Power supply device and air conditioner

Abstract

The invention discloses a power supply device and an air conditioner. The power supply device comprises a power supply circuit and a control module. The power supply circuit comprises an alternating current power supply end, an input filter capacitor, a rectifier module and a first inverter module for supplying power to the first motor, which are connected in sequence; the control module is configured to determine at least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the first inversion module as target switch tubes in response to continuous drop of the input voltage of the AC power supply end; and sending a first driving signal to the target switch tube, so that the input filter capacitor, the rectifier module, the target switch tube and a phase winding of the first motor corresponding to the target switch tube form a discharge loop. Quick discharge can be realized after the plug is unplugged, and electric control loss can be avoided at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioner power supply circuits, and in particular to a power supply device and an air conditioner. Background Art

[0002] At present, home appliances such as air conditioners need to meet the safety standard "GB4706.1-2005 Safety of Household and Similar Electrical Appliances", which requires that for products with plugs, the voltage between the live and neutral wires cannot exceed 34V within 1 second after the plug is unplugged. In order to meet the national magnetic compatibility standards and other EMC requirements, current home appliances generally have filter circuits, which contain X capacitors. X capacitors will discharge slowly after the plug is unplugged. Therefore, in order to meet safety requirements, current home appliances generally connect multiple discharge resistors in parallel between the live and neutral wires, but the increased resistance will cause an increase in electrical control losses, which is not conducive to improving the energy efficiency of the entire machine. Summary of the invention

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a power supply device and an air conditioner which can achieve rapid discharge after the plug is unplugged and avoid electrical control loss.

[0004] In a first aspect, an embodiment of the present invention provides a power supply device, including a power supply circuit and a control module; The power supply circuit comprises an AC power supply terminal, an input filter capacitor, a rectifier module and a first inverter module for supplying power to the first motor, which are connected in sequence; The control module is configured to: In response to the input voltage at the AC power supply end continuously decreasing, determining at least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the first inverter module as target switch tubes; A first driving signal is sent to the target switch tube, so that the input filter capacitor, the rectifier module, the target switch tube and the phase winding of the first motor corresponding to the target switch tube form a discharge loop.

[0005] The power supply device provided according to the embodiment of the present invention has at least the following beneficial effects: when the AC power supply end of the power supply device is in a power-off state, a first drive signal is sent to at least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the first inverter module to perform conduction control, thereby constructing a discharge circuit composed of an input filter capacitor, a rectifier module, a target switch tube and a phase winding of the first motor corresponding to the target switch tube, so as to discharge the input filter capacitor and fully utilize the existing circuit structure of the power supply device to construct the discharge circuit. There is no need to introduce additional hardware such as multiple discharge resistors in the related technology, thereby avoiding the electrical control loss caused by the additionally introduced hardware and reducing the cost.

[0006] According to the power supply device provided in some embodiments of the present invention, the power supply circuit further includes a second inverter module for supplying power to the second motor, and the second inverter module is connected in parallel with the first inverter module; The control module is further configured to: At least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the second inverter module are determined as target switch tubes.

[0007] According to the power supply device provided in some embodiments of the present invention, the first inverter module includes a first bridge arm, a second bridge arm and a third bridge arm, and the target switch tube includes one of the following situations: A first upper bridge arm switch tube of the first bridge arm and a second lower bridge arm switch tube of the second bridge arm; A first upper bridge arm switch tube of the first bridge arm, a second lower bridge arm switch tube of the second bridge arm, and a third lower bridge arm switch tube of the third bridge arm; a first upper bridge arm switch tube of the first bridge arm, a second upper bridge arm switch tube of the second bridge arm, and a third lower bridge arm switch tube of the third bridge arm.

[0008] According to the power supply device provided by some embodiments of the present invention, the power supply circuit further includes a power-on buffer module arranged between the input filter capacitor and the rectifier module, and the power-on buffer module includes a PTC resistor and a switch device connected in parallel.

[0009] According to the power supply device provided by some embodiments of the present invention, the power supply circuit further includes a power-on buffer module arranged between the rectifier module and the first inverter module, and the power-on buffer module includes a PTC resistor and a switch device connected in parallel.

[0010] According to the power supply device provided in some embodiments of the present invention, the control module is further configured to: While sending the first driving signal to the target switch tube, the switch device is controlled to be disconnected.

[0011] According to the power supply device provided in some embodiments of the present invention, the power supply circuit also includes a sampling resistor and a boost module arranged between the rectifier module and the first inverter module, the boost module includes a first inductor, a first switch tube, a first diode and a second capacitor, one end of the first inductor is connected to the rectifier module, the other end of the first inductor is connected to a switch pin of the first switch tube and the anode of the first diode, the cathode of the first diode is connected to one end of the second capacitor and the first inverter module, the other switch pin of the first switch tube is connected to one end of the sampling resistor, the other end of the second capacitor and the first inverter module, and the other end of the sampling resistor is connected to the rectifier module.

[0012] According to the power supply device provided in some embodiments of the present invention, the first drive signal is a pulse drive signal of a first duty cycle, the first duty cycle is less than or equal to an upper limit value of the duty cycle, and the upper limit value of the duty cycle is determined according to the minimum value of the maximum allowable current of the target switch tube, the maximum allowable current of the phase winding of the target switch tube, and the maximum allowable current of the sampling resistor.

[0013] According to the power supply device provided in some embodiments of the present invention, the power supply device further includes an input voltage detection unit for detecting the input voltage of the AC power supply end, and the control module is further configured as follows: Acquire the input voltage at multiple sampling moments within a first preset time period; The input voltage at each sampling moment is smaller than the input voltage at the previous sampling moment, and it is determined that the input voltage at the AC power supply end continues to decrease.

[0014] According to the power supply device provided in some embodiments of the present invention, the control module is further configured to: stop sending the first drive signal when the input voltage is less than a first safety voltage threshold.

[0015] According to the power supply device provided by some embodiments of the present invention, a bus voltage detection unit for detecting the bus voltage is provided on the output side of the boost module, and the control module is further configured as follows: The bus voltage is obtained, and when the bus voltage is less than a second safety voltage threshold, the first drive signal is stopped.

[0016] In a second aspect, an embodiment of the present invention provides an air conditioner, comprising the power supply device as described in the embodiment of the first aspect above.

[0017] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments; Figure 1 is a circuit schematic diagram of a power supply device provided in Embodiment 1 of the present invention; Figure 2is a circuit schematic diagram of a power supply device provided in Embodiment 2 of the present invention; Figure 3 is an equivalent circuit diagram of a first inverter module and a first motor provided in an embodiment of the present invention; Figure 4 is an equivalent circuit diagram of a discharge circuit corresponding to the first situation provided in the first embodiment of the present invention; Figure 5 is an equivalent circuit diagram of a discharge circuit corresponding to the second situation provided in the first embodiment of the present invention; Figure 6 is an equivalent circuit diagram of a discharge circuit corresponding to the third situation provided in the first embodiment of the present invention; Figure 7 is a circuit schematic diagram of a power supply device provided in Embodiment 3 of the present invention; Figure 8 is an equivalent circuit diagram of a discharge circuit corresponding to a situation of the power supply device provided in the third embodiment of the present invention; Fig. 9 It is an equivalent circuit diagram of a discharge circuit corresponding to a situation of the power supply device provided in the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0020] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0021] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, "above", "below", "within", etc. are understood to include the number itself, "any one" means one or more, "at least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. If there is a description of the first and the second, it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0022] It should be noted that the terms such as setting, installing, and connecting in the embodiments of the present invention should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the embodiments of the present invention in combination with the specific content of the technical solution. For example, the term "connection" can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected or indirectly connected through an intermediate medium.

[0023] It should be noted that the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] At present, home appliances such as air conditioners need to meet the safety standard "GB4706.1-2005 Safety of Household and Similar Electrical Appliances", which requires that for products with plugs, the voltage between the live and neutral wires cannot exceed 34V within 1 second after the plug is unplugged. In order to meet the national magnetic compatibility standards and other EMC requirements, current home appliances generally have filter circuits, which contain X capacitors. X capacitors will discharge slowly after the plug is unplugged. Therefore, in order to meet safety requirements, current home appliances generally connect multiple discharge resistors in parallel between the live and neutral wires, but the increased resistance will cause an increase in electrical control losses, which is not conducive to improving the energy efficiency of the entire machine.

[0025] Based on this, an embodiment of the present invention provides a power supply device and an air conditioner, which can achieve rapid discharge after the plug is unplugged and avoid electrical control loss.

[0026] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0027] Reference Figure 1 and Figure 2 , a first aspect of the present invention provides a power supply device, including a power supply circuit and a control module; The power supply circuit includes an AC power supply terminal, an input filter capacitor C1, a rectifier module and a first inverter module for supplying power to the first motor, which are connected in sequence; specifically, the AC power supply terminal includes a live wire terminal L and a neutral wire terminal N; the power supply circuit may also include a power-on buffer module, a boost module and a sampling resistor R2; the power-on buffer module includes a PTC resistor R1 and a switching device connected in parallel, and the switching device may be a relay RY1; the boost module is arranged between the rectifier module and the first inverter module, and the first inverter module includes a first inductor, a first switching tube IGBT, a first diode FRD and a second capacitor C2; the power-on buffer module may be arranged between the input filter capacitor C1 and the rectifier module, that is, the power-on buffer module is arranged on the input side of the rectifier module, for example, referring to Figure 1 As shown; the power-on buffer module can also be arranged between the rectifier module and the boost module, that is, the power-on buffer module is arranged on the output side of the rectifier module, for example, refer to Figure 2 More specifically, Figure 1For example, the live wire terminal L in the AC power supply end is connected to one end of the input filter capacitor C1 and one end of a pair of contacts of the PTC resistor R1 and the relay RY1, and the other end of the PTC resistor R1 and the other end of the pair of contacts of the relay RY1 are connected together and connected to an input end of the rectifier module; the neutral wire terminal N in the AC power supply end is connected to the other end of the input filter capacitor C1 and the other input end of the rectifier module; an output end of the rectifier module is connected to one end of the first inductor L1, the other end of the first inductor L1 is connected to a switch pin of the first switch tube IGBT and the anode of the first diode FRD, the cathode of the first diode FRD is connected to one end of the second capacitor C2 and an input end of the first inverter module, the other switch pin of the first switch tube IGBT is connected to one end of the sampling resistor R2, the other end of the second capacitor C2 and the other input end of the first inverter module, and the other output end of the rectifier module is connected to the other end of the sampling resistor R2.

[0028] It is understandable that in Figure 1 In the household appliance product of the power supply device shown, after the AC power supply end is connected to the mains, the AC power supply is filtered by the input filter capacitor C1, and then input to the rectifier module for rectification and converted into a DC power supply. The boost module adjusts the input DC voltage to a suitable voltage level, so that the first inverter module at the subsequent stage converts the DC power into a fixed-frequency and fixed-voltage or frequency-modulated and voltage-regulated AC power, and provides the required power to the load (such as the first motor). The input filter capacitor C1 will filter the power connected to the mains, and the input filter capacitor C1 is a capacitor connected across the live wire terminal L and the neutral wire terminal N, which is used to suppress differential mode interference. After the power supply device loses power (for example, unplugging the plug), due to the accumulation of charges at both ends of the input filter capacitor C1, it cannot be quickly released in a short time, and there will be a large residual pressure at both ends of the input filter capacitor C1, so that the safety standard of residual voltage less than 34V within 1s cannot be met between the neutral and live wires of the plug. When the power cord plug is unplugged, it is easy to cause electric shock to the human body, so it is necessary to quickly release the residual charge in the input filter capacitor C1.

[0029] It is worth noting that the function of the second capacitor C2 in the boost module is to store electrical energy so as to maintain a stable output voltage for supplying power to the subsequent inverter module. Therefore, in some power supply devices, in addition to releasing the electrical energy stored in the input filter capacitor C1, the second capacitor C2 in the boost module also needs to be considered.

[0030] like Figure 1As shown, the embodiment of the present invention takes an air conditioner as an example. If the power supply device in the air conditioner is in working state and the plug is suddenly unplugged, since the high-power loads such as the first motor are still in working state for a short time, the power stored in the input filter capacitor C1 and the second capacitor C2 of the boost module will be quickly consumed. However, if the air conditioner (or the power supply device) is in standby state, and the loads such as the first motor are in shutdown state, at this time, the power stored in the input filter capacitor C1 and the second capacitor C2 of the boost module is difficult to be quickly released.

[0031] In the power supply device provided in the embodiment of the present invention, the control module is configured as follows: In response to the input voltage at the AC power supply end continuously decreasing, at least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the first inverter module are determined as target switch tubes; A first driving signal is sent to the target switch tube, so that the input filter capacitor C1, the rectifier module, the target switch tube and the phase winding of the first motor corresponding to the target switch tube form a discharge loop.

[0032] According to the power supply device provided by the embodiment of the present invention, when the AC power supply end of the power supply device is in a power-off state, a first drive signal is sent to at least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the first inverter module to perform conduction control, thereby constructing a discharge circuit composed of an input filter capacitor C1, a rectifier module, a target switch tube and a phase winding of the first motor corresponding to the target switch tube, so as to discharge the input filter capacitor C1, make full use of the existing circuit structure of the power supply device to construct the discharge circuit, and do not need to introduce additional hardware such as multiple discharge resistors in the related technology, thereby avoiding the electric control loss caused by the additionally introduced hardware and reducing the cost.

[0033] Reference Figure 3 , Figure 3: is an equivalent circuit diagram of the first inverter module and the first motor. The first inverter module includes a first bridge arm, a second bridge arm and a third bridge arm. Specifically, the first bridge arm includes a first upper bridge arm switch tube U+ and a first lower bridge arm switch tube U-, the second bridge arm includes a second upper bridge arm switch tube V+ and a second lower bridge arm switch tube V-, and the third bridge arm includes a third upper bridge arm switch tube W+ and a third lower bridge arm switch tube W-; the first motor includes a three-phase winding, each phase winding is equivalent to a phase equivalent inductance and a phase equivalent resistance connected in series; the midpoint of the first bridge arm, that is, the first upper bridge arm switch tube U+ and the first The connection point of the lower bridge arm switch tube U- is connected to one end of the equivalent inductance of the first phase winding; the midpoint of the second bridge arm, that is, the connection point of the second upper bridge arm switch tube V+ and the second lower bridge arm switch tube V- is connected to one end of the equivalent inductance of the second phase winding; the midpoint of the third bridge arm, that is, the connection point of the third upper bridge arm switch tube W+ and the third lower bridge arm switch tube W- is connected to one end of the equivalent inductance of the third phase winding; one end of the equivalent resistance of the three-phase winding is connected together; that is, the three-phase winding of the first motor is star-connected. It can be understood that in some other embodiments, the first inverter module can include two bridge arms for four switch tubes, and the structure of the first inverter module can be selected according to the actual application scenario.

[0034] In the power supply device provided in some embodiments of the present invention, the target switch tube includes one of the following situations: Case 1: the target switch tube includes a first upper bridge arm switch tube U+ of the first bridge arm and a second lower bridge arm switch tube V- of the second bridge arm; Case 2: the target switch tube includes the first upper bridge arm switch tube U+ of the first bridge arm, the second lower bridge arm switch tube V- of the second bridge arm, and the third lower bridge arm switch tube W- of the third bridge arm; Case 3: The target switch tube includes a first upper bridge arm switch tube U+ of the first bridge arm, a second upper bridge arm switch tube V+ of the second bridge arm, and a third lower bridge arm switch tube W- of the third bridge arm.

[0035] It is understood that the equivalent situation of the discharge circuit corresponding to the first situation is referred to Figure 4 As shown; the equivalent situation of the discharge circuit corresponding to case 2 is shown in Figure 5 As shown; the equivalent situation of the discharge circuit corresponding to case 3 is shown in Figure 6 Specifically, Figure 6Taking the case of as an example, it can be seen that after the charge stored on the input filter capacitor C1 passes through the rectifier module, it is input together with the charge stored on the second capacitor C2 of the boost module to each upper bridge arm switch tube (the first upper bridge arm switch tube U+ of the first bridge arm and the second upper bridge arm switch tube V+ of the second bridge arm) that is turned on in the first inverter module, and then enters the corresponding phase winding in the first motor, and finally returns through each lower bridge arm switch tube (the third lower bridge arm switch tube W- of the third bridge arm) that is turned on in the first inverter module, forming a loop consumption, so that the residual charge in the input filter capacitor C1 and the second capacitor C2 can be quickly released. It is worth noting that when the AC power supply end of the power supply device is in a power-off state, the discharge circuit constructed for the input filter capacitor C1 does not introduce additional electronic devices, but makes full use of the existing circuit structure of the power supply device to construct it, thereby avoiding the electric control loss caused by the additionally introduced hardware and reducing the cost.

[0036] It should also be noted that, since the three-phase windings in the first inverter module are equivalent and can be replaced with each other, the target switch tube in situation one includes the first upper bridge arm switch tube U+ of the first bridge arm and the second lower bridge arm switch tube V- of the second bridge arm, which can be equivalent to the situation where the target switch tube includes the second upper bridge arm switch tube V+ of the second bridge arm and the third lower bridge arm switch tube W- of the third bridge arm, and can also be equivalent to the situation where the target switch tube includes the third upper bridge arm switch tube W+ of the third bridge arm and the first lower bridge arm switch tube U- of the first bridge arm; Similarly, the target switch tube in the second situation includes the first upper bridge arm switch tube U+ of the first bridge arm, the second lower bridge arm switch tube V- of the second bridge arm, and the third lower bridge arm switch tube W- of the third bridge arm, which can be equivalent to the situation that the target switch tube includes the second upper bridge arm switch tube V+ of the second bridge arm, the third lower bridge arm switch tube W- of the third bridge arm, and the first lower bridge arm switch tube U- of the first bridge arm, and can also be equivalent to the situation that the target switch tube includes the third upper bridge arm switch tube W+ of the third bridge arm, the first lower bridge arm switch tube U- of the first bridge arm, and the second lower bridge arm switch tube V- of the second bridge arm; Similarly, the target switch tube in situation three includes the first upper bridge arm switch tube U+ of the first bridge arm, the second upper bridge arm switch tube V+ of the second bridge arm, and the third lower bridge arm switch tube W- of the third bridge arm, which can be equivalent to the situation that the target switch tube includes the second upper bridge arm switch tube V+ of the second bridge arm, the third upper bridge arm switch tube W+ of the third bridge arm, and the first lower bridge arm switch tube U- of the first bridge arm, and can also be equivalent to the situation that the target switch tube includes the third upper bridge arm switch tube W+ of the third bridge arm, the first upper bridge arm switch tube U+ of the first bridge arm, and the second lower bridge arm switch tube V- of the second bridge arm.

[0037] Reference Figure 7In the power supply device provided in some embodiments of the present invention, the power supply circuit further includes a second inverter module for supplying power to the second motor, and the second inverter module is connected in parallel with the first inverter module; The control module is also configured to: At least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the second inverter module are determined as target switch tubes. It is understandable that various conduction conditions of the switch tubes in the second inverter module can refer to various conduction conditions of the switch tubes in the first inverter module, and will not be repeated here. Figure 8 for Figure 7 The switch tubes in the first inverter module and the second inverter module in the power supply device shown correspond to the equivalent conditions of the discharge circuit in the above-mentioned situation three. It should be noted that the conduction conditions of the switch tubes in the first inverter module and the second inverter module do not need to be limited to be the same, and can be any one of the various conduction conditions mentioned above. It can be understood that in the case where the power supply device is also provided with a plurality of inverter modules for supplying power to different loads, in order to improve the discharge efficiency, a plurality of inverter modules can be introduced into the discharge circuit, so that the discharge circuit is connected to a plurality of motor windings, so that the phase windings of a plurality of motors participate in the discharge process together, thereby realizing a more efficient and rapid discharge process. For example, referring to Figure 8 As shown, on the basis of the discharge circuit in which only a single motor participates, the existing load of the additional power supply device is connected to the discharge circuit to participate in the discharge together, thereby increasing the discharge speed.

[0038] In the power supply device provided in some embodiments of the present invention, the control module is further configured to: While sending the first drive signal to the target switch tube, the switch device is controlled to be disconnected. Figure 1 , Figure 2 or Figure 7 Relay RY1 in is disconnected.

[0039] It can be understood that when the relay RY1 is turned on, the relay RY1 is equivalent to short-circuiting the two ends of the PTC resistor R1, and the PTC resistor R1 is not connected to the discharge circuit. Figure 4 , Figure 5 , Figure 6 as well as Figure 8 As shown; when the relay RY1 is disconnected, the PTC resistor R1 is connected to the discharge circuit, corresponding to Figure 4 Equivalent diagram reference Fig. 9 As shown, corresponding to Figure 5 , Figure 6 as well as Figure 8 The equivalent diagram of can be obtained in the same way.

[0040] In addition, refer to Figure 1 , Figure 2 and Figure 7In the power supply device provided in some embodiments of the present invention, the power supply device also includes an input voltage detection unit for detecting the input voltage of the AC power supply end. The input voltage detection unit may include a sixth resistor R6, one end of the sixth resistor R6 is connected to the connection point between the rectifier module and the first inductor L1, and the other end of the sixth resistor R6 is connected to the control module. The control module can detect the voltage output by the rectifier module to the boost module through the sixth resistor R6; since the main function of the rectifier module is to convert the AC power connected to the AC power supply end into a DC power supply, and the rear modules of the power supply device all rely on the rectifier module for power supply, the voltage output by the rectifier module can represent the input voltage of the power supply device at the AC power supply end. At this time, if it is detected that the voltage output by the rectifier module to the boost module continues to decrease for a period of time, it can be considered that the AC power supply end is in a power-off state, that is, the power supply device is unplugged, and then the first inverter module can be immediately driven to make the turned-on inverter bridge arm switch tube, the input filter capacitor C1 and the phase winding of the first motor form a discharge circuit.

[0041] Continue to refer to Figure 1 , Figure 2 and Figure 7 The power supply device also includes a bus voltage detection unit for detecting the bus voltage. The bus voltage detection unit may include a seventh resistor R7. One end of the seventh resistor R7 is connected to the connection point between the cathode of the first diode FRD and the first inverter module. The other end of the seventh resistor R7 is connected to the control module. The control module can detect the output bus voltage of the boost module through the seventh resistor R7. Since the bus voltage is the voltage transmitted to the inverter module after rectification and boosting, the bus voltage is affected by the voltage level transmitted by the front-end circuit. Therefore, the bus voltage can reflect the input voltage of the AC power supply end, that is, the voltage between the zero and live wires of the plug. Therefore, if it is detected that the bus voltage continues to decrease for a period of time, it can be confirmed that the AC power supply end is in a power-off state, and then the first inverter module can be immediately driven to make the turned-on inverter bridge arm switch tube, the input filter capacitor C1 and the phase winding of the first motor form a discharge circuit.

[0042] Continue to refer to Figure 1 , Figure 2 and Figure 7 The control module is also connected to one end of the sampling resistor R2, and the control module can detect the loop current of the discharge loop through the sampling resistor R2. In addition, it should be noted that in addition to the current sampling function, the sampling resistor R2 can also be connected to the discharge loop to participate in the discharge.

[0043] In addition, refer to Figure 1 and Figure 2In the power-on stage of the power supply device, the PTC resistor R1 can be connected between the input filter capacitor C1 and the boost module to prevent the second capacitor C2 in the boost module from being impacted by surge current; when the power supply device is in the power-off state, the PTC resistor R1 can also be connected between the input filter capacitor C1 and the boost module, which is connected to the discharge circuit. Fig. 9 From the equivalent schematic diagram of the discharge circuit shown in the figure, it can be seen that a PTC resistor R1 is introduced between the input filter capacitor C1 and the second capacitor C2 of the boost module. At this time, the input filter capacitor C1, the PTC resistor R1, the rectifier module, the second capacitor C2, the bridge arm switch tube turned on in the first inverter module and the phase winding of the first motor constitute a discharge circuit. The charge stored on the input filter capacitor C1 passes through the PTC resistor R1 and the rectifier module in sequence, and is input into the bridge arm switch tube turned on in the first inverter module together with the charge stored on the second capacitor C2 of the boost module, and then enters the corresponding phase winding in the first motor to form a circuit consumption. At this time, the PTC resistor R1 and the phase winding of the first motor jointly consume the electric energy stored in the discharge circuit, thereby improving the discharge efficiency. When the power supply device is in the normal power supply stage, the PTC resistor R1 is bypassed through the first switch device RY1, thereby effectively reducing the electric control loss, realizing the reuse of the PTC resistor R1, and improving the system energy efficiency.

[0044] In the power supply device provided in some embodiments of the present invention, the first drive signal is a pulse drive signal with a first duty cycle, the first duty cycle is less than or equal to an upper limit value of the duty cycle, and the upper limit value of the duty cycle is determined based on the minimum value of the maximum allowable current of the target switch tube, the maximum allowable current of the phase winding of the target switch tube, and the maximum allowable current of the sampling resistor R2.

[0045] In this embodiment, the first drive signal is a pulse drive signal of a first duty cycle, that is, the target switch tubes in the first inverter module and the second inverter module are controlled by the duty cycle control method, so as to realize the control of the loop current in the discharge loop and avoid the loop current exceeding the limit. Specifically, the minimum value among the maximum allowable current of the target switch tube, the maximum allowable current of the phase winding of the target switch tube, and the maximum allowable current of the sampling resistor is recorded as the maximum allowable loop current Imax; the derating factor γ can be set to reserve a certain safety space, 0<γ≤1, and the maximum loop current ILmax corresponding to the duty cycle upper limit value Dutymax is the product of the maximum allowable loop current Imax and the derating factor γ, that is, ILmax=γ*Imax; therefore, in the process of the control module outputting the first drive signal, it is necessary to control the first duty cycle of the pulse drive signal so that the loop current IL of the discharge loop collected by the sampling resistor R2 does not exceed the maximum loop current ILmax corresponding to the duty cycle upper limit value Dutymax.

[0046] In the power supply device provided in some embodiments of the present invention, the power supply device further includes an input voltage detection unit for detecting an input voltage of an AC power supply end, and the control module is further configured as follows: Acquire input voltages at multiple sampling moments within a first preset time period; The input voltage at each sampling moment is lower than the input voltage at the previous sampling moment, and it is determined that the input voltage at the AC power supply end continues to decrease.

[0047] It can be understood that by obtaining the input voltage at the AC power supply end through the input voltage detection unit, it can be determined whether the power supply circuit is unplugged. Specifically, if the input voltage shows a continuous downward trend within the first preset time period, it can be determined that the AC power supply end is in a power-off state, that is, the power supply device is unplugged. Among them, the input voltage can be continuously sampled, and the input voltage sampled each time within the first preset time period can be arranged in chronological order to form time series data. Then, the time series data of the input voltage within the first preset time period can be fitted by a linear regression method to obtain the slope of the input voltage changing with time within the first preset time period. If the slope obtained by fitting is less than zero and the absolute value of the slope is greater than a certain threshold, it can be indicated that the downward trend of the input voltage is significant, confirming that the input voltage shows a continuous downward trend within the first preset time period.

[0048] In addition, the input voltage sampled each time within the first preset time period can be traversed, and the input voltages of adjacent sampling points (sampling moments) can be compared. If the input voltage of each sampling point is less than the input voltage of the previous sampling point in a preset proportion (such as more than 90%) of adjacent sampling points, then it can be determined that the input voltage shows a continuous downward trend within the first preset time period. According to actual needs and application scenarios, a voltage change threshold can be introduced in the comparison process of the input voltages at adjacent sampling moments. For each pair of adjacent sampling points in the time series data, the voltage change between them is calculated, that is, the voltage difference between the input voltages at two adjacent sampling moments. If the voltage change is less than the preset voltage difference threshold and is negative in a preset proportion (such as more than 90%) of adjacent sampling points, then it can be determined that the input voltage shows a continuous downward trend within the first preset time period.

[0049] In the power supply device provided in some embodiments of the present invention, the control module is further configured to: stop sending the first drive signal when the input voltage is less than a first safety voltage threshold.

[0050] In the power supply device provided in some embodiments of the present invention, a bus voltage detection unit for detecting the bus voltage is provided on the output side of the boost module, and the control module is further configured as follows: The bus voltage is obtained, and when the bus voltage is less than a second safety voltage threshold, the first drive signal is stopped.

[0051] It can be understood that when the AC power supply end is in a power-off state, the electric energy stored in the input filter capacitor C1 will be released in an attempt to maintain the voltage of the circuit. At this time, the input voltage of the power supply circuit is provided by the input filter capacitor C1. Therefore, a discharge loop is constructed to release the electric energy of the input filter capacitor C1 to quickly reduce the input voltage of the power supply circuit, that is, reduce the voltage between the zero and live wires of the plug. Therefore, when it is detected that the input voltage is lower than the first safety voltage threshold or the bus voltage is lower than the second safety voltage threshold, it can be considered that the safety requirements have been met, thereby stopping sending the first drive signal, completing the entire discharge process of the input filter capacitor C1, and resetting the first inverter module to avoid the inability to reset the first inverter module after the control module is completely powered off, which causes an impact on the first inverter module when the power supply circuit is powered on again.

[0052] In a second aspect, an embodiment of the present invention provides an air conditioner, comprising the power supply device of the embodiment of the first aspect above.

[0053] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed methods above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium or a non-transitory medium and a communication medium or a temporary medium. As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk DVD or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0054] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A power supply device, characterized in that: include: Power supply circuit and control module; The power supply circuit comprises an AC power supply terminal, an input filter capacitor, a rectifier module and a first inverter module for supplying power to the first motor, which are connected in sequence; The control module is configured to: In response to the input voltage at the AC power supply end continuously decreasing, determining at least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the first inverter module as target switch tubes; A first driving signal is sent to the target switch tube, so that the input filter capacitor, the rectifier module, the target switch tube and the phase winding of the first motor corresponding to the target switch tube form a discharge loop.

2. The power supply device according to claim 1, characterized in that: The power supply circuit further includes a second inverter module for supplying power to the second motor, the second inverter module being connected in parallel with the first inverter module; The control module is further configured to: At least one upper bridge arm switch tube and at least one lower bridge arm switch tube in the second inverter module are determined as target switch tubes.

3. The power supply device according to claim 1, characterized in that: The first inverter module includes a first bridge arm, a second bridge arm and a third bridge arm, and the target switch tube includes one of the following situations: A first upper bridge arm switch tube of the first bridge arm and a second lower bridge arm switch tube of the second bridge arm; A first upper bridge arm switch tube of the first bridge arm, a second lower bridge arm switch tube of the second bridge arm, and a third lower bridge arm switch tube of the third bridge arm; a first upper bridge arm switch tube of the first bridge arm, a second upper bridge arm switch tube of the second bridge arm, and a third lower bridge arm switch tube of the third bridge arm.

4. The power supply device according to claim 1, characterized in that: The power supply circuit further comprises a power-on buffer module arranged between the input filter capacitor and the rectifier module, and the power-on buffer module comprises a PTC resistor and a switch device connected in parallel.

5. The power supply circuit according to claim 1, characterized in that: The power supply circuit further includes a power-on buffer module disposed between the rectifier module and the first inverter module, and the power-on buffer module includes a PTC resistor and a switch device connected in parallel.

6. The power supply device according to claim 4 or 5, characterized in that: The control module is further configured to: While sending the first driving signal to the target switch tube, the switch device is controlled to be disconnected.

7. The power supply device according to claim 6, characterized in that: The power supply circuit also includes a sampling resistor and a boost module arranged between the rectifier module and the first inverter module. The boost module includes a first inductor, a first switch tube, a first diode and a second capacitor. One end of the first inductor is connected to the rectifier module, the other end of the first inductor is connected to a switch pin of the first switch tube and the anode of the first diode, the cathode of the first diode is connected to one end of the second capacitor and the first inverter module, the other switch pin of the first switch tube is connected to one end of the sampling resistor, the other end of the second capacitor and the first inverter module, and the other end of the sampling resistor is connected to the rectifier module.

8. The power supply device according to claim 7, characterized in that: The first drive signal is a pulse drive signal of a first duty cycle, the first duty cycle is less than or equal to an upper limit value of the duty cycle, and the upper limit value of the duty cycle is determined according to the minimum value of the maximum allowable current of the target switch tube, the maximum allowable current of the phase winding of the target switch tube, and the maximum allowable current of the sampling resistor.

9. The power supply device according to claim 1, characterized in that: The power supply device further includes an input voltage detection unit for detecting an input voltage of the AC power supply end, and the control module is further configured as follows: Acquire the input voltage at multiple sampling moments within a first preset time length; The input voltage at each sampling moment is smaller than the input voltage at the previous sampling moment, and it is determined that the input voltage at the AC power supply end continues to decrease.

10. The power supply device according to claim 9, characterized in that: The control module is further configured to stop sending the first driving signal when the input voltage is less than a first safety voltage threshold.

11. The power supply device according to claim 7, characterized in that: The output side of the boost module is provided with a bus voltage detection unit for detecting the bus voltage, and the control module is further configured as follows: The bus voltage is obtained, and when the bus voltage is less than a second safety voltage threshold, the first drive signal is stopped.

12. An air conditioner, characterized in that: Comprising the power supply device according to any one of claims 1 to 11.

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