CN116931645A - Photovoltaic air conditioner and power control method thereof - Google Patents

Abstract

The invention provides a photovoltaic air conditioner and a power control method thereof, wherein the photovoltaic air conditioner comprises: the motor is used for controlling the rotating speed according to the output power of the photovoltaic array; the controller is used for determining the reference power of the photovoltaic air conditioner and the output power of the photovoltaic array; when the reference power is unequal to the output power and the working interval is a preset interval, the PWM duty ratio is adjusted to obtain the disturbance duty ratio, and when the disturbance power corresponding to the disturbance duty ratio is unequal to the output power, the PWM duty ratio is controlled to be the preset duty ratio to adjust the output power of the photovoltaic array.

Description

Photovoltaic air conditioner and power control method thereof

Technical Field

The invention relates to the technical field of air conditioners, in particular to a photovoltaic air conditioner and a power control method thereof.

Background

The photovoltaic system generates power, and is generally connected with a power grid through an inverter to generate power or stored energy through a storage battery, and the photovoltaic system is required to be tracked by using a maximum power point in the application scene so as to maintain the maximum output power, so that the output power is provided for the photovoltaic air conditioner, or an active PFC (Power Factor Correction, power factor correction circuit) control method is used for providing the output power for the photovoltaic air conditioner.

However, when the photovoltaic system continuously works at the maximum output power, the photovoltaic air conditioner is easy to damage because the photovoltaic air conditioner has no energy storage function; when the photovoltaic system works in a power supply environment, the photovoltaic air conditioner can be caused to have the risks of out-of-control working points and incapability of working normally due to the particularity of photovoltaic output volt-ampere characteristics.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art.

Therefore, an object of the present invention is to provide a photovoltaic air conditioner, which can meet the required power of the photovoltaic air conditioner in real time by adaptively adjusting the output power of the photovoltaic array, ensure the normal operation of the photovoltaic air conditioner, and reduce the damage risk of the photovoltaic air conditioner.

To this end, a second object of the present invention is to propose a power control method of a photovoltaic air conditioner.

In order to achieve the above object, an embodiment of a first aspect of the present invention proposes a photovoltaic air conditioner including: the motor is used for controlling the rotating speed according to the output power of the photovoltaic array; the controller is used for determining the reference power of the photovoltaic air conditioner and the output power of the photovoltaic array; when the reference power is not equal to the output power and the working interval is a preset interval, PWM duty cycle is adjusted to obtain disturbance duty cycle, and when disturbance power corresponding to the disturbance duty cycle is not equal to the output power, the PWM duty cycle is controlled to be a preset duty cycle to adjust the output power of the photovoltaic array.

According to the photovoltaic air conditioner disclosed by the embodiment of the invention, the reference power of the photovoltaic air conditioner and the output power of the photovoltaic array are determined, when the reference power and the output power are unequal, the output power of the photovoltaic array is adaptively adjusted by adjusting the PWM duty ratio, so that the output power of the photovoltaic array meets the reference power of the photovoltaic air conditioner, the damage of the photovoltaic air conditioner caused by the overlarge output power of the photovoltaic array is avoided, the damage risk of the photovoltaic air conditioner is reduced, and the risk of out-of-control working points and abnormal working caused by the photovoltaic characteristics can be reduced by adaptively adjusting the output power of the photovoltaic array, thereby ensuring the normal operation of the photovoltaic air conditioner.

In some embodiments, when the working interval is a preset interval, the PWM duty cycle is adjusted to obtain a disturbance duty cycle, and when the disturbance power corresponding to the disturbance duty cycle is unequal to the output power, the controller is configured to: when the output power does not exceed the reference power and the working interval state is in a stable interval, increasing the PWM duty ratio to obtain a first disturbance duty ratio, and when the first disturbance power corresponding to the first disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio; when the output power does not exceed the reference power and the working interval state is in an unstable interval, reducing the PWM duty ratio to obtain a second disturbance duty ratio, and when the second disturbance power corresponding to the second disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio; when the output power exceeds the reference power and the working interval state is in a stable interval, reducing the PWM duty ratio to obtain a third disturbance duty ratio, and when the third disturbance power corresponding to the third disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio; and when the output power exceeds the reference power and the working interval state is in an unstable interval, increasing the PWM duty ratio to obtain a fourth disturbance duty ratio, and when the fourth disturbance power corresponding to the fourth disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio.

In some embodiments, when the first disturbance power corresponding to the first disturbance duty cycle is not equal to the output power, the controller is configured to: when the first disturbance power exceeds the output power, increasing the PWM duty ratio to be a first preset duty ratio; and when the first disturbance power does not exceed the output power, reducing the PWM duty cycle to a second preset duty cycle.

In some embodiments, when the second disturbance power corresponding to the second disturbance duty cycle is not equal to the output power, the controller is configured to: when the second disturbance power exceeds the output power, reducing the PWM duty cycle to a third preset duty cycle; and when the second disturbance power does not exceed the output power, increasing the PWM duty cycle to be a fourth preset duty cycle.

In some embodiments, when the third perturbation power corresponding to the third perturbation duty cycle is not equal to the output power, the controller is configured to: when the third disturbance power does not exceed the output power, reducing the PWM duty cycle to a fifth preset duty cycle; and when the third disturbance power exceeds the output power, increasing the PWM duty cycle to be a sixth preset duty cycle.

In some embodiments, when the fourth perturbation power corresponding to the fourth perturbation duty cycle is not equal to the output power, the controller is configured to: when the fourth disturbance power does not exceed the output power, increasing the PWM duty cycle to be a seventh preset duty cycle; and when the fourth disturbance power exceeds the output power, reducing the PWM duty cycle to an eighth preset duty cycle.

In some embodiments, the controller is further configured to: and controlling the PWM duty ratio to be unchanged when the reference power is equal to the output power.

In some embodiments, in determining the output power of the photovoltaic array, the controller is configured to: detecting output voltage and output current of the photovoltaic array; and determining the output power of the photovoltaic array according to the output voltage and the output current.

In some embodiments, when determining the reference power of the photovoltaic air conditioner, the controller is configured to: determining a target voltage value of the photovoltaic air conditioner; and determining the reference power of the photovoltaic air conditioner according to the target voltage value.

In order to achieve the above object, an embodiment of a second aspect of the present invention provides a power control method of a photovoltaic air conditioner, the method comprising: determining the reference power of a photovoltaic air conditioner and the output power of a photovoltaic array; when the reference power is not equal to the output power and the working interval is a preset interval, PWM duty cycle is adjusted to obtain disturbance duty cycle, and when disturbance power corresponding to the disturbance duty cycle is not equal to the output power, the PWM duty cycle is controlled to be a preset duty cycle to adjust the output power of the photovoltaic array.

According to the power control method of the photovoltaic air conditioner, the reference power of the photovoltaic air conditioner and the output power of the photovoltaic array are determined, when the reference power and the output power are unequal, the PWM duty ratio is adjusted to adaptively adjust the output power of the photovoltaic array, so that the output power of the photovoltaic array meets the reference power of the photovoltaic air conditioner, the damage of the photovoltaic air conditioner caused by overlarge output power of the photovoltaic array is avoided, the damage risk of the photovoltaic air conditioner is reduced, and the risk of out-of-control of a working point and incapability of working normally caused by photovoltaic characteristics can be reduced by adaptively adjusting the output power of the photovoltaic array, thereby ensuring the normal operation of the photovoltaic air conditioner.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic diagram of a related art PFC control method;

FIG. 2 is a schematic diagram of a photovoltaic array ampere characteristic curve;

fig. 3 is a block diagram of a photovoltaic air conditioner according to an embodiment of the present invention;

fig. 4 is a schematic view of the working principle of a photovoltaic air conditioner according to an embodiment of the present invention;

FIG. 5 is a schematic representation of a photovoltaic array ampere characteristic curve according to one embodiment of the present invention;

fig. 6 is a flowchart of a power control method of a photovoltaic air conditioner according to an embodiment of the present invention.

Description of the drawings: a photovoltaic air conditioner 1; a motor 11; a controller 12.

Detailed Description

Embodiments of the present invention will be described in detail below, by way of example with reference to the accompanying drawings.

In the related art, when the photovoltaic system continuously works at the maximum output power, namely PPV_max, which is larger than the consumption power of the air conditioner, the photovoltaic air conditioner is damaged due to the fact that the photovoltaic air conditioner has no energy storage function.

At present, a photovoltaic system adopts a maximum power point tracking control method, or as shown in fig. 1, is a schematic diagram of a related art PFC control method. The photovoltaic system adopts a general active PFC (Power Factor Correction, power factor correction circuit) control method, can stably and reliably work under the conventional power supply environment, and ensures the normal operation of an optical Fu Guangfu air conditioner or other electric appliances.

However, when the photovoltaic system adopts the maximum power point tracking control method, the real-time output power of the photovoltaic system needs to be kept consistent with the required power of the photovoltaic air conditioner or other electrical appliances, otherwise, the risk of damage of the photovoltaic air conditioner or other electrical appliances exists; or when the photovoltaic system adopts the general active PFC control method, when the photovoltaic system is directly used for supplying power to a light Fu Guangfu air conditioner or other electric appliances, the photovoltaic working point is out of control in a specific area of a photovoltaic performance curve, such as an unstable area shown in fig. 2, due to the specificity of photovoltaic output volt-ampere characteristics, so that the photovoltaic air conditioner or other electric appliances cannot work normally.

Therefore, under the condition that the photovoltaic system is directly powered, the photovoltaic air conditioner can adaptively control the photovoltaic output current and the photovoltaic operating point according to the power requirement of the photovoltaic air conditioner, ensure the normal operation of the photovoltaic air conditioner, prevent the problem that the photovoltaic air conditioner is easy to damage when the photovoltaic system keeps the maximum power output state, and reduce the phenomenon that the photovoltaic operating point is out of control in a specific region of a photovoltaic performance curve, so that the photovoltaic air conditioner cannot normally operate.

A photovoltaic air conditioner 1 according to an embodiment of the present invention is illustrated below with reference to fig. 2 to 5.

Fig. 3 is a block diagram of a photovoltaic air conditioner according to an embodiment of the present invention. The photovoltaic air conditioner 1 includes: a motor 11 and a controller 12, wherein,

the motor 11 is used for controlling the rotating speed according to the output power of the photovoltaic array; the controller 12 is used for determining the reference power of the photovoltaic air conditioner 1 and the output power of the photovoltaic array; when the reference power is not equal to the output power and the working interval is a preset interval, the PWM duty cycle is adjusted to obtain the disturbance duty cycle, and when the disturbance power corresponding to the disturbance duty cycle is not equal to the output power, the PWM duty cycle is controlled to be the preset duty cycle so as to adjust the output power of the photovoltaic array.

In the embodiment, as shown in fig. 4, a schematic diagram of the working principle of the photovoltaic air conditioner according to an embodiment of the present invention is shown. The controller 12 defines in advance an operation state variable of the photovoltaic air conditioner 1, for example, denoted by w, and sets the operation state variable w=1 when the photovoltaic air conditioner operates in a stable operation region of the photovoltaic voltammetric characteristic curve; when the photovoltaic air conditioner is set to work in an unstable working interval of the photovoltaic characteristic curve, the working state variable w=0, and the working state variable w is initialized to enable the working state variable w=1.

The controller 12 calculates the reference power of the photovoltaic air conditioner 1, for example, pref (k), and calculates the output power of the photovoltaic array, for example, P (k), after defining the operation state variable w of the photovoltaic air conditioner 1, determines the magnitude relation between the reference power Pref (k) of the photovoltaic air conditioner 1 and the output power P (k) of the photovoltaic array, and then determines the magnitude relation between the reference power Pref (k) of the photovoltaic air conditioner 1 and the output power P (k) of the photovoltaic array.

If the reference power Pref (k) of the photovoltaic air conditioner 1 is not equal to the output power P (k) of the photovoltaic array, the output power P (k) of the photovoltaic array is not matched with the reference power Pref (k) of the photovoltaic air conditioner 1, power adjustment is needed to ensure normal operation of the photovoltaic air conditioner 1, then the current working interval of the photovoltaic air conditioner 1 is detected, when the working interval of the photovoltaic air conditioner 1 is a preset interval, the PWM duty ratio is adjusted, the disturbance duty ratio is obtained, for example, the disturbance duty ratio is denoted as dΔ (k), the disturbance power corresponding to the disturbance duty ratio dΔ (k) is calculated, for example, the relationship between the disturbance power pΔ (k) and the output power P (k) is judged, when the disturbance power pΔ (k) is not equal to the output power P (k), the PWM duty ratio is controlled to be adjusted to be the preset duty ratio according to the power requirement of the photovoltaic air conditioner 1, the output power P (k) of the photovoltaic array is adaptively adjusted, and the motor 11 performs corresponding rotation speed control according to the adjusted output power P (k) of the photovoltaic array.

According to the photovoltaic air conditioner 1 provided by the embodiment of the invention, the reference power of the photovoltaic air conditioner 1 and the output power of the photovoltaic array are determined, when the reference power and the output power are unequal, the output power of the photovoltaic array is adaptively adjusted by adjusting the PWM duty ratio, so that the output power of the photovoltaic array meets the reference power of the photovoltaic air conditioner 1, the damage of the photovoltaic air conditioner 1 caused by the overlarge output power of the photovoltaic array is avoided, the damage risk of the photovoltaic air conditioner 1 is reduced, and the risk of out-of-control of the working point and incapability of normal working caused by the photovoltaic characteristics can be reduced by adaptively adjusting the output power of the photovoltaic array, thereby ensuring the normal operation of the photovoltaic air conditioner 1.

In some embodiments, when the working interval is a preset interval, the PWM duty cycle is adjusted to obtain a disturbance duty cycle, and when the disturbance power corresponding to the disturbance duty cycle is unequal to the output power, the controller is configured to: when the output power does not exceed the reference power and the working interval state is in a stable interval, increasing the PWM duty ratio to obtain a first disturbance duty ratio, and when the first disturbance power corresponding to the first disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio; when the output power does not exceed the reference power and the working interval state is in an unstable interval, reducing the PWM duty ratio to obtain a second disturbance duty ratio, and when the second disturbance power corresponding to the second disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio; when the output power exceeds the reference power and the working interval state is in a stable interval, reducing the PWM duty ratio to obtain a third disturbance duty ratio, and when the third disturbance power corresponding to the third disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio; when the output power exceeds the reference power and the working interval state is in an unstable interval, the PWM duty ratio is increased to obtain a fourth disturbance duty ratio, and when the fourth disturbance power corresponding to the fourth disturbance duty ratio is unequal to the output power, the PWM duty ratio is adjusted.

In an embodiment, if the reference power Pref (k) of the photovoltaic air conditioner 1 is not equal to the output power P (k) of the photovoltaic array, there may be an output power P (k) not exceeding the reference power Pref (k), i.e., P (k). Ltoreq.pref (k), then the current operation interval of the photovoltaic air conditioner 1 is detected, for example, as shown in fig. 2, when the operation interval state of the photovoltaic air conditioner 1 is in the stable interval, i.e., the operation state variable w=1, the PWM duty cycle is increased by a small margin, and the first disturbance duty cycle is obtained, for example, denoted as dΔ (k 1), i.e., the first disturbance duty cycle dΔ (k 1) =d (k) +d, where the disturbance D >0 is calculated, the first disturbance power corresponding to the first disturbance duty cycle dΔ (k 1) is denoted as pΔ (k 1), the magnitude relation between the first disturbance power pΔ (k 1) and the output power P (k) is determined, and the PWM duty cycle is adjusted when the first disturbance power pΔ (k 1) is not equal to the output power P (k).

If the reference power Pref (k) of the photovoltaic air conditioner 1 is not equal to the output power P (k) of the photovoltaic array, there may be an output power P (k) not exceeding the reference power Pref (k), i.e., P (k). Ltoreq.pref (k), then the current operation interval of the photovoltaic air conditioner 1 is detected, for example, as shown in fig. 2, when the operation interval state of the photovoltaic air conditioner 1 is in an unstable interval, i.e., the operation state variable w=0, the PWM duty cycle is reduced by a small margin, so as to obtain a second disturbance duty cycle, for example, denoted as dΔ (k 2), i.e., the second disturbance duty cycle dΔ (k 2) =d (k) -D, where disturbance D >0 is calculated, a second disturbance power corresponding to the second disturbance duty cycle dΔ (k 2) is denoted as pΔ (k 2), and the magnitude relation between the second disturbance power pΔ (k 2) and the output power P (k) is determined, and the PWM duty cycle is adjusted when the second disturbance power pΔ (k) is not equal to the output power P (k).

If the reference power Pref (k) of the photovoltaic air conditioner 1 is not equal to the output power P (k) of the photovoltaic array, there may be an output power P (k) exceeding the reference power Pref (k), that is, P (k) > Pref (k), and the current operation interval of the photovoltaic air conditioner 1 is detected, for example, as shown in fig. 2, when the operation interval state of the photovoltaic air conditioner 1 is in the stable interval, that is, the operation state variable w=1, the PWM duty ratio is reduced by a small margin, so as to obtain a third disturbance duty ratio, for example, denoted as dΔ (k 3), that is, a third disturbance duty ratio dΔ (k 3) =d (k) -D, where the disturbance D >0 is calculated, a third disturbance power corresponding to the third disturbance duty ratio dΔ (k 3) is denoted as pΔ (k 3), and the magnitude relation between the third disturbance power pΔ (k 3) and the output power P (k) is determined, and when the third disturbance power pΔ (k) is not equal, the PWM duty ratio is adjusted.

If the reference power Pref (k) of the photovoltaic air conditioner 1 is not equal to the output power P (k) of the photovoltaic array, there may be an output power P (k) exceeding the reference power Pref (k), that is, P (k) > Pref (k), then the current operation interval of the photovoltaic air conditioner 1 is detected, for example, as shown in fig. 2, when the operation interval state of the photovoltaic air conditioner 1 is in an unstable interval, that is, the operation state variable w=0, the PWM duty cycle is increased by a small margin, so as to obtain a fourth disturbance duty cycle, for example, denoted as dΔ (k 4), that is, the fourth disturbance duty cycle dΔ (k 4) =d (k) +d, where the disturbance D >0 is calculated, the fourth disturbance power corresponding to the fourth disturbance duty cycle dΔ (k 4) is denoted as pΔ (k 4), the magnitude relation between the fourth disturbance power pΔ (k 4) and the output power P (k) is determined, and the PWM duty cycle is adjusted when the fourth disturbance power pΔ (k 4) is not equal to the output power P (k).

In some embodiments, when the first disturbance power corresponding to the first disturbance duty cycle is not equal to the output power, the controller is configured to: when the first disturbance power exceeds the output power, increasing the PWM duty ratio to be a first preset duty ratio; and when the first disturbance power does not exceed the output power, reducing the PWM duty cycle to a second preset duty cycle.

In the embodiment, when the first disturbance power pΔ (k 1) exceeds the output power P (k), that is, pΔ (k 1) > P (k), the operating section state of the photovoltaic air conditioner 1 is considered to be in a stable section, the PWM duty cycle is greatly increased, so as to obtain a first preset duty cycle, for example, denoted as D (k+1), that is, the first preset duty cycle D (k+1) =d (k) +|Δd|, where |Δd| is an absolute value of the PWM duty cycle error, and the operating state variable w=1 is maintained, as shown in fig. 5, which is a schematic diagram of the photovoltaic array ampere characteristic curve according to an embodiment of the present invention. The current and voltage output by the photovoltaic array change direction from D to F.

When the first disturbance power pΔ (k 1) does not exceed the output power P (k), that is, pΔ (k 1) < P (k), the operating section state of the photovoltaic air conditioner 1 is considered to be in an unstable section, the PWM duty cycle is reduced, and a second preset duty cycle is obtained, for example, denoted as D (k+2), that is, the second preset duty cycle D (k+2) =d (k) - |Δd|, where |Δd| is the absolute value of the PWM duty cycle error, and the operating state variable w=0 is maintained, as shown in fig. 5, and the current and voltage change direction of the photovoltaic array output is moving from E to G.

In some embodiments, when the second disturbance power corresponding to the second disturbance duty cycle is not equal to the output power, the controller is configured to: when the second disturbance power exceeds the output power, the PWM duty ratio is reduced to a third preset duty ratio; and when the second disturbance power does not exceed the output power, increasing the PWM duty ratio to be a fourth preset duty ratio.

In an embodiment, when the second disturbance power pΔ (k 2) exceeds the output power P (k), that is, pΔ (k 2) > P (k), the operating section state of the photovoltaic air conditioner 1 is considered to be in an unstable section, the PWM duty cycle is greatly reduced, and a third preset duty cycle, for example, denoted as D (k+3), that is, a third preset duty cycle D (k+3) =d (k) - |Δd|, where |Δd| is an absolute value of the PWM duty cycle error, and the operating state variable w=0 is maintained, as shown in fig. 5, and the current and voltage variation directions of the photovoltaic array output are moved from E to G.

When the second disturbance power pΔ (k 2) does not exceed the output power P (k), that is, pΔ (k 2) < P (k), the operating section state of the photovoltaic air conditioner 1 is considered to be in a stable section, the PWM duty cycle is increased, and a fourth preset duty cycle is obtained, for example, denoted as D (k+4), that is, the fourth preset duty cycle D (k+4) =d (k) +|Δd|, where |Δd| is an absolute value of the PWM duty cycle error, and the operating state variable w=1 is maintained, as shown in fig. 5, where the current and voltage change direction of the photovoltaic array output is moving from D to F.

In some embodiments, when the third perturbation power corresponding to the third perturbation duty cycle is not equal to the output power, the controller is configured to: when the third disturbance power does not exceed the output power, the PWM duty ratio is reduced to a fifth preset duty ratio; and when the third disturbance power exceeds the output power, increasing the PWM duty ratio to be a sixth preset duty ratio.

In the embodiment, when the third disturbance power pΔ (k 3) does not exceed the output power P (k), that is, pΔ (k 3) < P (k), the operating section state of the photovoltaic air conditioner 1 is considered to be in the stable section, the PWM duty cycle is greatly reduced, and a fifth preset duty cycle, for example, D (k+5), that is, a fifth preset duty cycle D (k+5) =d (k) - |Δd|, where |Δd| is an absolute value of the PWM duty cycle error, and the operating state variable w=1 is maintained, as shown in fig. 5, and the current and voltage change directions of the photovoltaic array output at this time are moved from B to F.

When the third disturbance power pΔ (k 3) exceeds the output power P (k), that is, pΔ (k 3) > P (k), the operating section state of the photovoltaic air conditioner 1 is considered to be in an unstable section, the PWM duty cycle is increased, and a sixth preset duty cycle, for example, D (k+6), that is, a sixth preset duty cycle D (k+6) =d (k) +|Δd|, is obtained, where |Δd| is an absolute value of the PWM duty cycle error, and the operating state variable w=0 is maintained, as shown in fig. 5, and at this time, the current and voltage change direction of the photovoltaic array output is moved from B to G.

In some embodiments, when the fourth disturbance power corresponding to the fourth disturbance duty cycle is not equal to the output power, the controller is configured to: when the fourth disturbance power does not exceed the output power, increasing the PWM duty ratio to be a seventh preset duty ratio; and when the fourth disturbance power exceeds the output power, reducing the PWM duty cycle to be an eighth preset duty cycle.

In the embodiment, when the fourth disturbance power pΔ (k 4) does not exceed the output power P (k), that is, pΔ (k 4) < P (k), it is considered that the operating section state of the photovoltaic air conditioner 1 is in the unstable section, the PWM duty cycle is greatly increased, and a seventh preset duty cycle is obtained, for example, denoted as D (k+7), that is, a seventh preset duty cycle D (k+7) =d (k) - |Δd|, where |Δd| is an absolute value of the PWM duty cycle error, and the operating state variable w=0 is maintained, as shown in fig. 5, and at this time, the current and voltage variation directions of the photovoltaic array output are moved from B to G.

When the fourth disturbance power pΔ (k 4) exceeds the output power P (k), that is, pΔ (k 4) > P (k), the operating section state of the photovoltaic air conditioner 1 is considered to be in a stable section, the PWM duty cycle is reduced, and an eighth preset duty cycle, for example, denoted as D (k+8), that is, eighth preset duty cycle D (k+8) =d (k) +|Δd|, where|Δd| is an absolute value of the PWM duty cycle error, and the operating state variable w=1 is maintained, as shown in fig. 5, and at this time, the current and voltage change direction of the photovoltaic array output is moved from B to F.

In some embodiments, the controller is further configured to: when the reference power is equal to the output power, the PWM duty cycle is controlled to remain unchanged.

In the embodiment, after determining the reference power Pref (k) of the photovoltaic air conditioner and the output power P (k) of the photovoltaic array, the magnitude relation between the reference power Pref (k) of the photovoltaic air conditioner 1 and the output power P (k) of the photovoltaic array is determined, if the reference power Pref (k) of the photovoltaic air conditioner 1 is equal to the output power P (k) of the photovoltaic array, that is, pref (k) =p (k), the output power P (k) of the photovoltaic array is considered to be matched with the reference power Pref (k) of the photovoltaic air conditioner 1, and no power adjustment is required, and the air conditioner can operate normally, and the controller 12 controls the PWM duty ratio to remain unchanged.

In some embodiments, in determining the output power of the photovoltaic array, the controller 12 is configured to: detecting output voltage and output current of the photovoltaic array; the output power of the photovoltaic array is determined from the output voltage and the output current.

In an embodiment, the controller 12 detects the output voltage and the output current of the photovoltaic array in real time, and calculates the output power P (k) of the photovoltaic array at the current time according to the output voltage and the output current, so as to adaptively adjust the PWM duty cycle according to the output power P (k) of the photovoltaic array at the current time.

In some embodiments, when determining the reference power of the photovoltaic air conditioner 1, the controller 12 is configured to: determining a target voltage value of the photovoltaic air conditioner 1; the reference power of the photovoltaic air conditioner 1 is determined according to the target voltage value.

In an embodiment, the controller 12 determines the target voltage value of the photovoltaic air conditioner 1, and determines the reference power Pref (k) of the photovoltaic air conditioner 1 according to the target voltage value of the photovoltaic air conditioner 1, so as to determine the preset duty ratio of the PWM duty ratio according to the reference power Pref (k) of the photovoltaic air conditioner 1.

According to the photovoltaic air conditioner 1 provided by the embodiment of the invention, the reference power of the photovoltaic air conditioner 1 and the output power of the photovoltaic array are determined, when the reference power and the output power are unequal, the output power of the photovoltaic array is adaptively adjusted by adjusting the PWM duty ratio, so that the output power of the photovoltaic array meets the reference power of the photovoltaic air conditioner 1, the damage of the photovoltaic air conditioner 1 caused by the overlarge output power of the photovoltaic array is avoided, the damage risk of the photovoltaic air conditioner 1 is reduced, and the risk of out-of-control of the working point and incapability of normal working caused by the photovoltaic characteristics can be reduced by adaptively adjusting the output power of the photovoltaic array, thereby ensuring the normal operation of the photovoltaic air conditioner 1.

The following describes an example of a power control method of a photovoltaic air conditioner according to an embodiment of the present invention with reference to fig. 6.

As shown in fig. 6, the power control method of the photovoltaic air conditioner according to the embodiment of the present invention at least includes step S1 and step S2.

And S1, determining the reference power of the photovoltaic air conditioner and the output power of the photovoltaic array.

In an embodiment, by detecting the output voltage and the output current of the photovoltaic array in real time, calculating the output power of the photovoltaic array at the current moment according to the output voltage and the output current, for example, the output power is recorded as P (k); by determining the target voltage value of the photovoltaic air conditioner, the reference power of the photovoltaic air conditioner is determined according to the target voltage value of the photovoltaic air conditioner and is marked as Pref (k), so that the PWM duty ratio is adaptively adjusted according to the reference power Pref (k) of the photovoltaic air conditioner and the output power P (k) of the photovoltaic array.

And S2, when the reference power is not equal to the output power and the working interval is a preset interval, adjusting the PWM duty ratio to obtain a disturbance duty ratio, and when the disturbance power corresponding to the disturbance duty ratio is not equal to the output power, controlling the PWM duty ratio to be the preset duty ratio so as to adjust the output power of the photovoltaic array.

In an embodiment, when the reference power Pref (k) of the photovoltaic air conditioner is not equal to the output power P (k) of the photovoltaic array, the output power P (k) of the photovoltaic array is not matched with the reference power Pref (k) of the photovoltaic air conditioner, power adjustment is needed to ensure normal operation of the photovoltaic air conditioner, then a current working interval of the photovoltaic air conditioner is detected, when the working interval of the photovoltaic air conditioner is a preset interval, a PWM duty ratio is adjusted to obtain a disturbance duty ratio, for example, the disturbance duty ratio is denoted as Ddelta (k), the disturbance power corresponding to the disturbance duty ratio Ddelta (k) is calculated, for example, the disturbance power is denoted as Pdelta (k), the size relation between the disturbance power Pdelta (k) and the output power P (k) is judged, when the disturbance power Pdelta (k) is not equal to the output power P (k), the PWM duty ratio is controlled to be adjusted to be the preset duty ratio according to the power requirement of the photovoltaic air conditioner, the output power P (k) of the photovoltaic array is adaptively adjusted, and the corresponding rotation speed is controlled according to the adjusted output power P (k) of the photovoltaic array.

According to the power control method of the photovoltaic air conditioner, the reference power of the photovoltaic air conditioner and the output power of the photovoltaic array are determined, when the reference power and the output power are unequal, the PWM duty ratio is adjusted to adaptively adjust the output power of the photovoltaic array, so that the output power of the photovoltaic array meets the reference power of the photovoltaic air conditioner, the damage of the photovoltaic air conditioner caused by overlarge output power of the photovoltaic array is avoided, the damage risk of the photovoltaic air conditioner is reduced, and the risk of out-of-control of the working point and incapability of normal working caused by the photovoltaic characteristics can be reduced by adaptively adjusting the output power of the photovoltaic array, so that the normal operation of the photovoltaic air conditioner is ensured.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (10)

1. A photovoltaic air conditioner, comprising:

the motor is used for controlling the rotating speed according to the output power of the photovoltaic array;

the controller is used for determining the reference power of the photovoltaic air conditioner and the output power of the photovoltaic array;

when the reference power is not equal to the output power and the working interval is a preset interval, PWM duty cycle is adjusted to obtain disturbance duty cycle, and when disturbance power corresponding to the disturbance duty cycle is not equal to the output power, the PWM duty cycle is controlled to be a preset duty cycle to adjust the output power of the photovoltaic array.

2. The photovoltaic air conditioner according to claim 1, wherein when the working interval is a preset interval, the PWM duty cycle is adjusted to obtain a disturbance duty cycle, and when disturbance power corresponding to the disturbance duty cycle is not equal to the output power, the controller is configured to:

when the output power does not exceed the reference power and the working interval state is in a stable interval, increasing the PWM duty ratio to obtain a first disturbance duty ratio, and when the first disturbance power corresponding to the first disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio;

when the output power does not exceed the reference power and the working interval state is in an unstable interval, reducing the PWM duty ratio to obtain a second disturbance duty ratio, and when the second disturbance power corresponding to the second disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio;

when the output power exceeds the reference power and the working interval state is in a stable interval, reducing the PWM duty ratio to obtain a third disturbance duty ratio, and when the third disturbance power corresponding to the third disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio;

and when the output power exceeds the reference power and the working interval state is in an unstable interval, increasing the PWM duty ratio to obtain a fourth disturbance duty ratio, and when the fourth disturbance power corresponding to the fourth disturbance duty ratio is unequal to the output power, adjusting the PWM duty ratio.

3. The photovoltaic air conditioner of claim 2, wherein when the first disturbance power corresponding to the first disturbance duty cycle is unequal to the output power, the controller is configured to:

when the first disturbance power exceeds the output power, increasing the PWM duty ratio to be a first preset duty ratio;

and when the first disturbance power does not exceed the output power, reducing the PWM duty cycle to a second preset duty cycle.

4. The photovoltaic air conditioner of claim 2, wherein when the second disturbance power corresponding to the second disturbance duty cycle is unequal to the output power, the controller is configured to:

when the second disturbance power exceeds the output power, reducing the PWM duty cycle to a third preset duty cycle;

and when the second disturbance power does not exceed the output power, increasing the PWM duty cycle to be a fourth preset duty cycle.

5. The photovoltaic air conditioner of claim 2, wherein when the third perturbation power corresponding to the third perturbation duty cycle is unequal to the output power, the controller is configured to:

when the third disturbance power does not exceed the output power, reducing the PWM duty cycle to a fifth preset duty cycle;

and when the third disturbance power exceeds the output power, increasing the PWM duty cycle to be a sixth preset duty cycle.

6. The photovoltaic air conditioner of claim 2, wherein when the fourth disturbance power corresponding to the fourth disturbance duty cycle is unequal to the output power, the controller is configured to:

when the fourth disturbance power does not exceed the output power, increasing the PWM duty cycle to be a seventh preset duty cycle;

and when the fourth disturbance power exceeds the output power, reducing the PWM duty cycle to an eighth preset duty cycle.

7. The photovoltaic air conditioner of claim 1, wherein the controller is further configured to:

and controlling the PWM duty ratio to be unchanged when the reference power is equal to the output power.

8. The photovoltaic air conditioner of claim 1, wherein in determining the output power of the photovoltaic array, the controller is configured to:

detecting output voltage and output current of the photovoltaic array;

and determining the output power of the photovoltaic array according to the output voltage and the output current.

9. The photovoltaic air conditioner of claim 1, wherein when determining the reference power of the photovoltaic air conditioner, the controller is configured to:

determining a target voltage value of the photovoltaic air conditioner;

and determining the reference power of the photovoltaic air conditioner according to the target voltage value.

10. A power control method of a photovoltaic air conditioner, comprising:

determining the reference power of a photovoltaic air conditioner and the output power of a photovoltaic array;

when the reference power is not equal to the output power and the working interval is a preset interval, PWM duty cycle is adjusted to obtain disturbance duty cycle, and when disturbance power corresponding to the disturbance duty cycle is not equal to the output power, the PWM duty cycle is controlled to be a preset duty cycle to adjust the output power of the photovoltaic array.