A new energy power generation grid-connected converter control method, device, equipment and storage medium

Abstract

The application discloses a new energy power generation grid-connected converter control method, device and equipment and a storage medium, relates to the grid-connected control field, and comprises the following steps: acquiring voltage components and current components of a grid-connected point of the converter, and obtaining a short-circuit ratio accordingly; then, a first weight distribution coefficient is adaptively adjusted according to the short-circuit ratio; based on the adjusted coefficient, a target synchronization signal is obtained, and a control phase angle is calculated accordingly; then, a preset second weight distribution coefficient is acquired, and a current reference value is calculated by weighting and fusing a grid-connected type constant power control component and a network type constant voltage control component in a hybrid voltage outer ring according to the coefficient; then, a voltage reference value is calculated by performing PI control on a current inner ring through the current reference value; the voltage reference value is subjected to coordinate conversion according to the control phase angle, a modulation signal is generated by using the converted voltage reference value, and the converter is controlled to operate. The application can solve the problem that the proportional coefficients of two control loops are coupled with each other.

Description

Technical Field

[0001] This invention relates to the field of grid-connected control technology, and in particular to a control method, device, equipment and storage medium for a grid-connected converter for new energy power generation. Background Technology

[0002] Currently, large-scale renewable energy power generation devices, represented by wind power and photovoltaics, are continuously being integrated into the power grid, and the proportion of renewable energy power generation in the power system is increasing year by year. However, the output of renewable energy power generation is significantly affected by natural meteorological conditions such as sunlight intensity and wind speed, exhibiting strong randomness and large fluctuations in its output characteristics. This intermittent and uncertain power generation mode causes the grid equivalent strength (i.e., short-circuit ratio) at the renewable energy grid connection point to be in a state of continuous dynamic fluctuation. Against this backdrop, the grid-connected converter, as the core power conversion interface connecting renewable energy power generation units and the AC grid, directly determines the grid-connected operation quality and safety stability of the renewable energy power generation system through its control performance.

[0003] Currently, the control of grid-connected converters for new energy sources mainly falls into two major technical routes: grid-following control and grid-connecting control. In low short-circuit ratio, weak grid conditions, grid-following control results in strong coupling between the phase-locked loop (PLL) and the grid impedance, easily leading to system oscillations or even instability. In strong grid conditions, grid-connecting control, with its voltage source characteristics competing with the rigid voltage source of the strong grid, easily causes active and reactive power coupling oscillations, large dynamic response overshoot, and reduced stability margin. Therefore, neither a single grid-following nor grid-connecting control architecture can simultaneously meet the stability requirements under extreme conditions of both high and low short-circuit ratios. Summary of the Invention

[0004] This invention provides a control method, device, equipment, and storage medium for grid-connected converters for new energy power generation, which solves the problem of mutual coupling of the proportional coefficients of the two control loops when the parameters of the synchronous loop and the voltage outer loop are simultaneously adjusted adaptively in the existing adaptive hybrid control, thereby achieving safe and stable operation of the new energy grid-connected system.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a control method for a grid-connected converter for new energy power generation, comprising: Obtain the voltage and current components of the converter at the grid connection point, and determine the short-circuit ratio based on the voltage and current components; The first weighting coefficient between the grid-type phase-locked loop control component and the grid-type power synchronization control component in the hybrid synchronous control loop is adaptively adjusted according to the short-circuit ratio. Based on the adjusted first weight allocation coefficient, the first synchronization signal output by the grid-type phase-locked loop control component and the second synchronization signal output by the grid-type power synchronization control component are weighted and fused to obtain the target synchronization signal. The control phase angle is then calculated based on the target synchronization signal. Obtain the preset second weight allocation coefficient, and according to the second weight allocation coefficient, perform weighted fusion of the grid-type constant power control component and the grid-type constant voltage control component in the hybrid voltage outer loop to calculate the current reference value; The voltage reference value is calculated by performing PI control on the inner current loop using the current reference value. Based on the control phase angle, the voltage reference value is transformed into coordinates, and based on the voltage reference value after coordinate transformation, a modulation signal is generated to control the converter.

[0006] As a preferred embodiment, the step of obtaining the voltage and current components of the converter at the grid connection point and determining the short-circuit ratio based on the voltage and current components specifically includes: Obtain the voltage and current of the converter at the grid connection point; The voltage and current are transformed by coordinates to obtain voltage components and current components; The impedance of the strain gauge is calculated based on the voltage and current components, and the short-circuit ratio is calculated based on the impedance.

[0007] As a preferred embodiment, the voltage components include a d-axis voltage component and a q-axis voltage component, and the current components include a d-axis current component and a q-axis current component; the step of calculating the impedance of the strain gauge based on the voltage and current components, and calculating the short-circuit ratio based on the impedance, specifically includes: The impedance of the power grid is calculated based on the d-axis voltage component and q-axis voltage component, as well as the d-axis current component and q-axis current component. Based on the impedance, combined with the effective value of the grid voltage and the preset impedance angle, the short-circuit capacity is calculated. Based on the short-circuit capacity and the active power at the grid connection point, the short-circuit ratio is calculated.

[0008] As a preferred embodiment, the first weight allocation coefficient between the grid-type phase-locked loop control component and the grid-type power synchronization control component in the hybrid synchronization control loop, based on the short-circuit ratio, specifically includes: The value of the first weight allocation coefficient is determined based on the short-circuit ratio and in conjunction with the first preset threshold. The first weight allocation coefficient is used to allocate the first weight value of the grid-type phase-locked loop control component and the second weight value of the grid-type power synchronization control component, wherein the sum of the first weight value and the second weight value is 1.

[0009] As a preferred embodiment, the step of weighting and fusing the first synchronization signal output by the grid-type phase-locked loop control component and the second synchronization signal output by the grid-type power synchronization control component based on the adjusted first weight allocation coefficient to obtain a target synchronization signal, and calculating the control phase angle based on the target synchronization signal, specifically includes: The first synchronization signal is weighted according to the first weight value to obtain the first weighted signal; The second synchronization signal is weighted according to the second weight value to obtain the second weighted signal; The first weighted signal and the second weighted signal are superimposed to obtain the target synchronization signal; The angular frequency is determined based on the target synchronization signal, and the angular frequency is integrated to obtain the control phase angle.

[0010] As a preferred embodiment, the step of weighting and fusing the grid-based constant power control component and the grid-based constant voltage control component in the hybrid voltage outer loop according to the second weight allocation coefficient to calculate the current reference value specifically includes: Based on the second weight allocation coefficient, determine the third weight value corresponding to the grid-type constant power control component and the fourth weight value corresponding to the grid-type constant voltage control component; The first voltage regulation signal output by the grid-type constant power control component is weighted according to the third weight value to obtain the third weighted signal; The second voltage adjustment signal output by the network-type constant voltage control component is weighted according to the fourth weight value to obtain the fourth weighted signal; The third weighted signal and the fourth weighted signal are superimposed to obtain the target voltage adjustment signal; The current reference value is calculated based on the target voltage adjustment signal.

[0011] As a preferred embodiment, the step of obtaining a preset second weighting coefficient, and then, based on the second weighting coefficient, weighting and fusing the grid-type constant power control component and the grid-type constant voltage control component in the hybrid voltage outer loop to calculate the current reference value, specifically includes: Using the current reference value as input, PI control is performed on the inner current loop to obtain the second PI control parameter in the control process. Based on the second PI control parameters, combined with the converter-side current component and current reference value, the voltage reference value is calculated.

[0012] As a preferred embodiment, the step of performing coordinate transformation on the voltage reference value based on the control phase angle, and generating a modulation signal to control the converter based on the coordinate-transformed voltage reference value, specifically includes: Based on the control phase angle, the voltage reference value is transformed from the dq coordinate system to the abc coordinate system to obtain the target modulation voltage; The target modulation voltage is input to the PWM modulation unit to generate a modulation signal, and the converter is controlled based on the modulation signal.

[0013] As a preferred option, the method also includes: A simulation model of the converter grid-connected system is established, and a disturbance signal is set for the simulation model; Based on the disturbance signal, several simulated short-circuit ratios are generated, and under these simulated short-circuit ratios, a simulation model of the grid-connected system of the modulated signal-controlled converter is generated, and the control performance is verified.

[0014] Accordingly, the present invention also provides a control device for a grid-connected converter for new energy power generation, comprising: a control loop module and a line module; The control loop module is used to execute the new energy power generation grid-connected converter control method described in any of the above descriptions; The line module includes: a converter, a grid connection point, a capacitor, a first resistor-inductor module, and a second resistor-inductor module.

[0015] As a preferred embodiment, the converter, the first resistor-inductor module, and the second resistor-inductor module are connected in series in sequence. The grid connection point and capacitor are connected between the first resistor-inductor module and the second resistor-inductor module; The first resistor-inductor module includes: a first resistor and a first inductor; the first resistor and the first inductor are connected in series; The second resistor-inductor module includes: a second resistor and a second inductor; the second resistor and the second inductor are connected in series.

[0016] Accordingly, the present invention also provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the new energy power generation grid-connected converter control method as described in any of the above.

[0017] Accordingly, the present invention also provides a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the new energy power generation grid-connected converter control method as described above.

[0018] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: The technical solution of this invention determines the short-circuit ratio by acquiring the voltage and current components of the converter at the grid connection point. Then, based on the short-circuit ratio, it adaptively adjusts the first weight allocation coefficient between the grid-following phase-locked loop control component and the grid-connected power synchronization control component in the hybrid synchronous control loop. Simultaneously, it uses a preset fixed value, independent of the first weight allocation coefficient, as the second weight allocation coefficient for the hybrid voltage outer loop. That is, the first weight dynamically and adaptively adjusts with the short-circuit ratio to ensure synchronization accuracy under different grid strengths, while the second weight remains fixed to prevent repeated disturbances in the grid-following / grid-connected weights of the voltage outer loop due to fluctuations in the short-circuit ratio. This asymmetric control architecture of "adaptive synchronization loop and fixed voltage outer loop decoupling" fundamentally eliminates the positive feedback coupling path formed when both weight coefficients are dynamically adjusted with the short-circuit ratio in traditional schemes, avoiding mutual interference between control commands of the two control loops, and ensuring that the active and reactive power regulation channels remain independent. In scenarios with large fluctuations in the short-circuit ratio, this invention not only ensures that the synchronization loop can quickly track changes in the grid phase, but also allows the control parameters of the outer voltage loop to be independently tuned without introducing additional disturbances due to coefficient linkage. This effectively suppresses active and reactive power coupling oscillations and ensures that the system can maintain stable operation across a wide range of short-circuit ratios, from extremely weak grids to extremely strong grids. Attached Figure Description

[0019] Figure 1 : A flowchart illustrating the steps of a grid-connected converter control method for new energy power generation provided in an embodiment of the present invention; Figure 2 : This is a control block diagram of the hybrid synchronization control loop provided in an embodiment of the present invention; Figure 3 : This is a control block diagram of the hybrid voltage outer loop and current inner loop control provided in an embodiment of the present invention; Figure 4 : This is a structural diagram of the new energy power generation grid-connected converter control device provided in an embodiment of the present invention; Figure 5 : This is a waveform diagram of the grid connection point voltage, current, angular frequency, and active power response when SCR=1, provided in an embodiment of the present invention; Figure 6 : This is a waveform diagram of the grid connection point voltage, current, angular frequency, and active power response when SCR=10, provided in an embodiment of the present invention; Figure 7 The above is a waveform diagram of the grid connection point voltage, current, angular frequency and active power response when SCR=50, provided in an embodiment of the present invention. Detailed Implementation

[0020] 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, and 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.

[0021] Example 1 Please refer to Figure 1 The present invention provides a control method for a grid-connected converter for new energy power generation, comprising the following steps S101-S105: S101: Obtain the voltage and current components of the converter at the grid connection point, and determine the short-circuit ratio based on the voltage and current components.

[0022] In this embodiment, at the technical implementation level, the scheme takes the voltage and current components at the grid connection point as direct inputs. First, it transforms the electrical quantities in the three-phase stationary coordinate system to the synchronous rotating dq coordinate system through Park transformation to obtain the voltage component (d / q axis component) and the current component (d / q axis component). Then, based on the small-signal linearization method, it calculates the equivalent impedance of the power grid using the ratio of the voltage and current disturbance components, and completes the per-unit solution through the short-circuit ratio calculation formula to realize the short-circuit ratio of the power grid at the grid connection point, thereby achieving real-time and accurate identification of the power grid strength.

[0023] S102: Adjust the first weighting coefficient between the grid-type phase-locked loop control component and the grid-type power synchronization control component in the hybrid synchronization control loop according to the short-circuit ratio.

[0024] In this embodiment, based on the short-circuit ratio (SCR) obtained through online identification, the first weight allocation coefficient of the hybrid synchronous control loop is determined through a preset piecewise or adaptive function. When the short-circuit ratio (SCR) is high (for strong power grids), increase the first weighting allocation coefficient. The first weighting value of the power synchronization control component in the grid-type system is strengthened; when the short-circuit ratio (SCR) is low (weak grid), the first weighting allocation coefficient is reduced. To increase the second weight value of the control component (PLL) of the phase-locked loop.

[0025] In this embodiment, the first weight allocation coefficient is dynamically adapted to the power grid strength. With real-time adjustment of the SCR, the generation process of the control phase angle combines the weak grid stability of power synchronization control with the strong grid tracking accuracy of PLL control. This not only avoids the instability risk of a single control strategy under extreme grid conditions, but also provides a unified synchronous control framework for grid-connected converters in wide short-circuit ratio scenarios, effectively improving the system's operational stability and adaptability under wide fluctuations in grid strength.

[0026] S103: Based on the adjusted first weight allocation coefficient, the first synchronization signal output by the grid-type phase-locked loop control component and the second synchronization signal output by the grid-type power synchronization control component are weighted and fused to obtain the target synchronization signal. The control phase angle is calculated based on the target synchronization signal.

[0027] In this embodiment, the hybrid synchronization control loop integrates a phase-locked loop for grid-based control and a power synchronization control loop for grid-based control, and allocates a first weighting coefficient. Adaptive allocation is performed. The control components of the grid-type phase-locked loop are calculated using PI control, and the actual value of the q-axis voltage at the grid connection point is eliminated. With voltage reference value The deviation is used to output a first synchronization signal for grid synchronization; the grid-type power synchronization control component uses a virtual synchronizer to adjust the active power P, and outputs a second synchronization signal to construct the system frequency. The first weighting coefficient is used for allocation. The first weight value corresponding to the grid-type power synchronization control component and the second weight value corresponding to the grid-type phase-locked loop control component are determined. The first and second synchronization signals are weighted using the first and second weight values. The weighted first and second synchronization signals are then superimposed and compared with the rated angular frequency. Adding them together yields the target synchronization signal (i.e., the fused angular frequency). ), and then the angular frequency Perform integration to obtain the control phase angle used for subsequent coordinate transformation. .

[0028] In this embodiment, the hybrid voltage outer loop achieves smooth switching and complementary advantages of voltage control modes through dynamic adjustment of the proportional coefficient. Specifically, under strong grid conditions, grid-following voltage tracking is the primary mode to ensure harmonic suppression and tracking accuracy of the grid-connected current; under weak grid conditions, grid-supporting voltage is the primary mode to enhance the system's active support capability against voltage fluctuations. This effectively solves the adaptability problem of a single voltage control strategy in wide short-circuit ratio scenarios, avoiding current distortion caused by over-control under strong grid conditions and enhancing voltage support capability under weak grid conditions. This significantly improves the control stability and power quality of the grid-connected converter when the grid strength changes dynamically.

[0029] S104: Perform PI control on the inner current loop using the current reference value, and calculate the voltage reference value.

[0030] In this embodiment, the dq-axis current reference value generated by the hybrid voltage outer loop is used as input to the PI controller of the current inner loop. That is, the difference between the actual dq component of the grid-connected current and the reference value is obtained to obtain the current deviation signal. Subsequently, the deviation signal is adjusted by the d-axis and q-axis PI controllers respectively. The proportional element quickly suppresses the current error, the integral element eliminates the steady-state error, and the cross-coupling term and the grid voltage feedforward term in the dq coordinate system are superimposed to finally generate the voltage reference value in the dq coordinate system.

[0031] In this embodiment, the PI control of the inner current loop enables fast and accurate tracking of the grid-connected current, ensuring the dynamic response speed of the current reference value and eliminating steady-state error through the integral element, effectively suppressing current harmonics and distortion. At the same time, combined with feedforward and cross-coupling compensation, the anti-disturbance capability and decoupling performance of the control loop are improved, providing a stable voltage modulation reference for the grid-connected converter under wide short-circuit ratio conditions, and ensuring the quality of the current waveform and the stability of system operation.

[0032] S105: Based on the control phase angle, the voltage reference value is transformed into coordinates, and based on the voltage reference value after coordinate transformation, a modulation signal is generated to control the converter.

[0033] In this embodiment, using the control phase angle output by the hybrid synchronous control loop as a reference, the dq-axis voltage reference value generated by the inner current loop is transformed to the three-phase stationary abc coordinate system through the Parker inverse transform to obtain the three-phase voltage reference signal. Then, this three-phase reference signal is modulated and compared with a carrier wave to generate a PWM drive signal, which directly controls the power switching devices of the grid-connected converter, achieving closed-loop regulation of the output voltage and current.

[0034] In this embodiment, coordinate transformation is achieved based on dynamically adapted control phase angles, ensuring that the phase of the voltage reference value is always synchronized with the grid under different grid strengths, thus avoiding power oscillations and grid instability caused by phase deviations. Simultaneously, this scheme achieves a complete closed-loop link from control commands to power device drives, guaranteeing both the consistency of the control phase angle and the voltage reference value, and accurately outputting power quality that meets grid requirements, effectively improving the grid-connected stability and dynamic response performance of the converter under wide short-circuit ratio conditions.

[0035] It is understood that this invention proposes a hybrid control strategy for grid-connected converters of new energy power generation applicable to a wide short-circuit ratio range. By measuring the voltage and current at the converter's grid connection point, the dq-axis components are obtained through Parker transformation, and active and reactive power are calculated. Combined with system impedance, the system's short-circuit ratio is calculated. Then, based on the system's short-circuit ratio, the first weighting coefficient between the grid-linked phase-locked loop control component and the grid-connected power synchronization control component in the hybrid synchronous control loop is adaptively adjusted. Based on the adjusted first weighting coefficient, the first synchronization signal output by the grid-linked phase-locked loop control component and the second synchronization signal output by the grid-connected power synchronization control component are weighted and fused. The target synchronization signal is obtained, and the control phase angle is calculated based on the target synchronization signal. A preset second weight allocation coefficient is obtained, and the grid-following constant power control component and the grid-connected constant voltage control component in the hybrid voltage outer loop are weighted and fused according to the second weight allocation coefficient to calculate the current reference value. The current inner loop is PI controlled using the current reference value to calculate the voltage reference value. The voltage reference value is coordinate transformed according to the control phase angle, and a modulation signal is generated through the PWM module to control the converter. Finally, a simulation model of the converter grid-connected system is established in PSCAD / EMTDC, a disturbance signal is set, and the performance of the method is verified under different short-circuit ratios.

[0036] Implementing the above embodiments has the following effects: This application employs an asymmetric decoupling control architecture of "single-loop adaptive, single-loop fixed". Specifically, the synchronization control loop still adaptively adjusts its first weight allocation coefficient according to the short-circuit ratio change, independently undertaking the task of tracking and adapting to grid intensity fluctuations; while the second weight allocation coefficient of the voltage outer loop is preset to a fixed value independent of the first weight allocation coefficient, and does not adjust with the short-circuit ratio change throughout the grid-connected operation. The core function of this architecture design is to physically sever the positive feedback coupling path between the synchronization loop and the voltage outer loop—since the grid-following / grid-building weight of the voltage outer loop no longer changes dynamically with the short-circuit ratio, its response sensitivity to the phase fluctuations of the synchronization loop is constant at a preset stable operating point, and it no longer dynamically couples with the adaptive adjustment of the synchronization loop itself. When the synchronization loop experiences phase angle fluctuations due to changes in the first weighting coefficient, these fluctuations are transmitted to the voltage outer loop. The output deviation of the voltage outer loop depends only on its inherent transmission characteristics under fixed weights and is not amplified step-by-step by changes in the weighting coefficients. Similarly, when the output deviation of the voltage outer loop due to other disturbances is fed back to the synchronization loop, since the voltage outer loop itself does not introduce additional dynamic disturbances related to the short-circuit ratio, the feedback signal no longer carries disturbance components coupled with the changing trend of the synchronization loop, thus effectively avoiding mutual interference of control commands. The two control loops thus achieve true "each performing its own function without interference"—the synchronization loop focuses on dynamic tracking of grid strength, while the voltage outer loop provides stable voltage support and power regulation with a constant grid-to-grid ratio. The two are decoupled in the time domain and do not overlap in the frequency domain, fundamentally eliminating the inherent positive feedback oscillation risk of simultaneous dual-loop adaptation, and significantly improving the system's operational stability and dynamic response quality under wide short-circuit ratio fluctuations.

[0037] Example 2 This invention also provides several preferred embodiments of the control method for grid-connected converters for new energy power generation, specifically including: In a preferred embodiment, the step of obtaining the voltage and current components of the converter at the grid connection point and determining the short-circuit ratio based on the voltage and current components specifically includes: Obtain the voltage and current of the converter at the grid connection point; The voltage and current are transformed by coordinates to obtain voltage components and current components; The impedance of the strain gauge is calculated based on the voltage and current components, and the short-circuit ratio is calculated based on the impedance.

[0038] In this embodiment, the grid voltage and grid current signals in the three-phase stationary coordinate system are acquired in real time through the voltage and current sampling unit at the grid connection point. Then, the three-phase stationary electrical quantities are converted to the synchronous rotating dq coordinate system using Park transform to obtain voltage and current components, achieving decoupling from AC to DC quantities. Next, based on the voltage and current components in the dq domain, the equivalent resistance of the grid is calculated through small-signal disturbance analysis. Then, by combining the grid rated voltage and the converter rated power, the online calculation of SCR is completed using the short-circuit ratio formula, thereby realizing the real-time identification of the grid strength at the grid connection point.

[0039] In a preferred embodiment, the voltage components include a d-axis voltage component and a q-axis voltage component, and the current components include a d-axis current component and a q-axis current component. The step of calculating the impedance of the strain gauge based on the voltage and current components, and calculating the short-circuit ratio based on the impedance, specifically includes: The impedance of the power grid is calculated based on the d-axis voltage component and q-axis voltage component, as well as the d-axis current component and q-axis current component. Based on the impedance, combined with the effective value of the grid voltage and the preset impedance angle, the short-circuit capacity is calculated. Based on the short-circuit capacity and the active power at the grid connection point, the short-circuit ratio is calculated.

[0040] In this embodiment, the equivalent resistance of the power grid is calculated based on the voltage and current components in the dq domain through small-signal disturbance analysis. Furthermore, combining the grid rated voltage and converter rated power, the online calculation of SCR is performed using the short-circuit ratio formula. Additionally, the small-signal model can analyze the impact of the proportional gain in the hybrid control strategy on the small-disturbance stability of the system under different grid strengths. The small-signal disturbance analysis model can be: in, A The system state matrix is ​​the core matrix that describes the dynamic coupling relationship within the system. Its eigenvalues ​​(poles) directly determine the system stability, and the small-signal stability of the system is related to the eigenvalues ​​of this matrix. B The input matrix describes the impact of external input disturbances (such as grid voltage fluctuations and power reference value changes) on the system state variables; x represents the state variables, and y represents the input variables. in, This is the output phase angle value. Angular frequency, For the d-axis voltage outer loop PI controller, the integral state variable is... For the q-axis voltage outer loop PI controller, the integral state variable is... For the d-axis current inner loop PI controller, the integral state variable is denoted as ... denoted as denoted denoted as denoted denoted For the integral state variable of the q-axis current inner loop PI controller; The d-axis current reference value is generated by the voltage outer loop hybrid control. The q-axis current reference value is generated by the voltage outer loop hybrid control. This is the instruction used by the current inner-loop PI controller to calculate the d-axis voltage. This is the instruction used to calculate the q-axis voltage in a current inner-loop PI controller. The voltage component along the d-axis. The voltage component is the q-axis. The current component is the d-axis component. For the q-axis current component; u sd_ref The voltage reference value for the d-axis, u sq_ref P is the voltage reference value for the q-axis. ref This is the reference value for the active power of the grid-connected converter.

[0041] In this embodiment, the three-phase voltage and three-phase grid-connected current at the grid connection point are acquired in real time. Through Parker coordinate transformation, the AC electrical quantities in the stationary three-phase coordinate system are converted into voltage dq-axis components and current dq-axis components in the synchronously rotating dq coordinate system. Then, the dq voltage and current values ​​at the system's stable operating moment are selected as the steady-state operating point. Based on this, a small power or current reference disturbance is artificially introduced to cause small dynamic changes in the electrical quantities at the grid connection point. The real-time dq voltage and current components after the disturbance are acquired, and the steady-state operating point components are subtracted from the disturbed components to calculate the voltage small-signal disturbance increment and the current small-signal disturbance increment. Finally, the equivalent impedance of the grid in the dq domain is equivalent to an inductive impedance model containing resistance and inductance. Using the principle of small-signal linearization, the steady-state DC component is eliminated, retaining only the linear correlation between voltage and current disturbances. A simultaneous relationship is constructed using the two sets of dq-axis disturbance components to calculate the equivalent resistance and equivalent inductance parameters of the grid. Then, by integrating the resistance and inductive reactance, the amplitude and equivalent impedance of the grid are finally calculated.

[0042] In this embodiment, grid strength is typically measured by the short-circuit ratio (SCR), which is specifically the AC system short-circuit capacity divided by the active power of the equipment. The calculation formula is as follows: in, The three-phase short-circuit capacity at the grid connection point. This is the effective value of the grid line voltage. The impedance angle is the equivalent impedance of the power grid. The active power at the grid connection point. This represents the power grid impedance.

[0043] As a preferred solution of this embodiment, the adaptively adjusting a first weight distribution coefficient between the grid-following phase-locked loop control component and the grid-forming power synchronization control component in the hybrid synchronization control loop according to the short-circuit ratio specifically includes: determining the value of the first weight distribution coefficient according to the short-circuit ratio in combination with a first preset threshold; wherein the first weight distribution coefficient is configured to distribute a first weight value of the grid-following phase-locked loop control component and a second weight value of the grid-forming power synchronization control component, and the sum of the first weight value and the second weight value is 1.

[0044] In this embodiment, an adaptive value-taking method for the proportionality coefficient in the hybrid control strategy is proposed according to the stability of the system under different short-circuit ratios. For the first weight distribution coefficient of the synchronization control in the hybrid synchronization control , the adaptive value-taking method thereof is set as follows: Exemplarily, the sum of the first weight value of the grid-following phase-locked loop control component and the second weight value of the grid-forming power synchronization control component is 1.

[0045] Exemplarily, for the proportional coefficient of the phase-locked loop, under a strong power grid (SCR>3), the PLL is dominant and the power synchronization control is auxiliary; under a weak power grid (1<SCR<3), the two are balanced or the power synchronization is slightly dominant; under an extremely weak power grid (SCR<1.5), the power synchronization is dominant and the PLL is auxiliary. The specific values can be set according to the actual situation.

[0046] Exemplarily, for the second weight distribution coefficient K 2, it can be set according to the actual situation, for example, its value can be directly set as: .

[0047] As a preferred solution of this embodiment, the performing weighted fusion on the first synchronization signal output by the grid-following phase-locked loop control component and the second synchronization signal output by the grid-forming power synchronization control component based on the adjusted first weight distribution coefficient to obtain a target synchronization signal, and calculating a control phase angle according to the target synchronization signal specifically includes: weighting the first synchronization signal according to the first weight value to obtain a first weighted signal; weighting the second synchronization signal according to the second weight value to obtain a second weighted signal; superimposing the first weighted signal and the second weighted signal to obtain the target synchronization signal; The angular frequency is determined based on the target synchronization signal, and the angular frequency is integrated to obtain the control phase angle.

[0048] In this embodiment, the control strategy of the hybrid synchronization control loop integrates the phase-locked loop of grid-based control and the power synchronization control loop of grid-based control, and allocates the first weighting coefficient. Adaptive allocation is performed, using the first weight value and the second weight value, such as... Figure 2 As shown, the grid-connected control loop uses PI control calculations and eliminates the actual value of the q-axis voltage at the grid connection point. With voltage reference value To address the deviation, the network-type control system employs a virtual synchronous machine to adjust the active power P. Specifically, the first synchronization signal output by the network-type power synchronization control component is adjusted according to the first weight value. We perform weighting to obtain the first weighted signal. The second synchronization signal output by the control component of the phase-locked loop is adjusted according to the second weight value. We perform weighting to obtain the second weighted signal. The two are superimposed and combined with the angular frequency rating. The sums are used to obtain the target synchronization signal ω. Then, the control phase angle θ is obtained by integrating ω. The hybrid synchronization control strategy can be expressed as: In the formula, This is the output phase angle value; Angular frequency, This is the rated angular frequency. This represents the q-axis component of the grid-side voltage. P ref and P These are the reference value for the active power output of the converter and the active power, respectively. J The moment of inertia of the virtual synchronous generator; D The damping coefficient is... K 1 is the proportional coefficient for controlling the activation of the PLL phase-locked loop and power synchronization control. is the proportional coefficient for the proportional control of the PLL phase-locked loop, and s is the Laplace operator.

[0049] Based on the above equation, the state-space model of the hybrid synchronization control loop can be written as follows: As a preferred embodiment, the step of weighting and fusing the grid-based constant power control component and the grid-based constant voltage control component in the hybrid voltage outer loop according to the second weight allocation coefficient to calculate the current reference value specifically includes: Based on the second weight allocation coefficient, determine the third weight value corresponding to the grid-type constant power control component and the fourth weight value corresponding to the grid-type constant voltage control component; The first voltage regulation signal output by the grid-type constant power control component is weighted according to the third weight value to obtain the third weighted signal; The second voltage adjustment signal output by the network-type constant voltage control component is weighted according to the fourth weight value to obtain the fourth weighted signal; The third weighted signal and the fourth weighted signal are superimposed to obtain the target voltage adjustment signal; The current reference value is calculated based on the target voltage adjustment signal.

[0050] In this embodiment, the second weight allocation coefficient is a preset fixed value and is set independently of the first weight allocation coefficient. The hybrid voltage outer loop control strategy integrates constant power control of grid-based control and constant AC voltage control of grid-based control, and uses the second weight allocation coefficient... Distribution is performed. The grid-connected constant power control component uses PI control to adjust the d-axis voltage at the grid connection point. The active power P is regulated by virtual impedance control; the constant voltage control component of the grid-type system is regulated by PI control. and Specifically, the first voltage regulation signal output by the grid-type constant power control component is weighted according to the third weight value, and the second voltage regulation signal output by the grid-type constant voltage control component is weighted according to the fourth weight value. The two are then superimposed to obtain the target voltage regulation signal, and the current reference value is calculated accordingly. and Specifically, the control strategy for the hybrid voltage outer loop is as follows: in, and The dq-axis component of the converter-side current reference value. i sd and i sq Let dq be the current component at the grid connection point. This is the reference value for the d-axis voltage at the grid connection point. k p1 and k i1 , k p2 and k i2 , k p3 and k i4 This is the first PI control parameter.L s and R s These are virtual impedance control parameters.

[0051] Based on the above equation, the state-space equation for the outer loop of the hybrid voltage can be written as follows: In this embodiment, the second weight allocation coefficient is a preset fixed value, which is not dynamically adjusted with changes in the short-circuit ratio and is set independently of the first weight allocation coefficient. The aforementioned asymmetric decoupling architecture of "adaptive adjustment of the synchronization loop and fixed weight of the voltage outer loop" enables the hybrid synchronization control loop to independently undertake the task of tracking and adapting to grid intensity fluctuations, while the hybrid voltage outer loop provides stable voltage support and power regulation with a constant grid-following / grid-building weight ratio. The two perform their respective functions without interfering with each other.

[0052] As a preferred embodiment, the step of performing PI control on the inner current loop using the current reference value and calculating the voltage reference value specifically includes: Using the current reference value as input, PI control is performed on the inner current loop to obtain the second PI control parameter in the control process. Based on the second PI control parameters, combined with the converter-side current component and current reference value, the voltage reference value is calculated.

[0053] In this embodiment, the inner current loop uses PI control to regulate the output of the hybrid voltage outer loop. i vd_ref and i vq_ref The specific control strategy can be written as follows: in, and The dq-axis component of the converter-side voltage reference value. , , and The dq-axis components of the converter-side current and its reference value are given. k p4 and k i4 , k p5 and k i5 This is the second PI control parameter.

[0054] In a preferred embodiment, the step of performing coordinate transformation on the voltage reference value based on the control phase angle, and generating a modulation signal to control the converter based on the coordinate-transformed voltage reference value, specifically includes: Based on the control phase angle, the voltage reference value is transformed from the dq coordinate system to the abc coordinate system to obtain the target modulation voltage; The target modulation voltage is input to the PWM modulation unit to generate a modulation signal, and the converter is controlled based on the modulation signal.

[0055] In this embodiment, the control phase angle output by the hybrid synchronous control loop is used as the phase reference for the Parker inverse transform. The dq-axis voltage reference value output by the current inner loop is reverse-transformed from the synchronous rotating dq coordinate system to the three-phase stationary abc coordinate system to obtain the three-phase target modulation voltage. The three-phase modulation voltage is then sent to the PWM modulation unit. By comparing the amplitude with the carrier waveform and performing logic matching, a multi-channel pulse drive modulation signal is generated, which in turn drives the power switching devices of the grid-connected converter to complete the on / off control.

[0056] In this embodiment, coordinate transformation is completed by controlling the phase angle in real time, which can ensure that the voltage command phase is always accurately synchronized with the grid under different grid strengths, effectively suppressing power oscillation and grid-connected phase mismatch problems. By generating drive signals through PWM modulation, the amplitude and phase characteristics of the voltage reference command can be accurately replicated, optimizing the output power waveform quality, while realizing smooth and controllable adjustment of the converter output power, greatly improving the system's grid-connected operation stability and dynamic response capability under strong and weak grid conditions.

[0057] As a preferred embodiment, the method further includes: A simulation model of the converter grid-connected system is established, and a disturbance signal is set for the simulation model; Based on the disturbance signal, several simulated short-circuit ratios are generated, and under these simulated short-circuit ratios, a simulation model of the grid-connected system of the modulated signal-controlled converter is generated, and the control performance is verified.

[0058] In this embodiment, as an example, a system can be built using SIMULINK in MATLAB. Figure 4 The system simulation model shown employs the hybrid control strategy of this invention for grid-connected converters used in new energy power generation, applicable to a wide short-circuit ratio range. The active power reference value is set at... t A step change occurs at 1s as a disturbance signal. The hybrid control strategy of this invention, applicable to a wide short-circuit ratio range for grid-connected converters of new energy power generation, is used for example tests under short-circuit ratio (SCR) conditions of 1, 10, and 50. The grid-connected point voltage, angular frequency, and active power response waveforms for SCRs of 1, 10, and 50 are as follows: Figure 5 , Figure 6 and Figure 7 As shown in the figures above, the control strategy proposed in this invention maintains good stability even under extremely weak power grids with a short-circuit ratio of 1 and extremely strong power grids with a short-circuit ratio of 50.

[0059] Example 3 Please see Figure 4 The present invention also provides a control device for a grid-connected converter for new energy power generation, comprising: a control loop module and a line module.

[0060] The control loop module is used to execute the new energy power generation grid-connected converter control method as described in any of the above embodiments.

[0061] The line module includes: a converter, a grid connection point, a capacitor, a first resistor-inductor module, and a second resistor-inductor module.

[0062] As a preferred embodiment, the control loop module includes: The first unit is used to calculate the control phase angle based on the proportional coefficient through a hybrid synchronous control loop; The second unit is used to adaptively adjust the first weight allocation coefficient between the grid-type phase-locked loop control component and the grid-type power synchronization control component in the hybrid synchronization control loop according to the short-circuit ratio. The third unit is used to perform weighted fusion of the first synchronization signal output by the grid-type phase-locked loop control component and the second synchronization signal output by the grid-type power synchronization control component based on the adjusted first weight allocation coefficient to obtain the target synchronization signal, and to calculate the control phase angle based on the target synchronization signal. The fourth unit is used to obtain the preset second weight allocation coefficient, and according to the second weight allocation coefficient, to perform weighted fusion of the grid-type constant power control component and the grid-type constant voltage control component in the hybrid voltage outer loop, and to calculate the current reference value. The fifth unit is used to perform coordinate transformation on the voltage reference value based on the control phase angle; The sixth unit is used to generate a modulation signal to control the converter based on the voltage reference value after coordinate transformation.

[0063] As a preferred embodiment, the voltage components include a d-axis voltage component and a q-axis voltage component, and the current components include a d-axis current component and a q-axis current component; the step of calculating the impedance of the strain gauge based on the voltage and current components, and calculating the short-circuit ratio based on the impedance, specifically includes: The impedance of the power grid is calculated based on the d-axis voltage component and q-axis voltage component, as well as the d-axis current component and q-axis current component. Based on the impedance, combined with the effective value of the grid voltage and the preset impedance angle, the short-circuit capacity is calculated. Based on the short-circuit capacity and the active power at the grid connection point, the short-circuit ratio is calculated.

[0064] As a preferred embodiment, the first weight allocation coefficient between the grid-type phase-locked loop control component and the grid-type power synchronization control component in the hybrid synchronization control loop, based on the short-circuit ratio, specifically includes: The value of the first weight allocation coefficient is determined based on the short-circuit ratio and in conjunction with the first preset threshold. The first weight allocation coefficient is used to allocate the first weight value of the grid-type phase-locked loop control component and the second weight value of the grid-type power synchronization control component, wherein the sum of the first weight value and the second weight value is 1.

[0065] As a preferred embodiment, the step of weighting and fusing the first synchronization signal output by the grid-type phase-locked loop control component and the second synchronization signal output by the grid-type power synchronization control component based on the adjusted first weight allocation coefficient to obtain a target synchronization signal, and calculating the control phase angle based on the target synchronization signal, specifically includes: The first synchronization signal is weighted according to the first weight value to obtain the first weighted signal; The second synchronization signal is weighted according to the second weight value to obtain the second weighted signal; The first weighted signal and the second weighted signal are superimposed to obtain the target synchronization signal; The angular frequency is determined based on the target synchronization signal, and the angular frequency is integrated to obtain the control phase angle.

[0066] As a preferred embodiment, the step of weighting and fusing the grid-based constant power control component and the grid-based constant voltage control component in the hybrid voltage outer loop according to the second weight allocation coefficient to calculate the current reference value specifically includes: Based on the second weight allocation coefficient, determine the third weight value corresponding to the grid-type constant power control component and the fourth weight value corresponding to the grid-type constant voltage control component; The first voltage regulation signal output by the grid-type constant power control component is weighted according to the third weight value to obtain the third weighted signal; The second voltage adjustment signal output by the network-type constant voltage control component is weighted according to the fourth weight value to obtain the fourth weighted signal; The third weighted signal and the fourth weighted signal are superimposed to obtain the target voltage adjustment signal; The current reference value is calculated based on the target voltage adjustment signal.

[0067] As a preferred embodiment, the step of performing PI control on the inner current loop using the current reference value and calculating the voltage reference value specifically includes: Using the current reference value as input, PI control is performed on the inner current loop to obtain the second PI control parameter in the control process. Based on the second PI control parameters, combined with the converter-side current component and current reference value, the voltage reference value is calculated.

[0068] As a preferred embodiment, the step of performing coordinate transformation on the voltage reference value based on the control phase angle, and generating a modulation signal to control the converter based on the coordinate-transformed voltage reference value, specifically includes: Based on the control phase angle, the voltage reference value is transformed from the dq coordinate system to the abc coordinate system to obtain the target modulation voltage; The target modulation voltage is input to the PWM modulation unit to generate a modulation signal, and the converter is controlled based on the modulation signal.

[0069] As a preferred option, the method also includes: A simulation model of the converter grid-connected system is established, and a disturbance signal is set for the simulation model; Based on the disturbance signal, several simulated short-circuit ratios are generated, and under these simulated short-circuit ratios, a simulation model of the grid-connected system of the modulated signal-controlled converter is generated, and the control performance is verified.

[0070] In a preferred embodiment, the converter, the first resistor-inductor module, and the second resistor-inductor module are connected in series; the grid connection point and the capacitor are connected between the first resistor-inductor module and the second resistor-inductor module; the first resistor-inductor module includes a first resistor and a first inductor; the first resistor and the first inductor are connected in series; the second resistor-inductor module includes a second resistor and a second inductor; the second resistor and the second inductor are connected in series.

[0071] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the modules / units described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0072] Implementing the above embodiments has the following effects: The technical solution of this invention obtains the voltage and current components of the converter at the grid connection point, determines the corresponding short-circuit ratio and its corresponding proportional coefficient, and calculates the control phase angle output by the hybrid synchronous control loop, the current reference value output by the hybrid voltage outer loop, and the voltage reference value output by the current inner loop based on the proportional coefficient. Then, after coordinate transformation, the voltage reference value is generated, and a modulation signal is generated to control the converter. This ensures the stability of the converter line even when the short-circuit ratio fluctuates significantly, thus ensuring the safe and stable operation of the new energy grid-connected system. Compared with existing solutions that only use hybrid synchronous control strategies, the method proposed in this invention has a wider short-circuit ratio adaptation range and takes into account the advantages of both grid-following and grid-connected control architectures. The hybrid synchronous control loop adopts a hybrid control method based on adaptive proportional coefficients, and a hybrid control mechanism based on proportional coefficient allocation is introduced in the voltage outer loop to ensure that the overall system can maintain stable operation even when the short-circuit ratio changes significantly.

[0073] Example 4 Accordingly, the present invention also provides a terminal device, comprising: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the new energy power generation grid-connected converter control method as described in any of the above embodiments.

[0074] The terminal device in this embodiment includes a processor, a memory, and a computer program and computer instructions stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps described in Embodiment 1 above, for example... Figure 1 The steps S101 to S105 are shown. Alternatively, when the processor executes the computer program, it implements the functions of each module / unit in the above-described device embodiment.

[0075] For example, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the terminal device.

[0076] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the schematic diagram is merely an example of a terminal device and does not constitute a limitation on the terminal device. It may include more or fewer components than illustrated, or combine certain components, or different components. For example, the terminal device may also include input / output devices, network access devices, buses, etc.

[0077] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0078] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and by calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, applications required for at least one function, etc.; the data storage area may store data created based on the use of the mobile terminal, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, RAM, plug-in hard disk, smart media card (SMC), secure digital card (SD card), flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0079] Wherein, if the modules / units integrated in the terminal device are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by a processor, it can implement the steps of the various method embodiments described above. Wherein, the computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content contained in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0080] Example 5 Accordingly, the present invention also provides a computer-readable storage medium, the computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the new energy power generation grid-connected converter control method as described in any of the above embodiments.

[0081] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A control method for a grid-connected converter for new energy power generation, characterized in that, include: Obtain the voltage and current components of the converter at the grid connection point, and determine the short-circuit ratio based on the voltage and current components; The first weighting coefficient between the grid-type phase-locked loop control component and the grid-type power synchronization control component in the hybrid synchronous control loop is adaptively adjusted according to the short-circuit ratio. Based on the adjusted first weight allocation coefficient, the first synchronization signal output by the grid-type phase-locked loop control component and the second synchronization signal output by the grid-type power synchronization control component are weighted and fused to obtain the target synchronization signal. The control phase angle is then calculated based on the target synchronization signal. Obtain the preset second weight allocation coefficient, and according to the second weight allocation coefficient, perform weighted fusion of the grid-type constant power control component and the grid-type constant voltage control component in the hybrid voltage outer loop to calculate the current reference value; The voltage reference value is calculated by performing PI control on the inner current loop using the current reference value. Based on the control phase angle, the voltage reference value is transformed into coordinates, and based on the voltage reference value after coordinate transformation, a modulation signal is generated to control the converter.

2. The control method for a grid-connected converter for new energy power generation as described in claim 1, characterized in that, The process of acquiring the voltage and current components of the converter at the grid connection point and determining the short-circuit ratio based on these components specifically includes: Obtain the voltage and current of the converter at the grid connection point; The voltage and current are transformed by coordinates to obtain voltage components and current components; The impedance of the strain gauge is calculated based on the voltage and current components, and the short-circuit ratio is calculated based on the impedance.

3. The control method for a grid-connected converter for new energy power generation as described in claim 2, characterized in that, The voltage components include a d-axis voltage component and a q-axis voltage component, and the current components include a d-axis current component and a q-axis current component. The process of calculating the impedance of the strain gauge based on the voltage and current components, and calculating the short-circuit ratio based on the impedance, specifically includes: The impedance of the power grid is calculated based on the d-axis voltage component and q-axis voltage component, as well as the d-axis current component and q-axis current component. Based on the impedance, combined with the effective value of the grid voltage and the preset impedance angle, the short-circuit capacity is calculated. Based on the short-circuit capacity and the active power at the grid connection point, the short-circuit ratio is calculated.

4. The control method for a grid-connected converter for new energy power generation as described in claim 1, characterized in that, The first weighting allocation coefficient between the grid-type phase-locked loop control component and the grid-type power synchronization control component in the hybrid synchronous control loop, based on the short-circuit ratio, specifically includes: The value of the first weight allocation coefficient is determined based on the short-circuit ratio and in conjunction with the first preset threshold. Wherein, the first weight allocation coefficient is used to allocate the first weight value of the grid-type phase-locked loop control component and the second weight value of the grid-type power synchronization control component, and the sum of the first weight value and the second weight value is 1.

5. The control method for a grid-connected converter for new energy power generation as described in claim 4, characterized in that, Based on the adjusted first weight allocation coefficient, the first synchronization signal output by the grid-type phase-locked loop control component and the second synchronization signal output by the grid-type power synchronization control component are weighted and fused to obtain the target synchronization signal. The control phase angle is then calculated based on the target synchronization signal, specifically including: The first synchronization signal is weighted according to the first weight value to obtain the first weighted signal; The second synchronization signal is weighted according to the second weight value to obtain the second weighted signal; The first weighted signal and the second weighted signal are superimposed to obtain the target synchronization signal; The angular frequency is determined based on the target synchronization signal, and the angular frequency is integrated to obtain the control phase angle.

6. The control method for a grid-connected converter for new energy power generation as described in claim 1, characterized in that, The step of weighting and fusing the grid-based constant power control component and the grid-based constant voltage control component in the hybrid voltage outer loop according to the second weighting allocation coefficient, and calculating the current reference value, specifically includes: Based on the second weight allocation coefficient, determine the third weight value corresponding to the grid-type constant power control component and the fourth weight value corresponding to the grid-type constant voltage control component; The first voltage regulation signal output by the grid-type constant power control component is weighted according to the third weight value to obtain the third weighted signal; The second voltage adjustment signal output by the network-type constant voltage control component is weighted according to the fourth weight value to obtain the fourth weighted signal; The third weighted signal and the fourth weighted signal are superimposed to obtain the target voltage adjustment signal; The current reference value is calculated based on the target voltage adjustment signal.

7. The control method for a grid-connected converter for new energy power generation as described in claim 6, characterized in that, The step of performing PI control on the inner current loop using the current reference value and calculating the voltage reference value specifically includes: Using the current reference value as input, PI control is performed on the inner current loop to obtain the second PI control parameter in the control process. Based on the second PI control parameters, combined with the converter-side current component and current reference value, the voltage reference value is calculated.

8. The control method for a grid-connected converter for new energy power generation as described in claim 1, characterized in that, The step of transforming the voltage reference value into coordinates based on the control phase angle, and generating a modulation signal to control the converter based on the transformed voltage reference value, specifically includes: Based on the control phase angle, the voltage reference value is transformed from the dq coordinate system to the abc coordinate system to obtain the target modulation voltage; The target modulation voltage is input to the PWM modulation unit to generate a modulation signal, and the converter is controlled based on the modulation signal.

9. A control device for a grid-connected converter for new energy power generation, characterized in that, include: Control loop module and circuit module; The control loop module is used to execute the new energy power generation grid-connected converter control method as described in any one of claims 1-8; The line module includes: a converter, a grid connection point, a capacitor, a first resistor-inductor module, and a second resistor-inductor module.

10. The new energy power generation grid-connected converter control device as described in claim 9, characterized in that, The control loop module includes: The first unit is used to calculate the control phase angle based on the proportional coefficient through a hybrid synchronous control loop; The second unit is used to adaptively adjust the first weight allocation coefficient between the grid-type phase-locked loop control component and the grid-type power synchronization control component in the hybrid synchronization control loop according to the short-circuit ratio. The third unit is used to perform weighted fusion of the first synchronization signal output by the grid-type phase-locked loop control component and the second synchronization signal output by the grid-type power synchronization control component based on the adjusted first weight allocation coefficient to obtain the target synchronization signal, and to calculate the control phase angle based on the target synchronization signal. The fourth unit is used to obtain the preset second weight allocation coefficient, and according to the second weight allocation coefficient, to perform weighted fusion of the grid-type constant power control component and the grid-type constant voltage control component in the hybrid voltage outer loop, and to calculate the current reference value. The fifth unit is used to perform coordinate transformation on the voltage reference value based on the control phase angle; The sixth unit is used to generate a modulation signal to control the converter based on the voltage reference value after coordinate transformation.

11. The new energy power generation grid-connected converter control device as described in claim 9, characterized in that, The converter, the first resistor-inductor module, and the second resistor-inductor module are connected in series in sequence. The grid connection point and capacitor are connected between the first resistor-inductor module and the second resistor-inductor module; The first resistor-inductor module includes: a first resistor and a first inductor; the first resistor and the first inductor are connected in series; The second resistor-inductor module includes: a second resistor and a second inductor; the second resistor and the second inductor are connected in series.

12. A terminal device, characterized in that, The method includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor executes the computer program to implement the new energy power generation grid-connected converter control method as described in any one of claims 1 to 8.

13. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to perform the new energy power generation grid-connected converter control method as described in any one of claims 1 to 8.

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