CN-121726965-B - Bus current ripple suppression method, device and medium

CN121726965BCN 121726965 BCN121726965 BCN 121726965BCN-121726965-B

Abstract

The application discloses a bus current ripple suppression method, equipment and medium, which comprise the steps of acquiring electric quantity data of each direct current booster circuit in a current running state in real time, calculating phase shift angles required by each direct current booster circuit by taking the minimum total alternating current component output to a direct current bus by all the direct current booster circuits as a target based on the acquired electric quantity data, and carrying out phase modulation on driving signals of each direct current booster circuit according to the obtained phase shift angles. Both the apparatus and the medium are used to implement the methods described above. The application has the beneficial effects that the phase shift angle can be dynamically changed instead of fixed in the process of suppressing the bus current ripple, thereby solving the problem of poor bus current ripple suppression effect when the input voltage and the current are different. The minimized fundamental wave component of the current ripple or the effective value of the current ripple is directly selected as an optimization target, so that the heating value of the system can be effectively reduced.

Inventors

XU PO
JIANG LIANGJIE
SUN YONG
ZHANG TAO

Assignees

锦浪科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260213

Claims (4)

1. The bus current ripple suppression method is applied to a photovoltaic system with a plurality of paths of direct current boost circuits connected in parallel with a direct current bus through output, and is characterized by comprising the following steps of: Acquiring electric quantity data of each path of direct current booster circuit in the current running state in real time, wherein the electric quantity data comprises input voltage, output voltage, average current and duty ratio information; Based on the obtained electric quantity data, dynamically calculating the phase shift angle required by each path of direct current booster circuit by taking the minimum total alternating current component output by all the direct current booster circuits to the direct current bus as a target; carrying out phase modulation on driving signals of each path of direct current booster circuit according to the obtained phase shift angle; Based on the obtained electric quantity data, extracting fundamental wave components of the currents output by each path of direct current booster circuit to the direct current bus, taking the obtained fundamental wave components as space vectors, and calculating space vectors corresponding to all direct current booster circuits and the minimum phase to obtain the phase shift angle required by the minimum total alternating current component; When the number of paths N of the direct current booster circuits is more than 3 and the corresponding space vectors can be closed end to form a closed graph, calculating the phase shift angles of the direct current booster circuits comprises the following steps of taking the phase shift angle corresponding to one direct current booster circuit as a reference, combining the amplitude value of each fundamental wave component, and calculating the phase shift angles corresponding to the rest direct current booster circuits with the aim of maximizing the area of the closed graph formed by the space vectors.
2. The bus current ripple suppression method of claim 1, wherein the extraction of the fundamental component includes the following process: acquiring an inductance current waveform of the direct-current booster circuit in one switching period under a steady state; extracting an output current waveform corresponding to the direct current boost circuit from the inductance current waveform; Removing the direct current component of the output current waveform to obtain an alternating current component; Converting the waveform of the alternating current component into a rectangular wave under the condition that the area is unchanged; Performing Fourier expansion on the obtained rectangular wave to obtain a Fourier series expansion of the rectangular wave; the first term of the fourier series expansion is taken as the fundamental component.
3. An electronic device comprising a processor and a memory, the memory being configured to store a computer program, the processor being configured to implement the bus current ripple suppression method of claim 1 or 2 when the computer program is executed.
4. A computer readable storage medium, characterized in that the storage medium has stored thereon a computer program which, when executed by a processor, implements the bus current ripple suppression method according to claim 1 or 2.

Description

Bus current ripple suppression method, device and medium Technical Field The application relates to the technical field of new energy power generation, in particular to a bus current ripple suppression method, equipment and medium. Background When the inverter system injects sine wave alternating current into the power grid, the instantaneous power of the inverter system fluctuates, and the fluctuation is reflected to the direct current bus, so as to cause double frequency ripple of bus current and voltage, namely bus current ripple. Bus current ripple can bring a series of hazards, including reducing system efficiency, affecting MPPT tracking accuracy, reducing the service life of the device, etc. The traditional bus current ripple suppression method for the inverter system mainly comprises two methods, namely a fixed phase shifting method, namely that driving signals of all direct current booster circuits are sequentially delayed according to the number of the direct current booster circuits running in the inverter system, and an off-line traversing method, namely that the phase shifting angle with the minimum duty ratio of each channel and the peak value of the current ripple peak is calculated and stored in flash according to a mapping table, and the phase shifting angle is obtained in real time through table lookup when the method is used. For the fixed phase shifting method, the method is commonly used for the scene that the input and the output are all connected in parallel and the power of each direct current booster circuit is the same, and at the moment, a better ripple cancellation effect can be obtained by using the fixed phase shifting angle. In photovoltaic applications, however, each dc boost circuit has only its output connected to a common dc bus and its input connected to a different PV string. The voltage of the PV group strings is influenced by the quantity of PV plates configured by a user, the current is influenced by illumination, shielding conditions and the quantity of PV group strings connected in parallel, so that the input voltage and the current of each direct current booster circuit are different, and the ripple cancellation effect of a fixed phase shift angle is influenced. For the offline traversing method, the method mainly has two defects that firstly, the minimum peak value of the current ripple wave is equivalent to the minimum value of the current ripple wave output to the direct current bus, but the peak value of the current ripple wave is not in one-to-one correspondence with the heating of the passive device of the direct current bus and is strictly positively correlated with the heating of the passive device, the minimum peak value of the current ripple wave does not mean the minimum heating of the passive device, and the phase shift angle obtained through the scheme is deviated from the optimal result. And secondly, each path of direct current booster circuit is added, one dimension is required to be added to the mapping table, namely, the increase rate is exponential, and the mapping table is not beneficial to popularization into the application containing more paths of direct current booster circuits. Disclosure of Invention One of the objects of the present application is to provide a method for suppressing bus current ripple that can solve at least one of the above-mentioned drawbacks of the related art. Another object of the present application is to provide an electronic device capable of implementing a bus current ripple suppression method that solves at least one of the above-mentioned drawbacks of the related art. It is still another object of the present application to provide a computer-readable storage medium capable of implementing a bus current ripple suppression method that solves at least one of the above-mentioned drawbacks of the related art. The technical scheme includes that the bus current ripple suppression method is applied to a photovoltaic system with multiple paths of direct current booster circuits connected in parallel to a direct current bus through output, and comprises the steps of obtaining electric quantity data of each path of direct current booster circuit in a current running state in real time, wherein the electric quantity data comprise input voltage, output voltage, average current and duty ratio information, and based on the obtained electric quantity data, dynamically calculating phase shift angles required by each path of direct current booster circuit with the minimum total alternating current component output by all paths of direct current booster circuits to the direct current bus as a target, and carrying out phase modulation on driving signals of each path of direct current booster circuit according to the obtained phase shift angles. Preferably, based on the obtained electric quantity data, fundamental wave components of currents output by the direct current booster circuits to the direct current buses are extracted, t