Disturbance compensation circuit of energy storage converter and disturbance control system of energy storage converter

Abstract

The invention relates to a disturbance compensation circuit of an energy storage converter and a disturbance control system of the energy storage converter, one end of a compensation device is connected with a direct current power supply, the other end of the compensation device is connected with the energy storage converter, and the compensation device is used for compensating direct current provided by the direct current power supply and inputting the compensated direct current to the energy storage converter. A disturbance voltage is provided for the energy storage converter; the first end of the energy storage converter is connected with the anode of the direct-current power supply, and the second end is connected with the cathode of the direct-current power supply for converting direct current input by the compensation device into alternating current; the first end of the low-pass filter is connected with the second end of the energy storage converter; the first end of the power grid is connected in series with the second end of the low-pass filter, and the second end of the power grid is grounded. The disturbance compensation circuit of the energy storage converter has the characteristic of disturbance lossless injection. The disturbance control system of the energy storage converter is based on the disturbance compensation circuit of the energy storage converter, and has the characteristic of accurately regulating and controlling the disturbance voltage.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage controller modeling, and particularly to a disturbance compensation circuit for a power conversion system (PCS) of energy storage and a disturbance control system for a PCS of energy storage. Background Art

[0002] As a core component of an energy storage system, the performance of a power conversion system (PCS) of energy storage directly affects the operating efficiency, stability of the energy storage system, and its interaction ability with the external power grid. As a bidirectional energy conversion device, the energy storage PCS can effectively manage the energy flow between the energy storage device and the power grid or load, ensuring that alternating current is efficiently converted into direct current and stored in the battery during charging, and working in reverse during discharging to meet the energy requirements of the power grid or load. In addition, the energy storage PCS can also improve the power quality by adjusting reactive power, filtering harmonics, etc., and quickly respond to the power demand of the power grid, thereby stabilizing the voltage and frequency.

[0003] Due to the highly non-linear dynamic behavior of the energy storage PCS, the structural design and optimization of its control algorithm become particularly complex. In traditional methods, the mathematical model is mainly established based on the working principle of the energy storage PCS and the characteristics of power electronic components. However, during the modeling process, in order to obtain accurate model parameters, a large number of test disturbances are often added during the operation of the energy storage system, and these disturbances may affect the normal operation of the AC side and the DC side, resulting in the energy storage PCS system deviating from the steady-state operation state. Summary of the Invention

[0004] Based on this, it is necessary to provide a disturbance compensation circuit for a PCS of energy storage and a disturbance control system for a PCS of energy storage that can effectively implement the disturbance test of the PCS system for the above technical problems.

[0005] In a first aspect, the present application provides a disturbance compensation circuit for a PCS of energy storage, including:

[0006] A DC power supply;

[0007] A compensation device, one end of the compensation device is connected to the DC power supply, and the other end is connected to the PCS of energy storage, for compensating the direct current provided by the DC power supply and inputting the compensated direct current into the PCS of energy storage to provide a disturbance voltage for the PCS of energy storage;

[0008] A PCS of energy storage, the first end of the PCS of energy storage is connected to the positive pole of the DC power supply, and the second end of the PCS of energy storage is connected to the negative pole of the DC power supply, for converting the direct current input by the compensation device into alternating current and inputting the converted alternating current into a low-pass filter;

[0009] A low-pass filter, the first end of the low-pass filter is connected to the second end of the energy storage converter, and is used to eliminate high-frequency harmonics in the alternating current input by the energy storage converter;

[0010] A power grid, the first end of the power grid is connected in series with the second end of the low-pass filter, and the second end of the power grid is grounded, and is used to receive the electric energy output by the low-pass filter to distribute the electric energy to the power consumption terminals.

[0011] In one embodiment, a compensation device includes:

[0012] A DC-AC conversion unit, the first end of the DC-AC conversion unit is connected to the DC power supply, and is used to convert the direct current output by the DC power supply into alternating current;

[0013] A voltage conversion unit, the first end of the voltage conversion unit is connected to the second end of the DC-AC conversion unit, and is used to perform voltage conversion on the alternating current output by the DC-AC conversion unit;

[0014] An AC-DC conversion unit, the first end of the AC-DC conversion unit is connected to the second end of the voltage conversion unit, and the second end of the AC-DC conversion unit is connected to the energy storage converter, and is used to convert the alternating current output by the voltage conversion unit into direct current.

[0015] In one embodiment, the DC-AC conversion unit includes:

[0016] A first bridge arm, the first end of the first bridge arm is connected to the positive pole of the DC power supply, and the second end of the first bridge arm is connected to the negative pole of the DC power supply;

[0017] A second bridge arm, the first end of the second bridge arm is connected to the positive pole of the DC power supply, and the second end of the second bridge arm is connected to the negative pole of the DC power supply.

[0018] In one embodiment, the voltage conversion unit includes:

[0019] A resonance circuit, including a first inductor, an exciting inductor and a first capacitor connected in series in sequence; the first end of the resonance circuit is respectively connected to two switching tubes in the first bridge arm; the second end of the resonance circuit is respectively connected to two switching tubes in the second bridge arm;

[0020] A transformer, including a primary winding and a secondary winding, the primary winding is connected to the resonance circuit, and the secondary winding is connected to the AC-DC conversion unit, and is used to transfer the electric energy output by the resonance circuit to the AC-DC conversion unit.

[0021] In one embodiment, the AC-DC conversion unit includes:

[0022] A rectifier and filter circuit includes a second capacitor, a third bridge arm, a fourth bridge arm, a fifth bridge arm, and a sixth bridge arm. The first end of the second capacitor is connected to the first ends of the third bridge arm, the fourth bridge arm, the fifth bridge arm, and the sixth bridge arm, and the second end of the second capacitor is connected to the second ends of the third bridge arm, the fourth bridge arm, the fifth bridge arm, and the sixth bridge arm.

[0023] A second inductor, the first end of the second inductor is respectively connected to two switching tubes in the fifth bridge arm, and the second end of the second inductor is connected to the first end of the energy storage converter; the second end of the energy storage converter is respectively connected to two switching tubes in the sixth bridge arm.

[0024] In one embodiment, the first end of the primary winding is connected to the first end of the resonant circuit, and the second end of the primary winding is connected to the second end of the resonant circuit; the first end of the secondary winding is respectively connected to two switching tubes in the third bridge arm, and the second end of the secondary winding is respectively connected to two switching tubes in the fourth bridge arm.

[0025] In a second aspect, the present application further provides a disturbance control system device for an energy storage converter, including a disturbance compensation circuit and a controller of the energy storage converter according to any one of the first aspects;

[0026] The disturbance compensation circuit includes a DC power supply, a compensation device, and an energy storage converter;

[0027] A controller, the controller is connected to the disturbance compensation circuit, and is used to control the output voltage of the compensation device to adjust the input voltage of the energy storage converter; the input voltage of the energy storage converter is the sum of the output voltage of the DC power supply and the output voltage of the compensation device.

[0028] In one embodiment, the controller is further used to generate a modulation signal according to the difference between the output voltage of the DC power supply and the input voltage of the energy storage converter to control the power of the compensation device.

[0029] In one embodiment, the controller is further used to control the output voltage of the compensation device to be 0 when the bypass condition is met.

[0030] In one embodiment, the controller is further used to obtain the operating parameters of the energy storage converter according to the input voltage of the energy storage converter during the process of adjusting the input voltage of the energy storage converter, so as to perform digital twin modeling on the energy storage converter according to all operating parameters.

[0031] The disturbance compensation circuit of the above energy storage converter and the disturbance control system of the energy storage converter. One end of the compensation device is connected to the DC power supply, and the other end is connected to the energy storage converter. The first end of the energy storage converter is connected to the positive pole of the DC power supply, and the second end of the energy storage converter is connected to the negative pole of the DC power supply. The first end of the low-pass filter is connected to the second end of the energy storage converter, and the first end of the power grid is connected in series with the second end of the low-pass filter. The compensation device is used to compensate the direct current provided by the DC power supply, and input the compensated direct current into the energy storage converter to provide a disturbance voltage for the energy storage converter. By setting the voltage of the compensation device, the input voltage of the energy storage converter can be adjusted to achieve lossless injection of multiple groups of disturbances, ensuring the stable operation of the overall disturbance compensation circuit, and thus effectively realizing the disturbance test of the energy storage converter system. Since the first end of the energy storage converter is connected to the positive pole of the DC power supply and the second end is connected to the negative pole of the DC power supply, when the bypass compensation device is bypassed, the current provided by the DC power supply can be input into the energy storage converter to provide a stable voltage for the energy storage converter. In addition, due to the characteristic of the low-pass filter to eliminate high-frequency harmonics, the alternating current after filtering high-frequency harmonics by the low-pass filter is purer, can be input into the power grid more stably, reduces the occurrence probability of problems such as power grid voltage fluctuation and frequency offset caused by harmonics, and improves the stability and reliability of the power grid. Brief Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0033] Figure 1 It is the topological structure diagram of the disturbance compensation circuit of the energy storage converter in one embodiment;

[0034] Figure 2 It is the internal topological structure diagram of the compensation device in one embodiment;

[0035] Figure 3 It is the internal topological structure diagram of the compensation device in another embodiment;

[0036] Figure 4 It is the structural block diagram of the disturbance control system of the energy storage converter in one embodiment.

[0037] Description of the Reference Numerals:

[0038] 100 - DC power supply, 200 - compensation device, 210 - DC - AC conversion unit, 211 - first arm, 212 - second arm, 220 - transformer unit, 221 - resonant circuit, 222 - transformer, 230 - AC - DC conversion unit, 231 - rectifier filter circuit, 232 - second inductor, 300 - energy storage converter, 400 - low - pass filter, 500 - power grid, 600 - controller. Detailed implementation manners

[0039] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in the description of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0041] It can be understood that the terms "first", "second", etc. used in the present application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, the first inductor may be called the second inductor, and similarly, the second inductor may be called the first inductor. Both the first inductor and the second inductor are inductors, but they are not the same inductor.

[0042] It can be understood that "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is an electrical signal or data transfer between the connected circuits, modules, units, etc.

[0043] It can be understood that "at least one" means one or more, and "a plurality" means two or more. "At least a part of an element" means a part or all of the element.

[0044] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprise / include" or "have" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0045] In an exemplary embodiment, asFigure 1 As shown in the figure, a disturbance compensation circuit for an energy storage converter is provided, including a DC power supply 100, a compensation device 200, an energy storage converter 300, a low-pass filter 400, and a power grid 500. Among them, one end of the compensation device 200 is connected to the DC power supply 100, and the other end is connected to the energy storage converter 300, which is used to compensate the direct current provided by the DC power supply 100 and input the compensated direct current into the energy storage converter 300 to provide a disturbance voltage for the energy storage converter 300; the first end of the energy storage converter 300 is connected to the positive pole of the DC power supply 100, and the second end of the energy storage converter 300 is connected to the negative pole of the DC power supply 100, which is used to convert the direct current input by the compensation device 200 into alternating current and input the converted alternating current into the low-pass filter 400; the first end of the low-pass filter 400 is connected to the second end of the energy storage converter 300, which is used to eliminate high-frequency harmonics in the alternating current input by the energy storage converter 300; the first end of the power grid 500 is connected in series with the second end of the low-pass filter 400, and the second end of the power grid 500 is grounded, which is used to receive the electric energy output by the low-pass filter 400 to distribute the electric energy to the power consumption terminals.

[0046] Optionally, the compensation device 200 adopts a voltage control strategy, which can adjust the positive and negative polarities of the output voltage in real time, provide a suitable voltage disturbance for the energy storage converter 300, enable the energy storage converter 300 to better adapt to different working conditions, improve its power conversion efficiency and stability. At the same time, when testing and optimizing the performance of the energy storage converter 300, the voltage disturbance can be used as a test means to test the response ability of the energy storage converter 300 and the effectiveness of the control strategy.

[0047] Optionally, based on the series structure in the disturbance compensation circuit, the sum of the output voltage of the DC power supply 100 and the output voltage of the compensation device 200 is the DC bus voltage on the input side of the energy storage converter 300. By changing the voltage of the compensation device 200, the voltage distribution in the disturbance compensation circuit can be adjusted. Among them, the working mode of the energy storage converter 300 is current control, that is, the energy storage converter 300 precisely controls parameters such as the magnitude, frequency, and phase of the output current through a specific control strategy, so that the output current can track the given current reference value to meet the requirements for power quality and power transmission in different application scenarios and adjust the power exchange with the power grid 500 in real time.

[0048] In the above-mentioned disturbance compensation circuit of the energy storage converter, one end of the compensation device 200 is connected to the DC power supply 100, and the other end is connected to the energy storage converter 300. The first end of the energy storage converter 300 is connected to the positive pole of the DC power supply 100, and the second end of the energy storage converter 300 is connected to the negative pole of the DC power supply 100. The first end of the low-pass filter 400 is connected to the second end of the energy storage converter 300, and the first end of the power grid 500 is connected in series with the second end of the low-pass filter 400. The compensation device 200 is used to compensate the direct current provided by the DC power supply 100, and input the compensated direct current into the energy storage converter 300 to provide a disturbance voltage for the energy storage converter 300. By setting the voltage of the compensation device 200, the input voltage of the energy storage converter 300 can be adjusted, realizing the lossless injection of multiple groups of disturbances, ensuring the stable operation of the overall disturbance compensation circuit, and thus effectively realizing the disturbance test of the energy storage converter system. Since the first end of the energy storage converter 300 is connected to the positive pole of the DC power supply 100 and the second end is connected to the negative pole of the DC power supply 100, when the bypass compensation device 200, the current provided by the DC power supply 100 can be input into the energy storage converter 300 to provide a stable voltage for the energy storage converter 300. In addition, since the low-pass filter 400 has the characteristic of eliminating high-frequency harmonics, the alternating current after filtering high-frequency harmonics by the low-pass filter 400 is purer and can be input into the power grid 500 more stably, reducing the occurrence probability of problems such as voltage fluctuation and frequency deviation of the power grid 500 caused by harmonics, and improving the stability and reliability of the power grid 500.

[0049] In an exemplary embodiment, as Figure 2 shown, the compensation device 200 includes a DC-AC conversion unit 210, a voltage conversion unit 220, and an AC-DC conversion unit 230. Among them, the first end of the DC-AC conversion unit 210 is connected to the DC power supply 100, and is used to convert the direct current output by the DC power supply 100 into alternating current; the first end of the voltage conversion unit 220 is connected to the second end of the DC-AC conversion unit 210, and is used to perform voltage conversion on the alternating current output by the DC-AC conversion unit 210; the first end of the AC-DC conversion unit 230 is connected to the second end of the voltage conversion unit 220, and the second end of the AC-DC conversion unit 230 is connected to the energy storage converter 300, and is used to convert the alternating current output by the voltage conversion unit 200 into direct current.

[0050] Optionally, the DC-AC conversion unit 210 is connected to the DC power supply 100 and is used to convert the direct current output by the DC voltage 100 into alternating current. In practical applications, it is usually realized by an inverter circuit composed of power switching devices. By controlling the on and off duration of the power switching devices, the direct current is modulated into alternating current.

[0051] Optionally, the voltage conversion unit 220 is connected to the output end of the DC-AC conversion unit 210 and is used for performing voltage conversion on the converted alternating current. In practical applications, the voltage conversion unit 220 is usually composed of a transformer. By using the principle of electromagnetic induction and changing the turn ratio of the primary and secondary windings, the increase or decrease of the AC voltage can be achieved.

[0052] Optionally, the AC-DC conversion unit 230 is connected to the output end of the voltage conversion unit 220 and is used for converting the alternating current after voltage conversion into direct current again and inputting the direct current into the energy storage inverter 300. In practical applications, the AC-DC conversion unit 230 usually adopts a rectifier circuit. By processing the negative half cycle of the alternating current through the rectifier circuit, making it into the positive half cycle or performing phase control, finally, a direct current output is obtained.

[0053] In this embodiment, the DC-AC conversion unit 210 is connected to the DC power supply 100, the voltage conversion unit 220 is connected to the output end of the DC-AC conversion unit 210, the AC-DC conversion unit 230 is connected to the output end of the voltage conversion unit 220, and the second end of the AC-DC conversion unit 230 is connected to the energy storage inverter 300. By performing voltage conversion on the alternating current through the voltage conversion unit 220, the magnitude of the output DC voltage can be adjusted to meet the specific voltage requirements of the energy storage inverter 300. Due to the electrical isolation characteristic of the transformer, the voltage conversion unit 220 can electrically isolate the DC power supply 100 from the energy storage inverter 300, avoiding the influence of the faults on the DC power supply 100 side on the energy storage inverter 300 and improving the overall safety of the disturbance compensation circuit.

[0054] In an exemplary embodiment, as Figure 3 shown, the DC-AC conversion unit 210 includes a first bridge arm 211 and a second bridge arm 222. Among them, the first end of the first bridge arm 211 is connected to the positive pole of the DC power supply 100, and the second end of the first bridge arm 211 is connected to the negative pole of the DC power supply 100; the first end of the second bridge arm 222 is connected to the positive pole of the DC power supply 100, and the second end of the second bridge arm 222 is connected to the negative pole of the DC power supply 100.

[0055] Optionally, the first end of the first arm 211 is connected to the positive pole of the DC power supply 100, and the second end is connected to the negative pole of the DC power supply 100. Generally, an arm is composed of multiple power switching devices (such as IGBTs or MOSFETs). Assume that the first arm is composed of two switching devices connected in series. The drain (for MOSFET) or collector (for IGBT) of the upper half switching device is connected to the positive pole of the DC power supply, and the source (for MOSFET) or emitter (for IGBT) of the lower half switching device is connected to the negative pole of the DC power supply. The connection point of the two switching devices serves as the output end of the arm. Similarly, the first end of the second arm 212 is connected to the positive pole of the DC power supply 100, the second end is connected to the negative pole of the DC power supply 100, is also composed of multiple switching devices connected in series, and has an output end.

[0056] In this embodiment, the DC-AC conversion unit 210 includes a first arm 211 and a second arm 212. The first end of the first arm 211 is connected to the positive pole of the DC power supply 100, the second end of the first arm 211 is connected to the negative pole of the DC power supply 100, the first end of the second arm 212 is connected to the positive pole of the DC power supply 100, and the second end of the second arm 212 is connected to the negative pole of the DC power supply 100. By controlling the on and off states of the switching devices in the first arm 211 and the second arm 212, the voltage polarity and magnitude of the output end can be changed, thereby realizing the conversion from direct current to alternating current.

[0057] In an exemplary embodiment, still as Figure 3 shown, the voltage conversion unit 220 includes a resonant circuit 221 and a transformer 222. Among them, the resonant circuit 221 includes a first inductor, an exciting inductor, and a first capacitor connected in series in sequence; the first end of the resonant circuit 221 is respectively connected to two switching tubes in the first arm 211; the second end of the resonant circuit 221 is respectively connected to two switching tubes in the second arm 212; the transformer 222 includes a primary winding and a secondary winding. The primary winding is connected to the resonant circuit, and the secondary winding is connected to the AC-DC conversion unit 230, and is used to transfer the electric energy output by the resonant circuit 221 to the AC-DC conversion unit 230.

[0058] Optionally, the resonant circuit 221 is composed of a first inductor, an exciting inductor, and a first capacitor connected in series in sequence. This LC series resonant circuit has a specific resonant frequency. When the frequency of the input signal is equal to the resonant frequency, resonance will occur in the circuit. Among them, the first end of the resonant circuit 221 is respectively connected to two switching tubes in the first arm 211, and the second end is respectively connected to two switching tubes in the second arm 212, and is used to receive the alternating current signal output by the DC-AC conversion unit 210.

[0059] Optionally, the transformer 222 includes a primary winding and a secondary winding and operates based on the principle of electromagnetic induction. When an alternating current passes through the primary winding, an alternating magnetic field is generated in the iron core, and this alternating magnetic field induces an electromotive force in the secondary winding, thereby achieving the transfer of electrical energy and the transformation of voltage. Among them, the primary winding is connected to the resonant circuit 221 to receive the electrical energy output by the resonant circuit 221; the secondary winding is connected to the AC-DC conversion unit 230 to transfer the transformed electrical energy to the AC-DC conversion unit 230 for further processing.

[0060] In this embodiment, the voltage conversion unit 220 includes a resonant circuit 221 and a transformer 222. The first end of the resonant circuit 221 is respectively connected to two switching tubes in the first bridge arm 211, and the second end of the resonant circuit 221 is respectively connected to two switching tubes in the second bridge arm 212. The transformer 222 includes a primary winding and a secondary winding. The primary winding is connected to the resonant circuit, and the secondary winding is connected to the AC-DC conversion unit 230 for transferring the electrical energy output by the resonant circuit 221 to the AC-DC conversion unit 230. Since the resonant circuit 221 has the characteristic of soft switching, the resonant circuit 221 can be used to adjust the impedance of the circuit, effectively compensate the reactive power in the circuit, and improve the utilization rate of electrical energy.

[0061] In an exemplary embodiment, still as Figure 3 shown, the AC-DC conversion unit 230 includes a rectifier filter circuit 231 and a second inductor 232. Among them, the rectifier filter circuit 231 includes a second capacitor, a third bridge arm, a fourth bridge arm, a fifth bridge arm, and a sixth bridge arm. The first end of the second capacitor is connected to the first end of the third bridge arm, the first end of the fourth bridge arm, the first end of the fifth bridge arm, and the first end of the sixth bridge arm, and the second end of the second capacitor is connected to the second end of the third bridge arm, the second end of the fourth bridge arm, the second end of the fifth bridge arm, and the second end of the sixth bridge arm; the first end of the second inductor 232 is respectively connected to two switching tubes in the fifth bridge arm, and the second end of the second inductor is connected to the first end of the energy storage converter 300; the second end of the energy storage converter 300 is respectively connected to two switching tubes in the sixth bridge arm.

[0062] Optionally, the rectifying and filtering circuit 231 includes a third arm, a fourth arm, a fifth arm, and a sixth arm. Each arm is generally composed of power switching devices (such as diodes or controllable IGBTs, MOSFETs, etc.). These arms cooperate with each other to achieve the rectifying function of converting alternating current to direct current. Among them, the first end of the second capacitor is connected to the first ends of the four arms, and the second end is connected to the second ends of the four arms. Due to the characteristics of the capacitor to store and release charge, it can play a filtering role during the rectifying process. When the input alternating current is rectified, there will be certain fluctuations in the voltage. The capacitor can store charge when the voltage is high and release charge when the voltage is low, thereby smoothing the output voltage and reducing the voltage ripple.

[0063] Optionally, the first end of the second inductor 232 is respectively connected to two switching tubes in the fifth arm, and the second end is connected to the first end of the energy storage inverter 300. Since the inductor has an obstructive effect on the change of current, the second inductor and the capacitor in the rectifying and filtering circuit together constitute an LC filtering network. When the rectified direct current passes through the second inductor, the inductor will suppress the rapid change of current. When the current increases, the inductor will store energy; when the current decreases, the inductor will release energy, thereby further smoothing the current and reducing the current ripple.

[0064] In this embodiment, the AC-DC conversion unit 230 includes a rectifying and filtering circuit 231 and a second inductor 232. The rectifying and filtering circuit 231 includes a second capacitor, a third arm, a fourth arm, a fifth arm, and a sixth arm. The first end of the second capacitor is connected to the first ends of the third arm, the fourth arm, the fifth arm, and the sixth arm, and the second end of the second capacitor is connected to the second ends of the third arm, the fourth arm, the fifth arm, and the sixth arm. The first end of the second inductor 232 is respectively connected to two switching tubes in the fifth arm, and the second end of the second inductor is connected to the first end of the energy storage inverter 300. The second end of the energy storage inverter 300 is respectively connected to two switching tubes in the sixth arm. Through the filtering network composed of the second capacitor and the second inductor 232, the ripple of the output DC voltage can be effectively reduced, making the output direct current smoother.

[0065] In an exemplary embodiment, still as Figure 3 shown, the first end of the primary winding is connected to the first end of the resonant circuit 221, and the second end of the primary winding is connected to the second end of the resonant circuit 221; the first end of the secondary winding is respectively connected to two switching tubes in the third arm, and the second end of the secondary winding is respectively connected to two switching tubes in the fourth arm.

[0066] Optionally, the resonant circuit 221 forms a closed loop, and the alternating current signal output by the resonant circuit 221 is directly loaded onto the primary winding. When the resonant circuit 221 operates in the resonant state, an alternating current with a specific frequency and amplitude is generated. This alternating current generates an alternating current in the primary winding, and then an alternating magnetic field is generated in the iron core of the transformer 222. According to the law of electromagnetic induction, the alternating magnetic field induces an electromotive force in the secondary winding, thereby realizing the transfer of electrical energy from the primary side to the secondary side.

[0067] Optionally, the first end of the secondary winding is respectively connected to two switching tubes in the third bridge arm, and the second end is respectively connected to two switching tubes in the fourth bridge arm. The alternating current signal induced in the secondary winding is input into the rectifier-filter circuit 231. Since the bridge arms in the rectifier-filter circuit 231 are usually composed of power switching devices, using the unidirectional conductivity of these switching devices, the alternating current output by the secondary winding can be converted into direct current. Then, the rectified direct current is filtered through components such as filter capacitors and inductors to obtain a smooth direct current output.

[0068] In this embodiment, the transformer 222 is used to perform voltage transformation on the alternating current, and the magnitude of the output direct current voltage can be adjusted to meet the specific voltage requirements of the energy storage converter 300. Since the transformer 222 has the characteristic of electrical isolation, the voltage transformation unit 220 can electrically isolate the DC power supply 100 from the energy storage converter 300, avoiding the influence of faults on the DC power supply 100 side on the energy storage converter 300 and improving the overall safety of the disturbance compensation circuit.

[0069] In an exemplary embodiment, as Figure 4 shown, a disturbance control system for an energy storage converter is provided, including a disturbance compensation circuit of the energy storage converter and a controller 600; the disturbance compensation circuit includes a DC power supply 100, a compensation device 200, and an energy storage converter 300; the controller 600 is connected to the disturbance compensation circuit 410 and is used to control the output voltage of the compensation device 200 to adjust the input voltage of the energy storage converter 300; the input voltage of the energy storage converter 300 is the sum of the output voltage of the DC power supply 100 and the output voltage of the compensation device 200.

[0070] Optionally, the controller 600 collects various information related to the energy storage converter 300, including but not limited to the output voltage of the DC power supply 100, the input voltage and output current of the energy storage converter 300, the voltage and frequency of the power grid, etc. Through the built-in sensors and sampling circuits, these physical quantities are converted into electrical signals and digitized.

[0071] Specifically, the controller 600 analyzes the collected information in real time to determine whether the energy storage converter 300 is in a normal operating state and whether its input voltage needs to be adjusted. Based on the collected and analyzed information, the controller 600 determines the target output voltage value of the compensation device 200 according to a pre-set control strategy. The controller 600 generates corresponding control signals, usually pulse width modulation (PWM) signals, according to the calculated target output voltage value of the compensation device 200. By adjusting parameters such as the duty cycle and frequency of the PWM signal, the on and off times of the power switching devices (such as IGBTs, MOSFETs, etc.) in the compensation device 200 are controlled, thereby precisely adjusting the output voltage of the compensation device 200. Since the input voltage of the energy storage converter 300 is the sum of the output voltage of the DC power supply 100 and the output voltage of the compensation device 200, adjusting the output voltage of the compensation device 200 can achieve the adjustment of the input voltage of the energy storage converter 300.

[0072] In this embodiment, the disturbance control system of the energy storage converter includes a disturbance compensation circuit 410 of the energy storage converter and a controller 600. The disturbance compensation circuit 410 includes a DC power supply 100, a compensation device 200, and an energy storage converter 300. The controller 600 is connected to the disturbance compensation circuit 410. By adjusting the output voltage of the compensation device 200 through the controller 600, the input voltage of the energy storage converter 300 can be adjusted, realizing non-disturbing injection into the energy storage converter 300 and ensuring the overall stability of the disturbance control system.

[0073] In an exemplary embodiment, the controller 600 is further configured to generate a modulation signal according to the difference between the output voltage of the DC power supply 100 and the input voltage of the energy storage converter 300 to control the power of the compensation device 200.

[0074] Optionally, the controller 600 monitors the output voltage of the DC power supply 100 and the input voltage of the energy storage converter 300 in real time. Through an internal sampling circuit and an analog-to-digital conversion module, these two voltage signals are converted into digital signals, and a subtraction operation is performed to obtain the difference between them. The difference reflects the deviation degree of the input voltage of the energy storage converter 300 relative to the output voltage of the DC power supply 100 and is an important basis for the controller 600 to perform subsequent control.

[0075] Further, the controller 600 generates a modulation signal according to the calculated voltage difference value, and common control algorithms include the proportional-integral-derivative (PID) control algorithm. In PID control, the proportional term quickly adjusts the output according to the current voltage difference value, the integral term is used to eliminate the steady-state error of the system, and the derivative term adjusts in advance according to the change rate of the voltage difference value to improve the response speed and stability of the system. According to the PID calculation result, the controller 600 generates a corresponding pulse width modulation (PWM) signal as the modulation signal, and the duty cycle of the PWM signal is dynamically adjusted according to the magnitude and direction of the voltage difference value.

[0076] Further, the generated modulation signal is sent to the drive circuit of the compensation device 200. The compensation device 200 usually includes power switching devices (such as IGBTs or MOSFETs). The drive circuit controls the on and off times of these power switching devices according to the modulation signal. By changing the on time of the switching device, that is, changing the duty cycle of the PWM signal, the output power of the compensation device 200 is adjusted.

[0077] In this embodiment, since the output voltage of the DC power supply 100 fluctuates due to factors such as load changes and internal parameter changes of the power supply, by monitoring the voltage difference value in real time and adjusting the power of the compensation device 200, the controller 600 can quickly compensate for these voltage fluctuations and keep the input voltage of the energy storage converter 300 stable.

[0078] In an exemplary embodiment, the controller 600 is further configured to control the output voltage of the compensation device 200 to be 0 when the bypass condition is met.

[0079] Optionally, the controller 600 will monitor multiple parameters and status information in the system in real time to determine whether the bypass condition is met. For example, the controller detects a fault inside the compensation device 200 or for other test requirements, etc. When the bypass condition is met, the controller 600 will control the output voltage of the compensation device 200 to be 0, so that the direct current output by the DC power supply 100 directly enters the energy storage converter 300.

[0080] In this embodiment, by controlling the output voltage of the compensation device 200 to be 0 by the controller 600, the direct current output by the DC power supply 100 directly enters the energy storage converter 300, ensuring that the energy storage converter 300 can work in a more stable power supply environment and improving the stability of the system.

[0081] In an exemplary embodiment, the controller 600 is further configured to obtain the operating parameters of the energy storage converter according to the input voltage of the energy storage converter 300 during the process of adjusting the input voltage of the energy storage converter 300, so as to perform digital twin modeling on the energy storage converter 300 according to all the operating parameters.

[0082] Optionally, during the process of adjusting the input voltage of the energy storage converter 300, the controller 600 continuously monitors the input voltage of the energy storage converter 300. Meanwhile, by connecting to the sensors and communication interfaces inside the energy storage converter 300, various operating parameters are obtained, including but not limited to input current, output voltage, output current, power factor, temperature, frequency, etc.

[0083] Furthermore, based on the collected operating parameters, the controller 600 performs digital twin modeling on the energy storage converter 300 using appropriate modeling methods, such as establishing a mathematical model based on a physical model, etc. As the energy storage converter 300 operates and its operating parameters continuously change, the controller 600 will update the digital twin model in real time to enable it to accurately reflect the actual operating state of the energy storage converter 300.

[0084] In this embodiment, since the digital twin model can simulate the operating state of the energy storage converter 300 in real time, digital twin modeling is performed through the operating parameters collected by the controller 600, which can simulate the operating state of the energy storage converter 300 under different disturbance conditions and ensure the overall stability of the disturbance control system.

[0085] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity in description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope recorded in this application.

[0086] The above-described embodiments merely represent several implementation manners of this application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application shall be subject to the appended claims.

Claims

1. A disturbance compensation circuit for an energy storage converter, characterized in that: include: DC power supply; A compensation device, one end of which is connected to the DC power supply, and the other end of which is connected to the energy storage converter, for compensating the DC power provided by the DC power supply, and inputting the compensated DC power to the energy storage converter to provide a disturbance voltage for the energy storage converter; An energy storage converter, wherein a first end of the energy storage converter is connected to the positive electrode of the DC power supply, and a second end of the energy storage converter is connected to the negative electrode of the DC power supply, and is used to convert the DC power input by the compensation device into AC power, and input the converted AC power into a low-pass filter; A low-pass filter, wherein a first end of the low-pass filter is connected to a second end of the energy storage converter and is used to eliminate high-frequency harmonics in the alternating current input by the energy storage converter; A power grid, wherein a first end of the power grid is connected in series with a second end of the low-pass filter, and the second end of the power grid is grounded, and is used to receive the electric energy output by the low-pass filter to distribute the electric energy to a power consumption terminal.

2. The disturbance compensation circuit of the energy storage converter according to claim 1, characterized in that: The compensation device comprises: a DC-AC conversion unit, wherein a first end of the DC-AC conversion unit is connected to the DC power supply and is used to convert the DC power output by the DC power supply into AC power; A transformer unit, a first end of which is connected to a second end of the DC-AC conversion unit, and is used to transform the AC power output by the DC-AC conversion unit; An AC-DC conversion unit, wherein a first end of the AC-DC conversion unit is connected to a second end of the transformer unit, and a second end of the AC-DC conversion unit is connected to the energy storage inverter, for converting the AC power output by the transformer unit into DC power.

3. The disturbance compensation circuit of the energy storage converter according to claim 2, characterized in that: The DC-AC conversion unit comprises: A first bridge arm, wherein a first end of the first bridge arm is connected to a positive electrode of the DC power supply, and a second end of the first bridge arm is connected to a negative electrode of the DC power supply; A second bridge arm, wherein a first end of the second bridge arm is connected to the positive electrode of the DC power supply, and a second end of the second bridge arm is connected to the negative electrode of the DC power supply.

4. The disturbance compensation circuit of the energy storage converter according to claim 3, characterized in that: The transformer unit comprises: A resonant circuit, comprising a first inductor, an excitation inductor and a first capacitor connected in series in sequence; a first end of the resonant circuit is respectively connected to two switch tubes in the first bridge arm; a second end of the resonant circuit is respectively connected to two switch tubes in the second bridge arm; The transformer comprises a primary winding and a secondary winding, wherein the primary winding is connected to the resonant circuit, and the secondary winding is connected to the AC-DC conversion unit, and is used to transfer the electric energy output by the resonant circuit to the AC-DC conversion unit.

5. The disturbance compensation circuit of the energy storage converter according to claim 4, characterized in that: The AC-DC conversion unit comprises: A rectifier and filter circuit, comprising a second capacitor, a third bridge arm, a fourth bridge arm, a fifth bridge arm and a sixth bridge arm, wherein a first end of the second capacitor is connected to a first end of the third bridge arm, a first end of the fourth bridge arm, a first end of the fifth bridge arm, and a first end of the sixth bridge arm, and a second end of the second capacitor is connected to a second end of the third bridge arm, a second end of the fourth bridge arm, a second end of the fifth bridge arm, and a second end of the sixth bridge arm; A second inductor, wherein the first end of the second inductor is respectively connected to the two switch tubes in the fifth bridge arm, and the second end of the second inductor is connected to the first end of the energy storage converter; the second end of the energy storage converter is respectively connected to the two switch tubes in the sixth bridge arm.

6. The disturbance compensation circuit of the energy storage converter according to claim 5, characterized in that: The first end of the primary winding is connected to the first end of the resonant circuit, and the second end of the primary winding is connected to the second end of the resonant circuit; the first end of the secondary winding is respectively connected to the two switching tubes in the third bridge arm, and the second end of the secondary winding is respectively connected to the two switching tubes in the fourth bridge arm.

7. A disturbance control system for an energy storage converter, characterized in that: A disturbance compensation circuit and a controller for an energy storage converter comprising any one of claims 1 to 6; The disturbance compensation circuit includes a DC power supply, a compensation device and an energy storage converter; A controller is connected to the disturbance compensation circuit and is used to control the output voltage of the compensation device to adjust the input voltage of the energy storage converter; the input voltage of the energy storage converter is the sum of the output voltage of the DC power supply and the output voltage of the compensation device.

8. The disturbance control system of the energy storage converter according to claim 7, characterized in that: The controller is also used to generate a modulation signal according to the difference between the output voltage of the DC power supply and the input voltage of the energy storage converter to control the power of the compensation device.

9. The disturbance control system of the energy storage converter according to claim 7, characterized in that: The controller is also used to control the output voltage of the compensation device to be 0 when the bypass condition is met.

10. The disturbance control system of the energy storage converter according to claim 7, characterized in that: The controller is also used to obtain the operating parameters of the energy storage inverter according to the input voltage of the energy storage inverter during the process of adjusting the input voltage of the energy storage inverter, so as to perform digital twin modeling of the energy storage inverter according to all the operating parameters.

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