Multi-variable-current unit parallel system and control method and control device thereof

Abstract

The invention discloses a control method and a control device of a multi-variable-current unit parallel system and the multi-variable-current unit parallel system. The multi-variable-current-unit parallel system comprises a plurality of variable current units, the outputs of the variable current units are connected in parallel, and the control method comprises the steps that a first signal corresponding to each variable current unit is acquired, and the first signals are used for representing that the variable current units have fault abnormity; according to the obtained first signal, a first converter unit is controlled in batches to carry out wave sealing processing, and the first converter unit is the converter unit obtaining the first signal; and controlling the first converter unit without wave sealing to be in a working state so as to supply power to the load. According to the control method, the first converter units are controlled in batches according to the acquired first signal to carry out wave sealing treatment, so that the situation that too many converter units are in a wave sealing state at the same time is avoided, and the situation that load power supply cannot be guaranteed, and even system downtime occurs is avoided.

Description

Multi-converter parallel system and its control method and control device Technical Field

[0001] This application relates to the field of converter technology, and more specifically, to a control method, control device, and multi-converter parallel system. Background Technology

[0002] When a ground fault or short-circuit fault occurs in a parallel multi-converter system, it can lead to abnormal current and voltage, and even electric arcing, affecting the normal operation of the system. Fault signals can be detected by hardware circuitry, and then IGBT blocking can be used to verify whether a fault has actually occurred in the parallel multi-converter system. However, in related technologies, if the parallel multi-converter system is in an off-grid state, simultaneously blocking multiple converters to determine if a fault has occurred cannot guarantee power supply to the load, potentially leading to large-scale system downtime. Summary of the Invention

[0003] This application provides a control method, control device, and multi-converter parallel system.

[0004] This application provides a control method for a multi-converter parallel system, the multi-converter parallel system including multiple converter units, the outputs of the multiple converter units being connected in parallel, the control method including:

[0005] Acquire a first signal corresponding to each of the power converter units, the first signal being used to characterize the presence of a fault or abnormality in the power converter unit;

[0006] Based on the first signal obtained, the first converter unit is controlled in batches to perform wave blocking processing, and the first converter unit is the converter unit that obtained the first signal;

[0007] The first converter unit, which controls the unsealed waveform, is in operation to supply power to the load.

[0008] Thus, the control method and quality of the embodiments of this application control a set number of first converter units to perform wave blocking processing according to the acquired first signal, so that there are not too many converter units in the wave blocking state at the same time, thereby avoiding the inability to guarantee the power supply to the load, or even the system crash.

[0009] In some embodiments, the step of controlling the first converter unit to perform wave blocking processing in batches according to the acquired first signal includes:

[0010] Based on the order in which the first signal is transmitted, the first converter unit is controlled in batches to perform wave blocking processing.

[0011] In this way, by controlling the first converter unit to perform wave blocking processing in batches according to the order of the first signal, the converter unit that sends the first signal first can be processed first, so as to avoid equipment damage caused by failure to handle faults for a long time.

[0012] In some embodiments, after controlling the first converter unit to perform wave blocking processing in batches according to the acquired first signal, the control method further includes:

[0013] Determine whether the first converter unit undergoing the wave blocking process has actually experienced a fault or abnormality.

[0014] In this way, by controlling the first converter unit to perform waveform blocking processing in sequence according to the first signal, it is possible to determine whether the converter unit has actually experienced a fault or abnormality, and at the same time, it can avoid too many converter units blocking waveforms at the same time, which would cause the system to be unable to support the load power supply.

[0015] In some embodiments, the control method further includes:

[0016] If the first converter unit performs a waveform blocking process and determines that a fault or abnormality exists, all converter units are controlled to shut down.

[0017] Thus, if the first converter unit performs a waveform blocking process and a fault or abnormality is detected, all converter units are shut down to prevent the fault or abnormality from damaging the parallel system of multiple converter units.

[0018] In some implementations, if the first converter unit in the current batch undergoes waveform blocking and it is determined that no fault or abnormality exists, the control method further includes:

[0019] Control the first converter unit of the current batch to exit the wave blocking process;

[0020] Control the next batch of first converter units that have not undergone the aforementioned wave blocking process to perform the wave blocking process.

[0021] Thus, if it is determined that the first converter unit of the current batch that is undergoing waveform blocking has not actually experienced a fault or abnormality, the waveform blocking process for the first converter unit undergoing waveform blocking is lifted, and the waveform blocking process for the first converter unit of the next batch is controlled to be performed, in order to determine whether a fault or abnormality has actually occurred.

[0022] In some implementations, the number of first converter units is N, and the number of first converter units that are subjected to wave blocking processing in a batch is n, where n≥1 and n<N.

[0023] In this way, the number of first converter units in each batch is greater than or equal to 1, and each batch does not include all first converter units, so that not all first converter units are blocked at the same time. This allows the system to support the power supply requirements of the load while blocking multiple first converter units in batches.

[0024] In some embodiments, the first converter unit controlling the unblocked waveform is in an operational state to supply power to the load, including:

[0025] The first and second converter units, which are not controlled to block the signal, are in working condition to supply power to the load. The second converter unit is the converter unit that has not acquired the first signal.

[0026] In this way, by controlling the first converter unit that has not undergone waveform blocking and the second current and voltage that have not issued the first signal to maintain their working state, the system can still meet the power supply requirements of the load while some of the first converter units undergo waveform blocking to detect faults and anomalies.

[0027] In some embodiments, the first converter unit controlling the unblocked waveform is in an operational state to supply power to the load, including:

[0028] The first converter unit with unblocked waveform is controlled to operate in an overload state to meet the power supply requirements of the load. The operating power of the overload state exceeds the operating power of the converter unit in its normal operating state.

[0029] In this way, the first converter unit with unsealed waveform is in an overload working state, which can meet the power supply requirements of the load without damaging the converter unit.

[0030] In some embodiments, multiple converter units are sequentially connected via a communication bus for transmitting the first signal. Each converter unit includes a main control converter unit, which controls the converter unit to operate or perform wave blocking processing based on the first signal.

[0031] In this way, the first signal can be transmitted through the communication bus, and one of the converter units can be set as the master control converter unit. The master control converter unit can control the converter unit to work or perform wave blocking processing according to the first signal, so as to realize the control of the converter unit.

[0032] In some embodiments, the parallel system of multiple converter units includes a controller that is communicatively connected to each converter unit and is used to receive a first signal from the converter unit. The controller is also used to control the converter unit to operate or perform wave blocking processing based on the first signal.

[0033] Thus, by setting up a communication connection between the controller and the converter unit, the controller can receive the first signal and control the converter unit to perform wave blocking processing or operation.

[0034] In some embodiments, the converter unit includes a DC converter and / or an energy storage converter.

[0035] This application provides a control device for a multi-converter parallel system, the multi-converter parallel system including multiple converter units, the outputs of the multiple converter units being connected in parallel, and the control device including:

[0036] The acquisition module is used to acquire a first signal corresponding to each of the converter units, and the first signal is used to characterize the existence of a fault or abnormality in the converter unit;

[0037] The first control module is used to control the first converter unit to perform wave blocking processing in batches according to the first signal obtained; the first converter unit is the converter unit that obtains the first signal.

[0038] The second control module is used to control the first converter unit without a sealed waveform to be in working state so as to supply power to the load.

[0039] In some embodiments, the first control module includes:

[0040] The first control submodule is used to control the first converter unit to perform wave blocking processing in batches according to the order of the first signal transmission.

[0041] In some embodiments, the control device further includes:

[0042] The determination module is used to determine whether the first converter unit undergoing the wave blocking process has actually experienced a fault or abnormality.

[0043] In some embodiments, the control device further includes:

[0044] The third control module is used to control all the converter units to shut down when the first converter unit performs wave blocking processing and determines that there is a fault or abnormality.

[0045] In some implementations, if the first converter unit in the current batch undergoes waveform blocking and it is determined that no fault or abnormality exists, the control device further includes:

[0046] The fourth control module is used to control the first converter unit of the current batch to exit the wave blocking process;

[0047] The fifth control module is used to control the first converter units in the next batch that have not undergone the wave blocking process to perform the wave blocking process.

[0048] This application provides a multi-converter parallel system, the multi-converter parallel system including a controller and multiple converter units, the outputs of the multiple converter units being connected in parallel, the controller being used for:

[0049] Acquire a first signal corresponding to each of the power converter units, the first signal being used to characterize the presence of a fault or abnormality in the power converter unit;

[0050] Based on the first signal obtained, the first converter unit is controlled in batches to perform wave blocking processing, and the first converter unit is the converter unit that obtained the first signal;

[0051] The first converter unit, which controls the unsealed waveform, is in operation to supply power to the load.

[0052] In some embodiments, the multi-converter parallel system further includes multiple batteries, with one battery and one converter connected to each other. The converter is used to process the electrical energy of the batteries to supply power to the load.

[0053] This application provides a multi-converter parallel system, which includes a controller and multiple converter units. The outputs of the multiple converter units are connected in parallel. Each converter unit includes a main control converter unit, which is used for:

[0054] Acquire a first signal corresponding to each of the power converter units, the first signal being used to characterize the presence of a fault or abnormality in the power converter unit;

[0055] Based on the first signal obtained, the first converter unit is controlled in batches to perform wave blocking processing, and the first converter unit is the converter unit that obtained the first signal;

[0056] The first converter unit, which controls the unsealed waveform, is in operation to supply power to the load.

[0057] In some embodiments, the multi-converter parallel system further includes multiple batteries, with one battery and one converter connected to each other. The converter is used to process the electrical energy of the batteries to supply power to the load.

[0058] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0059] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0060] Figure 1 is a flowchart illustrating one of the control methods of certain embodiments of this application;

[0061] Figure 2 is one of the schematic diagrams of a multi-converter parallel system and load according to certain embodiments of this application;

[0062] Figure 3 is a second schematic flowchart of the control method of some embodiments of this application;

[0063] Figure 4 is a third schematic flowchart of the control method of some embodiments of this application;

[0064] Figure 5 is a fourth flowchart illustrating the control method of some embodiments of this application;

[0065] Figure 6 is a fifth flowchart illustrating the control method of certain embodiments of this application;

[0066] Figure 7 is a flowchart of a control method according to certain embodiments of this application (the sixth one).

[0067] Figure 8 is a second schematic diagram of a multi-converter parallel system and load according to certain embodiments of this application;

[0068] Figure 9 is a schematic diagram of a multi-converter parallel system and load according to certain embodiments of this application;

[0069] Figure 10 is a schematic diagram of the controller, converter unit, and load according to some embodiments of this application;

[0070] Figure 11 is a fourth schematic diagram of a multi-current unit parallel system and load according to certain embodiments of this application. Detailed Implementation

[0071] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0072] When a ground fault or short-circuit fault occurs in a multi-converter parallel system, it can lead to abnormal current and voltage, and even electric arcing, affecting the normal operation of the system. Fault signals can be detected by hardware circuitry, and then IGBT blocking can be used to verify whether a real fault has occurred in the multi-converter parallel system. When multiple converters are connected in parallel, system interference and other issues may cause multiple converters to detect a fault simultaneously, requiring blocking to determine if a real fault exists. In related technologies, if the multi-converter parallel system is in an off-grid state, simultaneously blocking multiple converters to determine a real fault cannot guarantee load power supply, potentially leading to system shutdown.

[0073] Based on the aforementioned problems to be solved, please refer to Figures 1 and 2. This application provides a control method for a multi-converter parallel system 100, which includes multiple converter units 10, with the outputs of the multiple converter units 10 connected in parallel. The control method includes:

[0074] Step 01: Obtain the first signal corresponding to each converter unit 10. The first signal is used to characterize the fault or abnormality of the converter unit 10.

[0075] Step 02: Based on the acquired first signal, control the first converter unit in batches to perform wave blocking processing. The first converter unit is the converter unit 10 that acquired the first signal.

[0076] Step 03: Control the first converter unit without shielding the waveform to be in working state to supply power to the load.

[0077] In some implementations, the processor can be used to acquire a first signal corresponding to each converter unit 10, the first signal being used to characterize a fault or abnormality in the converter unit 10; and to control the first converter units to perform wave blocking processing in batches according to the acquired first signal, the first converter unit being the converter unit 10 that acquired the first signal; and can also be used to control the first converter units that are not wave blocked to be in a working state to supply power to the load.

[0078] This application provides a control device for a multi-converter parallel system 100, which includes multiple converter units 10 with their outputs connected in parallel. The control device includes an acquisition module, a first control module, and a second control module. The acquisition module acquires a first signal corresponding to each converter unit 10, which indicates a fault or abnormality in the converter unit 10. The first control module controls the first converter units to perform waveform blocking processing in batches according to the acquired first signal, where the first converter unit is the converter unit 10 that has acquired the first signal. The second control module controls the unblocked first converter units to be in a working state to supply power to the load.

[0079] Specifically, the multi-converter parallel system 100 includes multiple converter units 10 connected in parallel, which can be energy storage systems, photovoltaic systems, etc. The converter unit 10 is a device capable of voltage conversion, such as a DC-DC converter, inverter, power conversion system (PCS), etc.

[0080] Faults and anomalies include over-temperature, arcing, hardware failure, and other anomalies requiring over-temperature protection, shutdown detection, etc. Whether a fault has actually occurred can be detected by performing waveform blocking on the converter unit 10. This embodiment uses arcing anomalies as an example for explanation.

[0081] Arcing abnormality refers to an abnormal situation where the converter unit 10 generates an electric arc discharge. In the event of an arcing abnormality, a considerable current may be generated, which may damage the converter unit 10 or even the parallel system of multiple converter units 100. Hardware circuits can be used to detect the current of the converter unit 10 and process and analyze the current to determine whether the converter unit 10 has an arcing abnormality.

[0082] Furthermore, if it is determined that the converter unit 10 has a fault or abnormality such as arcing, the converter unit 10 with the fault or abnormality outputs a first signal to indicate that it has a fault or abnormality.

[0083] In related technologies, waveform blocking can be used to verify whether a converter unit has truly malfunctioned, thus determining whether the fault is a misjudgment. In grid-connected scenarios, when multiple converter units are waveform blocked, the power supply to the load can still be guaranteed by the grid. However, in off-grid scenarios, if multiple converter units are simultaneously waveform blocked to verify faults, multiple converter units will cease operation at the same time. The remaining converter units will be unable to support the power supply to the load, potentially leading to system downtime.

[0084] Batch control of the first converter unit for waveform blocking refers to controlling one batch of first converter units for waveform blocking, then controlling another batch for waveform blocking, and so on, until all first converter units have undergone waveform blocking, thus completing the determination of whether a real fault or abnormality has occurred. It should be noted that the number of first converter units in a batch is less than the total number of first converter units; that is, not all first converter units are controlled for waveform blocking simultaneously.

[0085] While sequentially controlling a set number of first converter units to perform wave blocking processing to verify whether a fault or abnormality has actually occurred, other converter units 10 besides the set number of first converter units are controlled to work to supply power to the load. This ensures that the number of first converter units in wave blocking processing state is controlled each time, thereby ensuring uninterrupted power supply to the load and preventing unexpected system downtime.

[0086] In one embodiment, the converter unit 10 is a PCS. The controller 40 receives two first signals, controls one of the two PCS that issued the two first signals (as the first converter unit) to perform waveform blocking processing, and controls the other PSC that issued the first signal to be in working state to maintain power supply to the load.

[0087] In this way, by controlling a set number of first converter units to perform wave blocking processing according to the acquired first signal, too many converter units 10 will not be in the wave blocking state at the same time, thereby avoiding the inability to guarantee the power supply to the load or even the system shutdown.

[0088] Please refer to Figure 3. In some embodiments, step 02, based on the acquired first signal, involves controlling the first converter unit to perform wave blocking processing in batches, including:

[0089] Step 021: Based on the order of the first signals received, control the first converter unit to perform wave blocking processing in batches.

[0090] In some implementations, the processor can be used to control the first converter unit to perform wave blocking processing in batches according to the order in which the first signals are transmitted.

[0091] In some implementations, the first control module includes a first control submodule. The first control submodule is used to control the first converter unit to perform wave blocking processing in batches according to the order in which the acquired first signals are emitted.

[0092] Specifically, since the converter unit 10 that sends the first signal detects the fault abnormality first, and if the fault abnormality is not handled for a long time, it will damage the converter unit 10, or even damage the multi-converter parallel system 100. Therefore, according to the order in which the first signals are sent, a set number of first converter units can be controlled to perform waveform blocking processing, that is, the converter unit 10 that sends the first signal first is controlled to perform waveform blocking processing first, and the converter unit 10 that sends the first signal later is controlled to perform waveform blocking processing later. This is to avoid the converter unit 10 that sends the first signal first not being verified for a long time, which could lead to damage to the converter unit 10 or the multi-converter parallel system 100.

[0093] Furthermore, based on the order in which the first signal is emitted, the first converter units that emitted the first signal are divided into multiple batches, and the first converter units in each batch are subjected to waveform blocking processing in sequence. That is, the time when the first converter unit in the i-th batch undergoes waveform blocking processing emits the first signal is earlier than the time when the first converter unit in the (i+1)-th batch undergoes waveform blocking processing emits the first signal. In addition, while controlling the waveform blocking processing of one batch of first converter units each time, the first converter units outside that batch are in the working state.

[0094] In one embodiment, upon receiving two first signals, the PCS that first sends the first signal (as the first converter unit) is controlled to perform waveform blocking processing, and the PCS that sends the first signal later is controlled to be in working state to maintain power supply to the load.

[0095] Thus, by controlling the first converter unit to perform wave blocking processing in batches according to the order of the first signal, the converter unit 10 that sends the first signal first can be processed first, so as to avoid equipment damage caused by failure to process faults for a long time.

[0096] Referring to Figure 4, in some embodiments, after step 02, when the first converter unit is controlled to perform wave blocking processing in batches according to the acquired first signal, the control method further includes:

[0097] Step 04: Determine whether the first converter unit undergoing the wave blocking process has actually experienced a fault or abnormality.

[0098] In some implementations, the processor can be used to determine whether the first converter unit undergoing the blocking process has actually experienced a fault or abnormality.

[0099] In some implementations, the control device further includes a determination module. The determination module is used to determine whether the first converter unit undergoing the wave blocking process has actually experienced a fault or abnormality.

[0100] Specifically, by performing waveform blocking on converter unit 10, it can be determined whether converter unit 10 has actually malfunctioned or is abnormal, so as to perform corresponding control on the multi-converter unit parallel system 100. By controlling the first converter unit to perform waveform blocking in batches according to the first signal, it can be avoided that multiple converter units 10 are blocked at the same time, which would cause too many converter units 10 to fail to work normally and affect the power supply to the load.

[0101] Thus, by controlling the first converter unit to perform waveform blocking processing in sequence according to the first signal, it is possible to determine whether the converter unit 10 has actually malfunctioned or is abnormal, and at the same time, it is possible to avoid too many converter units 10 blocking waveforms at the same time, which would cause the system to be unable to support the load power supply.

[0102] Please refer to Figure 5. In some embodiments, the control method further includes:

[0103] Step 05: If the first converter unit performs wave blocking processing and a fault or abnormality is confirmed, control all converter units 10 to shut down.

[0104] In some implementations, the processor can be used to control all converter units 10 to shut down if the first converter unit performs a blocking process and determines that a fault or abnormality exists.

[0105] In some embodiments, the control device further includes a third control module. The third control module is used to control all converter units 10 to shut down if the first converter unit performs waveform blocking processing and determines that a fault or abnormality exists.

[0106] Specifically, troubleshooting the first converter unit verifies whether it truly has a fault. If at least one first converter unit undergoes waveform blocking and a fault is confirmed, to prevent damage to the multi-converter parallel system 100 caused by a genuine fault in converter unit 10, all converter units 10 are shut down, and the multi-converter parallel system 100 is also shut down to eliminate the cause of the fault. After troubleshooting, the operation of the multi-converter parallel system 100 can be restored.

[0107] Thus, if the first converter unit performs a waveform blocking process and a fault or abnormality is detected, all converter units 10 are controlled to shut down to prevent the fault or abnormality from damaging the multi-converter parallel system 100.

[0108] Referring to Figure 5, in some implementations, if the first converter unit of the current batch undergoes waveform blocking and it is determined that no fault or abnormality exists, the control method further includes:

[0109] Step 06: Control the first converter unit of the current batch to exit the wave blocking process;

[0110] Step 07: Control the first converter unit of the next batch that has not undergone wave blocking processing to perform wave blocking processing.

[0111] In some implementations, the processor can be used to control the first converter unit of the current batch to exit the wave blocking process; and to control the first converter unit of the next batch that has not undergone wave blocking process to undergo wave blocking process.

[0112] In some implementations, if the first converter unit of the current batch has undergone wave blocking processing and it is determined that there is no fault or abnormality, the control device further includes a fourth control module and a fifth control module. The fourth control module is used to control the first converter unit of the current batch to exit the wave blocking processing; the fifth control module is used to control the first converter unit of the next batch that has not undergone wave blocking processing to undergo wave blocking processing.

[0113] Specifically, after the first converter unit of the current batch undergoes waveform blocking processing and it is confirmed that there are no faults or abnormalities, the first converter unit of the current batch is controlled to exit waveform blocking processing, and the first converter unit of the next batch that has not undergone waveform blocking processing is controlled to undergo waveform blocking processing, so as to realize the switching between multiple batches. At the same time, the first converter unit that has completed waveform blocking processing is controlled to be in working state together with other first converter units that have not yet undergone waveform blocking processing, to supply power to the load.

[0114] In one embodiment, the multi-current unit parallel system includes PCS1, PCS2, PCS3, and PCS4. A first signal is received from PCS1, PCS2, and PCS3, with PCS1 sending the first signal first, followed by PCS2, and then PCS3. PCS1, PCS2, and PCS3 are divided into three batches based on the order in which they send the first signal. First, PCS1 is controlled to undergo a waveform blocking process to verify if it has any faults or abnormalities, and PCS2, PCS3, and PCS4 are controlled to be in an operating state to supply power to the load. If PCS1 does not have any faults or abnormalities, it is controlled to exit the waveform blocking process. Then, PCS2 is controlled to undergo waveform blocking, and PCS1, PCS3, and PCS4 are controlled to be in an operating state.

[0115] Thus, if it is determined that the first converter unit of the current batch that is undergoing waveform blocking has not actually experienced a fault or abnormality, the waveform blocking process for the first converter unit undergoing waveform blocking is lifted, and the waveform blocking process for the first converter unit of the next batch is controlled to be performed, in order to determine whether a fault or abnormality has actually occurred.

[0116] In some implementations, the number of first converter units is N, and the number of first converter units performing wave blocking processing in a batch is n, where n≥1 and n<N.

[0117] Specifically, to avoid all first converter units being blocked simultaneously, which would prevent them from meeting the power supply requirements of the load, all first converter units cannot be grouped into the same batch and subjected to blocking simultaneously. Therefore, the number of first converter units, n, needs to be less than the total number of first converter units, N, i.e., n < N.

[0118] In addition, each batch includes at least one first converter unit, so n≥1.

[0119] In one embodiment, the multi-current unit parallel system includes PCS1, PCS2, PCS3, and PCS4. A first signal is received from PCS1, PCS2, and PCS3, with PCS1 sending the first signal first, followed by PCS2, and then PCS3. Based on the order in which the first signals are sent, PCS1, PCS2, and PCS3 are divided into three batches. The first batch includes PCS1, the second batch includes PCS2, and the third batch includes PCS3.

[0120] In this way, the number of first converter units in each batch is greater than or equal to 1, and each batch does not include all first converter units, so that not all first converter units are blocked at the same time. This allows the system to support the power supply requirements of the load while blocking multiple first converter units in batches.

[0121] Referring to Figure 6, in some embodiments, step 03, controlling the first converter unit without shielding to be in an operating state to supply power to the load, includes:

[0122] Step 031: Control the first and second converter units without signal blocking to be in working state to supply power to the load. The second converter unit is the converter unit 10 that has not acquired the first signal.

[0123] In some implementations, the processor can be used to control the first and second converter units without signal blocking to operate in order to supply power to the load, wherein the second converter unit is the converter unit 10 that has not acquired the first signal.

[0124] In some embodiments, the second control device includes a second control submodule. The second control submodule is used to control the first and second converter units (without signal blocking) to operate in order to supply power to the load. The second converter unit is the converter unit 10 that has not received the first signal.

[0125] Specifically, when the first signal received is emitted by some converter units 10, the remaining converter units 10 that have not emitted the first signal do not need to be blocked, and can be controlled to maintain their working state so as to supply power to the load together with the first converter unit that has not been blocked each time.

[0126] In one embodiment, upon receiving two first signals, the PCS that first sends the first signal (as the first converter unit) is controlled to perform waveform blocking processing, and the PCS that sends the first signal later and the remaining PCS that does not send the first signal (the second converter unit) are controlled to be in working state to maintain power supply to the load.

[0127] In this way, by controlling the first converter unit that has not undergone waveform blocking and the second current and voltage that have not issued the first signal to maintain their working state, the system can still meet the power supply requirements of the load while some of the first converter units undergo waveform blocking to detect faults and anomalies.

[0128] Referring to Figure 7, in some embodiments, step 03, controlling the first converter unit without shielding to be in an operating state to supply power to the load, includes:

[0129] Step 032: Control the first converter unit without shielding to be in overload working state to meet the power supply requirements of the load. The working power of the overload working state exceeds the working power of the converter unit 10 in normal working state.

[0130] In some implementations, the processor can be used to control the first converter unit without a blocked waveform to be in an overload operating state in order to meet the power supply requirements of the load. The operating power of the overload operating state exceeds the operating power of the converter unit 10 in its normal operating state.

[0131] In some embodiments, the second control device includes a third control submodule. The third control submodule is used to control the first converter unit without shielding to operate in an overload state to meet the power supply requirements of the load. The operating power of the overload state exceeds the operating power of the converter unit 10 in its normal operating state.

[0132] Specifically, when some of the first converter units are in a waveform blocking state, the load's power demand may exceed the sum of the output power of the unblocked first and second converter units under normal operating conditions. Converter unit 10 has short-term overload capability, supporting overload output for a certain period, for example, capable of outputting 1.1 times the normal operating power for ten minutes; or capable of outputting 1.2 times the normal operating power for one minute. When converter unit 10 is in an overload operating state, its operating power exceeds its normal operating power. Therefore, when some of the first converter units are in a waveform blocking state, the remaining first converter units can be controlled to be in an overload state to support the load's power demand.

[0133] Furthermore, the time required to perform waveform blocking on the PCS to verify whether a fault or anomaly truly exists is very short, for example, only tens of milliseconds. Therefore, if the output under normal operating conditions cannot meet the power supply requirements of the load, the first converter unit (or the first converter unit and the second converter unit) without waveform blocking can be controlled to operate under overload conditions to meet the power supply requirements of the load. Short-term overload will not damage the converter unit 10.

[0134] Furthermore, in the unsealed first converter unit, some first converter units can be controlled to operate in an overload state while the operating frequency of the remaining unsealed first converter units is increased; alternatively, all first converter units can be controlled to operate in an overload state to support the power supply requirements of the load. The number of first converter units in an overload state is determined based on the operating power of converter unit 10 under normal operating conditions and the power supply requirements of the load. It should be noted that the operating frequency of the first converter units with increased operating frequency still meets the rated power requirement and is not in an overload state.

[0135] In this way, the first converter unit with unsealed waveform is in an overload working state, which can meet the power supply requirements of the load without damaging the converter unit 10.

[0136] Please refer to Figure 2. In some embodiments, multiple converter units 10 are sequentially connected via a communication bus 20. The communication bus 20 is used to transmit a first signal. Each converter unit 10 includes a main control converter unit 10, which is used to control the converter unit 10 to work or perform wave blocking processing according to the first signal.

[0137] Specifically, one of the converter units 10 can be pre-selected as the main control converter unit 11. The main control converter unit 11 and the remaining converter units 10 are all connected to the same communication bus 20. The communication bus 20 can be used to transmit a first signal. Each converter unit 10 can send a first signal to the communication bus 20 and obtain the first signal transmitted on the communication bus 20. The main control converter unit 11 controls the first converter unit that sent the first signal to perform waveform blocking processing according to the first signal transmitted on the communication bus 20. The communication bus 20 can be a CAN bus, CANFD bus, etc.

[0138] In one embodiment, referring to Figure 8, the converter unit 10 is connected to multiple batteries 30. The converter unit 10 includes multiple DC-DC converters and multiple PCS. The multiple DC-DC converters are interconnected via a communication bus 20, and the batteries 30, DC-DC converters, and PCS are connected in a one-to-one correspondence. Fault detection is performed by the DC-DC converters, and one of the DC-DC converters is the master control DC-DC converter (master control converter unit 11). The master control DC-DC converter controls the DC-DC converters that issued the first signal to perform wave blocking processing in batches according to the received first signal.

[0139] In another embodiment, referring to Figure 9, the converter unit 10 includes multiple PCSs. These PCSs are interconnected via a communication bus 20. The PCS performs fault detection and issues a first signal, with one PCS serving as the master control PCS (master control converter unit 11). The master control PCS controls the PCS issuing the first signal to perform wave blocking processing in batches based on the received first signal.

[0140] In this way, the first signal can be transmitted through the communication bus 20, and one of the converter units 10 can be set as the main control converter unit 11. The main control converter unit 11 can control the converter unit 10 to work or perform wave blocking according to the first signal, so as to realize the control of the converter unit 10.

[0141] Referring to Figure 10, in some embodiments, the multi-converter parallel system 100 includes a controller 40, which is communicatively connected to each converter 10 and is used to receive a first signal from the converter 10. The controller 40 is also used to control the converter 10 to work or perform wave blocking processing according to the first signal.

[0142] Specifically, a controller 40 can be installed inside or outside the converter unit 10. All converter units 10 are communicatively connected to the controller 40. The controller 40 can receive the first signal sent by the converter unit 10 and can also transmit control signals to the converter unit 10 to control the converter unit 10. For example, it can control a set number of first converter units to perform wave blocking processing.

[0143] Thus, the controller 40 is configured to communicate with the converter unit 10, enabling the controller 40 to receive the first signal and control the converter unit 10 to perform wave blocking processing or operation.

[0144] In some implementations, the converter unit includes a DC-DC converter and / or an energy storage converter.

[0145] Specifically, the converter unit can consist of only multiple DC-DC converters, multiple PCS converters, or multiple DC-DC converters and multiple PCS converters. The presence of a fault or abnormality can be detected by the DC-DC converters and a first signal can be issued, or the presence of a fault or abnormality can be detected by the PCS and a first signal can be issued. Thus, the presence of a fault or abnormality can be detected through both DC-DC converters and / or PCS converters.

[0146] Please refer to Figure 10. This application provides a multi-converter parallel system 100, which includes a controller 40 and multiple converter units 10. The outputs of the multiple converter units 10 are connected in parallel. The controller 40 is used to: acquire a first signal corresponding to each converter unit 10, the first signal being used to characterize the existence of a fault or abnormality in the converter unit 10; control the first converter units to perform waveform blocking processing in batches according to the acquired first signal, the first converter units being the converter units 10 that have acquired the first signal; and control the unblocked first converter units to be in working state to supply power to the load.

[0147] In some implementations, multiple converter units 10 are connected to the controller 40 via a bus 50. The bus 50 is used to transmit a first signal corresponding to each converter unit 10, which is used to characterize the existence of a fault or abnormality in the converter unit 10.

[0148] Specifically, a controller 40 can be set inside or outside the converter unit 10. All converter units 10 are connected to the controller 40 through the bus 50. The controller 40 can receive the first signal sent by the converter unit 10 according to the bus 50, and can also transmit control signals to the converter unit 10 through the bus 50 to realize the control of the converter unit 10.

[0149] Thus, the controller 40 is configured to communicate with the converter unit 10, so that the controller 40 can receive the first signal from the bus 50 and control the converter unit 10 to perform wave blocking processing or operation.

[0150] Please refer to Figure 2. This application provides a multi-converter parallel system 100, which includes a controller 40 and multiple converter units 10. The outputs of the multiple converter units 10 are connected in parallel. Each converter unit 10 includes a main control converter unit 10, which is used to: acquire a first signal corresponding to each converter unit 10, the first signal being used to characterize a fault or abnormality in the converter unit 10; control the first converter units to perform waveform blocking processing in batches according to the acquired first signal, the first converter units being the converter units 10 that acquired the first signal; and control the unblocked first converter units to be in a working state to supply power to the load.

[0151] Specifically, the main control converter unit 11 is one of the converter units 10 and can be configured by the user. Multiple converter units 10 are connected via a communication bus 20. The main control converter unit 11 can determine the first converter unit based on the first signal transmitted on the communication bus 20. It then divides the first converter units into batches and controls them to perform waveform blocking processing in batches. Simultaneously, it controls the remaining unblocked first and second converter units to operate normally to supply power to the load.

[0152] In one embodiment, referring to Figure 11, the multi-converter parallel system 100 includes multiple batteries 30, multiple DC-DC converters, and a PCS. The batteries 30 and DC-DC converters are in one-to-one correspondence, and the multiple DC-DC converters are connected in parallel to each other and are all connected to the PCS. Each DC-DC converter is connected to the PCS via a communication bus 20. The master control DC-DC converter controls the DC-DC converters that emit the first signal in batches to perform wave blocking processing.

[0153] In some embodiments, the multi-converter parallel system 100 further includes multiple batteries 30, with each battery 30 correspondingly connected to a converter 10, and the converter 10 processing the electrical energy of the battery 30 to supply power to the load.

[0154] Specifically, battery 30 includes energy storage batteries, photovoltaic cells, etc. Converter unit 10 is used to process the electrical energy of battery 30 to supply power to the load.

[0155] In one embodiment, the multi-converter parallel system 100 is a string-type cluster-level managed energy storage system, including multiple batteries 30 and multiple converter units 10. Each converter unit 10 is connected to a corresponding battery 30 to process the electrical energy output from the battery 30. The converter unit 10 outputs the processed electrical energy and combines it on the AC side. After combining, the energy is processed by a transformer to supply the load.

[0156] In a string-type cluster-level managed energy storage system, multiple PCSs or multiple DC-DC converters may simultaneously detect faults or anomalies due to system interference or other reasons, and issue a first signal. Based on the received first signal, a predetermined number of converter units 10 can be controlled as the first converter unit to undergo waveform blocking to verify whether a fault or anomaly has indeed occurred. The unblocked first converter unit is then kept in operation to maintain power supply to the load.

[0157] In this way, the converter unit 10 can process the electrical energy of the battery 30, and while some converter units 10 are subjected to waveform blocking, the remaining converter units 10 are in operation to maintain the processing of electrical energy from the battery 30, thereby maintaining the power supply to the load.

[0158] The above explanation of the control method in the embodiments of this application also applies to the multi-converter parallel system 100 in the embodiments of this application, and will not be repeated here.

[0159] This application provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the control method as described in any of the above embodiments.

[0160] It is understood that a computer program includes computer program code. Computer program code can be in the form of source code, object code, executable files, or some intermediate form. Computer-readable storage media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, external hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), and software distribution media, etc.

[0161] In the description of this specification, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with an embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, without contradiction, those skilled in the art can combine and integrate different embodiments or examples described in this specification, as well as features of different embodiments or examples.

[0162] Furthermore, the term "connection" should be interpreted broadly. For example, it can include fixed connections, detachable connections, or integral connections; it can include direct connections or indirect connections through an intermediate medium; and it can also include internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0163] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0164] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order according to the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0165] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A control method for a multi-converter parallel system, characterized in that, The multi-converter parallel system includes multiple converter units, and the outputs of the multiple converter units are connected in parallel. The control method includes: acquiring a first signal corresponding to each converter unit, the first signal being used to characterize the existence of a fault or abnormality in the converter unit; controlling the first converter units to perform waveform blocking processing in batches according to the acquired first signal, the first converter units being the converter units that acquired the first signal; and controlling the first converter units that are not waveform blocked to be in a working state to supply power to the load.

2. The control method according to claim 1, characterized in that, The step of controlling the first converter unit to perform wave blocking processing in batches according to the acquired first signal includes: controlling the first converter unit to perform wave blocking processing in batches according to the transmission order of the acquired first signal.

3. The control method according to claim 1, characterized in that, After controlling the first converter unit to perform wave blocking processing in batches according to the acquired first signal, the control method further includes: determining whether the first converter unit performing wave blocking processing has actually experienced a fault or abnormality.

4. The control method according to claim 3, characterized in that, The control method further includes: if the first converter unit performs wave blocking processing and determines that there is a fault or abnormality, controlling all the converter units to shut down.

5. The control method according to claim 3 or 4, characterized in that, If the first converter unit in the current batch undergoes wave blocking processing and it is determined that there is no fault or abnormality, the control method further includes: controlling the first converter unit in the current batch to exit the wave blocking processing; and controlling the first converter unit in the next batch that has not undergone wave blocking processing to undergo the wave blocking processing.

6. The control method according to claim 1, characterized in that, The number of the first converter units is N, and the number of the first converter units that are subjected to wave blocking processing in a batch is n, where n≥1 and n<N.

7. The control method according to claim 1, characterized in that, The control of the first converter unit without signal blocking to be in operation to supply power to the load includes: controlling the first converter unit without signal blocking and the second converter unit to be in operation to supply power to the load, wherein the second converter unit is the converter unit that has not acquired the first signal.

8. The control method according to claim 1, characterized in that, The control of the first converter unit without shielding to operate in order to supply power to the load includes: controlling the first converter unit without shielding to operate in an overload operating state to meet the power supply requirements of the load, wherein the operating power of the overload operating state exceeds the operating power of the converter unit in its normal operating state.

9. The control method according to claim 1, characterized in that, Multiple converter units are sequentially connected via a communication bus, which is used to transmit the first signal. Each converter unit includes a main control converter unit, which is used to control the converter unit to work or perform wave blocking processing according to the first signal.

10. The control method according to claim 1, characterized in that, The parallel system of multiple converter units also includes a controller, which is communicatively connected to each converter unit. The controller is used to receive a first signal from the converter unit and control the converter unit to work or perform wave blocking processing according to the first signal.

11. The control method according to claim 1, characterized in that, The converter unit includes a DC converter and / or an energy storage converter.

12. A control device for a multi-converter parallel system, characterized in that, The multi-converter parallel system includes multiple converter units, and the outputs of the multiple converter units are connected in parallel. The control device includes: an acquisition module, which is used to acquire a first signal corresponding to each converter unit, the first signal being used to characterize a fault or abnormality in the converter unit; a first control module, which is used to control the first converter units to perform waveform blocking processing in batches according to the acquired first signal, the first converter units being the converter units that acquired the first signal; and a second control module, which is used to control the first converter units that are not waveform blocked to be in a working state to supply power to the load.

13. The control device according to claim 12, characterized in that, The first control module includes a first control submodule, which is used to control the first converter unit to perform wave blocking processing in batches according to the order of the first signal transmission.

14. The control device according to claim 12, characterized in that, The control device further includes a determination module, which is used to determine whether the first converter unit undergoing the wave blocking process has actually experienced a fault or abnormality.

15. The control device according to claim 14, characterized in that, The control device further includes a third control module, which is used to control all the converter units to shut down when the first converter unit performs wave blocking processing and determines that there is a fault or abnormality.

16. The control device according to claim 14 or 15, characterized in that, If the first converter unit in the current batch undergoes wave blocking processing and it is determined that there is no fault or abnormality, the control device further includes: a fourth control module, which is used to control the first converter unit in the current batch to exit the wave blocking processing; and a fifth control module, which is used to control the first converter unit in the next batch that has not undergone wave blocking processing to undergo wave blocking processing.

17. A multi-converter parallel system, characterized in that, The multi-converter parallel system includes a controller and multiple converter units, with the outputs of the multiple converter units connected in parallel. The controller is configured to: acquire a first signal corresponding to each converter unit, the first signal being used to characterize a fault or abnormality in the converter unit; control the first converter units to perform waveform blocking processing in batches according to the acquired first signal, the first converter units being the converter units that acquired the first signal; and control the first converter units that are not waveform blocked to be in an operating state to supply power to the load.

18. The multi-converter parallel system according to claim 17, characterized in that, The multi-converter parallel system includes multiple batteries, with one battery and one converter connected to each other. The converter is used to process the electrical energy of the batteries to supply power to the load.

19. A multi-converter parallel system, characterized in that, The multi-converter parallel system includes a controller and multiple converter units, with the outputs of the multiple converter units connected in parallel. Each converter unit includes a main control converter unit, which is used to: acquire a first signal corresponding to each converter unit, the first signal being used to characterize a fault or abnormality in the converter unit; control the first converter units to perform waveform blocking processing in batches according to the acquired first signal, the first converter units being the converter units that acquired the first signal; and control the first converter units that are not waveform blocked to be in a working state to supply power to the load.

20. The multi-converter parallel system according to claim 19, characterized in that, The multi-converter parallel system includes multiple batteries, with one battery and one converter connected to each other. The converter is used to process the electrical energy of the batteries to supply power to the load.

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