Interlock for energy storage electrical protection device

Abstract

The present application relates to a method of controlling a protection circuit for providing power system support of an energy storage module (ESM) connected to an energy storage system (ESS), the energy storage module (ESM) having a positive terminal and a negative terminal, wherein two or more protection devices (pd1, pd2) of the protection circuit are arranged to be activated to establish two or more respective discharge paths between the positive terminal and the negative terminal, the method comprising: measuring (S01) an operating value of the energy storage module (ESM), and activating (S11) a first protection device (pd1) of the two or more protection devices if the measured operating value deviates from a predefined nominal operating value or nominal operating range; determining (S20) whether a predefined condition is fulfilled to activate a second protection device (pd2) of the two or more protection devices to further discharge the energy storage module (ESM), wherein the predefined condition comprises that the measured operating value is equal to or exceeds or falls below a first threshold value, and if the predefined condition is fulfilled, activating (S21) the second protection device (pd2). A control unit, a protection device and an energy storage system are also disclosed.

Description

Technical Field

[0001] This application relates to the field of power system support, and more specifically to a method for controlling a protection circuit of an energy storage module connected to an energy storage system, a protection circuit, a control unit, and an energy storage system. Background Technology

[0002] Flexible AC transmission system (FACTS) devices are typically static power electronic devices that can be installed in energy storage systems and AC transmission networks. Through series and / or shunt compensation, they can improve, for example, the network's power transmission capacity, stability, and controllability.

[0003] Energy storage systems for grid applications span a wide range of power demands, from a few MW to hundreds of MW. The higher MW range means that the storage unit contains a large number of energy storage modules, constructed in different topologies. These topologies can be rack-based / cabinet-based for various reasons, such as transportation and testing. One of these racks can store large amounts of energy (MJ range) and deliver large amounts of power (MW range), which can pose a risk to the equipment itself, nearby equipment, or people during low-impedance discharge events. When such a discharge event occurs, the forces and heat generated can be quite dangerous and can result from, for example, external short circuits or failures or malfunctions of switching equipment connected to the energy storage modules.

[0004] In view of the above, there is a need for power system support that can increase the stability of the power system. Summary of the Invention

[0005] The purpose of this disclosure is to provide an improved solution that mitigates the aforementioned drawbacks of existing solutions. Furthermore, a first objective of this disclosure is to provide a method for controlling a protection circuit connected to an energy storage module (such as the energy storage module of an energy storage system). This first objective is achieved by the method as claimed in claim 1. A second objective of this disclosure is to provide a control unit including means for performing the method. This second objective is achieved by the invention as claimed in claim 13. A third objective of this disclosure is to provide a protection circuit configured to be connected to an energy storage module. A fourth objective of this disclosure is to provide an energy storage system. This fourth objective is achieved by the energy storage system as claimed in claim 14. Additional advantages are achieved through the preferred embodiments listed in the claims and the embodiments listed below.

[0006] This invention is based on the inventor's understanding that in a circuit containing an energy storage module with positive and negative terminals, two or more protection devices are arranged to be activated to establish two or more corresponding discharge paths between the positive and negative terminals. The activation sequence of the first and second protection devices is critical for preventing short circuits, and this sequence can be ensured by interlocking the two or more protection devices so that they are activated sequentially. This typically solves several problems of the prior art, such as i) the situation where the activation timing sequence of the two or more protection devices is disordered, and ii) the situation where protection devices malfunction and cannot be activated. For example, activation timing is important when the activation sequence of the protection devices is critical, such as when the first protection device is arranged to provide a high-resistance discharge path and the second protection device is arranged to provide a low-resistance discharge path. When the energy storage module is charged to its nominal operating level, and if the second protection device is activated before the first protection device is activated, the energy of the energy storage module is discharged via a low-resistance discharge path. This may effectively cause a short circuit depending on the charge of the energy storage module. The short circuit may negatively affect the performance of the energy storage module and / or the protection circuit and / or any other electronic circuit connected to it.

[0007] Furthermore, this invention is based on the inventors' understanding that two or more protection devices can be interlocked by means of hardware interlocking and / or software interlocking. Hardware interlocking can, for example, prevent the physical activation of a subsequent protection device before the preceding protection device has been activated. Software interlocking can, for example, allow the subsequent protection device to be activated only in response to a control signal based on a measurement result of the operating value of the energy storage module and / or in response to verification that one or more predefined conditions (e.g., regarding the preceding protection device) are met.

[0008] The present invention generally allows for more robust controllability of protection circuitry to prevent unintended short circuits. Furthermore, it provides safer operation of the energy storage module. Additionally, it reduces the risk of predicted and / or unpredictable failures of the energy storage module and / or protection circuitry. It also reduces equipment risk near the affected energy storage module. Furthermore, it allows for a reduction in the risk of personal injury. Moreover, it reduces the risk of reduced availability of the energy storage module. Further, the above-described inventive concept advantageously allows for scalability, wherein any number of two or more protection devices can be interlocked via hardware interlocking and / or software interlocking.

[0009] According to a first aspect, a method is provided for controlling a protection circuit of an energy storage module connected to an energy storage system to provide power system support. The energy storage module has a positive terminal and a negative terminal. Two or more protection devices of the protection circuit are arranged to be activated to establish two or more corresponding discharge paths between the positive and negative terminals. The method further includes: measuring an operating value of the energy storage module, and activating a first protection device among the two or more protection devices if the measured operating value deviates from a predefined nominal operating value or nominal operating range; determining whether a predefined condition is met to activate a second protection device among the two or more protection devices to further discharge the energy storage module, wherein the predefined condition includes the measured operating value being equal to, exceeding, or falling below a first threshold, and activating the second protection device if the condition is met.

[0010] A protective device can refer to any device configured to operate between an inactive state and an active state, wherein the protective device in the inactive state substantially prevents discharge, and the protective device in the active state is capable of discharging. For example, a protective device may include a controllable switch, and optionally one or more other electrical components.

[0011] An energy storage module can refer to a module used for storing energy. An energy storage module may have a positive terminal and a negative terminal. An energy storage module may include one or more energy storage units. An energy storage module may include two or more energy storage units arranged in series and / or parallel. One or more energy storage units may be capacitors.

[0012] The operating value can be the voltage or current associated with the energy storage module.

[0013] This method can involve activating N protection devices, where N is an integer equal to 2 or any integer greater than 2. As an example, the number of protection devices can be 2, 3, 4, 5, 6, 7, 8, 9, 10 or more.

[0014] In addition to the measured operational value being equal to, exceeding, or falling below a first threshold, the predefined conditions may further include other conditions, such as one or more additional first thresholds. The first threshold can be selected based on the application.

[0015] According to one embodiment, the method includes: determining whether a predefined initial condition is met to activate a first protective device among two or more protective devices to discharge an energy storage module, wherein the predefined initial condition includes a measured operating value equal to, exceeding, or falling below an initial threshold; and if met, activating the first protective device among the two or more protective devices. This advantageously improves security and makes the controllability of the protective devices even more robust.

[0016] In addition to the measured operating value being equal to, exceeding, or falling below the initial threshold, the predefined initial conditions may further include other conditions, such as one or more additional initial thresholds. The initial thresholds can be selected based on the application.

[0017] According to one embodiment, a first protection device is activated by means of a first activation signal, wherein the first activation signal is allowed to propagate to activate the first protection device under the condition of applying a first control signal, the first control signal indicating that predefined initial conditions are met to activate the first protection device. The first activation signal may be based on or measured operating values.

[0018] According to one embodiment, the second protection device is activated by means of a second activation signal, wherein the second activation signal is allowed to propagate to activate the second protection device under the condition of applying a second control signal, the second control signal indicating that the predefined condition for activating the second protection device is met. The second activation signal may be based on or on a first activation signal.

[0019] According to one embodiment, two or more protection devices are arranged for sequential activation, and activation signals for subsequent protection devices can only be transmitted if the preceding protection device has already been activated.

[0020] According to one embodiment, two or more protection devices are arranged for sequential activation, and control signals for subsequent protection devices can only be transmitted if the preceding protection device has already been activated.

[0021] According to one embodiment, the measured operating value is a measured current or a measured voltage of the energy storage module. The operating value can be any other suitable parameter of the energy storage module or any parameter value of the protection circuitry.

[0022] According to one embodiment, two of two or more protection devices are activated via a series control / activation interlock or a parallel control / activation interlock. Any protection device can be activated via a series control / activation interlock or a parallel control / activation interlock. All protection devices can be activated via a series control / activation interlock or a parallel control / activation interlock. A control interlock can refer to a software interlock. An activation interlock can refer to a hardware interlock.

[0023] According to one embodiment, a first discharge path is associated with a first conductive resistance, and a second discharge path is associated with a second conductive resistance lower than the first conductive resistance.

[0024] According to one embodiment, the first conductive resistance of the first discharge path is provided by at least a first resistor, and / or the second conductive resistance of the second discharge path is provided by at least a second resistor, the cumulative series resistance of the second resistor being lower than the cumulative series resistance of the at least first resistor.

[0025] According to one embodiment, the method includes: after activating a second protection device, determining whether predefined additional conditions are met to activate additional protection devices to initiate further discharge of the energy storage module, wherein the predefined additional conditions include a measured operating value equal to or exceeding or falling below an additional threshold, and if met, activating the additional protection device.

[0026] In addition to the measured operating value being equal to, exceeding, or falling below another threshold, predefined additional conditions may further include additional conditions, such as one or more additional thresholds. These additional thresholds can be selected based on the application.

[0027] According to one embodiment, an additional protection device is activated by means of an additional activation signal, wherein the additional activation signal is allowed to propagate to activate the additional protection device under the condition of applying an additional control signal, the additional control signal indicating that a predefined additional condition is met.

[0028] According to a second aspect, a control unit is provided. The control unit includes means for performing the method according to the first aspect or any embodiment thereof. The control unit is configured to be communicatively connected to a protection circuit connected to an energy storage module of an energy storage system to provide power system support. The protection circuit includes two or more protection devices arranged to be activated by the control unit to establish two or more corresponding discharge paths between the positive and negative terminals of the energy storage module, wherein at least two of the two or more protection devices are controllably interlocked by means of hardware interlocking and software interlocking. The control unit is configured to control the protection circuit according to the method according to the first aspect or any embodiment thereof.

[0029] According to a third aspect, a protection circuit configured to be connected to an energy storage module is provided. The protection circuit includes two or more protection devices arranged to be activated to establish two or more corresponding discharge paths between the positive and negative terminals of the energy storage module, wherein at least two of the two or more protection devices are interlocked by means of hardware interlocking and software interlocking.

[0030] According to a fourth aspect, an energy storage system (ESS) for providing power system support is provided. The energy storage system includes an energy storage module having a positive terminal and a negative terminal. The energy storage system includes protection circuitry. The protection circuitry includes two or more protection devices arranged to be activated to establish two or more corresponding discharge paths between the positive and negative terminals of the energy storage module, wherein at least two of the two or more protection devices are interlocked by means of hardware interlocking and software interlocking. The energy storage system is configured such that when the two or more protection devices are activated, they establish corresponding two or more discharge paths between the positive and negative terminals. The energy storage system includes a control unit according to the second aspect or any embodiment thereof.

[0031] The energy storage system can be adapted for rack-mount designs (i.e., ESS racks), comprising multiple energy storage modules connected in parallel and / or series. The ESS can be adapted for floating designs. The ESS can be adapted for grounding connections. The grounding connection can be located at any suitable connection point of the ESS, such as at the midpoint of the ESS. The ESS can be adapted for low-voltage applications. Low voltage can mean equal to and / or less than 1500 V dc. The ESS can be adapted for high-voltage applications. High voltage can mean equal to and / or greater than 1 MV dc. The ESS can be adapted for intermediate-voltage applications. Intermediate voltage can mean in the range of 1500 V dc to 1 MV dc.

[0032] Power system support can refer to assistance in maintaining the stability and / or efficiency of the power grid. In other words, power system support can include any one or any combination of the following: frequency regulation, voltage control, reactive power compensation, load balancing, fault management, and black start capability.

[0033] As a non-limiting example, an energy storage system can be configured to be electrically connected to a power grid, such as a power grid. The energy storage system can be configured to store excess energy generated during periods of low demand and release the stored energy back into the grid during periods of peak demand, thereby supporting load balancing and reducing stress on generation assets. Additionally, the energy storage system can provide ancillary services, such as frequency regulation, voltage control, and spinning reserve support, to enhance grid stability. In some implementations, the system can operate in coordination with renewable energy sources, thereby mitigating fluctuations in power output and improving the overall reliability and resilience of the power grid.

[0034] As a non-limiting example, an energy storage system can be configured to be electrically connected to a power converter. The power converter can be configured to facilitate bidirectional energy flow between the energy storage system and the power grid (such as a power grid). The power converter can be configured to convert the stored energy to a suitable voltage and frequency for injection into the power grid, or to adapt the incoming energy for efficient storage. This configuration allows the energy storage system to store excess energy during periods of low demand and release energy during periods of peak demand, thereby providing power grid balancing and frequency regulation. Furthermore, the power converter can achieve seamless switching between charging and discharging modes, support reactive power compensation, and contribute to overall grid stability and power quality.

[0035] As a non-limiting example, energy storage systems can be used in conjunction with Flexible AC Transmission System (FACTS) devices to enhance grid performance. For instance, energy storage systems can support dynamic voltage regulation and reactive power compensation through devices such as Static Synchronous Compensators (STATCOMs) or Static VAR Compensators (SVCs). By pairing with FACTS devices, energy storage systems can rapidly inject or absorb active and reactive power, thereby helping to mitigate voltage instability, improve the power factor, and reduce transmission losses. This configuration can be particularly beneficial for integrating renewable energy sources, where energy storage systems can smooth power fluctuations and ensure stable grid operation. Furthermore, energy storage systems can enhance line utilization, alleviate grid congestion, and support islanded microgrids by providing backup power and facilitating seamless grid resynchronization after disturbances.

[0036] According to a fifth aspect of the invention, a computer program is provided. The computer program includes instructions that, when executed by a computer, cause the computer to perform a method according to the first aspect or any embodiment thereof.

[0037] A computer can refer to any device capable of receiving and processing information for a certain result based on a program, software, or sequence of instructions on how to process information. The information can be in the form of digital data. As a non-limiting example, a computer can be a server, a fixed computing device, or a portable computing device.

[0038] According to a sixth aspect, a computer-readable medium is provided. The computer-readable medium includes instructions that, when executed by a computer, cause the computer to perform the method according to the first aspect or any embodiment thereof. The computer-readable medium can be any suitable medium for including the instructions. The computer-readable medium can be a computer-readable storage medium.

[0039] The effects and features of the various additional aspects can be substantially similar to those described above in conjunction with the first aspect. The embodiments mentioned in connection with the first aspect are largely consistent with the various additional aspects. It should further be noted that, unless explicitly stated otherwise, the concept of the invention encompasses all possible combinations of features.

[0040] The present invention is defined by the appended independent claims, and embodiments thereof are set forth in the appended dependent claims, the following description and the accompanying drawings. Attached Figure Description

[0041] The invention will now be described in more detail with reference to the accompanying drawings, in which: Figures 1a to 1c This demonstrates how existing technology solutions work; Figure 2a The current graph of existing technology solutions is shown; Figure 2b A schematic diagram of a method according to an embodiment of the present disclosure is shown; Figure 3 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown; Figure 4 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown; Figure 5 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown; Figure 6 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown; Figure 7 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown; Figure 8 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown; Figure 9a A schematic diagram of an energy storage system according to an embodiment of the present disclosure is shown; Figure 9b A schematic diagram of an energy storage system according to an embodiment of the present disclosure is shown. Detailed Implementation

[0042] The principles and spirit of this disclosure will be described below with reference to illustrative embodiments. It should be understood that all these embodiments are given only to enable those skilled in the art to better understand and further practice this disclosure, and not to limit the scope of this disclosure. For example, features set forth or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. For clarity, not all features of an actual implementation are described in this specification. Of course, it should be understood that in the development of any such actual embodiment, many implementation-specific decisions need to be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from implementation to implementation. Furthermore, it should be understood that such development work may be complex and time-consuming, but will be a routine task for those skilled in the art who benefit from this disclosure.

[0043] The disclosed subject matter will now be described with reference to the accompanying drawings. Various structures, systems, and devices are schematically depicted in the drawings for illustrative purposes only, to avoid obscuring the description due to details well-known to those skilled in the art. Nevertheless, the drawings are included as illustrative examples for describing and explaining the disclosed subject matter. The words and phrases used herein should be understood and interpreted in accordance with the understanding of those skilled in the art. The consistent use of terms or phrases herein is not intended to imply a specific definition of a term or phrase, i.e., a definition different from the common and customary meaning understood by those skilled in the art. If a term or phrase is intended to have a specific meaning, i.e., a meaning different from that understood by those skilled in the art, such a specific definition will be clearly stated in the specification in a manner that directly and explicitly provides for the specific definition of that term or phrase.

[0044] Figures 1a to 1c The working principle of a prior art solution for a protection circuit used to discharge an energy storage module (ESM) is illustrated. The protection circuit includes a first protection device pd1 and a second protection device pd2, arranged to establish two discharge paths between the positive and negative terminals of the ESM. A resistor R is placed in the first discharge path. When the first protection device pd1 is closed before the second protection device pd2 is closed, the voltage difference between the positive and negative terminals of the ESM causes a first current i1 to flow in the first discharge path with resistor R. Therefore, the discharge of the energy storage module is limited by resistor R. When the second protection device pd2 is closed before the first protection device pd1 is closed, the voltage difference between the positive and negative terminals of the ESM causes a second current i2 to flow in the second discharge path without resistors. Therefore, the energy storage module is essentially short-circuited. Figure 2aThe diagram shows current curves for prior art solutions when the first protection device closes first and when the second protection device closes first. Therefore, the sequence of closing the protection devices may be essential for the safe dissipation of energy from the energy storage module.

[0045] Figure 2b A schematic diagram of a method according to an embodiment of the present disclosure is shown. The method is used to control the protection circuit of an energy storage module (ESM) of an energy storage system. The ESM has a positive terminal and a negative terminal. The protection circuit includes two or more protection devices pd1, pd2, which are arranged to be activated to establish two or more corresponding discharge paths between the positive and negative terminals. The method includes: measuring an operating value of the ESM in step S01; and activating a first protection device pd1 among the two or more protection devices in step S11 if the measured operating value deviates from a predefined nominal operating value or nominal operating range; determining in step S20 whether a predefined condition is met to activate a second protection device pd2 among the two or more protection devices to further discharge the ESM, wherein the predefined condition includes the measured operating value being equal to or exceeding a first threshold, and activating the second protection device pd2 in step S21 if the condition is met.

[0046] The method may optionally further include: determining whether S10 satisfies a predefined initial condition to activate the first protection device pd1 among the two or more protection devices to discharge the energy storage module ESM, wherein the predefined initial condition includes a measured operating value equal to or exceeding an initial threshold, and if satisfied, activating S11 the first protection device pd1 among the two or more protection devices.

[0047] The method may optionally further include: after activating the second protection device pd2, determining whether SN0 meets predefined additional conditions to activate another protection device pdN to initiate further discharge of the energy storage module ESM, wherein the predefined additional conditions include a measured operating value equal to or exceeding an additional threshold, and if met, activating the other protection device pdN of SN1.

[0048] Figure 3 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown. The energy storage module ESM has a positive terminal and a negative terminal. A protection circuit including N protection devices pd1, pd2, pdN is arranged to establish a corresponding discharge path between the positive and negative terminals of the energy storage module when activated. The operating value of the energy storage module ESM is measured by a measuring device MD. The measured operating value can be a measured current Im or a measured voltage of the energy storage module ESM.

[0049] If the measured operating value deviates from the predefined nominal operating value or the predefined nominal operating range, the first hardware interlock module HW-I is commanded to send the first activation signal AS1 to the first protection device pd1 to activate the first protection device pd1.

[0050] After activating the first protection device pd1, an activation signal AS1 is transmitted to a first software interlock module SW-I, which is configured to determine whether a predefined condition is met to activate a second protection device pd2 among the N protection devices to further discharge the energy storage module. The predefined condition includes a measured operating value equal to or exceeding a first threshold. If met, the second protection device pd2 is activated. The second protection device pd2 is activated by means of a second activation signal AS2, which is allowed to propagate to activate the second protection device pd2 under the condition of applying a second control signal CS2, which indicates that the predefined condition for activating the second protection device is met. Figure 3 As shown in the figure, the second control signal CS2 is sent from the first software interlock module SW-I to the second hardware interlock module HW-I, thereby commanding the second hardware interlock module HW-I to send the second activation signal AS2 to the second protection device pd2.

[0051] After activating the second protection device pd2, one or more additional protection devices pdN can be activated by means of additional control signals CSN and additional activation signals ASN from the corresponding pair of software interlock modules and hardware interlock modules.

[0052] Figure 4 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown. In this embodiment, a software interlock module is arranged after the measuring device MD and is configured to determine whether a predefined initial condition is met to activate a first protection device pd1 among the two or more protection devices to discharge the energy storage module ESM, wherein the predefined initial condition includes a measured operating value equal to or exceeding an initial threshold. The software interlock module is configured to activate the first protection device pd1 among the two or more protection devices by commanding a first hardware interlock module to activate the first protection device pd1 if the predefined initial condition is determined to be met. Each pair of software interlock modules and hardware interlock modules is arranged in a series interlocked manner.

[0053] Figure 5A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown. In this embodiment, the software interlock module in each pair of software interlock modules and hardware interlock modules is arranged after the hardware interlock module. The software interlock module in each pair of software interlock modules and hardware interlock modules is configured to receive corresponding activation signals AS1, AS2, ASN, and in response to corresponding control signals CS1, CS2, CSN, allow the corresponding activation signals AS1, AS2, ASN to propagate to the corresponding protection devices pd1, pd2, pdN to activate the corresponding protection devices pd1, pd2, pdN. Each pair of software interlock modules and hardware interlock modules is arranged in a series interlocking manner.

[0054] Figure 6 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown. In this embodiment, each pair of software interlock modules and hardware interlock modules are arranged in parallel interlocking manner. Therefore, the corresponding activation signals AS1, AS2, ASN are only allowed to propagate when the corresponding control signals CS1, CS2, CSN are applied.

[0055] Figure 7A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown. The energy storage module (ESM) has a positive terminal and a negative terminal. A protection circuit including a first protection device PD1 and a second protection device PD2 is arranged to establish a corresponding first discharge path and a second discharge path between the positive and negative terminals of the energy storage module when activated. The operating value of the energy storage module (ESM) is measured by a measuring device MD. The measured operating value may be a measured current Im or a measured voltage of the energy storage module (ESM). If the measured operating value deviates from a predefined nominal operating value or a predefined nominal operating range, a software interlock module arranged after the measuring device MD receives the measured operating value and determines whether a predefined initial condition is met to activate the first protection device PD1 among the two or more protection devices to discharge the energy storage module (ESM), wherein the predefined initial condition includes the measured operating value being equal to or exceeding an initial threshold. The software interlock module is configured to activate the first protection device PD1 by commanding a first hardware interlock module to activate the first protection device if the predefined initial condition is determined to be met. After activating the first protection device PD1, an activation signal AS1 is transmitted to a first software interlock module SW-I, which is configured to determine whether predefined conditions are met to activate the second protection device PD2 to further discharge the energy storage module. The predefined conditions include a measured operating value equal to or exceeding a first threshold. If met, the second protection device PD2 is activated. The second protection device PD2 is activated by means of a second activation signal AS2, which is allowed to propagate to activate the second protection device PD2 under the condition of applying a second control signal CS2, which indicates that the predefined conditions for activating the second protection device are met. Figure 7 As shown in the figure, the second control signal CS2 is sent from the first software interlock module SW-I to the second hardware interlock module HW-I, thereby commanding the second hardware interlock module HW-I to send the second activation signal AS2 to the second protection device pd2.

[0056] Figure 8 A schematic diagram of an energy storage module and protection circuit according to an embodiment of the present disclosure is shown. Figure 7 The illustrated embodiments are in Figure 8 The diagram is shown in more detail below. The energy storage module includes a first capacitor unit C1 arranged in series with the second capacitor unit C2. The first protection device pd1 includes at least a first switch Sw1. The second protection device pd2 includes at least a second switch Sw2. The first switch Sw1 is connected in series with the primary resistor R. The first switch Sw1 and the primary resistor R are connected between the positive terminal + and the negative terminal - of the energy storage module ESM.

[0057] The first protection device pd1 may optionally further include a status switch Di. The status switch Di can be configured to close and open in response to corresponding closing and opening actions of the first switch S1. The status switch Di can thus be used to confirm the status of switch S1, for example, to allow a status signal to be transmitted to the control unit.

[0058] The first protection device pd1 may further include an auxiliary switch Swi. When the auxiliary switch Swi is closed, the auxiliary switch connects the resistor Rs1 in parallel with the thyristor Thr.

[0059] The first protection device PD1 may further include a resistor. The resistor is used for filtering purposes to determine how quickly the interlock sequence should reach a threshold to proceed to the next step.

[0060] The protection circuit also includes a hardware interlock module HW-I and a software interlock module SW-I.

[0061] Regarding the hardware interlock module HW-I, the first resistor Rs1 and the thyristor Thr are connected in parallel. The source capacitor Cs and the second resistor Rs2 are connected in parallel. The source capacitor Cs and the second resistor Rs2 are connected between ground GND1, the first resistor Rs1, and the thyristor Thr.

[0062] Regarding the software interlock module SW-I, an OR gate is arranged to receive two inputs. The OR gate is provided with a signal indicating manual operation as the first input. The OR gate is provided with a signal indicating whether the current Im exceeds the threshold current Ith 1 as the second input. The OR gate is adapted to be signaled to activate a first logic switch Do1 as its output. Therefore, the first logic switch Do1 will be activated in response to a manual command or if the current Im is greater than the threshold current Ith 1.

[0063] Furthermore, the AND gate is arranged to receive three inputs. The AND gate is provided with Di as the first input. The AND gate is provided with Vc as the second input. The AND gate is provided with Im as the third input. The AND gate is adapted to be signaled to activate the second logic switch Do2 as its output. Therefore, if Di is high, if Vc is less than the threshold voltage Vth, and if the current Im is less than the threshold current ith2, the second logic switch Do1 will be activated.

[0064] The first logic switch Do1 is arranged to connect the charging unit CH-U to the first protection switch pd1. The second logic switch Do2 is arranged to connect the charging unit CH-U to the hardware interlock module HW-I.

[0065] The measuring device MD is arranged to measure the operating values ​​of the energy storage module ESM. Figure 8The values ​​are exemplified as voltage Vc and current Im. In the first step St1, the measured operating values ​​are provided to the software interlock module SW-I. If the current Im is greater than the first current threshold Ith, the first logic switch Do1 closes. In the second step St2, a signal is sent to the hardware interlock module HW-I, which then activates the first protection device pd1. Therefore, the energy storage module ESM begins to discharge via the primary resistor R and the first protection device pd1.

[0066] As the energy storage module ESM discharges, the voltage Vc decreases and the current Im decreases. In the third step, St3, the current Im, voltage Vc, and current through switch Di are supplied to the software interlock module SW-I. If the current Im is less than the current threshold ith2 and the voltage Vc is less than the voltage threshold Vth, and the current through Di is high, then the second logic switch Do2 closes. In the fourth step, St4, a signal is sent to the hardware interlock module HW-I. In the fifth step, St5, the thyristor Thr is activated to allow the signal to propagate to the second protection device pd2, and the second protection device pd2 closes.

[0067] Therefore, the protection circuit allows the energy storage module (ESM) to safely discharge via a first discharge path, which includes a primary resistor R and the first protection device pd1. Then, when safely discharging via the second discharge path, the second protection device pd1 is activated to allow further discharge. This provides robust controllability of the protection circuit, preventing the ESM from experiencing unwanted short circuits.

[0068] Figure 9a A schematic diagram of an energy storage system according to an embodiment of the present disclosure is shown. The energy storage system ESS includes at least a first string comprising one or more energy storage modules (ESMs). Each of the one or more ESMs in the first string of the ESS is connected to a protection circuit comprising two or more protection devices as disclosed herein. Optionally, the first string includes a bypass switch (BPS) arranged in parallel with resistor 11.

[0069] Figure 9b A schematic diagram of an energy storage system according to an embodiment of the present disclosure is shown. The energy storage system ESS is arranged in a line connected to converter 10.

[0070] While the foregoing describes embodiments of this disclosure, other and further embodiments may be devised without departing from the inventive concept discussed herein. However, the scope of the invention will be determined by the claims.

[0071] Item list of examples Example 1. A method for controlling a protection circuit of an energy storage module (ESM) of an energy storage system (ESS), the energy storage module (ESM) having a positive terminal and a negative terminal, wherein two or more protection devices (pd1, pd2) of the protection circuit are arranged to be activated to establish two or more corresponding discharge paths between the positive terminal and the negative terminal, the method comprising: - Measure (S01) the operating values ​​of the energy storage module (ESM), and - If the measured operating value deviates from the predefined nominal operating value or nominal operating range. ○ Activate (S11) the first protection device (pd1) of the two or more protection devices. ○ Determine (S20) whether a predefined condition is met to activate a second protection device (pd2) among the two or more protection devices to further discharge the energy storage module (ESM), wherein the predefined condition includes the measured operating value being equal to, exceeding, or falling below a first threshold, and If the conditions are met, then activate (S21) the second protection device (pd2).

[0072] Example 2. The method according to Example 1 includes: - Determine (S10) whether a predefined initial condition is met to activate the first protection device (pd1) among the two or more protection devices to discharge the energy storage module (ESM), wherein the predefined initial condition includes the measured operating value being equal to, exceeding, or falling below an initial threshold, and - If satisfied, activate (S11) the first protection device (pd1) of the two or more protection devices.

[0073] Example 3. According to the method of Example 2, the first protection device (pd1) is activated by means of a first activation signal (AS1), wherein the first activation signal (AS1) is allowed to propagate to activate the first protection device (pd1) under the condition of applying a first control signal (CS1), the first control signal (CS1) indicating that a predefined initial condition is met to activate the first protection device (pd1).

[0074] Example 4. The method according to any one of Examples 1 to 3, wherein the second protection device (pd2) is activated by means of a second activation signal (AS2), wherein the second activation signal (AS2) is allowed to propagate to activate the second protection device (pd2) under the condition of applying a second control signal (CS2), the second control signal (CS2) indicating that the predefined condition for activating the second protection device (pd2) is met.

[0075] Example 5. The method according to any one of the foregoing embodiments, wherein the two or more protection devices (pd1, pd2, pd...) N The following are configured for sequential activation, and transmission for subsequent protection devices (PD1, PD2) is only permitted if the preceding protection devices (PD1, PD2) have already been activated. N The activation signal (AS2, AS) N ).

[0076] Example 6. The method according to any one of the foregoing embodiments, wherein the two or more protection devices (pd1, pd2, pd...) N The following are configured for sequential activation, and transmission for subsequent protection devices (PD1, PD2) is only permitted if the preceding protection devices (PD1, PD2) have already been activated. N ) control signals (CS2, CS N ).

[0077] Example 7. The method according to any one of the foregoing embodiments, wherein the measured operating value is the measured current (Im) or the measured voltage (Vc) of the energy storage module (ESM).

[0078] Example 8. The method according to any one of the foregoing embodiments, wherein the two or more protection devices (pd1, pd2, pd...) N The two protection devices (pd1, pd2, pd) in the ) N ) Activated via series control / activation interlock or parallel control / activation interlock.

[0079] Example 9. The method according to any one of the foregoing embodiments, wherein the first discharge path is associated with a first conductive resistance, and the second discharge path is associated with a second conductive resistance lower than the first conductive resistance.

[0080] Example 10. The method according to Example 9, wherein the first conductive resistance of the first discharge path is provided by at least a first resistor (R), and / or wherein the second conductive resistance of the second discharge path is provided by at least a second resistor, the cumulative series resistance of the second resistor being lower than the cumulative series resistance of the at least first resistor.

[0081] Example 11. The method according to any one of Examples 1 to 10 further includes: - After activating the second protection device (PD2), determine whether (SN0) meets other predefined conditions to activate another protection device (PD). N To initiate further discharge of the energy storage module (ESM), wherein the predefined additional conditions include the measured operating value being equal to, exceeding, or falling below an additional threshold, and - If satisfied, activate (SN1) the additional protection device (PD). N ).

[0082] Example 12. The method according to Example 11, wherein the additional protection device (PD) N ) with the help of another activation signal (AS) N ) is activated, wherein the additional activation signal (AS) is allowed. N ) propagation to apply additional control signals (CS) N Activate the additional protection device (PD) under the condition of ) N The additional control signal (CS) N This indicates that additional predefined conditions must be met.

[0083] Example 13. A control unit comprising means for performing the method according to any one of Examples 1 to 12.

[0084] Example 14. A protection circuit for an energy storage module (ESM), the protection circuit comprising two or more protection devices (pd1, pd2, pd3, pd4, pd5, pd6, pd7, pd8, pd9, pd1, pd1, pd2, pd1 ... N The two or more protection devices are arranged to be activated to establish two or more corresponding discharge paths between the positive and negative terminals of the energy storage module (ESM), wherein the two or more protection devices (pd1, pd2, pd3) are configured to be activated to establish two or more corresponding discharge paths between the positive and negative terminals of the energy storage module (ESM). N At least two protection devices (pd1, pd2, pd) in ) N Interlocking is achieved through hardware interlocking and software interlocking.

[0085] Example 15. An energy storage system (ESS) comprising: an energy storage module (ESM) having a positive terminal and a negative terminal; and a protection circuit according to Example 14, wherein the protection circuit is arranged such that the two or more protection devices (pd1, pd2, pd3) are arranged to... N When activated, it establishes two or more corresponding discharge paths between the positive terminal and the negative terminal; and a control unit according to Embodiment 13.

Claims

1. A method for controlling a protection circuit, said protection circuit being connected to an energy storage module (ESM) of an energy storage system (ESS) to provide power system support, said energy storage module (ESM) having a positive terminal and a negative terminal, wherein, Two or more protection devices (PD1, PD2) of the protection circuit are arranged to be activated to establish two or more corresponding discharge paths between the positive terminal and the negative terminal, the method comprising: - Measure (S01) the operating values ​​of the energy storage module (ESM), and - If the measured operating value deviates from the predefined nominal operating value or nominal operating range. ○ Activate (S11) the first protection device (pd1) of the two or more protection devices. ○ Determine (S20) whether a predefined condition is met to activate a second protection device (pd2) among the two or more protection devices to further discharge the energy storage module (ESM), wherein the predefined condition includes the measured operating value being equal to, exceeding, or falling below a first threshold, and If the conditions are met, then activate (S21) the second protection device (pd2).

2. The method according to claim 1, comprising: - Determine (S10) whether a predefined initial condition is met to activate the first protection device (pd1) among the two or more protection devices to discharge the energy storage module (ESM), wherein the predefined initial condition includes the measured operating value being equal to, exceeding, or falling below an initial threshold, and - If satisfied, activate (S11) the first protection device (pd1) of the two or more protection devices.

3. The method according to claim 2, wherein, The first protection device (pd1) is activated by means of a first activation signal (AS1), wherein the first activation signal (AS1) is allowed to propagate to activate the first protection device (pd1) under the condition of applying a first control signal (CS1), the first control signal (CS1) indicating that a predefined initial condition is met to activate the first protection device (pd1).

4. The method according to any one of claims 1 to 3, wherein, The second protection device (pd2) is activated by means of a second activation signal (AS2), wherein the second activation signal (AS2) is allowed to propagate to activate the second protection device (pd2) under the condition of applying a second control signal (CS2), the second control signal (CS2) indicating that the predefined condition for activating the second protection device (pd2) is met.

5. The method according to any one of the preceding claims, wherein, The two or more protection devices (pd1, pd2, pd) N The following are configured for sequential activation, and transmission for subsequent protection devices (PD1, PD2) is only permitted if the preceding protection devices (PD1, PD2) have already been activated. N The activation signal (AS2, AS) N ).

6. The method according to any one of the preceding claims, wherein, The two or more protection devices (pd1, pd2, pd) N The following are configured for sequential activation, and transmission for subsequent protection devices (PD1, PD2) is only permitted if the preceding protection devices (PD1, PD2) have already been activated. N ) control signals (CS2, CS N ).

7. The method according to any one of the preceding claims, wherein, The measured operating value is the measured current (Im) or the measured voltage (Vc) of the energy storage module (ESM).

8. The method according to any one of the preceding claims, wherein, The two or more protection devices (pd1, pd2, pd) N The two protection devices (pd1, pd2, pd) in the ) N ) Activated via series control / activation interlock or parallel control / activation interlock.

9. The method according to any one of claims, wherein, The first discharge path is associated with a first conductive resistor, and the second discharge path is associated with a second conductive resistor that is lower than the first conductive resistor.

10. The method according to claim 9, wherein, The first conductive resistance of the first discharge path is provided by at least a first resistor (R), and / or the second conductive resistance of the second discharge path is provided by at least a second resistor, wherein the cumulative series resistance of the second resistor is lower than the cumulative series resistance of the at least first resistor.

11. The method according to any one of claims 1 to 10, further comprising: - After activating the second protection device (PD2), determine whether (SN0) meets other predefined conditions to activate another protection device (PD). N To initiate further discharge of the energy storage module (ESM), wherein the predefined additional conditions include the measured operating value being equal to, exceeding, or falling below an additional threshold, and - If satisfied, activate (SN1) the additional protection device (PD). N ).

12. The method according to claim 11, wherein, The additional protection device (pd) N ) with the help of another activation signal (AS) N ) is activated, wherein the additional activation signal (AS) is allowed. N ) propagation to apply additional control signals (CS) N Activate the additional protection device (PD) under the condition of ) N The additional control signal (CS) N This indicates that additional predefined conditions must be met.

13. A control unit configured to be communicatively connected to a protection circuit of an energy storage module (ESM) of an energy storage system (ESS), the protection circuit comprising two or more protection devices (pd1, pd2, pd3). N The two or more protection devices are arranged to be activated by the control unit to establish two or more corresponding discharge paths between the positive and negative terminals of the energy storage module (ESM), wherein, The two or more protection devices (pd1, pd2, pd) N At least two protection devices (pd1, pd2, pd) in ) N Interlocking can be controlled using hardware and software interlocks. The control unit is configured to control the protection circuit according to any one of claims 1 to 12.

14. An energy storage system (ESS) for providing power system support, the energy storage system (ESS) comprising: Energy storage module (ESM), the energy storage module having a positive terminal and a negative terminal, The protection circuit includes two or more protection devices (pd1, pd2, pd3, pd4). N The two or more protection devices are arranged to be activated to establish two or more corresponding discharge paths between the positive and negative terminals of the energy storage module (ESM), wherein the two or more protection devices (pd1, pd2, pd3) are configured to be activated to establish two or more corresponding discharge paths between the positive and negative terminals of the energy storage module (ESM). N At least two protection devices (pd1, pd2, pd) in ) N Interlocking can be controlled using hardware and software interlocks. The energy storage system (ESS) is configured such that the two or more protection devices (pd1, pd2, pd3) are connected to the power supply system. N When activated, two or more corresponding discharge paths are established between the positive and negative terminals, and The control unit according to claim 13 is communicatively connected to the protection circuit to control the protection circuit.

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