Idle stop control device

Abstract

To provide an idle stop control device capable of more appropriately performing a deterioration determination of a vehicle generator-motor.SOLUTION: A magnetic flux estimation unit 23 calculates a magnetic flux φ which is generated in a vehicle generator-motor 105 in any one of or both a driving time and a power generating time of the vehicle generator-motor 105. A deterioration determination unit 24 determines whether or not the magnetic flux φ calculated in the magnetic flux estimation unit 23 is within a set range. In a case where it is determined that a performance of the vehicle generator-motor 105 is deteriorated, the deterioration determination unit 24 outputs a command to inhibit an idle stop to an engine control unit 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an idle stop control device. [Background technology]

[0002] In a conventional control device for a vehicle equipped with an idle stop device, the power running time of the starter motor is accumulated. Then, based on the accumulated power running time, deterioration of the starter motor is determined. If it is determined that the starter motor is deteriorated, idle stop is prohibited (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-281237 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the control device of Patent Document 1, deterioration of the starter motor is judged based on the accumulated power running time of the starter motor. The starter motor operates when the engine is started or restarted, and only power running is required, so deterioration judgment is possible based on the accumulated power running time. However, in the case of a vehicle generator motor that also generates power, unless the deterioration judgment is performed during the operating state including power generation, there is a possibility that restart after idle stop will not be possible.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an idle stop control device that can more appropriately determine the deterioration of a vehicle generator-motor. [Means for solving the problem]

[0006] The idle stop control device of the present disclosure includes an MG control unit that controls a voltage application unit that applies voltage to an armature winding of a vehicle generator motor, and the MG control unit has a magnetic flux estimation unit that estimates magnetic flux generated in the vehicle generator motor when the vehicle generator motor is driven or when it generates electricity, or both, and a deterioration determination unit that determines whether the performance of the vehicle generator motor has deteriorated based on the magnetic flux estimated by the magnetic flux estimation unit, and the MG control unit performs control related to the idle stop of the vehicle generator motor based on the determination result by the deterioration determination unit. Effect of the Invention

[0007] According to the idle stop control device of the present disclosure, deterioration of a vehicle generator motor can be determined more appropriately. [Brief description of the drawings]

[0008] [Figure 1] 1 is a configuration diagram showing, in partial block form, the main parts of a vehicle according to a first embodiment. [Diagram 2] 2 is a schematic circuit diagram showing the vehicle generator motor, the first voltage application unit, the second voltage application unit, the field voltage application unit, and the MG control unit of FIG. 1. [Diagram 3] 1 is a graph showing a current vector in a rotating coordinate system. [Figure 4] 4 is a graph showing the relationship between the phase angle and the output torque. [Diagram 5] 4 is a graph showing the relationship between the output torque and magnet torque of a vehicle generator motor when the absolute value of the current is I. [Figure 6] 4 is a graph showing the relationship between field current and magnetic flux. [Figure 7] 3 is a flowchart showing the operation of the MG control unit in FIG. 2; [Figure 8] FIG. 11 is a configuration diagram showing, in partial block form, the main parts of a vehicle according to a second embodiment. [Figure 9] 9 is a flowchart showing the operation of the MG control unit in FIG. 8. [Figure 10]2 is a configuration diagram showing a first example of a processing circuit that realizes each function of the idle stop control device according to the first and second embodiments. FIG. [Figure 11] FIG. 4 is a configuration diagram showing a second example of the processing circuit that realizes each function of the idle stop control device according to the first and second embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments will be described with reference to the drawings. Embodiment 1 Fig. 1 is a block diagram showing the main parts of a vehicle according to embodiment 1. In Fig. 1, wheels 102 are provided at both ends of a drive shaft 101. An engine 104 is connected to the drive shaft 101 via a transmission 103.

[0010] The vehicle generator motor 105 is connected to the engine 104 via a belt (not shown). As an auxiliary of the engine 104, the vehicle generator motor 105 generates a driving force to rotate the pair of wheels 102. The vehicle generator motor 105 also generates electricity by utilizing the rotation of the engine 104.

[0011] Furthermore, when returning from an idle stop, the vehicle generator motor 105 generates a power torque to promote the rise in rotation of the engine 104, and restarts the engine 104 from a stopped state.

[0012] A first voltage application unit 106, a second voltage application unit 107, and a field voltage application unit 108 are connected to the vehicle generator motor 105.

[0013] The idle stop control device 1 includes an engine control unit 10 and an MG (Motor Generator) control unit 20.

[0014] The engine control unit 10 controls the engine 104. The engine 104 generates a driving torque for driving the vehicle in accordance with a control signal from the engine control unit 10. The driving torque is transmitted to a pair of wheels 102 via a transmission 103 and a drive shaft 101.

[0015] A plurality of signals are input to the engine control unit 10. The plurality of signals include an engine key switch signal, an accelerator opening signal, a brake pressure signal, a shift position signal of the transmission 103, a rotation speed signal of the engine 104, a vehicle speed signal, and the like.

[0016] The engine control unit 10 detects the operating conditions of the vehicle based on a plurality of input signals, and controls the engine 104 based on the detected operating conditions.

[0017] Furthermore, in order to improve fuel efficiency, the engine control unit 10 performs idle stop control to stop the engine 104 when the idle stop permission condition is satisfied and the idle stop prohibition condition is not met. Examples of the idle stop permission condition include deceleration before the vehicle is stopped, and the vehicle is stopped.

[0018] Furthermore, the engine control unit 10 transmits a control command to the MG control unit 20 when the idle stop recovery condition is satisfied after the idle stop control.

[0019] Based on the control command, the MG control unit 20 restarts the engine 104 using the vehicle generator motor 105. At this time, the MG control unit 20 controls the applied voltages in the first voltage application unit 106, the second voltage application unit 107, and the field voltage application unit 108, and controls the current flowing through the vehicle generator motor 105.

[0020] A specific idle stop permission condition is, for example, when the following (a) or (b) is satisfied and also when all of (c) to (e) are satisfied. The condition (e) will be described in detail later. (a) The vehicle speed is zero. (b) Fuel is being cut and the vehicle speed is below the speed setting. (c) The accelerator opening is equal to or smaller than the first opening setting value. (d) The brake pressure is equal to or greater than the first brake pressure setting value. (e) The performance of the vehicle generator motor 105 is normal.

[0021] A specific idle stop prohibition condition is, for example, when any one of the following conditions (f) to (h) is satisfied. Note that condition (h) will be described in detail later. (f) The engine water temperature is below the temperature setting. (g) The DC voltage is below the voltage setting. (h) The performance of the vehicle generator motor 105 is degraded.

[0022] A specific idle stop recovery condition is, for example, when any one of the following (i) to (k) is satisfied. (i) The accelerator opening is equal to or greater than the second opening setting value. (j) The brake pressure is equal to or lower than the second brake pressure setting value. (k) The steering torque is equal to or greater than the torque setting value.

[0023] FIG. 2 is a schematic circuit diagram showing the vehicle generator motor 105, the first voltage application unit 106, the second voltage application unit 107, the field voltage application unit 108, and the MG control unit 20 of FIG.

[0024] The vehicle generator motor 105 has two sets of armature windings, that is, a first armature winding 111 and a second armature winding 112, and a field winding 113. The vehicle generator motor 105 of the first embodiment is a field winding type AC rotating machine.

[0025] The first armature winding 111 is composed of a three-phase winding, i.e., a winding U1, a winding V1, and a winding W1. The second armature winding 112 is composed of a three-phase winding, i.e., a winding U2, a winding V2, and a winding W2. The first armature winding 111 and the second armature winding 112 are housed in a stator (not shown) of the vehicle generator motor 105 without being electrically connected to each other.

[0026] The field winding 113 is housed in a rotor (not shown) of the vehicle generator motor 105. The field winding 113 functions as an electromagnet when a field current is passed through it.

[0027] Here, a dual three-phase AC rotating machine having field winding 113 is used as an example, but similar effects can be obtained with an AC rotating machine with a magnet provided on the rotor, an AC rotating machine with four or more phases of armature windings, or an AC rotating machine with one or three or more sets of armature windings.

[0028] The first voltage application unit 106 applies a voltage to the first armature winding 111. The second voltage application unit 107 applies a voltage to the second armature winding 112. The field voltage application unit 108 applies a voltage to the field winding 113.

[0029] A DC voltage Vdc is applied to the first voltage application unit 106, the second voltage application unit 107, and the field voltage application unit 108 from a DC power supply 109. The DC power supply 109 is not particularly limited as long as it is a device that applies a DC voltage. Examples of devices that apply a DC voltage include a battery, a DC-DC converter, a diode rectifier, and a PWM (Pulse Width Modulation) rectifier.

[0030] A smoothing capacitor 110 is connected in parallel to the DC power supply 109. The smoothing capacitor 110 suppresses fluctuations in the bus current and stabilizes the DC current. Although not shown in detail here, in addition to the true capacitor capacitance C, there exists an equivalent series resistance Rc and a lead inductance Lc.

[0031] The first voltage application unit 106 uses, for example, an inverter which is an inverse conversion circuit, to convert the DC voltage Vdc into power and apply the voltage to the winding U1, the winding V1, and the winding W1. As a result, a current Iu1 flows through the winding U1, a current Iv1 flows through the winding V1, and a current Iw1 flows through the winding W1.

[0032] Specifically, the first voltage application unit 106 has three high potential side switch units Sup1, Svp1, and Swp1 and three low potential side switch units Sun1, Svn1, and Swn1. Each of the switch units Sup1, Svp1, Swp1, Sun1, Svn1, and Swn1 is turned on and off based on a corresponding one of the switching signals Qup1, Qvp1, Qwp1, Qun1, Qvn1, and Qwn1.

[0033] The second voltage application unit 107 uses, for example, an inverter which is an inverse conversion circuit, to convert the DC voltage Vdc into power and apply the voltage to the winding U2, the winding V2, and the winding W2. As a result, a current Iu2 flows through the winding U2, a current Iv2 flows through the winding V2, and a current Iw2 flows through the winding W2.

[0034] Specifically, the second voltage application unit 107 has three high potential side switch units Sup2, Svp2, and Swp2 and three low potential side switch units Sun2, Svn2, and Swn2. Each of the switch units Sup2, Svp2, Swp2, Sun2, Svn2, and Swn2 is turned on and off based on a corresponding one of the switching signals Qup2, Qvp2, Qwp2, Qun2, Qvn2, and Qwn2.

[0035] The field voltage application unit 108 uses, for example, a converter, to convert the DC voltage Vdc into power and applies the voltage to the field winding 113 of the vehicle generator motor 105. As a result, a field current If is passed through the field winding 113.

[0036] Specifically, the field voltage application unit 108 has two high potential side switch units Sp1 and Sp2 and two low potential side switch units Sn1 and Sn2. Each of the switch units Sp1, Sp2, Sn1, and Sn2 is turned on and off based on a corresponding one of the switching signals Qp1, Qp2, Qn1, and Qn2.

[0037] For example, if the value of each of the switching signals Qup1-Qwn1, Qup2-Qwn2, and Qp1-Qn2 is "1," the signal is a signal for turning on the corresponding switch unit. Also, if the value of each of the switching signals Qup1-Qwn1, Qup2-Qwn2, and Qp1-Qn2 is "0," the signal is a signal for turning off the corresponding switch unit.

[0038] Each of the switch sections Sup1 to Swn1, Sup2 to Swn2, and Sp1 to Sn2 is configured by connecting a semiconductor switch and a diode in anti-parallel. Examples of the semiconductor switch include an IGBT (Insulated Gate Bipolar Transistor), a bipolar transistor, and a MOS (Metal Oxide Semiconductor) power transistor.

[0039] If there is no need to change the direction of the current flowing through the field winding 113, the switch unit Sp2 may be kept off at all times.

[0040] The switch section Sn2 may also be always off or may be made of a diode, but because the resistance of a diode is high, turning on the semiconductor switch reduces the amount of heat generated.

[0041] The MG control unit 20 has, as functional blocks, a voltage command calculation unit 21, an output voltage generation unit 22, a magnetic flux estimation unit 23, and a deterioration determination unit 24.

[0042] The voltage command calculation unit 21 calculates a current command based on a control command from the engine control unit 10. Furthermore, the voltage command calculation unit 21 calculates voltage commands Vu1, Vv1, Vw1, voltage commands Vu2, Vv2, Vw2, and a field voltage command Vf based on the calculated current command, and outputs them to the output voltage generation unit 22.

[0043] The voltage commands Vu1, Vv1, and Vw1 are commands for applying voltages to the windings U1, V1, and W1, respectively. The voltage commands Vu2, Vv2, and Vw2 are commands for applying voltages to the windings U2, V2, and W2, respectively. The field voltage command Vf is a command for applying a voltage to the field winding 113.

[0044] A method for generating a current command will be described below. Fig. 3 is a graph showing a current vector in a rotating coordinate system. If the absolute value of the current vector is I and the phase angle from the q-axis is β, the d-axis current Id and the q-axis current Iq are given by equation (1).

[0045]

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[0046] FIG. 4 is a graph showing the relationship between the phase angle β and the output torque T. The thin solid line shows the output torque when the absolute value of the current is I. The dashed line shows the output torque when the absolute value of the current is 66.7% of I. The dashed line shows the output torque when the absolute value of the current is 33.3% of I.

[0047] The thick solid line A is a minimum current maximum torque curve for positive torque, and the thick solid line B is a minimum current maximum torque curve for negative torque.

[0048] The absolute value of the current required to output the same torque can be minimized by passing a combination of d-axis current and q-axis current on the minimum current maximum torque curves A and B. For this reason, the combination of d-axis current and q-axis current on the minimum current maximum torque curve is selected as the current command during normal operation for the required torque required by the control command.

[0049] For simplicity, only the combination of the d-axis current and the q-axis current has been described here, but the d-axis current, the q-axis current, and the field current that minimize the loss including the field current may be selected. In addition, when estimating the magnetic flux, a current command during magnetic flux estimation control, which will be described later, is selected.

[0050] Next, a method for calculating the voltage commands Vu1, Vv1, and Vw1 will be described. The voltage commands Vu1, Vv1, and Vw1 for the first armature winding 111 are determined by, for example, current feedback control.

[0051] In the current feedback control, currents Iu1, Iv1, and Iw1 flowing through the three-phase windings constituting the first armature winding 111 are detected by an existing current detector. The existing current detector is, for example, a shunt resistor. These currents Iu1, Iv1, and Iw1 are vectors in a fixed coordinate system. These currents Iu1, Iv1, and Iw1 are converted into a d-axis current Id1 and a q-axis current Iq1 in a rotating coordinate system.

[0052] After that, the d-axis voltage command Vd1 and the q-axis voltage command Vq1 are determined by proportional-integral control so that the deviation between the d-axis current Id1 and the d-axis current command Id1*, and the deviation between the q-axis current Iq1 and the q-axis current command Iq1*, respectively, become zero.

[0053] Then, the d-axis voltage command Vd1 and the q-axis voltage command Vq1 in the rotating coordinate system are converted into vectors in the fixed coordinate system to obtain voltage commands Vu1, Vv1, and Vw1.

[0054] The voltage commands Vu1, Vv1, and Vw1 may be obtained by feedforward control, control using an estimated value, or current feedback control.

[0055] In the feedforward control and the control using an estimated value, the input of the currents Iu1, Iv1, and Iw1 to the voltage command calculation unit 21 is not essential.

[0056] In addition, in the current feedback control, current commands Iu1*, Iv1*, Iw1* obtained by converting the d-axis current command Id1* and the q-axis current command Iq1* into vectors in a fixed coordinate system may be used.

[0057] The method of calculating the voltage commands Vu2, Vv2, and Vw2 for the second armature winding 112 is similar to the method of calculating the voltage commands Vu1, Vv1, and Vw1.

[0058] The voltage commands for the first armature winding 111 and the second armature winding 112 may be calculated by current feedback control using the d-axis sum current Id_sum, the q-axis sum current Iq_sum, the d-axis difference current Id_diff, and the q-axis difference current Iq_diff.

[0059] The d-axis sum current Id_sum is the sum of the d-axis current Id1 of the first armature winding 111 and the d-axis current Id2 of the second armature winding 112. The q-axis sum current Iq_sum is the sum of the q-axis current Iq1 of the first armature winding 111 and the q-axis current Iq2 of the second armature winding 112. The d-axis difference current Id_diff is the difference between the d-axis current Id1 of the first armature winding 111 and the d-axis current Id2 of the second armature winding 112. The q-axis difference current Iq_diff is the difference between the q-axis current Iq1 of the first armature winding 111 and the q-axis current Iq2 of the second armature winding 112.

[0060] Next, a method for calculating the field voltage command Vf will be described. The field voltage command Vf is obtained by, for example, current feedback control.

[0061] In the current feedback control, the field current If flowing through the field winding 113 is detected by an existing current detector. The existing current detector is, for example, a shunt resistor. After that, a field voltage command Vf is obtained by proportional-integral control so that the deviation between the field current If and the current command becomes zero.

[0062] The field voltage command Vf may be obtained by feedforward control or control using an estimated value.

[0063] In the feedforward control and the control using an estimated value, the input of the field current If to the voltage command calculation unit 21 is not essential.

[0064] The output voltage generating unit 22 modulates, by pulse width modulation, the voltage commands Vu1, Vv1, and Vw1 output from the voltage command calculating unit 21. As a result, the output voltage generating unit 22 outputs switching signals Qup1 to Qwn1 having pulse widths according to the voltage commands Vu1, Vv1, and Vw1.

[0065] The switching signals Qup1 to Qwn1 may be generated from the voltages Vu1', Vv1', and Vw1' modulated by a known modulation method, such as space vector modulation and two-phase modulation.

[0066] The method of generating the switching signals Qup2 to Qwn2 and the method of generating the switching signals Qp1 to Qn2 are similar to the method of generating the switching signals Qup1 to Qwn1.

[0067] The magnetic flux estimation unit 23 performs magnetic flux estimation control during either or both of driving and generating power of the vehicle generator motor 105. In addition, the magnetic flux estimation unit 23 calculates a magnetic flux φ generated in the vehicle generator motor 105 during the magnetic flux estimation control.

[0068] Specifically, the magnetic flux estimation unit 23 calculates the magnetic flux φ based on state values ​​and command values ​​of the first armature winding 111 and the second armature winding 112 during the magnetic flux estimation control. The state values ​​are d-axis currents Id1, Id2 and q-axis currents Iq1, Iq2. The command values ​​are d-axis voltage commands Vd1, Vd2 and q-axis voltage commands Vq1, Vq2.

[0069] In addition, to calculate the magnetic flux φ, a d-axis current command and a q-axis current command for the first armature winding 111 and the second armature winding 112, respectively, may be used instead of the d-axis current and the q-axis current of the first armature winding 111 and the second armature winding 112, respectively.

[0070] The deterioration determination unit 24 determines whether the magnetic flux φ calculated by the magnetic flux estimation unit 23 is within a set range. If the magnetic flux φ calculated by the magnetic flux estimation unit 23 deviates from the set range, the deterioration determination unit 24 determines that the performance of the vehicle generator motor 105 has deteriorated. If the deterioration determination unit 24 determines that the performance of the vehicle generator motor 105 has deteriorated, it outputs a command to the engine control unit 10 to prohibit idle stop.

[0071] 5 is a graph showing the relationship between the output torque and magnet torque of the vehicle generator motor 105 when the absolute value of the current is I. The solid line indicates the output torque of the vehicle generator motor 105. The dashed line indicates the magnet torque.

[0072] In Fig. 5, the difference between the solid line and the dashed line is the reluctance torque. In many cases, the magnet torque accounts for a large proportion of the output torque, and when the magnetic flux φ decreases, the output torque also decreases by that amount.

[0073] 6 is a graph showing the relationship between the field current If and the magnetic flux φ. The magnetic flux φ when the performance of the vehicle generator motor 105 is normal is shown by a solid line. The magnetic flux φ increases as the field current If increases. The magnetic flux φideal when the performance of the vehicle generator motor 105 is normal can be expressed as in equation (2).

[0074]

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[0075] For example, if the field magnet of the rotor is demagnetized due to some factor, the magnetic flux φ obtained by the magnetic flux estimation unit 23 will be as shown by the dashed line in FIG. 6 and will be lower than when the performance of the vehicle generator motor 105 is normal, regardless of the field current If. Therefore, the maximum value of the output torque of the vehicle generator motor 105 will be lower. If formula (3) is satisfied, the degradation determination unit 24 determines that the performance of the vehicle generator motor 105 has deteriorated and prohibits idle stop. Here, φth is a determination magnetic flux and is determined from the output torque required to restart the engine 104.

[0076]

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[0077] The deterioration determination unit 24 may determine the performance deterioration using the formula (4). In the formula (4), φmax is the magnetic flux at the maximum value of the outputtable field current, and φrun is the magnetic flux determined from the output torque Trun required to restart the engine 104.

[0078]

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[0079] For example, the magnetic flux φrun may be given by equation (5), where P is the number of pole pairs and Iq_sum_max is the maximum value of the q-axis sum current that can be output.

[0080]

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[0081] A method of giving a current command and a method of estimating the magnetic flux during magnetic flux estimation control will be described below.

[0082] A voltage equation relating to the field winding 113, the first armature winding 111, and the second armature winding 112 is given as shown in equation (6). In equation (6), ω is an electrical angular velocity. Ra is each resistance of the first armature winding 111 and the second armature winding 112. Rf is the resistance of the field winding 113. Ld is a d-axis self-inductance. Lq is a q-axis self-inductance. Lf is a self-inductance of the field winding 113. Md is a d-axis mutual inductance between the first armature winding 111 and the second armature winding 112. Mq is a q-axis mutual inductance between the first armature winding 111 and the second armature winding 112. Lmd is the mutual inductance between the first armature winding 111 and the field winding 113 and between the second armature winding 112 and the field winding 113. φf0 is the magnetic flux when the field current If is zero. s is the Laplace operator.

[0083]

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[0084] The magnetic flux φ is given by equation (7). In other words, the magnetic flux φ can be adjusted by the field current If.

[0085]

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[0086] Since the voltage that can be applied to each armature winding is equal to or less than the DC voltage Vdc, the condition under which the d-axis current and the q-axis current can be stably controlled to desired values ​​is as shown in equation (8). Therefore, by determining the field current If during magnetic flux estimation control in consideration of the voltage saturation condition in equation (8), the magnetic flux estimator 23 can output the d-axis currents Id1, Id2 and the q-axis currents Iq1, Iq2 according to the command values, and can estimate the magnetic flux φ with high accuracy.

[0087]

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[0088] When equation (9) is rearranged, equation (10) holds in the steady state. Here, Vd_sum is the d-axis sum voltage. Vq_sum is the q-axis sum voltage. Vd_diff is the d-axis difference voltage. Vq_diff is the q-axis difference voltage.

[0089]

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[0090]

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[0091] From equation (10), the magnetic flux φ can be calculated by equation (11).

[0092]

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[0093] The d-axis self-inductance Ld and the d-axis mutual inductance Md change due to magnetic saturation. Therefore, in order to accurately calculate the second term on the right side of the formula (11), the magnetic flux estimation unit 23 calculates the magnetic flux φ using, for example, a map that defines the relationship between the d-axis current, the q-axis current, and the field current and the inductance.

[0094] Furthermore, the resistance Ra of each of the first armature winding 111 and the second armature winding 112 changes depending on the temperature. Therefore, in order to accurately calculate the third term on the right side of equation (11), the magnetic flux estimation unit 23, for example, detects or estimates the temperature, and then calculates it using a map that predefines the relationship between the temperature and the resistance Ra.

[0095] Inductance changes mainly due to current, so the time constant of inductance change is relatively small. In contrast, resistance changes mainly due to temperature, so the time constant of resistance change is larger than the time constant of inductance change. Therefore, taking into account the calculation cycle of current control, the third term on the right side of equation (11), which represents the resistance component, can be considered constant as long as the current does not change.

[0096] Therefore, by controlling the d-axis sum current Id_sum to zero as in equation (12), the second term on the right-hand side of equation (11) is set to zero. This allows the influence on the magnetic flux φ to be limited to the influence of the resistance component as in equation (13), improving the estimation accuracy of the magnetic flux φ. Here, a case where two sets of armature windings are used is described, but even if only one set of armature windings is used, the magnetic flux φ can be calculated in a similar manner.

[0097]

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[0098]

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[0099] Furthermore, by controlling the q-axis sum current Iq_sum to zero as in equation (14), the second term on the right side of equation (13) is also set to zero. This allows the magnetic flux φ to be calculated by equation (15), thereby further improving the estimation accuracy of the magnetic flux.

[0100]

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[0101]

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[0102] If the number of pole pairs is P, the output torque is given by equation (16).

[0103]

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[0104] When equation (14) holds, the output torque is expressed by equation (17), so that the vehicle generator motor 105 can obtain a non-zero output torque.

[0105]

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[0106] The vehicle generator motor 105 of this embodiment has two sets of armature windings. Therefore, in order to obtain a powering torque, the MG control unit 20 only needs to control the d-axis difference current Id_diff and the q-axis difference current Iq_diff so that they have the same sign. In addition, in order to obtain a regenerative torque, the MG control unit 20 only needs to control the d-axis difference current Id_diff and the q-axis difference current Iq_diff so that they have opposite signs.

[0107] When the q-axis sum current Iq_sum satisfies equation (14), the magnet torque component in the first term on the right side of equation (16) becomes zero. Therefore, in order to obtain the output torque T, the output torque T needs to be provided by the reluctance torque component in the second term on the right side. Therefore, the magnetic flux estimation unit 23 identifies the resistance Ra of each armature winding in the second term on the right side of equation (13) from equation (18).

[0108]

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[0109] When the d-axis difference current Id_diff and the q-axis difference current Iq_diff are controlled so as to satisfy the equation (19), the resistance Ra of each armature winding can be calculated by the equation (20).

[0110]

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[0111]

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[0112] The magnetic flux φ is estimated by equation (21).

[0113]

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[0114] At this time, the output torque T is expressed by equation (22). Therefore, by using the following simple method, the vehicle generator motor 105 can obtain the output torque T while the magnetic flux φ is being estimated by the magnetic flux estimation unit 23. In the simple method, first, the d-axis current command Id1* for the first armature winding 111 and the d-axis current command Id2* for the second armature winding 112 are set to the same value. On the other hand, the q-axis current command Iq1* for the first armature winding 111 and the q-axis current command Iq2* for the second armature winding 112 are set to different values. According to this method, the output torque T can be expressed only by the magnet torque, so that it is easy to determine the current command for the required torque.

[0115]

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[0116] When the d-axis difference current Id_diff and the q-axis difference current Iq_diff are controlled so as to satisfy the equation (23), the resistance Ra of each armature winding is calculated by the equation (24).

[0117]

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[0118]

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[0119] At this time, the magnetic flux φ is estimated by equation (25).

[0120]

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[0121] The output torque T at this time is expressed by equation (22). Therefore, by using the following simple method, the vehicle generator motor 105 can obtain the output torque T while the magnetic flux φ is being estimated by the magnetic flux estimation unit 23. In the simple method, first, the q-axis current command Iq1* for the first armature winding 111 and the q-axis current command Iq2* for the second armature winding 112 are set to the same value. On the other hand, the d-axis current command Id1* for the first armature winding 111 and the d-axis current command Id2* for the second armature winding 112 are set to different values.

[0122] In order to set the output torque T during magnetic flux estimation control to zero, the voltage command calculation unit 21 sets the d-axis current commands Id1*, Id2* and the q-axis current commands Iq1*, Iq2* to zero, and the magnetic flux estimation unit 23 calculates the magnetic flux using the q-axis voltage commands Vq1, Vq2.

[0123] Next, although not shown in the figure, a case will be described where the vehicle generator motor 105 is an AC rotating machine having three sets of armature windings. The magnetic flux φ is given by equation (26). Therefore, by controlling the d-axis sum current Id_sum so as to satisfy equation (12), the magnetic flux estimation unit 23 can calculate the magnetic flux φ by equation (27).

[0124]

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[0125]

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[0126] Furthermore, by controlling the q-axis sum current Iq_sum to be zero as in equation (14), the magnetic flux estimation unit 23 can calculate the magnetic flux φ by equation (28).

[0127]

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[0128] At this time, the output torque T is given by equation (29). Therefore, the MG control unit 20 supplies d-axis currents Id1, Id2 and q-axis currents Iq1, Iq2 as shown in equation (30). Then, the MG control unit 20 sets the difference between the d-axis component of the current command of the first set of three pairs and the d-axis component of the current command of the second set, and the difference between the q-axis component of the current command of the first set and the q-axis component of the current command of the second set, to a non-zero value. This makes it possible to obtain a non-zero output torque.

[0129]

number

[0130]

number

[0131] Moreover, the resistance Ra of each armature winding in the second term on the right-hand side of equation (27) is identified by equation (31), as in the case of two sets. Here, Vd_diff12 is the d-axis difference voltage between the first and second sets. Vq_diff12 is the q-axis difference voltage between the first and second sets. Id_diff12 is the d-axis difference current between the first and second sets. Iq_diff12 is the q-axis difference current between the first and second sets.

[0132]

number

[0133] Although the above describes the case of an AC rotating machine having one to three sets of armature windings, similar effects can be obtained for an AC rotating machine having m sets of armature windings, where m is a natural number.

[0134] When the vehicle generator motor 105 has m sets of armature windings, where m is a natural number, the magnetic flux estimation unit 23 can calculate the magnetic flux using the q-axis component of the voltage command in a state in which the sum of the d-axis components of the m sets of current commands is controlled to be zero.

[0135] In an AC rotating machine in which the rotor is not provided with a field winding 113 but has a magnet, the magnetic flux φ is given by equation (32), where φm is the magnetic flux of the magnet. In an AC rotating machine in which the rotor is provided with a field winding 113 and a magnet, the magnetic flux φ is given by equation (33).

[0136]

number

[0137]

number

[0138] When a magnet is provided on the rotor, the drive torque at the time of starting is reduced due to demagnetization of the magnet. This prevents the engine 104 from being unable to restart even if idling stop is performed while the magnet is demagnetized.

[0139] Furthermore, when the rotor is provided with the field winding 113, the magnetic flux due to the field current If is easily saturated due to demagnetization of the magnet, and the drive torque decreases. This prevents the engine from being unable to restart even if an idle stop is performed while the magnet is demagnetized.

[0140] Fig. 7 is a flow chart showing the operation of the MG control unit 20 in Fig. 2. The MG control unit 20 executes the process shown in Fig. 7 at a preset timing.

[0141] First, in step S101, the MG control unit 20 calculates a current command. Then, in step S102, the MG control unit 20 calculates a voltage command. Then, in step S103, the MG control unit 20 outputs the voltage commands to the first voltage application unit 106, the second voltage application unit 107, and the field voltage application unit 108.

[0142] In addition, in step S104, the MG control unit 20 calculates the magnetic flux in the vehicle generator motor 105. Then, in step S105, the MG control unit 20 performs a deterioration determination of the performance of the vehicle generator motor 105. In other words, the MG control unit 20 determines whether the performance of the vehicle generator motor 105 is normal.

[0143] If it is determined that the performance of the vehicle generator motor 105 is normal, the MG control unit 20 permits idle stop in step S106, and ends the processing for that round.

[0144] On the other hand, if it is determined that the performance of the vehicle generator motor 105 is not normal, that is, if it is determined that the performance of the vehicle generator motor 105 has deteriorated, the MG control unit 20 prohibits idle stop in step S107. Then, the MG control unit 20 sends a command to prohibit idle stop to the engine control unit 10, and ends the processing for that time.

[0145] In such an idle stop control device 1, the MG control unit 20 has a magnetic flux estimation unit 23 and a deterioration determination unit 24. The magnetic flux estimation unit 23 estimates the magnetic flux generated in the vehicle generator motor 105 when the vehicle generator motor 105 is driven or when the vehicle generator motor 105 is generating electricity, or both. The deterioration determination unit 24 determines whether the performance of the vehicle generator motor 105 has deteriorated based on the magnetic flux estimated by the magnetic flux estimation unit 23.

[0146] Therefore, the deterioration of the vehicle generator motor 105 can be determined more appropriately.

[0147] Furthermore, the MG control unit 20 performs control regarding the idle stop of the vehicle generator motor 105 based on the result of the determination by the deterioration determination unit. The MG control unit 20 prohibits the idle stop when it is determined that the performance of the vehicle generator motor 105 has deteriorated. This makes it possible to avoid a situation in which the vehicle cannot return from the idle stop due to insufficient output torque at the time of restart.

[0148] Furthermore, the deterioration determination unit 24 determines whether the performance of the vehicle generator motor 105 has deteriorated based on the output torque required to restart the engine 104. Therefore, the deterioration determination can be performed based on the magnetic flux condition that ensures the minimum torque required for restarting, and the range in which the deterioration is determined can be limited.

[0149] Furthermore, the magnetic flux estimation unit 23 calculates the magnetic flux generated in the vehicle generator motor 105 based on the current flowing through the first armature winding 111 and the second armature winding 112 and the voltage command for the first voltage application unit 106 and the second voltage application unit 107. Therefore, by estimating the magnetic flux from the relationship between the current and the voltage, it is possible to easily determine the decrease in magnetic flux.

[0150] Furthermore, when the vehicle generator motor 105 has m sets of armature windings, where m is a natural number, the magnetic flux estimation unit 23 calculates the magnetic flux generated in the vehicle generator motor 105 by using the q-axis component of the voltage command in a state in which the sum of the d-axis components of the m sets of current commands is controlled to be zero. Therefore, by passing a current only through the q-axis, the term expressed by the product of the d-axis current and inductance can be ignored. This makes it possible to eliminate the need to consider the influence of inductance and to accurately estimate the magnetic flux generated in the vehicle generator motor 105.

[0151] Furthermore, when the vehicle generator motor 105 has two or more sets of armature windings, the magnetic flux estimation unit 23 eliminates the inductance term to calculate the magnetic flux generated in the vehicle generator motor 105. This makes it possible to estimate the magnetic flux generated in the vehicle generator motor 105 with high accuracy.

[0152] Embodiment 2 Next, Fig. 8 is a block diagram showing a part of a main part of a vehicle according to embodiment 2. The engine 104 is provided with a starting motor 114 in addition to the vehicle generator motor 105. The starting motor 114 is connected to the engine 104 via a belt or gears (not shown).

[0153] Furthermore, when the engine 104 is started, the starter motor 114 generates a drive torque to rotate the engine 104, and assists the operation of the engine 104 until it reaches a complete combustion.

[0154] During normal recovery from idle stop, the vehicle generator motor 105 is used. For this reason, the number of times the starter motor 114 can be used is designed to be smaller than the number of times the vehicle generator motor 105 can be used.

[0155] The engine control unit 10 drives the starting motor 114 to rotate the engine 104 when starting the engine 104. On the other hand, when returning normally from the idle stop, the engine control unit 10 transmits a control command to the MG control unit 20 to restart the engine 104 using the vehicle generator motor 105, as in the first embodiment.

[0156] However, when it is determined that the performance of the vehicle generator motor 105 has deteriorated, the MG control unit 20 uses the starter motor 114 to return from the idle stop.

[0157] Fig. 9 is a flowchart showing the operation of MG control unit 20 in Fig. 8. The processes from step S101 to step S105 are the same as those in the first embodiment.

[0158] If it is determined in step S105 that the performance of the vehicle generator motor 105 is normal, the MG control unit 20 permits the use of the vehicle generator motor 105 when returning from idle stop in step S201, and ends the processing for that round.

[0159] On the other hand, if it is determined that the performance of the vehicle generator motor 105 is not normal, that is, if it is determined that the performance of the vehicle generator motor 105 has deteriorated, the MG control unit 20 prohibits the use of the vehicle generator motor 105 when returning from idle stop in step S202. Then, the MG control unit 20 sends a command to the engine control unit 10 to use the starter motor 114 for returning from idle stop, and ends the processing for that round.

[0160] Except for the configuration shown in FIG. 8 and the operation shown in FIG. 9, the other configurations and operations are the same as those in the first embodiment.

[0161] With this type of idle stop control device 1 as well, it is possible to more appropriately determine the deterioration of the vehicle generator motor 105, and it is possible to obtain the same effects as those of the first embodiment.

[0162] Furthermore, when it is determined that the performance of the vehicle generator motor 105 has deteriorated, the MG control unit 20 uses the starting motor 114 to return from the idle stop. Therefore, even if the performance of the vehicle generator motor 105 has deteriorated, the idle stop can be performed and the engine 104 can be restarted.

[0163] Here, each function of the idle stop control device 1 according to the first and second embodiments is realized by a processing circuit. Fig. 10 is a configuration diagram showing a first example of a processing circuit that realizes each function of the idle stop control device 1 according to the first and second embodiments. The processing circuit 100 of the first example is dedicated hardware.

[0164] 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 of these. Each function of the idle stop control device 1 may be realized by an individual processing circuit 100, or each function may be realized by the processing circuit 100 collectively.

[0165] 11 is a configuration diagram showing a second example of the processing circuit that realizes each function of the idle stop control device 1 according to the first and second embodiments. The processing circuit 200 of the second example includes a processor 201 and a memory 202.

[0166] In the processing circuit 200, each function of the idle stop control device 1 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.

[0167] It can be said that the programs stored in the memory 202 cause the computer to execute the procedures or methods of each of the above-mentioned parts. Here, the memory 202 is, for example, a non-volatile or volatile semiconductor memory such as a random access memory (RAM), a read only memory (ROM), a flash memory, an erasable programmable read only memory (EPROM), an electrically erasable and programmable read only memory (EEPROM), etc. In addition, a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, a DVD, etc. also fall under the category of the memory 202.

[0168] It should be noted that some of the functions of the above-mentioned components may be realized by dedicated hardware, and other parts may be realized by software or firmware.

[0169] In this way, the processing circuitry can realize the functions of each of the above-mentioned units through hardware, software, firmware, or a combination of these. [Explanation of symbols]

[0170] 1 idle stop control device, 20 MG control unit, 21 voltage command calculation unit, 23 magnetic flux estimating unit, 24 deterioration determination unit, 105 vehicle generator motor, 106 first voltage application unit, 107 second voltage application unit, 111 first armature winding, 112 second armature winding, 114 starting motor.

Claims

1. An MG control unit that controls a voltage application unit that applies a voltage to an armature winding of a vehicle generator motor Equipped with The MG control unit is a magnetic flux estimating unit that estimates a magnetic flux generated in the vehicle generator-motor by performing a magnetic flux estimation control when the vehicle generator-motor is driven; a degradation determination unit that determines whether or not performance of the vehicle generator-motor is degraded based on the magnetic flux estimated by the magnetic flux estimation unit and a threshold value that is determined from an output torque of the vehicle generator-motor required for restarting the engine; It has The MG control unit performs control related to an idle stop of the engine based on a result of the determination by the deterioration determination unit, When performing the magnetic flux estimation control, the magnetic flux estimation unit converts a detection result of a current value flowing through the armature winding in response to a voltage command value into a state value, and estimates the magnetic flux based on the state value and the voltage command value. Idle stop control device.

2. 2. The idle stop control device according to claim 1, wherein the MG control unit prohibits the idle stop when it is determined that the performance of the vehicle generator motor has deteriorated.

3. 2. The idle stop control device according to claim 1, wherein the MG control unit uses a starter motor to return from the idle stop when it is determined that the performance of the vehicle generator motor has deteriorated.

4. The MG control unit is a voltage command calculation unit that calculates a current command value based on a control command input to the MG control unit, and calculates the voltage command value based on the current command value Further, The idle stop control device according to any one of claims 1 to 3.

5. When the vehicle generator motor has m sets of the armature windings, m being a natural number, 5. The idle stop control device according to claim 4, wherein the magnetic flux estimation unit calculates the magnetic flux using the q-axis component of the voltage command value in a state in which a d-axis sum current, which is a sum of d-axis components of the m sets of the current command values, is controlled to be zero.

6. In the case where the vehicle generator motor has m sets of the armature windings, m being an integer of 2 or more, When the magnetic flux is φ, the q-axis component of the voltage command value is Vq_sum, the electrical angular velocity is ω, the d-axis self-inductance is Ld, the d-axis mutual inductance is Md, the d-axis sum current is Id_sum, each resistance of the m sets of the armature windings is Ra, and the q-axis sum current, which is the sum of the q-axis components of the m sets of the current command values, is Iq_sum, [0010] 6. The idle stop control device according to claim 5, wherein the magnetic flux is calculated by deleting a term including the d-axis self-inductance Ld and the d-axis mutual inductance Md.

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