Control method and device of energy storage converter, energy storage system and electric equipment

Abstract

The embodiment of the invention relates to the field of energy storage, and provides a control method and device of an energy storage converter, an energy storage system and electric equipment. The energy storage converter comprises a fuse, a contactor, a circuit breaker and a semiconductor switch circuit, the fuse, the contactor, the circuit breaker and the semiconductor switch circuit are connected in series, and the control method of the energy storage converter comprises the following steps: obtaining an actual working current and a predetermined relationship of the fuse, the preset relation represents the corresponding relation between the current value of the fuse and the fusing time; according to the actual working current and a predetermined relationship, determining the actual allowable energy of the fuse; and under the condition that the difference between the actual let-through energy and the let-through energy threshold value of the fuse is greater than a preset threshold value, executing at least one of the following operations: adjusting the duty ratio of the semiconductor switching circuit so as to enable the energy storage converter to operate in a derating manner, turning off the circuit breaker and turning off the contactor. The problem that the operation and maintenance cost is increased due to the high rejection rate of a fuse in an existing energy storage converter is at least solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy storage, and in particular, to a control method and device of an energy storage converter, an energy storage system and an electrical equipment. BACKGROUND

[0002] In the existing technology of the power conversion system (PCS), a fuse is widely used as a key safety protection device in the circuit connection between the energy storage system and the power grid / load, to rapidly cut off the fault circuit by the instantaneous melting of the fuse body when a short circuit or overload occurs, thereby protecting the core power electronic devices such as IGBT (Insulated Gate Bipolar Transistor) from damage. However, this mechanism can only protect the circuit to a certain extent, and the melting of the fuse itself is often accompanied by irreversible physical changes, resulting in the loss of function of the fuse after melting once, which requires manual replacement. In the energy storage system, especially when the system is large in scale and the number of fuses is large, the high scrap rate caused by frequent melting not only increases the operation and maintenance cost, but also brings great inconvenience and low efficiency to the on-site maintenance. SUMMARY

[0003] The embodiments of the present application provide a control method and device of an energy storage converter, an energy storage system and an electrical equipment, to at least solve the problem of high scrap rate of the fuse in the existing energy storage converter increasing the operation and maintenance cost.

[0004] According to some embodiments of the present application, the embodiments of the present application provide a control method of an energy storage converter, the energy storage converter comprising a fuse, a contactor, a circuit breaker and a semiconductor switching circuit, the fuse, the contactor, the circuit breaker and the semiconductor switching circuit being connected in series, the control method of the energy storage converter comprising: obtaining an actual working current of the fuse and a predetermined relationship, the predetermined relationship representing a corresponding relationship between a current value of the fuse and a melting time; determining an actual allowed energy of the fuse according to the actual working current and the predetermined relationship; in the case that the difference between the actual allowed energy and the allowed energy threshold of the fuse is greater than a preset threshold, performing at least one of the following: adjusting the duty cycle of the semiconductor switching circuit to make the energy storage converter run at a reduced capacity, turning off the circuit breaker, and turning off the contactor.

[0005] In some embodiments, determining the actual let-through energy of the fuse according to the actual working current and the predetermined relationship comprises: determining, according to the actual working current, the actual working current corresponding fuse time as an actual fuse time from the predetermined relationship; and determining the actual let-through energy as a product of the square of the actual working current and the actual fuse time according to the actual working current and the actual fuse time.

[0006] In some embodiments, in the case that the difference between the actual let-through energy and the let-through energy threshold of the fuse is greater than a preset threshold, at least one of the following is performed: adjusting the duty cycle of the semiconductor switching circuit to make the energy storage converter operate at a reduced capacity, turning off the circuit breaker, and turning off the contactor, comprising: in the case that the actual fuse time is greater than a first time threshold, adjusting the duty cycle of the semiconductor switching circuit to make the energy storage converter operate at a first percentage of reduced capacity, the actual fuse time being the fuse time corresponding to the actual working current; in the case that the actual fuse time is greater than a second time threshold and less than or equal to the first time threshold, at least turning off the contactor; and in the case that the actual fuse time is less than or equal to the second time threshold, turning off the circuit breaker and the contactor.

[0007] In some embodiments, in the case that the actual fuse time is greater than a second time threshold and less than or equal to the first time threshold, at least turning off the contactor comprises: in the case that the actual fuse time is greater than a third time threshold and less than or equal to the first time threshold, controlling the fuse to continue to work for a first duration, and then turning off the contactor, the first duration being the difference between the actual fuse time and the third time threshold; and in the case that the actual fuse time is greater than the second time threshold and less than or equal to the third time threshold, controlling the fuse to continue to work for a second duration, and then turning off the contactor, the second duration being the difference between the actual fuse time and the second time threshold.

[0008] In some embodiments, the first time threshold is 100s-150s, the second time threshold is 1s-5s, and the third time threshold is 10s-50s.

[0009] In some embodiments, in the case that the actual fuse time is greater than a third time threshold and less than or equal to the first time threshold, the control method of the energy storage converter further comprises: adjusting the duty cycle of the semiconductor switching circuit to make the energy storage converter operate at a second percentage of reduced capacity within the first duration during which the fuse continues to work, the second percentage being greater than the first percentage.

[0010] In some embodiments, the first percentage is 10% to 30%, and the second percentage is 40% to 70%.

[0011] In some embodiments, after performing at least one of turning off the circuit breaker and turning off the contactor, the control method of the energy storage converter further comprises: determining an actual resistance of the fuse according to an actual working voltage of the fuse and the actual working current, the actual working voltage being a voltage value of the fuse obtained before at least one of turning off the circuit breaker and turning off the contactor; in a case where the actual resistance is greater than a resistance reference value of the fuse, controlling the energy storage converter to restart after replacing the fuse; and in a case where the actual resistance is less than or equal to the resistance reference value, controlling the energy storage converter to restart.

[0012] In some embodiments, the predetermined relationship is a fitting relationship obtained by data fitting on historical current values and historical fusing times of the fuse, and before determining the actual let-through energy of the fuse according to the actual working current and the predetermined relationship, the control method of the energy storage converter further comprises: obtaining an accumulated use duration of the fuse, an actual working temperature of the fuse corresponding to the actual working current, and a duration of the actual working current; determining a remaining life of the fuse according to a life prediction model of the fuse, the accumulated use duration, the actual working temperature, and the actual working current, the life prediction model being obtained by training a machine learning model using a plurality of sets of data, each set of data including a historical working current of the fuse, a historical duration corresponding to the historical working current, a historical working temperature, a historical accumulated use duration, and a historical use life; and adjusting a coefficient in the fitting relationship according to the remaining life and an adjustment strategy to obtain an adjusted fitting relationship, the adjustment strategy being determined according to the predetermined relationship corresponding to the fuse with different historical use lives.

[0013] According to some embodiments of the present application, another aspect of the embodiments of the present application provides a control device of an energy storage converter, the energy storage converter comprising a fuse, a contactor, a circuit breaker and a semiconductor switching circuit, the fuse, the contactor, the circuit breaker and the semiconductor switching circuit being connected in series, the control device of the energy storage converter comprising: a first acquisition module configured to acquire an actual working current of the fuse and a predetermined relationship, the predetermined relationship representing a correspondence between a current value of the fuse and a melting time; a first determination module configured to determine an actual let-through energy of the fuse according to the actual working current and the predetermined relationship; and an execution module configured to perform at least one of the following: adjusting a duty cycle of the semiconductor switching circuit to make the energy storage converter operate at a reduced capacity, turning off the circuit breaker and turning off the contactor, if a difference between the actual let-through energy and a let-through energy threshold of the fuse is greater than a preset threshold.

[0014] According to some embodiments of the present application, still another aspect of the embodiments of the present application provides an energy storage system, comprising: an energy storage device; an energy storage converter electrically connected to the energy storage device; and a control device of the energy storage converter, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs comprise a program for performing any of the control methods of the energy storage converter.

[0015] According to some embodiments of the present application, still another aspect of the embodiments of the present application provides an energy storage converter, comprising the control device of the energy storage converter.

[0016] The embodiments of the present application have at least the following advantages: the control method of the energy storage converter provided by the embodiments of the present application first acquires an actual working current of a fuse and a predetermined relationship representing a correspondence between a current value of the fuse and a melting time; then determines an actual let-through energy corresponding to the actual working current according to the actual working current and the predetermined relationship; and finally, if a difference between the actual let-through energy and a let-through energy threshold is greater than a preset threshold, it indicates that the fuse has a risk of melting, and at least one of adjusting a duty cycle of the semiconductor switching circuit, turning off the circuit breaker and turning off the contactor is performed to avoid the fuse from melting and being scrapped, and overcurrent and overvoltage protection of the energy storage converter is realized. BRIEF DESCRIPTION OF DRAWINGS

[0017] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which are shown by way of illustration in the figures. The embodiments disclosed in this document are not limited to the examples of the figures but extend across the full scope of the disclosure, unless otherwise specified. The figures in the drawings are not necessarily to scale and the dimensions of certain features could have been exaggerated for the sake of clarity. Embodiments disclosed in the specification or in the claims could be further clarified by referring to the figures in the drawings, as the skilled person will readily recognize. Obviously, additional figures could be derived from these figures by a person of ordinary skill in the art without paying creative effort.

[0018] Figure 1 A partial circuit structure schematic diagram of an energy storage converter provided in an embodiment of the present application;

[0019] Figure 2 A flowchart of a control method of an energy storage converter provided in an embodiment of the present application;

[0020] Figure 3 A circuit structure schematic diagram of a voltage sampling circuit provided in an embodiment of the present application;

[0021] Figure 4 A block diagram of a control device of an energy storage converter provided in an embodiment of the present application.

[0022] Among the above-mentioned drawings, the following reference signs are used:

[0023] 10, energy storage converter; 11, fuse; 12, contactor; 13, circuit breaker; 20, voltage sampling circuit; 21, sampling resistor; 22, first resistor; 23, second resistor; 24, third resistor; 25, fourth resistor; 26, operational amplifier; 30, analog-to-digital converter; 40, first acquisition module; 50, first determination module; 60, execution module. DETAILED DESCRIPTION

[0024] As can be known from the background, at present, when the voltage across the fuse exceeds the threshold value, the fuse avoids damage to the core device of the energy storage converter by fusing, but this causes the problem of high scrap rate of the fuse, increasing the operation and maintenance cost.

[0025] To solve the problem, the embodiment of the present application provides a control method of an energy storage converter, the energy storage converter comprising a fuse, a contactor, a circuit breaker and a semiconductor switch circuit, the fuse, the contactor, the circuit breaker and the semiconductor switch circuit being connected in series, the control method of the energy storage converter comprising: acquiring an actual working current of the fuse and a predetermined relationship, the predetermined relationship representing a corresponding relationship between a current value of the fuse and a melting time; determining an actual allowed energy of the fuse according to the actual working current and the predetermined relationship; in the case that a difference between the actual allowed energy and an allowed energy threshold of the fuse is greater than a preset threshold, performing at least one of the following: adjusting a duty cycle of the semiconductor switch circuit to make the energy storage converter operate at a reduced capacity, turning off the circuit breaker, and turning off the contactor.

[0026] In the description of the embodiments of the present application, the technical terms "first", "second", and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0027] In this paper, the reference to "embodiments" means that the specific features, structures or characteristics described in conjunction with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. The skilled in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0028] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the existence of A, the existence of A and B, and the existence of B. In addition, the character " / " in this paper generally represents a "or" relationship between the front and rear associated objects.

[0029] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0030] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0031] In the description of the embodiments of the present application, unless otherwise specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the terms in the embodiments of the present application can be understood according to the specific circumstances.

[0032] In the corresponding drawings of the embodiments of the present application, the thickness and area of the layer are enlarged for better understanding and convenience of description. When describing a component (such as a layer, a film, a region or a substrate) on or on the surface of another component, the component can be "directly" on the surface of the other component, or there can be a third component between the two components. On the contrary, when describing a component on the surface of another component or a component surface forming or providing another component, it means that there is no third component between the two components. In addition, when a component is described as "formed substantially" on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor on the edge of the entire surface.

[0033] In the description of the embodiments of the present application, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components can also be further included. In addition, when a layer, film, region or plate and the like are referred to as "on / over" another component, it can be "directly on" another component (i.e. between the surface of another component and another component without other components), or another component can exist therebetween. In addition, when a layer, film, region, plate and the like are "directly on" another component, or when a layer, film, region, plate and the like are on the surface of another component, it means that there is no other component therebetween.

[0034] The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments of the disclosure and the appended claims, the term "the" also is intended to include plural forms, unless the context clearly indicates otherwise. Portions of the components include layers, films, regions, or plates, among other components.

[0035] The embodiments of the present application will be described in detail with reference to the drawings. However, those skilled in the art can understand that in the embodiments of the present application, many technical details are proposed in order to make the reader better understand the present application. However, the technical solutions claimed by the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0036] The embodiments of the present application provide a control method of an energy storage converter, Figure 1 Exemplarily, a partial circuit structure schematic diagram of an energy storage converter is shown as Figure 1 As shown, the energy storage converter 10 includes a fuse 11, a contactor 12, a circuit breaker 13, and a semiconductor switch circuit (not shown in the figure), and the fuse 11, the contactor 12, the circuit breaker 13, and the semiconductor switch circuit are connected in series. Figure 2 is a flow chart of a control method of an energy storage converter according to an embodiment of the present application. As shown in Figure 2 The control method of the energy storage converter includes the following steps:

[0037] Step S201, obtaining an actual working current of a fuse and a predetermined relationship, the predetermined relationship representing a corresponding relationship between a current value of the fuse and a fuse time;

[0038] Optionally, the current value of the fuse and the actual working current are both instantaneous current values flowing through the fuse. The fuse time is a time interval from when the current exceeds the rated current of the fuse to when the fuse actually opens the circuit.

[0039] Step S202, determining an actual allowed energy of the fuse according to the actual working current and the predetermined relationship;

[0040] Specifically, the allowed energy of the fuse is the total energy that the fuse allows to pass through and eventually converts into heat to melt its fuse body during the entire process of the fuse melting. The allowed energy is also called Joule integral.

[0041] Step S203, in the case where the difference between the actual allowed energy and the allowed energy threshold of the fuse is greater than a preset threshold, at least one of the following is performed: adjusting the duty cycle of the semiconductor switch circuit to make the energy storage converter operate at a reduced capacity, turning off the circuit breaker, and turning off the contactor.

[0042] Specifically, in the case that the difference between the actual let-through energy and the let-through energy threshold of the fuse is greater than the preset threshold, the energy storage converter can be operated at a reduced capacity by adjusting the duty cycle of the semiconductor switching circuit alone to protect the fuse; the circuit breaker can be turned off alone to protect the fuse; the contactor can be turned off alone to protect the fuse; the semiconductor switching circuit can be adjusted and the circuit breaker can be turned off to protect the fuse by the combined action of the two actions; the semiconductor switching circuit can be adjusted and the contactor can be turned off to protect the fuse by the combined action of the two actions; the circuit breaker and the contactor can be turned off to protect the fuse; and the semiconductor switching circuit can be adjusted, the circuit breaker and the contactor can be turned off to jointly avoid the fuse from being scrapped.

[0043] According to the embodiment, the actual working current of the fuse and a predetermined relationship between the current value and the melting time of the fuse are first obtained; then the actual let-through energy corresponding to the actual working current is determined according to the actual working current and the predetermined relationship; and finally, in the case that the difference between the actual let-through energy and the let-through energy threshold is greater than the preset threshold, it is indicated that the fuse has a risk of melting, and at least one of adjusting the duty cycle of the semiconductor switching circuit, turning off the circuit breaker and turning off the contactor is performed to avoid the fuse from melting and being scrapped, and overcurrent and overvoltage protection of the energy storage converter is realized.

[0044] In actual application, the let-through energy threshold and the preset threshold can be determined according to empirical values or obtained through limited experiments.

[0045] In some embodiments, determining the actual let-through energy of the fuse according to the actual working current and the predetermined relationship includes: determining, from the predetermined relationship, the actual melting time corresponding to the actual working current as the actual melting time according to the actual working current; and determining the actual let-through energy as the product of the square of the actual working current and the actual melting time according to the actual working current and the actual melting time. This embodiment is based on the melting characteristics of the fuse. By calculating the product of the square of the actual working current and the actual melting time, the maximum energy allowed to pass through the fuse under the current working condition, i.e., the actual let-through energy, can be obtained, the melting risk of the fuse can be accurately evaluated, and the fuse can be avoided from melting by adjusting the operating state of the energy storage converter or directly cutting off the circuit before the fuse has a melting risk, thereby further reducing the system maintenance cost and system downtime caused by the melting of the fuse.

[0046] In other embodiments, the predetermined relationship can be obtained by introducing temperature compensation, aging compensation and other consideration parameters, thereby further ensuring the accuracy of the melting risk evaluation.

[0047] Optionally, the specific implementation of determining the actual melting time corresponding to the actual working current from the predetermined relationship according to the actual working current can be: according to the actual working current, the actual melting time corresponding to the actual working current is obtained by traversing the predetermined relationship through a table lookup method. Alternatively, the specific implementation of determining the actual melting time corresponding to the actual working current from the predetermined relationship according to the actual working current can also be: substituting the actual working current into the predetermined relationship to calculate the actual melting time corresponding to the actual working current.

[0048] According to still another embodiment of the present application, in the case that the difference between the actual let-through energy and the let-through energy threshold of the fuse is greater than a preset threshold, at least one of the following is performed: adjusting the duty cycle of the semiconductor switching circuit to make the energy storage converter operate at a reduced capacity, turning off the circuit breaker, and turning off the contactor, including: in the case that the actual melting time is greater than a first time threshold, adjusting the duty cycle of the semiconductor switching circuit to make the energy storage converter operate at a reduced capacity by a first percentage, the actual melting time being the melting time of the fuse corresponding to the actual working current; in the case that the actual melting time is greater than a second time threshold and less than or equal to the first time threshold, at least turning off the contactor; and in the case that the actual melting time is less than or equal to the second time threshold, turning off the circuit breaker and the contactor. This embodiment sets different melting time thresholds, compares the size relationship between the actual melting time and the melting time threshold in the case that the difference between the actual let-through energy and the let-through energy threshold of the fuse is greater than a preset threshold, to determine the degree of melting risk of the fuse, and thus takes different protective measures to adapt to the melting risk in different situations, further ensuring the safe operation of the energy storage system, further avoiding unnecessary system maintenance caused by the melting of the fuse, and further improving the operating efficiency of the energy storage system.

[0049] In addition, in the case that the actual melting time is small, the circuit connection is disconnected by the simultaneous action of the circuit breaker and the contactor. Since the sensitivity and reliability of the circuit breaker are relatively high, the problem that the contactor may not be able to be disconnected in time can be avoided, and the problem that the fuse is scrapped due to the failure of the contactor to disconnect in time is further avoided.

[0050] In some other embodiments, when the actual melting time is greater than the second time threshold and less than or equal to the first time threshold, at least turning off the contactor comprises: when the actual melting time is greater than a third time threshold and less than or equal to the first time threshold, controlling the fuse to continue to work for a first duration before turning off the contactor, the first duration being the difference between the actual melting time and the third time threshold; and when the actual melting time is greater than the second time threshold and less than or equal to the third time threshold, controlling the fuse to continue to work for a second duration before turning off the contactor, the second duration being the difference between the actual melting time and the second time threshold.

[0051] In the embodiments, when the actual melting time is greater than the third time threshold and less than or equal to the first time threshold, it means that the fuse is in an overload state for a period of time, but the melting time is relatively long, and there is still time to safely melt without causing the fuse to be scrapped. At this time, the contactor is over-delayed to turn off, and during the delay of turning off, the fuse can be attempted to be naturally restored or the overload current can be reduced to avoid unnecessary contactor actions and reduce potential fault points in the system. If the fuse fails to recover within the time, the contactor will be turned off to avoid the fuse from melting. When the actual melting time is greater than the second time threshold and less than or equal to the third time threshold, it means that the fuse is in a moderate overload state, and the melting time is shorter than the case, but still allows the system to take certain protection measures. At this time, the fuse is controlled to continue to work for a second duration before turning off the contactor, and the second duration is the difference between the actual melting time and the second time threshold. This strategy of delaying the contactor to turn off helps to avoid unnecessary protection actions triggered by transient overload, while ensuring that the fuse can be isolated in time before reaching a dangerous melting point, further reducing the waste of the fuse while ensuring the safety of the energy storage converter circuit.

[0052] In actual application, the first time threshold, the second time threshold, and the third time threshold can be determined according to empirical values or obtained through limited experiments.

[0053] Exemplarily, the first time threshold is 100s-150s, for example, the first time threshold can be 100s, 110s, 120s, 130s, 140s, or 150s, etc. The second time threshold is 1s-5s, for example, the second time threshold can be 1s, 2s, 3s, 4s, or 5s, etc. The third time threshold is 10s-50s, for example, the third time threshold can be 10s, 20s, 30s, 40s, or 50s, etc. The embodiment sets specific time thresholds to more accurately determine the risk of fusing the fuse. By setting different time thresholds, fuse fuses under different fusing risk levels are distinguished, and different protection measures are taken, which can more accurately determine the fusing risk of the fuse, so that appropriate protection measures are taken, which not only ensures the safe operation of the energy storage system, but also avoids the scrapping of the fuse.

[0054] In some embodiments, in the case where the actual fusing time is greater than the third time threshold and less than or equal to the first time threshold, the control method of the energy storage converter further includes: adjusting the duty cycle of the semiconductor switching circuit, so that the energy storage converter operates at a second percentage of rated power within the first time length during which the fuse continues to work, the second percentage being greater than the first percentage. In the embodiment, during the first time length of the delayed shutdown of the fuse, the energy storage converter is operated at a reduced power by adjusting the duty cycle of the semiconductor switching circuit, thereby reducing the current through the fuse to reduce the fusing risk of the fuse. If the fusing risk of the fuse is eliminated within the first time length, the energy storage converter does not need to be controlled to shut down, further avoiding unnecessary downtime and further improving operating efficiency. If the fusing risk of the fuse is not eliminated within the first time length, the fault circuit is cut off after the delay time reaches the first time length, thereby protecting the circuit and the fuse.

[0055] Optionally, the first percentage is 10%-30%. The first percentage is 10%, 15%, 20%, 25%, or 30%, etc. Optionally, the second percentage is 40%-70%. The second percentage is 40%, 45%, 50%, 55%, 60%, 65%, or 70%, etc. The present application distinguishes fuses under different fusing risk levels by setting different derating percentages, so that different protection measures are taken, which can further ensure the effectiveness of the derating control, thereby further relieving the immediate fusing risk of the fuse.

[0056] In some embodiments, after performing at least one of switching off the circuit breaker and switching off the contactor, the control method of the energy storage converter further comprises: determining an actual resistance of the fuse according to an actual working voltage of the fuse and the actual working current, the actual working voltage being a voltage value of the fuse obtained before at least one of switching off the circuit breaker and switching off the contactor; in a case where the actual resistance is greater than a resistance reference value of the fuse, replacing the fuse and then controlling the energy storage converter to restart; and in a case where the actual resistance is less than or equal to the resistance reference value, controlling the energy storage converter to restart. In this embodiment, the actual resistance of the fuse is monitored to determine whether the fuse needs to be replaced. If the fuse is damaged, its resistance will increase. By monitoring the actual resistance of the fuse, it can be more accurately determined whether the fuse is damaged and needs to be replaced, thereby avoiding the problem that the core power electronic devices in the circuit are damaged due to the fact that the damaged fuse cannot play a fusing protection role after the energy storage converter is restarted.

[0057] Specifically, the resistance reference value refers to a factory resistance value of the fuse.

[0058] According to still another optional scheme of the present application, the predetermined relationship is a fitting relationship obtained by data fitting on historical current values and historical fusing times of the fuse. Before determining the actual let-through energy of the fuse according to the actual working current and the predetermined relationship, the control method of the energy storage converter further comprises: obtaining an accumulated use duration of the fuse, an actual working temperature of the fuse corresponding to the actual working current, and a duration of the actual working current; determining a remaining life of the fuse according to a life prediction model of the fuse, the accumulated use duration, the actual working temperature, and the actual working current, the life prediction model being obtained by training a machine learning model using a plurality of sets of data, each set of data including a historical working current of the fuse, a historical duration corresponding to the historical working current, a historical working temperature, a historical accumulated use duration, and a historical use life; and adjusting a coefficient in the fitting relationship according to the remaining life and an adjustment strategy to obtain an adjusted fitting relationship, the adjustment strategy being determined according to the predetermined relationship corresponding to the fuse with different historical use lives.

[0059] In the embodiment, the remaining life prediction of the fuse is introduced, and a prediction model reflecting the aging characteristics of the fuse is constructed by training a plurality of sets of data including historical working current, historical duration, historical working temperature, historical cumulative use time length, and historical service life by using a machine learning model, so that the current state and future performance degradation trend of the fuse can be more accurately estimated. According to the remaining life of the fuse and the adjustment strategy, the coefficients in the fitting relationship between the fuse time and the current value are updated, the individual protection of the fuse is realized by considering the historical data and the current working environment of the fuse, and the accuracy of the fitting relationship is further improved, so that the accuracy of the subsequent control is further ensured. In addition, by dynamically adjusting the coefficients of the fitting relationship, the application can flexibly adapt to the changes of the state of the fuse, and the protection strategy can be adjusted according to the actual performance of the new fuse or the old fuse that will reach the service life.

[0060] Specifically, the cumulative use time length refers to the time length from the start of the current flowing through the fuse to the current time.

[0061] Optionally, when it is predicted that the remaining life of the fuse is short and less than a preset life value, the coefficients in the fitting relationship are adjusted, so that the calculation of the let-through energy of the fuse is more conservative, that is, the fuse time corresponding to the same current value in the adjusted fitting relationship is less than the fuse time corresponding to the current value in the fitting relationship before adjustment, so as to prevent the fuse from being prematurely or accidentally fused in the aging state. On the contrary, if the predicted remaining life is long and greater than the preset life value, the coefficients in the fitting relationship are adjusted to moderately relax the condition, that is, the fuse time corresponding to the same current value in the adjusted fitting relationship is greater than the fuse time corresponding to the current value in the fitting relationship before adjustment, to avoid unnecessary overprotection.

[0062] In other embodiments, in order to simplify the calculation process, the influence of the remaining life of the fuse on the let-through energy can also not be considered, that is, the predetermined relationship is obtained by: obtaining historical current values of a plurality of fuses and corresponding historical fuse times; fitting a plurality of historical current values and a plurality of corresponding historical fuse times to obtain the predetermined relationship.

[0063] In other embodiments, obtaining the predetermined relationship can further include: establishing a machine learning model; obtaining a plurality of historical environmental temperatures, a plurality of historical environmental humidities, a plurality of historical current values of the fuse, and a plurality of corresponding historical fuse times to obtain training data; inputting the training data into the machine learning model to train the machine learning model to obtain a trained machine learning model, and inputting the current environmental temperature and the current environmental humidity into the trained machine learning model to obtain the predetermined relationship.

[0064] In addition, in the case where the difference between the actual let-through energy and the let-through energy threshold of the fuse is less than or equal to the preset threshold, the sampling and monitoring of the working current of the fuse is continued.

[0065] In other optional embodiments, during the operation of the energy storage converter, the preset threshold of the pre-fuse isolation is continuously adjusted by learning the actual fuse breaking energy of the fuse, the load of the energy storage converter, and the changes of the power grid. For example, in the case of low load, the preset threshold can be appropriately increased to allow the fuse to withstand a greater degree of overload to reduce the frequency of protection actions. In periods of high load or frequent faults, the threshold is lowered to ensure that the circuit is protected safely and quickly in response to any abnormalities.

[0066] In specific applications, the current value of the fuse in the energy storage converter can be sampled in real time by using a voltage sampling circuit 20 as shown in Figure 3 As shown in Figure 3 The sampling resistor 21 is connected in parallel across the fuse in the voltage sampling circuit, and the current flowing through the fuse is sampled in cooperation with the first resistor 22, the second resistor 23, the third resistor 24, the fourth resistor 25, and the operational amplifier 26. The output end of the voltage sampling circuit 20 is connected to the analog-to-digital converter 30, and the actual current value flowing through the two ends of the fuse is obtained by analog-to-digital conversion. The first end of the first resistor 22 is electrically connected to the first end of the sampling resistor 21, the second end of the first resistor 22 is electrically connected to the first end of the third resistor 24 and the first input end of the operational amplifier 26, the second end of the third resistor 24 is electrically connected to the output end of the operational amplifier 26, the first end of the second resistor 23 is electrically connected to the second end of the sampling resistor 21, the second end of the second resistor 23 is electrically connected to the first end of the fourth resistor 25 and the second input end of the operational amplifier 26, and the second end of the fourth resistor 25 is grounded.

[0067] The present scheme designs a fuse breaking monitoring and pre-fuse isolation scheme, which can not only reduce the scrap rate of the fuse, but also play a role in overcurrent protection of the circuit. By sampling the voltage across the fuse, the fuse breaking time is monitored, and the protection switches (i.e., contactors and circuit breakers) before and after the fuse are combined to achieve early breaking of faults, thereby achieving protection of the fuse.

[0068] The application further provides a control device of the energy storage converter. The control device of the energy storage converter can be used to execute the control method of the energy storage converter. The device is used to realize the embodiments and preferred embodiments, which have been described above. As used below, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the device described in the embodiments is preferably realized in software, hardware or a combination of software and hardware is also possible and contemplated.

[0069] Figure 1 An exemplary partial circuit structure of the energy storage converter is shown in FIG. 1. As shown in FIG. 1, the energy storage converter 10 includes a fuse 11, a contactor 12, a circuit breaker 13 and a semiconductor switch circuit (not shown in the figure), which are connected in series. The control device of the energy storage converter provided by the application is described below. Figure 1

[0070] Figure 4 FIG. 2 is a schematic diagram of the control device of the energy storage converter according to the application. As shown in FIG. 2, the device includes: Figure 4

[0071] The first obtaining module 40 is configured to obtain an actual working current of the fuse and a predetermined relationship, which represents a correspondence between a current value of the fuse and a fuse time.

[0072] Optionally, the current value of the fuse and the actual working current are both instantaneous current values flowing through the fuse. The fuse time is a time interval from when the current exceeds the rated current of the fuse to when the fuse actually opens the circuit.

[0073] The first determining module 50 is configured to determine an actual allowed energy of the fuse according to the actual working current and the predetermined relationship.

[0074] Specifically, the allowed energy of the fuse is the total energy that the fuse allows to pass through and eventually converts into heat to melt its fuse body during the entire process of melting the fuse. The allowed energy is also called Joule integral.

[0075] The executing module 60 is configured to execute at least one of the following: adjusting a duty cycle of the semiconductor switch circuit to make the energy storage converter operate at a reduced capacity, turning off the circuit breaker and turning off the contactor, when a difference between the actual allowed energy and the allowed energy threshold of the fuse is greater than a preset threshold.

[0076] ​​Specifically, in the case that the difference between the actual let-through energy and the let-through energy threshold of the fuse is greater than the preset threshold, the energy storage converter can be operated at a reduced capacity by adjusting the duty cycle of the semiconductor switching circuit alone to protect the fuse; the circuit breaker can be turned off alone to protect the fuse; the contactor can be turned off alone to protect the fuse; the semiconductor switching circuit can be adjusted and the circuit breaker can be turned off to protect the fuse by the combined action of the two actions; the semiconductor switching circuit can be adjusted and the contactor can be turned off to protect the fuse by the combined action of the two actions; the circuit breaker and the contactor can be turned off to protect the fuse; and the semiconductor switching circuit can be adjusted, the circuit breaker and the contactor can be turned off to jointly avoid the fuse from being scrapped.

[0077] In the embodiments, the first acquisition module acquires the actual working current of the fuse and a predetermined relationship between the current value and the melting time of the fuse; the first determination module determines the actual let-through energy corresponding to the actual working current according to the actual working current and the predetermined relationship; and the execution module executes at least one of adjusting the duty cycle of the semiconductor switching circuit, turning off the circuit breaker and turning off the contactor when the difference between the actual let-through energy and the let-through energy threshold is greater than the preset threshold, to avoid the fuse from being melted and scrapped, and to simultaneously achieve overcurrent and overvoltage protection of the energy storage converter.

[0078] In actual application, the let-through energy threshold and the preset threshold can be determined according to empirical values or obtained through limited experiments.

[0079] In some embodiments, the first determination module includes a first determination submodule configured to determine the actual melting time corresponding to the actual working current from the predetermined relationship according to the actual working current, and a second determination submodule configured to determine the actual let-through energy as the product of the square of the actual working current and the actual melting time according to the actual working current and the actual melting time. In this embodiment, based on the melting characteristics of the fuse, the product of the square of the actual working current and the actual melting time is calculated to obtain the maximum energy allowed to pass through the fuse under the current working condition, i.e., the actual let-through energy, so that the melting risk of the fuse can be accurately evaluated, thereby avoiding the fuse from being melted by adjusting the operating state of the energy storage converter or directly cutting off the circuit before the fuse has a melting risk, and further reducing the system maintenance cost and system downtime caused by the melting of the fuse.

[0080] In other embodiments, the predetermined relationship can be obtained by introducing temperature compensation, aging compensation and other consideration parameters, so as to further ensure the accuracy of the melting risk evaluation.

[0081] Optionally, the first determining sub-module can comprise a traversing unit configured to traverse the predetermined relationship according to the actual working current to obtain the actual fusing time corresponding to the same current value of the actual working current by a table lookup method. Optionally, the first determining sub-module can further comprise a substituting unit configured to substitute the actual working current into the predetermined relationship to calculate the actual fusing time corresponding to the actual working current.

[0082] According to still some embodiments of the present application, the executing module comprises an adjusting sub-module configured to adjust the duty cycle of the semiconductor switching circuit to make the energy storage converter run at a first percentage of rated capacity when the actual fusing time is greater than a first time threshold, the actual fusing time being the fusing time of the fuse corresponding to the actual working current; a first shutting-down sub-module configured to shut down at least the contactor when the actual fusing time is greater than a second time threshold and less than or equal to the first time threshold; and a second shutting-down sub-module configured to shut down the circuit breaker and the contactor when the actual fusing time is less than or equal to the second time threshold. In this embodiment, different fusing time thresholds are set, and when the difference between the actual let-through energy and the let-through energy threshold of the fuse is greater than a preset threshold, the degree of fusing risk of the fuse is determined by comparing the size relationship between the actual fusing time and the fusing time threshold, so that different protection measures are taken to adapt to the fusing risk in different situations, which further ensures the safe operation of the energy storage system and further avoids unnecessary system maintenance caused by the fusing of the fuse, and further improves the operation efficiency of the energy storage system.

[0083] In addition, when the actual fusing time is small, the circuit connection is disconnected by the simultaneous action of the circuit breaker and the contactor. Since the sensitivity and reliability of the circuit breaker are relatively high, the problem that the contactor may not be disconnected in time can be avoided, and the problem that the fuse is scrapped due to the failure of the contactor to disconnect in time is further avoided.

[0084] In still some embodiments, the first shutting-down sub-module comprises a first control unit configured to control the contactor to be shut down after the fuse continues to work for a first time length when the actual fusing time is greater than a third time threshold and less than or equal to the first time threshold, the first time length being the difference between the actual fusing time and the third time threshold; and a second control unit configured to control the contactor to be shut down after the fuse continues to work for a second time length when the actual fusing time is greater than the second time threshold and less than or equal to the third time threshold, the second time length being the difference between the actual fusing time and the second time threshold.

[0085] In the embodiment, when the actual melting time is greater than the third time threshold and less than or equal to the first time threshold, it means that the fuse is in an overload state for a period of time, but the melting time is relatively long, and there is still time to safely melt without causing the fuse to be scrapped. At this time, the contactor is delayed to be turned off, and during the delay, the system can attempt to naturally recover or reduce the overload current before the fuse melts, thereby avoiding unnecessary contactor actions and reducing potential failure points in the system. If the fuse fails to recover within the time, the contactor will be turned off to avoid the fuse melting. When the actual melting time is greater than the second time threshold and less than or equal to the third time threshold, it means that the fuse is in a moderate overload state, and the melting time is shorter than the case, but still allows the system to take certain protection measures. At this time, the fuse is controlled to continue to work for a second time period, and the second time period is the difference between the actual melting time and the second time threshold. This strategy of delaying the contactor to be turned off helps to avoid unnecessary protection actions triggered by transient overload, while ensuring that the fuse can be isolated in time before reaching a dangerous melting point, thereby further reducing the waste of the fuse while ensuring the safety of the energy storage converter circuit.

[0086] In actual application, the first time threshold, the second time threshold, and the third time threshold can be determined according to empirical values or obtained through a limited number of experiments.

[0087] For example, the first time threshold is 100s-150s, such as 100s, 110s, 120s, 130s, 140s, or 150s. The second time threshold is 1s-5s, such as 1s, 2s, 3s, 4s, or 5s. The third time threshold is 10s-50s, such as 10s, 20s, 30s, 40s, or 50s. The embodiment sets specific time thresholds to more accurately determine the melting risk level of the fuse. By setting different time thresholds, the fuse under different melting risk levels can be distinguished, and different protection measures can be taken to more accurately determine the melting risk level of the fuse, thereby taking appropriate protection measures to ensure safe operation of the energy storage system and avoid fuse scrapping.

[0088] In some embodiments, the control device of the energy storage converter further comprises a first adjusting module configured to, in a case where the actual melting time is greater than the third time threshold and less than or equal to the first time threshold, adjust a duty cycle of the semiconductor switching circuit, so that the energy storage converter is operated at a second percentage of rated power within the first time duration during which the fuse continues to work, the second percentage being greater than the first percentage. In this embodiment, during the first time duration of fuse delay shutdown, the energy storage converter is operated at a reduced power by adjusting the duty cycle of the semiconductor switching circuit, so as to reduce the current through the fuse and reduce the risk of fuse melting. If the risk of fuse melting is eliminated within the first time duration, the energy storage converter does not need to be controlled to shut down, further avoiding unnecessary downtime and further improving operating efficiency. If the risk of fuse melting is not eliminated within the first time duration, the fault circuit is cut off after the delay duration reaches the first time duration, thereby protecting the circuit and the fuse.

[0089] Optionally, the first percentage is 10% to 30%. The first percentage can be 10%, 15%, 20%, 25%, or 30%, etc. Optionally, the second percentage is 40% to 70%. The second percentage can be 40%, 45%, 50%, 55%, 60%, 65%, or 70%, etc. By setting different percentages of rated power, the application can distinguish fuses with different degrees of melting risk and take different protection measures, which can further ensure the effectiveness of the rated power regulation and further alleviate the immediate melting risk of the fuse.

[0090] In some embodiments, the control device of the energy storage converter further comprises a second determining module configured to, after performing at least one of shutting down the circuit breaker and shutting down the contactor, determine an actual resistance of the fuse according to an actual operating voltage and an actual operating current of the fuse, the actual operating voltage being a voltage value of the fuse obtained before at least one of shutting down the circuit breaker and shutting down the contactor; a replacing module configured to, in a case where the actual resistance is greater than a resistance reference value of the fuse, replace the fuse and control the energy storage converter to restart; and a control module configured to, in a case where the actual resistance is less than or equal to the resistance reference value, control the energy storage converter to restart. In this embodiment, by monitoring the actual resistance of the fuse, it can be determined whether the fuse needs to be replaced. If the fuse is damaged, its resistance will increase. By monitoring the actual resistance of the fuse, it can be more accurately determined whether the fuse is damaged and needs to be replaced, thereby avoiding the problem that the core power electronic devices in the circuit are damaged due to the fact that the damaged fuse cannot play a role in fuse protection when the energy storage converter restarts.

[0091] Specifically, the resistance reference value refers to the factory resistance value of the fuse.

[0092] According to still another optional scheme of the present application, the predetermined relationship is a fitting relationship obtained by data fitting of historical current values and historical fusing time of the fuse, and the control device of the energy storage converter further comprises: a second acquisition module, configured to acquire a cumulative use duration of the fuse, an actual working temperature of the fuse corresponding to the actual working current, and a duration of the actual working current, before determining the actual allowed energy of the fuse according to the actual working current and the predetermined relationship; a third determination module, configured to determine a remaining life of the fuse according to a life prediction model of the fuse, the cumulative use duration, the actual working temperature, and the actual working current, the life prediction model being obtained by training a machine learning model using a plurality of groups of data, each group of data including historical working current of the fuse, historical duration corresponding to the historical working current, historical working temperature, historical cumulative use duration, and historical use life; and a second adjustment module, configured to adjust coefficients in the fitting relationship according to the remaining life and an adjustment strategy to obtain an adjusted fitting relationship, the adjustment strategy being determined according to the predetermined relationship corresponding to the fuse with different historical use life.

[0093] In the embodiments, the remaining life prediction of the fuse is introduced, a prediction model reflecting the aging characteristics of the fuse is constructed by training a plurality of groups of data including historical working current, historical duration, historical working temperature, historical cumulative use duration, and historical use life using a machine learning model, so as to more accurately estimate the current state and future performance degradation trend of the fuse, and the coefficients in the fitting relationship of the fusing time and the current value are updated according to the remaining life of the fuse and the adjustment strategy, thereby realizing the individualized protection of the fuse by considering the historical data and the current working environment of the fuse, further improving the accuracy of the fitting relationship, and further ensuring the accuracy of subsequent control. In addition, by dynamically adjusting the coefficients of the fitting relationship, the present application can flexibly adapt to the changes of the state of the fuse, and no matter whether it is a new fuse or an old fuse about to reach the use life, the protection strategy can be adjusted according to the actual performance.

[0094] Specifically, the cumulative use duration refers to the duration from the start of the current flowing through the fuse to the current time.

[0095] Optionally, when the predicted remaining life of the fuse is less than the preset life value, the coefficients in the fitting relationship are adjusted so that the calculation of the let-through energy of the fuse is more conservative, that is, the same current value corresponds to a shorter melting time in the adjusted fitting relationship than in the unadjusted fitting relationship, to prevent the fuse from melting prematurely or unexpectedly in an aging state. Conversely, if the predicted remaining life is greater than the preset life value, the coefficients in the fitting relationship are adjusted to relax the condition moderately, that is, the same current value corresponds to a longer melting time in the adjusted fitting relationship than in the unadjusted fitting relationship, to avoid unnecessary overprotection.

[0096] In other embodiments, to simplify the calculation process, the influence of the remaining life of the fuse on the let-through energy can also be ignored, that is, the first obtaining module includes: a first obtaining sub-module configured to obtain historical current values of a plurality of fuses and corresponding historical melting times; and a fitting sub-module configured to fit the plurality of historical current values and the corresponding plurality of historical melting times to obtain the predetermined relationship.

[0097] In other embodiments, the first obtaining module can further include: a establishing sub-module configured to establish a machine learning model; a second obtaining sub-module configured to obtain a plurality of historical ambient temperatures, a plurality of historical ambient humidities, a plurality of historical current values of the fuse, and a plurality of corresponding historical melting times to obtain training data; and an inputting sub-module configured to input the training data into the machine learning model, train the machine learning model to obtain a trained machine learning model, and input the current ambient temperature and the current ambient humidity into the trained machine learning model to obtain the predetermined relationship.

[0098] In addition, when the difference between the actual let-through energy and the let-through energy threshold of the fuse is less than or equal to the preset threshold, the sampling and monitoring of the operating current of the fuse continue.

[0099] In other optional embodiments, during the operation of the energy storage converter, the preset threshold of the pre-fuse isolation is continuously adjusted by learning the actual melting energy of the fuse, the load of the energy storage converter, and the change of the power grid. For example, in the case of low load, the preset threshold can be appropriately increased to allow the fuse to withstand a greater degree of overload to reduce the frequency of protection actions. In periods of high load or frequent faults, the threshold is lowered to ensure that the circuit is protected safely and quickly in response to any abnormalities.

[0100] In still another aspect, the embodiments of the present application also provide a kind of energy storage system, comprising: energy storage device;Energy storage converter, which is electrically connected with the energy storage device;The control device of the energy storage converter, comprising: one or more processors, memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include the control method of any one of the energy storage converter.

[0101] In the energy storage system, the control device of the energy storage converter is used to execute any one of the control methods, which first acquires the actual working current of the fuse and the predetermined relationship representing the relationship between the current value of the fuse and the melting time;Then, according to the actual working current and the predetermined relationship, the actual allowed energy corresponding to the actual working current is determined;Finally, in the case where the difference between the actual allowed energy and the allowed energy threshold is greater than the preset threshold, it is indicated that the fuse has a risk of melting, and at least one of adjusting the duty cycle of the semiconductor switching circuit, turning off the circuit breaker and turning off the contactor is executed to avoid the fuse from melting and scrapping, and at the same time, the overcurrent and overvoltage protection of the entire energy storage system is realized.

[0102] In still another aspect, the embodiments of the present application also provide a kind of energy storage system, comprising: energy storage device;Energy storage converter, which is electrically connected with the energy storage device;The control device of the energy storage converter, comprising: one or more processors, memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include the control method of any one of the energy storage converter.

[0103] The energy storage system includes any one of the control devices, which acquires the actual working current of the fuse and the predetermined relationship representing the relationship between the current value of the fuse and the melting time through the first acquisition module;According to the actual working current and the predetermined relationship, the actual allowed energy corresponding to the actual working current is determined through the first determination module;In the case where the difference between the actual allowed energy and the allowed energy threshold is greater than the preset threshold, it is indicated that the fuse has a risk of melting, and at least one of adjusting the duty cycle of the semiconductor switching circuit, turning off the circuit breaker and turning off the contactor is executed to avoid the fuse from melting and scrapping, and at the same time, the overcurrent and overvoltage protection of the energy storage system is realized.

[0104] The technical features of the above-described embodiments can be combined in any way, and to make the description concise, all possible combinations of the technical features in the embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present application.

[0105] From the above description, it can be seen that the embodiments of the present application achieve the following technical effects:

[0106] The control method of the energy storage converter provided in the application first acquires an actual working current of a fuse and a predetermined relationship representing a relationship between a current value and a melting time of the fuse; then determines an actual allowed energy corresponding to the actual working current according to the actual working current and the predetermined relationship; and finally, in the case that a difference between the actual allowed energy and an allowed energy threshold is greater than a preset threshold, it is indicated that the fuse has a melting risk, at this time, at least one of adjusting a duty cycle of the semiconductor switching circuit, turning off the circuit breaker and turning off the contactor is executed to avoid the fuse from melting and scrapping, and at the same time, overcurrent and overvoltage protection of the energy storage converter is realized.

[0107] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the application, and in actual application, various changes can be made in form and details without departing from the spirit and scope of the application. Any person skilled in the art can make various modifications and changes without departing from the spirit and scope of the application, therefore, the protection scope of the application should be limited by the scope defined in the claims.

Claims

1. A control method of an energy storage converter, characterized by, The energy storage converter comprises a fuse, a contactor, a circuit breaker and a semiconductor switch circuit, the fuse, the contactor, the circuit breaker and the semiconductor switch circuit are connected in series, and a control method of the energy storage converter comprises: acquiring an actual working current of the fuse and a predetermined relationship, the predetermined relationship representing a corresponding relationship between a current value of the fuse and a fuse-out time; determining an actual let-through energy of the fuse according to the actual working current and the predetermined relationship; in a case where a difference between the actual let-through energy and a let-through energy threshold of the fuse is greater than a preset threshold, at least one of the following is performed: adjusting a duty cycle of the semiconductor switch circuit to make the energy storage converter operate at a reduced capacity, turning off the circuit breaker, and turning off the contactor.

2. The control method of the energy storage converter according to claim 1, characterized by, The method further comprises: determining, according to the actual working current, that the fuse-out time corresponding to the actual working current in the predetermined relationship is an actual fuse-out time; determining, according to the actual working current and the actual fuse-out time, that the actual let-through energy is a product of a square of the actual working current and the actual fuse-out time.

3. The control method of the energy storage inverter according to claim 1, characterized by, in a case where a difference between the actual let-through energy and a let-through energy threshold of the fuse is greater than a preset threshold, at least one of the following is performed: adjusting a duty cycle of the semiconductor switch circuit to make the energy storage converter operate at a reduced capacity, turning off the circuit breaker, and turning off the contactor, comprises: in a case where the actual fuse-out time is greater than a first time threshold, adjusting the duty cycle of the semiconductor switch circuit to make the energy storage converter operate at a reduced capacity of a first percentage, the actual fuse-out time being the fuse-out time of the fuse corresponding to the actual working current; in a case where the actual fuse-out time is greater than a second time threshold and less than or equal to the first time threshold, at least turning off the contactor; in a case where the actual fuse-out time is less than or equal to the second time threshold, turning off the circuit breaker and the contactor.

4. The control method of the energy storage inverter according to claim 3, characterized by, in a case where the actual fuse-out time is greater than a second time threshold and less than or equal to the first time threshold, at least turning off the contactor, comprises: in a case where the actual fuse-out time is greater than a third time threshold and less than or equal to the first time threshold, controlling the fuse to continue working for a first duration before turning off the contactor, the first duration being a difference between the actual fuse-out time and the third time threshold; in a case where the actual fuse-out time is greater than the second time threshold and less than or equal to a third time threshold, controlling the fuse to continue working for a second duration before turning off the contactor, the second duration being a difference between the actual fuse-out time and the second time threshold.

5. The control method of the energy storage inverter according to claim 4, characterized by, The first time threshold is 100s-150s, the second time threshold is 1s-5s, and the third time threshold is 10s-50s.

6. The control method of the energy storage inverter according to claim 4, wherein in a case where the actual fuse-out time is greater than a third time threshold and less than or equal to the first time threshold, the control method of the energy storage converter further comprises: Adjust a duty cycle of the semiconductor switch circuit, so that the energy storage converter runs at a second percentage of capacity during the first duration of time in which the fuse continues to operate, the second percentage being greater than the first percentage.

7. The control method of the energy storage inverter according to claim 6, characterized by, The first percentage is 10% to 30%, and the second percentage is 40% to 70%.

8. The control method of the energy storage inverter according to claim 1, wherein After performing at least one of turning off the circuit breaker and turning off the contactor, the control method of the energy storage converter further includes: According to the actual operating voltage and the actual operating current of the fuse, the actual resistance of the fuse is determined, and the actual operating voltage is the voltage value of the fuse obtained before at least one of turning off the circuit breaker and turning off the contactor; In the case where the actual resistance is greater than the resistance reference value of the fuse, the energy storage converter is controlled to restart after the fuse is replaced; In the case where the actual resistance is less than or equal to the resistance reference value, the energy storage converter is controlled to restart.

9. The control method of the energy storage inverter according to claim 1, characterized by, The predetermined relationship is a fitting relationship obtained by data fitting of historical current values and historical fusing times of the fuse, and before determining the actual let-through energy of the fuse according to the actual operating current and the predetermined relationship, the control method of the energy storage converter further includes: Obtaining the cumulative use duration of the fuse, the actual operating temperature of the fuse corresponding to the actual operating current, and the duration of the actual operating current; According to the life prediction model of the fuse, the cumulative use duration, the actual operating temperature and the actual operating current, the remaining life of the fuse is determined, the life prediction model is obtained by training a machine learning model using a plurality of sets of data, each set of data including historical operating current, historical duration corresponding to the historical operating current, historical operating temperature, historical cumulative use duration and historical service life; According to the remaining life and the adjustment strategy, the coefficient in the fitting relationship is adjusted to obtain the adjusted fitting relationship, and the adjustment strategy is determined according to the predetermined relationship corresponding to the fuse with different historical service life.

10. A control device for an energy storage converter, characterized by The energy storage converter includes a fuse, a contactor, a circuit breaker and a semiconductor switch circuit, the fuse, the contactor, the circuit breaker and the semiconductor switch circuit are connected in series, and the control device of the energy storage converter includes: A first acquisition module is configured to acquire an actual operating current of a fuse and a predetermined relationship, the predetermined relationship representing a correspondence between current values and fusing times of the fuse; A first determination module is configured to determine an actual let-through energy of the fuse according to the actual operating current and the predetermined relationship; An execution module is configured to perform at least one of the following in the case where the difference between the actual let-through energy and the let-through energy threshold of the fuse is greater than a preset threshold: adjusting a duty cycle of the semiconductor switch circuit to make the energy storage converter run at a reduced capacity, turning off the circuit breaker, and turning off the contactor.

11. An energy storage system characterized by, The energy storage device; The energy storage converter is electrically connected to the energy storage device; ​ The control device of the energy storage converter comprises one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs comprise a program for executing the control method of the energy storage converter according to any one of claims 1 to 9.

12. An electrical device, characterized by The control device of the energy storage converter according to claim 10.

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