Communication unit and control method thereof, power converter and power conversion system

Abstract

The invention provides a communication unit and a control method thereof, a power converter and a power conversion system, and relates to the technical field of power electronics, and the communication unit comprises a plurality of magnetic rings, a power line communication unit, and a plurality of channel selection switches. A cable on the input side of each DC conversion circuit is provided with at least one magnetic ring; the signal end of the magnetic ring is connected with the signal end of the power line communication unit through at least one channel selection switch; the communication unit is used for switching on the channel selection switch corresponding to the first direct current conversion circuit and switching off the channel selection switch corresponding to the second direct current conversion circuit; the power line communication unit is controlled to send a device search signal, so that the direct current control device receiving the device search signal feeds back a response signal; and receiving the response signal, and taking the direct current control equipment corresponding to the received response signal as the direct current control equipment in the direct current string connected with the first direct current conversion circuit. The identification efficiency of the direct-current conversion circuit connected with the direct-current control equipment can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power electronics, and particularly relates to a communication unit and a control method thereof, a power converter and a power conversion system. BACKGROUND

[0002] A DC control device is used for controlling a DC source and connecting a DC conversion circuit in a power converter. For example, the DC control device can be an MLPE (Module Level Power Electronics), which generally refers to a photovoltaic optimizer, a shutdown device, a micro-inverter and the like.

[0003] The DC control device usually adopts a PLC (Power Line Communication) technology to establish a communication connection with the power converter. After the power converter communicates with the DC control device, the DC conversion circuit connected by each DC control device needs to be accurately identified.

[0004] At present, the DC conversion circuit connected by each DC control device is usually manually set by a person, or the DC conversion circuit connected by each DC control device is identified by using the power converter to control a string current. The identification efficiency of the DC conversion circuit connected by the DC control device is low. SUMMARY

[0005] The present application provides a communication unit and a control method thereof, a power converter and a power conversion system, so as to improve the identification efficiency of the DC conversion circuit connected by the DC control device.

[0006] According to a first aspect of an embodiment of the present application, a communication unit is provided, comprising: a plurality of magnetic rings, a power line communication unit, and a plurality of channel selection switches. The communication unit is in communication connection with a power converter, and the power converter comprises a plurality of DC conversion circuits; an input side of each DC conversion circuit is used for connecting at least one DC string; the DC string comprises at least one DC control device, an input end of the DC control device is used for connecting a DC source, and output ends of the DC control devices are connected in series to a DC side of the power converter; A cable at the input side of each DC conversion circuit is configured with at least one magnetic ring; a signal end of the magnetic ring is connected to a signal end of the power line communication unit through at least one channel selection switch; The communication unit is configured to turn on a channel selection switch corresponding to a first direct current conversion circuit and turn off a channel selection switch corresponding to a second direct current conversion circuit; the first direct current conversion circuit is one of the direct current conversion circuits in the power converter; the second direct current conversion circuit is a direct current conversion circuit other than the first direct current conversion circuit in the power converter; the channel selection switch corresponding to a direct current conversion circuit refers to a channel selection switch connected to a magnetic ring configured by the direct current conversion circuit. The control method comprises the following steps:

[0007] According to a second aspect of the embodiment of the present application, a power converter is provided, which comprises the communication unit according to the first aspect.

[0008] According to a third aspect of the embodiment of the present application, a power conversion system is provided, which comprises a power converter and the communication unit according to the first aspect. The communication unit is in communication connection with the power converter.

[0009] According to a fourth aspect of the embodiment of the present application, a control method of a communication unit is provided, the communication unit comprising: a plurality of magnetic rings, a power line communication unit, and a plurality of channel selection switches. The communication unit is in communication connection with a power converter, the power converter comprising a plurality of direct current conversion circuits; an input side of each direct current conversion circuit is configured to connect at least one direct current group string; the direct current group string comprises at least one direct current control device, an input end of the direct current control device is configured to connect a direct current source, and output ends of the direct current control devices are connected in series to a direct current side of the power converter; A cable at the input side of each direct current conversion circuit is configured with at least one magnetic ring; a signal end of the magnetic ring is connected to a signal end of the power line communication unit through at least one channel selection switch; The control method comprises the following steps: The communication unit is configured to turn on a channel selection switch corresponding to a first direct current conversion circuit and turn off a channel selection switch corresponding to a second direct current conversion circuit; the first direct current conversion circuit is one of the direct current conversion circuits in the power converter; the second direct current conversion circuit is a direct current conversion circuit other than the first direct current conversion circuit in the power converter; the channel selection switch corresponding to a direct current conversion circuit refers to a channel selection switch connected to a magnetic ring configured by the direct current conversion circuit. The power line communication unit is controlled to send a device search signal so that the DC control device that receives the device search signal can send a response signal; the response signal is received and the DC control device corresponding to the received response signal is designated as the DC control device in the DC string connected to the first DC-DC converter circuit.

[0010] In this application, the communication unit includes multiple magnetic rings, a power line communication unit, and multiple channel selection switches. Each DC-DC converter's input side cable is configured with at least one magnetic ring. The signal end of the magnetic ring is connected to the signal end of the power line communication unit via at least one channel selection switch. By configuring an independent magnetic ring for each DC-DC converter, the communication unit activates the channel selection switch corresponding to the first DC-DC converter and deactivates the channel selection switch corresponding to the second DC-DC converter. This enables the power line communication unit to establish communication connections only with DC control devices within the DC string connected to the first DC-DC converter, and not with DC control devices within the DC string connected to the second DC-DC converter. Therefore, after controlling the power line communication unit to send a device search signal, it can be determined that the DC control device corresponding to the received response signal is a DC control device within the DC string connected to the first DC-DC converter. This allows for the identification of DC-DC converters connected to DC control devices solely through power line communication, improving the identification efficiency of DC-DC converters connected to DC control devices. Attached Figure Description

[0011] 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.

[0012] Figure 1 This is a schematic diagram of the structure of a communication unit provided in an embodiment of this application.

[0013] Figure 2 This is a schematic diagram of another communication unit provided in an embodiment of this application.

[0014] Figure 3 This is a schematic diagram of another communication unit provided in an embodiment of this application.

[0015] Figure 4 This is a schematic diagram of another communication unit provided in an embodiment of this application.

[0016] Figure 5 This is a schematic diagram of another communication unit provided in an embodiment of this application.

[0017] Figure 6 This is a schematic diagram of another communication unit provided in an embodiment of this application.

[0018] Figure 7 This is a flowchart illustrating a control method for a communication unit provided in an embodiment of this application.

[0019] Figure 8 A flowchart illustrating another control method for a communication unit provided in an embodiment of this application.

[0020] Figure 9 A timing diagram of a control method for a communication unit provided in an embodiment of this application. Detailed Implementation

[0021] 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.

[0022] Exemplary communication unit This application provides a communication unit. The communication unit includes: multiple magnetic rings, a power line communication unit, and multiple channel selection switches; The communication unit is connected to the power converter, which includes multiple DC-DC converter circuits. The input side of each DC-DC converter circuit is used to connect at least one DC string. The DC string includes at least one DC control device. The input terminal of the DC control device is used to connect to a DC source, and the output terminal of each DC control device is connected in series to the DC side of the power converter. Each DC-DC converter circuit has at least one magnetic ring on the input side of its cable; the signal end of the magnetic ring is connected to the signal end of the power line communication unit via at least one channel selector switch.

[0023] In an exemplary embodiment, the power converter may include an inverter.

[0024] In the exemplary embodiment, the DC-DC converter circuit refers to a DC-DC conversion circuit.

[0025] In an exemplary embodiment, the communication unit may be an independent communication unit disposed outside the power converter and communicatively connected to the power converter; the communication unit may also be disposed inside the power converter as part of the power converter, and this application does not limit this.

[0026] In an exemplary embodiment, the DC source may include photovoltaic modules, and the DC control device may include an MLPE (Multi-Level Protected Equipment). The input of each DC control device may be connected to one or more DC sources. The DC string may include a photovoltaic string, which includes multiple photovoltaic modules connected in series or parallel. Each DC string may include one or more DC control devices.

[0027] In an exemplary embodiment, the cable on the input side of each DC-DC converter is configured with at least one magnetic ring, which may mean that the cable on the input side of each DC-DC converter passes through the interior of at least one magnetic ring.

[0028] In an exemplary embodiment, the power line communication unit may include at least one PLC chip.

[0029] In some embodiments, the communication unit has various structures, including but not limited to the following: Structure 1 like Figure 1 As shown, the input side of each DC-DC converter is used to connect to one DC string, and the cable on the input side of each DC-DC converter is equipped with a magnetic ring. The signal end of each magnetic ring is connected to the signal end of the power line communication unit through a channel selection switch. Figure 1 In this paper, the number of DC sources and DC control devices in each DC string is only for illustration, the number of DC conversion circuits in the power converter is only for illustration, and the number of magnetic rings and channel selection switches in the communication unit is only for illustration. This application does not impose any limitations on these.

[0030] Structure 2 like Figure 2 As shown, the input side of each DC-DC converter circuit is used to connect multiple DC strings. The cable on the input side of each DC-DC converter circuit is equipped with a magnetic ring. The signal end of each magnetic ring is connected to the signal end of the power line communication unit through a channel selection switch.

[0031] Figure 2 In this application, the number of DC sources and DC control devices in each DC string is only for illustration, the number of DC conversion circuits in the power converter is only for illustration, the number of magnetic rings and channel selection switches in the communication unit is only for illustration, and the number of DC strings connected to each DC conversion circuit is only for illustration. This application does not impose any limitations on these aspects.

[0032] Structure 3 like Figure 3 As shown, the input side of each DC-DC converter circuit is used to connect multiple DC strings. Each DC string cable is equipped with a magnetic ring, that is, the input side cable of each DC-DC converter circuit is equipped with multiple magnetic rings. The signal end of each magnetic ring is connected to the signal end of the power line communication unit through a channel selection switch.

[0033] Figure 3 In this application, the number of DC sources and DC control devices in each DC string is only for illustration, the number of DC conversion circuits in the power converter is only for illustration, the number of magnetic rings and channel selection switches in the communication unit is only for illustration, and the number of DC strings connected to each DC conversion circuit is only for illustration. This application does not impose any limitations on these aspects. Figure 3 In the middle, the communication unit includes multiple magnetic rings, power line communication units, and multiple channel selection switches. The DC-DC conversion circuit is actually located outside the communication unit.

[0034] In some embodiments, the communication unit is used to turn on the channel selection switch corresponding to the first DC-DC converter circuit and turn off the channel selection switch corresponding to the second DC-DC converter circuit; wherein, the first DC-DC converter circuit is a DC-DC converter circuit in the power converter; the second DC-DC converter circuit is a DC-DC converter circuit other than the first DC-DC converter circuit in the power converter; the channel selection switch corresponding to the DC-DC converter circuit refers to the channel selection switch connected by the magnetic ring configured in the DC-DC converter circuit. The control power line communication unit sends a device search signal so that the DC control device that receives the device search signal can send a response signal; the response signal is received and the DC control device corresponding to the received response signal is used as the DC control device in the DC string connected to the first DC-DC converter circuit.

[0035] In an exemplary embodiment, Figure 1 In this system, the input side of each DC-DC converter circuit is used to connect to one DC string. The cable on the input side of each DC-DC converter circuit is equipped with a ferrite core. The signal end of each ferrite core is connected to the signal end of the power line communication unit through a channel selection switch. This allows the DC-DC converter circuit connected to the DC control equipment to be identified solely through power line communication, thus improving the identification efficiency of the DC-DC converter circuit connected to the DC control equipment. Since the input side of each DC-DC converter circuit is used to connect to one DC string, it is also possible to identify the DC string where the DC control equipment is located solely through power line communication, further improving the identification efficiency of the DC string where the DC control equipment is located.

[0036] In an exemplary embodiment, Figure 2 In this system, the input side of each DC-DC converter circuit is used to connect multiple DC strings. The cable on the input side of each DC-DC converter circuit is equipped with a ferrite core. The signal end of each ferrite core is connected to the signal end of the power line communication unit through a channel selection switch. This allows the DC-DC converter circuit connected to the DC control equipment to be identified solely through power line communication, thus improving the identification efficiency of the DC-DC converter circuit connected to the DC control equipment. However, since the input side of each DC-DC converter circuit is used to connect multiple DC strings, it can only identify the DC-DC converter circuit connected to the DC control equipment, and cannot identify the DC string in which the DC control equipment is located.

[0037] In an exemplary embodiment, Figure 3 In this system, the input side of each DC-DC converter circuit is used to connect multiple DC strings. Each DC string cable is equipped with a ferrite core, meaning that the input side cable of each DC-DC converter circuit has multiple ferrite cores. The signal terminal of each ferrite core is connected to the signal terminal of the power line communication unit via a channel selection switch. This allows multiple channel selection switches corresponding to the first DC-DC converter circuit to be activated simultaneously, enabling the identification of the DC-DC converter circuit connected to the DC control equipment solely through power line communication. This improves the identification efficiency of the DC-DC converter circuit connected to the DC control equipment. Furthermore, simultaneously activating multiple channel selection switches corresponding to the first DC-DC converter circuit allows the power line communication unit to communicate simultaneously with the multiple DC strings connected to the first DC-DC converter circuit, improving overall communication efficiency. Since each DC string cable is equipped with a ferrite core, only one channel selection switch corresponding to a DC string can be activated at a time, enabling the identification of the DC string containing the DC control equipment solely through power line communication, further improving the identification efficiency of the DC string containing the DC control equipment.

[0038] In an exemplary embodiment, the device search signal may include a network beacon.

[0039] In an exemplary embodiment, the communication unit controls the power line communication unit to send a device search signal, causing the DC control device receiving the device search signal to send a response signal. The DC control device receiving the device search signal determines whether the signal strength of the device search signal is greater than a preset value. If the signal strength of the device search signal is greater than the preset value, the DC control device sends a response signal back to the power line communication unit. This reduces signal crosstalk, as the signal strength of interfering signals will be less than the preset value, further improving the recognition accuracy of the DC-DC converter circuit connected to the DC control device.

[0040] In this application, the communication unit includes multiple magnetic rings, a power line communication unit, and multiple channel selection switches. Each DC-DC converter's input side cable is configured with at least one magnetic ring. The signal end of the magnetic ring is connected to the signal end of the power line communication unit via at least one channel selection switch. By configuring an independent magnetic ring for each DC-DC converter, the communication unit activates the channel selection switch corresponding to the first DC-DC converter and deactivates the channel selection switch corresponding to the second DC-DC converter. This enables the power line communication unit to establish communication connections only with DC control devices within the DC string connected to the first DC-DC converter, and not with DC control devices within the DC string connected to the second DC-DC converter. Therefore, after controlling the power line communication unit to send a device search signal, it can be determined that the DC control device corresponding to the received response signal is a DC control device within the DC string connected to the first DC-DC converter. This allows for the identification of DC-DC converters connected to DC control devices solely through power line communication, improving the identification efficiency of DC-DC converters connected to DC control devices.

[0041] The magnetic ring enables isolated signal coupling between DC control equipment and channel selection switches. The voltage of the cable on the input side of each DC-DC converter circuit is high voltage, while the voltage at the signal end of each magnetic ring is low voltage, which can improve the safety of the power line communication unit.

[0042] In an exemplary embodiment, the communication unit may further include a processor, which is connected to the control terminal of each channel selection switch and to the power line communication unit. The processor is used to turn on the channel selection switch corresponding to the first DC-DC converter circuit and turn off the channel selection switch corresponding to the second DC-DC converter circuit; wherein, the first DC-DC converter circuit is a DC-DC converter circuit in the power converter; the second DC-DC converter circuit is a DC-DC converter circuit other than the first DC-DC converter circuit in the power converter; the channel selection switch corresponding to the DC-DC converter circuit refers to the channel selection switch connected by the magnetic ring configured in the DC-DC converter circuit. The control power line communication unit sends a device search signal so that the DC control device that receives the device search signal can send a response signal; the response signal is received and the DC control device corresponding to the received response signal is used as the DC control device in the DC string connected to the first DC-DC converter circuit.

[0043] In an exemplary embodiment, the processor may be an ARM (Advanced RISC Machine, RISC microprocessor) or other types of processors, and this application does not limit this to them.

[0044] In an exemplary embodiment, the processor controls the power line communication unit to send a device search signal, so that the DC control device that receives the device search signal can send a response signal. The DC control device sends the response signal to the power line communication unit, and the power line communication unit forwards the response signal to the processor.

[0045] In some embodiments, the communication unit is specifically configured to extract the identifier of the DC control device from the response signal; according to the mapping relationship between the identifier of the channel selection switch and the identifier of the DC-DC converter, based on the identifier of the channel selection switch corresponding to the first DC-DC converter, find the identifier of the first DC-DC converter; and establish the mapping relationship between the identifier of the DC control device and the identifier of the first DC-DC converter. This achieves the binding between the DC control device and the first DC-DC converter.

[0046] In an exemplary embodiment, the identifier of the DC control device may include the address information of the DC control device, or it may include other types of identifiers, as long as the DC control device can be uniquely identified based on its identifier.

[0047] In an exemplary embodiment, the communication unit may pre-store the mapping relationship between the identifiers of the channel selection switch and the identifiers of the DC-DC converter circuit. For example, the processor in the communication unit may pre-store the mapping relationship between the identifiers of the channel selection switch and the identifiers of the DC-DC converter circuit. The connection relationship between the DC-DC converter circuit and the channel selection switch, where a mapping relationship exists between the identifiers, is that the magnetic ring configured in the DC-DC converter circuit connects to the channel selection switch.

[0048] In some embodiments, the communication unit is specifically used to acquire the signal strength of the response signal; when the signal strength of the response signal is greater than the signal strength threshold, the DC control device corresponding to the received response signal is used as the DC control device in the DC string connected to the first DC converter circuit.

[0049] The signal strength of the response signal is filtered by a signal strength threshold, which can reduce signal crosstalk. The signal strength of the interference signal will be less than the signal strength threshold, further improving the recognition accuracy of the DC-DC converter circuit connected to the DC control equipment.

[0050] In some embodiments, the communication unit is further configured to, if no response signal is received within a preset time period, disconnect the channel selection switch corresponding to the first DC-DC converter circuit, turn on the channel selection switch corresponding to the third DC-DC converter circuit, and disconnect the channel selection switch corresponding to the fourth DC-DC converter circuit; wherein, the third DC-DC converter circuit is one of the DC-DC converter circuits in the second DC-DC converter circuit; and the fourth DC-DC converter circuit is a DC-DC converter circuit in the second DC-DC converter circuit other than the third DC-DC converter circuit. The control power line communication unit sends a device search signal so that the DC control device that receives the device search signal can send a response signal; it receives the response signal and uses the DC control device corresponding to the received response signal as the DC control device in the DC string connected to the third DC converter circuit.

[0051] It can sequentially identify the DC control devices within the DC string connected to each DC-DC converter circuit. By switching the conduction state of the channel selection switches corresponding to each DC-DC converter circuit, it is possible to identify the DC-DC converter circuits connected to the DC control devices solely through power line communication, thereby improving the identification efficiency of the DC-DC converter circuits connected to the DC control devices.

[0052] In some embodiments, the power line communication unit includes at least one power line communication subunit; the signal terminal of each power line communication subunit is connected to the signal terminal of at least one magnetic ring via at least one channel selection switch.

[0053] In an exemplary embodiment, the power line communication subunit may include a PLC chip.

[0054] In some embodiments, the communication unit has various structures, including but not limited to the following: Structure 4 like Figure 4 As shown, the input side of each DC-DC converter circuit is used to connect to one DC string. The cable on the input side of each DC-DC converter circuit is equipped with a ferrite core. The signal terminal of each ferrite core is connected to the signal terminal of the power line communication subunit via a channel selection switch. The signal terminal of each power line communication subunit is connected to the signal terminal of at least one ferrite core via at least one channel selection switch.

[0055] Figure 4 In this application, the number of DC sources and DC control devices in each DC string is only for illustration purposes, the number of DC conversion circuits in the power converter is only for illustration purposes, the number of magnetic rings and channel selection switches in the communication unit is only for illustration purposes, the number of power line communication sub-units in the power line communication unit is only for illustration purposes, and the number of DC strings that each power line communication sub-unit communicates with is only for illustration purposes. This application does not impose any limitations on these aspects.

[0056] Structure 5 like Figure 5 As shown, the input side of each DC-DC converter circuit is used to connect multiple DC strings. The cable on the input side of each DC-DC converter circuit is equipped with a ferrite core. The signal terminal of each ferrite core is connected to the signal terminal of the power line communication unit via a channel selection switch. The signal terminal of each power line communication subunit is connected to the signal terminal of at least one ferrite core via at least one channel selection switch.

[0057] Figure 5In this application, the number of DC sources and DC control devices in each DC string is only for illustration purposes, the number of DC conversion circuits in the power converter is only for illustration purposes, the number of magnetic rings and channel selection switches in the communication unit is only for illustration purposes, the number of DC strings connected to each DC conversion circuit is only for illustration purposes, the number of power line communication sub-units in the power line communication unit is only for illustration purposes, and the number of DC strings that each power line communication sub-unit communicates with is only for illustration purposes. This application does not impose any limitations on these aspects.

[0058] Figure 5 Although each power line communication subunit is shown to communicate with a DC string connected to a DC-DC converter circuit, in reality, each power line communication subunit can also communicate with multiple DC strings connected to DC-DC converter circuits, and this application does not limit this.

[0059] Structure 6 like Figure 6 As shown, the input side of each DC-DC converter circuit is used to connect multiple DC strings. Each DC string cable is configured with a ferrite core, meaning that the input side cable of each DC-DC converter circuit has multiple ferrite cores. The signal terminal of each ferrite core is connected to the signal terminal of the power line communication unit via a channel selector switch. The signal terminal of each power line communication subunit is connected to the signal terminal of at least one ferrite core via at least one channel selector switch.

[0060] Figure 6 In this application, the number of DC sources and DC control devices in each DC string is only for illustration purposes, the number of DC conversion circuits in the power converter is only for illustration purposes, the number of magnetic rings and channel selection switches in the communication unit is only for illustration purposes, the number of DC strings connected to each DC conversion circuit is only for illustration purposes, the number of power line communication sub-units in the power line communication unit is only for illustration purposes, and the number of DC strings that each power line communication sub-unit communicates with is only for illustration purposes. This application does not impose any limitations on these aspects. Figure 6 In this case, the DC-DC converter circuit is actually located outside the communication unit.

[0061] Figure 6 Although each power line communication subunit is shown to communicate with a DC string connected to a DC-DC converter circuit, in reality, each power line communication subunit can also communicate with multiple DC strings connected to DC-DC converter circuits, and this application does not limit this.

[0062] In some embodiments, the communication unit is further configured to perform the following operations for each power line communication subunit: Turn on the channel selection switch corresponding to the fifth DC-DC converter circuit and turn off the channel selection switch corresponding to the sixth DC-DC converter circuit; wherein, the fifth DC-DC converter circuit is one of the DC-DC converter circuits corresponding to the power line communication subunit; the sixth DC-DC converter circuit is the DC-DC converter circuit other than the fifth DC-DC converter circuit in the DC-DC converter circuits corresponding to the power line communication subunit; the DC-DC converter circuit corresponding to the power line communication subunit refers to the DC-DC converter circuit where the magnetic ring connected to the power line communication subunit is located. The control power line communication subunit sends a device search signal so that the DC control device that receives the device search signal can send a response signal; it receives the response signal and uses the DC control device corresponding to the received response signal as the DC control device in the DC string connected to the fifth DC-DC converter circuit.

[0063] In an exemplary embodiment, the communication unit may further include a processor, which is connected to the control terminal of each channel selection switch and to each power line communication subunit.

[0064] In an exemplary embodiment, the number of power line communication subunits and the number of channel selection switches connected to each power line communication subunit can be determined based on the load capacity of the power line communication subunit and the number of DC strings connected to the communication unit.

[0065] The communication unit can simultaneously control multiple power line communication subunits and DC control devices within the DC string connected to the DC converter circuit, thereby improving overall communication efficiency. Each power line communication subunit can establish a communication connection only with the DC control devices within the DC string connected to the fifth DC converter circuit, and cannot establish a communication connection with the DC control devices within the DC string connected to the sixth DC converter circuit. Therefore, after controlling the power line communication subunit to send a device search signal, it can be determined that the DC control device corresponding to the received response signal is the DC control device within the DC string connected to the fifth DC converter circuit. This enables the identification of the DC converter circuit connected to the DC control device solely through power line communication, improving the identification efficiency of the DC converter circuit connected to the DC control device.

[0066] In the exemplary embodiment, the power line communication carrier frequency of the power line communication subunit is no greater than a preset frequency, which can reduce signal crosstalk. For example, the preset frequency can be 150kHz, and other values ​​can be used as needed; this application does not limit this.

[0067] In the exemplary embodiment, the average PLC signal strength of each DC string is no greater than a preset current value, which can reduce signal crosstalk. For example, the preset current value can be 5mA, and it can also be other values ​​as needed; this application does not limit this.

[0068] In an exemplary embodiment, the magnetic saturation current of the magnetic ring is not less than a preset saturation current value. For example, the preset saturation current value can be 20A, and it can also be other values ​​as needed; this application does not limit this. The current in a DC string is relatively large; if the magnetic saturation current of the magnetic ring is too small, it will affect the communication quality.

[0069] Exemplary power converter Accordingly, embodiments of this application also provide a power converter, including the communication unit provided in any of the above embodiments of this application.

[0070] In an exemplary embodiment, the power converter may include an inverter.

[0071] For technical details not described in detail in this embodiment, please refer to the specific content of the communication unit provided in the above embodiments of this application, which will not be repeated here.

[0072] Exemplary power conversion system Accordingly, embodiments of this application also provide a power conversion system, including a power converter and a communication unit provided in any of the above embodiments of this application; The communication unit is connected to the power converter.

[0073] In an exemplary embodiment, the power converter may include an inverter.

[0074] For technical details not described in detail in this embodiment, please refer to the specific content of the communication unit provided in the above embodiments of this application, which will not be repeated here.

[0075] Exemplary methods Please see Figure 7 In one exemplary embodiment, a control method for a communication unit is provided. The communication unit includes: multiple magnetic rings, a power line communication unit, and multiple channel selection switches; the communication unit is communicatively connected to a power converter, which includes multiple DC-DC converter circuits; the input side of each DC-DC converter circuit is used to connect at least one DC string; the DC string includes at least one DC control device, the input terminal of which is used to connect to a DC source, and the output terminal of each DC control device is connected in series to the DC side of the power converter; the cable on the input side of each DC-DC converter circuit is configured with at least one magnetic ring; the signal terminal of the magnetic ring is connected to the signal terminal of the power line communication unit through at least one channel selection switch. The communication unit itself can be the entity executing the control method for the communication unit.

[0076] In an exemplary embodiment, the communication unit may further include a processor, which is connected to the control terminal of each channel selection switch and to the power line communication unit. The processor in the communication unit may also be the entity executing the control method of the communication unit.

[0077] In an exemplary embodiment, the communication unit may be an independent communication unit disposed outside the power converter and communicatively connected to the power converter; the communication unit may also be disposed inside the power converter as part of the power converter, and this application does not limit this.

[0078] like Figure 7 As shown, the control method of the communication unit includes: Step S101: Turn on the channel selection switch corresponding to the first DC-DC converter circuit and turn off the channel selection switch corresponding to the second DC-DC converter circuit.

[0079] The first DC-DC converter is a DC-DC converter in the power converter; the second DC-DC converter is a DC-DC converter other than the first DC-DC converter in the power converter; the channel selection switch corresponding to the DC-DC converter refers to the channel selection switch connected by the magnetic ring configured in the DC-DC converter.

[0080] Step S102: Control the power line communication unit to send a device search signal so that the DC control device that receives the device search signal can send a response signal.

[0081] Step S103: Receive the response signal and use the DC control device corresponding to the received response signal as the DC control device in the DC string connected to the first DC converter circuit.

[0082] In an exemplary embodiment, the device search signal may include a network beacon.

[0083] In an exemplary embodiment, the communication unit controls the power line communication unit to send a device search signal, causing the DC control device receiving the device search signal to send a response signal. The DC control device receiving the device search signal determines whether the signal strength of the device search signal is greater than a preset value. If the signal strength of the device search signal is greater than the preset value, the DC control device sends a response signal back to the power line communication unit. This reduces signal crosstalk, as the signal strength of interfering signals will be less than the preset value, further improving the recognition accuracy of the DC-DC converter circuit connected to the DC control device.

[0084] In this application, the communication unit includes multiple magnetic rings, a power line communication unit, and multiple channel selection switches. Each DC-DC converter's input side cable is configured with at least one magnetic ring. The signal end of the magnetic ring is connected to the signal end of the power line communication unit via at least one channel selection switch. By configuring an independent magnetic ring for each DC-DC converter, the communication unit activates the channel selection switch corresponding to the first DC-DC converter and deactivates the channel selection switch corresponding to the second DC-DC converter. This enables the power line communication unit to establish communication connections only with DC control devices within the DC string connected to the first DC-DC converter, and not with DC control devices within the DC string connected to the second DC-DC converter. Therefore, after controlling the power line communication unit to send a device search signal, it can be determined that the DC control device corresponding to the received response signal is a DC control device within the DC string connected to the first DC-DC converter. This allows for the identification of DC-DC converters connected to DC control devices solely through power line communication, improving the identification efficiency of DC-DC converters connected to DC control devices.

[0085] The magnetic ring enables isolated signal coupling between DC control equipment and channel selection switches. The voltage of the cable on the input side of each DC-DC converter circuit is high voltage, while the voltage at the signal end of each magnetic ring is low voltage, which can improve the safety of the power line communication unit.

[0086] In some embodiments, the control method for the communication unit further includes: extracting the identifier of the DC control device from the response signal; searching for the identifier of the first DC conversion circuit based on the identifier of the channel selection switch corresponding to the first DC conversion circuit, according to the mapping relationship between the identifier of the channel selection switch and the identifier of the DC conversion circuit; and establishing a mapping relationship between the identifier of the DC control device and the identifier of the first DC conversion circuit. This achieves the binding between the DC control device and the first DC conversion circuit.

[0087] In an exemplary embodiment, the identifier of the DC control device may include the address information of the DC control device, or it may include other types of identifiers, as long as the DC control device can be uniquely identified based on its identifier.

[0088] In an exemplary embodiment, the communication unit may pre-store the mapping relationship between the identifiers of the channel selection switch and the identifiers of the DC-DC converter circuit. For example, the processor in the communication unit may pre-store the mapping relationship between the identifiers of the channel selection switch and the identifiers of the DC-DC converter circuit. The connection relationship between the DC-DC converter circuit and the channel selection switch, where a mapping relationship exists between the identifiers, is that the magnetic ring configured in the DC-DC converter circuit connects to the channel selection switch.

[0089] In some embodiments, step S103, which designates the DC control device corresponding to the received response signal as the DC control device within the DC string connected to the first DC-DC converter circuit, includes: acquiring the signal strength of the response signal; and, if the signal strength of the response signal is greater than a signal strength threshold, designating the DC control device corresponding to the received response signal as the DC control device within the DC string connected to the first DC-DC converter circuit.

[0090] The signal strength of the response signal is filtered by a signal strength threshold, which can reduce signal crosstalk. The signal strength of the interference signal will be less than the signal strength threshold, further improving the recognition accuracy of the DC-DC converter circuit connected to the DC control equipment.

[0091] In some embodiments, such as Figure 8 As shown, the control method for the communication unit also includes: Step S201: If no response signal is received within a preset time period, disconnect the channel selection switch corresponding to the first DC-DC converter circuit, turn on the channel selection switch corresponding to the third DC-DC converter circuit, and disconnect the channel selection switch corresponding to the fourth DC-DC converter circuit.

[0092] The third DC-DC converter circuit is one of the DC-DC converter circuits in the second DC-DC converter circuit; the fourth DC-DC converter circuit is the DC-DC converter circuit in the second DC-DC converter circuit other than the third DC-DC converter circuit.

[0093] Step S202: Control the power line communication unit to send a device search signal so that the DC control device that receives the device search signal can send a response signal.

[0094] Step S203: Receive the response signal and use the DC control device corresponding to the received response signal as the DC control device in the DC string connected to the third DC converter circuit.

[0095] It can sequentially identify the DC control devices within the DC string connected to each DC-DC converter circuit. By switching the conduction state of the channel selection switches corresponding to each DC-DC converter circuit, it is possible to identify the DC-DC converter circuits connected to the DC control devices solely through power line communication, thereby improving the identification efficiency of the DC-DC converter circuits connected to the DC control devices.

[0096] In some embodiments, the power line communication unit includes at least one power line communication subunit; the signal terminal of each power line communication subunit is connected to the signal terminal of at least one magnetic ring through at least one channel selection switch. The control methods for the communication unit also include: Perform the following operations for each power line communication subunit: Turn on the channel selection switch corresponding to the fifth DC-DC converter circuit and turn off the channel selection switch corresponding to the sixth DC-DC converter circuit; wherein, the fifth DC-DC converter circuit is one of the DC-DC converter circuits corresponding to the power line communication subunit; the sixth DC-DC converter circuit is the DC-DC converter circuit other than the fifth DC-DC converter circuit in the DC-DC converter circuits corresponding to the power line communication subunit; the DC-DC converter circuit corresponding to the power line communication subunit refers to the DC-DC converter circuit where the magnetic ring connected to the power line communication subunit is located. The control power line communication subunit sends a device search signal so that the DC control device that receives the device search signal can send a response signal. It receives the response signal and uses the DC control device corresponding to the received response signal as the DC control device in the DC string connected to the fifth DC converter circuit.

[0097] The communication unit can simultaneously control multiple power line communication subunits and DC control devices within the DC string connected to the DC converter circuit, thereby improving overall communication efficiency. Each power line communication subunit can establish a communication connection only with the DC control devices within the DC string connected to the fifth DC converter circuit, and cannot establish a communication connection with the DC control devices within the DC string connected to the sixth DC converter circuit. Therefore, after controlling the power line communication subunit to send a device search signal, it can be determined that the DC control device corresponding to the received response signal is the DC control device within the DC string connected to the fifth DC converter circuit. This enables the identification of the DC converter circuit connected to the DC control device solely through power line communication, improving the identification efficiency of the DC converter circuit connected to the DC control device.

[0098] In some embodiments, such as Figure 9 The figure shown is a timing diagram of a control method for a communication unit provided in an embodiment of this application. Figure 9In this system, the communication unit is located inside the inverter. The communication unit activates the channel selection switch corresponding to the first DC-DC converter circuit and deactivates the channel selection switch corresponding to the second DC-DC converter circuit. The communication unit controls the power line communication unit to send a network beacon to the MLPEs within the DC string connected to the first DC-DC converter circuit. The MLPEs within the DC string connected to the first DC-DC converter circuit determine whether the signal strength of the network beacon is greater than a preset value. If the signal strength of the network beacon is greater than the preset value, the MLPEs within the DC string connected to the first DC-DC converter circuit send a response signal to the power line communication unit. The response signal includes the MLPE's address information, i.e., reporting the MLPE's address information to apply for network access. The communication unit receives the response signal forwarded by the power line communication unit. The signal strength of the response signal is filtered by a threshold. If the signal strength of the response signal is greater than the signal strength threshold, the MLPE is registered for network access. The MLPE enters the network, and the network access information is synchronized. The communication unit binds the MLPE and the first DC-DC converter circuit. If no MLPE reports, the system switches to the next DC-DC converter circuit, and the MLPEs within the DC strings connected to each DC-DC converter circuit can be determined sequentially. The system can identify DC-DC converter circuits connected to MLPEs using only PLC, improving the efficiency of automatic network construction between inverters and MLPEs. Moreover, compared to using inverters to control string current to identify DC-DC converter circuits connected to each MLPE, it reduces the system complexity of automatic network construction between inverters and MLPEs, reduces the interdependence and coupling between system functional modules, and improves the reliability of system network construction.

[0099] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0100] The units and sub-units in the various embodiments of this application can be merged, divided, and deleted according to actual needs.

[0101] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0102] 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 communication unit, characterized in that, include: Multiple magnetic rings, power line communication unit, and multiple channel selection switch; The communication unit is communicatively connected to the power converter, which includes multiple DC-DC conversion circuits. The input side of each DC-DC converter circuit is used to connect at least one DC string; the DC string includes at least one DC control device, the input terminal of the DC control device is used to connect to a DC source, and the output terminal of each DC control device is connected in series to the DC side of the power converter; Each DC-DC converter circuit has at least one magnetic ring configured on its input side cable; the signal terminal of the magnetic ring is connected to the signal terminal of the power line communication unit via at least one channel selection switch. The communication unit is used to turn on the channel selection switch corresponding to the first DC-DC converter circuit and turn off the channel selection switch corresponding to the second DC-DC converter circuit; wherein, the first DC-DC converter circuit is one of the DC-DC converter circuits in the power converter; the second DC-DC converter circuit is a DC-DC converter circuit other than the first DC-DC converter circuit in the power converter; the channel selection switch corresponding to the DC-DC converter circuit refers to the channel selection switch connected by the magnetic ring configured in the DC-DC converter circuit. The power line communication unit is controlled to send a device search signal so that the DC control device that receives the device search signal can send a response signal; the response signal is received and the DC control device corresponding to the received response signal is designated as the DC control device in the DC string connected to the first DC-DC converter circuit.

2. The communication unit according to claim 1, characterized in that, The communication unit is specifically used to acquire the signal strength of the response signal; when the signal strength of the response signal is greater than the signal strength threshold, the DC control device corresponding to the received response signal is used as the DC control device in the DC string connected to the first DC converter circuit.

3. The communication unit according to claim 1, characterized in that, The communication unit is further configured to, if no response signal is received within a preset time period, disconnect the channel selection switch corresponding to the first DC-DC converter circuit, turn on the channel selection switch corresponding to the third DC-DC converter circuit, and disconnect the channel selection switch corresponding to the fourth DC-DC converter circuit; wherein, the third DC-DC converter circuit is one of the second DC-DC converter circuits; and the fourth DC-DC converter circuit is a DC-DC converter circuit other than the third DC-DC converter circuit in the second DC-DC converter circuit. The power line communication unit is controlled to send a device search signal so that the DC control device that receives the device search signal can send a response signal; the response signal is received and the DC control device corresponding to the received response signal is designated as the DC control device in the DC string connected to the third DC converter circuit.

4. The communication unit according to claim 1, characterized in that, The power line communication unit includes at least one power line communication subunit; the signal terminal of each power line communication subunit is connected to the signal terminal of at least one magnetic ring through at least one of the channel selection switches. The communication unit is also configured to perform the following operations for each power line communication subunit: Turn on the channel selection switch corresponding to the fifth DC-DC converter circuit and turn off the channel selection switch corresponding to the sixth DC-DC converter circuit; wherein, the fifth DC-DC converter circuit is one of the DC-DC converter circuits corresponding to the power line communication subunit; the sixth DC-DC converter circuit is any DC-DC converter circuit other than the fifth DC-DC converter circuit in the DC-DC converter circuits corresponding to the power line communication subunit; the DC-DC converter circuit corresponding to the power line communication subunit refers to the DC-DC converter circuit where the magnetic ring connected to the power line communication subunit is located; The power line communication subunit is controlled to send a device search signal so that the DC control device that receives the device search signal can send a response signal; the response signal is received and the DC control device corresponding to the received response signal is designated as the DC control device in the DC string connected to the fifth DC-DC converter circuit.

5. A power converter, characterized in that, Includes the communication unit as described in any one of claims 1 to 4.

6. A power conversion system, characterized in that, Includes a power converter and a communication unit as described in any one of claims 1 to 4; The communication unit is communicatively connected to the power converter.

7. A control method for a communication unit, characterized in that, The communication unit includes: multiple magnetic rings, a power line communication unit, and multiple channel selection switches; The communication unit is communicatively connected to the power converter, which includes multiple DC-DC converter circuits. The input side of each DC-DC converter circuit is used to connect at least one DC string. The DC string includes at least one DC control device. The input terminal of the DC control device is used to connect to a DC source, and the output terminal of each DC control device is connected in series to the DC side of the power converter. Each DC-DC converter circuit has at least one magnetic ring configured on its input side cable; the signal terminal of the magnetic ring is connected to the signal terminal of the power line communication unit via at least one channel selection switch. The control method includes: Turn on the channel selection switch corresponding to the first DC-DC converter circuit and turn off the channel selection switch corresponding to the second DC-DC converter circuit; wherein, the first DC-DC converter circuit is one of the DC-DC converter circuits in the power converter; the second DC-DC converter circuit is another DC-DC converter circuit in the power converter besides the first DC-DC converter circuit; the channel selection switch corresponding to the DC-DC converter circuit refers to the channel selection switch connected by the magnetic ring configured in the DC-DC converter circuit; The power line communication unit is controlled to send a device search signal so that the DC control device that receives the device search signal can send a response signal; the response signal is received and the DC control device corresponding to the received response signal is designated as the DC control device in the DC string connected to the first DC-DC converter circuit.

8. The control method for the communication unit according to claim 7, characterized in that, The step of using the DC control device corresponding to the received response signal as the DC control device within the DC string connected to the first DC converter circuit includes: Obtain the signal strength of the response signal; If the signal strength of the response signal is greater than the signal strength threshold, the DC control device corresponding to the received response signal is designated as the DC control device within the DC string connected to the first DC converter circuit.

9. The control method for the communication unit according to claim 7, characterized in that, The control method further includes: If no response signal is received within a preset time period, the channel selection switch corresponding to the first DC-DC converter circuit is disconnected, the channel selection switch corresponding to the third DC-DC converter circuit is turned on, and the channel selection switch corresponding to the fourth DC-DC converter circuit is disconnected; wherein, the third DC-DC converter circuit is one of the second DC-DC converter circuits; and the fourth DC-DC converter circuit is a DC-DC converter circuit other than the third DC-DC converter circuit in the second DC-DC converter circuit. The power line communication unit is controlled to send a device search signal, so that the DC control device that receives the device search signal will send a response signal. The system receives a response signal and uses the DC control device corresponding to the received response signal as the DC control device within the DC string connected to the third DC converter circuit.

10. The control method for the communication unit according to claim 7, characterized in that, The power line communication unit includes at least one power line communication subunit; Each of the power line communication subunits has its signal terminal connected to at least one of the magnetic rings' signal terminals via at least one of the channel selection switches. The method further includes: Perform the following operations for each power line communication subunit: Turn on the channel selection switch corresponding to the fifth DC-DC converter circuit and turn off the channel selection switch corresponding to the sixth DC-DC converter circuit; wherein, the fifth DC-DC converter circuit is one of the DC-DC converter circuits corresponding to the power line communication subunit; the sixth DC-DC converter circuit is any DC-DC converter circuit other than the fifth DC-DC converter circuit in the DC-DC converter circuits corresponding to the power line communication subunit; the DC-DC converter circuit corresponding to the power line communication subunit refers to the DC-DC converter circuit where the magnetic ring connected to the power line communication subunit is located; The power line communication subunit is controlled to send a device search signal, so that the DC control device that receives the device search signal will send a response signal. The system receives a response signal and uses the DC control device corresponding to the received response signal as the DC control device within the DC string connected to the fifth DC converter circuit.

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