims 1 to 7 or 14 to 17.

19. An electric vehicle (2000) comprising a data processing device (3000), including means for executing the method according to any one of claims 1 to 7 or 14 to 17 and / or a powertrain and / or grid system (1000) according to any one of claims 8 to 17.

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