Power supply circuit, multi-phase filter circuit and temperature control equipment

Abstract

The invention provides a power supply circuit, a multi-phase filter circuit and temperature control equipment, and belongs to the technical field of power sources. According to the power supply circuit, a Y capacitor is connected between a working zero line connecting line and a grounding line connecting line in a bridging mode, and when multi-phase unbalanced current occurs, the Y capacitor is connected with the Y capacitor in a bridging mode; the current in the working zero line connecting line can flow back to the neutral point of the multi-phase transformer in the multi-phase power supply through the Y capacitor, so that the leakage protector connected with the front end of the power supply circuit can detect the working zero line current. Therefore, the power supply circuit provided by the invention can effectively reduce or avoid the false tripping of the leakage protector, reduces the leakage current of the whole load equipment, and improves the power utilization safety of the equipment.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to a power supply circuit, a multi-phase filter circuit and a temperature control device. Background Art

[0002] Most of the power of refrigeration equipment, air conditioners and other equipment comes from three-phase motor loads such as compressors, fans, and water pumps. For these three-phase loads, the working neutral line (N line) is usually not used by the load. However, in the power supply circuit of the three-phase load, due to the imbalance of the three-phase voltage or the imbalance of the three-phase load design, current will appear in the N line, and the three-phase load is not connected to the N line. The leakage protector (residual current protector) configured at the input end of the equipment may be unable to detect the N line current caused by the imbalance of the three-phase load, and it is easy to malfunction, causing the equipment to leak current, which is not conducive to the safe use of the equipment. Summary of the invention

[0003] In order to solve the existing technical problems, the present application provides a power supply circuit, a multi-phase filter circuit and a temperature control device that can effectively reduce the leakage current of the equipment.

[0004] According to a first aspect of an embodiment of the present application, there is provided a power supply circuit, comprising a multi-phase live wire connection line, a working neutral wire connection line, a Y capacitor and a ground wire connection line;

[0005] The multi-phase live wire connection line is used to receive multi-phase alternating current to supply power to a multi-phase load, and the multi-phase load is electrically connected to at least two phase live wire connection lines of the multi-phase live wire connection lines; wherein the multi-phase alternating current is output by a multi-phase alternating current power supply and input to the multi-phase live wire connection line via a leakage protector;

[0006] The working neutral line connecting line is connected to the working neutral line output terminal of the leakage protector;

[0007] The first end of the Y capacitor is connected to the working neutral line connection line, the second end of the Y capacitor is connected to the ground line connection line, and the ground line connection line is connected to the ground line of the multi-phase AC power supply.

[0008] Optionally, the power supply circuit further includes a multi-phase filter circuit, and the multi-phase filter circuit includes a common-mode inductor and a plurality of X capacitors;

[0009] The inductor coils of the common mode inductor are respectively arranged on each phase live line of the multi-phase live line and the working neutral line, the first end of each capacitor of the plurality of X capacitors is respectively connected to the corresponding phase live line of the multi-phase live line, and the second end of each capacitor of the plurality of X capacitors is respectively connected to the working neutral line.

[0010] Optionally, the plurality of X capacitors include a first group of X capacitors and a second group of X capacitors;

[0011] The first end of each capacitor in the first group of X capacitors is respectively connected to the input end of each corresponding inductor coil in the common mode inductor, and the first end of each capacitor in the second group of X capacitors is respectively connected to the output end of each corresponding inductor coil in the common mode inductor.

[0012] Optionally, the multi-phase filtering circuit further includes a plurality of filtering resistors;

[0013] The first end of each resistor in the multiple filter resistors is respectively connected to the output end of each corresponding inductor coil in the common mode inductor, and the second end of each resistor in the multiple filter resistors is respectively connected to the working neutral line connection line.

[0014] Optionally, the multi-phase filter circuit and the Y capacitor are integrated in a filter housing.

[0015] Optionally, the power supply circuit further comprises a drive control circuit connected to the multi-phase live wire connection line, the drive control circuit being used to input the multi-phase alternating current into the multi-phase load and / or convert the three-phase alternating current into a corresponding drive voltage and then input it into the multi-phase load;

[0016] The drive control circuit comprises a frequency converter, the input end of the frequency converter is connected to the multi-phase live wire connection line, and the output end of the frequency converter is connected to the first type of load in the multi-phase load; and / or;

[0017] The drive control circuit comprises an AC contactor, a first end of the AC contactor is connected to the multi-phase live wire connecting line, and a second end of the AC contactor is connected to a second type of load in the multi-phase load.

[0018] Optionally, the first type of load includes a compressor, a water pump and a fan, the frequency converter includes a first frequency converter, a second frequency converter and a third frequency converter, the input ends of the first frequency converter, the second frequency converter and the third frequency converter are respectively connected to the multi-phase live wire connection line, and the output ends of the first frequency converter, the second frequency converter and the third frequency converter are respectively connected to the compressor, the water pump and the fan; and / or,

[0019] The second type of load is a heater.

[0020] Optionally, the power supply circuit further includes a transformer and a first AC / DC converter, the primary winding of the transformer is connected between two-phase live wires in the multi-phase live wire connection line, and the secondary winding of the transformer is connected to the input end of the first AC / DC converter; and / or,

[0021] A second AC / DC converter is also included, wherein an input end of the second AC / DC converter is connected to the multi-phase live wire connection line to receive the multi-phase alternating current.

[0022] According to a second aspect of an embodiment of the present application, there is provided a multi-phase filter, comprising a multi-phase live wire connection line, a working neutral wire connection line, a ground wire connection line, a filter circuit and a Y capacitor;

[0023] The filter circuit comprises a common mode inductor and a plurality of X capacitors, wherein each inductor coil of the common mode inductor is respectively arranged on each phase live line of the multi-phase live line connection line and the working neutral line connection line, a first end of each capacitor of the plurality of X capacitors is respectively connected to a corresponding phase live line of the multi-phase live line connection line, and a second end of each capacitor of the plurality of X capacitors is respectively connected to the working neutral line connection line;

[0024] The first end of the Y capacitor is connected to the working neutral line connection line, and the second end of the Y capacitor is connected to the ground line connection line.

[0025] According to a third aspect of an embodiment of the present application, a temperature control device is provided, comprising a multi-phase load and any one of the power supply circuits described above, wherein the power supply circuit is connected to the multi-phase load and is used to supply power to the multi-phase load;

[0026] The multi-phase load includes at least one of a compressor, a water pump and a fan.

[0027] As can be seen from the above, the power supply circuit provided in the embodiment of the present application is connected by a Y capacitor across the working neutral line connection line and the ground line connection line. When a multi-phase unbalanced current occurs, the current in the working neutral line connection line can flow back to the neutral point of the multi-phase transformer in the multi-phase power supply through the Y capacitor, so that the leakage protector connected to the front end of the power supply circuit can detect the working neutral line current. Therefore, the power supply circuit provided in the embodiment of the present application can effectively reduce or avoid the false tripping of the leakage protector, reduce the leakage current of the load device, and improve the power safety of the equipment. The multi-phase filter circuit and temperature control device provided in the embodiment of the present application can achieve the same effect as the power supply circuit provided in the embodiment of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings:

[0029] Figure 1 A schematic diagram of the structure of a power supply circuit provided according to some embodiments of the present application;

[0030] Figure 2A schematic diagram of the structure of a multi-phase filter circuit in a power supply circuit provided according to some embodiments of the present application;

[0031] Figure 3 A schematic diagram of a power supply circuit according to other embodiments of the present application;

[0032] Figure 4 A schematic diagram of the structure of a polyphase filter provided in some embodiments of the present application.

[0033] Figures 1 to 4 The corresponding relationship between the reference numerals and the component names is as follows:

[0034] 01-multi-phase AC power supply; 1-leakage protector; 2-power supply circuit; 3-first type load; 4-second type load; 11-leakage protection switch; 12-current transformer; 21-multi-phase filter circuit; 22-circuit breaker; 23-frequency converter; 24-AC contactor; 25-first AC / DC converter; 26-second AC / DC converter; 27-first connector; 28-second connector; 231-first frequency converter; 232-second frequency converter; 233-third frequency converter; 31-compressor; 32-water pump; 33-fan; 21`-filter housing;

[0035] La-first phase live wire; Lb-second phase live wire; Lc-third phase live wire; LN-working neutral wire; LPE-ground wire; La`-first phase live wire connection wire; Lb`-second phase live wire connection wire; Lc`-third phase live wire connection wire; LN`-working neutral wire connection wire; LG ground wire connection wire; PLa-first phase filter input terminal; PLb-second phase filter input terminal; PLc-third phase filter input terminal; PLN-neutral line filter input terminal; P la`-first phase filter output terminal; PLb`-second phase filter output terminal; PLc`-third phase filter output terminal; PLN`-neutral line filter output terminal; G-first ground terminal; G`-second ground terminal;

[0036] TR-transformer; Cy-Y capacitor; Cy1-first Y capacitor; Cy2-second Y capacitor; L1-first common mode inductor, L2-second common mode inductor; Cx11-first X capacitor; Cx12-second X capacitor; Cx13-third X capacitor; Cx21-fourth X capacitor; Cx22-fifth X capacitor; Cx23-sixth X capacitor; Cx31-seventh X capacitor; Cx32-eighth X capacitor; Cx33-ninth X capacitor; R1-first filter resistor; R2-second filter resistor; R3-third filter resistor. DETAILED DESCRIPTION

[0037] The technical solution of the present application is further elaborated in detail below in conjunction with the accompanying drawings and specific embodiments of the specification.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit the implementation of this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] In the description of this application, unless otherwise specified, "plurality" means two or more than two. In addition, in the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] Based on the problem that the three-phase load in the temperature control device is not connected to the working neutral line, which easily causes leakage current in the temperature control device, an existing solution is to rely on switch designs such as relays to separate the Y capacitor in the power supply circuit of the temperature control device from the ground, so as to achieve the purpose of reducing the leakage current of the unit. However, the inventors of the present application found in the process of research that this existing solution can only reduce the leakage current when the compressor of the temperature control device is not turned on or the device is not running, and the operation of the device is easily affected by internal conduction disturbances, resulting in functional degradation and abnormality. To this end, the present application provides a power supply circuit that can effectively reduce the leakage current of the device during the operation of the device, and while reducing the leakage current, it will not cause the decline and abnormality of the operating function of the device. The power supply circuit provided in the embodiment of the present application is used to supply power to a multi-phase load, wherein the multi-phase load can be but is not limited to a three-phase load, such as a compressor, a water pump and / or a fan in a temperature control device.

[0041] See also Figure 1As shown, it is a schematic diagram of the structure of the power supply circuit provided according to some embodiments of the present application. A leakage protector 1 is provided between the power supply circuit 2 provided in some embodiments of the present application and the multi-phase AC power supply 01, and the multi-phase AC power supply 01 has a multi-phase live wire, and each phase live wire in the multi-phase live wire is used to output one-phase AC power. The multi-phase AC power supply 01 can be a three-phase AC power supply, and can be specifically a three-phase five-wire AC power supply. The three-phase five-wire AC power supply includes a three-phase five-wire AC transformer and a three-phase live wire, a working neutral wire LN and a ground wire LPE drawn from the three-phase five-wire AC transformer. Among them, the three-phase live wires are respectively a first-phase live wire La, a second-phase live wire Lb and a third-phase live wire Lc. When the multi-phase AC power supply 01 is a three-phase five-wire AC power supply, the multi-phase live wire connection line of the power supply circuit 2 includes a first-phase live wire connection line La` connected to the first-phase live wire La, a second-phase live wire connection line Lb` connected to the second-phase live wire Lb, and a third-phase live wire connection line Lc` connected to the third-phase live wire Lc. The input end of the leakage protector 1 includes a multi-phase live wire input end and a working neutral wire input end, and the output end of the leakage protector 1 includes a multi-phase live wire output end and a working neutral wire output end. The multi-phase live wire input end of the leakage protector 1 is used to be connected to the multi-phase live wire of the multi-phase AC power supply 01, and the neutral wire input end of the leakage protector 1 is connected to the working neutral wire end of the multi-phase AC power 01. The multi-phase live wire output end of the leakage protector 1 is connected to the multi-phase live wire connection line of the power supply circuit 2, and the neutral wire output end of the leakage protector 1 is connected to the working neutral wire connection line of the power supply circuit 2. A leakage protection switch 11 and a current transformer 12 are connected between the input end and the output end of the leakage protector 1. The leakage protector 1 detects the current difference between the multi-phase live wire connection line and the working neutral wire connection line based on the current transformer 12. When the current difference exceeds a preset value, the leakage protection switch 11 is disconnected to perform leakage protection.

[0042] The power supply circuit 2 also includes a Y capacitor Cy and a grounding line connection line LG, and the grounding line connection line LG is connected to the grounding line LPE of the multi-phase AC power supply 01. Specifically, the power supply circuit 2 also includes a first connector 27, and the working neutral line connection line LN' is connected to the neutral line output end of the leakage protector 1 through the first connector 27. The first end of the Y capacitor Cy is connected to the working neutral line connection line LN', and the second end is connected to the grounding line connection line LG. Specifically, the power supply circuit 2 also includes a second connector 28, and the grounding line connection line LG is connected to the grounding line LPE of the multi-phase AC power supply 01 through the second connector 28.

[0043] The multi-phase live wire connection line in the power supply circuit 2 is used to receive the multi-phase alternating current output by the multi-phase alternating current power supply 01 to supply power to the multi-phase load. The multi-phase load is electrically connected to at least two phase live wire connection lines in the multi-phase live wire connection line, and the multi-phase load is in a disconnected state from the working neutral line connection line LN`, that is, the working neutral line connection line LN` is not connected to the multi-phase load. The multi-phase alternating current received by the multi-phase live wire connection line is output by the multi-phase alternating current power supply 01 and input to the multi-phase live wire connection line via the leakage protector 1. It should be noted that in some embodiments, the Y capacitor Cy may include a plurality of capacitors connected in parallel between the working neutral line connection line LN` and the grounding line connection line LG, which will be described in detail in the embodiments described later.

[0044] As can be seen from the above, the power supply circuit 2 provided in the embodiment of the present application connects a Y capacitor across the working neutral line connection line LN' and the ground line connection line LG. When there is a multi-phase unbalanced current caused by factors such as unbalanced multi-phase loads, the current in the working neutral line connection line LN' can flow back to the neutral point of the multi-phase transformer in the multi-phase power supply through the Y capacitor, so that the leakage protector 1 can detect the working neutral line current. Therefore, when the power supply circuit 2 provided in the embodiment of the present application supplies power to a multi-phase unbalanced load, it can effectively reduce or avoid the false tripping of the leakage protector 1, reduce the leakage current of the entire load equipment, and improve the power safety of the equipment.

[0045] Please continue reading Figure 1 As shown, in some embodiments, the power supply circuit 2 further includes a multi-phase filter circuit 21, wherein the circuit structure diagram of the multi-phase filter circuit 21 is as shown in FIG. Figure 2 As shown. The multi-phase filter circuit 21 is arranged on the multi-phase live wire connection line and the working neutral wire connection line, and includes a common mode inductor and a plurality of X capacitors. Specifically, each inductor coil of the common mode inductor is respectively arranged on each phase live wire connection line in the multi-phase live wire connection line and the working neutral wire connection line LN', the first end of each capacitor in the plurality of X capacitors is respectively connected to the corresponding phase live wire in the multi-phase live wire connection line, and the second end of each capacitor in the plurality of X capacitors is respectively connected to the working neutral wire connection line LN'. The multi-phase filter circuit 21 is used for filtering the power supply circuit of the multi-power supply circuit 2 to improve the power supply stability.

[0046] The input end of the multiphase filter circuit 21 includes a multiphase filter input end and a zero line filter input end PLN, the output end of the multiphase filter circuit 21 includes a multiphase filter output end and a zero line filter output end PLN', the multiphase filter input end is connected to the multiphase live wire correspondingly, the zero line filter input end PLN is connected to the working zero line LN, and the multiphase filter output end is connected to the multiphase load or to the driving circuit of the multiphase load. If the multiphase filter circuit 21 is a three-phase filter circuit, the multiphase filter input end includes a first phase filter input end PLa connected to the first phase live wire La, a second phase filter input end PLb connected to the second phase live wire Lb, and a third phase filter input end PLc connected to the third phase live wire Lc; the multiphase filter output end includes a first phase filter output end Pla', a second phase filter output end PLb' connected to the second phase live wire Lb, and a third phase filter output end PLc' connected to the third phase live wire Lc.

[0047] Specifically, in some embodiments, the power supply circuit 2 provided in the embodiment of the present application is used to supply power to a three-phase load, wherein the three-phase load may be a three-phase unbalanced load, and the three-phase load is not provided with a working neutral line access terminal, that is, the three-phase load is not electrically connected to the working neutral line connection line LN'. The multi-phase filter circuit 21 is specifically a three-phase filter circuit, and its common-mode inductance may include but is not limited to Figure 2 The first common mode inductor L1 and the second common mode inductor L2 are shown. In other embodiments, the multi-phase filter circuit 21 may include only one common mode inductor or a plurality of common mode inductors, wherein the plurality of common mode inductors are connected in series between the multi-phase live wire connection line and the working neutral wire connection line LN'.

[0048] Continue reading Figure 2 As shown, the multiple X capacitors of the multi-phase filter circuit 21 include a first group of X capacitors and a second group of X capacitors. The first end of each capacitor in the first group of X capacitors is respectively connected to the input end of each corresponding inductor coil in the common mode inductor, and the first end of each capacitor in the second group of X capacitors is respectively connected to the output end of each corresponding inductor coil in the common mode inductor. The second group of X capacitors connected to the output end of the first common mode inductor L1 is equivalent to the first group of capacitors connected to the input end of the second common mode inductor L2, that is, each common mode inductor has a group of X capacitors at its input and output ends. The multi-phase filter circuit 21 takes a three-phase filter circuit as an example. The first group of X capacitors connected to the input end of the first common-mode inductor L1 includes a first X capacitor Cx11, a second X capacitor Cx12 and a third X capacitor C13. The second group of X capacitors connected to the output end of the first common-mode inductor L1 includes a fourth X capacitor Cx21, a fifth X capacitor Cx22 and a sixth X capacitor C23. The third group of X capacitors connected to the output end of the second common-mode inductor L2 includes a seventh X capacitor Cx31, an eighth X capacitor Cx32 and a ninth X capacitor C33.

[0049] Furthermore, in some embodiments, the Y capacitor Cy further includes a first Y capacitor Cy1 connected between the first common-mode inductor L1 and the second common-mode inductor L2 and a second Y capacitor Cy2 connected to the output end of the second common-mode inductor L2, and the first Y capacitor Cy1 and the second Y capacitor Cy2 are connected in parallel between the working neutral line connection line LN` and the ground line connection line LG.

[0050] Please continue reading Figure 2 As shown, the multi-phase filter circuit 21 also includes a plurality of filter resistors. The first end of each resistor in the plurality of filter resistors is respectively connected to the output end of each corresponding inductor coil in the common mode inductor, and the second end of each resistor in the plurality of filter resistors is respectively connected to the working zero line connection line LN'. Specifically, still taking the three-phase filter circuit as an example, the filter resistors include a first filter resistor R1, a second filter resistor R2 and a third filter resistor R3 connected to the output end of the first common mode inductor L1. The first common mode inductor L1 and the second common mode inductor L2 are connected in series, and each filter resistor is connected between the first common mode inductor L1 and the second common mode inductor L2 to cooperate with the second group of X capacitors to form a low-pass channel, which is conducive to increasing the filtering effect of the multi-phase filter circuit.

[0051] Please continue reading Figure 2 As shown, the power supply circuit 2 further includes a plurality of ground terminals, such as a first ground terminal G and a second ground terminal G', and the plurality of ground terminals are arranged on the ground wire connection line LG. Arranging a plurality of ground terminals is conducive to improving the stability and reliability of the power supply circuit.

[0052] See also Figure 3 As shown, it is a schematic diagram of the structure of the power supply circuit provided according to some other embodiments of the present application. In this embodiment, the multi-phase filter circuit 21 and the Y capacitor are integrated in the filter housing 21' to form a multi-phase filter with a working zero line. If the multi-phase filter circuit 21 is a three-phase filter circuit, the multi-phase filter circuit 21 and the Y capacitor are integrated in the filter housing 21' to form a multi-phase filter with a working zero line. Figure 4 The multi-phase five-wire filter shown in the figure integrates the multi-phase filter circuit 21 and the Y capacitor into one body, which facilitates the wiring of the power supply circuit 2.

[0053] Please continue reading Figure 1 and Figure 3 As shown, the power supply circuit 2 also includes a drive control circuit, which is connected between the multi-phase live wire connection line and the multi-phase load, and is used to control the multi-phase AC power on the multi-phase live wire connection line to power the multi-phase load. Specifically, the drive control circuit includes a frequency converter 23, the input end of the frequency converter 23 is connected to the multi-phase live wire connection line, and the output end of the frequency converter 23 is connected to the first type of load 3 in the multi-phase load. The first type of load 3 refers to a variable frequency three-phase load, such as a compressor, a fan and / or a water pump in a temperature control device.

[0054] In other embodiments, the power supply circuit 2 further includes a circuit breaker 22, which is disposed at the filter input end of the multi-phase filter circuit 21 and is used to disconnect the power supply circuit when an abnormality occurs in the power supply circuit of the multi-phase load to protect the multi-phase load.

[0055] Specifically, the power supply circuit 2 is used to supply power to the three-phase load in the temperature control device, and the frequency converter 23 includes a first frequency converter 231, a second frequency converter 232 and a third frequency converter 233. The first type of load 3 in the three-phase load of the temperature control device includes a compressor 31, a water pump 32 and a fan 33. The first frequency converter 231, the second frequency converter 232 and the third frequency converter 233 are respectively connected to the output end of the multi-phase filter circuit 21. The input ends of the first frequency converter 231, the second frequency converter 232 and the third frequency converter 233 are respectively connected to the three-phase live wire connection line, and the output ends of the first frequency converter 231, the second frequency converter 232 and the third frequency converter 233 are respectively connected to the compressor 31, the water pump 32 and the fan 33. Specifically, the second type of load in the three-phase load includes a heater 4, and the power supply circuit 2 also includes an AC contactor 24, which is connected between the three-phase live wire connection line and the heater.

[0056] Furthermore, the power supply circuit 2 further includes a transformer TR and a first AC / DC converter 25, wherein the primary winding of the transformer TR is connected between two phase live wires in the multi-phase live wire connection line, and the secondary winding of the transformer is connected to the input end of the first AC / DC converter 25. The transformer TR is used to transform the alternating current output from the multi-phase live wire connection line to the input end of the first AC / DC converter 25, so as to be converted by the first AC / DC converter 25 into a first direct current supply voltage output to supply power to a first power consumption unit in the temperature control device, such as a sensor in the temperature control device.

[0057] Furthermore, the power supply circuit 2 also includes a second AC / DC converter 26, the input end of the second AC / DC converter 26 is connected to the multi-phase live wire connection line to receive multi-phase alternating current and convert the multi-phase alternating current into a second DC power supply voltage output to power a second power unit in the temperature control device. The second power unit can be but is not limited to an MCU.

[0058] The following takes the power supply circuit 2 using a three-phase five-wire power supply as an example. Figure 1 or Figure 3 The power supply circuit 2 provided in some embodiments of the present application is further described in detail. The power supply circuit 2 provided in some embodiments of the present application is used to supply power to the three-phase load in the temperature control device. The temperature control device can be an air conditioner, and the three-phase load includes a compressor, a fan, a water pump and a heater. The multi-phase filter circuit 21 and the Y capacitor in the power supply circuit 2 are integrated into one, forming a Figure 4The three-phase five-wire filter shown in the figure can ensure that the three-phase balanced current of the temperature control device can flow in from the working neutral line filter input end of the three-phase five-wire filter for filtering, and flow back to the neutral point end of the front three-phase five-wire transformer (400V transformer) through the Y capacitor in the three-phase five-wire filter. Based on the residual current mutual inductance principle of the leakage protector, when I(N)+I(L)=0, the vector sum of the magnetic flux generated by I(N) and I(L) in the mutual inductor is 0, and the leakage protection will not be triggered at this time. I(N) is the current flowing through the working neutral line connection line LN`, and I(L) is the current flowing through the multi-phase live line connection line.

[0059] The power supply circuit 2 provided in some embodiments of the present application connects a customized three-phase five-wire filter in the power supply loop, and uses the Y capacitor of the working line connection line LN` line to the ground line connection line LG in the three-phase five-wire filter, so that the unbalanced current generated by the three-phase unbalanced load of the temperature control device flows back to the neutral point of the front-end transformer through the Y capacitor in the power supply circuit 2, thereby effectively reducing the leakage current of part of the temperature control device.

[0060] In some embodiments, the present application also provides a multi-phase filter, which includes a multi-phase live wire connection line, a working neutral wire connection line, a ground wire connection line, a filter circuit and a Y capacitor; the filter circuit includes a common mode inductor and a plurality of X capacitors, each inductor coil of the common mode inductor is respectively arranged on each phase live wire connection line and the working neutral wire connection line in the multi-phase live wire connection line, the first end of each capacitor in the plurality of X capacitors is respectively connected to the corresponding phase live wire in the multi-phase live wire connection line, and the second end of each capacitor in the plurality of X capacitors is respectively connected to the working neutral wire connection line. The first end of the Y capacitor is connected to the working neutral wire connection line, and the second end of the Y capacitor is connected to the ground wire connection line. The multi-phase filter provided in the embodiment of the present application is connected to the power supply circuit of the three-phase load, and can achieve the same technical effect as the power supply circuit provided in the embodiment of the present application, which will not be repeated here.

[0061] For details, please refer to Figure 4 As shown, it is a schematic diagram of the structure of a multi-phase filter provided in some embodiments of the present application. In some embodiments, the multi-phase filter provided in the present application is a three-phase five-wire filter. Figure 4 The structure of the polyphase filter shown has been described above and will not be repeated here.

[0062] In some embodiments, the present application further provides a temperature control device, which includes a multi-phase load and a power supply circuit 2 provided according to any embodiment of the present application, and the power supply circuit 2 is connected to the multi-phase load for supplying power to the multi-phase load. Among them, the multi-phase load of the temperature control device includes at least one of a compressor, a water pump and a fan, and the temperature control device can be an air conditioner. The temperature control device provided in the embodiment of the present application and the power supply circuit 2 provided in the embodiment of the present application can achieve the same technical effect, which will not be repeated here.

[0063] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power supply circuit, characterized in that: Including multi-phase live wire connection wire, working neutral wire connection wire, Y capacitor and ground wire connection wire; The multi-phase live wire connection line is used to receive multi-phase alternating current to supply power to a multi-phase load, and the multi-phase load is electrically connected to at least two phase live wire connection lines of the multi-phase live wire connection lines; wherein the multi-phase alternating current is output by a multi-phase alternating current power supply and input to the multi-phase live wire connection line via a leakage protector; The working neutral line connecting line is connected to the working neutral line output terminal of the leakage protector; The first end of the Y capacitor is connected to the working neutral line connection line, the second end of the Y capacitor is connected to the ground line connection line, and the ground line connection line is connected to the ground line of the multi-phase AC power supply.

2. The power supply circuit according to claim 1, characterized in that: Also included is a multi-phase filter circuit, wherein the multi-phase filter circuit includes a common mode inductor and a plurality of X capacitors; The inductor coils of the common mode inductor are respectively arranged on each phase live line of the multi-phase live line and the working neutral line, the first end of each capacitor of the plurality of X capacitors is respectively connected to the corresponding phase live line of the multi-phase live line, and the second end of each capacitor of the plurality of X capacitors is respectively connected to the working neutral line.

3. The power supply circuit according to claim 2, characterized in that: The plurality of X capacitors include a first group of X capacitors and a second group of X capacitors; The first end of each capacitor in the first group of X capacitors is respectively connected to the input end of each corresponding inductor coil in the common mode inductor, and the first end of each capacitor in the second group of X capacitors is respectively connected to the output end of each corresponding inductor coil in the common mode inductor.

4. The power supply circuit according to claim 3, characterized in that: The multi-phase filter circuit also includes a plurality of filter resistors; The first end of each resistor in the multiple filter resistors is respectively connected to the output end of each corresponding inductor coil in the common mode inductor, and the second end of each resistor in the multiple filter resistors is respectively connected to the working neutral line connection line.

5. The power supply circuit according to claim 2, characterized in that: The multi-phase filter circuit and the Y capacitor are integrated in a filter housing.

6. The power supply circuit according to any one of claims 1 to 5, characterized in that: It also includes a frequency converter, wherein the input end of the frequency converter is connected to the multi-phase live wire connection line, and the output end of the frequency converter is connected to the first type of load in the multi-phase load; and / or; It also includes an AC contactor, a first end of which is connected to the multi-phase live wire connecting line, and a second end of which is connected to a second type of load in the multi-phase load.

7. The power supply circuit according to claim 6, characterized in that: The first type of load includes a compressor, a water pump and a fan, the frequency converter includes a first frequency converter, a second frequency converter and a third frequency converter, the input ends of the first frequency converter, the second frequency converter and the third frequency converter are respectively connected to the multi-phase live wire connection line, and the output ends of the first frequency converter, the second frequency converter and the third frequency converter are respectively connected to the compressor, the water pump and the fan; and / or, The second type of load is a heater.

8. The power supply circuit according to any one of claims 1 to 5, characterized in that: It also includes a transformer and a first AC / DC converter, wherein the primary winding of the transformer is connected between two phase live wires in the multi-phase live wire connection line, and the secondary winding of the transformer is connected to the input end of the first AC / DC converter; and / or, A second AC / DC converter is also included, wherein an input end of the second AC / DC converter is connected to the multi-phase live wire connection line to receive the multi-phase alternating current.

9. A multi-phase filter, comprising a multi-phase live wire connection line, a working neutral wire connection line, a ground wire connection line, a filter circuit and a Y capacitor; The filtering circuit comprises a common mode inductor and a plurality of X capacitors, wherein each inductor coil of the common mode inductor is respectively arranged on each phase live line of the multi-phase live line and the working neutral line, a first end of each capacitor of the plurality of X capacitors is respectively connected to a corresponding phase live line of the multi-phase live line, and a second end of each capacitor of the plurality of X capacitors is respectively connected to the working neutral line; The first end of the Y capacitor is connected to the working neutral line connection line, and the second end of the Y capacitor is connected to the ground line connection line.

10. A temperature control device, characterized in that: A method comprising a multi-phase load and a power supply circuit as claimed in any one of claims 1 to 8, wherein the power supply circuit is connected to the multi-phase load and is used to supply power to the multi-phase load; The multi-phase load includes at least one of a compressor, a water pump and a fan.

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