DEVICE FOR CONTROLLING AN ENGINE

Abstract

A device for controlling a motor (16) is provided, the motor having a housing (25) in which a stator (28) and a rotor (27) are arranged. The motor is cooled by a cooling oil (30) in the housing. The device includes a control unit (24) configured to control the motor. The control unit (24) has a temperature increase operating mode for heating the cooling oil using heat generated by the resistance of a coil (29) provided in the stator.

Description

BACKGROUND Technical area

[0001] The present invention relates to a device for controlling a motor which is cooled by a cooling oil in a housing. Related state of the art

[0002] A technique for preventing motor overheating is disclosed, for example, in JP 2013-85388A. The technique according to JP 2013-85388A is equipped with an oil temperature sensor for detecting the temperature of cooling oil in a motor housing. It calculates a winding temperature based on the oil temperature detected by this sensor, as well as the motor's heat capacity and thermal resistance, and then detects a motor temperature based on this winding temperature. If this detected motor temperature is a predetermined value or higher, the motor's torque is controlled.

[0003] In an engine cooled by a cooling oil within a housing, such as the engine according to JP 2013-85388A, if the cooling oil temperature is low during a cooling cycle or similar event, the viscosity of the cooling oil will increase. Consequently, the engine's rotational load becomes high, resulting in a significant flow resistance loss due to the cooling oil (i.e., a loss caused by the rotational load due to the cooling oil).

[0004] Publication JP 2005 - 348 535 A describes a motor control device and an associated control method. If the temperature of the cooling oil used to cool a drive motor does not exceed a certain temperature, the control device adjusts the input voltage and current of the drive motor in such a way that the copper loss of the drive motor increases, thereby heating the cooling oil and reducing its viscosity. This ensures a consistent flow rate of the cooling oil even at low temperatures.

[0005] Publication JP 2011-220478A describes a warm-up control device for a vehicle drive system. Early warm-up control of a transmission is implemented to promote transmission warm-up by increasing the temperature of the automatic transmission fluid (ATF), by increasing the heating value of the AC motor, and by increasing the reactive power that does not contribute to torque generation from the AC motor during transmission warm-up. With this early warm-up control, the heating value of the AC motor can be increased without generating torque when the AC motor's rotation is stopped (when the target torque is zero). Furthermore, the heating value of the AC motor can be increased while maintaining the target torque when the AC motor's rotation is driven.In this way, the ATF temperature can be increased early by reliably increasing the heating value of the AC motor without being affected by an operating condition of the vehicle (the target torque of the motor).

[0006] German patent application DE 10 2013 216 738 A1 describes a temperature-based control system for an electric machine. A vehicle is provided with at least one electric machine capable of propelling the vehicle. An oil circulation system circulates oil through the electric machines. A control system directs the electric machines to meet torque requirements. The control system uses the oil temperature in the oil circulation system to regulate the torque output of the electric machines. In the event of a fault or failure of the oil temperature sensors, the control system estimates the oil temperature from the temperature of coils within the electric machine. The estimated oil temperature is used instead of the measured oil temperature to regulate the torque outputs in such a way as to maintain the torque requirements.

[0007] German patent application DE 10 2013 009 518 A1 describes a motor vehicle equipped with a fuel heating system. It describes a method for operating a fuel pump in a motor vehicle to deliver liquid fuel. An electric motor of the fuel pump is supplied with three-phase current containing a torque-generating q-component via an inverter. To provide fuel heating for the liquid fuel being delivered, at least one signal value correlated with the temperature of the liquid fuel is determined, and this signal value is compared to a respective limit value. The limit value indicates whether the fuel needs to be heated.If the comparison reveals that the fuel needs to be heated, the inverter changes a d-component of the three-phase current, so that the changed d-component results in additional reactive power being converted in the electric motor, which in turn causes ohmic losses in the electric motor (26).

[0008] Taking into account the foregoing, exemplary embodiments of the present invention are aimed at providing a device for controlling a motor which can reduce a flow resistance loss due to a cooling oil of the motor. SUMMARY

[0009] This is achieved by a device for controlling a motor according to claim 1. Advantageous embodiments are specified in the dependent claims.

[0010] According to a first embodiment, a device for controlling a motor is provided, the motor having a housing in which a stator and a rotor are arranged. The motor is cooled by a cooling oil in the housing. The device includes a control unit configured to control the motor, wherein the control unit has a temperature increase operating mode for heating the cooling oil using heat generated by the resistance of a coil provided in the stator.

[0011] The invention is not limited to a configuration in which a motor is cooled by a cooling oil enclosed in a housing, but also includes a configuration in which a motor is cooled by a cooling oil introduced into a housing from the outside.

[0012] In this configuration, the motor is controlled in temperature-enhancing mode to heat the cooling oil using heat generated by the coil's resistance, thus actively heating the cooling oil. As a result, even if the cooling oil temperature is low and its viscosity is high during cooling or similar situations, the cooling oil temperature can be rapidly increased, and its viscosity can be rapidly reduced (i.e., a rotational load due to the cooling oil can be rapidly reduced), thereby minimizing flow resistance losses caused by the motor's cooling oil.

[0013] The temperature-increase operating mode is a motor control mode with a current amplitude and phase that differ from those of a normal operating mode, in which the motor is controlled with a current amplitude and phase that effectively delivers the required motor torque. In this way, compared to the normal operating mode, electrical power that does not contribute to torque generation is increased, thus increasing the coil temperature and the cooling oil temperature while achieving the required torque. That is to say, the normal operating mode reduces power consumption, whereas the temperature-increase operating mode increases power consumption more than the normal operating mode.

[0014] Furthermore, an inverter for driving the motor and a battery for supplying electrical power to the motor are provided. In the temperature-increased operating mode, the control unit preferably has a function to configure the current phase of the motor to be further delayed than in the normal operating mode. In this way, a negative d-axis current (i.e., an excitation current) is reduced compared to the normal operating mode, thereby preventing demagnetization of the permanent magnet (i.e., preventing irreversible demagnetization). Additionally, the temperatures of the inverter and the battery can be increased by increased losses in the inverter due to a deterioration of the power factor and by an increase in the battery's power output.

[0015] In the aforementioned temperature intensification operating mode, the aforementioned control unit is configured to switch between a delay temperature intensification operating mode, in which the current phase of the aforementioned motor is configured to be delayed or lagging further than in the aforementioned normal operating mode, and an advance temperature intensification operating mode, in which the current phase of the aforementioned motor is configured to be advanced or leading further than in the aforementioned normal operating mode, according to at least one parameter from the temperature of the aforementioned inverter and the current amplitude of the aforementioned motor. In this way, if an increase in inverter temperature and / or protection against demagnetization of the permanent magnet is unnecessary, the operating mode can be switched to the advance temperature intensification operating mode.In this forward temperature increase operating mode, compared to the retard temperature increase operating mode, a deterioration of the power factor is suppressed, thus reducing the output of a battery and suppressing battery deterioration.

[0016] Preferably, in the aforementioned temperature increase operating mode, when the required torque of the aforementioned motor is 0, the aforementioned control unit can configure the current phase of the aforementioned motor to be a phase in which no torque is generated (for example, 0 degrees or 180 degrees). In this way, even when the required torque of the motor is 0, the temperature of the cooling oil can be increased while the required torque is achieved (that is, without generating any torque).

[0017] Preferably, a cooling oil temperature sensor can be provided for detecting the temperature of the aforementioned cooling oil, wherein the aforementioned control unit can be configured to switch from the aforementioned normal operating mode to the aforementioned temperature-increase operating mode when the temperature of the aforementioned cooling oil, as detected by the aforementioned cooling oil temperature sensor, is a predetermined value A or less. In this way, the temperature of the cooling oil is detected directly by the cooling oil temperature sensor, whereby the temperature increase of the cooling oil is determined reliably and accurately, and thus the operating mode can be switched to the temperature-increase operating mode.

[0018] Preferably, the aforementioned control unit can be configured to switch from the aforementioned temperature-enhancement operating mode to the aforementioned normal operating mode when the temperature of the aforementioned cooling oil, as detected by the aforementioned cooling oil temperature sensor, is a predetermined value B or higher than the predetermined value A. In this way, a hysteresis feature can be imparted to the switching between the normal and temperature-enhancement operating modes based on the temperature of the cooling oil (that is, hysteresis is provided in the switching parameters of the normal and temperature-enhancement operating modes), thereby preventing frequent switching between operating modes.

[0019] Additionally, there is a relationship between the coil temperature and the cooling oil temperature. Consequently, a coil temperature sensor may preferably be provided to detect the temperature of the aforementioned coil. The aforementioned control unit may be configured to switch from the aforementioned normal operating mode to the aforementioned temperature-increase operating mode when the temperature of the aforementioned coil, as detected by the aforementioned coil temperature sensor, is a predetermined value °C or less. In this way, even in cases where the cooling oil temperature sensor is not installed, the need for a temperature increase of the cooling oil is accurately determined based on the coil temperature detected by the coil temperature sensor, thus enabling the operating mode to be switched to the temperature-increase operating mode.

[0020] Preferably, the aforementioned control unit can be configured to switch from the aforementioned temperature-enhancement operating mode to the aforementioned normal operating mode when the temperature of the aforementioned coil, as detected by the aforementioned coil temperature sensor, is a predetermined value D or higher than the aforementioned predetermined value C. In this way, the switching between the normal and temperature-enhancement operating modes based on the coil temperature can be given a hysteresis characteristic, thereby preventing frequent switching between operating modes.

[0021] Additionally, there is a relationship between the coil temperature and the cooling oil temperature, whereby the cooling oil temperature can consequently be estimated from the coil temperature. Accordingly, a coil temperature sensor can preferably be provided to detect the temperature of the aforementioned coil, wherein the aforementioned control unit can be configured to estimate the temperature of the aforementioned cooling oil based on the coil temperature detected by the aforementioned coil temperature sensor and to switch the aforementioned normal operating mode to the aforementioned temperature boost operating mode when the estimated cooling oil temperature, which is the estimated value, is a predetermined value E or less.In this way, even in a case where the cooling oil temperature sensor is not installed, the need for increasing the temperature of the cooling oil can be accurately determined based on the estimated cooling oil temperature, which is estimated from the temperature of the coil, thus allowing the operating mode to be switched to the temperature increase operating mode.

[0022] Preferably, the aforementioned control unit can be configured to switch from the aforementioned temperature-enhancement operating mode to the aforementioned normal operating mode when the aforementioned estimated cooling oil temperature is a predetermined value F or higher than the aforementioned predetermined value E. In this way, the switching between the normal operating mode and the temperature-enhancement operating mode based on the estimated cooling oil temperature can be given a hysteresis characteristic, thereby preventing frequent switching between operating modes.

[0023] Additionally, there is a relationship between the outside air temperature, the engine non-running time (i.e., the time elapsed since the engine entered a non-driven state), and the cooling oil temperature, whereby the cooling oil temperature can consequently be estimated from the outside air temperature and the engine non-running time.Accordingly, preferably an outside air temperature sensor can be provided to detect the outside air temperature, wherein the aforementioned control unit can be configured to estimate the temperature of the aforementioned cooling oil based on the aforementioned outside air temperature detected by the aforementioned outside air temperature sensor and an elapsed time of a time during which the aforementioned engine enters a non-driven state, and to switch the aforementioned normal operating mode to the aforementioned temperature enhancement operating mode when the estimated cooling oil temperature, which is the estimated value, is a predetermined value G or less.In this way, even in a case where the cooling oil temperature sensor is not installed, the need for increasing the temperature of the cooling oil can be accurately determined based on the estimated cooling oil temperature, which is estimated from the outside air temperature and the engine non-running time, thus allowing the operating mode to be switched to the temperature increase operating mode.

[0024] Preferably, an inverter for driving the aforementioned motor, a battery for supplying electrical power to the aforementioned motor, and a buck-boost converter connected between the aforementioned battery and the aforementioned inverter can be provided, wherein the aforementioned control unit can be configured to control switching between the aforementioned normal operating mode and the aforementioned temperature-enhancing operating mode based on an output voltage of the aforementioned buck-boost converter. In this way, to switch to the temperature-enhancing operating mode, the output voltage of the buck-boost converter is configured to be low in order to perform field attenuation control, thereby further shifting the current phase of the motor towards the forward or reverse side.The advantage side can be changed from that of the normal operating mode.

[0025] Preferably, the aforementioned cooling oil is enclosed in a sealed space within the aforementioned housing and stored at a height higher than the lowest part of the aforementioned rotor and lower than the rotor's shaft. In an oil-tight configuration where the cooling oil is enclosed in the sealed space within the housing, if the cooling oil is at a low temperature, the flow resistance loss due to the cooling oil tends to be large; however, by applying the present invention, the flow resistance loss due to the cooling oil can be effectively reduced.Additionally, by storing the cooling oil up to a height higher than the lowest part of the rotor, internal heat from the motor is effectively transferred to the housing via the cooling oil, thus allowing it to be released to the outside of the motor and effectively cooling it. Furthermore, by storing the cooling oil up to a height lower than the rotor's rotating shaft, a sufficient amount of the cooling oil is effectively contained, thus appropriately suppressing any rotational load on the motor caused by the cooling oil.

[0026] The present invention is preferably applied to an engine that is mounted as a drive motor of a vehicle. In this way, by reducing flow resistance losses due to the engine's cooling oil, a negative impact on vehicle performance (for example, a deterioration in fuel efficiency) can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a diagram illustrating a schematic configuration of a control system of a hybrid vehicle in a first embodiment of the present invention; Fig. Figure 2 shows a longitudinal section diagram illustrating a schematic configuration of a machine tool; Fig. Figure 3 shows a block diagram illustrating torque control of the MG; Fig. Figure 4 shows a diagram illustrating a normal operating mode and a temperature increase operating mode; Fig. Figure 5 shows a flowchart illustrating the processing sequence of an operating mode switching routine according to the first embodiment; Fig. Figure 6 shows a diagram illustrating a delay temperature increase operating mode; Fig. Figure 7 shows a diagram illustrating a forward temperature increase operating mode; Fig. Figure 8 shows a diagram illustrating a zero-torque temperature increase operating mode; Fig. Figure 9 shows a flowchart illustrating the processing sequence of an operating mode switching routine according to a second embodiment; Fig. Figure 10 shows a diagram illustrating a schematic configuration of a control system of a hybrid vehicle according to a third embodiment; Fig. Figure 11 shows a diagram illustrating a relationship between coil temperature and cooling oil temperature; Fig. Figure 12 shows a flowchart illustrating the processing sequence of an operating mode switching routine according to the third embodiment; Fig. Figure 13 shows a flowchart illustrating the processing sequence of an operating mode switching routine according to a fourth embodiment; Fig. Figure 14 shows a diagram illustrating a schematic configuration of a control system of a hybrid vehicle according to a fifth embodiment; Fig. Figure 15 shows a diagram illustrating a relationship between an outside air temperature, an MG non-drive time and a cooling oil temperature; Fig. Figure 16 shows a flowchart illustrating the processing sequence of an operating mode switching routine according to the fifth embodiment; Fig. Figure 17 shows a diagram illustrating a schematic configuration of a control system of a hybrid vehicle according to a sixth embodiment; and Fig. Figure 18 shows a diagram illustrating a schematic configuration of a control system of a hybrid vehicle according to a seventh embodiment. DESCRIPTION OF SPECIFIC EXAMPLES OF EXECUTION

[0027] Exemplary embodiments of the present invention are described in more detail below with reference to the accompanying drawing, which illustrates such embodiments. However, the present invention can be embodied in many different forms and should not be construed as being limited to the exemplary embodiments given herein. Rather, these exemplary embodiments are provided in such a way that this disclosure will be careful and complete, conveying the full scope of the invention to a person skilled in the art. Reference numerals refer to identical elements. First embodiment

[0028] A first embodiment of the present invention is described with reference to the Fig. 1 to 5 described.

[0029] First, with reference to Fig. 1. A schematic configuration of a control system of a hybrid vehicle is described.

[0030] A power engine 11, which is a power source for a vehicle, and a transmission 12 connected to this power engine 11 are mounted at the front of the vehicle. The transmission 12 is a mechanical transmission, which can be a multi-stage transmission that switches gears stepwise between a plurality of gear stages, or it can be a continuously variable transmission (CVT) that continuously shifts a rotational speed or vehicle speed. This power engine 11 and this transmission 12 are arranged transversely in such a way that the axial direction of an output shaft (i.e., a crankshaft) of the power engine 11 becomes a right-left direction of the vehicle.Power from the output shaft of the power machine 11 is transmitted to the transmission 12, wherein power from an output shaft of this transmission 12 is transmitted to a drive shaft 14 of a wheel 15 via a differential gear mechanism 13 or the like.

[0031] Furthermore, a small-diameter motor-generator (hereinafter referred to as "MG") 16, which is a power source for the vehicle, and a small-diameter reduction gear 17, connected to this MG 16, are mounted at the rear of the engine 11 and the transmission 12. The MG 16 and the reduction gear 17 are arranged vertically such that the axial direction of an output shaft is an anteroposterior direction of the vehicle. An output shaft of the reduction gear 17 is connected to a connecting gear 19 of a differential gear mechanism 13 (that is, a gear into which the power of the output shaft of the transmission 12 is input) via a transfer device 20.In this way, power from an output shaft of the MG 16 is transferred to the reduction gear 17, the power of the output shaft of this reduction gear 17 being transferred to the drive shaft 14 of the wheel 14 via the transfer device 20, the differential gear mechanism 13 or the like.

[0032] Additionally, an inverter 21 is connected to a high-voltage battery 22 for driving the MG 16, with electrical power being transferred between the MG 16 and the high-voltage battery 22 via the inverter 21. The high-voltage battery 22 is a DC power supply comprising a rechargeable battery or the like. The inverter 21 converts the DC voltage from the high-voltage battery 22 into an AC voltage to drive the MG 16.

[0033] An HV-ECU 23 is a control device for comprehensive control of the entire vehicle, reading output signals from various types of sensors and switches (for example, an acceleration sensor, a gear switch, a brake switch, a vehicle speed sensor, etc.) and recording the vehicle's operating status. This HV-ECU 23 transmits / receives a control signal or a data signal between an MG-ECU 24 and a power machine ECU (not shown). The MG-ECU 24 is a control device for controlling an inverter 21 to control the MG 16, and the power machine ECU is a control device for controlling the operation of the power machine 11.

[0034] The HV-ECU 23 controls the motor 11, the MG 16, or the like via a respective ECU according to the vehicle's operating status. The HV-ECU 23 switches between driving modes, for example, between motor-driven mode, assisted driving mode, and EV driving mode. In motor-driven mode, the vehicle is driven solely by the power of motor 11 and the MG 16. In assisted driving mode, the vehicle is driven by both motor 11 and MG 16, providing assisted driving. In EV driving mode, EV driving, in which the wheel 15 is driven only by power from the MG 16 to make the vehicle move, is carried out within the power machine 11 and the MG 16.

[0035] Additionally, when the vehicle is braked (for example, when braking power is generated, when the accelerator is released, or when the brake is applied), the HV-ECU 23 switches the driving mode to a regenerative power generation mode. In this regenerative power generation mode, the power from the wheel 15 drives the motor 16, thereby generating regenerative power to convert the vehicle's kinetic energy into electrical energy. The generated regenerative electrical power is then charged into the high-voltage battery 22.

[0036] Next, a schematic configuration of the MG 16 will be shown with reference to Fig. 2 described.

[0037] A housing 25 of the MG 16 contains a rotor 27, which rotates integrally with a rotating shaft 26, and a stator 28, which is arranged on a circumferential side of this rotor 27. A coil 29, comprising a plurality of phase windings, is wound around the stator 28.

[0038] Additionally, a cooling oil 30 for cooling the MG 16 is enclosed in a sealed space within the housing 25. This cooling oil 30 is stored up to the lowest point of the rotor 27 when the MG 16 is stationary, that is, up to a height higher than the point closest to the ground within a rotor's outer circumferential surface and lower than the rotor shaft 26. When the MG 16 rotates, the cooling oil 30 is drawn in by the rotation of the rotor 27 and distributed within the housing 25. The cooling oil 30 is a fluid with insulating properties and can also be used as a lubricant in vehicles, such as an automatic transmission fluid (ATF) for an automatic transmission.

[0039] Furthermore, a cooling oil temperature sensor 32 is provided in the housing 25 of the MG 16 for detecting the temperature of the cooling oil 30. This cooling oil temperature sensor 32 is installed in a position that is immersed in the cooling oil 30 and separated from the coil 29 (i.e., a position that does not come into contact with the coil 29). As shown in Fig. As illustrated in Figure 1, an output signal from the cooling oil temperature sensor 32 of the MG-ECU 24 is input.

[0040] Next, a torque control system for the MG 16 will be developed with reference to Fig. 3 described.

[0041] The MG 16, for example, is a three-phase permanent magnet synchronous motor with an embedded permanent magnet and a rotary position sensor 33 for detecting the rotational position θ of the rotor 27 (i.e., the angle of rotation). Based on a three-phase six-arm voltage command signal UU, UL, VU, VL, WU, WL output by the MG-ECU 24, the inverter 21 converts the DC voltage of the high-voltage battery 22 into a three-phase AC voltage U, V, W to drive the MG 16. A U-phase current iu, flowing in a U phase, and a W-phase current iw, flowing in a W phase, of the MG 16 are detected by a current sensor 34.

[0042] The MG-ECU 24 controls the inverter 21 in such a way that an output torque of the MG 16 becomes a required torque (i.e., a torque command value) to perform torque control for adjusting an AC voltage applied to the MG 16. In this torque control, a current-f / b control is performed to regulate the power supply of the MG 16 in order to reduce a deviation between a current command value based on the required torque output by the HV-ECU 23 and a current sensing value based on an output from the current sensor 34, as described below. Here, in a dq coordinate system, which is a rotating coordinate system set as a rotor rotation coordinate of the MG 16, control of both a d-axis current id and a q-axis current iq is performed independently.

[0043] The MG-ECU 24 first calculates a command current vector (a d-axis current command value Id, a q-axis current command value Iq) on the basis of the required torque and speed of the MG 16 by means of a mapping or characteristic map, a mathematical equation or the like in a current command conversion device 35.

[0044] Subsequently, a current F / B control unit 36 ​​calculates a detected current vector (a d-axis current detection value id, a q-axis current detection value iq), which is a detected value of a current flowing through the MG 16, based on a U-phase current iu and a W-phase current iw of the MG 16 detected by the current sensor 34, and a rotor rotation position θ of the MG 16 detected by the rotation position sensor 33.Furthermore, a d-axis voltage command value Vd is calculated by a PI controller or the like in such a way that a deviation Δid between the d-axis current command value Id and the d-axis current sensing value id becomes small, while at the same time a q-axis voltage command value Vq is calculated by a PI controller or the like in such a way that a deviation Δiq between a q-axis current command value Iq and a q-axis current sensing value iq is obtained, and thus a command voltage vector (d-axis voltage command value Vd, q-axis voltage command value Vq) is obtained.

[0045] Subsequently, a PWM conversion device calculates 37 three-phase voltage command values ​​Vu, Vv, Vw by means of three-phase modulation or two-phase modulation based on the command voltage vector (d-axis voltage command value Vd, q-axis voltage command value Vq) and the rotor rotation position θ of the MG 16. These three-phase voltage command values ​​Vu, Vv, Vw are then converted into three-phase six-arm voltage command signals UU, UL, VU, VL, WU, WL by a sinusoidal PWM control system. These three-phase six-arm voltage command signals UU, UL, VU, VL, WU, WL are output to the inverter 21.

[0046] Meanwhile, in the MG 16, which is cooled by the cooling oil 30 in the housing 25, the viscosity of the cooling oil 30 increases when its temperature is low during cooling or similar processes. This results in a high rotational load on the rotor 27, leading to a significant flow resistance loss due to the cooling oil 30 (i.e., a loss caused by the rotational load due to the cooling oil 30).

[0047] Accordingly, in this first embodiment, the MG-ECU 24 performs an operating mode switching routine as described below. Fig. 5, which switches between a normal operating mode and a temperature-enhancing operating mode as described below. If the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is a predetermined value or less, the normal operating mode is switched to the temperature-enhancing operating mode, and if the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is higher than a predetermined value, the temperature-enhancing operating mode is switched back to the normal operating mode.

[0048] The normal operating mode is a mode for controlling the MG 16 with a current amplitude and a current phase that delivers the required torque of the MG 16 in the most effective way. As described in Fig. As illustrated in Figure 4, in normal operating mode a command current vector (d-axis current command value Id, q-axis current command value Iq) is set at an operating point where the current amplitude and current phase, with which the required torque is most effectively delivered, are set in a smooth torque curve that delivers the required torque of the MG 16, whereby the current-F / B control of the MG 16 is executed. In this way, electrical power can be reduced.

[0049] The temperature increase operating mode is an operating mode in which the cooling oil 30 is heated using heat generated by the resistance of the coil 29, and the MG 16 is controlled with current amplitude and current phase that differ from those of the normal operating mode. In this first embodiment, as shown in Fig. As illustrated in Figure 4, in the temperature-increase operating mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current phase of the MG 16 is delayed or lags further than in the normal operating mode in the uniform torque curve for outputting the required torque of the MG 16. That is, the current-F / B control of the MG 16 is executed at an operating point where the electrical power is greater than that in a control case at the operating point in the normal operating mode. In the first embodiment, the operating point in the temperature-increase operating mode is a point on a uniform torque curve, whereby the point is further delayed or lags behind.lags (right side in the figure) as a point specified on the uniform torque curve in normal operating mode, whereby it can be appropriately selected to what degree the point should be on the retardation side or lagging side.

[0050] The processing content of the operating mode switching routine is described below. Fig. 5 described, which is implemented by the MG-ECU 24 in this first embodiment.

[0051] The operating mode switching routine, which is in Fig. As shown in Figure 5, the process is executed repeatedly in a predetermined cycle during a switching-on time of the MG-ECU 24 and plays a role as a control unit in the patent claims.

[0052] When this routine is activated, the temperature of the cooling oil 30, which is detected by the cooling oil temperature sensor 32, is first read in step 101.

[0053] The routine then proceeds to step 102, where it determines whether the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is a predetermined value or less. The predetermined value is set to be a temperature (for example, 0°C) at which the flow resistance loss due to the cooling oil 30 exceeds an acceptable level.

[0054] In step 102, if it is determined that the temperature of the cooling oil 30 is a predetermined value or less, the routine proceeds to step 103, switching from a normal operating mode to a temperature-enhancing operating mode (or maintaining the temperature-enhancing operating mode). In this temperature-enhancing operating mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current phase of the MG 16 is delayed or lags further than in the normal operating mode in the smooth torque curve for outputting the required torque of the MG 16, whereby the current F / B control of the MG 16 is executed.Additionally, if the required torque of the MG 16 in the temperature increase operating mode is 0, the operating mode can be a zero-torque temperature increase operating mode, which is described in the second embodiment mentioned below.

[0055] Meanwhile, in the aforementioned step 102, if it is determined that the temperature of the cooling oil 30 is higher than a predetermined value, the routine proceeds to step 104, switching from a temperature increase operating mode to a normal operating mode (or maintaining the normal operating mode). In this normal operating mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set such that the current amplitude and current phase are adjusted to deliver the required torque most effectively along the smooth torque curve for output of the MG 16, thereby executing the current F / B control of the MG 16.

[0056] In this first embodiment described above, when the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is a predetermined value or less, the MG 16 is controlled in temperature increase mode to heat the cooling oil 30 using heat generated by the resistance of the coil 29, thus actively heating the cooling oil 30. Therefore, even if the temperature of the cooling oil 30 is low and its viscosity is high during a cooling cycle or similar operation, the temperature of the cooling oil 30 can be immediately increased, and its viscosity can be immediately reduced (i.e., a rotational load due to the cooling oil 30 can be immediately reduced), thereby reducing the flow resistance loss of the MG 16 due to the cooling oil 30.

[0057] Additionally, in this first embodiment, the temperature increase operating mode is configured to be an operating mode in which the MG 16 is controlled with a current amplitude and current phase that differ from those of the normal operating mode, in which the MG 16 is controlled with the current amplitude and current phase that most effectively deliver the required torque of the MG 16. Therefore, compared to the normal operating mode, an electrical power that does not contribute to torque generation is increased, thereby increasing the heating value of the coil 29 and raising the temperature of the cooling oil 30, while achieving the required torque.

[0058] Furthermore, in this first embodiment, the current phase of the magnet 16 is delayed or lags further in the temperature-increased operating mode than in the normal operating mode. For this reason, a negative d-axis current (i.e., an excitation current) is reduced compared to the normal operating mode, thereby preventing demagnetization of the permanent magnet (i.e., preventing irreversible demagnetization). Additionally, the temperatures of the inverter 21 and the high-voltage battery 22 can be increased by an increase in losses of the inverter 21 due to a deterioration of the power factor and an increase in the power output of the high-voltage battery 22.

[0059] Additionally, in this first embodiment, the cooling oil 30 is enclosed in a sealed space within the housing 25 and stored at a height higher than the lowest part of the rotor 21 and lower than the rotating shaft 26 of the rotor 27. In an oil-tight configuration where the cooling oil 30 is enclosed in the sealed space within the housing 25, if the cooling oil 30 is at a low temperature, the flow resistance loss due to the cooling oil 30 tends to be large; however, by controlling the MG 16 in the temperature-enhancing operating mode, the flow resistance loss due to the cooling oil 30 can be effectively reduced.Additionally, by storing the cooling oil 30 up to a height higher than the lowest part of the rotor 27, internal heat from the MG 16 is effectively transferred to the housing 25 via the cooling oil 30 and can thus be released to the outside of the MG 16, thereby effectively cooling the MG 16. Furthermore, by storing the cooling oil 30 up to a height lower than the rotating shaft 26 of the rotor 27, a quantity of the cooling oil 30 that would otherwise be contained is appropriately suppressed, thus appropriately suppressing a rotational load on the MG 16 due to the cooling oil 30.

[0060] Furthermore, in this first embodiment, by reducing the flow resistance loss due to the cooling oil 30 of the motor unit 16 (MG 16), which is installed as a power source of a vehicle, a negative impact on vehicle performance (for example, a deterioration in fuel efficiency) can be suppressed. In the case of a hybrid vehicle, for example, in EV driving mode, the negative impact, when there is a flow resistance loss due to the cooling oil 30 of the MG 16, reduces the output torque of the MG 16, thus requiring the driver to press the accelerator pedal more. Consequently, the motor unit 11 is started unnecessarily, and in some cases, fuel efficiency is reduced. Second embodiment

[0061] Next, the second embodiment of the present invention will be described using Fig. 6 to Fig. 9 described. However, an explanation of a part that is substantially the same or similar to the first embodiment described above is omitted or simplified, whereas a part that differs from the first embodiment described above is mainly described.

[0062] In this second embodiment, the MG-ECU 24 performs an operating mode switching routine as described below. Fig. 9, which switches between normal operating mode and temperature enhancement operating mode as described below. If the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is a predetermined value A (i.e., a first predetermined value) or less, the normal operating mode is switched to the temperature enhancement operating mode, and if the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is a predetermined value B (i.e., a second predetermined value) or more than the predetermined value A, the temperature enhancement operating mode is switched back to normal operating mode.

[0063] In addition, in this second embodiment, in the temperature increase operating mode, a delay temperature increase operating mode, in which the current phase of the MG 16 is delayed or lags behind further than in the normal operating mode, and an advance temperature increase operating mode, in which the current phase of the MG 16 is advanced or leads ahead further than in the normal operating mode, are switched according to the temperature of the converter 21 and the current amplitude of the MG 16.

[0064] As it is in Fig. As illustrated in Figure 6, in the delay temperature increase operating mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current phase of the MG 16 is delayed or lags further than in the normal operating mode in the uniform torque curve for outputting the required torque of the MG 16, whereby the current F / B control of the MG 16 is executed.

[0065] As it is in Fig. As illustrated in Figure 7, in the advance temperature increase operating mode a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current phase of the MG 16 is advanced further or leads in the uniform torque curve for outputting the required torque of the MG 16 than in the normal operating mode, whereby the current F / B control of the MG 16 is executed.

[0066] Furthermore, in this second embodiment, in the temperature increase operating mode, when the required torque of the MG 16 is zero, the operating mode is switched to a zero-torque temperature increase operating mode in which the current phase of the MG 16 does not generate any torque. As described in Fig. As illustrated in Figure 8, in the zero-torque temperature increase operating mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current phase of the MG 16 is a phase with which no torque is generated (for example, 0 degrees or 180 degrees), whereby the current F / B control of the MG 16 is executed. In this case, the q-axis current command value Iq is set to 0.

[0067] The processing content of the operating mode switching routine is described below. Fig. 9 described, which is implemented by the MG-ECU 24 in this second embodiment.

[0068] When this routine is activated, the temperature of the cooling oil 30, which is detected by the cooling oil temperature sensor 32, is first read in step 201.

[0069] The routine then proceeds to step 202 and determines whether the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is a predetermined value A or less. The predetermined value A is set to be a temperature at which the flow resistance loss due to the cooling oil 30 exceeds an acceptable level.

[0070] In this step 202, if it is determined that the temperature of the cooling oil 30 is the predetermined value A or less, the routine proceeds to step 203, switching from a normal operating mode to a temperature enhancement operating mode (or maintaining the temperature enhancement operating mode).

[0071] In this temperature intensification operating mode, if the required torque of the MG 16 differs from 0, the delay temperature intensification operating mode and the advance temperature intensification operating mode are switched according to the temperature of the inverter 21 and the current amplitude of the MG 16. In this case, based on the temperature of the inverter 21, it is determined, for example, whether the temperature is in a range where a temperature intensification of the inverter 21 is not required, while at the same time, based on the current amplitude of the MG 16, it is determined whether the temperature is in a range where protection against demagnetization of the permanent magnet is not required.As a result, if it is determined that the temperature is in the range where temperature increase of the inverter 21 is required, or in the range where protection against demagnetization of the permanent magnet is required, the operating mode is switched to the delayed temperature increase mode. Meanwhile, if it is determined that the temperature is in the range where temperature increase of the inverter 21 is not required, and in the range where protection against demagnetization of the permanent magnet is not required, the operating mode is switched to the accelerated temperature increase mode.

[0072] In the delay temperature increase operating mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current phase of the MG 16 is delayed or lags further than in the normal operating mode in the uniform torque curve for outputting the required torque of the MG 16, whereby the current F / B control of the MG 16 is executed (see Fig. 6).

[0073] In the advance temperature increase operating mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current phase of the MG 16 is advanced further or leads in the uniform torque curve for outputting the required torque of the MG 16 than in the normal operating mode, whereby the current F / B control of the MG 16 is executed (see Fig. 7).

[0074] Additionally, in temperature intensification mode, if the required torque of the MG 16 is 0, the operating mode is switched to zero-torque temperature intensification mode. In this zero-torque temperature intensification mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current phase of the MG 16 is a phase with which no torque is generated (for example, 0 degrees or 180 degrees), whereby the current F / B control of the MG 16 is executed (see Fig. 8).

[0075] Meanwhile, in the aforementioned step 202, if it is determined that the temperature of the cooling oil 30 is higher than the predetermined value A, the routine proceeds to step 204. In this step 204, it is determined whether the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is the predetermined value B or higher. Here, the predetermined value B is set to be slightly higher than the predetermined value A.

[0076] In step 204, if it is determined that the temperature of the cooling oil 30 is the predetermined value B or higher, the routine proceeds to step 205, switching from temperature increase mode to normal mode (or maintaining normal mode). In normal mode, a command current vector (d-axis current command value Id, q-axis current command value Iq) is set in such a way that the current amplitude and phase with which the required torque is most effectively delivered are set in the smooth torque curve for outputting the required torque of the MG 16, thereby executing the current F / B control of the MG 16.

[0077] In this second embodiment described above, when the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is a predetermined value A or less, the normal operating mode is switched to the temperature-increase operating mode. Conversely, when the temperature of the cooling oil 30, as detected by the cooling oil temperature sensor 32, is a predetermined value B or more than the predetermined value A, the temperature-increase operating mode is switched back to the normal operating mode. Therefore, since the temperature of the cooling oil 30 is detected directly by the cooling oil temperature sensor 32, the need for temperature increase of the cooling oil 30 is reliably and accurately determined, and the operating mode can thus be switched to the temperature-increase operating mode.Furthermore, a hysteresis property can be added to the switching between the normal operating mode and the temperature increase operating mode based on the temperature of the cooling oil 30 (that is, hysteresis is provided at the switching determination values ​​A, B of the normal operating mode and the temperature increase operating mode), thereby preventing frequent switching of the operating mode.

[0078] In this second embodiment, the delayed temperature increase mode and the accelerated temperature increase mode are switched between in the temperature increase operating mode according to the temperature of the inverter 21 and the current amplitude of the MG 16. Thus, if the temperature increase of the inverter 21 and protection against demagnetization of the permanent magnet are not necessary, the operating mode can be switched to the accelerated temperature increase mode. In this accelerated temperature increase mode, compared to the delayed temperature increase mode, a degradation of the power factor is suppressed, thereby reducing the output of the high-voltage battery 22 and preventing its degradation.

[0079] Furthermore, in this second embodiment, in the temperature increase operating mode, when the required torque of the MG 16 is zero, the operating mode is switched to the zero-torque temperature increase operating mode. In this way, even when the required torque of the MG 16 is zero, the temperature of the cooling oil 30 can be increased while the required torque is achieved (that is, without generating any torque). Third example

[0080] Next, a third embodiment of the present invention will be described using Fig. 10 to Fig. 12 described. However, an explanation of a part that is substantially the same or similar to the second embodiment described above is omitted or simplified, whereas a part that differs from the second embodiment described above is mainly described.

[0081] In this third embodiment, as it is in Fig. Figure 10 illustrates a coil temperature sensor 38 for detecting the temperature of the coil 29 in the housing 25 of the MG 16. As shown in Fig. As illustrated in Figure 11, there is a relationship between the temperature of the coil 29 and the temperature of the cooling oil 30.

[0082] Accordingly, in this third embodiment, the MG-ECU 24 performs an operating mode switching routine as described below. Fig. 12, which switches between normal operating mode and temperature-enhancing operating mode as described below. If the temperature of the coil 29, as detected by the coil temperature sensor 38, is a predetermined value C (which is a third predetermined value) or less, the normal operating mode is switched to the temperature-enhancing operating mode, and if the temperature of the coil 29, as detected by the coil temperature sensor 38, is a predetermined value D (that is, a fourth predetermined value) or more, which is higher than the predetermined value C, the temperature-enhancing operating mode is switched back to the normal operating mode.

[0083] The following describes the processing content of an operating mode switching routine according to Fig. 12 described, which is implemented by the MG-ECU 24 in this third embodiment.

[0084] When this routine is activated, the temperature of coil 29, which is detected by the coil temperature sensor 38, is first read in step 301.

[0085] The routine then proceeds to step 302, where it determines whether the temperature of the coil 29, as detected by the coil temperature sensor 38, is a predetermined value C or less. The predetermined value C is set to be a temperature at which the flow resistance loss due to the cooling oil 30 exceeds an acceptable level.

[0086] In step 302, if it is determined that the temperature of coil 29 is a predetermined value C or less, the routine proceeds to step 303, switching from normal operating mode to temperature intensification mode (or maintaining temperature intensification mode). In this temperature intensification mode, if the required torque of MG 16 is different from 0, the delay temperature intensification mode and the advance temperature intensification mode are switched according to the temperature of inverter 21 and the current amplitude of MG 16. Additionally, in temperature intensification mode, if the required torque of MG 16 is 0, the operating mode is switched to zero-torque temperature intensification mode.

[0087] Meanwhile, in the aforementioned step 302, if it is determined that the temperature of the cooling oil 29 is higher than the predetermined value C, the routine proceeds to step 304. In this step 304, it is determined whether the temperature of the coil 29, as detected by the coil temperature sensor 38, is at or above the predetermined value D. Here, the predetermined value D is set to be slightly higher than the predetermined value C.

[0088] In this step 304, if it is determined that the temperature of coil 29 is the predetermined value D or more, the routine proceeds to step 305, switching from the temperature increase mode to the normal mode (or maintaining the normal mode).

[0089] In this third embodiment described above, when the temperature of the coil 29, as detected by the coil temperature sensor 38, is the predetermined value C or less, the normal operating mode is switched to the temperature-increasing operating mode. Conversely, when the temperature of the coil 29, as detected by the coil temperature sensor 38, is the predetermined value D or greater than the predetermined value C, the temperature-increasing operating mode is switched back to the normal operating mode. Therefore, even in cases where the cooling oil temperature sensor is not installed, the need for temperature intensification of the cooling oil 30 is accurately determined based on the temperature of the coil 29 as detected by the coil temperature sensor 38, thus enabling the operating mode to be switched to the temperature-intensifying operating mode.Furthermore, a hysteresis property can be added to the switching between the normal operating mode and the temperature-enhancing operating mode based on the temperature of the coil 29 (that is, hysteresis is provided at the switching determination values ​​C, D of the normal operating mode and the temperature-enhancing operating mode), thereby preventing frequent switching of the operating mode. Fourth embodiment

[0090] Next, a fourth embodiment of the present invention will be described using the Fig. 13 described. However, an explanation of a part that is substantially the same or similar to the third embodiment mentioned above is omitted or simplified, whereas a part that differs from the third embodiment mentioned above is mainly described.

[0091] In this fourth embodiment, the coil temperature sensor 38 is again provided to detect the temperature of the coil 29. As described above, there is a relationship between the temperature of the coil 29 and the temperature of the cooling oil 30, and consequently, the temperature of the cooling oil 30 can be estimated from the temperature of the coil 29.

[0092] Accordingly, in this fourth embodiment, the MG-ECU 24 performs an operating mode switching routine as described below. Fig. 13, which switches between normal operating mode and temperature enhancement operating mode as described below. The temperature of the cooling oil 30 is estimated based on the temperature of the coil 29, which is detected by the coil temperature sensor 38. If the estimated cooling oil temperature, which is the estimated value, is a predetermined value E (i.e., a fifth predetermined value) or less, the normal operating mode is switched to the temperature enhancement operating mode. If the estimated cooling oil temperature is a predetermined value F (i.e., a sixth predetermined value) or more, which is higher than the predetermined value E, the temperature enhancement operating mode is switched back to the normal operating mode.

[0093] The following is a processing content of an operating mode switching routine according to Fig. 13 described, which is implemented by the MG-ECU 24 in this fourth embodiment.

[0094] When this routine is activated, the temperature of the coil 29, which is detected by the coil temperature sensor 38, is first read out in Figure 401.

[0095] The routine then proceeds to step 402, where the temperature of the cooling oil 30 is estimated using a map, mathematical equation, or similar method based on the temperature of the coil 29, which is detected by the coil temperature sensor 38. The estimated value is then set as the estimated cooling oil temperature. The map, mathematical equation, or similar method for estimating the temperature of the cooling oil 30 based on the temperature of the coil 29 is generated in advance using test data, design data, or similar data and stored in a ROM or similar of the MG-ECU 24 (or the HV-ECU 23).

[0096] The routine then proceeds to step 403 and determines whether the estimated cooling oil temperature is a predetermined value E or less. The predetermined value E is set to be a temperature at which the flow resistance loss due to the cooling oil 30 exceeds an acceptable level.

[0097] In step 403, if it is determined that the estimated cooling oil temperature is the predetermined value E or less, the routine proceeds to step 404, switching from normal operation to temperature intensification mode (or maintaining temperature intensification mode). In this temperature intensification mode, if the required torque of the MG 16 is different from 0, the delay temperature intensification mode and the advance temperature intensification mode are switched according to the temperature of the inverter 21 and the current amplitude of the MG 16. Additionally, in the temperature intensification mode, if the required torque of the MG 16 is 0, the operating mode is switched to zero-torque temperature intensification mode.

[0098] Meanwhile, in the aforementioned step 403, if it is determined that the estimated cooling oil temperature is higher than the predetermined value E, the routine proceeds to step 405. In this step 405, it is determined whether the estimated cooling oil temperature is equal to or greater than the predetermined value F. Here, the predetermined value F is adjusted to be slightly higher than the predetermined value E.

[0099] In this step 405, if it is determined that the estimated cooling oil temperature is the predetermined value F or greater, the routine proceeds to step 406, switching from temperature enhancement mode to normal mode (or maintaining normal mode).

[0100] In this fourth embodiment described above, the temperature of the cooling oil 30 is estimated based on the temperature of the coil 29, which is detected by the coil temperature sensor 38, wherein if the estimated cooling oil temperature is the predetermined value E or less, the normal operating mode is switched to the temperature enhancement operating mode, wherein if the estimated cooling oil temperature is the predetermined value F or more, which is higher than the predetermined value E, the temperature enhancement operating mode is switched to the normal operating mode.For this reason, even in a case where the cooling oil temperature sensor is not installed, the need for increasing the temperature of the cooling oil 30 is accurately determined based on the estimated cooling oil temperature, which is estimated from the temperature of the coil 29, thus enabling the operating mode to be switched to the temperature-increase mode. Furthermore, a hysteresis property can be added to the switching between normal and temperature-increase modes based on the estimated cooling oil temperature (that is, hysteresis is provided for the switching parameters E and F of the normal and temperature-increase modes), thereby preventing frequent switching between operating modes. Fifth embodiment

[0101] Next, a fifth embodiment of the present invention will be described using Fig. 14 to Fig. 16 described. However, an explanation of a part that is substantially the same or similar to the second embodiment described above is omitted or simplified, whereas a part that differs from the second embodiment described above is mainly described.

[0102] In this fifth embodiment, as it is in Fig. Figure 14 illustrates an outdoor air temperature sensor 39 for measuring outdoor air temperature. As shown in Fig. As illustrated in Figure 15, there is a relationship between the outside air temperature, an MG non-drive time (that is, an elapsed time of a time during which the MG 16 enters a non-driven state) and the temperature of the cooling oil 30, whereby the temperature of the cooling oil 30 can consequently be estimated from the outside air temperature and the MG non-drive time.

[0103] Accordingly, in this fifth embodiment, the MG-ECU 24 performs an operating mode switching routine as described below. Fig. 16, which switches between normal operating mode and temperature enhancement operating mode as described below. The temperature of the cooling oil 30 is estimated based on the outside air temperature, detected by the outside air temperature sensor 39, and the MG non-drive time, wherein if an estimated cooling oil temperature, which is the estimated value, is a predetermined value G (that is, a seventh predetermined value) or less, the normal operating mode is switched to a temperature enhancement operating mode.

[0104] The processing content of the operating mode switching routine is described below. Fig. 16 described, which is implemented by the MG-ECU 24 in this fifth embodiment.

[0105] When this routine is activated, the outside air temperature is first read out in Figure 501, which is recorded by the outside air temperature sensor 39.

[0106] The routine then proceeds to step 502, estimating the temperature of the cooling oil 30 as described below.

[0107] While the MG 16 is not being driven (i.e., during a drive stop), the temperature of the cooling oil 30 is estimated by a mapping, map, mathematical equation, or the like, based on the ambient air temperature, as measured by the ambient air temperature sensor 39, and the MG's non-drive time. The estimated value is then set as the estimated cooling oil temperature. The mapping, map, mathematical equation, or the like for estimating the temperature of the cooling oil 30 based on the ambient air temperature and the MG's non-drive time is generated in advance using test data, design data, or the like, and stored in a ROM or similar of the MG ECU 24 (or the HV ECU 23).

[0108] Meanwhile, while the MG 16 is being driven, the temperature of the cooling oil 30 is estimated by a mapping, map, mathematical equation, or the like, based on the MG drive time (i.e., the time elapsed since the start of a drive of the MG 16) and the drive current of the MG 16, with the estimated value being set as the estimated cooling oil temperature. The mapping, map, mathematical equation, or the like for estimating the temperature of the cooling oil 30 based on the MG drive time and the drive current of the MG 16 is generated in advance using test data, design data, or the like, and stored in a ROM or the like of the MG-ECU 24 (or the HV-ECU 23).

[0109] The routine then proceeds to step 503 and determines whether the estimated cooling oil temperature is at or below the predetermined value G. The predetermined value G is set to be a temperature at which the flow resistance loss due to the cooling oil 30 exceeds an acceptable level.

[0110] In step 503, if the estimated cooling oil temperature is determined to be the predetermined value E or less, the routine proceeds to step 504, switching from normal operation to temperature intensification mode (or maintaining temperature intensification mode). In this temperature intensification mode, if the required torque of the MG 16 is different from 0, the delay temperature intensification mode and the advance temperature intensification mode are switched according to the temperature of the inverter 21 and the current amplitude of the MG 16. Additionally, in the temperature intensification mode, if the required torque of the MG 16 is 0, the operating mode is switched to zero-torque temperature intensification mode.

[0111] Meanwhile, in the aforementioned step 503, if it is determined that the estimated cooling oil temperature is higher than the predetermined value G, the routine proceeds to step 505. In this step 505, it is determined whether the estimated cooling oil temperature is one or more predetermined value H (that is, one-eighth of the predetermined value). Here, the predetermined value H is set to be slightly higher than the predetermined value G.

[0112] In this step 505, if it is determined that the estimated cooling oil temperature is the predetermined value H or greater, the routine proceeds to step 506, switching from temperature enhancement mode to normal mode (or maintaining normal mode).

[0113] In this fifth embodiment described above, the temperature of the cooling oil 30 is estimated based on the ambient air temperature, detected by the ambient air temperature sensor 39, and the machine tool's non-operating time. If the estimated cooling oil temperature is the predetermined value G or less, the normal operating mode is switched to the temperature-increasing operating mode. Therefore, even in cases where the cooling oil temperature sensor is not installed, the need to increase the temperature of the cooling oil 30 is accurately determined based on the estimated cooling oil temperature, which is derived from the ambient air temperature and the machine tool's non-operating time. This allows the operating mode to be switched to the temperature-increasing operating mode.

[0114] In addition, in each of the aforementioned second to fifth embodiments, the delayed temperature increase mode and the accelerated temperature increase mode are switched in the temperature increase mode according to both the temperature of the inverter 21 and the current amplitude of the motor unit 16. However, the switching is not limited to this; in the temperature increase mode, the delayed temperature increase mode and the accelerated temperature increase mode can be switched according to a parameter derived from the temperature of the inverter 21 and the current amplitude of the motor unit 16. Alternatively, in the temperature increase mode, either the delayed temperature increase mode or the accelerated temperature increase mode can be used continuously. Sixth embodiment

[0115] Next, a sixth embodiment of the present invention is described using Fig. 17 described. However, an explanation of a part that is substantially the same or similar to the first embodiment described above is omitted or simplified, whereas a part that differs from the first embodiment described above is mainly described.

[0116] In this sixth embodiment, as shown in Fig. As illustrated in Figure 17, a buck-boost converter 40 is connected between the high-voltage battery 22 and the inverter 21, whereby electrical power is transferred between the MG 16 and the high-voltage battery 22 via the buck-boost converter 40 and the inverter 21. The buck-boost converter 40 boosts the DC voltage of the high-voltage battery 22 to make the input voltage of the inverter 21 higher than the DC voltage of the high-voltage battery 22. The inverter 21 converts the DC voltage boosted by the buck-boost converter 40 into an AC voltage to drive the MG 16.

[0117] In this sixth embodiment, the MG-ECU 24 additionally controls the switching between normal operating mode and temperature amplification operating mode via the output voltage of the buck-boost converter 40. Specifically, the output voltage of the buck-boost converter 40 is varied within a range between a high-side voltage (e.g., 400 V) and a low-side voltage (e.g., 200 V) that is lower than this high-side voltage. When the output voltage of the buck-boost converter 40 is the low-side voltage, a weak field region in which field attenuation control of the MG 16 is performed is significantly amplified more than when it is the high-side voltage.In this process, the field attenuation control reduces a magnetic flux in the d-axis direction using a demagnetization effect through an armature reaction, for example by supplying a negative d-axis current (i.e., an excitation current).

[0118] Furthermore, when switching from normal to temperature-enhancing mode, the output voltage of the buck-boost converter 40 is configured to be the low-side voltage to perform field attenuation control, thereby changing the current phase of the MG 16 to be further advanced than in normal mode. Conversely, when switching back to normal mode, the output voltage of the buck-boost converter 40 is switched to the high-side voltage to perform field-enhancing control, thereby returning the current phase of the MG 16 to a phase of normal operation. Therefore, switching between normal and temperature-enhancing modes is possible by toggling the output voltage of the buck-boost converter 40.The switching of operating modes by this buck-boost converter 40 can be implemented in the first to fifth embodiments mentioned above. Seventh embodiment

[0119] Next, a seventh embodiment of the present invention will be described using Fig. 18 described. However, an explanation of a part that is substantially the same or similar to the first embodiment described above is omitted or simplified, whereas a part that differs from the first embodiment described above is mainly described.

[0120] In this seventh embodiment, as described in Fig. As illustrated in Figure 18, the output signal of the cooling oil temperature sensor 32 is input to the HV-ECU 23. Alternatively, the output signal of the coil temperature sensor 38 or the output signal of the ambient air temperature sensor 39 is input to the HV-ECU 23. Furthermore, the operating mode switching described in the aforementioned embodiments 1 to 6 is performed by this HV-ECU 23. An effect identical to that of the aforementioned embodiments can also be obtained in this way.

[0121] Additionally, in each of the aforementioned embodiments, some or all of the functions performed by the MG-ECU 24 and HV-ECU 23 may be configured with one or more ICs or the like in the manner of hardware.

[0122] In each of the aforementioned embodiments, the cooling oil 30 is stored at a height lower than the rotating shaft 26 of the rotor 27. However, this height is not limited; the cooling oil 30 can be stored at a height higher than the rotating shaft 26 of the rotor 27. Additionally, the cooling oil 30 can be configured to circulate to the outside of the MG 16.

[0123] Additionally, in each of the aforementioned embodiments, the cooling oil 39 is enclosed within the housing 25 and configured not to circulate through the inside and outside of the housing. However, an opening may be provided in the housing, and an oil line connected to an oil cooling device or an oil pump may be connected to this opening. In this case, the cooling oil 39 is configured to move into and out of the inside and outside of the housing.

[0124] On the other hand, the present invention is not limited to a hybrid vehicle that incorporates the features described in Fig.The present invention comprises a configuration shown in Figure 1 or the like, and can be applied to the engine of a hybrid vehicle having various types of configurations in which a power unit and an engine are arranged as a power source or power source of the vehicle. Furthermore, the present invention is not limited to a hybrid vehicle and can be applied to the engine of an electric vehicle in which only one engine is arranged as a power source of the vehicle. Finally, the present invention can be applied to an engine that is distinct from a power source of a vehicle.

[0125] Additionally, in each of the embodiments described above, the uniform torque curve can have a width within a range that does not cause any problem in practical use.

[0126] A device for controlling a motor (16) is provided, the motor having a housing (25) in which a stator (28) and a rotor (27) are arranged. The motor is cooled by a cooling oil (30) in the housing. The device includes a control unit (24) configured to control the motor. The control unit (24) has a temperature increase operating mode for heating the cooling oil using heat generated by the resistance of a coil (29) provided in the stator.

Claims

[1] Device for controlling a motor (16) comprising a housing (25) in which a stator (28) and a rotor (27) are arranged, wherein the motor (16) is cooled by a cooling oil (30) in the housing (25), the device comprising: a control unit (24) configured to control the motor (16), wherein the control unit (24) has a temperature increase operating mode for heating the cooling oil (30) using heat generated by a resistance of a coil (29) provided in the stator (28), wherein The temperature increase operating mode is an operating mode for controlling the motor (16) with a current amplitude and a current phase that differ from those of a normal operating mode, in which the motor (16) is controlled with a current amplitude and a current phase with which a required torque of the motor (16) is effectively output, thereby increasing the electrical power that does not contribute to torque generation in order to increase a heating value of the coil (29). the device further comprises: a converter (21) for driving the motor (16); and a battery (22) for supplying electrical power to the motor, wherein in the temperature increase operating mode the control unit (24) has a function to configure the current phase of the motor (16) to be delayed or lag behind further than in the normal operating mode, where The control unit (24) is configured to switch between a delay temperature increase operating mode, in which the current phase of the motor (16) is configured to be delayed or lag behind further than in the normal operating mode when temperature increase of the inverter (21) or protection against demagnetization of the permanent magnets of the motor (16) is necessary, and an advance temperature increase operating mode, in which the current phase of the motor (16) is configured to be advanced or lead further than in the normal operating mode when temperature increase of the inverter (21) and protection against demagnetization of the permanent magnets are not necessary, according to at least one parameter from the temperature of the inverter (21) and the current amplitude of the motor (16). [2] Device according to claim 1, wherein the control unit (24) configures the current phase of the motor (16) to be a phase with which no torque is generated when the required torque of the motor (16) in the temperature increase operating mode is 0. [3] Device according to claim 1 or 2, further comprising a cooling oil temperature sensor (32) for detecting the cooling oil (30), wherein the control unit (24) switches from the normal operating mode to the temperature increase operating mode when the temperature of the cooling oil (30) detected by the cooling oil temperature sensor (32) is a first predetermined value (A) or less. [4] Device according to claim 3, wherein the control unit (24) switches from the temperature increase operating mode to the normal operating mode when the temperature of the cooling oil (30) detected by the cooling oil temperature sensor (32) is a second predetermined value (B) or more that is higher than the first predetermined value (A). [5] Device according to claim 1 or 2, further comprising a coil temperature sensor (38) for detecting the temperature of the coil (29), wherein the control unit (24) is configured to switch from the normal operating mode to the temperature magnification operating mode when the temperature of the coil (29) detected by the coil temperature sensor (38) is a third predetermined value (C) or less. [6] Device according to claim 5, wherein the control unit (24) is configured to switch from the temperature increase operating mode to the normal operating mode when the temperature of the coil (29) detected by the coil temperature sensor (38) is a fourth predetermined value (D) or more that is higher than the third predetermined value (C). [7] Device according to claim 1 or 2, further comprising a coil temperature sensor (38) for detecting the temperature of the coil (29), wherein the control unit (24) is configured to estimate the temperature of the cooling oil (30) based on the temperature of the coil (29) detected by the coil temperature sensor (38) and to switch from the normal operating mode to the temperature boost operating mode when the estimated cooling oil temperature, which is the estimated value, is one fifth predetermined value (E) or less. [8] Device according to claim 7, wherein the control unit (24) is configured to switch from the temperature increase operating mode to the normal operating mode when the estimated cooling oil temperature is a sixth predetermined value (F) or more that is higher than the fifth predetermined value (E). [9] Device according to claim 1 or 2, further comprising an outside air temperature sensor (39) for detecting an outside air temperature, wherein the control unit (24) is configured to estimate the temperature of the cooling oil (30) based on the outside air temperature detected by the outside air temperature sensor (39) and an elapsed time of a time during which the motor (16) enters a non-driven state, and to switch from the normal operating mode to the temperature increase operating mode when the estimated cooling oil temperature, which is the estimated value, is one seventh predetermined value (G) or less. [10] Device according to any one of claims 1 to 9, further comprising: a step-down / step-up converter (40) connected between the battery (22) and the inverter (21), wherein the control unit (24) is configured to control switching between the normal operating mode and the temperature increase operating mode based on an output voltage of the buck-boost converter (40). [11] Device according to any one of claims 1 to 10, wherein the cooling oil (30) is enclosed in a closed space in the housing (25) and is stored up to a height position which is higher than a lowest part of the rotor (27) and lower than a rotating shaft of the rotor (27). [12] Device according to any one of claims 1 to 11, wherein the motor (16) is mounted as a drive motor of a vehicle.

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