A universal power converter for switched reluctance motor and a control method thereof

Abstract

A universal power converter of switched reluctance motor and a control method thereof, the power converter is composed of a universal main circuit of switched reluctance motor and an excitation and power supply circuit, the universal main circuit of switched reluctance motor absorbs electric energy output from the excitation and power supply circuit, the universal main circuit of switched reluctance motor outputs electric energy and connects the excitation and power supply circuit, the universal main circuit of switched reluctance motor is composed of thirteen switching tubes, four diodes, one capacitor and each phase winding of switched reluctance motor, four working modes can be realized through control of relevant switching tubes, diversified functions such as direct current with step-up or step-down voltage and alternating current are obtained, the excitation and power supply circuit has an isolation link and can output variable voltage, overall multi-function low-loss four-quadrant operation is realized, and the power converter is suitable for application in the field of switched reluctance motor system for various application scenarios.

Description

Technical Field

[0001] This invention relates to the field of motor systems, and more specifically to a versatile converter system that adapts to multifunctional needs and is used for four-quadrant operation of a switched reluctance motor. Background Technology

[0002] Switched reluctance motors, with their simple and robust structure, winding-free rotor, high temperature and high speed resistance, and adaptability to harsh environments, are low in cost. The direction of the phase winding current is independent of the torque direction, which makes it very convenient to realize power generation and four-quadrant operation. They should have broad application prospects.

[0003] Power converters are an indispensable core component for switched reluctance motors (SRMs). Unlike traditional motor systems, without a power converter, a SRM cannot perform even the most basic rotation. With the continuous changes and advancements in application fields, traditional power converters often cannot meet diverse needs. For example, when a SRM operates as a generator, it is common to directly output DC power via a power converter. If the system requires AC output, a separate inverter is needed, increasing cost and reducing efficiency. Furthermore, some applications require a direct voltage boost output during power generation, while others require a step-down output, often necessitating the use of different power converters. Additionally, some applications require frequent switching between power generation and motoring modes, which also requires a single power converter. In short, more versatile composite power converters are an inevitable development trend to meet diverse needs.

[0004] The diversification of functional requirements often leads to the extensive use of switching transistors in power electronic systems such as power converters, as well as the resulting switching losses, which reduce system efficiency and reliability, and sometimes even outweigh the benefits. Therefore, the four-quadrant composite use of the same power converter and the minimization of the number of switching transistors used for switching control in each operating mode are inevitable technological development trends.

[0005] In the field of switched reluctance motor systems, various voltage quantities such as generator voltage, supply voltage, and excitation voltage during generator operation can be regulated by a power converter. This eliminates the need for additional transformer devices when required, which is also the industry trend.

[0006] Furthermore, when power converters have diverse functions, especially feedback functions, they often require additional dedicated isolation devices due to their different grounding. This inevitably increases the system size, weight, cost, and losses, causing significant problems. Summary of the Invention

[0007] Purpose of the invention: The purpose of this invention is to provide a switched reluctance motor composite power converter system and its control method that can achieve four operating modes, including direct boost and direct buck output, reverse polarity output, DC and AC output, real-time operation with a small number of switching transistors, variable voltage, built-in isolation, and convenient four-quadrant operation.

[0008] Technical solution: A universal power converter for switched reluctance motors, comprising a universal main circuit for switched reluctance motors and an excitation and power supply circuit. The universal main circuit for switched reluctance motors absorbs electrical energy output from the excitation and power supply circuit, and outputs electrical energy and connects to the excitation and power supply circuit.

[0009] The general main circuit of a switched reluctance motor includes: a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch, a first bidirectional switch, a second bidirectional switch, a third bidirectional switch, a fourth bidirectional switch, a first phase winding, a second phase winding, a third phase winding, a fourth phase winding, a first diode, a second diode, a third diode, a fourth diode, and a first capacitor. The anode of the first switch serves as the positive input terminal of the general main circuit of the switched reluctance motor. The cathode of the first switch is connected to the anodes of the second and third switches, and the cathode of the third switch is connected to the anode of the fifth switch. One end of the first bidirectional switch, one end of the second bidirectional switch, one end of the third bidirectional switch, one end of the fourth bidirectional switch, and the cathode of the second diode are also included. The other end of the first bidirectional switch is connected to one end of the first phase winding, the other end of the second bidirectional switch, the other end of the third bidirectional switch, and the other end of the fourth bidirectional switch is connected to one end of the fourth phase winding. The other end of the phase winding is connected to the other end of the second phase winding, the other end of the third phase winding, the other end of the fourth phase winding, the cathode of the second switch transistor K2, the anode of the fourth switch transistor, and the cathode of the first diode. The anode of the first diode is connected to the cathode of the fourth switch transistor, the cathode of the sixth switch transistor, and the anode of the third diode. The anode of the second diode is connected to the cathode of the fifth switch transistor, the cathode of the seventh switch transistor, and the anode of the fourth diode. The cathode of the fourth diode is connected to the anode of the seventh switch transistor, the anode of the ninth switch transistor, and one end of the first capacitor, and serves as the first output terminal of the general main circuit of the switched reluctance motor. The cathode of the third diode is connected to the anode of the sixth switch transistor, the anode of the eighth switch transistor, and the other end of the first capacitor, and serves as the second output terminal of the general main circuit of the switched reluctance motor. The cathode of the eighth switch transistor is connected to the cathode of the ninth switch transistor and serves as the negative input terminal of the general main circuit of the switched reluctance motor. All bidirectional switches are bidirectional controllable power electronic switching devices. Each bidirectional switch is composed of two unidirectional fully controllable power electronic switching devices connected in antiparallel. The other switches are unidirectional fully controllable power electronic switching devices.

[0010] When the excitation and power supply circuits output electrical energy to the input terminals of the general-purpose main circuit of the switched reluctance motor, the switching reluctance motor can operate in four selectable modes:

[0011] First Operating Mode: Based on the fundamental theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit acts as the excitation power source. According to the rotor position information, when the first phase winding needs to be engaged, the first, second, fifth, and eighth switching transistors, as well as the forward-conducting first bidirectional switching transistor, are closed, entering the first operating stage of the first phase winding, i.e., the excitation stage during generator operation. The electrical energy provided by the excitation and power supply circuit excites the first phase winding through the first, second, first bidirectional switching transistor, fifth, fourth diode, and eighth switching transistor, and simultaneously... The first capacitor is charged and outputs power. According to the rotor position information, when the first working stage of the first phase winding needs to end, the first switch, the second switch, and the eighth switch are disconnected, and the sixth switch is closed to enter the second working stage of the first phase winding, which is the power generation stage during generator operation. The energy stored in the first phase winding charges the first capacitor and outputs electrical energy through the first bidirectional switch, the fifth switch, the fourth diode, the sixth switch, and the first diode. According to the rotor position information, when the second working stage of the first phase winding needs to end, the fifth switch, the sixth switch, and the first bidirectional switch are disconnected, and the first phase winding operation ends.

[0012] The only difference between the operation control process of the remaining phase windings and that of the first phase winding is that, according to the rotor position information, when the second phase winding, the third phase winding, and the fourth phase winding are working respectively, the second bidirectional switch, the third bidirectional switch, and the fourth bidirectional switch connected in series with each other replace the first bidirectional switch, and according to the rotor position information, when each phase winding is working, its respective bidirectional switch connected in series is forward-biased.

[0013] When the switched reluctance motor is running as a motor, the excitation and power supply circuit serves as the power source. Based on the real-time rotor position information, which differs from that used when the motor is running as a generator, the circuit controls the operation of each phase winding and the corresponding switching transistors. The operation control process is the same as when the motor is running as a generator.

[0014] Second operating mode: Based on the basic theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit acts as the excitation power source. According to the rotor position information, when the first phase winding needs to be engaged, the first, second, fifth, and ninth switching transistors, as well as the forward-conducting first bidirectional switching transistor, are first closed, entering the first operating stage of the first phase winding, i.e., the excitation stage during generator operation. The electrical energy provided by the excitation and power supply circuit excites the first phase winding through the first, second, first bidirectional switching transistor, fifth switching transistor, fourth diode, and ninth switching transistor. According to the rotor position... According to the rotor position information, when the first working stage of the first phase winding needs to end, the ninth switch is disconnected and the eighth switch is closed, entering the second working stage of the first phase winding, which is the power generation stage of the generator. The first phase winding is connected in series with the output terminal of the excitation and power supply circuit, and charges the first capacitor and outputs electrical energy through the first switch, the second switch, the first bidirectional switch, the fifth switch, the fourth diode, and the eighth switch. According to the rotor position information, when the second working stage of the first phase winding needs to end, the first switch, the second switch, the fifth switch, the eighth switch, and the first bidirectional switch are disconnected, and the first phase winding M ends its operation.

[0015] The only difference between the operation control process of the remaining phase windings and that of the first phase winding is that, according to the rotor position information, when the second phase winding, the third phase winding, and the fourth phase winding are working respectively, the second bidirectional switch, the third bidirectional switch, and the fourth bidirectional switch connected in series with each other replace the first bidirectional switch, and according to the rotor position information, when each phase winding is working, its respective bidirectional switch connected in series is forward-biased.

[0016] When the switched reluctance motor is running as a motor, the excitation and power supply circuit serves as the power source. Based on the real-time rotor position information, which differs from that used when the motor is running as a generator, the circuit controls the operation of each phase winding and the corresponding switching transistors. The operation control process is the same as when the motor is running as a generator.

[0017] The third operating mode: Based on the basic theory and working principle of switched reluctance motors, when the switched reluctance motor is running as a generator, the excitation and power supply circuit acts as the excitation power source. According to the rotor position information, when the first phase winding needs to be engaged, the first, second, fifth, and ninth switching transistors, as well as the forward-conducting first bidirectional switching transistor, are first closed, entering the first operating stage of the first phase winding, i.e., the excitation stage when running as a generator. The electrical energy provided by the excitation and power supply circuit is supplied to the first phase winding via the first, second, first bidirectional switching transistor, fifth switching transistor, fourth diode, and ninth switching transistor. According to the rotor position information, when the first working stage of the first phase winding needs to end, the first switch, the second switch, and the ninth switch are disconnected, and the sixth switch is closed to enter the second working stage of the first phase winding, which is the power generation stage during generator operation. The energy stored in the first phase winding is charged to the first capacitor and output as electrical energy through the first bidirectional switch, the fifth switch, the fourth diode, the sixth switch, and the first diode D1. According to the rotor position information, when the second working stage of the first phase winding needs to end, the fifth switch, the sixth switch, and the first bidirectional switch are disconnected, and the operation of the first phase winding ends.

[0018] The only difference between the operation control process of the remaining phase windings and that of the first phase winding is that, according to the rotor position information, when the second phase winding, the third phase winding, and the fourth phase winding are working respectively, the second bidirectional switch, the third bidirectional switch, and the fourth bidirectional switch connected in series with each other replace the first bidirectional switch, and according to the rotor position information, when each phase winding is working, its respective bidirectional switch connected in series is forward-biased.

[0019] When the switched reluctance motor is running as a motor, the excitation and power supply circuit serves as the power source. Based on the real-time rotor position information, which differs from that used when the motor is running as a generator, the circuit controls the operation of each phase winding and the corresponding switching transistors. The operation control process is the same as when the motor is running as a generator.

[0020] Fourth Operating Mode: Based on the fundamental theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit acts as the excitation power source. According to the rotor position information, when the first phase winding needs to be engaged, the first, second, fifth, and eighth switching transistors, as well as the forward-conducting first bidirectional switching transistor, are closed, entering the first operating stage of the first phase winding, i.e., the excitation stage during generator operation. The electrical energy provided by the excitation and power supply circuit excites the first phase winding through the first, second, first bidirectional switching transistor, fifth, fourth diode, and eighth switching transistor, while also charging and outputting the first capacitor. According to the rotor position information, when the first phase winding needs to be engaged in the first operating stage... At the end, the first, second, and eighth switches are disconnected, and the sixth switch is closed, entering the second working stage of the first phase winding, which is the power generation stage of the generator operation. The energy stored in the first phase winding charges the first capacitor and outputs electrical energy through the first bidirectional switch, the fifth switch, the fourth diode, the sixth switch, and the first diode. According to the rotor position information, when the second working stage of the first phase winding needs to end, the fifth, sixth, and first bidirectional switches are disconnected, and the first phase winding operation ends. According to the rotor position information, when the second phase winding needs to be put into operation, the first, third, fourth, and ninth switches are closed, and the second bidirectional switch is closed in reverse, entering the second phase winding operation. The second phase winding enters its first operating stage, which is the excitation stage during generator operation. The electrical energy supplied by the excitation and power supply circuit is used to excite the second phase winding via the first, third, second bidirectional, fourth, third, and ninth switching transistors. Simultaneously, it reverse-charges the first capacitor and outputs it in reverse. At this time, the polarity of the output terminal of the switched reluctance motor's general-purpose main circuit is opposite to that of the previous operating phase winding (i.e., the first phase winding). Based on the rotor position information, when the first operating stage of the second phase winding needs to end, the first, third, and ninth switching transistors are disconnected, and the seventh switching transistor is closed, entering the second operating stage of the second phase winding, which is the generation stage during generator operation. The energy stored in the second phase winding is then transmitted through the second bidirectional switch... The first phase winding, consisting of a first diode, a fourth diode, a third diode, a seventh diode, and a second diode, charges the first capacitor in reverse and outputs electrical energy in reverse. Based on the rotor position information, when the second phase winding's second operating stage needs to end, the fourth, seventh, and second bidirectional diodes are disconnected, ending the second phase winding's operation. When the third phase winding needs to be activated based on the rotor position information, the operating control process differs from the first phase winding in that the third bidirectional diode replaces the first bidirectional diode; otherwise, the process is the same. Similarly, when the fourth phase winding needs to be activated based on the rotor position information, the operating control process differs from the second phase winding in that the fourth bidirectional diode replaces the second bidirectional diode; otherwise, the process continues in this manner, with adjacent phase windings outputting electrical energy in opposite polarities.

[0021] When the switched reluctance motor is running as a motor, the excitation and power supply circuit serves as the power source. Based on the real-time rotor position information, which differs from that used when the motor is running as a generator, the circuit controls the operation of each phase winding and the corresponding switching transistors. The operation control process is the same as when the motor is running as a generator.

[0022] The excitation and power supply circuit includes: a tenth switch, an eleventh switch, a twelfth switch, a thirteenth switch, a fourteenth switch, a fifth diode, a sixth diode, a seventh diode, an eighth diode, a ninth diode, a tenth diode, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a three-winding transformer, and a first inductor. The anode of the tenth switch is connected to the anode of the twelfth switch and serves as the positive input terminal of the excitation and power supply circuit. The cathode of the tenth switch is connected to the anode of the eleventh switch and one end of the primary winding of the three-winding transformer. The cathode of the twelfth switch is connected to the anode of the thirteenth switch and the other end of the primary winding of the three-winding transformer. The cathode of the eleventh switch is connected to the cathode of the thirteenth switch and serves as the negative input terminal of the excitation and power supply circuit. One end of the first winding on the secondary side of the three-winding transformer is connected to the anode of the fifth diode and the cathode of the sixth diode. The other end of the first winding on the secondary side of the three-winding transformer is connected to... One end of the second capacitor and one end of the third capacitor are connected. One end of the second winding on the secondary side of the three-winding transformer is connected to the anode of the seventh diode and the cathode of the eighth diode. The other end of the second winding on the secondary side of the three-winding transformer is connected to one end of the fourth capacitor and one end of the fifth capacitor. The cathode of the fifth diode is connected to the other end of the second capacitor, the cathode of the ninth diode, and one end of the first inductor. The anode of the sixth diode is connected to the other end of the third capacitor, the cathode of the fourteenth switch, and the cathode of the tenth diode. The anode of the fourteenth switch is connected to the cathode of the seventh diode, the anode of the ninth diode, and the other end of the fourth capacitor. The anode of the eighth diode is connected to the anode of the tenth diode, the other end of the fifth capacitor, and one end of the sixth capacitor, and serves as the negative terminal of the excitation and power supply circuit output. The other end of the first inductor is connected to the other end of the sixth capacitor and serves as the positive terminal of the excitation and power supply circuit output. All switches are three-terminal fully controlled power electronic switching devices with built-in anti-parallel diodes.

[0023] When the excitation and power supply circuit is working, it is controlled by five switching transistors: the tenth, eleventh, twelfth, thirteenth, and fourteenth. These five switching transistors all operate in PWM mode. The PWM switching frequencies of the tenth, eleventh, twelfth, and thirteenth switching transistors are the same, and their duty cycles are also the same and less than 0.5. The phase difference between the tenth and eleventh switching transistors is 180 degrees, and the phase difference between the twelfth and thirteenth switching transistors is also 180 degrees. The PWM switching frequency of the fourteenth switching transistor is twice that of the other four switching transistors. Furthermore, the twelfth and fourteenth switching transistors are turned on simultaneously, and the thirteenth and fourteenth switching transistors (K14) are turned on simultaneously. When the tenth switching transistor is turned off, the fourteenth switching transistor is turned off, and when the eleventh switching transistor is turned off, the fourteenth switching transistor is turned off. By adjusting the PWM duty cycle of each switching transistor, the output of the excitation and power supply circuit is controlled.

[0024] The beneficial effects of this invention are:

[0025] The four operating modes of the general main circuit for switched reluctance motors can all realize four-quadrant operation control of switched reluctance motors, which is highly versatile. Although there are 13 switching transistors, more than 50% of the switching transistors do not perform switching operations in each operating stage, and even fewer switching transistors are required in some operating stages, so the overall switching loss is not high.

[0026] In the first operating mode of the general main circuit of the switched reluctance motor, as a generator, continuous current output is possible in both operating stages, improving the quality of the output power. Furthermore, during the excitation stage, the excitation power supply, phase windings, and generator output terminals are connected in series. If the output of the excitation and power supply circuits changes, the generator output voltage (generator voltage) can be adjusted. As can be seen from the two-stage operation, the generator voltage is lower than the phase winding voltage or the excitation voltage, meaning the generator output has a voltage reduction effect. In addition, by adjusting the switching transistors, this mode can also achieve a reverse polarity output mode with different operating stages but the same effect, i.e., according to the attached diagram... Figure 6.3 Excitation, attached Figure 6.4 It generates electricity and can produce reverse polarity output, while other performance characteristics are the same as in this mode.

[0027] In the second operating mode of the general main circuit of the switched reluctance motor, when it is running as a generator, it is different from the first operating mode. In this mode, the excitation power supply, phase winding and generator output terminal are connected in series during the generator generation stage. If the output of the excitation and power supply circuit changes at this time, the voltage of the generator output terminal can be adjusted. It can be clearly seen from the two-stage operation process that the generator voltage is greater than the phase winding voltage and the excitation voltage, that is, the generator output has a direct voltage boosting effect.

[0028] In the third operating mode of the general main circuit of the switched reluctance motor, when operating as a generator, it is impossible to clearly determine the relationship between the generated voltage and the phase winding voltage and the excitation voltage, that is, there is a voltage boosting or bucking effect; the common feature of the first three operating modes is that when operating as a generator, they all output DC power.

[0029] The fourth operating mode of the general main circuit of the switched reluctance motor allows adjacent working phase windings to adopt different specific control modes. When operating as a generator, it can obtain electrical energy output with opposite polarity, that is, directly outputting alternating current. It can adapt to switched reluctance motors with any number of phases. However, when the number of phase windings is odd (3 phases or more), the operating control mode of each phase winding is different when it is in operation, and the output electrical energy is of opposite polarity. For switched reluctance generators with an even number of phase windings (four phases or more), each phase winding always follows a control mode during operation.

[0030] The excitation and power supply circuits have built-in and adjustable magnetic isolation components. When connecting the general main circuit of the switched reluctance motor to the input terminal for feedback self-excitation, no special isolation component is required, saving volume, weight and cost, and reducing losses. Whether for the excitation of the switched reluctance generator or for the speed control of the switched reluctance motor, the adjustable excitation voltage and supply voltage provide a foundation for improving system performance. Attached Figure Description

[0031] Figure 1 The diagram shown is a structural diagram of a universal power converter for switched reluctance motors according to the present invention.

[0032] Figure 2 The diagram shown is a general main circuit structure diagram of the switched reluctance motor of the present invention.

[0033] Figure 3.1 The diagram shows the first working stage of the first phase winding in the first working mode of the general main circuit of the switched reluctance motor of the present invention.

[0034] Figure 3.2 The diagram shows the second working stage of the first phase winding in the first working mode of the general main circuit of the switched reluctance motor of the present invention.

[0035] Figure 4.1 The diagram shows the first working stage of the first phase winding in the second working mode of the general main circuit of the switched reluctance motor of the present invention.

[0036] Figure 4.2 The diagram shows the second working stage of the first phase winding in the second working mode of the general main circuit of the switched reluctance motor of the present invention.

[0037] Figure 5.1 The diagram shows the first working stage of the first phase winding in the third working mode of the general main circuit of the switched reluctance motor of the present invention.

[0038] Figure 5.2 The diagram shows the second working stage of the first phase winding in the third working mode of the general main circuit of the switched reluctance motor of the present invention.

[0039] Figure 6.1 The diagram shows the first working stage of the first phase winding in the fourth working mode of the general main circuit of the switched reluctance motor of the present invention.

[0040] Figure 6.2 The diagram shows the second working stage of the first phase winding in the fourth working mode of the general main circuit of the switched reluctance motor of the present invention.

[0041] Figure 6.3 The diagram shows the first working stage of the second phase winding in the fourth working mode of the general main circuit of the switched reluctance motor of the present invention.

[0042] Figure 6.4 The diagram shows the second working stage of the second phase winding in the fourth working mode of the general main circuit of the switched reluctance motor of the present invention.

[0043] Figure 7 The diagram shown is a structural diagram of the excitation and power supply circuit of this invention.

[0044] Figure 8 The diagram shown is a timing diagram of the switching transistors in the excitation and power supply circuit of this invention. Detailed Implementation

[0045] A universal power converter for switched reluctance motors and its control method are disclosed. The power converter consists of a universal main circuit 1 for switched reluctance motors and an excitation and power supply circuit 2, as shown in the attached figure. Figure 1 As shown, the general main circuit 1 of the switched reluctance motor absorbs electrical energy from the excitation and power supply circuit 2. The general main circuit 1 of the switched reluctance motor outputs electrical energy. If the general main circuit 1 of the switched reluctance motor outputs DC power, it can be connected to the input terminal of the excitation and power supply circuit 2 as its input electrical energy. The switched reluctance motor in this embodiment has a four-phase winding structure. When the switched reluctance motor is running as a generator, the excitation and power supply circuit 2 serves as the excitation power supply, and its output voltage is the excitation voltage. When the switched reluctance motor is running as a motor, the excitation and power supply circuit 2 serves as the power supply.

[0046] The general main circuit 1 of the switched reluctance motor includes: a first switch K1, a second switch K2, a third switch K3, a fourth switch K4, a fifth switch K5, a sixth switch K6, a seventh switch K7, an eighth switch K8, a ninth switch K9, a first bidirectional switch S1, a second bidirectional switch S2, a third bidirectional switch S3, a fourth bidirectional switch S4, a first phase winding M, a second phase winding N, a third phase winding P, a fourth phase winding Q, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, and a first capacitor C1, as shown in the attached diagram. Figure 2As shown, the anode of the first switch transistor K1 serves as the positive input terminal of the general-purpose main circuit 1 of the switched reluctance motor. The cathode of the first switch transistor K1 is connected to the anodes of the second switch transistor K2 and the third switch transistor K3. The cathode of the third switch transistor K3 is connected to the anode of the fifth switch transistor K5, one end of the first bidirectional switch transistor S1, one end of the second bidirectional switch transistor S2, one end of the third bidirectional switch transistor S3, one end of the fourth bidirectional switch transistor S4, and the cathode of the second diode D2. The other end of the first bidirectional switch transistor S1 is connected to one end of the first phase winding M, and the other end of the second bidirectional switch transistor S2... One end of the first phase winding M is connected to one end of the second phase winding N, the other end of the third bidirectional switch S3 is connected to one end of the third phase winding P, the other end of the fourth bidirectional switch S4 is connected to one end of the fourth phase winding Q, the other end of the first phase winding M is connected to the other end of the second phase winding N, the other end of the third phase winding P, the other end of the fourth phase winding Q, the cathode of the second switch K2, the anode of the fourth switch K4, and the cathode of the first diode D1. The anode of the first diode D1 is connected to the cathode of the fourth switch K4, the cathode of the sixth switch K6, and the anode of the third diode D3. The anode of diode D2 is connected to the cathodes of the fifth switch K5, the seventh switch K7, and the anode of the fourth diode D4. The cathode of the fourth diode D4 is connected to the anodes of the seventh switch K7, the ninth switch K9, and one end of the first capacitor C1, serving as the first output terminal of the general main circuit 1 for the switched reluctance motor. The cathode of the third diode D3 is connected to the anodes of the sixth switch K6, the eighth switch K8, and the other end of the first capacitor C1, serving as the second output terminal of the general main circuit 1 for the switched reluctance motor. The cathode of the eighth switch K8 is connected to the cathode of the ninth switch K9, serving as the negative input terminal of the general main circuit 1 for the switched reluctance motor. All bidirectional switches are bidirectional controllable power electronic switching devices. Each bidirectional switch consists of two unidirectional fully controllable power electronic switching devices connected in antiparallel. Other switches are unidirectional fully controllable power electronic switching devices, including power MOSFETs or IGBTs. The first phase winding M, the second phase winding N, the third phase winding P, and the fourth phase winding Q constitute the four-phase windings of the switched reluctance motor in this embodiment.

[0047] When the excitation and power supply circuit 2 outputs electrical energy to the input terminals of the universal main circuit 1 for the switched reluctance motor, the switching reluctance motor can operate in four selectable modes:

[0048] First Operating Mode: Based on the fundamental theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit 2 serves as the excitation power source. According to the rotor position information, when the first phase winding M needs to be engaged, the first switch K1, the second switch K2, the fifth switch K5, the eighth switch K8, and the forward-conducting first bidirectional switch S1 are first closed, entering the first operating stage of the first phase winding M, i.e., the excitation stage during generator operation, as shown in the attached diagram. Figure 3.1 As shown, the electrical energy provided by the excitation and power supply circuit 2 is used to excite the first phase winding M via the first switch K1, the second switch K2, the first bidirectional switch S1, the fifth switch K5, the fourth diode D4, and the eighth switch K8. Simultaneously, it charges the first capacitor C1 and outputs the power. Based on the rotor position information, when the first working stage of the first phase winding M needs to end, the first switch K1, the second switch K2, and the eighth switch K8 are disconnected, and the sixth switch K6 is closed, entering the second working stage of the first phase winding M, which is the power generation stage during generator operation, as shown in the attached diagram. Figure 3.2 As shown, the energy stored in the first phase winding M is charged to the first capacitor C1 and output as electrical energy through the first bidirectional switch S1, the fifth switch K5, the fourth diode D4, the sixth switch K6, and the first diode D1; according to the rotor position information, when the second working stage of the first phase winding M needs to end, the fifth switch K5, the sixth switch K6, and the first bidirectional switch S1 are disconnected, and the working of the first phase winding M ends.

[0049] The operation control process of the remaining phase windings is basically the same as that of the first phase winding M. The only difference is that, according to the rotor position information, when the second phase winding N, the third phase winding P, and the fourth phase winding Q are working respectively, the second bidirectional switch S2, the third bidirectional switch S3, and the fourth bidirectional switch S4 connected in series with each other replace the first bidirectional switch S1. According to the rotor position information, when each phase winding is working, its series bidirectional switch can be forward-biased.

[0050] When the switched reluctance motor is running as a motor, the excitation and power supply circuit 2 serves as the power source. The switched reluctance motor has different control times, and the operation of each phase winding and each switching transistor is controlled according to the rotor position information. The operation control process is the same as when it is running as a generator. However, since the phase windings mainly absorb electrical energy to generate mechanical energy, the electrical energy received at the first capacitor C1 terminal is much less. It is mainly the electrical energy converted from the residual magnetism of each phase winding and part of the electrical energy output of the excitation and power supply circuit 2.

[0051] Second operating mode: Based on the basic theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit 2 serves as the excitation power supply. According to the rotor position information, when the first phase winding M needs to be put into operation, the first switch K1, the second switch K2, the fifth switch K5, the ninth switch K9, and the forward-conducting first bidirectional switch S1 are first closed, entering the first operating stage of the first phase winding M, i.e., the excitation stage during generator operation, as shown in the attached diagram. Figure 4.1As shown, the electrical energy provided by the excitation and power supply circuit 2 excites the first phase winding M through the first switch K1, the second switch K2, the first bidirectional switch S1, the fifth switch K5, the fourth diode D4, and the ninth switch K9. Based on the rotor position information, when the first working stage of the first phase winding M needs to end, the ninth switch K9 is disconnected, and the eighth switch K8 is closed, entering the second working stage of the first phase winding M, which is the power generation stage during generator operation, as shown in the attached diagram. Figure 4.2 As shown, the first phase winding M is connected in series with the output terminal of the excitation and power supply circuit 2, and charges the first capacitor C1 and outputs electrical energy through the first switch K1, the second switch K2, the first bidirectional switch S1, the fifth switch K5, the fourth diode D4, and the eighth switch K8. According to the rotor position information, when the second working stage of the first phase winding M needs to end, the first switch K1, the second switch K2, the fifth switch K5, the eighth switch K8, and the first bidirectional switch S1 are disconnected, and the working of the first phase winding M ends.

[0052] The operation control process of the remaining phase windings is basically the same as that of the first phase winding M. The only difference is that, according to the rotor position information, when the second phase winding N, the third phase winding P, and the fourth phase winding Q are working respectively, the second bidirectional switch S2, the third bidirectional switch S3, and the fourth bidirectional switch S4 connected in series with each other replace the first bidirectional switch S1. According to the rotor position information, when each phase winding is working, its series bidirectional switch can be forward-biased.

[0053] When the switched reluctance motor is running as a motor, the excitation and power supply circuit 2 serves as the power source. The switched reluctance motor has different control times, and the operation of each phase winding and each switching transistor is controlled according to the rotor position information. The operation control process is the same as when it is running as a generator. However, since the phase windings mainly absorb electrical energy to generate mechanical energy, the electrical energy received at the first capacitor C1 terminal is much less. It is mainly the electrical energy converted from the residual magnetism of each phase winding and part of the electrical energy output of the excitation and power supply circuit 2.

[0054] Third operating mode: Based on the basic theory and working principle of switched reluctance motors, when the switched reluctance motor is running as a generator, the excitation and power supply circuit 2 serves as the excitation power supply. According to the rotor position information, when the first phase winding M needs to be put into operation, the first switch K1, the second switch K2, the fifth switch K5, the ninth switch K9, and the first bidirectional switch S1 (forward conduction) are first closed and turned on, entering the first operating stage of the first phase winding M, that is, the excitation stage when running as a generator, as shown in the attached diagram. Figure 5.1As shown, the electrical energy provided by the excitation and power supply circuit 2 excites the first phase winding M through the first switch K1, the second switch K2, the first bidirectional switch S1, the fifth switch K5, the fourth diode D4, and the ninth switch K9. According to the rotor position information, when the first working stage of the first phase winding M needs to end, the first switch K1, the second switch K2, and the eighth switch K8 are disconnected, and the sixth switch K6 is closed, entering the second working stage of the first phase winding M, which is the power generation stage during generator operation, as shown in the attached diagram. Figure 5.2 As shown, the energy stored in the first phase winding M is charged to the first capacitor C1 and output as electrical energy through the first bidirectional switch S1, the fifth switch K5, the fourth diode D4, the sixth switch K6, and the first diode D1; according to the rotor position information, when the second working stage of the first phase winding M needs to end, the fifth switch K5, the sixth switch K6, and the first bidirectional switch S1 are disconnected, and the working of the first phase winding M ends.

[0055] The operation control process of the remaining phase windings is basically the same as that of the first phase winding M. The only difference is that, according to the rotor position information, when the second phase winding N, the third phase winding P, and the fourth phase winding Q are working respectively, the second bidirectional switch S2, the third bidirectional switch S3, and the fourth bidirectional switch S4 connected in series with each other replace the first bidirectional switch S1. According to the rotor position information, when each phase winding is working, its series bidirectional switch can be forward-biased.

[0056] When the switched reluctance motor is running as a motor, the excitation and power supply circuit 2 serves as the power source. The switched reluctance motor has different control times, and the operation of each phase winding and each switching transistor is controlled according to the rotor position information. The operation control process is the same as when it is running as a generator. However, since the phase windings mainly absorb electrical energy to generate mechanical energy, the electrical energy received at the first capacitor C1 terminal is much less. It is mainly the electrical energy converted from the residual magnetism of each phase winding and part of the electrical energy output of the excitation and power supply circuit 2.

[0057] Fourth operating mode: Based on the basic theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit 2 serves as the excitation power supply. According to the rotor position information, when the first phase winding M needs to be put into operation, the first switch K1, the second switch K2, the fifth switch K5, the eighth switch K8, and the forward-conducting first bidirectional switch S1 are first closed, entering the first operating stage of the first phase winding M, i.e., the excitation stage during generator operation, as shown in the attached diagram. Figure 6.1As shown, the electrical energy provided by the excitation and power supply circuit 2 is used to excite the first phase winding M via the first switch K1, the second switch K2, the first bidirectional switch S1, the fifth switch K5, the fourth diode D4, and the eighth switch K8. Simultaneously, it charges the first capacitor C1 and outputs the power. Based on the rotor position information, when the first working stage of the first phase winding M needs to end, the first switch K1, the second switch K2, and the eighth switch K8 are disconnected, and the sixth switch K6 is closed, entering the second working stage of the first phase winding M, which is the power generation stage during generator operation, as shown in the attached diagram. Figure 6.2 As shown, the energy stored in the first phase winding M is charged to the first capacitor C1 via the first bidirectional switch S1, the fifth switch K5, the fourth diode D4, the sixth switch K6, and the first diode D1, and outputs electrical energy. According to the rotor position information, when the second working stage of the first phase winding M needs to end, the fifth switch K5, the sixth switch K6, and the first bidirectional switch S1 are disconnected, and the first phase winding M ends its operation. According to the rotor position information, when the second phase winding N needs to be put into operation, the first switch K1, the third switch K3, the fourth switch K4, the ninth switch K9 are closed, and the second bidirectional switch S2 is reverse-biased, entering the first working stage of the second phase winding N, which is the excitation stage during generator operation, as shown in the attached diagram. Figure 6.3 As shown, the electrical energy provided by the excitation and power supply circuit 2 is used to excite the second phase winding N through the first switch K1, the third switch K3, the second bidirectional switch S2, the fourth switch K4, the third diode D3, and the ninth switch K9. Simultaneously, it reverse-charges the first capacitor C1 and outputs the power. At this time, the polarity of the output terminal of the general-purpose main circuit 1 of the switched reluctance motor is opposite to that of the previous working phase winding, i.e., the first phase winding M. According to the rotor position information, when the first working stage of the second phase winding N needs to end, the first switch K1, the third switch K3, and the ninth switch K9 are disconnected, and the seventh switch K7 is closed, entering the second working stage of the second phase winding N, which is the power generation stage during generator operation, as shown in the attached diagram. Figure 6.4As shown, the energy stored in the second phase winding N is reverse-charged to the first capacitor C1 via the second bidirectional switch S2, the fourth switch K4, the third diode D3, the seventh switch K7, and the second diode D2, and outputs electrical energy. According to the rotor position information, when the second working stage of the second phase winding N needs to end, the fourth switch K4, the seventh switch K7, and the second bidirectional switch S2 are disconnected, and the second phase winding N ends its operation. According to the rotor position information, when the third phase winding P needs to be put into operation, the difference in the working control process compared to the first phase winding M is that the third bidirectional switch S3 replaces the first bidirectional switch S1; the rest is the same. According to the rotor position information... When the fourth phase winding Q needs to be put into operation, the difference between the operation control process and that of the second phase winding N is that the fourth bidirectional switch S4 replaces the second bidirectional switch S2, while the rest is the same. In this way, the output polarity of the electrical energy when adjacent phase windings are working is opposite, so that the switched reluctance generator can directly output AC electrical energy. Furthermore, when the number of phase windings of the switched reluctance motor is even (such as the four-phase winding in this embodiment, as well as six-phase or eight-phase windings, etc.), the operation control process of each phase winding remains unchanged. When the number of phase windings of the switched reluctance motor is odd (three-phase or five-phase windings, etc.), the operation control process of each phase winding will alternately output electrical energy of opposite polarity.

[0058] When the switched reluctance motor is running as a motor, the excitation and power supply circuit 2 serves as the power source. The switched reluctance motor has different control times, and the operation of each phase winding and each switching transistor is controlled according to the rotor position information. The operation control process is the same as when it is running as a generator. However, since the phase windings mainly absorb electrical energy to generate mechanical energy, the electrical energy received at the first capacitor C1 terminal is much less. It is mainly the electrical energy converted from the residual magnetism of each phase winding and part of the electrical energy output from the excitation and power supply circuit 2, and the output terminal is AC.

[0059] The four operating modes of the switched reluctance motor can be freely selected according to different system requirements. It can directly step down the voltage, directly step up the voltage, output DC or AC power, etc., and each mode can achieve four-quadrant operation.

[0060] The excitation and power supply circuit 2 includes: tenth switch K10, eleventh switch K11, twelfth switch K12, thirteenth switch K13, fourteenth switch K14, fifth diode D5, sixth diode D6, seventh diode D7, eighth diode D8, ninth diode D9, tenth diode D10, second capacitor C2, third capacitor C3, fourth capacitor C4, fifth capacitor C5, sixth capacitor C6, three-winding transformer TW, and first inductor L1, as shown in the appendix. Figure 7As shown, the anode of the tenth switch K10 is connected to the anode of the twelfth switch K12, serving as the positive input terminal of the excitation and power supply circuit 2. The cathode of the tenth switch K10 is connected to the anode of the eleventh switch K11 and one end of the primary winding a of the three-winding transformer TW. The cathode of the twelfth switch K12 is connected to the anode of the thirteenth switch K13 and the other end of the primary winding a of the three-winding transformer TW. The cathode of the eleventh switch K11 is connected to the cathode of the thirteenth switch K13, serving as the negative input terminal of the excitation and power supply circuit 2. One end of the first winding b of the secondary side of the three-winding transformer TW is connected to the anode of the fifth diode D5 and the cathode of the sixth diode D6. The other end of the first winding b of the secondary side of the three-winding transformer TW is connected to one end of the second capacitor C2 and one end of the third capacitor C3. One end of the second winding c of the secondary side of the three-winding transformer TW is connected to the anode of the seventh diode D7 and the cathode of the eighth diode D8. The other end of the second winding c on the secondary side is connected to one end of the fourth capacitor C4 and one end of the fifth capacitor C5. The cathode of the fifth diode D5 is connected to the other end of the second capacitor C2, the cathode of the ninth diode D9, and one end of the first inductor L1. The anode of the sixth diode D6 is connected to the other end of the third capacitor C3, the cathode of the fourteenth switch K14, and the cathode of the tenth diode D10. The anode of the fourteenth switch K14 is connected to the cathode of the seventh diode D7, the anode of the ninth diode D9, and the other end of the fourth capacitor C4. The anode of the eighth diode D8 is connected to the anode of the tenth diode D10, the other end of the fifth capacitor C5, and one end of the sixth capacitor C6, and serves as the negative terminal of the excitation and power supply circuit 2. The other end of the first inductor L1 is connected to the other end of the sixth capacitor C6 and serves as the positive terminal of the excitation and power supply circuit 2. All switches are three-terminal fully controlled power electronic switching devices with built-in anti-parallel diodes.

[0061] When the excitation and power supply circuit 2 is working, it is controlled by controlling five switching transistors: the tenth switching transistor K10, the eleventh switching transistor K11, the twelfth switching transistor K12, the thirteenth switching transistor K13, and the fourteenth switching transistor K14. These five switching transistors all operate in PWM mode, and their switching timing diagrams are attached. Figure 8As shown, GK10, GK11, GK12, GK13, and GK14 represent the switching signals of the tenth switch K10, the eleventh switch K11, the twelfth switch K12, the thirteenth switch K13, and the fourteenth switch K14, respectively. Within one period T, there are eight operating logic modes. The four switches K10, K11, K12, and K13 have the same switching frequency and the same duty cycle less than 0.5. The tenth switch K10 and the eleventh switch K11 have a phase difference of 180 degrees. The 12th switch K12 and the 13th switch K13 are 180 degrees out of phase. The PWM switching frequency of the 14th switch K14 is twice that of the other four switches. When the 12th switch K12 is turned on, the 14th switch K14 is turned on simultaneously. When the 13th switch K13 is turned on, the 14th switch K14 is turned on simultaneously. When the 10th switch K10 is turned off, the 14th switch K14 is turned off simultaneously. When the 11th switch K11 is turned off, the 14th switch K14 is turned off simultaneously. Under the above constraints, the PWM duty cycle of each switch is adjusted to regulate the output of the excitation and power supply circuit 2.

[0062] The electrical energy at the input terminal of the excitation and power supply circuit 2 can come from the output electrical energy feedback when the switched reluctance motor operates as a generator and outputs DC power. The excitation and power supply circuit 2 serves as the excitation power source, which can also come from the DC grid terminal connected to the output terminal of the general main circuit 1 of the switched reluctance motor, or from other types of power sources connected to the general main circuit 1 of the switched reluctance motor. If it is an AC power source, it needs to be rectified before being input to the excitation and power supply circuit 2.

[0063] When dealing with switched reluctance motors with other phase winding numbers than the four-phase winding structure described in this embodiment, from the attached... Figure 2 It is evident that the only difference is the addition or deletion of windings and the number of series branches of bidirectional switching transistors. The operation of different phase windings and related control are still based on real-time rotor position information. There are no new technical features. Therefore, this invention is necessarily within the protection scope for non-four-phase winding switched reluctance motors.

Claims

1. A universal power converter for switched reluctance motors, comprising a universal main circuit for switched reluctance motors and an excitation and power supply circuit, characterized in that the universal main circuit for switched reluctance motors absorbs electrical energy output from the excitation and power supply circuit, and the universal main circuit for switched reluctance motors outputs electrical energy and connects to the excitation and power supply circuit.

2. The universal power converter for switched reluctance motors according to claim 1, wherein the universal main circuit for switched reluctance motors includes: The technical features of the following components are: a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, a fifth switching transistor, a sixth switching transistor, a seventh switching transistor, an eighth switching transistor, a ninth switching transistor, a first bidirectional switching transistor, a second bidirectional switching transistor, a third bidirectional switching transistor, a fourth bidirectional switching transistor, a first phase winding, a second phase winding, a third phase winding, a fourth phase winding, a first diode, a second diode, a third diode, a fourth diode, and a first capacitor. The anode of the first switching transistor serves as the positive input terminal of the general-purpose main circuit of the switched reluctance motor. The cathode of the first switching transistor is connected to the anodes of the second and third switching transistors. The cathode of the third switching transistor is connected to the anode of the fifth switching transistor, one end of the first bidirectional switching transistor, one end of the second bidirectional switching transistor, one end of the third bidirectional switching transistor, one end of the fourth bidirectional switching transistor, and the cathode of the second diode. The other end of the first bidirectional switching transistor is connected to one end of the first phase winding, the other end of the second bidirectional switching transistor is connected to one end of the second phase winding, the other end of the third bidirectional switching transistor is connected to one end of the third phase winding, and the other end of the fourth bidirectional switching transistor is connected to one end of the fourth phase winding. The other end of the first phase winding is connected to the other ends of the second, third, and fourth phase windings, the cathode of the second switching transistor, the anode of the fourth switching transistor, and the cathode of the first diode. The anode of the first diode is connected to... The fourth switch cathode, the sixth switch cathode, and the third diode anode are connected. The second diode anode is connected to the fifth switch cathode, the seventh switch cathode, and the fourth diode anode. The fourth diode cathode is connected to the seventh switch anode, the ninth switch anode, and one end of the first capacitor, serving as the first output terminal of the general-purpose main circuit of the switched reluctance motor. The third diode cathode is connected to the sixth switch anode, the eighth switch anode, and the other end of the first capacitor, serving as the second output terminal of the general-purpose main circuit of the switched reluctance motor. The eighth switch cathode is connected to the ninth switch cathode, serving as the negative input terminal of the general-purpose main circuit of the switched reluctance motor. All bidirectional switches are bidirectionally controllable power electronic switching devices. Each bidirectional switch consists of two unidirectional fully controllable power electronic switching devices connected in antiparallel. The other switches are all unidirectional fully controllable power electronic switching devices.

3. The control method for a universal power converter for a switched reluctance motor according to claims 1 and 2, wherein the technical feature is that, under the premise that the output power of the excitation and power supply circuit is provided to the input terminals of the universal main circuit of the switched reluctance motor, the method is characterized in that... The operation of a switched reluctance motor, i.e., the general main circuit of a switched reluctance motor, has four operating modes: First Operating Mode: Based on the fundamental theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit acts as the excitation power source. According to the rotor position information, when the first phase winding needs to be engaged, the first, second, fifth, and eighth switching transistors, as well as the forward-conducting first bidirectional switching transistor, are closed, entering the first operating stage of the first phase winding, i.e., the excitation stage during generator operation. The electrical energy provided by the excitation and power supply circuit excites the first phase winding through the first, second, first bidirectional switching transistor, fifth, fourth diode, and eighth switching transistor, and simultaneously... The first capacitor is charged and outputs power. According to the rotor position information, when the first working stage of the first phase winding needs to end, the first switch, the second switch, and the eighth switch are disconnected, and the sixth switch is closed to enter the second working stage of the first phase winding, which is the power generation stage during generator operation. The energy stored in the first phase winding charges the first capacitor and outputs electrical energy through the first bidirectional switch, the fifth switch, the fourth diode, the sixth switch, and the first diode. According to the rotor position information, when the second working stage of the first phase winding needs to end, the fifth switch, the sixth switch, and the first bidirectional switch are disconnected, and the first phase winding operation ends. The only difference between the operation control process of the remaining phase windings and that of the first phase winding is that, according to the rotor position information, when the second phase winding, the third phase winding, and the fourth phase winding are working respectively, the second bidirectional switch, the third bidirectional switch, and the fourth bidirectional switch connected in series with each other replace the first bidirectional switch, and according to the rotor position information, when each phase winding is working, its respective bidirectional switch connected in series is forward-biased. When the switched reluctance motor is running as a motor, the excitation and power supply circuit serves as the power source. Based on the real-time rotor position information, which is different from that when the generator is running, it controls the operation of each phase winding and the corresponding switching transistor. The operation control process is the same as when it is running as a generator. Second operating mode: Based on the basic theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit acts as the excitation power source. According to the rotor position information, when the first phase winding needs to be engaged, the first, second, fifth, and ninth switching transistors, as well as the forward-conducting first bidirectional switching transistor, are first closed, entering the first operating stage of the first phase winding, i.e., the excitation stage during generator operation. The electrical energy provided by the excitation and power supply circuit excites the first phase winding through the first, second, first bidirectional switching transistor, fifth switching transistor, fourth diode, and ninth switching transistor. According to the rotor position... According to the rotor position information, when the first working stage of the first phase winding needs to end, the ninth switch is disconnected and the eighth switch is closed, entering the second working stage of the first phase winding, which is the power generation stage of the generator. The first phase winding is connected in series with the output terminal of the excitation and power supply circuit, and charges the first capacitor and outputs electrical energy through the first switch, the second switch, the first bidirectional switch, the fifth switch, the fourth diode, and the eighth switch. According to the rotor position information, when the second working stage of the first phase winding needs to end, the first switch, the second switch, the fifth switch, the eighth switch, and the first bidirectional switch are disconnected, and the first phase winding M ends its operation. The only difference between the operation control process of the remaining phase windings and that of the first phase winding is that, according to the rotor position information, when the second phase winding, the third phase winding, and the fourth phase winding are working respectively, the second bidirectional switch, the third bidirectional switch, and the fourth bidirectional switch connected in series with each other replace the first bidirectional switch, and according to the rotor position information, when each phase winding is working, its respective bidirectional switch connected in series is forward-biased. When the switched reluctance motor is running as a motor, the excitation and power supply circuit serves as the power source. Based on the real-time rotor position information, which is different from that when the generator is running, it controls the operation of each phase winding and the corresponding switching transistor. The operation control process is the same as when it is running as a generator. The third operating mode: Based on the basic theory and working principle of switched reluctance motors, when the switched reluctance motor is running as a generator, the excitation and power supply circuit acts as the excitation power source. According to the rotor position information, when the first phase winding needs to be engaged, the first, second, fifth, and ninth switching transistors, as well as the forward-conducting first bidirectional switching transistor, are first closed, entering the first operating stage of the first phase winding, i.e., the excitation stage when running as a generator. The electrical energy provided by the excitation and power supply circuit is supplied to the first phase winding via the first, second, first bidirectional switching transistor, fifth switching transistor, fourth diode, and ninth switching transistor. According to the rotor position information, when the first working stage of the first phase winding needs to end, the first switch, the second switch, and the ninth switch are disconnected, and the sixth switch is closed to enter the second working stage of the first phase winding, which is the power generation stage during generator operation. The energy stored in the first phase winding is charged to the first capacitor and output as electrical energy through the first bidirectional switch, the fifth switch, the fourth diode, the sixth switch, and the first diode D1. According to the rotor position information, when the second working stage of the first phase winding needs to end, the fifth switch, the sixth switch, and the first bidirectional switch are disconnected, and the operation of the first phase winding ends. The only difference between the operation control process of the remaining phase windings and that of the first phase winding is that, according to the rotor position information, when the second phase winding, the third phase winding, and the fourth phase winding are working respectively, the second bidirectional switch, the third bidirectional switch, and the fourth bidirectional switch connected in series with each other replace the first bidirectional switch, and according to the rotor position information, when each phase winding is working, its respective bidirectional switch connected in series is forward-biased. When the switched reluctance motor is running as a motor, the excitation and power supply circuit serves as the power source. Based on the real-time rotor position information, which is different from that when the generator is running, it controls the operation of each phase winding and the corresponding switching transistor. The operation control process is the same as when it is running as a generator. Fourth operating mode: Based on the basic theory and working principle of switched reluctance motors, when the switched reluctance motor operates as a generator, the excitation and power supply circuit acts as the excitation power source. According to the rotor position information, when the first phase winding needs to be engaged, the first, second, fifth, and eighth switching transistors, as well as the forward-conducting first bidirectional switching transistor, are first closed and activated, entering the first operating stage of the first phase winding, i.e., the excitation stage during generator operation. The electrical energy provided by the excitation and power supply circuit passes through the first, second, first bidirectional switching transistors, fifth switching transistors, fourth diode, and the... Eight switching transistors excite the first phase winding, simultaneously charging the first capacitor and outputting power. Based on rotor position information, when the first operating stage of the first phase winding needs to end, the first, second, and eighth switching transistors are disconnected, and the sixth switching transistor is closed, entering the second operating stage of the first phase winding, which is the power generation stage during generator operation. The energy stored in the first phase winding charges the first capacitor and outputs electrical energy through the first bidirectional switching transistor, the fifth switching transistor, the fourth diode, the sixth switching transistor, and the first diode. Based on rotor position information, when the second operating stage of the first phase winding needs to end... When the fifth, sixth, and first bidirectional switches are disconnected, the first phase winding operation ends. Based on the rotor position information, when the second phase winding needs to be engaged, the first, third, fourth, and ninth switches are closed, along with the reverse-biased second bidirectional switch, entering the first operating stage of the second phase winding, which is the excitation stage during generator operation. The excitation and power supply circuit's electrical energy excites the second phase winding via the first, third, second bidirectional, fourth, third, and ninth switches, and simultaneously excites the first phase winding. The container is reverse charged and outputs in reverse. At this time, the polarity of the output terminal of the general main circuit of the switched reluctance motor is opposite to that of the previous working winding, i.e., the first phase winding. According to the rotor position information, when the first working stage of the second phase winding needs to end, the first switch, the third switch, and the ninth switch are disconnected, and the seventh switch is closed and turned on, entering the second working stage of the second phase winding, which is the power generation stage when the generator is running. The energy stored in the second phase winding is reverse charged to the first capacitor through the second bidirectional switch, the fourth switch, the third diode, the seventh switch, and the second diode, and the energy is output in reverse. Based on the rotor position information, when the second phase winding needs to finish its second operating stage, the fourth switch, the seventh switch, and the second bidirectional switch are disconnected, and the second phase winding operation ends. When the third phase winding needs to be activated, the operating control process differs from that of the first phase winding in that the third bidirectional switch is replaced by the first bidirectional switch; otherwise, the process is the same. Similarly, when the fourth phase winding needs to be activated, the operating control process differs from that of the second phase winding in that the fourth bidirectional switch is replaced by the second bidirectional switch; this continues, with adjacent phase windings operating at opposite polarities of output power. When the switched reluctance motor is running as a motor, the excitation and power supply circuit serves as the power source. Based on the real-time rotor position information, which differs from that used when the motor is running as a generator, the circuit controls the operation of each phase winding and the corresponding switching transistors. The operation control process is the same as when the motor is running as a generator.

4. The universal power converter for switched reluctance motors according to claim 1, wherein the excitation and power supply circuit comprises: The technical features of the tenth, eleventh, twelfth, thirteenth, and fourteenth switching transistors, the fifth, sixth, seventh, eighth, ninth, and tenth diodes, the second, third, fourth, fifth, and sixth capacitors, the three-winding transformer, and the first inductor are as follows: The anode of the tenth switch is connected to the anode of the twelfth switch and serves as the positive input terminal of the excitation and power supply circuit. The cathode of the tenth switch is connected to the anode of the eleventh switch and one end of the primary winding of the three-winding transformer. The cathode of the twelfth switch is connected to the anode of the thirteenth switch and the other end of the primary winding of the three-winding transformer. The cathode of the eleventh switch is connected to the cathode of the thirteenth switch and serves as the negative input terminal of the excitation and power supply circuit. One end of the first winding on the secondary side of the three-winding transformer is connected to the anode of the fifth diode and the cathode of the sixth diode. The other end of the first winding on the secondary side of the three-winding transformer is connected to one end of the second capacitor and one end of the third capacitor. One end of the second winding on the secondary side of the three-winding transformer is connected to the anode of the seventh diode and the cathode of the twelfth switch. The cathodes of eight diodes are connected to the other end of the second winding on the secondary side of the three-winding transformer, which is connected to one end of the fourth capacitor and one end of the fifth capacitor. The cathode of the fifth diode is connected to the other end of the second capacitor, the cathode of the ninth diode, and one end of the first inductor. The anode of the sixth diode is connected to the other end of the third capacitor, the cathode of the fourteenth switch, and the cathode of the tenth diode. The anode of the fourteenth switch is connected to the cathode of the seventh diode, the anode of the ninth diode, and the other end of the fourth capacitor. The anode of the eighth diode is connected to the anode of the tenth diode, the other end of the fifth capacitor, and one end of the sixth capacitor, and serves as the negative terminal of the excitation and power supply circuit output. The other end of the first inductor is connected to the other end of the sixth capacitor and serves as the positive terminal of the excitation and power supply circuit output. All switching transistors are three-terminal fully controlled power electronic switching devices with built-in anti-parallel diodes.

5. A control method for a universal power converter for a switched reluctance motor according to claims 1 and 4, characterized in that, when the excitation and power supply circuit is working, it is controlled by controlling five switching transistors: the tenth, eleventh, twelfth, thirteenth, and fourteenth. All five switching transistors operate in PWM mode. The PWM switching frequencies of the tenth, eleventh, twelfth, and thirteenth switching transistors are the same, and their duty cycles are also the same and less than 0.

5. The phase difference between the tenth and eleventh switching transistors is 180 degrees, and the phase difference between the twelfth and thirteenth switching transistors is 180 degrees. The PWM switching frequency of the fourteenth switching transistor is twice that of the other four switching transistors. Furthermore, the twelfth and fourteenth switching transistors are turned on simultaneously, and the thirteenth and fourteenth switching transistors (K14) are turned on simultaneously. When the tenth switching transistor is turned off, the fourteenth switching transistor is turned off, and when the eleventh switching transistor is turned off, the fourteenth switching transistor is turned off. By adjusting the PWM duty cycle of each switching transistor, the output of the excitation and power supply circuit is controlled.

Images