Switching device of motor, control method of switching device, compressor and air conditioner

Abstract

The invention discloses a switching device of a motor and a control method thereof, a compressor and an air conditioner, the switching device comprises a first group of switching tubes, a second group of switching tubes and a third group of switching tubes, the first group of switching tubes are connected between the second end of a first winding and the first end of a second winding, and the third group of switching tubes are connected between the second winding and the third winding. The second group of switching tubes is connected between the first end of the first set of windings and the first end of the second set of windings, and the third group of switching tubes is connected between the second ends of two adjacent phases of windings in the first set of windings; and controlling the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes to be a first set on-off mode or a second set on-off mode, and adjusting the connection mode between the first set of windings and the second set of windings to be a first set connection mode or a second set connection mode. According to the scheme, the IGBT with the fly-wheel diode is used for forming the switching device of the motor, the connection mode of the two windings of the motor is switched under the condition that the motor is not stopped, the switching efficiency is high, and the user experience is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and specifically relates to a motor switching device and a control method thereof, a compressor and an air conditioner, and more particularly to a motor winding series-parallel switching device and a control method thereof, a compressor and an air conditioner. Background Art

[0002] In recent years, motors (such as high-speed permanent magnet synchronous motors) have been increasingly used in the refrigeration industry. In order to ensure the stability of the motor's high-frequency operation, the back-EMF coefficient must be reduced when designing the motor. The reduction in the back-EMF coefficient will lead to a decrease in low-frequency energy efficiency. The motor with switched windings can change its back-EMF coefficient by changing the connection state of the winding, so that when the motor runs at low frequency, the back-EMF coefficient is higher; and when it runs at high frequency, the back-EMF coefficient is lower. In this way, both low-frequency energy efficiency is guaranteed and high-frequency stable operation can be met.

[0003] When switching windings of a motor, the relevant solution uses relays or contactors as switches to switch the windings, and the motor must be shut down before switching, which causes the equipment where the motor is located to be unable to operate continuously, affecting the user experience.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a switching device for a motor and a control method thereof, a compressor and an air conditioner, so as to solve the problem that a motor for switching windings uses a relay or a contactor as a switch to switch the windings, and must be shut down before switching, resulting in the inability of the equipment where the motor is located to continue to operate, affecting the user experience. By using an IGBT with a freewheeling diode as a switching switch, the series-parallel switching of the first set of windings and the second set of windings of the motor can be achieved without stopping the motor, and the switching efficiency is high and it is beneficial to improve the user experience.

[0006] The present invention provides a switching device for a motor, wherein the motor has a first set of windings and a second set of windings, wherein the first set of windings and the second set of windings are both three-phase windings; the switching device for the motor comprises: a first group of switch tubes, a second group of switch tubes and a third group of switch tubes; the first group of switch tubes is connected between the second end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings, and the second ends of the three-phase windings of the second set of windings are connected to form a center point; the second group of switch tubes is connected between the first end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings; the third group of switch tubes is connected between the second ends of two adjacent phase windings in the three-phase winding of the first set of windings; wherein the first group of switch tubes comprises : three IGBT combinations; the second group of switch tubes includes: three IGBT combinations; the third group of switch tubes includes: two IGBT combinations; in the first group of switch tubes, the second group of switch tubes and the third group of switch tubes, each IGBT combination includes two IGBTs connected in reverse series; wherein, when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is the first set on-off mode, the connection mode between the first set of windings and the second set of windings is the first set connection mode; when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is the second set on-off mode, the connection mode between the first set of windings and the second set of windings is the second set connection mode.

[0007] In some embodiments, each IGBT combination includes: a first IGBT and a second IGBT, and the first IGBT and the second IGBT are both equipped with a freewheeling diode; wherein the collector of the first IGBT is connected to the collector of the second IGBT, and the anode of the freewheeling diode of the first IGBT is connected to the anode of the freewheeling diode of the second IGBT, so that the current of each IGBT combination can flow in both directions.

[0008] In some embodiments, in the first group of switch tubes, three IGBT combinations include: a first IGBT combination, a second IGBT combination, and a third IGBT combination; the first IGBT combination, the second IGBT combination, and the third IGBT combination are correspondingly connected between the second end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings; in the second group of switch tubes, three IGBT combinations include: a fourth IGBT combination, a fifth IGBT combination, and a sixth IGBT combination; the fourth IGBT combination, the fifth IGBT combination, and the sixth IGBT combination are correspondingly connected between the first end of the three-phase winding of the first set of windings. between the first end and the first end of the three-phase winding of the second set of windings; in the third group of switch tubes, two IGBT combinations include: a seventh IGBT combination and an eighth IGBT combination; the seventh IGBT combination and the eighth IGBT combination are respectively connected between the second ends of two adjacent phase windings in the three-phase winding of the first set of windings; wherein the first IGBT combination, the second IGBT combination, the third IGBT combination, the fourth IGBT combination, the fifth IGBT combination, the sixth IGBT combination, the seventh IGBT combination and the eighth IGBT combination have the same structure, and each IGBT combination includes two IGBTs connected in reverse series.

[0009] In some embodiments, the three-phase winding of the first set of windings includes: a U1 phase winding, a V1 phase winding, and a W1 phase winding; the three-phase winding of the second set of windings includes: a U2 phase winding, a V2 phase winding, and a W2 phase winding, and the second end of the U2 phase winding, the second end of the V2 phase winding, and the second end of the W2 phase winding are connected to form a center point; wherein the first IGBT combination is connected between the second end of the U1 phase winding and the first end of the U2 phase winding; the second IGBT combination is connected between the second end of the V1 phase winding and the first end of the V2 phase winding; the third IGBT combination is connected between the W1 phase winding and the V2 phase winding. The fourth IGBT combination is connected between the first end of the U1 phase winding and the first end of the U2 phase winding; the fifth IGBT combination is connected between the first end of the V1 phase winding and the first end of the V2 phase winding; the sixth IGBT combination is connected between the first end of the W1 phase winding and the first end of the W2 phase winding; the seventh IGBT combination is connected between the second end of the U1 phase winding and the second end of the V1 phase winding; the eighth IGBT combination is connected between the second end of the V1 phase winding and the second end of the W1 phase winding.

[0010] In some embodiments, the first set on-off mode is that all IGBTs in the first group of switch tubes are turned on, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned off, and the first set connection mode is the series connection between the first set of windings and the second set of windings; the second set on-off mode is that all IGBTs in the first group of switch tubes are turned off, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned on, and the second set connection mode is the parallel connection between the first set of windings and the second set of windings.

[0011] Matching the above-mentioned device, the present invention further provides a compressor on the other hand, including: the switching device of the motor mentioned above.

[0012] Matching the above-mentioned device, the present invention provides an air conditioner on another aspect, including: the above-mentioned compressor, or the above-mentioned motor switching device.

[0013] Matching the above-mentioned device, the present invention provides a control method for a switching device of a motor on another aspect, comprising: during the operation of the motor, determining whether a winding switching instruction of the motor is received; if a winding switching instruction of the motor is received, controlling the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes according to the winding switching instruction of the motor to realize the switching of the connection mode between the first set of windings and the second set of windings; wherein, when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is a first set on-off mode, the connection mode between the first set of windings and the second set of windings is a first set connection mode; when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is a second set on-off mode, the connection mode between the first set of windings and the second set of windings is a second set connection mode.

[0014] In some embodiments, according to the winding switching instruction of the motor, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes are controlled to realize the switching of the connection mode between the first set of windings and the second set of windings, including: determining whether the winding switching instruction of the motor is a set first instruction or a set second instruction; wherein the set first instruction is an instruction for making the connection mode between the first set of windings and the second set of windings a first set connection mode; the set second instruction is an instruction for making the connection mode between the first set of windings and the second set of windings a second set connection mode; if the winding switching instruction of the motor is the set first instruction, then the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes are controlled to be the first set on-off mode, so that the connection mode between the first set of windings and the second set of windings is the first set connection mode; if the winding switching instruction of the motor is the set second instruction, then the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes are controlled to be the second set on-off mode, so that the connection mode between the first set of windings and the second set of windings is the second set connection mode.

[0015] In some embodiments, the first set on-off mode is that all IGBTs in the first group of switch tubes are turned on, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned off, and the first set connection mode is the series connection between the first set of windings and the second set of windings; the second set on-off mode is that all IGBTs in the first group of switch tubes are turned off, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned on, and the second set connection mode is the parallel connection between the first set of windings and the second set of windings.

[0016] Therefore, the scheme of the present invention uses sixteen IGBTs connected in parallel in pairs and with freewheeling diodes to form a switching device for a motor with two sets of windings. In the switching device of the motor, every two IGBTs among the sixteen IGBTs are connected in reverse series to form a combination to obtain eight IGBT combinations. The eight IGBT combinations are divided into a first group of switch tubes, a second group of switch tubes and a third group of switch tubes. The first terminal of each IGBT combination in the first group of switch tubes is connected to the second end of the three-phase of the first set of windings and the first end of the three-phase of the second set of windings. The first terminal of each IGBT combination in the second group of switch tubes is connected to the first end of the three-phase of the first set of windings and the first end of the three-phase of the second set of windings. The third group of switch tubes Each IGBT combination in the tube is connected in series between the second ends of the three phases of the first set of windings; when the received winding switching instruction is a series instruction, the first group of switch tubes is controlled to be turned on, and the second group of switch tubes and the third group of switch tubes are both turned off; when the received winding switching instruction is a parallel instruction, the first group of switch tubes is controlled to be turned off, and the second group of switch tubes and the third group of switch tubes are both turned on, so as to realize the series-parallel switching of the first set of windings and the second set of windings of the motor without stopping the motor; thus, by using a switching device composed of IGBTs with freewheeling diodes as a switching switch, the series-parallel switching of the first set of windings and the second set of windings of the motor is realized without stopping the motor, and the switching efficiency is high and it is beneficial to improve the user experience.

[0017] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of a switching device for a motor of the present invention;

[0020] Figure 2 A schematic diagram of the circuit structure of an embodiment of a device for switching winding series-parallel connection of a motor of the present invention;

[0021] Figure 3 It is a schematic diagram of the equivalent circuit structure of the winding series-parallel switching device of the motor of the present invention when the windings are connected in series;

[0022] Figure 4 It is a schematic diagram of the equivalent circuit structure of the winding series-parallel switching device of the motor of the present invention when the windings are connected in parallel;

[0023] Figure 5 It is a schematic diagram of the control flow of the winding series-parallel switching device of the motor of the present invention during winding switching;

[0024] Figure 6 A schematic flow chart of an embodiment of a method for controlling a switching device of a motor of the present invention;

[0025] Figure 7 A schematic flow chart of an embodiment of controlling the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes in the method of the present invention;

[0026] Figure 8 Schematic diagram of the connection mode of a P-channel IGBT combination, wherein (a) is a schematic diagram of connection mode 1, and (b) is a schematic diagram of connection mode 2;

[0027] Fig. 9 Schematic diagram of the connection method of an N-channel IGBT combination, wherein (a) is a schematic diagram of connection method one, and (b) is a schematic diagram of connection method two. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] Considering that when the motor with switched windings switches the windings, the relevant schemes use relays or contactors as switches to switch the windings, such as some schemes that use relays to switch between star and delta, and some schemes that use AC contactors to switch between series and parallel. However, to change the winding connection state through relays or contactors, the machine must be shut down before switching the windings, because if the machine is not shut down for switching, arcing will occur at the moment of switching the contacts of the relay or contactor, which will pose a serious threat to reliability and safety. If relays or contactors are used for shutdown switching, the user experience will be worse. For example: when the motor is shut down for switching, the equipment where the motor is located, such as the compressor, will have a process of shutting down and restarting. During this period of shutdown, the equipment where the compressor is located, such as the air conditioner, will not continue to cool or heat. If the air conditioner that the user is using suddenly stops, there will be no continuous supply of cold or hot air, resulting in a worse user experience.

[0030] Therefore, the solution of the present invention proposes a switching device for a motor, specifically a series-parallel switching device for a motor winding. By using multiple IGBTs connected in parallel in pairs and with freewheeling diodes as switching switches, the windings can be switched without stopping the motor. The entire switching process can be completed safely and quickly, and the winding switching can be completed without stopping the motor, which is beneficial to improving user experience.

[0031] According to an embodiment of the present invention, a switching device for a motor is provided. Figure 1 The schematic diagram of the structure of an embodiment of the device of the present invention is shown. The motor has a first set of windings and a second set of windings, and the first set of windings and the second set of windings are both three-phase windings; the switching device of the motor includes: a first group of switch tubes, a second group of switch tubes and a third group of switch tubes; the first group of switch tubes is connected between the second end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings, and the second ends of the three-phase windings of the second set of windings are connected to form a center point; the second group of switch tubes is connected between the first end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings; the third group of switch tubes is connected between the second ends of two adjacent phase windings in the three-phase winding of the first set of windings. Figure 2 FIG. 1 is a schematic diagram of a circuit structure of an embodiment of a winding series-parallel switching device for a motor of the present invention. Figure 2 As shown, the motor winding series-parallel switching device consists of sixteen IGBTs (such as Figure 2 The motor is composed of IGBT Q1~Q16 in the motor, and the motor has two sets of windings, namely a first set of windings (such as winding 1) and a second set of windings (such as winding 2), each set of windings has three phases, the three phases of the first set of windings are U1, V1, W1, and the three phases of the second set of windings are U2, V2, W2. The motor winding series-parallel switching device is connected to the two sets of windings of the motor to form the winding switching circuit of the motor; the winding switching circuit of the motor is arranged at the output end of the inverter, and the inverter is a single inverter; the three-phase connection ends of the output end of the single inverter are correspondingly connected to the three-phase connection ends in the winding switching circuit of the motor. Among them, the first group of switch tubes includes: three IGBT combinations; the second group of switch tubes includes: three IGBT combinations; the third group of switch tubes includes: two IGBT combinations; in the first group of switch tubes, the second group of switch tubes and the third group of switch tubes, each IGBT combination includes two IGBTs connected in reverse series (such as in Figure 2 Among the IGBTs Q1 to Q16, every two IGBTs are connected in reverse series to form a combination).

[0032] Among them, when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is the first set on-off mode, the connection mode between the first set of windings and the second set of windings is the first set connection mode; when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is the second set on-off mode, the connection mode between the first set of windings and the second set of windings is the second set connection mode.

[0033] exist Figure 2 In the example shown, the first end of each phase of the first set of windings is also connected to the inverter, specifically, the first end of each phase of the first set of windings is connected to the connection end of the corresponding phase of the three phases at the output end of the inverter; the second end of each phase of the first set of windings is connected to the winding series-parallel switching device of the motor. The first end of each phase of the second set of windings is connected to the winding series-parallel switching device of the motor, and the second end of each phase of the second set of windings is connected together to form a center point. For example: the connection end of the U phase at the output end of the inverter is connected to the first end of the U1 phase of the first set of windings, and the second end of the U1 phase of the first set of windings is connected to the winding series-parallel switching device of the motor; the connection end of the V phase at the output end of the inverter is connected to the first end of the V1 phase of the first set of windings, and the second end of the V1 phase of the first set of windings is connected to the winding series-parallel switching device of the motor; the connection end of the W phase at the output end of the inverter is connected to the first end of the W1 phase of the first set of windings, and the second end of the W1 phase of the first set of windings is connected to the winding series-parallel switching device of the motor; the first end of the U2 phase of the second set of windings is connected to the winding series-parallel switching device of the motor, the first end of the V2 phase of the second set of windings is connected to the winding series-parallel switching device of the motor, the first end of the W2 phase of the second set of windings is connected to the winding series-parallel switching device of the motor, the second end of the U2 phase of the second set of windings, the second end of the V2 phase of the second set of windings, and the second end of the W2 phase of the second set of windings are connected to form a center point. Only in this way can the connection mode of the first set of windings and the second set of windings be switched between series and parallel. When connected in series, the back electromotive force is high, which is suitable for low-frequency operation with high energy efficiency; when connected in parallel, the back electromotive force is low, which is suitable for high-frequency operation. By realizing the series-parallel switching of the first set of windings and the second set of windings, both low-frequency energy efficiency and high-frequency stable operation can be guaranteed.

[0034] The solution of the present invention proposes a device and a control scheme suitable for series-parallel switching of motor windings, by using a plurality of IGBTs (such as Figure 2 The IGBTs with freewheeling diodes (Q1~Q16) in the circuit are used as switching switches, which can switch windings without stopping the motor. The entire switching process can be completed safely and quickly, and winding switching can be completed without stopping the motor, which is beneficial to improving user experience.

[0035] In some embodiments, each IGBT combination includes: a first IGBT and a second IGBT, and the first IGBT and the second IGBT are both provided with a freewheeling diode, that is, each of the first IGBT and the second IGBT is connected in parallel with a reverse freewheeling diode.

[0036] In the solution of the present invention, the IGBT can be a P-channel IGBT or an N-channel IGBT. The connection directions of the two IGBTs and their respective freewheeling diodes are different, and there are two connection modes for the combination of the two IGBTs.

[0037] Among them, the connection mode of the P-channel IGBT and its freewheeling diode corresponds to the connection mode of the following sixteen IGBTs: the emitter of each IGBT is connected to the cathode of the freewheeling diode of each IGBT, and the collector of each IGBT is connected to the anode of the freewheeling diode of each IGBT. The connection mode of the first P-channel IGBT combination is: the collector of the first IGBT is connected to the collector of the second IGBT, and the anode of the freewheeling diode of the first IGBT is connected to the anode of the freewheeling diode of the second IGBT. For details, please refer to Figure 8 (a) is an example. For example: the collector of the first IGBT is connected to the collector of the second IGBT, and the anode of the freewheeling diode of the first IGBT is connected to the anode of the freewheeling diode of the second IGBT, so that the current of each IGBT combination can flow in both directions. Among them, since the first IGBT and the second IGBT are connected in reverse series, each of the first IGBT and the second IGBT is connected in parallel with a reverse freewheeling diode, and the parallel reverse freewheeling diodes can ensure the bidirectional flow of current in each IGBT combination.

[0038] In addition, the connection mode of the second P-channel IGBT combination is: the emitter of the first IGBT is connected to the emitter of the second IGBT, and the cathode of the freewheeling diode of the first IGBT is connected to the cathode of the freewheeling diode of the second IGBT. Figure 8 (b) shows the example.

[0039] The following is an illustrative description using a P-channel IGBT as an example. Figure 2In the example shown, taking the P-channel IGBT as an example, there are sixteen IGBTs, specifically IGBT Q1, IGBT Q2, IGBT Q3, IGBT Q4, IGBT Q5, IGBT Q6, IGBT Q7, IGBT Q8, IGBT Q9, IGBT Q10, IGBT Q11, IGBT Q12, IGBT Q13, IGBT Q14, IGBT Q15, IGBT Q16, and IGBT Q1~Q16 are all IGBTs with freewheeling diodes, IGBT Q1 has a freewheeling diode D1, IGBT Q2 has a freewheeling diode D2, IGBT Q3 has a freewheeling diode D3, IGBT Q4 has a freewheeling diode D4, IGBT Q5 has a freewheeling diode D5, IGBT Q6 has a freewheeling diode D6, IGBT Q7 has a freewheeling diode D7, IGBT Q8 has a freewheeling diode D8, IGBT Q9 has a freewheeling diode D9, IGBT Q10 has a freewheeling diode D11, and IGBT Q11 has a freewheeling diode D12. Q11 has a freewheeling diode D11, IGBT Q12 has a freewheeling diode D12, IGBT Q13 has a freewheeling diode D13, IGBT Q14 has a freewheeling diode D14, IGBT Q15 has a freewheeling diode D15, and IGBT Q16 has a freewheeling diode D16. In IGBT Q1-Q16, the emitter of each IGBT is connected to the cathode of the freewheeling diode of each IGBT, and the collector of each IGBT is connected to the anode of the freewheeling diode of each IGBT. In IGBT Q1-Q16, every two IGBTs are connected in reverse series to form a combination, and there are a total of eight IGBT combinations (such as Figure 2 The IGBT Q1 and IGBT Q2 in the figure are one IGBT combination, and so on).

[0040] Specifically, taking a P-channel IGBT as an example, the emitter of IGBT Q1 is connected to the cathode of the freewheeling diode D1 of IGBT Q1, the collector of IGBT Q1 is connected to the anode of the freewheeling diode D1 of IGBT Q1, the collector of IGBT Q1 is connected to the collector of IGBT Q2, the emitter of IGBT Q2 is connected to the cathode of the freewheeling diode D2 of IGBT Q2, and the collector of IGBT Q2 is connected to the anode of the freewheeling diode D2 of IGBT Q2, forming a first IGBT combination. The emitter of IGBT Q3 is connected to the cathode of the freewheeling diode D3 of IGBT Q3, the collector of IGBT Q3 is connected to the anode of the freewheeling diode D3 of IGBT Q3, the collector of IGBT Q3 is connected to the collector of IGBT Q4, the emitter of IGBT Q4 is connected to the cathode of the freewheeling diode D4 of IGBT Q4, and the collector of IGBT Q4 is connected to the anode of the freewheeling diode D4 of IGBT Q4, forming a second IGBT combination. The emitter of IGBT Q5 is connected to the cathode of the freewheeling diode D5 of IGBT Q5, the collector of IGBT Q5 is connected to the anode of the freewheeling diode D5 of IGBT Q5, the collector of IGBT Q5 is connected to the collector of IGBT Q6, the emitter of IGBT Q6 is connected to the cathode of the freewheeling diode D6 of IGBT Q6, and the collector of IGBT Q6 is connected to the anode of the freewheeling diode D6 of IGBT Q6, forming a third IGBT combination. The emitter of IGBT Q7 is connected to the cathode of the freewheeling diode D7 of IGBT Q7, the collector of IGBT Q7 is connected to the anode of the freewheeling diode D7 of IGBT Q7, the collector of IGBT Q7 is connected to the collector of IGBT Q8, the emitter of IGBT Q8 is connected to the cathode of the freewheeling diode D8 of IGBT Q8, and the collector of IGBT Q8 is connected to the anode of the freewheeling diode D8 of IGBT Q8, forming a fourth IGBT combination. The emitter of IGBT Q9 is connected to the cathode of the freewheeling diode D9 of IGBT Q9, the collector of IGBT Q9 is connected to the anode of the freewheeling diode D9 of IGBT Q9, the collector of IGBT Q9 is connected to the collector of IGBT Q10, the emitter of IGBT Q10 is connected to the cathode of the freewheeling diode D10 of IGBT Q10, and the collector of IGBT Q10 is connected to the anode of the freewheeling diode D10 of IGBT Q10, forming a fifth IGBT combination.The emitter of IGBT Q11 is connected to the cathode of the freewheeling diode D11 of IGBT Q11, the collector of IGBT Q11 is connected to the anode of the freewheeling diode D11 of IGBT Q11, the collector of IGBT Q11 is connected to the collector of IGBT Q12, the emitter of IGBT Q12 is connected to the cathode of the freewheeling diode D12 of IGBT Q12, and the collector of IGBT Q12 is connected to the anode of the freewheeling diode D12 of IGBT Q12, forming a sixth IGBT combination. The emitter of IGBT Q13 is connected to the cathode of the freewheeling diode D13 of IGBT Q13, the collector of IGBT Q13 is connected to the anode of the freewheeling diode D13 of IGBT Q13, the collector of IGBT Q13 is connected to the collector of IGBT Q14, the emitter of IGBT Q14 is connected to the cathode of the freewheeling diode D14 of IGBT Q14, and the collector of IGBT Q14 is connected to the anode of the freewheeling diode D14 of IGBT Q14, forming a seventh IGBT combination. The emitter of IGBT Q15 is connected to the cathode of the freewheeling diode D15 of IGBT Q15, the collector of IGBT Q15 is connected to the anode of the freewheeling diode D15 of IGBT Q15, the collector of IGBT Q15 is connected to the collector of IGBT Q16, the emitter of IGBT Q16 is connected to the cathode of the freewheeling diode D16 of IGBT Q16, and the collector of IGBT Q16 is connected to the anode of the freewheeling diode D16 of IGBT Q16, forming an eighth IGBT combination.

[0041] exist Figure 2In the example shown, taking the P-channel IGBT as an example, for each of the first IGBT combination, the second IGBT combination, the third IGBT combination, the fourth IGBT combination, the fifth IGBT combination, the sixth IGBT combination, the seventh IGBT combination, and the eighth IGBT combination, each IGBT combination has two terminals, namely the first terminal and the second terminal. For example: the first terminal of the first IGBT combination is the emitter of IGBT Q1, and the second terminal is the emitter of IGBT Q2, the first terminal of the second IGBT combination is the emitter of IGBT Q3, and the second terminal is the emitter of IGBT Q4, the first terminal of the third IGBT combination is the emitter of IGBT Q5, and the second terminal is the emitter of IGBT Q6, the first terminal of the fourth IGBT combination is the emitter of IGBT Q7, and the second terminal is the emitter of IGBT Q8, the first terminal of the fifth IGBT combination is the emitter of IGBT Q9, and the second terminal is the emitter of IGBT Q10, the first terminal of the sixth IGBT combination is the emitter of IGBT Q11, and the second terminal is the emitter of IGBT Q12, the first terminal of the seventh IGBT combination is the emitter of IGBT Q13, and the second terminal is the emitter of IGBT Q14, the first terminal of the eighth IGBT combination is the emitter of IGBT Q15, and the second terminal is the emitter of IGBT Q16.

[0042] In addition, the connection mode of the N-channel IGBT and the freewheeling diode corresponds to the connection mode of the following sixteen IGBTs: the emitter of each IGBT is connected to the anode of the freewheeling diode of each IGBT, and the collector of each IGBT is connected to the cathode of the freewheeling diode of each IGBT, which is the opposite of the P-channel IGBT. The connection mode of the N-channel IGBT combination is: the emitter of the first IGBT is connected to the emitter of the second IGBT, and the cathode of the freewheeling diode of the first IGBT is connected to the cathode of the freewheeling diode of the second IGBT. For details, please refer to Fig. 9 (b) shows the example.

[0043] That is, in the solution of the present invention, the connection mode of the first N-channel IGBT combination is: the collector of the first IGBT is connected to the collector of the second IGBT, and the cathode of the freewheeling diode of the first IGBT is connected to the cathode of the freewheeling diode of the second IGBT. Fig. 9Alternatively, the second N-channel IGBT combination is connected in such a way that the emitter of the first IGBT is connected to the emitter of the second IGBT, and the anode of the freewheeling diode of the first IGBT is connected to the anode of the freewheeling diode of the second IGBT. For details, see Fig. 9 (b) shows the example.

[0044] In the solution of the present invention, sixteen IGBTs connected in parallel in pairs and with freewheeling diodes are used to form a switching device for the motor. Winding switching can be performed without stopping the motor, and the entire switching process can be completed safely and quickly, so that winding switching can be completed without stopping the motor, which is beneficial to improving user experience.

[0045] In some embodiments, in the first group of switching tubes, three IGBT combinations include: a first IGBT combination, a second IGBT combination and a third IGBT combination; the first IGBT combination, the second IGBT combination and the third IGBT combination are correspondingly connected between the second end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings.

[0046] In the second group of switch tubes, three IGBT combinations include: a fourth IGBT combination, a fifth IGBT combination, and a sixth IGBT combination; the fourth IGBT combination, the fifth IGBT combination, and the sixth IGBT combination are correspondingly connected between the first end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings.

[0047] In the third group of switch tubes, two IGBT combinations include: a seventh IGBT combination and an eighth IGBT combination; the seventh IGBT combination and the eighth IGBT combination are respectively connected between the second ends of two adjacent phase windings in the three-phase windings of the first set of windings; specifically, the seventh IGBT combination is connected between the second end of the first phase winding and the second end of the second phase winding in the three-phase windings of the first set of windings; the eighth IGBT combination is connected between the second end of the second phase winding and the second end of the third phase winding in the three-phase windings of the first set of windings; wherein the first phase winding in the three-phase windings of the first set of windings is such as the U1 phase winding, the second phase winding in the three-phase windings of the first set of windings is such as the V1 phase winding, and the third phase winding in the three-phase windings of the first set of windings is such as the W1 phase winding.

[0048] The first IGBT combination, the second IGBT combination, the third IGBT combination, the fourth IGBT combination, the fifth IGBT combination, the sixth IGBT combination, the seventh IGBT combination and the eighth IGBT combination have the same structure, and each IGBT combination includes two IGBTs connected in reverse series.

[0049] exist Figure 2 In the example shown, the eight IGBT combinations, namely the first IGBT combination, the second IGBT combination, the third IGBT combination, the fourth IGBT combination, the fifth IGBT combination, the sixth IGBT combination, the seventh IGBT combination and the eighth IGBT combination, are divided into a first group of switch tubes, a second group of switch tubes and a third group of switch tubes according to their circuit connection states.

[0050] In the scheme of the present invention, sixteen IGBTs connected in parallel in pairs and with freewheeling diodes are used to form eight IGBT combinations, namely the first IGBT combination, the second IGBT combination, the third IGBT combination, the fourth IGBT combination, the fifth IGBT combination, the sixth IGBT combination, the seventh IGBT combination, and the eighth IGBT combination, thereby forming a switching device for the motor. The windings can be switched without stopping the motor, and the entire switching process can be completed safely and quickly, so that the windings can be switched without stopping the motor, which is beneficial to improving user experience.

[0051] In some embodiments, the three-phase windings of the first set of windings include: U1 phase winding, V1 phase winding and W1 phase winding; the three-phase windings of the second set of windings include: U2 phase winding, V2 phase winding and W2 phase winding, and the second end of the U2 phase winding, the second end of the V2 phase winding and the second end of the W2 phase winding are connected to form a center point.

[0052] Among them, the first IGBT combination is connected between the second end of the U1 phase winding and the first end of the U2 phase winding. The second IGBT combination is connected between the second end of the V1 phase winding and the first end of the V2 phase winding. The third IGBT combination is connected between the second end of the W1 phase winding and the first end of the W2 phase winding. The fourth IGBT combination is connected between the first end of the U1 phase winding and the first end of the U2 phase winding. The fifth IGBT combination is connected between the first end of the V1 phase winding and the first end of the V2 phase winding. The sixth IGBT combination is connected between the first end of the W1 phase winding and the first end of the W2 phase winding. The seventh IGBT combination is connected between the second end of the U1 phase winding and the second end of the V1 phase winding. The eighth IGBT combination is connected between the second end of the V1 phase winding and the second end of the W1 phase winding.

[0053] exist Figure 2 In the example shown, the first group of switch tubes is composed of three IGBT combinations, specifically, a first IGBT combination, a second IGBT combination, and a third IGBT combination ( Figure 2 In the combination, they are IGBT Q1, IGBT Q2, IGBT Q3, IGBT Q4, and IGBT Q5, IGBT Q6, respectively. The first terminal of each IGBT combination in the first IGBT combination, the second IGBT combination, and the third IGBT combination is connected to the second end of the first set of three-phase windings, and the second terminal is connected to the first end of the second set of three-phase windings. Specifically, the connection end of the U phase at the output end of the inverter is connected to the first end of the U1 phase of the first set of windings, the second end of the U1 phase of the first set of windings is connected to the first terminal of the first IGBT combination, and the second terminal of the first IGBT combination is connected to the first end of the U2 phase of the second set of windings; the connection end of the V phase at the output end of the inverter is connected to the first end of the V1 phase of the first set of windings, the second end of the V1 phase of the first set of windings is connected to the first terminal of the second IGBT combination, and the second terminal of the second IGBT combination is connected to the first end of the V2 phase of the second set of windings; the connection end of the W phase at the output end of the inverter is connected to the first end of the W1 phase of the first set of windings, the second end of the W1 phase of the first set of windings is connected to the first terminal of the third IGBT combination, and the second terminal of the third IGBT combination is connected to the first end of the W2 phase of the second set of windings; the second end of the U2 phase of the second set of windings, the second end of the V2 phase of the second set of windings, and the second end of the W2 phase of the second set of windings are connected to form a center point.

[0054] The second group of switch tubes is composed of three IGBT combinations, specifically the fourth IGBT combination, the fifth IGBT combination, and the sixth IGBT combination ( Figure 2 The first connection terminal of each of the fourth IGBT combination, the fifth IGBT combination and the sixth IGBT combination is connected to the first end of the three-phase first set of windings and the first end of the three-phase second set of windings. Specifically, the connection end of the U phase at the output end of the inverter is connected to the first end of the U1 phase of the first set of windings, the second end of the U1 phase of the first set of windings is connected to the first terminal of the fourth IGBT combination, and the second terminal of the fourth IGBT combination is connected to the first end of the U2 phase of the second set of windings; the connection end of the V phase at the output end of the inverter is connected to the first end of the V1 phase of the first set of windings, the second end of the V1 phase of the first set of windings is connected to the first terminal of the fifth IGBT combination, and the second terminal of the fifth IGBT combination is connected to the first end of the V2 phase of the second set of windings; the connection end of the W phase at the output end of the inverter is connected to the first end of the W1 phase of the first set of windings, the second end of the W1 phase of the first set of windings is connected to the first terminal of the sixth IGBT combination, and the second terminal of the sixth IGBT combination is connected to the first end of the W2 phase of the second set of windings; the second end of the U2 phase of the second set of windings, the second end of the V2 phase of the second set of windings, and the second end of the W2 phase of the second set of windings are connected to form a center point.

[0055] The third group of switch tubes is composed of two IGBT combinations, specifically the seventh IGBT combination and the eighth IGBT combination ( Figure 2 In the figure, the seventh IGBT combination and the eighth IGBT combination are connected in series between the second ends of the three phases of the first winding. Specifically, the connection end of the U phase of the output end of the inverter is connected to the first end of the U1 phase of the first winding, and the second end of the U1 phase of the first winding is connected to the first connection terminal of the seventh IGBT combination; the connection end of the V phase of the output end of the inverter is connected to the first end of the V1 phase of the first winding, and the second end of the V1 phase of the first winding is connected to the second connection terminal of the seventh IGBT combination, and the second connection terminal of the seventh IGBT combination is connected to the first connection terminal of the eighth IGBT combination; the connection end of the W phase of the output end of the inverter is connected to the first end of the W1 phase of the first winding, and the second end of the W1 phase of the first winding is connected to the second connection terminal of the eighth IGBT combination.

[0056] It can be seen that the first group of switch tubes is composed of three IGBTs. Figure 2The first terminal of each IGBT combination is connected to the second end of the first set of three-phase windings and the first end of the second set of three-phase windings. The second set of switch tubes is composed of three IGBT combinations. Figure 2 The third group of switch tubes consists of two IGBT combinations, Figure 2 In the figure, they are IGBT Q13, IGBT Q14 combination and IGBT Q15, IGBTQ16 combination, each IGBT combination is connected in series between the second ends of the three phases of the first set of windings. This arrangement can realize the switching between the connection mode of the first set of windings and the second set of windings between series and parallel, and realize the series-parallel switching of the first set of windings and the second set of windings, which can ensure both low-frequency energy efficiency and high-frequency stable operation, and the motor does not need to be shut down.

[0057] In some embodiments, the first setting on-off mode is that all IGBTs in the first group of switch tubes are turned on, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned off, and the first setting connection mode is that the first set of windings and the second set of windings are connected in series. The second setting on-off mode is that all IGBTs in the first group of switch tubes are turned off, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned on, and the second setting connection mode is that the first set of windings and the second set of windings are connected in parallel.

[0058] That is to say, when all IGBTs in the first group of switch tubes are turned on and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned off, the first set of windings and the second set of windings are connected in series; when all IGBTs in the first group of switch tubes are turned off and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned on, the first set of windings and the second set of windings are connected in parallel.

[0059] Figure 3 is a schematic diagram of an equivalent circuit structure of the winding series-parallel switching device of the motor of the present invention when the windings are connected in series, Figure 4The figure is a schematic diagram of the equivalent circuit structure of the motor winding series-parallel switching device of the present invention when the windings are connected in parallel. In the scheme of the present invention, the control scheme of the device for switching the motor windings in series-parallel also includes a drive control module. When the drive control module receives the winding series connection instruction, the drive control module controls the first group of switch tubes to be turned on, and the second group of switch tubes and the third group of switch tubes to be turned off (the equivalent circuit principle at this time is shown in FIG. Figure 3 When the drive control module receives the parallel command, the drive control module controls the first group of switch tubes to turn off, and the second group of switch tubes and the third group of switch tubes to turn on (the equivalent circuit principle at this time is shown in Figure 4 shown).

[0060] Figure 5 FIG. 1 is a schematic diagram of the control flow of the winding series-parallel switching device of the motor of the present invention during winding switching. Figure 5 As shown, the control process of the motor winding series-parallel switching device during winding switching includes:

[0061] Step 1: upon receiving a winding switching instruction, determine whether the next state of the motor winding switching is a series instruction or a parallel instruction: if it is a series instruction, execute step 2; if it is a parallel instruction, execute step 3.

[0062] Step 2. When the drive control module receives the series connection instruction, the drive control module controls the first group of switch tubes to be turned on, and the second and third groups of switch tubes to be turned off. Only in this way can the connection mode of the first set of windings and the second set of windings be switched to series connection, and the series-parallel switching of the first set of windings and the second set of windings be realized, which can ensure both low-frequency energy efficiency and high-frequency stable operation, and the motor does not need to be shut down.

[0063] Step 3. When the drive control module receives the parallel instruction, the drive control module controls the first group of switch tubes to turn off, and the second and third groups of switch tubes to turn on. Only in this way can the connection mode of the first set of windings and the second set of windings be switched to parallel, and the series-parallel switching of the first set of windings and the second set of windings be realized, which can ensure both low-frequency energy efficiency and high-frequency stable operation, and the motor does not need to be shut down.

[0064] In the scheme of the present invention, sixteen IGBTs connected in parallel in pairs and with freewheeling diodes are used to form a first group of switch tubes, a second group of switch tubes and a third group of switch tubes, thereby forming a switching device for the motor. By controlling the on and off modes of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes, winding switching can be performed without stopping the motor, and the entire switching process can be completed safely and quickly, thereby achieving winding switching without stopping the motor, which is beneficial to improving user experience.

[0065] According to the technical solution of the present invention, sixteen IGBTs connected in parallel in pairs and with freewheeling diodes are used to form a switching device for a motor having two sets of windings. In the switching device of the motor, two IGBTs among the sixteen IGBTs are connected in reverse series to form a combination to obtain eight IGBT combinations. The eight IGBT combinations are divided into a first group of switch tubes, a second group of switch tubes and a third group of switch tubes. The first connection terminal of each IGBT combination in the first group of switch tubes is connected to the second end of the three-phase of the first set of windings and the first end of the three-phase of the second set of windings. The first connection terminal of each IGBT combination in the second group of switch tubes is connected to the first end of the three-phase of the first set of windings and the first end of the three-phase of the second set of windings. The third group of switch tubes is connected to the first end of the three-phase of the first set of windings. Each IGBT combination in the switch tube is connected in series between the second ends of the three phases of the first set of windings; when the received winding switching instruction is a series instruction, the first group of switch tubes is controlled to be turned on, and the second group of switch tubes and the third group of switch tubes are both turned off; when the received winding switching instruction is a parallel instruction, the first group of switch tubes is controlled to be turned off, and the second group of switch tubes and the third group of switch tubes are both turned on, so as to realize the series-parallel switching of the first set of windings and the second set of windings of the motor without stopping the motor; thus, by using a switching device composed of IGBTs with freewheeling diodes as a switching switch, the series-parallel switching of the first set of windings and the second set of windings of the motor is realized without stopping the motor, and the switching efficiency is high and it is beneficial to improve the user experience.

[0066] According to an embodiment of the present invention, a compressor corresponding to a switching device of a motor is also provided. The air conditioner may include: the switching device of the motor described above.

[0067] Since the processing and functions implemented by the compressor of this embodiment basically correspond to the embodiments, principles and examples of the device, for the details not described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0068] According to an embodiment of the present invention, an air conditioner corresponding to a switching device of a motor is also provided. The air conditioner may include: the compressor described above, or the switching device of the motor described above.

[0069] Since the processing and functions implemented by the air conditioner of this embodiment basically correspond to the embodiments, principles and examples of the device, for the details not described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0070] According to an embodiment of the present invention, a control method for a switching device of a motor corresponding to the switching device of the motor is also provided, such as Figure 6 The flow chart of an embodiment of the method of the present invention is shown in FIG. The control method of the switching device of the motor may include: step S110 to step S120.

[0071] In step S110 , during the operation of the motor, it is determined whether a winding switching instruction of the motor is received.

[0072] At step S120, if a winding switching instruction of the motor is received, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes are controlled according to the winding switching instruction of the motor to achieve the switching of the connection mode between the first set of windings and the second set of windings; of course, if the motor winding switching instruction of the motor is not received, the motor is controlled to maintain the current operation.

[0073] Wherein, when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is the first set on-off mode, the connection mode between the first set of windings and the second set of windings is the first set connection mode. When the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is the second set on-off mode, the connection mode between the first set of windings and the second set of windings is the second set connection mode.

[0074] The solution of the present invention proposes a device and a control scheme suitable for series-parallel switching of motor windings, by using a plurality of IGBTs (such as Figure 2 The IGBTs with freewheeling diodes (Q1~Q16) in the circuit are used as switching switches, which can switch windings without stopping the motor. The entire switching process can be completed safely and quickly, and winding switching can be completed without stopping the motor, which is beneficial to improving user experience.

[0075] In some embodiments, in step S120, according to the winding switching instruction of the motor, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes are controlled to realize the specific process of switching the connection mode between the first set of windings and the second set of windings. See the following exemplary description.

[0076] Combine the following Figure 7 The flowchart of an embodiment of controlling the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes in the method of the present invention is shown, which further illustrates the specific process of controlling the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes in step S120, including: step S210 to step S230.

[0077] Step S210, determining whether the winding switching instruction of the motor is a set first instruction or a set second instruction; wherein the set first instruction is an instruction for making the connection mode between the first set of windings and the second set of windings a first set connection mode; the set second instruction is an instruction for making the connection mode between the first set of windings and the second set of windings a second set connection mode.

[0078] Step S220, if the winding switching instruction of the motor is a set first instruction, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is controlled to be a first set on-off mode, so that the connection mode between the first set of windings and the second set of windings is the first set connection mode.

[0079] Step S230, if the winding switching instruction of the motor is a set second instruction, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is controlled to be a second set on-off mode, so that the connection mode between the first set of windings and the second set of windings is the second set connection mode.

[0080] In the scheme of the present invention, sixteen IGBTs connected in parallel in pairs and with freewheeling diodes are used to form a first group of switch tubes, a second group of switch tubes and a third group of switch tubes, thereby forming a switching device for the motor. By controlling the on and off modes of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes, winding switching can be performed without stopping the motor, and the entire switching process can be completed safely and quickly, thereby achieving winding switching without stopping the motor, which is beneficial to improving user experience.

[0081] In some embodiments, the first setting on-off mode is that all IGBTs in the first group of switch tubes are turned on, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned off, and the first setting connection mode is that the first set of windings and the second set of windings are connected in series. The second setting on-off mode is that all IGBTs in the first group of switch tubes are turned off, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned on, and the second setting connection mode is that the first set of windings and the second set of windings are connected in parallel.

[0082] That is to say, when all IGBTs in the first group of switch tubes are turned on and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned off, the first set of windings and the second set of windings are connected in series; when all IGBTs in the first group of switch tubes are turned off and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned on, the first set of windings and the second set of windings are connected in parallel.

[0083] Figure 3 is a schematic diagram of an equivalent circuit structure of the winding series-parallel switching device of the motor of the present invention when the windings are connected in series, Figure 4 The figure is a schematic diagram of the equivalent circuit structure of the motor winding series-parallel switching device of the present invention when the windings are connected in parallel. In the scheme of the present invention, the control scheme of the device for switching the motor windings in series-parallel also includes a drive control module. When the drive control module receives the winding series connection instruction, the drive control module controls the first group of switch tubes to be turned on, and the second group of switch tubes and the third group of switch tubes to be turned off (the equivalent circuit principle at this time is shown in FIG. Figure 3 When the drive control module receives the parallel command, the drive control module controls the first group of switch tubes to turn off, and the second group of switch tubes and the third group of switch tubes to turn on (the equivalent circuit principle at this time is shown in Figure 4 shown).

[0084] Figure 5 FIG. 1 is a schematic diagram of the control flow of the winding series-parallel switching device of the motor of the present invention during winding switching. Figure 5 As shown, the control process of the motor winding series-parallel switching device during winding switching includes:

[0085] Step 1: upon receiving a winding switching instruction, determine whether the next state of the motor winding switching is a series instruction or a parallel instruction: if it is a series instruction, execute step 2; if it is a parallel instruction, execute step 3.

[0086] Step 2. When the drive control module receives the series connection instruction, the drive control module controls the first group of switch tubes to be turned on, and the second and third groups of switch tubes to be turned off. Only in this way can the connection mode of the first set of windings and the second set of windings be switched to series connection, and the series-parallel switching of the first set of windings and the second set of windings be realized, which can ensure both low-frequency energy efficiency and high-frequency stable operation, and the motor does not need to be shut down.

[0087] Step 3. When the drive control module receives the parallel instruction, the drive control module controls the first group of switch tubes to turn off, and the second and third groups of switch tubes to turn on. Only in this way can the connection mode of the first set of windings and the second set of windings be switched to parallel, and the series-parallel switching of the first set of windings and the second set of windings be realized, which can ensure both low-frequency energy efficiency and high-frequency stable operation, and the motor does not need to be shut down.

[0088] Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the switching device of the aforementioned motor, for the details not exhaustive in the description of this embodiment, please refer to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be made here.

[0089] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0090] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A switching device for a motor, characterized in that: The motor has a first set of windings and a second set of windings, and both the first set of windings and the second set of windings are three-phase windings; The switching device of the motor includes: a first group of switch tubes, a second group of switch tubes and a third group of switch tubes; the first group of switch tubes is connected between the second end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings, and the second ends of the three-phase windings of the second set of windings are connected to form a center point; the second group of switch tubes is connected between the first end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings; the third group of switch tubes is connected between the second ends of two adjacent phase windings in the three-phase winding of the first set of windings; wherein, The first group of switch tubes includes: three IGBT combinations; the second group of switch tubes includes: three IGBT combinations; the third group of switch tubes includes: two IGBT combinations; in the first group of switch tubes, the second group of switch tubes and the third group of switch tubes, each IGBT combination includes two IGBTs connected in reverse series; Wherein, when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is a first set on-off mode, the connection mode between the first set of windings and the second set of windings is a first set connection mode; When the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is the second set on-off mode, the connection mode between the first set of windings and the second set of windings is the second set connection mode.

2. The switching device of the motor according to claim 1, characterized in that: Each IGBT combination includes: a first IGBT and a second IGBT, and the first IGBT and the second IGBT are both provided with a freewheeling diode; wherein, The collector of the first IGBT is connected to the collector of the second IGBT, and the anode of the freewheeling diode of the first IGBT is connected to the anode of the freewheeling diode of the second IGBT, so that the current of each IGBT combination can flow bidirectionally.

3. The switching device of the motor according to claim 1 or 2, characterized in that: in, In the first group of switch tubes, three IGBT combinations include: a first IGBT combination, a second IGBT combination and a third IGBT combination; the first IGBT combination, the second IGBT combination and the third IGBT combination are correspondingly connected between the second end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings; In the second group of switch tubes, three IGBT combinations include: a fourth IGBT combination, a fifth IGBT combination, and a sixth IGBT combination; the fourth IGBT combination, the fifth IGBT combination, and the sixth IGBT combination are correspondingly connected between the first end of the three-phase winding of the first set of windings and the first end of the three-phase winding of the second set of windings; In the third group of switch tubes, two IGBT combinations include: a seventh IGBT combination and an eighth IGBT combination; the seventh IGBT combination and the eighth IGBT combination are respectively connected between the second ends of two adjacent phase windings in the three-phase windings of the first set of windings; Among them, the first IGBT combination, the second IGBT combination, the third IGBT combination, the fourth IGBT combination, the fifth IGBT combination, the sixth IGBT combination, the seventh IGBT combination and the eighth IGBT combination have the same structure, and each IGBT combination includes two IGBTs connected in reverse series.

4. The switching device of the motor according to claim 3, characterized in that: The three-phase windings of the first set of windings include: U1 phase winding, V1 phase winding and W1 phase winding; the three-phase windings of the second set of windings include: U2 phase winding, V2 phase winding and W2 phase winding, the second end of the U2 phase winding, the second end of the V2 phase winding and the second end of the W2 phase winding are connected to form a center point; wherein, The first IGBT combination is connected between the second end of the U1 phase winding and the first end of the U2 phase winding; The second IGBT combination is connected between the second end of the V1 phase winding and the first end of the V2 phase winding; The third IGBT combination is connected between the second end of the W1 phase winding and the first end of the W2 phase winding; The fourth IGBT combination is connected between the first end of the U1 phase winding and the first end of the U2 phase winding; The fifth IGBT combination is connected between the first end of the V1 phase winding and the first end of the V2 phase winding; The sixth IGBT combination is connected between the first end of the W1 phase winding and the first end of the W2 phase winding; The seventh IGBT combination is connected between the second end of the U1 phase winding and the second end of the V1 phase winding; The eighth IGBT combination is connected between the second end of the V1 phase winding and the second end of the W1 phase winding.

5. The switching device of a motor according to any one of claims 1 to 4, characterized in that: in, The first setting on-off mode is that all IGBTs in the first group of switch tubes are turned on, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned off, and the first setting connection mode is that the first set of windings and the second set of windings are connected in series; The second setting on-off mode is that all IGBTs in the first group of switch tubes are turned off, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned on, and the second setting connection mode is that the first set of windings and the second set of windings are connected in parallel.

6. A compressor, characterized in that: include: A switching device for an electric motor as claimed in any one of claims 1 to 5.

7. An air conditioner, characterized in that: include: A switching device for a motor as claimed in any one of claims 1 to 5, or a compressor as claimed in claim 6.

8. A method for controlling a switching device of a motor according to any one of claims 1 to 5, characterized in that: include: During the operation of the motor, determining whether a winding switching instruction of the motor is received; If a winding switching instruction of the motor is received, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes are controlled according to the winding switching instruction of the motor to switch the connection mode between the first set of windings and the second set of windings; Wherein, when the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is a first set on-off mode, the connection mode between the first set of windings and the second set of windings is a first set connection mode; When the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is the second set on-off mode, the connection mode between the first set of windings and the second set of windings is the second set connection mode.

9. The control method of the switching device of the motor according to claim 8, characterized in that: According to the winding switching instruction of the motor, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes are controlled to realize the switching of the connection mode between the first set of windings and the second set of windings, including: Determine whether the winding switching instruction of the motor is a set first instruction or a set second instruction; wherein the set first instruction is an instruction for making the connection mode between the first set of windings and the second set of windings a first set connection mode; and the set second instruction is an instruction for making the connection mode between the first set of windings and the second set of windings a second set connection mode; If the winding switching instruction of the motor is a set first instruction, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is controlled to be a first set on-off mode, so that the connection mode between the first set of windings and the second set of windings is the first set connection mode; If the winding switching instruction of the motor is a set second instruction, the on-off mode of the first group of switch tubes, the second group of switch tubes and the third group of switch tubes is controlled to be the second set on-off mode, so that the connection mode between the first set of windings and the second set of windings is the second set connection mode.

10. The control method of the switching device of the motor according to claim 8 or 9, characterized in that: in, The first setting on-off mode is that all IGBTs in the first group of switch tubes are turned on, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned off, and the first setting connection mode is that the first set of windings and the second set of windings are connected in series; The second setting on-off mode is that all IGBTs in the first group of switch tubes are turned off, and all IGBTs in the second group of switch tubes and all IGBTs in the third group of switch tubes are turned on, and the second setting connection mode is that the first set of windings and the second set of windings are connected in parallel.

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