Power converter connection device identification method and power converter

Abstract

This disclosure provides a method for identifying connected devices using a power converter and a power converter itself. The power converter includes a power conversion circuit, a DC connection port, a grid connection port, and a common connection port. The DC side of the power conversion circuit is electrically connected to the DC connection port, and the AC side of the power conversion circuit is electrically connected to both the grid connection port and the common connection port. The common connection port is compatible with various types of connected devices. The method includes: responding to the device connection condition of the common connection port; within a preset time window, detecting the electrical transformation characteristics of the common connection port, including at least one of voltage transformation characteristics and current transformation characteristics; and determining the device type corresponding to the detected electrical transformation characteristics from a pre-set correspondence between electrical transformation characteristics and device types, and using this as the device type of the device connected to the common connection port. This disclosure improves the safety of using the power converter.

Description

Technical Field

[0001] This disclosure relates to the field of new energy technology, and more specifically, to a method for identifying power converter connection devices and a power converter. Background Technology

[0002] Currently, power converters such as PCS (Power Conversion System) only have grid-connected and off-grid ports, limiting their application scenarios. Users need to purchase different types or models of power converters for different application scenarios. Therefore, it is necessary to optimize the applicability of power converters.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this disclosure is to provide a method for identifying connected devices of a power converter and a power converter, in order to solve the problem of limited application scenarios of power converters in the prior art.

[0005] According to a first aspect of the present disclosure, a method for identifying connected devices of a power converter is provided. The power converter includes a power conversion circuit, a DC connection port, a grid connection port, and a common connection port. The DC side of the power conversion circuit is electrically connected to the DC connection port, and the AC side of the power conversion circuit is electrically connected to both the grid connection port and the common connection port. The common connection port is adapted to connect to multiple types of access devices. The method includes: responding to the device access condition of the common connection port; within a preset time window, detecting electrical transformation characteristics of the common connection port, the electrical transformation characteristics including at least one of voltage transformation characteristics and current transformation characteristics; determining the device type corresponding to the detected electrical transformation characteristics from a preset correspondence between electrical transformation characteristics and device types, and using this as the device type of the device connected to the common connection port.

[0006] According to a second aspect of the present disclosure, a power converter is provided, including a common connection port, the power converter being configured to perform the method as described in any of the preceding claims.

[0007] According to a third aspect of this disclosure, an electronic device is provided, including the power converter described above.

[0008] According to a fourth aspect of this disclosure, a computer-readable storage medium is provided having a program stored thereon that, when executed by a processor, implements the power converter connection device identification method as described in any of the preceding claims.

[0009] According to a fifth aspect of this disclosure, a computer program product is provided, comprising a computer program, characterized in that, when executed by a processor, the computer program implements the steps of the method as described in any of the preceding claims.

[0010] This embodiment of the disclosure provides a common connection port on the power converter that can connect to multiple devices. In response to device access signals, it automatically identifies the type of access device connected to the common connection port based on the electrical conversion characteristics of the common connection port. This enables the power converter to automatically adapt to different access devices, significantly improving the system's adaptability, expanding the application scenarios of the power converter, and enhancing the operational safety of the power converter through automatic identification.

[0011] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0012] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0013] Figure 1 This is a flowchart of a power converter connection device identification method in an exemplary embodiment of this disclosure.

[0014] Figure 2 This is a schematic diagram of a power converter in an exemplary embodiment of this disclosure.

[0015] Figure 3 This is a flowchart illustrating the determination of three device types in an exemplary embodiment of this disclosure.

[0016] Figure 4 This is a schematic diagram illustrating device type detection in conjunction with user-defined device types in an exemplary embodiment of this disclosure.

[0017] Figure 5 This is a schematic diagram illustrating device type detection in conjunction with user-defined device types in an exemplary embodiment of this disclosure.

[0018] Figure 6 This is a schematic diagram illustrating the setting of multiple sets of thresholds in an exemplary embodiment of this disclosure. Detailed Implementation

[0019] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of the specific details omitted, or other methods, components, apparatus, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0020] Furthermore, the accompanying drawings are merely illustrative of this disclosure, and the same reference numerals in the drawings denote the same or similar parts, thus repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0021] The exemplary embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0022] Figure 1 This is a flowchart of a power converter connection device identification method in an exemplary embodiment of this disclosure. Figure 1 The method 100 shown can be applied to a power converter, which includes a power conversion circuit, a DC connection port, a grid connection port, and a common connection port. The DC side of the power conversion circuit is electrically connected to the DC connection port, and the AC side of the power conversion circuit is electrically connected to both the grid connection port and the common connection port. The common connection port is adapted to connect various types of access devices. A detailed description of the power converter is provided in subsequent embodiments.

[0023] refer to Figure 1 The power converter connection device identification method 100 may include: Step S1: In response to the device access condition of the common connection port, within a preset time window, detect the electrical transformation characteristics of the common connection port, wherein the electrical transformation characteristics include at least one of voltage transformation characteristics and current transformation characteristics; Step S2: Determine the device type corresponding to the detected electrical transformation feature from the pre-set correspondence between electrical transformation features and device types, and use this as the device type of the device connected to the common connection port.

[0024] The method of this disclosure embodiment can be executed by the controller of a power converter equipped with a common connection port, also known as a multi-function port or GEN port (General Port), which is configured to flexibly connect to various power sources or loads. On power converters equipped with common connection ports, if users manually configure the type of connected device, incorrect configuration is prone to occur. Such problems may be difficult to detect in the early stages of system operation, but can easily trigger malfunctions in protection mechanisms or damage to equipment when switching between grid-connected and islanded states. Furthermore, with the widespread application of low-voltage energy storage systems, the types and number of devices connected to the multi-function port are continuously increasing, and the frequency of misconnection problems will also rise accordingly, posing significant challenges to the stable operation and subsequent maintenance of the system.

[0025] This embodiment of the disclosure provides a common connection port on the power converter that can connect to multiple devices. In response to device access signals, it automatically identifies the type of access device connected to the common connection port based on the electrical conversion characteristics of the common connection port. This enables the power converter to automatically adapt to different access devices, significantly improving the system's adaptability, expanding the application scenarios of the power converter, and enhancing the operational safety of the power converter through automatic identification.

[0026] Figure 2 This is a schematic diagram of a power converter in an exemplary embodiment of this disclosure.

[0027] In the embodiments disclosed herein, the power converter includes, but is not limited to, photovoltaic power converter, energy storage power converter (PCS), and integrated photovoltaic-energy storage unit.

[0028] Power converters may include, for example, DC / DC converters and / or DC / AC converters (inverters). That is, a power converter may include only a DC / DC converter, only a DC / AC converter (inverter), or both a DC / DC converter and a DC / AC converter (inverter).

[0029] refer to Figure 2In an exemplary embodiment, the power converter 200 includes a power conversion circuit 21, a DC connection port 22, a grid connection port 23, and a common connection port 24. The power conversion circuit 21 may simultaneously include a DC / DC converter 211 and a DC / AC converter (inverter) 212. The DC / DC converter 211 can connect to photovoltaic systems, batteries, diesel generators, etc., while the DC / AC converter (inverter) 212 can be used to connect to the power grid, loads, etc. The DC side of the power conversion circuit 21 is electrically connected to the DC connection port 22, and the AC side of the power conversion circuit 200 is electrically connected to both the grid connection port 23 and the common connection port 24. The common connection port 24 is adapted to connect various types of access devices.

[0030] exist Figure 2 In the illustrated embodiment, the common connection port 24 is configured to connect to the DC / AC converter (inverter) 212. In other embodiments of this disclosure, the common connection port 24 may also be configured to connect to the DC / DC converter 211, or the common connection port 24 may be configured to connect both the DC / DC converter 211 and the DC / AC converter (inverter) 212.

[0031] The following is a detailed description of each step in the power converter connection device identification method 100.

[0032] In step S1, in response to the device access condition of the common connection port, within a preset time window, the electrical transformation characteristics of the common connection port are detected. The electrical transformation characteristics include at least one of voltage transformation characteristics and current transformation characteristics.

[0033] In an exemplary embodiment, when the controller of the power converter detects a pre-set device access condition (e.g., a device access signal) at the common connection port, it can execute method 100 to start automatically detecting the device type.

[0034] In an exemplary embodiment, prior to detecting the electrical transformation characteristics of the common connection port, the method may further include: responding to a device access signal by sending a pre-start signal to the access device.

[0035] The purpose of sending a pre-start signal is to provide the connected device with the start command it may need. For example, when the connected device is a diesel generator, the pre-start signal can be used to trigger the generator's start control circuit, bringing the generator into an operational state; when the connected device is a photovoltaic system, the pre-start signal is used to establish an initial electrical connection, enabling the photovoltaic modules to output current for subsequent voltage, current, and islanding status detection; when the connected device is a load, the pre-start signal can be used to trigger the load to start or enter a set operating state.

[0036] By sending a pre-start signal, the power converter can bring the connected devices into an identifiable electrical state without entering formal operation, thereby providing stable detection conditions for subsequent detection of electrical transformation characteristics of common connection ports and confirmation of device type.

[0037] In some embodiments, the pre-start signal may include a DC output control signal and an output test voltage. Sending the pre-start signal to the access device can be achieved, for example, by outputting a DC output control signal or an output test voltage to the access device through a common connection port. The DC output control (Direct Output, DO) signal is used to control the on / off state of the output circuit of the common connection port to establish a stable electrical output channel. The output test voltage is a low-voltage DC test level set by the controller, used to provide an initial excitation voltage to the access device, enabling the device to be identified to enter a detectable operating state. This avoids the inability to detect port electrical parameters due to the lack of excitation voltage, thus preventing accurate identification of the device type.

[0038] In other embodiments, sending a pre-start signal to the access device may also include: establishing a communication connection with the access device through a preset communication method; and sending a pre-start signal to the access device through the preset communication method. The preset communication method includes wired communication and wireless communication. Wired communication methods include, but are not limited to, CAN bus communication, RS485 serial communication, Ethernet PLC power line communication, and hard-contact switch interlocking communication. Wireless communication methods include, but are not limited to, LoRa narrowband communication, WiFi, Bluetooth short-range pairing, and 4G / 5G cellular network communication. After the power converter establishes a communication link with the access device, the power converter can first complete the device handshake and identity verification before sending the pre-start signal.

[0039] Since the startup commands for different access devices are not necessarily the same, the specific types and number of pre-start signals can be either one or multiple (i.e., multiple pre-start signals are output sequentially to start possible access devices). For example, the controller of a power converter can send a first pre-start signal and a second pre-start signal to the access device in sequence. The first pre-start signal is adapted to the startup triggering logic of conventional power generation equipment such as diesel generators, while the second pre-start signal is adapted to the power-on activation logic of DC power sources such as photovoltaic systems. By outputting different pre-start signals in a time-sharing and category-based manner, the startup requirements of various typical access devices can be covered, improving the compatibility and accuracy of device type identification.

[0040] In an exemplary embodiment, the transmission order of various pre-start signals can be pre-configured based on the type probability of the accessed devices, differences in electrical characteristics, and identification security. For example, the corresponding pre-start signals can be output sequentially according to the priority of conventional power generation equipment, DC power supply equipment, and load equipment; alternatively, based on historical access statistics, the pre-start signals corresponding to devices with higher frequency of occurrence can be output first. By setting a reasonable output order, the time spent on device type determination can be shortened while ensuring identification accuracy, thereby improving the adaptive identification efficiency of the power converter for different accessed devices.

[0041] When sending multiple pre-start signals, the power converter can also send them through one or more communication methods, including sending them directly through the common connection port as mentioned above, and sending them through the preset communication method mentioned above.

[0042] After sending the pre-start signal, the electrical transformation characteristics of the common connection port are detected.

[0043] Of course, in other embodiments, a pre-start signal may not be sent, and the access device may be manually turned on or configured by the device operator to bring the access device into a recognizable electrical state. In this scenario, the power converter may also be configured to respond to the device access signal and directly begin detecting the electrical transformation characteristics of the common connection port.

[0044] In this embodiment, the electrical transformation characteristics of the common connection port are detected within a preset time window to avoid prolonged waiting without identification results, which could lead to the device entering a dead loop. The preset time window can be pre-set and adaptively adjusted based on the startup response characteristics, electrical setup time, and system identification stability requirements of different access devices supported by the current power converter.

[0045] When setting the specific value of the preset time window, it is necessary to consider that the preset time window can ensure that different types of access devices can complete the startup process such as internal circuit conduction, voltage establishment, and output stabilization after receiving the pre-start signal, so as to avoid unstable electrical parameters, signal distortion, or misjudgment due to sampling too early, thereby improving the reliability and consistency of device type detection.

[0046] In an exemplary embodiment, the preset time window is determined based on the longest detection wait time (i.e., startup response time) of the device types supported by the common connection port of the power converter. The preset time window should be greater than the maximum value of the buffer time for multiple device types to ensure that the electrical state of the connected device with the longest startup time has been sufficiently stable at the time of sampling, thereby improving identification accuracy. For example, if the common connection port of the power converter supports the connection of a diesel generator, a photovoltaic system, and a load, and the startup response time of the diesel generator is 80ms, the startup response time of the photovoltaic system is 150ms, and the startup response time of the load is 100ms, then the preset time window Δt should be set to be greater than 150ms.

[0047] In an exemplary embodiment, a preset time window can be adjusted based on the current ambient temperature. This is because ambient temperature directly affects the conduction delay, voltage build-up speed, and electrical response characteristics of the internal circuitry of the connected device. This is especially true for devices containing semiconductor devices or mechanical actuators, such as photovoltaic systems and diesel generators, where temperature changes can cause shifts in their startup response time. For example, in low-temperature environments, the capacitor charging speed of photovoltaic modules slows down, the action delay of the generator control circuit increases, and the corresponding electrical stabilization time is prolonged; while in high-temperature environments, the response speed of some devices increases, and the startup build-up time is shortened.

[0048] Therefore, in the exemplary embodiment, the ambient temperature can be detected in real time, and the duration of the preset time window can be dynamically adjusted based on the preset temperature-response time mapping relationship, so that the sampling timing always matches the actual stable moment of the access device under different temperature conditions, thereby further improving the accuracy and robustness of the power converter in identifying device type across the entire temperature operating range.

[0049] In an exemplary embodiment, the detected electrical transformation characteristics of the common wiring port include at least one of voltage transformation characteristics and current transformation characteristics. The voltage transformation characteristics include, for example, a voltage value, and the current transformation characteristics include, for example, current direction and current value.

[0050] Return to reference Figure 2 In some embodiments, voltage sampling devices and current sampling devices (as shown in the figure) can be set on the connection path of the common connection port to detect the electrical transformation characteristics of the common connection port.

[0051] After detecting voltage transformation characteristics and current transformation characteristics, the voltage value can be output based on the voltage transformation characteristics, and the current direction can be determined based on the current transformation characteristics. In subsequent steps, different preset durations are determined according to different judgment requirements to calculate the current value or current accumulation within the preset duration. The current accumulation refers to the cumulative result of sampling the current within the preset duration. In an exemplary embodiment, the current accumulation is, for example, the current integral value.

[0052] It should be noted that the detection of electrical transformation characteristics, such as voltage and current transformation characteristics, begins with the sending of a pre-start signal (serving as the start time of the preset time window) or with the receipt of a device access signal, and ends when the device type is determined or the preset time window ends. That is, after determining the device type, the detection of electrical transformation characteristics at the common connection port stops; if the device type determination fails and the preset time window has not ended, the detection of electrical transformation characteristics at the common connection port continues until either of the above two conditions (determining the device type or the preset time window ending) is met.

[0053] After detecting the electrical transformation feature, proceed to step S2, where the device type corresponding to the detected electrical transformation feature is determined from the pre-set correspondence between electrical transformation features and device types, and this device type is used as the device type of the device connected to the common wiring port.

[0054] In an exemplary embodiment, the first step is to determine whether the voltage is constant, in order to prioritize the differentiation between fuel-powered generators with autonomous voltage-building capabilities and other passive or low-voltage devices. Fuel-powered generators can independently establish a stable AC voltage after receiving a pre-start signal, without relying on a power converter for power supply. This results in significant differences in electrical characteristics compared to photovoltaic systems and ordinary loads. Therefore, prioritizing voltage amplitude can quickly eliminate non-generator devices, improving identification efficiency.

[0055] In some embodiments, the device type can be determined to be a fuel generator when the voltage value V(t) is greater than a preset voltage threshold and the current value is less than a preset current threshold within a first preset time period. For example, a preset voltage threshold corresponding to a diesel generator can be set. If the voltage is 220V, and the following is detected within 100ms after startup (this duration is only an example and is limited to outputting the detection result at the end of this duration): (1) Then it is further determined whether the current value is less than the preset current threshold within the first preset time period.

[0056] The first preset duration is, for example, 100ms, and the preset current threshold can be a relatively small value to help determine that the current value I(t)≈0 within the first preset duration.

[0057] When I(t)≈0, the device type of the access device connected to the common terminal is determined to be a diesel generator. This is because a fuel generator is an independent active power generation device with an internal excitation and power drive structure. After starting, it can independently establish a stable output voltage with a high amplitude, and when it is not connected to a load or not connected to the grid with a power converter, its external output current is approximately zero.

[0058] Therefore, when the detected voltage value is greater than the preset voltage threshold, it indicates that a high-voltage electrical signal has been autonomously established by the external device at the port; at the same time, the current value is less than the preset current threshold within the first preset time period, indicating that the external device only outputs voltage but there is no obvious current flowing into or out of the power converter, which is consistent with the typical electrical characteristics of a fuel generator starting under no-load conditions. Based on this, the device type can be accurately determined to be a fuel generator.

[0059] In some embodiments, the comparison with the preset current threshold may also be the current accumulation or the current integral value. For example, when the voltage value V(t) is greater than the preset voltage threshold and the current integral value within a first preset time period is less than the preset current threshold, the device type is determined to be a fuel generator.

[0060] Therefore, by combining the characteristics of voltage stability and current non-response, rapid identification of fuel generators can be achieved.

[0061] The fuel-fired generators disclosed herein include, but are not limited to, diesel generators, gasoline generators, gas generators, kerosene generators, and other internal combustion power generation equipment powered by fossil fuels.

[0062] Furthermore, if a non-zero voltage value is detected within a preset time window, and the voltage value does not satisfy formula (1), the device type is further identified based on the current transformation characteristics.

[0063] In an exemplary embodiment, when the voltage value is less than or equal to a preset voltage threshold, the current direction is the inflow direction, and the current value is greater than or equal to zero within a second preset time period, the device type is determined to be a power generation device.

[0064] This is because a voltage value less than or equal to a preset voltage threshold indicates that the connected device does not have the ability to independently establish a high voltage, which is different from a fuel generator; the current direction is the direction of flowing into the power converter, indicating that energy is transferred from the external device to the power converter, excluding load-type devices; a current value greater than or equal to zero indicates that the external device continuously provides electrical energy, meeting the basic electrical characteristics of the power generation equipment.

[0065] Similarly, the current integral value within the second preset time period can also be used for the judgment, which will not be elaborated here.

[0066] In this disclosure, the types of power generation equipment include, but are not limited to, photovoltaic systems, small DC power generation devices, and other renewable energy power generation equipment. In exemplary embodiments, photovoltaic power generation systems include, but are not limited to, photovoltaic modules, photovoltaic strings, and photovoltaic arrays.

[0067] In some embodiments, in order to further identify the type of power generation equipment, after determining that the equipment type is power generation equipment, islanding detection is performed on the common connection port, and if the islanding detection result shows that islanding operation characteristics are present, the equipment type is further determined to be a photovoltaic system.

[0068] Specifically, the islanding detection and photovoltaic system identification process is as follows: First, to avoid misjudgment, PID (Passive Island Detection) is performed on the common connection port. By monitoring whether the voltage and frequency parameters of the common connection port deviate from the normal range, it is confirmed that the current common connection port is in an islanded operation state, providing a reliable premise for subsequent photovoltaic system identification.

[0069] In an exemplary embodiment, after confirming that the common connection port is in an islanded state, the common connection port is controlled to output a set inverter voltage V to the outside. inverter (Usually the system rated voltage, such as 220V or 230V); Subsequently, the current transformation characteristic I(t) of the common connection port is detected in real time, and the detected current transformation characteristic is integrated within a second preset time Δt (e.g., 200ms). If the detected current direction is from the outside into the multi-function port, and the current integral value satisfies formula (2): (2) Therefore, the power generation equipment can be identified as a photovoltaic system.

[0070] As a weak-source power generation device, the output characteristics of a photovoltaic (PV) system depend on external voltage support. In islanded mode (without grid support), a current-source PV system cannot actively output stable power. It can only output current when it receives a stable voltage and phase from an external source. Therefore, when the common terminal provides inverter voltage as support, the current flows from the PV system into the power converter (i.e., into the common terminal), and continuous current input will make the integral value greater than 0. Other types of power generation devices (such as small DC generators) can output current autonomously without external voltage excitation in islanded mode. Their current characteristics differ significantly from those of PV systems. This difference allows for the differentiation of PV systems from other power generation devices, effectively avoiding misidentification.

[0071] In some embodiments, to accurately identify a photovoltaic system, after determining that the equipment type is a power generation device, harmonic spectrum analysis can be performed on the current transformation characteristics of the common connection port. If the harmonic spectrum analysis results correspond to a photovoltaic system, the equipment type is determined to be a photovoltaic system. This is because the current transformation characteristics of some photovoltaic systems may contain specific harmonic features. Therefore, by adding a harmonic analysis module during the detection process to perform spectrum analysis on the current transformation characteristics, the presence of inherent harmonic components of the photovoltaic system can be detected. If harmonic signals of a specific frequency are detected, it can assist in determining that it is a photovoltaic system, thereby improving the accuracy and robustness of equipment type identification.

[0072] In other embodiments, the device type is determined to be a load when the voltage value is less than or equal to a preset voltage threshold, the current direction is outflow direction, and the current value (or current accumulation / current integral value) is greater than or equal to a preset current value within a second preset time period.

[0073] After the load device is connected to the common connection port, it will continuously absorb energy from the power converter. Therefore, the current conversion characteristic should be a continuous positive output (i.e., current flows out of the multi-function port).

[0074] After DO control or voltage is turned on, the current transformation characteristic I(t) is continuously monitored. If the current integral value satisfies the following within the second preset time period Δt: (3) It is then determined to be a smart load. The preset current value... The minimum load current threshold is preset, which is usually between 1A and 5A, depending on the system's rated power.

[0075] Therefore, the load type can be accurately identified by the continuity and amplitude characteristics of the current.

[0076] In addition to determining device type using the methods described above, some embodiments can construct multi-dimensional identification models that comprehensively analyze voltage, current, temperature, and frequency signals. By introducing multi-feature fusion algorithms, such as support vector machines (SVM) or neural networks, device type can be identified more accurately. This method is particularly suitable for complex operating conditions or high-noise environments.

[0077] Figure 3 This is a flowchart illustrating the determination of three device types in an exemplary embodiment of this disclosure.

[0078] refer to Figure 3 In an exemplary embodiment, the determination can be performed in the order of voltage value, current direction, and finally current value to obtain the device type determination result in one go.

[0079] In Event 301, the responding device is in the connected condition and sends a pre-start signal to the common connection port; In event 302, determine whether the voltage transformation characteristics of the common connection port are detected within the preset time window. If yes, proceed to event 303; otherwise, report an error. In event 303, the voltage value is determined based on the voltage transformation characteristics; Event 304: Determine if the voltage value is greater than the preset voltage threshold. If yes, proceed to event 305; otherwise, proceed to event 306. In event 305, the current transformation characteristics are obtained, and it is determined whether the current value within the first preset time period is less than the preset current threshold. If it is, the equipment type is determined to be a fuel generator; otherwise, an error is reported. In event 306, the current transformation characteristics are obtained, and the current direction is determined. If it is the inflow direction, proceed to event 307; if it is the outflow direction, proceed to event 308. In event 307, islanding detection is performed, and the islanding detection result is obtained. If the islanding detection result indicates an islanded state, the equipment type is determined to be a photovoltaic system. If the islanding detection result indicates a non-islanded state, the equipment type is determined to be other power generation equipment. In event 308, determine whether the current is continuously flowing out. If so, determine that the device type is a load; otherwise, report an error.

[0080] In event 308, to determine whether the current is continuously flowing out, the current integral value can be used according to formula (3).

[0081] The above detection process can be integrated into the embedded control unit of the power converter and implemented through a software module. In an exemplary embodiment, the control unit of the power converter executes the detection process after the device is connected. First, it sends a DO control signal or outputs a test voltage to the connected device through the common connection port. Then, it enters the signal detection stage to detect the electrical transformation characteristics such as current transformation characteristics and voltage transformation characteristics of the common connection port. Next, based on the detected voltage and current data, it executes the judgment logic in formulas (1), (2), and (3) in sequence, and finally outputs the device type identification result.

[0082] This process can be executed automatically upon system startup, or it can be performed as a secondary verification after the user sets the device type to ensure that the settings are consistent with reality. To enhance system robustness, a safe mode can be entered in case of identification failure or signal abnormality, limiting the output power of the multi-function port or entering an alarm state, awaiting manual confirmation.

[0083] In some embodiments, after determining the device type, the result can be compared with the device type set by the user as a prerequisite for the operation of the power converter.

[0084] Figure 4This is a schematic diagram illustrating device type detection in conjunction with user-defined device types in an exemplary embodiment of this disclosure.

[0085] refer to Figure 4 In an exemplary embodiment, method 100 further includes: Step S3: Record the device type of the access device connected to the common connection port as the first device type; Step S4: Obtain the device type set by the user; Step S5: When the device type set by the user is different from the first device type, a reminder signal is sent to the user.

[0086] In some embodiments, the power converter allows users to configure the device type of the connected access device.

[0087] In an exemplary embodiment, in this scenario, the device type detection process of the power converter can be performed automatically after the device is connected. After obtaining the device type detection result, the device type detection result is recorded as the first device type. Next, the first device type is compared with the device type set by the user.

[0088] If the first device type matches the device type set by the user, it can either provide a "device type set correctly" message or not provide a message and directly control the power converter to work according to the normal process.

[0089] If the first device type does not match the device type set by the user, an alert signal will be sent. The alert signal can be sent through various means such as sound, light, electricity, or a display screen.

[0090] After sending a reminder signal, the system can wait for the user to change the device type settings. Once the user changes the device type to match the first device type, the system will control the power converter to continue operating according to the first device type.

[0091] In some embodiments, the user can actively control the power converter to continue operating according to the currently set device type. This active control can be achieved by clicking multiple buttons or entering verification information (such as a verification code or pattern selection). If the user controls the power converter to continue operating according to the currently set device type, there may be an error in the device type determination. In this case, the event and the corresponding user-set device type can be recorded for subsequent troubleshooting of the execution process of method 100.

[0092] In other embodiments, the power converter may be set to stop operating if the first device type is inconsistent with the device type set by the user, thereby improving operational safety.

[0093] In some embodiments, to facilitate remote monitoring by maintenance personnel, the device type identification results can be uploaded to the backend management system via a communication module. If a device type mismatch is detected, the backend management system can automatically trigger an alarm and display the identification results and suggested actions on the user interface. This embodiment is applicable to distributed energy storage systems or large-scale power plants, helping to reduce on-site maintenance costs and improve the intelligence level of system management.

[0094] In addition, in some embodiments, the device type set by the user can be obtained before determining the device type, and the verification can be performed specifically for that device type, thereby improving the detection efficiency.

[0095] Figure 5 This is a schematic diagram illustrating device type detection in conjunction with user-defined device types in an exemplary embodiment of this disclosure.

[0096] refer to Figure 5 In an exemplary embodiment, method 100 further includes: Step S01: Obtain the device type set by the user; Step S02: Determine the expected electrical transformation characteristics corresponding to the device type set by the user; Step S03: When the electrical transformation characteristics of the common wiring port do not match the expected electrical transformation characteristics, a reminder signal is sent to the user.

[0097] exist Figure 5 In the illustrated embodiment, steps S01 and S03 can be executed before, after, or between steps S1 to S3, rather than sequentially.

[0098] For example, while performing step S1, the device can respond to the device access signal, obtain the device type set by the user, and thus determine the expected electrical transformation characteristics corresponding to the device type. The expected electrical transformation characteristics include, but are not limited to, expected voltage value characteristics, expected current direction, current integration window duration, expected current integration value corresponding to the current integration window duration, etc.

[0099] Next, the voltage transformation characteristics of the common connection port are detected within a preset time window. If no voltage signal is detected, an error is reported to the user. (Reference) Figure 3 Event 302 is shown.

[0100] If a voltage signal is detected, the voltage value is determined based on the voltage transformation characteristics. It is then directly checked whether the voltage value matches the expected voltage value. If they do not match, a reminder signal (or error report) is sent directly to the user. If they match, the current transformation characteristics are acquired, and the current direction is determined based on these characteristics. The current direction is then checked whether it matches the expected current direction. If they do not match, a reminder signal (or error report) is sent directly to the user. If the current direction matches the expected current direction, the current integral value corresponding to the current integration window duration is acquired. The current integral value corresponding to the current integration window duration is checked whether it matches the expected current integral value. If they do not match, a reminder signal (or error report) is sent directly to the user. If they match, the device type set by the user is determined to be correct.

[0101] Therefore, by directly verifying the device type set by the user, and verifying only one voltage or current characteristic at a time, errors in the device type set by the user can be detected earlier, greatly improving the verification efficiency.

[0102] After sending a reminder signal to the user, you can refer to [the relevant documentation] for instructions on how to control the power converter's operation. Figure 4 The description of the illustrated embodiments will not be repeated here.

[0103] It should be noted that, Figure 5 The verification process of the illustrated embodiment can be compared with... Figure 1 The device type confirmation process in the illustrated embodiment can be executed simultaneously or separately, for example... Figure 5 The verification process shown can be triggered by a single button or control signal, thus enabling targeted device verification at multiple stages, including power converter startup, device connection, and anomaly detection during normal operation. Furthermore, even when executed individually... Figure 5 During the verification process of the illustrated embodiment, if it is found that the device type set by the user is inconsistent with the electrical characteristics of the access device of the common wiring port, a device type determination needs to be performed so that the user and the power converter can understand the cause of the fault.

[0104] In some embodiments, diesel generators, photovoltaic systems or load devices from different brands may differ in terms of startup response, voltage stability and current change rate. Therefore, to improve system compatibility, multiple threshold groups can be preset to achieve accurate detection of various devices.

[0105] Figure 6 This is a schematic diagram illustrating the setting of multiple sets of thresholds in an exemplary embodiment of this disclosure.

[0106] refer to Figure 6 In an exemplary embodiment, step S2 may include: Step S21: Obtain N threshold groups, each threshold group including multiple corresponding voltage thresholds and current thresholds, N≥2; Step S22: Based on the i-th threshold group, determine the device type of the access device connected to the common wiring port according to the electrical transformation characteristics, and obtain the i-th device type judgment result; Step S23: Determine the device type based on the N device type judgment results corresponding to the N threshold groups.

[0107] exist Figure 6 In the illustrated embodiment, to improve the compatibility of the detection system, multiple threshold groups can be preset in the control unit.

[0108] In some embodiments, each threshold group can be named according to the device brand or model. Then, when the power converter starts up, the device type set by the user is obtained, and the most matching threshold group, i.e. the identification standard, is selected according to the device type set by the user to perform device type judgment or device type verification.

[0109] In other embodiments, it can also be directly followed Figure 6 In the illustrated embodiment, based on N threshold groups, N device type judgments are performed, and then the device type is determined based on the N device type judgment results. For example, when most of the N device type judgment results are error reports and a small portion are for fuel generators, the device type can be determined to be a fuel generator.

[0110] The threshold group can include not only preset voltage thresholds and preset current thresholds, but also different preset time window values. Those skilled in the art can set these according to actual needs, which will not be elaborated here.

[0111] In some embodiments, regardless of whether one or more threshold groups are set, historical identification data can be trained using machine learning algorithms to adaptively adjust each threshold (including preset time window values) to dynamically adapt to a wider range of device types.

[0112] In some embodiments, the power converter supports multiple common connection ports, or allows the connection of multiple devices or parallel devices. In this case, a multi-channel sampling method can be used, as described in the above embodiments, to detect the signal characteristics of each branch (e.g., each common connection port, or multiple access devices connected to the same common connection port). When detecting multiple access devices connected to the same common connection port, the device being detected each time can be switched using a control signal or a pre-start signal. By analyzing the current and voltage of each branch separately, independent identification of the access type of multiple devices can be achieved. Therefore, the method of this disclosure is applicable to distributed load access or multi-source parallel scenarios, further improving the system's flexibility and detection accuracy.

[0113] This disclosure, through the introduction of an automatic identification mechanism for electrical conversion characteristics, eliminates the need for users to set the access device type, preventing user errors from causing malfunctions in both the power converter and the access device. This significantly improves the operational reliability of both the power converter and the access device, enabling it to adapt to various access devices.

[0114] Furthermore, in the exemplary embodiments, combining voltage and current characteristics for detection significantly improves the accuracy of device detection. For example, in the identification process of a photovoltaic system, a test voltage is output in an islanded state, and the presence of current is detected after the test voltage is output. Compared to detection based solely on static voltage, this effectively reduces the false positive rate, maintaining high stability even in the presence of voltage drift or environmental interference. Moreover, by using current integral values ​​for identification, for example, only identifying a device as a load when the current integral value indicates continuous energy absorption, false identification problems caused by instantaneous current fluctuations can be effectively avoided.

[0115] Finally, the embodiments disclosed herein can be fully integrated into the embedded control unit of the power converter without the need for additional hardware devices. Its detection process can be completed automatically during the installation phase, and potential configuration errors can be detected before the system is first run. This can reduce the probability of system function failure caused by incorrect connection, and significantly reduce the workload and cost of later maintenance.

[0116] In summary, the embodiments of this disclosure achieve high-precision, high-efficiency, and high-robust detection of multi-functional port device types through automatic identification of electrical signal characteristics. This not only effectively solves the systemic risks caused by incorrect device type settings in the prior art, but also provides solid technical support for the intelligent configuration and operation and maintenance of low-voltage energy storage systems.

[0117] Corresponding to the above method embodiments, this disclosure also provides a power converter connection device identification device, which can be used to execute the above method embodiments.

[0118] In an exemplary embodiment of this disclosure, a power converter capable of implementing the above method is also provided. The power converter includes a common connection port (multi-function port) and a control module, which is used to execute the power converter connection device identification method as described in any of the above embodiments.

[0119] The types of power converters include, but are not limited to, photovoltaic grid-connected power converters, energy storage converters (PCS), hybrid power converters, string power converters, distributed inverters, and power conversion devices with multi-functional external interfaces.

[0120] In addition to the common connection port and control module, the structure of the power converter also includes, but is not limited to, a sampling module, a drive module, an isolation drive circuit, a voltage detection unit, a current detection unit, a power switching transistor unit, a filter circuit, a communication module, a protection circuit, a heat dissipation module, and a power supply module. The embodiments disclosed herein do not limit the specific structure of the power converter.

[0121] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0122] Those skilled in the art will understand that various aspects of the embodiments of this disclosure can be implemented as a system, method, or program product. Therefore, various aspects of the embodiments of this disclosure can be specifically implemented as: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software aspects, collectively referred to herein as a "circuit," "module," or "system."

[0123] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0124] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible implementations, various aspects of the embodiments of this disclosure may also be implemented as a program product including program code, which, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the present disclosure described in the "Exemplary Methods" section above.

[0125] The program product for implementing the above-described method according to embodiments of this disclosure can employ a portable compact disc read-only memory (CD-ROM) and include program code, and can run on a terminal device, such as a personal computer. However, the program product of embodiments of this disclosure is not limited thereto. In this document, a readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0126] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0127] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0128] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0129] Program code for performing the operations of embodiments of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0130] Furthermore, the above figures are merely illustrative representations of the processes included in the methods of exemplary embodiments of the present disclosure, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0131] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and concept of this disclosure are indicated by the claims.

Claims

1. A power converter connection device identification method, characterized by, The power converter includes a power conversion circuit, a DC connection port, a grid connection port, and a common connection port. The DC side of the power conversion circuit is electrically connected to the DC connection port, and the AC side of the power conversion circuit is electrically connected to both the grid connection port and the common connection port. The common connection port is adapted to connect to various types of access devices. The method includes: In response to the device access status of the common connection port, the electrical transformation characteristics of the common connection port are detected within a preset time window. The electrical transformation characteristics include at least one of voltage transformation characteristics and current transformation characteristics. From the pre-set correspondence between electrical transformation characteristics and device types, the device type corresponding to the detected electrical transformation characteristics is determined as the device type of the device connected to the common connection port.

2. The power converter connection device identification method of claim 1, wherein, The voltage transformation feature includes a voltage value, and the current transformation feature includes a current value; The step of determining the device type corresponding to the detected electrical transformation feature from a pre-set correspondence between electrical transformation features and device types, and the device type of the device connected to the common connection port, includes: When the voltage value at the common connection port is greater than a preset voltage threshold and the current value within a first preset time period is less than a preset current threshold, the device type is determined to be a fuel generator.

3. The power converter connection apparatus identification method of claim 1, wherein, From the pre-set correspondence between electrical transformation characteristics and device types, the device type corresponding to the detected electrical transformation characteristic is determined. The device types of the devices connected to the common wiring port include: When the voltage value at the common connection port is less than or equal to a preset voltage threshold, the current direction at the common connection port is inflow direction, and the current value is greater than or equal to zero within a second preset time period, the equipment type is determined to be a power generation equipment.

4. The power converter connection apparatus identification method of claim 3, wherein, Also includes: After determining that the equipment type is a power generation device, islanding detection is performed on the common connection port; When the islanding detection result indicates the presence of islanding operation characteristics, the equipment type is determined to be a photovoltaic system.

5. The power converter connection device identification method of claim 3 or 4, wherein, Also includes: After determining that the equipment type is a power generation device, harmonic spectrum analysis is performed on the current transformation characteristics of the common connection port; When the harmonic spectrum analysis results correspond to a photovoltaic inverter, the equipment type is determined to be a photovoltaic system.

6. The power converter connection apparatus identification method of claim 1, wherein, From the pre-set correspondence between electrical transformation characteristics and device types, the device type corresponding to the detected electrical transformation characteristic is determined. The device types of the devices connected to the common wiring port include: When the voltage value at the common connection port is less than or equal to a preset voltage threshold, the current direction at the common connection port is outflow, and the current value is greater than or equal to a preset current value within a second preset time period, the device type is determined to be a load.

7. The power converter connection apparatus identification method of claim 1, wherein, Also includes: The device type of the access device connected to the common connection port is denoted as the first device type; Get the device type set by the user; When the device type set by the user is different from the first device type, a reminder signal is sent to the user.

8. The power converter connection apparatus identification method of claim 1, wherein, From the pre-set correspondence between electrical transformation characteristics and device types, the device type corresponding to the detected electrical transformation characteristics is determined. The device type for the device connected to the common connection port also includes: Get the device type set by the user; Determine the expected electrical transformation characteristics corresponding to the device type set by the user; When the electrical transformation characteristics of the common connection port do not match the expected electrical transformation characteristics, a reminder signal is sent to the user.

9. The power converter connection apparatus identification method of claim 1, wherein, From the pre-set correspondence between electrical transformation characteristics and device types, the device type corresponding to the detected electrical transformation characteristics is determined. The device type for the device connected to the common connection port also includes: Obtain N threshold groups, each threshold group including multiple corresponding voltage thresholds and current thresholds, where N≥2; Based on the i-th threshold group, the device type of the access device connected to the common wiring port is determined according to the electrical transformation characteristics, and the i-th device type determination result is obtained; The device type is determined based on the N device type judgment results corresponding to the N threshold groups.

10. The power converter connection apparatus identification method of claim 1, wherein, The preset time window is determined based on the longest detection wait time for the device type supported by the common connection port of the power converter.

11. The power converter connection apparatus identification method of claim 10, wherein, Also includes: The preset time window is adjusted according to the current ambient temperature.

12. The power converter connection device identification method of claim 1, wherein, Also includes: After determining the device type, stop detecting the electrical transformation characteristics of the common connection port.

13. The power converter connection apparatus identification method of claim 1, wherein, Before detecting the electrical transformation characteristics of the common wiring port, the method further includes: In response to the device access signal, a pre-start signal is sent to the access device.

14. The power converter connection apparatus identification method of claim 13, wherein, Sending a pre-start signal to the access device includes: The DC output control signal or test voltage is output through the common wiring port.

15. The power converter connection apparatus identification method of claim 13, wherein, Sending a pre-start signal to the access device includes: A communication connection is established with the access device through a preset communication method; The pre-start signal is sent to the access device through the preset communication method.

16. A power converter, comprising: Including a common connection port, the power converter is used to perform the method as described in any one of claims 1 to 15.

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