Method, device and equipment for adjusting grid-connected and off-grid converter and medium

Abstract

The invention discloses an adjusting method and device of a grid-connected and off-grid converter, equipment and a medium, and belongs to the technical field of smart power grids. The method is applied to a three-phase four-wire three-level energy storage converter, the energy storage converter comprises a direct current part, an inverter and an alternating current part which are connected in sequence, the alternating current part is used for being connected with an alternating current power grid, and a grid-connected and off-grid switching device is arranged on the side, close to the alternating current power grid, of the alternating current part; the direct current part comprises an energy storage battery and a direct current side filter capacitor which are connected in sequence; the alternating current part comprises an inverter side filter inductor, an alternating current side filter capacitor, a network side filter inductor and an alternating current load; the method comprises the steps that the working mode of an energy storage converter, alternating current side working parameters and the battery state of an energy storage battery are obtained, the working mode is determined based on the operation mode of the energy storage converter and the battery state of the energy storage battery, and the operation mode comprises a grid-connected mode and an offline mode; the alternating current side working parameters are converted from a three-phase coordinate system to a dq coordinate system, PQ calculation and common-mode differential-mode calculation are carried out, and a feedback value of the energy storage converter is obtained; and adjusting the energy storage converter based on the feedback value, the working mode and the battery state of the energy storage battery. According to the method, the energy storage converter can stably work according to the control instruction, and on the basis of smooth grid-connected and off-grid switching, the energy storage battery on the direct current side is protected, so that the safety and high efficiency of the whole system are guaranteed.

Description

Technical Field

[0001] The present application belongs to the field of smart grid technology, and in particular, relates to a method, device, equipment and medium for regulating an on-grid and off-grid converter. Background Art

[0002] As a key component connecting the energy storage system and the power grid, the performance of the energy storage inverter directly affects the stability and reliability of the power system. The on-grid and off-grid energy storage inverter is not only required to have high efficiency in energy conversion, but also to be able to smoothly switch between on-grid mode and off-grid mode to meet diverse operating requirements.

[0003] The working status of energy storage batteries in grid-connected operations has become more important. Real-time monitoring and effective control of battery status can significantly extend the service life of energy storage inverters while improving their operational reliability. However, current control strategies often do not fully consider important factors such as overcharge protection of energy storage batteries. In order to achieve more efficient and precise control, it is usually necessary to collect multiple parameters of the energy storage inverter, such as battery voltage, current, temperature, SOC (state of charge), SOH (state of health), load demand, external environmental conditions, etc., and then take corresponding measures. However, this protection method with batteries as the monitoring object does not effectively coordinate with the control of the energy storage inverter, which may cause the battery to operate under inappropriate working conditions, resulting in accelerated capacity decay or premature failure.

[0004] Therefore, it is urgent to develop a new regulation method to fully incorporate the battery protection mechanism when the energy storage inverter is switched on and off the grid. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a method, device, equipment and medium for regulating an on-grid and off-grid converter, which fully incorporates a battery protection mechanism when the energy storage converter is switched on and off the grid.

[0006] In a first aspect, the present application provides a method for regulating an on-grid and off-grid converter, which is applied to a three-phase four-wire three-level energy storage converter, wherein the energy storage converter comprises a DC part, an inverter and an AC part connected in sequence, wherein the AC part is used to connect to an AC power grid, and an on-grid and off-grid switching device is provided on a side of the AC part close to the AC power grid;

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

[0008] The method comprises:

[0009] Acquire the working mode of the energy storage converter, the AC side working parameters and the battery status of the energy storage battery, wherein the working mode is determined based on the operation mode of the energy storage converter and the battery status of the energy storage battery, and the operation mode includes a grid-connected mode and an offline mode;

[0010] 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;

[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 the present 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 The capacitor voltage v C , AC load voltage v L One or more of the following, the feedback value includes an active power feedback value and a reactive power feedback value;

[0013] The AC side operating parameters are converted 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, including:

[0014] The inductor current i L1 , the capacitor voltage v C and the load voltage v L Perform coordinate transformation to obtain the capacitor voltage v in the dq coordinate system. C The voltage component v Cd 、v Cq , inductor current i L1 The current component i L1d 、i L1q , and the load voltage v L The voltage component v Ld 、v Lq ;

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

[0016] The inductor current i L1 The abc components are calculated for common and differential modes to obtain the inverter side filter inductance L f1 The current i L1The differential mode feedback value i L1xDM and the common mode feedback value i L1CM .

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

[0018] When the operation mode is the grid-connected mode, based on the active power feedback value and the active power feedback value, the inductor current i is obtained. L1 The 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 working mode and the battery status;

[0019] When the operation mode is off-grid mode, based on the voltage component v Lq and the voltage component v Ld , and the inductor current i is obtained L1 The 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 working mode and battery status.

[0020] According to an embodiment of the present application, when the operation mode is the grid-connected mode, based on the active power feedback value and the active power feedback value, the inductor current i is obtained. L1 The 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 working mode and the battery state, including:

[0021] When the working mode is the grid-connected power control charging mode and the grid power control discharging mode, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current iL1 The d-axis command value i * L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; The d-axis command value i * L1d and q-axis command value i * L1q Perform dq / abc transformation to obtain the inductor current i L1 abc three-phase reference value i * L1x , the differential mode feedback value i is converted into L1xDM With three-phase reference value i * L1x For comparison, the differential-mode modulation waves are respectively sent to the quasi-resonant controller QPR to obtain differential-mode modulation waves, and the differential-mode modulation waves are superimposed with the common-mode modulation waves to obtain three-phase modulation waves, and the energy storage converter is adjusted by the three-phase modulation waves.

[0022] According to an embodiment of the present application, when the operation mode is the grid-connected mode, based on the active power feedback value and the active power feedback value, the inductor current i is obtained. L1 The 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 working mode and the battery state, including:

[0023] When the working mode is the constant voltage charging mode and the energy storage battery is in the second state, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; Set the DC side voltage reference upper limit value V bat_ref_H and DC side voltage feedback value v bus_fb After comparison, it 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 , regulating the energy storage converter to trickle charge the energy storage battery;

[0024] When the working mode is the suspended discharge mode and the energy storage battery is in the first state, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; Set the DC side voltage reference upper limit value V bat_ref_H and DC side voltage feedback value v bus_fb After comparison, it 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 inverter to suspend discharging of the energy storage battery.

[0025] According to one embodiment of the present application, when the operation mode is an off-grid mode, the operation mode includes: a load voltage control mode and a discharge stop mode;

[0026] When the operation mode is off-grid mode, based on the voltage component v Lq and the voltage component v Ld , and the inductor current i is obtained L1 The 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 working mode and the battery state, including:

[0027] When the working mode is the load voltage control mode and the energy storage battery is in the second state, the load voltage v L The d-axis reference value v* Ld With voltage component v Ld After comparison, it is sent to the load voltage PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Set the load voltage v L The voltage component v Lq With q-axis reference value v * Lq After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q , the q-axis command value i * L1q and the d-axis command value i * L1d After dq / abc coordinate transformation, the current is sent to the inner loop to compare the load voltage v L To exercise control;

[0028] When the working 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 running.

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

[0030] When it is determined that the energy storage converter is switched from the grid-connected mode to the off-grid mode, the inverter-side filter inductor L f1 The current i L1 drops to 0, and controls the load voltage v of the AC load L Tracking the grid voltage v of the AC grid g , and controlling the grid-connected disconnecting switch in the grid-connected and off-grid switching device to be disconnected, and the energy storage converter is in island mode;

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

[0032] In a second aspect, the present application provides a regulating device for an on-grid and off-grid converter, which is applied to a three-phase four-wire three-level energy storage converter, wherein the energy storage converter comprises a DC part, an inverter and an AC part connected in sequence, wherein the AC part is used to connect to an AC power grid, and the AC part is provided with an on-grid and off-grid switching device on a side close to the AC power grid;

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

[0034] The device comprises:

[0035] An acquisition module, configured to acquire, according to the working mode of the energy storage converter, an AC side working parameter of the energy storage converter corresponding to the working mode, wherein the working mode is determined based on the operation mode of the energy storage converter and the battery state of the energy storage battery, and the operation mode includes a grid-connected mode and an offline mode;

[0036] A first processing module is used to convert the AC side working 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] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for regulating an on-grid and off-grid converter as described in the first aspect above is implemented.

[0039] In a fourth aspect, the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the method for regulating an on-grid and off-grid converter as described in the first aspect above is implemented.

[0040] In a fifth aspect, the present application provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the regulation method of the grid-connected and off-grid converter as described in the first aspect.

[0041] In a sixth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the regulation method of the grid-connected and off-grid converter as described in the first aspect above.

[0042] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application.

[0043] The present application provides a method, device, equipment and medium for regulating an on-grid and off-grid converter, which has the following beneficial effects compared with the prior art:

[0044] (1) By performing coordinate transformation and common-differential mode calculation on the AC side working parameters, the energy storage inverter is adjusted in combination with the working mode and battery status. Only the working parameters of the AC part are required, which reduces the difficulty and cost of parameter collection. When the energy storage inverter faces different grid instructions and switches between grid and off-grid, the battery protection mechanism is fully incorporated, which can not only maintain stable operation but also switch smoothly between grid connection and off-grid. The charging and discharging protection of the energy storage battery is also comprehensively considered to ensure the safety and efficiency of the entire system, strengthen the health monitoring and protection of the energy storage battery, and ensure its long-term safe and efficient operation. This comprehensive control strategy can better adapt to changes in the power market and technological development.

[0045] (2) It can switch between various working modes continuously and smoothly according to the size of the inductor current on the inverter side and the charging and discharging requirements of the energy storage battery on the DC side. The transient overshoot is small, which provides a guarantee for the long-term stable operation of the system and ensures 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 service life of the battery. In addition, the control strategy reduces the sampling link of the grid-side inductor current, which can save costs and achieve higher economic benefits.

[0046] (3) The control strategy is less complex and easy to implement in a digital control environment. It focuses on the charge and discharge protection of the energy storage battery and can provide 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 the L1 current, there is a certain error, but it can be controlled within the allowable error range, which can show great advantages under the requirements of the new standard. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0048] Figure 1 This is the structural intention of the grid-connected and off-grid energy storage converter provided in the embodiment of the present application;

[0049] Figure 2 It is a topological structure diagram of a three-phase four-wire T-type three-level energy storage converter provided in an embodiment of the present application;

[0050] Figure 3 It is a flow chart of a method for regulating an on-grid and off-grid converter provided in an embodiment of the present application;

[0051] Figure 4 It is a schematic diagram of four grid-connected working modes of the grid-connected and off-grid energy storage converter provided in the embodiment of the present application;

[0052] Figure 5 It is a schematic diagram of two off-grid working modes of the on-grid and off-grid energy storage converter provided in the embodiment of the present application;

[0053] Figure 6 is the SOC of the energy storage battery provided in the embodiment of the present application, and the DC side current i bat , DC side voltage v bus Schematic diagram of the waveform;

[0054] Figure 7 It is a schematic diagram of a grid-connected steady-state working waveform of an energy storage converter provided in an embodiment of the present application when the SOC of the DC-side energy storage battery is high;

[0055] Figure 8 It is a schematic diagram of a grid-connected steady-state working waveform of an energy storage converter provided in an embodiment of the present application when the SOC of the DC-side energy storage battery is low;

[0056] Fig. 9 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0058] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0059] In the following, in combination with the accompanying drawings, the adjustment method of the grid-connected and off-grid converter, the adjustment device of the grid-connected and off-grid converter, the electronic device and the readable storage medium provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

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

[0061] The terminal includes, but is not limited to, a portable communication device such as a mobile phone or tablet computer with a touch-sensitive surface (e.g., a touch screen display and / or a touch pad). It should also be understood that in some embodiments, the terminal may not be a portable communication device, but a desktop computer with a touch-sensitive surface (e.g., a touch screen display and / or a touch pad).

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

[0063] The adjustment method for an off-grid converter provided in the embodiment of the present application, the execution subject of the adjustment method for an off-grid converter may be an electronic device or a functional module or functional entity in the electronic device that can implement the adjustment method for an off-grid converter. The electronic devices mentioned in the embodiment of the present application include but are not limited to mobile phones, tablet computers, computers, cameras, and wearable devices. The adjustment method for an off-grid converter provided in the embodiment of the present application is described below using an electronic device as an execution subject as an example.

[0064] like Figure 1 As shown, the method is applied to a three-phase four-wire three-level energy storage converter, the energy storage converter comprises a DC part, an inverter and an AC part connected in sequence, the AC part is used to connect to an AC power grid, and the AC part is provided with an on-grid and off-grid switching device on a side close to the AC power grid;

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

[0066] The DC side filter capacitors include C bus1 , C bus2 , inverter side filter inductor L f1 Including L f1a , L f1b , L f1c , neutral line 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 load includes Load_fa, Load_fb, and Load_fc.

[0067] exist Figure 1In the figure, the energy storage converter is a grid-connected and off-grid type, including a main circuit and a control circuit. The gray box below is a control strategy structure diagram proposed in this application, such as 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 as follows in Table 1:

[0069] Table 1 Main parameters

[0070] AC side load output voltage <![CDATA[V Load ]]> 230V(RMS) Switching frequency of 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 inductance <![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 adjustment method of the grid-connected and off-grid converter includes:

[0072] Step 310: Acquire the working mode of the energy storage converter, AC side working parameters and the battery status of the energy storage battery, wherein the working mode is determined based on the operation mode of the energy storage converter and the battery status of the energy storage battery, and the operation mode includes a grid-connected mode and an 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 battery state can be characterized as the SOC state 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 state is low, and the charge amount of the energy storage battery is small. For example, the charge of the energy storage battery is less than 20%.

[0076] When the energy storage battery is in the second state, the SOC state is high, and the charge capacity of the battery is close to full charge, for example, the charge capacity of the energy storage battery is 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 working mode of the energy storage converter, the AC side working parameters and the battery status of the energy storage battery, the method further includes:

[0079] When it is determined that the energy storage converter is switched from the grid-connected mode to the off-grid mode, the inverter-side filter inductor L f1 The current i L1 drops to 0, and controls the load voltage v of the AC load LTracking the grid voltage v of the AC grid g , and controlling the grid-connected disconnecting switch in the grid-connected and off-grid switching device to be disconnected, and the energy storage converter is in island mode;

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

[0081] After the on-grid and off-grid switching device is switched, the controller receives the control instruction 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 , grid-side filter inductor current i L2_fb , AC load voltage feedback value v Load_fb , and send the sampled values ​​to the controller designed by this method to realize various modes and functions of the grid-connected and off-grid energy storage converter.

[0083] Adjust the position of the 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, the switch S3 can be adjusted to the corresponding position according to the different battery states in the grid-connected mode;

[0085] The AC side switch control strategy switches the energy storage converter to a specific on-grid or off-grid mode. The on-grid mode sends the command value to the corresponding inner loop controller, and the off-grid mode directly outputs the single-loop calculation value to obtain a 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 The capacitor voltage v C , AC load voltage v L One or more of the following, the feedback value includes an active power feedback value and a reactive power feedback value;

[0087] The AC side operating parameters are converted 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, including:

[0088] The inductor current i L1 , the capacitor voltage v C and the load voltage v L Perform coordinate transformation to obtain the capacitor voltage v in the dq coordinate system. C The voltage component v Cd 、v Cq , inductor current i L1 The current component i L1d 、i L1q , and the load voltage v L The voltage component v Ld 、v Lq ;

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

[0090] The inductor current i L1 The abc components are calculated for common and differential modes to obtain the inverter side filter inductance L f1 The current i L1 The differential mode feedback value i L1xDM and the common mode feedback value i L1CM .

[0091] For the inverter side filter inductor L f1 The current i L1 The differential mode feedback value i L1xDM , x=a,b,c.

[0092] In this embodiment, the AC side current sampling uses only one sampling link of L1 current, eliminating the need to sample the grid side inductor current, thus saving costs and having high economic benefits.

[0093] In some embodiments, adjusting the energy storage converter based on the feedback value, the working mode and the battery state of the energy storage battery includes:

[0094] When the operation mode is the grid-connected mode, based on the active power feedback value and the active power feedback value, the inductor current i is obtained. L1 The 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 working mode and the battery status;

[0095] When the operation mode is off-grid mode, based on the voltage component v Lq and the voltage component v Ld , and the inductor current i is obtained L1 The 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 working mode and battery status.

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

[0097] In the process of adjusting the energy storage inverter, switches S1 and S2 can be adjusted to the corresponding positions according to the battery status of the energy storage battery and the grid-connected and off-grid mode; the outer loop output value is transformed into the inner loop differential mode command value after coordinate transformation, and the inner loop inductor current common differential mode decoupling control obtains the modulation wave.

[0098] For the 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 The differential mode feedback value i L1xDM The command value i obtained after the coordinate transformation of the outer loop output value * L1x (x=a, b, c) are compared and sent to the QPR controller to obtain the differential mode modulated wave.

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

[0100] In some embodiments, Figure 4 As shown, when the operation mode is the grid-connected mode, based on the active power feedback value and the active power feedback value, the inductor current i is obtained. L1 The 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 working mode and the battery state, including:

[0101] When the working mode is the grid-connected power control charging mode and the grid power control discharging mode, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; The d-axis command value i * L1d and q-axis command value i * L1q Perform dq / abc transformation to obtain the inductor current i L1 abc three-phase reference value i * L1x , the differential mode feedback value i is converted into L1xDM With three-phase reference value i * L1x For comparison, the differential-mode modulation waves are respectively sent to the quasi-resonant controller QPR to obtain differential-mode modulation waves, and the differential-mode modulation waves are superimposed with the common-mode modulation waves to obtain three-phase modulation waves, and the energy storage converter is adjusted by the three-phase modulation waves.

[0102] In some embodiments, when the operation mode is the grid-connected mode, the inductor current i is obtained based on the active power feedback value and the active power feedback value. L1 The 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 working mode and the battery state, including:

[0103] When the working mode is the constant voltage charging mode and the energy storage battery is in the second state, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current i L1 The d-axis command value i *L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; Set the DC side voltage reference upper limit value V bat_ref_H and DC side voltage feedback value v bus_fb After comparison, it 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 , regulating the energy storage converter to trickle charge the energy storage battery;

[0104] When the working mode is the suspended discharge mode and the energy storage battery is in the first state, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; Set the DC side voltage reference upper limit value V bat_ref_H and DC side voltage feedback value v bus_fb After comparison, it 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 inverter to suspend discharging of the energy storage battery.

[0105] When running in grid-connected mode, you 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 sends power. * 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 The d-axis command value i * L1d , reactive power feedback value Q and its reference value Q* After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; The d-axis command value i * L1d and q-axis command value i * L1q Perform dq / abc transformation to obtain the inductor current i L1 abc three-phase reference value i * L1x (x=a,b,c). The inner loop controller uses the inverter side filter inductor L f1 The differential feedback value on i L1xDM With three-phase reference value i * L1x For comparison, the differential-mode modulation waves are sent to the quasi-resonant controller QPR to obtain differential-mode modulation waves, which are superimposed with the common-mode modulation waves to obtain three-phase modulation waves, thereby realizing the regulation and control of the grid-connected current.

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

[0108] By comparing the grid-connected power control charging mode and the constant voltage charging mode, the command value is calculated and the larger value is selected as the inner loop current i L1 Controlled d-axis reference value i * L1d , thereby smoothly 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 is greater than 0 and the SOC state of the energy storage battery is high, the AC grid absorbs power. * After being compared with the feedback value P, it is sent to the outer loop PI controller to calculate the inverter side filter inductance L f1 The d-axis command value i * L1d , the feedback value Q of reactive power and its reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q After dq / abc transformation, the abc three-phase reference value i 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 is sent to the quasi-resonant controller QPR to obtain the differential mode modulation wave, which is superimposed with the common mode modulation wave to obtain the three-phase modulation wave, so as to realize the regulation and control of the grid-connected current.

[0110] Suspend discharge mode. When the SOC state of the energy storage battery is low, it cannot continue to discharge. The q axis is still controlled by reactive power, and the d axis is controlled by the DC side voltage reference upper limit value V bat_ref_H With feedback value v bus_fb After comparison, it is sent to the DC side voltage outer loop PI controller to obtain the corresponding d-axis command value i * L1d , take over the battery discharge status to protect the battery and suspend discharge.

[0111] By comparing the grid-connected power control discharge mode and the suspended discharge mode to calculate the command value, the smaller value is selected as the inner loop current i L1 Controlled d-axis reference value i * L1d , thereby smoothly switching between the grid-connected power control discharge mode and the suspended discharge mode.

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

[0113] When the operation mode is off-grid mode, based on the voltage component v Lq and the voltage component v Ld , and the inductor current i is obtained L1 The 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 working mode and the battery state, including:

[0114] When the working mode is the load voltage control mode and the energy storage battery is in the second state, the load voltage v L The d-axis reference value v * Ld With voltage component v Ld After comparison, it is sent to the load voltage PI controller to obtain the inductor current i L1 The d-axis command value i *L1d ; Set the load voltage v L The voltage component v Lq With q-axis reference value v * Lq After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q , the q-axis command value i * L1q and the d-axis command value i * L1d After dq / abc coordinate transformation, the current is sent to the inner loop to compare the load voltage v L To exercise control;

[0115] When the working 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 running.

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

[0117] Load voltage control mode. When the energy storage battery SOC state is high, the AC load voltage d-axis reference value v * Ld With feedback value v Ld After comparison, it is sent to the load voltage PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ;q-axis feedback value v of load voltage Lq With its reference value v * Lq After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q After the dq / abc coordinate transformation is performed on the two together, they are sent to the current inner loop to control the load voltage.

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

[0119] In this embodiment, it is possible to switch between various working modes continuously and smoothly according to the size of the inverter side inductor current and the charging and discharging requirements of the DC side energy storage battery, with a small transient overshoot, which provides a guarantee for the long-term stable operation of the system, ensuring that the energy storage converter can operate stably in any mode, and also comprehensively considers the charging and discharging protection of the energy storage battery, thereby improving the reliability of operation and effectively extending the service life of the battery. In addition, the control strategy reduces the sampling link of the grid-side inductor current, which can save costs and achieve higher economic benefits.

[0120] According to the adjustment method of the grid-connected and off-grid converter provided in the embodiment of the present application, by performing coordinate transformation and common-differential mode calculation on the AC side working parameters, the energy storage converter is adjusted in combination with the working mode and the battery status. Only the working parameters of the AC part are required, which reduces the difficulty and cost of parameter collection. When the energy storage converter faces different grid instructions and switches between grid-connected and off-grid, the battery protection mechanism is fully incorporated, which can maintain stable operation and switch smoothly between grid-connected and off-grid. The charging and discharging protection of the energy storage battery is also comprehensively considered to ensure the safety and efficiency of the entire system, strengthen the health monitoring and protection of the energy storage battery, and ensure its long-term safe and efficient operation. This comprehensive control strategy can better adapt to changes in the power 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 the grid-connected power control discharge mode to the grid-connected power control charging mode.

[0122] exist Figure 6 The SOC of the energy storage battery under this dynamic process is shown in the figure. The DC side current i bat , DC side voltage v bus From the waveform, it can be found that the charge and discharge switching process is continuous and smooth, and the DC side current control is stable.

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

[0124] In this case, the SOC (%) of the energy storage battery is set at a higher level, and the reference value is set so that there is a tendency for the AC side to charge the energy storage converter. By measuring the charging current of the energy storage battery on the DC side and the battery voltage, it can be determined whether the constant voltage control loop is working properly. If it is found that the charging current value on the DC side is very small, and the voltage of the energy storage battery is stable at the reference upper limit, then the effectiveness of this control method can be verified. When the battery SOC is high, the voltage control loop on the DC side can provide extended protection for the battery and realize trickle charging.

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

[0126] In this case, the SOC (%) of the energy storage battery is set to a lower level, and the reference value is set so that the energy storage converter has a tendency to discharge to the AC grid. By measuring the discharge current and battery voltage of the DC side energy storage battery, the working condition of the constant voltage control loop can be judged. If the discharge current value on the DC side is very small and the voltage of the energy storage battery is stable at the reference lower limit, the effectiveness of this control method can be verified. When the battery SOC is low, the voltage control loop on the DC side will implement over-discharge protection on the battery, thereby suspending the discharge process.

[0127] In this embodiment, the control strategy is less complex and easy to implement in a digital control environment. It focuses on the charge and discharge protection of the energy storage battery, and can provide effective support for the stable operation of the DC side energy storage battery, thereby improving the operational reliability of the system. 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 the L1 current, there is a certain error, but it can be controlled within the allowable error range, which can show a greater advantage under the requirements of the new standard.

[0128] The regulating method of the on-grid and off-grid converter provided in the embodiment of the present application can be performed by a regulating device of the on-grid and off-grid converter. In the embodiment of the present application, the regulating device of the on-grid and off-grid converter is used as an example to illustrate the regulating method of the on-grid and off-grid converter provided in the embodiment of the present application.

[0129] The embodiment of the present application also provides a regulating device for an on-grid and off-grid converter, which is applied to a three-phase four-wire three-level energy storage converter, wherein the energy storage converter comprises a DC part, an inverter and an AC part connected in sequence, wherein the AC part is used to connect to an AC power grid, and an on-grid and off-grid switching device is provided on a side of the AC part close to the AC power grid;

[0130] The DC part includes an energy storage battery and a DC side filter capacitor connected in sequence, and the AC part 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 and off-grid converter comprises:

[0132] An acquisition module, configured to acquire, according to the working mode of the energy storage converter, an AC side working parameter of the energy storage converter corresponding to the working mode, wherein the working mode is determined based on the operation mode of the energy storage converter and the battery state of the energy storage battery, and the operation mode includes a grid-connected mode and an offline mode;

[0133] A first processing module is used to convert the AC side working 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 of the grid-connected and off-grid converter provided in the embodiment of the present application, by performing coordinate transformation and common-differential mode calculation on the working parameters on the AC side, the energy storage converter is adjusted in combination with the working mode and the battery status. Only the working parameters of the AC part are required, which reduces the difficulty and cost of parameter collection. When the energy storage converter faces different grid instructions and switches between grid-connected and off-grid, the battery protection mechanism is fully incorporated, which can maintain stable operation and switch smoothly between grid-connected and off-grid. The charging and discharging protection of the energy storage battery is also comprehensively considered to ensure the safety and efficiency of the entire system, strengthen the health monitoring and protection of the energy storage battery, and ensure its long-term safe and efficient operation. This comprehensive control strategy can better adapt to changes in the power market and technological development.

[0136] The regulating device of the grid-connected and off-grid converter in the embodiment of the present application can be an electronic device, or a component in the electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal, or it can be other devices other than the terminal. Exemplarily, the electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, a vehicle-mounted electronic device, a mobile Internet device (Mobile Internet Device, MID), an augmented reality (Augmented Reality, AR) / virtual reality (Virtual Reality, VR) device, a robot, a wearable device, an ultra-mobile personal computer (Ultra-Mobile Personal Computer, UMPC), a netbook or a personal digital assistant (Personal Digital Assistant, PDA), etc., and can also be a server, a network attached storage (Network Attached Storage, NAS), a personal computer (Personal Computer, PC), a television (Television, TV), a teller machine or a self-service machine, etc., which is not specifically limited in the embodiment of the present application.

[0137] The regulating device of the grid-connected and off-grid converter in the embodiment of the present application may be a device having an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0138] The regulating device for the grid-connected and off-grid converter provided in the embodiment of the present application can implement various processes implemented in the regulating method embodiment for the grid-connected and off-grid converter in the above-mentioned embodiment, and will not be described again here to avoid repetition.

[0139] In some embodiments, Fig. 9 As shown, an embodiment of the present application 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, each process of the above-mentioned embodiment of the adjustment method for the grid-connected and off-grid converter is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

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

[0141] An embodiment of the present application also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the various processes of the above-mentioned embodiment of the adjustment method for the grid-connected and off-grid converter are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

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

[0143] An embodiment of the present application also provides a computer program product, including a computer program, which implements the above-mentioned adjustment method of the grid-connected and off-grid converter when executed by a processor.

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

[0145] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned embodiment of the adjustment method for the grid-connected and off-grid converter, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0146] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0147] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0148] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the adjustment method of the grid-connected and off-grid converter of each embodiment of the present application.

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

[0150] In the description of the present application, “plurality” means two or more.

[0151] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0152] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

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

Claims

1. A method for regulating an on-grid and off-grid converter, characterized in that: An energy storage converter applied to a three-phase four-wire three-level system, the energy storage converter comprising a DC part, an inverter and an AC part connected in sequence, the AC part being used to connect to an AC power grid, and the AC part being provided with an on-grid and off-grid switching device on a side close to the AC power grid; The DC part includes an energy storage battery and a DC side filter capacitor connected in sequence, and the AC part includes an inverter side filter inductor, an AC side filter capacitor, a grid side filter inductor and an AC load; The method comprises: Acquire the working mode of the energy storage converter, the AC side working parameters and the battery status of the energy storage battery, wherein the working mode is determined based on the operation mode of the energy storage converter and the battery status of the energy storage battery, and the operation mode includes a grid-connected mode and an offline mode; 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 energy storage converter is adjusted based on the feedback value, the operating mode and the battery state of the energy storage battery.

2. The method for adjusting the grid-connected and off-grid converter according to claim 1, characterized in that: The AC side operating parameters include the inverter side filter inductance L f1 The inductor current i L1 , AC side filter capacitor C f The capacitor voltage v C , AC load voltage v L One or more of the following, the feedback value includes an active power feedback value and a reactive power feedback value; The AC side operating parameters are converted 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, including: The inductor current i L1 , the capacitor voltage v C and the load voltage v L Perform coordinate transformation to obtain the capacitor voltage v in the dq coordinate system. C The voltage component v Cd 、v Cq , inductor current i L1 The current component i L1d 、i L1q , and the load voltage v L The voltage component v Ld 、v Lq ; For the current component i L1d 、i L1q , and the voltage component v Cd 、v Cq Perform PQ calculation and low-pass filtering to obtain active power feedback value P and reactive power feedback value Q; The inductor current i L1 The abc components are calculated for common and differential modes to obtain the inverter side filter inductance L f1 The current i L1 The differential mode feedback value i L1xDM and the common mode feedback value i L1CM .

3. The method for adjusting the on-grid and off-grid converter according to claim 2, characterized in that: Based on the feedback value, the working mode and the battery state of the energy storage battery, the energy storage converter is adjusted, including: When the operation mode is the grid-connected mode, based on the active power feedback value and the active power feedback value, the inductor current i is obtained. L1 The 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 working mode and the battery status; When the operation mode is off-grid mode, based on the voltage component v Lq and the voltage component v Ld , and the inductor current i is obtained L1 The 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 working mode and battery status.

4. The method for adjusting the grid-connected and off-grid converter according to claim 3, characterized in that: When the operation mode is the grid-connected mode, based on the active power feedback value and the active power feedback value, the inductor current i is obtained. L1 The 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 working mode and the battery state, including: When the working mode is the grid-connected power control charging mode and the grid power control discharging mode, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; The d-axis command value i * L1d and q-axis command value i * L1q Perform dq / abc transformation to obtain the inductor current i L1 abc three-phase reference value i * L1x , the differential mode feedback value i is converted into L1xDM With three-phase reference value i * L1x For comparison, the differential-mode modulation waves are respectively sent to the quasi-resonant controller QPR to obtain differential-mode modulation waves, and the differential-mode modulation waves are superimposed with the common-mode modulation waves to obtain three-phase modulation waves, and the energy storage converter is adjusted by the three-phase modulation waves.

5. The method for regulating the on-grid and off-grid converter according to claim 3, characterized in that: When the operation mode is the grid-connected mode, based on the active power feedback value and the active power feedback value, the inductor current i is obtained. L1 The 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 working mode and the battery state, including: When the working mode is the constant voltage charging mode and the energy storage battery is in the second state, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; Set the DC side voltage reference upper limit value V bat_ref_H and DC side voltage feedback value v bus_fb After comparison, it 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 , regulating the energy storage converter to trickle charge the energy storage battery; When the working mode is the suspended discharge mode and the energy storage battery is in the first state, the active power reference value P * After being compared with the active power feedback value P, it is sent to the outer loop PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Combine reactive power feedback value Q with reactive power reference value Q * After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q ; Set the DC side voltage reference upper limit value V bat_ref_H and DC side voltage feedback value v bus_fb After comparison, it 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 inverter to suspend discharging of the energy storage battery.

6. The method for regulating an on-grid and off-grid converter according to claim 3, characterized in that: In the case where the operation mode is an off-grid mode, the operation modes include: a load voltage control mode and a discharge stop mode; When the operation mode is off-grid mode, based on the voltage component v Lq and the voltage component v Ld , and the inductor current i is obtained L1 The 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 working mode and the battery state, including: When the working mode is the load voltage control mode and the energy storage battery is in the second state, the load voltage v L The d-axis reference value v * Ld With voltage component v Ld After comparison, it is sent to the load voltage PI controller to obtain the inductor current i L1 The d-axis command value i * L1d ; Set the load voltage v L The voltage component v Lq With q-axis reference value v * Lq After comparison, it is sent to the outer loop PI controller to obtain the inductor current i L1 The q-axis command value i * L1q , the q-axis command value i * L1q and the d-axis command value i * L1d After dq / abc coordinate transformation, the current is sent to the inner loop to compare the load voltage v L To exercise control; When the working 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 running.

7. The method for regulating an on-grid and off-grid converter according to claim 1, characterized in that: Before obtaining the working mode of the energy storage converter, the AC side working parameters and the battery state of the energy storage battery, the method further includes: When it is determined that the energy storage converter is switched from the grid-connected mode to the off-grid mode, the inverter-side filter inductor L f1 The current i L1 drops to 0, and controls the load voltage v of the AC load L Tracking the grid voltage v of the AC grid g , and controlling the grid-connected disconnecting switch in the grid-connected and off-grid switching device to be disconnected, and the energy storage converter is in island mode; When it is determined that the energy storage converter switches from the off-grid mode to the grid-connected mode, the load voltage v is controlled L Tracking grid voltage v g , close the grid-connected isolating switch, and the energy storage converter switches to the grid-connected current and DC side voltage control mode.

8. A regulating device for an on-grid and off-grid converter, characterized in that: An energy storage converter applied to a three-phase four-wire three-level system, the energy storage converter comprising a DC part, an inverter and an AC part connected in sequence, the AC part being used to connect to an AC power grid, and the AC part being provided with an on-grid and off-grid switching device on a side close to the AC power grid; The DC part includes an energy storage battery and a DC side filter capacitor connected in sequence, and the AC part includes an inverter side filter inductor, an AC side filter capacitor, a grid side filter inductor and an AC load; The device comprises: An acquisition module, configured to acquire, according to the working mode of the energy storage converter, an AC side working parameter of the energy storage converter corresponding to the working mode, wherein the working mode is determined based on the operation mode of the energy storage converter and the battery state of the energy storage battery, and the operation mode includes a grid-connected mode and an offline mode; A first processing module is used to convert the AC side working 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 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.

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, the regulation method of the grid-connected and off-grid converter according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the regulating method of the grid-connected and off-grid converter as claimed in any one of claims 1 to 7 is implemented.

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