CN-122026706-A - Derating control method and device, photovoltaic air conditioner and storage medium

CN122026706ACN 122026706 ACN122026706 ACN 122026706ACN-122026706-A

Abstract

The application relates to a derating control method, a device, a photovoltaic air conditioner and a storage medium, wherein the derating control method comprises the steps of obtaining a first element temperature and a first element temperature change rate of a power element in a photovoltaic inverter in a first preset time period, determining a target threshold range in a plurality of reference threshold ranges according to the first element temperature and the first element temperature change rate, determining target derating power according to the target threshold range, determining that the target derating power is smaller than rated power of the power element, generating a first derating control signal based on the target derating power, and outputting the first derating control signal to the power element, wherein the first derating control signal is used for indicating the power element to work according to the target derating power. The embodiment of the application can ensure that the temperature of the power element is maintained in a safe range, avoid overheat damage, furthest reserve the output efficiency of the inverter, prevent the loss of generated energy caused by excessive derating and consider the reliability of equipment and the energy utilization efficiency.

Inventors

Ning Jiehua
HUANG MENG
MAO CHAOYANG
TANG WENQIANG
NI ZIRONG

Assignees

珠海格力电器股份有限公司

Dates

Publication Date: 20260512
Application Date: 20251229

Claims (10)

1. A derating control method, comprising: Acquiring a first element temperature and a first element temperature change rate of a power element in a photovoltaic inverter in a first preset time period; Determining a target threshold range from a plurality of reference threshold ranges according to the first element temperature and the first element temperature change rate; Determining target derated power according to the target threshold range, wherein the target derated power is smaller than rated power of the power element; And generating a first derating control signal based on the target derating power and outputting the first derating control signal to the power element, wherein the first derating control signal is used for indicating the power element to work according to the target derating power.
2. The derating control method according to claim 1, wherein determining a target threshold range among a plurality of reference threshold ranges from the first element temperature and the first element temperature change rate comprises: determining whether the first element temperature is greater than any preset temperature threshold; If the first element temperature is greater than any preset temperature threshold, determining whether the first element temperature change rate is within a reference threshold range corresponding to the preset temperature threshold; and if the first element temperature change rate is in a reference threshold range corresponding to the preset temperature threshold, determining the reference threshold range as a target threshold range.
3. The derating control method as recited in claim 1, wherein determining a target derating power based on the target threshold range comprises: determining a reference derated power according to the target threshold range; Generating a second derating control signal based on the reference derating power and outputting to the power element, the second derating control signal being used to instruct the power element to operate at the reference derating power; acquiring a second element temperature change rate of a power element in the photovoltaic inverter in a second preset time period; and determining the target derating power according to the temperature change rate of the second element.
4. A derating control method as defined in claim 3, wherein determining the target derating power based on the second element temperature rate of change comprises: determining whether the second element temperature change rate is within a reference threshold range corresponding to the reference derated power; and if the temperature change rate of the second element is within a reference threshold range corresponding to the reference derated power, determining the reference derated power as the target derated power.
5. The derating control method as recited in claim 3, wherein determining the target derating power based on the second element temperature rate of change further comprises: If the second element temperature change rate is located outside a reference threshold range corresponding to the reference derated power, determining the reference threshold range in which the second element temperature change rate is located as a target threshold range; and re-executing the step of determining the reference derating power according to the target threshold range until the component temperature change rate in any preset time period is within the reference threshold range corresponding to the reference derating power, and determining the reference derating power as the target derating power.
6. A derating control method as claimed in claim 3, wherein determining a reference derating power from the target threshold range comprises: determining a target derating grade in a plurality of preset derating grades according to the target threshold range; determining a target derating coefficient from a plurality of candidate derating coefficients corresponding to the target derating level; obtaining rated power of the photovoltaic inverter; And determining the reference derated power according to the target derated coefficient and the rated power.
7. The derating control method as recited in claim 6, wherein determining a target derating coefficient among a plurality of candidate derating coefficients corresponding to the target derating level comprises: Determining the current times of determining the reference derating power step according to the target threshold range after determining that the first element temperature is greater than any preset temperature threshold; And determining the candidate derating coefficient corresponding to the current times as the target derating coefficient in a plurality of candidate derating coefficients corresponding to the target derating level.
8. A derating control device, comprising: the acquisition module is used for acquiring the first element temperature and the first element temperature change rate of the power element in the photovoltaic inverter in a first preset time period; a first determining module, configured to determine a target threshold range from a plurality of reference threshold ranges according to the first element temperature and the first element temperature change rate; The second determining module is used for determining target derating power according to the target threshold range, and the target derating power is smaller than the rated power of the power element; the generating module is used for generating a first derating control signal based on the target derating power and outputting the first derating control signal to the power element, and the first derating control signal is used for indicating the power element to work according to the target derating power.
9. The photovoltaic air conditioner is characterized by comprising a photovoltaic inverter, a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus; a memory for storing a computer program; A processor, configured to implement the derating control method according to any one of claims 1 to 7 when executing a program stored in a memory.
10. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a derating control method program, which when executed by a processor, implements the steps of the derating control method according to any one of claims 1-7.

Description

Derating control method and device, photovoltaic air conditioner and storage medium Technical Field The application relates to the technical field of air conditioners, in particular to a derating control method and device, a photovoltaic air conditioner and a storage medium. Background In the face of increasingly severe environmental and energy crisis, new energy sources such as wind power, solar energy and the like become important ways for improving energy structures and realizing sustainable development. The inverter converts unstable renewable resources into stable electric energy, and is a key support for realizing energy structure and sustainable development. The photovoltaic inverter converts Direct Current (DC) generated by the photovoltaic module into Alternating Current (AC) meeting the power grid standard, the implementation process is to continuously turn on and off by means of the power element, and the stable operation of the power element is the basis for ensuring the safe operation of the inverter. Under the high-frequency switch condition, the power element can generate a large amount of heat, so that the temperature is too high, and the photovoltaic inverter is unstable in operation. In conventional over-temperature protection schemes, two levels of protection are typically provided, with the system alerting of over-temperature and switching to a preset derated power operation, e.g., 50% of rated power, when the temperature exceeds a threshold of 1, e.g., 100 ℃, and with the system standing horse shutdown when the temperature exceeds a threshold of 2. The preset derating power is static and one-cut, and cannot adapt to real-time working conditions (such as over-high ambient temperature, ageing of devices, poor heat dissipation and the like), so that the derating is possibly excessive, and the derating can also be called as over-protection, for example, the inverter can stably operate 80% of rated power (the temperature is stabilized to be less than a threshold value 2) under the current working conditions, and the operation according to the preset 50% of rated power directly causes the reduction of the generated energy, so that the capability of the inverter is not exerted. The derating may be insufficient, and the inverter may be operated at 30% of rated power under the current operating condition, and operate at 50% of the rated power, which may cause the temperature to continuously increase until the trigger temperature threshold 2 is stopped, and may also cause the power generation loss. Disclosure of Invention The application provides a derating control method, a derating control device, a photovoltaic air conditioner and a storage medium, which aim to solve the technical problems of finding out an optimal derating coefficient and considering the output capacity and over-temperature protection of a photovoltaic inverter under the current running condition of the inverter. In a first aspect, the present application provides a derating control method, including: Acquiring a first element temperature and a first element temperature change rate of a power element in a photovoltaic inverter in a first preset time period; Determining a target threshold range from a plurality of reference threshold ranges according to the first element temperature and the first element temperature change rate; Determining target derated power according to the target threshold range, wherein the target derated power is smaller than rated power of the power element; And generating a first derating control signal based on the target derating power and outputting the first derating control signal to the power element, wherein the first derating control signal is used for indicating the power element to work according to the target derating power. Optionally, determining a target threshold range from among a plurality of reference threshold ranges according to the first element temperature and the first element temperature change rate includes: determining whether the first element temperature is greater than any preset temperature threshold; If the first element temperature is greater than any preset temperature threshold, determining whether the first element temperature change rate is within a reference threshold range corresponding to the preset temperature threshold; and if the first element temperature change rate is in a reference threshold range corresponding to the preset temperature threshold, determining the reference threshold range as a target threshold range. Optionally, determining the target derated power according to the target threshold range includes: determining a reference derated power according to the target threshold range; Generating a second derating control signal based on the reference derating power and outputting to the power element, the second derating control signal being used to instruct the power element to operate at the reference derating power; acquiring a second element temp