Regulation methods, devices, equipment and media for on-grid and off-grid converters

Abstract

This application discloses a method, device, equipment, and medium for regulating a grid-connected / off-grid converter, belonging to the field of smart grid technology. It is applied to a three-phase four-wire three-level energy storage converter, which includes a DC section, an inverter, and an AC section connected in sequence. The AC section is used to connect to the AC grid, and a grid-connected / off-grid switching device is installed on the side of the AC section closest to the AC grid. The DC section includes an energy storage battery and a DC-side filter capacitor connected in sequence, and the AC section includes an inverter-side filter inductor, an AC-side filter capacitor, a grid-side filter inductor, and an AC load. The method includes: acquiring the operating mode of the energy storage converter, AC-side operating parameters, and the battery state of the energy storage battery. The operating mode is determined based on the operating mode of the energy storage converter and the battery state, including grid-connected mode and offline mode; converting the AC-side operating parameters from the three-phase coordinate system to the dq coordinate system and performing PQ calculation and common-mode differential-mode calculation to obtain the feedback value of the energy storage converter; and regulating the energy storage converter based on the feedback value, operating mode, and battery state. In this method, the energy storage converter can operate stably and smoothly switch off-grid according to control commands, while protecting the energy storage battery on the DC side, ensuring the safety and efficiency of the entire system.

Description

Technical Field

[0001] This application belongs to the field of smart grid technology, and in particular relates to a regulation method, device, equipment and medium for a grid-connected and off-grid converter. Background Technology

[0002] As a key component connecting energy storage systems and the power grid, the performance of energy storage converters directly affects the stability and reliability of the power system. Grid-connected and off-grid energy storage converters not only require high energy conversion efficiency but also the ability to smoothly switch between grid-connected and off-grid modes to meet diverse operational needs.

[0003] The operating status of energy storage batteries during grid-connected operation is receiving increasing attention. Real-time monitoring and effective control of battery status can significantly extend the lifespan of energy storage converters and improve their operational reliability. However, current control strategies often fail to adequately consider crucial factors such as overcharge protection for energy storage batteries. To achieve more efficient and precise control, it is typically necessary to collect multiple parameters from the energy storage converter, such as battery voltage, current, temperature, SOC (State of Charge), SOH (State of Health), load demand, and external environmental conditions, and then take corresponding measures. However, this battery-based protection method lacks effective coordination with the control of the energy storage converter, which may lead to the battery operating under unsuitable conditions, resulting in accelerated capacity decay or premature failure.

[0004] Therefore, there is an urgent need to develop a new regulation method that fully incorporates battery protection mechanisms when the energy storage converter switches between grid and off-grid operation. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a regulation method, device, equipment, and medium for grid-connected and off-grid converters, which fully incorporates a battery protection mechanism during grid-connected / off-grid switching of the energy storage converter.

[0006] In a first aspect, this application provides a regulation method for a grid-connected and off-grid converter, applied to a three-phase four-wire three-level energy storage converter. The energy storage converter includes a DC section, an inverter, and an AC section connected in sequence. The AC section is used to connect to the AC power grid, and the AC section is provided with a grid-connected and off-grid switching device on the side close to the AC power grid.

[0007] The DC section includes an energy storage battery and a DC-side filter capacitor connected in sequence, and the AC section includes an inverter-side filter inductor, an AC-side filter capacitor, a grid-side filter inductor, and an AC load.

[0008] The method includes:

[0009] The operating mode, AC side operating parameters, and battery status of the energy storage converter are obtained. The operating mode is determined based on the operating mode of the energy storage converter and the battery status of the energy storage battery. The operating mode includes grid-connected mode and offline mode.

[0010] The AC side operating parameters are transformed from the three-phase coordinate system to the dq coordinate system, and PQ calculation and common-mode differential-mode calculation are performed to obtain the feedback value of the energy storage converter.

[0011] The energy storage converter is adjusted based on the feedback value, the operating mode, and the battery state of the energy storage battery.

[0012] According to one embodiment of this application, the AC side operating parameters include the inverter-side filter inductance L. f1 The inductor current i L1 AC side filter capacitor C f capacitor voltage v C The load voltage V of the AC load L One or more of the following, the feedback values ​​include active power feedback values ​​and reactive power feedback values;

[0013] The AC side operating parameters are transformed from the three-phase coordinate system to the dq coordinate system, and PQ calculation and common-mode differential-mode calculation are performed to obtain the feedback values ​​of the energy storage converter, including:

[0014] For the inductor current i L1 The capacitor voltage v C and the load voltage v L By performing coordinate transformation, the capacitor voltage v in the dq coordinate system is obtained. C voltage component v Cd v Cq Inductor current i L1 current component i L1d 、i L1q and load voltage v L voltage component v Ld v Lq ;

[0015] For the current component i L1d 、i L1q and voltage component v Cd v Cq Perform PQ calculations and low-pass filtering to obtain the active power feedback value P and reactive power feedback value Q;

[0016] For the inductor current i L1 The common-mode calculation is performed on the abc components to obtain the inverter-side filter inductance L. f1 Current i on L1Differential feedback value i L1xDM and common mode feedback value i L1CM .

[0017] According to one embodiment of this application, adjusting the energy storage converter based on the feedback value, the operating mode, and the battery state of the energy storage battery includes:

[0018] In the grid-connected operating mode, the inductor current i is obtained based on the active power feedback value and the active power feedback value. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted according to the operating mode and battery status.

[0019] In the off-grid operating mode, based on voltage component v Lq and voltage component v Ld The inductor current i is obtained. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted according to the operating mode and battery status.

[0020] According to one embodiment of this application, in the grid-connected operating mode, the inductor current i is obtained based on the active power feedback value and the active power feedback value. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1d Adjusting the energy storage converter according to the operating mode and battery state includes:

[0021] When the operating modes are grid-connected power control charging mode and grid power control discharging mode, the active power reference value P will be... * The current i is compared with the active power feedback value P and then fed into the outer loop PI controller to obtain the inductor current i.L1 d-axis command value i * L1d The reactive power feedback value Q is compared with the reactive power reference value Q. * The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q ; the d-axis command value i * L1d and q-axis command value i * L1q Perform a dq / abc transformation to obtain the inductor current i. L1 The three-phase reference value i of abc * L1x The differential feedback value i is transmitted through the inner loop controller. L1xDM Compared with the three-phase reference value i * L1x The differential-mode modulated wave is obtained by comparing the two signals and feeding them into the quasi-resonant controller QPR. The differential-mode modulated wave is then superimposed with the common-mode modulated wave to obtain the three-phase modulated wave, which is used to regulate the energy storage converter.

[0022] According to one embodiment of this application, in the grid-connected operating mode, the inductor current i is obtained based on the active power feedback value and the active power feedback value. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1d Adjusting the energy storage converter according to the operating mode and battery state includes:

[0023] When the operating mode is constant voltage charging mode and the energy storage battery is in the second state, the active power reference value P will be... * The current i is compared with the active power feedback value P and then fed into the outer loop PI controller to obtain the inductor current i. L1 d-axis command value i * L1d The reactive power feedback value Q is compared with the reactive power reference value Q. * The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q ; Set the upper limit of the DC side voltage reference value V bat_ref_H With DC side voltage feedback value v bus_fb The result of the comparison is sent to the DC-side voltage outer loop PI controller to obtain the corresponding d-axis command value i.* L1d According to the q-axis command value i * L1q and the d-axis command value i * L1d Adjust the energy storage converter to trickle charge the energy storage battery;

[0024] When the operating mode is the paused discharge mode and the energy storage battery is in the first state, the active power reference value P will be... * The current i is compared with the active power feedback value P and then fed into the outer loop PI controller to obtain the inductor current i. L1 d-axis command value i * L1d The reactive power feedback value Q is compared with the reactive power reference value Q. * The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q ; Set the upper limit of the DC side voltage reference value V bat_ref_H With DC side voltage feedback value v bus_fb The result of the comparison is sent to the DC-side voltage outer loop PI controller to obtain the corresponding d-axis command value i. * L1d According to the q-axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted to pause the discharge of the energy storage battery.

[0025] According to one embodiment of this application, when the operating mode is off-grid mode, the working mode includes: load voltage control mode and discharge stop mode;

[0026] In the off-grid operating mode, based on voltage component v Lq and voltage component v Ld The inductor current i is obtained. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1d Adjusting the energy storage converter according to the operating mode and battery state includes:

[0027] When the operating mode is load voltage control mode and the energy storage battery is in the second state, the load voltage v will be... L d-axis reference value v* Ld With voltage component v Ld The result of the comparison is fed into the load voltage PI controller to obtain the inductor current i. L1 d-axis command value i * L1d ; the load voltage v L voltage component v Lq With q-axis reference value v * Lq The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q The q-axis command value i * L1q and the d-axis command value i * L1d After performing the dq / abc coordinate transformation, the current is fed into the inner current loop to measure the load voltage v. L To take control;

[0028] When the operating mode is the discharge stop mode and the energy storage battery is in the first state, the discharge will be terminated, and the energy storage converter will also stop operating.

[0029] According to one embodiment of this application, before obtaining the operating mode of the energy storage converter, the AC side operating parameters, and the battery state of the energy storage battery, the method further includes:

[0030] When it is determined that the energy storage converter is switching from grid-connected mode to off-grid mode, the inverter-side filter inductor L... f1 current i L1 Reduce to 0, and control the load voltage v of the AC load. L Tracking the grid voltage v of the AC power grid g And control the grid disconnection switch in the grid-connected / off-grid switching device to open, so that the energy storage converter is in islanded mode;

[0031] When it is determined that the energy storage converter has switched from off-grid mode to grid-connected operation mode, the load voltage v is controlled. L Tracking grid voltage v g When the grid-connected isolating switch is closed, the energy storage converter switches to the grid-connected current and DC-side voltage control mode.

[0032] Secondly, this application provides a regulating device for a grid-connected and off-grid converter, which is applied to a three-phase four-wire three-level energy storage converter. The energy storage converter includes a DC section, an inverter and an AC section connected in sequence. The AC section is used to connect to the AC power grid. The AC section is provided with a grid-connected and off-grid switching device on the side close to the AC power grid.

[0033] The DC section includes an energy storage battery and a DC-side filter capacitor connected in sequence, and the AC section includes an inverter-side filter inductor, an AC-side filter capacitor, a grid-side filter inductor, and an AC load.

[0034] The device includes:

[0035] The acquisition module is used to acquire the AC side operating parameters of the energy storage converter corresponding to the operating mode of the energy storage converter. The operating mode is determined based on the operating mode of the energy storage converter and the battery state of the energy storage battery. The operating mode includes grid-connected mode and offline mode.

[0036] The first processing module is used to convert the AC side operating parameters from the three-phase coordinate system to the dq coordinate system, and perform PQ calculation and common-mode differential-mode calculation to obtain the feedback value of the energy storage converter.

[0037] The second processing module is used to adjust the energy storage converter based on the feedback value and the battery state of the energy storage battery.

[0038] Thirdly, this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the regulation method for the on-grid and off-grid converter as described in the first aspect above.

[0039] Fourthly, this application provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the regulation method for on-grid and off-grid converters as described in the first aspect above.

[0040] Fifthly, this application provides a chip including a processor and a communication interface, the communication interface being coupled to the processor, the processor being used to run programs or instructions to implement the regulation method for grid-connected and off-grid converters as described in the first aspect.

[0041] Sixthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the regulation method for on-grid and off-grid converters as described in the first aspect above.

[0042] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application.

[0043] The regulation method, apparatus, equipment, and medium for on-grid and off-grid converters provided in this application have the following advantages over the prior art:

[0044] (1) By performing coordinate transformation and common differential mode calculation on the AC side operating parameters, and combining the operating mode and battery status, the energy storage converter is adjusted. Only the AC part operating parameters are needed, which reduces the difficulty and cost of parameter acquisition. When the energy storage converter faces different grid commands, when the energy storage converter switches between grid connection and off-grid, the battery protection mechanism is fully incorporated. It can maintain stable operation and smooth switching between grid connection and off-grid. It also comprehensively considers the charging and discharging protection of the energy storage battery, ensuring the safety and efficiency of the entire system. It strengthens the health monitoring and protection of the energy storage battery, ensuring its long-term safe and efficient operation. This comprehensive control strategy can better adapt to the changes in the power market and the development of technology.

[0045] (2) It can continuously and smoothly switch between various operating modes according to the magnitude of the inverter-side inductor current and the charging and discharging requirements of the DC-side energy storage battery, with small transient overshoot, ensuring the long-term stable operation of the system and guaranteeing that the energy storage converter can operate stably in any mode. It also comprehensively considers the charging and discharging protection of the energy storage battery, thereby improving the reliability of operation and effectively extending the battery's service life. In addition, the control strategy reduces the sampling stage of the grid-side inductor current, which can save costs and achieve higher economic benefits.

[0046] (3) The control strategy has low complexity, making it easy to implement in a digital control environment. It focuses on the charging and discharging protection of the energy storage battery, providing effective support for the stable operation of the DC-side energy storage battery, thereby improving the system's operational reliability. At the same time, although the grid-connected reactive power under this control method includes the reactive power of the capacitor due to the sampling of L1 current, resulting in a certain error, it can be controlled within the allowable error range, demonstrating significant advantages under the new standard requirements. Attached Figure Description

[0047] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0048] Figure 1 This is a schematic diagram of the on-grid and off-grid energy storage converter structure provided in the embodiments of this application;

[0049] Figure 2 This is a topology diagram of a three-phase four-wire T-type three-level energy storage converter provided in the embodiments of this application;

[0050] Figure 3 This is a schematic flowchart of the regulation method for a grid-connected / off-grid converter provided in an embodiment of this application;

[0051] Figure 4 These are schematic diagrams of the four grid-connected operating modes of the grid-connected and off-grid energy storage converter provided in the embodiments of this application;

[0052] Figure 5 This is a schematic diagram of two off-grid operating modes of the grid-connected and off-grid energy storage converter provided in the embodiments of this application;

[0053] Figure 6 The energy storage battery SOC provided in this application embodiment has a DC side current i bat DC side voltage v bus A schematic diagram of the waveform;

[0054] Figure 7 This is a schematic diagram of the grid-connected steady-state operating waveform of the energy storage converter when the DC-side energy storage battery has a high SOC, as provided in the embodiments of this application.

[0055] Figure 8 This is a schematic diagram of the grid-connected steady-state operating waveform of the energy storage converter when the DC-side energy storage battery SOC is low, as provided in the embodiments of this application.

[0056] Figure 9 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0057] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0058] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0059] The following description, in conjunction with the accompanying drawings, details the regulation method, regulation device, electronic equipment, and readable storage medium of the grid-connected and off-grid converter provided in this application, through specific embodiments and application scenarios.

[0060] Among them, the regulation method of the grid-connected and off-grid converter can be applied to the terminal, and can be executed by the hardware or software in the terminal.

[0061] The terminal includes, but is not limited to, portable communication devices such as mobile phones or tablets with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads). It should also be understood that, in some embodiments, the terminal may not be a portable communication device, but rather a desktop computer with touch-sensitive surfaces (e.g., touchscreen displays and / or touchpads).

[0062] The following embodiments describe a terminal including a display and a touch-sensitive surface. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, mouse, and joystick.

[0063] The regulation method for a grid-connected converter provided in this application embodiment can be executed by an electronic device or a functional module or entity in an electronic device that can implement the regulation method for the grid-connected converter. The electronic devices mentioned in this application embodiment include, but are not limited to, mobile phones, tablets, computers, cameras, and wearable devices. The regulation method for a grid-connected converter provided in this application embodiment will be described below using an electronic device as the execution subject.

[0064] like Figure 1 As shown, this method is applied to a three-phase four-wire three-level energy storage converter. The energy storage converter includes a DC section, an inverter, and an AC section connected in sequence. The AC section is used to connect to the AC power grid, and the AC section is equipped with a grid-connected / off-grid switching device on the side closest to the AC power grid.

[0065] The DC section includes an energy storage battery and a DC-side filter capacitor connected in sequence, and the AC section includes an inverter-side filter inductor, an AC-side filter capacitor, a grid-side filter inductor, and an AC load.

[0066] DC-side filter capacitors include C bus1 C bus2 Inverter-side filter inductor L f1 Including L f1a L f1b L f1c Neutral inductance L f1n AC side filter capacitor C f Including C fa C fb C fc Grid-side filter inductor L f2 Including L f2a L f2b L f2c The AC loads include Load_fa, Load_fb, and Load_fc.

[0067] exist Figure 1In the diagram, the energy storage converter is of the grid-connected / off-grid type, including the main circuit and the control circuit. The gray box below shows the block diagram of the control strategy proposed in this application. Figure 2 As shown, the core part of the energy storage converter in the main circuit is a three-phase four-wire T-type three-level structure.

[0068] Figure 2 The main parameters are shown in Table 1 below:

[0069] Table 1 Main Parameters

[0070] AC side load output voltage <![CDATA[V Load ]]> 230V(RMS) The switching frequency of the three-phase inverter <![CDATA[f s ]]> 15kHz Output frequency <![CDATA[f o ]]> 50Hz Inverter-side filter inductor <![CDATA[L f1 ]]> 62.7μH Grid-side filter inductor <![CDATA[L f2 ]]> 18.5μH Neutral inductor <![CDATA[L fn ]]> 43.4μH Filter capacitor <![CDATA[C f ]]> 100μF DC-side split capacitor <![CDATA[C bus1 ,C bus2 ]]> 6900μF Energy storage battery operating voltage range / 790V~864V DC side voltage reference upper limit <![CDATA[V bat_ref_H ]]> 864V DC side voltage reference lower limit <![CDATA[V bat_ref_L ]]> 790V

[0071] like Figure 3 As shown, the regulation method of this grid-connected / off-grid converter includes:

[0072] Step 310: Obtain the operating mode of the energy storage converter, the AC side operating parameters, and the battery status of the energy storage battery. The operating mode is determined based on the operating mode of the energy storage converter and the battery status of the energy storage battery. The operating mode includes grid-connected mode and offline mode.

[0073] Step 320: Convert the AC side operating parameters from the three-phase coordinate system to the dq coordinate system, and perform PQ calculation and common-mode differential-mode calculation to obtain the feedback value of the energy storage converter;

[0074] Step 330: Adjust the energy storage converter based on the feedback value, the operating mode, and the battery state of the energy storage battery.

[0075] The state of a battery can be characterized as the state of charge (SOC) of the energy storage battery, including a first state and a second state. When the energy storage battery is in the first state, the SOC is low, and the energy storage battery has less charge. For example, the energy storage battery has less than 20% charge.

[0076] When the energy storage battery is in its second state, its SOC is relatively high, and the battery is close to fully charged, for example, the energy storage battery has a charge greater than 80%.

[0077] The inverter is a three-phase four-wire T-type three-level energy storage converter.

[0078] In some embodiments, before obtaining the operating modes of the energy storage converter, the AC side operating parameters, and the battery state of the energy storage battery, the method further includes:

[0079] When it is determined that the energy storage converter is switching from grid-connected mode to off-grid mode, the inverter-side filter inductor L... f1 current i L1 Reduce to 0, and control the load voltage v of the AC load. LTracking the grid voltage v of the AC power grid g And control the grid disconnection switch in the grid-connected / off-grid switching device to open, so that the energy storage converter is in islanded mode;

[0080] When it is determined that the energy storage converter has switched from off-grid mode to grid-connected operation mode, the load voltage v is controlled. L Tracking grid voltage v g When the grid-connected isolating switch is closed, the energy storage converter switches to the grid-connected current and DC-side voltage control mode.

[0081] After the off-grid switching device performs the switching, the controller receives the control command from the upper layer and performs the control corresponding to the working mode.

[0082] In actual implementation, the DC-side current feedback value i is obtained through multi-channel sampling. bat_fb DC side voltage feedback value v bus_fb AC side filter capacitor voltage v C Current i C The current i of the grid-side filter inductor L2_fb AC load voltage feedback value v Load_fb The sampled values ​​are sent to the controller designed in this method to realize various modes and functions of the on-grid and off-grid energy storage converter.

[0083] Adjust the position of control switch S1 or S2 according to different requirements for grid-connected power control accuracy and DC side current reference value control;

[0084] The sampled values ​​are sent to the outer loop controller of the corresponding mode to calculate the corresponding command value. In particular, in the grid-connected mode, the switch S3 can be adjusted to the corresponding position according to the different battery states.

[0085] The energy storage converter is switched to a specific grid-connected or off-grid mode by the AC side switch control strategy. The grid-connected mode sends the command value to the corresponding inner loop controller, while the off-grid mode directly outputs the single-loop calculated value to obtain the modulation signal.

[0086] In some embodiments, the AC side operating parameters include the inverter-side filter inductance L. f1 The inductor current i L1 AC side filter capacitor C f capacitor voltage v C The load voltage V of the AC load L One or more of the following, the feedback values ​​include active power feedback values ​​and reactive power feedback values;

[0087] The AC side operating parameters are transformed from the three-phase coordinate system to the dq coordinate system, and PQ calculation and common-mode differential-mode calculation are performed to obtain the feedback values ​​of the energy storage converter, including:

[0088] For the inductor current i L1 The capacitor voltage v C and the load voltage v L By performing coordinate transformation, the capacitor voltage v in the dq coordinate system is obtained. C voltage component v Cd v Cq Inductor current i L1 current component i L1d 、i L1q and load voltage v L voltage component v Ld v Lq ;

[0089] For the current component i L1d 、i L1q and voltage component v Cd v Cq Perform PQ calculations and low-pass filtering to obtain the active power feedback value P and reactive power feedback value Q;

[0090] For the inductor current i L1 The common-mode calculation is performed on the abc components to obtain the inverter-side filter inductance L. f1 Current i on L1 Differential feedback value i L1xDM and common mode feedback value i L1CM .

[0091] For the inverter-side filter inductor L f1 Current i on L1 Differential feedback value i L1xDM , x = a, b, c.

[0092] In this embodiment, AC side current sampling uses only one sampling stage, L1 current, eliminating the need to sample grid-side inductor current, which saves costs and has high economic benefits.

[0093] In some embodiments, the energy storage converter is adjusted based on the feedback value, the operating mode, and the battery state of the energy storage battery, including:

[0094] In the grid-connected operating mode, the inductor current i is obtained based on the active power feedback value and the active power feedback value. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1dThe energy storage converter is adjusted according to the operating mode and battery status.

[0095] In the off-grid operating mode, based on voltage component v Lq and voltage component v Ld The inductor current i is obtained. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted according to the operating mode and battery status.

[0096] Through the inverter-side filter inductor L f1 Inductor current i L1 q-axis command value i * L1q It enables various modes and functions of on-grid and off-grid energy storage converters.

[0097] During the adjustment of the energy storage converter, switches S1 and S2 can be adjusted to the corresponding positions according to the battery status of the energy storage battery and the grid connection / off-grid mode; the outer loop output value is transformed into the inner loop differential mode command value, and the inner loop inductor current common differential mode decoupling control is used to obtain the modulation wave.

[0098] For inner-loop control, the inductor current i L1 The differential-mode and common-mode components are decoupled and controlled, and the inductor current i L1 Differential feedback value i L1xDM The command value i obtained after coordinate transformation with the outer loop output value * L1x (x=a,b,c) is compared and then fed into the QPR controller to obtain a differential modulated wave.

[0099] Inductor current i L1 common-mode component i L1CM After being compared with the reference value of 0, the signal is sent to the QPR controller to obtain the common-mode modulated wave.

[0100] In some embodiments, such as Figure 4 As shown, in the grid-connected operating mode, the inductor current i is obtained based on the active power feedback value and the active power feedback value. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i *L1q and the d-axis command value i * L1d Adjusting the energy storage converter according to the operating mode and battery state includes:

[0101] When the operating modes are grid-connected power control charging mode and grid power control discharging mode, the active power reference value P will be... * The current i is compared with the active power feedback value P and then fed into the outer loop PI controller to obtain the inductor current i. L1 d-axis command value i * L1d The reactive power feedback value Q is compared with the reactive power reference value Q. * The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q ; the d-axis command value i * L1d and q-axis command value i * L1q Perform a dq / abc transformation to obtain the inductor current i. L1 The three-phase reference value i of abc * L1x The differential feedback value i is transmitted through the inner loop controller. L1xDM Compared with the three-phase reference value i * L1x The differential-mode modulated wave is obtained by comparing the two signals and feeding them into the quasi-resonant controller QPR. The differential-mode modulated wave is then superimposed with the common-mode modulated wave to obtain the three-phase modulated wave, which is used to regulate the energy storage converter.

[0102] In some embodiments, when the operating mode is grid-connected, the inductor current i is obtained based on the active power feedback value and the active power feedback value. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1d Adjusting the energy storage converter according to the operating mode and battery state includes:

[0103] When the operating mode is constant voltage charging mode and the energy storage battery is in the second state, the active power reference value P will be... * The current i is compared with the active power feedback value P and then fed into the outer loop PI controller to obtain the inductor current i. L1 d-axis command value i *L1d The reactive power feedback value Q is compared with the reactive power reference value Q. * The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q ; Set the upper limit of the DC side voltage reference value V bat_ref_H With DC side voltage feedback value v bus_fb The result of the comparison is sent to the DC-side voltage outer loop PI controller to obtain the corresponding d-axis command value i. * L1d According to the q-axis command value i * L1q and the d-axis command value i * L1d Adjust the energy storage converter to trickle charge the energy storage battery;

[0104] When the operating mode is the paused discharge mode and the energy storage battery is in the first state, the active power reference value P will be... * The current i is compared with the active power feedback value P and then fed into the outer loop PI controller to obtain the inductor current i. L1 d-axis command value i * L1d The reactive power feedback value Q is compared with the reactive power reference value Q. * The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q ; Set the upper limit of the DC side voltage reference value V bat_ref_H With DC side voltage feedback value v bus_fb The result of the comparison is sent to the DC-side voltage outer loop PI controller to obtain the corresponding d-axis command value i. * L1d According to the q-axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted to pause the discharge of the energy storage battery.

[0105] When operating in grid-connected mode, it can switch between the following working modes:

[0106] Grid-connected power control charging mode. When the active power feedback value P of the AC grid is less than 0 and the SOC state of the energy storage battery is low, the AC grid generates power. Power is supplied through the AC grid's active power reference value P. * After being compared with the reverse active power feed value P, it is sent to the outer loop PI controller to calculate the inductor current i. L1 d-axis command value i * L1d The reactive power feedback value Q and its reference value Q* The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q ; the d-axis command value i * L1d and q-axis command value i * L1q Perform a dq / abc transformation to obtain the inductor current i. L1 The three-phase reference value i of abc * L1x (x = a, b, c). The inner loop controller uses the inverter-side filter inductor L. f1 Differential feedback value i L1xDM Compared with the three-phase reference value i * L1x The signals are compared and fed into the quasi-resonant controller QPR to obtain differential mode modulation waves. These waves are then superimposed with common mode modulation waves to obtain three-phase modulation waves, thereby achieving the regulation and control of the grid-connected current.

[0107] Constant voltage charging mode. When the energy storage battery has a high SOC, the q-axis is still controlled by reactive power, and the d-axis is controlled by referencing the upper limit value V of the DC side voltage. bat_ref_H With feedback value v bus_fb The result of the comparison is sent to the DC-side voltage outer loop PI controller to obtain the corresponding d-axis command value i. * L1d It takes over the battery charging status to protect the battery, trickle charging.

[0108] By comparing the calculated command values ​​in grid-connected power control charging mode and constant voltage charging mode, the larger value is selected as the inner loop current i. L1 Controlled d-axis reference value i * L1d This allows for a smooth switching between constant voltage charging mode and grid-connected power control charging mode.

[0109] Grid-connected power control discharge mode. When the active power P of the AC grid > 0 and the SOC of the energy storage battery is high, the AC grid absorbs power. The reference value P of the active power of the AC grid is used. * After being compared with the feedback value P, the result is sent to the outer loop PI controller to calculate the inverter-side filter inductance L. f1 d-axis command value i * L1d The feedback value Q of reactive power and its reference value Q * The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q After dq / abc transformation, the three-phase reference value i of abc is obtained. *L1x (x = a, b, c). The inner loop passes through the inverter-side filter inductor L. f1 The three-phase differential mode current is compared with the three-phase reference value and sent to the quasi-resonant controller QPR to obtain the differential mode modulation wave. After being superimposed with the common mode modulation wave, the three-phase modulation wave is obtained, thereby realizing the regulation and control of the grid-connected current.

[0110] Discharge pause mode. When the energy storage battery's SOC is low, it cannot continue discharging. The q-axis is still controlled by reactive power, and the d-axis is controlled by referencing the upper limit value V of the DC side voltage. bat_ref_H With feedback value v bus_fb The result of the comparison is sent to the DC-side voltage outer loop PI controller to obtain the corresponding d-axis command value i. * L1d It takes over the battery discharge state to protect the battery and suspends discharge.

[0111] By comparing the magnitudes of the command values ​​calculated under grid-connected power control discharge mode and paused discharge mode, the smaller value is selected as the inner loop current i. L1 Controlled d-axis reference value i * L1d This allows for a smooth switch between grid-connected power control discharge mode and paused discharge mode.

[0112] In some embodiments, such as Figure 5 As shown, when the operating mode is off-grid mode, the working modes include: load voltage control mode and discharge stop mode;

[0113] In the off-grid operating mode, based on voltage component v Lq and voltage component v Ld The inductor current i is obtained. L1 q-axis command value i * L1q and d-axis command value i * L1d Based on the q-axis command value i * L1q and the d-axis command value i * L1d Adjusting the energy storage converter according to the operating mode and battery state includes:

[0114] When the operating mode is load voltage control mode and the energy storage battery is in the second state, the load voltage v will be... L d-axis reference value v * Ld With voltage component v Ld The result of the comparison is fed into the load voltage PI controller to obtain the inductor current i. L1 d-axis command value i *L1d ; the load voltage v L voltage component v Lq With q-axis reference value v * Lq The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q The q-axis command value i * L1q and the d-axis command value i * L1d After performing the dq / abc coordinate transformation, the current is fed into the inner current loop to measure the load voltage v. L To take control;

[0115] When the operating mode is the discharge stop mode and the energy storage battery is in the first state, the discharge will be terminated, and the energy storage converter will also stop operating.

[0116] Off-grid operation mode specifically includes the following two working modes:

[0117] Load voltage control mode. When the energy storage battery has a high SOC, the AC load voltage d-axis reference value v is... * Ld With feedback value v Ld The result of the comparison is fed into the load voltage PI controller to obtain the inductor current i. L1 d-axis command value i * L1d ; q-axis feedback value of load voltage v Lq Its reference value v * Lq The result of the comparison is fed into the outer loop PI controller to obtain the inductor current i. L1 q-axis command value i * L1q After the two are transformed together into dq / abc coordinates, the result is fed into the inner current loop to control the load voltage.

[0118] Discharge Stop Mode. The system is in an abnormal operating state. When the SOC of the energy storage battery is low, the discharge will be terminated, and the energy storage converter will also stop operating.

[0119] In this embodiment, continuous and smooth switching between various operating modes can be achieved based on the magnitude of the inverter-side inductor current and the charging and discharging requirements of the DC-side energy storage battery. This results in minimal transient overshoot, ensuring long-term stable operation of the system and guaranteeing stable operation of the energy storage converter in any mode. Furthermore, the control strategy comprehensively considers the charging and discharging protection of the energy storage battery, thereby improving operational reliability and effectively extending battery life. In addition, the control strategy reduces the sampling stage of the grid-side inductor current, saving costs and achieving higher economic benefits.

[0120] According to the regulation method of the grid-connected / off-grid converter provided in this application embodiment, the energy storage converter is regulated by performing coordinate transformation and common-mode calculation on the AC side operating parameters, combined with the operating mode and battery status. Only the AC part operating parameters are required, reducing the difficulty and cost of parameter acquisition. When the energy storage converter faces different grid commands, it fully incorporates the battery protection mechanism when switching between grid connection and off-grid, which can maintain stable operation and smooth switching between grid connection and off-grid. It also comprehensively considers the charging and discharging protection of the energy storage battery, ensuring the safety and efficiency of the entire system, strengthening the health monitoring and protection of the energy storage battery, and ensuring its long-term safe and efficient operation. This comprehensive control strategy can better adapt to changes in the electricity market and technological development.

[0121] like Figure 6 As shown, the system controls the current of the DC-side energy storage battery, and the working waveform of the energy storage converter during the dynamic switching process from grid-connected power control discharge mode to grid-connected power control charging mode.

[0122] exist Figure 6 The diagram illustrates the state of charge (SOC) of the energy storage battery and the DC-side current i during this dynamic process. bat DC side voltage v bus The waveform shows that the charging and discharging switching process is continuous and smooth, and the DC side current control is stable.

[0123] like Figure 7 As shown, to verify the extended protection function, the grid-connected steady-state operating waveform of the energy storage converter when the DC-side energy storage battery SOC is high includes the energy storage battery SOC and the DC-side current i. bat DC side voltage v bus Waveform.

[0124] In this scenario, the SOC (%) of the energy storage battery is set at a relatively high level, while a reference value is set to encourage the AC side to charge the energy storage converter. By measuring the charging current and battery voltage of the DC-side energy storage battery, the normal operation of the constant voltage control loop can be determined. If the DC-side charging current is found to be very small, and the battery voltage is stable at the upper reference limit, the effectiveness of this control method can be verified. When the battery SOC is high, the DC-side voltage control loop can provide extended protection for the battery, enabling trickle charging.

[0125] like Figure 8 As shown, to verify the over-discharge protection function, the grid-connected steady-state operating waveform of the energy storage converter is shown when the DC-side energy storage battery SOC is low, including the energy storage battery SOC and the DC-side current i. bat DC side voltage v bus Waveform.

[0126] In this scenario, the SOC (%) of the energy storage battery is set to a low level, while a reference value is set to encourage the energy storage converter to discharge into the AC grid. The operation of the constant voltage control loop can be determined by measuring the discharge current and battery voltage of the DC-side energy storage battery. If the DC-side discharge current is very small and the battery voltage is stable at the lower reference limit, the effectiveness of this control method can be verified. When the battery SOC is low, the DC-side voltage control loop will implement over-discharge protection for the battery, thereby pausing the discharge process.

[0127] In this embodiment, the control strategy has low complexity, making it easy to implement in a digital control environment. It emphasizes the charging and discharging protection of the energy storage battery, providing effective support for the stable operation of the DC-side energy storage battery, thereby improving the system's operational reliability. Meanwhile, although the grid-connected reactive power under this control method includes the reactive power of the capacitor due to sampling the L1 current, resulting in some error, it can be controlled within the allowable error range, demonstrating significant advantages under the new standard requirements.

[0128] The regulation method for grid-connected and off-grid converters provided in this application can be executed by a regulation device for the grid-connected and off-grid converter. This application uses the example of a regulation device for the grid-connected and off-grid converter executing the regulation method for the grid-connected and off-grid converter to illustrate the regulation device for the grid-connected and off-grid converter provided in this application.

[0129] This application embodiment also provides a regulating device for a grid-connected and off-grid converter, applied to a three-phase four-wire three-level energy storage converter. The energy storage converter includes a DC section, an inverter, and an AC section connected in sequence. The AC section is used to connect to the AC power grid, and the AC section is provided with a grid-connected and off-grid switching device on the side close to the AC power grid.

[0130] The DC section includes an energy storage battery and a DC-side filter capacitor connected in sequence, and the AC section includes an inverter-side filter inductor, an AC-side filter capacitor, a grid-side filter inductor, and an AC load.

[0131] The regulating device of the grid-connected / off-grid converter includes:

[0132] The acquisition module is used to acquire the AC side operating parameters of the energy storage converter corresponding to the operating mode of the energy storage converter. The operating mode is determined based on the operating mode of the energy storage converter and the battery state of the energy storage battery. The operating mode includes grid-connected mode and offline mode.

[0133] The first processing module is used to convert the AC side operating parameters from the three-phase coordinate system to the dq coordinate system, and perform PQ calculation and common-mode differential-mode calculation to obtain the feedback value of the energy storage converter.

[0134] The second processing module is used to adjust the energy storage converter based on the feedback value and the battery state of the energy storage battery.

[0135] According to the regulating device for the grid-connected / off-grid converter provided in this application embodiment, the energy storage converter is regulated by performing coordinate transformation and common-mode calculation on the AC side operating parameters, combined with the operating mode and battery status. Only the AC part operating parameters are required, reducing the difficulty and cost of parameter acquisition. When the energy storage converter faces different grid commands, it fully incorporates the battery protection mechanism when switching between grid connection and off-grid, which can maintain stable operation and smooth switching between grid connection and off-grid. It also comprehensively considers the charging and discharging protection of the energy storage battery, ensuring the safety and efficiency of the entire system, strengthening the health monitoring and protection of the energy storage battery, and ensuring its long-term safe and efficient operation. This comprehensive control strategy can better adapt to changes in the electricity market and technological development.

[0136] The regulating device of the grid-connected / off-grid converter in this application embodiment can be an electronic device or a component of an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices besides a terminal. For example, the electronic device can be a mobile phone, tablet computer, laptop computer, PDA, in-vehicle electronic device, mobile internet device (MID), augmented reality (AR) / virtual reality (VR) device, robot, wearable device, ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA), etc. It can also be a server, network attached storage (NAS), personal computer (PC), television (TV), ATM, or self-service machine, etc. This application embodiment does not specifically limit the specific devices.

[0137] The regulating device of the grid-connected / off-grid converter in this embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this embodiment does not specifically limit its use.

[0138] The regulating device for the grid-connected and off-grid converter provided in this application embodiment can realize the various processes implemented in the regulating method embodiment of the grid-connected and off-grid converter as described above. To avoid repetition, it will not be described again here.

[0139] In some embodiments, such as Figure 9 As shown, this application embodiment also provides an electronic device 900, including a processor 901, a memory 902, and a computer program stored in the memory 902 and executable on the processor 901. When the program is executed by the processor 901, it implements the various processes of the above-described on-grid and off-grid converter regulation method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0140] It should be noted that the electronic devices in the embodiments of this application include the mobile electronic devices and non-mobile electronic devices described above.

[0141] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described embodiments of the regulation method for on-grid and off-grid converters and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0142] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0143] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described regulation method for on-grid and off-grid converters.

[0144] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0145] This application also provides a chip, which includes a processor and a communication interface. The communication interface and the processor are coupled. The processor is used to run programs or instructions to implement the various processes of the above-described embodiments of the regulation method for on-grid and off-grid converters, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0146] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0147] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0148] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the regulation method of the on-grid and off-grid converter of the various embodiments of this application.

[0149] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0150] In the description of this application, "multiple" means two or more.

[0151] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0152] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0153] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for regulating a grid-connected or off-grid converter, characterized in that, An energy storage converter is applied to a three-phase four-wire three-level system. The energy storage converter includes a DC section, an inverter, and an AC section connected in sequence. The AC section is used to connect to the AC power grid. The AC section is equipped with a grid-connected / off-grid switching device on the side closest to the AC power grid. The DC section includes an energy storage battery and a DC-side filter capacitor connected in sequence, and the AC section includes an inverter-side filter inductor, an AC-side filter capacitor, a grid-side filter inductor, and an AC load. The method includes: The operating mode, AC side operating parameters, and battery status of the energy storage converter are obtained. The operating mode is determined based on the operating mode of the energy storage converter and the battery status of the energy storage battery. The operating mode includes grid-connected mode and off-grid mode. The AC side operating parameters are transformed from the three-phase coordinate system to the dq coordinate system, and PQ calculation and common-mode differential-mode calculation are performed to obtain the feedback value of the energy storage converter. The AC side operating parameters include the inverter-side filter inductance. L f1 Inductor current i L1 AC side filter capacitor C f capacitor voltage v C AC load voltage v L ; For the inductor current i L1 The capacitor voltage v C and the load voltage v L Perform coordinate transformations to obtain the following results: dq Capacitor voltage in coordinate system v C voltage component v Cd , v Cq Inductor current i L1 Current component i L1d , i L1q and load voltage v L voltage component v Ld 、v Lq ; The energy storage converter is adjusted based on the feedback value of the energy storage converter, the operating mode, and the battery state of the energy storage battery. In the off-grid mode of operation, based on voltage components v Lq and voltage components v Ld The inductor current is obtained. i L1 of q Axis command value i * L1q and d-axis command value i * L1d Based on the above q Axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted according to the operating mode and battery status. When the operating mode is off-grid mode, the operating modes include: load voltage control mode and discharge stop mode; When the operating mode is load voltage control mode and the energy storage battery is in the second state, the load voltage will be... v L of d Axis reference value v * Ld With voltage component v Ld The load voltage is then compared. PI The controller obtains the inductor current. i L1 of d Axis command value i * L1d ; load voltage v L voltage component v Lq and q Axis reference value v * Lq After comparison, it is sent to the outer ring. PI The controller obtains the inductor current. i L1 of q Axis command value i * L1q , will the q Axis command value i * L1q and the d-axis command value i * L1d conduct dq / abc After coordinate transformation, the current inner loop is fed into the load voltage. v L To take control; When the operating mode is the discharge stop mode and the energy storage battery is in the first state, the discharge will be terminated, and the energy storage converter will also stop operating.

2. The regulation method for a grid-connected / off-grid converter according to claim 1, characterized in that, The feedback values ​​of the energy storage converter include active power feedback values ​​and reactive power feedback values. The AC side operating parameters are transformed from the three-phase coordinate system to the dq coordinate system, and PQ calculations and common-mode and differential-mode calculations are performed to obtain the feedback values ​​of the energy storage converter, including: For the current component i L1d , i L1q and voltage components v Cd , v Cq conduct PQ The active power feedback value is obtained by calculation and low-pass filtering. P and reactive power feedback value Q ; For the inductor current i L1 of abc The common-mode calculation of the components yields the inverter-side filter inductance. L f1 Current on i L1 Differential feedback value i L1xDM and common mode feedback value i L1CM .

3. The regulation method for a grid-connected / off-grid converter according to claim 2, characterized in that, Based on the feedback value of the energy storage converter, the operating mode, and the battery state of the energy storage battery, the energy storage converter is adjusted, including: In the grid-connected operating mode, the inductor current is obtained based on the active power feedback value and the reactive power feedback value. i L1 of q Axis command value i * L1q and d-axis command value i * L1d Based on the above q Axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted according to the operating mode and battery status.

4. The regulation method for a grid-connected / off-grid converter according to claim 3, characterized in that, In the grid-connected operating mode, the inductor current is obtained based on the active power feedback value and the reactive power feedback value. i L1 of q Axis command value i * L1q and d-axis command value i * L1d Based on the above q Axis command value i * L1q and the d-axis command value i * L1d Adjusting the energy storage converter according to the operating mode and battery state includes: When the operating modes are grid-connected power control charging mode and grid power control discharging mode, the active power reference value will be... P * With active power feedback value P After comparison, it is sent to the outer ring. PI The controller obtains the inductor current. i L1 of d Axis command value i * L1d ;Reactive power feedback value Q Reactive power reference value Q * After comparison, it is sent to the outer ring. PI The controller obtains the inductor current. i L1 of q Axis command value i * L1q ; will the d Axis command value i * L1d and q Axis command value i * L1q conduct dq / abc Transformation yields the inductor current. i L1 of abc Three-phase reference value i * L1x The differential feedback value is transmitted through the inner loop controller. i L1xDM Compared with three-phase reference values i * L1x The data are compared and then fed into the quasi-resonant controller. QPR A differential-mode modulation wave is obtained, and a three-phase modulation wave is obtained by superimposing the differential-mode modulation wave with the common-mode modulation wave. The energy storage converter is regulated by the three-phase modulation wave, where x = a, b, c.

5. The regulation method for a grid-connected / off-grid converter according to claim 3, characterized in that, In the grid-connected operating mode, the inductor current is obtained based on the active power feedback value and the reactive power feedback value. i L1 of q Axis command value i * L1q and d-axis command value i * L1d Based on the above q Axis command value i * L1q and the d-axis command value i * L1d Adjusting the energy storage converter according to the operating mode and battery state includes: When the operating mode is constant voltage charging mode and the energy storage battery is in the second state... q The shaft is controlled by reactive power. d Shaft through DC side voltage reference upper limit value V bat_ref_H With feedback value v bus_fb After comparison, the voltage is sent to the DC side outer loop. PI The controller receives the corresponding d Axis command value i * L1d The system takes over the battery charging status to protect the battery and adjusts the energy storage converter to trickle charge the energy storage battery. When the operating mode is the paused discharge mode and the energy storage battery is in the first state, the active power reference value will be... P * With active power feedback value P After comparison, it is sent to the outer ring. PI The controller obtains the inductor current. i L1 of d Axis command value i * L1d ;Reactive power feedback value Q Reactive power reference value Q * After comparison, it is sent to the outer ring. PI The controller obtains the inductor current. i L1 of q Axis command value i * L1q ; Set the upper limit of the DC side voltage reference value V bat_ref_H DC side voltage feedback value v bus_fb After comparison, the voltage is sent to the DC side outer loop. PI The controller receives the corresponding d Axis command value i * L1d According to the above q Axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted to pause the discharge of the energy storage battery.

6. The regulation method for a grid-connected / off-grid converter according to claim 3, characterized in that, In the off-grid mode of operation, based on voltage components v Lq and voltage components v Ld The inductor current is obtained. i L1 of q Axis command value i * L1q and d-axis command value i * L1d Based on the above q Axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted according to the operating mode and battery status.

7. The regulation method for a grid-connected / off-grid converter according to claim 1, characterized in that, Before obtaining the operating modes of the energy storage converter, the AC side operating parameters, and the battery state of the energy storage battery, the method further includes: When it is determined that the energy storage converter is switching from grid-connected mode to off-grid mode, the inverter-side filter inductor... L f1 current i L1 Reduce to 0, and control the load voltage of the AC load. v L Tracking the grid voltage of the AC power grid v g And control the grid disconnection switch in the grid-connected / off-grid switching device to open, so that the energy storage converter is in islanded mode; When it is determined that the energy storage converter has switched from off-grid mode to grid-connected operation mode, the load voltage is controlled. v L Tracking grid voltage v g When the grid-connected isolating switch is closed, the energy storage converter switches to the grid-connected current and DC-side voltage control mode.

8. A regulating device for a grid-connected / off-grid converter, characterized in that, An energy storage converter is applied to a three-phase four-wire three-level system. The energy storage converter includes a DC section, an inverter, and an AC section connected in sequence. The AC section is used to connect to the AC power grid. The AC section is equipped with a grid-connected / off-grid switching device on the side closest to the AC power grid. The DC section includes an energy storage battery and a DC-side filter capacitor connected in sequence, and the AC section includes an inverter-side filter inductor, an AC-side filter capacitor, a grid-side filter inductor, and an AC load. The device includes: The acquisition module is used to acquire the AC side operating parameters of the energy storage converter corresponding to the operating mode of the energy storage converter. The operating mode is determined based on the operating mode of the energy storage converter and the battery state of the energy storage battery. The operating mode includes grid-connected mode and off-grid mode. The first processing module is used to convert the AC side operating parameters from the three-phase coordinate system to the dq coordinate system, and perform PQ calculation and common-mode differential-mode calculation to obtain the feedback value of the energy storage converter. The AC side operating parameters include the inverter-side filter inductance. L f1 Inductor current i L1 AC side filter capacitor C f capacitor voltage v C AC load voltage v L ; For the inductor current i L1 The capacitor voltage v C and the load voltage v L Perform coordinate transformations to obtain the following results: dq Capacitor voltage in coordinate system v C voltage component v Cd , v Cq Inductor current i L1 Current component i L1d , i L1q and load voltage v L voltage component v Ld 、v Lq ; The second processing module is used to adjust the energy storage converter based on the feedback value of the energy storage converter and the battery state of the energy storage battery. In the off-grid mode of operation, based on voltage components v Lq and voltage components v Ld The inductor current is obtained. i L1 of q Axis command value i * L1q and d-axis command value i * L1d Based on the above q Axis command value i * L1q and the d-axis command value i * L1d The energy storage converter is adjusted according to the operating mode and battery status. When the operating mode is off-grid mode, the operating modes include: load voltage control mode and discharge stop mode; When the operating mode is load voltage control mode and the energy storage battery is in the second state, the load voltage will be... v L of d Axis reference value v * Ld With voltage component v Ld The load voltage is then compared. PI The controller obtains the inductor current. i L1 of d Axis command value i * L1d ; load voltage v L voltage component v Lq and q Axis reference value v * Lq After comparison, it is sent to the outer ring. PI The controller obtains the inductor current. i L1 of q Axis command value i * L1q , will the q Axis command value i * L1q and the d-axis command value i * L1d conduct dq / abc After coordinate transformation, the current inner loop is fed into the load voltage. v L To take control; When the operating mode is the discharge stop mode and the energy storage battery is in the first state, the discharge will be terminated, and the energy storage converter will also stop operating.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the regulation method for the on-grid and off-grid converter as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the regulation method for the grid-connected and off-grid converter as described in any one of claims 1-7.

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