Line detection method and energy storage system

Abstract

The invention provides a line detection method and an energy storage system, the energy storage system comprises at least one energy storage unit, the energy storage unit comprises a current conversion device and an energy storage battery having a corresponding relation with the current conversion device, and the method comprises the following steps: when the energy storage system is in a running state, the current conversion device is connected with the energy storage battery; based on at least one of the first electric energy parameter of the current conversion device, the operation state of the current conversion device, the second electric energy parameter of the energy storage battery and the operation state of the energy storage battery, carrying out charging and discharging abnormity detection on the energy storage battery; and if it is detected that an energy storage battery in the energy storage unit has a preset type of charging and discharging abnormity and the duration of the preset type of charging and discharging abnormity is greater than a duration threshold corresponding to the preset type, determining that a line between a current conversion device in the energy storage unit and the energy storage battery is abnormal. According to the invention, the abnormity of the line between the converter device and the energy storage battery can be rapidly and accurately detected.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and more specifically, to a line detection method and an energy storage system. Background Technology

[0002] As a crucial bridge connecting energy storage battery arrays and the power grid, the core responsibility of the energy storage converter is to precisely control the battery's charge and discharge cycles, achieving efficient conversion between DC and AC power. Through intelligent charge and discharge management strategies, the converter can ensure that the energy storage system responds to the power dispatch commands of the power grid, meeting the needs of flexible dispatch.

[0003] However, with the increasing complexity of energy storage systems, there is a risk of misconnection in the wiring between the converter and the battery pack. This could lead to overcharging or over-discharging of the batteries during long-term operation, ultimately damaging the overall performance and lifespan of the energy storage system. Therefore, effectively preventing and resolving such problems has become an important issue in ensuring the stable operation of energy storage systems. Summary of the Invention

[0004] In view of this, this application provides a line detection method and an energy storage system, which can quickly and accurately detect line abnormalities between the converter device and the energy storage battery. The specific solution is as follows:

[0005] A line detection method is applied to an energy storage system, the energy storage system including at least one energy storage unit, the energy storage unit including a converter and an energy storage battery corresponding to the converter; the method includes:

[0006] When the energy storage system is in operation, based on at least one of the first electrical energy parameters of the converter, the operating status of the converter, the second electrical energy parameters of the energy storage battery, and the operating status of the energy storage battery, abnormal charging and discharging of the energy storage battery in the energy storage unit is detected.

[0007] If a preset type of charging / discharging abnormality is detected in the energy storage battery of the energy storage unit, and the duration of the preset type of charging / discharging abnormality is greater than the duration threshold corresponding to the preset type, then it is determined that there is a circuit abnormality between the converter and the energy storage battery in the energy storage unit.

[0008] Optionally, in the above method, the first electrical energy parameter includes at least one of the current, voltage, and power of the converter; the second electrical energy parameter includes at least one of the remaining charge, current, and voltage of the energy storage battery.

[0009] Accordingly, the step of detecting charging and discharging anomalies in the energy storage unit based on at least one of the first electrical energy parameters of the converter, the operating status of the converter, the second electrical energy parameters of the energy storage battery, and the operating status of the energy storage battery includes:

[0010] If the energy storage battery is in a fault state, the converter is in a shutdown state, and the current of the energy storage battery exceeds the limit, then it is determined that the energy storage battery of the energy storage unit has a preset first type of charging and discharging abnormality.

[0011] If the energy storage battery is not in a fault state, the remaining power of the energy storage battery is greater than the preset power limit protection threshold, the power of the converter is zero, and the current of the energy storage battery exceeds the preset charging current threshold, then it is determined that the energy storage battery of the energy storage unit has a preset second type of charging and discharging abnormality.

[0012] If the energy storage battery is not in a fault state, the remaining power of the energy storage battery is less than a preset lower limit value, the power of the converter is zero, and the current of the energy storage battery exceeds a preset discharge current threshold, then it is determined that the energy storage battery of the energy storage unit has a preset third type of charging and discharging abnormality.

[0013] If the energy storage battery is not in a fault state, the remaining power of the energy storage battery does not exceed the preset upper limit value, the remaining power of the energy storage battery does not exceed the preset lower limit value, the energy storage unit is in operation, and a mismatch is detected between the current of the converter and the current of the energy storage battery, then it is determined that the energy storage unit has a preset fourth type of charging and discharging abnormality.

[0014] If the energy storage battery is not in a fault state, the remaining power of the energy storage battery does not exceed the preset upper limit value, the remaining power of the energy storage battery does not exceed the preset lower limit value, the energy storage unit is in operation, and a voltage mismatch is detected between the converter and the energy storage battery, then it is determined that the energy storage unit has a preset fifth type of charging and discharging abnormality.

[0015] Optionally, the process of detecting a mismatch between the current of the converter and the current of the energy storage battery in the above method includes:

[0016] Determine the fluctuating current corresponding to the current of the converter device;

[0017] The target current fluctuation range corresponding to the converter is determined based on the current of the energy storage battery and the fluctuating current.

[0018] If the current of the converter is not within the target current fluctuation range, it is determined that the current of the converter and the current of the energy storage battery are mismatched.

[0019] Optionally, the process of detecting a voltage mismatch between the converter and the energy storage battery in the above method includes:

[0020] Determine the voltage fluctuation corresponding to the voltage of the converter device;

[0021] The target voltage fluctuation range corresponding to the converter is determined based on the voltage of the energy storage battery and the fluctuating voltage.

[0022] If the voltage of the converter is not within the target voltage fluctuation range, it is determined that the voltage of the converter is mismatched with the voltage of the energy storage battery.

[0023] Optionally, the above method includes detecting charging and discharging anomalies in the energy storage unit based on at least one of the first electrical energy parameters of the converter, the operating state of the converter, the second electrical energy parameters of the energy storage battery, and the operating state of the energy storage battery, comprising:

[0024] Detect whether the first electrical energy parameter in the converter device matches the second electrical energy parameter of the energy storage battery;

[0025] If the first electrical energy parameter in the converter device does not match the second electrical energy parameter of the energy storage battery, it is determined that there is a charging / discharging abnormality in the energy storage battery in the energy storage unit.

[0026] Optionally, after determining that there is a circuit anomaly between the converter and the energy storage battery in the energy storage unit, the above method further includes:

[0027] The system controls the energy storage system to stop operating and outputs the identifiers of the converter in the energy storage power supply and the energy storage battery.

[0028] Optionally, after controlling the energy storage system to stop operating, the above method further includes:

[0029] Receive user fault configuration operations;

[0030] When the fault configuration operation is of the first type, control the activation of all units in the energy storage system except for the energy storage unit with line abnormality.

[0031] When the fault configuration operation is the second type of fault configuration operation, the correspondence between the converter and the energy storage battery in the energy storage unit with the line abnormality is changed; after the correspondence between the converter and the energy storage battery is changed, the energy storage system is controlled to start.

[0032] An energy storage system, comprising:

[0033] The control device and at least one energy storage unit; each energy storage unit includes a converter and an energy storage battery corresponding to the converter;

[0034] The converter in each of the energy storage units is used to convert the AC power in the grid to DC power and output the converted DC power to the energy storage battery connected to the converter, or to convert the DC power in the energy storage battery connected to the converter to AC power and output the converted AC power to the grid.

[0035] The energy storage battery in each of the energy storage units is used to store the direct current output by the converter connected to the energy storage battery, or to output the direct current to the converter connected to the energy storage battery.

[0036] The control device is configured to, when the energy storage system is in operation, perform charge / discharge anomaly detection on the energy storage battery in each energy storage unit based on at least one of the first electrical energy parameters of the converter device in each energy storage unit and the second electrical energy parameters of the energy storage battery; if a preset type of charge / discharge anomaly is detected in any energy storage battery in the energy storage unit, and the duration of the preset type of charge / discharge anomaly is greater than the duration threshold corresponding to the preset type, then it is determined that there is a line anomaly between the converter device and the energy storage battery in the energy storage unit.

[0037] The aforementioned system may optionally also include: a battery information collector;

[0038] The battery information collector is used to collect battery data of the energy storage batteries in each of the energy storage units; and to send the collected battery data of each energy storage battery to the control device; the battery data of each energy storage battery includes the operating status of each energy storage battery and second power data.

[0039] The aforementioned system may optionally also include: a transformer;

[0040] The transformer is connected to the AC side of the converter in each of the energy storage units, and is used to step up the AC power output from at least one of the converters and transmit the stepped-up AC power to the power grid, or to step down the AC power in the power grid and transmit the stepped-down AC power to at least one of the converters.

[0041] Compared with the prior art, this application has the following beneficial effects:

[0042] This application provides a line detection method and an energy storage system, applied to an energy storage system including at least one energy storage unit. Each energy storage unit includes a converter and a corresponding energy storage battery. The method includes: when the energy storage system is in operation, detecting charging / discharging anomalies in the energy storage battery within the energy storage unit based on at least one of a first electrical energy parameter of the converter, the operating state of the converter, a second electrical energy parameter of the energy storage battery, and the operating state of the energy storage battery; if a preset type of charging / discharging anomaly is detected in the energy storage battery within the energy storage unit, and the duration of the preset type of charging / discharging anomaly exceeds a duration threshold corresponding to the preset type, then a line anomaly between the converter and the energy storage battery within the energy storage unit is determined. Applying the method provided in this application, line anomalies between the converter and the energy storage battery can be detected quickly and accurately. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0044] Figure 1 This application provides a method flow for a line detection method.

[0045] Figure 2 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application;

[0046] Figure 3 This is a schematic diagram of another energy storage system provided in an embodiment of this application;

[0047] Figure 4 A flowchart for detecting power line anomalies is provided in an embodiment of this application. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] Based on this, this application provides a line detection method applied to a control device in an energy storage system. The energy storage system further includes at least one energy storage unit, each energy storage unit including a converter and an energy storage battery corresponding to the converter. The flowchart of the method is as follows: Figure 1 As shown, it specifically includes:

[0050] S101: When the energy storage system is in operation, based on at least one of the first electrical energy parameters of the converter, the second electrical energy parameters of the energy storage battery, the operating status of the converter, and the operating status of the energy storage battery, abnormal charging and discharging of the energy storage battery in the energy storage unit is detected.

[0051] In this embodiment, the first electrical energy parameter of the converter may include at least one of the current, voltage, and power of the converter; the second electrical energy parameter of the energy storage battery may include at least one of the remaining charge, current, and voltage of the energy storage battery.

[0052] In this embodiment, charging and discharging anomalies of the energy storage battery are detected based on one of the first and second electrical energy parameters, combined with the operating status of the energy storage battery and the operating status of the converter. Optionally, the operating status of the energy storage battery can characterize at least one of the following: whether the energy storage battery has malfunctioned, whether the energy storage battery is in a state of maximum remaining charge protection, and whether the energy storage battery is in a state of minimum remaining charge protection; the operating status of the converter can characterize whether the converter has stopped. In some embodiments, if the voltage of the energy storage battery exceeds a preset voltage operating range, the capacity of the energy storage battery is less than a preset capacity threshold, the temperature of the energy storage battery exceeds a preset temperature range, or the current of the energy storage battery exceeds a preset current operating range, it can be determined that the energy storage battery has malfunctioned, i.e., the energy storage battery is in a fault state; otherwise, it can be determined that the energy storage battery has not malfunctioned. If the charging amount of the energy storage battery corresponding to the converter reaches the upper limit or the discharging amount reaches the lower limit, the converter can be controlled to stop, so that the converter is in a stopped state; otherwise, the converter can be controlled to operate normally.

[0053] For example, if the energy storage battery malfunctions and the converter is shut down, and the current and voltage parameters in the second electrical parameters of the energy storage battery indicate that the battery is still charging or discharging, then it can be determined that the energy storage battery has a charging / discharging abnormality. Alternatively, if the energy storage battery and converter are operating normally, and the energy storage battery is in the upper limit of remaining capacity protection state, but the current and voltage parameters in the second electrical parameters indicate that the battery is still charging, then it can be determined that the energy storage battery has a charging / discharging abnormality. Or, if the energy storage battery and converter are operating normally, and the energy storage battery is in the lower limit of remaining capacity protection state, but the current and voltage parameters in the second electrical parameters indicate that the battery is still discharging, then it can be determined that the energy storage battery has a charging / discharging abnormality. Or, if the energy storage battery and converter are operating normally, but the first electrical parameters of the converter and the second electrical parameters of the energy storage battery do not match, then it can be determined that the energy storage battery has a charging / discharging abnormality. It should be noted that a charging / discharging abnormality can refer to at least one of the following abnormalities: charging abnormality or discharging abnormality.

[0054] In some embodiments, based on at least one of a first electrical energy parameter of the converter in the energy storage unit and a second electrical energy parameter of the energy storage battery, abnormal charging and discharging detection is performed on the energy storage battery in the energy storage unit, including:

[0055] Check whether the first electrical energy parameter in the converter device matches the second electrical energy parameter of the energy storage battery;

[0056] If the first electrical energy parameter in the converter device does not match the second electrical energy parameter of the energy storage battery, it is determined that there is an abnormal charging and discharging of the energy storage battery in the energy storage unit.

[0057] In this embodiment, it is possible to detect whether the current in the first electrical energy parameter matches the current in the second electrical energy parameter; to detect whether the voltage in the first electrical energy parameter matches the voltage in the second electrical energy parameter; if the current and / or voltage do not match between the first electrical energy parameter and the second electrical energy parameter, it can be determined that the energy storage battery has a charging and discharging abnormality.

[0058] S102: If a preset type of charging and discharging abnormality is detected in the energy storage battery in the energy storage unit, and the duration of the preset type of charging and discharging abnormality is greater than the duration threshold corresponding to the preset type, then it is determined that there is a circuit abnormality between the converter and the energy storage battery in the energy storage unit.

[0059] In this embodiment, if a certain type of charging and discharging abnormality occurs continuously, and the duration of the charging and discharging abnormality of the preset type is greater than the duration threshold corresponding to the preset type, it indicates that there is an abnormality in the circuit between the converter device and the energy storage battery in the energy storage unit. Specifically, it may be that the power line connection between the converter device and the energy storage battery is incorrect, or the correspondence between the converter device and the energy storage battery is configured incorrectly.

[0060] Optionally, the duration thresholds for different preset types can be the same or different, and can be configured by technical personnel based on actual needs.

[0061] In some embodiments, after detecting a preset type of charging and discharging abnormality in the energy storage battery, the number of times the preset type of charging and discharging abnormality occurs can be counted. If the number of times the preset type of charging and discharging abnormality occurs is greater than the threshold number corresponding to the preset type, then it is determined that there is a line abnormality between the converter device and the energy storage battery in the energy storage unit.

[0062] The method provided in the embodiments of this application can quickly and accurately detect line abnormalities between the converter and the energy storage battery.

[0063] In one embodiment provided in this application, based on the above-described scheme, optionally, based on at least one of the first electrical energy parameters of the converter, the second electrical energy parameters of the energy storage battery, the operating state of the converter, and the operating state of the energy storage battery, abnormal charging and discharging detection is performed on the energy storage battery in the energy storage unit, including:

[0064] If the energy storage battery is in a fault state, the converter is in a shutdown state, or the current of the energy storage battery exceeds the limit, then it is determined that the energy storage battery of the energy storage unit has a preset first type of charging and discharging abnormality.

[0065] If the energy storage battery is not in a fault state, the remaining capacity of the energy storage battery is greater than the preset upper limit protection threshold, the power of the converter is zero, and the current of the energy storage battery exceeds the preset charging current threshold, then it is determined that the energy storage battery of the energy storage unit has a preset second type of charging and discharging abnormality.

[0066] If the energy storage battery is not in a fault state, the remaining power of the energy storage battery is less than the preset lower limit of power, the power of the converter is zero, and the current of the energy storage battery exceeds the preset discharge current threshold, then it is determined that the energy storage battery of the energy storage unit has a preset third type of charging and discharging abnormality.

[0067] If the energy storage battery is not in a fault state, the remaining energy storage battery does not exceed the preset upper limit value, the remaining energy storage battery does not exceed the preset lower limit value, the energy storage unit is in operation, and a mismatch is detected between the current of the converter and the current of the energy storage battery, then it is determined that the energy storage unit has a preset fourth type of charging and discharging abnormality.

[0068] If the energy storage battery is not in a fault state, the remaining energy storage battery capacity does not exceed the preset upper limit, the remaining energy storage battery capacity does not exceed the preset lower limit, the energy storage unit is in operation, and a voltage mismatch is detected between the converter and the energy storage battery, then it is determined that the energy storage unit has a preset fifth type of charging and discharging abnormality.

[0069] In this embodiment, if the above situation does not occur, it can be determined that the energy storage unit does not have any charging or discharging abnormalities.

[0070] In this embodiment, it can first detect whether the energy storage battery is in a fault state; if the energy storage battery is in a fault state, it can detect whether the converter has been shut down and whether the current of the energy storage battery exceeds the limit; if the energy storage battery is not in a fault state, it can detect whether the energy storage battery is in a state of maximum remaining charge protection; if the energy storage battery is in a state of maximum remaining charge protection, it can detect whether the power of the converter is zero and whether the current of the energy storage battery exceeds a preset charging current threshold; if the energy storage battery is not in a state of maximum remaining charge protection, it can detect whether the energy storage battery is in a state of minimum remaining charge protection; if the energy storage battery is in a state of minimum remaining charge protection, it can detect whether the power of the converter is zero and whether the current of the energy storage battery exceeds a preset discharging current threshold; if the energy storage battery is not in a state of minimum remaining charge protection, it can detect whether the converter is in a running state; if the converter is in a running state, it can detect whether the current I1 of the converter and the current I2 of the energy storage battery match; it can also detect whether the voltage U1 of the converter and the voltage U2 of the energy storage battery match.

[0071] Optionally, the duration thresholds corresponding to the first, second, and third preset types can all be 10 seconds; the duration thresholds corresponding to the fourth and fifth preset types can all be 30 seconds; the duration thresholds corresponding to each preset type can be set and changed by technicians according to actual needs, and this application embodiment does not limit the duration thresholds corresponding to each preset type.

[0072] In one embodiment provided in this application, based on the above-described solution, optionally, the process of detecting a mismatch between the current of the converter and the current of the energy storage battery includes:

[0073] Determine the fluctuating current corresponding to the current of the converter device;

[0074] The target current fluctuation range of the converter device is determined based on the current of the energy storage battery and the fluctuating current.

[0075] If the current of the converter is not within the target current fluctuation range, it is determined that the current of the converter and the current of the energy storage battery are mismatched.

[0076] Optionally, the fluctuating current I3 corresponding to the current I1 of the converter can be calculated from the current I1 and a preset first fluctuation coefficient; the specific calculation method for the fluctuating current I3 is as follows:

[0077] I3=I1*K1+G

[0078] Wherein, K1 is the first fluctuation coefficient, which can be set to 9% or 10%, etc.; G is the compensation value, which can be 2A. Optionally, the first fluctuation system and the compensation value can be configured by the user according to actual needs.

[0079] In some embodiments, the control device may receive a first fluctuation coefficient configuration operation from a user and update a second fluctuation coefficient in response to the first fluctuation coefficient configuration operation.

[0080] Optionally, the target current fluctuation range is (I A I B ), where I A =|I2|-|I3|, I B =|I2|+|I3|.

[0081] In this embodiment, if the current I1 of the converter is within the target current fluctuation range (I A I B Within this range, it can be determined that the current of the converter device matches the current of the energy storage battery.

[0082] In one embodiment provided in this application, based on the above-described solution, optionally, the process of detecting a voltage mismatch between the converter and the energy storage battery includes:

[0083] Determine the voltage fluctuation corresponding to the voltage of the converter unit;

[0084] The target voltage fluctuation range for the converter device is determined based on the voltage and fluctuation of the energy storage battery.

[0085] If the voltage of the converter is not within the target voltage fluctuation range, it is determined that the voltage of the converter is mismatched with the voltage of the energy storage battery.

[0086] Optionally, the fluctuation voltage U3 corresponding to the voltage U1 of the converter can be calculated from the voltage U1 and a preset second fluctuation coefficient; the specific calculation method for the fluctuation voltage U3 is as follows:

[0087] U3=U1*K2

[0088] Wherein, K2 is the second fluctuation coefficient, which can be set to 4% or 5%, etc.; the second fluctuation coefficient can be configured by the user according to actual needs. In some embodiments, the control device can receive the user's second fluctuation coefficient configuration operation and update the second fluctuation coefficient in response to the second fluctuation coefficient configuration operation.

[0089] Optionally, the target voltage fluctuation range is (U A U B ), where U A=|U2|-|U3|, U B =|U2|+|U3|.

[0090] In this embodiment, if the voltage U1 of the converter is within the target voltage fluctuation range (U A U B Within this range, it can be determined that the voltage of the converter device matches the voltage of the energy storage battery.

[0091] In one embodiment provided in this application, based on the above-described solution, optionally, after determining that there is a circuit abnormality between the converter device and the energy storage battery in the energy storage unit, the method further includes:

[0092] The system controls the energy storage system to stop operating and outputs the identifiers of the converter and the energy storage battery in the energy storage power supply.

[0093] In one embodiment provided in this application, based on the above-described solution, optionally, after controlling the energy storage system to stop operating, the method further includes:

[0094] Receive user fault configuration operations;

[0095] In the case of a fault configuration operation of type 1, the control system starts up all units in the energy storage system except for energy storage units with line malfunctions.

[0096] In the case of a fault configuration operation of type 2, the correspondence between the converter and the energy storage battery in the energy storage unit with line abnormality is changed; after the correspondence between the converter and the energy storage battery is changed, the energy storage system is started.

[0097] See Figure 2 This is a schematic diagram of an energy storage system provided in an embodiment of this application. The energy storage system includes:

[0098] The control device 201 and at least one energy storage unit 202; each energy storage unit 202 includes a converter and an energy storage battery corresponding to the converter;

[0099] The converter in each energy storage unit 202 is used to convert the AC power in the grid to DC power and output the converted DC power to the energy storage battery connected to the converter, or to convert the DC power in the energy storage battery connected to the converter to AC power and output the converted AC power to the grid.

[0100] The energy storage battery in each energy storage unit 202 is used to store the DC power output by the converter connected to the energy storage battery, or to output the DC power to the converter connected to the energy storage battery.

[0101] The control device 201 is used to detect charging and discharging abnormalities of the energy storage battery in each energy storage unit based on at least one of the first electrical energy parameters of the converter device in each energy storage unit and the second electrical energy parameters of the energy storage battery when the energy storage system is in operation; if a preset type of charging and discharging abnormality is detected in any energy storage battery in the energy storage unit, and the duration of the preset type of charging and discharging abnormality is greater than the duration threshold corresponding to the preset type, then it is determined that there is a line abnormality between the converter device and the energy storage battery in the energy storage unit.

[0102] In one embodiment provided in this application, based on the above-described solution, the energy storage system may optionally include: a battery information collector;

[0103] The battery information collector is used to collect battery data of the energy storage batteries in each energy storage unit; the collected battery data of each energy storage battery is sent to the control device; the battery data of each energy storage battery includes the operating status of each energy storage battery and the second energy data.

[0104] In one embodiment provided in this application, based on the above-described solution, the energy storage system may optionally include: a transformer;

[0105] The transformer is connected to the AC side of the converter in each energy storage unit to step up the AC output of at least one converter and transmit the stepped-up AC to the power grid, or to step down the AC in the power grid and transmit the stepped-down AC to at least one converter.

[0106] See Figure 3This is a schematic diagram of another energy storage system provided in this application embodiment, including a control device LC, multiple converters PCS (i.e., the converter devices mentioned above), multiple battery cells (i.e., the energy storage batteries mentioned above), a battery information collector BSC, and a transformer; each converter corresponds one-to-one with each battery cell; if the correspondence is configured correctly and the power line connection is correct, the system can charge and discharge normally. If an abnormal pairing occurs, such as the actual correspondence being PCS1 corresponding to battery cell 1 and PCS2 corresponding to battery cell 2, but incorrectly set on the LC to PCS1 corresponding to battery cell 2 and PCS2 corresponding to battery cell 1. If battery cell 1 has a higher SOC and battery cell 2 has a lower SOC, then when the system responds to scheduling such as a charging command, all PCS will charge simultaneously. When battery cell 1's SOC reaches its upper limit, PCS2 will shut down, while PCS1 will continue charging. This will lead to overcharging of battery cell 1 and may even cause a safety accident, while battery cell 2 will never be able to charge to its upper SOC limit. Similarly, if battery cell 1 has a higher SOC and battery cell 2 has a lower SOC, then when the system responds to scheduling such as a discharging command, all PCS will discharge simultaneously. When battery cell 2's SOC discharges to its lower limit, PCS1 will shut down, while PCS2 will continue discharging. This will lead to over-discharging of battery cell 2, while battery cell 2 will never be able to discharge to its lower SOC limit.

[0107] Based on this, in this embodiment, as Figure 4 As shown, the system can sequentially detect whether there is a power line abnormality in the battery cell corresponding to each PCS. After a power line abnormality fault is triggered, the system will stop and upload and display the serial numbers of the abnormal PCS and battery cell. In LC, there are settings options to determine the subsequent handling plan for this fault. After stopping, the user can choose to ignore the abnormality and restart. In this case, devices with misconnected power lines between the corresponding PCS and battery pack will not start. If the setting is to not ignore the abnormality, the user needs to reconfigure the correspondence between the PCS and battery according to the abnormality prompt and click start. If there is no abnormality, the fault is resolved; if not, the serial numbers of the abnormal PCS and battery cell will be displayed again.

[0108] The specific process for detecting power line abnormalities in the battery cells corresponding to each PCS is as follows:

[0109] When a battery cell fails and the PCS is shut down, if the corresponding battery system current is not 0 (battery system current >10A or <-10A, current threshold can be set) and lasts for more than 10 seconds, a power line abnormality fault is triggered.

[0110] If the battery system is fault-free and has a secondary protection against the upper limit of SOC, and the corresponding PCS power is 0, and the battery is continuously charged (battery system current < -10A, current threshold can be set) for more than 10 seconds, then a power line abnormal fault will be triggered.

[0111] If the battery system is fault-free and has SOC lower limit secondary protection, and the corresponding PCS power is 0, if the battery continues to discharge (battery system current > 10A, current threshold can be set) for more than 10 seconds, a power line abnormal fault will be triggered.

[0112] When the battery system is fault-free and there are no upper or lower limit secondary protections, if the DC current of the PCS (I1) and the DC current of the battery system (I2) are inconsistent (fluctuation current I3 = I1 * 10% + 2A, |I2| - |I3| < |I1| < |I2| + |I3|, if I1 is within this range, the current is considered to be consistent; the current fluctuation percentage can be set, the default is 10%) for more than 30 seconds, then a power line abnormal fault is triggered; to prevent misjudgment at low current, the fluctuation current I3 is increased by an additional 2A.

[0113] When the battery system is fault-free and there are no upper or lower limit secondary protections, if the PCS DC voltage (U1) and the battery system bus voltage (U2) are inconsistent (fluctuation voltage U3 = U1 * 5%, |U2| - |U3| < |U1| < |U2| + |U3|, if U1 is within this range, the voltage is considered to be consistent, and the voltage fluctuation percentage can be set, with a default of 5%) for more than 30 seconds, an abnormal fault in the power line will be triggered.

[0114] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A circuit detection method, characterized in that, The method is applied to an energy storage system, the energy storage system including at least one energy storage unit, the energy storage unit including a converter and an energy storage battery corresponding to the converter; the method includes: When the energy storage system is in operation, based on at least one of the first electrical energy parameters of the converter, the operating status of the converter, the second electrical energy parameters of the energy storage battery, and the operating status of the energy storage battery, abnormal charging and discharging of the energy storage battery in the energy storage unit is detected. If a preset type of charging / discharging abnormality is detected in the energy storage battery of the energy storage unit, and the duration of the preset type of charging / discharging abnormality is greater than the duration threshold corresponding to the preset type, then it is determined that there is a circuit abnormality between the converter and the energy storage battery in the energy storage unit.

2. The method according to claim 1, characterized in that, The first electrical energy parameter includes at least one of the current, voltage, and power of the converter; the second electrical energy parameter includes at least one of the remaining charge, current, and voltage of the energy storage battery. Accordingly, the step of detecting charging and discharging anomalies in the energy storage unit based on at least one of the first electrical energy parameters of the converter, the operating status of the converter, the second electrical energy parameters of the energy storage battery, and the operating status of the energy storage battery includes: If the energy storage battery is in a fault state, the converter is in a shutdown state, and the current of the energy storage battery exceeds the limit, then it is determined that the energy storage battery of the energy storage unit has a preset first type of charging and discharging abnormality. If the energy storage battery is not in a fault state, the remaining power of the energy storage battery is greater than the preset power limit protection threshold, the power of the converter is zero, and the current of the energy storage battery exceeds the preset charging current threshold, then it is determined that the energy storage battery of the energy storage unit has a preset second type of charging and discharging abnormality. If the energy storage battery is not in a fault state, the remaining power of the energy storage battery is less than a preset lower limit value, the power of the converter is zero, and the current of the energy storage battery exceeds a preset discharge current threshold, then it is determined that the energy storage battery of the energy storage unit has a preset third type of charging and discharging abnormality. If the energy storage battery is not in a fault state, the remaining power of the energy storage battery does not exceed the preset upper limit value, the remaining power of the energy storage battery does not exceed the preset lower limit value, the energy storage unit is in operation, and a mismatch is detected between the current of the converter and the current of the energy storage battery, then it is determined that the energy storage unit has a preset fourth type of charging and discharging abnormality. If the energy storage battery is not in a fault state, the remaining power of the energy storage battery does not exceed the preset upper limit value, the remaining power of the energy storage battery does not exceed the preset lower limit value, the energy storage unit is in operation, and a voltage mismatch is detected between the converter and the energy storage battery, then it is determined that the energy storage unit has a preset fifth type of charging and discharging abnormality.

3. The method according to claim 2, characterized in that, The process of detecting a mismatch between the current of the converter and the current of the energy storage battery includes: Determine the fluctuating current corresponding to the current of the converter device; The target current fluctuation range corresponding to the converter is determined based on the current of the energy storage battery and the fluctuating current. If the current of the converter is not within the target current fluctuation range, it is determined that the current of the converter and the current of the energy storage battery are mismatched.

4. The method according to claim 2, characterized in that, The process of detecting a voltage mismatch between the converter and the energy storage battery includes: Determine the voltage fluctuation corresponding to the voltage of the converter device; The target voltage fluctuation range corresponding to the converter is determined based on the voltage of the energy storage battery and the fluctuating voltage. If the voltage of the converter is not within the target voltage fluctuation range, it is determined that the voltage of the converter is mismatched with the voltage of the energy storage battery.

5. The method according to claim 1, characterized in that, The method of detecting abnormal charging and discharging of the energy storage battery in the energy storage unit based on at least one of the first electrical energy parameters of the converter, the operating status of the converter, the second electrical energy parameters of the energy storage battery, and the operating status of the energy storage battery includes: Detect whether the first electrical energy parameter in the converter device matches the second electrical energy parameter of the energy storage battery; If the first electrical energy parameter in the converter device does not match the second electrical energy parameter of the energy storage battery, it is determined that there is a charging / discharging abnormality in the energy storage battery in the energy storage unit.

6. The method according to claim 1, characterized in that, After determining that there is an anomaly in the circuit between the converter and the energy storage battery in the energy storage unit, the method further includes: The system controls the energy storage system to stop operating and outputs the identifiers of the converter in the energy storage power supply and the energy storage battery.

7. The method according to claim 6, characterized in that, After the energy storage system is stopped from operating, the method further includes: Receive user fault configuration operations; When the fault configuration operation is of the first type, control the activation of all units in the energy storage system except for the energy storage unit with line abnormality. When the fault configuration operation is the second type of fault configuration operation, the correspondence between the converter and the energy storage battery in the energy storage unit with the line abnormality is changed; after the correspondence between the converter and the energy storage battery is changed, the energy storage system is controlled to start.

8. An energy storage system, characterized in that, include: The control device and at least one energy storage unit; each energy storage unit includes a converter and an energy storage battery corresponding to the converter; The converter in each of the energy storage units is used to convert the AC power in the grid to DC power and output the converted DC power to the energy storage battery connected to the converter, or to convert the DC power in the energy storage battery connected to the converter to AC power and output the converted AC power to the grid. The energy storage battery in each of the energy storage units is used to store the direct current output by the converter connected to the energy storage battery, or to output the direct current to the converter connected to the energy storage battery. The control device is configured to, when the energy storage system is in operation, perform charge / discharge anomaly detection on the energy storage battery in each energy storage unit based on at least one of the first electrical energy parameters of the converter device in each energy storage unit and the second electrical energy parameters of the energy storage battery; if a preset type of charge / discharge anomaly is detected in any energy storage battery in the energy storage unit, and the duration of the preset type of charge / discharge anomaly is greater than the duration threshold corresponding to the preset type, then it is determined that there is a line anomaly between the converter device and the energy storage battery in the energy storage unit.

9. The system according to claim 8, characterized in that, Also includes: Battery information collector; The battery information collector is used to collect battery data of the energy storage battery in each of the energy storage units; The collected battery data for each energy storage battery is sent to the control device; the battery data for each energy storage battery includes the operating status of each energy storage battery and the second power data.

10. The system according to claim 8, characterized in that, Also includes: transformer; The transformer is connected to the AC side of the converter in each of the energy storage units, and is used to step up the AC power output from at least one of the converters and transmit the stepped-up AC power to the power grid, or to step down the AC power in the power grid and transmit the stepped-down AC power to at least one of the converters.

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