CN113835464A - Photovoltaic control method, device, system and storage medium - Google Patents
Photovoltaic control method, device, system and storage medium Download PDFInfo
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Abstract
The application relates to a photovoltaic control method, a photovoltaic control device, a photovoltaic control system and a storage medium. The method comprises the following steps: acquiring a first feedback current and a first duty ratio; and determining a target duty ratio according to the first feedback current and the first duty ratio, and adjusting a pulse width modulation signal according to the target duty ratio by the pre-converter after the first time, so as to adjust the output current of the pre-converter and generate current disturbance, thereby adjusting the output power of the photovoltaic control system. The tracking of the maximum power point is realized only by the feedback current fed back by the post converter, the output power of the photovoltaic control system is not required to be regulated and controlled by sampling the output voltage and the output current of the photovoltaic array, and compared with the prior art, a pre-stage feedback loop for sampling the voltage and the current is omitted, so that components in the photovoltaic control system are reduced, the size of the photovoltaic control system is reduced, and the manufacturing cost of the system is reduced.
Description
Technical Field
The present application relates to the field of power electronics technologies, and in particular, to a photovoltaic control method, apparatus, system, and storage medium.
Background
The photovoltaic control is usually realized by a Maximum Power Point Tracking (MPPT for short) system, and the MPPT system is an electrical system which enables a photovoltaic panel to output more electric energy by adjusting the working state of an electrical module and can effectively store direct current generated by a solar cell panel in a storage battery, so that the problem of domestic and industrial electricity consumption in remote areas and tourist areas which cannot be covered by a conventional Power grid can be effectively solved, and no environmental pollution is generated.
The MPPT system is generally controlled by a two-stage photovoltaic inverter including a DC/DC pre-stage converter and a DC/AC post-stage converter, and the conventional control scheme is: the front-stage converter realizes maximum power point tracking and photovoltaic array output voltage lifting, and the rear-stage converter is responsible for controlling the network access current quality. However, in the control scheme, the pre-stage converter needs to sample the output voltage and the output current of the photovoltaic array through a feedback loop to realize maximum power point tracking, so that the MPPT system has more components, and the MPPT system is large in size and high in manufacturing cost.
Disclosure of Invention
In order to solve the technical problems of high manufacturing cost and large size of the existing MPPT system, the application provides a photovoltaic control method, a device, a system and a storage medium.
In a first aspect, the present application provides a photovoltaic control method, including:
acquiring a first feedback current and a first duty ratio, wherein the first feedback current is a current output by an outer ring voltage circuit in the photovoltaic control system at a first moment, and the first duty ratio is a duty ratio of a preceding converter in the photovoltaic control system at the first moment;
determining a target duty cycle according to the first feedback current and the first duty cycle, wherein the target duty cycle is used for adjusting the output power of the photovoltaic control system.
Optionally, the determining a target duty cycle according to the first feedback current and the first duty cycle includes:
and determining a target duty ratio according to a first variation between the first feedback current and a second variation between the first duty ratio and a second duty ratio, wherein the first feedback current is a current output by the outer ring voltage circuit at a second moment, the second duty ratio is a duty ratio output by the pre-converter at a second moment, and the second moment is earlier than the first moment.
Optionally, the determining a target duty cycle according to a first variation between the first current and the second current and a second variation between the first duty cycle and the second duty cycle comprises:
determining a step function output value according to the ratio of the first variable quantity to the second variable quantity;
obtaining a duty ratio difference value according to the product of the step function output value and a gain constant;
and obtaining the target duty ratio according to the sum of the duty ratio difference value and the numerical value of the first duty ratio.
Optionally, after the obtaining the first duty cycle, the method further includes:
and determining a third feedback current according to a first variation between the first feedback current and the second feedback current and a second variation between the first duty ratio and the second duty ratio, wherein the third feedback current is used as a current fed back to a preceding converter by a subsequent converter at a third moment, and the first moment is earlier than the third moment.
Optionally, determining a third feedback current according to a first variation between the first feedback current and the second feedback current and a second variation between the first duty cycle and the second duty cycle comprises:
and when the first variation is larger than a first threshold and the second variation is larger than a second threshold, or the first variation is smaller than the first threshold and the second variation is larger than the second threshold, taking the sum of the first variation and the first feedback current as the third feedback current.
Optionally, determining a third feedback current according to a first variation between the first feedback current and the second feedback current and a second variation between the first duty cycle and the second duty cycle comprises:
and when the first variation is smaller than a first threshold and the second variation is smaller than a second threshold, or the first variation is larger than the first threshold and the second variation is smaller than the second threshold, taking the difference between the first feedback current and the first variation as the third feedback current.
In a second aspect, the present application provides a photovoltaic control apparatus comprising:
the photovoltaic control system comprises a data acquisition module, a feedback module and a duty ratio acquisition module, wherein the data acquisition module is used for acquiring a first feedback current and a first duty ratio, the first feedback current is a current output by an outer ring voltage circuit in the photovoltaic control system at a first moment, and the first duty ratio is a duty ratio of a preceding converter in the photovoltaic control system at the first moment;
and the power adjusting module is used for determining a target duty ratio according to the first feedback current and the first duty ratio, wherein the target duty ratio is used for adjusting the output power of the photovoltaic control system.
In a third aspect, the present application provides a computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor implementing the following steps when executing the computer program:
the photovoltaic control system comprises a data acquisition module, a feedback module and a duty ratio acquisition module, wherein the data acquisition module is used for acquiring a first feedback current and a first duty ratio, the first feedback current is a current output by an outer ring voltage circuit in the photovoltaic control system at a first moment, and the first duty ratio is a duty ratio of a preceding converter in the photovoltaic control system at the first moment;
and the power adjusting module is used for determining a target duty ratio according to the first feedback current and the first duty ratio, wherein the target duty ratio is used for adjusting the output power of the photovoltaic control system.
In a fourth aspect, the present application provides a photovoltaic control system, the system comprising:
a photovoltaic array for converting solar energy into electrical energy;
the preceding-stage converter is connected with the photovoltaic array and used for receiving the output voltage and the output current of the photovoltaic array and regulating the output voltage according to the duty ratio fed back by the photovoltaic control device to obtain the regulated voltage after being regulated;
the photovoltaic control device is connected with the preceding-stage converter and the subsequent-stage converter and is used for adjusting the duty ratio of the preceding-stage converter according to the feedback current output by the outer ring voltage circuit;
the backward converter is connected with the forward converter and used for performing voltage conversion on the regulated voltage output by the forward converter to obtain converted alternating voltage;
and the filter is connected with the post converter and used for filtering the alternating voltage, and the filtered alternating voltage is used for generating the output power of the photovoltaic control system.
In a fifth aspect, the present application provides a computer readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of:
the photovoltaic control system comprises a data acquisition module, a feedback module and a duty ratio acquisition module, wherein the data acquisition module is used for acquiring a first feedback current and a first duty ratio, the first feedback current is a current output by an outer ring voltage circuit in the photovoltaic control system at a first moment, and the first duty ratio is a duty ratio of a preceding converter in the photovoltaic control system at the first moment;
and the power adjusting module is used for determining a target duty ratio according to the first feedback current and the first duty ratio, wherein the target duty ratio is used for adjusting the output power of the photovoltaic control system.
Based on the photovoltaic control method, a first feedback current and a first duty ratio are obtained, wherein the first feedback current is the current output by an outer ring voltage circuit in the photovoltaic control system at a first moment, and the first duty ratio is the duty ratio of a preceding converter in the photovoltaic control system at the first moment; and determining a target duty ratio according to the first feedback current and the first duty ratio, and adjusting a pulse width modulation signal (PWM signal) by the pre-converter according to the target duty ratio after the first time so as to adjust the output current of the pre-converter and generate current disturbance, thereby adjusting the output power of the photovoltaic control system. The tracking of the maximum power point is realized only by the feedback current fed back by the post converter, the output power of the photovoltaic control system is not required to be regulated and controlled by sampling the output voltage and the output current of the photovoltaic array, and compared with the prior art, a pre-stage feedback loop for sampling the voltage and the current is omitted, so that components in the photovoltaic control system are reduced, the size of the photovoltaic control system is reduced, and the manufacturing cost of the system is reduced.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.
FIG. 1 is a schematic diagram of a photovoltaic control system according to one embodiment;
FIG. 2 is a detailed schematic diagram of a photovoltaic control system in one embodiment;
FIG. 3 is a schematic flow diagram of a photovoltaic control method in one embodiment;
FIG. 4 is a schematic illustration of an I-V characteristic of a photovoltaic array in one embodiment;
FIG. 5 is a block diagram of a photovoltaic control apparatus according to an embodiment;
FIG. 6 is a diagram illustrating an internal structure of a computer device according to an embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Fig. 1 is an application environment diagram of a photovoltaic control method in one embodiment. Referring to fig. 1, the photovoltaic control method is applied to a photovoltaic control system. This photovoltaic control system includes:
a photovoltaic array 110 for converting solar energy into electrical energy.
In particular, PV Strings in FIG. 2 is used to indicate the photovoltaic array 110, PpvFor indicating the output power, P, of the photovoltaic array 110pv＝Ipv*Vpv，IpvIndicating the output current, V, of the photovoltaic array 110pvIndicating the output voltage of the photovoltaic array 110.
And the pre-converter 120 is connected to the photovoltaic array 110, and is configured to receive the output voltage and the output current of the photovoltaic array 110, and adjust the output voltage according to a duty ratio fed back by the photovoltaic control device 170, so as to obtain an adjusted voltage after being adjusted.
Specifically, the converter may be classified by function into a boost converter, a buck converter, and a buck-boost converter. The converters may be classified into a direct current-direct current (DC-DC) converter, a direct current-alternating current-direct current (DC-AC-DC) converter, and a direct current-alternating current (DC-AC) converter according to the implementation principle. In the present embodiment, the pre-converter 120 employs a BOOST direct current-direct current (DC-DC) converter, and BOOST in fig. 2 indicates the pre-converter 120.
And a photovoltaic control device 170 connected to the pre-converter 120 and the post-converter 130, for adjusting the duty ratio of the pre-converter 120 according to the feedback current output by the outer loop voltage circuit 150.
And a post-converter 130, connected to the pre-converter 120, for performing voltage conversion on the regulated voltage output by the pre-converter 120 to obtain a converted ac voltage.
In the present embodiment, the post-converter 130 is a direct current-alternating current (DC-AC) converter, the Inverter in fig. 2 is used to indicate the post-converter 130, and referring to fig. 2, the post-stage adopts a voltage-current dual-loop control strategy, the output of the outer-loop voltage circuit 150 is used as the input current amplitude of the inner-loop current circuit 160, i.e. the DC bus voltage is given
And a sampling voltage VdcAfter PI modulation, the voltage is further regulated to the slave network side voltage VgThe signals obtained by the phase-locked loop are multiplied to obtain the input current amplitude of the inner loop current circuit 160
The inner loop current circuit 160 will again
And the current i from the network sidegAfter subtraction, the pulse width modulation signal PWM of the post-converter 130 is output in combination with the carrier signal after PR quasi-resonance controlinvBy width modulation signal PWMinvTo control the quality of the network access current.
The outer loop voltage circuit 150 includes a first subtractor and a PI controller in fig. 2, the first subtractor is used for setting the dc bus voltage to a given value
And a sampling voltage VdcPerforming a subtraction operation, the inner loop current circuit 160 includes a second subtractor for subtracting the input current amplitude, a PR controller and a multiplier in FIG. A
And the current i from the network sidegAnd performing subtraction operation. Sampling voltage VdcIs a constant, the output power of the photovoltaic array 110 and the feedback current I of the post-converter 130refProportional, therefore, by detecting IrefWithout sampling the output current I of the photovoltaic array 110 to detect the MPPT controlpvAnd an output voltage Vpv. The implementation mode adopts the traditional PI control strategy for the outer ring voltage circuit 150 and the quasi-resonance PR control strategy for the inner ring current circuit 160, so as to improve the control precision.
And a filter 140 connected to the post-converter 130 and configured to filter the ac voltage, where the filtered ac voltage is used to generate output power of the photovoltaic control system. Filter in fig. 2 is used to indicate the Filter 140.
The traditional MPPT control method is realized by a preceding feedback loop, and the output voltage V of the photovoltaic array 110 needs to be sampledpvAnd an output current IpvBy an output voltage VpvAnd an output current IpvMPPT control is realized, and therefore a preceding-stage feedback loop needs to be additionally arranged, components of a photovoltaic control system are increased, and the photovoltaic control system is large in size and high in manufacturing cost.
In this embodiment, the MPPT control can be realized by only acquiring the feedback current of the post-converter 130 to modulate the duty ratio of the pre-converter 120 without adding a pre-feedback loop, thereby simplifying the photovoltaic control system, reducing the volume of the photovoltaic control system, and reducing the system cost.
In one embodiment, fig. 3 is a flow chart illustrating a photovoltaic control method according to one embodiment, and referring to fig. 2, a photovoltaic control method is provided. The present embodiment is mainly exemplified by applying the method to the photovoltaic control apparatus 170 in fig. 1, and the photovoltaic control method specifically includes the following steps:
step S210, a first feedback current and a first duty ratio are obtained.
In the present embodiment, the first feedback current is a current output by the outer loop voltage circuit 150 in the photovoltaic control system at a first time, and the first duty ratio is a duty ratio of the pre-converter 120 in the photovoltaic control system at the first time.
Step S220, determining a target duty ratio according to the first feedback current and the first duty ratio, wherein the target duty ratio is used for adjusting the output power of the photovoltaic control system.
In this embodiment, after the first time, the pre-converter 120 adjusts the pulse width modulation signal (PWM signal) of the pre-converter 120 according to the target duty ratio, and further adjusts the output current of the pre-converter 120, so as to generate current disturbance, thereby adjusting the output power of the photovoltaic control system, and as the output voltage of the photovoltaic array 110 is higher, the photovoltaic control system can output more electric quantity through maximum power tracking adjustment, thereby improving the charging efficiency of the photovoltaic control system to the storage battery.
The tracking of the maximum power point is realized only by the feedback current fed back by the post-converter 130, the output power of the photovoltaic control system is not required to be regulated and controlled by sampling the output voltage and the output current of the photovoltaic array 110, and compared with the prior art, a pre-stage feedback loop for sampling the voltage and the current is omitted, so that components in the photovoltaic control system are reduced, the size of the photovoltaic control system is reduced, and the manufacturing cost of the system is reduced.
In one embodiment, the determining a target duty cycle from the first feedback current and the first duty cycle comprises: and determining a target duty ratio according to a first variation between the first feedback current and the second feedback current and a second variation between the first duty ratio and the second duty ratio.
Specifically, the first feedback current is a current output by the outer loop voltage circuit 150 at a second time, the second duty cycle is a duty cycle of the pre-converter 120 at the second time, the second time is earlier than the first time, that is, the second time is a time before and closest to the first time, and the first feedback current is denoted as Iref(k) And the second feedback current is denoted as Iref(k-1), the first transformation amount is recorded as Δ Iref＝Iref(k)-Iref(k-1), the first duty cycle is recorded as DkOf 1 atTwo duty cycles are noted as Dk-1If the first duty cycle is Δ D ═ Dk-Dk-1The adjustment direction of the photovoltaic control system is determined through the variation of the feedback current and the variation of the duty ratio, that is, the target duty ratio of the pre-converter 120 after the first time is determined, and the output power of the photovoltaic control system is influenced by changing the duty ratio of the pre-converter 120, so that the output power of the photovoltaic control system and the output power of the photovoltaic array 110 are close to reach the maximum power point, thereby realizing the maximum power point tracking and improving the charging efficiency of the storage battery.
In one embodiment, the determining a target duty cycle from a first amount of change between the first and second currents and a second amount of change between the first and second duty cycles comprises: determining a step function output value according to the ratio of the first variable quantity to the second variable quantity; obtaining a duty ratio difference value according to the product of the step function output value and a gain constant; and obtaining the target duty ratio according to the sum of the duty ratio difference value and the numerical value of the first duty ratio.
Specifically, the calculation formula of the duty ratio difference value is as follows:
ΔD＝ξ*sgn(ΔIref/ΔD)
where ξ is a gain constant, which can be customized according to actual conditions, and ξ is 0.05 in this embodiment, and sgn function is a step function for determining Δ IrefThe sign of the sum Delta D determines the magnitude of the subsequent feedback current, and the target duty ratio is recorded as Dk+1＝Dk+ΔD。
In one embodiment, after the obtaining the first duty cycle, the method further comprises: and determining a third feedback current according to a first variation between the first feedback current and the second feedback current and a second variation between the first duty ratio and the second duty ratio, wherein the third feedback current is used as a current fed back to the forward converter 120 by the backward converter 130 at a third moment, and the first moment is earlier than the third moment.
Specifically, based on the above embodimentStep function according to the first variation DeltaIrefAnd the second variation deltaD determines the magnitude of a third feedback current, denoted as Iref(k +1), namely the third time is the next time after the first time, and in the case that the first time indicates the current time, the feedback current magnitude at the next time can be determined according to the first transformation amount and the second transformation amount at the current time, so as to determine the adjustment direction of the feedback current.
In one embodiment, determining a third feedback current based on a first amount of change between the first feedback current and the second feedback current, and a second amount of change between the first duty cycle and the second duty cycle comprises: and when the first variation is larger than a first threshold and the second variation is larger than a second threshold, or the first variation is smaller than the first threshold and the second variation is larger than the second threshold, taking the sum of the first variation and the first feedback current as the third feedback current.
Specifically, the first threshold and the second threshold are both 0 to realize the step function in the above embodiment, and the I-V characteristic curve and the P-V characteristic curve of the photovoltaic array 110 may be divided into a current source region and a voltage source region, as shown in fig. 4, where the boundary line is the maximum power point voltage VmTo limit, VmV 'is not a fixed value and varies with ambient light and temperature'mThe maximum power point voltage value after the follow-up change.
When the photovoltaic array 110 operates in the current source region, the duty ratio of the pre-stage converter 120 decreases as the feedback current increases, that is, the duty ratio increases in inverse proportion to the feedback current; when the photovoltaic array 110 operates in the voltage source region, the duty cycle of the pre-converter 120 increases as the feedback current increases, i.e., the duty cycle increases in proportion to the feedback current.
First variation Δ IrefIf the current feedback current is larger than 0, the feedback current at the current time is larger than the previous feedback current, that is, the feedback current tends to increase, the second variation Δ D is larger than 0, and the duty ratio of the previous converter 120 at the current time is larger than the previous duty ratio, that is, the duty ratio of the previous converter 120 is larger than 0The duty cycle increases with increasing feedback current, i.e., the photovoltaic array 110 is currently operating in the voltage source region.
First variation Δ IrefLess than 0, which indicates that the feedback current at the current time is less than the feedback current at the previous time, that is, the feedback current is in a downward trend, the second variation Δ D is greater than 0, which indicates that the duty ratio of the previous converter 120 at the current time is greater than the duty ratio at the previous time, that is, the duty ratio of the previous converter 120 is in an increasing trend, and the duty ratio is increased along with the decrease of the feedback current, that is, the photovoltaic array 110 is currently operated in the current source region.
At Δ Iref> 0 and Δ D > 0, or is, Δ IrefIf < 0 and Δ D > 0, the third feedback current is Iref(k+1)＝Iref(k)+ΔIrefAnd increasing the feedback current at the next moment until the duty ratio conversion amount of the pre-stage converter 120 is less than zero, so that the output power of the photovoltaic control system approaches the maximum power point.
In one embodiment, determining a third feedback current based on a first amount of change between the first feedback current and the second feedback current, and a second amount of change between the first duty cycle and the second duty cycle comprises: and when the first variation is smaller than a first threshold and the second variation is smaller than a second threshold, or the first variation is larger than the first threshold and the second variation is smaller than the second threshold, taking the difference between the first feedback current and the first variation as the third feedback current.
Specifically, the first variation Δ IrefLess than 0, which indicates that the feedback current at the current time is smaller than the feedback current at the previous time, that is, the feedback current is in a downward trend, the second variation Δ D is less than 0, which indicates that the duty ratio of the previous converter 120 at the current time is smaller than the duty ratio at the previous time, that is, the duty ratio of the previous converter 120 is in a downward trend, and the duty ratio is reduced as the feedback current is reduced, that is, the photovoltaic array 110 operates in the voltage source region.
First variation Δ IrefAbove 0, the feedback current increasesWhen the second variation Δ D is smaller than 0, the duty ratio of the pre-stage converter 120 is in a decreasing trend, and the duty ratio decreases as the feedback current increases, that is, the photovoltaic array 110 operates in the current source region.
At Δ Iref< 0 and Δ D < 0, or, Δ IrefWhen the current is greater than 0 and Delta D is less than 0, the third feedback current is Iref(k+1)＝Iref(k)-ΔIrefAnd increasing the feedback current at the next moment until the duty ratio conversion amount of the pre-stage converter 120 is larger than zero, so that the output power of the photovoltaic control system approaches the maximum power point.
Fig. 3 is a schematic flow chart of a photovoltaic control method according to an embodiment. It should be understood that, although the steps in the flowchart of fig. 3 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 3 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.
In one embodiment, as shown in fig. 5, there is provided a photovoltaic control apparatus 170 comprising:
a data obtaining module 310, configured to obtain a first feedback current and a first duty ratio, where the first feedback current is a current output by an outer ring voltage circuit 150 in the photovoltaic control system at a first time, and the first duty ratio is a duty ratio of a pre-stage converter 120 in the photovoltaic control system at the first time;
a power adjustment module 320 configured to determine a target duty cycle according to the first feedback current and the first duty cycle, wherein the target duty cycle is used to adjust an output power of the photovoltaic control system.
In one embodiment, the power adjustment module 320 is further configured to:
determining a target duty ratio according to a first variation between the first feedback current and a second feedback current, and a second variation between the first duty ratio and a second duty ratio, wherein the first feedback current is a current output by the outer loop voltage circuit 150 at a second time, the second duty ratio is a duty ratio output by the pre-converter 120 at a second time, and the second time is earlier than the first time.
In one embodiment, the power adjustment module 320 is further configured to:
determining a step function output value according to the ratio of the first variable quantity to the second variable quantity;
obtaining a duty ratio difference value according to the product of the step function output value and a gain constant;
and obtaining the target duty ratio according to the sum of the duty ratio difference value and the numerical value of the first duty ratio.
In one embodiment, after obtaining the first duty cycle, the power adjustment module 320 is further configured to:
and determining a third feedback current according to a first variation between the first feedback current and the second feedback current and a second variation between the first duty ratio and the second duty ratio, wherein the third feedback current is used as a current fed back to the forward converter 120 by the backward converter 130 at a third moment, and the first moment is earlier than the third moment.
In one embodiment, the power adjustment module 320 is further configured to:
and when the first variation is larger than a first threshold and the second variation is larger than a second threshold, or the first variation is smaller than the first threshold and the second variation is larger than the second threshold, taking the sum of the first variation and the first feedback current as the third feedback current.
In one embodiment, the power adjustment module 320 is further configured to:
and when the first variation is smaller than a first threshold and the second variation is smaller than a second threshold, or the first variation is larger than the first threshold and the second variation is smaller than the second threshold, taking the difference between the first feedback current and the first variation as the third feedback current.
FIG. 6 is a diagram illustrating an internal structure of a computer device in one embodiment. The computer device may specifically be the photovoltaic control apparatus 170 in fig. 1. As shown in fig. 6, the computer apparatus includes a processor, a memory, a network interface, an input device, and a display screen connected through a system bus. Wherein the memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program which, when executed by the processor, causes the processor to implement the photovoltaic control method. The internal memory may also have a computer program stored therein, which, when executed by the processor, causes the processor to perform the photovoltaic control method. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on the shell of the computer equipment, an external keyboard, a touch pad or a mouse and the like.
Those skilled in the art will appreciate that the architecture shown in fig. 6 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.
In one embodiment, the photovoltaic control apparatus 170 provided herein may be implemented in the form of a computer program that is executable on a computer device as shown in fig. 6. The memory of the computer device may store various program modules that make up the photovoltaic control apparatus 170, such as the data acquisition module 310 and the power adjustment module 320 shown in fig. 5. The computer program constituted by the respective program modules causes the processor to execute the steps in the photovoltaic control method of the respective embodiments of the present application described in the present specification.
The computer apparatus shown in fig. 6 may perform the step of acquiring a first feedback current and a first duty ratio by using the data acquisition module 310 in the photovoltaic control apparatus 170 shown in fig. 5, where the first feedback current is a current output by the outer loop voltage circuit 150 in the photovoltaic control system at a first time, and the first duty ratio is a duty ratio of the pre-converter 120 in the photovoltaic control system at the first time. The computer device may determine a target duty cycle from the first feedback current and the first duty cycle, where the target duty cycle is used to regulate the output power of the photovoltaic control system, which may be performed by a power regulation module 320.
In one embodiment, a computer device is provided, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor implementing the method of any of the above embodiments when executing the computer program.
In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, carries out the method of any of the above embodiments.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by instructing the relevant hardware through a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), double-rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), synchronous Link (Synchlink) DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and bus dynamic RAM (RDRAM).
It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A photovoltaic control method, the method comprising:
acquiring a first feedback current and a first duty ratio, wherein the first feedback current is a current output by an outer ring voltage circuit in the photovoltaic control system at a first moment, and the first duty ratio is a duty ratio of a preceding converter in the photovoltaic control system at the first moment;
determining a target duty cycle according to the first feedback current and the first duty cycle, wherein the target duty cycle is used for adjusting the output power of the photovoltaic control system.
2. The method of claim 1, wherein determining a target duty cycle from the first feedback current and the first duty cycle comprises:
and determining a target duty ratio according to a first variation between the first feedback current and a second variation between the first duty ratio and a second duty ratio, wherein the first feedback current is a current output by the outer ring voltage circuit at a second moment, the second duty ratio is a duty ratio output by the pre-converter at a second moment, and the second moment is earlier than the first moment.
3. The method of claim 2, wherein determining a target duty cycle from a first amount of change between the first and second currents and a second amount of change between the first and second duty cycles comprises:
determining a step function output value according to the ratio of the first variable quantity to the second variable quantity;
obtaining a duty ratio difference value according to the product of the step function output value and a gain constant;
and obtaining the target duty ratio according to the sum of the duty ratio difference value and the numerical value of the first duty ratio.
4. The method of claim 2, wherein after obtaining the first duty cycle, the method further comprises:
and determining a third feedback current according to a first variation between the first feedback current and the second feedback current and a second variation between the first duty ratio and the second duty ratio, wherein the third feedback current is used as a current fed back to a preceding converter by a subsequent converter at a third moment, and the first moment is earlier than the third moment.
5. The method of claim 4, wherein determining a third feedback current based on a first amount of change between the first feedback current and the second feedback current and a second amount of change between the first duty cycle and the second duty cycle comprises:
and when the first variation is larger than a first threshold and the second variation is larger than a second threshold, or the first variation is smaller than the first threshold and the second variation is larger than the second threshold, taking the sum of the first variation and the first feedback current as the third feedback current.
6. The method of claim 4, wherein determining a third feedback current based on a first amount of change between the first feedback current and the second feedback current and a second amount of change between the first duty cycle and the second duty cycle comprises:
and when the first variation is smaller than a first threshold and the second variation is smaller than a second threshold, or the first variation is larger than the first threshold and the second variation is smaller than the second threshold, taking the difference between the first feedback current and the first variation as the third feedback current.
7. A photovoltaic control apparatus, characterized in that the apparatus comprises:
the photovoltaic control system comprises a data acquisition module, a feedback module and a duty ratio acquisition module, wherein the data acquisition module is used for acquiring a first feedback current and a first duty ratio, the first feedback current is a current output by an outer ring voltage circuit in the photovoltaic control system at a first moment, and the first duty ratio is a duty ratio of a preceding converter in the photovoltaic control system at the first moment;
and the power adjusting module is used for determining a target duty ratio according to the first feedback current and the first duty ratio, wherein the target duty ratio is used for adjusting the output power of the photovoltaic control system.
8. A photovoltaic control system, the system comprising:
a photovoltaic array for converting solar energy into electrical energy;
the preceding-stage converter is connected with the photovoltaic array and used for receiving the output voltage and the output current of the photovoltaic array and regulating the output voltage according to the duty ratio fed back by the photovoltaic control device to obtain the regulated voltage after being regulated;
the photovoltaic control device is connected with the preceding-stage converter and the subsequent-stage converter and is used for adjusting the duty ratio of the preceding-stage converter according to the feedback current output by the outer ring voltage circuit;
the backward converter is connected with the forward converter and used for performing voltage conversion on the regulated voltage output by the forward converter to obtain converted alternating voltage;
and the filter is connected with the post converter and used for filtering the alternating voltage, and the filtered alternating voltage is used for generating the output power of the photovoltaic control system.
9. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the steps of the method of any of claims 1 to 6 are implemented when the computer program is executed by the processor.
10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 6.
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