Photovoltaic power generation control system, control method, equipment, medium and product
By combining photovoltaic arrays with DC-DC boost converters, DC bus capacitors, DC-AC inverters, and LCL filters, along with multi-mode control and PI regulators, the problem of traditional photovoltaic power generation systems being unable to meet grid demands under high penetration rates has been solved. This enables photovoltaic power plants to actively participate in the grid, improving grid stability and security.
Patent Information
- Application Number
- CN202511237608.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2025-11-18
AI Technical Summary
Traditional photovoltaic power generation systems cannot meet the requirements for safe, stable and efficient operation of the power grid under high penetration rates. In particular, the inherent volatility and uncontrollability of photovoltaic systems pose challenges to the power grid when photovoltaic penetration is high.
The photovoltaic array is sequentially connected to a DC-DC boost converter, a DC bus capacitor, a DC-AC inverter, and an LCL filter. Combined with the front-end DC/DC control module and the back-end DC/AC control module, multi-mode operation control of the photovoltaic array is realized, including maximum power point tracking, power limiting, power reserve, and power change rate control. With the help of a PI regulator and pulse width modulation signal, the photovoltaic output power is precisely regulated.
It enables photovoltaic power plants to flexibly respond to grid demands, improves grid stability and security, ensures grid-connected power quality, reduces reactive power losses, and promotes the consumption of a high proportion of renewable energy.
Smart Images
Figure CN120978853A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of photovoltaic power generation technology, and in particular to a photovoltaic power generation control system, control method, equipment, medium and product. Background Technology
[0002] As a clean and renewable energy source, photovoltaic (PV) power generation has experienced explosive growth globally in recent years. With the improvement in PV module efficiency and the continuous decline in cost, large-scale PV power plants and distributed PV systems are being connected to the grid at an unprecedented rate. This rapid growth has brought about a significant change: the penetration rate of PV in the grid, that is, the proportion of PV power generation in the total grid load, has increased significantly. In some regional grids or during specific periods, PV has even become the primary source of electricity.
[0003] The core objective of traditional photovoltaic (PV) power generation system design is to maximize power generation, and its core control strategy is maximum power point tracking (MPPT). The MPPT controller continuously adjusts the operating point of the PV array to ensure it always operates at the point that outputs maximum power under current sunlight and temperature conditions. This approach is efficient and reasonable when PV penetration is low because it maximizes the utilization of solar energy resources.
[0004] However, as photovoltaic (PV) penetration in the power grid reaches a high level, its inherent volatility and uncontrollability begin to pose serious challenges to the safe, stable, and economical operation of the grid. With high PV penetration, the traditional MPPT (Maximum Power Generation Platform) model, which only pursues maximum power generation, can no longer meet the needs of modern power grids for safe, stable, and efficient operation. The power grid has placed clear requirements on PV power plants for flexible power output to enable active support and participation in ancillary services. Summary of the Invention
[0005] The purpose of this application is to provide a photovoltaic power generation control system, control method, equipment, medium and product that can realize the transformation of photovoltaic power plants from passive power generation units to active grid participants, improve grid stability and security, and promote the consumption of a high proportion of renewable energy.
[0006] To achieve the above objectives, this application provides the following solution:
[0007] In one aspect, this application provides a photovoltaic power generation control system. The photovoltaic array is connected to the power grid sequentially via a DC-DC boost converter, a DC bus capacitor, a DC-AC inverter, and an LCL filter. The DC-DC boost converter boosts the output voltage of the photovoltaic array, the DC bus capacitor smooths voltage fluctuations at the output of the DC-DC boost converter, the DC-AC inverter converts DC power into AC power compatible with the power grid, and the LCL filter removes high-frequency noise from the output voltage of the DC-AC inverter. The photovoltaic power generation control system includes a front-end DC / DC control module and a back-end DC / AC control module. The front-end DC / DC control module determines the operating mode of the photovoltaic array based on its maximum available power, actual output power, and grid-side power. The first PI regulator adjusts the pulse duty cycle according to the photovoltaic array's operating mode, generates a pulse width modulation signal, and controls the DC-DC boost converter. The photovoltaic array's operating modes include: maximum power point tracking mode, power limiting control mode, power reserve control mode, and power rate of change control mode. The subsequent DC / AC control module performs transient power suppression based on the grid-side power and the photovoltaic array's actual output power, generates an additional reference voltage for the DC bus, and then uses a second PI regulator to perform PI regulation based on the error value between the DC bus reference voltage and the additional reference voltage and DC bus voltage. Based on the output of the second PI regulator and the grid-side voltage phase signal, voltage signal, and current signal, a space vector pulse width modulation signal is generated to control the DC-AC inverter.
[0008] Optionally, the front-end DC / DC control module includes: a maximum available power prediction unit, a photovoltaic output power calculation unit, an operating mode determination unit, a first PI regulator, and a pulse width modulation generator; the maximum available power prediction unit is used to predict the maximum available power of the photovoltaic array in real time based on environmental monitoring data and historical output power data; the photovoltaic output power calculation unit is used to calculate the actual output power of the photovoltaic array based on the voltage and current signals on the output side of the photovoltaic array; the operating mode determination unit is used to determine the operating mode of the photovoltaic array based on the maximum available power of the photovoltaic array, the actual output power of the photovoltaic array, and the grid-side power; the first PI regulator is used to perform PI regulation according to the operating mode of the photovoltaic array, adjust the pulse duty cycle, and generate a pulse width modulation signal through the pulse width modulation generator to realize the control of the DC-DC boost converter.
[0009] Optionally, the downstream DC / AC control module includes: a grid-side power calculation unit, a transient power suppression control unit, a second PI regulator, a phase-locked loop unit, a current controller, and a space vector pulse width modulation generator; the grid-side power calculation unit is used to calculate the grid-side power based on the grid-side voltage and current signals; the transient power suppression control unit is used to perform transient power suppression based on the grid-side power and the actual output power of the photovoltaic array, and generate an additional reference voltage for the DC bus; the second PI regulator is used to perform PI regulation based on the error value between the DC bus reference voltage and the additional reference voltage and DC bus voltage; the phase-locked loop unit is used to determine the voltage phase signal based on the grid-side voltage signal; the current controller is used to generate a control signal based on the output of the second PI regulator and the grid-side voltage phase signal, voltage signal, and current signal, and generates a space vector pulse width modulation signal through the space vector pulse width modulation generator to achieve control of the DC-AC inverter.
[0010] Optionally, the maximum power point tracking mode controls the photovoltaic array to output maximum power under any environmental conditions; the power limiting control mode controls the actual output power of the photovoltaic array and limits the actual output power of the photovoltaic array to not exceed a preset power threshold; the power reserve control mode adjusts the actual output power of the photovoltaic array to be lower than the maximum available power and reserves a certain amount of power to cope with frequency events or voltage fluctuations in the power grid; and the power change rate control mode limits the change rate of the actual output power of the photovoltaic array to not exceed a preset change rate threshold.
[0011] Secondly, this application provides a photovoltaic power generation control method, wherein the photovoltaic array is connected to the power grid in sequence through a DC-DC boost converter, a DC bus capacitor, a DC-AC inverter, and an LCL filter; the DC-DC boost converter is used to boost the output voltage of the photovoltaic array, the DC bus capacitor is used to smooth the voltage fluctuations of the output of the DC-DC boost converter, the DC-AC inverter is used to convert the DC power into AC power compatible with the power grid, and the LCL filter is used to filter out high-frequency noise in the output voltage of the DC-AC inverter.
[0012] The photovoltaic power generation control method includes the following steps:
[0013] The operating mode of the photovoltaic array is determined based on its maximum available power, actual output power, and grid-side power. The operating modes of the photovoltaic array include: maximum power point tracking (MPPT), power limiting control, power reserve control, and power rate of change control.
[0014] The first PI regulator adjusts the pulse duty cycle according to the working mode of the photovoltaic array, generates a pulse modulation signal, and controls the DC-DC boost converter.
[0015] Transient power suppression is performed based on the grid-side power and the actual output power of the photovoltaic array to generate an additional reference voltage for the DC bus.
[0016] The second PI regulator performs PI regulation based on the error value between the DC bus reference voltage and the DC bus additional reference voltage and the DC bus voltage.
[0017] Based on the output of the second PI regulator and the voltage phase signal, voltage signal, and current signal from the grid side, a space vector pulse modulation signal is generated to control the DC-AC inverter.
[0018] Optionally, before determining the operating mode of the photovoltaic array based on the maximum available power of the photovoltaic array, the actual output power of the photovoltaic array, and the grid-side power, the photovoltaic power generation control method further includes the following steps:
[0019] Based on environmental monitoring data and historical output power data, the maximum available power of the photovoltaic array is predicted in real time.
[0020] The actual output power of the photovoltaic array is calculated based on the voltage and current signals at the output side of the photovoltaic array.
[0021] Calculate the grid-side power based on the voltage and current signals from the grid side.
[0022] Optionally, before generating a space vector pulse modulation signal based on the output of the second PI regulator and the voltage phase signal, voltage signal, and current signal from the grid side, and controlling the DC-AC inverter, the photovoltaic power generation control method further includes:
[0023] The voltage phase signal on the grid side is determined based on the voltage signal on the grid side.
[0024] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the photovoltaic power generation control method described above.
[0025] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the photovoltaic power generation control method described above.
[0026] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the photovoltaic power generation control method described above.
[0027] According to the specific embodiments provided in this application, the following technical effects are disclosed:
[0028] This application provides a photovoltaic power generation control system, control method, equipment, medium, and product. In this photovoltaic power generation control system, for a photovoltaic array connected to the grid sequentially via a DC-DC boost converter, a DC bus capacitor, a DC-AC inverter, and an LCL filter, the front-end DC / DC control module determines the photovoltaic array's operating mode based on the array's maximum available power, actual output power, and grid-side power. A first PI regulator adjusts the pulse duty cycle according to the photovoltaic array's operating mode, generating a pulse width modulation (PWM) signal to control the DC-DC boost converter. By determining the operating mode, maximum power point tracking (improving solar energy utilization), power limiting (avoiding output exceeding grid capacity), power reserve (reserving power for rapid grid response), and power rate control (reducing the impact of power surges on the grid) can be achieved. The first PI regulator and the PWM signal... The combination of these two technologies enables precise power control, ensuring flexible photovoltaic output response to grid demands. The downstream DC / AC control module performs transient power suppression based on grid power and the actual output power of the photovoltaic array, generating an additional reference voltage for the DC bus. Then, a second PI regulator performs PI adjustment based on the error between the DC bus reference voltage, the additional reference voltage, and the DC bus voltage. Based on the output of the second PI regulator and the grid-side voltage phase, voltage, and current signals, a space vector pulse width modulation (SVM) signal is generated to control the DC-AC inverter. Transient power suppression buffers excessive pulsating energy, suppresses transient power surges, avoids severe fluctuations in DC bus voltage, and improves system transient stability. The second PI regulation, combined with the SVM signal and grid phase information, ensures inverter output synchronization with the grid, reducing reactive power losses and guaranteeing grid-connected power quality. Attached Figure Description
[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0030] Figure 1 This is a schematic diagram of a photovoltaic power generation control system provided in an embodiment of this application.
[0031] Figure 2 This is a schematic diagram of the front-end DC / DC control flow of a photovoltaic power generation control system provided in an embodiment of this application.
[0032] Figure 3 This is a schematic diagram of the downstream DC / AC control process of a photovoltaic power generation control system provided in one embodiment of this application.
[0033] Figure 4 This is a flowchart of a photovoltaic power generation control method provided in an embodiment of this application.
[0034] Figure 5 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation
[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0036] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0037] This application provides a photovoltaic power generation control system. In one exemplary embodiment, such as... Figure 1 As shown, the photovoltaic array PV passes through a DC-DC boost converter and a DC bus capacitor C in sequence. dc The DC-AC inverter and LCL filter are connected to the power grid. The photovoltaic array (PV) is the system's energy source, consisting of multiple photovoltaic cells used to convert solar energy into electrical energy. After boosting and inversion, the AC power converted by the DC-AC inverter is transmitted to users or the public power grid for user consumption or grid-connected power generation.
[0038] A DC-DC boost converter is used to increase the output voltage (V) of a photovoltaic array (PV). pv The DC-DC boost converter in photovoltaic systems typically uses a boost converter to increase the DC voltage from a lower voltage to a higher voltage. A boost converter consists of a switching element, an inductor, a diode, and a capacitor. When the switching element is on, the inductor stores energy; when the switching element is off, the energy in the inductor is transferred to the output through the diode, thus boosting the voltage. The capacitor smooths the output voltage and reduces ripple. The converter is controlled by a pulse-width modulation (PWM) signal to regulate the output voltage of the photovoltaic array. The DC bus capacitor C... dcUsed to smooth voltage fluctuations at the output of a DC-DC boost converter; a DC-AC inverter is used to convert direct current into grid-compatible alternating current; for example, the neutral-point clamped inverter (NPC) is a widely used inverter topology in medium- and high-voltage high-power photovoltaic power generation systems. This inverter achieves multi-level output by clamping at the DC-side midpoint, while also exhibiting good harmonic control performance, making it suitable for medium- and high-voltage photovoltaic power generation systems. The inverter is controlled by a space vector pulse width modulation (SVPWM) signal to optimize the output waveform. An LCL filter is used to filter out high-frequency noise in the DC-AC inverter output voltage, improving power quality. This photovoltaic power generation control system includes a front-end DC / DC control module and a back-end DC / AC control module.
[0039] The front-end DC / DC control module is used to determine the maximum available power P of the photovoltaic array PV. avai The actual output power P of the photovoltaic array PV pv and grid-side power P g The operating mode of the photovoltaic array PV is determined, and the pulse duty cycle is adjusted by the first PI regulator according to the operating mode of the photovoltaic array PV to generate a pulse width modulation signal g. b It also controls the DC-DC boost converter; the photovoltaic array PV has the following operating modes: maximum power point tracking mode (MPPT), power limiting control mode (PLC), power reserve control mode (PRC), and power rate of change control mode (PRRC).
[0040] Specifically, the front-end DC / DC control module includes: a maximum available power prediction unit, a photovoltaic output power calculation unit, an operating mode determination unit, a first PI regulator, and a pulse width modulation generator; the maximum available power prediction unit is used to predict the maximum available power of the photovoltaic array (PV) in real time based on environmental monitoring data (illuminance and ambient temperature) and historical output power data; the photovoltaic output power calculation unit is used to calculate the maximum available power of the photovoltaic array (PV) based on the voltage signal v at the output side of the PV. pv and current signal i pv Calculate the actual output power P of the photovoltaic array PV. pv The operating mode determination unit is used to determine the maximum available power P of the photovoltaic array PV. avai The actual output power P of the photovoltaic array PV pv and grid-side power P g The operating mode of the photovoltaic array (PV) is determined; the first PI regulator is used to perform PI regulation according to the operating mode of the photovoltaic array (PV), adjust the pulse duty cycle, and generate a pulse width modulation signal g through the pulse width modulation generator. b This is to achieve control of the DC-DC boost converter. The first proportional-integral (PI) regulator is used to regulate the photovoltaic power, and the control signal g generated by the pulse width modulation generator is used to control the photovoltaic power. bBy adjusting the on and off times of the switching elements, the charging and discharging processes of the inductors and capacitors in the DC / DC boost converter are controlled, thereby achieving precise power control.
[0041] The maximum power point tracking mode controls the photovoltaic array (PV) to output maximum power under any environmental conditions; the power limiting control mode controls the actual output power of the PV array, limiting the actual output power of the PV array to not exceed a preset power threshold; the power reserve control mode adjusts the actual output power of the PV array to below the maximum available power, reserving a certain amount of power to cope with frequency events or voltage fluctuations in the power grid; and the power change rate control mode limits the change rate of the actual output power of the PV array to not exceed a preset change rate threshold.
[0042] The subsequent DC / AC control module is used to determine the grid-side power P. g And the actual output power P of the photovoltaic array PV pv Perform transient power suppression and generate an additional reference voltage for the DC bus. Then, the second PI regulator is used based on the DC bus reference voltage. Additional reference voltage to DC bus and DC bus voltage v dc The error value is adjusted by PI regulation, and the result of the second PI regulator output is compared with the voltage phase signal θ on the grid side. g Voltage signal v g and current signal i g Generates a space vector pulse width modulation signal g inv It also controls the DC-AC inverter.
[0043] Specifically, the downstream DC / AC control module includes: a grid-side power calculation unit, a transient power suppression control unit, a second PI regulator, a phase-locked loop unit, a current controller, and a space vector pulse width modulation generator; the grid-side power calculation unit is used to calculate the voltage signal v from the grid side. g and current signal i g Calculate the grid-side power P g The transient power suppression control unit is used to adjust the power output P on the grid side. g And the actual output power P of the photovoltaic array PV pv Perform transient power suppression and generate an additional reference voltage for the DC bus. The second PI regulator is used to adjust the DC bus reference voltage. Additional reference voltage to DC bus and DC bus voltage v dc The error value is adjusted by PI; the phase-locked loop unit is used to adjust the voltage signal v from the grid side. g Determine the voltage phase signal θg The phase-locked loop (PLL) synchronous inverter outputs a voltage phase signal θ with the grid. g This ensures stable power transmission. The current controller is used to adjust the output of the second PI regulator based on the voltage phase signal θ from the grid side. g Voltage signal v g and current signal i g A control signal is generated, and a space vector pulse width modulation signal g is generated through a space vector pulse width modulation generator. inv This is to achieve control of the DC-AC inverter. Based on the space vector pulse width modulation signal g... inv As a switching signal for the DC-AC inverter, it regulates the inverter's output current to match the grid current. Simultaneously, the current controller also receives the grid voltage v. g and the grid phase signal θ from the PLL g This is to ensure that the DC-AC inverter output is synchronized with the power grid.
[0044] A transient power suppression control unit (TPDC) is introduced to buffer excessive pulsating energy and appropriately suppress transient power, ensuring the power quality of the photovoltaic system. This involves adding an additional control loop based on the actual output power P of the photovoltaic array. pv With grid-side power P g Generates an additional reference voltage for the DC bus.
[0045] Furthermore, the power-voltage control gain k pv This is crucial for TPDC performance. When k pv When it is large, the DC bus voltage v dc It can deviate significantly from the rated value to buffer transient power. However, the deviation of the DC bus voltage is limited by operating requirements, such as capacitor life, modulation requirements, and converter stability. Therefore, k pv It should be subject to DC bus voltage v dc Deviation limits and transient power constraints must be considered. Furthermore, the proportional gain of the first PI regulator must be taken into account, as it affects the DC bus voltage v. dc The response time. In extreme cases, the DC bus voltage v dc It will deviate to the limit value to buffer transient power; therefore, the maximum power-voltage control gain... It can be calculated in the following ways:
[0046]
[0047] in, This indicates the maximum permissible value of the DC bus voltage. k is the reference value for the DC bus voltage.pdc It is the proportional coefficient of the first PI controller, and Then it is k pv The upper limit.
[0048] In one exemplary embodiment of this application, such as Figure 2 The flowchart shown illustrates the specific steps of the front-end DC / DC control process of this photovoltaic power generation control system:
[0049] A1. Real-time monitoring of environmental parameters such as light intensity and temperature provides data support for maximum available power prediction.
[0050] A2. Based on historical data and environmental monitoring data, predict the maximum available power P of the photovoltaic array. avai .
[0051] A3. Based on the predicted maximum available power P avai The actual power P collected and calculated pv and grid-side power P g Adjust the operating mode of the photovoltaic array to allow it to operate in different modes, such as Maximum Power Point Tracking (MPPT), Power Limiting Control (PLC), Power Reserve Control (PRC), and Rate of Change Control (PRRC).
[0052] A4. A PWM signal is generated through the first PI regulator, and the duty cycle g is adjusted according to the working mode of the photovoltaic array. b This enables control of the DC-DC boost converter, boosting the output voltage of the photovoltaic array to a level suitable for subsequent processing.
[0053] Under normal circumstances, the photovoltaic array operates in MPPT, and the PLC controls the operation by setting a preset power threshold P. limit In practice, PRC is based on the predicted maximum available power P. avai and grid-side power P g To reserve a certain amount of power ΔP, PRRC is achieved by judging whether the rate of change of photovoltaic output power exceeds a preset rate of change threshold r. * This is achieved through [the means].
[0054] The purpose of Maximum Power Point Tracking (MPPT) is to ensure that a photovoltaic (PV) array outputs maximum power under any given environmental conditions. MPPT algorithms are typically implemented based on the current-voltage (IV) characteristic curve of the PV array. The following describes an MPPT control strategy based on the incremental conductance method, an improvement on the incremental conductance method. This method calculates the increment of conductance to more accurately track the maximum power point. The formula for determining this is:
[0055]
[0056] Where G is the conductance, dP pv and dv pv These are the output power P pv and voltage v pv The derivative of G. If G > 0, then decrease the voltage V; if G < 0, then increase the voltage V, until G = 0, at which point the maximum power point is found.
[0057] Power limiting control PLC control mode limits the photovoltaic output power to not exceed the preset power threshold P limit This control ensures that under no circumstances will the output of the photovoltaic array exceed the maximum power that the grid or equipment can safely handle; the determination formula is as follows:
[0058] P pv =min(P avai ,P limit ).
[0059] Among them, P pv It is the actual output power, P avai P is the predicted maximum available power of the photovoltaic array. limit The operator determines the power P on the grid side based on the grid side. g The preset power threshold is set.
[0060] The power reserve control (PRC) strategy adjusts the actual photovoltaic power to below the maximum available power P. avai A certain amount of power ΔP is reserved. This reserved power can be quickly mobilized when needed to cope with frequency events or voltage fluctuations in the power grid. The determination formula is as follows:
[0061] P pv =P avai -ΔP.
[0062] ΔP is the reserved power margin, which can be dynamically adjusted based on forecasts and grid demand.
[0063] The power rate change control (PRRC) strategy limits the rate of change of photovoltaic output power within a specific range. * To avoid grid frequency fluctuations caused by rapid power changes, the judgment formula is as follows:
[0064]
[0065] Wherein, ΔP t It is the change in power over a period of time, where Δt is the time interval and r is the power change over that period of time. * It is a preset rate of change threshold.
[0066] These four control modes are implemented by the operating mode determination unit based on the grid demand power and photovoltaic power generation. Simply put, when the grid load changes or a fault occurs, requiring less power or needing a certain photovoltaic power margin, or when a fault causes a rapid change in grid power, the operating mode determination unit can implement different response strategies to work together on the photovoltaic array, ensuring stable system operation while improving the overall reliability and flexibility of the grid. By rationally configuring these control parameters, different grid conditions and demands can be effectively addressed.
[0067] In another exemplary embodiment of this application, such as Figure 3 The flowchart shown illustrates the specific steps of the downstream DC / AC control process of this photovoltaic power generation control system:
[0068] B1. Collect the voltage v of the power grid. g and current i g The phase θ of the phase-locked loop unit synchronizing the grid voltage g .
[0069] B2. Based on the calculated grid-side power P g and the output power P of the photovoltaic array pv An additional reference voltage for the DC bus is generated through TPDC control.
[0070] B3. The DC bus reference voltage is adjusted via the second PI regulator. Actual DC bus voltage v dc and additional reference voltage for DC bus The signal is processed and its output signal is adjusted according to the error.
[0071] B4. Receive the output signal from the second PI regulator and the grid voltage v. g Current i g and phase θ g The control signal is generated by the current controller.
[0072] B5. The output of the current controller is fed into SVPWM to generate a pulse width modulation signal g based on the output of the current controller. inv It is used to control the switching elements of a DC-AC inverter, thereby regulating the inverter's output voltage and current to synchronize it with the power grid and meet the required power quality requirements.
[0073] In summary, the photovoltaic power generation control system proposed in this application is a highly efficient and intelligent energy conversion and management system capable of precise power regulation to more effectively manage and utilize solar energy resources and improve grid compatibility. Through various advanced control technologies and strategies, it achieves efficient, stable, and intelligent management of photovoltaic power generation, transforming photovoltaic power plants from passive power generation units to active grid participants, enhancing grid stability and security, promoting the high-proportion consumption of renewable energy, and providing strong technical support for the widespread application of photovoltaic energy.
[0074] Based on the same inventive concept, this application also provides a photovoltaic power generation control method. The solution provided by this control method is similar to the solution described in the above-described control system. In an exemplary embodiment, such as... Figure 4 As shown, a photovoltaic power generation control method is provided, including the following steps:
[0075] C1. Determine the operating mode of the photovoltaic array based on its maximum available power, actual output power, and grid-side power. The operating modes of the photovoltaic array include: maximum power point tracking (MPPT), power limiting control, power reserve control, and power rate of change control.
[0076] C2. The pulse duty cycle is adjusted by the first PI regulator according to the working mode of the photovoltaic array, a pulse modulation signal is generated, and the DC-DC boost converter is controlled.
[0077] C3. Based on the grid-side power and the actual output power of the photovoltaic array, transient power suppression is performed to generate an additional reference voltage for the DC bus.
[0078] C4. The second PI regulator performs PI regulation based on the error value between the DC bus reference voltage and the DC bus additional reference voltage and the DC bus voltage.
[0079] C5. Based on the output of the second PI regulator and the voltage phase signal, voltage signal and current signal on the grid side, a space vector pulse modulation signal is generated and used to control the DC-AC inverter.
[0080] As an optional implementation, before determining the operating mode of the photovoltaic array based on the maximum available power of the photovoltaic array, the actual output power of the photovoltaic array, and the grid-side power, the photovoltaic power generation control method further includes the following steps:
[0081] D1. Based on environmental monitoring data and historical output power data, predict the maximum available power of the photovoltaic array in real time.
[0082] D2. Calculate the actual output power of the photovoltaic array based on the voltage and current signals on the output side of the photovoltaic array.
[0083] D3. Calculate the grid-side power based on the voltage and current signals on the grid side.
[0084] In this implementation method, before generating a space vector pulse modulation signal based on the output of the second PI regulator and the voltage phase signal, voltage signal, and current signal on the grid side, and controlling the DC-AC inverter, the photovoltaic power generation control method further includes: determining the voltage phase signal on the grid side based on the voltage signal on the grid side.
[0085] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 5 As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it can implement the photovoltaic power generation control method provided in the above method embodiments, or implement the front-end DC / DC control flow and the back-end DC / AC control flow of the photovoltaic power generation control system provided in the above system embodiments.
[0086] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0087] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.
[0088] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.
[0089] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.
[0090] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.
[0091] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).
[0092] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.
[0093] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0094] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A photovoltaic power generation control system, characterized in that, The photovoltaic array is connected to the power grid sequentially through a DC-DC boost converter, a DC bus capacitor, a DC-AC inverter, and an LCL filter. The DC-DC boost converter is used to boost the output voltage of the photovoltaic array. The DC bus capacitor is used to smooth the voltage fluctuations at the output of the DC-DC boost converter. The DC-AC inverter is used to convert the DC power into AC power compatible with the power grid. The LCL filter is used to filter out high-frequency noise in the output voltage of the DC-AC inverter. The photovoltaic power generation control system includes a front-end DC / DC control module and a back-end DC / AC control module. The front-end DC / DC control module determines the operating mode of the photovoltaic array based on the maximum available power of the photovoltaic array, the actual output power of the photovoltaic array, and the grid-side power. It then adjusts the pulse duty cycle using a first PI regulator to generate a pulse width modulation signal and control the DC-DC boost converter. The operating modes of the photovoltaic array include: maximum power point tracking mode, power limiting control mode, power reserve control mode, and power rate of change control mode. The back-end DC / AC control module performs transient power suppression based on the grid-side power and the actual output power of the photovoltaic array, generates an additional reference voltage for the DC bus, and then performs PI regulation using a second PI regulator based on the error between the DC bus reference voltage and the additional reference voltage and the DC bus voltage. Finally, based on the output of the second PI regulator and the voltage phase signal, voltage signal, and current signal from the grid side, it generates a space vector pulse width modulation signal and controls the DC-AC inverter.
2. The photovoltaic power generation control system according to claim 1, characterized in that, The front-end DC / DC control module includes: a maximum available power prediction unit, a photovoltaic output power calculation unit, an operating mode determination unit, a first PI regulator, and a pulse width modulation generator. The maximum available power prediction unit is used to predict the maximum available power of the photovoltaic array in real time based on environmental monitoring data and historical output power data. The photovoltaic output power calculation unit is used to calculate the actual output power of the photovoltaic array based on the voltage and current signals on the output side of the photovoltaic array. The operating mode determination unit is used to determine the operating mode of the photovoltaic array based on the maximum available power of the photovoltaic array, the actual output power of the photovoltaic array, and the grid-side power. The first PI regulator is used to perform PI regulation according to the operating mode of the photovoltaic array, adjust the pulse duty cycle, and generate a pulse width modulation signal through the pulse width modulation generator to control the DC-DC boost converter.
3. The photovoltaic power generation control system according to claim 1, characterized in that, The downstream DC / AC control module includes: a grid-side power calculation unit, a transient power suppression control unit, a second PI regulator, a phase-locked loop unit, a current controller, and a space vector pulse width modulation generator. The grid-side power calculation unit calculates the grid-side power based on the grid-side voltage and current signals. The transient power suppression control unit performs transient power suppression based on the grid-side power and the actual output power of the photovoltaic array, generating an additional reference voltage for the DC bus. The second PI regulator performs PI regulation based on the error between the DC bus reference voltage and the additional reference voltage and the DC bus voltage. The phase-locked loop unit determines the voltage phase signal based on the grid-side voltage signal. The current controller generates a control signal based on the output of the second PI regulator and the grid-side voltage phase signal, voltage signal, and current signal, and generates a space vector pulse width modulation signal through the space vector pulse width modulation generator to control the DC-AC inverter.
4. The photovoltaic power generation control system according to claim 1, characterized in that, The maximum power point tracking mode controls the photovoltaic array to output maximum power under any environmental conditions; the power limiting control mode controls the actual output power of the photovoltaic array, limiting the actual output power of the photovoltaic array to not exceed a preset power threshold; the power reserve control mode adjusts the actual output power of the photovoltaic array to be lower than the maximum available power, reserving a certain amount of power to cope with frequency events or voltage fluctuations in the power grid; the power change rate control mode limits the change rate of the actual output power of the photovoltaic array to not exceed a preset change rate threshold.
5. A photovoltaic power generation control method, characterized in that, The photovoltaic array is connected to the power grid sequentially through a DC-DC boost converter, a DC bus capacitor, a DC-AC inverter, and an LCL filter. The DC-DC boost converter is used to boost the output voltage of the photovoltaic array. The DC bus capacitor is used to smooth the voltage fluctuations at the output of the DC-DC boost converter. The DC-AC inverter is used to convert the DC power into AC power compatible with the power grid. The LCL filter is used to filter out high-frequency noise in the output voltage of the DC-AC inverter. The photovoltaic power generation control method includes: The operating mode of the photovoltaic array is determined based on the maximum available power of the photovoltaic array, the actual output power of the photovoltaic array, and the grid-side power; the operating modes of the photovoltaic array include: maximum power point tracking mode, power limiting control mode, power reserve control mode, and power rate of change control mode. The pulse duty cycle is adjusted by the first PI regulator according to the working mode of the photovoltaic array, a pulse modulation signal is generated, and the DC-DC boost converter is controlled. Transient power suppression is performed based on the grid-side power and the actual output power of the photovoltaic array to generate an additional reference voltage for the DC bus. The second PI regulator performs PI regulation based on the error value between the DC bus reference voltage and the DC bus additional reference voltage and the DC bus voltage; Based on the output of the second PI regulator and the voltage phase signal, voltage signal, and current signal from the grid side, a space vector pulse modulation signal is generated to control the DC-AC inverter.
6. The photovoltaic power generation control method according to claim 5, characterized in that, Before determining the operating mode of the photovoltaic array based on its maximum available power, actual output power, and grid-side power, the photovoltaic power generation control method further includes: Based on environmental monitoring data and historical output power data, the maximum available power of the photovoltaic array is predicted in real time. The actual output power of the photovoltaic array is calculated based on the voltage and current signals at the output side of the photovoltaic array. Calculate the grid-side power based on the voltage and current signals from the grid side.
7. The photovoltaic power generation control method according to claim 5, characterized in that, Before generating a space vector pulse modulation signal based on the output of the second PI regulator and the voltage phase signal, voltage signal, and current signal from the grid side, and controlling the DC-AC inverter, the photovoltaic power generation control method further includes: The voltage phase signal on the grid side is determined based on the voltage signal on the grid side.
8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the photovoltaic power generation control method according to any one of claims 5-7.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the photovoltaic power generation control method according to any one of claims 5-7.
10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the photovoltaic power generation control method according to any one of claims 5-7.