Control method for DC bus voltage fluctuation suppression and related device

Abstract

The invention provides a control method for DC bus voltage fluctuation suppression and a related device. The control method for DC bus voltage fluctuation suppression comprises the steps that a model of an electrical spring with a power switch device is constructed, and the electrical spring is arranged between a DC bus and an adjustable load; determining the fluctuation power of the DC bus based on the DC bus voltage reference value and the actual voltage value of the DC bus; and adjusting the consumption power of the adjustable load by controlling the switching state of the power switching device based on the fluctuation power, so that the direct current bus voltage reference value is equal to the direct current bus voltage actual value. According to the invention, the electrical spring is connected between the DC bus and the adjustable load, the voltage fluctuation of the DC bus is suppressed, and the anti-interference capability of the power distribution network system is greatly improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of power voltage fluctuation regulation, and in particular to a control method and related device for suppressing direct current bus voltage fluctuation. Background Art

[0002] DC bus voltage fluctuation refers to the phenomenon that the voltage changes rapidly in a short period of time. The degree of voltage fluctuation is usually measured by the voltage amplitude fluctuation value and the fluctuation frequency. This fluctuation not only affects the stable operation of the DC microgrid, but may also cause damage to the connected loads and distributed energy equipment.

[0003] Due to the uncertainty and intermittency of distributed energy, the output of micro-sources such as wind power and photovoltaic power is unstable, which directly affects the operation of the DC distribution network and leads to the instability of the bus voltage. In addition, due to the rapid development and popularization of new energy electric vehicles, they are connected to the power grid on a large scale, which greatly increases the complexity of the operation of the power grid. Given the immaturity of V2G technology, new energy electric vehicles cause large-scale load switching when charging, which further causes power quality problems in the DC distribution network, the most obvious of which is the fluctuation of the bus voltage. Such problems will reduce the power supply quality, cause relay malfunctions, threaten the safe operation of the system, and hinder the consumption of new energy. It is urgent to study effective governance technologies.

[0004] At present, the strategies for managing voltage fluctuations in DC distribution networks include additional equipment management, such as parallel comprehensive management circuits, which mainly achieve the management of power quality issues such as voltage fluctuations through the hybrid connection of DAB, DC active filters and other equipment. Energy storage participation in regulation is also a mainstream method, which effectively manages the power balance of the DC distribution network bus by controlling the charging and discharging strategy of energy storage batteries to ensure the stable operation of the system.

[0005] However, additional equipment can only compensate for specific power quality issues in a targeted manner. At the same time, due to the low switching frequency and low power density of the equipment, it is necessary to solve the problem of low switching frequency, improve the control algorithm and optimize the configuration of the device. In addition, the additional equipment will involve more complex circuits, complex designs and low economic benefits. When the energy storage power station is charged and discharged at high power, due to the influence of battery internal resistance and power changes, large voltage fluctuations are likely to occur, which may cause system voltage instability. Summary of the invention

[0006] The present disclosure aims to at least solve the above-mentioned technical problems existing in the prior art.

[0007] To this end, an object of the present disclosure is to provide a control method for suppressing DC bus voltage fluctuations, the control method for suppressing DC bus voltage fluctuations comprising:

[0008] Constructing a model of an electrical spring having a power switching device, wherein the electrical spring is disposed between a DC bus and an adjustable load;

[0009] Determine the fluctuating power of the DC bus based on the DC bus voltage reference value and the actual value of the DC bus voltage;

[0010] Based on the fluctuating power, the switching state of the power switch device is controlled to adjust the power consumption of the adjustable load so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0011] In some embodiments, the model of the electrical spring having the power switching device is constructed, and the electrical spring is arranged between the DC bus and the adjustable load. The model of the electrical spring is expressed as:

[0012]

[0013] Among them, C1 is the DC bus side capacitor, C2 is the filter capacitor, u dc is the DC bus voltage, u L is the adjustable load voltage, i is the input current, i L is the inductor current, L is the energy storage inductor, D is the duty cycle of the power switching device S, and R is the resistance of the adjustable load.

[0014] In some embodiments, adjusting the power consumption of the adjustable load by controlling the switching state of the power switch device based on the fluctuating power so that the DC bus voltage reference value is equal to the DC bus voltage actual value includes:

[0015] Based on the fluctuating voltage corresponding to the fluctuating power, an output signal is obtained through a sliding mode controller;

[0016] determining a duty cycle based on the output signal;

[0017] The power consumption of the adjustable load is adjusted based on the duty cycle so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0018] In some embodiments, obtaining an output signal through a sliding mode controller based on the fluctuating voltage corresponding to the fluctuating power includes:

[0019] Determine the sliding surface;

[0020] determining a reaching law, wherein the reaching law enables the fluctuating voltage to reach the sliding mode surface and slide along the sliding mode surface;

[0021] An output signal is obtained based on the model of the electrical spring, the sliding surface, and the reaching law.

[0022] In some embodiments, the sliding surface is expressed as s=cx1+x2, where s is the selected sliding surface, c is a constant greater than zero, x1 and x2 are user-defined state variables, and x1 is the DC bus voltage reference value u dc_ref and the actual value of the DC bus voltage u dc The difference,

[0023] The reaching law is expressed as: ε>0, where c is a constant greater than zero, ε is the convergence coefficient, and sgn(s) is the sign function of the sliding surface s;

[0024] The output signal is expressed as:

[0025] Where, C1 is the DC bus side capacitor, u dc is the actual value of the DC bus voltage, u dc_ref is the DC bus voltage reference value, u L is the adjustable load voltage, i is the input current, i L is the inductor current.

[0026] In some embodiments, determining the duty cycle based on the output signal comprises:

[0027] A duty cycle is determined based on the output signal and the amplitude of the pulse width modulation.

[0028] In some embodiments, the electrical spring includes at least a DC-DC converter, a power switching device, and an LC filter.

[0029] Another object of the present disclosure is to provide a DC bus voltage fluctuation suppression control device, comprising:

[0030] A model building module, used for building a model of an electrical spring having a power switching device, wherein the electrical spring is arranged between a DC bus and an adjustable load;

[0031] A fluctuating power determination module, used for determining the fluctuating power of the DC bus based on a DC bus voltage reference value and an actual value of the DC bus voltage;

[0032] A voltage regulating module is used to regulate the power consumption of the adjustable load by controlling the switching state of the power switch device based on the fluctuating power, so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0033] Another object of the present disclosure is to provide a storage medium storing a computer program, wherein the computer program performs the steps of the above method when executed by a processor.

[0034] Another object of the present disclosure is to provide an electronic device, comprising at least a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps of the above method when executing the computer program in the memory.

[0035] The control method and related device for suppressing DC bus voltage fluctuation provided by the embodiments of the present disclosure have the following beneficial effects:

[0036] The control method for suppressing DC bus voltage fluctuations includes: constructing a model of an electrical spring with a power switching device, the electrical spring being arranged between the DC bus and the adjustable load; determining the fluctuating power of the DC bus based on the DC bus voltage reference value and the actual value of the DC bus voltage; adjusting the power consumption of the adjustable load by controlling the switching state of the power switching device based on the fluctuating power, so that the DC bus voltage reference value is equal to the actual value of the DC bus voltage. When ES is not introduced, the bus voltage fluctuates to a large extent. The method disclosed in the present invention can efficiently suppress voltage fluctuations, and the anti-interference ability of the distribution network system is greatly improved. The design method of the main circuit of the electrical spring is simple and easy to implement, has high economic benefits, is suitable for actual working conditions, does not require external additional equipment in the DC distribution network, and effectively utilizes the role of non-critical loads in the distribution network, so that it has controllability and can stabilize the DC distribution network voltage well. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0038] Figure 1 is a schematic diagram of an electrical spring in an embodiment of the present disclosure;

[0039] Figure 2 is a schematic diagram of the steps of a control method for suppressing DC bus voltage fluctuations in an embodiment of the present disclosure;

[0040] Figure 3 is a schematic diagram of the steps of a control method for suppressing DC bus voltage fluctuations in an embodiment of the present disclosure;

[0041] Figure 4 is a schematic diagram of a sliding mode control reaching condition of a control method for suppressing DC bus voltage fluctuation in an embodiment of the present disclosure;

[0042] Figure 5 is a sliding mode control block diagram of a control method for suppressing DC bus voltage fluctuations in an embodiment of the present disclosure;

[0043] Figure 6 is a schematic diagram of light intensity fluctuation in a specific embodiment of the present disclosure;

[0044] Figure 7 It is a schematic diagram of bus voltage in a specific embodiment of the present disclosure.

[0045] Reference numerals:

[0046] 1. DC bus; 2. Electrical spring; 3. Adjustable load. DETAILED DESCRIPTION

[0047] Various aspects and features of the present disclosure are described herein with reference to the drawings.

[0048] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present disclosure will occur to those skilled in the art.

[0049] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the general description of the present disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

[0050] These and other characteristics of the present disclosure will become apparent from the following description of a preferred form of embodiment given as a non-limiting example, with reference to the attached drawings.

[0051] It should also be understood that, although the present disclosure has been described with reference to some specific examples, those skilled in the art will be able to realize many other equivalent forms of the present disclosure that have the features described in the claims and are therefore within the scope of protection defined thereby.

[0052] The above and other aspects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0053] Specific embodiments of the present disclosure are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments claimed are merely examples of the present disclosure, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of ways with substantially any suitable detailed structure.

[0054] The first embodiment of the present disclosure provides a control method for suppressing DC bus voltage fluctuations. DC bus voltage fluctuations refer to the phenomenon that the voltage changes rapidly in a short period of time. The degree of voltage fluctuation is usually measured by the voltage amplitude fluctuation value and the fluctuation frequency. Such fluctuations not only affect the stable operation of the DC microgrid, but may also cause damage to the connected loads and distributed energy equipment. Figure 1-Figure 3 As shown, the control method for suppressing DC bus voltage fluctuations includes:

[0055] S1: constructing a model of an electrical spring 2 having a power switching device, wherein the electrical spring 2 is arranged between a DC bus 1 and an adjustable load 3;

[0056] The electrical spring (ES) includes at least a DC-DC converter, a power switch device and an LC filter. Specifically, the electrical spring 2 includes an energy storage inductor L, a DC bus side capacitor C1, a filter capacitor C2, a DC-DC converter and a power switch device (marked at S in the figure), wherein a DC-DC converter is installed at the power switch device.

[0057] The mathematical model of the electrical spring (ES) can be expressed as:

[0058]

[0059] Among them, C1 is the DC bus side capacitor, C2 is the filter capacitor, u dc is the DC bus voltage, u L is the adjustable load voltage, i is the input current, i L is the inductor current, L is the energy storage inductor, D is the duty cycle of the power switching device S, and R is the resistance of the adjustable load.

[0060] The electrical spring 2 adjusts the duty cycle of the equivalent buck converter circuit by controlling the switching of the power switch device, thereby changing the voltage u of the adjustable load 3. L , that is, the entire electrical spring 2 can be equivalent to a resistance of R eq The value of the virtual resistance depends on the change of the duty cycle D, which enables it to track the power fluctuations in the distribution network and compensate for them, thereby stabilizing the voltage of the DC distribution network.

[0061] The electrical spring 2 is connected to the DC bus 1. The design method is simple and easy, with high economic benefits and applicable to actual working conditions. There is no need to connect additional equipment such as energy storage equipment connected in parallel to the micro-source to the DC distribution network. In addition, the role of non-critical loads (adjustable loads 3, such as loads in the lighting system) in the distribution network is effectively utilized to make it adjustable and stabilize the voltage of the DC distribution network.

[0062] S2: determining the fluctuating power of the DC bus 1 based on the voltage reference value of the DC bus 1 and the actual voltage value of the DC bus 1;

[0063] u dc_ref For the control target to be achieved, for example, for a 750V distribution network, 750V is the reference value. In practice, due to disturbances and other reasons, it may not be maintained at the reference value, but maintained at the actual value u dc The fluctuating voltage corresponding to the fluctuating power refers to the voltage reference value u of DC bus 1. dc_ref The actual value of the voltage u of DC bus 1 dc The difference x1 between them, the variable x1 is the size of the voltage value that needs to be adjusted.

[0064] S3: Based on the fluctuating power, the switching state of the power switch device is controlled to adjust the power consumption of the adjustable load 3 so that the reference value of the DC bus 1 voltage is equal to the actual value of the DC bus 1 voltage.

[0065] Specifically include:

[0066] S301: obtaining an output signal through a sliding mode controller based on a fluctuating voltage corresponding to the fluctuating power;

[0067] Sliding mode control is a system that, without considering the initial state, moves the controlled trajectory toward the plane under a series of control actions, then reaches the plane, finally slides along the plane and finally stops at the equilibrium point. The plane that guides the trajectory line to move is called the sliding surface. Since the characteristics and parameters of the system only depend on the designed switching hyperplane and have nothing to do with external interference, the sliding mode variable structure control has strong robustness. Specifically, adjust the voltage reference value u of DC bus 1 dc_ref The actual value of the voltage u of DC bus 1 dc Equal, using the sliding mode control algorithm, under the action of sliding mode control, the controller changes purposefully and continuously in a jump manner according to the current state of the system, forcing the system to move along the predetermined "sliding mode" state trajectory, and after reaching the plane, it slides along it and finally reaches the equilibrium point. When designing a sliding mode controller, two points should be considered: one is to design a suitable sliding surface; the other is that the system must quickly reach the designed sliding surface under control, that is, the consideration of the approach method.

[0068] Specifically include:

[0069] S3011: Determine the sliding surface;

[0070] Specifically, the sliding surface is expressed as s = cx1 + x2;

[0071] Among them, s is the selected sliding surface, c is a constant greater than zero, x1 and x2 are custom state variables, x1 is the DC bus voltage reference value u dc_refand the actual value of the DC bus voltage u dc The difference,

[0072]

[0073] S3012: Determine a reaching law, which makes the fluctuating voltage reach the sliding surface and slide along the sliding surface; Figure 4 As shown, the sliding mode control conditions must be met:

[0074]

[0075] The above formula can be equivalent to It means that any point outside the sliding plane s = 0 can approach the sliding surface. There is no clear requirement for this reaching law, but in order to improve the dynamic performance of this control method, the constant speed reaching law, power reaching law, exponential reaching law or general reaching law are generally selected.

[0076] In this embodiment, the constant speed approaching law is selected: the approaching law is expressed as:

[0077] Where c is a constant greater than zero, ε is the convergence coefficient, and sgn(s) is the sign function of the sliding surface s;

[0078] Among them, ε describes the speed of approaching sgn(s).

[0079] S3013: Obtain an output signal based on the model, sliding surface and reaching law of the electrical spring 2.

[0080] Specifically, the output signal is expressed as:

[0081] Where, C1 is the DC bus side capacitor, u dc is the actual value of the DC bus voltage, u dc_ref is the DC bus voltage reference value, u L is the adjustable load voltage, i is the input current, i L is the inductor current.

[0082] The control rate and stability are guaranteed by sliding mode control, and the design of sliding mode and the selection of convergence law can be selected according to the actual working conditions. At the same time, it has strong robustness to external interference. The application of electric spring 2 can effectively solve the relevant power quality problems in DC distribution network.

[0083] For example, when the motion trajectory of the system moves along the sliding surface s=cx1+x2=0, x1 can be expressed as:

[0084] x1=u dc_ref -u dc =me -ct ;

[0085] Among them, m is a constant coefficient, and eventually x1 will tend to 0, that is, reach u dc =u dc_ref control effect.

[0086] S302: Determine a duty cycle based on the output signal;

[0087] The duty cycle refers to the proportion of the power-on time to the total time in a pulse cycle. Specifically, the power switch device S has two working states, in which the power switch device S is always on, the adjustable load 3 works normally, and does not participate in the voltage regulation; in the other working state, the power switch device S is not always on in a working cycle, and the terminal voltage of the controllable load can be changed by changing the duty cycle D, thereby changing the power consumption of the adjustable load 3, so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0088] Specifically, the duty cycle is determined based on the output signal and the amplitude of the pulse width modulation (PWM).

[0089] The control method of pulse width modulation is to control the on and off of the switching devices of the inverter circuit so that the output end obtains a series of pulses with equal amplitude but inconsistent width, and uses these pulses to replace the sine wave or the required waveform. That is, multiple pulses are generated in half a cycle of the output waveform, so that the equivalent voltage of each pulse is a sine waveform, and the output obtained is smooth and low-order harmonic waveform. In the PWM waveform, the amplitude of each pulse is equal. To change the amplitude of the equivalent output sine wave, just change the width of each pulse according to the same proportional coefficient. Therefore, in the inverter, the pulse voltage output by the PWM inverter circuit is the amplitude of the DC side voltage, that is, u=D.

[0090] For example, when the arrival time and interference are not taken into account, the equivalent control quantity u of the converter is obtained: eq , further analysis of the system stability to obtain the equivalent control u of the converter eq is the ideal duty cycle of the converter. When considering arrival time and interference, convergence law and interference compensation terms are generally added for compensation. This polynomial is defined as the switching control u sw Therefore, the fixed-frequency PWM sliding mode controller generally uses the equivalent control quantity plus the switching control quantity, that is: u = u eq +u sw , assuming that the amplitude of PWM control is 1, then the control law of DC / DC converter is u=D=u eq +u sw .

[0091] S303: Regulating the power consumption of the adjustable load 3 based on the duty cycle so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0092] By adjusting the duty cycle, the terminal voltage of the controllable load can be adjusted, and then the power consumption of the adjustable load 3 can be adjusted to reach u dc =u dc_ref The control effect indicates that the DC bus voltage reference value is consistent with the DC bus voltage actual value.

[0093] The present invention connects an electrical spring 2 in a DC distribution network, and changes its virtual resistance by effectively adjusting a non-critical adjustable load 3 in the system, thereby changing its power to compensate for the power fluctuation on the grid side, thereby achieving the purpose of stabilizing the voltage level of the DC distribution network; a variable structure control strategy based on a sliding mode is proposed, so that the electrical spring 2 can realize control switching according to the set sliding mode, and can effectively manage power quality problems on the DC grid side.

[0094] The present disclosure may also adopt other control methods to replace sliding mode control, such as PI control. Figure 7 The simulation results show that the sliding mode control has faster response speed, higher accuracy and stronger stability than other control methods such as PI.

[0095] By way of specific examples and with reference to Figure 5 The present disclosure is described in detail.

[0096] Select the following key parameters, u dc_ref =750V, C1=1500μf, C2=1000μf, L=0.5mH, R=50Ω, ε=10, c=1000.

[0097] 1.u dc_ref with u dc Subtract and get variable x1;

[0098] 2. The variable x1 is converted into an output signal u by the sliding mode controller;

[0099] 3. The output signal u is subjected to PWM (pulse width modulation) to obtain a duty cycle D;

[0100] 4. Control u by controlling the duty cycle D of the DC-DC converter of the electric spring (ES) dc The purpose of further achieving u dc =u dc_ref The effect is to suppress the voltage fluctuation of the DC bus.

[0101] Figure 6 This is a schematic diagram of the light intensity of photovoltaic power generation during the simulation process, which is used to simulate the fluctuation of DC distribution network voltage caused by the change of photovoltaic output.

[0102] Figure 7 The figure is a schematic diagram of the bus voltage of the DC distribution network. It can be seen from the figure that when the photovoltaic output power changes, the bus voltage fluctuates greatly when the electrical spring is not introduced, and the voltage drops to 710V at the lowest. When the light intensity is restored, there is an overshoot of about 0.8%; the electrical spring under PI control (PI-ES) has a certain degree of suppression of voltage fluctuations, and the lowest voltage rises to 745V, and there is a certain degree of overshoot when the light intensity is restored; the electrical spring under sliding mode control (SMC-ES) can effectively suppress fluctuations, and the bus voltage is almost stable at 750V, and the system's anti-interference ability is greatly improved, which verifies the effectiveness of the electrical spring 2 based on sliding mode control in managing voltage fluctuations.

[0103] Based on the same inventive concept as the first embodiment, the second embodiment of the present disclosure provides a DC bus voltage fluctuation suppression control device, comprising:

[0104] A model building module, used for building a model of an electrical spring 2 having a power switching device, wherein the electrical spring 2 is arranged between a DC bus and an adjustable load 3;

[0105] A fluctuating power determination module, used for determining the fluctuating power of the DC bus based on a DC bus voltage reference value and an actual DC bus voltage value;

[0106] The voltage regulation module is used to adjust the power consumption of the adjustable load 3 by controlling the switching state of the power switch device based on the fluctuating power, so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0107] Furthermore, the voltage regulation module includes:

[0108] An output signal acquisition unit, used for acquiring an output signal through a sliding mode controller based on a fluctuating voltage corresponding to the fluctuating power;

[0109] a duty cycle determining unit, configured to determine the duty cycle based on the output signal;

[0110] The voltage regulating unit is used to regulate the power consumption of the adjustable load 3 based on the duty cycle so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0111] Furthermore, the output signal acquisition unit includes:

[0112] The sliding surface determination subunit is used to determine the sliding surface;

[0113] The reaching law determination subunit is used to determine the reaching law so that the fluctuating voltage reaches the sliding mode surface and slides along the sliding mode surface;

[0114] The output signal acquisition subunit is used to acquire the output signal based on the model, sliding surface and reaching law of the electric spring 2.

[0115] The sliding surface is expressed as s=cx1+x2, where s is the selected sliding surface, c is a constant greater than zero, x1 and x2 are custom state variables, and x1 is the DC bus voltage reference value u dc_ref and the actual value of the DC bus voltage u dc The difference,

[0116] The reaching law is expressed as: Where c is a constant greater than zero, ε is the convergence coefficient, and sgn(s) is the sign function of the sliding surface s;

[0117] The output signal is expressed as:

[0118] Where, C1 is the DC bus side capacitor, u dc is the actual value of the DC bus voltage, u dc_ref is the DC bus voltage reference value, u L is the adjustable load voltage, i is the input current, i L is the inductor current.

[0119] Furthermore, the mathematical model of the electrical spring 2 is:

[0120]

[0121] Among them, C1 is the DC bus side capacitor, C2 is the filter capacitor, u dc is the DC bus voltage, u L is the adjustable load voltage, i is the input current, i L is the inductor current, L is the energy storage inductor, D is the duty cycle of the power switching device S, and R is the resistance of the adjustable load.

[0122] Furthermore, the electrical spring 2 at least includes a DC-DC converter, a power switch device and an LC filter.

[0123] In this embodiment, the power consumption of the adjustable load 3 is adjusted by controlling the switching state of the power switch device of the electric spring 2; based on the power consumption of the adjustable load 3, the DC bus voltage reference value is adjusted to be consistent with the actual value of the DC bus voltage. When ES is not introduced, the bus voltage fluctuates to a large extent. The method disclosed in this disclosure can effectively suppress voltage fluctuations, and the anti-interference ability of the distribution network system is greatly improved.

[0124] The main circuit design method of electric spring 2 is simple and easy, with high economic benefits, suitable for actual working conditions, no need to connect additional equipment to the DC distribution network, and effectively utilizes the role of non-critical loads in the distribution network, making it controllable and able to stabilize the DC distribution network voltage well.

[0125] A third embodiment of the present disclosure provides a storage medium storing a computer program. When the computer program is executed by a processor, the steps of implementing the above method include:

[0126] S11: constructing a model of an electrical spring 2 having a power switching device, wherein the electrical spring 2 is arranged between a DC bus and an adjustable load 3;

[0127] S12: determining the fluctuating power of the DC bus based on the DC bus voltage reference value and the DC bus voltage actual value;

[0128] S13: Based on the fluctuating power, the switching state of the power switch device is controlled to adjust the power consumption of the adjustable load 3 so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0129] Of course, other steps of the control method can also be used to implement the above embodiment.

[0130] In this embodiment, the power consumption of the adjustable load 3 is adjusted by controlling the switching state of the power switch device of the electric spring 2; based on the power consumption of the adjustable load 3, the DC bus voltage reference value is adjusted to be consistent with the actual value of the DC bus voltage. When ES is not introduced, the bus voltage fluctuates to a large extent. The method disclosed in this disclosure can effectively suppress voltage fluctuations, and the anti-interference ability of the distribution network system is greatly improved.

[0131] The main circuit design method of electric spring 2 is simple and easy, with high economic benefits, suitable for actual working conditions, no need to connect additional equipment to the DC distribution network, and effectively utilizes the role of non-critical loads in the distribution network, making it controllable and able to stabilize the DC distribution network voltage well.

[0132] A fourth embodiment of the present disclosure provides an electronic device, the electronic device including at least a memory and a processor, the memory storing a computer program, and the processor implementing the steps of the above method when executing the computer program in the memory, specifically including:

[0133] S21: constructing a model of an electrical spring 2 having a power switching device, wherein the electrical spring 2 is arranged between a DC bus and an adjustable load 3;

[0134] S22: determining the fluctuating power of the DC bus based on the DC bus voltage reference value and the DC bus voltage actual value;

[0135] S23: Based on the fluctuating power, the switching state of the power switch device is controlled to adjust the power consumption of the adjustable load 3 so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

[0136] In this embodiment, the power consumption of the adjustable load 3 is adjusted by controlling the switching state of the power switch device of the electric spring 2; based on the power consumption of the adjustable load 3, the DC bus voltage reference value is adjusted to be consistent with the actual value of the DC bus voltage. When ES is not introduced, the bus voltage fluctuates to a large extent. The method disclosed in this disclosure can effectively suppress voltage fluctuations, and the anti-interference ability of the distribution network system is greatly improved.

[0137] The main circuit design method of electric spring 2 is simple and easy, with high economic benefits, suitable for actual working conditions, no need to connect additional equipment to the DC distribution network, and effectively utilizes the role of non-critical loads in the distribution network, making it controllable and able to stabilize the DC distribution network voltage well.

[0138] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0139] 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.

[0140] 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.

[0141] In the embodiments provided in the present application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. 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 through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0142] 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.

[0143] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0144] If the integrated module 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-mentioned embodiment method, and can also 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-mentioned motor torque control method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0145] In addition, the features of the embodiments shown in the drawings of the present application or the various embodiments mentioned in this specification are not necessarily understood as independent embodiments. Instead, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the drawings.

[0146] The embodiments described above 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, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A control method for suppressing DC bus voltage fluctuations, characterized in that: include: Constructing a model of an electrical spring having a power switching device, wherein the electrical spring is disposed between a DC bus and an adjustable load; Determine the fluctuating power of the DC bus based on the DC bus voltage reference value and the actual value of the DC bus voltage; Based on the fluctuating power, the switching state of the power switch device is controlled to adjust the power consumption of the adjustable load so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

2. The control method for suppressing DC bus voltage fluctuation according to claim 1, characterized in that: The model of the electrical spring having the power switch device is constructed, and the electrical spring is arranged between the DC bus and the adjustable load. The model of the electrical spring is expressed as: Among them, C1 is the DC bus side capacitor, C2 is the filter capacitor, u dc is the DC bus voltage, u L is the adjustable load voltage, i is the input current, i L is the inductor current, L is the energy storage inductor, D is the duty cycle of the power switching device S, and R is the resistance of the adjustable load.

3. The control method for suppressing DC bus voltage fluctuation according to claim 2, characterized in that: Adjusting the power consumption of the adjustable load by controlling the switching state of the power switch device based on the fluctuating power so that the DC bus voltage reference value is equal to the DC bus voltage actual value includes: Based on the fluctuating voltage corresponding to the fluctuating power, an output signal is obtained through a sliding mode controller; determining a duty cycle based on the output signal; The power consumption of the adjustable load is adjusted based on the duty cycle so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

4. The control method for suppressing DC bus voltage fluctuation according to claim 3, characterized in that: The obtaining of an output signal through a sliding mode controller based on the fluctuating voltage corresponding to the fluctuating power includes: Determine the sliding surface; determining a reaching law, wherein the reaching law enables the fluctuating voltage to reach the sliding mode surface and slide along the sliding mode surface; An output signal is obtained based on the model of the electrical spring, the sliding surface, and the reaching law.

5. The control method for suppressing DC bus voltage fluctuation according to claim 4, characterized in that: The sliding surface is expressed as s=cx1+x2, where s is the selected sliding surface, c is a constant greater than zero, x1 and x2 are user-defined state variables, and x1 is the DC bus voltage reference value u dc_ref and the actual value of the DC bus voltage u dc The difference, The reaching law is expressed as: ε>0, where c is a constant greater than zero, ε is the convergence coefficient, and sgn(s) is the sign function of the sliding surface s; The output signal is expressed as: Where, C1 is the DC bus side capacitor, u dc is the actual value of the DC bus voltage, u dc_ref is the DC bus voltage reference value, u L is the adjustable load voltage, i is the input current, i L is the inductor current.

6. The control method for suppressing DC bus voltage fluctuation according to claim 4, characterized in that: The determining of the duty cycle based on the output signal comprises: A duty cycle is determined based on the output signal and the amplitude of the pulse width modulation.

7. The control method for suppressing DC bus voltage fluctuation according to claim 1, characterized in that: The electrical spring at least includes a DC-DC converter, a power switch device and an LC filter.

8. A DC bus voltage fluctuation suppression control device, characterized in that: include: A model building module, used for building a model of an electrical spring having a power switching device, wherein the electrical spring is arranged between a DC bus and an adjustable load; A fluctuating power determination module, used for determining the fluctuating power of the DC bus based on a DC bus voltage reference value and an actual value of the DC bus voltage; A voltage regulating module is used to regulate the power consumption of the adjustable load by controlling the switching state of the power switch device based on the fluctuating power, so that the DC bus voltage reference value is equal to the DC bus voltage actual value.

9. A storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. An electronic device, comprising at least a memory and a processor, wherein a computer program is stored in the memory, wherein: The processor implements the steps of the method of any one of claims 1 to 7 when executing the computer program on the memory.

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