Hybrid power supply device, control method thereof, and air conditioner

Abstract

The application discloses a hybrid power supply device, a control method thereof and an air conditioner. The device comprises a photovoltaic positive electrode of a solar photovoltaic assembly, which is connected to the cathode of a diode module and the anode of a bus capacitor unit after passing through a first switch module and a first voltage boosting module; a photovoltaic negative electrode, which is connected to the first voltage boosting module and also connected to the anode of the diode module; commercial power, which is connected to the anode of the diode module after passing through a second switch module and a rectifier module; the rectifier module, which is also connected to a second voltage boosting module and the cathode of the bus capacitor unit, and the cathode of the bus capacitor unit is grounded; wherein the first direct current voltage output by the photovoltaic power supply unit and the second direct current voltage output by the commercial power supply unit are superimposed to obtain a direct current bus voltage. The device superimposes the first direct current voltage on the second direct current voltage to reduce the voltage boosting ratio of the photovoltaic voltage boosting circuit, thereby reducing the power consumption and temperature rise of the inductor and the switch tube in the photovoltaic voltage boosting circuit and improving the reliability of the photovoltaic voltage boosting circuit.

Description

Technical Field

[0001] This invention belongs to the field of power supply technology, specifically relating to a hybrid power supply device and its control method, and an air conditioner, particularly to a circuit and its control method for an air conditioner that uses a hybrid AC and photovoltaic power supply with voltage superposition. Background Technology

[0002] For solar cell arrays, the output voltage V is affected and controlled by the number of solar cell arrays, the connection method of the solar cell arrays (such as series or parallel), the solar irradiance, and the maximum output power algorithm, resulting in a wide range of output voltage V, which may be as low as about 30V.

[0003] In some hybrid power supply systems and methods (such as hybrid power supply systems and methods for air conditioning), the solar cell array and the AC power supply supply power to the bus voltage Vdc respectively. Both the Boost1 boost circuit (i.e., the boost chopper circuit) and the Boost2 boost circuit output the DC bus voltage Vdc. When the voltage V output by the solar cell array is low (e.g., V = 50VDC), because it needs to be boosted to a higher voltage (e.g., V = 380VDC), the inductor in the Boost1 boost circuit needs a larger inductance, and the switching transistor in the Boost1 boost circuit needs a higher switching frequency and duty cycle. This results in high power consumption and high temperature of the inductor and switching transistor in the Boost1 boost circuit, reducing the long-term reliability of the Boost1 boost circuit.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a hybrid power supply device, its control method, and an air conditioner to solve the problem of high power consumption and temperature rise in the boost circuit of the solar array output voltage boost circuit when the output voltage of the solar array is low and needs to be boosted to a higher voltage. This is because the output voltage boost circuit of the solar array requires a large inductance and a high switching frequency and duty cycle of the switching transistors, which reduces the long-term reliability of the boost circuit. The invention achieves this by superimposing the output voltage of the solar array onto the rectified DC power of the AC power supply, thereby reducing the boost ratio of the boost circuit of the solar array output voltage boost circuit, and thus reducing the power consumption and temperature rise of the inductors and switching transistors in the boost circuit of the solar array output voltage boost circuit, which is beneficial to improving the reliability of the boost circuit of the solar array output voltage boost circuit.

[0006] This invention provides a hybrid power supply device, comprising: a photovoltaic power supply unit, a mains power supply unit, a hybrid power supply unit, and a bus capacitor unit; the hybrid power supply unit includes: a diode module; wherein, the photovoltaic power supply unit includes: a solar photovoltaic module, a first switching module, and a first boost module; the positive photovoltaic electrode of the solar photovoltaic module is connected to the first input terminal of the first boost module after passing through the first switching module; the first output terminal of the first boost module is connected to the cathode of the diode module on one side and to the positive electrode of the bus capacitor unit on the other side; the negative photovoltaic electrode of the solar photovoltaic module is connected to the second input terminal of the first boost module on one side and to the anode of the diode module on the other side; the boost ratio of the first boost module can be less than a set boost ratio; The mains power supply unit includes: a rectifier module, a second switch module, and a second boost module. After the mains power passes through the second switch module and the rectifier module, the first output terminal of the rectifier module is connected to the first input terminal of the second boost module. The first output terminal of the second boost module is connected to the anode of the diode module. The second output terminal of the rectifier module is connected to the first input terminal of the second boost module on one side and to the negative terminal of the bus capacitor unit on the other side, and is grounded. The first DC voltage output by the photovoltaic power supply unit and the second DC voltage output by the mains power supply unit are superimposed and output to the DC bus of the hybrid power supply device to obtain the DC bus voltage. The bus capacitor unit can output the DC bus voltage of the hybrid power supply device to supply the load.

[0007] In some embodiments, the hybrid power supply unit further includes: a first voltage regulator module and / or a second voltage regulator module; wherein, the first voltage regulator module is used to regulate the first DC voltage output by the photovoltaic power supply unit; a first connection terminal of the first voltage regulator module is connected to the cathode of the diode module; a second connection terminal of the first voltage regulator module is connected to the anode of the diode module; the second voltage regulator module is used to regulate the second DC voltage output by the mains power supply unit; a first connection terminal of the second voltage regulator module is connected to the anode of the diode module; and a second connection terminal of the second voltage regulator module is connected to the negative terminal of the bus capacitor unit.

[0008] In some embodiments, the first voltage regulator module includes a first capacitor module; and / or the second voltage regulator module includes a second capacitor module.

[0009] In conjunction with the above-described hybrid power supply device, the present invention further provides an air conditioner comprising: the hybrid power supply device described above.

[0010] In conjunction with the aforementioned air conditioner, this invention further provides a control method for a hybrid power supply device for an air conditioner, wherein when the air conditioner is not started, both the first switch module and the second switch module are disconnected; the control method for the hybrid power supply device includes: when the air conditioner needs to be started, controlling the second switch module to close, so as to use the second DC voltage output by the mains power supply unit to supply power to the DC bus of the hybrid power supply device, and then using the DC bus voltage output by the bus capacitor unit through the DC bus to supply power to the air conditioner after passing through the inverter; detecting the photovoltaic voltage output by the solar photovoltaic module in the photovoltaic power supply unit, and determining whether the detected photovoltaic voltage output by the solar photovoltaic module is greater than a set first voltage threshold; if it is determined that the detected photovoltaic voltage output by the solar photovoltaic module is greater than a set first voltage threshold; If the output photovoltaic voltage is greater than the first voltage threshold, the first switch module is controlled to close, so that the first DC voltage output by the photovoltaic power supply unit is superimposed on the second DC voltage output by the mains power supply unit, and together they supply power to the DC bus of the hybrid power supply device. After the DC bus voltage obtained by the DC bus of the hybrid power supply device reaches the set start-up voltage, the air conditioner is controlled to start and run. If it is determined that the detected photovoltaic voltage output by the solar photovoltaic module is less than or equal to the first voltage threshold, at least one of the switching frequency and duty cycle of the second switch module in the second boost module is increased, so as to increase the second DC voltage output by the mains power supply unit. After the DC bus voltage obtained by the DC bus of the hybrid power supply device reaches the set start-up voltage, the air conditioner is controlled to start and run.

[0011] In some embodiments, the control method for the hybrid power supply device of the air conditioner further includes: adjusting the DC bus voltage obtained by the DC bus of the hybrid power supply device; wherein, adjusting the DC bus voltage obtained by the DC bus of the hybrid power supply device includes: during the operation of the air conditioner after startup, detecting the DC bus voltage obtained by the DC bus of the hybrid power supply device, and determining whether the detected DC bus voltage obtained by the DC bus of the hybrid power supply device is greater than or equal to a set second voltage threshold; if it is determined that the detected DC bus voltage obtained by the DC bus of the hybrid power supply device is greater than or equal to the second voltage threshold, then it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device can still meet the power supply requirements of the air conditioner; if it is determined that the detected DC bus voltage obtained by the DC bus of the hybrid power supply device is less than the second voltage threshold, then it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device can no longer meet the power supply requirements of the air conditioner, and controlling the first boost module and / or the first boost module to raise the DC bus voltage obtained by the DC bus of the hybrid power supply device to meet the power supply requirements of the air conditioner.

[0012] In some embodiments, controlling the first boost module and / or the first boost module to raise the DC bus voltage of the hybrid power supply device to a level sufficient to meet the power supply requirements of the air conditioner includes any of the following control methods: When the photovoltaic power supply unit and the mains power supply unit are jointly powered, controlling the switching frequency and / or duty cycle of the first switching transistor module in the first boost module to increase the first DC voltage output by the photovoltaic power supply unit, thereby raising the DC bus voltage of the hybrid power supply device to a level sufficient to meet the power supply requirements of the air conditioner; When the photovoltaic power supply unit and the mains power supply unit are jointly powered, or when the mains power supply unit is powered alone, controlling the switching frequency and / or duty cycle of the second switching transistor module in the second boost module to increase the second DC voltage output by the mains power supply unit, thereby raising the DC bus voltage of the hybrid power supply device to a level sufficient to meet the power supply requirements of the air conditioner; When the photovoltaic power supply unit and the mains power supply unit are jointly powered... The system controls the switching frequency and / or duty cycle of the first switching transistor module in the first boost module to increase the first DC voltage output by the photovoltaic power supply unit, and controls the switching frequency and / or duty cycle of the second switching transistor module in the second boost module to increase the second DC voltage output by the mains power supply unit, thereby increasing the DC bus voltage obtained by the DC bus of the hybrid power supply device to meet the power supply requirements of the air conditioner. The operation of controlling the switching frequency and / or duty cycle of the first switching transistor module in the first boost module to increase the first DC voltage output by the photovoltaic power supply unit is performed when the power supply capacity of the solar photovoltaic module has not reached a set limit. If the power supply capacity of the solar photovoltaic module has reached the set limit, then only the switching frequency and / or duty cycle of the second switching transistor module in the second boost module can be increased to increase the second DC voltage output by the mains power supply unit, thereby increasing the DC bus voltage obtained by the DC bus of the hybrid power supply device to meet the power supply requirements of the air conditioner.

[0013] In some embodiments, the control method for the hybrid power supply device of the air conditioner further includes: monitoring the power supply capacity of the solar photovoltaic module; wherein, monitoring the power supply capacity of the solar photovoltaic module includes: during the operation of the air conditioner after startup, detecting the first current output by the solar photovoltaic module in the photovoltaic power supply unit after passing through the first switching module, and detecting the second current output by the rectifier module in the mains power supply unit; determining whether the first current output by the solar photovoltaic module is greater than a preset first current threshold; if it is determined that the first current output by the solar photovoltaic module is less than or equal to the first current threshold, then it is determined that the power supply capacity of the solar photovoltaic module has not reached the set limit value; if it is determined that the first current output by the solar photovoltaic module is greater than the first current threshold, then it is determined that the power supply capacity of the solar photovoltaic module has reached the set limit value, and the power supply capacity of the hybrid power supply device is adjusted.

[0014] In some embodiments, adjusting the power supply capability of the hybrid power supply device includes: when it is determined that the power supply capability of the solar photovoltaic module has reached a set limit value, reducing the switching frequency and / or duty cycle of the first switching transistor module in the first boost module, so that the first current output by the solar photovoltaic module is reduced to the first current threshold; and increasing the switching frequency and / or duty cycle of the second switching transistor module in the second boost module, so that the second current output by the rectifier module is increased; until the sum of the first current output by the solar photovoltaic module and the second current output by the rectifier module meets the power supply requirements of the air conditioner, stopping the increase of the switching frequency and / or duty cycle of the second switching transistor module.

[0015] In some embodiments, the control method for the hybrid power supply device of the air conditioner further includes: adjusting the power supply levels of the photovoltaic power supply unit and the mains power supply unit; wherein, adjusting the power supply levels of the photovoltaic power supply unit and the mains power supply unit includes: determining the required power of the air conditioner, denoted as the total power;

[0016] The photovoltaic voltage of the solar photovoltaic module in the photovoltaic power supply unit is detected, and the first current output by the solar photovoltaic module in the photovoltaic power supply unit is detected; the power supply power of the photovoltaic power supply unit is determined and recorded as photovoltaic power; if the photovoltaic voltage of the solar photovoltaic module is greater than a preset third voltage threshold, the first current output by the solar photovoltaic module is less than a preset first current threshold, and the photovoltaic power of the photovoltaic power supply unit is greater than the total power of the air conditioner, then the second switching module is controlled to shut down so that the air conditioner operates in a first hybrid power supply state; if the photovoltaic voltage of the solar photovoltaic module is less than or equal to the preset third voltage threshold, and / or the first current output by the solar photovoltaic module is greater than or equal to the preset first current threshold, and / or the photovoltaic power of the photovoltaic power supply unit is greater than the preset first current threshold .... If the total power of the air conditioner is less than or equal to the total power of the air conditioner, the second switching module is controlled to remain on so that the air conditioner operates in the second hybrid power supply state; if the photovoltaic voltage of the solar photovoltaic module is less than a preset first voltage threshold, the first switching module is controlled to disconnect so that the air conditioner operates in the third hybrid power supply state; wherein, in the first or second hybrid power supply state, it is necessary to monitor the power supply capacity of the solar photovoltaic module and / or adjust the DC bus voltage obtained by the DC bus of the hybrid power supply device; in the third hybrid power supply state, it is necessary to adjust the power supply capacity of the mains power supply unit by controlling the switching frequency and / or duty cycle of the second switching tube module in the second boost module to meet the power supply requirements of the total power of the air conditioner.

[0017] Therefore, the solution of this invention, through a hybrid power supply system for solar cell arrays and AC power, superimposes the output voltage of the solar cell array onto the rectified DC power of the AC power supply, thereby increasing the output voltage of the solar cell array. When boosting the output voltage of the solar cell array to the DC bus voltage, a photovoltaic boost circuit with a small boost ratio can be used to boost the output voltage of the solar cell array to the DC bus voltage. Thus, by superimposing the output voltage of the solar cell array onto the rectified DC power of the AC power supply, the boost ratio of the boost circuit for the output voltage of the solar cell array can be reduced, thereby reducing the power consumption and temperature rise of the inductor and switching transistor in the boost circuit for the output voltage of the solar cell array, which is beneficial to improving the reliability of the boost circuit for the output voltage of the solar cell array.

[0018] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a structure of an embodiment of the hybrid power supply device of the present invention;

[0021] Figure 2 A schematic diagram of an embodiment of a circuit that provides hybrid power supply by superimposing the voltages of photovoltaic power and AC mains power;

[0022] Figure 3 This is a schematic flowchart of an embodiment of the control method for the hybrid power supply device of the air conditioner of the present invention;

[0023] Figure 4 This is a schematic flowchart of an embodiment of the method of the present invention, which involves adjusting the DC bus voltage obtained from the DC bus of the hybrid power supply device.

[0024] Figure 5 This is a flowchart illustrating an embodiment of the method of the present invention for monitoring the power supply capability of the solar photovoltaic module;

[0025] Figure 6 This is a flowchart illustrating an embodiment of adjusting the power supply capability of the hybrid power supply device in the method of the present invention.

[0026] Figure 7 This is a schematic flowchart of an embodiment of the method of the present invention, which adjusts the power supply levels of the photovoltaic power supply unit and the mains power supply unit.

[0027] Figure 8 A schematic diagram illustrating the workflow of an embodiment of a control method for a circuit that provides hybrid power supply by superimposing the voltages of photovoltaic power and AC mains power. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] Considering that in a photovoltaic (PV) or solar cell power supply system where the AC mains power supplies the DC bus voltage Vdc separately, the voltage output from the PV modules or solar cell array needs to be boosted to the DC bus voltage via a boost circuit. When the solar cell array voltage is low (e.g., the output voltage V = 50VDC), the boost ratio is large because it needs to be boosted to a higher voltage (e.g., the output voltage V = 380VDC). Boost ratio = Boosted voltage / Initial voltage.

[0030] For example, when V = 50VDC and Vdc = 380VDC, the boost ratio = 380VDC / 50VDC = 7.6. The inductor in the Boost1 boost circuit needs a larger inductance value, and the switching transistor in the Boost1 boost circuit needs a higher switching frequency and duty cycle, which leads to high power consumption and high temperature of the inductor and the switching transistor itself, reducing the long-term reliability of the Boost1 boost circuit.

[0031] Therefore, for situations where the output voltage of solar photovoltaic modules (such as solar cell arrays) is low and needs to be boosted to a higher voltage, the present invention proposes a hybrid power supply device. Specifically, it is a circuit topology based on voltage superposition hybrid power supply, and more specifically, it is a circuit for air conditioning that uses voltage superposition AC and photovoltaic hybrid power supply to reduce the voltage difference of photovoltaic voltage boost, thereby reducing the inductance and switching transistor losses and temperature rise in the boost circuit of the solar photovoltaic module, improving the reliability of the boost circuit of the solar photovoltaic module, and extending the service life of key components (such as inductors and switching transistors) in the boost circuit of the solar photovoltaic module.

[0032] According to an embodiment of the present invention, a hybrid power supply device is provided. See also Figure 1 The diagram shows a structural schematic of an embodiment of the device of the present invention. The hybrid power supply device may include: a photovoltaic power supply unit, a mains power supply unit, a hybrid power supply unit, and a bus capacitor unit, such as the third capacitor C3. The hybrid power supply unit includes: a diode module, such as the third diode D3.

[0033] The photovoltaic power supply unit includes: a solar photovoltaic module, a first switching module, and a first boost module. The first switching module is, for example, a first switch K1, and the first boost module is, for example, a first boost circuit. The positive photovoltaic electrode of the solar photovoltaic module is connected to the first input terminal of the first boost module after passing through the first switching module. The first output terminal of the first boost module is connected to the cathode of the diode module and the positive electrode of the bus capacitor unit. The negative photovoltaic electrode of the solar photovoltaic module is connected to the second input terminal of the first boost module and the anode of the diode module. The boost ratio of the first boost module can be less than a set boost ratio. This set boost ratio can be defined as the ratio of the DC bus voltage to the photovoltaic power supply voltage (i.e., the photovoltaic voltage before boosting).

[0034] The mains power supply unit includes: a rectifier module, a second switching module, and a second boost module. The rectifier module is such as a rectifier bridge, the second switching module is such as a second switch K2, and the second boost module is such as a second Boost circuit. After the mains power passes through the second switching module and the rectifier module, the first output terminal of the rectifier module is connected to the first input terminal of the second boost module. The first output terminal of the second boost module is connected to the anode of the diode module. The second output terminal of the rectifier module is connected to the first input terminal of the second boost module on one hand, and to the negative terminal of the bus capacitor unit and grounded on the other.

[0035] The first DC voltage output by the photovoltaic power supply unit and the second DC voltage output by the mains power supply unit are superimposed and output to the DC bus of the hybrid power supply device to obtain the DC bus voltage. The bus capacitor unit can output the DC bus voltage of the hybrid power supply device to supply the load. The first DC voltage is VDC1, the second DC voltage is VDC2, and the DC bus voltage is VDC3. The load can be either a DC load or an AC load. If it is an AC load, an inverter is needed to convert the DC bus voltage to AC power for the AC load.

[0036] The present invention provides a circuit based on a hybrid power supply of photovoltaic and AC mains voltage superposition. The photovoltaic output voltage is superimposed on the DC power after rectification of AC mains, thereby boosting the photovoltaic output voltage. When the photovoltaic output voltage is boosted to the DC bus voltage, a boost circuit with a small boost ratio can be used. This is suitable for air conditioning systems with photovoltaic modules and AC mains power supply in the range of 30VDC to 80VDC.

[0037] For example, if a photovoltaic module outputs a voltage of 50VDC, it needs to be boosted to 380VDC, resulting in a boost ratio of over 7 times. The solution of this invention superimposes the photovoltaic voltage onto the DC voltage after rectification by the mains power. The DC voltage after rectification from 220VAC mains power is approximately 300VDC. After voltage superposition, the DC bus voltage will reach approximately 350VDC, which is then boosted to 380VDC, resulting in a boost ratio of approximately 1.1 times (boost ratio = 380VDC / 350VDC).

[0038] Thus, due to the low boost ratio of the photovoltaic boost circuit, the selection of inductors and switching transistors is easier and less expensive, resulting in lower self-loss and temperature rise during operation. By superimposing the photovoltaic output voltage onto the rectified DC power from the AC mains, the boost ratio is reduced, solving the problems of high inductance, high switching frequency, and high duty cycle in photovoltaic boost circuits caused by a high boost ratio. This reduces losses and temperature rise in the photovoltaic boost circuit, improves circuit reliability, and extends the lifespan of key components.

[0039] In some embodiments, the hybrid power supply unit further includes: a first voltage regulator module and / or a second voltage regulator module, wherein the first voltage regulator module is such as a first capacitor C1 and the second voltage regulator module is such as a second capacitor C2.

[0040] The first voltage regulator module is used to regulate the first DC voltage output by the photovoltaic power supply unit. The first connection terminal of the first voltage regulator module is connected to the cathode of the diode module. The second connection terminal of the first voltage regulator module is connected to the anode of the diode module.

[0041] The second voltage regulator module is used to regulate the second DC voltage output by the mains power supply unit. The first connection terminal of the second voltage regulator module is connected to the anode of the diode module. The second connection terminal of the second voltage regulator module is connected to the cathode of the bus capacitor unit.

[0042] Figure 2 A schematic diagram of an embodiment of a circuit that provides a hybrid power supply by superimposing the voltages of photovoltaic power and AC mains power. (See diagram below.) Figure 2 As shown, in a circuit where the voltage of the photovoltaic power source and the AC mains power source are superimposed and mixed, the solar photovoltaic module and the AC mains power source are external power sources.

[0043] exist Figure 2 In the example shown, the solar photovoltaic (PV) module supplies power to the air conditioner, and the PV voltage provided by the solar PV module is DC+. This DC+ PV voltage, after passing through the first switch K1 and the first Boost converter, is output to the hybrid voltage regulator unit. After passing through the hybrid voltage regulator unit, the output DC bus voltage VDC3 is sent to the bus capacitor C3. The DC bus voltage VDC3, after passing through the bus capacitor C3, powers the motor in the air conditioner's compressor via the inverter.

[0044] The first switch K1 can be a DC contactor, DC relay, etc. The first boost circuit boosts the photovoltaic voltage DC+ to a suitable first DC voltage VDC1, while simultaneously executing the maximum power point tracking (MPPT) algorithm to maximize the output power of the solar photovoltaic module. The first boost circuit includes: a first inductor L1, a first diode D1, and a first switch Q1. The hybrid voltage regulator unit includes: a first capacitor C1, a second capacitor C2, and a third diode D3. The first capacitor C1 and the second capacitor C2 serve both voltage regulation and energy storage functions.

[0045] Specifically, the photovoltaic voltage is DC+, which is input to the anode of the first diode D1 after passing through the first switch K1 and the first inductor L1. The cathode of the first diode D1 is connected to the first terminal of the first capacitor C1. The first terminal of the first capacitor C1 is also connected to the cathode of the third diode D3. The first terminal of the first capacitor C1 is also connected to the positive terminal of the bus capacitor C3. The positive terminal of the bus capacitor C3 is connected to the DC bus voltage VDC3. The photovoltaic negative terminal of the solar photovoltaic module is connected to the emitter of the first switch Q1. The collector of the first switch Q1 is connected to the anode of the first diode D1. The base of the first switch Q1 serves as a control terminal, used to receive control signals from the first switch Q1, such as duty cycle signals.

[0046] The negative terminal of the solar photovoltaic module is also connected to the second terminal of the first capacitor C1. The negative terminal of the solar photovoltaic module is also connected to the anode of the third diode D3.

[0047] exist Figure 2 In the example shown, AC mains power (i.e., AC power supply) powers the air conditioner. After passing through the second switch K2 and the rectifier bridge, the AC mains power outputs DC power. The voltage of this DC power, i.e., the rectified voltage, is DB+. The rectified voltage DB+ is then output to the hybrid voltage regulator unit after passing through the second Boost converter. After passing through the hybrid voltage regulator unit, the DC bus voltage VDC3 is output to the bus capacitor C3. The DC bus voltage VDC3, after passing through the bus capacitor C3, powers the motor in the air conditioner's compressor via the inverter.

[0048] The second switch K2 can be an AC contactor, AC relay, etc. The other end of the second switch K2 is connected to the rectifier bridge. The second boost circuit includes: a second inductor, a second diode, and a second switching transistor. The function of the second boost circuit is to boost DB+ ​​to a suitable second DC voltage VDC2 when needed. The second DC voltage VDC2 supplies power to the DC bus through the third diode D3.

[0049] Specifically, the positive terminal DB+ of the rectified voltage is connected to the anode of the second diode D2 via the second inductor L2. The cathode of the second diode D2 is connected to the first terminal of the second capacitor C2, and the cathode of the second diode D2 is also connected to the anode of the third diode D3. The collector of the second switching transistor Q2 is connected to the anode of the second diode D2. The negative terminal of the rectified voltage is connected to the emitter of the second switching transistor Q2, and the emitter of the second switching transistor Q2 is grounded (i.e., the DC ground of the control circuit). The base of the second diode D2 serves as a control terminal, used to receive control signals from the second switching transistor Q2, such as the duty cycle signal.

[0050] The function of the third capacitor C3 is to stabilize, store energy, and filter the DC bus voltage VDC3. The DC bus voltage VDC3 is the voltage resulting from the superposition of the first DC voltage VDC1 and the second DC voltage VDC2. The DC bus voltage VDC3 supplies power to the internal loads of the air conditioner, such as the compressor motor. The inverter in a household air conditioner is generally an intelligent power module (IPM), which drives the motor in the air conditioner compressor to operate at a variable frequency by controlling the switching transistors inside the inverter.

[0051] In some embodiments, the first voltage regulator module includes a first capacitor module, such as a first capacitor C1. And / or, the second voltage regulator module includes a second capacitor module, such as a second capacitor C2.

[0052] In related solutions, the negative terminal of the solar photovoltaic module is connected to the negative terminal of the rectified DC power supply, meaning the negative terminal of the photovoltaic module shares a common ground with the negative terminal of the DC bus voltage. However, in this invention, a first capacitor C1, a second capacitor C2, and a third diode D3 are added. The negative terminal of the photovoltaic module is connected to the second DC voltage VDC2 (i.e., the connection point of the first capacitor C1, the second capacitor C2, the second diode, and the third diode D3). This superimposes the output voltage of the solar photovoltaic module onto the second DC voltage VDC2, making the voltage between the cathode of the first diode D1 and the DC ground of the control circuit equal to the first DC voltage VDC1 + the second DC voltage VDC2. The first DC voltage VDC1 is the voltage between the cathode of the first diode D1 and the connection point of the first capacitor C1, the second capacitor C2, the second diode D2, and the third diode D3.

[0053] By employing the technical solution of this invention, a hybrid power supply system for solar cell arrays and AC power is used. The output voltage of the solar cell array is superimposed on the rectified DC power from the AC power supply, thereby increasing the output voltage of the solar cell array. When boosting the output voltage of the solar cell array to the DC bus voltage, a photovoltaic boost circuit with a small boost ratio is used, which can effectively boost the output voltage of the solar cell array to the DC bus voltage. Therefore, by superimposing the output voltage of the solar cell array on the rectified DC power from the AC power supply, the boost ratio of the boost circuit for the output voltage of the solar cell array can be reduced. This reduces the power consumption and temperature rise of the inductors and switching transistors in the boost circuit, thus improving the reliability of the boost circuit for the output voltage of the solar cell array.

[0054] According to an embodiment of the present invention, an air conditioner corresponding to a hybrid power supply device is also provided. This air conditioner may include the hybrid power supply device described above.

[0055] Since the processing and functions implemented by the air conditioner in this embodiment are basically corresponding to the embodiments, principles and examples of the device, any details not covered in the description of this embodiment can be found in the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0056] According to embodiments of the present invention, a control method for a hybrid power supply device for an air conditioner, corresponding to an air conditioner, is also provided, such as... Figure 3 The diagram shows a flowchart of an embodiment of the method of the present invention. In the hybrid power supply device, the first boost module has a first switching module, such as a first switching transistor Q1. The second boost module has a second switching module, such as a second switching transistor Q2. When the air conditioner is not started, both the first and second switching modules are disconnected. The control method of the hybrid power supply device for the air conditioner includes steps S110 to S140.

[0057] In step S110, when the air conditioner needs to be started, the second switch module is controlled to close so that the second DC voltage output by the mains power supply unit can be used to supply power to the DC bus of the hybrid power supply device. Then, the DC bus voltage output by the DC bus capacitor unit is used to supply power to the air conditioner through the inverter, specifically to supply power to the motor of the compressor in the air conditioner.

[0058] In step S120, when the DC bus of the hybrid power supply device is powered by the second DC voltage output by the mains power supply unit, the photovoltaic voltage output by the solar photovoltaic module in the photovoltaic power supply unit is detected, and it is determined whether the detected photovoltaic voltage output by the solar photovoltaic module is greater than a set first voltage threshold.

[0059] In step S130, if it is determined that the photovoltaic voltage output by the detected solar photovoltaic module is greater than the first voltage threshold, then the first switch module is controlled to close, so that the first DC voltage output by the photovoltaic power supply unit is superimposed on the second DC voltage output by the mains power supply unit, and together they supply power to the DC bus of the hybrid power supply device. After the DC bus voltage obtained by the hybrid power supply device reaches the set start-up voltage, the air conditioner is controlled to start and run. That is, the air conditioner is controlled to start and run when both the first switch module and the second switch module are closed.

[0060] In step S140, if it is determined that the photovoltaic voltage output by the detected solar photovoltaic module is less than or equal to the first voltage threshold, the first switching module is controlled to continue to be disconnected, and at least one of the switching frequency and duty cycle of the second switching tube module in the second boost module is increased to increase the second DC voltage output by the mains power supply unit. After the DC bus voltage obtained by the DC bus of the hybrid power supply device reaches the set start-up voltage, the air conditioner is controlled to start and run.

[0061] Figure 8 A schematic diagram illustrating the workflow of an embodiment of a control method for a circuit that provides hybrid power supply by superimposing the voltages of photovoltaic power and AC mains power. (See attached diagram.) Figure 8 As shown, the control method for a circuit that uses a hybrid power supply combining photovoltaic power and AC mains voltage superposition includes: The first stage, i.e., the hybrid power supply control method during startup, includes:

[0062] Step 11: Upon startup, control the second switch K2 to close, initially using only AC mains power to supply power to the air conditioner. With the second switch K2 closed, the second DC voltage VDC2 is energized, and the DC bus voltage VDC3 is equal to the second DC voltage VDC2 minus the voltage drop across the third diode D3. Then, proceed to step 12.

[0063] Step 12: Detect whether the photovoltaic voltage DC+ output by the solar photovoltaic module is greater than the set first voltage threshold Vst1.

[0064] If the photovoltaic voltage DC+ output by the solar photovoltaic module is less than or equal to the first voltage threshold Vst1, it indicates that the solar photovoltaic module cannot supply power. The first switch K1 remains open, and the air conditioner continues to be powered solely by AC mains power. When only AC mains power is used to supply the air conditioner, the second switch Q2 operates, and the second Boost circuit boosts the rectified mains voltage DB+, ensuring that the second DC voltage VDC2 meets the requirements of the DC bus voltage VDC3. The switching frequency and duty cycle of the second switch Q2 are controlled to ensure that the fluctuation of the DC bus voltage VDC3 remains within the allowable range.

[0065] Specifically, controlling the switching frequency and duty cycle of the second switch Q2 ensures that the fluctuation of the DC bus voltage VDC3 remains within acceptable limits. This can be achieved as follows: First, the second switch Q2 is turned on, current flows through the second inductor L2, and the current in the second switch Q2 increases rapidly, storing energy in the second inductor L2. Then, the second switch Q2 is turned off, allowing current to flow through the second inductor L2 and the second diode D2 to supply the bus. At this point, the current decreases rapidly, and the second inductor L2 releases energy. The voltage VDC2 at this point equals the voltage across the second inductor L2 plus the rectified voltage DB, achieving a voltage boost effect. During the boost process, the higher the duty cycle or switching frequency of the second switch Q2, the greater the current flowing through the second inductor L2, the greater the energy stored in the second inductor L2, and the higher the boosted voltage. Monitoring the DC bus voltage VDC3, when it falls below a certain threshold, increases the duty cycle or switching frequency of the second switch Q2, raising the voltage VDC2 and thus raising the DC bus voltage VDC3. When the DC bus voltage VDC3 is higher than a certain threshold, the duty cycle or switching frequency of the second switching transistor Q2 is reduced, causing the voltage VDC2 to decrease, thereby reducing the DC bus voltage VDC3.

[0066] If the photovoltaic voltage DC+ output by the solar photovoltaic module is greater than the first voltage threshold Vst1, it indicates that the solar photovoltaic module can supply power. The first switch K1 is then closed to allow the solar photovoltaic module to supply power, while simultaneously using AC mains power to supply power to the air conditioner. Thus, when the solar photovoltaic module can supply power, the first switch K1 is closed. With the first switch K1 closed, the first DC voltage VDC1 is superimposed on the second DC voltage VDC2, and the DC bus voltage VDC3 is the superimposed voltage. Then, proceed to step 13.

[0067] Step 13: Start the load to get it running.

[0068] In some embodiments, the control method for the hybrid power supply device of the air conditioner further includes: adjusting the DC bus voltage obtained from the DC bus of the hybrid power supply device.

[0069] The following is combined with Figure 4 The schematic diagram shown is a flowchart of an embodiment of the method of the present invention for adjusting the DC bus voltage obtained by the DC bus of the hybrid power supply device. The specific process of adjusting the DC bus voltage obtained by the DC bus of the hybrid power supply device is further explained, including steps S210 to S230.

[0070] Step S210: During the operation of the air conditioner after it is started, the DC bus voltage obtained by the DC bus of the hybrid power supply device is detected, and it is determined whether the detected DC bus voltage obtained by the DC bus of the hybrid power supply device is greater than or equal to the set second voltage threshold.

[0071] Step S220: If it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device is greater than or equal to the second voltage threshold, then it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device can still meet the power supply requirements of the air conditioner.

[0072] Step S230: If it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device is less than the second voltage threshold, then it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device can no longer meet the power supply requirements of the air conditioner, and the first boost module and / or the first boost module are controlled to make the DC bus voltage obtained by the DC bus of the hybrid power supply device rise to meet the power supply requirements of the air conditioner.

[0073] like Figure 8 As shown, the control method for a circuit that uses a hybrid power supply of photovoltaic power and AC mains voltage superposition also includes: a second stage.

[0074] In step 13 of the first phase, the load is started to get it running, and then steps 14 and 21 are executed respectively.

[0075] Step 14: Since the compressor and other loads of the air conditioner will pull down the DC bus voltage VDC3 when running, detect the DC bus voltage VDC3, and then proceed to step 15.

[0076] Step 15: Compare whether the detected DC bus voltage VDC3 is less than the set second voltage threshold Vst2.

[0077] If the detected DC bus voltage VDC3 is greater than or equal to the set second voltage threshold Vst2, the current boost parameters of the second Boost circuit are maintained, such as keeping the switching frequency and duty cycle of the second switch Q2 in the second Boost circuit unchanged.

[0078] When the detected DC bus voltage VDC3 is less than the second voltage threshold Vst2, it is determined that the DC bus voltage VDC3 is too low and needs to be increased.

[0079] In some implementations, step S230 controls the first boost module and / or the first boost module to raise the DC bus voltage obtained by the DC bus of the hybrid power supply device to a level sufficient to meet the power supply requirements of the air conditioner, including any of the following control methods:

[0080] The first control scenario: When the photovoltaic power supply unit and the mains power supply unit are supplying power together, the switching frequency and / or duty cycle of the first switching transistor module in the first boost module are controlled to increase the first DC voltage output by the photovoltaic power supply unit, thereby increasing the DC bus voltage obtained by the DC bus of the hybrid power supply device to meet the power supply requirements of the air conditioner.

[0081] The second control scenario: When the photovoltaic power supply unit and the mains power supply unit supply power together, or when the mains power supply unit supplies power alone, the switching frequency and / or duty cycle of the second switching transistor module in the second boost module are increased to increase the second DC voltage output by the mains power supply unit, thereby increasing the DC bus voltage obtained by the DC bus of the hybrid power supply device to meet the power supply requirements of the air conditioner.

[0082] The third control scenario: When the photovoltaic power supply unit and the mains power supply unit are supplying power together, the switching frequency and / or duty cycle of the first switching transistor module in the first boost module are controlled to increase the first DC voltage output by the photovoltaic power supply unit. In addition, the switching frequency and / or duty cycle of the second switching transistor module in the second boost module are increased to increase the second DC voltage output by the mains power supply unit. This results in the DC bus voltage obtained by the DC bus of the hybrid power supply device rising to a level that can meet the power supply requirements of the air conditioner.

[0083] The operation of controlling the switching frequency and / or duty cycle of the first switching transistor module in the first boost module to increase the first DC voltage output by the photovoltaic power supply unit is performed when the power supply capacity of the solar photovoltaic module has not reached the set limit. If the power supply capacity of the solar photovoltaic module has reached the set limit, then only the switching frequency and / or duty cycle of the second switching transistor module in the second boost module can be increased to increase the second DC voltage output by the mains power supply unit, thereby raising the DC bus voltage obtained by the DC bus of the hybrid power supply device to a level sufficient to meet the power supply requirements of the air conditioner.

[0084] Specifically, in combination Figure 8 In the example shown, in the second stage, when the detected DC bus voltage VDC3 is less than the second voltage threshold Vst2, indicating that the DC bus voltage VDC3 is too low, the first switch Q1 of the first Boost circuit needs to operate. By controlling the switching frequency and duty cycle of the first switch Q1, such as increasing the switching frequency and duty cycle of the first switch Q1, the DC bus voltage VDC3 is guaranteed to be greater than or equal to the second voltage threshold Vst2.

[0085] And / or, if the detected DC bus voltage VDC3 is less than the second voltage threshold Vst2, and it is determined that the DC bus voltage VDC3 is too low, if the detected DC bus voltage VDC3 is less than the set second voltage threshold Vst2, then the switching frequency and duty cycle of the second switch Q2 in the second Boost circuit are controlled, such as increasing the switching frequency and / or duty cycle of the second switch Q2 in the second Boost circuit to raise the DC bus voltage VDC3.

[0086] In some embodiments, the control method for the hybrid power supply device of the air conditioner further includes: monitoring the power supply capability of the solar photovoltaic module.

[0087] The following is combined with Figure 5 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for monitoring the power supply capability of the solar photovoltaic module. It further illustrates the specific process of monitoring the power supply capability of the solar photovoltaic module, including steps S310 to S340.

[0088] Step S310: During the operation of the air conditioner after it is started, the first current output by the solar photovoltaic module in the photovoltaic power supply unit after passing through the first switching module is detected, and the second current output by the rectifier module in the mains power supply unit is detected.

[0089] Step S320: Determine whether the first current output by the solar photovoltaic module is greater than a preset first current threshold.

[0090] Step S330: If it is determined that the first current output by the solar photovoltaic module is less than or equal to the first current threshold, then it is determined that the power supply capacity of the solar photovoltaic module has not reached the set limit value.

[0091] Step S340: If it is determined that the first current output by the solar photovoltaic module is greater than the first current threshold, then it is determined that the power supply capacity of the solar photovoltaic module has reached the set limit value, and the power supply capacity of the hybrid power supply device is adjusted.

[0092] Specifically, in combination Figure 8 The example shown, in the second stage, the control method for the circuit that uses a hybrid power supply of photovoltaic power and AC mains voltage superposition also includes:

[0093] Step 21: Detect the first current I1 output by the solar photovoltaic module through the first switch K1, and detect the second current I2 output by the AC mains power through the rectifier bridge.

[0094] Step 22: Detect whether the first current I1 is greater than the set first current threshold Ist1: If the first current I1 is greater than the set first current threshold Ist1, it means that the photovoltaic power supply capacity of the solar photovoltaic module is about to reach the limit value, and AC mains power is required at the same time.

[0095] In some implementations, combined Figure 6 The schematic diagram shown is a flowchart of an embodiment of the method of the present invention for adjusting the power supply capability of the hybrid power supply device. It further illustrates the specific process of adjusting the power supply capability of the hybrid power supply device in step S340, including steps S410 to S430.

[0096] Step S410: If it is determined that the power supply capacity of the solar photovoltaic module has reached a set limit, reduce the switching frequency and / or duty cycle of the first switching transistor module in the first boost module, so that the first current output by the solar photovoltaic module is reduced to the first current threshold. And,

[0097] Step S420: Increase the switching frequency and / or duty cycle of the second switching transistor module in the second boost module to increase the second current output by the rectifier module.

[0098] Step S430: Stop increasing the switching frequency and / or duty cycle of the second switching module until the sum of the first current output by the solar photovoltaic module and the second current output by the rectifier module meets the power supply requirements of the air conditioner.

[0099] Specifically, in combination Figure 8 In the example shown, in the second stage, when the photovoltaic power supply capacity of the solar photovoltaic module is about to reach its limit and AC mains power is required simultaneously, on the one hand, the first current I1 is limited: the switching frequency and duty cycle of the first switch Q1 are controlled to reduce the first current I1 to be equal to the first current threshold Ist1. On the other hand, the switching frequency and duty cycle of the second switch Q2 are controlled to increase the second current I2, so that the sum of the first current I1 and the second current I2 meets the operating requirements of the air conditioning load.

[0100] In some embodiments, the control method for the hybrid power supply device of the air conditioner further includes: adjusting the power supply levels of the photovoltaic power supply unit and the mains power supply unit.

[0101] The following is combined with Figure 7 The schematic diagram shows an embodiment of the method of the present invention for adjusting the power supply level of the photovoltaic power supply unit and the mains power supply unit. It further illustrates the specific process of adjusting the power supply level of the photovoltaic power supply unit and the mains power supply unit, including steps S510 to S550.

[0102] Step S510: Determine the required power of the air conditioner, denoted as the total power.

[0103] Step S520: Detect the photovoltaic voltage of the solar photovoltaic module in the photovoltaic power supply unit, and detect the first current output by the solar photovoltaic module in the photovoltaic power supply unit. Determine the power supply power of the photovoltaic power supply unit, denoted as photovoltaic power.

[0104] Step S530: If the photovoltaic voltage of the solar photovoltaic module is greater than a preset third voltage threshold, the first current output by the solar photovoltaic module is less than a preset first current threshold, and the photovoltaic power of the photovoltaic power supply unit is greater than the total power of the air conditioner, then the second switching module is controlled to shut down so that the air conditioner operates in the first hybrid power supply state.

[0105] Step S540: If the photovoltaic voltage of the solar photovoltaic module is less than or equal to a preset third voltage threshold, and / or the first current output by the solar photovoltaic module is greater than or equal to a preset first current threshold, and / or the photovoltaic power of the photovoltaic power supply unit is less than or equal to the total power of the air conditioner, then control the second switch module to continue to be turned on so that the air conditioner operates in the second hybrid power supply state.

[0106] Step S550: If the photovoltaic voltage of the solar photovoltaic module is less than a preset first voltage threshold, the first switch module is controlled to disconnect so that the air conditioner operates in the third hybrid power supply state.

[0107] In either the first or second hybrid power supply state, it is necessary to monitor the power supply capacity of the solar photovoltaic module and / or adjust the DC bus voltage obtained by the DC bus of the hybrid power supply device.

[0108] In the third hybrid power supply state, the power supply capacity of the mains power supply unit needs to be adjusted by controlling the switching frequency and / or duty cycle of the second switching transistor module in the second boost module in order to meet the power supply requirements of the total power of the air conditioner.

[0109] Specifically, in combination Figure 8 The example shown, in the second phase, includes a hybrid power supply control method during operation, comprising:

[0110] In the first hybrid power supply state, the solar photovoltaic power supply (i.e., the photovoltaic voltage provided by the solar photovoltaic module) and the AC power supply are supplied simultaneously, but the second switch Q2 of the second Boost circuit of the AC current does not work.

[0111] In the second hybrid power supply state, the solar photovoltaic power supply and the AC power supply are supplied simultaneously, and the second switching transistor of the second Boost circuit of the AC current is activated.

[0112] In the third hybrid power supply state, the AC power supply is provided separately. After rectification, the AC mains power is supplied to the DC bus through the second Boost circuit and the third diode D3.

[0113] Step 31: If the air conditioner compressor is an inverter air conditioner compressor, calculate the total power Pout required by the entire air conditioner unit based on the target operating frequency of the inverter air conditioner compressor.

[0114] The calculation of the required power output (Pout) for the entire air conditioner unit can be achieved by considering the difference between the set temperature and the actual ambient temperature, as well as the air conditioner's own conditions (pipe temperature, exhaust temperature), and using a power-temperature curve obtained from testing. For example, if the actual ambient temperature is 40℃ and the set temperature is 16℃, the system pressure of the air conditioner is determined based on the pipe and exhaust temperatures. If the pressure is relatively low, the air conditioner compressor can operate at a high frequency. The required power output (Pout) is then calculated based on the compressor's operating frequency and the system pressure. A larger difference between the actual ambient temperature and the set temperature results in a larger required power output (Pout). Conversely, a smaller difference results in a smaller required power output (Pout).

[0115] Step 32: Based on the working status of the first switch Q1 and the second switch Q2, determine whether the air conditioner is operating in the first mixed power supply state or the second mixed power supply state:

[0116] When the air conditioner is operating in the first mixed power supply state, proceed to steps 33, 34, 35, and 36.

[0117] When the air conditioner is operating in the second hybrid power supply state, proceed to step 37.

[0118] Step 33: Since the compressor and other loads of the air conditioner will pull down the DC bus voltage VDC3 when running, detect the DC bus voltage VDC3 and then proceed to step 34.

[0119] Step 34: Compare whether the detected DC bus voltage VDC3 is greater than or equal to the set second voltage threshold Vst2.

[0120] If the detected DC bus voltage VDC3 is greater than or equal to the second voltage threshold Vst2, then it is determined that the DC bus voltage VDC3 can meet the load drive requirements.

[0121] When the detected DC bus voltage VDC3 is less than the second voltage threshold Vst2, it is determined that the DC bus voltage VDC3 is too low, and the first switch Q1 of the first Boost circuit needs to operate. By controlling the switching frequency and duty cycle of the first switch Q1, such as increasing the switching frequency and duty cycle of the first switch Q1, the DC bus voltage VDC3 is guaranteed to be greater than or equal to the second voltage threshold Vst2.

[0122] Here, when the detected DC bus voltage VDC3 is less than the second voltage threshold Vst2, and it is determined that the DC bus voltage VDC3 is too low, the switching frequency and duty cycle of the second switch Q2 in the second Boost circuit can also be controlled. For example, the switching frequency and / or duty cycle of the second switch Q2 in the second Boost circuit can be increased to raise the DC bus voltage VDC3.

[0123] Of course, if the detected DC bus voltage VDC3 is less than the second voltage threshold Vst2, indicating that the DC bus voltage VDC3 is too low, the DC bus voltage VDC3 can be increased preferentially through the photovoltaic solar modules. If the first current I1 output by the photovoltaic solar modules is greater than the set first current threshold Ist1, the first current I1 is limited: the switching frequency and duty cycle of the first switch Q1 are controlled to reduce the first current I1 to be equal to the first current threshold Ist1. At the same time, the switching frequency and duty cycle of the second switch Q2 are controlled to increase the second current I2, so that the sum of the first current I1 and the second current I2 meets the operating requirements of the air conditioning load.

[0124] Step 35: Detect the first current I1 output by the solar photovoltaic module through the first switch K1, and calculate the power Pdc provided by the photovoltaic to the air conditioner by using the detected photovoltaic voltage DC+ and the value of the first current I1.

[0125] Step 36: Compare the detected photovoltaic voltage DC+ with the set third voltage threshold Vst3, and simultaneously compare the first current I1 with the set first current threshold Ist1. Compare the photovoltaic power Pdc with the total power Pout.

[0126] (1) When the first condition is met, namely: the photovoltaic voltage DC+ > the third voltage threshold Vst3, the first current I1 < the first current threshold Ist1, and the photovoltaic power Pdc > the total power Pout, it is determined that the solar photovoltaic module can provide enough power to the air conditioner, and the second switch Q2 of the second Boost boost circuit of the AC mains power does not need to work and operates in the first hybrid power supply state.

[0127] (2) When the first condition is not met, namely: the power supplied by the solar photovoltaic module to the air conditioner is insufficient, the second switch Q2 of the second Boost circuit of the AC current needs to work. By controlling the switching frequency and duty cycle of the second switch Q2, it operates in the second hybrid power supply state.

[0128] (3) When the photovoltaic voltage DC+ < the first voltage threshold Vst1, it is determined that the photovoltaic voltage DC+ is too low and the solar photovoltaic module cannot supply power. The first switch K1 is opened and the third hybrid power supply state is entered.

[0129] Step 37: Detect the second current I2 output from the AC mains power through the rectifier bridge, and detect the rectified voltage DB+. Calculate the AC mains power Pac provided by the AC mains power using DB+ and the second current I2. Control the switching frequency and duty cycle of the second switch Q2 to control the second current I2, ensuring that the mains power Pac + photovoltaic power Pdc ≥ total power Pout, thus meeting the operating requirements of the air conditioning load. In the third hybrid power supply state, the photovoltaic power Pdc is 0.

[0130] This invention proposes a hybrid power supply circuit topology based on voltage superposition. The output DC voltage of the low-voltage solar photovoltaic module power supply is superimposed with the rectified DC voltage of the AC mains power to form the bus DC voltage. During startup, AC mains power is used first, followed by power from the photovoltaic power supply. During operation, the load size is calculated by detecting the DC bus voltage, photovoltaic DC voltage, current, and load current, and the boost circuit is controlled to power the load from the photovoltaic system. When the photovoltaic power supply is insufficient or unable to supply power, the boost circuit after AC mains rectification is activated to power the load from the AC mains power.

[0131] Thus, the solution of the present invention addresses the situation where the output voltage of a solar photovoltaic module (such as a solar cell array) is low and needs to be boosted to a higher voltage. By superimposing the photovoltaic output voltage onto the DC power after rectification of the AC mains, the voltage difference of the photovoltaic voltage boost can be reduced, thereby reducing the inductance and switching losses and temperature rise in the boost circuit of the solar photovoltaic module, improving the reliability of the boost circuit of the solar photovoltaic module, and extending the service life of key components (such as inductors and switching transistors) in the boost circuit of the solar photovoltaic module.

[0132] Since the processing and functions implemented by the method in this embodiment are basically the same as the aforementioned embodiments, principles and examples of air conditioners, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0133] The technical solution of this embodiment uses a hybrid power supply system for solar cell arrays and AC power. By superimposing the output voltage of the solar cell array onto the rectified DC power of the AC power, the output voltage of the solar cell array is increased. When boosting the output voltage of the solar cell array to the DC bus voltage, a photovoltaic boost circuit with a small boost ratio can be used to boost the output voltage of the solar cell array to the DC bus voltage. This results in lower losses and temperature rise of the inductor and switching transistor in the photovoltaic boost circuit, which helps to extend the service life of the photovoltaic boost circuit and ensure the reliability of the long-term operation of the photovoltaic boost circuit.

[0134] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0135] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A hybrid power supply device, characterized in that, include: Photovoltaic power supply unit, mains power supply unit, hybrid power supply unit and bus capacitor unit; The hybrid power supply unit includes: a diode module; wherein, The photovoltaic power supply unit includes: a solar photovoltaic module, a first switching module, and a first boost module; the positive photovoltaic electrode of the solar photovoltaic module is connected to the first input terminal of the first boost module after passing through the first switching module; the first output terminal of the first boost module is connected to the cathode of the diode module on one side and the positive electrode of the bus capacitor unit on the other side; the negative photovoltaic electrode of the solar photovoltaic module is connected to the second input terminal of the first boost module on one side and the anode of the diode module on the other side; the boost ratio of the first boost module can be less than a set boost ratio. The mains power supply unit includes: a rectifier module, a second switch module, and a second boost module; after the mains power passes through the second switch module and the rectifier module, the first output terminal of the rectifier module is connected to the first input terminal of the second boost module; the first output terminal of the second boost module is connected to the anode of the diode module; the second output terminal of the rectifier module is connected to the first input terminal of the second boost module on one hand, and to the negative terminal of the bus capacitor unit on the other hand, and is grounded. The first DC voltage output by the photovoltaic power supply unit and the second DC voltage output by the mains power supply unit are superimposed and output to the DC bus of the hybrid power supply device to obtain the DC bus voltage; the bus capacitor unit can output the DC bus voltage of the hybrid power supply device to supply the load. When the air conditioner is not started, both the first switch module and the second switch module are disconnected; the control method for the hybrid power supply device of the air conditioner includes: When the air conditioner needs to be started, the second switch module is controlled to close so that the second DC voltage output by the mains power supply unit can be used to supply power to the DC bus of the hybrid power supply device. Then, the DC bus voltage output by the DC bus capacitor unit is used to supply power to the air conditioner through the inverter. The photovoltaic voltage output by the solar photovoltaic module in the photovoltaic power supply unit is detected, and it is determined whether the detected photovoltaic voltage output by the solar photovoltaic module is greater than a set first voltage threshold. If it is determined that the photovoltaic voltage output by the detected solar photovoltaic module is greater than the first voltage threshold, the first switch module is controlled to close so that the first DC voltage output by the photovoltaic power supply unit is superimposed on the second DC voltage output by the mains power supply unit, and together they supply power to the DC bus of the hybrid power supply device. After the DC bus voltage obtained by the DC bus of the hybrid power supply device reaches the set start-up voltage, the air conditioner is controlled to start and run. If it is determined that the photovoltaic voltage output by the detected solar photovoltaic module is less than or equal to the first voltage threshold, then at least one of the switching frequency and duty cycle of the second switching tube module in the second boost module is increased to increase the second DC voltage output by the mains power supply unit. After the DC bus voltage obtained by the DC bus of the hybrid power supply device reaches the set start-up voltage, the air conditioner is controlled to start and run.

2. The hybrid power supply device according to claim 1, characterized in that, The hybrid power supply unit further includes: a first voltage regulator module and / or a second voltage regulator module; wherein, The first voltage regulator module is used to regulate the first DC voltage output by the photovoltaic power supply unit; the first connection terminal of the first voltage regulator module is connected to the cathode of the diode module; the second connection terminal of the first voltage regulator module is connected to the anode of the diode module. The second voltage regulator module is used to regulate the second DC voltage output by the mains power supply unit; the first connection terminal of the second voltage regulator module is connected to the anode of the diode module; the second connection terminal of the second voltage regulator module is connected to the negative terminal of the bus capacitor unit.

3. The hybrid power supply device according to claim 2, characterized in that, in, The first voltage regulator module includes: a first capacitor module; and / or, the second voltage regulator module includes: a second capacitor module.

4. The hybrid power supply device according to claim 1, characterized in that, The control method for the hybrid power supply device of the air conditioner further includes: adjusting the DC bus voltage obtained from the DC bus of the hybrid power supply device; The adjustment of the DC bus voltage obtained from the DC bus of the hybrid power supply device includes: During the operation of the air conditioner after it is started, the DC bus voltage obtained by the DC bus of the hybrid power supply device is detected, and it is determined whether the detected DC bus voltage obtained by the DC bus of the hybrid power supply device is greater than or equal to a set second voltage threshold. If it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device is greater than or equal to the second voltage threshold, then it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device can still meet the power supply requirements of the air conditioner. If it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device is less than the second voltage threshold, then it is determined that the DC bus voltage obtained by the DC bus of the hybrid power supply device can no longer meet the power supply requirements of the air conditioner, and the first boost module and / or the first boost module are controlled to raise the DC bus voltage obtained by the DC bus of the hybrid power supply device to a level that can meet the power supply requirements of the air conditioner.

5. The hybrid power supply device according to claim 4, characterized in that, Controlling the first boost module and / or the first boost module to raise the DC bus voltage obtained by the DC bus of the hybrid power supply device to a level sufficient to meet the power supply requirements of the air conditioner includes any of the following control methods: When the photovoltaic power supply unit and the mains power supply unit are jointly powered, the switching frequency and / or duty cycle of the first switching transistor module in the first boost module are controlled to increase the first DC voltage output by the photovoltaic power supply unit, thereby increasing the DC bus voltage obtained by the DC bus of the hybrid power supply device to meet the power supply requirements of the air conditioner. When the photovoltaic power supply unit and the mains power supply unit supply power together, or when the mains power supply unit supplies power alone, the switching frequency and / or duty cycle of the second switching transistor module in the second boost module are increased to increase the second DC voltage output by the mains power supply unit, thereby increasing the DC bus voltage obtained by the DC bus of the hybrid power supply device to meet the power supply requirements of the air conditioner. When the photovoltaic power supply unit and the mains power supply unit are jointly powered, the switching frequency and / or duty cycle of the first switching transistor module in the first boost module are controlled to increase the first DC voltage output by the photovoltaic power supply unit. In addition, the switching frequency and / or duty cycle of the second switching transistor module in the second boost module are increased to increase the second DC voltage output by the mains power supply unit. This increases the DC bus voltage obtained by the DC bus of the hybrid power supply device to a level that meets the power supply requirements of the air conditioner. The operation of controlling the switching frequency and / or duty cycle of the first switching transistor module in the first boost module to increase the first DC voltage output by the photovoltaic power supply unit is performed when the power supply capacity of the solar photovoltaic module has not reached the set limit value. If the power supply capacity of the solar photovoltaic module has reached the set limit value, then only the switching frequency and / or duty cycle of the second switching transistor module in the second boost module can be increased to increase the second DC voltage output by the mains power supply unit, thereby increasing the DC bus voltage obtained by the DC bus of the hybrid power supply device to meet the power supply requirements of the air conditioner.

6. The hybrid power supply device according to any one of claims 1, 4, and 5, characterized in that, The control method for the hybrid power supply device of the air conditioner further includes: monitoring the power supply capacity of the solar photovoltaic module; Monitoring the power supply capability of the solar photovoltaic modules includes: During the operation of the air conditioner after it is started, the first current output by the solar photovoltaic module in the photovoltaic power supply unit after passing through the first switching module is detected, and the second current output by the rectifier module in the mains power supply unit is detected. Determine whether the first current output by the solar photovoltaic module is greater than a preset first current threshold. If it is determined that the first current output by the solar photovoltaic module is less than or equal to the first current threshold, then it is determined that the power supply capacity of the solar photovoltaic module has not reached the set limit value. If it is determined that the first current output by the solar photovoltaic module is greater than the first current threshold, then it is determined that the power supply capacity of the solar photovoltaic module has reached the set limit value, and the power supply capacity of the hybrid power supply device is adjusted.

7. The hybrid power supply device according to claim 6, characterized in that, Adjusting the power supply capability of the hybrid power supply device includes: If it is determined that the power supply capacity of the solar photovoltaic module has reached a set limit, the switching frequency and / or duty cycle of the first switching transistor module in the first boost module are reduced, so that the first current output by the solar photovoltaic module is reduced to the first current threshold; and, Increase the switching frequency and / or duty cycle of the second switching transistor module in the second boost module to increase the second current output by the rectifier module; The increase in the switching frequency and / or duty cycle of the second switching module will cease once the sum of the first current output by the solar photovoltaic module and the second current output by the rectifier module meets the power supply requirements of the air conditioner.

8. The hybrid power supply device according to claim 6, characterized in that, The control method for the hybrid power supply device of the air conditioner further includes: adjusting the power supply levels of the photovoltaic power supply unit and the mains power supply unit; The adjustment of the power supply levels of the photovoltaic power supply unit and the mains power supply unit includes: The required power of the air conditioner is determined and denoted as the total power. The photovoltaic voltage of the solar photovoltaic module in the photovoltaic power supply unit is detected, the first current output by the solar photovoltaic module in the photovoltaic power supply unit is detected, and the power supply power of the photovoltaic power supply unit is determined and recorded as photovoltaic power. If the photovoltaic voltage of the solar photovoltaic module is greater than a preset third voltage threshold, the first current output by the solar photovoltaic module is less than a preset first current threshold, and the photovoltaic power of the photovoltaic power supply unit is greater than the total power of the air conditioner, then the second switching module is controlled to shut down so that the air conditioner operates in the first hybrid power supply state. If the photovoltaic voltage of the solar photovoltaic module is less than or equal to a preset third voltage threshold, and / or the first current output by the solar photovoltaic module is greater than or equal to a preset first current threshold, and / or the photovoltaic power of the photovoltaic power supply unit is less than or equal to the total power of the air conditioner, then the second switch module is controlled to continue to be turned on so that the air conditioner operates in the second hybrid power supply state. If the photovoltaic voltage of the solar photovoltaic module is less than a preset first voltage threshold, the first switch module is controlled to disconnect so that the air conditioner operates in a third hybrid power supply state. In either the first or second hybrid power supply state, it is necessary to monitor the power supply capacity of the solar photovoltaic module and / or adjust the DC bus voltage obtained by the DC bus of the hybrid power supply device. In the third hybrid power supply state, the power supply capacity of the mains power supply unit needs to be adjusted by controlling the switching frequency and / or duty cycle of the second switching transistor module in the second boost module in order to meet the power supply requirements of the total power of the air conditioner.

9. An air conditioner, characterized in that, include: The hybrid power supply device as described in any one of claims 1 to 8.

Images