Energy storage converter and control method for high-voltage ride-through

Abstract

The present invention discloses an energy storage converter and a control method for high-voltage ride-through. The energy storage converter includes a DC-side switch, a DCDC power module, a DC / AC power module, an output filter module, and a controller. The first end of the DC-side switch is connected to the positive pole of the energy storage DC side, and the second end of the DC-side switch is connected to the positive pole of the input side of the DC / AC power module. The negative pole of the input side of the DCDC power module is connected to the negative pole of the energy storage DC side. The positive pole of the output side of the DCDC power module is connected to the positive pole of the input side of the DC / AC power module, and the negative pole of the output side of the DCDC power module is connected to the negative pole of the input side of the DC / AC power module. The three-phase lines of the output of the DC / AC power module are connected to the input end of the output filter module, and the output end of the output filter module is connected to the grid side. The controller is configured to control the DC-side switch, the DCDC power module, the DC / AC power module, and the output filter module. The DCDC power module includes an H-bridge circuit composed of four IGBT modules, a supercapacitor module connected in series to the H-bridge circuit, and an inductor.

Description

Technical Field

[0001] The present invention relates to the field of energy storage power systems, and particularly to an energy storage converter and a control method for high-voltage ride-through. Background Art

[0002] In the current energy storage power system, according to the national standard requirements, the energy storage converter needs to have the ability of high-voltage ride-through when the grid voltage suddenly rises. That is, when the grid voltage rises, the energy storage converter needs to provide reactive power support, and after the grid recovers, it needs to quickly restore power. In some specific application scenarios, the grid may require the energy storage system to continue to provide active power during high-voltage ride-through to maintain power supply stability.

[0003] In the existing high-voltage ride-through technologies, the energy storage converter can only provide reactive power support and cannot provide necessary active power support during high-voltage ride-through, and thus cannot be applied to some specific application scenarios.

[0004] In view of this, how to provide an energy storage converter and a control method for high-voltage ride-through that can provide a certain amount of active power support during high-voltage ride-through is a technical problem that needs to be solved in this technical field. Summary of the Invention

[0005] The main advantage of the present invention is to provide an energy storage converter. When the energy storage converter encounters a high-voltage ride-through condition and the energy storage DC side voltage is low, the energy storage converter can provide a certain amount of active power support while providing high-voltage support, and does not reduce the power consumption efficiency during operation, which is beneficial to improving the grid adaptability of the energy storage converter.

[0006] Another advantage of the present invention is to provide a control method for high-voltage ride-through based on the energy storage converter. After the energy storage converter completes high-voltage ride-through, it can quickly connect the energy storage DC side to the energy storage converter, reduce the recovery time of active power after a fault ride-through, and ensure that the energy storage converter provides active power support during the entire switching process.

[0007] Correspondingly, according to an embodiment of the present invention, an energy storage converter having at least one of the foregoing advantages includes:

[0008] A DC-side switch, a DCDC power module, a DC / AC power module, an output filter module, and a controller. The first end of the DC-side switch is adapted to be connected to the positive pole of the energy storage DC side of the energy storage DC side. The second end of the DC-side switch is connected to the positive pole of the DC / AC power module input side of the DC / AC power module. The negative pole of the DCDC power module input side of the DCDC power module is adapted to be connected to the negative pole of the energy storage DC side of the energy storage DC side. The positive pole of the DCDC power module output side of the DCDC power module is connected to the positive pole of the DC / AC power module input side of the DC / AC power module. The negative pole of the DCDC power module output side of the DCDC power module is connected to the negative pole of the DC / AC power module input side of the DC / AC power module. The three-phase lines of the output of the DC / AC power module are connected to the input end of the output filter module. The output end of the output filter module is adapted to be connected to the grid side. The controller is configured to control the DC-side switch, the DCDC power module, the DC / AC power module, and the output filter module. The DCDC power module includes an H-bridge circuit composed of four IGBT modules G1, G2, G3, and G4, a supercapacitor module connected in series to the H-bridge circuit, and an inductor.

[0009] Correspondingly, the present invention further provides a control method for high-voltage ride-through, which is based on the energy storage converter and includes the following steps:

[0010] Step S1: Obtain the voltage V bat and current I bat detected by the first voltage and current sensing module; obtain the voltage V cap and current I cap detected by the second voltage and current sensing module; obtain the voltage V net and current I net detected by the third voltage and current sensing module; obtain the voltage V bat0 of the energy storage DC side;

[0011] Step S2: Obtain the target active power P out_ref and target reactive power Q out_ref that the energy storage converter needs to provide; calculate the actual active power P net and actual reactive power Q net actually output by the energy storage converter according to the voltage V out and current I out ;

[0012] Step S3: Use the difference between the target active power P out_ref and the actual active power P out as the input of the first active PI control, and the output of the first active PI control is the voltage V d; with the target reactive power Q out-ref and the actual reactive power Q out The difference is used as the input of the first reactive PI control, and the output of the first reactive PI control is the voltage V q ;

[0013] Step S4: According to the voltage V net and the current I net , the voltage V on the d-axis is obtained through dq transformation d1 , and the voltage V on the q-axis q1 ;

[0014] Step S5: Using the difference between the voltage V d and the voltage V d1 as the input of the second active PI control, and the output of the second active PI control is the voltage V d2 ; Using the difference between the voltage V q and the voltage V q1 as the input of the second reactive PI control, and the output of the second reactive PI control is the voltage V q2 ; According to the voltage V d2 and the voltage V q2 , calculate and generate the PWM signal of the IGBT module of the DC / AC power module;

[0015] Step S6: Judge the magnitude of the voltage V net and the set first voltage threshold V net_ref . If V net > V net_ref , execute step S61 next. If V net ≤V net_ref , execute step S62 next;

[0016] Step S62: Judge the state of the DC side switch. The state flag K DC_flag of the DC side switch has an initial value of 0, indicating that the DC side switch is closed. K DC_flag equals 1 indicating that the DC side switch is open. Among them, if K DC_flag = 1, control the DCDC power module to enter the boost mode, set the target output voltage of the DCDC power module to the voltage V bat0 , use the difference between the voltage V bat0 and the voltage V bat as the input of the PI control of the DCDC power module, and control the duty cycle of the IGBT modules G1 and G4 of the DCDC power module according to the output of the PI control of the DCDC power module until the voltage V bat0 and the voltage V bat The absolute value of the difference is less than the set second voltage threshold V th , close the DC side switch, and set the state flag K of the DC side switchDC_flag Set it to 0, and then jump back to step S1; if K DC_flag = 0, control the DCDC power module to enter the buck mode, and set the target output voltage of the DCDC power module to voltage V bat -V th , and use the difference between voltage V bat -V th and voltage V cap as the input of the PI control of the DCDC power module, and control the duty cycles of the IGBT modules G2 and G3 of the DCDC power module according to the output of the PI control of the DCDC power module, and then jump back to step S1;

[0017] Step S61 further includes steps:

[0018] Step S611: Calculate the third voltage threshold V bat2 , where ; calculate the active power P bat of the DC side of the energy storage, where ;

[0019] Step S612: Judge the magnitudes of the third voltage threshold V bat2 and voltage V bat0 , and the magnitude of the sum of the active power P bat of the DC side of the energy storage plus the set active power threshold P th and the target active power P out_ref . If V bat2 > V bat0 and P bat + P th < P out_ref , then execute step S613 next, otherwise, jump back to step S1;

[0020] Step S613: Judge the state of the DC side switch. If K DC_flag = 1, then execute step S614 next. If K DC_flag = 0, first disconnect the DC side switch, mark the state of the DC side switch K DC_flag as 1, and start timing, and then execute step S614;

[0021] Step S614: Control the DCDC power module to enter the boost mode, and set the target output voltage of the DCDC power module to V bat2 , and use the difference between V bat2 and voltage V bat as the input of the PI control of the DCDC power module, and control the duty cycles of the IGBT modules G1 and G4 of the DCDC power module according to the output of the PI control of the DCDC power module;

[0022] Step S615, determine K DC_flag the time when it is equal to 1 and the set maximum continuous time T for high-voltage ride-through max in terms of magnitude. If K DC_flag the time when it is equal to 1 is greater than T max , disconnect the AC side switch; otherwise, jump back to Step S1.

[0023] Combined with the following description and the accompanying drawings of the specification, the above and other advantages of the present invention will be fully demonstrated.

[0024] The above and other advantages and features of the present invention are fully demonstrated through the following detailed description of the present invention and the accompanying drawings of the specification.

[0025] The description of the invention content is not regarded as an essential technical feature identifying the present invention, nor as a limitation on the protection scope of the present invention. Brief Description of the Drawings

[0026] Figure 1 is a schematic diagram of an energy storage converter according to an embodiment of the present invention.

[0027] Figure 2 is a schematic diagram of a control method for high-voltage ride-through of an energy storage converter according to an embodiment of the present invention.

[0028] Figure 3 is a schematic diagram of Step S61 of the control method for high-voltage ride-through according to an embodiment of the present invention.

[0029] In the figure:

[0030] 1. Energy storage converter; 11. DC side switch; 111. First end; 112. Second end; 12. DCDC power module; 121. Negative pole of the input side of the DCDC power module; 122. Positive pole of the output side of the DCDC power module; 123. Negative pole of the output side of the DCDC power module; 124. Supercapacitor module; 13. DC / AC power module; 131. Positive pole of the input side of the DC / AC power module; 132. Negative pole of the input side of the DC / AC power module; 133. Three-phase line; 14. Output filter module; 141. Input end; 142. Output end; 143. AC side switch; 15. Controller; CV1. First voltage and current sensing module; CV2. Second voltage and current sensing module; CV3. Third voltage and current sensing module; G1 - G10. IGBT modules; L dc , Inductor; C d1 -C d2 , Capacitor; R f , Filter resistor; L f , Filter inductor; C f, filter capacitor; 2, energy storage DC side; 21, positive pole of energy storage DC side; 22, negative pole of energy storage DC side; 3, grid side. Specific embodiments

[0031] The following description is provided to enable a person of ordinary skill in the art to implement the present invention. Other obvious substitutions, modifications, and variations can be envisioned by a person of ordinary skill in the art. Therefore, the scope of protection of the present invention should not be limited by the exemplary embodiments described herein.

[0032] A person of ordinary skill in the art should understand that, unless specifically stated herein, the term "a" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of the element can be multiple.

[0033] A person of ordinary skill in the art should understand that, unless specifically stated herein, the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. refer to the orientation or position based on the orientation or position shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element involved must have a specific orientation or position. Therefore, the above terms should not be construed as a limitation to the present invention.

[0034] Referring to the accompanying drawings of the specification of the present invention Figure 1, the energy storage converter 1 according to an embodiment of the present invention is illustrated. The energy storage converter 1 includes a DC side switch 11, a DCDC power module 12, a DC / AC power module 13, an output filter module 14, and a controller 15. The first end 111 of the DC side switch 11 is connected to the positive pole 21 of the energy storage DC side of the energy storage DC side 2, and the second end 112 of the DC side switch 11 is connected to the positive pole 131 of the DC / AC power module input side of the DC / AC power module 13. The negative pole 121 of the DCDC power module input side of the DCDC power module 12 is connected to the negative pole 22 of the energy storage DC side of the energy storage DC side 2. The positive pole 122 of the DCDC power module output side of the DCDC power module 12 is connected to the positive pole 131 of the DC / AC power module input side of the DC / AC power module 13, and the negative pole 123 of the DCDC power module output side of the DCDC power module 12 is connected to the negative pole 132 of the DC / AC power module input side of the DC / AC power module 13. The three-phase line 133 output by the DC / AC power module 13 is connected to the input end 141 of the output filter module 14, and the output end 142 of the output filter module 14 is connected to the grid side 3. The controller 15 is configured to control the DC side switch 11, the DCDC power module 12, the DC / AC power module 13, and the output filter module 14.

[0035] Specifically, the DCDC power module 12 includes an H-bridge circuit composed of four IGBT modules G1, G2, G3, G4, a supercapacitor module 124 connected in series to the H-bridge circuit, and an inductor L dc . The control ends of the four IGBT modules G1, G2, G3, G4 are respectively communicatively connected to the controller 15 to control the actions of the four IGBT modules G1, G2, G3, G4 through the controller 15, thereby realizing the control of the boost mode and the buck mode of the DCDC power module 12. When the DCDC power module 12 is in the boost mode, the IGBT modules G1 and G4 act, and the IGBT modules G2 and G3 stop acting, and electric energy is boosted from the supercapacitor module 124 to the DC / AC power module 13; when the DCDC power module 12 is in the buck mode, the IGBT modules G1 and G4 stop acting, and the IGBT modules G2 and G3 act, and electric energy is bucked from the DC / AC power module 13 to the supercapacitor module 124. Based on the above-described DCDC power module 12 configured with the supercapacitor module 124 of the present invention, when the energy storage converter 1 encounters a high-voltage crossing condition and the voltage of the energy storage DC side 2 is low, the energy storage converter 1 can provide a certain amount of active power support while providing high-voltage support, and does not reduce the power consumption efficiency during operation, which is beneficial to improving the grid adaptability of the energy storage converter 1.

[0036] Further, the DC / AC power module 13 includes six IGBT modules G5, G6, G7, G8, G9, G10 and two capacitors C d1 , C d2 to form a three-phase bridge circuit. The control terminals of the six IGBT modules G5, G6, G7, G8, G9, G10 are respectively communicatively connected to the controller 15 to control the operations of the six IGBT modules G5, G6, G7, G8, G9, G10 through the controller 15.

[0037] Further, the output filter module 14 includes three filter resistors R f , three filter inductors L f , three filter capacitors C f and three AC side switches 143. The three AC side switches 143 are arranged close to the output terminal 142 of the output filter module 14. The corresponding filter resistors R f , the filter inductors L f and the AC side switches 143 are sequentially connected in series in the corresponding branches. One ends of the three filter capacitors C f are connected together, and the other ends are respectively connected to the corresponding branches, and the connection points of the other ends and the corresponding branches are located between the corresponding filter inductors L f and the AC side switches 143.

[0038] Further, the energy storage converter 1 further includes a first voltage and current sensing module CV1, a second voltage and current sensing module CV2 and a third voltage and current sensing module CV3. The detection point of the first voltage and current sensing module CV1 is located at the second end 112 of the DC side switch 11 for detecting the DC voltage and current on the input side of the energy storage converter 1. When the DC side switch 11 is closed, the first voltage and current sensing module CV1 also equivalently detects the voltage of the energy storage DC side 2 and the current flowing between the energy storage DC side 2 and the energy storage converter 1. The detection point of the second voltage and current sensing module CV2 is located at the positive electrode of the supercapacitor module 124 and the inductor L dcBetween them, it is used to detect the DC voltage and current of the supercapacitor module 124. The detection point of the third voltage and current sensing module CV3 is located between the output terminal 142 of the output filtering module 14 and the grid side 3, and is used to detect the AC voltage and current on the output side of the energy storage converter 1. The first voltage and current sensing module CV1, the second voltage and current sensing module CV2, and the third voltage and current sensing module CV3 are respectively communicatively connected to the controller 15 to obtain corresponding voltage values and current values through the controller 15. The controller 15 is also communicatively connected to the energy storage DC side 2 for obtaining the voltage of the energy storage DC side 2. The controller 15 is also communicatively connected to the energy management controller of the system for obtaining the target active power and target reactive power that the energy storage converter 1 needs to provide.

[0039] According to another aspect of the present invention, as shown in the appended Figure 2 and appended Figure 3 figures, based on the above-mentioned energy storage converter 1 of the present invention, the present invention further provides a control method for high-voltage ride-through, including the following steps:

[0040] Step S1: Obtain the voltage V bat and current I bat detected by the first voltage and current sensing module; obtain the voltage V cap and current I cap detected by the second voltage and current sensing module; obtain the voltage V net and current I net detected by the third voltage and current sensing module; obtain the voltage V bat0 of the energy storage DC side;

[0041] Step S2: Obtain the target active power P out_ref and target reactive power Q out_ref that the energy storage converter needs to provide; calculate the actual active power P net and actual reactive power Q net actually output by the energy storage converter according to the voltage V out and current I out ;

[0042] Step S3: Use the difference between the target active power P out_ref and the actual active power P out as the input of the first active PI control, and the output of the first active PI control is the voltage V d ; use the difference between the target reactive power Q out-ref and the actual reactive power Q out as the input of the first reactive PI control, and the output of the first reactive PI control is the voltage V q ;

[0043] Step S4: According to the voltage V net and the current I net , obtain the voltage V d1 on the d-axis and the voltage V q1 on the q-axis through dq transformation;

[0044] Step S5: Use the difference between the voltage V d and the voltage V d1 as the input of the second active PI control, and the output of the second active PI control is the voltage V d2 ; use the difference between the voltage V q and the voltage V q1 as the input of the second reactive PI control, and the output of the second reactive PI control is the voltage V q2 ; calculate and generate the PWM signal of the IGBT module of the DC / AC power module according to the voltage V d2 and the voltage V q2 ;

[0045] Step S6: Judge the magnitude relationship between the voltage V net and the set first voltage threshold V net_ref . If V net >V net_ref , execute step S61 next. If V net ≤V net_ref , execute step S62 next;

[0046] Step S62: Judge the state of the DC-side switch. The state flag K DC_flag of the DC-side switch has an initial value of 0, indicating that the DC-side switch is closed. K DC_flag equal to 1 indicates that the DC-side switch is open. Among them, if K DC_flag =1, control the DCDC power module to enter the boost mode, set the target output voltage of the DCDC power module to the voltage V bat0 , use the difference between the voltage V bat0 and the voltage V bat as the input of the PI control of the DCDC power module, and control the duty cycles of the IGBT modules G1 and G4 of the DCDC power module according to the output of the PI control of the DCDC power module until the absolute value of the difference between the voltage V bat0 and the voltage V bat is less than the set second voltage threshold V th , then close the DC-side switch, set the state flag K DC_flag of the DC-side switch to 0, and then jump back to step S1; if K DC_flag =0, control the DCDC power module to enter the buck mode, set the target output voltage of the DCDC power module to the voltage V bat -V th , according to the voltage Vbat -V th The difference from the voltage V cap is used as the input of the PI control of the DCDC power module. According to the output of the PI control of the DCDC power module, the duty cycles of the IGBT modules G2 and G3 of the DCDC power module are controlled. Then, it jumps back to step S1;

[0047] Step S61 further includes the steps of:

[0048] Step S611: Calculate the third voltage threshold V bat2 , where ; Calculate the active power P bat on the DC side of the energy storage, where ;

[0049] Step S612: Judge the magnitudes of the third voltage threshold V bat2 and the voltage V bat0 , and the magnitude of the sum of the active power P bat on the DC side of the energy storage plus the set active power threshold P th and the target active power P out_ref . If V bat2 > V bat0 and P bat + P th < P out_ref , the subsequent step S613 is executed. Otherwise, it jumps back to step S1;

[0050] Step S613: Judge the state of the DC side switch. If K DC_flag = 1, the subsequent step S614 is executed. If K DC_flag = 0, first disconnect the DC side switch, mark the state of the DC side switch as K DC_flag and set it to 1, and start timing. Then, execute step S614;

[0051] Step S614: Control the DCDC power module to enter the boost mode, and set the target output voltage of the DCDC power module to V bat2 . Use the difference between V bat2 and the voltage V bat as the input of the PI control of the DCDC power module. According to the output of the PI control of the DCDC power module, control the duty cycles of the IGBT modules G1 and G4 of the DCDC power module;

[0052] Step S615: Judge the magnitude of the time when K DC_flag is equal to 1 and the set maximum duration T max for high-voltage ride-through. If the time when K DC_flag is equal to 1 is greater than T max, disconnect the AC side switch, otherwise, jump back to step S1.

[0053] It is worth mentioning that the control method of the high-voltage ride-through can quickly connect the energy storage DC side 2 to the energy storage converter 1 after the energy storage converter 1 completes the high-voltage ride-through. Before and after the DC side switch 11 is closed, the super capacitor module 124 and the DCDC power module 12 provide active support to ensure that the energy storage converter 1 provides active support during the entire switching process, reducing the recovery time of active power after fault ride-through. In addition, the control method of the high-voltage ride-through, in the high-voltage ride-through process, the super capacitor module 124 and the DCDC power module 12 provide active support, which has more beneficial practical significance compared to the traditional ride-through method that cannot provide active support.

[0054] Those skilled in the art will appreciate that the above embodiments are merely examples, wherein features of different embodiments may be combined with each other to obtain implementation methods that are easily conceivable based on the contents disclosed in the present invention but are not explicitly indicated in the drawings.

[0055] Those skilled in the art should understand that the above description and the embodiments shown in the drawings are only for illustrative explanation of the present invention, rather than for limitation of the present invention. All equivalent implementations, modifications and improvements within the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A energy storage converter, characterized in that, Comprising: A DC-side switch, a DCDC power module, a DC / AC power module, an output filtering module, a first voltage and current sensing module, a second voltage and current sensing module, a third voltage and current sensing module, and a controller, wherein a first terminal of the DC-side switch is adapted to be connected to the positive pole of the energy storage DC side of the energy storage DC side, a second terminal of the DC-side switch is connected to the positive pole of the DC / AC power module input side of the DC / AC power module, a negative pole of the DCDC power module input side of the DCDC power module is adapted to be connected to the negative pole of the energy storage DC side of the energy storage DC side, a positive pole of the DCDC power module output side of the DCDC power module is connected to the positive pole of the DC / AC power module input side of the DC / AC power module, a negative pole of the DCDC power module output side of the DCDC power module is connected to the negative pole of the DC / AC power module input side of the DC / AC power module, three-phase lines of the output of the DC / AC power module are connected to the input end of the output filtering module, an output end of the output filtering module is adapted to be connected to the grid side, the controller is configured to control the DC-side switch, the DCDC power module, the DC / AC power module, and the output filtering module, the DCDC power module includes an H-bridge circuit composed of four IGBT modules G1, G2, G3, G4, a supercapacitor module and an inductor connected in series to the H-bridge circuit, wherein a detection point of the first voltage and current sensing module is located at the second terminal of the DC-side switch, a detection point of the second voltage and current sensing module is located between the positive pole of the supercapacitor module and the inductor, a detection point of the third voltage and current sensing module is located between the output end of the output filtering module and the grid side, the first voltage and current sensing module, the second voltage and current sensing module, and the third voltage and current sensing module are respectively communicatively connected to the controller, wherein, When the voltage V detected by the third voltage and current sensing module net ≤ the set first voltage threshold V net_ref , and the DC side switch is in the off state, control the DCDC power module to enter the boost mode, and set the target output voltage of the DCDC power module to the voltage V of the energy storage DC side bat0 , use the difference between the voltage V bat0 and the voltage V detected by the first voltage and current sensing module bat as the input of the PI control of the DCDC power module, and control the IGBT module of the DCDC power module according to the output of the PI control of the DCDC power module until the absolute value of the difference between the voltage V bat0 and the voltage V bat is less than the set second voltage threshold V th , then close the DC side switch; When the voltage V detected by the third voltage and current sensing module net ≤ the set first voltage threshold V net_ref , and when the DC side switch is in the closed state, control the DCDC power module to enter the buck mode, and set the target output voltage of the DCDC power module to the voltage V bat -V th , and use the difference between the voltage V bat -V th detected by the third voltage and current sensing module and the voltage V cap detected by the second voltage and current sensing module as the input of the PI control of the DCDC power module, and control the IGBT module of the DCDC power module according to the output of the PI control of the DCDC power module.

2. The energy storage converter according to claim 1, characterized in that, When the DCDC power module is in boost mode, IGBT modules G1 and G4 act, and IGBT modules G2 and G3 stop acting; when the DCDC power module is in buck mode, IGBT modules G1 and G4 stop acting, and IGBT modules G2 and G3 act.

3. The energy storage converter according to claim 2, wherein The DC / AC power module includes a three-phase bridge circuit composed of six IGBT modules G5, G6, G7, G8, G9, G10 and two capacitors.

4. The energy storage converter according to claim 3, characterized in that The output filtering module includes three AC-side switches, and the three AC-side switches are arranged close to the output end of the output filtering module.

5. The energy storage converter according to claim 4, wherein The output filtering module further includes three filtering resistors, three filtering inductors and three filtering capacitors. The corresponding filtering resistors, filtering inductors and AC-side switches are connected in series in corresponding branches in sequence. One ends of the three filtering capacitors are connected together, and the other ends are respectively connected to the corresponding branches, and the connection points of the other ends to the corresponding branches are located between the corresponding filtering inductors and the AC-side switches.

6. The energy storage converter according to claim 5, wherein, The controller is further adapted to be communicatively connected to the energy storage DC side for obtaining the voltage of the energy storage DC side.

7. The energy storage converter according to claim 6, wherein The controller is also adapted to be communicatively connected to the energy management controller of the system for obtaining the target active power and the target reactive power that the energy storage converter needs to provide.

8. A control method for high-voltage ride-through, based on the energy storage converter according to any one of claims 1-7, characterized in that, including the steps: Step S1: Obtain the voltage V detected by the first voltage-current sensing module bat and the current I bat ; Obtain the voltage V detected by the second voltage-current sensing module cap and the current I cap ; Obtain the voltage V detected by the third voltage-current sensing module net and the current I net ; Obtain the voltage V on the DC side of the energy storage bat0 ; Step S2: Obtain the target active power P that the energy storage converter needs to provide out_ref and the target reactive power Q out_ref ; Calculate the actual active power P net and the actual reactive power Q net actually output by the energy storage converter according to the voltage V out and the current I out ; Step S3: Use the difference between the target active power P out_ref and the actual active power P out as the input of the first active PI control, and the output of the first active PI control is the voltage V d ; Use the difference between the target reactive power Q out-ref and the actual reactive power Q out as the input of the first reactive PI control, and the output of the first reactive PI control is the voltage V q ; Step S4. According to voltage V net and current I net , obtain the voltage V d1 on the d-axis and the voltage V q1 on the q-axis through dq transformation; Step S5: Use the difference between voltage V d and voltage V d1 as the input of the second active PI control, and the output of the second active PI control is voltage V d2 ; use the difference between voltage V q and voltage V q1 as the input of the second reactive PI control, and the output of the second reactive PI control is voltage V q2 ; calculate and generate the PWM signal of the IGBT module of the DC / AC power module according to voltage V d2 and voltage V q2 . Step S6, determine the voltage V net and the set first voltage threshold V net_ref . If V net > V net_ref , subsequently execute step S61. If V net ≤ V net_ref , subsequently execute step S62; Step S62: Determine the status of the DC-side switch, with the status flag K of the DC-side switch DC_flag The initial value is 0, indicating that the DC-side switch is closed, and K DC_flag being equal to 1 indicates that the DC-side switch is open. Among them, if K DC_flag = 1, control the DCDC power module to enter the boost mode, and set the target output voltage of the DCDC power module to voltage V bat0 , and use the difference between voltage V bat0 and voltage V bat as the input of the PI control of the DCDC power module. Control the duty cycles of the IGBT modules G1 and G4 of the DCDC power module according to the output of the PI control of the DCDC power module until the absolute value of the difference between voltage V bat0 and voltage V bat is less than the set second voltage threshold V th . Then, close the DC-side switch, and set the status flag K DC_flag of the DC-side switch to 0. After that, jump back to step S1; if K DC_flag = 0, control the DCDC power module to enter the buck mode, and set the target output voltage of the DCDC power module to voltage V bat - V th , and use the difference between voltage V bat - V th and voltage V cap as the input of the PI control of the DCDC power module. Control the duty cycles of the IGBT modules G2 and G3 of the DCDC power module according to the output of the PI control of the DCDC power module. After that, jump back to step S1; Step S61 further includes the steps: Step S611, calculate the third voltage threshold V bat2 , where ; calculate the active power P of the DC side of the energy storage bat , where ; Step S612, determine the magnitude of the third voltage threshold V bat2 and the voltage V bat0 , as well as the active power P bat on the DC side of the energy storage plus the set active power threshold P th , and the magnitude of the sum with the target active power P out_ref . If V bat2 > V bat0 and P bat + P th < P out_ref , then execute step S613 next. Otherwise, jump back to step S1; Step S613: Determine the state of the DC-side switch. If K DC_flag = 1, then proceed to step S614. If K DC_flag = 0, first disconnect the DC-side switch, set the status flag K DC_flag of the DC-side switch to 1, start timing, and then proceed to step S614; Step S614: Control the DCDC power module to enter the boost mode, and set the target output voltage of the DCDC power module to V bat2 , with V bat2 and the voltage V bat as the input of the PI control of the DCDC power module, and control the duty cycles of the IGBT modules G1 and G4 of the DCDC power module according to the output of the PI control of the DCDC power module; Step S615: Determine K DC_flag the time when it is equal to 1 and the maximum duration T of high-voltage ride-through set max in magnitude. If the time when K DC_flag is equal to 1 is greater than T max , disconnect the AC side switch; otherwise, jump back to Step S1.

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