rotating electrical machines

Abstract

The present invention aims to provide a rotating electric machine that can more reliably detect temperature abnormalities in three-phase winding groups even when the rotor is in a locked state while reducing the number of temperature detectors. [Solution] The control device 50 has a temperature monitoring unit. The temperature monitoring unit monitors the temperature of the first winding group 22 based on a signal from a first temperature detector 41. The temperature monitoring unit also monitors the temperature of the second winding group 23 based on a signal from a second temperature detector 42. The temperature monitoring unit also estimates the temperature of the third winding group 24 based on the conduction state and current value of the current in each of the first winding group 22, the second winding group 23, and the third winding group 24.

Description

[Technical Field]

[0001] The present disclosure relates to a rotating electric machine. [Background technology]

[0002] In conventional electrical equipment, of the U-phase winding, V-phase winding, and W-phase winding, a protection device is provided for each of the U-phase winding and V-phase winding. Each protection device is composed of a thermal fuse and a thermal protector. Each protection device detects abnormal temperatures and cuts off the electrical circuit (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-143210 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional electrical equipment such as the one described above, protection devices are provided on only two of the three phase windings. Therefore, while it is possible to detect abnormal temperatures during normal operation when the temperatures of the three phase windings rise evenly, it may not be possible to detect abnormal temperatures in the windings of phases that are not equipped with protection devices when the rotor is locked in any position.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a rotating electric machine that can more reliably detect temperature abnormalities in three-phase winding groups even when the rotor is locked, while reducing the number of temperature detectors. [Means for solving the problem]

[0006] The rotating electric machine according to the present disclosure comprises a rotating electric machine main body having a stator and a rotor that rotates relative to the stator, a plurality of temperature detectors provided on the stator, and a control device that controls the rotating electric machine main body, wherein the stator has a first winding group that is a winding group of one of three phases, a second winding group that is a winding group of a phase different from the first winding group among the three phases, and a third winding group that is a winding group of a phase different from the first winding group and the second winding group among the three phases, the plurality of temperature detectors comprising a first temperature detector that detects the temperature of the first winding group and a second temperature detector that detects the temperature of the second winding group, and the control device has a temperature monitoring unit that monitors the temperature of the first winding group based on a signal from the first temperature detector, monitors the temperature of the second winding group based on a signal from the second temperature detector, and estimates and monitors the temperature of the third winding group based on the current conduction state and current value in each of the three phase winding groups. [Effects of the Invention]

[0007] According to the rotating electrical machine of the present disclosure, it is possible to more reliably detect temperature abnormalities in the three-phase winding groups even in an operating state in which the rotor is locked, while reducing the number of temperature detectors. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a half cross-sectional view of a rotating electric machine according to a first embodiment. [Figure 2] FIG. 2 is a block diagram showing the control device of FIG. 1. [Figure 3] 2 is an explanatory diagram showing an example of time changes in three-phase AC currents flowing through the first winding group, the second winding group, and the third winding group in FIG. 1. FIG. [Figure 4] 4 is an explanatory diagram showing the flow of currents flowing through the first winding group, the second winding group, and the third winding group in case t1 of FIG. 3. FIG. [Figure 5] 4 is an explanatory diagram showing the flow of currents flowing through the first winding group, the second winding group, and the third winding group in case t4 of FIG. 3. FIG. [Figure 6] 4 is an explanatory diagram showing the flow of currents flowing through the first winding group, the second winding group, and the third winding group in case t6 of FIG. 3. FIG. [Figure 7] 4 is a table showing a method for estimating the temperature of the third winding group in cases t1, t4, and t6 of FIG. 3. [Figure 8] 3 is a flowchart showing a temperature monitoring process of the temperature monitoring unit in FIG. 2; [Figure 9] 4 is an explanatory diagram showing the flow of currents flowing through the first winding group, the second winding group, and the third winding group of the second embodiment in case t1 of FIG. 3. FIG. [Figure 10] 4 is an explanatory diagram showing the flow of currents flowing through the first winding group, the second winding group, and the third winding group of the second embodiment in case t4 of FIG. 3. FIG. [Figure 11] 4 is an explanatory diagram showing the flow of currents flowing through the first winding group, the second winding group, and the third winding group in the second embodiment in case t6 in FIG. 3. FIG. [Figure 12] 2 is a configuration diagram showing a first example of a processing circuit that realizes each function of the control device according to the first and second embodiments. FIG. [Figure 13] 10 is a configuration diagram showing a second example of a processing circuit that realizes each function of the control device according to the first and second embodiments. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. Embodiment 1 1 is a half cross-sectional view showing, in part, a block diagram, a rotating electric machine according to Embodiment 1. The rotating electric machine of Embodiment 1 includes a rotating electric machine body 10, a plurality of temperature detectors, and a control device 50.

[0010] The rotating electrical machine body 10 has a cylindrical casing 11 , a stator 20 , and a rotor 30 .

[0011] The stator 20 has a cylindrical stator core 21, a first winding group 22, a second winding group 23, and a third winding group 24.

[0012] The stator core 21 is fixed to the inside of the casing 11. The stator core 21 has a cylindrical yoke 21a and a plurality of teeth 21b.

[0013] The outer peripheral surface of the yoke 21a is in contact with the inner peripheral surface of the casing 11. The teeth 21b are spaced apart from one another in the circumferential direction of the yoke 21a and protrude inward from the yoke 21a. Slots 21c are formed between adjacent teeth 21b.

[0014] The first winding group 22 is a winding group for any one of the three phases. That is, a current of any one of the U-phase, V-phase, and W-phase, that is, the U-phase in this example, flows through the first winding group 22.

[0015] The second winding group 23 is a winding group of three phases different from the first winding group 22. That is, a current of a phase different from the first winding group 22, among the U phase, V phase, and W phase, a V phase current in this example, flows through the second winding group 23.

[0016] The third winding group 24 is a winding group of three phases, different from the first winding group 22 and the second winding group 23. That is, a current of a phase different from the first winding group 22 and the second winding group 23, among the U phase, V phase, and W phase, i.e., a W phase current in this example, flows through the third winding group 24.

[0017] Each of the first winding group 22, the second winding group 23, and the third winding group 24 is made up of a plurality of windings 25. In Fig. 1, only one of the plurality of windings 25 is shown, and the remaining windings 25 are omitted. Each winding 25 is wound around a corresponding one of the teeth 21b and inserted into two corresponding slots 21c.

[0018] The rotor 30 is provided inside the stator 20 with a gap between them. The rotor 30 rotates relative to the stator 20.

[0019] The plurality of temperature detectors include a first temperature detector 41 and a second temperature detector 42. The first temperature detector 41 detects the temperature of the first winding group 22. The second temperature detector 42 detects the temperature of the second winding group 23.

[0020] The first temperature detector 41 is disposed in the slot 21c at a position where the two windings 25 included in the first winding group 22 are adjacent to each other. The second temperature detector 42 is disposed in the slot 21c at a position where the two windings 25 included in the second winding group 23 are adjacent to each other.

[0021] Each of the first temperature detector 41 and the second temperature detector 42 is fixed to the rotating electrical machine body 10 using a material that has high thermal conductivity and electrical insulation, such as silicone.

[0022] The first temperature detector 41 and the second temperature detector 42 are each connected to a control device 50. The control device 50 controls the rotating electrical machine body 10. The control device 50 is configured by, for example, a microcontroller.

[0023] Fig. 2 is a block diagram showing the control device 50 of Fig. 1. The control device 50 has a temperature monitoring unit 51 as a functional block. The temperature monitoring unit 51 monitors the temperature of the first winding group 22 based on a signal from the first temperature detector 41. The temperature monitoring unit 51 also monitors the temperature of the second winding group 23 based on a signal from the second temperature detector 42. The temperature monitoring unit 51 also estimates and monitors the temperature of the third winding group 24.

[0024] The temperature monitoring unit 51 includes a temperature estimation unit 51a and a determination unit 51b. The temperature estimation unit 51a estimates the temperature of the third winding group 24 based on the conduction state and current value of each of the three-phase winding groups, i.e., the first winding group 22, the second winding group 23, and the third winding group 24.

[0025] The determination unit 51b determines whether or not a temperature abnormality has occurred in the first winding group 22 based on a signal from the first temperature detector 41. The determination unit 51b also determines whether or not a temperature abnormality has occurred in the second winding group 23 based on a signal from the second temperature detector 42.

[0026] Furthermore, the determination unit 51b determines whether or not a temperature abnormality has occurred in the third winding group 24, based on the temperature of the third winding group 24 estimated by the temperature estimation unit 51a. The control device 50 controls the rotating electrical machine main body 10 based on the determination result by the determination unit 51b.

[0027] Next, we will explain a method for estimating the temperature of the third winding group 24. Fig. 3 is an explanatory diagram showing an example of the change over time of three-phase AC currents flowing through the first winding group 22, the second winding group 23, and the third winding group 24 in Fig. 1.

[0028] In Figure 3, cases t1, t3, t5, t7, t9, and t11 are cases where positive or negative current flows through all phases of winding 25. Cases t2, t4, t6, t8, t10, and t12 are cases where no current flows through any one phase of winding 25. Also in Figure 3, the amplitude of the current in each phase is I.

[0029] Fig. 4 is an explanatory diagram showing the flow of current flowing through the first winding group 22, the second winding group 23, and the third winding group 24 in case t1 of Fig. 3. In the first embodiment, the first winding group 22, the second winding group 23, and the third winding group 24 are connected by a Y connection.

[0030] In the following description, the direction in which current flows from each phase to the neutral point is referred to as the + direction, and the direction in which current flows from the neutral point to each phase is referred to as the - direction.

[0031] Temperature monitoring unit 51 in the first embodiment does not measure all three-phase currents Iu, Iv, and Iw, but measures two-phase currents Iu and Iv and estimates Iw from the relationship Iu + Iv + Iw = 0. Temperature estimation unit 51a estimates, from the calculated currents Iu, Iv, and Iw, the temperature of the winding group through which a current of a magnitude close to Iw flows, among Iu and Iv, as being equivalent to the temperature of third winding group 24.

[0032] Specifically, the temperature estimator 51a calculates the difference ΔIuw between the absolute value of Iu and the absolute value of Iw, and the difference ΔIvw between the absolute value of Iv and the absolute value of Iw, and if ΔIuw > ΔIvw, determines that the temperature of the third winding group 24 is equivalent to the temperature of the second winding group 23. If ΔIuw < ΔIvw, the temperature estimator 51a determines that the temperature of the third winding group 24 is equivalent to the temperature of the first winding group 22.

[0033] In case t1 shown in Figure 4, if the absolute value of the current Iu flowing in the U phase is I, the absolute value of the current Iv flowing in the V phase and the absolute value of the current Iw flowing in the W phase are both (1 / 2) × I.

[0034] Therefore, ΔIuw=I-(1 / 2)×I=(1 / 2)×I. Also, ΔIvw=(1 / 2)×I-(1 / 2)×I=0. As a result, the temperature estimator 51a estimates that the temperature of the third winding group 24 is equivalent to the temperature of the second winding group 23.

[0035] 5 is an explanatory diagram showing the flow of currents through the first winding group 22, the second winding group 23, and the third winding group 24 in case t4 in FIG. 3. In case t4, no current flows through the U phase. The absolute value of the current Iv flowing through the V phase is (2 / 3)×I. The absolute value of the current Iw flowing through the W phase is (2 / 3)×I.

[0036] Therefore, the difference ΔIwu between the absolute value of Iw and the absolute value of Iu is ΔIwu = (2 / 3) × I - 0 = (2 / 3) × I. Furthermore, the difference ΔIvw between the absolute value of Iv and the absolute value of Iw is ΔIvw = (2 / 3) × I - (2 / 3) × I = 0. As a result, the temperature estimator 51a estimates that the temperature of the third winding group 24 is equivalent to the temperature of the second winding group 23.

[0037] In this way, when no current flows in either of the two phases other than the W phase, the temperature estimator 51a estimates that the temperature of the third winding group 24 is equivalent to the temperature of the winding group through which current flows. That is, when Iu=0 and Iv≠0, the temperature of the third winding group 24 is estimated to be equivalent to the temperature of the second winding group 23. Also, when Iu≠0 and Iv=0, the temperature of the third winding group 24 is estimated to be equivalent to the temperature of the first winding group 22.

[0038] 6 is an explanatory diagram showing the flow of currents through the first winding group 22, the second winding group 23, and the third winding group 24 in case t6 in FIG. 3. In case t6, no current flows through the W phase. The absolute value of the current Iu flowing through the U phase is (2 / 3)×I. The absolute value of the current Iv flowing through the V phase is (2 / 3)×I.

[0039] In this way, when no current flows through the third winding group 24, the temperature estimator 51a estimates that there is no temperature rise in the third winding group 24.

[0040] The method of estimating the temperature of the third winding group 24 in the above cases t1, t4, and t6 can be summarized as shown in the table in FIG.

[0041] Fig. 8 is a flowchart showing the temperature monitoring process of the temperature monitoring unit 51 in Fig. 2. The temperature monitoring unit 51 periodically executes the temperature monitoring process in Fig. 8 in a usage state in which the rotor 30 is locked.

[0042] 8 starts, the temperature monitoring unit 51 detects the temperature of the first winding group 22 in step S101. The temperature monitoring unit 51 also detects the temperature of the second winding group 23 in step S102. The temperature monitoring unit 51 also estimates the temperature of the third winding group 24 in step S103.

[0043] Thereafter, in step S104, the temperature monitoring unit 51 determines whether a temperature abnormality exists in any of the first winding group 22, the second winding group 23, and the third winding group 24. If a temperature abnormality exists, the temperature monitoring unit 51 performs temperature protection in step S105. An example of temperature protection is to cut off power to the three-phase winding groups. If no temperature abnormality exists, the temperature monitoring unit 51 ends the processing for that round.

[0044] In such a rotating electric machine, two temperature detectors, namely a first temperature detector 41 and a second temperature detector 42, are used as the multiple temperature detectors. A temperature monitoring unit 51 monitors the temperature of the first winding group 22 based on a signal from the first temperature detector 41, and monitors the temperature of the second winding group 23 based on a signal from the second temperature detector 42. The temperature monitoring unit 51 also estimates and monitors the temperature of the third winding group 24 based on the current conduction state and current value in each of the three-phase winding groups.

[0045] Therefore, while reducing the number of temperature detectors, it is possible to more reliably detect temperature abnormalities in the three-phase winding groups even when the rotor 30 is locked, and more appropriate temperature protection can be implemented, thereby reducing the cost of the rotating electric machine.

[0046] The first temperature detector 41 is disposed at a position where the two windings 25 included in the first winding group 22 are adjacent to each other. The second temperature detector 42 is disposed at a position where the two windings 25 included in the second winding group 23 are adjacent to each other.

[0047] Therefore, with a simple configuration, it is possible to more accurately detect the temperatures of the first winding group 22 and the second winding group 23. This makes it possible to reduce the cost of the rotating electric machine.

[0048] Furthermore, when current is flowing through all of the winding groups, the temperature monitoring unit 51 estimates that the temperature of the winding group, of the first winding group 22 and the second winding group 23, through which a current of a magnitude similar to that of the third winding group 24 is flowing is equivalent to the temperature of the third winding group 24. Furthermore, when current is not flowing through either the first winding group 22 or the second winding group 23, the temperature monitoring unit 51 estimates that the temperature of the winding group, of the first winding group 22 or the second winding group 23 through which a current is flowing is equivalent to the temperature of the third winding group 24. Furthermore, when current is not flowing through the third winding group 24, the temperature monitoring unit 51 estimates that there is no temperature rise in the third winding group 24.

[0049] Therefore, when the rotor 30 is locked, even if the first temperature detector 41 or the second temperature detector 42 is provided in a winding group through which no current flows, the temperature of the third winding group 24 can be estimated more accurately. This makes it possible to more reliably detect temperature abnormalities in the three-phase winding groups even when the rotor 30 is locked in any position.

[0050] The first winding group 22 may be a V-phase winding group or a W-phase winding group. Similarly, the second winding group 23 may be a U-phase winding group or a W-phase winding group. Similarly, the third winding group 24 may be a U-phase winding group or a V-phase winding group. That is, the first temperature detector 41 and the second temperature detector may be provided in the winding groups of any two of the three phases.

[0051] Embodiment 2 Next, a rotating electric machine according to embodiment 2 will be described. In embodiment 1, the first winding group 22, the second winding group 23, and the third winding group 24 are connected by a Y connection. In contrast, in embodiment 2, the first winding group 22, the second winding group 23, and the third winding group 24 are connected by a Delta connection.

[0052] Other configurations and temperature monitoring methods in the second embodiment are the same as those in the first embodiment.

[0053] Fig. 9 is an explanatory diagram showing the flow of current flowing through the first winding group 22, the second winding group 23, and the third winding group 24 of the second embodiment in case t1 of Fig. 3. Fig. 10 is an explanatory diagram showing the flow of current flowing through the first winding group 22, the second winding group 23, and the third winding group 24 of the second embodiment in case t4 of Fig. 3. Fig. 11 is an explanatory diagram showing the flow of current flowing through the first winding group 22, the second winding group 23, and the third winding group 24 of the second embodiment in case t6 of Fig. 3.

[0054] 9, 10, and 11, the direction in which current flows from each phase to the delta-connected winding is defined as the positive direction, and the direction in which current flows from the delta-connected winding to each phase is defined as the negative direction. Each current is defined as follows:

[0055] Line current: Iu, Iv, Iw Phase current: Ivu, Iwv, Iuw Iu=3 1 / 2 ×Ivu Iv=3 1 / 2 ×Iwv Iw=3 1 / 2 ×Iuw

[0056] In the second embodiment, the phase currents Ivu, Iwv, and Iuw flowing through the Δ connection are calculated from the line currents Iu, Iv, and Iw. Then, similar to the first embodiment, the temperature of the third winding group 24, to which neither the first temperature detector 41 nor the second temperature detector 42 is attached, is estimated.

[0057] With this configuration, the same effects as those of the first embodiment can be obtained.

[0058] Each function of the control device 50 according to the first and second embodiments is realized by a processing circuit. Fig. 12 is a configuration diagram showing a first example of a processing circuit that realizes each function of the control device 50 according to the first and second embodiments. The processing circuit 100 of the first example is dedicated hardware.

[0059] The processing circuit 100 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each function of the control device 50 may be realized by a separate processing circuit 100, or all functions may be realized by the processing circuit 100.

[0060] 13 is a configuration diagram showing a second example of a processing circuit that realizes each function of the control device 50 according to the first and second embodiments. The processing circuit 200 of the second example includes a processor 201 and a memory 202.

[0061] The processor 201 may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor, a microcontroller, or a digital signal processor (DSP).

[0062] In the processing circuit 200, each function of the control device 50 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the memory 202. The processor 201 realizes each function by reading and executing the programs stored in the memory 202.

[0063] It can also be said that the programs stored in memory 202 cause the computer to execute the procedures or methods of the above-mentioned sections. Here, memory 202 refers to non-volatile or volatile semiconductor memory, such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), and EEPROM (Electrically Erasable and Programmable Read Only Memory). Magnetic disks, flexible disks, optical disks, compact disks, minidisks, DVDs, and the like also fall under memory 202.

[0064] It should be noted that some of the functions of the above-described units may be realized by dedicated hardware, and other parts may be realized by software or firmware.

[0065] In this way, the processing circuit can realize the functions of each of the above-mentioned units by hardware, software, firmware, or a combination of these. [Explanation of symbols]

[0066] 10 Rotating electric machine body, 20 Stator, 22 First winding group, 23 Second winding group, 24 Third winding group, 30 Rotor, 41 First temperature detector, 42 Second temperature detector, 50 Control device, 51 Temperature monitoring unit.

Claims

1. a rotating electric machine body having a stator and a rotor that rotates relative to the stator; a plurality of temperature detectors provided on the stator; and a control device for controlling the rotating electrical machine body; Equipped with The stator includes: a first winding group that is a winding group for one of the three phases; a second winding group which is a winding group of a phase different from the first winding group among the three phases; a third winding group which is a winding group of a phase different from the first winding group and the second winding group among the three phases; It has the plurality of temperature detectors include a first temperature detector that detects the temperature of the first winding group and a second temperature detector that detects the temperature of the second winding group; The control device has a temperature monitoring unit, The temperature monitoring unit monitoring the temperature of the first winding group based on a signal from the first temperature detector; monitoring the temperature of the second winding group based on a signal from the second temperature detector; a rotating electric machine that estimates and monitors the temperature of the third winding group based on the conduction state and current value of each of the three-phase winding groups;

2. the first temperature detector is disposed at a position where two windings included in the first winding group are adjacent to each other, 2. The rotating electric machine according to claim 1, wherein the second temperature detector is disposed at a position where two windings included in the second winding group are adjacent to each other.

3. The temperature monitoring unit When currents are flowing through all of the first winding group, the second winding group, and the third winding group, it is estimated that the temperature of the winding group among the first winding group and the second winding group through which a current of a magnitude similar to that of the third winding group is flowing is equivalent to the temperature of the third winding group; When no current flows through either the first winding group or the second winding group, it is estimated that the temperature of the winding group through which current flows, out of the first winding group or the second winding group, is equivalent to the temperature of the third winding group; 3. The rotating electric machine according to claim 1, wherein when no current flows through the third winding group, it is estimated that there is no temperature rise in the third winding group.

Images