A phase control method, device and equipment of inverter output and storage medium

Abstract

The application discloses a phase control method, device and equipment of inverter output and a storage medium, and the method comprises the following steps: acquiring the theoretical real power of inverter output according to the output voltage frequency of the inverter; determining the frequency adjustment compensation parameter according to the maximum power threshold value, target control current, maximum current threshold value and theoretical real power of the inverter; determining the target output voltage phase of the inverter according to the target active power and current actual active power of the inverter and the frequency adjustment compensation parameter; and calculating the three-phase voltage of the inverter output according to the target output voltage phase. The frequency adjustment compensation parameter is added in the frequency adjustment control link of the inverter, the maximum current and maximum power output of the inverter are limited, the inverter can still maintain the voltage source characteristics after current limiting, the safety operation of the inverter is ensured, the stability of the inverter is improved, and the inverter can support the power grid as much as possible when the inverter is connected to the grid.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a method, apparatus, device, and computer-readable storage medium for phase control of inverter output. Background Technology

[0002] An inverter is a device that converts direct current (DC) power into alternating current (AC). With the increasing penetration of distributed renewable energy sources, more and more inverters are being connected to the grid, significantly reducing the total damping and inertia provided by traditional generators. This results in a faster frequency change rate and decreased interference immunity when the grid is exposed to disturbances. To address this issue, the concept of Virtual Synchronous Generator (VSG) control technology has been proposed. This technology mimics the operating mechanism of a synchronous generator, enabling grid-connected inverters to provide grid-supported inertia performance, frequency, and voltage support, thereby improving grid stability.

[0003] In existing technologies, the inverter's output current limiting circuit is placed between its voltage and current dual closed-loop control. When the voltage loop's output reference current exceeds a certain threshold, the limiting circuit activates, changing the current loop's reference input current to limit the current. Under normal circumstances, current limiting control does not function. However, when the inverter experiences significant disturbances or operates under unstable conditions, current limiting control will activate to prevent excessive current generation and subsequent complex transient transitions. But after triggering current limiting, the VSG (Voltage Source Control) becomes a current source control output, losing its voltage source characteristics. This can easily lead to instability in weak grid conditions, and its limiting transient transition process is complex with poor power angle stability. Therefore, how to limit the inverter's output current while maintaining its voltage source characteristics, thereby ensuring safe operation and improving inverter stability, is a pressing issue that needs to be addressed. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, device, and computer-readable storage medium for phase control of inverter output, so as to limit the output current of the inverter while maintaining the voltage source characteristics of the inverter, thereby improving the stability of the inverter while ensuring its safe operation.

[0005] To solve the above-mentioned technical problems, the present invention provides a phase control method for inverter output, comprising:

[0006] Based on the inverter's output voltage frequency, obtain the theoretical true power output of the inverter.

[0007] The frequency regulation compensation parameters are determined based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical actual power.

[0008] The target output voltage phase of the inverter is determined based on the target active power of the inverter, the current actual active power, and the frequency regulation compensation parameters.

[0009] Based on the target output voltage phase, calculate the three-phase voltage of the inverter output so that the inverter output power is less than or equal to the maximum power threshold and the output current is less than or equal to the maximum current threshold.

[0010] In some embodiments, the frequency regulation compensation parameter is the compensation parameter in the frequency regulation control of the phase-locked loop of the uninterruptible power supply (UPS).

[0011] In some embodiments, the frequency regulation compensation parameter is a compensation parameter in the frequency regulation control of the virtual synchronous generator (VSG).

[0012] In some embodiments, the frequency adjustment compensation parameter is an angular velocity compensation factor.

[0013] In some embodiments, determining the frequency regulation compensation parameters based on the inverter's maximum power threshold, target control current, maximum current threshold, and the theoretical true power includes:

[0014] If the target control current is less than the maximum current threshold and the theoretical actual power is less than the maximum power threshold, then the angular velocity compensation factor is determined to be 0.

[0015] If the target control current is less than the maximum current threshold and the theoretical true power is greater than or equal to the maximum power threshold, then through ω offset =(P ref -K f *(Δf / f N )*P N -P m ) / (D*ω0), determine the angular velocity compensation factor; where ω offset P is the angular velocity compensation factor. ref For the active power command of VSG, K f ω is the active frequency modulation coefficient. o Let Δf be the frequency of the output voltage, and Δf = ff. N f N For the rated frequency, P N The rated active power is P, f is the frequency of the inverter, and P is the rated active power. m Where D is the maximum power threshold, and D is the frequency damping coefficient of the VSG;

[0016] If the target control current is greater than or equal to the maximum current threshold, then through ω offset =(P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N -P m ) / (D*ω0), determine the angular velocity compensation factor; where, T j These are inertial characteristic parameters.

[0017] In some embodiments, obtaining the theoretical true power output of the inverter based on the inverter's output voltage frequency includes:

[0018] The theoretical true power output of the inverter is determined based on the rate of change of the inverter's output voltage frequency.

[0019] In some embodiments, the theoretical true power output of the inverter is determined based on the rate of change of the inverter's output voltage frequency.

[0020] like Then through P real =P ref -K f *(Δf / f N )*P N Determine the theoretical true power; where J is the virtual inertia coefficient of the VSG, ω o P is the frequency of the output voltage. real For the theoretical true power, P ref For the active power command of VSG, K f The active frequency regulation coefficient is Δf = ff. N f N For the rated frequency, P N The rated active power is f, and the frequency of the inverter is f.

[0021] like Then through P real =P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N Determine the theoretical true power; where T j These are inertial characteristic parameters.

[0022] The present invention also provides a phase control device for inverter output, comprising:

[0023] The theoretical acquisition module is used to obtain the theoretical true power output of the inverter based on the inverter's output voltage frequency;

[0024] The compensation determination module is used to determine the frequency regulation compensation parameters based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical true power.

[0025] The phase determination module is used to determine the target output voltage phase of the inverter based on the target active power of the inverter, the current actual active power, and the frequency adjustment compensation parameters.

[0026] The inverter output module is used to calculate the three-phase voltage of the inverter output based on the target output voltage phase, so that the output power of the inverter is less than or equal to the maximum power threshold and the output current is less than or equal to the maximum current threshold.

[0027] The present invention also provides a phase control device for inverter output, comprising:

[0028] Memory, used to store computer programs;

[0029] A processor is used to implement the steps of the phase control method for the inverter output as described above when executing the computer program.

[0030] In addition, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the phase control device for inverter output as described above.

[0031] The present invention provides a phase control method for inverter output, comprising: obtaining the theoretical true power of the inverter output based on the inverter's output voltage frequency; determining frequency regulation compensation parameters based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical true power; determining the target output voltage phase of the inverter based on the inverter's target active power, current actual active power, and frequency regulation compensation parameters; and calculating the three-phase voltage of the inverter output based on the target output voltage phase, so that the inverter's output power is less than or equal to the maximum power threshold and the output current is less than or equal to the maximum current threshold.

[0032] As can be seen, this invention limits the maximum current and maximum power output of the inverter by adding frequency regulation compensation parameters to the inverter's frequency regulation control stage. This allows the inverter to maintain its voltage source characteristics even after current limiting, ensuring safe operation while improving its stability and enabling it to support the grid as much as possible when connected to the grid. Furthermore, this invention also provides a phase control device, equipment, and computer-readable storage medium for inverter output, which also possess the aforementioned beneficial effects. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 A flowchart illustrating a phase control method for inverter output provided in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of a typical VSG control system architecture;

[0036] Figure 3 A schematic diagram of the VSG control system structure for another phase control method of inverter output provided in an embodiment of the present invention;

[0037] Figure 4 The waveform diagram shows the overcurrent test of another phase control method for inverter output provided in an embodiment of the present invention.

[0038] Figure 5 This is a structural block diagram of a phase control device for inverter output provided in an embodiment of the present invention;

[0039] Figure 6 This is a schematic diagram of the structure of a phase control device for inverter output provided in an embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of the specific structure of a phase control device for inverter output provided in an embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Please refer to Figure 1 , Figure 1 A flowchart illustrating a phase control method for inverter output provided in an embodiment of the present invention. The method may include:

[0043] Step 101: Obtain the theoretical true power output of the inverter based on the inverter's output voltage frequency.

[0044] It is understood that the inverter output phase control method provided in this embodiment can be applied to the virtual synchronous generator (VSG) control process of the inverter. For example, grid-connected inverters can use the method provided in this embodiment to adjust the phase of the VSG (i.e., the target output voltage phase, such as...). Figure 1 and 2 θ ref This method limits the inverter's maximum current and maximum power output. The phase control method for inverter output provided in this embodiment can also be applied to other inverter control scenarios, such as UPS (Uninterruptible Power System) inverters. In the UPS's phase-locked loop, the phase can be adjusted using the method provided in this embodiment, thereby adjusting the three-phase voltage output of the inverter and limiting its maximum current and maximum power output. This embodiment does not impose any limitations on this.

[0045] Correspondingly, taking the VSG control process of an inverter as an example, the conventional VSG control process can be as follows: Figure 2 As shown, the control equations for its power loop are as follows:

[0046]

[0047] Among them, P ref (like Figure 2 In this context, `Pref` refers to the active power command of the VSG. e (like Figure 2 In this context, P represents the actual active power of the VSG, and Q represents the actual active power of the VSG. ref (like Figure 2 In this context, Qref) represents the reactive power command of the VSG, Q e (like Figure 2 In this context, Q) represents the actual reactive power output of the VSG, and ω oω represents the output voltage frequency (i.e., the voltage frequency output value). n U is the rated value of the output voltage frequency. n U represents the amplitude of the grid output voltage. o The rated voltage amplitude of the power grid, D, J, k q and k u These are the frequency damping coefficient, virtual inertia coefficient, voltage droop coefficient, and reactive inertia coefficient of the VSG, respectively. Figure 2 In the middle, E represents the reactive power loop output excitation voltage of the VSG.

[0048] Accordingly, in this embodiment, a compensation parameter (i.e., a frequency regulation compensation parameter) can be added to the frequency regulation control loop in the VSG control process to limit the inverter power output and achieve the purpose of limiting overcurrent; such as Figure 3 As shown, an angular velocity compensation factor ω can be added to the frequency regulation control loop. offset , in ω offset Under the influence of VSG, the control equations of the power loop can be transformed into:

[0049]

[0050] Furthermore, equation (2) can be simplified to:

[0051]

[0052] If the inverter's current is within the normal operating range, i.e., I ref <I m And P real <P m I ref For the target control current (i.e., the control current setpoint), I m P is the maximum current threshold of the inverter (i.e., the maximum current the inverter can withstand). real P represents the theoretical true power (i.e., the theoretically calculated true power). m This is the maximum power threshold of the inverter (i.e., the maximum power allowed by the inverter); at this time, ω offset It can be 0, meaning the VSG control loop is not affected by amplitude limitation.

[0053] When the inverter experiences overcurrent and its theoretical power output exceeds its maximum power output, the following can be calculated: ΔI = I ref -I m ΔP=P real -P m Theoretical true power P real This can be the theoretically calculated value of the actual output power after superimposing the frequency modulation and inertia outputs. Without limitations, the inverter will experience overload, leading to overcurrent disconnection. Therefore, ω can be set... offset=ΔP / (D*ω) o This allows the inverter's output power to be controlled at P. m This achieves the purpose of limiting traffic.

[0054] Further analysis of the above formula: The calculation of ΔP is divided into the following two cases: when That is, when the rate of change of the inverter's output voltage frequency is 0, the frequency is stable. This formula can be transformed into... At this point, the actual power value can be determined from the power setpoint (P). ref The frequency (f) determines P, that is, at this time P real The value is affected by the power setpoint and primary frequency modulation, and the theoretical true power can be calculated: P real =P ref -K f *(Δf / f N )*P N ;when That is, when the rate of change of the inverter's output voltage frequency is not zero, the theoretical true power P is... real Influenced by the power setpoint, primary frequency modulation, and inertia, the theoretical true power, determined by the power setpoint, frequency, and rate of frequency change, can be calculated as: P real =P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N Among them, K f The active frequency regulation coefficient is Δf = ff. N f N For the rated frequency, P N Where T is the rated active power, f is the inverter frequency, and T is the inverter frequency. j These are inertial characteristic parameters.

[0055] In other words, in this step, the processor can determine the theoretical true power output of the inverter based on the rate of change of the inverter's output voltage frequency. For example, when the rate of change of the inverter's output voltage frequency is 0, the theoretical true power is determined based on the active power command, the active power frequency regulation coefficient, the inverter's frequency, and the rated frequency. When the rate of change of the inverter's output voltage frequency is not 0, the theoretical true power is determined based on the active power command, the active power frequency regulation coefficient, the inverter's frequency, the rated frequency, and the inertial characteristic parameters. For example, when the inverter output phase control method provided in this embodiment is applied to the inverter's VSG control process, the processor can... In the case of P real =P ref -K f*(Δf / f N )*P N Determine the theoretical true power; In the case of P real =P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N Determine the theoretical true power; where J is the virtual inertia coefficient of VSG, ω o P is the output voltage frequency. real For the theoretical true power, P ref For the active power command of VSG, K f The active frequency regulation coefficient is Δf = ff. N f N For the rated frequency, P N Where T is the rated active power, f is the inverter frequency, and T is the inverter frequency. j These are inertial characteristic parameters.

[0056] Accordingly, when the phase control method for inverter output provided in this embodiment is applied to the phase-locked loop of a UPS, it can be set in a similar manner to the above scheme to calculate the theoretical value of the actual power of the inverter output (i.e., the theoretical actual power) based on the inverter's output voltage frequency.

[0057] Step 102: Determine the frequency regulation compensation parameters based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical actual power.

[0058] In this embodiment, the frequency regulation compensation parameter can be a compensation parameter in the frequency regulation control loop of the inverter, such as a compensation parameter in the frequency regulation control of the VSG or a compensation parameter in the frequency regulation control of the UPS phase-locked loop. The specific parameter type of the frequency regulation compensation parameter in this embodiment can be set by the designer according to the practical scenario and user needs. For example, if the frequency regulation compensation parameter is a compensation parameter in the frequency regulation control of the VSG, such as... Figure 3 As shown, the frequency regulation compensation parameter can be the angular velocity compensation factor (ω) in the frequency regulation control of the VSG. offset The frequency regulation compensation parameter can also be the power compensation factor or other compensation factors in the frequency regulation control of the VSG. As long as the frequency regulation control loop can adjust the phase of the three-phase voltage to be output by the inverter by adding the frequency regulation compensation parameter, and limit the output power and output current of the inverter, this embodiment does not impose any restrictions on this.

[0059] Correspondingly, the specific method by which the processor determines the frequency regulation compensation parameters based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical actual power in this step can be set by the designer according to the practical scenario and user needs. For example, it can be applied to the VSG control process of the inverter, and the frequency regulation compensation parameter can be the angular velocity compensation factor (ω). offset In the case of a target control current less than the maximum current threshold and a theoretical actual power less than the maximum power threshold, the processor can determine the angular velocity compensation factor to be 0; when the target control current is less than the maximum current threshold and the theoretical actual power is greater than or equal to the maximum power threshold, it can determine the angular velocity compensation factor to be 0 through ω. offset =(P ref -K f *(Δf / f N )*P N -P m ) / (D*ω0), determine the angular velocity compensation factor; when the target control current is greater than or equal to the maximum current threshold, use ω offset =(P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N -P m ) / (D*ω0), determine the angular velocity compensation factor; thereby realizing the adaptive adjustment of the angular velocity compensation factor, and enabling the inverter to maintain maximum power output after current limiting, ensuring the maximum grid support capacity that the inverter can obtain.

[0060] In other words, we can combine the above formula: ΔI=I ref -I m ΔP=P real -P m ω offset =ΔP / (D*ω) o ), P real =P ref -K f *(Δf / f N )*P N and P real =P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N The angular velocity compensation factor (ω) is obtained. offset The adaptive determination method for )

[0061]

[0062] As shown in the above formula, ω offset Adaptive computation allows the processor to detect the target control current (IG) in real time during VSG operation. ref ) and maximum current threshold (I m Theoretical true power (P) real ) and maximum power threshold (P m The relationship between ω and ω is used to determine the angular velocity compensation factor. offset The compensation value is entered into the loop control to limit the maximum power output of the VSG, thereby maintaining the maximum power output under overcurrent conditions and limiting the overcurrent.

[0063] Correspondingly, the aforementioned angular velocity compensation factor (ω) offset The adaptive calculation method is illustrated using the inverter's maximum power threshold and maximum current threshold as boundaries, aiming to ensure the inverter can support the grid as much as possible when connected, meaning the inverter's output power can be equal to the maximum power threshold. Alternatively, an adaptive calculation of the angular velocity compensation factor can be performed using power and current limit thresholds that are lower than the maximum power and current thresholds, thus limiting the inverter's output power to be less than the maximum power threshold. This embodiment does not impose any such restrictions.

[0064] Step 103: Determine the target output voltage phase of the inverter based on the inverter's target active power, current actual active power, and frequency regulation compensation parameters.

[0065] Understandably, in this step, the processor can adjust the inverter's target active power (e.g., ...) Figure 2 (Pref in the text), the current actual active power (e.g.) Figure 2 P) and frequency adjustment compensation parameters (such as angular velocity compensation factor ω) offset This determines the phase of the three-phase voltage to be output by the inverter (i.e., the target output voltage phase).

[0066] Correspondingly, the specific method by which the processor determines the target output voltage phase of the inverter based on the inverter's target active power, current actual active power, and frequency adjustment compensation parameters in this step can be set by the designer according to the practical scenario and user requirements. For example, it can be set in a way similar to the conventional inverter output phase determination method, only with the addition of frequency adjustment compensation parameters. Figure 3 As shown, the frequency adjustment compensation parameter is the angular velocity compensation factor ω. offsetAt this time, the processor can perform frequency regulation control using the input target active power (Pref) and the current actual active power (P), while superimposing the rated value of the output voltage frequency (ω). n Subtract the angular velocity compensation factor (ω) when offset Thus, the target output voltage phase (θ) of the frequency regulation control output is obtained. ref Correspondingly, when the frequency regulation compensation parameter is the compensation parameter in the frequency regulation control of the UPS's phase-locked loop, it can be processed using a similar process to the frequency regulation control process of a conventional UPS's phase-locked loop, except that the frequency regulation compensation parameter is added during the processing. This embodiment does not impose any limitations on this.

[0067] Step 104: Calculate the three-phase voltage of the inverter output based on the target output voltage phase, so that the inverter output power is less than or equal to the maximum power threshold and the output current is less than or equal to the maximum current threshold.

[0068] In this embodiment, the processor can calculate the three-phase voltage to be inverted by the inverter based on the determined target output voltage phase, such as... Figure 2 and 3 The parameters ua_ref, ub_ref, and uc_ref in the inverter ensure that when the inverter outputs three-phase voltage, the inverter's output power is less than or equal to the maximum power threshold and the output current is less than or equal to the maximum current threshold.

[0069] Accordingly, the specific method by which the processor calculates the three-phase output voltage of the inverter based on the target output voltage phase in this embodiment can be set by the designer. For example, it can be implemented in a way that is the same as or similar to the conventional method of calculating three-phase voltage using phase. Figure 3 As shown, the processor can utilize the target output voltage phase (θ) ref The reactive power loop output excitation voltage (E) of the voltage regulation control loop of the VSG is used to calculate the three-phase voltages (ua_ref, ub_ref, and uc_ref), i.e., ua_ref = E * sin(θ). ref ), ub_ref ​​= E*sin(θ) ref -2 / 3π) and ub_ref=E*sin(θ) ref +2 / 3π).

[0070] For example, the prototype uses, such as Figure 3 When the VSG control strategy is shown, the inverter has a 1.7mH series inductor on the grid-connected side, operates at full load and connected to the grid, and is controlled by a voltage source VSG control algorithm; before time t0, the prototype operates at full load, and at time t0 the grid frequency jumps from 50Hz to 45Hz. The prototype design K f For 20, Tj The value is 8.96. If current limiting is not applied, the prototype will trigger overcurrent protection; if... Figure 4 As shown, at time t0, the control system calculates ω offset The compensation loop control limits the maximum current and maximum power output, ensuring that the machine does not disconnect from the grid and maintains full-load operation. During continuous operation at 45Hz, the prototype can still maintain current limiting and limit the maximum power output to support the grid at its maximum capacity (1.3 times overload capacity). It can be seen that the inverter in this embodiment has a very fast current limiting response speed and is effective for overcurrent phenomena caused by primary frequency regulation and inertia response. Moreover, it does not affect the overall control of VSG and has no impact on the system when the limiting is not triggered.

[0071] In this embodiment, the present invention limits the maximum current and maximum power output of the inverter by adding frequency regulation compensation parameters to the frequency regulation control stage of the inverter. This allows the inverter to maintain voltage source characteristics even after current limiting, thereby improving the stability of the inverter while ensuring its safe operation and enabling it to support the grid as much as possible when connected to the grid.

[0072] Corresponding to the above method embodiments, this invention also provides a phase control device for inverter output. The phase control device for inverter output described below and the phase control method for inverter output described above can be referred to in correspondence.

[0073] Please refer to Figure 5 , Figure 5 This is a structural block diagram of an inverter output phase control device provided in an embodiment of the present invention. The device may include:

[0074] The theoretical acquisition module 10 is used to obtain the theoretical true power output of the inverter based on the inverter's output voltage frequency.

[0075] The compensation determination module 20 is used to determine the frequency regulation compensation parameters based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical real power.

[0076] The phase determination module 30 is used to determine the target output voltage phase of the inverter based on the inverter's target active power, the current actual active power, and the frequency regulation compensation parameters.

[0077] The inverter output module 40 is used to calculate the three-phase voltage of the inverter output based on the target output voltage phase, so that the inverter output power is less than or equal to the maximum power threshold and the output current is less than or equal to the maximum current threshold.

[0078] In some embodiments, the frequency regulation compensation parameter is the compensation parameter in the frequency regulation control of the phase-locked loop of the uninterruptible power supply (UPS).

[0079] In some embodiments, the frequency regulation compensation parameter is the compensation parameter in the frequency regulation control of the virtual synchronous generator (VSG).

[0080] In some embodiments, the frequency adjustment compensation parameter is an angular velocity compensation factor.

[0081] In some embodiments, the compensation determination module 20 may include:

[0082] The first determining submodule is used to determine the angular velocity compensation factor as 0 if the target control current is less than the maximum current threshold and the theoretical actual power is less than the maximum power threshold.

[0083] The second determining submodule is used to determine whether the target control current is less than the maximum current threshold and the theoretical actual power is greater than or equal to the maximum power threshold, and then through ω offset =(P ref -K f *(Δf / f N )*P N -P m ) / (D*ω0), determine the angular velocity compensation factor; where ω offset P is the angular velocity compensation factor. ref For the active power command of VSG, K f ω is the active frequency modulation coefficient. o For the output voltage frequency, Δf = ff N f N For the rated frequency, P N Where P is the rated active power, f is the inverter frequency, and P is the inverter frequency. m Where D is the maximum power threshold and D is the frequency damping coefficient of the VSG;

[0084] The third determining submodule is used to determine whether the target control current is greater than or equal to the maximum current threshold, and then via ω. offset =(P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N -P m ) / (D*ω0), determine the angular velocity compensation factor; where, T j These are inertial characteristic parameters.

[0085] In some embodiments, the theoretical acquisition module 10 may be specifically used to determine the theoretical true power output of the inverter based on the rate of change of the inverter's output voltage frequency.

[0086] In some embodiments, the theory acquisition module 10 may include:

[0087] The first calculation submodule is used for... Then through P real =P ref -K f *(Δf / f N )*P N Determine the theoretical true power; where J is the virtual inertia coefficient of VSG, ω o P is the output voltage frequency. real For the theoretical true power, P ref For the active power command of VSG, K f The active frequency regulation coefficient is Δf = ff. N f N For the rated frequency, P N Where f is the rated active power, and f is the frequency of the inverter;

[0088] The second calculation submodule is used for... Then through P real =P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N Determine the theoretical true power; where T j These are inertial characteristic parameters.

[0089] In this embodiment, the present invention limits the maximum current and maximum power output of the inverter by adding frequency regulation compensation parameters to the frequency regulation control stage of the inverter. This allows the inverter to maintain voltage source characteristics even after current limiting, thereby improving the stability of the inverter while ensuring its safe operation and enabling it to support the grid as much as possible when connected to the grid.

[0090] Corresponding to the above method embodiments, this invention also provides a phase control device for inverter output. The phase control device for inverter output described below and the phase control method for inverter output described above can be referred to in correspondence.

[0091] Please refer to Figure 6 , Figure 6 This is a schematic diagram of a phase control device for inverter output provided in an embodiment of the present invention. The phase control device may include:

[0092] Memory D1 is used to store computer programs;

[0093] Processor D2 is used to implement the steps of the phase control method for inverter output provided in the above method embodiments when executing a computer program.

[0094] For details, please refer to Figure 7 , Figure 7 This is a schematic diagram illustrating the specific structure of a phase control device for inverter output provided in an embodiment of the present invention. The phase control device can vary significantly depending on its configuration or performance, and may include one or more central processing units (CPUs) 322 (e.g., one or more processors) and a memory 332, and one or more storage media 330 (e.g., one or more mass storage devices) storing application programs 342 or data 344. The memory 332 and storage media 330 can be temporary or persistent storage. The program stored in the storage media 330 may include one or more modules (not shown in the diagram), each module including a series of instruction operations on the device. Furthermore, the central processing unit 322 may be configured to communicate with the storage media 330 and execute the series of instruction operations in the storage media 330 on the phase control device 301.

[0095] The phase control device 301 may also include one or more power supplies 326, one or more wired or wireless network interfaces 350, one or more input / output interfaces 358, and / or one or more operating systems 341. Examples include Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™, etc.

[0096] Among them, the phase control device 301 can be a VSG-controlled inverter, such as a grid-connected inverter; or it can be a UPS device.

[0097] The steps in the power supply control method described above can be implemented by the structure of the phase control device of the inverter output.

[0098] Corresponding to the above method embodiments, this invention also provides a computer-readable storage medium. The computer-readable storage medium described below and the phase control method for inverter output described above can be referred to in correspondence.

[0099] A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the phase control method for the inverter output described in the above method embodiments.

[0100] The computer-readable storage medium can specifically be a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, or any other readable storage medium capable of storing program code.

[0101] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0102] The present invention has provided a detailed description of a phase control method, apparatus, device, and computer-readable storage medium for inverter output. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely illustrative of the method and its core ideas. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A phase control method for inverter output, characterized in that, include: Based on the inverter's output voltage frequency, obtain the theoretical true power output of the inverter. The frequency regulation compensation parameters are determined based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical actual power. The target output voltage phase of the inverter is determined based on the target active power of the inverter, the current actual active power, and the frequency regulation compensation parameters. Based on the target output voltage phase, calculate the three-phase voltage of the inverter output so that the inverter output power is less than or equal to the maximum power threshold and the output current is less than or equal to the maximum current threshold.

2. The phase control method for inverter output according to claim 1, characterized in that, The frequency regulation compensation parameter is the compensation parameter in the frequency regulation control of the phase-locked loop of the uninterruptible power supply (UPS).

3. The phase control method for inverter output according to claim 1, characterized in that, The frequency regulation compensation parameter is the compensation parameter in the frequency regulation control of the virtual synchronous generator (VSG).

4. The phase control method for inverter output according to claim 3, characterized in that, The frequency adjustment compensation parameter is the angular velocity compensation factor.

5. The phase control method for inverter output according to claim 4, characterized in that, The step of determining the frequency regulation compensation parameters based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical actual power includes: If the target control current is less than the maximum current threshold and the theoretical actual power is less than the maximum power threshold, then the angular velocity compensation factor is determined to be 0. If the target control current is less than the maximum current threshold and the theoretical true power is greater than or equal to the maximum power threshold, then through ω offset =(P ref -K f *(Δf / f N )*P N -P m ) / (D*ω0), determine the angular velocity compensation factor; where ω offset P is the angular velocity compensation factor. ref For the active power command of VSG, K f ω is the active frequency modulation coefficient. o Let Δf be the frequency of the output voltage, and Δf = ff. N f N For the rated frequency, P N The rated active power is P, f is the frequency of the inverter, and P is the rated active power. m Where D is the maximum power threshold, and D is the frequency damping coefficient of the VSG; If the target control current is greater than or equal to the maximum current threshold, then through ω offset =(P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N -P m ) / (D*ω0), determine the angular velocity compensation factor; where, T j These are inertial characteristic parameters.

6. The phase control method for inverter output according to claim 1, characterized in that, The step of obtaining the theoretical true power output of the inverter based on the inverter's output voltage frequency includes: The theoretical true power output of the inverter is determined based on the rate of change of the inverter's output voltage frequency.

7. The phase control method for inverter output according to claim 6, characterized in that, Determining the theoretical true power output of the inverter based on the rate of change of the inverter's output voltage frequency includes: like Then through P real =P ref -K f *(Δf / f N )*P N Determine the theoretical true power; where J is the virtual inertia coefficient of the VSG, ω o P is the frequency of the output voltage. real For the theoretical true power, P ref For the active power command of VSG, K f The active frequency regulation coefficient is Δf = ff. N f N For the rated frequency, P N The rated active power is f, and the frequency of the inverter is f. like Then through P real =P ref -K f *(Δf / f N )*P N -(T j / f N )*(df / dt)*P N Determine the theoretical true power; where T j These are inertial characteristic parameters.

8. A phase control device for inverter output, characterized in that, include: The theoretical acquisition module is used to obtain the theoretical true power output of the inverter based on the inverter's output voltage frequency; The compensation determination module is used to determine the frequency regulation compensation parameters based on the inverter's maximum power threshold, target control current, maximum current threshold, and theoretical true power. The phase determination module is used to determine the target output voltage phase of the inverter based on the target active power of the inverter, the current actual active power, and the frequency adjustment compensation parameters. The inverter output module is used to calculate the three-phase voltage of the inverter output based on the target output voltage phase, so that the output power of the inverter is less than or equal to the maximum power threshold and the output current is less than or equal to the maximum current threshold.

9. A phase control device for inverter output, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the steps of the phase control method for the inverter output as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the phase control device for the inverter output as described in any one of claims 1 to 7.

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