JP2021069202A - Rotating motor system - Google Patents

Abstract

To provide a rotating motor system that can control to flow currents of both positive and negative directions to a field winding, and has a simple configuration.SOLUTION: A rotating motor system 10 includes: a rotating motor 30 including a field winding 34; a battery group 16 in which a first battery 15a and a second battery 15b are connected in series; a pair of busbars 28a and 28b to which a voltage of the battery group 16 is applied; a field converter 24 that is connected between the busbars 28a and 28b and allows current to flow to the field winding 34; and a control device 12 for controlling the field converter 24. The field converter 24 includes an arm A1 connected between the busbars 28a and 28b, the arm A1 consists of two switching elements S1 and S2 controlled by the control device 12 connected in series, one end of the field winding 34 is connected to ap between the two switching elements S1 and S2 of the arm A1 of the field converter 24, and the other end of the field winding 34 is connected to bp between the first battery 15a and the second battery 15b.SELECTED DRAWING: Figure 1

Description

The present invention relates to a system of rotary motors including armature windings and field windings.

Conventionally, there is known a rotary electric motor which includes an armature winding and a field winding and can change a rotational torque by a field magnetic flux generated by passing a field current through the field winding. Such a system of a rotary motor includes a driving device (hereinafter referred to as a field converter) for passing a field current through a field winding, and the field converter is configured to include a plurality of switching elements. .. The control device controls the on / off of each switching element of the field converter and controls the field current (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-85799

A rotary motor system having a simple structure is desired because it is possible to control both a positive current (strong field current) and a negative current (weak field current) to flow through the field winding.

An object of the present invention is to provide a rotary electric motor system capable of controlling a current flowing through a field winding in both positive and negative directions and having a simple configuration.

The rotary motor system of the present invention is a battery configured by connecting a rotary motor including an armature winding that generates a rotating magnetic field and a field winding that generates a field magnetic flux, and a first battery and a second battery in series. A group, a pair of bus wires to which the voltage of the battery group is directly or boosted and applied, an inverter connected between the bus wires and passing a current through the armature winding, and a field connected between the bus wires. A field converter for passing an electric current through a magnetic winding, a control device for controlling the inverter and the field converter, and the field converter includes an arm connected between the bus wires and described as described above. The arm is configured by connecting two switching elements controlled by the control device in series, and one end of the field winding is connected between the two switching elements of the arm of the field converter, and the field is connected. The other end of the magnetic winding is connected between the first battery and the second battery.

Further, in the rotary electric motor system of the present invention, the first battery includes one or a plurality of battery cells, the second battery also includes one or a plurality of battery cells, and the battery cell included in the first battery. And the number of battery cells included in the second battery may be the same.

Further, the rotary electric motor system of the present invention may further include an active cell balancer that equalizes the charge amount of the first battery and the charge amount of the second battery.

According to the present invention, it is possible to control the flow of current in both positive and negative directions through the field winding by the two switching elements of the field converter, and since the field converter contains few switching elements, the rotary motor system Can be a simple configuration.

It is a circuit diagram of the rotary electric motor system which concerns on embodiment of this invention. It is a block block diagram of the control device shown in FIG. It is a figure which shows each sensor detection value with respect to the torque command value of the rotary electric motor system which concerns on embodiment of this invention. It is a figure which shows each sensor detection value with respect to the torque command value of the rotary electric motor system including the H arm converter of the prior art. It is a figure which shows each sensor detection value with respect to the torque command value of the rotary electric motor system including the 1-arm converter of the prior art. It is a circuit diagram of the rotary electric motor system which concerns on another embodiment of this invention. It is a circuit diagram of the rotary electric motor system including the H arm converter of the prior art. It is a circuit diagram of the rotary electric motor system including the 1-arm converter of the prior art.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. The configuration described below is an example for explanation, and can be appropriately changed according to the specifications of the rotary motor system and the like. Similar elements are designated by the same reference numerals in all drawings, and duplicate description will be omitted. Further, when a plurality of embodiments and modifications are included in the following, it is assumed from the beginning that those characteristic portions are appropriately combined and used.

FIG. 1 is a circuit diagram of the rotary electric motor system 10 according to the present embodiment. The rotary motor system 10 includes a battery group 16 in which a first battery 15a and a second battery 15b are connected in series, a pair of bus bars 28a and 28b to which the voltage vb of the battery group 16 is applied, and bus bars 28a and 28b. It includes a capacitor 22, a field converter 24, and an inverter 26 connected between them, a control device 12 for controlling the field converter 24 and the inverter 26, and a rotary electric motor 30.

The rotary motor 30 includes a stator and a rotor, and the stator is an electric machine that passes a field winding 34 that passes a direct current that creates a field in the rotor and an alternating current that generates a torque in the rotor by interacting with the field. A child winding 32 (also referred to as a three-phase winding) is provided. The field winding 34 generates a field magnetic flux, and the armature winding 32 generates a rotating magnetic field. Although it is assumed here that the stator is provided with the field winding 34, the rotor or a member around the rotor may be provided with the field winding 34.

The battery group 16 is a power source for the rotary electric motor 30. The first battery 15a includes one or more battery cells 14, and the second battery 15b also includes one or more battery cells 14. In the present embodiment, the number of battery cells 14 included in the first battery 15a and the number of battery cells 14 included in the second battery 15b are the same. In FIG. 1, for convenience of illustration, the number of battery cells 14 included in each of the first battery 15a and the second battery 15b is three, but the number may be appropriately adjusted according to the specifications of the battery cells and the like. Be changed. The output voltages of the first battery 15a and the second battery 15b are vb1 and vb2, respectively, and in this embodiment, vb1 and vb2 are the same voltage or substantially the same voltage. The output voltage vb of the battery group 16 is the sum of vb1 and vb2.

The field converter 24 includes an arm A1 in which two switching elements S1 and S2 are connected in series. Diodes are connected in parallel to both ends of the switching elements S1 and S2 so that a current in the direction opposite to the current direction of the switching elements S1 and S2 flows. The arm A1 of the field converter 24 is connected between the bus 28a and 28b, and one end of the field winding 34 is connected between the switching elements S1 and S2 (midpoint a) of the arm A1. The other end of 34 is connected to bp between the first battery 15a and the second battery 15b (bb between the negative electrode of the first battery 15a and the positive electrode of the second battery 15b). The control device 12 controls the on / off of the two switching elements S1 and S2, and controls the direction and magnitude of the field current if flowing through the field winding 34 by changing the on / off period. A current sensor 40 is provided in the current path of the field current if. The detected value of the field current if detected by the current sensor 40 (hereinafter, also referred to as the field current detected value if) is transmitted to the control device 12.

The inverter 26 is a three-phase inverter. Specifically, the inverter 26 includes a U-phase arm B1, a V-phase arm B2, and a W-phase arm B3 connected between the bus bars 28a and 28b. Two switching elements Sa and Sb are connected in series to each arm B1, B2 and B3, and a diode is connected to both ends of each switching element Sa and Sb so that a current in a direction opposite to the current direction of each switching element flows. Are connected in parallel. The armature winding 32 includes a U-phase winding through which a U-phase current flows, a V-phase winding through which a V-phase current flows, and a W-phase winding through which a W-phase current flows. In FIG. 1, the U-phase winding, the V-phase winding, and the W-phase winding are designated by u, v, and w, respectively. The control device 12 controls the current (three-phase current) of the armature winding 32 (three-phase winding) by controlling the on / off of each switching element of the inverter 26. In FIG. 1, the winding of each phase of the armature winding 32 (three-phase winding) is shown in a simplified manner, and only one is used for each phase. However, in reality, a plurality of windings are used for each phase. The wires are connected in series.

One end of the U-phase winding is connected to the midpoint between the switching elements Sa and Sb of the U-phase arm B1. One end of the V-phase winding is connected to the midpoint between the switching elements Sa and Sb of the V-phase arm B2. One end of the W-phase winding is connected to the midpoint between the switching elements Sa and Sb of the W-phase arm B3. The other ends of the U-phase winding, the V-phase winding and the W-phase winding are commonly connected at the neutral point G.

The current iu flowing in the U-phase winding is detected by the current sensor 38u, the detected value is transmitted to the control device 12, and the current iv flowing in the V-phase winding is detected by the current sensor 38v, and the detected value is controlled. It is transmitted to the device 12. Since the windings of each phase of the three-phase windings are commonly connected at the neutral point G, the sum of the currents iu, iv, and iw flowing through the windings of each phase becomes zero. Therefore, the control device 12 Can acquire the current iwa flowing through the W-phase winding from the detected values iu and iv.

The rotary electric motor 30 is provided with a rotation angle sensor 36 (for example, a resolver). The rotation angle position (hereinafter referred to as rotation angle) θe of the rotor detected by the rotation angle sensor 36 is sent to the control device 12.

The control device 12 has the gate signals GS1 and GS2 of the switching elements S1 and S2 of the field converter 24 and the gate signal GI of the switching element of the inverter 26 (here, the inverter 26) based on the generated or input torque command value. The gate signals of the six switching elements of the above are collectively indicated by the reference numeral GI). The torque command value is derived from the accelerator opening degree and the vehicle speed by referring to a map or the like in the control device 12, for example, when the rotary electric motor system 10 is mounted on the vehicle. The unit including the field converter 24, the inverter 26, and the control device 12 is called a power control unit (PCU).

FIG. 2 is a block configuration diagram of the control device 12. The control device 12 includes a current command map 60, a plurality of adders 62a, 62b, 62c, 62d, 62e, three PI controllers (also referred to as proportional integration controllers) 64a, 64b, 64c, and non-interference control. It includes a device 66, a dq-axis-3 phase converter 68, and two PWM70a and 70b. Here, the current command map 60 is a map of the dq-axis current command values idr, iqr, and field current command value ifr associated with the torque command value Tr.

When the torque command value Tr is given, the control device 12 acquires the dq-axis current command values idr and iqr corresponding to the torque command value Tr using the current command map 60. Here, the control device 12 previously sets the three-phase current detection values (acquired values for the w phase) iu, iv, and iwa to the dq-axis current detection value id using the rotation angle θe of the rotary motor 30 (rotor). , Converted to iq. Then, the control device 12 calculates the error between the d-axis current command value idr and the d-axis current detection value id with the adder 62a, and performs proportional integration control with the PI controller 64a so that this error approaches zero. The d-axis voltage command value vdr is set. Similarly, the control device 12 calculates the error between the q-axis current command value iqr and the q-axis current detection value iq with the adder 62c, and performs proportional integration control with the PI controller 64b so that this error approaches zero. , The q-axis voltage command value vqr is set. Next, the dq-axis voltage command values vdr and vqr are adjusted by using the non-interfering controller 66 and the adders 62b and 62d so as to eliminate the error due to the interference between the windings of the rotary motor 30. Then, in the dq-axis-3 phase converter 68, the control device 12 uses the rotation angle θe of the rotary motor 30 (rotor) to change the dq-axis voltage command values vdr and vqr to the three-phase voltage command values vur, vvr and vwr. After conversion, the PWM 70a generates a gate signal GI for each switching element of the inverter 26 based on the three-phase voltage command values vur, vvr, and vwr.

Further, when the torque command value Tr is given, the control device 12 acquires the field current command value ifr corresponding to the torque command value Tr by using the current command map 60. Then, the control device 12 calculates the error between the field current command value ifr and the field current detection value if with the adder 62e, and performs proportional integration control with the PI controller 64c so that this error approaches zero. Then, the field voltage command value vfr is set. Then, the control device 12 generates the gate signals GS1 and GS2 of the switching elements S1 and S2 of the field converter 24 based on the field voltage command value vfr in the PWM 70b.

Next, the relationship between the on / off of the switching elements S1 and S2 of the field converter 24 and the field current if will be described. As described above, one end of the field winding 34 is connected to the midpoint a of the arm A1 of the field converter 24, and the other end of the field winding 34 is the first battery 15a and the second battery. It is connected to bp for 15b (see FIG. 1). When the switching element S1 is turned on and S2 is turned off, the ap point is electrically connected to the positive electrode of the first battery 15a, and the bp point is electrically connected to the negative electrode of the first battery 15a. The potential of is higher by vb1 than the potential of the bp point (potential of the ap point> potential of the bp point), and the output voltage vb1 of the first battery 15a is applied to the field winding 34. The field current if flows from the ap point to the bp point. That is, a positive voltage is applied to the field winding 34, and the field current if flows in the positive direction (the direction indicated by the solid arrow of if shown in FIG. 1).

On the other hand, when the switching element S1 is turned off and S2 is turned on, the ap point is electrically connected to the negative electrode of the second battery 15b, and the bp point is electrically connected to the positive electrode of the second battery 15b. The potential at the bp point is higher by vb2 than the potential at the ap point (potential at the bp point> potential at the ap point), and the output voltage vb2 of the second battery 15b is applied to the field winding 34. The field current if flows from the bp point to the ap point. That is, a negative voltage is applied to the field winding 34, and the field current if flows in the negative direction (the direction opposite to the direction indicated by the solid arrow of if shown in FIG. 1).

The control device 12 uses the gate signals GS1 and GS2 of the switching elements S1 and S2 of the field converter 24 to obtain a period t1 in which S1 is on and S2 is off, and a period t2 in which S1 is off and S2 is on. The ratio df (= t1 / t2, also referred to as duty ratio df) is controlled. As a result, the control device 12 sets the field current if to 0 (A) and controls the magnitudes of the currents in the positive and negative directions of the field current if.

Here, as shown in FIG. 1, the rotary electric motor system 10 includes an active cell balancer 50 that equalizes the charge amount of the first battery 15a and the charge amount of the second battery 15b. When the switching element S1 of the field converter 24 is turned on and S2 is turned off, the power of the first battery 15a is supplied to the field winding 34, the switching element S1 of the field converter 24 is turned off, and S2 is turned on. Then, the power of the second battery 15b is supplied to the field winding 34. Therefore, depending on the duty ratio df, the power consumption of the first battery 15a and the second battery 15b may be biased, and the charge amounts of the first battery 15a and the second battery 15b may differ. However, even in this case, by providing the active cell balancer 50, it is possible to equalize the charge amounts of the first battery 15a and the second battery 15b.

According to the rotary motor system 10 described above, although the field converter 24 has only two switching elements S1 and S2, the field winding 34 has a positive current (strong field current). It is possible to control the flow of both a negative current (also called a field weakening current). Since the field current if can be controlled to flow in both the positive and negative directions in this way, the current responsiveness of the field current if can be increased when the torque command value is increased or decreased. For example, when the field current if is flowing in the positive direction with a relatively large current value, when the field current if is reduced to 0 (A) according to the torque command value, the field current according to the present embodiment is used. Since it is possible to control the flow of the if in the negative direction, the field current if can be changed to 0 (A) in a short time. Further, according to the rotary motor system 10 described above, since the field converter 24 has a simple configuration, it is also advantageous in terms of cost of the rotary motor system 10 or the power control unit (PCU).

Here, the rotary motor system of the prior art will be briefly described, and then the difference in operation between the rotary motor system 10 of the present embodiment and the rotary motor system of the prior art will be introduced.

FIG. 7 is a circuit diagram of the rotary electric motor system 110 of the prior art. This prior art rotary motor system 110 also includes a field converter 124, which includes a first arm A11 and a second arm A12 connected between the bus 28a, 28b. The first arm A11 is configured by connecting the switching elements S11 and S12 in series, and the second arm A12 is configured by connecting the switching elements S13 and S14 in series. One end of the field winding 34 is connected to the midpoint a of the first arm A11, and the other end of the field winding 34 is connected to the midpoint bp of the second arm A12. The rotary electric motor system 110 of the prior art can pass currents in both positive and negative directions through the field winding 34, but there are also four switching elements of the field converter 124. The field converter 124 of the prior art will also be referred to hereinafter as an H-arm converter.

Further, FIG. 8 is a circuit diagram of another rotary electric motor system 210 according to the prior art. The rotary electric motor system 210 of the prior art also includes a field converter 224, and the field converter 224 includes an arm A21 connected between the bus bars 28a and 28b. The arm A21 is configured by connecting switching elements S21 and S22 in series. One end of the field winding 34 is connected to the midpoint a of the arm A21, and the other end of the field winding 34 is connected to the bus 28b (bp point) on one side. In the rotary electric motor system 210 of the prior art, the field converter 224 is composed of two switching elements S21 and S22, but the ap point of the field converter 124 can output only the same or higher potential as the bp point ( Since the bp point can output only the same or lower potential as the ap point), only the current in the positive direction can flow through the field winding 34. The field converter 224 of the prior art is also referred to as a 1-arm converter hereafter.

FIG. 3 is a diagram showing each sensor detection value with respect to the torque command value of the rotary electric motor system 10 of the present embodiment. In the three graphs of FIG. 3, the broken line indicates the command value, the solid line indicates the sensor detection value, and the horizontal axis is the time axis common to each graph. In FIG. 3, the upper graph shows the time change of the torque command value (broken line) and the torque detection value (solid line), and the middle graph shows the field current command value (broken line) and the field current detection value (solid line). The time change is shown in the lower graph, and the time change of the field voltage detection value (solid line) is shown. The field voltage is a voltage applied to the field winding 34. FIG. 3 shows each value when the torque command value is raised from 0 to a predetermined value, the torque command value is maintained at the predetermined value for a while, and then the torque command value is returned to 0 again. Further, FIG. 4 is a diagram showing each sensor detection value with respect to the torque command value of the rotary electric motor system 110 including the H-arm converter of the prior art, and the one corresponding to the graph of FIG. 3 is shown. Further, FIG. 5 is a diagram showing each sensor detection value with respect to the torque command value of the rotary electric motor system 210 including the one-arm converter of the prior art, and the one corresponding to the graph of FIG. 3 is shown.

Comparing the detected values of FIG. 3 (the present embodiment) and FIG. 4 (in the case of the conventional H-arm converter), the torque and field current responsiveness of the present embodiment is the case of the conventional H-arm converter. It can be seen that the torque and field current responsiveness are close to each other. That is, according to the present embodiment, although the number of switching elements is smaller than that of the conventional H-arm converter, the same responsiveness as the torque and field current in the case of the H-arm converter is obtained.

Further, comparing the detected values of FIG. 3 (the present embodiment) and FIG. 5 (in the case of the conventional 1-arm converter), the present embodiment has a torque command value as compared with the case of the conventional 1-arm converter. It can be seen that the responsiveness of the torque and the field current when is changed from a predetermined value to 0 is excellent. In particular, in the case of the conventional one-arm converter, since only the voltage in the positive direction can be applied to the field winding 34, it can be seen that the responsiveness of the field current is poor as shown in FIG.

As can be seen from the above, the rotary motor system 10 of the present embodiment has two advantages that the circuit configuration is simple and the field current if in both positive and negative directions can flow through the field winding 34. This is advantageous as compared with the rotary motor systems 110 and 210 (FIGS. 7 and 8) of the above.

Next, another embodiment of the present invention will be described. In the embodiment described above, the voltage vb of the battery group 16 is directly applied to the pair of bus lines 28a and 28b. However, the voltage vb of the battery group 16 may be boosted, and a voltage vc higher than the voltage vb may be applied to the pair of bus 28a, 28b. FIG. 6 is a circuit diagram of the rotary electric motor system 90 in that case. The difference between the rotary motor system 90 of FIG. 6 and the rotary motor system 10 of FIG. 1 is that in the rotary motor system 90 of FIG. 6, a boost converter 18 is arranged between the battery group 16 and the field converter 24. is there. The boost converter 18 includes an arm A0 in which two switching elements Su1 and Su2 are connected in series, and a reactor 20. Diodes are connected in parallel to both ends of the switching elements Su1 and Su2. The arm A0 of the boost converter 18 is connected between the bus bars 28a and 28b, one end of the reactor 20 is connected to the midpoint of the arm A0, and the other end of the reactor 20 is connected to the positive side of the battery group 16. The control device 12 boosts the output voltage vb of the battery group 16 by controlling the on / off of the switching elements Su1 and Su2 of the boost converter 18 using the gate signals GSu1 and GSu2, and between the bus bars 28a and 28b. A voltage vc is applied. The ratio of the voltage vc to the voltage vb (boosting ratio) changes depending on the on / off period of the switching elements Su1 and Su2. According to this configuration, a voltage vc higher than the output voltage vb of the battery group 16 can be applied to the inverter 26. Further, also in this configuration, as in the rotary motor system 10 of FIG. 1, a current can be passed through the field winding 34 in both positive and negative directions.

In each of the above-described embodiments, the number of battery cells 14 included in the first battery 15a and the number of battery cells 14 included in the second battery 15b are the same. However, the number of battery cells 14 included in the first battery 15a and the number of battery cells 14 included in the second battery 15b may be different. Further, in each of the above-described embodiments, the output voltage vb1 of the first battery 15a and the output voltage vb2 of the second battery 15b are set to the same voltage or substantially the same voltage, but vb1 and vb2 may be set to different voltages. .. Further, in each of the above-described embodiments, the rotary electric motor systems 10 and 90 are provided with the active cell balancer 50, but the active cell balancer 50 is not an essential configuration and may be omitted.

10, 90, 110, 210 rotary motor system, 12 controller, 14 battery cell, 15a 1st battery, 15b 2nd battery, 16 battery group, 17, 22 capacitors, 18 boost converter, 20 reactors, 24, 124, 224 Field converter, 26 inverter, 28a, 28b bus, 30 rotation motor, 32 armature winding (three-phase winding), 34 field winding, 36 rotation angle sensor, 38u, 38v, 40 current sensor, 50 active Cell balancer, 60 current command map, 62a, 62b, 62c, 62d, 60e adder, 64a, 64b, 64c PI controller, 66 non-interfering controller, 68 dq axis-3 phase converter, 70a, 70b PWM, S1, S2, S11, S12, S13, S14, S21, S22, Sa, Sb, Su1, Su2 switching element, A1, A21 arm, A11 first arm, A12 second arm, B1 U-phase arm, B2 V-phase arm , B3 W phase arm.

Claims (3)

An armature winding that generates a rotating magnetic field, a rotating motor that includes a field winding that generates a field magnetic flux, and
A group of batteries in which the first battery and the second battery are connected in series,
A pair of busbars to which the voltage of the battery group is applied directly or boosted,
An inverter connected between the busbars and passing a current through the armature winding,
A field converter connected between the busbars and passing a current through the field winding,
A control device for controlling the inverter and the field converter is provided.
The field converter includes an arm connected between the busbars, and the arm is configured by connecting two switching elements controlled by the control device in series.
One end of the field winding is connected between two switching elements of the arm of the field converter, and the other end of the field winding is connected between the first battery and the second battery. ,
A rotary motor system that features this. The rotary electric motor system according to claim 1.
The first battery includes one or more battery cells, and the second battery also includes one or more battery cells.
The number of battery cells included in the first battery is the same as the number of battery cells included in the second battery.
A rotary motor system that features this. The rotary electric motor system according to claim 1 or 2.
An active cell balancer that equalizes the charge amount of the first battery and the charge amount of the second battery is further provided.
A rotary motor system that features this.

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