Energy storage converter control method and device, computer equipment and storage medium

Abstract

The invention relates to an energy storage converter control method and device, computer equipment, a storage medium and a computer program product. The method comprises the following steps: inputting a voltage deviation between a voltage reference value of an energy storage converter in the energy storage system and an actual voltage value of the energy storage converter into a robust controller corresponding to a voltage loop of the energy storage system to obtain a current reference value of a current loop of the energy storage system; the robust controller is obtained through processing based on a control object transfer model; inputting a current deviation between the current reference value and an actual current value of the energy storage converter to a linear controller corresponding to a current loop, and applying the actual current value to the current loop to obtain a voltage instruction value of the energy storage converter in the energy storage system; and modulating the voltage instruction value to obtain a control driving signal of the energy storage converter. By adopting the method, stable control on the energy storage converter can be realized, so that the operation stability and robustness of an energy storage system under uncertain fluctuation are improved.

Description

Technical Field

[0001] The present application relates to the technical field of new energy power generation, and particularly to a control method, device, computer device, storage medium and computer program product for an energy storage converter. Background Art

[0002] Renewable energy is intermittent and unstable. With the rapid growth of renewable energy, power converters (Power Conversion System, PCS) have been widely used. The advantage of a power converter is that it is completely controllable and can achieve bidirectional power flow according to system requirements. As more new energy devices are connected to the power grid, the changes and disturbances in the power grid are gradually increasing, and the stable and reliable operation of the power converter has also become an important issue for the safe operation of the power grid.

[0003] In traditional technologies, the control signal of the power converter can be generated by means of fuzzy control to improve the stable operation of the power converter in a multi-interference environment. However, the fuzzy control method is difficult to debug, the parameter design is complex, and it cannot maintain the stable operation of the power converter in extreme environments. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a control method, device, computer device, computer-readable storage medium and computer program product for an energy storage converter that can improve the operation stability and robustness of the power converter and the energy storage system.

[0005] In a first aspect, the present application provides a control method for an energy storage converter. The method includes:

[0006] Input the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model;

[0007] Input the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and apply the actual current value to the current loop to obtain the voltage command value of the energy storage converter;

[0008] Perform modulation processing on the voltage command value to obtain the control drive signal of the energy storage converter.

[0009] In one embodiment, before inputting the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system, it further includes:

[0010] According to the control object transfer model, a sensitivity model of the energy storage system is constructed;

[0011] According to the sensitivity model, a controller optimization model is constructed; the initial robust controller is taken as the optimization objective in the controller optimization model;

[0012] Through the controller optimization model, iterative update processing is performed on the initial robust controller to obtain the optimized robust controller.

[0013] In one embodiment, constructing a controller optimization model according to the sensitivity model includes:

[0014] Obtain a calibration matrix and a stable transfer model;

[0015] According to the calibration matrix, the sensitivity model, and the stable transfer model, the controller optimization model is constructed.

[0016] In one embodiment, inputting the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system, includes:

[0017] Obtain the d-axis voltage deviation between the voltage reference value of the energy storage converter on the d-axis and the actual voltage value of the energy storage converter on the d-axis, and obtain the q-axis voltage deviation between the voltage reference value of the energy storage converter on the q-axis and the actual voltage value of the energy storage converter on the q-axis;

[0018] Process the d-axis voltage deviation through the robust controller corresponding to the voltage loop to obtain the current reference value of the current loop on the d-axis;

[0019] Process the q-axis voltage deviation through the robust controller to obtain the current reference value of the current loop on the q-axis.

[0020] In one embodiment, inputting the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and applying the actual current value to the current loop to obtain the voltage command value of the energy storage converter, includes:

[0021] Obtain the d-axis current deviation between the current reference value of the current loop on the d-axis and the actual current value of the energy storage converter on the d-axis, and obtain the q-axis current deviation between the current reference value of the current loop on the q-axis and the actual current value of the energy storage converter on the q-axis;

[0022] Based on the actual value of the current of the energy storage converter on the d-axis and the filter inductor data of the energy storage converter, obtain the d-axis application value on the current loop;

[0023] Based on the actual value of the current of the energy storage converter on the q-axis and the filter inductor data, obtain the q-axis application value on the current loop;

[0024] Through the linear controller, process the d-axis current deviation and the d-axis application value to obtain the d-axis voltage command value of the energy storage converter;

[0025] Through the linear controller, process the q-axis current deviation and the q-axis application value to obtain the q-axis voltage command value of the energy storage converter.

[0026] In one embodiment, modulating the voltage command value to obtain the control drive signal of the energy storage converter includes:

[0027] Perform pulse width modulation processing on the d-axis voltage command value and the q-axis voltage command value to obtain the control drive signal of the energy storage converter;

[0028] Wherein, the control drive signal is used to stably control the energy storage converter.

[0029] In a second aspect, the present application also provides an energy storage converter control device. The device includes:

[0030] A reference value obtaining module, configured to input the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system to the robust controller corresponding to the voltage loop of the energy storage system, and obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model;

[0031] An instruction value generating module, configured to input the current deviation between the current reference value and the actual current value of the energy storage converter to the linear controller corresponding to the current loop, and apply the actual current value to the current loop, to obtain the voltage command value of the energy storage converter;

[0032] A drive signal generating module, configured to modulate the voltage command value to obtain the control drive signal of the energy storage converter.

[0033] In a third aspect, the present application also provides a computer device. The computer device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0034] Input the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model;

[0035] Input the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and apply the actual current value to the current loop to obtain the voltage command value of the energy storage converter;

[0036] Perform modulation processing on the voltage command value to obtain the control drive signal of the energy storage converter.

[0037] In a fourth aspect, the present application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0038] Input the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model;

[0039] Input the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and apply the actual current value to the current loop to obtain the voltage command value of the energy storage converter;

[0040] Perform modulation processing on the voltage command value to obtain the control drive signal of the energy storage converter.

[0041] In a fifth aspect, the present application also provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0042] Input the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model;

[0043] Input the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and apply the actual current value to the current loop to obtain the voltage command value of the energy storage converter;

[0044] The voltage command value is modulated to obtain the control drive signal of the energy storage converter.

[0045] The above energy storage converter control method, device, computer device, storage medium and computer program product input the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model; input the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and apply the actual current value to the current loop to obtain the voltage command value of the energy storage converter in the energy storage system; the voltage command value is modulated to obtain the control drive signal of the energy storage converter. By using this method, based on the voltage-current double-loop structure, the voltage loop uses a robust controller and the current loop uses a linear controller, which can analyze and assist the uncertain energy storage system using the robust controller, improve the robust stability for unstructured uncertain system disturbances and nominal performance requirements, so as to output a control drive signal that can stably control the energy storage converter, and then realize the stable control of the energy storage converter, and also improve the operation stability and robustness of the energy storage system under uncertain fluctuations, so as to better adapt to the changes and disturbances under a weak power grid. Description of the Drawings

[0046] Figure 1 It is an application environment diagram of the energy storage converter control method in an embodiment;

[0047] Figure 2 It is a schematic flowchart of the energy storage converter control method in an embodiment;

[0048] Figure 3 It is a schematic flowchart of the steps to obtain the updated robust controller in an embodiment;

[0049] Figure 4 It is a schematic structural diagram of the robust controller in an embodiment;

[0050] Figure 5 It is a schematic structural diagram of the voltage-current double-loop control in an embodiment;

[0051] Figure 6 It is a schematic flowchart of the energy storage converter control method in another embodiment;

[0052] Figure 7 It is a schematic diagram of the energy storage converter connected to a weak power grid in an embodiment;

[0053] Figure 8 It is a structural block diagram of the energy storage converter control device in an embodiment;

[0054] Figure 9 It is the internal structure diagram of a computer device in an embodiment. Specific implementation manners

[0055] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0056] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data need to comply with relevant regulations.

[0057] The energy storage converter control method provided by the embodiment of the present application can be applied to, for example Figure 1 the application environment shown in the figure. Among them, the energy storage system 10 includes an energy storage battery 101 and an energy storage inverter 102 connected to each other. The data storage system can store the data that the energy storage system 10 needs to process. The data storage system can be integrated on the server, or can be placed in the cloud or other network servers.

[0058] In one embodiment, as Figure 2 shown in the figure, an energy storage converter control method is provided. Taking the energy storage system in Figure 1 as an example for description, it includes the following steps:

[0059] Step S201: Input the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained by processing based on the control object transfer model.

[0060] Among them, the energy storage converter refers to a power device used to change the characteristics of current or voltage. In practical applications, the energy storage converter can control the flow of current at different times by controlling switching elements (such as thyristors, etc.), so as to achieve the conversion of current or voltage. By adjusting the switching frequency and switching mode of the switch, the energy storage converter can meet various voltage and current conversion requirements.

[0061] Among them, the energy storage system refers to the technology and equipment for storing electric energy. The energy storage system mainly stores electric energy when the power demand is low and releases electric energy during peak demand periods. The energy storage system can include energy storage batteries (such as lithium-ion batteries), energy storage converters, etc.

[0062] Among them, the voltage loop refers to the control loop used to control the output voltage of the energy storage system. The voltage loop can monitor the output voltage of the energy storage system and adjust it according to the set target voltage. The voltage loop is one of the important control loops in the energy storage system. Specifically, the voltage loop can be the outer voltage loop. The voltage loop is mainly responsible for achieving precise control of the voltage and reducing the voltage fluctuation of the energy storage system when the load changes. By adjusting the output of the converter, the voltage loop can enable the energy storage system to maintain within a specific voltage range, ensuring compatibility with the power grid.

[0063] Among them, the robust controller is used to enable the energy storage system to have the ability to resist uncertainties and disturbances, ensuring that the energy storage system can still maintain stability and performance under model uncertainties and external disturbances.

[0064] Specifically, the energy storage system can pre-analyze the controlled objects with uncertainties in the energy storage system, and then construct a robust controller corresponding to the outer voltage loop of the energy storage system. During the operation of the energy storage system, it can also read the voltage reference value and the actual voltage value of the energy storage converter, and then calculate the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter, and then input the voltage deviation into the robust controller corresponding to the outer voltage loop of the energy storage system, so as to process the voltage deviation through the robust controller, and then output the current reference value of the inner current loop of the energy storage system.

[0065] Among them, the voltage reference value refers to the target voltage value set for the energy storage system, that is, the expected output voltage. The voltage reference value can be regarded as an ideal value.

[0066] Among them, the actual voltage value refers to the actually measured output voltage, which reflects the current voltage state of the energy storage converter.

[0067] In practical applications, when the actual voltage value is not equal to the voltage reference value, an error signal will be generated, and the output of the energy storage system will be adjusted through a controller (such as a PI controller, a robust controller, etc.) until the actual voltage value approaches the desired voltage reference value.

[0068] Furthermore, the grid side of the power grid is associated with the energy storage system. It is also possible to obtain the voltage deviation between the voltage reference value on the grid side and the actual voltage value on the grid side, and input it into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system.

[0069] Step S202: Input the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and apply the actual current value to the current loop to obtain the voltage command value of the energy storage converter in the energy storage system.

[0070] Among them, the current loop refers to the control loop used to control the output current of the energy storage system. The current loop can monitor the output current of the energy storage system in real time and compare it with the set target current. The current loop is one of the important control loops in the energy storage system. Specifically, the current loop can be the inner current loop. The main function of the current loop is to control the current output to ensure that the current does not exceed the safe operating range of the power equipment during the charging and discharging processes. The voltage outer loop and the current inner loop usually work together to ensure the operation stability and efficiency of the energy storage system under various working conditions.

[0071] Among them, the linear controller controls by means of the proportional part and the integral part of the error (i.e., deviation) between the target value and the actual value (such as the current reference value and the actual current value). The linear controller can be a PI (Proportional-Integral) controller. The proportional part of the linear controller is used to control according to the current error and respond quickly to changes; the integral part of the linear controller is used to accumulate past errors, eliminate steady-state errors, and ensure the long-term accuracy of the energy storage system.

[0072] Among them, the voltage command value, which can also be called the voltage signal value, refers to the value used to indicate or set the voltage signal in the energy storage system.

[0073] Specifically, the energy storage system can also obtain the actual current value of the energy storage converter, such as directly reading the actual current value of the energy storage converter, or receiving the actual current value sent by the energy storage converter in real time. The energy storage system calculates the current deviation between the current reference value of the current inner loop and the actual current value of the energy storage converter, then inputs the current deviation into the corresponding linear controller (such as a PI controller) of the current inner loop, and applies the actual current value to the current loop to obtain the current application value, so as to process the current deviation and the current application value through the linear controller, and further output the voltage command value of the energy storage converter in the energy storage system.

[0074] Among them, the current reference value refers to the target current value set for the energy storage system, representing the expected output current. The current reference value can be regarded as the ideal current value required to operate or control the energy storage system.

[0075] Among them, the actual current value refers to the actual output current obtained through measurement, reflecting the current state of the energy storage converter at present.

[0076] Step S203: Modulate the voltage command value to obtain the control drive signal of the energy storage converter.

[0077] Among them, the control drive signal refers to the signal used to control the switching state of the switching elements inside the energy storage converter.

[0078] Specifically, the energy storage system can also convert the voltage command value into a corresponding modulation signal through signal modulation processing, and then generate a control drive signal for the energy storage converter; the energy storage converter can control the switching elements inside it based on the control drive signal to achieve robust control of the current or voltage of the energy storage system.

[0079] In the above energy storage converter control method, the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter is input to the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model; the current deviation between the current reference value and the actual current value of the energy storage converter is input to the linear controller corresponding to the current loop, and the actual current value is applied to the current loop to obtain the voltage command value of the energy storage converter in the energy storage system; the voltage command value is modulated to obtain the control drive signal of the energy storage converter. By using this method, based on the voltage-current double-loop structure, the voltage loop uses a robust controller and the current loop uses a linear controller, which can analyze and assist the uncertain energy storage system using the robust controller, improve the robust stability for unstructured uncertain system disturbances and nominal performance requirements, so as to output a control drive signal that can stably control the energy storage converter, and then achieve stable control of the energy storage converter, and also improve the operation stability and robustness of the energy storage system under uncertain fluctuations, thus better adapting to the changes and disturbances under a weak power grid.

[0080] In one embodiment, as Figure 3 shown, before the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system is input to the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system in the above step S201, it further includes:

[0081] Step S301, construct a sensitivity model of the energy storage system according to the control object transfer model.

[0082] Figure 4 As shown in the structural schematic diagram of the robust controller, in practical applications, there is a control object in the energy storage system that is affected by disturbance signals and has multiplicative uncertainty, that is, a multiplicative uncertain object. The multiplicative uncertain object can be identified by the following formula:

[0083]

[0084] In the formula, is the multiplicative uncertain object; is a fixed stable transfer function, designed according to different system weighted sensitivities; is to satisfy infinity Variable transfer function; Is the control object transfer model; s represents the Laplace operator.

[0085] Among them, the control object transfer model can be expressed by the following formula:

[0086]

[0087] In the formula, Is the grid inductance data; 、 Are the grid connection point d and q axis currents respectively; Is the grid connection point d axis voltage; Is the grid angular frequency; s represents the Laplace operator; among them, 、 、 And Are obtained by measurement;

[0088] Based on the robust controller, the sensitivity model of the control object transfer model can be obtained. The sensitivity model of the control object transfer model can be expressed by the following formula:

[0089]

[0090] In the formula, Is the feedback controller, Is the sensitivity function of the control object transfer model, Is a fixed stable transfer function, Is to satisfy infinity Variable transfer function, Is the nominal control object transfer model; s represents the Laplace operator;

[0091] The sensitivity function of the nominal closed-loop energy storage system Is expressed as follows:

[0092]

[0093] In the formula, Is the sensitivity model of the energy storage system; Is the robust controller; Is the control object transfer model; s represents the Laplace operator.

[0094] Step S302, according to the sensitivity model, construct a controller optimization model; the controller optimization model takes the initial robust controller as the optimization goal.

[0095] Specifically, the energy storage system can also design an initial controller optimization model based on the sensitivity model, that is, regarding the solution of the robust controller as an optimization problem, and iteratively optimizing to solve the optimal robust controller through multiple iterations. The energy storage system can set the iterative optimization model for solving the robust controller as the controller optimization model to iteratively optimize the initially set robust controller (i.e., the initial robust controller) through the controller optimization model.

[0096] Step S303: Through the controller optimization model, perform iterative update processing on the initial robust controller to obtain an updated robust controller.

[0097] The energy storage system can use H ∞ optimization method to iteratively optimize the initial robust controller. Specifically, first set an initial calibration matrix D(0) for the energy storage system, and then calculate the initial robust controller K using the initial calibration matrix D(0). After obtaining the initial robust controller K, the energy storage system can recalculate the calibration matrix D at each iteration to minimize the value in the controller optimization model, substitute the newly calculated calibration matrix D into the calculation of the new robust controller K, and repeat the iteration multiple times until the updated robust controller K is finally obtained. In this embodiment, through the control object transfer model, the sensitivity model of the energy storage system is constructed; then, based on the sensitivity model, the controller optimization model is constructed; finally, through the controller optimization model, iterative update processing is performed on the initial robust controller to obtain an updated robust controller. Using the updated robust controller to replace the pi controller in the traditional voltage loop can analyze and process the energy storage system with uncertainties, and can maximize the stability and robustness of the closed-loop energy storage system.

[0098] In one embodiment, step S302 above, constructing the controller optimization model according to the sensitivity model specifically includes the following content: obtaining the calibration matrix and the stable transfer model; constructing the controller optimization model according to the calibration matrix, the sensitivity model, and the stable transfer model.

[0099] Among them, the calibration matrix is used to linearize the state or output of the energy storage system to help the robust controller converge to the actual value more efficiently and accurately during the iteration process.

[0100] Specifically, based on the above steps S301 to S303, it can be analyzed that: if and only if the infinity norm

[0101] is satisfied, the robust controller can stabilize the energy storage system. As shown, if and only if the infinity norm Figure 4 is satisfied, when and only when the infinity norm When, the robust controller can make the energy storage system robust; where is the output weight function which can be obtained by weighting the sensitivity model according to the actual scenario requirements of the energy storage system.

[0102] In practical applications, selecting the output weight function to participate in the iterative optimization process of the robust controller can make the tracking error very small at the frequency of . At this time, the robust controller can provide good tracking performance. The DK Iteration Method is used to obtain a tighter upper bound by using a calibration matrix D, that is . At this time, the calibration matrix here is also a frequency function . Therefore, the iterative optimization problem of the robust controller is a two-parameter minimization problem. Therefore, the constructed controller optimization model can be expressed by the following formula:

[0103]

[0104] In the formula, inf is the input; sup is the iteration; is the number of iterations; in this embodiment, , is the K ∞ function that is locally Lipschitz on (0, ∞).

[0105] In this embodiment, the DK iteration method is used to solve the nonlinear optimization problem of the robust controller. Through the calibration matrix, the sensitivity model and the stable transfer model, a controller optimization model is constructed. Then, in the subsequent steps, the initial robust controller can be iterated through the controller optimization model to gradually obtain the optimal solution of the robust controller, effectively improving the reliability and robustness of the processed robust controller, and helping to improve the stability and robustness of the energy storage system.

[0106] In one embodiment, in step S201, the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system is input to the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system, which specifically includes the following: obtaining the d-axis voltage deviation between the voltage reference value of the energy storage converter on the d-axis and the actual voltage value of the energy storage converter on the d-axis, and obtaining the q-axis voltage deviation between the voltage reference value of the energy storage converter on the q-axis and the actual voltage value of the energy storage converter on the q-axis; processing the d-axis voltage deviation through the robust controller corresponding to the voltage loop to obtain the current reference value of the current loop on the d-axis; processing the q-axis voltage deviation through the robust controller to obtain the current reference value of the current loop on the q-axis.

[0107] Figure 5 It is a schematic diagram of the structure of voltage-current double-loop control. Specifically, as Figure 5 shown, the energy storage system can input the d-axis voltage deviation between the voltage reference value of the energy storage converter on the d-axis and the actual voltage value of the energy storage converter on the d-axis , and the q-axis voltage deviation between the voltage reference value of the energy storage converter on the q-axis and the actual voltage value of the energy storage converter on the q-axis into the robust controller corresponding to the outer voltage loop for processing, and then calculate the current reference value of the current loop on the d-axis and the current reference value of the current loop on the q-axis . In Figure 5 , dq represents the d-axis and q-axis, which is a coordinate transformation in motor control; abc represents three-phase power consumption, a represents phase a, b represents phase b, and c represents phase c.

[0108] In practical applications, the calculation processes of the current reference value of the current loop on the d-axis and the current reference value of the current loop on the q-axis can be expressed by the following formulas:

[0109]

[0110] In the formula, represents the robust controller, obtained from the above steps S301 to S303; and are obtained by measurement; s represents the Laplace operator.

[0111] In this embodiment, by multiplying the voltage deviation between the voltage reference values and the actual voltage values of the energy storage converter on the d- and q-axes by the robust controller, the current reference values of the current inner loop on the d- and q-axes can be calculated. The robust controller effectively optimizes the voltage deviation of the voltage outer loop, and can increase the stability of the energy storage system while improving the transient stability margin.

[0112] In one embodiment, in the above step S202, the current deviation between the current reference value and the actual current value of the energy storage converter is input to the linear controller corresponding to the current loop, and the actual current value is applied to the current loop to obtain the voltage command value of the energy storage converter in the energy storage system, which specifically includes the following contents: obtaining the d-axis current deviation between the current reference value of the current loop on the d-axis and the actual current value of the energy storage converter on the d-axis, and obtaining the q-axis current deviation between the current reference value of the current loop on the q-axis and the actual current value of the energy storage converter on the q-axis; obtaining the d-axis application value on the current loop according to the actual current value of the energy storage converter on the d-axis and the filter inductor data of the energy storage converter; obtaining the q-axis application value on the current loop according to the actual current value of the energy storage converter on the q-axis and the filter inductor data; processing the d-axis current deviation and the d-axis application value through the linear controller to obtain the d-axis voltage command value of the energy storage converter; processing the q-axis current deviation and the q-axis application value through the linear controller to obtain the q-axis voltage command value of the energy storage converter.

[0113] Specifically, as Figure 5 shown, the energy storage system can input the q-axis current deviation between the current reference value of the current loop on the d-axis and the actual current value of the energy storage converter on the d-axis, as well as the q-axis current deviation between the current reference value of the current loop on the q-axis and the actual current value of the energy storage converter on the q-axis, into the linear controller (such as a PI regulator) of the inner current loop together, and then add the actual current value of the energy storage converter on the q-axis multiplied by a coefficient to the d-axis and q-axis current loops respectively after multiplying the actual current value of the energy storage converter on the d-axis to obtain the d-axis and q-axis application values on the current loop, and finally output the voltage command values of the energy storage converter on the d-axis and q-axis and .

[0114] In practical applications, the calculation process of the voltage command values of the energy storage converter on the d-axis and q-axis and can be expressed by the following formula:

[0115]

[0116] In the formula, is the voltage angular frequency of the energy storage converter, which is obtained by measurement; and are obtained by measurement; L is the filter inductor data of the energy storage converter; and They are the proportional coefficient and integral coefficient of the d-axis current loop respectively, which can be set according to different energy storage systems; and They are the proportional coefficient and integral coefficient of the PI regulation of the q-axis current loop respectively; they can be designed according to different systems; s represents the Laplace operator.

[0117] In this embodiment, through the current deviation between the current reference values of the d-axis and q-axis of the current inner loop and the actual current values of the energy storage converter on the d-axis and q-axis, the product with the linear controller, and the current application values on the d-axis and q-axis of the current inner loop, the voltage command values of the energy storage converter on the d-axis and q-axis can be calculated. The current deviation of the current inner loop is effectively optimized through the linear controller, further improving the stability of the energy storage system.

[0118] In one embodiment, in step S203 above, the voltage command value is modulated to obtain the control drive signal of the energy storage converter, which specifically includes the following content: performing pulse width modulation on the d-axis voltage command value and the q-axis voltage command value to obtain the control drive signal of the energy storage converter; wherein, the control drive signal is used to stably control the energy storage converter.

[0119] Specifically, as Figure 5 shown, the energy storage system can also perform space vector pulse width modulation (SVPWM) on the d-axis voltage command value and the q-axis voltage command value to obtain the control drive signal of the energy storage converter; furthermore, the energy storage system can stably control the switching elements in the energy storage converter through the control drive signal.

[0120] In this embodiment, the control drive signal that can stably control the energy storage converter is obtained, thereby realizing the stable control of the energy storage converter, and also improving the operation stability and robustness of the energy storage system under uncertain fluctuations, so as to better adapt to the changes and disturbances under a weak power grid.

[0121] In one embodiment, as Figure 6 shown, another control method for the energy storage converter is provided. Taking the application of this method to the Figure 1 energy storage system as an example for illustration, it includes the following steps:

[0122] Step S601, according to the control object transfer model, construct the sensitivity model of the energy storage system; according to the sensitivity model, construct the controller optimization model; the controller optimization model takes the initial robust controller as the optimization target.

[0123] Step S602, through the controller optimization model, perform iterative update processing on the initial robust controller to obtain the updated robust controller.

[0124] Step S603: Obtain the d-axis voltage deviation between the voltage reference value of the energy storage converter on the d-axis and the actual voltage value of the energy storage converter on the d-axis, and obtain the q-axis voltage deviation between the voltage reference value of the energy storage converter on the q-axis and the actual voltage value of the energy storage converter on the q-axis.

[0125] Step S604: Process the d-axis voltage deviation through the robust controller corresponding to the voltage loop to obtain the current reference value of the current loop on the d-axis; process the q-axis voltage deviation through the robust controller to obtain the current reference value of the current loop on the q-axis.

[0126] Step S605: Obtain the d-axis current deviation between the current reference value of the current loop on the d-axis and the actual current value of the energy storage converter on the d-axis, and obtain the q-axis current deviation between the current reference value of the current loop on the q-axis and the actual current value of the energy storage converter on the q-axis.

[0127] Step S606: Obtain the d-axis application value on the current loop according to the actual current value of the energy storage converter on the d-axis and the filter inductor data of the energy storage converter; obtain the q-axis application value on the current loop according to the actual current value of the energy storage converter on the q-axis and the filter inductor data.

[0128] Step S607: Process the d-axis current deviation and the d-axis application value through a linear controller to obtain the d-axis voltage command value of the energy storage converter.

[0129] Step S608: Process the q-axis current deviation and the q-axis application value through a linear controller to obtain the q-axis voltage command value of the energy storage converter.

[0130] Step S609: Perform pulse width modulation processing on the d-axis voltage command value and the q-axis voltage command value to obtain the control drive signal of the energy storage converter; wherein, the control drive signal is used to stably control the energy storage converter.

[0131] The above energy storage converter control method can achieve the following beneficial effects: Based on the voltage-current double-loop structure, the voltage loop uses a robust controller and the current loop uses a linear controller, which can analyze and assist the uncertain energy storage system using the robust controller, improve the robust stability for the unstructured uncertain system disturbance and nominal performance requirements, thereby outputting a control drive signal that can stably control the energy storage converter, and then realizing the stable control of the energy storage converter, and also improving the operation stability and robustness of the energy storage system under uncertain fluctuations, so as to better adapt to the changes and disturbances under a weak power grid.

[0132] To more clearly illustrate the energy storage converter control method provided by the embodiments of the present disclosure, the above energy storage converter control method will be specifically described below with a specific embodiment. Another energy storage converter control method is provided, which can be applied to Figure 1 the energy storage system in

[0133] Figure 7 FIG. is a schematic diagram of an energy storage converter connected to a weak grid. First, a voltage loop robust controller is designed; then, the deviation between the voltage reference value and the actual voltage value is input into the robust controller, and the current reference value of the current loop is obtained through processing; then, the deviation between the current reference value and the actual current value fed back by the energy storage converter is input into the PI controller corresponding to the current loop and voltage feedforward is added, and the voltage command of the energy storage converter is obtained through processing; the voltage command is modulated to generate a driving signal for the energy storage converter.

[0134] In this embodiment, based on the voltage-current double-loop structure, the voltage loop uses a robust controller and the current loop uses a linear controller. It can analyze and assist the uncertain energy storage system using the robust controller, improve the robust stability for unstructured uncertain system disturbances and nominal performance requirements, so as to output a control driving signal that can stably control the energy storage converter, and then realize the stable control of the energy storage converter. It also improves the operation stability and robustness of the energy storage system under uncertain fluctuations, so as to better adapt to the changes and disturbances under a weak grid.

[0135] It should be understood that although the steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or steps in other steps.

[0136] Based on the same inventive concept, the embodiments of the present application also provide an energy storage converter control device for implementing the above-mentioned energy storage converter control method. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the energy storage converter control device provided below can refer to the limitations on the energy storage converter control method in the above text, and will not be repeated here.

[0137] In one embodiment, as Figure 8As shown, a control device 800 for an energy storage converter is provided, including: a reference value obtaining module 801, a command value generating module 802, and a drive signal generating module 803, where:

[0138] The reference value obtaining module 801 is configured to input the voltage deviation between the voltage reference value and the actual voltage value of the energy storage converter in the energy storage system into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained by processing based on the control object transfer model.

[0139] The command value generating module 802 is configured to input the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and apply the actual current value to the current loop to obtain the voltage command value of the energy storage converter.

[0140] The drive signal generating module 803 is configured to perform modulation processing on the voltage command value to obtain the control drive signal of the energy storage converter.

[0141] In one embodiment, the control device 800 for the energy storage converter further includes a controller obtaining module, configured to construct a sensitivity model of the energy storage system according to the control object transfer model; construct a controller optimization model according to the sensitivity model; the controller optimization model takes the initial robust controller as the optimization target; through the controller optimization model, perform iterative update processing on the initial robust controller to obtain the updated robust controller.

[0142] In one embodiment, the control device 800 for the energy storage converter further includes a controller optimization module, configured to obtain a calibration matrix and a stable transfer model; construct a controller optimization model according to the calibration matrix, the sensitivity model, and the stable transfer model.

[0143] In one embodiment, the reference value obtaining module 801 is further configured to obtain the d-axis voltage deviation between the voltage reference value of the energy storage converter on the d-axis and the actual voltage value of the energy storage converter on the d-axis, and obtain the q-axis voltage deviation between the voltage reference value of the energy storage converter on the q-axis and the actual voltage value of the energy storage converter on the q-axis; process the d-axis voltage deviation through the robust controller corresponding to the voltage loop to obtain the current reference value of the current loop on the d-axis; process the q-axis voltage deviation through the robust controller to obtain the current reference value of the current loop on the q-axis.

[0144] In one embodiment, the instruction value generation module 802 is further configured to obtain the d-axis current deviation between the current reference value of the current loop on the d-axis and the actual current value of the energy storage converter on the d-axis, and obtain the q-axis current deviation between the current reference value of the current loop on the q-axis and the actual current value of the energy storage converter on the q-axis; obtain the d-axis application value on the current loop according to the actual current value of the energy storage converter on the d-axis and the filter inductor data of the energy storage converter; obtain the q-axis application value on the current loop according to the actual current value of the energy storage converter on the q-axis and the filter inductor data; process the d-axis current deviation and the d-axis application value through a linear controller to obtain the d-axis voltage command value of the energy storage converter; process the q-axis current deviation and the q-axis application value through a linear controller to obtain the q-axis voltage command value of the energy storage converter.

[0145] In one embodiment, the drive signal generation module 803 is further configured to perform pulse width modulation processing on the d-axis voltage command value and the q-axis voltage command value to obtain the control drive signal of the energy storage converter; wherein, the control drive signal is used to stably control the energy storage converter.

[0146] Each module in the above energy storage converter control device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0147] In one embodiment, a computer device is provided. The computer device can be an energy storage system, and its internal structure diagram can be as Figure 9 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data such as actual voltage values and actual current values. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements an energy storage converter control method.

[0148] Those skilled in the art can understand, Figure 9The structure shown is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0149] In one embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0150] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0151] In one embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0152] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0153] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0154] The above-described embodiments merely represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for controlling an energy storage converter, characterized in that: The method comprises: The voltage deviation between the voltage reference value of the energy storage converter in the energy storage system and the actual voltage value of the energy storage converter is input into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model; Inputting the current deviation between the current reference value and the actual current value of the energy storage converter into the linear controller corresponding to the current loop, and applying the actual current value to the current loop to obtain the voltage command value of the energy storage converter; The voltage command value is modulated to obtain a control drive signal for the energy storage converter.

2. The method according to claim 1, characterized in that: Before inputting the voltage deviation between the voltage reference value of the energy storage converter in the energy storage system and the actual voltage value of the energy storage converter into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system, the method further includes: Constructing a sensitivity model of the energy storage system according to the control object transfer model; A controller optimization model is constructed based on the sensitivity model; the controller optimization model takes the initial robust controller as an optimization target; The initial robust controller is iteratively updated through the controller optimization model to obtain the updated robust controller.

3. The method according to claim 2, characterized in that The controller optimization model is constructed according to the sensitivity model, including: Obtain calibration matrix and stable transfer model; The controller optimization model is constructed based on the calibration matrix, the sensitivity model and the stable transfer model.

4. The method according to claim 1, characterized in that: The step of inputting a voltage deviation between a voltage reference value of an energy storage converter in an energy storage system and an actual voltage value of the energy storage converter into a robust controller corresponding to a voltage loop of the energy storage system to obtain a current reference value of a current loop of the energy storage system comprises: Obtaining a d-axis voltage deviation between a voltage reference value of the energy storage converter on the d-axis and an actual voltage value of the energy storage converter on the d-axis, and obtaining a q-axis voltage deviation between a voltage reference value of the energy storage converter on the q-axis and an actual voltage value of the energy storage converter on the q-axis; The d-axis voltage deviation is processed by a robust controller corresponding to the voltage loop to obtain a current reference value of the current loop on the d-axis; The q-axis voltage deviation is processed by the robust controller to obtain a current reference value of the current loop on the q-axis.

5. The method according to claim 4, characterized in that The step of inputting the current deviation between the current reference value and the actual current value of the energy storage converter into a linear controller corresponding to the current loop, and applying the actual current value to the current loop to obtain a voltage command value of the energy storage converter comprises: Obtaining a d-axis current deviation between a current reference value of the current loop on the d-axis and an actual current value of the energy storage converter on the d-axis, and obtaining a q-axis current deviation between a current reference value of the current loop on the q-axis and an actual current value of the energy storage converter on the q-axis; Obtaining a d-axis application value on the current loop according to the actual current value of the energy storage converter on the d-axis and the filter inductance data of the energy storage converter; According to the actual current value of the energy storage converter on the q-axis and the filter inductance data, obtaining the q-axis application value on the current loop; Processing the d-axis current deviation and the d-axis application value through the linear controller to obtain a d-axis voltage command value of the energy storage converter; The q-axis current deviation and the q-axis application value are processed by the linear controller to obtain the q-axis voltage command value of the energy storage converter.

6. The method according to claim 5, characterized in that The step of modulating the voltage command value to obtain a control drive signal for the energy storage converter includes: Performing pulse width modulation processing on the d-axis voltage command value and the q-axis voltage command value to obtain a control drive signal of the energy storage converter; Wherein, the control drive signal is used to stably control the energy storage converter.

7. An energy storage converter control device, characterized in that: The device comprises: A reference value obtaining module is used to input the voltage deviation between the voltage reference value of the energy storage converter in the energy storage system and the actual voltage value of the energy storage converter into the robust controller corresponding to the voltage loop of the energy storage system to obtain the current reference value of the current loop of the energy storage system; the robust controller is obtained based on the control object transfer model; An instruction value generating module, used for inputting a current deviation between the current reference value and an actual current value of the energy storage converter into a linear controller corresponding to the current loop, and applying the actual current value to the current loop to obtain a voltage instruction value of the energy storage converter; The drive signal generating module is used to modulate the voltage command value to obtain a control drive signal for the energy storage converter.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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