Optical storage direct current bus voltage control method and device and nonvolatile storage medium

Abstract

The invention discloses an optical storage direct current bus voltage control method and device and a nonvolatile storage medium. The method comprises the following steps: acquiring the output power of the photovoltaic energy storage system; collecting an actual voltage value of a direct current bus connected with the photovoltaic energy storage system; correcting the actual voltage value of the direct-current bus to obtain a corrected voltage value of the direct-current bus; determining the control output power of the direct current bus according to the corrected voltage value; and adjusting the actual voltage value of the DC bus based on the control output power and the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus. The technical problem that the voltage is unstable due to the fact that the direct-current bus voltage is difficult to adjust accurately in real time at present is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic energy storage systems, and in particular to a photovoltaic energy storage DC bus voltage control method and device and a non-volatile storage medium. Background Art

[0002] As the penetration rate of renewable energy generation continues to increase, its impact on the stability of the power grid and the quality of power is becoming increasingly significant. In particular, when external conditions such as light intensity change, the output power of the photovoltaic storage system will also fluctuate, thereby affecting the stability of the DC bus voltage. Maintaining the stability of the DC bus voltage is crucial to ensure the reliable operation of the system and the quality of power. However, it is currently difficult to accurately adjust the voltage of the DC bus in real time, resulting in insufficient voltage stability.

[0003] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0004] The embodiments of the present invention provide a method and device for controlling a photovoltaic storage DC bus voltage and a non-volatile storage medium, so as to at least solve the technical problem that it is difficult to accurately adjust the DC bus voltage in real time, resulting in voltage instability.

[0005] According to one aspect of an embodiment of the present invention, a method for controlling the voltage of a photovoltaic-storage DC bus is provided, comprising: obtaining the output power of a photovoltaic energy storage system; collecting an actual voltage value of a DC bus connected to the photovoltaic energy storage system; correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus; determining a controlled output power of the DC bus based on the corrected voltage value; and adjusting the actual voltage value of the DC bus based on the controlled output power and the output power of the photovoltaic energy storage system to obtain a target voltage of the DC bus.

[0006] Optionally, obtaining the output power of the photovoltaic energy storage system includes: collecting the current value and voltage value of the photovoltaic energy storage system at the same time; and determining the output power of the photovoltaic energy storage system based on the current value and voltage value of the photovoltaic energy storage system.

[0007] Optionally, the actual voltage value of the DC bus is corrected to obtain a corrected voltage value of the DC bus, including: obtaining a target reference voltage value of the DC bus: generating an error signal based on the actual voltage value and the target reference voltage value; determining a correction signal based on a preset disturbance signal and the error signal, wherein the disturbance signal characterizes the influence of the DC bus and the photovoltaic energy storage system on the voltage value of the DC bus; based on the correction signal, correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus.

[0008] Optionally, obtaining a target reference voltage value of the DC bus includes: obtaining an initial reference voltage value of the DC bus; and correcting the initial reference voltage value based on a disturbance signal to obtain a target reference voltage value of the DC bus.

[0009] Optionally, based on the control output power and the output power of the photovoltaic energy storage system, the actual voltage value of the DC bus is adjusted to obtain a target voltage of the DC bus, including: determining a power difference between the control output power and the output power of the photovoltaic energy storage system; based on the power difference, adjusting the voltage of the DC bus by adjusting the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus.

[0010] Optionally, based on the power difference, the output power of the photovoltaic energy storage system is adjusted, including: generating an adjustment signal based on the power difference; adjusting the maximum power point of the photovoltaic energy storage system according to the adjustment signal to obtain a target maximum power point of the photovoltaic energy storage system; and adjusting the output power of the photovoltaic energy storage system based on the target maximum power point.

[0011] According to another aspect of an embodiment of the present invention, a photovoltaic energy storage DC bus voltage control device is also provided, including: an acquisition module, used to acquire the output power of the photovoltaic energy storage system; a collection module, used to collect the actual voltage value of the DC bus connected to the photovoltaic energy storage system; a correction module, used to correct the actual voltage value of the DC bus to obtain the corrected voltage value of the DC bus; a determination module, used to determine the control output power of the DC bus according to the corrected voltage value; an adjustment module, used to adjust the actual voltage value of the DC bus based on the control output power and the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus.

[0012] According to another aspect of an embodiment of the present invention, a non-volatile storage medium is provided, the non-volatile storage medium including a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute any one of the above-mentioned photovoltaic storage DC bus voltage control methods.

[0013] According to another aspect of the embodiments of the present invention, a computer device is provided, comprising a processor, the processor being used to run a program, wherein when the program is run, any one of the above-mentioned photovoltaic storage DC bus voltage control methods is executed.

[0014] According to another aspect of the embodiments of the present invention, there is further provided a computer program product, including a computer program, which implements any one of the above-mentioned photovoltaic energy storage DC bus voltage control methods when executed by a processor.

[0015] In the embodiment of the present invention, a photovoltaic energy storage DC bus voltage control method is adopted, by obtaining the output power of the photovoltaic energy storage system; collecting the actual voltage value of the DC bus connected to the photovoltaic energy storage system; correcting the actual voltage value of the DC bus to obtain the corrected voltage value of the DC bus; determining the controlled output power of the DC bus according to the corrected voltage value; adjusting the actual voltage value of the DC bus based on the controlled output power and the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus, thereby achieving the purpose of adjusting the voltage of the DC bus in real time and accurately, thereby realizing the technical effect of stabilizing the voltage, and further solving the technical problem that it is currently difficult to adjust the DC bus voltage in real time and accurately, resulting in voltage instability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A hardware structure block diagram of a computer terminal for implementing a method for controlling a photovoltaic storage DC bus voltage is shown;

[0018] Figure 2 It is a flow chart of a method for controlling a photovoltaic storage DC bus voltage according to an embodiment of the present invention;

[0019] Figure 3 is a control principle diagram of a photovoltaic storage DC bus voltage control method provided according to an optional embodiment of the present invention;

[0020] Figure 4 It is a control strategy principle diagram of maintaining DC bus voltage stability using a photovoltaic storage DC bus voltage control method ADRC according to an optional embodiment of the present invention;

[0021] Figure 5 It is a structural block diagram of a photovoltaic storage DC bus voltage control device provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] According to an embodiment of the present invention, a method embodiment of a photovoltaic storage DC bus voltage control method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0025] The method embodiment provided in the first embodiment of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 1 The hardware structure block diagram of a computer terminal for implementing a method for controlling the voltage of a photovoltaic storage DC bus is shown in FIG. Figure 1 As shown, the computer terminal 10 may include one or more (102a, 102b, ..., 102n are used to illustrate) processors (the processor may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 104 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the BUS bus), a network interface, a power supply and / or a camera. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations are shown.

[0026] It should be noted that the one or more processors and / or other data processing circuits described above may generally be referred to herein as "data processing circuits". The data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. In addition, the data processing circuit may be a single independent processing module, or may be incorporated in whole or in part into any of the other components in the computer terminal 10. As described in the embodiments of the present application, the data processing circuit acts as a processor control (e.g., selection of a variable resistor terminal path connected to an interface).

[0027] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the photovoltaic storage DC bus voltage control method in the embodiment of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, the photovoltaic storage DC bus voltage control method of the above-mentioned application program is realized. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computer terminal 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0028] The display may be, for example, a touch screen liquid crystal display (LCD) that enables a user to interact with a user interface of the computer terminal 10 .

[0029] Figure 2 FIG. 1 is a flow chart of a method for controlling a photovoltaic storage DC bus voltage according to an embodiment of the present invention. Figure 2 As shown, the method comprises the following steps:

[0030] Step S202, obtaining the output power of the photovoltaic energy storage system.

[0031] In this step, the output power acquisition of the photovoltaic energy storage system mainly depends on real-time monitoring and calculation of the operating status of the photovoltaic array and the energy storage device, which can be achieved through the following steps: Use voltage sensors and current sensors to collect the output voltage and current data of the photovoltaic array. These sensors are usually installed at the input end of the photovoltaic inverter to ensure the accuracy and real-time nature of the data. The voltage sensor measures the voltage of the photovoltaic array, while the current sensor measures the current of the photovoltaic array. For energy storage devices, it is necessary to collect the voltage and current data of the battery to understand the charging and discharging status of the battery. These data are collected by voltage sensors and current sensors, which can be installed at the output end of the battery or on the DC bus of the energy storage system. The collected voltage and current data are transmitted to a data processing unit, such as a microprocessor or a dedicated power electronic controller. These data processing units calculate the real-time output power of the photovoltaic array and the energy storage device.

[0032] Step S204, collecting the actual voltage value of the DC bus connected to the photovoltaic energy storage system.

[0033] In this step, the voltage of the DC bus connected to the photovoltaic energy storage system can be collected. Specifically, a sensor can be used, for example, a high-precision voltage sensor, such as a Hall effect sensor, a resistor divider or a photocoupler, which can measure the DC voltage and convert the voltage signal into a processable electrical signal. The voltage sensor can be installed on the DC bus between the photovoltaic energy storage system and the power grid to ensure that the contact between the sensor and the bus is good and can accurately reflect the voltage state of the bus.

[0034] Step S206, correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus.

[0035] In this step, the actual value of the DC bus voltage is corrected because there are uncertainties in the actual system, including model errors, parameter changes, and external disturbances. By correcting the actual value, these uncertainties can be estimated and compensated through control algorithms (such as active disturbance rejection control ADRC), thereby improving control accuracy and system stability.

[0036] Step S208: determining the controlled output power of the DC bus according to the corrected voltage value.

[0037] In this step, the controlled output power of the DC bus can be calculated according to the corrected voltage value. The controlled output power is determined according to the actual value of the corrected DC bus voltage, which is achieved through the closed-loop control logic in the power electronic system.

[0038] Step S210, based on the control output power and the output power of the photovoltaic energy storage system, the actual voltage value of the DC bus is adjusted to obtain a target voltage of the DC bus.

[0039] In this step, Figure 3 is a control principle diagram of a photovoltaic storage DC bus voltage control method according to an optional embodiment of the present invention, such as Figure 3 As shown in the figure, after the ADRC corrects the reference value and actual value of the DC bus voltage, the obtained control output is compared with the power generated by the photovoltaic storage, and then transmitted to the active loop of the virtual synchronous generator. By adjusting the power input from the photovoltaic storage to the grid, the DC bus voltage is controlled. The process of adjusting the actual voltage value of the DC bus to achieve the target voltage based on the control output power and the output power of the photovoltaic energy storage system is actually a dynamic adjustment process of closed-loop control. According to the control signal generated by the controller, the output power of the photovoltaic energy storage system is adjusted. The adjusted power output will affect the DC bus voltage, and this change needs to be monitored in real time. Through the feedback loop, the new DC bus voltage value is input into the control system again for the next round of error detection. This is an iterative process. The controller will continuously monitor the voltage error, generate control signals, and adjust the system power output until the error between the actual value and the target value of the DC bus voltage is minimized or controlled within a predetermined range. During the adjustment process, the control system needs to be able to handle various possible disturbances, such as changes in light intensity, temperature fluctuations, and grid load changes, to ensure the stability of the DC bus voltage. Active disturbance rejection controllers (such as ADRC) are able to observe and compensate for these disturbances in real time through their internal extended state observer (ESO) and nonlinear state error feedback (NLSEF) modules.

[0040] Among them, the basic components of ADRC include Extended State Observer (ESO) and Nonlinear State Error Feedback (NLSEF). Extended State Observer (ESO): ESO is responsible for real-time estimation and observation of disturbances in the system, including unknown external disturbances, internal parameter changes, and model uncertainty. Based on the input and output information of the system, ESO uses a nonlinear observation algorithm to estimate the disturbance and introduce it into the system model as a new state, thereby converting the original system into a more controllable form. Nonlinear State Error Feedback (NLSEF): The NLSEF module calculates the control signal of the system based on the disturbance estimation results observed by ESO. It is a control method based on state feedback, but it introduces nonlinear functions, which can more effectively handle nonlinear and uncertain systems. The design of NLSEF usually includes a nonlinear function and a linear controller. Through the combination of the two, a control signal that can quickly respond to disturbances and restore the system state can be generated. Based on the control output power and the output power of the photovoltaic energy storage system, the closed-loop control system can adjust the DC bus voltage in real time to ensure that it is stable near the target value, thereby improving the power quality and the overall performance of the power electronics system.

[0041] Figure 4 FIG. 1 is a schematic diagram of a control strategy for maintaining a stable DC bus voltage according to a photovoltaic storage DC bus voltage control method ADRC provided in an optional embodiment of the present invention. Figure 4 As shown, the DC bus voltage reference value DC bus voltage tracking signal of ESO with ADRC The comparison value is input into NLSEF and the control signal is output . Control signal Compare with the observed signal of ESO, and transmit the compensation value to ESO and virtual synchronous generator to obtain the DC bus voltage value .

[0042] Through the above steps, the purpose of adjusting the voltage of the DC bus in real time and accurately is achieved, thereby realizing the technical effect of stabilizing the voltage, and further solving the technical problem that it is currently difficult to accurately adjust the DC bus voltage in real time, resulting in unstable voltage.

[0043] As an optional embodiment, obtaining the output power of the photovoltaic energy storage system includes: collecting the current value and voltage value of the photovoltaic energy storage system at the same time; and determining the output power of the photovoltaic energy storage system based on the current value and voltage value of the photovoltaic energy storage system.

[0044] Optionally, the current and voltage values ​​of the photovoltaic energy storage system at the same time can be collected, and then the output power of the photovoltaic energy storage system can be determined according to the relevant formula. exist The values ​​of the moments are as follows:

[0045]

[0046] in, For the solar storage system The voltage value corresponding to the output power of the photovoltaic storage at the moment is For the solar storage system The current value corresponding to the photovoltaic storage output power at that moment.

[0047] As an optional embodiment, the actual voltage value of the DC bus is corrected to obtain a corrected voltage value of the DC bus, including: obtaining a target reference voltage value of the DC bus: generating an error signal based on the actual voltage value and the target reference voltage value; determining a correction signal based on a preset disturbance signal and an error signal, wherein the disturbance signal characterizes the influence of the DC bus and the photovoltaic energy storage system on the voltage value of the DC bus; based on the correction signal, correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus.

[0048] Optionally, the target reference value of the DC bus can be obtained, and then an error signal is generated based on the actual voltage value and the target reference voltage value. The error signal is used to characterize the difference between the current system state and the desired state, and is the basis for the control algorithm to adjust. In ADRC, the disturbance signal often includes various uncertainties and disturbances inside and outside the system, such as power grid fluctuations, changes in light intensity, etc. These disturbance signals are observed and estimated in real time through the extended state observer (ESO) module in ADRC. ESO can estimate disturbances and uncertainties as new states of the system in real time, thereby enhancing the adaptability and robustness of the control system. The observed disturbance signal is combined with the error signal to analyze the impact of both on the system. The disturbance signal provides information about the instability of the system, while the error signal directly reflects the deviation of the control target. Based on the disturbance signal and the error signal, a correction signal is generated through the nonlinear state error feedback (NLSEF) module of ADRC. The NLSEF module calculates the control signal through a nonlinear function based on the disturbance estimate and the error signal. The control signal is intended to compensate for the disturbance and reduce the error, thereby achieving the purpose of stabilizing the DC bus voltage. The correction signal (i.e., control signal) is applied to the photovoltaic energy storage system to adjust its output power to change the voltage on the DC bus.

[0049] Specifically, determining the controlled output power of the DC bus to achieve the target voltage value is achieved through a closed-loop control algorithm, of which active disturbance rejection control (ADRC) is an effective option. The following are the specific steps for determining the controlled output power of the DC bus based on ADRC:

[0050] Error detection: First, measure the actual voltage value of the DC bus in real time, compare it with the set target voltage value, and calculate the voltage error. The voltage error reflects the deviation between the current voltage and the target voltage, and is the basis for the control algorithm to adjust the power.

[0051] Control signal generation: The voltage error is input into the extended state observer (ESO) of ADRC, which can observe and estimate the disturbances inside and outside the system in real time, including load changes, grid voltage fluctuations, light intensity changes, etc. At the same time, the error signal is input into the nonlinear state error feedback (NLSEF) module, which generates the control signal through nonlinear function calculation based on the error signal and the observation results of ESO.

[0052] Power regulation: The generated control signal is used to regulate the output power of the photovoltaic energy storage system. This may involve adjusting the maximum power point tracking (MPPT) mechanism, changing the charge and discharge state of the energy storage battery, adjusting the output current of the inverter, etc., to increase or decrease the power fed into the DC bus. The size and direction of the control signal depends on the size and direction of the voltage error, as well as the setting of the internal parameters of the ADRC.

[0053] System response monitoring: The adjusted power output will affect the DC bus voltage. The control system needs to monitor this change in real time, input the new DC bus voltage value into the ADRC again, and perform the next round of error detection and control signal generation to form a closed-loop feedback mechanism.

[0054] Iterative correction: This is a continuous iterative process until the error between the actual value of the DC bus voltage and the target voltage value is minimized or controlled within a predetermined range. ADRC can respond quickly to voltage changes and achieve precise power regulation through its unique disturbance observation and compensation capabilities.

[0055] Among them, the control strategy formula of the active disturbance rejection controller is as follows:

[0056]

[0057] in, is the angular velocity of the virtual synchronous generator, is the rated angular velocity, It is the control signal output by ADRC. is the active power output by the virtual synchronous generator, is the inertia of the virtual synchronous generator, is the damping of the virtual synchronous generator.

[0058] The ADRC includes the NLSEF module and the ESO module, where the NLSEF module is used to perform nonlinear calculations on the error signal, and the ESO module is used to expand the nonlinear factors of the DC bus voltage, model uncertainty, and internal and external disturbances into a new state and perform real-time observations. The calculation formula of the ESO module is:

[0059]

[0060] in, is the tracking signal of the DC bus voltage, is the total internal and external disturbance of the system, and is the ESO gain, is the nonlinear factor, is the filtering factor; .

[0061] The calculation formula of the NLSEF module is: ,in, is the gain of ADRC, is the compensation term of the system, is the nonlinear factor, is the filtering factor, , .

[0062] Through the above steps, ADRC can generate control signals through a closed-loop control mechanism based on the real-time measured DC bus voltage value, thereby adjusting the output power of the photovoltaic energy storage system, and ultimately achieving the purpose of stabilizing the DC bus voltage near the target value. This process reflects the application of intelligent control algorithms in modern power electronic systems, which can effectively respond to internal and external disturbances in the system and improve power quality and system stability.

[0063] As an optional embodiment, obtaining a target reference voltage value of the DC bus includes: obtaining an initial reference voltage value of the DC bus; and correcting the initial reference voltage value based on a disturbance signal to obtain a target reference voltage value of the DC bus.

[0064] Optionally, correction of the reference value of the DC voltage is necessary in the control of power electronic systems, because power electronic systems (such as photovoltaic energy storage systems, electric vehicle charging stations, etc.) are affected by various disturbances and uncertainties, such as light intensity, temperature, grid fluctuations, load changes, etc. These disturbances can directly or indirectly affect the stability of the DC bus voltage. In order to offset the effects of these disturbances, it is necessary to observe and estimate the disturbances through control strategies (such as active disturbance rejection control ADRC), and then correct the reference voltage value, that is, to correct it according to the disturbance signal to adapt to the changes in the disturbance and achieve more stable voltage control. By correcting the reference value of the DC voltage, the power electronic system can better cope with various uncertainties and dynamic changes, maintain stable operation, improve control accuracy and system performance, while ensuring safety and reliability. This is crucial in modern power electronic systems and renewable energy technologies, and helps to achieve more efficient and stable power conversion and management.

[0065] As an optional embodiment, based on the control output power and the output power of the photovoltaic energy storage system, the actual voltage value of the DC bus is adjusted to obtain the target voltage of the DC bus, including: determining the power difference between the control output power and the output power of the photovoltaic energy storage system; based on the power difference, adjusting the voltage of the DC bus by adjusting the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus.

[0066] Optionally, the difference between the controlled output power and the real-time output power of the photovoltaic energy storage system is determined, and the output power of the photovoltaic energy storage system is adjusted based on the difference to adjust the DC bus voltage and reach the target voltage value. Specifically, the controlled output power is compared with the real-time output power of the photovoltaic energy storage system to calculate the power difference. If the controlled output power is greater than the real-time output power, it indicates that the power output of the photovoltaic energy storage system needs to be increased; otherwise, the power output needs to be reduced. Based on the power difference, the adjustment direction and amplitude of the output power of the photovoltaic energy storage system are determined. For example, if the power needs to be increased, the maximum power point tracking (MPPT) strategy of the photovoltaic array can be adjusted, or the discharge state and discharge depth of the energy storage battery can be changed; if the power needs to be reduced, it may be necessary to reduce the output of the photovoltaic array or increase the charge state of the battery.

[0067] As an optional embodiment, the output power of the photovoltaic energy storage system is adjusted based on the power difference, including: generating an adjustment signal based on the power difference; adjusting the maximum power point of the photovoltaic energy storage system according to the adjustment signal to obtain a target maximum power point of the photovoltaic energy storage system; and adjusting the output power of the photovoltaic energy storage system based on the target maximum power point.

[0068] Optionally, the output power of the photovoltaic energy storage system is adjusted based on the power difference to maintain the DC bus voltage stability. Specifically, the following steps can be followed: First, the controlled output power obtained according to the control strategy (such as active disturbance rejection control ADRC) is compared with the current actual output power of the photovoltaic energy storage system to calculate the power difference. The power difference can be quantified as the power level required to adjust to maintain the target voltage. Based on the calculated power difference, an adjustment signal is generated through a control algorithm (such as a PID controller, a fuzzy controller, ADRC, etc.). The adjustment signal contains the direction and magnitude of the adjustment, which guides the photovoltaic energy storage system on how to change its output power in response to the power difference. The adjustment signal is used to adjust the operating point of the photovoltaic energy storage system. In photovoltaic systems, this process usually involves the adjustment of the maximum power point tracking (MPPT) strategy. The MPPT algorithm (such as the perturbation observation method and the incremental conductance method) recalculates the optimal operating point of the photovoltaic array based on the adjustment signal to achieve a new target maximum power point. This target maximum power point is determined based on the current power difference, light, temperature, and system status. Having determined the target maximum power point, the PV energy storage system can adjust the control parameters of its converter, such as the duty cycle of the DC-DC converter, to ensure that the PV array operates at the new maximum power point. In an energy storage system, this may involve adjusting the charge or discharge state of the battery to increase or decrease the power provided by the system to the DC bus. In addition, if the system includes an inverter, the control parameters of the inverter may also need to be adjusted to inject enough power into the grid or absorb power from the grid. The adjusted output power of the PV energy storage system will affect the DC bus voltage. Through a closed-loop feedback mechanism, the voltage of the DC bus is continuously measured, compared with the target voltage value, and the power difference is calculated again. Then, the above steps (generating an adjustment signal, determining the target maximum power point, and adjusting the output power) are repeated until the DC bus voltage stabilizes near the target value.

[0069] Here is a specific example:

[0070] S1: Sample the voltage and current of the photoelectric storage array at the same time;

[0071] S2: Use the voltage and current of S1 to calculate the real-time output power of the solar energy storage system;

[0072] S3: sampling the DC bus voltage;

[0073] S4: After the DC bus voltage reference value and actual value are corrected based on ADRC, the obtained control output is compared with the power generated by the photovoltaic storage and transmitted to the active loop of the virtual synchronous generator. By adjusting the power input from the photovoltaic storage to the grid, the DC bus voltage is controlled.

[0074] S5: Through the above-mentioned grid-connected virtual synchronous generator DC bus voltage control strategy, the maximum power point of the photovoltaic energy storage grid-connected virtual synchronous generator is released to maintain the stability of the DC bus voltage.

[0075] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0076] Through the description of the above implementation methods, those skilled in the art can clearly understand that the photovoltaic storage DC bus voltage control method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course it 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 the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD), and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods of various embodiments of the present invention.

[0077] According to an embodiment of the present invention, a photovoltaic storage DC bus voltage control device for implementing the photovoltaic storage DC bus voltage control method is also provided. Figure 5 is a structural block diagram of a photovoltaic storage DC bus voltage control device provided according to an embodiment of the present invention, such as Figure 5 As shown, the photovoltaic storage DC bus voltage control device includes: an acquisition module 502, a collection module 504, a correction module 506, a determination module 508 and an adjustment module 510. The photovoltaic storage DC bus voltage control device is described below.

[0078] The acquisition module 502 is used to acquire the output power of the photovoltaic energy storage system.

[0079] The acquisition module 504 is connected to the acquisition module 502 and is used to acquire the actual voltage value of the DC bus connected to the photovoltaic energy storage system.

[0080] The correction module 506 is connected to the acquisition module 504 and is used to correct the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus.

[0081] The determination module 508 is connected to the correction module 506 and is used to determine the controlled output power of the DC bus according to the corrected voltage value.

[0082] The adjustment module 510 is connected to the determination module 508 and is used to adjust the actual voltage value of the DC bus based on the control output power and the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus.

[0083] It should be noted that the acquisition module 502, the acquisition module 504, the correction module 506, the determination module 508 and the adjustment module 510 correspond to steps S202 to S210 in the embodiment, and the examples and application scenarios implemented by the multiple modules and the corresponding steps are the same, but are not limited to the contents disclosed in the above embodiment. It should be noted that the above modules, as part of the device, can be run in the computer terminal 10 provided in the embodiment.

[0084] An embodiment of the present invention may provide a computer device. Optionally, in this embodiment, the computer device may be located in at least one network device among multiple network devices of a computer network. The computer device includes a memory and a processor.

[0085] Among them, the memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the photovoltaic storage DC bus voltage control method and device in the embodiment of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, realizing the above-mentioned photovoltaic storage DC bus voltage control method. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computer terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0086] The processor can call the information and application programs stored in the memory through the transmission device to execute the following steps: obtain the output power of the photovoltaic energy storage system; collect the actual voltage value of the DC bus connected to the photovoltaic energy storage system; correct the actual voltage value of the DC bus to obtain the corrected voltage value of the DC bus; determine the controlled output power of the DC bus based on the corrected voltage value; adjust the actual voltage value of the DC bus based on the controlled output power and the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus.

[0087] Optionally, the processor may also execute the program code of the following steps: obtaining the output power of the photovoltaic energy storage system, including: collecting the current value and voltage value of the photovoltaic energy storage system at the same time; and determining the output power of the photovoltaic energy storage system based on the current value and voltage value of the photovoltaic energy storage system.

[0088] Optionally, the processor may also execute the following steps of program code: correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus, including: obtaining a target reference voltage value of the DC bus: generating an error signal based on the actual voltage value and the target reference voltage value; determining a correction signal based on a preset disturbance signal and an error signal, wherein the disturbance signal characterizes the influence of the DC bus and the photovoltaic energy storage system on the voltage value of the DC bus; and correcting the actual voltage value of the DC bus based on the correction signal to obtain a corrected voltage value of the DC bus.

[0089] Optionally, the processor may also execute the following program code: obtaining a target reference voltage value of the DC bus, including: obtaining an initial reference voltage value of the DC bus; and correcting the initial reference voltage value based on a disturbance signal to obtain a target reference voltage value of the DC bus.

[0090] Optionally, the processor may also execute the following program code: based on the control output power and the output power of the photovoltaic energy storage system, adjusting the actual voltage value of the DC bus to obtain the target voltage of the DC bus, including: determining the power difference between the control output power and the output power of the photovoltaic energy storage system; based on the power difference, adjusting the voltage of the DC bus by adjusting the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus.

[0091] Optionally, the processor may also execute program code for the following steps: adjusting the output power of the photovoltaic energy storage system based on the power difference, including: generating an adjustment signal based on the power difference; adjusting the maximum power point of the photovoltaic energy storage system according to the adjustment signal to obtain a target maximum power point of the photovoltaic energy storage system; and adjusting the output power of the photovoltaic energy storage system based on the target maximum power point.

[0092] By adopting the embodiment of the present invention, a method for controlling the voltage of a photovoltaic-storage DC bus is provided, which obtains the output power of the photovoltaic energy storage system; collects the actual voltage value of the DC bus connected to the photovoltaic energy storage system; corrects the actual voltage value of the DC bus to obtain the corrected voltage value of the DC bus; determines the controlled output power of the DC bus according to the corrected voltage value; and adjusts the actual voltage value of the DC bus based on the controlled output power and the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus, thereby achieving the purpose of adjusting the voltage of the DC bus in real time and accurately, thereby realizing the technical effect of stabilizing the voltage, and further solving the technical problem that it is currently difficult to adjust the DC bus voltage in real time and accurately, resulting in voltage instability.

[0093] A person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a non-volatile storage medium, and the storage medium may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0094] The embodiment of the present invention further provides a non-volatile storage medium. Optionally, in this embodiment, the non-volatile storage medium can be used to store the program code executed by the photovoltaic energy storage DC bus voltage control method provided in the above embodiment.

[0095] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group.

[0096] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: obtaining the output power of the photovoltaic energy storage system; collecting the actual voltage value of a DC bus connected to the photovoltaic energy storage system; correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus; determining the controlled output power of the DC bus based on the corrected voltage value; and adjusting the actual voltage value of the DC bus based on the controlled output power and the output power of the photovoltaic energy storage system to obtain a target voltage of the DC bus.

[0097] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing the following steps: obtaining the output power of the photovoltaic energy storage system, including: collecting the current value and voltage value of the photovoltaic energy storage system at the same time; based on the current value and voltage value of the photovoltaic energy storage system, determining the output power of the photovoltaic energy storage system.

[0098] Optionally, in this embodiment, the non-volatile storage medium is configured to store program codes for executing the following steps: correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus, including: obtaining a target reference voltage value of the DC bus: generating an error signal based on the actual voltage value and the target reference voltage value; determining a correction signal based on a preset disturbance signal and an error signal, wherein the disturbance signal characterizes the influence of the DC bus and the photovoltaic energy storage system on the voltage value of the DC bus; based on the correction signal, correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus.

[0099] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing the following steps: obtaining a target reference voltage value of the DC bus, including: obtaining an initial reference voltage value of the DC bus; based on a disturbance signal, correcting the initial reference voltage value to obtain the target reference voltage value of the DC bus.

[0100] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing the following steps: based on the control output power and the output power of the photovoltaic energy storage system, adjusting the actual voltage value of the DC bus to obtain a target voltage of the DC bus, including: determining a power difference between the control output power and the output power of the photovoltaic energy storage system; based on the power difference, adjusting the voltage of the DC bus by adjusting the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus.

[0101] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for executing the following steps: adjusting the output power of the photovoltaic energy storage system based on the power difference, including: generating an adjustment signal based on the power difference; adjusting the maximum power point of the photovoltaic energy storage system according to the adjustment signal to obtain a target maximum power point of the photovoltaic energy storage system; and adjusting the output power of the photovoltaic energy storage system based on the target maximum power point.

[0102] An embodiment of the present invention further provides a computer program product, including a computer program. Optionally, in this embodiment, when the computer program is executed by a processor, it can achieve: obtaining the output power of the photovoltaic energy storage system; collecting the actual voltage value of a DC bus connected to the photovoltaic energy storage system; correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus; determining the controlled output power of the DC bus based on the corrected voltage value; and adjusting the actual voltage value of the DC bus based on the controlled output power and the output power of the photovoltaic energy storage system to obtain a target voltage of the DC bus.

[0103] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0104] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0105] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0106] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0107] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0108] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0109] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for controlling the voltage of a photovoltaic energy storage DC bus, characterized in that: include: Obtain the output power of the photovoltaic energy storage system; Collecting an actual voltage value of a DC bus connected to the photovoltaic energy storage system; Correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus; Determining a controlled output power of the DC bus according to the corrected voltage value; Based on the controlled output power and the output power of the photovoltaic energy storage system, the actual voltage value of the DC bus is adjusted to obtain a target voltage of the DC bus.

2. The method according to claim 1, characterized in that The obtaining of the output power of the photovoltaic energy storage system comprises: Collecting the current value and voltage value of the photovoltaic energy storage system at the same time; Based on the current value and the voltage value of the photovoltaic energy storage system, the output power of the photovoltaic energy storage system is determined.

3. The method according to claim 1, characterized in that: The correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus includes: Get the target reference voltage value of the DC bus: generating an error signal based on the actual voltage value and the target reference voltage value; Determine a correction signal based on a preset disturbance signal and the error signal, wherein the disturbance signal represents the influence of the DC bus and the photovoltaic energy storage system on the voltage value of the DC bus; Based on the correction signal, the actual voltage value of the DC bus is corrected to obtain a corrected voltage value of the DC bus.

4. The method according to claim 3, characterized in that: The obtaining of the target reference voltage value of the DC bus includes: Obtaining an initial reference voltage value of the DC bus; Based on the disturbance signal, the initial reference voltage value is corrected to obtain a target reference voltage value of the DC bus.

5. The method according to claim 1, characterized in that The step of adjusting the actual voltage value of the DC bus based on the controlled output power and the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus includes: Determining a power difference between the controlled output power and the output power of the photovoltaic energy storage system; Based on the power difference, the voltage of the DC bus is adjusted by adjusting the output power of the photovoltaic energy storage system to obtain a target voltage of the DC bus.

6. The method according to claim 5, characterized in that The step of adjusting the output power of the photovoltaic energy storage system based on the power difference includes: generating an adjustment signal based on the power difference; According to the adjustment signal, adjusting the maximum power point of the photovoltaic energy storage system to obtain a target maximum power point of the photovoltaic energy storage system; Based on the target maximum power point, the output power of the photovoltaic energy storage system is adjusted.

7. A photovoltaic energy storage DC bus voltage control device, characterized in that: include: An acquisition module, used to acquire the output power of the photovoltaic energy storage system; A collection module, used to collect the actual voltage value of the DC bus connected to the photovoltaic energy storage system; A correction module, used for correcting the actual voltage value of the DC bus to obtain a corrected voltage value of the DC bus; A determination module, used to determine the controlled output power of the DC bus according to the corrected voltage value; The adjustment module is used to adjust the actual voltage value of the DC bus based on the controlled output power and the output power of the photovoltaic energy storage system to obtain the target voltage of the DC bus.

8. A non-volatile storage medium, characterized in that: The non-volatile storage medium includes a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute the photovoltaic storage DC bus voltage control method described in any one of claims 1 to 6.

9. A computer device, characterized in that: include: Memory and processor, The memory stores a computer program; The processor is used to execute the computer program stored in the memory, and when the computer program is running, the processor executes the photovoltaic energy storage DC bus voltage control method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the photovoltaic energy storage DC bus voltage control method described in any one of claims 1 to 6 is implemented.

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