JP5214344B2 - Electric pump device - Google Patents

Description

  The present invention relates to an electric pump device, for example, an electric pump device suitable for use as a fluid pressure pump that supplies hydraulic oil to an automatic transmission mechanism such as a hybrid vehicle.

  It is known to control an oil pressure control device by driving an electric pump device to secure a necessary oil pressure to a oil pressure supply device used as a hydraulic power source of a vehicle transmission mechanism (see, for example, Patent Document 1). ).

  Further, a torque control device for a permanent magnet synchronous motor is known that can realize highly accurate torque control even in the entire speed range from a low speed range to a high speed range (see, for example, Patent Document 2).

JP 2006-161850 A JP 2005-039912 A

  However, in both Patent Documents 1 and 2, the upper limit number of rotations used in the speed control unit that limits the upper limit number of rotations of the motor is a fixed value set in advance. For this reason, for example, when the power supply voltage decreases, the motor characteristics change, and the motor upper limit rotational speed becomes lower than a fixed value used in the speed control unit. For this reason, the speed control unit does not operate and enters the voltage saturation region, which causes a problem of unstable control. In addition, when the power supply voltage is high, the motor upper limit rotational speed increases and is limited by a fixed value used for the speed control unit, so that there is a problem that the characteristics of the high rotational speed region cannot be sufficiently output.

  An object of the present invention is to provide an electric pump device capable of setting an appropriate upper limit rotational speed and stably controlling the motor below the set motor upper limit rotational speed even when the motor characteristics change due to fluctuations in power supply voltage. There is to do.

(1) In order to achieve the above object, the present invention provides a fluid pressure feed pump that supplies a fluid pressure to a fluid circuit, a brushless motor that provides a rotational driving force to the fluid pressure feed pump, and an external control of the brushless motor. A brushless motor control device that rotates in response to a signal, and the brushless motor is an electric pump device that is driven by electric power converted from DC power of a power source into three-phase AC power, and the brushless motor control The device sets an upper limit rotational speed that is an upper limit value of the rotational speed of the brushless motor based on the voltage of the power source, and the upper limit rotational value is increased as the voltage increases. with an upper limit rotation speed calculation means for outputting a speed value, the upper limit rotation speed calculation means, by dividing the voltage of the power supply in the induced voltage constant of the brushless motor The value is obtained by the so that to the upper limit rotational speed of the.
With such a configuration, even when the motor characteristics change due to fluctuations in the power supply voltage, it is possible to set an appropriate upper limit rotational speed and stably control the motor at or below the set motor upper limit rotational speed.

(2) In the above (1), preferably, the upper limit rotational speed calculation means sets the value obtained by dividing the voltage of the power source by the induced voltage constant of the brushless motor and the safety factor as the upper limit rotational speed. It is a thing.

  According to the present invention, even when the motor characteristics change due to fluctuations in the power supply voltage, an appropriate upper limit rotational speed can be set, and stable control can be performed at or below the set motor upper limit rotational speed.

Hereinafter, the configuration and operation of an electric pump device according to an embodiment of the present invention will be described with reference to FIGS.
Initially, the whole structure of the electric pump apparatus by this embodiment is demonstrated using FIG.
FIG. 1 is a block diagram showing an overall configuration of an electric pump device according to an embodiment of the present invention.

  The electric pump device 1 includes a brushless motor control device 3, a brushless motor 4, and a fluid pressure pump 5. The fluid pressure oil pump 5 is referred to as an oil pump 5 in the following description.

  The brushless motor control device 3 controls the output torque of the brushless motor 4 by the three-phase AC power supplied to the brushless motor 4 based on the torque command from the host control device 20 and drives the oil pump 5.

  The brushless motor 4 is a permanent magnet field type synchronous motor driven by three-phase AC power, and the rotation is controlled by the electric power supplied from the brushless motor control device 3. The brushless motor control device 3 includes an inverter inside, converts the DC power of the power source 23 into three-phase AC power, and supplies the converted power to the brushless motor 4. The power source 23 is an in-vehicle battery and outputs, for example, a DC voltage of 14V. The voltage of the power source 23 varies between 10V and 16V, for example, depending on the state of the battery.

  The oil stored in the oil pan 6 is sucked by the oil pump 5 and supplied to the automatic transmission mechanism 8 through the oil passages L1 and L2. The oil passage L2 is provided with a check valve 7 for preventing the oil from flowing backward from the automatic transmission mechanism 8 to the oil pump 5 side when the oil pump 5 is stopped. The oil that has lubricated the automatic transmission mechanism 8 is returned to the oil pan 6 through the oil passage L3.

  The automatic transmission mechanism 8 is provided with an oil temperature sensor 9 that detects the oil temperature of the oil. The oil temperature of the oil detected by the oil temperature sensor 9 is sent to the host controller 20. The host controller 20 outputs a torque command value to the brushless motor controller 3 and also supplies oil temperature information of oil.

Next, the configuration of the brushless motor 4 used in the electric pump device according to the present embodiment will be described with reference to FIG.
FIG. 2 is a cross-sectional view showing a configuration of a brushless motor used in the electric pump device according to the embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

  The brushless motor 4 includes a stator 405 fixed to the housing 404 and a rotor 406 fixed to the output shaft 401. Three-phase AC power is supplied to the armature winding of the stator 405 from the brushless motor control device 3 shown in FIG. The rotor 406 includes a permanent magnet 407 held on the outer periphery of the rotor core. Permanent magnets. It may be embedded in the rotor core.

  The output shaft 401 is held on the bracket 408 by a bearing 402F and on the housing 404 by a bearing 402R. The rotor 406 can rotate with respect to the stator 405. An oil seal 403 is provided between the bracket 408 and the output shaft 401 to prevent oil from entering the motor.

  Next, the configuration of the brushless motor control device 3 used in the electric pump device according to the present embodiment will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a block diagram showing a configuration of a brushless motor control device used in the electric pump device according to the embodiment of the present invention. FIG. 4 is a detailed block diagram of the upper limit rotational speed calculation unit in FIG. The same reference numerals as those in FIG. 1 indicate the same parts.

  As shown in FIG. 3, the brushless motor control device 3 that controls the driving of the brushless motor 4 includes a current command generation unit 308, a current control unit 301, a voltage command creation unit 303, a power conversion unit 304, a magnetic pole position, An estimation and speed estimation unit 305, a coordinate conversion unit 306, a phase current reproduction unit 307, a speed control unit 311, an upper limit rotational speed calculation unit 312, a DC power source VB, a current detection unit S1, a subtraction unit 309, 310.

  The host controller 20 outputs a torque command τ * and an oil temperature To to the brushless motor controller 3.

  Next, the operation of the brushless motor control device 3 will be described.

  In FIG. 3, the current command generation unit 308 calculates a d-axis current command value Id * and a q-axis current command value Iq * based on the input torque command τ *, and outputs it to the subtraction unit 310.

  The phase current reproduction unit 307 receives the current Ist detected by the current detection unit S <b> 1 and outputs currents Iu, Iv, and Iw that reproduce the three-phase current flowing through the brushless motor 4 to the coordinate conversion unit 306. The coordinate conversion unit 306 uses the currents Iu, Iv, and Iw that are the outputs of the phase current reproduction unit 307 and the magnetic pole position estimation θc output from the magnetic pole position estimation and speed estimation unit 305 to obtain rotor orthogonal coordinates. Coordinates are converted to the dc-dq axis, and detection currents Idc and Iqc are output.

  The speed control unit 311 receives the estimated speed value ω1 output from the magnetic pole position estimation and speed estimation unit 305 and the upper limit rotation value ω0 output from the upper limit rotation number calculation unit 312 as inputs, and rotates below the upper limit rotation number. Speed control is performed to control the number, and the calculated Iqlmt is output to the subtraction unit 310. The upper limit rotational speed calculation unit 312 outputs an upper limit rotational value ω0 that is an upper limit value of the rotational speed of the brushless motor 4 based on the DC voltage VB of the power supply 23. Upper limit rotational speed calculation unit 312 outputs upper limit rotational speed value ω0 such that upper limit rotational speed value ω0 increases as DC voltage VB increases. The detailed contents of the upper limit rotational speed calculation unit 312 will be described later with reference to FIG.

  In the subtraction units 309 and 310, Iqlmt that is the output of the speed control unit 311 and Idc and Iqc that are the output of the coordinate conversion unit 306 with respect to the current command values Id * and Iq * that are the outputs of the current command generation unit 308. Are calculated and input to the current control unit 301. The current control unit 301 calculates and outputs current command values Id ** and Iq ** so that the inputted deviation becomes zero.

  The voltage command generation unit 303 calculates three-phase voltage command values Vu, Vv, and Vw using the output of the current control unit 301 and the estimated motor rotational speed ω1 that is the output of the magnetic pole position estimation and speed estimation unit 305. And output to the power conversion unit 304. The power conversion unit 304 is an inverter that converts the DC power of the DC power supply VB into three-phase AC power. The power conversion unit 304 controls the voltage applied to the brushless motor 4 based on the outputs Vu, Vv, and Vw of the voltage command creation unit 303, rotates the brushless motor 4, and generates a desired torque.

  Next, the detailed content of the upper limit rotational speed calculation unit 312 will be described with reference to FIG.

The upper limit rotational speed calculation unit 312 includes a calculation unit 312A and an induced voltage constant storage unit 312B. Based on the voltage VB [V] of the power supply 23 and the induced voltage constant Ke [V / (rad / sec)] stored in the induced voltage constant storage unit 312B, the calculation unit 312A follows the following equation (1). The upper limit rotational speed ω0 is calculated.

ω0 = VB / Ke (1)

The induced voltage constant Ke varies depending on the shape, size, output, etc. of the brushless motor, but is, for example, 0.05 [V / (rad / sec)]. Therefore, if the power supply voltage VB is 14 V according to the equation (1), the upper limit rotational speed ω0 is 2800 rpm. If the power supply voltage VB is 10V, the upper limit rotational speed ω0 is 2000 rpm. As described above, the upper limit rotational speed calculation unit 312 outputs the upper limit rotational speed value ω0 such that the higher the DC voltage VB, the higher the upper limit rotational speed value ω0. The induced voltage constant Ke is slightly different due to an error in manufacturing even if the shape, size, output, etc. of the brushless motor are designed to be the same. In such a case, the induced voltage constant Ke may be measured and used for each individual brushless motor. However, after measuring the induced voltage constants Ke of a plurality of brushless motors, the average value of these values is used. Is also good.

  The upper limit number of revolutions may be output as it is by ω0 calculated by the above equation, or may be a value multiplied by a safety factor (for example, 0.9).

  Next, another configuration of the upper limit rotation speed calculation unit in the brushless motor control device used in the electric pump device according to the present embodiment will be described with reference to FIG.

  FIG. 5 is a block diagram showing another configuration of the upper limit rotational speed calculation unit in the brushless motor control device used in the electric pump device according to the embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

The upper limit rotational speed calculation unit 312 ′ includes a map 312C. The map 312C holds an upper limit rotational speed ω0 set in advance for each power supply voltage VB. The computing unit 312 ′ computes the upper limit rotational speed ω0 for the voltage VB [V] of the power source 23 using the map 312C.
The upper limit rotation speed ω0 held in the map 312C holds the value calculated from the power supply voltage VB and the induced voltage constant Ke based on the above equation (1). Further, the upper limit rotational speed ω0 held in the map 312C is calculated from the power supply voltage VB and the induced voltage constant Ke based on the above formula (1). A value obtained by multiplying the rate (for example, 0.9) may be held. For example, the higher side of the power supply voltage (for example, 16 V or higher) with respect to the value calculated from the power supply voltage VB and the induced voltage constant Ke. The upper limit rotational speed ω0 is slightly lower than the calculated induced voltage constant Ke, and the upper limit rotational speed is slightly higher than the calculated induced voltage constant Ke on the low power supply voltage side (for example, 12 V or less). ω0 may be set and held. In these cases, the upper limit rotational speed calculation unit 312 ′ calculates the upper limit rotational speed ω0 based on the power supply voltage VB.

As described above, according to the present embodiment, by providing the speed control unit that limits the rotation speed so as to operate below the upper limit rotation speed of the brushless motor, even if the motor characteristics change due to fluctuations in the power supply voltage. Thus, an appropriate upper limit rotational speed can be set by the speed control unit, and the motor can be stably controlled below the upper limit rotational speed of the motor.

It is a block diagram showing the whole electric pump device composition by one embodiment of the present invention. It is sectional drawing which shows the structure of the brushless motor used for the electric pump apparatus by embodiment of this invention. It is a block diagram which shows the structure of the brushless motor control apparatus used for the electric pump apparatus by one Embodiment of this invention. FIG. 4 is a detailed block diagram of an upper limit rotation speed calculation unit in FIG. 3. It is a block diagram which shows the other structure of the upper limit rotation speed calculating part in the brushless motor control apparatus used for the electric pump apparatus by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric pump apparatus 2 ... Fluid circuit 3 ... Brushless motor control apparatus 4 ... Brushless motor 5 ... Fluid pressure pump 20 ... High order command apparatus 23 ... Power supply 312 ... Upper limit rotation speed calculating part

Claims (2)

A fluid pressure pump for supplying fluid pressure to the fluid circuit, a brushless motor for applying a rotational driving force to the fluid pressure pump, and a brushless motor control device for rotationally driving the brushless motor in accordance with an external control signal ,
The brushless motor is an electric pump device driven by electric power converted from three-phase AC power from DC power of a power source,
The brushless motor control device sets an upper limit rotational speed that is an upper limit value of the rotational speed of the brushless motor based on the voltage of the power source, and the upper limit rotational value increases as the voltage increases. to, with the upper limit rotational speed calculation means for outputting the upper limit rotational speed value, the upper limit rotation speed calculation means, that you and the upper limit rotational speed value obtained by dividing the voltage of the power supply in the induced voltage constant of the brushless motor An electric pump device characterized. The electric pump device according to claim 1,
The upper limit rotational speed calculation means uses the value obtained by dividing the voltage of the power source by the induced voltage constant of the brushless motor multiplied by a safety factor as the upper limit rotational speed .

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