CN104142008A - Photovoltaic air conditioner and photovoltaic air conditioning system - Google Patents

Abstract

The invention discloses a photovoltaic air conditioner and a photovoltaic air conditioning system. Wherein, photovoltaic air conditioner includes: an air conditioning load; the alternating current side of the inverter circuit is connected with the air conditioner load and the commercial power grid respectively, and the direct current side of the inverter circuit is connected with the photovoltaic cell panel and used for converting direct current output by the photovoltaic cell panel into alternating current required by the work of the air conditioner load; the rectification circuit is connected between the inverter circuit and the commercial power grid and is used for converting alternating current output by the commercial power grid into direct current; and the movable positions of the movable contact of the relay comprise a first position and a second position, the alternating current side of the inverter circuit is communicated with the air conditioner load under the condition that the movable contact is positioned at the first position, and the alternating current side of the inverter circuit is communicated with the commercial power grid under the condition that the movable contact is positioned at the second position. According to the invention, the effect of reducing the cost of the photovoltaic air conditioning system is achieved.

Description

Photovoltaic air conditioner and photovoltaic air conditioning system

technical field

The invention relates to the field of air conditioners, in particular to a photovoltaic air conditioner and a photovoltaic air conditioner system.

Background technique

Existing photovoltaic air conditioners can realize photovoltaic grid-connected functions, photovoltaic power supply functions for air conditioners, and grid-connected and air-conditioner power supplies at the same time. However, existing photovoltaic air conditioners usually have two sets of inverter systems, one for grid-connected power generation and one for driving air-conditioning loads, such as compressors.

Since in photovoltaic air conditioners, the cost of inverter circuit power conversion devices occupies a large part of the entire photovoltaic air conditioner, therefore, the use of two sets of inverter systems will inevitably increase the cost of photovoltaic air conditioners, which will affect the promotion of photovoltaic air conditioners. Use poses a huge hurdle.

Aiming at the problem in the prior art that the cost of the photovoltaic air conditioner is high due to the use of two sets of inverter systems, no effective solution has been proposed yet.

Contents of the invention

The main purpose of the present invention is to provide a photovoltaic air conditioner and a photovoltaic air conditioning system to solve the problem in the prior art that the cost of the photovoltaic air conditioning system is high due to the use of two sets of inverter systems.

In order to achieve the above purpose, according to one aspect of the present invention, a photovoltaic air conditioner is provided. The photovoltaic air conditioner according to the present invention includes: an air conditioner load; an inverter circuit, the AC side of the inverter circuit is connected to the air conditioner load and the mains grid respectively, and the DC side of the inverter circuit is connected to a photovoltaic cell panel for connecting the photovoltaic The direct current output by the battery panel is converted into the alternating current required by the air conditioner load; the rectifier circuit is connected between the inverter circuit and the mains grid to convert the alternating current output by the mains grid into direct current; and the relay is connected to the inverter Between the AC side of the circuit and the air-conditioning load, and between the AC side of the inverter circuit and the mains grid, the movable position of the movable contact of the relay includes the first position and the second position, when the movable contact is in the first position In the case of the first position, the AC side of the inverter circuit is connected to the air conditioner load, and when the movable contact is in the second position, the AC side of the inverter circuit is connected to the mains grid.

Further, the photovoltaic air conditioner further includes: a control circuit connected to the relay, and when the movable contact is in the second position, the control circuit is used to control the movable contact to switch to the first position when an island effect occurs.

Further, the control circuit includes: a sampling and conditioning circuit for sampling the grid information of the mains power grid; a main controller connected to the sampling and conditioning circuit for performing logic operations according to the received signal to control the relay Connection status is controlled.

Further, the DC potential output by the rectifier circuit has a pulsating DC voltage, and the photovoltaic air conditioner also includes: a booster circuit, connected between the photovoltaic cell panel and the DC side of the inverter circuit, for the output of the photovoltaic cell panel. Boost the voltage to obtain the first direct current; the PFC circuit is connected between the rectifier circuit and the DC side of the inverter circuit, and is used to boost the pulsating voltage output by the rectifier circuit to obtain the second direct current, wherein the boost circuit Both the PFC circuit and the DC bus are connected to the DC side of the inverter circuit.

Further, the control circuit is connected to the boost circuit and the PFC circuit respectively, wherein, when the movable contact is in the first position, the control circuit is used to control the PFC circuit to output the second direct current to the DC bus, and control the step-up The voltage of the first direct current output by the circuit is lower than the voltage of the second direct current; when the movable contact is in the first position, the control circuit is used to output the first direct current to the direct current bus through the booster circuit, and control the output of the PFC circuit The voltage of the second direct current is lower than the voltage of the first direct current; when the movable contact is in the first position, the control circuit controls the boost circuit and the PFC circuit respectively, so that the voltages of the first direct current and the second direct current are the same; When the head is in the second position, the control circuit is used to sample the grid information of the mains power grid, and control the voltage of the first direct current output by the booster circuit to be higher than the second direct current output by the PFC circuit or control to cut off the connection of the PFC circuit, The control circuit is also used to control the inverter circuit to invert the voltage of the direct current bus into alternating current and merge it into the mains power grid.

Further, the photovoltaic air conditioner also includes: a power supply circuit, connected to the DC bus and the control circuit, for providing DC power to the control circuit; a human-computer interaction circuit, connected to the control circuit, for realizing human-computer data interaction.

Further, the human-computer interaction circuit includes: a display circuit, connected to the control circuit, for displaying the working status and parameter information of the photovoltaic air conditioner; and a button circuit, connected to the control circuit, for realizing manual operation of the photovoltaic air conditioner. control.

Further, the photovoltaic air conditioner also includes: a first filter circuit, connected between the photovoltaic cell panel and the booster circuit, for filtering the common-mode and differential-mode interference input by the photovoltaic cell panel.

Further, the photovoltaic air conditioner also includes: a second filter circuit, connected between the mains grid and the rectification circuit, for filtering the high-frequency conduction and radiation generated by the photovoltaic air conditioner.

Further, the photovoltaic air conditioner also includes a filter inductor, the first end of the filter inductor is connected to the mains grid, and the second end of the filter inductor is connected to a relay for shaping the alternating current incorporated into the mains grid.

In order to achieve the above object, according to another aspect of the present invention, a photovoltaic air conditioning system is provided. The photovoltaic air conditioner system according to the present invention includes: the above photovoltaic air conditioner, the photovoltaic air conditioner is connected to the mains grid; the photovoltaic battery panel is connected to the photovoltaic air conditioner, and is used to provide electric energy to the photovoltaic air conditioner.

According to an embodiment of the present invention, the photovoltaic air conditioner includes: an air conditioner load; an inverter circuit, the AC side of the inverter circuit is connected to the air conditioner load, the DC side of the inverter circuit is connected to a photovoltaic battery panel, It is used to convert the direct current output by the photovoltaic panel into the alternating current required by the air-conditioning load; the rectifier circuit is connected between the inverter circuit and the mains power grid, and is used to convert the output of the mains power grid The alternating current is converted into direct current; and the relay is connected between the alternating current side of the inverter circuit and the air conditioner load, and is connected between the alternating current side of the inverter circuit and the utility grid, and the relay The movable position of the movable contact includes a first position and a second position. When the movable contact is in the first position, the AC side of the inverter circuit is connected to the air conditioner load. When the head is in the second position, the AC side of the inverter circuit is connected to the mains grid, which solves the problem of high cost of the photovoltaic air conditioner due to the use of two sets of inverter systems, and achieves a reduction in the cost of the photovoltaic air conditioner. effect on the cost of the appliance.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Fig. 1 is a schematic structural view of a photovoltaic air conditioner according to an embodiment of the present invention; and

Fig. 2 is a schematic structural diagram of a preferred photovoltaic air conditioner according to an embodiment of the present invention.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is an embodiment of a part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first" and "second" in the description and claims of the present invention and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It should be understood that the data so used may be interchanged under appropriate circumstances for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, e.g. a system, product or device comprising a series of elements need not be limited to those elements explicitly listed, but may include other components not expressly listed or inherent to the system, product or equipment.

An embodiment of the present invention provides a photovoltaic air conditioner.

Fig. 1 is a schematic structural view of a photovoltaic air conditioner according to an embodiment of the present invention. As shown in FIG. 1 , the photovoltaic air conditioner includes: an air conditioner load 11 , an inverter circuit 12 , a rectifier circuit 13 and a relay 14 .

Air conditioning loads may be, for example, compressors, DC fans, and the like.

The AC side of the inverter circuit 12 is connected to the air-conditioning load 11 and the mains power grid 16 respectively, and the DC side of the inverter circuit 12 is connected to the photovoltaic panel 15 for converting the direct current (DC) output by the photovoltaic panel 15 into Alternating current (AC). The alternating current may be the alternating current required for the air conditioner load 11 to work, or the alternating current for grid connection. The rectifier circuit 13 is connected between the inverter circuit 12 and the mains power grid 16, and is used to convert the alternating current output by the mains power grid 16 into direct current. converted to a pulsating forward voltage.

The relay 14 is connected between the AC side of the inverter circuit 12 and the air-conditioning load 11, and between the AC side of the inverter circuit 12 and the mains power grid 16, and the relay is used to switch the load object (air-conditioning load) of the inverter circuit 12 or mains grid).

Specifically, the movable position of the movable contact of the relay 14 includes a first position and a second position. When the movable contact is in the first position, the AC side of the inverter circuit 12 is connected to the air-conditioning load 11, and the movable contact When the head is in the second position, the AC side of the inverter circuit 12 is connected to the commercial power grid 16 . The load object (air conditioning load or mains grid) connected to the inverter circuit is switched by controlling the position of the movable contact. When the movable contact is at the first position, the photovoltaic air conditioner is in the air conditioning mode, and the air conditioner load is working. The electric energy required for its work can be the electric energy provided by the photovoltaic panel, or the electric energy provided by the mains grid, or two. When the movable contact is in the second position, the photovoltaic air conditioner is in the grid-connected power generation mode, the air conditioner load does not work, and the electric energy output by the photovoltaic panel is incorporated into the mains grid.

Specifically, the above-mentioned air-conditioning load can be the compressor of the air conditioner. In the embodiment of the present invention, the photovoltaic grid-connected inverter module and the air-conditioning compressor drive module are combined into one, and the grid-connected work or the compressor can be realized by switching the load through the relay. Work.

Compared with the existing photovoltaic controller, the photovoltaic air conditioner in the embodiment of the present invention saves an inverter module and its radiator and corresponding drive circuit, and saves the grid-connected control relay used in the inverter, which greatly reduces the cost of the photovoltaic air conditioner. It is beneficial to the popularization and popularization of photovoltaic air conditioners and is more practical.

According to an embodiment of the present invention, the photovoltaic air conditioner includes: an air conditioner load; an inverter circuit, the AC side of the inverter circuit is connected to the air conditioner load, and the DC side of the inverter circuit is connected to the photovoltaic cell panel for outputting the photovoltaic cell panel The direct current is converted into the alternating current required by the air conditioner load; the rectifier circuit is connected between the inverter circuit and the mains grid, and is used to convert the alternating current output by the mains grid into direct current; and the relay is connected to the alternating current of the inverter circuit. side and the air-conditioning load, and connected between the AC side of the inverter circuit and the mains grid, the movable position of the movable contact of the relay includes the first position and the second position, when the movable contact is in the first position Next, the AC side of the inverter circuit is connected to the air-conditioning load, and when the movable contact is in the second position, the AC side of the inverter circuit is connected to the mains grid, which solves the problem of photovoltaic power failure due to the use of two sets of inverter systems. The problem of high cost of the air conditioner achieves the effect of reducing the cost of the photovoltaic air conditioner.

Fig. 2 is a schematic structural diagram of a preferred photovoltaic air conditioner according to an embodiment of the present invention. As shown in FIG. 2 , the photovoltaic air conditioner also includes a control circuit 17 which is connected to the relay 14 (not shown in the figure). Wherein, the movable contacts of the relay 14 include K1, K2 and K3, the above-mentioned first position is the position A shown in the figure, and the second position is the position B shown in the figure. When the movable contacts K1～K3 are in the second position B, the control circuit 17 is used to control the movable contacts K1～K3 to switch to the first position when the islanding effect occurs, wherein the movable contacts K1～K3 are in the second position B. In the first position, the AC side of the inverter circuit 12 is disconnected from the mains grid 16 .

When the movable contacts K1-K3 are in the second position B, the photovoltaic air conditioner is in the grid-connected power generation mode. Among them, when the island effect occurs, the control circuit controls the relay to cut off the connection between the inverter circuit and the mains power grid, so that there is no need to add a grid-connected control relay, which further reduces the cost of the photovoltaic air conditioner.

Preferably, the control circuit 17 includes: a sampling and conditioning circuit for sampling the grid information of the mains power grid 16; a main controller connected to the sampling and conditioning circuit for performing logic based on the received sampling signal, that is, the above-mentioned grid information Operation to control the connection state of the relay. Wherein, when it is detected that the mains grid is powered off, the AC side of the control inverter circuit 12 is disconnected from the mains grid 16 .

Specifically, the control circuit 17 includes a main controller, a sampling and conditioning circuit, a protection circuit, a driving circuit, and the like. The sampling and conditioning circuit mainly samples different analog signals such as voltage, current, frequency, phase, temperature, etc., and performs level conversion, and then inputs them to the main controller; the protection circuit mainly controls abnormal conditions such as overvoltage, overcurrent, and overheating Power device emergency shutdown protection to ensure the safety of components, equipment and personal; the drive circuit provides sufficient drive current to control the power device to turn on and off in time.

The photovoltaic air conditioner in the embodiment of the present invention has an island detection function. By sampling the grid information of the grid, when it is detected that the grid is powered off, the electrical connection between the inverter circuit and the grid is disconnected in time, and the load is switched to compressor.

Preferably, the direct current output by the rectification circuit is direct current with pulsating voltage, and the photovoltaic air conditioner further includes a boost circuit 18 and a PFC circuit 19 . The boost circuit 18 is connected between the photovoltaic cell panel 15 and the DC side of the inverter circuit 12, and is used to boost the DC power output by the photovoltaic cell panel 15 to obtain a first DC power. The booster circuit 18 is used to boost the low-voltage direct current of the photovoltaic cell panel to a high-voltage direct current, that is, the first direct current, and simultaneously perform maximum power point tracking (MPPT) of the photovoltaic output, that is, the booster circuit 18 may include an MPPT module, so that the booster circuit 18 has The maximum power point tracking function collects the output voltage and current of the photovoltaic current through the MPPT module, calculates the power, and controls and tracks the maximum power point output by the photovoltaic panel 15 . The boost circuit 18 may be a boost circuit or a DC/DC circuit or a combination of both.

The PFC circuit 19 is connected between the rectifier circuit 13 and the DC side of the inverter circuit 12, and is used to boost the pulsating voltage output by the rectifier circuit 13 to obtain a second direct current, wherein the booster circuit 18 and the PFC circuit 19 are both It is connected to the DC side of the inverter circuit 12 through a DC bus 20 .

The PFC circuit is used to boost the pulsating voltage output by the rectifier circuit 13 to obtain a second direct current, and connect it to the direct current bus 20. Meanwhile, the PFC circuit also has a power factor correction function to make the input voltage and the input current in phase.

Preferably, the control circuit 17 is connected to the boost circuit 18 and the PFC circuit 19 respectively, wherein, when the movable contacts K1-K3 are in the first position A, the control circuit 17 is used to control the PFC circuit 19 to convert the second direct current Output to the DC bus 20, and control the voltage of the first direct current output by the booster circuit 18 to be lower than the voltage of the second direct current, then the output of the booster circuit 18 is clamped by the voltage of the DC bus 20, and the photovoltaic air conditioner consumes the energy of the mains grid. This mode is the same as the normal air conditioner working mode.

When the movable contacts K1-K3 are in the first position A, the control circuit 17 is used to output the first direct current to the direct current bus 20 through the booster circuit 18, and control the voltage of the second direct current output by the PFC circuit 19 to be lower than the first direct current. If there is a DC voltage, the output of the PFC is clamped by the voltage of the DC bus 20, and the photovoltaic air conditioner consumes the energy input by the photovoltaic panel.

When the movable contact photovoltaic air conditioner is in the first position A, the control circuit 17 controls the boost circuit 18 and the PFC circuit 19 respectively, so that the voltages of the first direct current and the second direct current are the same, and jointly provide energy for the direct current bus 20, The air conditioner load 11 obtains energy required for work from the DC bus 20 .

When the movable contact is at the second position B, the control circuit 17 is used to sample the grid information of the mains grid 16, and control the voltage of the first direct current output by the booster circuit 18 to be higher than the second direct current output by the PFC circuit 19 Or control to cut off the connection of the PFC circuit 19 , and the control circuit 17 is also used to control the inverter circuit 12 to invert the voltage of the DC bus 20 into AC power and merge it into the mains grid 16 .

Specifically, the photovoltaic air conditioner in the embodiment of the present invention has four working modes:

① Ordinary air-conditioning mode: Same as the ordinary air-conditioning mode, the photovoltaic air conditioner obtains the required energy from the mains grid 16 .

② Photovoltaic power supply mode: the photovoltaic air conditioner consumes the energy of the photovoltaic battery panel 15 .

③Mixed power supply mode: the mains power grid 16 and the photovoltaic panel 15 jointly provide the required energy for the photovoltaic air conditioner.

④Grid-connected power generation mode: the electric energy generated by the photovoltaic panel 15 is merged into the mains grid 16 .

Among them, ① ordinary air-conditioning mode: relays K1-K3 are closed to point A, the photovoltaic air conditioner is switched to air-conditioning mode, and the control circuit 17 converts the AC power of the mains power grid 16 into high-voltage direct current through the rectifier circuit 13 and the PFC circuit 19 and then sends it to DC Bus 20, control the booster circuit 18 to make its output voltage (i.e. the voltage of the first direct current) smaller than the output voltage of the PFC circuit 19 (i.e. the voltage of the second direct current), then the output of the booster circuit 18 is clamped by the voltage of the DC bus 20 , the photovoltaic air conditioner consumes the energy of the mains power grid 16, and this mode is the same as the normal air conditioner working mode.

② Photovoltaic power supply mode: relays K1-K3 are closed to point A, and the photovoltaic air conditioner is switched to the air-conditioning mode. The control circuit 17 controls the boost circuit 18 to boost the output voltage of the photovoltaic panel 15 and send it to the DC bus 20 to control the PFC circuit 19 make its output voltage (i.e. the voltage of the second direct current) less than the output voltage of the booster circuit 18 (i.e. the voltage of the first direct current), then the output of the PFC circuit 19 is clamped by the voltage of the direct current bus 20, and the photovoltaic air conditioner consumes photovoltaic cells The energy input by the plate 15.

③Hybrid power supply mode: relays K1-K3 are closed to point A, the photovoltaic air conditioner is switched to air-conditioning mode, and the control circuit 17 controls the boost circuit 18 and the PFC circuit 19 respectively, so that the output voltages of the two are the same, that is, the first direct current and the second direct current. The direct currents have the same voltage and jointly provide energy for the direct current bus 20 , and the air conditioner load 11 obtains energy required for work from the direct current bus 20 .

④Grid-connected power generation mode: relays K1-K3 are closed to point B, the photovoltaic air conditioner is switched to the grid-connected power generation mode, the control circuit 17 samples the voltage of the mains power grid 16 to obtain grid information (voltage, amplitude, phase, etc.), the control circuit 17 Control the booster circuit 18 to make its output voltage (i.e. the voltage of the first direct current) higher than the output voltage of the PFC circuit 19 (i.e. the voltage of the second direct current) or cut off the PFC circuit 19, which is provided by the photovoltaic panel 15 for the direct current bus 20 energy, control the inverter circuit 12 to invert the voltage of the DC bus 20 into AC power, and merge it into the commercial power grid 16 .

The above working modes are not fixed, and the working mode of the photovoltaic air conditioner changes with the output power of the photovoltaic panel and the power required by the air conditioner load. For example, since the output power of the photovoltaic cell panel 15 is greatly affected by illumination and shading, when working in the air-conditioning mode, it is preferred to work in (2) the photovoltaic power supply mode. When the output power of the photovoltaic cell panel 15 is less than the required power of the air conditioner , the photovoltaic air conditioner is switched to ③ mixed power supply mode, when the photovoltaic input voltage is lower than the minimum input voltage of the booster circuit 18 (such as no light or low light at night), the photovoltaic air conditioner is switched to ① normal air conditioning mode.

Among them, when the light is low, the output power of the solar photovoltaic panel is small, and the photovoltaic output power is low at this time. When the photovoltaic air conditioner is working, the relays K1~K3 are attracted to point A. It is still powered by the mains power grid, and its working mode is exactly the same as that of ordinary air conditioners.

When the light is sufficient and the photovoltaic air conditioner needs to be turned on, the relays K1~K3 are pulled to point A, and the photovoltaic inverter provides the energy required for the operation of the photovoltaic air conditioner.

When the operating power of the photovoltaic air conditioner is greater than the power provided by the photovoltaic panel, the photovoltaic panel and the mains grid will jointly provide the energy required for the operation of the photovoltaic air conditioner.

When the light is sufficient and the photovoltaic air conditioner does not need to be turned on, the relays K1~K3 are pulled to point B, and the photovoltaic inverter starts to work, feeding the energy output by the photovoltaic panel to the mains grid.

Preferably, the photovoltaic air conditioner further includes: a power supply circuit 21 and a human-computer interaction circuit 22 . The power supply circuit 21 is respectively connected with the DC bus 20 and the control circuit 17 for providing DC power to the control circuit 17; the human-computer interaction circuit 22 is connected with the control circuit 17 for realizing human-computer data interaction.

The power supply circuit 21 can provide stable DC power for various low-voltage electrical equipment (including control circuits). The human-computer interaction circuit can be used to realize human-computer interaction, such as displaying the operating status of the photovoltaic air conditioner, receiving control instructions input by the user to control the photovoltaic air conditioner, and so on.

Further, the human-computer interaction circuit 22 includes: a display circuit, connected to the control circuit 17, for displaying the working status and parameter information of the photovoltaic air conditioner; manual control of the device.

Specifically, the human-computer interaction circuit 22 includes a display circuit, a button circuit, etc., and realizes interactive functions such as display, manual control, and voice prompts. The display circuit is used to display the system working status, parameters, statistical information, etc. in an intuitive way; the button circuit is used to realize various control functions of the air conditioner.

Preferably, the photovoltaic air conditioner also includes a first filter circuit 23, which is connected between the photovoltaic cell panel 15 and the booster circuit 18, and is used to filter the input common mode and differential mode interference of the photovoltaic cell panel 15. filter.

The first filter circuit 23 may be a photovoltaic input EMI filter circuit, which is used to filter out common-mode and differential-mode interference input through the photovoltaic panel 15, and protect against lightning and surges.

Preferably, the photovoltaic air conditioner further includes a second filter circuit 24 connected between the mains grid 16 and the rectifier circuit 13 for filtering the high-frequency conduction and radiation generated by the photovoltaic air conditioner.

The second filter circuit 24 can be an AC input EMI filter circuit, which is used to filter out the high-frequency conduction and radiation generated when the inverter air conditioner works, and reduce the interference to the mains grid 16 .

As shown in Figure 2, the photovoltaic air conditioner also includes a filter inductor 25, the first end of the filter inductor 25 is connected to the mains grid 16, and the second end of the filter inductor 25 is connected to a relay for The alternating current of the power grid 16 is shaped. Specifically, the filter inductor 25 can be connected to the mains grid 16 through the second filter circuit 24 .

When the photovoltaic air conditioner is in the grid-connected power generation mode, the grid-connected current is shaped by the filter inductor 25 , so that the electric energy output by the photovoltaic panel is connected to the grid-connected current of the mains grid 16 to meet the requirements of the mains grid 16 .

The photovoltaic air conditioner according to the embodiment of the present invention will be described in detail below with reference to FIG. 2 .

The photovoltaic air conditioner of the embodiment of the present invention mainly includes an AC input EMI filter circuit, that is, a second filter circuit 24, a full-bridge rectifier circuit, that is, a rectifier circuit 13, a PFC circuit 19, a power supply circuit 21, a control circuit 17, a human-computer interaction circuit 22, an inverter The inverter circuit 12, the compressor, namely the air conditioner load 11, the photovoltaic input EMI filter circuit, namely the first filter circuit 23, the boost circuit 18, and the relays K1-K3 for switching loads, namely the relay 14.

The AC input EMI filter circuit is used to filter out the high-frequency conduction and radiation generated when the inverter air conditioner is working, and reduce the interference to the mains power grid.

The full bridge rectifier circuit is used to convert the AC voltage into a pulsating voltage.

The PFC circuit 19 is used to boost the pulsating voltage output by the rectifier circuit 13 to obtain a second direct current, and connect it to the direct current bus 20. Meanwhile, the PFC circuit 19 also has a power factor correction function to make the input voltage and the input current in phase.

The power supply circuit 21 is used to provide stable DC power for various low-voltage electrical equipment.

The compressor is used to drive the flow and state transition of the refrigerant in the air-conditioning pipeline, so as to realize the cooling or heating operation of the air conditioner.

The photovoltaic input EMI filter circuit is used to filter out the common mode and differential mode interference input by the photovoltaic panel, as well as lightning protection and surge protection.

The boost circuit 18 is used to boost the low-voltage direct current of the photovoltaic cell panel 15 to a high-voltage direct current, and at the same time perform maximum power point tracking (MPPT) of the photovoltaic output.

The inverter circuit 12 can not only invert the direct current into frequency-adjustable three-phase alternating current to supply to the compressor, but also can invert it into single-phase or three-phase power frequency current and merge it into the commercial power grid 16 .

The relay 14 is used to switch the load object (compressor or mains grid) of the inverter circuit 12 .

The human-computer interaction circuit 22 includes a display circuit, a button circuit, etc., and realizes interactive functions such as display, manual control, and voice prompts. The display circuit is used to display the system working status, parameters, statistical information, etc. in an intuitive way; the button circuit is used to realize various control functions of the air conditioner.

The control circuit 17 includes a main controller, a sampling and conditioning circuit, a protection circuit, a driving circuit, and the like. The sampling and conditioning circuit mainly samples different analog signals such as voltage, current, frequency, phase, temperature, etc., and performs level conversion, and then inputs them to the main controller; the protection circuit mainly controls abnormal conditions such as overvoltage, overcurrent, and overheating Power device emergency shutdown protection to ensure the safety of components, equipment and personal; the drive circuit provides sufficient drive current to control the power device to turn on and off in time.

The above boost circuit 18 has an MPPT function, collects the output voltage and current of the photovoltaic current through the MPPT algorithm, calculates the power, and controls and tracks the maximum power point output by the photovoltaic panel.

The above-mentioned photovoltaic air conditioner has an islanding detection function. The mains grid voltage is sampled through the islanding detection algorithm. When it is detected that the mains grid is powered off, the load is switched to the compressor and the electrical connection between the inverter circuit and the mains grid is disconnected in time.

The above-mentioned photovoltaic air conditioner has a grid voltage detection function, which can detect the amplitude, frequency and phase information of the grid voltage, and transmit these information to the main controller to control the inverter circuit 12 to work in the grid-connected state.

The photovoltaic air conditioner of the embodiment of the present invention has the following several working modes as follows:

① Ordinary air-conditioning mode: relays K1-K3 are closed to point A, the photovoltaic air conditioner is switched to air-conditioning mode, and the control circuit 17 converts the AC power of the mains grid 16 into high-voltage DC power through the rectifier circuit 13 and the PFC circuit 19 and then sends it to the DC bus 20 , the booster circuit 18 is controlled to make its output voltage (i.e. the voltage of the first direct current) smaller than the output voltage of the PFC circuit 19 (i.e. the voltage of the second direct current), then the output of the booster circuit 18 is clamped by the voltage of the DC bus 20, and the photovoltaic The air conditioner consumes the energy of the mains power grid 16, and this mode is the same as the common air conditioner working mode.

② Photovoltaic power supply mode: relays K1-K3 are closed to point A, and the photovoltaic air conditioner is switched to the air-conditioning mode. The control circuit 17 controls the boost circuit 18 to boost the output voltage of the photovoltaic panel 15 and send it to the DC bus 20 to control the PFC circuit 19 make its output voltage (i.e. the voltage of the second direct current) less than the output voltage of the booster circuit 18 (i.e. the voltage of the first direct current), then the output of the PFC circuit 19 is clamped by the voltage of the direct current bus 20, and the photovoltaic air conditioner consumes photovoltaic cells The energy input to the board.

③Hybrid power supply mode: relays K1-K3 are closed to point A, the photovoltaic air conditioner is switched to air-conditioning mode, and the control circuit 17 controls the boost circuit 18 and the PFC circuit 19 respectively, so that the output voltages of the two are the same, that is, the first direct current and the second direct current. The direct currents have the same voltage and jointly provide energy for the direct current bus 20 , and the air conditioner load 11 obtains energy required for work from the direct current bus 20 .

④Grid-connected power generation mode: relays K1-K3 are closed to point B, the photovoltaic air conditioner is switched to the grid-connected power generation mode, the control circuit 17 samples the voltage of the mains power grid 16 to obtain grid information (voltage, amplitude, phase, etc.), the control circuit 17 Control the booster circuit 18 to make its output voltage (i.e. the voltage of the first direct current) higher than the output voltage of the PFC circuit 19 (i.e. the voltage of the second direct current) or cut off the PFC circuit 19, which is provided by the photovoltaic panel 15 for the direct current bus 20 energy, control the inverter circuit 12 to invert the voltage of the DC bus 20 into AC power, and merge it into the commercial power grid 16 .

The above working modes are not fixed, and the working mode of the photovoltaic air conditioner changes with the output power of the photovoltaic panel and the power required by the air conditioner load. For example, since the output power of the photovoltaic cell panel 15 is greatly affected by illumination and shading, when working in the air-conditioning mode, it is preferred to work in (2) the photovoltaic power supply mode. When the output power of the photovoltaic cell panel 15 is less than the required power of the air conditioner , the photovoltaic air conditioner is switched to ③ mixed power supply mode, when the photovoltaic input voltage is lower than the minimum input voltage of the booster circuit 18 (such as no light or low light at night), the photovoltaic air conditioner is switched to ① normal air conditioning mode.

Among them, when the light is low, the output power of the solar photovoltaic panel is small, and the photovoltaic output power is low at this time. When the photovoltaic air conditioner is working, the relays K1~K3 are attracted to point A, and the photovoltaic air conditioner is working at this time. It is still powered by the mains, and its working mode is exactly the same as that of ordinary air conditioners.

When the light is sufficient and the photovoltaic air conditioner needs to be turned on, the relays K1~K3 are pulled to point A, and the photovoltaic inverter provides the energy required for the operation of the photovoltaic air conditioner.

When the operating power of the photovoltaic air conditioner is greater than the power provided by the photovoltaic panel, the photovoltaic panel and the mains grid will jointly provide the energy required for the operation of the photovoltaic air conditioner.

When the light is sufficient and the photovoltaic air conditioner does not need to be turned on, the relays K1~K3 are pulled to point B, and the photovoltaic inverter starts to work, feeding the energy output by the photovoltaic panel to the mains grid.

The embodiment of the present invention also provides a photovoltaic air conditioning system. The photovoltaic air-conditioning system includes: a photovoltaic air conditioner, which is connected to a mains power grid; a photovoltaic battery panel, which is connected to the photovoltaic air conditioner, and is used to provide electric energy to the photovoltaic air conditioner. Wherein, the photovoltaic air conditioner is the photovoltaic air conditioner provided by the embodiment of the present invention. For a specific description of the photovoltaic air-conditioning system, reference may be made to the description of the photovoltaic air conditioner in the above-mentioned embodiments of the present invention, which will not be repeated here.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (11)

1. a photovoltaic air-conditioner, is characterized in that, comprising:

Air-conditioning load;

Inverter circuit, the AC of described inverter circuit is connected respectively with utility grid with described air-conditioning load, and the DC side of described inverter circuit is connected with photovoltaic battery panel, for the direct current of described photovoltaic battery panel output is converted into alternating current;

Rectification circuit, is connected between described inverter circuit and described utility grid, for the alternating current of described utility grid output is converted into direct current; And

Relay, be connected between the AC and described air-conditioning load of described inverter circuit, and be connected between the AC and described utility grid of described inverter circuit, the moving position of the movable contact of described relay comprises primary importance and the second place, at described movable contact in primary importance in the situation that, the AC of described inverter circuit and described air-conditioning load are connected, at described movable contact, in the second place in the situation that, the AC of described inverter circuit and described utility grid are connected.

2. photovoltaic air-conditioner according to claim 1, it is characterized in that, described photovoltaic air-conditioner also comprises: control circuit, be connected with described relay, at described movable contact, in the second place in the situation that, described control circuit is switched to primary importance for control described movable contact in the situation that producing island effect, wherein, in the situation of described movable contact in described primary importance, the AC of described inverter circuit and described utility grid disconnect.

3. photovoltaic air-conditioner according to claim 2, is characterized in that, described control circuit comprises:

Sampling and modulate circuit, for the electric network information of the described utility grid of sampling; And

Master controller, is connected with described sampling and modulate circuit, for carrying out logical operation according to the sampled signal receiving, the connection status of relay is controlled.

4. photovoltaic air-conditioner according to claim 2, is characterized in that, the direct current of described rectification circuit output is the direct current with the voltage of pulsation, and described photovoltaic air-conditioner also comprises:

Booster circuit, is connected between described photovoltaic battery panel and the DC side of described inverter circuit, for the direct current of described photovoltaic battery panel output is boosted, obtains the first direct current; And

Pfc circuit, is connected between described rectification circuit and the DC side of described inverter circuit, for the voltage of the pulsation of described rectification circuit output is boosted, obtains the second direct current,

Wherein, described booster circuit is all connected with the DC side of described inverter circuit by dc bus with described pfc circuit.

5. photovoltaic air-conditioner according to claim 4, is characterized in that, described control circuit is connected respectively with described pfc circuit with described booster circuit, wherein,

At described movable contact in described primary importance in the situation that, described control circuit is used for controlling described pfc circuit and exports described the second direct current to described dc bus, and the first galvanic voltage of controlling the output of described booster circuit is less than described the second galvanic voltage;

At described movable contact in described primary importance in the situation that, described control circuit is for exporting described dc bus by described booster circuit to by described the first direct current, and controls the second galvanic voltage that described pfc circuit exports and be less than described the first galvanic voltage;

At described movable contact, in described primary importance in the situation that, described control circuit is controlled respectively described booster circuit and described pfc circuit, makes described the first direct current identical with described the second galvanic voltage;

At described movable contact in the described second place in the situation that, described control circuit is for the electric network information of the described utility grid of sampling, and control the first galvanic voltage of described booster circuit output higher than the connection of the second direct current or the described pfc circuit of control cut-out of described pfc circuit output, described control circuit is also that alternating current is incorporated to described utility grid for controlling described inverter circuit by the voltage inversion of described dc bus.

6. photovoltaic air-conditioner according to claim 4, is characterized in that, described photovoltaic air-conditioner also comprises:

Power supply circuits, are connected respectively with described control circuit with described dc bus, for providing direct current energy to described control circuit;

Man-machine interaction circuit, is connected with described control circuit, for realizing man-machine data interaction.

7. photovoltaic air-conditioner according to claim 6, is characterized in that, described man-machine interaction circuit comprises:

Display circuit, is connected with described control circuit, for showing duty and the parameter information of described photovoltaic air-conditioner; And

Key circuit, is connected with described control circuit, for realizing the manual control to described photovoltaic air-conditioner.

8. photovoltaic air-conditioner according to claim 4, is characterized in that, described photovoltaic air-conditioner also comprises:

The first filter circuit, is connected between described photovoltaic battery panel and described booster circuit, for the common and different mode of described photovoltaic battery panel input is disturbed and filtered.

9. photovoltaic air-conditioner according to claim 1, is characterized in that, described photovoltaic air-conditioner also comprises:

The second filter circuit, is connected between described utility grid and described rectification circuit, for high-frequency conduction and radiation that described photovoltaic air-conditioner is produced, filters.

10. according to the photovoltaic air-conditioner described in any one in claim 1 to 5, it is characterized in that, described photovoltaic air-conditioner also comprises:

Filter inductance, the first end of described filter inductance is connected with described utility grid, and the second end of described filter inductance is connected with described relay, for carrying out shaping to being incorporated into the alternating current of described utility grid.

11. 1 kinds of photovoltaic air-conditioning systems, is characterized in that, comprising:

Photovoltaic air-conditioner in claim 1 to 10 described in any one, described photovoltaic air-conditioner is connected with utility grid;

Photovoltaic battery panel, is connected with described photovoltaic air-conditioner, for providing electric energy to described photovoltaic air-conditioner.