Method and device for suppressing transient overvoltage of new energy inverter

Abstract

The invention provides a new energy inverter transient overvoltage suppression method and device, and the method comprises the steps: calculating a first voltage reference value of a virtual node, determining a modulation voltage component under a two-phase rotating coordinate system according to the first voltage reference value and an adaptive variable adjustment coefficient, and carrying out the suppression of the transient overvoltage of a new energy inverter. It can be seen that under the condition that transient overvoltage occurs, the suppression method provided by the invention can reduce the modulation voltage component through the self-adaptive variable adjustment coefficient, so that suppression of the transient overvoltage is realized through the modulation voltage component, and the reliability of suppression of the transient overvoltage is improved. The adaptive variable adjustment coefficient can be calculated according to the terminal voltage of the new energy inverter. When transient overvoltage occurs, the self-adaptive variable adjustment coefficient can be reduced, and the second voltage reference value of the virtual node can be reduced, so that the suppression of the bridge arm voltage can be realized, and finally, the suppression of the transient overvoltage can be reliably realized.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a method and device for suppressing transient overvoltage of a new energy inverter. Background Art

[0002] In order to compensate for the reactive power consumed by new energy stations and their transmission lines, a large number of reactive power compensation equipment are usually installed in new energy stations, collection areas, DC converter stations and other locations. However, after an AC short circuit fault, DC commutation failure or DC lockout occurs in the power grid, the reactive power compensation equipment cannot be withdrawn in time and injects excess reactive power into the power grid, causing the power grid voltage to overvoltage. At the moment of fault occurrence and clearing, electrical quantities such as voltage and current suddenly change, causing the new energy controller to output a higher modulation voltage, causing transient overvoltage in the new energy inverter. Transient overvoltage can cause new energy units to disconnect from the grid, so the transient overvoltage problem has become a major factor restricting the development of new energy.

[0003] In order to suppress the transient overvoltage of the new energy inverter, the suppression method provided by the related art usually reduces the reactive current reference value during the low voltage ride-through period to speed up the inverter reactive fallback speed, but the reduction of the reactive current reference value will affect the voltage support performance during the low voltage ride-through period. In addition, even if the new energy inverter does not output current at all during the fault period, transient overvoltage may still occur. Therefore, the suppression method provided by the related art has low reliability in suppressing transient overvoltage. Summary of the invention

[0004] In order to solve the problem of low suppression reliability in the prior art, the present application provides a method for suppressing transient overvoltage of a new energy inverter, which may include:

[0005] The first voltage reference value of the virtual node is calculated according to the three-phase terminal current of the new energy inverter and the current reference value in the two-phase rotating coordinate system. The modulation voltage component in the two-phase rotating coordinate system is determined according to the first voltage reference value and the adaptive variable adjustment coefficient. The transient overvoltage of the new energy inverter is suppressed according to the modulation voltage component.

[0006] In some possible implementations, calculating the first voltage reference value of the virtual node according to the three-phase terminal current of the new energy inverter and the current reference value in the two-phase rotating coordinate system includes:

[0007] The three-phase terminal current of the new energy inverter is subjected to Park transformation to obtain the d-axis current component and the q-axis current component of the new energy inverter in a two-phase rotating coordinate system.

[0008] The d-axis current component is current controlled according to the d-axis current reference value in the two-phase rotating coordinate system to obtain a d-axis first voltage reference value of the virtual node.

[0009] The q-axis current component is current controlled according to the q-axis current reference value in the two-phase rotating coordinate system to obtain a q-axis first voltage reference value of the virtual node.

[0010] Exemplarily, the d-axis first voltage reference value and the q-axis first voltage reference value satisfy:

[0011]

[0012] Among them, u vdref1 Indicates the first voltage reference value of the d-axis, u vqref1 Represents the first voltage reference value of the q axis. dref Indicates the d-axis current reference value, i qref Indicates the q-axis current reference value. d represents the d-axis current component, i q Represents the q-axis current component. K p_Gi Represents the first proportionality coefficient, K i_Gi Represents the first integral coefficient, K d represents the decoupling coefficient, H i represents the current feedback coefficient, and s represents a complex variable.

[0013] In some other possible implementations, determining a modulation voltage component in a two-phase rotating coordinate system according to a first voltage reference value and an adaptive variable adjustment coefficient includes:

[0014] The adaptive variable adjustment coefficient is calculated according to the terminal voltage of the new energy inverter.

[0015] The three-phase voltage of the virtual node is subjected to Park transformation to obtain the voltage component of the virtual node.

[0016] The voltage component of the virtual node is controlled according to the adaptive variable adjustment coefficient to obtain a modulated voltage component.

[0017] Optionally, the adaptive variable adjustment coefficient satisfies:

[0018] K uv =1-K down (H u u term -u HV )

[0019] Among them, K uv Represents the adaptive variable adjustment coefficient, K down Represents the decreasing slope of the adaptive variable adjustment coefficient, u term Indicates terminal voltage, u HV Indicates the preset start threshold. u Represents the voltage feedback coefficient. Satisfying K uvmin ≤K uv ≤Kuvmax , K uvmin Represents the lower limit of the adaptive variable adjustment coefficient, K uvmax Indicates the upper limit of the adaptive variable adjustment coefficient.

[0020] Furthermore, the voltage component of the virtual node is controlled according to the adaptive variable adjustment coefficient to obtain a modulated voltage component, including:

[0021] The adaptive variable adjustment coefficient is multiplied by the d-axis first voltage reference value to obtain the d-axis second voltage reference value of the virtual node, and the adaptive variable adjustment coefficient is multiplied by the q-axis first voltage reference value to obtain the q-axis second voltage reference value of the virtual node.

[0022] The d-axis voltage component of the virtual node is voltage-controlled according to the d-axis second voltage reference value to obtain the d-axis modulated voltage component, and the q-axis voltage component of the virtual node is voltage-controlled according to the q-axis second voltage reference value to obtain the q-axis modulated voltage component.

[0023] Optionally, the modulation voltage component satisfies:

[0024]

[0025] Among them, u md represents the d-axis modulation voltage component, u mq represents the q-axis modulation voltage component. vdref represents the d-axis second voltage reference value of the virtual node, u vqref Indicates the q-axis second voltage reference value of the virtual node. vd represents the d-axis voltage component of the virtual node, u vq K represents the q-axis voltage component of the virtual node. p_Gu Represents the second proportionality coefficient, K i_Gu represents the second integral coefficient, H u represents the voltage feedback coefficient, and s represents a complex variable.

[0026] In some other possible implementations, the transient overvoltage of the new energy inverter is suppressed according to the modulation voltage component, including:

[0027] The modulation voltage components in the two-phase rotating coordinate system are subjected to Park transformation to obtain the three-phase modulation voltage of the new energy inverter.

[0028] The three-phase modulation voltage is modulated to obtain a driving signal.

[0029] Transient overvoltage is suppressed according to the driving signal.

[0030] On the other hand, the present application provides a device for suppressing transient overvoltage of a new energy inverter, comprising:

[0031] The calculation module is used to calculate the first voltage reference value of the virtual node according to the three-phase terminal current of the new energy inverter and the current reference value in the two-phase rotating coordinate system.

[0032] The determination module is used to determine the modulation voltage component in the two-phase rotating coordinate system according to the first voltage reference value and the adaptive variable adjustment coefficient.

[0033] The suppression module is used to suppress the transient overvoltage of the new energy inverter according to the modulation voltage component.

[0034] In some possible implementations, the computing module is specifically used to:

[0035] The three-phase terminal current of the new energy inverter is subjected to Park transformation to obtain the d-axis current component and the q-axis current component of the new energy inverter in a two-phase rotating coordinate system.

[0036] The d-axis current component is current controlled according to the d-axis current reference value in the two-phase rotating coordinate system to obtain a d-axis first voltage reference value of the virtual node.

[0037] The q-axis current component is current controlled according to the q-axis current reference value in the two-phase rotating coordinate system to obtain a q-axis first voltage reference value of the virtual node.

[0038] Optionally, the d-axis first voltage reference value and the q-axis first voltage reference value satisfy:

[0039]

[0040] Among them, u vdref1 Indicates the first voltage reference value of the d-axis, u vqref1 Represents the first voltage reference value of the q axis. dref Indicates the d-axis current reference value, i qref Indicates the q-axis current reference value. d represents the d-axis current component, i q Represents the q-axis current component. K p_Gi Represents the first proportionality coefficient, K i_Gi Represents the first integral coefficient, K d represents the decoupling coefficient, H i represents the current feedback coefficient, and s represents a complex variable.

[0041] Furthermore, the module is specifically used to:

[0042] The adaptive variable adjustment coefficient is calculated according to the terminal voltage of the new energy inverter.

[0043] The three-phase voltage of the virtual node is subjected to Park transformation to obtain the voltage component of the virtual node.

[0044] The voltage component of the virtual node is controlled according to the adaptive variable adjustment coefficient to obtain a modulated voltage component.

[0045] Exemplarily, the adaptive variable adjustment coefficient satisfies:

[0046] K uv =1-K down (H u u term -u HV )

[0047] Among them, K uv Represents the adaptive variable adjustment coefficient, K down Represents the decreasing slope of the adaptive variable adjustment coefficient, u term Indicates terminal voltage, u HV Indicates the preset start threshold. u Represents the voltage feedback coefficient. Satisfying K uvmin ≤K uv ≤K uvmax , K uvmin Represents the lower limit of the adaptive variable adjustment coefficient, K uvmax Indicates the upper limit of the adaptive variable adjustment coefficient.

[0048] In some other possible implementations, the determination module is specifically used to:

[0049] The adaptive variable adjustment coefficient is multiplied by the d-axis first voltage reference value to obtain the d-axis second voltage reference value of the virtual node, and the adaptive variable adjustment coefficient is multiplied by the q-axis first voltage reference value to obtain the q-axis second voltage reference value of the virtual node.

[0050] The d-axis voltage component of the virtual node is voltage-controlled according to the d-axis second voltage reference value to obtain the d-axis modulated voltage component, and the q-axis voltage component of the virtual node is voltage-controlled according to the q-axis second voltage reference value to obtain the q-axis modulated voltage component.

[0051] Optionally, the modulation voltage component satisfies:

[0052]

[0053] Among them, u md represents the d-axis modulation voltage component, u mq represents the q-axis modulation voltage component. vdref represents the d-axis second voltage reference value of the virtual node, u vqref Indicates the q-axis second voltage reference value of the virtual node. vd represents the d-axis voltage component of the virtual node, u vq K represents the q-axis voltage component of the virtual node. p_GuRepresents the second proportionality coefficient, K i_Gu represents the second integral coefficient, H u represents the voltage feedback coefficient, and s represents a complex variable.

[0054] In some further possible implementations, the suppression module is used to:

[0055] The modulation voltage components in the two-phase rotating coordinate system are subjected to Park transformation to obtain the three-phase modulation voltage of the new energy inverter.

[0056] The three-phase modulation voltage is modulated to obtain a driving signal.

[0057] Transient overvoltage is suppressed according to the driving signal.

[0058] On the other hand, the present application also provides a computer device, including: one or more processors.

[0059] A processor is used to execute one or more programs.

[0060] When one or more programs are executed by one or more processors, the suppression method as described above is implemented.

[0061] In another aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, the above-mentioned suppression method is implemented.

[0062] Compared with the prior art, the beneficial effects of this application are:

[0063] In the method for suppressing transient overvoltage of a new energy inverter provided in the present application, a first voltage reference value of a virtual node is calculated based on the three-phase terminal current of the new energy inverter and the current reference value in a two-phase rotating coordinate system. The modulation voltage component in the two-phase rotating coordinate system is determined based on the first voltage reference value and the adaptive variable adjustment coefficient. The transient overvoltage of the new energy inverter is suppressed based on the modulation voltage component. It can be seen that in the event of a transient overvoltage, the modulation voltage component can be reduced by an adaptive variable adjustment coefficient, and then the transient overvoltage is suppressed by the modulation voltage component, thereby improving the reliability of suppressing the transient overvoltage.

[0064] The present application can calculate the adaptive variable adjustment coefficient according to the terminal voltage of the new energy inverter. In the event of transient overvoltage, the adaptive variable adjustment coefficient will decrease, which will reduce the second voltage reference value of the virtual node, thereby suppressing the bridge arm voltage and finally reliably suppressing the transient overvoltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0066] Figure 1 A schematic flow chart of a method for suppressing transient overvoltage of a new energy inverter in an embodiment of the present application;

[0067] Figure 2 Another schematic flow chart of a method for suppressing transient overvoltage of a new energy inverter in an embodiment of the present application;

[0068] Figure 3 A schematic diagram of the relationship between the adaptive variable adjustment coefficient and the terminal voltage of the new energy inverter in the embodiment of the present application;

[0069] Figure 4 It is a schematic diagram of the terminal voltage, active current and reactive current waveforms of the new energy inverter when the adaptive variable adjustment coefficient is not introduced in the related art;

[0070] Figure 5 A schematic diagram of the terminal voltage, active current and reactive current waveforms of the new energy inverter when an adaptive variable adjustment coefficient is introduced in an embodiment of the present application;

[0071] Figure 6 This is a schematic structural diagram of a device for suppressing transient overvoltage of a new energy inverter in an embodiment of the present application. DETAILED DESCRIPTION

[0072] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0073] The terms "first", "second", etc. in the specification embodiments, claims, and drawings of the present application are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, including a series of steps or units. The method, system, product, or device is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0074] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0075] Embodiment 1:

[0076] The present application embodiment provides a method for suppressing transient overvoltage of a new energy inverter, such as Figure 1 The suppression method 100 comprises the following steps:

[0077] Step S1: According to the three-phase terminal current of the new energy inverter (which can be used as i a 、i b 、i c The current reference value in the two-phase rotating coordinate system (which can be represented by i dref 、i qref ) calculates the first voltage reference value of the virtual node (including the d-axis first voltage reference value u of the virtual node vdref1 and the q-axis first voltage reference value u of the virtual node vqref1 ).

[0078] Step S2: According to the first voltage reference value (i.e. u vdref1 and u vqref1 ) and adaptive variable adjustment coefficient (which can be used with K uv Determine the modulation voltage component (d-axis modulation voltage component u) in the two-phase rotating coordinate system md and the q-axis modulation voltage component u mq ).

[0079] Step S3: According to the modulation voltage component (i.e. u md and u mq )Suppress the transient overvoltage of new energy inverters.

[0080] In some possible implementations, in step S1, according to the three-phase terminal current i of the new energy inverter a 、i b 、i c and the current reference value i in the two-phase rotating coordinate systemdref 、i qref Calculate the first voltage reference value u of the virtual node vdref1 、u vqref1 ,include:

[0081] The three-phase terminal current i of the new energy inverter a 、i b 、i c Perform Park transformation to obtain the d-axis current component i of the new energy inverter in the two-phase rotating coordinate system. d and the q-axis current component i q .

[0082] like Figure 2 As shown, according to the d-axis current reference value i in the two-phase rotating coordinate system dref For the d-axis current component i d Perform current control to obtain the d-axis first voltage reference value u of the virtual node vdref1 It can also be understood that the d-axis current reference value i in the two-phase rotating coordinate system is dref and the d-axis current component i d Input current controller, the current controller can output the d-axis first voltage reference value u of the virtual node vdref1 . Figure 2 In, G i (s) represents a current controller.

[0083] According to the q-axis current reference value i in the two-phase rotating coordinate system qref For the q-axis current component i q Perform current control to obtain the q-axis first voltage reference value u of the virtual node vqref1 It can also be understood that the q-axis current reference value i in the two-phase rotating coordinate system is qref and the q-axis current component i q Input current controller, the current controller can output the d-axis first voltage reference value u of the virtual node vdref1 .

[0084] Exemplarily, the d-axis first voltage reference value u vdref1 and the q-axis first voltage reference value u vqref1 satisfy:

[0085]

[0086] Among them, u vdref1 Indicates the first voltage reference value of the d-axis, u vqref1 Represents the first voltage reference value of the q axis. dref Indicates the d-axis current reference value, i qref Indicates the q-axis current reference value. drepresents the d-axis current component, i q Represents the q-axis current component. K p_Gi represents the first proportionality coefficient, that is, the proportionality coefficient of the current controller, K i_Gi Represents the first integral coefficient, that is, the integral coefficient of the current controller. K d represents the decoupling coefficient, H i represents the current feedback coefficient, and s represents a complex variable.

[0087] In some other possible implementations, in step S2, according to the first voltage reference value u vdref1 、u vqref1 and adaptive variable adjustment coefficient K uv Determine the modulation voltage component u in the two-phase rotating coordinate system md 、u mq ,include:

[0088] like Figure 2 As shown, according to the terminal voltage of the new energy inverter (can be used term Indicates that through Figure 2 Three-phase terminal voltage u of new energy inverter ta 、u tb 、u tc Calculate the adaptive variable adjustment coefficient K uv .

[0089] The three-phase voltage of the virtual node (can be used va 、u vb 、u vc ) to perform Park transformation and obtain the voltage component of the virtual node (which can be obtained by u vd 、u vq express).

[0090] According to the adaptive variable adjustment coefficient K uv The voltage component u of the virtual node vd 、u vq Perform voltage control to obtain the d-axis modulation voltage component u md and the q-axis modulation voltage component u mq .

[0091] Optional, adaptive variable adjustment coefficient K uv satisfy:

[0092] K uv =1-K down (H u u term -u HV )

[0093] Among them, K downIndicates the decreasing slope of the adaptive variable adjustment coefficient, according to the terminal voltage u term When the sudden increase is 1.3pu, K uv The parameter design is carried out with the requirement of decreasing to 0.8, K down It can be 1. HV Indicates the preset startup threshold, which can be 1.1pu. u Represents the voltage feedback coefficient. Satisfying K uvmin ≤K uv ≤K uvmax . K uvmin Represents the lower limit of the adaptive variable adjustment coefficient, which can be 0.7. uvmax Represents the upper limit of the adaptive variable adjustment coefficient, which can be 1.

[0094] Adaptive variable adjustment coefficient K uv With the terminal voltage u term If the terminal voltage u term Below the start threshold u HV , then the adaptive variable adjustment coefficient K uv Keep it at 1 to lock the voltage regulation function. When transient overvoltage occurs, the adaptive variable regulation coefficient K uv Automatically decreases, and the terminal voltage u term The larger the adaptive variable adjustment coefficient K is, the uv The smaller the value, the relationship between the adaptive variable adjustment coefficient and the terminal voltage of the new energy inverter is as follows: Figure 3 shown.

[0095] Furthermore, according to the adaptive variable adjustment coefficient K uv The voltage component u of the virtual node vd 、u vq Perform voltage control to obtain the d-axis modulation voltage component u md and the q-axis modulation voltage component u mq ,include:

[0096] like Figure 2 As shown, the adaptive variable adjustment coefficient K uv and the d-axis first voltage reference value (can be vdref1 The d-axis second voltage reference value of the virtual node can be obtained by multiplying vdref denoted), and the adaptive variable adjustment coefficient K uv and the q-axis first voltage reference value (can be vqref1 The q-axis second voltage reference value of the virtual node (which can be expressed by u vqref denoted). That is, u vdref =K uv u vdref1 ,u vqref=K uv u vqref1 .

[0097] According to the d-axis second voltage reference value u vdref For the d-axis voltage component of the virtual node (which can be expressed by u vd The voltage is controlled by the d-axis modulation voltage component u md , and according to the q-axis second voltage reference value u vqref The q-axis voltage component of the virtual node (can be expressed as u vq The voltage is controlled by the q-axis modulation voltage component u mq It can also be understood that the d-axis second voltage reference value u vdref and the d-axis voltage component u of the virtual node vd Input voltage controller, the voltage controller can output d-axis modulation voltage component u md Similarly, the q-axis second voltage reference value u vqref and the q-axis voltage component u of the virtual node vq Input voltage controller, the voltage controller can output q-axis modulation voltage component u mq . Figure 2 In, G u (s) represents a voltage controller.

[0098] Optionally, the modulation voltage component satisfies:

[0099]

[0100] Among them, u md represents the d-axis modulation voltage component, u mq represents the q-axis modulation voltage component. vdref represents the d-axis second voltage reference value of the virtual node, u vqref Indicates the q-axis second voltage reference value of the virtual node. vd represents the d-axis voltage component of the virtual node, u vq K represents the q-axis voltage component of the virtual node. p_Gu Represents the second proportional coefficient, that is, the proportional coefficient of the voltage controller. K i_Gu Represents the second integral coefficient, that is, the integral coefficient of the voltage controller. u represents the voltage feedback coefficient, and s represents a complex variable.

[0101] In some other possible implementations, in step S3, according to the modulation voltage component u md 、u mq Suppress transient overvoltage of new energy inverters, including:

[0102] like Figure 2As shown, according to the phase θ of the new energy inverter, the modulation voltage component u in the two-phase rotating coordinate system is md 、u mq Perform Park transformation to obtain the three-phase modulation voltage u of the new energy inverter ma 、u mb 、u mc .

[0103] The three-phase modulation voltage u ma 、u mb 、u mc Modulation (such as sinusoidal pulse width modulation, ie, SPWM modulation) is performed to obtain a driving signal DS.

[0104] The transient overvoltage is suppressed according to the driving signal DS. It can be imagined that the inverter bridge of the new energy inverter is controlled according to the driving signal DS, and the semiconductor devices of the bridge arm in the inverter bridge will act accordingly to achieve the bridge arm voltage (i.e. Figure 2 u inva 、u invb 、u invc ) to achieve the suppression of transient overvoltage.

[0105] refer to Figure 2 The new energy inverter in the embodiment of the present application may include an inverter bridge 1 and a filter module 2. The filter module 2 may include an inductor L1, an inductor L2 and a capacitor C. Figure 2 in, u s Indicates the voltage of the power grid, L s Represents the impedance of the power grid.

[0106] The suppression effect of the method for suppressing power frequency overvoltage of the new energy inverter provided in the embodiment of the present application is verified below. Figure 4 The terminal voltage u of the new energy inverter is shown when the adaptive variable voltage regulation coefficient is not introduced. term , active current i P and reactive current i Q Waveform. Figure 4 In the figure, the horizontal axis represents time t. Figure 4 It can be seen that at the moment of fault clearing, the terminal voltage u term The peak value is as high as 1.42pu. Figure 5 The terminal voltage u of the new energy inverter after the introduction of the adaptive variable voltage regulation coefficient is shown. term , active current i P and reactive current i Q Waveform. Figure 5 In the figure, the horizontal axis represents time t. Figure 5 It can be seen that by lowering the voltage of the virtual node, the transient overvoltage can be quickly suppressed, and the terminal voltage u termThe peak value is limited to 1.32pu, and the peak value is reduced by 0.1pu, and the transient overvoltage suppression effect is significant. Figure 4 and Figure 5 It can be found that the introduction of adaptive variable voltage regulation coefficient can significantly reduce the terminal voltage of the new energy inverter and has a good suppression effect on transient overvoltage.

[0107] Embodiment 2:

[0108] Based on the same inventive concept, the embodiment of the present application also provides a device for suppressing transient overvoltage of a new energy inverter, such as Figure 6 As shown. The suppression device 200 comprises:

[0109] The calculation module 21 is used to calculate the three-phase terminal current of the new energy inverter (which can be calculated using i a 、i b 、i c The current reference value in the two-phase rotating coordinate system (which can be represented by i dref 、i qref ) calculates the first voltage reference value of the virtual node (including the d-axis first voltage reference value u of the virtual node vdref1 and the q-axis first voltage reference value u of the virtual node vqref1 ).

[0110] The determination module 22 is used to determine the voltage according to the first voltage reference value (i.e., u vdref1 and u vqref1 ) and adaptive variable adjustment coefficient (which can be used with K uv Determine the modulation voltage component (d-axis modulation voltage component u) in the two-phase rotating coordinate system md and the q-axis modulation voltage component u mq ).

[0111] The suppression module 23 is used to suppress the voltage component (i.e., u md and u mq )Suppress the transient overvoltage of new energy inverters.

[0112] In some possible implementations, the calculation module 21 is specifically used to:

[0113] The three-phase terminal current i of the new energy inverter a 、i b 、i c Perform Park transformation to obtain the d-axis current component i of the new energy inverter in the two-phase rotating coordinate system. d and the q-axis current component i q .

[0114] like Figure 2As shown, according to the d-axis current reference value i in the two-phase rotating coordinate system dref For the d-axis current component i d Perform current control to obtain the d-axis first voltage reference value u of the virtual node vdref1 It can also be understood that the d-axis current reference value i in the two-phase rotating coordinate system is dref and the d-axis current component i d Input current controller, the current controller can output the d-axis first voltage reference value u of the virtual node vdref1 . Figure 2 In, G i (s) represents a current controller.

[0115] According to the q-axis current reference value i in the two-phase rotating coordinate system qref For the q-axis current component i q Perform current control to obtain the q-axis first voltage reference value u of the virtual node vqref1 It can also be understood that the q-axis current reference value i in the two-phase rotating coordinate system is qref and the q-axis current component i q Input current controller, the current controller can output the d-axis first voltage reference value u of the virtual node vdref1 .

[0116] Optionally, the d-axis first voltage reference value and the q-axis first voltage reference value satisfy:

[0117]

[0118] Among them, u vdref1 Indicates the first voltage reference value of the d-axis, u vqref1 Represents the first voltage reference value of the q axis. dref Indicates the d-axis current reference value, i qref Indicates the q-axis current reference value. d represents the d-axis current component, i q Represents the q-axis current component. K p_Gi Represents the first proportional coefficient, that is, the proportional coefficient of the current controller, K i_Gi Represents the first integral coefficient, that is, the integral coefficient of the current controller. K d represents the decoupling coefficient, H i represents the current feedback coefficient, and s represents a complex variable.

[0119] Furthermore, the determination module 22 is specifically used for:

[0120] like Figure 2 As shown, according to the terminal voltage of the new energy inverter (can be used term Indicates that, including the A phase terminal voltage u ta 、B phase terminal voltage utb 、C phase terminal voltage u tc ) Calculate the adaptive variable adjustment coefficient K uv .

[0121] The three-phase voltage of the virtual node (can be used va 、u vb 、u vc ) to perform Park transformation and obtain the voltage component of the virtual node (which can be obtained by u vd 、u vq express).

[0122] According to the adaptive variable adjustment coefficient K uv The voltage component u of the virtual node vd 、u vq Perform voltage control to obtain the d-axis modulation voltage component u md and the q-axis modulation voltage component u mq .

[0123] Exemplarily, the adaptive variable adjustment coefficient satisfies:

[0124] K uv =1-K down (H u u term -u HV )

[0125] Among them, K down Indicates the decreasing slope of the adaptive variable adjustment coefficient, according to the terminal voltage u term When the sudden increase is 1.3pu, K uv The parameter design is carried out with the requirement of decreasing to 0.8, K down It can be 1. HV Indicates the preset startup threshold, which can be 1.1pu. u Represents the voltage feedback coefficient. Satisfying K uvmin ≤K uv ≤K uvmax . K uvmin Represents the lower limit of the adaptive variable adjustment coefficient, which can be 0.7. uvmax Represents the upper limit of the adaptive variable adjustment coefficient, which can be 1.

[0126] Adaptive variable adjustment coefficient K uv With the terminal voltage u term If the terminal voltage u term Below the start threshold u HV , then the adaptive variable adjustment coefficient K uv Keep it at 1 to lock the voltage regulation function. When transient overvoltage occurs, the adaptive variable regulation coefficient K uv Automatically decreases, and the terminal voltage uterm The larger the adaptive variable adjustment coefficient K is, the uv The smaller the value, the relationship between the adaptive variable adjustment coefficient and the terminal voltage of the new energy inverter is as follows: Figure 3 shown.

[0127] In some other possible implementations, the determination module 22 is specifically configured to:

[0128] like Figure 2 As shown, the adaptive variable adjustment coefficient K uv and the d-axis first voltage reference value (can be vdref1 The d-axis second voltage reference value of the virtual node can be obtained by multiplying vdref denoted), and the adaptive variable adjustment coefficient K uv and the q-axis first voltage reference value (can be vqref1 The q-axis second voltage reference value of the virtual node (which can be expressed by u vqref denoted by ). That is, u vdref =K uv u vdref1 ,u vqref =K uv u vqref1 .

[0129] According to the d-axis second voltage reference value u vdref For the d-axis voltage component of the virtual node (which can be expressed by u vd The voltage is controlled by the d-axis modulation voltage component u md , and according to the q-axis second voltage reference value u vqref The q-axis voltage component of the virtual node (can be expressed as u vq The voltage is controlled by the q-axis modulation voltage component u mq It can also be understood that the d-axis second voltage reference value u vdref and the d-axis voltage component u of the virtual node vd Input voltage controller, the voltage controller can output d-axis modulation voltage component u md Similarly, the q-axis second voltage reference value u vqref and the q-axis voltage component u of the virtual node vq Input voltage controller, the voltage controller can output q-axis modulation voltage component u mq . Figure 2 In, G u (s) represents a voltage controller.

[0130] Optionally, the modulation voltage component satisfies:

[0131]

[0132] Among them, u md represents the d-axis modulation voltage component, u mq represents the q-axis modulation voltage component. vdref represents the d-axis second voltage reference value of the virtual node, u vqref Indicates the q-axis second voltage reference value of the virtual node. vd represents the d-axis voltage component of the virtual node, u vq K represents the q-axis voltage component of the virtual node. p_Gu Represents the second proportional coefficient, that is, the proportional coefficient of the voltage controller. K i_Gu Represents the second integral coefficient, that is, the integral coefficient of the voltage controller. u represents the voltage feedback coefficient, and s represents a complex variable.

[0133] In some further possible implementations, the suppression module 23 is used to:

[0134] like Figure 2 As shown, according to the phase θ of the new energy inverter, the modulation voltage component u in the two-phase rotating coordinate system is md 、u mq Perform Park transformation to obtain the three-phase modulation voltage u of the new energy inverter ma 、u mb 、u mc .

[0135] The three-phase modulation voltage u ma 、u mb 、u mc Modulation (such as sinusoidal pulse width modulation, ie, SPWM modulation) is performed to obtain a driving signal DS.

[0136] The transient overvoltage is suppressed according to the driving signal DS. It can be imagined that the inverter bridge of the new energy inverter is controlled according to the driving signal DS, and the semiconductor devices of the bridge arm in the inverter bridge will act accordingly to achieve the bridge arm voltage (i.e. Figure 2 u inva 、u invb 、u invc ) to achieve the suppression of transient overvoltage.

[0137] Embodiment 3:

[0138] Based on the same inventive concept, the embodiment of the present application also provides a computer device, which includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the suppression method provided in the above embodiment.

[0139] Embodiment 4:

[0140] Based on the same inventive concept, the embodiment of the present application also provides a computer-readable storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space that stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the suppression method provided in the above embodiment.

[0141] Those skilled in the art will appreciate that the embodiments of the application may be provided as methods, systems, or computer program products. Therefore, the application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0142] The application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0143] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0144] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0145] The above are merely embodiments of the application and are not intended to limit the application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the application are included in the scope of the claims of the pending application.

Claims

1. A method for suppressing transient overvoltage of a new energy inverter, characterized in that: include: Calculate a first voltage reference value of the virtual node according to the three-phase terminal current of the new energy inverter and the current reference value in the two-phase rotating coordinate system; Determine a modulation voltage component in a two-phase rotating coordinate system according to the first voltage reference value and an adaptive variable adjustment coefficient; The transient overvoltage of the new energy inverter is suppressed according to the modulation voltage component.

2. The suppression method according to claim 1, characterized in that: The calculating the first voltage reference value of the virtual node according to the three-phase terminal current of the new energy inverter and the current reference value in the two-phase rotating coordinate system includes: Performing a Park transformation on the three-phase terminal current of the new energy inverter to obtain a d-axis current component and a q-axis current component of the new energy inverter in a two-phase rotating coordinate system; Performing current control on the d-axis current component according to the d-axis current reference value in the two-phase rotating coordinate system to obtain a d-axis first voltage reference value of the virtual node; The q-axis current component is current controlled according to the q-axis current reference value in the two-phase rotating coordinate system to obtain a q-axis first voltage reference value of the virtual node.

3. The suppression method according to claim 2, characterized in that: The d-axis first voltage reference value and the q-axis first voltage reference value satisfy: Among them, u vdref1 represents the first voltage reference value of the d-axis, u vqref1 represents the q-axis first voltage reference value; i dref represents the d-axis current reference value, i qref represents the q-axis current reference value; i d represents the d-axis current component, i q represents the q-axis current component; K p_Gi Represents the first proportionality coefficient, K i_Gi Represents the first integral coefficient, K d represents the decoupling coefficient, H i represents the current feedback coefficient, and s represents a complex variable.

4. The suppression method according to claim 2, characterized in that: The determining of the modulation voltage component in the two-phase rotating coordinate system according to the first voltage reference value and the adaptive variable adjustment coefficient includes: Calculating the adaptive variable adjustment coefficient according to the terminal voltage of the new energy inverter; Performing a Park transformation on the three-phase voltage of the virtual node to obtain a voltage component of the virtual node; The voltage component of the virtual node is voltage-controlled according to the adaptive variable adjustment coefficient to obtain the modulated voltage component.

5. The suppression method according to claim 4, characterized in that: The adaptive variable adjustment coefficient satisfies: K uv =1-K down (H u u term -u HV ) Among them, K uv represents the adaptive variable adjustment coefficient, K down represents the decreasing slope of the adaptive variable adjustment coefficient, u term represents the terminal voltage, u HV Indicates the preset start threshold; H u Represents the voltage feedback coefficient; satisfies K uvmin ≤K uv ≤K uvmax , K uvmin represents the lower limit of the adaptive variable adjustment coefficient, K uvmax Indicates the upper limit of the adaptive variable adjustment coefficient.

6. The suppression method according to claim 4, characterized in that: The step of performing voltage control on the voltage component of the virtual node according to the adaptive variable adjustment coefficient to obtain the modulated voltage component includes: Multiplying the adaptive variable adjustment coefficient by the d-axis first voltage reference value to obtain the d-axis second voltage reference value of the virtual node, and multiplying the adaptive variable adjustment coefficient by the q-axis first voltage reference value to obtain the q-axis second voltage reference value of the virtual node; The d-axis voltage component of the virtual node is voltage-controlled according to the d-axis second voltage reference value to obtain a d-axis modulated voltage component, and the q-axis voltage component of the virtual node is voltage-controlled according to the q-axis second voltage reference value to obtain a q-axis modulated voltage component.

7. The suppression method according to claim 4, characterized in that: The modulation voltage component satisfies: Among them, u md represents the d-axis modulation voltage component, u mq represents the q-axis modulation voltage component; u vdref represents the d-axis second voltage reference value of the virtual node, u vqref represents the q-axis second voltage reference value of the virtual node; u vd represents the d-axis voltage component of the virtual node, u vq represents the q-axis voltage component of the virtual node; K p_Gu Represents the second proportionality coefficient, K i_Gu represents the second integral coefficient, H u represents the voltage feedback coefficient, and s represents a complex variable.

8. The suppression method according to claim 1, characterized in that: The suppressing the transient overvoltage of the new energy inverter according to the modulation voltage component includes: Performing a Park transformation on the modulation voltage component in the two-phase rotating coordinate system to obtain a three-phase modulation voltage of the new energy inverter; Modulating the three-phase modulation voltage to obtain a driving signal; The transient overvoltage is suppressed according to the driving signal.

9. A device for suppressing transient overvoltage of a new energy inverter, characterized in that: include: A calculation module, used for calculating a first voltage reference value of a virtual node according to a three-phase terminal current of the new energy inverter and a current reference value in a two-phase rotating coordinate system; A determination module, configured to determine a modulation voltage component in a two-phase rotating coordinate system according to the first voltage reference value and an adaptive variable adjustment coefficient; A suppression module is used to suppress the transient overvoltage of the new energy inverter according to the modulation voltage component.

10. The suppression device according to claim 9, characterized in that The calculation module is specifically used for: Performing a Park transformation on the three-phase terminal current of the new energy inverter to obtain a d-axis current component and a q-axis current component of the new energy inverter in a two-phase rotating coordinate system; Performing current control on the d-axis current component according to the d-axis current reference value in the two-phase rotating coordinate system to obtain a d-axis first voltage reference value of the virtual node; The q-axis current component is current controlled according to the q-axis current reference value in the two-phase rotating coordinate system to obtain a q-axis first voltage reference value of the virtual node.

11. The suppression device according to claim 10, characterized in that The d-axis first voltage reference value and the q-axis first voltage reference value satisfy: Among them, u vdref1 represents the first voltage reference value of the d-axis, u vqref1 represents the q-axis first voltage reference value; i dref represents the d-axis current reference value, i qref represents the q-axis current reference value; i d represents the d-axis current component, i q represents the q-axis current component; K p_Gi Represents the first proportionality coefficient, K i_Gi Represents the first integral coefficient, K d represents the decoupling coefficient, H i represents the current feedback coefficient, and s represents a complex variable.

12. The suppression device according to claim 10, characterized in that The determination module is specifically used for: Calculating the adaptive variable adjustment coefficient according to the terminal voltage of the new energy inverter; Performing a Park transformation on the three-phase voltage of the virtual node to obtain a voltage component of the virtual node; The voltage component of the virtual node is voltage-controlled according to the adaptive variable adjustment coefficient to obtain the modulated voltage component.

13. The suppression device according to claim 12, characterized in that The adaptive variable adjustment coefficient satisfies: K uv =1-K down (H u u term -u HV ) Among them, K uv represents the adaptive variable adjustment coefficient, K down represents the decreasing slope of the adaptive variable adjustment coefficient, u term represents the terminal voltage, u HV Indicates the preset start threshold; H u Represents the voltage feedback coefficient; satisfies K uvmin ≤K uv ≤K uvmax , K uvmin represents the lower limit of the adaptive variable adjustment coefficient, K uvmax Indicates the upper limit of the adaptive variable adjustment coefficient.

14. The suppression device according to claim 12, characterized in that The determination module is specifically used for: Multiplying the adaptive variable adjustment coefficient by the d-axis first voltage reference value to obtain the d-axis second voltage reference value of the virtual node, and multiplying the adaptive variable adjustment coefficient by the q-axis first voltage reference value to obtain the q-axis second voltage reference value of the virtual node; The d-axis voltage component of the virtual node is voltage-controlled according to the d-axis second voltage reference value to obtain a d-axis modulated voltage component, and the q-axis voltage component of the virtual node is voltage-controlled according to the q-axis second voltage reference value to obtain a q-axis modulated voltage component.

15. The suppression device according to claim 12, characterized in that The modulation voltage component satisfies: Among them, u md represents the d-axis modulation voltage component, u mq represents the q-axis modulation voltage component; u vdref represents the d-axis second voltage reference value of the virtual node, u vqref represents the q-axis second voltage reference value of the virtual node; u vd represents the d-axis voltage component of the virtual node, u vq represents the q-axis voltage component of the virtual node; K p_Gu Represents the second proportionality coefficient, K i_Gu represents the second integral coefficient, H u represents the voltage feedback coefficient, and s represents a complex variable.

16. The suppression device according to claim 9, characterized in that The suppression module is used to: Performing a Park transformation on the modulation voltage component in the two-phase rotating coordinate system to obtain a three-phase modulation voltage of the new energy inverter; Modulating the three-phase modulation voltage to obtain a driving signal; The transient overvoltage is suppressed according to the driving signal.

17. A computer device, characterized in that: include: one or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the suppression method according to any one of claims 1 to 8 is implemented.

18. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the suppression method according to any one of claims 1 to 8 is implemented.

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