Stabilization of voltage and frequency at common connection points in industrial facilities

Abstract

The industrial facility (10) connected to a power transmission grid (14) comprises a power distribution grid (16) connected to the power transmission grid (14) at a point of common coupling (12), at least one load (20) connected to the power distribution grid (16) via at least one power electronics block (22), where each power electronics block (22) is adapted to convert a current from the power distribution grid (16) into a current supplied to a respective load (20), each power electronics block (22) comprising a load responder component (34) adapted to determine a load demand (50) of the respective load (20), and at least one compensator (30) connected to the power distribution grid (16), where each compensator (30) is , adapted to stabilize a frequency and / or a voltage of a current in the power distribution network (16), each compensator (30) comprising a compensator responder component (32) adapted to receive a stabilization command (56) and apply the stabilization command (56) to a respective compensator (30), and a power controller (36) in data communication with the one or more load responder components (34) and the one or more compensator responder components (32), wherein the power controller (36) is adapted to receive load demands (50) from the one or more load responder components (34), determine stabilization commands (56) from the load demands (50), and send the stabilization commands (56) to the one or more compensator responder components (32).

Description

Technical Field

[0001] The present invention relates to industrial facilities connected to a power grid. The present invention further relates to a method, a computer program, a computer-readable medium, and a controller for stabilizing the voltage and / or frequency at the common connection point of an industrial facility with the power grid.

Background Art

[0002] Variable energy source-based grids rely on power electronics, and when their contribution is high, such grids can be referred to as power electronics dominated grids (PEDG). These grids are characterized by the fact that the strength of the grid fluctuates, the inertia is low and fluctuates, and the short-circuit power is low. For example, due to the weather dependence of some variable energy sources, the power generation mix can constantly change.

[0003] The operation in these grids is susceptible to problems of steady state and transient stability. In particular, transient events on the grid side and the load side can have a profound impact due to rapid changes in active and reactive power, and can affect the system voltage and frequency.

[0004] In contrast to conventional grids, in PEDG, voltage and frequency can be closely coupled. This close coupling can amplify the impact of transient events and can lead to problems of voltage and frequency stability.

[0005] Transient events include load shedding of hydrogen production units, load shedding of electric arc furnaces, inrush currents in high-power converter transformers, arc-induced instability, symmetric and asymmetric faults on the load side, symmetric and asymmetric faults on the grid side, load limiting, etc. During the aforementioned transient events, including rapid changes in active and reactive power, the balance between supply and demand may be disrupted, which can lead to changes in voltage and frequency. In conventional robust grids, changes in power components do not affect system voltage and frequency. However, in PEDG, such scenarios can lead to widespread disturbances across industrial facilities and the grid. US 2008 / 278 000 A1 describes an internal grid connected to a load and a power source, which is connected to a larger grid. A universal connection device connecting the internal grid to the larger grid comprises a power quality compensator that absorbs or generates reactive power and an energy storage device that absorbs and generates active power. In this way, the universal connection device can stabilize the frequency and control the voltage within the internal grid. The paper "Modelling of Large Size Electrolyzer for Electrical Grid Stability Studies in Real Time Digital Simulation" by PKS Ayivor et al., 3rd International Hybrid Power Systems Workshop, 1 January 2018 (2018-01-01), pages 1-8, describes a method for simulating an electrolyzer to model the power input drawn from the electric grid. US 2014 / 103 727 A1 describes an island grid power supply with a controller adapted to communicate over fiber optic lines. US 6 274 851 B1 describes a controller for electric arc furnaces. US 2003 / 076 075 A1 describes a system for stabilizing the voltage of an electric arc furnace by controlling an adjustable reactance device to change the reactive power. EP 2 437 370 A2 describes an industrial controller adapted for target-based load management in industrial facilities with multiple loads. [Overview of the Initiative]

[0006] The object of the present invention is to provide a control system and control method that enables the operation of industrial facilities having strong and / or dynamically fluctuating loads in a weak grid, particularly a grid mainly supplied by power electronics blocks that power electric arc furnaces and renewable energy sources.

[0007] This objective is achieved by the subject matter of the independent claim. Further illustrative embodiments will become apparent from the dependent claims and the following description.

[0008] A first aspect of the present invention relates to an industrial facility connected to a power grid. The industrial facility may be equipped with electrical loads and / or be adapted to handle medium voltages such as voltages exceeding 6 kV and / or high currents such as voltages exceeding 100 A. The power-electrical system and / or power-electrical components of the industrial facility may be power electronics blocks such as power grids, inverters, rectifiers, and converters, passive and active filters, power loads, and power sources. Such power loads may be any electrical devices that consume power, such as motors, arc furnaces, etc. Such power sources may be any electrical devices that provide power, such as battery storage systems, fuel cells, etc.

[0009] The power grid may be supplied by renewable energy sources and / or fluctuating power sources.

[0010] According to embodiments of the present invention, an industrial facility comprises a distribution network connected to a power grid at a common junction. The distribution network may comprise one or more electrical cables for connecting the common junction to the power and electrical components of the industrial facility. The common junction may be a point where the industrial facility interfaces with a public network or an energy service provider. The common junction may be a high-voltage or medium-voltage bus or a substation.

[0011] A distribution grid can connect loads and power sources, as well as further power-electrical components, to a transmission grid. On the one hand, the voltage and / or frequency of power at common junctions can fluctuate due to instability in the transmission grid. On the other hand, the voltage and / or frequency of power at common junctions may fluctuate due to changes in the load demand of industrial facilities. Using the systems and methods described herein, the voltage and / or frequency at common junctions can be stabilized by following the control of components of the industrial facility. For example, this may be beneficial when the industrial facility includes a hydrogen-supplying ore pelletizing plant with or without an electric arc furnace. Without the controls and systems described herein, a weakly unstable grid can be destabilized by the operation of the pelletizing plant and / or arc furnace, particularly during transient events until the industrial facility or at least its components must be reduced or switched off for stability reasons.

[0012] According to embodiments of the present invention, an industrial facility comprises at least one load connected to a power grid via at least one power electronics block. The load may be any electrical device that consumes power. There may be one or more power electronics blocks for each load. Each power electronics block is adapted to convert current from the power grid into current supplied to its respective load. The power electronics blocks may be of the natural commutation or forced commutation converter type. They may also be of the direct or indirect converter type. For example, a power electronics block may be a rectifier, an inverter, or a converter. A power electronics block may comprise a power semiconductor switch, which may be controlled to provide the functions of the power electronics block.

[0013] According to embodiments of the present invention, each power electronics block comprises a load responder component adapted to meet and / or determine the load demands of its respective load. Generally, the load responder component may be part of the controller of the power electronics block. The load responder component may be a module such as a hardware or software module of the controller. The load responder determines the load demands of the load, such as the power needs of the load which may refer to active power and / or reactive power, as well as / or power quality issues such as harmonics, power factor, flicker, etc. This load demand may be sent via a data communication line to a central controller and / or power controller for further processing.

[0014] The load response component may determine further information, such as information about changes in the state of the load, indicating that the load will increase and / or decrease its power demand in the future. The load response component may also determine electrical measurement information, such as active power and reactive power, at the load input, etc.

[0015] Load response components can also receive power control information about the distribution network, such as that a load should reduce its power demand in the future. For example, an industrial facility may receive information that its power source may be disconnected from the grid, and therefore the industrial facility must reduce its power demand. Power control information can be received from a central controller and / or power controllers via a data communication line.

[0016] According to embodiments of the present invention, an industrial facility comprises at least one compensator connected to a power distribution network. Each compensator is adapted to stabilize the voltage and / or frequency in the power distribution network. The compensator may be any electrical device that stabilizes the voltage and / or frequency of the power distribution network, and therefore the power transmission network. Note that there may be loads that are also compensators, such as motors that can be operated as generators. The compensator may comprise a power supply, a filter, a reactor, etc.

[0017] Different compensators may respond to grid changes at different rates. Controllable electrical filters may respond more quickly to load changes compared to energy storage systems and / or mechanical compensators. Synchronous capacitors may provide faster inertial support compared to energy storage systems.

[0018] According to embodiments of the present invention, each compensator comprises a compensator responder component adapted to receive a stabilization command and apply the stabilization command to its respective compensator.

[0019] Generally, compensator-responder components may be part of the compensator controller. Compensator-responder components may be modules such as hardware or software modules of the controller.

[0020] Stabilization commands may be information relating to stabilizing voltage and / or frequency in a power distribution network. For example, they may include commands for increasing or decreasing voltage, or for providing active or reactive power support. Stabilization commands may be executed by each compensator via control of compensator-responder components. Stabilization commands may be received from a central controller and / or power controller via a data communication line.

[0021] The compensator-responder component can determine further information, such as information about changes in the state of a compensator, including whether a compensator, such as an energy storage unit, is depleted. The compensator-responder component can also determine electrical measurement information, such as active power and reactive power, at the compensator input, etc. The electrical measurement information can be sent via a data communication line to a central controller and / or power controller for further processing.

[0022] According to an embodiment of the present invention, an industrial facility includes a power controller that communicates with one or more load responder components and one or more compensator responder components. All data such as electrical measurement information, state change information, and / or load demand received from the responder components can be processed by the power controller to control the voltage and / or frequency in the distribution network. From the received data, the power controller determines stabilization commands and / or power control information and sends them to the respective responder components.

[0023] This can be done by adjusting the setpoints for the loads and compensators, i.e., the stabilization commands and / or power control information can include setpoints for the respective loads and / or compensators. The setpoints for normal operation can be communicated from the power controller to all load and compensator responders. The power controller also receives measurement values from the distribution network. The power controller maintains models of the distribution network, loads, and compensators. When the voltage and / or frequency of the distribution network deviates from predefined limits, the power controller adjusts the setpoints so that the voltage and / or frequency remains within these limits. For this purpose, measurement values and / or models can be used. According to an embodiment of the present invention, the power controller is adapted to receive load demand from one or more load responder components, determine a stabilization command from the load demand, and send the stabilization command to one or more compensator responder components.

[0024] Disturbances in the transmission network and industrial facility can cause sudden changes in the active and reactive power at the point of common coupling. This rapid variation can cause voltage and frequency fluctuations that affect the process stability of the transmission network and industrial facility. To compensate for this, the industrial facility includes a combination of controllable loads and compensators with their respective load responder components and compensator responder components, which are adjusted by the power controller. This configuration performs a power balancing response by injecting and / or absorbing and / or providing inertial power to maintain the voltage and frequency within acceptable limits.

[0025] Inertial power may be related to the frequency and the active power. For example, when there is a disturbance such as loading shedding in a low-inertia system, it can instantaneously affect the frequency due to the mismatch of the active power. In a conventional grid, synchronous machines can provide automatic inertial support due to the kinetic energy stored in their rotors. This prevents an instantaneous drop in the frequency. In a power distribution network that relies on power electronics, inertial support provided by synchronous machines may be lacking. In this case, inertial support from the load side can prevent an instantaneous rise or fall in the frequency caused by a disturbance. Since synchronous condensers are directly connected to the power distribution network, they can provide automatic inertial support. As a further means, other elements, such as hydrogen generation units, can be increased or decreased to provide frequency support by varying their active power consumption. The first response can be made via a synchronous condenser, and the next response can be made via a hydrogen generation unit, whereby their active power consumption is regulated.

[0026] According to an embodiment of the present invention, the power controller is connected to one or more load responder components and one or more compensator responder components via a data communication line adapted to transmit data packages within less than 25 μs. Such a data communication line may be referred to as a high-speed data communication line or a high-speed data communication line. The data communication can be as fast as the control system including the power controller and the responder components is adapted to react to changes in voltage and / or frequency so that direct control of the instantaneous voltage in the power distribution network is possible. In other words, the data communication can be fast enough to achieve a reaction faster than the period of the voltage in the power distribution network. In this way, the power controller can adjust the individual load responder components and compensator responder components by a high-speed point-to-point connection.

[0027] According to embodiments of the present invention, the power controller is connected to one or more load responder components and one or more compensator responder components via an optical fiber data communication line. The optical fiber line, which may be made of glass, is adapted to provide high-speed data communication as described above.

[0028] According to embodiments of the present invention, one of the at least one compensators is a controlled electrical compensator comprising at least one of a resistor, an inductor, and a capacitor. An example of such a controlled compensator that provides an active power compensator is a static power compensator.

[0029] In general, controlled compensators for reactive power include synchronous capacitors, static reactive power compensators, self-excited static reactive power compensators, instantaneous voltage drop compensators, integrated power flow controllers, transmission line power flow controllers, etc.

[0030] According to embodiments of the present invention, at least one of the compensators is a controlled mechanical compensator comprising a rotational inertia element, such as a heavy drum, driven by an electric motor / generator with or without a converter and / or power electronics block for controlling the flow of energy from the power grid to the drum and the reverse flow of energy. Such a device may be a synchronous capacitor with or without a flywheel and / or may provide rotational inertia.

[0031] According to embodiments of the present invention, at least one of the compensators is a controlled energy storage system, such as a fuel cell, battery bank, and / or capacitor bank connected to a hydrogen tank. The energy storage system may also include converters and / or power electronics blocks for controlling the flow of energy from the power grid to the energy storage element and the reverse flow of energy.

[0032] According to embodiments of the present invention, each of one or more power electronics blocks comprises at least one of a rectifier and an inverter. Generally, a power electronics block may consist of power electronics components such as diodes, thyristors, and transistors, which are controlled by their respective controllers. The controller may provide the response components.

[0033] According to embodiments of the present invention, at least one of the loads is an arc furnace. The arc furnace can generate significant disturbances in the power grid, which can be compensated for by a control system such as those described herein.

[0034] According to embodiments of the present invention, at least one of the loads comprises an electrolytic cell bank and / or a fuel cell. The electrolytic cell bank may be used to convert electrical energy into chemical energy stored in a hydrogen tank. The hydrogen can be converted back into electrical energy by the fuel cell. Such a load may also be considered a compensator.

[0035] According to embodiments of the present invention, the industrial facility may also be equipped with a hydrogen-supplied ore pelletizing plant, which is supplied with hydrogen from a hydrogen tank. In this way, an energy surplus from the power grid can be compensated by generating hydrogen, which can then be used to supply the ore pelletizing plant or to generate electricity via a fuel cell.

[0036] According to embodiments of the present invention, the industrial facility further comprises an automation controller adapted to control loads. The automation controller may be a PLC controller (programmable logic controller). The automation controller may be used to coordinate process requirements with components such as loads that control the processes of the industrial facility. The automation controller functions as a superimposed controller. The automation controller typically includes and / or determines process information such as setpoints, which are used to maintain the process and to perform emergency actions related to the process via the control components.

[0037] The automation controller communicates with the power controller, for example, via a data communication line, using slower data communication than the data communication between the power controller and the transponder components. For example, the automation controller may be connected to the power controller via a fieldbus. In this way, the power controller collaborates with the automation controller and utilities to provide steady-state support.

[0038] According to embodiments of the present invention, the industrial facility further comprises a utility interface for receiving external data provided to the industrial facility. The utility interface may also communicate with a power controller. The utility interface may be used to receive information about the power grid, such as the connection of power to and disconnection of power from the power grid. Such information may also be used to adjust loads and compensators.

[0039] A further aspect of the present invention relates to a method for stabilizing voltage and / or frequency at common connection points with a power grid for industrial facilities. This method can be performed by a power controller together with a transponder component, and / or more generally by a compensator and load controller.

[0040] According to embodiments of the present invention, the method comprises receiving load demand from one or more load responder components. Load demand may be received via a data communication line connecting the power controller to the load. Load demand may include information about the power beads of each load.

[0041] According to embodiments of the present invention, the method comprises receiving state change information from one or more load responder components and / or one or more compensators. Load demand may be received via a data communication line connecting the power controller to the load and compensators. The state change information may describe, for example, that the corresponding load will increase and / or decrease its power demand in the future, and / or that the corresponding compensator, such as an energy storage unit, is depleted.

[0042] According to embodiments of the present invention, the method comprises receiving electrical measurement information from one or more load response components and / or one or more compensators. The electrical measurement information may be received via a data communication line connecting the power controller to the load and compensators. The electrical measurement information may include voltage, current, active power, reactive power, etc., measured by each response component, and / or voltage, current, active power, reactive power, etc., derived from such measurements by each response component.

[0043] According to embodiments of the present invention, the method comprises determining stabilization commands and / or power control information from load demand, state change information, and / or electrical measurement information using a power controller.

[0044] Generally, the purpose of a power controller is to maintain voltages and frequencies within the distribution network and / or common junctions within permissible limits. These permissible limits may be set by the power controller.

[0045] The power controller may determine the compensation and / or response of the load and compensator to achieve this objective. Depending on the required compensation, such as encoded in the load demand, and based on the available reserve, such as encoded in state change information from the compensator, setpoints may be determined to provide, for example, frequency support, active power, and / or reactive power compensation. Stabilization commands and / or power control information may include such setpoints. If it is not possible to fully compensate the load demand of the load, power control information may be determined, which may, for example, notify the load to reduce its power consumption.

[0046] According to embodiments of the present invention, the method comprises sending a stabilization command to one or more compensator-responder components and / or sending power control information to one or more load-responder components. This information may be sent via a high-speed data communication line as described above.

[0047] According to embodiments of the present invention, the method comprises controlling loads and / or compensators based on stabilization commands and / or power control information. Such control may be performed by controllers of each load and / or compensator.

[0048] Voltage and frequency can be considered key parameters of the control methods performed by the power controller. The reliable operation of industrial facilities depends on their magnitudes remaining within acceptable limits. During disturbances from the power grid or one or more loads, particularly in power grids with low short-circuit power and low inertia, these values ​​may exceed acceptable limits due to changes in active and reactive power. This can affect one or more loads and lead to instability in the power grid and / or industrial facilities, for example, resulting from protection-related trips. During these critical situations, fast, controlled compensation of active and reactive power is provided by methods to ensure system stability. This control method compensates for changes in power components and prevents voltage and frequency changes from exceeding acceptable limits. This enables process continuity. In particular, load responders such as hydrogen production units, including electrolytic cell banks and storage units and high-power fuel cells, as well as compensators such as battery storage systems, can be used for controlled compensation of active and reactive power.

[0049] Further aspects of the present invention relate to a computer program adapted to perform the methods described above and below when executed by a processor, and a computer-readable medium in which such a computer program is stored.

[0050] For example, the method may be implemented by a control system of an industrial facility, the control system may consist of one or more controllers, each controller comprising memory and a processor. Such a controller may comprise a power controller, a load responder component, and / or a compensator responder component, all of which may be the controller of the industrial facility, or at least part of or a module of the controller.

[0051] Computer-readable media can be hard disks, USB (Universal Serial Bus) storage devices, RAM (Random Access Memory), ROM (Read-Only Memory), EPROM (Erasable Programmable Read-Only Memory), or flash memory. Computer-readable media can also be data communication networks that enable the download of program code, such as the Internet. Generally, computer-readable media can be non-temporary or temporary media.

[0052] Further aspects of the present invention relate to a power controller adapted to perform the methods described above and below. The power controller may consist of one or more controller components, and / or comprises them. Each controller component may include memory and a processor. Some or all of the power components may be provided by a module of the industrial facility's controller. The controller components of the power controller may be interconnected by high-speed data communication lines and / or fiber optic-based data communication lines.

[0053] It should be understood that the characteristics of power controllers described above and below may be the same as the characteristics of industrial facilities, methods, computer programs, and computer-readable media described above and below, and vice versa.

[0054] These and other aspects of the present invention will become apparent from and be illustrated by the embodiments described below.

[0055] The subject matter of the present invention will be described in more detail below with reference to the illustrative embodiments shown in the accompanying figures. [Brief explanation of the drawing]

[0056] [Figure 1] An industrial facility according to an embodiment of the present invention is schematically shown. [Figure 2]This diagram shows a flowchart for a method to stabilize voltage and / or frequency at common junctions in industrial facilities. [Modes for carrying out the invention]

[0057] The reference symbols used in the figures and their meanings are listed in a summary format in the reference symbol list. As a general rule, identical parts are given the same reference symbols in the figures.

[0058] Figure 1 shows an industrial facility 10 connected to a power grid 14 via a common connection point 12. The power grid 14 may be a power grid supplied by renewable energy sources and / or fluctuating power sources.

[0059] The industrial facility 10 includes a distribution network 16 consisting of transmission lines 18. The distribution network 16 is connected to the transmission network 14 at a common junction 12. The distribution network 16 may include one or more transmission lines 18, such as electrical cables, for connecting the common junction 12 to the power and electrical components of the industrial facility 10. The connection may be via switchgear or circuit breakers to the busbars of the distribution network 16.

[0060] The industrial facility 10 further comprises loads 20, 20a, and 20b connected to the power distribution network 16 via a power electronics block 22. Generally, the loads can be any electrical devices that consume power. Load 20a is an arc furnace. The arc furnace 20a may generate large disturbances in the power distribution network 16, which can be compensated by methods and control systems as described herein.

[0061] Load 20b comprises an electrolytic cell bank and / or fuel cell connected to a hydrogen tank 26 via pipeline 24. The electrolytic cell bank may be used to convert electrical energy into chemical energy stored in the hydrogen tank 26. The chemical energy of hydrogen can be converted back into electrical energy by the fuel cell.

[0062] The industrial facility 10 may also include, for example, a hydrogen supply ore pelletizing plant 28 that is supplied by hydrogen from a hydrogen tank 26 via a further pipeline 24.

[0063] Each power electronics block 22 is connected to its respective load 20 via a transmission line 18. Each power electronics block 22 is adapted to convert current from the distribution network 16 into current supplied to its respective load 20. The power electronics block 22 may include rectifiers, inverters, and / or converters. Generally, the power electronics block 22 may consist of power electronics components such as diodes, thyristors, and transistors, controlled by their respective controllers. The power electronics block 22 may include power semiconductor switches that can be controlled to provide the functions of the power electronics block 22.

[0064] Furthermore, the industrial facility 10 includes compensators 30 connected to the power distribution network 16. Each compensator 30 is adapted to stabilize the voltage and / or frequency in the power distribution network 16. Generally, the compensators 30 can be any electrical device that stabilizes the voltage and / or frequency of the power distribution network 16, and therefore the power transmission network 14. Note that there may be loads 20, such as load 20b, which can also be considered compensators 30.

[0065] The compensator 30a is a controlled energy storage system such as a capacitor bank or battery bank. The energy storage system 30a may also include converters and / or power electronics blocks for controlling the flow of energy from the power grid 16 to the energy storage elements and the reverse energy flow.

[0066] Compensator 30b is a controlled mechanical compensator comprising a rotational inertia element, such as a heavy drum driven by an electric motor / generator, together with a converter and / or power electronics block, for controlling the flow of energy from the distribution network 16 to the drum and the reverse energy flow. Compensator 30b may also be a synchronous capacitor with or without a flywheel and / or may provide rotational inertia.

[0067] Compensator 30c is a controlled electrical compensator comprising at least one of a resistor, an inductor, and a capacitor. An example of such a controlled compensator 30c that provides an active power compensator is a static watt compensator.

[0068] Generally, the controlled compensator 30 for reactive power includes a synchronous capacitor, a static bar compensator, a static synchronous compensator, a dynamic voltage restorer, an integrated power flow controller, a line-to-line power flow controller, and the like.

[0069] Each of the power electronics block 22 and the compensator 30 comprises a transponder component 32, 34. The transponder components 32, 34 may be part of the controller of the respective power electronics block 22 or the respective compensator 30. The transponder components 32, 34 may be modules such as hardware or software modules of such a controller. The compensator 30 has a compensator transponder component 32. The power electronics block 22 has a load transponder component 34.

[0070] The transponder components 32 and 34 communicate data with the power controller 36 of the industrial facility 10. The power controller 36 is responsible for controlling the active and reactive power supplied to the distribution network 16 by the load 20 and the compensator 30, and / or keeping the voltage and frequency of the distribution network 16 within limits.

[0071] The power controller 36 is connected to the transponders 32 and 34 via a data communication line 38 adapted to transmit data packages within 25 μs. For example, the protocol used could be a power link. The data communication line 38 could be an optical fiber data communication line. In this way, data communication may also not be disturbed by electromagnetic fields generated in the industrial facility by power electronics blocks 22, etc.

[0072] The industrial facility 10 further includes an automation controller 40 adapted to control the processes performed by the load 20. The automation controller 40 communicates with the power controller 36 via a data communication line 42, using slower data communication than data communication via the communication line 38. For example, the automation controller 40 may be connected to the power controller 36 via a fieldbus.

[0073] Furthermore, the industrial facility 10 is equipped with a utility interface 44 for receiving external data provided to the industrial facility 10. The utility interface 44 also communicates with the power controller 36. This data communication may be carried out via the data communication line 38 as described above. The utility interface 44 may be used to receive information about the power grid, such as the connection of power to and disconnection of power from the power grid. Such information may also be used by the power controller 36 to adjust the load 20 and compensator 30. The utility interface 44 may also communicate with the automation controller 40, which may be done via the data communication line 42, for example, via a fieldbus, as described above.

[0074] Figure 2 shows a flowchart of a method for stabilizing the voltage and / or frequency at the common connection point 12 between the industrial facility 10 and the power grid 14. This method is performed by the power controller 36 together with the transponder components 32, 34, and / or more generally by the controllers of the load 20 and the compensator 30.

[0075] In step S10, the load demand 50 is received from the load responder component 34. The load demand 50 may include information about the power needs of each load 20.

[0076] In step S12, state change information 52 is received from the load responder component 34 and / or the compensator responder component 32. The state change information 52 may describe, for example, that the corresponding load 20 will increase and / or decrease its power demand in the future, and / or trip due to protection-related reasons, and / or that the corresponding compensator 30, such as an energy storage unit, is depleted.

[0077] In step S14, electrical measurement information 54 is received from the load responder component 34 and / or the compensator responder component 32. The electrical measurement information 54 may include voltage, current, active power, reactive power, etc., measured by each responder component, and / or voltage, current, active power, reactive power, etc., derived from such measurements by each responder component 32, 34.

[0078] The load demand 50, state change information 52, and electrical measurement information 54 are transmitted to the power controller 36 via the data communication line 38.

[0079] In step S16, the power controller 36 determines a stabilization command 56 and / or power control information 58 from the load demand 50, state change information 52, and / or electrical measurement information 54. Generally, the purpose of the power controller 36 is to maintain the voltage and frequency within the distribution network 16 and / or common junction 12 within permissible limits. These permissible limits may be set by the power controller 36.

[0080] The power controller 36 determines the compensation and / or response of the load 20 and the compensator 30 to achieve this objective. Depending on the required compensation, such as encoded in the load demand 50, and based on the available reserve, such as encoded in the state change information 52 from the compensator 30, setpoints may be determined to provide, for example, inertial response, active power and / or reactive power compensation. The inertial response from the synchronous capacitor may be automatic due to its rotational mass. The inertial response from other compensators, such as an electrolytic cell or battery storage system, may have to be controlled by setpoints. Stabilization commands 56 and / or power control information 58 may include such setpoints. If it is not possible to fully compensate the load demand 50 of the load 20, power control information 58 may be determined, which notifies the load 20 to reduce its power consumption.

[0081] The stabilization command 56 may be information relating to stabilizing the voltage and / or frequency in the power distribution network 16. For example, it may include commands for increasing or decreasing the voltage, or for providing active or reactive power support. The stabilization command 56 may be executed by each compensator 30 via the control of the compensator-responder component 32. In step S18, the power controller 36 sends the stabilization command 56 to the compensator-responder component 32 and power control information 58 to the load-responder component 34. This information is sent via the data communication line 38.

[0082] In step S20, the compensator responder component 32 applies stabilization commands 56 to each compensator 30. The load responder component 34 applies power control information 58 to the power electronics block 22 and the load 20.

[0083] The power electronics block 22, the load 20, and / or the compensator 30 are controlled based on stabilization commands 56 and / or power control information 58. Such control may be performed by controllers for each load and / or compensator.

[0084] During normal operation, the automated controller 40 can communicate setpoints to individual load responder components 34 via the power controller 36. Based on information exchange with load and responder components 32, 34, and information about the distribution network 16 from measurements, the power controller 36 further adjusts the setpoints and / or transmits the setpoints to the load and responder components 32, 34 in order to maintain voltage and frequency in the distribution network 16 within acceptable limits. The automated controller 40 can also provide the power controller 36 with information regarding load forecasts or weather-dependent power generation forecasts, which can be used to further adjust the setpoints for the load 20 and compensator 30.

[0085] In the event of unforeseen circumstances, such as during load limiting, the utility interface 44 may communicate directly with the power controller 36, which may control the load 20 by overriding setpoints from the automation controller 40 and / or send setpoints directly to the load and responder components 32, 34. In another example, when there is a load interruption due to process or electrical system-related reasons, the power controller 36 may receive this information from the respective load responder components 34 or interpret it based on direct measurements.

[0086] Based on available information, the power controller 36 may send a stabilization command 56 to the compensator responder component 32, taking into account the amount of compensation required to maintain voltage and frequency. When the compensation reserve is reached, the power controller 36 sends power control information 58 to loads 20, such as hydrogen units, to increase or decrease their production or to receive support from a battery storage system. This combined operation allows the power controller 36 to keep voltage and frequency within acceptable limits to enable process continuity. In a further example, in the event of a grid failure, the power controller 36 may initiate voltage support to the distribution network 16 by changing the setpoints for the compensator 30 and loads 20.

[0087] In this way, voltage and frequency stability at the common coupling point 12 can be achieved by using a controlled load 20 and a compensator 30. Depending on the scenario, i.e., voltage or frequency support or both, this combination provides inertial response, reactive power support and / or active power support. Inertial support can be automatically provided by a synchronous capacitor combined with a flywheel. Controlled inertial support can be provided by using a hydrogen generation unit and / or a battery storage system.

[0088] Although the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or illustrative and not limiting, and the present invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments can be understood and achieved by those skilled in the art in carrying out the claimed invention from a consideration of the drawings, disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude plurals. A single processor or controller or other unit may perform the functions of several items described in the claims. The mere fact that certain means are described in different dependent claims does not imply that combinations of these means cannot be used advantageously. No reference numeral in the claims should be construed as limiting the scope. [Explanation of Symbols]

[0089] 10 Industrial Facilities 12 Common connection point 14 Power grid 16 Power distribution network 18 Power transmission lines 20 load 20a AC or DC arc furnace 20b Electrolytic cell bank and / or fuel cell 22 Power Electronics Block 24 pipelines 26 Hydrogen tanks 28. Ore pelletizing plant 30 Compensator 30a Energy Storage System 30b mechanical compensator 30c electrical compensator 32 Compensator-responder components 34 Load Response Components 36 Power Controller 38. Data communication lines 40 Automation Controllers 42 Data communication lines 44 Utility Interfaces 50 load demand 52 Status Change Information 54 Electrical Measurement Information 56 Stabilization Commands 58 Power control information The following is a direct reproduction of the claims as originally filed. [1] An industrial facility (10) connected to a power grid (14), wherein the industrial facility (10) is At the common connection point (12), the distribution network (16) is connected to the transmission network (14), At least one load (20) connected to the distribution network (16) via at least one power electronics block (22), wherein each power electronics block (22) is adapted to convert current from the distribution network (16) into current supplied to each load (20), and each power electronics block (22) comprises a load responder component (34) adapted to determine the load demand (50) of each load (20), At least one compensator (30) connected to the distribution network (16), wherein each compensator (30) is adapted to stabilize the frequency and / or voltage of the current in the distribution network (16), and each compensator (30) comprises a compensator responder component (32) adapted to receive a stabilization command (56) and to apply the stabilization command (56) to the respective compensator (30), A power controller (36) that communicates data with one or more load response components (34) and one or more compensator response components (32), wherein the power controller (36) is configured to receive load demand (50) from one or more load response components (34), determine a stabilization command (56) from the load demand (50), and send the stabilization command (56) to one or more compensator response components (32). Industrial facilities (10) equipped with the following. [2] The power controller (36) is connected to one or more of the load responder components (34) and one or more of the compensator responder components (32) via a data communication line (38) adapted to transmit data packages within 25 μs, in the industrial facility (10) described in [1]. [3] The power controller (36) is connected via an optical fiber data communication line (38) to one or more load responder components (34) and one or more compensator responder components (32) in the industrial facility (10) as described in [1] or [2]. [4] An industrial facility (10) according to any one of the [1] to [3], wherein at least one of the compensators (30) is a controlled electrical compensator (30c) comprising at least one of a resistor, an inductor, and a capacitor. [5] An industrial facility (10) according to any one of the compensators (30) is a controlled mechanical compensator (30b) having a rotational inertia element, as described in any one of [1] to [4]. [6] At least one of the compensators (30) is a controlled energy storage system (30a) in the industrial facility (10) described in any one of [1] to [5]. [7] The power electronics block (22) comprises at least one of a rectifier and an inverter, as described in any one of [1] to [6], the industrial facility (10). [8] An industrial facility (10) according to any one of the loads (20a) of which at least one is an arc furnace. [9] An industrial facility (10) according to any one of the loads (20b) wherein at least one of the loads (20b) comprises an electrolytic cell bank and / or a fuel cell.

[10] The industrial facility (10) according to any one of [1] to [9], further comprising an automation controller (40) adapted to control the load (20), wherein the automation controller (40) communicates data with the power controller (36).

[11] The industrial facility (10) according to any one of [1] to

[10] , further comprising a utility interface (44) for receiving external data provided to the industrial facility (10), wherein the utility interface (44) communicates data with the power controller (36).

[12] A method for stabilizing voltage and / or frequency at a common connection point (12) between an industrial facility (10) described in any one of items [1] to

[11] and a power grid (14), wherein the method is: The power controller (36) is used to receive load demand (50) from one or more load response components (34), The power controller (36) is used to determine a stabilization command (56) from the load demand (50), A method comprising sending the stabilization command (56) to one or more of the compensator responder components (32).

[13] A computer program which, when executed by a processor, is adapted to perform the method described in

[12] .

[14]

[13] A computer-readable medium on which the computer programs described in

[13] are stored. A power controller (36) adapted to perform the method described in

[15]

[12] .

Claims

1. An industrial facility (10) connected to a power transmission network (14), wherein the industrial facility (10) is At the common connection point (12), the distribution network (16) is connected to the transmission network (14), At least one power electronics block (22) and At least one load (20) connected to the distribution network (16) via at least one of the power electronics blocks (22), wherein each power electronics block (22) is adapted to convert current from the distribution network (16) into current supplied to each load (20), and each power electronics block (22) comprises a load responder component (34) adapted to determine the load demand (50) of each load (20), At least one compensator (30) connected to the distribution network (16), wherein each compensator (30) is adapted to stabilize the frequency and / or voltage of the current in the distribution network (16), and each compensator (30) comprises a compensator responder component (32) adapted to receive a stabilization command (56) and to apply the stabilization command (56) to the respective compensator (30), A power controller (36) that communicates data with one or more load responder components (34) and one or more compensator responder components (32), wherein the power controller (36) is configured to receive load demand (50) from one or more load responder components (34), determine a stabilization command (56) from the load demand (50), and send the stabilization command (56) to one or more compensator responder components (32), and the power controller (36) is connected to one or more load responder components (34) and one or more compensator responder components (32) via an optical fiber data communication line (38). An automated controller (40) adapted to control the load (20), wherein the automated controller (40) communicates with the power controller (36) via a data communication line (42) at a slower rate than the data communication between the power controller (36) and the compensator-responder component (32). Industrial facilities (10) equipped with the following:

2. The industrial facility (10) according to claim 1, wherein the power controller (36) is connected to one or more of the load responder components (34) and one or more of the compensator responder components (32) via a data communication line (38) adapted to transmit data packages within 25 μs.

3. The industrial facility (10) according to claim 1 or 2, wherein at least one of the compensators (30) is a controlled electrical compensator (30c) comprising at least one of a resistor, an inductor, and a capacitor.

4. The industrial facility (10) according to claim 1 or 2, wherein at least one of the compensators (30) is a controlled mechanical compensator (30b) having a rotational inertia element.

5. The industrial facility (10) according to claim 1 or 2, wherein at least one of the compensators (30) is a controlled energy storage system (30a).

6. The industrial facility (10) according to claim 1 or 2, wherein the power electronics block (22) comprises at least one of a rectifier and an inverter.

7. The industrial facility (10) according to claim 1 or 2, wherein at least one of the loads (20a) is an arc furnace.

8. The industrial facility (10) according to claim 1 or 2, wherein at least one of the loads (20b) comprises an electrolytic cell bank and / or a fuel cell.

9. The industrial facility (10) according to claim 1 or 2, further comprising a utility interface (44) for receiving external data provided to the industrial facility (10), wherein the utility interface (44) communicates data with the power controller (36).

10. A method for stabilizing voltage and / or frequency at a common connection point (12) between an industrial facility (10) and a power grid (14) according to claim 1 or 2, wherein the method is: The power controller (36) is used to receive load demand (50) from one or more load response components (34), The power controller (36) is used to determine a stabilization command (56) from the load demand (50), A method comprising sending the stabilization command (56) to one or more of the compensator responder components (32).

11. A computer program, which, when executed by a processor, is adapted to perform the method described in claim 10.

12. A computer-readable medium storing the computer program described in claim 11.

13. A power controller (36) adapted to perform the method described in claim 10.

Images