Method and device for distinguishing network construction type converter and network following type converter

Abstract

The invention provides a method and device for distinguishing a network-building type converter and a network-following type converter, and relates to the field of power equipment maintenance, and the method comprises the steps: determining the three-phase voltage and current analog quantity after phase deviation according to the three-phase voltage and current of a converter grid-connected point and a deviation phase angle; and performing start-up stable regulation control on the converter according to the three-phase voltage and current analog quantity after phase deviation, and distinguishing the type of the converter according to a preset grid-connected operation characteristic judgment condition. According to the method and the device, the network construction type converter control equipment and the network following type converter control equipment can be distinguished from different grid-connected characteristics presented by the network construction type converter and the network following type converter.

Description

Technical Field

[0001] The present application relates to the field of power equipment maintenance, and specifically to a method and device for distinguishing between a grid-forming converter and a grid-following converter. Background Art

[0002] With the in-depth research on grid-building control technology, grid-building converter technology has been demonstrated and promoted. The promotion and application of large-scale grid-building technology will inevitably require further differentiation between grid-building equipment and traditional grid-following equipment. At present, grid-building converter control technology is in the development stage. Different technical solutions present different grid-connected characteristics, and there is a lack of mature judgment standards for the grid-connected characteristics of grid-building technology. Therefore, there is currently a lack of mature solutions to distinguish between grid-building converters and grid-following converters based on the external characteristics of new energy equipment.

[0003] This section is intended to provide a background or context to the embodiments of the invention recited in the claims. No description herein is admitted to be prior art by inclusion in this section. Summary of the invention

[0004] In response to the problems in the prior art, the present application provides a method and device for distinguishing between a grid-forming inverter and a grid-following inverter, which can distinguish between a grid-forming inverter control device and a grid-following inverter control device based on the different grid-connected characteristics presented by the grid-forming inverter and the grid-following inverter.

[0005] In order to solve the above technical problems, this application provides the following technical solutions:

[0006] In a first aspect, the present application provides a method for distinguishing a grid-forming converter from a grid-following converter, comprising:

[0007] Determine the three-phase voltage and current analog quantity after phase shift according to the three-phase voltage and current of the converter grid connection point and the shift phase angle;

[0008] The inverter is started up and stabilized according to the three-phase voltage and current analog quantities after the phase shift, and the inverter type is distinguished according to the preset grid-connected operation characteristic judgment conditions; wherein the inverter types include grid-forming inverters and grid-following inverters.

[0009] Furthermore, the three-phase voltage and current analog quantity after phase shift includes three-phase instantaneous voltage and three-phase instantaneous current; the offset phase angle includes the A-phase voltage phase; the three-phase voltage and current analog quantity after phase shift determined according to the three-phase voltage and current at the grid-connected point of the converter and the offset phase angle includes:

[0010] Performing phase-locked control on the three-phase voltages in the three-phase voltage and current to obtain the voltage phase of phase A;

[0011] Under the A-phase voltage phase, coordinate transformation is performed on the three-phase voltage to obtain the three-phase instantaneous voltage;

[0012] Under the A-phase voltage phase, coordinate transformation is performed on three-phase currents in the three-phase voltage and current to obtain the three-phase instantaneous current.

[0013] Further, the performing phase-locked control on the three-phase voltages in the three-phase voltage and current to obtain the A-phase voltage phase includes:

[0014] Performing coordinate rotation on the three-phase voltage to obtain a corresponding Q-axis voltage component;

[0015] The Q-axis voltage component is filtered, PI controlled and integrated in sequence to obtain the A-phase voltage phase.

[0016] Further, the coordinate transformation of the three-phase voltage is performed under the A-phase voltage phase to obtain the three-phase instantaneous voltage, including:

[0017] Under the A-phase voltage phase, coordinate transformation is performed on the three-phase voltage to obtain corresponding D-axis voltage component and Q-axis voltage component;

[0018] At a phase corresponding to the sum of the A-phase voltage phase angle and a preset first phase angle, coordinate transformation is performed on the D-axis voltage component and the Q-axis voltage component to obtain the three-phase instantaneous voltage.

[0019] Further, the coordinate transformation of the three-phase currents in the three-phase voltage and current is performed under the A-phase voltage phase to obtain the three-phase instantaneous current, including:

[0020] Under the A-phase voltage phase, coordinate transformation is performed on the three-phase current to obtain corresponding D-axis current components and Q-axis current components;

[0021] At a phase corresponding to the sum of the A-phase voltage phase angle and a preset second phase angle, coordinate transformation is performed on the D-axis current component and the Q-axis current component to obtain the three-phase instantaneous current.

[0022] Furthermore, the starting stability regulation control of the converter is performed according to the three-phase voltage and current analog quantity after the phase shift, and the converter type is distinguished according to the preset grid-connected operation characteristic judgment condition, including:

[0023] Calculate the active component and reactive component of the converter grid connection point according to the three-phase instantaneous voltage and the three-phase instantaneous current;

[0024] Inputting the active component and the reactive component into the converter, and performing startup stability regulation control on the converter;

[0025] If the converter can start normally and operate normally at the full power target value, the device is judged to be a grid-connected converter, otherwise the device is judged to be a grid-following converter; wherein the grid-connected operation characteristic judgment condition includes that the converter can start normally and operate normally at the full power target value.

[0026] In a second aspect, the present application provides a device for distinguishing between a grid-forming converter and a grid-following converter, comprising:

[0027] A voltage and current simulation unit, used to determine the three-phase voltage and current simulation quantity after phase shift according to the three-phase voltage and current of the converter grid connection point and the shift phase angle;

[0028] A grid-forming and grid-following distinguishing unit is used to perform startup stability regulation and control on the converter according to the three-phase voltage and current analog quantities after the phase shift, and to distinguish the converter type according to the preset grid-connected operation characteristic judgment conditions; wherein the converter type includes a grid-forming converter and a grid-following converter.

[0029] Furthermore, the three-phase voltage and current analog quantities after the phase shift include three-phase instantaneous voltage and three-phase instantaneous current; the shifted phase angle includes the A-phase voltage phase; the voltage and current simulation unit includes:

[0030] A voltage phase determination module is used to perform phase-locked control on the three-phase voltages in the three-phase voltage and current to obtain the A-phase voltage phase;

[0031] An instantaneous voltage determination module, used for performing coordinate transformation on the three-phase voltage under the phase of the A-phase voltage to obtain the three-phase instantaneous voltage;

[0032] The instantaneous current determination module is used to perform coordinate transformation on the three-phase currents in the three-phase voltage and current under the A-phase voltage phase to obtain the three-phase instantaneous current.

[0033] Furthermore, the voltage phase determination module includes:

[0034] A Q-axis component determination module, used for performing coordinate rotation on the three-phase voltage to obtain a corresponding Q-axis voltage component;

[0035] The A-phase phase determination module is used to perform filtering, PI control and integration processing on the Q-axis voltage component in sequence to obtain the A-phase voltage phase.

[0036] Furthermore, the instantaneous voltage determination module includes:

[0037] A voltage component calculation module, used for performing coordinate transformation on the three-phase voltage under the A-phase voltage phase to obtain corresponding D-axis voltage component and Q-axis voltage component;

[0038] The instantaneous voltage calculation module is used to perform coordinate transformation on the D-axis voltage component and the Q-axis voltage component at a phase corresponding to the sum of the A-phase voltage phase angle and a preset first phase angle to obtain the three-phase instantaneous voltage.

[0039] Furthermore, the instantaneous current determination module includes:

[0040] A current component calculation module, used for performing coordinate transformation on the three-phase current under the A-phase voltage phase to obtain corresponding D-axis current components and Q-axis current components;

[0041] The instantaneous current calculation module is used to perform coordinate transformation on the D-axis current component and the Q-axis current component at a phase corresponding to the sum of the A-phase voltage phase angle and a preset second phase angle to obtain the three-phase instantaneous current.

[0042] Furthermore, the network building and network differentiation unit includes:

[0043] A power calculation module, used for calculating the active component and reactive component of the converter grid connection point according to the three-phase instantaneous voltage and the three-phase instantaneous current;

[0044] A power input module, used to input the active component and reactive component into the converter, and to perform startup stability regulation and control on the converter;

[0045] The grid-connected and grid-following distinguishing module is used to determine that the device is a grid-connected converter if the converter can start normally and operate normally at the full power target value, otherwise the device is a grid-following converter; wherein the grid-connected operation characteristic judgment condition includes that the converter can start normally and operate normally at the full power target value.

[0046] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for distinguishing between a grid-forming converter and a grid-following converter when executing the program.

[0047] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for distinguishing between a grid-forming converter and a grid-following converter.

[0048] In a fifth aspect, the present application provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the method for distinguishing between a grid-forming converter and a grid-following converter.

[0049] In view of the problems in the prior art, the present application provides a method and device for distinguishing between a grid-forming converter and a grid-following converter, which can distinguish between a grid-following converter and a grid-forming converter by using the grid-connected voltage and current phase offset method. Specifically, a block diagram of a phase offset algorithm is established, and a determination method and strategy for distinguishing between a grid-forming converter and a grid-following converter is proposed. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 A flow chart of a method for distinguishing between a grid-forming converter and a grid-following converter in an embodiment of the present application;

[0052] Figure 2 This is a flow chart of determining the three-phase voltage and current analog quantities after phase shift in an embodiment of the present application;

[0053] Figure 3 This is a flow chart for obtaining the voltage phase of phase A in an embodiment of the present application;

[0054] Figure 4 This is a flow chart for obtaining three-phase instantaneous voltage in an embodiment of the present application;

[0055] Figure 5 This is a flow chart for obtaining three-phase instantaneous current in an embodiment of the present application;

[0056] Figure 6 A flow chart for distinguishing between grid-building type and grid-following type converters in the embodiment of the present application;

[0057] Figure 7 A structural diagram of a device for distinguishing between a grid-forming converter and a grid-following converter in an embodiment of the present application;

[0058] Figure 8 This is a structural diagram of a voltage and current simulation unit in an embodiment of the present application;

[0059] Fig. 9 This is a structural diagram of a voltage phase determination module in an embodiment of the present application;

[0060] Fig.10 is a structural diagram of an instantaneous voltage determination module in an embodiment of the present application;

[0061] Fig.11 is a structural diagram of an instantaneous current determination module in an embodiment of the present application;

[0062] Fig.12 This is a structural diagram of the network construction and network differentiation unit in the embodiment of the present application;

[0063] Fig.13 A schematic diagram of the structure of an electronic device in an embodiment of the present application;

[0064] Fig.14 This is a schematic diagram of the A-phase voltage phase obtained by calculation by the phase-locked loop in the embodiment of the present application;

[0065] Fig.15 It is a schematic diagram of obtaining three-phase instantaneous voltage by using the three-phase voltage offset algorithm in the embodiment of the present application;

[0066] Fig.16 It is a schematic diagram of obtaining three-phase instantaneous current by using the three-phase current offset algorithm in the embodiment of the present application;

[0067] Fig.17 A schematic diagram of a method for calculating active and reactive power under phase offset in an embodiment of the present application;

[0068] Fig.18 It is a schematic diagram for distinguishing the test process of a grid-building type converter and a grid-following type converter in an embodiment of the present application. DETAILED DESCRIPTION

[0069] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0070] The information collected in the technical solution of this application is information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of relevant data comply with the relevant laws, regulations and standards of relevant countries and regions, take necessary confidentiality measures, do not violate public order and good morals, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0071] Provide users with corresponding operation entrances for them to choose to agree or reject the automated decision-making results; if the user chooses to reject, the expert decision-making process will be entered.

[0072] In one embodiment, see Figure 1 In order to distinguish a grid-forming converter control device from a grid-following converter control device based on the different grid-connected characteristics presented by the grid-forming converter and the grid-following converter, the present application provides a method for distinguishing a grid-forming converter from a grid-following converter, including:

[0073] S101: Determine the three-phase voltage and current analog quantities after the voltage and current phases are shifted according to the three-phase voltage and current and the shift phase angle of the converter grid connection point;

[0074] S102: Perform startup stability regulation control on the converter according to the three-phase voltage and current analog quantities after the phase shift, and distinguish the converter type according to the preset grid-connected operation characteristic judgment conditions; wherein the converter types include grid-forming converters and grid-following converters.

[0075] It can be understood that the method provided in the present application for distinguishing between a grid-forming converter and a grid-following converter comprises the following specific steps:

[0076] ① By establishing a semi-physical simulation platform for the converter, a simulation platform integrating the converter physical object, host computer and simulation machine is established.

[0077] ② The host computer establishes a simulation circuit model, extracts the voltage and current analog signals of the converter grid connection point from the simulation circuit, and changes the output waveform of the voltage and current analog signals through the algorithm provided in this application, and then transmits the analog waveform to the converter lower computer for control through simulation.

[0078] ③ Through the test process provided in this application, semi-physical debugging of the converter grid-connected characteristics is realized.

[0079] ④ Carry out grid-connected debugging of the converter, analyze the external characteristics of the converter such as voltage, current and power through the algorithm provided in this application, and then further distinguish between grid-building type equipment and grid-following type equipment through the judgment method provided in this application.

[0080] The topology of the controller hardware online test platform can be found in Fig.14 As shown. The hardware part includes the converter physical controller, simulator and host computer. The software part is the simulation model. The converter control and protection are implemented by the converter physical controller, while the power grid model and converter main circuit are implemented by the simulation model. The simulator and converter physical controller realize signal interaction through analog / digital channels. For the connection method, see Fig.14 shown. Fig.14 The figure shows the semi-physical test diagram of the converter, which can at least be applied to the grid-following converter equipment and grid-building converter equipment in new energy stations such as wind turbines, photovoltaic units, SVG (static synchronous condenser), and energy storage. Fig.14In the embodiment of the present application, the execution subject can be a physical controller of the converter, wherein the physical controller of the converter is connected to the simulator and the host computer, and the analog information and digital information of the converter obtained by simulation are output by the simulator and transmitted to the physical controller of the converter to realize the control of the main circuit of the converter. The grid-connected simulation test of the physical controller of the converter can establish a test simulation environment for distinguishing between grid-following converter equipment and grid-building converter equipment, so as to ensure the effectiveness of the method in actual working conditions.

[0081] In order to distinguish between network-following devices and network-building devices, this application proposes a phase shift algorithm, which is as follows:

[0082] By establishing a semi-physical simulation platform and a converter simulation circuit topology platform, the voltage and current analog signals of the converter grid connection point can be collected through the transformer. Assume that the analog three-phase voltage signal sampled at the converter grid connection point is: Among them, U s is the voltage amplitude, wt+α us is the voltage phase, α us is the initial voltage phase angle of the system, and t is the time. Assume that the sampled analog three-phase current signal is I s is the voltage amplitude, wt+α is is the current phase, α is is the initial current phase angle of the system, w is the speed at the industrial frequency, the value is 314, pi is the pi, and t is the time.

[0083] After sampling the phase of the three-phase grid-connected point voltage and current analog quantity, the phase offset algorithm is used to obtain the offset three-phase voltage signal. The three-phase current signal is

[0084] From the above description, it can be seen that the method for distinguishing between a grid-forming converter and a grid-following converter provided in the present application can use the method of grid-connected voltage and current phase shift to distinguish between a grid-following converter and a grid-forming converter. Specifically, a block diagram of a phase shift algorithm is established, and a determination method and strategy for distinguishing between a grid-forming converter and a grid-following converter is proposed.

[0085] In one embodiment, see Figure 2 The three-phase voltage and current analog quantity after phase shift includes three-phase instantaneous voltage and three-phase instantaneous current; the offset phase angle includes the voltage phase of phase A; the three-phase voltage and current analog quantity after phase shift is determined according to the three-phase voltage and current of the converter grid connection point and the preset offset phase angle, including:

[0086] S201: performing phase-locked control on the three-phase voltages in the three-phase voltage and current to obtain the voltage phase of phase A;

[0087] S202: performing coordinate transformation on the three-phase voltage at the A-phase voltage phase to obtain the three-phase instantaneous voltage;

[0088] S203: Under the A-phase voltage phase, coordinate transformation is performed on three-phase currents in the three-phase voltage and current to obtain the three-phase instantaneous current.

[0089] It is understandable that the phase shift algorithm is described in steps S201 to S203. Through the above phase shift algorithm, the instantaneous value U of the three-phase voltage and current at the grid-connected point of the converter can be obtained. sa , U sb , U sc ,I sa ,I sb ,I sc And the instantaneous value U of the three-phase voltage and current after phase shift sa '、U sb '、U sc '、I sa '、I sb '、I sc '. Next, the three-phase voltage and current analog quantities after phase shift can be sent to the controller of the converter through the simulator to control the voltage, current and power of the converter grid connection point. Finally, the converter output control signal is sent to the host computer topology circuit to control the voltage and current signals of the converter grid connection point.

[0090] From the above description, it can be seen that the method provided in the present application for distinguishing between a grid-forming converter and a grid-following converter can determine the analog values ​​of the three-phase voltage and current after phase shift based on the three-phase voltage and current at the converter grid-connected point and a preset offset phase angle.

[0091] Specifically, see Figure 3 , the phase-locked control of the three-phase voltage in the three-phase voltage and current to obtain the A-phase voltage phase includes:

[0092] S301: performing coordinate rotation on the three-phase voltage to obtain a corresponding Q-axis voltage component;

[0093] S302: Filter, PI control and integrate the Q-axis voltage component in sequence to obtain the A-phase voltage phase.

[0094] It can be understood that step S301 to step S303 describe how to obtain the A-phase voltage phase.

[0095] The sampled ABC three-phase voltage can be controlled by a phase-locked loop to obtain the phase of the A phase voltage. Among them, the three-phase phase-locked loop control is a method for determining the waveform phase. The present application provides a three-phase voltage phase-locking method based on a synchronous rotating coordinate system (dq coordinate system). The control block diagram is shown in Fig.15 As shown. The three-phase voltage is obtained by rotating the coordinate system V q Component, and then V q The components are controlled by the filter, controller, and integral link to form a phase signal. Finally, the phase of the A phase voltage wt+α is obtained. us . Fig.15 The symbol V sa 、V sb 、V sc Respectively represent the A phase voltage, B phase voltage, and C phase voltage; V q represents the q-axis voltage.

[0096] From the above description, it can be seen that the method for distinguishing between a grid-forming converter and a grid-following converter provided in the present application can perform phase-locked control on the three-phase voltage in the three-phase voltage and current to obtain the A-phase voltage phase.

[0097] Specifically, see Figure 4 , the coordinate transformation of the three-phase voltage is performed under the phase of the A-phase voltage to obtain the three-phase instantaneous voltage, including:

[0098] S401: performing coordinate transformation on the three-phase voltage at the A-phase voltage phase to obtain corresponding D-axis voltage component and Q-axis voltage component;

[0099] S402: performing coordinate transformation on the D-axis voltage component and the Q-axis voltage component at a phase corresponding to the sum of the A-phase voltage phase angle and the first phase angle to obtain the three-phase instantaneous voltage.

[0100] Understandably, see Fig.16 As shown, the three-phase voltage is in the phase of phase A voltage wt+α us After the dq decomposition algorithm, the voltage d-axis component V in the dq coordinate system is obtained. d , q-axis component V q . V d 、V q exist The three-phase instantaneous voltage is obtained by inverse transformation in the dq coordinate system under the phase in is the first phase angle.

[0101] Fig.16 The symbol V sa 、V sb 、Vsc Respectively represent the A phase voltage, B phase voltage, and C phase voltage; V q represents the q-axis voltage, V d Represents the d-axis voltage; V sa1 、V sb1 、V sc1 They respectively represent the instantaneous voltage of phase A, the instantaneous voltage of phase B, and the instantaneous voltage of phase C obtained by coordinate transformation of the three-phase voltage under the phase A voltage.

[0102] From the above description, it can be seen that the method for distinguishing between a grid-forming converter and a grid-following converter provided in the present application can perform coordinate transformation on the three-phase voltage under the A-phase voltage phase to obtain the three-phase instantaneous voltage.

[0103] In one embodiment, see Figure 5 , the coordinate transformation of the three-phase currents in the three-phase voltage and current is performed under the A-phase voltage phase to obtain the three-phase instantaneous current, including:

[0104] S501: performing coordinate transformation on the three-phase current under the A-phase voltage phase to obtain corresponding D-axis current component and Q-axis current component;

[0105] S502: performing coordinate transformation on the D-axis current component and the Q-axis current component at a phase corresponding to the sum of the A-phase voltage phase angle and the second phase angle to obtain the three-phase instantaneous current.

[0106] Understandably, see Fig.17 As shown, the three-phase current is in phase A voltage phase wt+α us After the dq decomposition algorithm, the d-axis component of the current in the dq coordinate system is obtained. d , q-axis component I q I d ,I q exist The three-phase instantaneous voltage is obtained by inverse transformation in the dq coordinate system under the phase in is the second phase angle.

[0107] From the above description, it can be seen that the method provided in the present application for distinguishing between a grid-forming converter and a grid-following converter can perform coordinate transformation on the three-phase currents in the three-phase voltage and current under the A-phase voltage phase to obtain the three-phase instantaneous current.

[0108] In one embodiment, see Figure 6 , the starting stability regulation control of the converter is performed according to the three-phase voltage and current analog quantity after the phase shift, and the converter type is distinguished according to the preset grid-connected operation characteristic judgment condition, including:

[0109] S601: Calculate the active component and reactive component of the converter grid connection point according to the three-phase instantaneous voltage and the three-phase instantaneous current;

[0110] S602: inputting the active component and the reactive component into the converter, and performing startup stability regulation control on the converter;

[0111] S603: If the converter can start normally and operate normally at the full power target value, the device is determined to be a grid-connected converter; otherwise, the device is determined to be a grid-following converter; wherein the grid-connected operation characteristic judgment condition includes that the converter can start normally and operate normally at the full power target value.

[0112] It can be understood that the grid-forming converter achieves stable operation by directly controlling the power signal balance, while the grid-following converter mostly achieves stable operation by directly controlling the voltage and current signals.

[0113] In the test of distinguishing between a grid-forming inverter and a grid-following inverter, the embodiment of the present application actively offsets the phase of the voltage and current control quantities; for a grid-following inverter, changing the voltage and current phases can easily cause control instability or even an inability to start the machine, while for a grid-forming inverter, even if the voltage and current phases are changed, the corresponding active and reactive power control quantities can be balanced, thereby achieving the distinction between the two.

[0114] Therefore, in the embodiment of the present application, by changing the offset phase, the three-phase instantaneous voltage and the three-phase instantaneous current are changed, so as to achieve the differentiation of the converter type according to the above principle. Steps S101 to S102 in the embodiment of the present application can be understood as an experimental process. In an experimental process, the offset phase is often not changed after it is set. If the offset phase is not set appropriately, resulting in the failure to distinguish the converter type in the experiment, the offset phase can be changed and another experiment can be conducted. The experiment again will also go through the process from step S101 to step S102. Changing the offset phase refers to setting For different values, see below for details.

[0115] in, is the first phase angle; is the second phase angle.

[0116] First, power calculation is performed. After obtaining the voltage and current signals after phase shift, the active component P and reactive component Q of the inverter grid connection point can be calculated through the power algorithm. There are many power calculation algorithms. This application provides a method for calculating power based on a rotating coordinate system. The input d-axis and q-axis components of the three-phase voltage and current after phase shift are calculated through the active component calculation formula Reactive component calculation formula The instantaneous power component can be determined, see Fig.18 When substituting it into the calculation formula, we can Fig.18 V d1 、V q1 ,I d1 ,I q1 Substitute them into the previous formula respectively. Fig.18 For descriptions of other symbols in , see above.

[0117] Next, determine the offset angle.

[0118] Generally, setting Ideally for grid-connected converter equipment Angle range is [0, pi], grid-type converter equipment The angle range is approximately In order to effectively distinguish between grid-forming converters and grid-following converters and prevent power over-limit faults caused by excessive phase angle deviation, the Angle, final Angle range recommended

[0119] Specifically, a phase shift angle is set.

[0120] ①Settings At this time, test whether the inverter can start normally. If the equipment can start normally, gradually increase the angle.

[0121] ②Settings At this time, because the phase angle deviation is small, generally speaking, both the grid-forming and grid-following converters should be able to start normally. After starting, by adjusting the power output, generally speaking, both the grid-forming and grid-following devices can be stable according to different command values. If the converter cannot start normally or operate stably at the full power target value under the phase deviation angle, it cannot be used as a basis for distinguishing between grid-forming and grid-following converters.

[0122] ③Settings At this time, because the phase angle deviation becomes smaller, it is generally difficult for the grid-type converter to start normally. Considering the differences in different technical routes of the converter, further judgment is needed. After the machine can be started normally, the control type can be further determined by adjusting the power output. Under the test conditions, the grid-following type converter has large voltage and current harmonics at the grid connection point or cannot operate stably at the full power target value (command value), while the grid-building type converter can operate stably at the full power target value. This can be used as a reference for distinguishing between grid-building type and grid-following type converters.

[0123] ④Settings Generally, the converter equipment cannot start normally or cannot operate normally at the full power target value. It can be preliminarily determined that the device is a grid-following device. At this point, if the converter device can start normally and can operate normally at the full power target value, it can be preliminarily determined that the device is a grid-building device, which needs further verification.

[0124] ⑤Settings At this time, if the converter equipment can still start normally and can operate stably at the full power target value, it can be basically determined that the equipment is a grid-forming device.

[0125] According to different network construction technology routes, set too large At the full power target value, the device may not operate normally. In this case, the test power target value can be appropriately reduced.

[0126] From the above description, it can be seen that the method for distinguishing between grid-forming type converters and grid-following type converters provided in the present application can perform startup stability adjustment control according to the three-phase voltage and current analog quantities after the phase shift, and at different offset phase angles, distinguish between grid-forming type converters and grid-following type converters according to the grid-connected operation characteristics judgment conditions presented by the preset converter.

[0127] Based on the same inventive concept, the embodiments of the present application also provide a device for distinguishing between a grid-type converter and a grid-following converter, which can be used to implement the method described in the above embodiments, as described in the following embodiments. Since the principle of solving the problem by the device for distinguishing between a grid-type converter and a grid-following converter is similar to the method for distinguishing between a grid-type converter and a grid-following converter, the implementation of the device for distinguishing between a grid-type converter and a grid-following converter can refer to the implementation of the method for determining the software performance benchmark, and the repetitions will not be repeated. As used below, the terms "unit" or "module" may be a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0128] In one embodiment, see Figure 7 In order to distinguish a grid-forming converter control device from a grid-following converter control device based on the different grid-connected characteristics presented by the grid-forming converter and the grid-following converter, the present application provides a device for distinguishing a grid-forming converter from a grid-following converter, including:

[0129] The voltage and current simulation unit 701 is used to determine the three-phase voltage and current simulation value after phase shift according to the three-phase voltage and current at the grid-connected point of the converter and the preset offset phase angle;

[0130] The grid-forming and grid-following distinguishing unit 702 is used to perform startup stability regulation and control on the converter according to the three-phase voltage and current analog quantities after the phase shift, and distinguish the converter type according to the preset grid-connected operation characteristic judgment conditions; wherein the converter type includes a grid-forming converter and a grid-following converter.

[0131] In one embodiment, see Figure 8 The three-phase voltage and current analog quantities after phase shift include three-phase instantaneous voltage and three-phase instantaneous current; the voltage and current simulation unit 701 includes:

[0132] A voltage phase determination module 801 is used to perform phase-locked control on the three-phase voltages in the three-phase voltage and current to obtain a voltage phase of phase A;

[0133] The instantaneous voltage determination module 802 is used to perform coordinate transformation on the three-phase voltage under the phase of the A-phase voltage to obtain the three-phase instantaneous voltage;

[0134] The instantaneous current determination module 803 is used to perform coordinate transformation on the three-phase currents in the three-phase voltage and current under the A-phase voltage phase to obtain the three-phase instantaneous current.

[0135] In one embodiment, see Fig. 9 , the voltage phase determination module 801 comprises:

[0136] A Q-axis component determination module 901 is used to perform coordinate rotation on the three-phase voltage to obtain a corresponding Q-axis voltage component;

[0137] The A-phase phase determination module 902 is used to perform filtering, PI control and integration processing on the Q-axis voltage component in sequence to obtain the A-phase voltage phase.

[0138] In one embodiment, see Fig.10 , the instantaneous voltage determination module 802 comprises:

[0139] A voltage component calculation module 1001 is used to perform coordinate transformation on the three-phase voltage under the A-phase voltage phase to obtain corresponding D-axis voltage component and Q-axis voltage component;

[0140] The instantaneous voltage calculation module 1002 is used to perform coordinate transformation on the D-axis voltage component and the Q-axis voltage component at a phase corresponding to the sum of the A-phase voltage phase angle and the first phase angle to obtain the three-phase instantaneous voltage.

[0141] In one embodiment, see Fig.11 , the instantaneous current determination module 803 comprises:

[0142] A current component calculation module 1101 is used to perform coordinate transformation on the three-phase current under the A-phase voltage phase to obtain corresponding D-axis current components and Q-axis current components;

[0143] The instantaneous current calculation module 1102 is used to perform coordinate transformation on the D-axis current component and the Q-axis current component at a phase corresponding to the sum of the A-phase voltage phase angle and the second phase angle to obtain the three-phase instantaneous current.

[0144] In one embodiment, see Fig.12 The network building and network distinguishing unit 702 includes:

[0145] A power calculation module 1201 is used to calculate the active component and reactive component of the converter grid connection point according to the three-phase instantaneous voltage and the three-phase instantaneous current;

[0146] A power input module 1202, configured to set a first phase angle equal to a second phase angle, and adjust the first phase angle and the second phase angle to vary within a preset range;

[0147] The grid-building and grid-following distinguishing module 1203 is used to input the active component and the reactive component into the converter. If the converter can start normally and operate normally under the full power target value, the device is determined to be a grid-building converter, otherwise the device is determined to be a grid-following converter.

[0148] From the hardware level, in order to distinguish the grid-type converter control device from the grid-following converter control device based on the different grid-connected characteristics presented by the grid-type converter and the grid-following converter, the present application provides an embodiment of an electronic device for implementing all or part of the content of the method for distinguishing between the grid-type converter and the grid-following converter, and the electronic device specifically includes the following content:

[0149] Processor, memory, communication interface and bus; wherein the processor, memory and communication interface communicate with each other through the bus; the communication interface is used to realize information transmission between the device for distinguishing between grid-forming converter and grid-following converter and related equipment such as core business system, user terminal and related database; the logic controller can be a desktop computer, tablet computer and mobile terminal, etc., but the present embodiment is not limited thereto. In the present embodiment, the logic controller can be implemented with reference to the embodiment of the method for distinguishing between grid-forming converter and grid-following converter in the embodiment, and the embodiment of the device for distinguishing between grid-forming converter and grid-following converter, and the contents thereof are incorporated herein, and the repeated parts are not repeated.

[0150] It is understandable that the user terminal may include a smart phone, a tablet electronic device, a network set-top box, a portable computer, a desktop computer, a personal digital assistant (PDA), a vehicle-mounted device, a smart wearable device, etc. Among them, the smart wearable device may include smart glasses, a smart watch, a smart bracelet, etc.

[0151] In practical applications, part of the method for distinguishing between a grid-forming converter and a grid-following converter can be performed on the electronic device side as described above, or all operations can be completed in the client device. The selection can be made based on the processing capability of the client device and the limitations of the user's usage scenario. This application does not limit this. If all operations are completed in the client device, the client device may also include a processor.

[0152] The client device may have a communication module (i.e., a communication unit) that can communicate with a remote server to achieve data transmission with the server. The server may include a server on the task scheduling center side, and other implementation scenarios may also include a server on an intermediate platform, such as a server on a third-party server platform that has a communication link with the task scheduling center server. The server may include a single computer device, or a server cluster consisting of multiple servers, or a server structure of a distributed device.

[0153] Fig.13 FIG. 9 is a schematic block diagram of the system structure of the electronic device 9600 according to an embodiment of the present application. Fig.13 As shown, the electronic device 9600 may include a central processor 9100 and a memory 9140; the memory 9140 is coupled to the central processor 9100. It is worth noting that Fig.13 is exemplary; other types of structures may also be used to supplement or replace this structure to implement telecommunication functions or other functions.

[0154] In one embodiment, the method function of distinguishing between a grid-forming converter and a grid-following converter may be integrated into the central processor 9100. The central processor 9100 may be configured to perform the following control:

[0155] S101: Determine the three-phase voltage and current analog quantities after the voltage and current phases are shifted according to the three-phase voltage and current and the shift phase angle of the converter grid connection point;

[0156] S102: Perform startup stability regulation control on the converter according to the three-phase voltage and current analog quantities after the phase shift, and distinguish the converter type according to the preset grid-connected operation characteristic judgment conditions; wherein the converter types include grid-forming converters and grid-following converters.

[0157] From the above description, it can be seen that the method for distinguishing between a grid-forming converter and a grid-following converter provided in the present application can use the method of grid-connected voltage and current phase shift to distinguish between a grid-following converter and a grid-forming converter. Specifically, a block diagram of a phase shift algorithm is established, and a determination method and strategy for distinguishing between a grid-forming converter and a grid-following converter is proposed.

[0158] In another embodiment, the device for distinguishing between a grid-forming inverter and a grid-following inverter can be configured separately from the central processing unit 9100. For example, the device for distinguishing between a grid-forming inverter and a grid-following inverter of the data composite transmission device can be configured as a chip connected to the central processing unit 9100, and the function of the method for distinguishing between a grid-forming inverter and a grid-following inverter is realized through the control of the central processing unit.

[0159] like Fig.13 As shown, the electronic device 9600 may also include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It is worth noting that the electronic device 9600 does not necessarily have to include Fig.13 In addition, the electronic device 9600 may also include Fig.13 For components not shown, reference may be made to the prior art.

[0160] like Fig.13 As shown, the central processing unit 9100 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor device and / or logic device. The central processing unit 9100 receives input and controls the operation of various components of the electronic device 9600.

[0161] The memory 9140 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices. The above-mentioned information related to the failure may be stored, and a program for executing the relevant information may also be stored. The CPU 9100 may execute the program stored in the memory 9140 to implement information storage or processing, etc.

[0162] The input unit 9120 provides input to the central processing unit 9100. The input unit 9120 is, for example, a key or a touch input device. The power supply 9170 is used to provide power to the electronic device 9600. The display 9160 is used to display display objects such as images and texts. The display may be, for example, an LCD display, but is not limited thereto.

[0163] The memory 9140 may be a solid-state memory, such as a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It may also be a memory that saves information even when the power is off, can be selectively erased, and is provided with more data, examples of which are sometimes referred to as EPROMs, etc. The memory 9140 may also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 may include an application / function storage unit 9142, which is used to store application programs and function programs or processes for executing the operation of the electronic device 9600 through the central processor 9100.

[0164] The memory 9140 may also include a data storage unit 9143 for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 may include various drivers for communication functions of the electronic device and / or for executing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0165] The communication module 9110 is a transmitter / receiver that sends and receives signals via the antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processor 9100 to provide input signals and receive output signals, which may be the same as the case of a conventional mobile communication terminal.

[0166] Based on different communication technologies, multiple communication modules 9110 may be provided in the same electronic device, such as a cellular network module, a Bluetooth module and / or a wireless LAN module. The communication module (transmitter / receiver) 9110 is also coupled to a speaker 9131 and a microphone 9132 via an audio processor 9130 to provide an audio output via the speaker 9131 and receive an audio input from the microphone 9132, thereby realizing a common telecommunication function. The audio processor 9130 may include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 9130 is also coupled to the central processor 9100, so that recording can be performed on the local machine through the microphone 9132, and the sound stored on the local machine can be played through the speaker 9131.

[0167] The embodiments of the present application also provide a computer-readable storage medium capable of implementing all steps of the method for distinguishing between a grid-forming converter and a grid-following converter in the above embodiments, where the execution subject is a server or a client. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, all steps of the method for distinguishing between a grid-forming converter and a grid-following converter in the above embodiments are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0168] S101: Determine the three-phase voltage and current analog quantities after the voltage and current phases are shifted according to the three-phase voltage and current and the shift phase angle of the converter grid connection point;

[0169] S102: Perform startup stability regulation control on the converter according to the three-phase voltage and current analog quantities after the phase shift, and distinguish the converter type according to the preset grid-connected operation characteristic judgment conditions; wherein the converter types include grid-forming converters and grid-following converters.

[0170] From the above description, it can be seen that the method for distinguishing between a grid-forming converter and a grid-following converter provided in the present application can use the method of grid-connected voltage and current phase shift to distinguish between a grid-following converter and a grid-forming converter. Specifically, a block diagram of a phase shift algorithm is established, and a determination method and strategy for distinguishing between a grid-forming converter and a grid-following converter is proposed.

[0171] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0172] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (apparatus), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0173] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0174] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0175] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for distinguishing a grid-forming converter from a grid-following converter, characterized in that: include: Determine the three-phase voltage and current analog quantity after phase shift according to the three-phase voltage and current of the converter grid connection point and the shift phase angle; The inverter is started up and stabilized according to the three-phase voltage and current analog quantities after the phase shift, and the inverter type is distinguished according to the preset grid-connected operation characteristic judgment conditions; wherein the inverter types include grid-forming inverters and grid-following inverters.

2. The method for distinguishing between a grid-connected converter and a grid-following converter according to claim 1, characterized in that: The three-phase voltage and current analog quantity after phase shift includes three-phase instantaneous voltage and three-phase instantaneous current; the offset phase angle includes the A-phase voltage phase; the three-phase voltage and current analog quantity after phase shift determined according to the three-phase voltage and current at the grid-connected point of the converter and the offset phase angle includes: Performing phase-locked control on the three-phase voltages in the three-phase voltage and current to obtain the voltage phase of phase A; Under the A-phase voltage phase, coordinate transformation is performed on the three-phase voltage to obtain the three-phase instantaneous voltage; Under the A-phase voltage phase, coordinate transformation is performed on three-phase currents in the three-phase voltage and current to obtain the three-phase instantaneous current.

3. The method for distinguishing between a grid-connected converter and a grid-following converter according to claim 2, characterized in that: The phase-locking control of the three-phase voltages in the three-phase voltage and current to obtain the A-phase voltage phase includes: Performing coordinate rotation on the three-phase voltage to obtain a corresponding Q-axis voltage component; The Q-axis voltage component is filtered, PI controlled and integrated in sequence to obtain the A-phase voltage phase.

4. The method for distinguishing between a grid-connected converter and a grid-following converter according to claim 2, characterized in that: The coordinate transformation of the three-phase voltage is performed under the A-phase voltage phase to obtain the three-phase instantaneous voltage, including: Under the A-phase voltage phase, coordinate transformation is performed on the three-phase voltage to obtain corresponding D-axis voltage component and Q-axis voltage component; At a phase corresponding to the sum of the A-phase voltage phase angle and a preset first phase angle, coordinate transformation is performed on the D-axis voltage component and the Q-axis voltage component to obtain the three-phase instantaneous voltage.

5. The method for distinguishing between a grid-connected converter and a grid-following converter according to claim 4, characterized in that: The coordinate transformation of the three-phase currents in the three-phase voltage and current is performed under the A-phase voltage phase to obtain the three-phase instantaneous current, including: Under the A-phase voltage phase, coordinate transformation is performed on the three-phase current to obtain corresponding D-axis current components and Q-axis current components; At a phase corresponding to the sum of the A-phase voltage phase angle and a preset second phase angle, coordinate transformation is performed on the D-axis current component and the Q-axis current component to obtain the three-phase instantaneous current.

6. The method for distinguishing between a grid-connected converter and a grid-following converter according to claim 5, characterized in that: The step of controlling the start-up stability of the converter according to the three-phase voltage and current analog quantities after the phase shift, and distinguishing the converter type according to the preset grid-connected operation characteristic judgment conditions, includes: Calculate the active component and reactive component of the converter grid connection point according to the three-phase instantaneous voltage and the three-phase instantaneous current; Inputting the active component and the reactive component into the converter, and performing startup stability regulation control on the converter; If the converter can start normally and operate normally at the full power target value, the device is judged to be a grid-connected converter, otherwise the device is judged to be a grid-following converter; wherein the grid-connected operation characteristic judgment condition includes that the converter can start normally and operate normally at the full power target value.

7. A device for distinguishing a grid-forming converter from a grid-following converter, characterized in that: include: A voltage and current simulation unit, used to determine the three-phase voltage and current simulation quantity after phase shift according to the three-phase voltage and current of the converter grid connection point and the shift phase angle; A grid-forming and grid-following distinguishing unit is used to perform startup stability regulation and control on the converter according to the three-phase voltage and current analog quantities after the phase shift, and to distinguish the converter type according to the preset grid-connected operation characteristic judgment conditions; wherein the converter type includes a grid-forming converter and a grid-following converter.

8. The device for distinguishing between a grid-connected converter and a grid-following converter according to claim 7, characterized in that: The three-phase voltage and current analog quantities after the phase shift include three-phase instantaneous voltage and three-phase instantaneous current; the shifted phase angle includes the A-phase voltage phase; the voltage and current simulation unit includes: A voltage phase determination module is used to perform phase-locked control on the three-phase voltages in the three-phase voltage and current to obtain the A-phase voltage phase; An instantaneous voltage determination module, used for performing coordinate transformation on the three-phase voltage under the phase of the A-phase voltage to obtain the three-phase instantaneous voltage; The instantaneous current determination module is used to perform coordinate transformation on the three-phase currents in the three-phase voltage and current under the A-phase voltage phase to obtain the three-phase instantaneous current.

9. The device for distinguishing between a grid-connected converter and a grid-following converter according to claim 8, characterized in that: The voltage phase determination module comprises: A Q-axis component determination module, used for performing coordinate rotation on the three-phase voltage to obtain a corresponding Q-axis voltage component; The A-phase phase determination module is used to perform filtering, PI control and integration processing on the Q-axis voltage component in sequence to obtain the A-phase voltage phase.

10. The device for distinguishing between a grid-type converter and a grid-following converter according to claim 8, characterized in that: The instantaneous voltage determination module comprises: A voltage component calculation module, used for performing coordinate transformation on the three-phase voltage under the A-phase voltage phase to obtain corresponding D-axis voltage component and Q-axis voltage component; The instantaneous voltage calculation module is used to perform coordinate transformation on the D-axis voltage component and the Q-axis voltage component at a phase corresponding to the sum of the A-phase voltage phase angle and a preset first phase angle to obtain the three-phase instantaneous voltage.

11. The device for distinguishing between a grid-type converter and a grid-following converter according to claim 10, characterized in that: The instantaneous current determination module comprises: A current component calculation module, used for performing coordinate transformation on the three-phase current under the A-phase voltage phase to obtain corresponding D-axis current components and Q-axis current components; The instantaneous current calculation module is used to perform coordinate transformation on the D-axis current component and the Q-axis current component at a phase corresponding to the sum of the A-phase voltage phase angle and a preset second phase angle to obtain the three-phase instantaneous current.

12. The device for distinguishing between a grid-connected converter and a grid-following converter according to claim 11, characterized in that: The network building and network differentiation unit includes: A power calculation module, used for calculating the active component and reactive component of the converter grid connection point according to the three-phase instantaneous voltage and the three-phase instantaneous current; A power input module, used for inputting the active component and the reactive component into the converter, and performing startup stability regulation control on the converter; A grid-building and grid-following differentiation module is used to determine that the device is a grid-building converter if the converter can start normally and operate normally at the full power target value, otherwise the device is a grid-following converter; wherein the grid-connected operation characteristic judgment condition includes that the converter can start normally and operate normally at the full power target value.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method for distinguishing between a grid-connecting converter and a grid-following converter as described in any one of claims 1 to 6 are implemented.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for distinguishing between a grid-connecting converter and a grid-following converter as described in any one of claims 1 to 6 are implemented.

15. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of the method for distinguishing between a grid-connecting converter and a grid-following converter as described in any one of claims 1 to 6 are implemented.

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