Energy storage valve submodule, under-damped oscillation suppression method and energy storage valve

Abstract

The invention belongs to the technical field of power electronics, and provides an energy storage valve submodule, an under-damped oscillation suppression method and an energy storage valve, an active suppression circuit used for generating suppression waveform output is arranged in the energy storage valve submodule, and the suppression waveform is used for suppressing under-damped oscillation of an internal harmonic oscillation circuit. The problems of battery deterioration, shortened service life and even direct damage caused by over-current of the battery due to underdamped oscillation are solved.

Description

Technical Field

[0001] The present application belongs to the field of power electronics technology, and in particular relates to an energy storage valve submodule, a method for suppressing under-damped oscillations, and an energy storage valve. Background Art

[0002] In the new energy storage field, the core component of the cascade type direct-mounted energy storage valve system is the energy storage valve submodule composed of a power circuit and a battery module. When the energy storage valve submodule is switched on and off, the rapid opening of the switch element of the power circuit (for example, at the us level) can be regarded as a current source step excitation to the network, which will cause the battery current to over-current, resulting in battery degradation, reduced life, or even direct damage. Summary of the invention

[0003] In view of the above problems, the present application provides an energy storage valve submodule, a method for suppressing under-damped oscillations and an energy storage valve, aiming to solve the problem of battery overcurrent when the energy storage valve submodule is switched on and off.

[0004] In a first aspect, an embodiment of the present application provides an energy storage valve submodule, comprising a power circuit, a battery module, and an active suppression circuit, wherein the power circuit comprises an energy storage element;

[0005] The battery module is connected to the power circuit via a DC bus, the energy storage element is connected in parallel with the battery module via the DC bus, the active suppression circuit is connected in series or in parallel with the battery module via the DC bus, and the internal resistance and inductance of the energy storage valve submodule and the energy storage element form a harmonic oscillation circuit;

[0006] The active suppression circuit is used to generate a suppression waveform and output it to the DC bus;

[0007] The suppression waveform is used to suppress under-damped oscillation of the harmonic oscillation circuit.

[0008] In the technical solution of the embodiment of the present application, an active suppression circuit for generating a suppression waveform output is provided in the energy storage valve submodule, and the suppression waveform is used to suppress the under-damped oscillation of the internal harmonic oscillation circuit, so as to solve the problem of battery current overcurrent caused by under-damped oscillation when the energy storage valve submodule is switched on and off, resulting in battery degradation, reduced life, or even direct damage.

[0009] In some embodiments, the active suppression circuit includes an inductive element, a capacitive energy storage element, and a switch module;

[0010] The inductive element is connected to the DC bus, and the switch module is connected to the capacitive energy storage element;

[0011] The switch module is used to be connected to the control circuit, and is controlled by a preset control signal output by the control circuit to switch back and forth between the on and off states, so as to trigger the capacitive energy storage element and the inductive element to switch back and forth between the coupling and decoupling states to generate the suppression waveform.

[0012] In the technical solution of the embodiment of the present application, the switch module is switched back and forth between the on and off states, triggering the capacitive energy storage element and the inductive element to switch back and forth between the coupling and decoupling states to generate a suppressive current waveform equal to the harmonic and reactive components of the under-damped oscillation and opposite in direction, which is injected into the DC bus, thereby improving the risk of overcurrent of the battery due to under-damped oscillation.

[0013] In some embodiments, the switch module includes a first switch element and a second switch element, the first switch element is connected in series with the second switch element and then connected in parallel with the capacitive energy storage element, the first end of the inductive element is connected to the series node of the first switch element and the second switch element, and the second end of the inductive element is connected to the positive pole of the DC bus.

[0014] In the technical solution of the embodiment of the present application, an implementation method of an active suppression circuit is provided, which uses a first switch element and a second switch element to trigger a capacitive energy storage element and an inductive element to switch back and forth between coupling and decoupling states to generate a suppression waveform, and the control method is simple and reliable.

[0015] In some embodiments, the capacitive energy storage element includes a second capacitor, and the inductive element includes a first inductor.

[0016] In the technical solution of the embodiment of the present application, an implementation method of an active suppression circuit is provided, in which the second capacitor is used as an energy storage element to store and release electrical energy and to form resonance with the first inductor.

[0017] In some embodiments, the active suppression circuit includes a third capacitor, a first end of the third capacitor is connected to the first end of the inductive element, and a second end of the third capacitor is connected to the negative electrode of the DC bus.

[0018] In the technical solution of the embodiment of the present application, the third capacitor is used to suppress the filtering and correction effect of the waveform.

[0019] In some embodiments, the power circuit further includes a third switch element, and the third switch element is connected in parallel with the energy storage element.

[0020] In the technical solution of the embodiment of the present application, when the power circuit is connected to the battery module, the energy storage element can be charged first, thereby reducing the impact of large current on the battery module and improving the reliability of the energy storage valve submodule.

[0021] In some embodiments, the power circuit includes a half-bridge circuit or a full-bridge circuit, and the half-bridge circuit or the full-bridge circuit is connected in parallel with the energy storage element.

[0022] In the technical solution of the embodiment of the present application, by adopting the above solution, flexible configuration of the power circuit is achieved, and the flexibility of the design of the energy storage valve submodule is improved.

[0023] In a second aspect, an embodiment of the present application further provides a method for suppressing under-damped oscillations, which is applied to the energy storage valve submodule as described above, and the suppression method includes:

[0024] Obtaining a first current reference signal according to the charge and discharge state of the energy storage valve submodule, the voltage of the battery module, and the voltage of the active suppression circuit;

[0025] Obtaining a second current reference signal according to the charge and discharge state of the energy storage valve submodule, the charge and discharge current of the battery module, and the maximum charge and discharge current of the battery module;

[0026] generating a driving signal according to the first current reference signal, the second current reference signal and the current of the active suppression circuit;

[0027] The driving signal is used to drive the active suppression circuit to generate a suppression waveform output to the DC bus, and the suppression waveform is used to suppress under-damped oscillation of the harmonic oscillation circuit.

[0028] In the technical solution of the embodiment of the present application, the current characteristics of the two oscillation sources, the active suppression circuit and the battery module in the energy storage valve submodule, are obtained, and these two current characteristics are used as reference signals to process with the current of the active suppression circuit to generate a modulation signal, and then the modulation signal is generated to drive the active suppression circuit to generate a suppression waveform that suppresses the under-damped oscillation of the harmonic oscillation circuit and outputs it to the DC bus, thereby improving the problem of battery overcurrent and damage to the battery.

[0029] In some embodiments, obtaining the first current reference signal according to the charge and discharge state of the energy storage valve submodule, the voltage of the battery module, and the voltage of the active suppression circuit includes:

[0030] Acquiring the voltage of the battery module and the voltage of the active suppression circuit, and determining the charge and discharge state of the energy storage valve submodule;

[0031] Determine a voltage outer loop reference value according to the voltage of the battery module and the charge and discharge state of the energy storage valve submodule;

[0032] The first current reference signal is obtained by performing a PI operation based on the difference between the voltage outer loop reference value and the voltage of the active suppression circuit.

[0033] In the technical solution of the embodiment of the present application, a voltage reference selection controller is used in the voltage outer loop to determine the voltage of the battery module as the reference value of the voltage outer loop based on the voltage of the battery module and the charging and discharging state of the energy storage valve submodule, and the difference between the voltage and the voltage of the active suppression circuit is subjected to PI operation to obtain a first current reference signal, and the first current reference signal indicates the relationship between the voltage of the active suppression circuit and the reference value of the voltage outer loop; it should be noted that the introduction of the voltage reference selection controller can optimize the no-load loss of the under-damped oscillation peak current active suppression circuit during charging and discharging of the energy storage valve submodule.

[0034] In the technical solution of the embodiment of the present application, in some embodiments, the second current reference signal is obtained according to the charge and discharge state of the energy storage valve submodule, the charge and discharge current of the battery module, and the maximum charge and discharge current of the battery module, including:

[0035] Acquiring the charge and discharge current of the battery module, and determining the charge and discharge state of the energy storage valve submodule and the maximum charge and discharge current of the battery module;

[0036] A current difference obtained by subtracting the amplitude of the charge and discharge current of the battery module from the maximum charge and discharge current of the battery module;

[0037] Using the current difference as the second current reference signal for setting;

[0038] Among them, if the current difference is a negative value, the second current reference signal is set to 0; if the current difference is a positive value, when the energy storage valve submodule is in a charging state, the second current reference signal is set to a positive value, and when the energy storage valve submodule is in a discharging state, the second current reference signal is set to a negative value.

[0039] In the technical solution of the embodiment of the present application, the maximum charge and discharge current allowed by the battery module is used as a reference, and the difference between the charge and discharge current of the battery module and the maximum charge and discharge current allowed is used as the second current reference signal. The second current reference signal indicates the charge and discharge current characteristics of the battery module, such as the charging state, the discharging state, and the size of the overcurrent, so that the under-damped oscillation suppression method of the present application can generate a corresponding suppression waveform according to the charge and discharge current characteristics.

[0040] In some embodiments, the step of generating a driving signal according to the first current reference signal, the second current reference signal and the current of the active suppression circuit includes:

[0041] Adding the first current reference signal and the second current reference signal to obtain a current inner loop current reference signal;

[0042] Subtracting the current inner loop current reference signal from the current of the active suppression circuit to obtain a current error;

[0043] Performing PI operation according to the current error to obtain a modulation signal;

[0044] The drive signal for driving the active suppression circuit is generated based on the modulation signal modulation.

[0045] In the technical solution of the embodiment of the present application, the current characteristics of the two oscillation sources are superimposed to obtain a current inner loop current reference signal, and the current regulator performs PI operation according to the current error between the current inner loop current reference signal and the current of the active suppression circuit to obtain a drive signal for adjusting the suppression waveform, so that the suppression waveform can suppress the under-damped oscillation of the internal harmonic oscillation circuit, solve the battery current overcurrent caused by the under-damped oscillation, resulting in battery degradation, reduced life, and even direct damage

[0046] In a third aspect, an embodiment of the present application further provides an energy storage valve, which includes a plurality of energy storage valve sub-modules connected in series as described above; and / or includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for suppressing under-damped oscillations as described above when executing the computer program.

[0047] In the technical solution of the embodiment of the present application, the energy storage valve submodule is provided with an active suppression circuit for generating a suppression waveform output, and the suppression waveform is used to suppress the under-damped oscillation of the internal harmonic oscillation circuit, thereby solving the battery current overcurrent caused by the under-damped oscillation, resulting in battery degradation, reduced life, and even direct damage.

[0048] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0050] Figure 1 A schematic structural diagram of an energy storage valve submodule is shown;

[0051] Figure 2 The equivalent RLC circuit of the energy storage valve submodule is shown;

[0052] Figure 3 A schematic structural diagram of an energy storage valve submodule provided in an embodiment of the present application is shown;

[0053] Figure 4 A schematic structural diagram of an energy storage valve submodule provided in an embodiment of the present application is shown;

[0054] Figure 5 A schematic structural diagram of an energy storage valve submodule provided in an embodiment of the present application is shown;

[0055] Figure 6 A flow chart of a method for suppressing under-damped oscillations provided by an embodiment of the present application is shown;

[0056] Figure 7 A flow chart of a method for suppressing under-damped oscillations provided by an embodiment of the present application is shown;

[0057] Figure 8 A control loop diagram of a method for suppressing under-damped oscillations provided by an embodiment of the present application is shown;

[0058] Fig. 9 A flow chart of a method for suppressing under-damped oscillations provided by an embodiment of the present application is shown;

[0059] Fig.10 A flow chart of a method for suppressing under-damped oscillations provided by an embodiment of the present application is shown;

[0060] Fig.11 A schematic structural diagram of an energy storage device provided in one embodiment of the present application is shown. DETAILED DESCRIPTION

[0061] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0063] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0064] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0065] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0066] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0067] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0068] See also Figure 1 and Figure 2 , Figure 1 shows a schematic structural diagram of an energy storage valve submodule, Figure 2The equivalent RLC circuit of the energy storage valve submodule is shown. In the field of new energy storage, the core component of the cascaded direct-mounted energy storage valve system is the energy storage valve submodule composed of a power circuit and a battery module. The internal resistance (R), the inductance (L) of the energy storage valve submodule and the capacitance (C) of the power circuit form an underdamped parallel harmonic oscillator, namely an RLC circuit. When the energy storage valve submodule is switched, the rapid opening (us level) of the insulated-gate bipolar transistor (IGBT) can be regarded as a current source step excitation to the network, which will cause the battery current to oscillate underdamped, and ultimately cause the following hazards: 1. The battery current is overcurrent, causing battery damage, deterioration, reduced life, etc.; 2. The capacitor current increases by about 30%, resulting in an increase in the weight, volume and cost of the capacitor; 3. The energy storage valve submodule frequently reports battery overcurrent faults during operation, causing the energy storage valve to be frequently forced to shut down. For the above-mentioned RLC resonance problem, there are mainly the following three conventional passive solutions in the relevant technology:

[0069] 1. Reduce inductance, but the stray inductance in the energy storage valve submodule is difficult to reduce due to the cabinet inductance and the length of the busbar; 2. Increase resistance, but the increase in resistance in the energy storage valve submodule will lead to kW-level losses, resulting in reduced system efficiency; 3. Increase capacitance, but the capacitance needs to be increased to hundreds of mF in the energy storage valve submodule, which has poor applicability and unbearable costs. In addition, there is an active solution to the problem of harmful harmonics in DC circuits - DC parallel active filters, but the DC active filters in related technologies are mostly used to achieve the smoothing of pulsating power and the suppression of double-frequency ripple currents. Their topological parameters and control methods are all aimed at the smoothing of pulsating power and the suppression of double-frequency ripple currents, and cannot be applied to the active suppression of the peak current of the under-damped oscillation of the battery module in the energy storage valve submodule.

[0070] Therefore, in order to solve the problem that the oscillation peak value of the battery module current in the cascade type direct-mounted energy storage valve system is too high due to RLC underdamping, the present application proposes an active suppression method for underdamped oscillation peak current that can be applied to the energy storage valve submodule.

[0071] According to some embodiments of the present application, referring to Figure 3 and Figure 4 , Figure 3 The structure diagram of the energy storage valve submodule provided in one embodiment of the present application is shown. Figure 4 The schematic diagram of the structure of the energy storage valve submodule provided in one embodiment of the present application is shown. For the convenience of explanation, only the parts related to the present embodiment are shown, which are described in detail as follows:

[0072] The energy storage valve submodule includes a power circuit 110, a battery module V BATand an active suppression circuit 120 , the power circuit 110 includes an energy storage element C0 ;

[0073] Battery Module V BAT The energy storage element C0 is connected to the power circuit 110 through the DC bus and the battery module V BAT In parallel, the active suppression circuit 120 is connected to the battery module V BAT In series or parallel, the internal resistance R of the energy storage valve module CD 、Miscellaneous feelings S1 +L S2 and the energy storage element C0 form a harmonic oscillation circuit (see Figure 2 ); the active suppression circuit 120 is used to generate a suppression waveform output to the DC bus; the suppression waveform is used to suppress the under-damped oscillation of the harmonic oscillation circuit.

[0074] Among them, the battery module V BAT It is understood that for underdamped oscillations, the battery module V BAT It is one of the oscillation sources, or even the main oscillation source. The active suppression circuit 120 includes an energy storage element, which is one of the oscillation sources of the suppression signal. The energy storage element C0 is generally a capacitor, and its functions can be energy storage, filtering, and voltage stabilization.

[0075] Specifically, the active suppression circuit 120 is based on its own output voltage and / or current and the battery module V BAT The voltage and / or charge / discharge current of the battery module V is used to generate a corresponding reference signal, and then a compensation current (i.e., a suppression signal) equal in magnitude and opposite in direction to the underdamped oscillation harmonics and reactive components is generated according to the reference signal and injected into the DC bus to make the battery module V BAT The charge and discharge current is relatively stable. This solves the problem of battery current overcurrent caused by underdamped oscillation when the energy storage valve module is switched on and off, which leads to battery degradation, reduced life, and even direct damage.

[0076] The active suppression circuit 120 is composed of fully controlled devices (including but not limited to IGBT, gate turn-off thyristor

[0077] The active suppression circuit 120 is composed of a gate-turn-off transistor (GTO), a metal-oxide semiconductor field-effect transistor (MOSFET), etc.), a resistor, a capacitor, and an inductor. It can be understood that these resistors, capacitors, and inductors can be separately set electronic components, or they can be equivalent to the resistance, capacitance, and inductance properties of the original electronic components in the energy storage valve submodule. The connection mode of the active suppression circuit 120 with the DC bus includes but is not limited to parallel connection, series connection, series-parallel connection, etc. At the same time, the active suppression circuit 120 can be applied to a half-bridge energy storage valve submodule (such as Figure 3 As shown), it can also be used for full-bridge energy storage valve submodules (such as Figure 4 shown).

[0078] In some embodiments, reference Figure 5 , Figure 5 1 shows a schematic structural diagram of an energy storage valve submodule provided in an embodiment of the present application, wherein the active suppression circuit 120 includes an inductive element L1, a capacitive energy storage element C1 and a switch module 122;

[0079] The inductive element L1 is connected to the DC bus, and the switch module 122 is connected to the capacitive energy storage element C1; the switch module 122 is used to be connected to a control circuit (not shown), and is controlled by a preset control signal output by the control circuit to switch back and forth between the on and off states, so as to trigger the capacitive energy storage element C1 and the inductive element L1 to switch back and forth between the coupling and decoupling states to generate a suppression waveform.

[0080] It is understood that the conduction of the switch module 122 includes full conduction and partial conduction, and the coupling of the trigger capacitive energy storage element C1 and the inductive element L1 can be parallel coupling or series coupling, thereby forming an LC circuit to generate a suppression waveform. It is understood that the LC circuit can also be connected with the internal resistance R of the energy storage valve submodule. CD An RLC circuit is formed to generate a suppression waveform. The capacitive energy storage element C1 will serve as the power source of the active suppression circuit 120; because it is used to generate an oscillation signal (ie, a suppression signal), the capacitive energy storage element C1 can also be called an oscillation source.

[0081] The control circuit may be a submodule controller (SubModule Controller, SMC) or a battery management controller (Battery Management Controller, BMC) of the energy storage valve submodule. The control circuit may be considered to be a part of the active suppression circuit 120, and may also be set separately as a controller of the active suppression circuit 120. The preset control signal is, for example, a pulse signal, and the amplitude and frequency of the suppression waveform may be adjusted by adjusting the width and frequency of the pulse signal.

[0082] In some embodiments, the capacitive energy storage element C1 includes a capacitor, which may be a separately arranged capacitor or an electronic component with equivalent capacitance, and the capacitor may be one or more series-parallel connections. The inductive element L1 includes an inductor, which may be a separately arranged inductor or an electronic component with equivalent inductance. The capacitor is used as an energy storage element to store and release electrical energy, and to form an LC resonant circuit with the first inductor.

[0083] In the technical solution of the embodiment of the present application, the switch module 122 is switched back and forth between the on and off states, triggering the capacitive energy storage element C1 and the inductive element L1 to switch back and forth between the coupling and decoupling states to generate a suppression current waveform equal to the harmonic and reactive components of the under-damped oscillation and opposite in direction, which is injected into the DC bus, thereby improving the risk of overcurrent of the battery due to the under-damped oscillation.

[0084] In some embodiments, please refer to Figure 5 In some embodiments, the switch module 122 includes a first switch element S1 and a second switch element S2. The first switch element S1 and the second switch element S2 are connected in series and then connected in parallel with the capacitive energy storage element C1. The first end of the inductive element L1 is connected to the series node of the first switch element S1 and the second switch element S2, and the second end of the inductive element L1 is connected to the positive pole of the DC bus.

[0085] The first switch element S1 and the second switch element S2 are fully controlled devices, such as IGBT, GTO, MOSFET, etc. In some cases, the preset control signal controls the first switch element S1 to turn on so that the capacitive energy storage element C1 is coupled with the inductive element L1, and the capacitive energy storage element C1 will discharge the inductive element L1, or the inductive element L1 will charge the capacitive energy storage element C1. In some cases, when the first switch element S1 is turned off, the preset control signal controls the second switch element S2 to turn on so that the inductive element L1 has a discharge loop to release the suppression current to the DC bus, or forms a charging loop for the inductive element L1 itself. In this embodiment, the switch module 122 is a half-bridge topology composed of two switch elements. In other embodiments, the switch module 122 can be set to a full-bridge topology composed of four switch elements.

[0086] In the technical solution of the embodiment of the present application, an active suppression circuit 120 is provided through a DC bus and a battery module V BAT In the parallel implementation, the first switch element S1 and the second switch element S2 are used to trigger the capacitive energy storage element C1 and the inductive element L1 to switch back and forth between the coupling and decoupling states to generate the suppression waveform. The control method is simple and reliable. In other embodiments, the active suppression circuit 120 is connected to the battery module V via the current bus. BAT Implementation in series to produce a suppression waveform.

[0087] In some embodiments, please refer to Figure 5 The active suppression circuit 120 includes a third capacitor C2, a first end of the third capacitor C2 is connected to the first end of the inductive element L1, and a second end of the third capacitor C2 is connected to the negative electrode of the DC bus. The third capacitor C2 is used for filtering and correcting the suppression waveform. It can be understood that the third capacitor C2 also has a considerable energy storage function.

[0088] In some embodiments, please refer to Figure 3 and Figure 4 The power circuit 110 further includes third switch elements T1, T2, and the third switch elements T1, T2 are connected in parallel with the energy storage element C0.

[0089] The third switch elements T1 and T2 may be multiple, and the multiple third switch elements T1 and T2 are connected in series and / or in parallel, and the energy storage element C0 is connected in parallel with the multiple third switch elements T1 and T2 connected in series and / or in parallel. In a specific implementation, the multiple third switch elements T1 and T2 connected in series and / or in parallel include a half-bridge circuit (see Figure 3 ) or full bridge circuit (see Figure 4 ). When the power circuit 110 is connected to the battery module V BAT When charging, the energy storage element C0 can be charged first, thereby reducing the impact of the large current on the third switch elements T1 and T2 and improving the reliability of the energy storage valve submodule.

[0090] In the technical solution of the embodiment of the present application, the power circuit 110 includes a half-bridge circuit or a full-bridge circuit. It should be noted that the half-bridge circuit is a power circuit 110 including two switch tubes, and the full-bridge circuit is a power circuit 110 including four switch tubes. The half-bridge circuit has low cost and a simple circuit; the full-bridge circuit has high cost and a relatively complex circuit. However, the full-bridge circuit has less interference than the half-bridge circuit and has higher reliability. Flexible configuration of the power circuit 110 is achieved, and the flexibility of the design of the energy storage valve submodule is improved.

[0091] In some embodiments, the present application also provides a method for suppressing under-damped oscillations, which is applied to the energy storage valve submodule as described above. Figure 6 , Figure 6 A flowchart of a method for suppressing underdamped oscillations provided in an embodiment of the present application is shown, combined with Figure 3 and Figure 6 For the convenience of explanation, only the parts related to this embodiment are shown, which are described in detail as follows:

[0092] The method for suppressing underdamped oscillations comprises the following steps:

[0093] Step S110, obtaining a first current reference signal according to the charge and discharge state of the energy storage valve submodule, the voltage of the battery module, and the voltage of the active suppression circuit;

[0094] Step S120, obtaining a second current reference signal according to the charge and discharge state of the energy storage valve submodule, the charge and discharge current of the battery module, and the maximum charge and discharge current of the battery module;

[0095] Step S130, generating a driving signal according to the first current reference signal, the second current reference signal and the current of the active suppression circuit;

[0096] The driving signal is used to drive the active suppression circuit to generate a suppression waveform output to the DC bus, and the suppression waveform is used to suppress the under-damped oscillation of the harmonic oscillation circuit.

[0097] Among them, the charge and discharge state of the energy storage valve submodule includes a charging state and a discharging state. The charge and discharge state of the energy storage valve submodule and the battery module V BAT The voltage (also V in the figure) BAT Indicates), charge and discharge current i BAT It can be directly obtained through the battery management system (BMS), and the voltage V of the active suppression circuit 120 DC 、Current i L It can be detected by setting up a detection circuit.

[0098] Specifically, the control circuit (or control loop) is configured with a voltage reference selection controller, which recognizes the charge and discharge state of the energy storage valve submodule and collects the voltage of the battery module V BAT The voltage of the terminal is used to determine the voltage outer loop reference value, and then the voltage is calculated with the voltage of the active suppression circuit 120 to obtain the first current reference signal i L_ref1 ; In addition, the current battery module V BAT Charge and discharge current i BAT With battery module V BAT Maximum charge and discharge current I BAT_max The second current reference signal i is obtained by L_ref2 . Thereafter, the first current reference signal i L_ref1 , the second current reference signal iL_ref2 Get the current inner loop current reference signal i L_ref Then the current i of the active suppression circuit 120 can be obtained L The current reference signal i L_ref The error that exists can also represent the error between the suppression waveform and the under-damped oscillation of the harmonic oscillation circuit. Therefore, a corresponding drive signal can be generated according to the error, thereby driving the active suppression circuit to generate a suppression waveform output to the DC bus to suppress the under-damped oscillation of the harmonic oscillation circuit.

[0099] In the technical solution of the embodiment of the present application, by obtaining the active suppression circuit 120 in the energy storage valve submodule and the battery module V BAT The current characteristics of the two oscillation sources are processed as reference signals together with the current of the active suppression circuit 120 to generate a modulation signal, and then the modulation signal is used to drive the active suppression circuit 120 to generate a suppression waveform that suppresses the under-damped oscillation of the harmonic oscillation circuit and outputs it to the DC bus, thereby improving the problem of battery overcurrent and damage to the battery.

[0100] In some embodiments, see Figure 7 and Figure 8 , Figure 7 A flow chart of a method for suppressing under-damped oscillations provided by an embodiment of the present application is shown. Figure 8 A control loop diagram of a method for suppressing underdamped oscillations provided by an embodiment of the present application is shown, combined with Figure 3 , Figure 7 and Figure 8 For the sake of convenience, only the part related to this embodiment is shown, which is described in detail as follows: Step S110 specifically includes:

[0101] Step S111, obtaining the voltage of the battery module and the voltage of the active suppression circuit, and determining the charge and discharge state of the energy storage valve submodule;

[0102] Step S112, determining a voltage outer loop reference value according to the voltage of the battery module and the charge and discharge state of the energy storage valve submodule;

[0103] Step S113, obtaining a first current reference signal through PI operation according to the difference between the voltage outer loop reference value and the voltage of the active suppression circuit.

[0104] Among them, as mentioned above, the battery module V BAT The voltage of the active suppression circuit 120 can be obtained through the BMS. DC Refers to the voltage of the capacitive energy storage element C1, which can be detected by setting up a detection circuit. The charge and discharge state of the energy storage valve submodule is used to measure the charge and discharge state of the battery module V BATThe voltage amplitude is based on the voltage outer loop reference value to be positive or negative. In one example, the energy storage valve submodule is in the charging state, and the voltage reference selection controller sets the voltage outer loop reference value V ref Set to a positive value for the battery module V BAT The voltage of the energy storage valve submodule is in the discharge state, and the voltage reference selection controller sets the voltage outer loop reference value V ref Set the battery module V to a negative value BAT The PI (Poportional, Integral) operation can be implemented by a voltage regulator to obtain a first current reference signal i L_ref1 .

[0105] In the technical solution of the embodiment of the present application, the first current reference signal indicates the voltage V of the active suppression circuit 120. DC and the voltage outer loop reference value V ref It should be noted that the introduction of the voltage reference selection controller can optimize the no-load loss of the under-damped oscillation peak current active suppression circuit 120 when the energy storage valve submodule is charged and discharged.

[0106] In some embodiments, see Fig. 9 , Fig. 9 A flowchart of a method for suppressing under-damped oscillations provided by an embodiment of the present application is shown. Figure 3 , Figure 8 and Fig. 9 For the sake of convenience, only the part related to this embodiment is shown, which is described in detail as follows: Step S120 specifically includes:

[0107] Step S121, acquiring the charge and discharge current of the battery module, and determining the charge and discharge state of the energy storage valve submodule and the maximum charge and discharge current of the battery module;

[0108] Step S122, subtracting the amplitude of the charge and discharge current of the battery module from the maximum charge and discharge current of the battery module to obtain a current difference;

[0109] In step S123, the current difference is used as a second current reference signal.

[0110] Among them, as mentioned above, the battery module V BAT The charge and discharge current i BAT , and the charge and discharge status of the energy storage valve module and the battery module V BAT Maximum charge and discharge current I BAT_max can be obtained through BMS. When the energy storage valve submodule is in charging state, the battery module V BAT The charge and discharge current i BAT Indicates charging current, maximum charge and discharge current I BAT_maxIndicates the maximum charging current. When the energy storage valve module is in the discharge state, the battery module V BAT The charge and discharge current i BAT Indicates discharge current, maximum charge and discharge current I BAT_max Indicates the maximum discharge current. Battery module V BAT The charge and discharge current i BAT The amplitude can be obtained by setting a positive limiter in the control circuit.

[0111] The symbol selector in the control circuit obtains the charge and discharge state of the energy storage valve submodule to give the second current reference signal i L_ref2 is positive or negative. Among them, the current difference Δi L_ref This means that the underdamped oscillation is not caused by the charge and discharge current i BAT (i.e. battery module V BAT ), so the second current reference signal i is set L_ref2 is 0. Current difference Δi L_ref If it is a positive value, it means the charge and discharge current i BAT Therefore, when the energy storage valve submodule is in the charging state, the second current reference signal i L_ref2 is a positive value, and when the energy storage valve submodule is in the discharge state, the second current reference signal i is set L_ref2 Is a negative value.

[0112] In the technical solution of the embodiment of the present application, the battery module V BAT The maximum allowed charge and discharge current I BAT_max For reference, according to the battery module V BAT The charge and discharge current i BAT The maximum allowed charge and discharge current I BAT_max The difference between the two is used as the second current reference signal i L_ref2 , the second current reference signal i L_ref2 Indicates the battery module V BAT The charge and discharge current characteristics, such as the charge state, the discharge state, and the overcurrent size, facilitate the under-damped oscillation suppression method of the present application to generate a corresponding suppression waveform according to the charge and discharge current characteristics.

[0113] In some embodiments, see Fig.10 , Fig.10 A flowchart of a method for suppressing under-damped oscillations provided by an embodiment of the present application is shown. Figure 3 , Figure 8 and Fig.10 For the sake of convenience, only the part related to this embodiment is shown, which is described in detail as follows: Step S130 specifically includes:

[0114] Step S131, adding the first current reference signal and the second current reference signal to obtain a current inner loop current reference signal;

[0115] Step S132, subtracting the current inner loop current reference signal from the current of the active suppression circuit to obtain a current error;

[0116] Step S133, performing PI operation according to the current error to obtain a modulation signal;

[0117] Step S134: generating a driving signal for driving the active suppression circuit based on the modulation signal modulation.

[0118] Wherein, the current i of the active suppression circuit 120 is L Refers to the current of the inductive element L1, which can be detected by setting a detection circuit. The PI operation can be implemented by a current regulator, and the obtained modulation signal includes duty cycle information. Therefore, the control circuit can generate a corresponding drive signal according to the modulation signal.

[0119] The driving signal controls the switches S1 and S2 of the active suppression circuit 120 in an orderly manner, thereby realizing the current i L Control, further control the voltage of the capacitive energy storage element C1 and the battery module V BAT Suppression of charge and discharge current peaks.

[0120] In the technical solution of the embodiment of the present application, the current characteristics of the two oscillation sources are superimposed to obtain a current inner loop current reference signal, and the current regulator adjusts the current inner loop current reference signal and the current i of the active suppression circuit 120 according to the current inner loop current reference signal. L The current error is subjected to PI operation to obtain a driving signal for adjusting the suppression waveform, so that the suppression waveform can suppress the under-damped oscillation of the internal harmonic oscillation circuit, thereby solving the problem of battery overcurrent caused by under-damped oscillation, which leads to battery degradation, reduced life, or even direct damage.

[0121] In a third aspect, an embodiment of the present application further provides an energy storage valve, which includes a plurality of energy storage valve sub-modules connected in series as above; and / or includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the steps of the method for suppressing under-damped oscillations as above are implemented.

[0122] Fig.11 This is a schematic diagram of the structure of an energy storage device 11 provided in an embodiment of the present application. Fig.11 As shown, the energy storage device 11 includes: a processor 12, a memory 13, and a computer program 14 stored in the memory 13 and executable on the processor 12. When the processor 12 executes the computer program 14, the steps of the method for suppressing under-damped oscillation in the above embodiment are implemented.

[0123] In a specific implementation, the energy storage device 11 may be an energy storage valve submodule or an energy storage valve as described above. Those skilled in the art may understand that Fig.11 This is only an example of the energy storage device 11 and does not constitute a limitation on the energy storage device 11 . The energy storage device 11 may include more or fewer components than shown in the figure, or a combination of certain components, or different components, such as input and output devices, network access devices, etc.

[0124] The processor 12 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0125] In some embodiments, the memory 13 may be an internal storage unit of the energy storage device 11, such as a hard disk or memory of the energy storage device 11. In other embodiments, the memory 13 may also be an external storage device of the energy storage device 11, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the energy storage device 11. Further, the memory 13 may also include both an internal storage unit of the energy storage device 11 and an external storage device. The memory 13 is used to store an operating system, an application program, a boot loader, data, and other programs. The memory 13 may also be used to temporarily store data that has been output or is to be output.

[0126] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0127] An embodiment of the present application provides a computer program product, which, when executed on a computer, enables the computer to execute the steps in the above-mentioned method embodiments.

[0128] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above method embodiments, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above method embodiments can be implemented. Among them, the computer program includes computer program code, which can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device that can carry the computer program code to the camera / terminal device, recording medium, computer memory, ROM (Read-Only Memory), RAM (Random Access Memory), CD-ROM (Compact Disc Read-Only Memory), magnetic tape, floppy disk and optical data storage device. The computer-readable storage medium mentioned in the present application can be a non-volatile storage medium, in other words, it can be a non-transient storage medium.

[0129] It should be understood that all or part of the steps to implement the above embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The computer instructions can be stored in the above-mentioned computer readable storage medium.

[0130] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0131] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0132] In the embodiments provided in the present application, it should be understood that the disclosed modules / devices and methods can be implemented in other ways. For example, the module / device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0133] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A storage valve submodule, characterized in that: It includes a power circuit, a battery module and an active suppression circuit, wherein the power circuit includes an energy storage element; The battery module is connected to the power circuit via a DC bus, the energy storage element is connected in parallel with the battery module via the DC bus, the active suppression circuit is connected in series or in parallel with the battery module via the DC bus, and the internal resistance and inductance of the energy storage valve submodule and the energy storage element form a harmonic oscillation circuit; The active suppression circuit is used to generate a suppression waveform and output it to the DC bus; The suppression waveform is used to suppress under-damped oscillation of the harmonic oscillation circuit.

2. The energy storage valve submodule according to claim 1, characterized in that: The active suppression circuit includes an inductive element, a capacitive energy storage element and a switch module; The inductive element is connected to the DC bus, and the switch module is connected to the capacitive energy storage element; The switch module is used to be connected to the control circuit, and is controlled by a preset control signal output by the control circuit to switch back and forth between the on and off states, so as to trigger the capacitive energy storage element and the inductive element to switch back and forth between the coupling and decoupling states to generate the suppression waveform.

3. The energy storage valve submodule according to claim 2, characterized in that: The switch module includes a first switch element and a second switch element. The first switch element is connected in series with the second switch element and then connected in parallel with the capacitive energy storage element. The first end of the inductive element is connected to the series node of the first switch element and the second switch element, and the second end of the inductive element is connected to the positive pole of the DC bus.

4. The energy storage valve submodule according to claim 2 or 3, characterized in that: The capacitive energy storage element includes a second capacitor, and the inductive element includes a first inductor.

5. The energy storage valve submodule according to claim 3, characterized in that: The active suppression circuit includes a third capacitor, a first end of the third capacitor is connected to the first end of the inductive element, and a second end of the third capacitor is connected to the negative electrode of the DC bus.

6. The energy storage valve submodule according to any one of claims 1 to 3, characterized in that: The power circuit further includes a third switch element, and the third switch element is connected in parallel with the energy storage element.

7. The energy storage valve submodule according to any one of claims 1 to 3, characterized in that: The power circuit further includes a half-bridge circuit or a full-bridge circuit, and the half-bridge circuit or the full-bridge circuit is connected in parallel with the energy storage element.

8. A method for suppressing underdamped oscillations, characterized in that: Applied to the energy storage valve submodule according to any one of claims 1 to 7, the suppression method comprises: Obtaining a first current reference signal according to the charge and discharge state of the energy storage valve submodule, the voltage of the battery module, and the voltage of the active suppression circuit; Obtaining a second current reference signal according to the charge and discharge state of the energy storage valve submodule, the charge and discharge current of the battery module, and the maximum charge and discharge current of the battery module; generating a driving signal according to the first current reference signal, the second current reference signal and the current of the active suppression circuit; The driving signal is used to drive the active suppression circuit to generate a suppression waveform output to the DC bus, and the suppression waveform is used to suppress under-damped oscillation of the harmonic oscillation circuit.

9. The method for suppressing underdamped oscillations according to claim 8, characterized in that: The step of obtaining a first current reference signal according to the charge and discharge state of the energy storage valve submodule, the voltage of the battery module, and the voltage of the active suppression circuit includes: Acquiring the voltage of the battery module and the voltage of the active suppression circuit, and determining the charge and discharge state of the energy storage valve submodule; Determine a voltage outer loop reference value according to the voltage of the battery module and the charge and discharge state of the energy storage valve submodule; The first current reference signal is obtained by performing a PI operation based on the difference between the voltage outer loop reference value and the voltage of the active suppression circuit.

10. The method for suppressing underdamped oscillations according to claim 8, characterized in that: The second current reference signal is obtained according to the charge and discharge state of the energy storage valve submodule, the charge and discharge current of the battery module, and the maximum charge and discharge current of the battery module, including: Acquiring the charge and discharge current of the battery module, and determining the charge and discharge state of the energy storage valve submodule and the maximum charge and discharge current of the battery module; A current difference obtained by subtracting the amplitude of the charge and discharge current of the battery module from the maximum charge and discharge current of the battery module; Setting the second current reference signal according to the current difference; Among them, if the current difference is a negative value, the second current reference signal is set to 0; if the current difference is a positive value, when the energy storage valve submodule is in a charging state, the second current reference signal is set to a positive value, and when the energy storage valve submodule is in a discharging state, the second current reference signal is set to a negative value.

11. The method for suppressing underdamped oscillations according to claim 8, characterized in that: The step of generating a driving signal according to the first current reference signal, the second current reference signal and the current of the active suppression circuit comprises: Adding the first current reference signal and the second current reference signal to obtain a current inner loop current reference signal; Subtracting the current inner loop current reference signal from the current of the active suppression circuit to obtain a current error; Performing PI operation according to the current error to obtain a modulation signal; The drive signal for driving the active suppression circuit is generated based on the modulation signal modulation.

12. An energy storage valve, characterized in that: The energy storage valve comprises a plurality of energy storage valve submodules connected in series as claimed in any one of claims 1 to 7; and / or The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for suppressing under-damped oscillation as claimed in any one of claims 8 to 11 are implemented.

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