JPH0947028A - Dead time compensator, dead time compensation method, motor drive and motor driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate distortion from current waveform and to prevent fluctuation in the output torque from a motor. SOLUTION: The dead time compensator comprises a current command value generation means 80, means 83 for determining the polarity of current command value, and means 81 for performing dead time compensation based on the output pulse width of a PWM signal generated based on the current command value, the polarity of current command value, a dead time. When a current command value is generated from the current command value generation means 80, a PWM signal is generated and the polarity of current command value is determined. The dead time compensation means 81 then performs dead time compensation based on the output pulse width of PWM signal, the polarity of current command value, and the dead time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dead time compensation device, a dead time compensation method, a motor drive device and a motor drive method.

[0002]

2. Description of the Related Art Conventionally, an electric vehicle uses a motor composed of a rotor and a stator coil,
The motor is driven by supplying the phase current controlled by the motor driving device to the stator coil. In this case, the controller for motor control is
Current command value generation means, current comparison means, pulse width modulation (P
WM) signal generating means, triangular wave generating means, and the like. Then, the current command value generating means generates a three-phase sine wave signal composed of a U phase, a V phase, and a W phase corresponding to the position of the rotor based on the torque command value, and the sine wave signal is generated. The current command value is output to the current comparison means.

The current comparison means compares the current command value with the phase current fed back from the motor and outputs the deviation to the pulse width modulation signal generation means. The pulse width modulation signal generating means compares the input deviation with the reference triangular wave from the triangular wave generating means,
A three-phase pulse width modulation signal having a pulse width corresponding to the current command value is generated and the pulse width modulation signal is output to the base drive circuit.

The base drive circuit generates a transistor drive signal corresponding to the pulse width modulation signal,
The transistor drive signal is output to the inverter. The inverter has six transistors, turns on the transistors only while the transistor drive signal is on, generates phase currents of three phases, and supplies the phase currents to the stator coil.

By the way, in the inverter, 3
In order to generate a phase current of each phase, three pairs of transistors in which upper and lower transistors are connected in series are arranged. Then, by turning on the upper transistor and turning off the lower transistor, a positive polarity phase current can be supplied to the stator coil, that is, the motor, and the upper transistor is turned off and the lower transistor is turned on. By turning on
A negative polarity phase current can be supplied to the motor.

By the way, since the upper and lower transistors are connected in series, if both transistors are turned on at the same time for a short time, a short circuit occurs and the transistors are destroyed. Therefore, a dead time is provided so that a delay occurs when each transistor is turned on. In this case, the diode connected to the negative side of the power supply conducts when the phase current has a positive polarity,
During the dead time, the output voltage of the inverter has a negative polarity and the time during which the output voltage has a positive polarity is shortened accordingly.

On the other hand, when the phase current has a negative polarity, the diode connected to the positive side of the power supply conducts, so that the output voltage of the inverter has a positive polarity during the dead time.
The time when the output voltage has the negative polarity is shortened accordingly. Therefore, in order to compensate the error due to the dead time, when the polarity of the phase current is positive, the dead time is added to the output pulse width of the pulse width modulation signal, and when the polarity of the phase current is negative, The dead time is subtracted from the output pulse width of the pulse width modulation signal.

[0008]

However, in the above-mentioned conventional motor drive device, it is necessary to determine whether the polarity of the phase current is positive or negative. Therefore, dead time compensation is performed to output the inverter output. It takes time to generate the voltage. That is, the dead time compensation is performed by the dead time compensation means in the pulse width modulation signal generation means, but the polarity of the phase current is judged by the phase current fed back to the current comparison means.

However, after the phase current is fed back to the current comparison means, the current comparison means compares the current command value with the phase current and outputs the deviation to the pulse width modulation signal generation means. At the same time, the pulse width modulation signal generating means compares the deviation with the reference triangular wave from the triangular wave generating means to generate a three-phase pulse width modulation signal having a pulse width corresponding to the current command value, Since the pulse width modulation signal is output to the base drive circuit, the dead time compensation is performed after the polarity of the phase current is detected, and it takes a long time for the inverter to generate the output voltage. turn into.

Therefore, in the vicinity of the zero crossings of the phase currents of the three phases, the polarity when the polarity of the phase current is judged may differ from the polarity when the output voltage is generated from the inverter. For example, in the vicinity of the zero cross where the polarity of the phase current changes from positive to negative, the dead time may be added although the dead time should be subtracted from the output pulse width of the pulse width modulation signal. Further, in the vicinity of the zero cross where the polarity of the phase current changes from negative to positive, the dead time may be subtracted although the dead time should be added to the output pulse width of the pulse width modulation signal.

Therefore, instead of compensating the error due to the dead time, the error is further increased. As a result, in the vicinity of the zero cross of the phase current, not only distortion (distortion) occurs in the current waveform, but also the torque generated by the motor fluctuates. The present invention solves the problems of the conventional motor drive device described above, and the current waveform is not distorted and the torque generated by the motor is not changed. An object of the present invention is to provide a motor drive device and a motor drive method.

[0012]

Therefore, in the dead time compensating device of the present invention, a current command value generating means for generating a current command value and a current command value polarity determining means for determining the polarity of the current command value. And an output pulse width of the pulse width modulation signal generated based on the current command value,
A dead time compensating means for performing dead time compensation based on the polarity of the current command value and the dead time.

In the dead time compensating method of the present invention, the current command value is generated, the polarity of the current command value is judged, and the output pulse width of the pulse width modulation signal generated based on the current command value, Dead time compensation is performed based on the polarity of the current command value and the dead time. In the motor drive device of the present invention, a motor and six transistors are provided, and an inverter that supplies a phase current of three phases to the motor by turning on / off each transistor and each transistor of the inverter is provided. A dead time circuit for outputting a transistor drive signal and a controller for motor control.

The motor control controller is
A current command value generating means for generating a current command value, a current command value polarity determining means for determining the polarity of the current command value, a current for obtaining a deviation by comparing the current command value with the phase current fed back from the motor Pulse width modulation for generating a three-phase pulse width modulation signal having an output pulse width corresponding to the current command value based on the comparison means and the deviation, and outputting the pulse width modulation signal to the dead time circuit. A signal generating means is provided.

Further, the pulse width modulation signal generating means includes dead time compensation means for performing dead time compensation based on the output pulse width of the pulse width modulation signal, the polarity of the current command value, and the dead time. In the motor driving method of the present invention, a transistor driving signal is output to each transistor of the inverter, each transistor is turned on / off to generate a phase current of three phases, and the phase current is supplied to the motor to drive the motor. It is supposed to do.

Then, a current command value is generated, the polarity of the current command value is judged, and the current command value and the phase current fed back from the motor are compared to obtain a deviation,
A three-phase pulse width modulation signal having a pulse width corresponding to the current command value is generated based on the deviation, and based on the output pulse width of the pulse width modulation signal, the polarity of the current command value, and the dead time. Perform dead time compensation.

[0017]

According to the present invention, as described above, in the dead time compensating device, the current command value generating means for generating the current command value and the current command value polarity for judging the polarity of the current command value. And a dead time compensating means for performing dead time compensation based on the output pulse width of the pulse width modulation signal generated based on the current command value, the polarity of the current command value, and the dead time.

In this case, when the current command value generating means generates the current command value, the pulse width modulation signal is generated based on the current command value and the polarity of the current command value is determined. Then, the dead time compensation means performs dead time compensation based on the output pulse width of the pulse width modulation signal, the polarity of the current command value, and the dead time.

Therefore, in the vicinity of the zero cross of the phase current, the polarity of the current command value and the polarity of the phase current generated by the inverter become the same. as a result,
In the vicinity of the zero crossing of the phase current, the current waveform is not distorted, and the torque generated by the motor can be prevented from fluctuating. In the dead time compensation method of the present invention, a current command value is generated, the polarity of the current command value is determined, the output pulse width of the pulse width modulation signal generated based on the current command value, the current command Dead time compensation is performed based on the polarity of the value and the dead time.

In this case, when the current command value is generated, the pulse width modulation signal is generated based on the current command value and the polarity of the current command value is determined. Then, dead time compensation is performed based on the output pulse width of the pulse width modulation signal, the polarity of the current command value, and the dead time. Therefore, in the vicinity of the zero cross of the phase current, the polarity of the current command value and the polarity of the phase current generated by the inverter become the same. As a result, in the vicinity of the zero crossing of the phase current, the current waveform is not distorted, and the torque generated by the motor can be prevented from fluctuating.

In the motor drive device of the present invention, a motor and six transistors are provided, and an inverter that supplies three-phase currents to the motor by turning on and off each transistor, and each of the inverters. It has a dead time circuit that outputs a transistor drive signal to the transistor, and a motor control controller. In this case, when the dead time circuit outputs a transistor drive signal to each transistor of the inverter, the transistor is turned on / off by the transistor drive signal, and a three-phase current is supplied to the motor.

The motor control controller includes a current command value generating means for generating a current command value, a current command value polarity determining means for determining the polarity of the current command value,
A current comparison unit that obtains a deviation by comparing the current command value with the phase current fed back from the motor, and a three-phase pulse width modulation signal having an output pulse width corresponding to the current command value based on the deviation. And pulse width modulation signal generation means for generating the pulse width modulation signal and outputting the pulse width modulation signal to the dead time circuit.

Further, the pulse width modulation signal generating means includes dead time compensation means for performing dead time compensation based on the output pulse width of the pulse width modulation signal, the polarity of the current command value, and the dead time. In this case, dead time is provided to prevent the upper and lower transistors from being turned on at the same time, and the dead time compensating means compensates the dead time based on the output pulse width, the polarity of the current command value, and the dead time. And compensates for the error caused by providing the dead time.

Therefore, in the vicinity of the zero crossing of the phase current, the polarity of the current command value and the polarity of the phase current generated by the inverter become the same. as a result,
In the vicinity of the zero crossing of the phase current, the current waveform is not distorted, and the torque generated by the motor can be prevented from fluctuating. In the motor driving method of the present invention, a transistor driving signal is output to each transistor of the inverter, each transistor is turned on / off to generate a phase current of three phases, and the phase current is supplied to the motor to drive the motor. It is supposed to do.

In this case, when a transistor drive signal is output to each transistor of the inverter, the transistor is turned on / off by the transistor drive signal to supply a three-phase current to the motor. Then, a current command value is generated, the polarity of the current command value is determined, the current command value and the phase current fed back from the motor are compared to obtain a deviation, and the current command value is determined based on the deviation. A pulse width modulation signal of three phases having a pulse width corresponding to is generated, and dead time compensation is performed based on the output pulse width of the pulse width modulation signal, the polarity of the current command value, and the dead time.

In this case, the polarity of the current command value and the polarity of the phase current generated by the inverter become the same in the vicinity of the zero cross of the phase current. As a result, in the vicinity of the zero crossing of the phase current, the current waveform is not distorted, and the torque generated by the motor can be prevented from fluctuating.

[0027]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a functional block diagram of a motor drive device according to an embodiment of the present invention. In the figure,
Reference numeral 80 denotes a current command value generating means for generating a current command value, 8
3 is a current command value polarity determining means for determining the polarity of the current command value, 81 is an output pulse width of the pulse width modulation signal generated based on the current command value, the polarity of the current command value, and the dead time. It is a dead time compensating means for performing dead time compensation based on.

FIG. 2 is a block diagram of a motor drive device according to the embodiment of the present invention, and FIG. 3 is a block diagram of a motor control controller according to the embodiment of the present invention. In the figure, reference numeral 11 denotes a vehicle control controller for controlling the entire electric vehicle.
, The amount of accelerator pedal depression by the operation of Aruserupedaru not shown theta, brake depression amount B _r by the operation of the brake pedal, not shown, and shift position signal S _h corresponding to the shift position of the shift lever (not shown) is input.

Then, the vehicle control controller 11
A torque command value generating means 11a, said torque command value generating means 11a is the accelerator depression amount theta, to generate a torque command value T _q based on the brake depression amount B _r and the shift position signal S _h, the motor control It outputs to the controller 12 for. Further, the vehicle control controller 1
1 generates a drive signal D _r and outputs it to the motor control controller 12.

The motor control controller 12 has a current command value generating means 21, a current comparing means 22, a pulse width modulation (PWM) signal generating means 23, a triangular wave generating means 25 and the like. Then, the current command value generating means 21 generates a three-phase sine wave signal composed of a U phase, a V phase, and a W phase corresponding to the position of the rotor based on the torque command value T _q , The sine wave signal is the current command value i _U , i
It is output to the current comparison means 22 as _{V 1} and i _W.

Further, the current comparing means 22 compares the current command values i _U , i _V , i _W with the phase currents I _U , I _W fed back from the motor 13, and the deviation Δ thereof.
i _U , Δi _V , and Δi _W are pulse width modulation signal generating means 23.
Output to Actually, since only the two phase currents I _U and I _W are fed back from the motor 13, only the deviations ΔI _U and ΔI _W can be obtained.

Then, the pulse width modulation signal generating means 2
Reference numeral 3 compares the input deviations ΔI _U , ΔI _V , ΔI _W with the reference triangular wave from the triangular wave generating means 25, and outputs the output pulse width t _U corresponding to the current command values i _U , i _V , i _W. ,
a three-phase pulse width modulation signal P _U having t _V and t _W ,
P _V , P _W are generated to generate the pulse width modulation signal P _U ,
It outputs P _V and P _W to the base drive circuit 15.

The base drive circuit 15 has a dead time circuit 10. The dead time circuit 10 corresponds to the pulse width modulation signal P _U and has a U phase upper gate signal G _UU and a U phase lower gate signal G U. _UL is made to correspond to the pulse width modulation signal P _V and the V-phase upper-stage gate signals G _VU and V
The phase lower gate signal G _VL is caused to correspond to the pulse width modulation signal P _W , and the W phase upper gate signal G _WU and the W phase lower gate signal G _WL are generated as transistor drive signals, respectively, and the transistor drive signal is generated by the inverter 16 Output to.

The inverter 16 is not shown in the figure.
The transistor drive signal has six transistors.
The transistor is turned on only when the
Current I_U, I_V, I_WTo generate the phase current I_U,
I_V, I_WIs a stator coil (not shown) of the motor 13.
Supply to Le. Also, the phase current I_U, I_V, I_WIs
Feedback to the motor control controller 12
It is. Usually, from Kirchhoff's law, 2 out of 3 phases
It is possible to control three phases by controlling.
In the present invention, the phase current I _U, I_WThe motor control
Feedback to the controller 12
I have.

Then, the motor control controller 12
In step 1, the speed v is calculated based on the magnetic pole position signal b indicating the rotor position detected by the rotor position detecting means 26, and the calculated speed v is output to the vehicle control controller 11. Further, the motor control controller 12 controls the phase current I
_U, I _V, if I _W flows abnormally generates an abnormality signal A _L as a fail, and outputs to the vehicle control controller 11. Furthermore, the voltage from the battery 20 is
It is necessary when calculating the output pulse widths t _U , t _V , and t _W.

By the way, in the inverter 16, three pairs of upper and lower transistors connected in series are arranged in order to generate three-phase currents I _U , I _V , and I _W. For the transistor, the U-phase upper-stage gate signal G _UU , U-phase lower-stage gate signal G _UL , V-phase upper-stage gate signal G _VU , V-phase lower-stage gate signal G _VL , W-phase upper-stage gate signal G _WU and W-phase lower-stage gate signal It outputs _GWL .

By turning on the upper transistor and turning off the lower transistor, a positive polarity current can be supplied to the stator coil, that is, the motor, and the upper transistor is turned off and the lower transistor is turned on. It is possible to supply a negative polarity current to the motor by turning on the transistor. In this case, since the upper and lower transistors are connected in series, if both transistors are simultaneously turned on for a short time, a short circuit will occur.

Therefore, in the dead time circuit 10,
U-phase upper gate signal G _UU , U-phase lower gate signal G _UL , V
The dead time T _d is provided so that a delay occurs when the phase upper gate signal G _VU , the V phase lower gate signal G _VL , the W phase upper gate signal G _WU, and the W phase lower gate signal G _WL become high level. It is designed to be used. The dead time circuit 10 includes a U-phase upper gate signal G _UU , a U-phase lower gate signal G _UL , a V-phase upper gate signal G _VU , a V-phase lower gate signal G _VL , and a W-phase upper gate signal G _WU and W. The phase lower gate signal G _WL is generated and output to the inverter 16.

Further, the pulse width modulation signal generating means 23
Has a dead time T_dCaused by the provision of
A dead time compensating means 81 is provided to compensate the error.
Is established. The dead time compensating means 81 is configured to change the pulse width.
Key signal P_U, P_V, P_WTo the dead time circuit 10
Current command value i at the time of outputting_U, I_V, I_Wof
Determine whether the polarity is positive or negative, and set the current command value.
i_U, I_V, I_WIf the polarity of the
Key signal P_U, P_V, P_WOutput pulse width t_U, T_V, T
_WDead time T_dAnd current command value i_U,
i_V, I_WIf the polarity of is negative, the pulse width modulated signal
P_U, P_V, P_WOutput pulse width t_U, T_V, T _WFrom
Dead time T_dCompensating pulse by subtracting
Width T_U, T_V, T _WIs calculated.

FIG. 4 is a diagram showing an inverter and a base drive circuit in the embodiment of the present invention. In the figure,
13 is a motor, 16 is an inverter, 20 is a battery, T
r1 to Tr6 are transistors, C is each transistor Tr
This is a capacitor for smoothing the current flowing through 1 to Tr6. Diodes are connected between the collectors and emitters of the transistors Tr1 to Tr6.
Then, the upper transistors Tr1, Tr3, Tr5
And each of the lower transistors Tr2, Tr4, Tr6 are connected in series to form three pairs of transistors Tr1, Tr2, transistors Tr3, Tr4, and transistors Tr5, Tr6. , Tr2, transistor Tr3,
Three phase currents I _U , I _V , and I _W (FIG. 2) are generated between Tr4 and between the transistors Tr5 and Tr6.

Reference numeral 10 is a dead time circuit. The dead time circuit 10 includes transistors Tr1 and Tr2,
Transistors Tr3, Tr4 and transistor Tr
5, delay circuits 31 and 32 formed corresponding to Tr6
Having. For convenience of explanation, the transistor Tr3,
The delay circuit corresponding to Tr4 is not shown. Here, since each of the delay circuits has the same structure, only the delay circuit 31 will be described.

The delay circuit 31 includes buffers B1 to B4,
Resistors R1 to R8, capacitors C1 and C2, diode D
1 to D4, corresponding U-phase pulse width modulation signal P
_U is input to the buffers B1 and B3. In this case, since the buffer B3 comprises an inverter, the buffer B1
Output signal of the buffer B3 and the output signal of the buffer B3 are inverted from each other, and are connected to the diode D via the resistors R1 and R5, respectively.
1 and D3 are input to the anodes. Note that the resistance value r1 of the resistance R1 and the resistance value r2 of the resistance R2, and the resistance value r5 of the resistance R5 and the resistance value r6 of the resistance R6 have a relationship of r1 << r2 r5 << r6, respectively.

The cathodes of the diodes D1 and D3 are connected to a power supply (not shown) via pull-up resistors R2 and R6, and also connected to the ground via capacitors C1 and C2. The resistor R is provided between the cathodes of the diodes D1 and D3 and the power source.
Diodes D2 and D4 are connected in parallel with 2 and R6.

Further, the cathodes of the diodes D1 and D3 are connected to the buffer B via resistors R3 and R7, respectively.
2 and B4, and pull-up voltage is input to the buffers B2 and B4. Then, the buffers B2 and B4
Is output as U-phase upper-stage gate signal G _UU and U-phase lower-stage gate signal G _{UL to} the bases of the transistors Tr1 and Tr2 via resistors R4 and R8, respectively.

Therefore, when the pulse width modulation signal P _U input to the buffer B1 becomes high level, the pull-up voltage rises as the capacitor C1 is charged,
When the pull-up voltage becomes higher than the reference value, the U-phase upper gate signal G _UU becomes high level. In this case, the delay until the pull-up voltage becomes higher than the reference value after the pulse width modulation signal P _U becomes high level becomes the dead time T _d .

Then, when the pulse width modulation signal P _U becomes high level, the output signal of the buffer B3 becomes low level, the capacitor C2 is rapidly discharged through the resistor R5, and the pull-up voltage immediately drops, When the pull-up voltage becomes lower than the reference value, the U-phase lower gate signal G _UL becomes low level. In this case, there is no delay until the pull-up voltage becomes lower than the reference value after the pulse width modulation signal P _U becomes high level.

On the other hand, when the pulse width modulation signal P _U input to the buffer B1 becomes low level, the capacitor C1 is rapidly discharged through the resistor R1, the pull-up voltage immediately drops, and the pull-up voltage becomes the reference. When it becomes lower than the value, the U-phase upper gate signal G _UU becomes low level. In this case, after the pulse width modulation signal P _U becomes low level,
There is no delay until the pull-up voltage becomes lower than the reference value.

Further, the pulse width modulation signal P_UIs low level
Then, the output signal of the buffer B3 becomes high level.
, And pull up as the capacitor C2 is charged.
Voltage rises and the pull-up voltage is higher than the reference value.
Then, U-phase lower gate signal G _ULGoes high. This
, The pulse width modulation signal P_UBecame low level
Then, there is a delay until the pull-up voltage becomes higher than the reference value.
Dead time T_dbecome.

Next, the operation of the motor drive device having the above construction will be described. FIG. 5 is a main flowchart showing the operation of the motor drive device in the embodiment of the present invention. Step S1 Initial setting is performed. Step S2 Motor controller 12 (FIG. 2)
Input the torque command value T _q to. Step S3 The current command value generating means 21 calculates the current command values i _U , i _V , i _W based on the torque command value T _q .

Then, the main flow chart is executed.
While interrupting, every 100 [μs] interrupt processing shown in FIG.
Work. FIG. 6 is a dead time in the embodiment of the present invention.
Compensation time chart, FIG. 7 in the embodiment of the present invention
Flowchart showing 100 μs interrupt processing of motor drive device
It is. Step S11 Phase current I_U, I_WMotor control (Fig. 2)
The feed bar is added to the current comparison means 22 of the controller 12
Click to enter. In step S12, the magnetic pole position of the rotor of the motor 13 is set to the current
Input to the command value generating means 21. Step S13: The motor control controller 12 is speed
Calculate v. Step S14: Illustration of the motor control controller 12
The voltage command value calculation means does not use the current command value i_U, I_V,
i_WAnd the deviation of the phase current ΔI_U, ΔI_V, ΔI_WBased on
To calculate the voltage command value. Step S15 The pulse width modulation signal generating means 23
Based on the voltage command value and the battery voltage, change the pulse width.
Key signal P_U, P_V, P_WOutput pulse width t_U, T _V, T
_WIs calculated. Step S16 The dead time compensation means 81 uses the current finger.
I i_U, I_V, I_WDead time compensation based on the polarity of
Compensation processing, pulse width modulation signal P_U, P_V, P _WComplement
Compensation pulse width T_U, T_V, T_WIs calculated.

That is, as shown in FIG. 6, at the timing t ₀ , the current command value generating means 21 generates the current command values i _U , i _V , i _W , and the pulse width modulation signal generating means 23 outputs the output pulse width t. The calculation of _U , t _V , t _W is started, and the dead time compensating means 81 uses the compensation pulse widths T _U , T
The calculation of _V and T _W is started. Then, at the timing t ₁ , the pulse width modulation signals P _U , P _V , P _W after the dead time compensation are output to the dead time circuit 10.

Further, the timing t₂At the pulse
Width modulation signal P_U, P_V, P_WPhase current I corresponding to_U, I
_V, I_WIs generated. Here, the current command value i_U,
i_V, I_WPolarity depends on the calculation result of step S3
I know in advance. Therefore, the dead time compensation
Compensation means 81₀~ T₁Compensation between
Pulse width T_U, T_V, T_WTo start the calculation of
Timing t₂Phase current I generated at_U, I
_V, I_WCurrent command value i corresponding to_U, I_V, I_WPolarity
Is positive or negative, and the current command value i_U, I
_V, I_WIs positive, the pulse width modulation signal P
_U, P _V, P_WOutput pulse width t_U, T_V, T_WTo
Time T_dAnd current command value i_U, I_V, I_Wof
If the polarity is negative, the pulse width modulation signal P_U, P_V,
P_WOutput pulse width t_U, T_V, T_WFrom dead time
T_dIs subtracted.

Thus, near the zero cross, the current command values i _U , i generated at the timing t ₀
The polarities of _V and i _W are the same as the polarities of the phase currents I _U , I _V and I _W generated by the inverter 16. In step S17, the values of the compensation pulse widths T _U , T _V , and T _W are set in the PWM timer (not shown).

Therefore, the pulse width modulation signals P _U , P _V and P _W are at high level until the PWM timer times out. FIG. 8 is a flow chart showing the operation of dead time compensation processing in the embodiment of the present invention. In step S31, it is determined whether the output pulse width t _U is 0. When the output pulse width t _U is 0, the process proceeds to step S35, and when it is not 0, the process proceeds to step S32. Step S32 the current command value at the timing t ₂ i
Determine if _U is greater than or _equal to 0. Current command value i _U
If is greater than or equal to 0, the process proceeds to step S33, and if less than 0, the process proceeds to step S34. Step S33: Output pulse width t _U and dead time T _d
The value obtained by adding is set as the value of the compensation pulse width T _U. Step S34 Output pulse width t _U to dead time T
_The value obtained by subtracting _d is set as the value of the compensation pulse width T _U. In step S35, it is determined whether the output pulse width t _V is 0. If the output pulse width t _V is 0, the process proceeds to step S39, and if it is not 0, the process proceeds to step S36. Step S36 the current command value at the timing t ₂ i
_Judge whether _V is 0 or more. Current command value i _V
If is 0 or more, the process proceeds to step S37, and if it is less than 0, the process proceeds to step S38. Step S37: Output pulse width t _V and dead time T _d
The value obtained by adding is set as the value of the compensation pulse width T _V. Step S38 Output pulse width t _V to dead time T
_The value obtained by subtracting _d is set as the value of the compensation pulse width T _V. In step S39, it is determined whether the output pulse width t _W is 0. If the output pulse width t _W is 0, the process ends, and if it is not 0, the process proceeds to step S40. Step S40 Current command value i at timing t _2
Judge whether _W is 0 or more. Current command value i _W
If is greater than or equal to 0, the process proceeds to step S41, and if less than 0, the process proceeds to step S42. Step S41 Output pulse width t _W and dead time T _d
The value obtained by adding is set as the value of the compensation pulse width T _W. Step S42 Output pulse width t _W to dead time T
_The value obtained by subtracting _d is set as the value of the compensation pulse width T _W.

By the way, in this embodiment, the phase having the smallest (negatively large) voltage among the voltage command values obtained in step S14 is turned off in full in step S15. Therefore, steps S31, S35 and S39 are provided so that the route is passed when it is not necessary to compensate the dead time T _d . Further, when the pulse width modulated signal is in the full-on state, the pulse width modulated signal whose output pulse width t _V is always 1 can be passed through the route.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and they are not excluded from the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a motor drive device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a motor drive device according to an embodiment of the present invention.

FIG. 3 is a block diagram of a motor control controller according to an embodiment of the present invention.

FIG. 4 is a diagram showing an inverter and a base drive circuit according to an embodiment of the present invention.

FIG. 5 is a main flowchart showing an operation of the motor drive device in the embodiment of the present invention.

FIG. 6 is a time chart of dead time compensation in the embodiment of the present invention.

FIG. 7 shows a motor drive device 10 according to an embodiment of the present invention.
It is a flowchart which shows a 0 microsecond interruption process.

FIG. 8 is a flowchart showing an operation of dead time compensation processing in the embodiment of the present invention.

[Explanation of symbols]

10 Dead Time Circuit 12 Motor Control Controller 13 Motor 15 Base Drive Circuit 16 Inverter 80 Current Waveform Control Circuit 81 Dead Time Compensation Means 83 Current Command Value Calculation Means G _UU U Phase Upper Gate Signal G _UL U Phase Lower Gate Signal G _VU V phase upper gate signal G _VL V-phase lower gate signal G _WU W phase upper stage gate signal G _WL W-phase lower gate signal T _U, T _V, T _W compensation pulse width T _d dead time T _q torque command value Tr1~Tr6 transistor i _U , i _V , i _W current command value I _U , I _V , I _W phase current t _U , t _V , t _W output pulse width P _U , P _V , P _W pulse width modulation signal

Claims (4)

[Claims] 1. A current command value generating means for generating a current command value, a current command value polarity judging means for judging the polarity of the current command value, and a pulse width modulation signal generated based on the current command value. Dead time compensating means for performing dead time compensation based on the output pulse width, the polarity of the current command value, and the dead time. 2. A current command value is generated, the polarity of the current command value is determined, the output pulse width of the pulse width modulation signal generated based on the current command value, the polarity of the current command value, and A dead time compensation method characterized by performing dead time compensation based on dead time. 3. A motor and six transistors are provided,
And an inverter that supplies three-phase currents to the motor by turning on / off each transistor, a dead time circuit that outputs a transistor drive signal to each transistor of the inverter, and a motor control controller. At the same time, the motor control controller is
A current command value generating means for generating a current command value, a current command value polarity determining means for determining the polarity of the current command value, a current for obtaining a deviation by comparing the current command value with the phase current fed back from the motor Pulse width modulation for generating a three-phase pulse width modulation signal having an output pulse width corresponding to the current command value based on the comparison means and the deviation, and outputting the pulse width modulation signal to the dead time circuit. The pulse width modulation signal generation means includes dead time compensation means for performing dead time compensation based on the output pulse width of the pulse width modulation signal, the polarity of the current command value, and the dead time. A motor drive device characterized by: 4. A transistor drive signal is output to each transistor of the inverter to turn on each transistor.
In a motor driving method of turning off to generate phase currents of three phases and supplying the phase currents to a motor for driving, a current command value is generated, the polarity of the current command value is determined, and the current command value A deviation is obtained by comparing with the phase current fed back from the motor, a 3-phase pulse width modulation signal having a pulse width corresponding to the current command value is generated based on the deviation, and the deviation of the pulse width modulation signal is generated. A motor driving method, wherein dead time compensation is performed based on an output pulse width, a polarity of the current command value, and a dead time.