CN-122018626-A - Maximum power automatic optimizing method and system for photovoltaic inverter

CN122018626ACN 122018626 ACN122018626 ACN 122018626ACN-122018626-A

Abstract

The invention belongs to the technical field of photovoltaic power generation, and provides a method and a system for automatically optimizing the maximum power of a photovoltaic inverter, wherein the method comprises the steps of obtaining key parameters of the photovoltaic inverter and the current bus voltage, wherein the key parameters at least comprise an automatic optimizing voltage range and an automatic optimizing disturbance time step; and judging whether the obtained current bus voltage is in an automatic optimizing voltage range, if not, adjusting the IGBT duty ratio of the DC/DC boosting unit of the photovoltaic inverter, calculating the power generation power of the photovoltaic inverter after adjustment, optimizing the variable step voltage disturbance based on the power generation power of the photovoltaic inverter after adjustment to obtain the maximum power of the photovoltaic inverter, and completing the automatic optimizing of the maximum power of the photovoltaic inverter.

Inventors

JIANG PEIPENG
LIU ZHICHENG
HOU JINGWEI
ZHANG ZHIJIAN
LI YUAN
Fu Taolin
WANG DAHAI

Assignees

山东华电节能技术有限公司

Dates

Publication Date: 20260512
Application Date: 20251219

Claims (10)

1. The maximum power automatic optimizing method of the photovoltaic inverter is characterized by comprising the following steps of: obtaining key parameters of a photovoltaic inverter and current bus voltage, wherein the key parameters at least comprise an automatic optimizing voltage range and an automatic optimizing disturbance time step; judging whether the obtained current bus voltage is in an automatic optimizing voltage range, if not, adjusting the IGBT duty ratio of the DC/DC boosting unit of the photovoltaic inverter, and calculating the power generation power of the photovoltaic inverter after adjustment; And optimizing the variable step voltage disturbance based on the adjusted generated power of the photovoltaic inverter to obtain the maximum power of the photovoltaic inverter, and completing the automatic optimizing of the maximum power of the photovoltaic inverter.
2. The method for automatically optimizing the maximum power of a photovoltaic inverter according to claim 1, wherein the step-variable voltage disturbance optimizing comprises the following steps: applying initial voltage disturbance, measuring the power generated by the photovoltaic inverter after the disturbance, and calculating the ratio of the power generated by the photovoltaic inverter to the voltage variation to obtain the power-voltage variation rate; Calculating the next voltage disturbance step by using a variable step algorithm based on the current power-voltage change rate and the historical power-voltage change rate; applying the obtained next voltage disturbance step length, updating the voltage of the direct current bus, and calculating new photovoltaic power generation power and power-voltage change rate; and iteratively calculating the next voltage disturbance step length and the power-voltage change rate until a preset convergence condition is met, and completing variable step length voltage disturbance optimizing.
3. The method for automatically optimizing the maximum power of a photovoltaic inverter according to claim 2, wherein the preset convergence condition is that the absolute value of the power variation of the voltage disturbance is smaller than a set threshold value for several consecutive times.
4. The method of automatic optimizing maximum power of a photovoltaic inverter according to claim 2, wherein when the optimizing process converges to the vicinity of the maximum power point, a steady-state maintenance mode is entered, voltage disturbance is reduced or suspended, power variation is continuously monitored, if drift occurs at the maximum power point, the optimizing process is restarted, in the optimizing process, the step size of the voltage disturbance and the voltage value are monitored in real time, if continuous divergence of the step size or continuous exceeding of the optimizing range of the voltage is detected, automatic optimizing abnormality is determined, automatic optimizing is intervened, and a fault alarm is issued.
5. The method for automatically optimizing maximum power of a photovoltaic inverter according to claim 4, wherein the judging condition of continuous divergence of step sizes is that when the absolute value of the voltage disturbance step sizes calculated for a plurality of times continuously increases and exceeds a safety threshold or the voltage of a direct current bus continuously exceeds an automatic optimizing voltage range, the MPPT controller judges that the automatic optimizing is likely to generate divergency oscillation or have faults such as local shielding, component damage and the like, and the MPPT controller forcibly resets the disturbance step sizes to an automatic optimizing base voltage step size or pulls the voltage back to the starting point of the optimizing range to trigger a fault alarm signal.
6. The automatic optimizing method for maximum power of a photovoltaic inverter according to claim 1, wherein the automatic optimizing method for maximum power of a photovoltaic inverter is realized based on an automatic optimizing device for maximum power of a photovoltaic inverter, and the automatic optimizing device for maximum power of a photovoltaic inverter at least comprises a photovoltaic matrix, a photovoltaic matrix direct current bus, a DC/DC boosting unit, an inversion unit direct current bus, a DC/AC inversion unit, an alternating current filtering unit, a power grid and an MPPT control unit.
7. A maximum power automatic optimizing system of a photovoltaic inverter, comprising: An acquisition module configured to acquire key parameters of the photovoltaic inverter and a current bus voltage, the key parameters including at least an automatic optimizing voltage range, an automatic optimizing disturbance time step; The judging module is configured to judge whether the acquired current bus voltage is in an automatic optimizing voltage range, if not, the IGBT duty ratio of the DC/DC boosting unit of the photovoltaic inverter is adjusted, and the power generation power of the photovoltaic inverter after adjustment is calculated; and the optimizing module is configured to perform optimizing of variable step voltage disturbance based on the adjusted power generation power of the photovoltaic inverter, obtain the maximum power of the photovoltaic inverter and complete automatic optimizing of the maximum power of the photovoltaic inverter.
8. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the steps of the method for automatic maximum power optimization of a photovoltaic inverter according to any one of claims 1-6.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and running on the processor, characterized in that the processor implements the steps of the method for automatic optimizing the maximum power of a photovoltaic inverter according to any one of claims 1-6 when executing the program.
10. A computer program product comprising software code, characterized in that a program in said software code performs the steps of the method for automatic maximum power optimization of a photovoltaic inverter according to any of claims 1-6.

Description

Maximum power automatic optimizing method and system for photovoltaic inverter Technical Field The invention belongs to the technical field of photovoltaic power generation, and particularly relates to a maximum power automatic optimizing method and system of a photovoltaic inverter. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. Under different external conditions, such as panel temperature, irradiance, load, etc., photovoltaic cells present different and unique maximum power points. Therefore, if the photovoltaic power generation system cannot timely adjust the working state of the photovoltaic cell according to the change of the external environment, the maximum power is used for converting light energy into electric energy, the generated energy of the photovoltaic power station can be reduced, and the economic benefit is lost. With respect to photovoltaic cell maximum power point tracking, it is currently basically implemented in photovoltaic inverters. Common maximum power point tracking modes include a voltage disturbance method, a conductance increment method, an artificial intelligence-based maximum power point tracking (Maximum power point tracking, abbreviated as MPPT) control method and the like. The voltage disturbance method and the conductivity increment method are simpler, but have the problems of misjudgment and oscillation, and though the misjudgment and the oscillation are improved by the measures of changing step length, introducing hysteresis comparison, introducing center difference and the like, the misjudgment and the oscillation can not be completely avoided, and the working condition judgment of a plurality of measures is complex. The MPPT control method based on artificial intelligence can accurately obtain the maximum power point, requires longer training and learning besides larger calculation force, and needs to accumulate again once abnormality (such as a photovoltaic panel is shielded) occurs. Disclosure of Invention In order to solve the problems, the invention provides a maximum power automatic optimizing method and system of a photovoltaic inverter, which are based on a step-variable mechanism of a power-voltage change rate, so that the step size of the photovoltaic inverter can be automatically reduced when the photovoltaic inverter is close to a maximum power point, steady-state oscillation near the maximum power point is eliminated through a steady-state maintenance mode, and the tracking precision and the power generation efficiency of the maximum power of the photovoltaic inverter are obviously improved. According to some embodiments, the first scheme of the present invention provides a method for automatically optimizing maximum power of a photovoltaic inverter, which adopts the following technical scheme: a maximum power automatic optimizing method of a photovoltaic inverter comprises the following steps: obtaining key parameters of a photovoltaic inverter and current bus voltage, wherein the key parameters at least comprise an automatic optimizing voltage range and an automatic optimizing disturbance time step; judging whether the obtained current bus voltage is in an automatic optimizing voltage range, if not, adjusting the IGBT duty ratio of the DC/DC boosting unit of the photovoltaic inverter, and calculating the power generation power of the photovoltaic inverter after adjustment; And optimizing the variable step voltage disturbance based on the adjusted generated power of the photovoltaic inverter to obtain the maximum power of the photovoltaic inverter, and completing the automatic optimizing of the maximum power of the photovoltaic inverter. As a further technical limitation, the variable step voltage disturbance optimizing process is as follows: applying initial voltage disturbance, measuring the power generated by the photovoltaic inverter after the disturbance, and calculating the ratio of the power generated by the photovoltaic inverter to the voltage variation to obtain the power-voltage variation rate; Calculating the next voltage disturbance step by using a variable step algorithm based on the current power-voltage change rate and the historical power-voltage change rate; applying the obtained next voltage disturbance step length, updating the voltage of the direct current bus, and calculating new photovoltaic power generation power and power-voltage change rate; and iteratively calculating the next voltage disturbance step length and the power-voltage change rate until a preset convergence condition is met, and completing variable step length voltage disturbance optimizing. Further, the preset convergence condition is that absolute values of power changes of continuous voltage disturbance for several times are smaller than a set threshold value. Further, when the optimizing process is converged near the maximum power point, a steady-state m