WO2022041919A1

WO2022041919A1 - Method, apparatus, and device for controlling photovoltaic device, and photovoltaic system

Info

Publication number: WO2022041919A1
Application number: PCT/CN2021/098920
Authority: WO
Inventors: 安宏迪; 俞贤桥; 肖尊辉; 陈宁宁; 张宁波
Original assignee: 珠海格力电器股份有限公司
Priority date: 2020-08-26
Filing date: 2021-06-08
Publication date: 2022-03-03
Also published as: CN111864806B; CN111864806A

Abstract

Provided are a method, apparatus, and device for controlling a photovoltaic device, and a photovoltaic system. The method comprises: acquiring an operating state of an electrical device (S200); acquiring a grid frequency of an AC grid to which the electrical device is connected (S400); if the grid frequency is greater than a preset frequency threshold and if the electrical device is in operation, controlling a photovoltaic device to stop feeding electricity to the AC grid (S600); and if the grid frequency is greater than the preset frequency threshold and if the electrical device is not in operation, controlling the photovoltaic device to reduce a generated power (S800). The method uses the operating state of the electrical device to control the photovoltaic device, thereby allowing energy provided by the photovoltaic device to the electrical device to be appropriately used, and preventing inefficient use of the generated photovoltaic power. When the grid frequency is detected to be greater than the preset frequency threshold, the photovoltaic device stops feeding electricity to the AC grid or reduces the generated power, so as to mitigate the impact of photovoltaic power generation on grid stability, thereby improving operational reliability.

Description

Photovoltaic equipment control method, device, equipment and photovoltaic system

Cross References to Relevant Publications

The present disclosure is based on and claims the priority of the CN publication number 202010870647.5 and the publication date is August 26, 2020, and the disclosure content of the CN publication is hereby incorporated into the present disclosure as a whole.

technical field

The present disclosure relates to the technical field of power generation equipment, and in particular, to a photovoltaic equipment control method, device, equipment, and photovoltaic system.

Background technique

With the increase in the types and quantity of electrical equipment, in recent years, countries around the world have begun to widely use photovoltaic power generation to relieve grid pressure. Various distributed power generation and micro-grid systems have become the current The focus of the research. The photovoltaic power used in the electrical equipment comes from the sun and does not pollute the environment. When the light is insufficient, the electrical equipment can also draw electricity from the power grid, which does not affect the normal use of the electrical equipment.

However, due to the random fluctuation of photovoltaic power generation, when photovoltaic equipment, electrical equipment and the grid are connected together, when the frequency of the grid fluctuates, due to the increase in the number and scale of photovoltaic equipment, photovoltaic equipment will increase the stability of the grid. Therefore, the use of electrical equipment is affected, and the performance of traditional photovoltaic equipment is not good.

SUMMARY OF THE INVENTION

According to an aspect of the present disclosure, there is provided a photovoltaic device control method, comprising the following steps:

Obtain the working state of the electrical equipment; the working state includes a running state and a non-running state;

Obtain the grid frequency of the AC grid connected to the electrical equipment;

When the grid frequency is greater than a preset frequency threshold and the electrical equipment is in a running state, the photovoltaic equipment is controlled to stop feeding power to the AC grid; both the electrical equipment and the AC grid are connected to the photovoltaic equipment ;

When the grid frequency is greater than the preset frequency threshold and the electrical equipment is in a non-operating state, the photovoltaic equipment is controlled to reduce power generation.

In some embodiments of the present disclosure, the preset frequency threshold includes a first frequency threshold and a second frequency threshold, the second frequency threshold is smaller than the first frequency threshold; the when the grid frequency is greater than the preset frequency threshold, and when the electrical equipment is in the running state, controlling the photovoltaic equipment to stop feeding power to the AC power grid, including:

When the grid frequency is greater than the second frequency threshold and less than or equal to the first frequency threshold, and the electrical equipment is in a running state, the photovoltaic equipment is controlled to stop feeding power to the alternating current grid.

In some embodiments of the present disclosure, when the grid frequency is greater than a preset frequency threshold and the electrical device is in a running state, controlling the photovoltaic device to stop feeding power to the AC grid includes:

When the grid frequency is greater than the first frequency threshold and the electrical equipment is in a running state, the photovoltaic equipment is controlled to stop.

In some embodiments of the present disclosure, when the grid frequency is greater than the first frequency threshold and the electrical equipment is in a running state, after controlling the photovoltaic equipment to stop, the method further includes:

After the photovoltaic device is shut down for a preset protection period, the grid frequency of the AC grid connected to the acquired electrical device is returned.

In some embodiments of the present disclosure, the preset frequency threshold includes a first frequency threshold and a second frequency threshold, the second frequency threshold is smaller than the first frequency threshold; the when the grid frequency is greater than the preset frequency When the frequency threshold is set and the electrical equipment is not running, controlling the photovoltaic equipment to reduce the power generation, including:

When the grid frequency is greater than the second frequency threshold and less than or equal to the first frequency threshold, and the electrical equipment is in a non-operating state, the photovoltaic equipment is controlled to reduce the generated power.

In some embodiments of the present disclosure, when the grid frequency is greater than the preset frequency threshold and the electrical equipment is in a non-operating state, controlling the photovoltaic equipment to reduce the power generation includes:

When the grid frequency is greater than the first frequency threshold and the electrical equipment is in a non-operating state, the photovoltaic equipment is controlled to stop feeding power to the alternating current grid.

In some embodiments of the present disclosure, when the grid frequency is greater than the first frequency threshold and the electrical device is in a non-operating state, after controlling the photovoltaic device to stop feeding power to the AC grid, Also includes:

After the photovoltaic device stops feeding power to the AC grid for a preset protection period, returning to the obtained grid frequency of the AC grid connected to the electrical device.

In some embodiments of the present disclosure, after acquiring the grid frequency of the AC grid connected to the electrical device, the method further includes:

When the grid frequency is greater than the preset frequency threshold, record the abnormal state of the grid frequency.

In some embodiments of the present disclosure, a photovoltaic equipment control apparatus is provided, including:

a working state obtaining module, used for obtaining the working state of the electrical equipment; the working state includes a running state and a non-running state;

The grid frequency acquisition module is used to acquire the grid frequency of the AC grid connected to the electrical equipment;

a first control module, configured to control the photovoltaic equipment to stop feeding power to the AC power grid when the grid frequency is greater than a preset frequency threshold and the electrical equipment is in a running state; the electrical equipment and the AC The grid is connected to the photovoltaic equipment;

A second control module, configured to control the photovoltaic device to reduce power generation when the grid frequency is greater than the preset frequency threshold and the electrical device is in a non-operating state.

In some embodiments of the present disclosure, a photovoltaic device control device is provided, including a control device, a sampling circuit and a detector, the sampling circuit is connected to an AC power grid, the detector is connected to the electrical equipment, the sampling circuit and The detectors are all connected to the control device, and the sampling circuit is used to collect the grid frequency of the AC power grid connected to the electrical equipment and send it to the control device. The detector is used to detect the working state of the electrical equipment and send it to the control device. A control device for controlling photovoltaic equipment according to the above method.

In some embodiments of the present disclosure, a photovoltaic system is provided, including photovoltaic equipment, electrical equipment, an alternating current grid, and the above photovoltaic equipment control equipment, wherein the electrical equipment and the alternating current grid are both connected to the photovoltaic equipment, The electrical equipment is also connected to the AC power grid.

In some embodiments of the present disclosure, the electrical device is an air conditioner.

Description of drawings

FIG. 1 is a flowchart of a method for controlling a photovoltaic device in some embodiments of the present disclosure;

FIG. 2 is a flowchart of a photovoltaic device control method in other embodiments of the present disclosure;

FIG. 3 is a block diagram of a system including an air conditioning system, an electrical device, and an AC power grid in some embodiments of the present disclosure;

FIG. 4 is a flowchart of a method for controlling a photovoltaic device according to further embodiments of the present disclosure.

detailed description

In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure will be described more fully hereinafter through the embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, but not to limit the present disclosure.

Aiming at the problem of poor performance of traditional photovoltaic equipment, the present disclosure proposes a photovoltaic equipment control method, device, equipment and photovoltaic system. The photovoltaic equipment control method, device, equipment and photovoltaic system can reduce the impact of photovoltaic power generation on the power grid. The effect of instability, the technical effect of improving the reliability of use.

In some embodiments of the present disclosure, referring to FIG. 1 , a method for controlling photovoltaic equipment is provided. The method is implemented based on a system formed by electrical equipment, photovoltaic equipment, and an AC power grid. The electrical equipment is connected to the photovoltaic equipment, and the photovoltaic equipment can obtain the output generated by the photovoltaic equipment. The electrical energy is used for its own work, and the electrical equipment is also connected to the AC power grid, and can use the electrical energy from the AC power grid. and the AC grid to obtain electricity. Photovoltaic equipment is also connected to the AC power grid, and can transmit the generated electric energy to the AC power grid for power feeding. The photovoltaic equipment control method can be implemented by a control device, wherein the control device can be a device independent of the photovoltaic equipment, the electrical equipment and the AC grid, or the existing control in the photovoltaic equipment, the electrical equipment and the AC grid can be used. In order to save the cost of hardware, the device can be selected according to actual needs, as long as those skilled in the art can realize it. The type of electrical equipment is not unique. In the above embodiments of the present disclosure, the electrical equipment is an air conditioner as an example. The air conditioner includes an air conditioner external unit and an air conditioner internal unit. The air conditioner can work with the electric energy provided by the photovoltaic equipment. The photovoltaic electric energy comes from the sun and does not pollute the environment. When the light is insufficient, the external air conditioner can also draw electricity from the power grid, which does not affect the normal use of the air conditioner. The photovoltaic equipment control method includes the following steps:

Step S200: Acquire the working state of the electrical equipment.

In some embodiments of the present disclosure, the working state includes a running state and a non-running state. When executing the photovoltaic equipment control method, the working state of the electrical equipment is detected first, which provides a basis for subsequently providing different control steps for different working states of the electrical equipment. Generally speaking, the working state includes a running state and a non-working state. It can be understood that in some other embodiments of the present disclosure, the working state may also include other states, such as a low-power running state and a high-power running state, and the subsequent control The process can refer to the control process of the similar working state. For example, when the electrical equipment is in a low-power operating state, the subsequent steps can be performed according to the situation that the electrical equipment is not operating, which can be adjusted according to actual needs.

In some embodiments of the present disclosure, the method of acquiring the working state of the electrical equipment is not unique. For example, a sensor may be used to detect the working parameters of the electrical equipment, the sensor is connected to the control device, and the sensor sends the detected parameter to the control device. The control device determines the working state of the electrical equipment according to the received parameters. Taking the electrical equipment as an air conditioner as an example, the sensor can be used to detect the working parameters of the air conditioner, and the control device judges whether the compressor is running normally according to the working parameters detected by the sensor, thereby judging whether the air conditioner is running or not running.

Step S400: Obtain the grid frequency of the AC grid to which the electrical device is connected.

In some embodiments of the present disclosure, both the electrical equipment and the photovoltaic equipment are connected to the AC power grid, and the frequency fluctuation of the AC power grid will affect the working performance of the entire system. Obtain the grid frequency of the AC power grid connected to the electrical equipment, and judge whether the grid frequency is normal based on this, and realize the monitoring of the grid frequency, which is conducive to improving the working performance of photovoltaic equipment and electrical equipment. The way to obtain the grid frequency of the AC grid is not unique. For example, the grid frequency of the AC grid can be sampled through a sampling circuit, the sampling circuit is connected to the control device, and the sampling circuit sends the collected grid frequency to the control device for subsequent processing. . Optionally, the sampling circuit can sample the grid frequency at preset time intervals and send it to the control device, simplifying the control process, and the sampling circuit can also sample the grid frequency in real time and send it to the control device to improve the effectiveness of grid frequency monitoring. .

Step S600: when the grid frequency is greater than the preset frequency threshold and the electrical equipment is in a running state, control the photovoltaic equipment to stop feeding power to the AC grid.

In some embodiments of the present disclosure, both the electrical equipment and the AC power grid are connected to photovoltaic equipment, and the photovoltaic equipment can not only supply power to the electrical equipment, but also feed the AC power grid. When the control device judges that the grid frequency is greater than the preset frequency threshold, consider that the grid frequency is abnormal at this time, and carry out follow-up control combined with the working state of the electrical equipment to control the photovoltaic equipment to stop feeding power to the AC grid, reduce the power generation of the photovoltaic equipment, and avoid The excessive power generation of photovoltaic equipment aggravates the fluctuation of grid frequency. When the electrical equipment is in the running state, considering that the electrical equipment needs power at this time, on the basis of controlling the photovoltaic equipment to stop feeding the AC power grid, the photovoltaic equipment can be controlled to supply power to the electrical equipment, and the electrical equipment can be used normally. Further The power generation of photovoltaic equipment is less than the power consumption of electrical equipment, ensuring that the electricity generated by photovoltaic power generation is completely consumed by electrical equipment and cannot generate electricity to the grid. Scalable, on the basis of controlling the photovoltaic equipment to stop feeding power to the AC power grid, the photovoltaic equipment can also be controlled to stop generating electricity to the electrical equipment, further reducing the impact of the photovoltaic equipment power generation on the frequency fluctuation of the power grid.

Step S800: When the grid frequency is greater than the preset frequency threshold and the electrical equipment is in a non-operational state, control the photovoltaic equipment to reduce the generating power.

In some embodiments of the present disclosure, when the control device determines that the grid frequency is greater than the preset frequency threshold, the grid frequency is considered abnormal at this time, and the subsequent control is performed in combination with the working state of the electrical equipment to control the photovoltaic equipment to reduce the generated power and reduce the photovoltaic equipment. To avoid the excessive power generation of photovoltaic equipment and aggravate the fluctuation of grid frequency. Specifically, controlling the photovoltaic equipment to reduce the power generation can be controlling the photovoltaic equipment to reduce the generating power to a certain value, or controlling the photovoltaic equipment to stop generating power, which can be adjusted according to actual needs. When the electrical equipment is not running, considering that the electrical equipment does not need electricity at this time, the photovoltaic equipment can not generate electricity to the electrical equipment. By controlling the photovoltaic equipment in combination with the working state of the electrical equipment, the energy provided by the photovoltaic equipment to the electrical equipment can be reasonably used to avoid the waste of photovoltaic power generation. The grid feeds or reduces the power generation, which reduces the influence of photovoltaic power generation on the instability of the grid, and has high reliability.

In some embodiments of the present disclosure, the preset frequency threshold includes a first frequency threshold and a second frequency threshold, the second frequency threshold is smaller than the first frequency threshold, see FIG. 2 , step S600 includes step S620 .

Step S620 : when the grid frequency is greater than the second frequency threshold and less than or equal to the first frequency threshold, and the electrical equipment is in a running state, control the photovoltaic equipment to stop feeding power to the AC grid.

Specifically, the number of preset frequency thresholds is not unique. In some embodiments of the present disclosure, the number of preset frequency thresholds is two, including a first frequency threshold and a second frequency threshold, and the second frequency threshold is smaller than the first frequency threshold. Frequency threshold, the first frequency threshold and the second frequency threshold can divide the frequency into three intervals, and the obtained grid frequency is compared with the first frequency threshold and the second frequency threshold. According to the comparison result, it can be determined that the obtained frequency threshold is in the range. In which interval, different subsequent controls can be made on the frequency thresholds in different intervals, which improves the accuracy of the control. The values of the first frequency threshold and the second frequency threshold are not unique, and can be determined by those skilled in the art according to actual needs. In some embodiments of the present disclosure, the first frequency threshold may be 52 Hz, and the second frequency threshold may be 50.25 Hz Hz. It can be understood that in other disclosed embodiments, the first frequency threshold and the second frequency threshold may also be other values.

In some embodiments of the present disclosure, when the obtained grid frequency is greater than 50.25 Hz and less than or equal to 52 Hz, it is considered that the grid frequency is high. At this time, if the electrical equipment is in the running state, the photovoltaic equipment can be controlled to stop feeding power to the AC grid to reduce the power generation of the photovoltaic equipment. Further, since the grid frequency is not too high at this time, the photovoltaic equipment can be controlled to Electrical equipment generates electricity, and electrical equipment can be used normally. The power generation of photovoltaic equipment is less than the power consumption of electrical equipment, ensuring that the electricity generated by photovoltaic power generation is completely consumed by electrical equipment and cannot generate electricity to the grid. In addition to reducing the impact of photovoltaic equipment power generation on the frequency of the power grid, it can also use electrical equipment to work and be reliable.

In some embodiments of the present disclosure, referring to FIG. 2 , step S600 includes step S640.

Step S640: When the grid frequency is greater than the first frequency threshold and the electrical equipment is in a running state, control the photovoltaic equipment to stop.

In some embodiments of the present disclosure, taking the first frequency threshold as 52 Hz and the second frequency threshold as 50.25 Hz as an example, when the grid frequency is greater than the first frequency threshold, that is, when the grid frequency exceeds 52 Hz, the grid frequency is considered to be too high. Even if the electrical equipment is running, in order to reduce the power generation of the photovoltaic equipment and reduce the impact of the power generation of the photovoltaic equipment on the frequency of the power grid, the photovoltaic equipment is controlled to stop at this time, so that the photovoltaic equipment neither feeds the AC power grid nor supplies power to the power grid. The electrical equipment generates electricity to improve the stability of the electrical equipment and the operation of the AC power grid.

In some embodiments of the present disclosure, after step S640 , the photovoltaic device control method further includes step 660 .

Step 660: Return to step S400 after the photovoltaic device is shut down for the preset protection period.

In some embodiments of the present disclosure, after the photovoltaic equipment is shut down, a period of protection needs to pass. If the time is not reached, the shutdown state of the system will not be restored, so as to avoid frequent startup and shutdown of the equipment and excessive workload caused by operation, thereby improving the The working performance of photovoltaic equipment. After the photovoltaic equipment has been shut down for the preset protection period, the protection time has been met. At this time, the process returns to step S400, and the control device re-acquires the grid frequency of the AC grid connected to the electrical equipment, and executes the subsequent steps in sequence, that is, according to the obtained grid frequency The corresponding steps are performed according to the magnitude relationship of the preset frequency domain threshold in the frequency domain. After the photovoltaic equipment is shut down for the preset protection period, return to step S400, and return to the previous steps to continuously obtain the grid frequency, and perform corresponding steps according to the relationship between the obtained grid frequency and the preset frequency threshold, so as to realize continuous monitoring of the grid frequency , after the photovoltaic equipment stops for a preset protection period and then returns to the previous steps, it can avoid frequent starting and stopping of the equipment and excessive workload caused by working, which is beneficial to improve the working performance of the photovoltaic equipment and the equipment connected to it. The specific duration of the preset protection period is not unique. It can be set according to the standard in the national standard GB/T 37408. Generally speaking, the preset protection period can take a value within 60s-300s, and it is not less than 60s. Affect the normal use of photovoltaic equipment.

In some embodiments of the present disclosure, the preset frequency threshold includes a first frequency threshold and a second frequency threshold, the second frequency threshold is smaller than the first frequency threshold, see FIG. 2 , step S800 includes step S820 .

Step S820 : when the grid frequency is greater than the second frequency threshold and less than or equal to the first frequency threshold, and the electrical equipment is in a non-operational state, control the photovoltaic equipment to reduce the generated power.

Specifically, the number of preset frequency thresholds is not unique. In some embodiments of the present disclosure, the number of preset frequency thresholds is two, including a first frequency threshold and a second frequency threshold, and the second frequency threshold is smaller than the first frequency threshold. Frequency threshold, the first frequency threshold and the second frequency threshold can divide the frequency into three intervals, and the obtained grid frequency is compared with the first frequency threshold and the second frequency threshold. According to the comparison result, it can be determined that the obtained frequency threshold is in the range. In which interval, different subsequent controls can be made on the frequency thresholds in different intervals, which improves the accuracy of the control. The values of the first frequency threshold and the second frequency threshold are not unique, and can be determined by those skilled in the art according to actual needs. In some embodiments of the present disclosure, the first frequency threshold may be 52 Hz, and the second frequency threshold may be 50.25 Hz Hz. It can be understood that, in other embodiments of the present disclosure, the first frequency threshold and the second frequency threshold may also be other values.

In some embodiments of the present disclosure, taking the first frequency threshold as 52 Hz and the second frequency threshold as 50.25 Hz as an example, when the grid frequency is greater than the second frequency threshold and less than or equal to the first frequency threshold, that is, the grid frequency is greater than 50.25 Hz, When it is less than or equal to 52Hz, it is considered that the frequency of the grid is high, and the electrical equipment is not running and will not consume the power of the photovoltaic equipment. At this time, the photovoltaic equipment is controlled to reduce the generating power, and the photovoltaic equipment enters the generating power limit state. The power feeds the AC power grid, and the power generation is controlled according to the frequency of the power grid. While the power generation of the photovoltaic equipment is reasonably utilized, the influence of the excessive power generation of the photovoltaic equipment on the frequency fluctuation of the power grid is reduced.

In some embodiments of the present disclosure, referring to FIG. 2 , step S800 includes step S840.

Step S840: When the grid frequency is greater than the first frequency threshold and the electrical equipment is in a non-operating state, control the photovoltaic equipment to stop feeding power to the AC grid.

In some embodiments of the present disclosure, taking the first frequency threshold as 52 Hz and the second frequency threshold as 50.25 Hz as an example, when the grid frequency is greater than the first frequency threshold, that is, when the grid frequency exceeds 52 Hz, it is considered that the grid frequency is too high, and the The electrical equipment is not running and will not consume the power of the photovoltaic equipment. The photovoltaic equipment is equivalent to stopping power supply to the electrical equipment. At this time, the photovoltaic equipment is controlled to stop feeding the AC grid, so that the photovoltaic equipment neither feeds the AC grid nor Do not generate electricity to electrical equipment to improve the stability of electrical equipment and AC grid operation.

In some embodiments of the present disclosure, after step S840 , the photovoltaic device control method further includes step 860 .

Step 860: Return to step S400 after the photovoltaic device stops feeding the AC power grid for the preset protection period.

In some embodiments of the present disclosure, after the photovoltaic device stops feeding power to the AC power grid, a protection period of a certain period of time is required. If the time is not reached, the shutdown state of the system will not be restored, which can avoid frequent startup and shutdown of the device and workload caused by work. is too large, thereby improving the working performance of photovoltaic equipment. After the photovoltaic equipment stops feeding power to the AC power grid for the preset protection period, the protection time has been met, and then returns to step S400, and the control device re-acquires the power grid frequency of the AC power grid to which the electrical equipment is connected, and executes the subsequent steps in sequence, namely, Corresponding steps are performed according to the acquired magnitude relationship of the preset frequency thresholds in the frequency domain of the power grid. Return to step S400 after the photovoltaic equipment stops feeding power to the AC power grid for the preset protection period. Returning to the previous steps, the grid frequency can be continuously obtained, and corresponding steps are performed according to the relationship between the obtained grid frequency and the preset frequency threshold, so as to realize the control of the grid frequency. The continuous monitoring of the grid frequency can also prevent the equipment from starting and stopping frequently and the work load is too large, which is beneficial to improve the working performance of the photovoltaic equipment and the equipment connected to it. The specific duration of the preset protection period is not unique. It can be set according to the standard in the national standard GB/T 37408. Generally speaking, the preset protection period can take a value within 60s-300s, and it is not less than 60s. Affect the normal use of photovoltaic equipment.

In some embodiments of the present disclosure, after step S400 , the photovoltaic device control method further includes step 500 . Wherein, step 500 may be performed simultaneously with step S600 or step S800.

Step 500: When the grid frequency is greater than the preset frequency threshold, record the abnormal state of the grid frequency.

In some embodiments of the present disclosure, specifically, the abnormal state of the power grid frequency can be recorded by setting the flag bit, and the abnormal state of the power grid frequency can be cleared by setting the flag position to 1, and correspondingly, when the power grid frequency is less than the preset frequency threshold, the abnormal state can be cleared. Record, specifically set the flag position to 0 to indicate that the grid frequency is normal. In some embodiments of the present disclosure, taking the preset frequency threshold including the first frequency threshold and the second frequency threshold as an example, the number of flag bits may be two, including the over-under-frequency protection flag bit and the anti-feeding network flag bit, When the obtained grid frequency is greater than the second frequency threshold, the anti-feeding network flag is set to 1; when the obtained grid frequency is less than or equal to the second frequency threshold, the anti-feeding network flag is reset to 0; when the obtained grid frequency is greater than When the first frequency threshold is set, the over-under-frequency protection flag is set to 1, and when the obtained grid frequency is less than or equal to the first frequency threshold, the over-under-frequency protection flag is reset to 0. When the grid frequency is greater than the preset frequency threshold, it is considered that the grid frequency is abnormal at this time. A flag bit is set in the memory of the control device. When the grid frequency is abnormal, the corresponding flag bit is set, and during subsequent processing, the abnormal state of the grid frequency can be quickly obtained according to the status of the flag bit, which is convenient to use. The number of flag bits is not unique, and can be adjusted according to the number of preset frequency thresholds or according to actual needs.

The above photovoltaic equipment control method first obtains the working state of the electrical equipment, and then obtains the grid frequency of the AC power grid connected to the electrical equipment. When the grid frequency is greater than the preset frequency threshold and the electrical equipment is in the running state, the photovoltaic equipment is controlled. Stop feeding power to the AC grid. When the grid frequency is greater than the preset frequency threshold and the electrical equipment is not running, the photovoltaic equipment is controlled to reduce the power generation, wherein the electrical equipment and the AC grid are both connected to the photovoltaic equipment. By controlling the photovoltaic equipment in combination with the working state of the electrical equipment, the energy provided by the photovoltaic equipment to the electrical equipment can be reasonably used to avoid the waste of photovoltaic power generation. The grid feeds or reduces the power generation, which reduces the influence of photovoltaic power generation on the instability of the grid, and has high reliability.

In order to better understand the above embodiments, detailed explanations are given below in conjunction with some specific embodiments. In the above-mentioned embodiments of the present disclosure, a method for controlling photovoltaic equipment is provided. The electrical equipment is an air conditioning system, and the power generation power limitation of photovoltaic equipment is performed by collecting the frequency on the grid side and determining the working state of the current air conditioning system. control. By reducing and limiting the power generation to reduce the impact on the power grid, and confirming the use status of the air conditioning system, the energy generated by the photovoltaic equipment can be reasonably used for the air conditioning system, so as to maximize the photovoltaic power generation and avoid the waste of photovoltaic power generation. .

Taking the electrical equipment as an air-conditioning system as an example, FIG. 3 is a block diagram of a system including an air-conditioning system, electrical equipment and an AC power grid in some embodiments of the present disclosure. Provide photovoltaic energy for the air conditioning system, the photovoltaic equipment is connected to the DC/DC circuit to the DC bus part, the air conditioner internal unit draws power from the DC bus, when the air conditioning system does not start, or when the photovoltaic power generation is greater than the power consumption of the air conditioning system, the photovoltaic energy will be The energy is transferred to the power grid through the bidirectional AC/DC circuit part, and the external unit of the air conditioner takes power from the photovoltaic side preferentially. The first frequency threshold is the grid frequency limit 1, the second frequency threshold is the grid frequency limit 2, the grid frequency limit 1 refers to the grid frequency collected by the photovoltaic air conditioning system reaching a certain limit, and the grid frequency limit 2 refers to the photovoltaic air conditioner The grid frequency collected by the system reaches a certain limit, the grid frequency limit 2 is less than the grid frequency limit 1, and the photovoltaic power generation limit refers to the reduction or reduction of photovoltaic power generation in a certain relationship according to the grid frequency.

In some embodiments of the present disclosure, specifically, referring to FIG. 4 , when the photovoltaic device control method is executed, it is first detected whether the air conditioning part is running. When the air conditioning part is running, the system detects that the grid frequency increases to a certain limit, for example When it is detected that the grid frequency is 52Hz, the system over-under-frequency protection flag is set, the system reports over-under-frequency protection, and both the photovoltaic part and the air conditioner part are shut down. At this time, the air conditioner cannot be used, and the photovoltaic cannot generate electricity to the grid. When it is detected that the grid frequency is less than 52Hz, and the over-under-frequency protection flag is 1, a certain protection period needs to pass. If the time is not reached, the system shutdown state will not recover. If the protection time has been met, the system will re-detect whether the grid frequency exceeds 52Hz. If it exceeds 52Hz, the system will continue to report the over-under-frequency fault and continue to stop. If it does not exceed 52Hz, the system over-under-frequency protection flag will be reset. In this case, when the grid frequency is greater than the frequency limit 2, for example, when the frequency limit 2 is 50.25Hz, the position of the system anti-feeding network flag is set, the air conditioner part is in normal use, and the photovoltaic power generation part is less than the power consumption of the air conditioner to ensure that the photovoltaic power generation is completely consumed by the air conditioner , unable to generate electricity to the grid. If it is detected that the grid frequency meets the reset condition of the anti-feed grid flag, it means that the grid has returned to normal use at this time, the air conditioner is in normal use at this time, and the photovoltaic power generation is not restricted, and can generate electricity to the grid at the maximum power.

In some embodiments of the present disclosure, when the air conditioning part is not running, the system is in a pure photovoltaic power generation state, and when the system detects that the grid frequency increases to a certain limit, for example, when the grid frequency is detected to be 52 Hz, the system is over-frequency and under-frequency When the protection flag is set, the system reports under-frequency protection, the photovoltaic part is disconnected, and the photovoltaic cannot generate electricity to the grid. When it is detected that the grid frequency is less than 52Hz, and the over-under-frequency protection flag is 1, a certain protection period needs to pass. If the time is not reached, the system shutdown state will not recover. If the protection time has been met, the system will re-detect whether the grid frequency exceeds 52Hz. If it exceeds 52Hz, the system will continue to report the over-under-frequency fault and continue to stop. If it does not exceed 52Hz, the system over-under-frequency protection flag will be reset. In this case, when the grid frequency is greater than the frequency limit 2, for example, when the frequency limit 2 is 50.25Hz, the system enters the power generation limit state. At this time, the power generation power is controlled according to the size of the grid frequency. When the grid frequency returns to within 50.25Hz When the power grid is considered stable, the system will no longer limit the power generation of the photovoltaic air conditioning system.

In some embodiments of the present disclosure, a photovoltaic equipment control device is provided, including a working state acquisition module, a grid frequency acquisition module, a first control module, and a second control module, where the working state acquisition module is used to obtain the working state of electrical equipment , the working state includes an operating state and a non-operating state, the grid frequency acquisition module is used to acquire the grid frequency of the AC grid connected to the electrical equipment, and the first control module is used when the grid frequency is greater than the preset frequency threshold and the electrical equipment is in In the running state, the photovoltaic equipment is controlled to stop feeding power to the AC power grid, and both the electrical equipment and the AC power grid are connected to the photovoltaic equipment. Control photovoltaic equipment to reduce power generation.

In some embodiments of the present disclosure, the photovoltaic device control apparatus further includes a recording module, the recording module is configured to, after the grid frequency acquisition module acquires the grid frequency of the AC grid connected to the electrical equipment, when the grid frequency is greater than a preset frequency threshold, Record the abnormal state of grid frequency.

The above photovoltaic equipment control device first obtains the working state of the electrical equipment, and then obtains the grid frequency of the AC power grid connected to the electrical equipment. When the grid frequency is greater than the preset frequency threshold and the electrical equipment is in the running state, the photovoltaic equipment is controlled. Stop feeding power to the AC grid. When the grid frequency is greater than the preset frequency threshold and the electrical equipment is not running, the photovoltaic equipment is controlled to reduce the power generation, wherein the electrical equipment and the AC grid are both connected to the photovoltaic equipment. By controlling the photovoltaic equipment in combination with the working state of the electrical equipment, the energy provided by the photovoltaic equipment to the electrical equipment can be reasonably used to avoid the waste of photovoltaic power generation. The grid feeds or reduces the power generation, which reduces the influence of photovoltaic power generation on the instability of the grid, and has high reliability.

In some embodiments of the present disclosure, a photovoltaic device control device is provided, including a control device, a sampling circuit and a detector, the sampling circuit is connected to an AC power grid, the detector is connected to electrical equipment, the sampling circuit and the detector are both connected to the control device, and the sampling circuit is connected to the control device. The circuit is used to collect the grid frequency of the AC power grid connected to the electrical equipment and send it to the control device, the detector is used to detect the working state of the electrical equipment and send it to the control device, and the control device is used to control the photovoltaic equipment according to the above method.

The above photovoltaic equipment control equipment first obtains the working state of the electrical equipment, and then obtains the grid frequency of the AC power grid connected to the electrical equipment. When the grid frequency is greater than the preset frequency threshold and the electrical equipment is in the running state, the photovoltaic equipment is controlled. Stop feeding power to the AC grid. When the grid frequency is greater than the preset frequency threshold and the electrical equipment is not running, the photovoltaic equipment is controlled to reduce the power generation, wherein the electrical equipment and the AC grid are both connected to the photovoltaic equipment. By controlling the photovoltaic equipment in combination with the working state of the electrical equipment, the energy provided by the photovoltaic equipment to the electrical equipment can be reasonably used to avoid the waste of photovoltaic power generation. The grid feeds or reduces the power generation, which reduces the influence of photovoltaic power generation on the instability of the grid, and has high reliability.

In some embodiments of the present disclosure, a photovoltaic system is provided, including photovoltaic equipment, electrical equipment, an AC power grid, and the above photovoltaic equipment control equipment, the electrical equipment and the AC power grid are both connected to the photovoltaic equipment, and the electrical equipment is also connected to the AC grid. It can be understood that the photovoltaic equipment control equipment can be independent of the photovoltaic equipment, electrical equipment, and AC power grid, or can add corresponding functions to the existing controllers in the photovoltaic equipment, electrical equipment, and AC power grid to act as photovoltaic equipment. Device control device usage.

In some embodiments of the present disclosure, the electrical device is an air conditioner. Photovoltaic equipment provides photovoltaic energy for the air-conditioning system. The photovoltaic equipment is connected to the DC/DC circuit to the DC bus, and the internal unit of the air conditioner draws power from the DC bus. When the air-conditioning system does not start, or when the photovoltaic power generation is greater than the power consumption of the air-conditioning system, the photovoltaic The energy will be transferred to the power grid through the bidirectional AC/DC circuit part, and the external unit of the air conditioner will take power from the photovoltaic side preferentially.

The above photovoltaic system first obtains the working state of the electrical equipment, and then obtains the grid frequency of the AC power grid connected to the electrical equipment. When the grid frequency is greater than the preset frequency threshold and the electrical equipment is in the running state, the photovoltaic equipment is controlled to stop sending to the grid. AC grid feeding, when the grid frequency is greater than the preset frequency threshold and the electrical equipment is not running, the photovoltaic equipment is controlled to reduce the generated power, wherein the electrical equipment and the AC grid are both connected to the photovoltaic equipment. Combining with the working state of the electrical equipment to control the photovoltaic equipment, the energy provided by the photovoltaic equipment to the electrical equipment can be reasonably used to avoid the waste of photovoltaic power generation. The grid feeds or reduces the power generation, which reduces the influence of photovoltaic power generation on the instability of the grid, and has high reliability.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present disclosure, and the descriptions thereof are relatively specific and detailed, but should not be construed as a limitation on the scope of the disclosed patent. It should be noted that, for those skilled in the art, without departing from the concept of the present disclosure, several modifications and improvements can be made, which all belong to the protection scope of the present disclosure. Accordingly, the scope of protection of the present disclosure should be determined by the appended claims.

Claims

A method for controlling photovoltaic equipment, comprising the following steps:

Obtain the working state of the electrical equipment; the working state includes a running state and a non-running state;

Obtain the grid frequency of the AC grid connected to the electrical equipment;

When the grid frequency is greater than a preset frequency threshold and the electrical equipment is in a running state, the photovoltaic equipment is controlled to stop feeding power to the AC grid; both the electrical equipment and the AC grid are connected to the photovoltaic equipment ;

When the grid frequency is greater than the preset frequency threshold and the electrical equipment is in a non-operating state, the photovoltaic equipment is controlled to reduce the generated power.
The photovoltaic device control method according to claim 1, wherein the preset frequency threshold includes a first frequency threshold and a second frequency threshold, and the second frequency threshold is smaller than the first frequency threshold; When the grid frequency is greater than a preset frequency threshold, and the electrical equipment is in a running state, controlling the photovoltaic equipment to stop feeding power to the AC grid, including:

When the grid frequency is greater than the second frequency threshold and less than or equal to the first frequency threshold, and the electrical equipment is in a running state, the photovoltaic equipment is controlled to stop feeding power to the alternating current grid.
The photovoltaic equipment control method according to claim 2, wherein when the grid frequency is greater than a preset frequency threshold and the electrical equipment is in a running state, the photovoltaic equipment is controlled to stop feeding the AC grid. electricity, including:

When the grid frequency is greater than the first frequency threshold and the electrical equipment is in a running state, the photovoltaic equipment is controlled to stop.
The photovoltaic equipment control method according to claim 3, wherein when the grid frequency is greater than the first frequency threshold and the electrical equipment is in a running state, after controlling the photovoltaic equipment to stop, Also includes:

After the photovoltaic device is shut down for a preset protection period, the grid frequency of the AC grid connected to the acquired electrical device is returned.
The photovoltaic device control method according to claim 1, wherein the preset frequency threshold includes a first frequency threshold and a second frequency threshold, and the second frequency threshold is smaller than the first frequency threshold; When the grid frequency is greater than the preset frequency threshold, and the electrical equipment is in a non-operational state, controlling the photovoltaic equipment to reduce the generated power, including:

When the grid frequency is greater than the second frequency threshold and less than or equal to the first frequency threshold, and the electrical equipment is in a non-operating state, the photovoltaic equipment is controlled to reduce the generated power.
The photovoltaic equipment control method according to claim 5, wherein when the grid frequency is greater than the preset frequency threshold and the electrical equipment is in a non-operational state, the photovoltaic equipment is controlled to reduce power generation power, including:

When the grid frequency is greater than the first frequency threshold and the electrical equipment is in a non-operating state, the photovoltaic equipment is controlled to stop feeding power to the alternating current grid.
The method for controlling photovoltaic equipment according to claim 6, wherein when the grid frequency is greater than the first frequency threshold and the electrical equipment is in a non-operating state, the photovoltaic equipment is controlled to stop sending power to the photovoltaic equipment. After the AC power grid is fed, it also includes:

After the photovoltaic device stops feeding power to the AC grid for a preset protection period, returning to the obtained grid frequency of the AC grid connected to the electrical device.
The method for controlling photovoltaic equipment according to claim 1, wherein after acquiring the grid frequency of the AC grid connected to the electrical equipment, the method further comprises:

When the grid frequency is greater than the preset frequency threshold, record the abnormal state of the grid frequency.
A photovoltaic equipment control device, characterized in that it includes:

a working state obtaining module, used to obtain the working state of the electrical equipment; the working state includes a running state and a non-running state;

The grid frequency acquisition module is used to acquire the grid frequency of the AC grid connected to the electrical equipment;

a first control module, configured to control the photovoltaic equipment to stop feeding power to the AC power grid when the grid frequency is greater than a preset frequency threshold and the electrical equipment is in a running state; the electrical equipment and the AC The grid is connected to the photovoltaic equipment;

A second control module, configured to control the photovoltaic device to reduce power generation when the grid frequency is greater than the preset frequency threshold and the electrical device is in a non-operating state.
A photovoltaic equipment control device is characterized in that it includes a control device, a sampling circuit and a detector, the sampling circuit is connected to an AC power grid, the detector is connected to the electrical equipment, and both the sampling circuit and the detector are Connected to the control device, the sampling circuit is used to collect the grid frequency of the AC power grid connected to the electrical equipment and send it to the control device, the detector is used to detect the working state of the electrical equipment and send it to the control device, the The control device is used for controlling photovoltaic equipment according to the method of any one of claims 1-8.
A photovoltaic system, characterized in that it includes photovoltaic equipment, electrical equipment, an alternating current grid, and a photovoltaic equipment control device according to claim 10 , wherein the electrical equipment and the alternating current grid are both connected to the photovoltaic equipment, and The electrical equipment is also connected to the AC power grid.
The photovoltaic system according to claim 11, wherein the electrical equipment is an air conditioner.