JPH1051904A - Power converter in electric car with transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent regeneration feeling at every gear position by outputting a regenerative torque command which makes a regenerative torque a value set beforehand, when the deceleration exceeds a limit value. SOLUTION: A deceleration limit value set as well as the deceleration of a motor obtained by differentiating the real number of revolution ωr are inputted into a regenerative torque limiter 21 and compared. Besides, a torque command T1 for a first speed and a torque command T2 at gear positions other than the first speed set are inputted into the regenerative torque limiter 21, and the regenerative torque command T2 for fourth and fifth speeds is outputted when the deceleration of the motor revolution is larger than the limit value. And the torque command T1 for a first speed is outputted when the deceleration of the motor revolution is smaller than the limit value. As the result, it becomes possible to obtain an excellent regeneration feeling according to the degree of deceleration of the motor revolution, and to perform regeneration having an excellent regeneration feeling at any gear position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter suitable for regenerative control in an electric vehicle with a transmission (hereinafter referred to as EV).

[0002]

2. Description of the Related Art The drive of an EV is controlled by so-called vector control using, for example, an induction motor (IM) as a drive source. Here, an outline of the vector control in FIG. 5, divided first primary current is hitting the control on the excitation current I ₀ and the torque current I _t, by controlling independently, fast torque Response and high-precision control are realized.
In general, in order to prevent transient phenomena, the excitation current I _{0 is} independent of the operating state, except in special cases such as constant output operation.
Is controlled by vector control.

[0003] In order to obtain this torque current I _t is calculated by the current command calculation and protection control circuit 2, the brake command for the circuit 2 is accelerator opening command circuit 1a for driving, and braking The circuit is connected to a circuit 1b, and furthermore, each information of a motor temperature, an inverter temperature, and a battery voltage is inputted to perform protection control. Here, one in which the current calculation and protection control circuit 2, and outputs a torque current I _t which is proportional to the accelerator opening Upon driving, and outputs a constant excitation current I _0.

[0004] The slip frequency calculation unit 3 is: And the torque current command I _t, the excitation current command I ₀ orthogonal thereto from the induction motor ₄ of the secondary time constant tau _2, obtaining the slip frequency omega _s. The speed detector ₅ obtains the rotational speed ω _r of the induction motor 4.

The slip frequency ω _s is added to the detected speed value ω _r of the induction motor 4 to be converted into a primary angular speed ω. The angular speed ω is integrated by an integration operation unit 6 to obtain a phase angle θ.

[0006] The current control unit 7 a torque current command I _t and excitation current respectively of the torque current with respect to instruction I ₀ detected value I _tFB
And the exciting current detection value after calculation by the proportional integral operation from a deviation between I _0FB, further torque-axis voltage control signal V _t and the excitation axis voltage addition and subtraction to the rotating coordinate interference component of the induction motor machine for both operation result obtaining a control signal V _0.

The torque current detection value _ItFB and the excitation current detection value _I0FB are calculated from the two-phase current detection values of the induction motor 4. In this calculation, the two-phase currents I _U and I _W are converted into digital values by the A / D converter 8 respectively, and a V-phase current detection value I _V is also obtained by adding the two, and the respective current values I _U , I _W and I _W It converted from I _V in a two-phase alternating current of fixed coordinates in three-phase / two-phase converter 9, which converts the torque current detection value I _tFB rotational coordinates and the exciting current detection value I _0FB coordinate transformation unit 10.

The decoupling voltage control signals V _t and V ₀ from the current controller 7 are converted into a primary voltage command V _{1 of} polar coordinates and a phase angle φ by a coordinate converter 11, and further converted to a polar coordinate / three-phase converter 12. The three-phase voltage commands V _U , V
_The signals are converted into V and _{VW and} are used as output voltage control signals of the PWM inverter 13.

The PWM inverter 13 has a three-phase voltage command V
_{According to U} , V _V , and V _W , the DC current of the vehicle-mounted battery B is converted into a three-phase AC current and supplied to the induction motor 4. Thus, the induction motor 4 is driven, and the EV runs.

[0010]

In controlling the induction motor 4 by the above-described vector control, regenerative control is performed to extend the travelable distance for EV running by a battery, and the engine braking and the engine braking in an engine vehicle are performed. Regenerative control is also performed in order to produce the same brake feeling.

However, in performing the regenerative control, in the case of an EV with a transmission, the driving force of the EV changes depending on the gear position of the transmission even if the regenerative torque of the motor is the same. That is, the gear ratio of the transmission is exemplified as in the following Table 1.

[0012]

[Table 1]

Under this gear ratio, for example, when a good regenerative feeling is set in the fifth gear, the regeneration is too strong in the first gear, and a good regenerative feeling is set in the first gear. In 5th gear, regeneration is too weak. Thus, depending on the position of the transmission,
Regeneration may be too strong or too weak.

The present invention has been made in view of the above-described problems, and provides a power converter of an electric vehicle with a transmission that can obtain a good regenerative feeling at all gear positions.

[0015]

The present invention that achieves the above object has the following matters specifying the invention. (1) In an electric vehicle with a transmission that performs vector control of a motor based on a torque current command and an excitation current command output from a current command calculation / protection control circuit to which an accelerator opening and a brake command are input, the above current command calculation / protection The control circuit is characterized in that a motor deceleration acceleration and a deceleration acceleration limit value are inputted and compared, and when the deceleration exceeds the limit value, a regenerative torque command for setting a regenerative torque to a preset value is output. (2) In an electric vehicle with a transmission that performs vector control of a motor based on a torque current command and an excitation current command output from a current command calculation / protection control circuit to which an accelerator opening and a brake command are input, the above current command calculation / protection The control circuit is characterized in that a difference between the deceleration / acceleration limit value and the motor deceleration is obtained, and a regenerative torque command obtained by subtracting the difference is obtained. (3) In the above (2), the difference is calculated by PI control or I
A regenerative torque command subtraction signal is obtained through P control. (4) In the above (1) or (2), another regenerative torque control is performed when the brake is depressed.

The regenerative torque command is optimized by not outputting the regenerative torque command directly due to the motor deceleration exceeding the limit value.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of the present invention will be described with reference to FIGS. In current calculation and protection control circuit 2 shown in FIG 5 described above, mainly a torque command value is calculated by the accelerator opening and the brake command determined torque current command I _0. The current command calculation / protection control circuit 2 also outputs a regenerative torque command value at the time of regeneration, that is, an operation of applying the engine brake. In this case, when the regenerative torque, which is the motor output, is the same, for example, between the first gear and the third gear, the speed of the first gear is lower than that of the automobile. That is, the deceleration is large. For this reason, for example, a torque command value that provides a good regenerative feeling in a fifth speed gear or the like and a torque command value that provides a good regenerative feeling in the first speed gear are separated. Select and output the command value.

FIG. 1 shows a regenerative torque limiter 21 built in the current command calculation / protection control circuit 2. The regeneration torque limiter 21 is entered limit value of the set deceleration the motor deceleration obtained by differentiating the actual motor rotation speed omega _r is inputted, it is compared. Also, the regenerative torque limiter 2
The 1, the torque command T ₂ of the in gear other than the torque command T ₁ and the first speed for the first speed which is set is input. Then, in the regenerative torque limiter 21, when the deceleration of the motor rotation is greater than the limit value is output regenerative torque command T ₂ of the for 4-speed 5-speed, if deceleration of the motor rotation is smaller than the limit value Is the torque command T for the first speed
₁ is output. Therefore, a good regenerative feeling can be obtained according to the degree of the deceleration of the motor rotation.

FIG. 2 shows another example. In an EV with a transmission, a good regenerative feeling is obtained in all gears by changing the regenerative torque itself so that the deceleration becomes equal to or less than a set value. It is like that. In the example shown in FIG. 1, the torque command is obtained by a two-stage T ₁ and T _2. In the example of FIG. This is to obtain an optimal torque command value. That is,
As shown in FIG. 2, the motor deceleration obtained by differentiating the motor rotation speed is added and subtracted from the regenerative acceleration limit value at the matching point 22. After that, it is added to the regenerative torque command T at the addition point 25. In this case, the limiter 24 limits the torque so as not to adjust in the direction of increasing the regenerative torque value, so that the regenerative torque is adjusted so that the regenerative torque becomes the set value only when the deceleration exceeds the set value. Therefore, the deceleration is always equal to or less than the set value. Thus,
Good regenerative feeling can be obtained in all gears.

FIG. 3 shows a modification of FIG. 2, in which the torque adjustment is performed only by the proportional gain K. In order to improve the controllability of the control, the proportional and integral sections 2 are used.
In 6, 27, PI control or IP control can be performed. In this case, it is necessary to provide a limiter for preventing the regenerative torque from increasing in the integration (I) circuit in addition to the limiter 24.

In the case of regenerative braking, some EVs are controlled so that when the brake pedal is further depressed, the regenerative amount is increased to stop the vehicle. Although the regeneration amount is limited in FIGS. 1 to 3, it is also possible to issue the regeneration torque command while preventing the regeneration torque limit when the brake is depressed. FIG. 4 shows a system for changing the regenerative torque when the brake is depressed. In FIG. 4, a torque command selector 28 is provided. In the torque command selector 28, a driving torque command value determined by the accelerator pedal depression amount and a regenerative torque command value (regenerative torque value) determined by the brake pedal depression amount A torque command 1) and a regenerative torque command value (regenerative torque command 2) determined by the circuits shown in FIGS. 1 to 3 are input, and the driving torque command> the regenerative torque command 1> the regenerative torque command 2 The torque command is selected in order and the command torque is output. Therefore, when the regenerative torque command 1 in which the brake pedal is depressed is present, the command 1 is output in preference to the regenerative torque command 2.

Although the induction motor 4 is described in FIG. 1, any type of motor may be used, such as a DC motor.

[0023]

As described above, according to the present invention, in the EV with the transmission, a good regenerative feeling can be obtained regardless of the gear position.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an embodiment of the present invention.

FIG. 2 is a block diagram of another example.

FIG. 3 is a block diagram of a modification of FIG. 2;

FIG. 4 is a block diagram of still another example.

FIG. 5 is a block diagram of belt control.

[Explanation of symbols]

 2 Current command calculation / protection control circuit 21, 24 Limiter 22, 25 Addition point 23, 26 Proportional part 27 Integral part 28 Torque command selector

Claims (4)

[Claims] An electric vehicle with a transmission that performs vector control of a motor based on a torque current command and an excitation current command output from a current command calculation / protection control circuit to which an accelerator opening and a brake command are input. In the protection control circuit, the motor deceleration acceleration and the deceleration acceleration limit value are input and compared, and when the deceleration exceeds the limit value, a regenerative torque command is output that sets the regenerative torque to a preset value. Power converter. 2. An electric vehicle with a transmission for performing vector control of a motor based on a torque current command and an excitation current command output from a current command calculation / protection control circuit to which an accelerator opening and a brake command are input. A power converter characterized in that the protection control circuit obtains a difference between the deceleration / acceleration limit value and the motor deceleration, and obtains a regenerative torque command obtained by subtracting the difference. 3. The power converter according to claim 2, wherein the difference is a subtraction signal of a regenerative torque command via PI control or IP control. 4. The power converter according to claim 1, wherein another regenerative torque control is performed when the brake is depressed.