Power control method and device for grid-friendly inverter, inverter and panoramic monitoring system

Abstract

This application provides a grid-friendly inverter power control method, device, inverter, and panoramic monitoring system. The method includes: receiving a target power command; the target power command includes a target power value for the inverter to respond to power dispatch; within the dispatch response time, performing multiple controls on the inverter output according to a control loop; in each control, determining a first power error value based on the target power value and the actual power value of the inverter output collected in that control, and using the first power error value as the input to the power loop in the control loop within that control; the first power error value is the sum of a power compensation value and a second power error value, the power compensation value changing from a preset value to zero in multiple control operations, and having the same sign as the second power error value; the second power error value in each control is the difference between the target power value and the actual power value of the inverter output collected each time. This application can improve the response efficiency of inverter power dispatch.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a grid-friendly inverter power control method, device, inverter and panoramic monitoring system. Background Technology

[0002] With the rapid development of new energy sources, the number of new energy power plants, such as photovoltaic power plants, is constantly increasing. Inverters are the core grid-connected unit of new energy power plants, converting the direct current (DC) generated in the plant into alternating current (AC) for transmission to the power grid. During grid faults or disturbances, new energy power plants can participate in the primary frequency regulation of the grid. By responding to power dispatch commands issued by the grid dispatch center, they can quickly adjust the active power output of the inverter to offset power imbalances on the grid side, thereby maintaining grid frequency stability.

[0003] In new energy power plants, after receiving power dispatch instructions from the power grid dispatch center, the host computer needs to allocate power and decompose the instructions according to the operating status of each inverter. Then, through the data acquisition system, it sends out the decomposed target power instructions for each individual inverter one by one. Each inverter adjusts according to the target power instructions it receives, changes its output power, and feeds back the final adjustment results to the host computer. This dispatch response process usually takes a long time, such as 1 second. However, as the requirements for new energy power plants to participate in primary frequency regulation continue to increase, the existing response speed can no longer meet the dispatch response needs of the power grid. Summary of the Invention

[0004] This application provides a grid-friendly inverter power control method, device, inverter, and panoramic monitoring system to improve the response efficiency of inverter power dispatch and quickly respond to grid power dispatch.

[0005] In a first aspect, embodiments of this application provide a grid-friendly inverter power control method, including: Receive a target power command; the target power command includes the target power value for the inverter to perform power scheduling response; Within the scheduling response time, the inverter output is controlled multiple times according to the control loop; wherein, in each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in that control, and the first power error value is used as the input of the power loop in the control loop within that control; In the multiple control operations, the first power error value is the sum of the power compensation value and the second power error value. The power compensation value changes from a preset value to zero in the multiple control operations and is consistent with the sign of the second power error value. In each control operation, the second power error value is the difference between the target power value and the actual power value output by the inverter collected each time.

[0006] In one possible implementation, prior to the multiple control operations performed on the inverter output according to the control loop, the method further includes: Calculate the initial power error between the target power value and the currently acquired actual power value output by the inverter; The preset value is obtained based on the preset compensation coefficient and the initial power error value.

[0007] In one possible implementation, prior to the multiple control operations performed on the inverter output according to the control loop, the method further includes: Calculate the unit change value based on the preset value and the scheduling response duration; A linear function of the power compensation value change is established, with the unit change value as the slope and the preset value as the intercept.

[0008] In one possible implementation, calculating the unit change value based on the preset value and the scheduling response duration includes: The compensation duration is determined based on the scheduling response duration and the communication duration of the target power command; the compensation duration is less than or equal to a preset difference; the preset difference is the difference between the scheduling response duration and the communication duration. Calculate the ratio of the preset value to the compensation duration to obtain the unit change value.

[0009] In one possible implementation, determining the first power error value based on the target power value and the actual power value of the inverter output acquired during this control operation includes: Obtain the actual power value of the inverter output collected during this control, as well as the power compensation value during this control; Calculate the sum of the target power value and the power compensation value to obtain the compensated target power value in this control. The difference between the compensated target power value and the actual power value is calculated to obtain the first power error value in this control.

[0010] In one possible implementation, determining the first power error value based on the target power value and the actual power value of the inverter output acquired during this control operation includes: Obtain the actual power value of the inverter output collected during this control, as well as the power compensation value during this control; Calculate the difference between the target power value and the actual power value to obtain the second power error value in this control. The sum of the second power error value and the power compensation value in this control is calculated to obtain the first power error value in this control.

[0011] In one possible implementation, the control loop is a proportional-integral control loop; The process of controlling the inverter output multiple times according to the control loop includes: In each control operation, the second power error value obtained from that control is calculated using proportional-integral calculation to obtain the target current value of the inverter. The current error value in this control is obtained based on the difference between the target current value and the actual current value of the inverter collected in this control. Adjust the inverter's drive signal based on the current error value; Based on the adjusted drive signal, the output of the inverter is controlled to adjust the actual power output of the inverter.

[0012] Secondly, embodiments of this application provide a grid-friendly inverter power control device, including: A receiving module is used to receive a target power command; the target power command includes the target power value for the inverter to perform power scheduling response; The control module is used to control the output of the inverter multiple times according to the control loop within the scheduling response time; wherein, in each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in this control, and the first power error value is used as the input of the power loop in the control loop within this control; In the multiple control operations, the first power error value is the sum of the power compensation value and the second power error value. The power compensation value changes from a preset value to zero in the multiple control operations and is consistent with the sign of the second power error value. In each control operation, the second power error value is the difference between the target power value and the actual power value output by the inverter collected each time.

[0013] Thirdly, embodiments of this application provide an inverter, including a controller, which is used to implement the methods described in the first aspect or any possible implementation of the first aspect.

[0014] Fourthly, embodiments of this application provide a panoramic monitoring system, including a host computer, data acquisition equipment, and multiple inverters as described in the third aspect above.

[0015] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect or any possible implementation of the first aspect.

[0016] The beneficial effects of the embodiments in this application compared with the prior art are: This application embodiment receives a target power command, which includes a target power value for the inverter to perform power scheduling response. The inverter performs power scheduling response according to the received target power command. During the scheduling response time, the inverter output is controlled multiple times using a control loop. In each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in that control, and this first power error value is used as the input of the power loop in the control loop within that control. The actual power output of the inverter can be adjusted using the first power error value so that the inverter outputs according to the requirements of the target power command. The first power error value in the multiple control operations is the sum of the power compensation value and the second power error value. The power error value changes from a preset value to zero in the multiple control operations and is consistent with the sign of the second power error value. The second power error value is the difference between the target power value and the actual power value of the inverter output collected each time. That is, the input of the power loop in the control loop changes from the second power error value to the first power error value. The absolute value of the power error value of the input power loop increases, which increases the difference in the power adjustment process and increases the amplitude of power adjustment in each control. This increases the change of the inverter's output power in each control, allowing the actual power of the inverter to reach the target power value more quickly and improving the response efficiency of the inverter's power scheduling. Furthermore, since the power compensation value changes from a preset value to zero in multiple control cycles, after the power compensation value changes to zero, the power error value of the input power loop is the second power error value, and it will not increase the power error value further. This ensures that the actual power output of the inverter still reaches the target power value, meeting the scheduling response requirements of the target power command. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art 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.

[0018] Figure 1 This is an application scenario diagram of the grid-friendly inverter power control method provided in the embodiments of this application; Figure 2 This is a flowchart illustrating the implementation of the grid-friendly inverter power control method provided in this application embodiment; Figure 3 This is a schematic diagram of the control loop of the inverter provided in the embodiments of this application; Figure 4 This is a schematic diagram of the power change of the control inverter before compensation provided in the embodiments of this application; Figure 5This is a schematic diagram of the power change adjusted by the controlled inverter after compensation, provided in an embodiment of this application. Figure 6 This is a schematic diagram of the structure of the grid-friendly inverter power control device provided in the embodiments of this application. Detailed Implementation

[0019] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0021] Figure 1 This diagram illustrates an application scenario for the grid-friendly inverter power control method provided in this application. (Example:) Figure 1 As shown, taking a photovoltaic power station as an example, the photovoltaic modules in the photovoltaic power station can generate low-voltage direct current. The low-voltage direct current can be converted into high-voltage direct current through a direct current-to-direct current (DC / DC) converter. Then, the high-voltage direct current can be converted into alternating current (AC) through a direct current-to-alternating current (DC / AC) converter, i.e., an inverter, so as to supply the grid.

[0022] Photovoltaic power output is intermittent and fluctuates. If directly connected to the grid, it will impact grid parameters such as voltage and frequency. The grid dispatch center can issue power dispatch instructions to photovoltaic power plants. Through precise power dispatch instructions, the output voltage and power of photovoltaic power plants can be ensured, so that the grid can meet the supply and demand balance requirements.

[0023] In a photovoltaic (PV) power plant, a host computer, such as an Automatic Generation Control (AGC), receives power dispatch instructions from the power grid dispatch center, obtains the total power output required by the entire PV power plant, and calculates the target power output for each inverter. The AGC then uses power line carrier communication (PLC) to transmit the target power value for each inverter to the corresponding PV data acquisition unit. The PV data acquisition unit then transmits the value to the inverter, adjusting its output power to match the target power value. Furthermore, after adjusting its output power, the inverter feeds back the final result to the AGC.

[0024] The process from the AGC issuing the target power value to receiving feedback from the inverter typically takes a considerable amount of time, such as one second. However, as the requirements for photovoltaic power plants to participate in dispatch response continue to increase, such as the need to complete inverter power adjustment within hundreds of milliseconds from the issuance of the command, the existing response speed cannot meet the ever-increasing demands of dispatch response.

[0025] To improve the response speed of photovoltaic power plants participating in dispatching, this application focuses on adjusting the inverter's output power, accelerating the adjustment speed, and reducing the adjustment time, thereby improving the response efficiency of inverter power dispatching. In the embodiments of this application, after the inverter receives the target power value, within the dispatching response time, the inverter output is controlled multiple times using a control loop. In each control, the error between the target power value and the actual power value of the inverter is compensated. The compensated error value is used as the input to the control loop, increasing the absolute value of the error value input to the control loop, increasing the difference in the power adjustment process, and increasing the amplitude of power adjustment in each control. This increases the variation of the inverter's output power in each control, allowing the actual power of the inverter to reach the target power value more quickly, thus improving the response efficiency of inverter power dispatching.

[0026] See Figure 2 The document illustrates a flowchart of the implementation of the grid-friendly inverter power control method provided in this embodiment, which is described in detail below: Step 201: Receive target power command; the target power command includes the target power value for the inverter to respond to power scheduling.

[0027] In this embodiment, the host computer sends a target power command to the inverter. This target power command includes the target power value for power scheduling of the inverter, that is, the power value that the inverter is required to achieve during power scheduling. Within the scheduling response time, the inverter needs to adjust its output to the target power value to complete the scheduling response.

[0028] Step 202: Within the scheduling response time, the inverter output is controlled multiple times according to the control loop; wherein, in each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in that control, and the first power error value is used as the input of the power loop in the control loop within that control.

[0029] In multiple control operations, the first power error value is the sum of the power compensation value and the second power error value. The power compensation value changes from a preset value to zero in multiple control operations and is consistent with the sign of the second power error value. In each control operation, the second power error value is the difference between the target power value and the actual power value of the inverter output collected each time.

[0030] The aforementioned scheduling response time is the time required for the completion of power scheduling of the inverter, that is, the time required from the time the host computer issues the target power command to the time when the inverter completes the power adjustment and feeds back the result to the host computer.

[0031] A control loop refers to a closed loop consisting of the forward path and the feedback path that control the inverter output. It can include error-free tracking of a given bus voltage reference value, error-free tracking of a given current reference value, and error-free tracking of a given power reference value. Error-free tracking can be achieved through closed-loop control algorithms, such as proportional-integral (PI) control algorithms and proportional-integral-derivative (PID) control algorithms.

[0032] Among them, error-free tracking for a given bus voltage reference value is the bus voltage loop, error-free tracking for a given current reference value is the current loop, and error-free tracking for a given power reference value is the power loop. Taking PI control as an example, such as... Figure 3 As shown, P ref Given a power reference value, i.e., the target power value, P fbd The actual power output of the inverter is collected, and after PI calculation in the power loop of the control loop, the power loop can output the first current reference value I. ref1 U busref Given a reference value for the bus voltage, U busfbd The actual bus voltage value of the inverter is collected, and after PI calculation by the bus voltage loop, the bus voltage loop outputs a second current reference value I. ref2 Two current reference values ​​are input to the current loop as the given current reference value I. ref Simultaneously, obtain the actual current value I of the inverter. fbdThis is used to perform PI calculations for the current loop. The current loop ultimately outputs a drive signal to adjust the inverter, such as a pulse-width modulation (PWM) signal. This drive signal controls the switching on and off of the transistors in the inverter, adjusting the inverter's output voltage, current, and power.

[0033] The target power value in the target power command is the given power reference value in the power loop, which the inverter needs to track and reach. In error-free tracking within the control loop, the difference between the target power value and the actual power output of the inverter each time it is collected—that is, the second power error value—is typically used for calculations in the power loop. For example, if the target power command requires the inverter's power output to increase from 50kW to 100kW, then... Figure 4 As shown, the given power reference value of the power loop, that is, the target power value, changes from 50kW to 100kW and is maintained at 100kW. The output power of the inverter gradually increases from 50kW to 100kW.

[0034] However, in this embodiment, a power compensation value is added based on the second power error value. The first power error value, obtained by summing the power compensation value and the second power error value, is used to calculate the power loop. Since the power compensation value and the second power error value have the same sign, and the absolute value of the first power error value is greater than the absolute value of the second power error value, the power error is amplified by the power compensation value. When calculating the power loop, a larger absolute value of the error leads to more adjustments in the primary control, thereby achieving the target power value more quickly.

[0035] Here, the inverter output ultimately needs to reach the target power value; therefore, the power compensation value also needs to eventually change to zero to avoid power loop overshoot. The power compensation value can gradually change from a preset value to zero, or it can change directly from the preset value to zero. When gradually changing from the preset value to zero, the absolute value of the power compensation value can gradually decrease to zero.

[0036] The preset value can be determined based on the target power value, the actual power output of the inverter, or a pre-set value that can increase the power adjustment range in each control cycle without causing overshoot. The sign of the preset value is the same as that of the second power error value. If the actual power value is less than the target power value, the actual power value needs to be increased, the second power error value is positive, and the sign of the preset value is positive; if the actual power value is greater than the target power value, the actual power value needs to be decreased, the second power error value is negative, and the sign of the preset value is negative.

[0037] To facilitate comparison and understanding, the power compensation value is added to the target power value, such as... Figure 5As shown, the given power reference value for the power loop changes from 50kW to 105kW, where 100kW is the target power value and 5kW is the preset power compensation value. The given power reference value gradually decreases to 100kW and remains at 100kW. The inverter's output power gradually increases from 50kW to 100kW. (Comparison) Figure 4 and Figure 5 It can be seen that after increasing the power compensation value, the inverter output power increases from 50kW to 100kW faster and in less time.

[0038] Optionally, the control loop is a proportional-integral control loop.

[0039] In this embodiment, the inverter output is controlled multiple times according to the control loop. This can be done as follows: In each control, the second power error value obtained from the previous control is calculated using proportional-integral calculation to obtain the target current value of the inverter; the current error value in the previous control is obtained based on the difference between the target current value and the actual current value of the inverter collected in the previous control; the drive signal of the inverter is adjusted based on the current error value; and the output of the inverter is controlled based on the adjusted drive signal to adjust the actual power of the inverter output.

[0040] In this embodiment, a PI control loop can be used to implement the power loop and the current loop. In each control cycle, the output of the power loop or the current loop can be calculated using the PI control formula.

[0041] The formula for PI control can be: In the formula, This represents the calculation result of the formula, that is, the output of the power loop or current loop. This represents the proportionality coefficient. Represents the integral coefficient. This represents the error value. In the power loop, This is the first power error value. and The value is set according to the needs of the power loop. In the current loop, This is the current error value. and The value is set according to the needs of the current loop and can be different from the value in the power loop.

[0042] Here, in each control cycle, the second power error value of that control cycle is calculated using proportional-integral methods to obtain the target current value of the inverter. This allows for current loop control, thereby indirectly and precisely controlling the power output of the inverter by controlling the current output of the inverter.

[0043] The target current value is used as the input to the current loop, thus obtaining a given current reference value. The difference between the target current value and the actual inverter current value acquired during this control cycle is used to obtain the current error value for this control cycle. This current error value is then used for PI calculations in the current loop to obtain the adjusted inverter drive signal. This drive signal is then used to drive the switching transistors in the inverter, changing the inverter's output current and thus adjusting the actual output power of the inverter.

[0044] In addition, the bus voltage loop also performs PI calculations based on the given bus voltage reference value and the actual bus voltage value to obtain the current compensation value. This current compensation value is also input into the current loop to accurately obtain the current error value. For example, the sum of the target current value and the current compensation value is used as the given current reference value.

[0045] This application embodiment receives a target power command, which includes a target power value for the inverter to perform power scheduling response. The inverter performs power scheduling response according to the received target power command. During the scheduling response time, the inverter output is controlled multiple times using a control loop. In each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in that control, and this first power error value is used as the input of the power loop in the control loop within that control. The actual power output of the inverter can be adjusted using the first power error value so that the inverter outputs according to the requirements of the target power command. The first power error value in the multiple control operations is the sum of the power compensation value and the second power error value. The power error value changes from a preset value to zero in the multiple control operations and is consistent with the sign of the second power error value. The second power error value is the difference between the target power value and the actual power value of the inverter output collected each time. That is, the input of the power loop in the control loop changes from the second power error value to the first power error value. The absolute value of the power error value of the input power loop increases, which increases the difference in the power adjustment process and increases the amplitude of power adjustment in each control. This increases the change of the inverter's output power in each control, allowing the actual power of the inverter to reach the target power value more quickly and improving the response efficiency of the inverter's power scheduling. Furthermore, since the power compensation value changes from a preset value to zero in multiple control cycles, after the power compensation value changes to zero, the power error value of the input power loop is the second power error value, and it will not increase the power error value further. This ensures that the actual power output of the inverter still reaches the target power value, meeting the scheduling response requirements of the target power command.

[0046] In some embodiments, before performing multiple control operations on the inverter output according to the control loop, an initial power error value between the target power value and the currently acquired actual power value of the inverter output can be calculated; a preset value is obtained based on a preset compensation coefficient and the initial power error value.

[0047] In this embodiment, before performing multiple control operations, the actual power value of the inverter's current output can be collected. Using this actual power value and the target power value, a preset value is determined. This actual power value is the initial actual power value of the inverter before any adjustments are made. The difference between the target power value and this actual power value represents the power adjustment required by the inverter. Therefore, using the initial power error value to determine the preset value allows the preset value to accurately match the deviation between the target power value and the inverter's actual power value, ensuring faster inverter adjustment while preventing overshoot of the inverter's output power.

[0048] Here, the compensation factor is a parameter that balances the adjustment speed and stability of the inverter. It can be determined empirically or obtained from the inverter's power dispatch calibration. For example, the compensation factor can range from 1% to 20%, such as 3%, 5%, 8%, 10%, 13%, 15%, and 18%.

[0049] Taking a target power command requiring the inverter's power output to increase from 50kW to 100kW as an example, if the actual power is 50kW and the target power is 100kW, then the initial power error is 50kW. Assuming a compensation factor of 10%, the preset value is 5kW. Assuming a compensation factor of 5%, the preset value is 2.5kW.

[0050] Accordingly, the compensation coefficient is 5%, and the power compensation value can be reduced by 1% in each control cycle. In the first control cycle of multiple control cycles, the compensation coefficient is 5%, and the power compensation value is the preset value; in the second control cycle, the compensation coefficient is 4%; in the third control cycle, it is 3%; in the fourth control cycle, it is 2%; in the fifth control cycle, it is 1%; and in the sixth control cycle, the compensation coefficient is 0, so that the power compensation value gradually changes from the preset value to zero. The percentage reduction in the power compensation value in each control cycle can be determined by the compensation coefficient and the number of control cycles.

[0051] In some embodiments, before controlling the inverter output multiple times according to the control loop, a unit change value can be calculated based on a preset value and the scheduling response time; a linear function of the power compensation value change is established with the unit change value as the slope and the preset value as the intercept.

[0052] In this embodiment, the power compensation value changes from a preset value to zero during multiple control operations. This change can be a smooth, predictable, and linear decrease to zero during multiple control operations, avoiding power overshoot or oscillation caused by sudden changes in the power compensation value.

[0053] Here, the dispatch response time is the time it takes for the inverter to complete the dispatch response, and the power compensation value needs to change to zero within the dispatch response time. Therefore, within the dispatch response time, the unit change value of the power compensation value can be calculated with a preset value as the starting point of the power compensation value change and zero as the ending point of the power compensation value change.

[0054] This unit change is the change in power compensation value per unit time, determining the rate of change of the compensation value. Simultaneously, since the preset value is the starting point for the change in power compensation value, a linear function of the change in power compensation value can be established using the slope and intercept.

[0055] Here, the linear function can be a linear function in the continuous time domain. If the power compensation value changes with time during the scheduling response duration, then the expression for the linear function can be: In the formula, Indicates the power compensation value. This represents the slope of a linear function in the continuous time domain. Indicates duration, This represents the preset value, i.e., the intercept.

[0056] A linear function can also be a linear function of the discrete control cycle. Since the duration required for each control cycle is the same in multiple control operations, the variable of time can be transformed into the variable of the number of control cycles. For example, if a control cycle is performed every 72 microseconds, the change in the power compensation value over 72 microseconds can be calculated as the slope. Accordingly, the expression for the linear function can be obtained as follows: In the formula, The slope of the linear function representing the discrete control cycle. This indicates the number of times the number of times can be controlled.

[0057] Furthermore, the value of the aforementioned linear function is only taken from the preset value to zero to ensure control effectiveness. Once the power compensation value reaches zero, zero is always selected as the value, and no further value is taken from the linear function. For a linear function in the continuous time domain, the independent variable is duration. The maximum duration of change less than or equal to the power compensation value (the duration from the preset value to zero). For a linear function with a discrete control cycle, the number of independent control variables. The maximum number of changes less than or equal to the power compensation value (the number of times the control changes from the preset value to zero).

[0058] Optionally, the unit change value can be calculated based on the preset value and the scheduling response duration. This can be done by: first determining the compensation duration based on the scheduling response duration and the communication duration of the target power command; the compensation duration being less than or equal to the preset difference; the preset difference being the difference between the scheduling response duration and the communication duration; and then calculating the ratio of the preset value to the compensation duration to obtain the unit change value.

[0059] In this embodiment, the scheduling response time is the time from when the host computer issues the target power command to when the inverter completes the adjustment and feeds back to the host computer, including the time for the inverter to actually perform the adjustment, protocol transmission, verification, and data acquisition delays. The communication time is the time it takes for the target power command to be issued to the inverter, and effective compensation cannot be performed within the communication time.

[0060] The preset difference between the dispatch response time and the communication time is the theoretical maximum effective compensation time for the power compensation value. Therefore, the value of the compensation time needs to consider the inverter's own adjustment and the communication time to ensure that the compensation time does not exceed the preset difference, avoiding exceeding the upper limit of the dispatch response time and affecting the inverter's dispatch response performance. For example, if the dispatch response time is 60ms and the communication time is 25ms, the compensation time can be selected as 30ms. Alternatively, the compensation time can be predetermined using the dispatch response time and communication time, and the predetermined compensation time can be directly used for calculation when calculating unit change values.

[0061] Here, after obtaining the compensation duration, for a linear function in the continuous time domain, the ratio of the preset value to the compensation duration can be directly calculated to obtain the unit change value.

[0062] In some embodiments, determining the first power error value based on the target power value and the actual power value of the inverter output acquired in the current control can be achieved by: firstly acquiring the actual power value of the inverter output acquired in the current control, and the power compensation value in the current control; then calculating the sum of the target power value and the power compensation value to obtain the compensated target power value in the current control; and finally, calculating the difference between the compensated target power value and the actual power value to obtain the first power error value in the current control.

[0063] In the power loop, the target power value is the given power reference value of the power loop. In this embodiment, a power compensation value can be added to the target power value to compensate for the target power value. The sum of the target power value and the power compensation value, i.e., the compensated target power value, is used as the given power reference value of the power loop.

[0064] Here, the sign of the power compensation value is the same as that of the second power error value. If the actual power value is less than the target power value, the power compensation value is positive. If the actual power value is greater than the target power value, the power compensation value is negative. Correspondingly, the larger deviation between the compensated target power value and the actual power value allows the power loop to track the equivalent target with a larger offset in the early stage of control, accelerating power adjustment, and then track the original target power value in the later stage, achieving precise convergence while balancing response speed and stability.

[0065] Then, by taking the difference between the compensated target power value and the actual power value, we can obtain the power error value after compensation using the power compensation value, which is the first power error value in this control, and then carry out the control of the subsequent power loop.

[0066] In other embodiments, determining the first power error value based on the target power value and the actual power value of the inverter output acquired in this control can also be achieved by: first obtaining the actual power value of the inverter output acquired in this control, and the power compensation value in this control; then calculating the difference between the target power value and the actual power value to obtain the second power error value in this control; finally, calculating the sum of the second power error value and the power compensation value in this control to obtain the first power error value in this control.

[0067] Alternatively, instead of compensating for the target power value, compensation can be directly applied to the power error value. In this embodiment, the difference between the target power value and the actual power value is first calculated according to the power loop to obtain the second power error value, thus clarifying the deviation between the target power value and the actual power value. Then, the second power error value is compensated using the power compensation value, increasing the deviation between the target power value and the actual power value, resulting in the compensated power error value, which is the first power error value. This first power error value is then used for subsequent power loop control.

[0068] This embodiment shares the same core principle as the previous embodiments: increasing the deviation between the target power value and the actual power value to achieve rapid adjustment in the early stages. The difference lies in that this embodiment directly compensates for the power error value, while the previous embodiments compensated for the target power value. Both achieve the same effect.

[0069] Furthermore, in the above embodiments, the power compensation value changes from a preset value to zero during multiple control operations. Therefore, it is necessary to obtain the power compensation value for each control operation. Taking a linear function in the continuous time domain as an example, the power compensation value can be obtained by calculating the linear function value at the corresponding time of each control operation.

[0070] This application embodiment receives a target power command, which includes a target power value for the inverter to perform power scheduling response. The inverter performs power scheduling response according to the received target power command. During the scheduling response time, the inverter output is controlled multiple times using a control loop. In each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in that control, and this first power error value is used as the input of the power loop in the control loop within that control. The actual power output of the inverter can be adjusted using the first power error value so that the inverter outputs according to the requirements of the target power command. The first power error value in the multiple control operations is the sum of the power compensation value and the second power error value. The power error value changes from a preset value to zero in the multiple control operations and is consistent with the sign of the second power error value. The second power error value is the difference between the target power value and the actual power value of the inverter output collected in each control cycle. This means the input to the power loop in the control loop changes from the second power error value to the first power error value, increasing the absolute value of the power error value in the input power loop. This increases the difference in the power adjustment process, increasing the amplitude of power adjustment in each control cycle, thereby improving the change in the inverter's output power in each control cycle. This allows the inverter's actual power to reach the target power value more quickly, improving the response efficiency of the inverter's power scheduling. Furthermore, since the power compensation value changes from a preset value to zero in multiple control cycles, after the power compensation value reaches zero, the power error value in the input power loop becomes the second power error value, preventing further increases in the power error value. This ensures that the inverter's final actual output power still reaches the target power value, meeting the scheduling response requirements of the target power command. Specifically, using the difference between the target power value and the actual power value of the inverter output collected before multiple control cycles to determine the preset value allows the preset value to accurately match the deviation between the target power value and the inverter's actual power value, ensuring faster inverter adjustment while avoiding overshoot of the inverter's output power. The power compensation value changes from a preset value to zero during multiple control operations. By establishing a linear function within the corresponding scheduling time, the change in the power compensation value can be represented by a linear function, so that the power compensation value decreases smoothly and predictably to zero linearly, avoiding power overshoot or oscillation caused by sudden changes in the power compensation value.

[0071] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0072] The following are device embodiments of this application. For details not described in detail, please refer to the corresponding method embodiments described above.

[0073] Figure 6A schematic diagram of the grid-friendly inverter power control device provided in an embodiment of this application is shown. For ease of explanation, only the parts related to the embodiment of this application are shown, and are described in detail below: like Figure 6 As shown, the grid-friendly inverter power control device 60 includes: The receiving module 61 is used to receive the target power command; the target power command includes the target power value for the inverter to perform power scheduling response.

[0074] The control module 62 is used to control the output of the inverter multiple times according to the control loop within the scheduling response time; wherein, in each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in this control, and the first power error value is used as the input of the power loop in the control loop within this control; In multiple control operations, the first power error value is the sum of the power compensation value and the second power error value. The power compensation value changes from a preset value to zero in multiple control operations and is consistent with the sign of the second power error value. In each control operation, the second power error value is the difference between the target power value and the actual power value of the inverter output collected each time.

[0075] In one possible implementation, the grid-friendly inverter power control device 60 further includes a determining module for: Calculate the initial power error between the target power value and the currently acquired actual power value of the inverter output; The preset value is obtained based on the preset compensation coefficient and the initial power error value.

[0076] In one possible implementation, the determining module is also used for: Calculate the unit change value based on the preset value and the scheduling response time; A linear function of the power compensation value change is established, with the unit change value as the slope and the preset value as the intercept.

[0077] In one possible implementation, the module is specifically used for: The compensation duration is determined based on the scheduling response time and the communication duration of the target power command; the compensation duration is less than or equal to the preset difference; the preset difference is the difference between the scheduling response time and the communication duration. Calculate the ratio of the preset value to the compensation duration to obtain the unit change value.

[0078] In one possible implementation, the control module 62 is specifically used for: Obtain the actual power output value of the inverter collected during this control, as well as the power compensation value during this control; Calculate the sum of the target power value and the power compensation value to obtain the compensated target power value in this control. The difference between the compensated target power value and the actual power value is calculated to obtain the first power error value in this control.

[0079] In one possible implementation, the control module 62 is specifically used for: Obtain the actual power output value of the inverter collected during this control, as well as the power compensation value during this control; Calculate the difference between the target power value and the actual power value to obtain the second power error value in this control. The sum of the second power error value and the power compensation value in this control is calculated to obtain the first power error value in this control.

[0080] In one possible implementation, the control loop is a proportional-integral control loop; Control module 62 is specifically used for: In each control cycle, the second power error value obtained from that control cycle is calculated using proportional-integral calculation to obtain the target current value of the inverter. The current error value in this control is obtained by the difference between the target current value and the actual current value of the inverter collected in this control. Adjust the inverter's drive signal based on the current error value; Based on the adjusted drive signal, the inverter output is controlled to adjust the actual output power of the inverter.

[0081] For the sake of convenience and brevity, only the above division of functional modules / units is used as an example. In actual applications, the above functions can be assigned to different functional modules / units as needed.

[0082] This application also provides an inverter and a panoramic monitoring system. For details not described in detail, please refer to the corresponding method embodiments described above.

[0083] In some embodiments, the inverter includes a controller for implementing the methods described in the various embodiments above.

[0084] In some embodiments, refer to Figure 1 A panoramic monitoring system can include a host computer, data acquisition equipment, and multiple inverters as described above. It is an intelligent monitoring system applied to new energy power plants such as photovoltaic power plants and wind farms, enabling the monitoring and control of multiple inverters within the photovoltaic power station.

[0085] Here, the panoramic monitoring system can realize panoramic full-process monitoring and control of functions such as monitoring controllable resources of new energy power plants, monitoring sub / supersynchronous oscillations, and millisecond-level real-time tracking and lean control, which can effectively improve the economic efficiency of new energy power plant operation and the stability of the power grid.

[0086] This application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the methods described in the above-described method embodiments.

[0087] This application also provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the methods in the above-described method embodiments.

[0088] Computer programs include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. Computer-readable media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0089] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0090] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A grid-friendly inverter power control method, characterized in that, include: Receive a target power command; the target power command includes the target power value for the inverter to perform power scheduling response; Within the scheduling response time, the inverter output is controlled multiple times according to the control loop; wherein, in each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in that control, and the first power error value is used as the input of the power loop in the control loop within that control; In the multiple control operations, the first power error value is the sum of the power compensation value and the second power error value. The power compensation value changes from a preset value to zero in the multiple control operations and is consistent with the sign of the second power error value. In each control operation, the second power error value is the difference between the target power value and the actual power value output by the inverter collected each time.

2. The grid-friendly inverter power control method according to claim 1, characterized in that, Before performing multiple controls on the inverter output according to the control loop, the method further includes: Calculate the initial power error between the target power value and the currently acquired actual power value output by the inverter; The preset value is obtained based on the preset compensation coefficient and the initial power error value.

3. The grid-friendly inverter power control method according to claim 1, characterized in that, Before performing multiple controls on the inverter output according to the control loop, the method further includes: Calculate the unit change value based on the preset value and the scheduling response duration; A linear function of the power compensation value change is established, with the unit change value as the slope and the preset value as the intercept.

4. The grid-friendly inverter power control method according to claim 3, characterized in that, The step of calculating the unit change value based on the preset value and the scheduling response duration includes: The compensation duration is determined based on the scheduling response duration and the communication duration of the target power command; the compensation duration is less than or equal to a preset difference; the preset difference is the difference between the scheduling response duration and the communication duration. Calculate the ratio of the preset value to the compensation duration to obtain the unit change value.

5. The grid-friendly inverter power control method according to any one of claims 1 to 4, characterized in that, The step of determining the first power error value based on the target power value and the actual power value of the inverter output collected during this control includes: Obtain the actual power value of the inverter output collected during this control, as well as the power compensation value during this control; Calculate the sum of the target power value and the power compensation value to obtain the compensated target power value in this control. The difference between the compensated target power value and the actual power value is calculated to obtain the first power error value in this control.

6. The grid-friendly inverter power control method according to any one of claims 1 to 4, characterized in that, The step of determining the first power error value based on the target power value and the actual power value of the inverter output collected during this control includes: Obtain the actual power value of the inverter output collected during this control, as well as the power compensation value during this control; Calculate the difference between the target power value and the actual power value to obtain the second power error value in this control. The sum of the second power error value and the power compensation value in this control is calculated to obtain the first power error value in this control.

7. The grid-friendly inverter power control method according to any one of claims 1 to 4, characterized in that, The control loop is a proportional-integral control loop; The process of controlling the inverter output multiple times according to the control loop includes: In each control operation, the second power error value obtained from that control is calculated using proportional-integral calculation to obtain the target current value of the inverter. The current error value in this control is obtained based on the difference between the target current value and the actual current value of the inverter collected in this control. Adjust the inverter's drive signal based on the current error value; Based on the adjusted drive signal, the output of the inverter is controlled to adjust the actual power output of the inverter.

8. A grid-friendly inverter power control device, characterized in that, include: A receiving module is used to receive a target power command; the target power command includes the target power value for the inverter to perform power scheduling response; The control module is used to control the output of the inverter multiple times according to the control loop within the scheduling response time; wherein, in each control, a first power error value is determined based on the target power value and the actual power value of the inverter output collected in this control, and the first power error value is used as the input of the power loop in the control loop within this control; In the multiple control operations, the first power error value is the sum of the power compensation value and the second power error value. The power compensation value changes from a preset value to zero in the multiple control operations and is consistent with the sign of the second power error value. In each control operation, the second power error value is the difference between the target power value and the actual power value output by the inverter collected each time.

9. An inverter, characterized in that, Includes a controller for implementing the method as described in any one of claims 1 to 7.

10. A panoramic monitoring system, characterized in that, It includes a host computer, data acquisition equipment, and multiple inverters as described in claim 9.

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