Current control device and current control method based on active resonance suppression

Abstract

The application discloses a current control device and a current control method based on active resonance suppression. The current control device comprises a current controller, an active resonance suppression component, a filter capacitor current compensation component and a filter inductance voltage drop compensation component. The current input end of the current controller is connected with the current signal input end and the current feedback end. The first voltage output end of the current controller is connected with the second voltage output end. The second voltage output end is also connected with the input end of the active resonance suppression component. The connection point of the first voltage output end and the second voltage output end is connected with the input end of the filter capacitor current compensation component and the filter reactance filter inductance voltage drop compensation end. The output end of the filter inductance voltage drop compensation component is connected with the filter inductance voltage drop compensation end. The current control device is suitable for the current control of three-phase alternating current motors and alternating current power grids, can simultaneously suppress the resonance generated by the control excitation and the motor counter electromotive force or the power grid voltage harmonics, and improves the reliability of resonance suppression.

Description

Technical Field

[0001] This invention relates to the technical field of energy storage control, and in particular to a current control device and current control method based on active resonance suppression. Background Technology

[0002] In the flywheel energy storage industry, both the high energy efficiency of flywheel motors and the power quality of AC grids require sufficient attenuation of high-order harmonics in the three-phase current. Therefore, motor inverters and grid-connected inverters often need to be configured with LC filters for joint use.

[0003] The use of LC filters introduces the risk of resonance in current control. The filter's inductance and capacitance, along with the motor's leakage inductance and the grid's line inductance, form an inherent resonant frequency. When the frequency bands of the high-frequency control voltage excitation and the motor's back EMF / grid voltage harmonics are close to this inherent resonant frequency, active resonance suppression is needed to avoid overcurrent leakage caused by resonance. Current technologies typically achieve suppression by using external sensors to measure the capacitor voltage and compensate the current control setpoint. This method has high hardware costs, and its suppression capability is significantly reduced when the current loop bandwidth is limited (especially in low-carrier frequency applications). Therefore, existing technologies applied to grid and motor current control in the energy storage industry cannot reliably suppress resonance. Summary of the Invention

[0004] This invention provides a current control device and method based on active resonance suppression, aiming to solve the problem that existing technologies applied to power grid and motor current control in the energy storage industry cannot reliably suppress resonance.

[0005] In a first aspect, embodiments of the present invention disclose a current control device based on active resonance suppression, wherein the current control device includes a current controller, an active resonance suppression component, a filter capacitor current compensation component, and a filter inductor voltage drop compensation component; the current controller outputs a given voltage for the inverter;

[0006] The current input terminal of the current controller is connected to both the current signal input terminal and the current feedback terminal; the current signal input terminal is used to input a given current value, and the current feedback terminal is used to input a feedback current value.

[0007] The first voltage output terminal of the current controller is connected to the second voltage output terminal, and the first voltage output terminal and the second voltage output terminal output a first voltage value and a second voltage value that are proportionally and integrally regulated respectively.

[0008] The second voltage output terminal is also connected to the input terminal of the active resonance suppression component; the connection point between the first voltage output terminal and the second voltage output terminal is connected to the input terminal of the filter capacitor current compensation component and the filter inductor voltage drop compensation terminal; the output terminal of the filter inductor voltage drop compensation component is connected to the filter inductor voltage drop compensation terminal, and the filter inductor voltage drop compensation terminal is used to output the corresponding inverter given voltage;

[0009] The output feedback terminal is connected to the input terminal of the filter inductor voltage drop compensation component and the output terminal of the filter capacitor current compensation component, and the connection point serves as the current compensation terminal; the current compensation terminal is connected to the output terminal of the active resonance suppression component and serves as the current feedback terminal; the output feedback terminal is used to input the driver output feedback current.

[0010] Secondly, embodiments of the present invention disclose a current control method based on active resonance suppression, wherein the current control method is applied to a current control device based on active resonance suppression as described in the first aspect above, and the method includes:

[0011] The current compensation of the driver output feedback current input to the output feedback terminal is performed based on the current of the filter capacitor output by the filter capacitor current compensation component to obtain the corresponding load feedback current.

[0012] The load feedback current is compensated based on the oscillation suppression current output by the active resonance suppression component to obtain the corresponding feedback current value;

[0013] The given current value and the feedback current value are synchronously input into the current controller for calculation to obtain the corresponding controller output voltage;

[0014] According to the adjustment rules, the current controller outputs a first voltage value and a second voltage value corresponding to the controller output voltage from the first voltage output terminal and the second voltage output terminal, respectively.

[0015] The voltage drop compensation of the controller output voltage is performed based on the compensation voltage output by the filter inductor voltage drop compensation component to obtain the corresponding inverter given voltage, which is then output through the filter inductor voltage drop compensation terminal.

[0016] The active resonance suppression component performs resonance suppression on the second voltage value output from the second voltage output terminal, obtains the corresponding oscillation suppression current, and outputs it.

[0017] This application discloses a current control device and method based on active resonance suppression. The current control device includes a current controller, an active resonance suppression component, a filter capacitor current compensation component, and a filter inductor voltage drop compensation component. The current input terminal of the current controller is connected to both a current signal input terminal and a current feedback terminal. A first voltage output terminal of the current controller is connected to a second voltage output terminal. The second voltage output terminal is also connected to the input terminal of the active resonance suppression component. The connection point between the first and second voltage output terminals is connected to both the input terminal of the filter capacitor current compensation component and the filter inductor voltage drop compensation terminal. The output terminal of the filter inductor voltage drop compensation component is connected to the filter inductor voltage drop compensation terminal. The above-mentioned current control device is suitable for current control of three-phase AC motors and AC power grids. It can simultaneously suppress resonance generated by control excitation and motor back EMF or grid voltage harmonics, and can significantly improve the reliability of resonance suppression. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A structural diagram of a current control device based on active resonance suppression provided in an embodiment of the present invention;

[0020] Figure 2 This is a structural diagram of the active resonance suppression component provided in an embodiment of the present invention;

[0021] Figure 3 An equivalent circuit diagram of the active resonance suppression component provided in an embodiment of the present invention;

[0022] Figure 4 A flowchart of a current control method based on active resonance suppression provided in an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram illustrating the application effect of the current control method based on active resonance suppression provided in an embodiment of the present invention.

[0024] Reference numerals: 11. Current controller; 12. Active resonance suppression component; 13. Filter capacitor current compensation component; 14. Filter inductor voltage drop compensation component; 121. First suppression unit; 122. Second suppression unit; L f , filter inductor; C f Filter capacitor; R damp Damping resistor. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0027] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0028] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0029] This invention discloses a current control device based on active resonance suppression, such as... Figure 1As shown, the current control device includes a current controller 11, an active resonance suppression component 12, a filter capacitor current compensation component 13, and a filter inductor voltage drop compensation component 14. The current controller 11 outputs a given voltage to the inverter. The current input terminal of the current controller 11 is connected to both a current signal input terminal and a current feedback terminal. The current signal input terminal is used to input a given current value, and the current feedback terminal is used to input a feedback current value. The first voltage output terminal of the current controller 11 is connected to a second voltage output terminal, and the first voltage output terminal and the second voltage output terminal output corresponding proportional and integral regulated first voltage values ​​and second voltage values. The second voltage output terminal is also connected to the active resonance suppression component 14. The input terminal of the control component 12 is connected; the connection point between the first voltage output terminal and the second voltage output terminal is connected to the input terminal of the filter capacitor current compensation component and the filter inductor voltage drop compensation terminal; the output terminal of the filter inductor voltage drop compensation component 14 is connected to the filter inductor voltage drop compensation terminal, which is used to output the corresponding inverter given voltage; the output feedback terminal is connected to the input terminal of the filter inductor voltage drop compensation component 14 and the output terminal of the filter capacitor current compensation component 13, and the connection point serves as the current compensation terminal; the current compensation terminal is connected to the output terminal of the active resonance suppression component 12 and serves as the current feedback terminal; the output feedback terminal is used to input the driver output feedback current.

[0030] In this application, the first and second voltage output terminals of the current controller output a first voltage value and a second voltage value respectively according to the adjustment rules. The first and second voltage values ​​refer to the two parts of voltage output by proportional and integral regulation. The active resonance suppression component is a module used to generate oscillation suppression current, which can be implemented using a feedback loop based on a proportional-integral controller, for example, by detecting the proportional term of the output voltage and generating a compensation current; its main purpose is to suppress voltage signals at the resonant frequency. Further, the filter capacitor current compensation is a unit used to compensate for capacitor current errors, which can be implemented using a capacitor equivalent model, for example, by multiplying the input voltage by the capacitance to obtain the capacitor current. Therefore, the filter inductor voltage drop compensation component is a module used to compensate for inductor voltage drops, specifically implemented using an inductance equivalent model, for example, by using a calculation unit based on inductor parameters, such as calculating the voltage drop based on the current and inductance values; its main purpose is to ensure the accuracy of the output voltage. Specifically, the current compensation terminal refers to the node used to synthesize the compensation current. This can be implemented using an adder circuit, for example, by summing multiple compensation signals; or using a software summation module, such as accumulating compensation values ​​in a digital system, primarily to generate the final feedback current value. This application, through the synergistic effect of the above features, achieves output voltage separation and targeted handling of resonance problems. It can operate solely relying on the standard inverter feedback signal without modifying the current controller structure or introducing additional hardware, thus avoiding stability issues caused by filter phase shift and reducing computational load.

[0031] The current controller establishes an electrical connection with the bus to acquire the back EMF frequency of the motor or the voltage frequency of the power grid. Its current input terminal is simultaneously connected to both a current signal input terminal and a current feedback terminal. The current signal input terminal receives the externally given current value, while the current feedback terminal receives the compensated feedback current value. The first and second voltage output terminals of the current controller are interconnected, and based on the spectral characteristics of the controller's output voltage, they calculate and output the first and second voltage values. The first voltage value corresponds to the non-high-frequency voltage component, and the second voltage value corresponds to the high-frequency voltage component. The second voltage output terminal is connected to the input terminal of the active resonance suppression component, allowing the high-frequency voltage component to be transmitted to this component for resonance processing. The connection point between the first and second voltage output terminals is simultaneously connected to the input terminal of the filter capacitor current compensation component and the filter inductor voltage drop compensation terminal. The voltage signal at this connection point serves as the input source for the filter capacitor current compensation component. The output terminal of the filter inductor voltage drop compensation component is connected to the filter inductor voltage drop compensation terminal to output the compensated inverter setpoint voltage. The output feedback terminal connects to the input terminal of the filter inductor voltage drop compensation component and the output terminal of the filter capacitor current compensation component; the connection point between the two is defined as the current compensation terminal. The current compensation terminal is further connected to the output terminal of the active resonance suppression component, together forming the current feedback terminal. This output feedback terminal receives the feedback current signal output by the driver. Thus, the driver output feedback current, after being processed by the filter inductor voltage drop compensation component and the filter capacitor current compensation component, forms a load feedback current at the current compensation terminal. This load feedback current is then superimposed on the oscillation suppression current generated by the active resonance suppression component, and finally used as the feedback current value input to the current controller to achieve closed-loop control.

[0032] In a more specific embodiment, such as Figure 2 As shown, the active resonance suppression component 12 includes a first suppression unit 121 and a second suppression unit 122. The two input terminals of the first suppression unit 121 are respectively connected to the second voltage output terminal and the sampling input terminal. The output terminal of the first suppression unit 121 is connected to one input terminal of the second suppression unit 122, and the other input terminal of the second suppression unit 122 is connected to the parameter input terminal. The output terminal of the second suppression unit 122 serves as the output terminal of the active resonance suppression component 12. Specifically, the second voltage value corresponds to the voltage proportional term of the high-frequency voltage component in the controller output voltage, and the first voltage value corresponds to the voltage integral term of the non-high-frequency voltage component in the controller output voltage. The controller output voltage is the sum of the voltage values ​​output by the current controller 11.

[0033] The active resonance suppression component mainly consists of a first suppression unit and a second suppression unit, which work together to achieve active resonance suppression. The first suppression unit performs primary suppression, while the second suppression unit performs secondary suppression. As a specific implementation, the solution of this application is implemented as follows: the parameter input terminal is configured as a digital communication interface to receive suppression parameters transmitted from the host computer; the initial compensation current is generated internally by a digital signal processor; the secondary suppression process is implemented in the digital signal processor, where the initial compensation current is multiplied by the suppression parameters using a multiplication instruction to obtain the oscillation suppression current. Specifically, the digital signal processor can be a TI TMS320F28379D microcontroller, whose built-in floating-point unit is used to efficiently perform multiplication operations.

[0034] Through the above technical solution, this application effectively reduces the computational complexity of the secondary suppression process, avoids the additional delay introduced by complex filtering calculations, ensures the real-time performance and effectiveness of resonance suppression under high carrier frequency conditions, and thus improves the stability and reliability of the current control system.

[0035] Since the resonance is mainly composed of high-frequency voltage components, in order to suppress the high-frequency voltage components, the output voltage of the controller can be adjusted and calculated to obtain a first voltage value and a second voltage value. The second voltage value corresponds to the voltage proportional term of the high-frequency voltage components, and the first voltage value corresponds to the voltage integral term of the non-high-frequency voltage components (the frequency of its voltage components is lower than that of the second voltage value).

[0036] This application's technical solution effectively suppresses LC filter resonance through voltage component separation and feedback signal compensation mechanisms. High-frequency voltage components are specifically processed to generate an oscillation suppression current, which directly acts on the voltage signal at the resonant frequency. This avoids resonance problems caused by control excitation, motor back EMF, or grid voltage harmonics, and the suppression capability is not limited by the current loop bandwidth. The collaborative work of the filter capacitor current compensation component and the filter inductor voltage drop compensation component ensures the accuracy of the feedback signal and the precision of the output voltage. It eliminates the need to acquire LC filter capacitor voltage or current signals, relying solely on standard inverter feedback for operation. Therefore, the current controller structure remains intact, avoiding stability degradation caused by filter phase shift. Simultaneously, the algebraic operation significantly reduces the computational load, making the system highly versatile and easy to implement, suitable for current control scenarios involving three-phase AC motors and AC power grids.

[0037] This invention also discloses a current control method based on active resonance suppression, wherein the current control method is applied to a current control device based on active resonance suppression as described in the above embodiments, such as... Figure 4 As shown, the current control method includes steps S110 to S160.

[0038] S110. Based on the filter capacitor current output by the filter capacitor current compensation component, the driver output feedback current input to the output feedback terminal is compensated to obtain the corresponding load feedback current.

[0039] Among them, the driver output feedback current I sdq This refers to the three-phase output current of the flywheel motor driver or grid inverter; current compensation can be performed by directly reducing the current of the filter capacitor. I dq,cf Feedback current from the driver output I sdq The current is accumulated to obtain the load feedback current; or the filter capacitor current is calculated based on the weighting parameters. I dq,cf Feedback current from the driver output I sdq Perform a weighted summation, such as setting the filter capacitor current. I dq,cf The weighting parameter is 0.2, and the driver output feedback current is... I sdq If the weighting parameter is 0.95, then the load feedback current obtained by weighted summation is... I ldq 0.2× I dq,cf +0.95× I sdq .

[0040] S120. Based on the oscillation suppression current output by the active resonance suppression component, the load feedback current is compensated to obtain the corresponding feedback current value.

[0041] Furthermore, based on the oscillation suppression current output by the active resonance suppression component... I dq,damp Feedback current to load I ldq Perform current compensation to obtain the corresponding feedback current value. I dq The oscillation suppression current can be directly applied. I dq,damp With load feedback current I ldq The values ​​are accumulated to obtain the feedback current value. I dq Alternatively, the oscillation suppression current can be adjusted based on weighting parameters. I dq,damp With load feedback current I ldq By performing a weighted summation, the corresponding feedback current value is obtained. Idq The specific process of weighted summation is similar to step S110.

[0042] S130. The given current value and the feedback current value are synchronously input into the current controller for calculation to obtain the corresponding controller output voltage.

[0043] Given current value I dq * With feedback current value I ldq A synchronous input current controller is used to perform calculations to obtain the controller's output voltage. U dq * This solution calculation process is implemented based on the internal calculation logic of the current controller.

[0044] S140, the current controller outputs a first voltage value and a second voltage value corresponding to the controller output voltage from the first voltage output terminal and the second voltage output terminal respectively, according to the adjustment rule.

[0045] The current controller adjusts the output voltage according to the set regulation rules. U dq * The adjustment calculation is performed, and the corresponding first voltage value is obtained. U dq,i * and the second voltage value U dq,p * Then the first voltage value U dq,i * The second voltage value is output through the first voltage output terminal. U dq,p * It is output via the second voltage output terminal.

[0046] Specifically, in some embodiments of this application, a first voltage value and a second voltage value corresponding to the controller output voltage are output from the first voltage output terminal and the second voltage output terminal respectively according to the adjustment rules to achieve resonance suppression. However, in its implementation process, if the traditional filter method is used for frequency separation, the system stability will decrease due to the filter phase shift, and the calculation complexity is high. It is impossible to accurately isolate the target suppression frequency component, which limits the resonance suppression effect. Especially under high carrier frequency conditions, it is difficult to effectively dynamically adjust for a specific resonance frequency.

[0047] In a specific embodiment, step S140 specifically includes: performing integral adjustment calculation on the deviation between the given current value and the feedback current value according to the integral adjustment function in the adjustment rule to obtain the corresponding first voltage value and outputting it; and performing proportional adjustment calculation on the deviation between the given current value and the feedback current value according to the proportional adjustment function in the adjustment rule to obtain the corresponding second voltage value and outputting it.

[0048] Specifically, the solution in this application calculates the controller output voltage using both proportional and integral terms. The first voltage value is obtained by integrally adjusting the deviation between the given current value and the feedback current value using an integral adjustment function within the adjustment rules, which includes an integral term. The second voltage value is obtained by proportionally adjusting the deviation between the given current value and the feedback current value using a proportional adjustment function within the adjustment rules, which also includes a proportional term. This method, based on the naturally generated integral and proportional outputs within the inherent regulator, avoids the phase shift problem introduced by traditional time-domain filters, ensuring the accuracy of voltage signal acquisition. It also greatly simplifies the calculation process, enabling the system to dynamically respond to changes in resonant frequency under different operating conditions, thereby optimizing the accuracy and efficiency of active resonance suppression.

[0049] As a preferred embodiment, the solution of this application is specifically implemented as follows: the current controller uses a digital signal processor to realize proportional-integral regulation, and outputs the integral and proportional regulation terms as the first voltage value and the second voltage value, respectively; the active resonance suppression component generates an oscillation suppression current based on the second voltage value to achieve precise suppression of the resonant frequency component.

[0050] S150. Based on the compensation voltage output by the filter inductor voltage drop compensation component, the controller output voltage is compensated for voltage drop to obtain the corresponding inverter setpoint voltage. U dq,out * It is then output via the voltage drop compensation terminal of the filter inductor.

[0051] The compensation voltage can be based on the output of the filter inductor voltage drop compensation component. U dq,Lf For the controller output voltage U dq * Perform voltage drop compensation; performing voltage drop compensation can compensate the voltage. U dq,Lf With the controller output voltage U dq * The values ​​are accumulated to obtain the inverter's setpoint voltage. U dq,out * Alternatively, the compensation voltage can be adjusted based on weighting parameters. Udq,Lf With the controller output voltage U dq * The inverter's setpoint voltage is obtained by performing a weighted summation. U dq,out * .

[0052] S160. The active resonance suppression component performs resonance suppression on the second voltage value output by the second voltage output terminal to obtain the corresponding oscillation suppression current and output it.

[0053] Furthermore, the second voltage value of the active resonance suppression component can be used to suppress this. U dq,p * Resonance suppression is performed to obtain the corresponding oscillation suppression current. I dq,damp It then outputs the current, thereby achieving current control based on feedback regulation.

[0054] In a specific embodiment, such as Figure 2 As shown, step S160 specifically includes: suppressing the second voltage value of the second voltage output terminal once according to the sampling parameters input at the sampling input terminal to obtain the corresponding initial compensation current; and suppressing the initial compensation current a second time according to the suppression parameters input at the parameter input terminal to obtain the corresponding oscillation suppression current.

[0055] Specifically, the second voltage value is suppressed once based on the sampling parameters to obtain the initial compensation current. Then, the initial compensation current is suppressed a second time based on the suppression parameters to obtain the oscillation suppression current. The equivalent circuit diagram for active resonance suppression is shown below. Figure 3 As shown.

[0056] In a specific embodiment, the step of suppressing the second voltage value at the second voltage output terminal based on the sampling parameters input at the sampling input terminal to obtain the corresponding initial compensation current includes: multiplying the second voltage value, the frequency value in the sampling parameters, and the capacitance value to perform the first suppression and obtain the corresponding initial compensation current. Specifically, the step of suppressing the initial compensation current a second time based on the suppression parameters input at the parameter input terminal to obtain the corresponding oscillation suppression current includes: multiplying the initial compensation current by the suppression parameters to perform the second suppression and obtain the corresponding oscillation suppression current.

[0057] Wherein, the frequency value is w e This means the frequency of the motor's back EMF or the voltage frequency of the power grid obtained from the busbar; the capacitance is C. f This refers to the capacitance of the filter capacitor in an LC filter. The suppression parameter is also known as the equivalent suppression factor K. damp .

[0058] Among them, the parameter input terminal refers to the input interface for receiving external adjustment signals, which can be implemented using a digital communication interface or an analog signal port, with the aim of providing the system with dynamically adjustable suppression strength parameters; the suppression parameter refers to the coefficient variable used to adjust the resonance suppression effect, which can be implemented using a fixed calibration value or a real-time updated adjustable parameter, with the aim of flexibly adapting the suppression strength according to changes in the system's resonance characteristics; the initial compensation current refers to the intermediate current signal generated after the first suppression process, which can be implemented using a discrete signal in the digital domain or a continuous signal in the analog domain, with the aim of serving as the basic input source for the second suppression; the second suppression refers to the resonance component elimination process implemented for the initial compensation current, which can be implemented using algebraic operations or filtering algorithms, with the aim of accurately eliminating high-frequency resonance components; the oscillation suppression current refers to the final compensation signal generated after the second suppression, which can be implemented using a digital signal or an analog voltage signal, with the aim of effectively compensating the feedback current to suppress system resonance.

[0059] Specifically, the solution in this application achieves secondary suppression by directly multiplying the initial compensation current by the suppression parameter, avoiding complex operations such as filtering or iterative calculations. Since this multiplication operation is based on the real-time state of the initial compensation current, the accuracy and immediacy of resonance suppression are ensured. Given that only basic multiplication operations are involved, the computational load is kept to a very low level, significantly reducing system resource consumption. Therefore, while maintaining the real-time response capability of current control, the stability risks caused by computational delays are effectively avoided, making it particularly suitable for high carrier frequency applications.

[0060] like Figure 3 As shown, the principle of suppressing active resonance is analogous to a hardware circuit equivalent to connecting a virtual damping resistor in parallel with the capacitor. Its equivalent circuit structure consists of a filter inductor L. f Filter capacitor C f and damping resistor R damp Composition; for the resonant excitation source on the input side of the filter (high-frequency component of the control excitation) and the resonant excitation source on the output side of the filter (motor back EMF / grid voltage harmonics), the damping resistor R damp Both can effectively suppress [damping]; specifically, the equivalent damping resistance R damp The resistance value is a multiple of the filter's characteristic impedance:

[0061] (1);

[0062] Among them, K R C is a multiple corresponding to the circuit characteristics of the LC filter. f L represents the capacitance of the filter capacitor in an LC filter. f This represents the inductance value of the filter inductor in the LC filter.

[0063] Since the damping resistor is connected in parallel across the filter capacitor, the equivalent control is achieved by injecting an additional equivalent damping current. I dq,damp According to Ohm's law:

[0064] (2);

[0065] The damping current injection can be achieved by superimposing the damping current onto the given current. However, due to the high frequency of the damping current, effective injection cannot be achieved when the current loop bandwidth is limited. Therefore, an equivalent implementation method is adopted by subtracting the damping current from the current feedback. Wherein, w LC This is the inherent resonant frequency of the LC filter.

[0066] The inherent resonant frequency w of the LC filter LC Since it is in the high-frequency range, only the high-frequency voltage, i.e., the voltage proportional term, is taken as the excitation for calculating the damping current, that is:

[0067] (3);

[0068] At the same time w LC The maximum value of the fundamental frequency w of the inverter operation e , max Ratio K LC There are minimum value constraints, for example:

[0069] (4);

[0070] Therefore, equation (3) can be simplified to:

[0071] (5);

[0072] When the inverter operates at a low fundamental frequency, the amplitude of the resonance disturbance is very low, and resonance suppression can be achieved through the inherent regulation of the current controller. Therefore, an additional frequency weighting coefficient K is introduced. w To ensure that suppression current is injected only in the region where active resonance suppression is required:

[0073] (6);

[0074] From equation (6), we can see that K w For w e A continuous function, when the driver outputs at zero frequency, the weighting coefficient K w The weighting coefficient K is 0 when the driver output frequency is at its maximum. w The value is 1; the weighting coefficients in the middle interval transition linearly.

[0075] Introducing frequency weighting coefficient K w Then, the damping current compensation amount can be simplified to:

[0076] (7);

[0077] In equation (7) above, the equivalent inhibition factor K damp for:

[0078] (8).

[0079] Then, according to formula (7), the corresponding solution can be obtained for the second voltage value. U dq,p * Corresponding oscillation suppression current I dq,damp w in formula (7) e C f and K damp All of these are known quantities.

[0080] In this regard, this application further proposes that the frequency value is the back EMF frequency of the motor or the voltage frequency of the power grid; and the capacitance is the capacitance of the filter capacitor. In practical applications, the back EMF frequency value can be obtained through a motor encoder or a motor model, the power grid voltage frequency value can be obtained through voltage detection and software phase-locked loop, and the capacitor capacitance is a known hardware parameter.

[0081] In a specific embodiment, the method further includes: the filter capacitor current compensation component performs current compensation based on the input controller output voltage to obtain the corresponding filter capacitor current.

[0082] The filter capacitor current compensation component can be implemented based on capacitor parameters through algebraic operations. For example, the voltage value at the connection point between the first and second voltage output terminals can be multiplied by the filter capacitor value to directly obtain the filter capacitor current compensation signal. The specific formula is as follows:

[0083] (9);

[0084] In the formula, w e C is the electrical angular frequency of the motor's back EMF or the mains voltage. f Let J be the capacitance of the filter capacitor and J be the rotation transformation matrix, which is expressed as: The filter inductor voltage drop compensation component can specifically generate the inverter's setpoint voltage by measuring the output current and multiplying it by the filter inductor parameters. The specific formula is as follows:

[0085] (10);

[0086] In the formula, w e Lf is the electrical angular frequency of the motor back EMF or the grid voltage, and Lf is the inductance of the filter inductor.

[0087] Furthermore, the driver output feedback current input at the output feedback terminal is combined with the signal output by the filter capacitor current compensation component at the current compensation terminal, effectively separating the load current component and avoiding interference from the filter state on the feedback signal.

[0088] This application's technical solution effectively suppresses LC filter resonance through voltage component separation and feedback signal compensation mechanisms. High-frequency voltage components are specifically processed to generate an oscillation suppression current, which directly acts on the voltage signal at the resonant frequency. This avoids resonance problems caused by control excitation, motor back EMF, or grid voltage harmonics, and the suppression capability is not limited by the current loop bandwidth. The collaborative work of the filter capacitor current compensation component and the filter inductor voltage drop compensation component ensures the accuracy of the feedback signal and the precision of the output voltage. It eliminates the need to acquire LC filter capacitor voltage or current signals, relying solely on standard inverter feedback for operation. Therefore, the current controller structure remains intact, avoiding stability degradation caused by filter phase shift. Simultaneously, the algebraic operation significantly reduces the computational load, making the system highly versatile and easy to implement, suitable for current control scenarios involving three-phase AC motors and AC power grids.

[0089] Figure 5 The diagram shows the suppression effect of this solution on resonance caused by back EMF harmonics in a flywheel motor drive. "Active suppression disabled" means the active resonance suppression function is not enabled, i.e., the aforementioned current control method based on active resonance suppression is not executed. "Active suppression activated" means the active resonance suppression function is enabled, and the aforementioned current control method based on active resonance suppression is executed and performs its corresponding function. As can be seen from the diagram, after active resonance suppression is enabled, the current and speed oscillation amplitudes generated by the 5th and 7th harmonics of the back EMF are significantly attenuated. Where i sd For the excitation current, i sq For torque current, u d,out * represents the direct-axis voltage, u q,out * represents the quadrature-axis voltage, and n represents the motor speed. All of the above parameters can be acquired through the flywheel motor driver. The horizontal axis in the curve represents the number of sampling points, and each sampling point corresponds to a voltage value / current value / speed.

[0090] The advantages of the technical method presented in this application include: the method is based on a standard three-phase inverter hardware platform, only collecting the inverter's DC bus voltage and three-phase output current, without needing to collect the LC filter capacitor voltage or current; the method is based on a standard current controller structure, achieving active resonance suppression only through a feedback signal compensation stage, without any modification to the controller itself, ensuring a highly modular control structure; the method does not require filter processing, effectively avoiding the stability degradation caused by filter phase shift; the method only requires simple algebraic operations, with a negligible increase in computational load, thus eliminating the limitation of high carrier frequency operating conditions.

[0091] The core innovation of this embodiment lies in combining the filter capacitor current compensation component and the active resonance suppression component through a cascaded compensation mechanism. Based on voltage regulation rules, high-frequency components are obtained, thereby simultaneously suppressing resonance caused by control excitation and motor back EMF / grid voltage harmonics without relying solely on the standard inverter feedback signal or acquiring LC filter capacitor voltage or current. This achieves the technical effects of avoiding current loop bandwidth limitations, eliminating stability degradation caused by filter phase shift, and significantly reducing computational load. Specifically, this scheme utilizes the filter capacitor current compensation component to directly separate the load current component, ensuring the feedback signal is not affected by resonance interference. Simultaneously, the controller output voltage is calculated using voltage regulation rules to obtain high-frequency and non-high-frequency components, enabling the active resonance suppression component to generate oscillation suppression current only for high-frequency voltage components. This achieves filter-free algebraic processing, ensuring robustness of resonance suppression while avoiding computational bottlenecks under high carrier frequency conditions. Therefore, the current controller structure remains intact, meeting the general control requirements of three-phase AC motors and AC grids without additional hardware modifications, significantly improving the system's ease of implementation and engineering applicability.

[0092] This invention discloses a current control device and method based on active resonance suppression. The current control device includes a current controller, an active resonance suppression component, a filter capacitor current compensation component, and a filter inductor voltage drop compensation component. The current input terminal of the current controller is connected to both a current signal input terminal and a current feedback terminal. A first voltage output terminal of the current controller is connected to a second voltage output terminal. The second voltage output terminal is also connected to the input terminal of the active resonance suppression component. The connection point between the first and second voltage output terminals is connected to both the input terminal of the filter capacitor current compensation component and the filter inductor voltage drop compensation terminal. The output terminal of the filter inductor voltage drop compensation component is connected to the filter inductor voltage drop compensation terminal. This current control device is suitable for current control of three-phase AC motors and AC power grids. It can simultaneously suppress resonance generated by the control excitation and the motor back EMF or grid voltage harmonics, significantly improving the reliability of resonance suppression.

[0093] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A current control device based on active resonance suppression, characterized in that, The current control device includes a current controller, an active resonance suppression component, a filter capacitor current compensation component, and a filter inductor voltage drop compensation component; the current controller outputs the inverter's set voltage. The current input terminal of the current controller is connected to both the current signal input terminal and the current feedback terminal. The current signal input terminal is used to input a given current value, and the current feedback terminal is used to input a feedback current value; The first voltage output terminal of the current controller is connected to the second voltage output terminal, and the first voltage output terminal and the second voltage output terminal output a first voltage value and a second voltage value that are proportionally and integrally regulated respectively. The current controller outputs a first voltage value and a second voltage value corresponding to the controller output voltage from the first voltage output terminal and the second voltage output terminal, respectively, according to the adjustment rules. This includes: performing integral adjustment calculation on the deviation between the given current value and the feedback current value according to the integral adjustment function in the adjustment rules to obtain and output the corresponding first voltage value; performing proportional adjustment calculation on the deviation between the given current value and the feedback current value according to the proportional adjustment function in the adjustment rules to obtain and output the corresponding second voltage value; the second voltage value corresponds to the voltage proportional term of the high-frequency voltage component in the controller output voltage, and the first voltage value corresponds to the voltage integral term of the non-high-frequency voltage component in the controller output voltage; the controller output voltage is the sum of the voltage values ​​output by the current controller. The second voltage output terminal is also connected to the input terminal of the active resonance suppression component; the connection point between the first voltage output terminal and the second voltage output terminal is connected to the input terminal of the filter capacitor current compensation component and the filter inductor voltage drop compensation terminal; the output terminal of the filter inductor voltage drop compensation component is connected to the filter inductor voltage drop compensation terminal, and the filter inductor voltage drop compensation terminal is used to output the corresponding inverter given voltage; The active resonance suppression component performs resonance suppression on the second voltage value output from the second voltage output terminal to obtain a corresponding oscillation suppression current and outputs it, including: suppressing the second voltage value at the second voltage output terminal once according to the sampling parameters input at the sampling input terminal to obtain a corresponding initial compensation current; and suppressing the initial compensation current a second time according to the suppression parameters input at the parameter input terminal to obtain a corresponding oscillation suppression current. The output feedback terminal is connected to the input terminal of the filter inductor voltage drop compensation component and the output terminal of the filter capacitor current compensation component, and the connection point serves as the current compensation terminal; the current compensation terminal is connected to the output terminal of the active resonance suppression component and serves as the current feedback terminal; the output feedback terminal is used to input the driver output feedback current.

2. The current control device based on active resonance suppression according to claim 1, characterized in that, The active resonance suppression component includes a first suppression unit and a second suppression unit; The two input terminals of the first suppression unit are respectively connected to the second voltage output terminal and the sampling input terminal; the output terminal of the first suppression unit is connected to one input terminal of the second suppression unit, and the other input terminal of the second suppression unit is connected to the parameter input terminal; the output terminal of the second suppression unit serves as the output terminal of the active resonance suppression component.

3. A current control method based on active resonance suppression, characterized in that, The current control method is applied to the current control device based on active resonance suppression as described in any one of claims 1-2, wherein the current control method comprises: The current compensation of the driver output feedback current input to the output feedback terminal is performed based on the current of the filter capacitor output by the filter capacitor current compensation component to obtain the corresponding load feedback current. The load feedback current is compensated based on the oscillation suppression current output by the active resonance suppression component to obtain the corresponding feedback current value; The given current value and the feedback current value are synchronously input into the current controller for calculation to obtain the corresponding controller output voltage; According to the adjustment rules, the current controller outputs a first voltage value and a second voltage value corresponding to the controller output voltage from the first voltage output terminal and the second voltage output terminal, respectively. The voltage drop compensation of the controller output voltage is performed based on the compensation voltage output by the filter inductor voltage drop compensation component to obtain the corresponding inverter given voltage, which is then output through the filter inductor voltage drop compensation terminal. The active resonance suppression component performs resonance suppression on the second voltage value output from the second voltage output terminal, obtains the corresponding oscillation suppression current, and outputs it.

4. The current control method based on active resonance suppression according to claim 3, characterized in that, The method further includes: the filter capacitor current compensation component performs current compensation based on the input controller output voltage to obtain the corresponding filter capacitor current.

5. The current control method based on active resonance suppression according to claim 4, characterized in that, The step of suppressing the second voltage value at the second voltage output terminal based on the sampling parameters input at the sampling input terminal to obtain the corresponding initial compensation current includes: The second voltage value, the frequency value in the sampling parameters, and the capacitance are multiplied together to perform a suppression and obtain the corresponding initial compensation current.

6. The current control method based on active resonance suppression according to claim 5, characterized in that, The frequency value is the back EMF frequency of the motor or the voltage frequency of the power grid.

7. The current control method based on active resonance suppression according to claim 4, characterized in that, The process of performing secondary suppression on the initial compensation current based on the suppression parameter input at the parameter input terminal to obtain the corresponding oscillation suppression current includes: The initial compensation current is multiplied by the suppression parameter to perform secondary suppression and obtain the corresponding oscillation suppression current.

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