JP2015126626A - Motor drive control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor drive control device which has inexpensive circuit configuration and nonetheless performs advance angle control with high accuracy.SOLUTION: A drive control device 1 for a motor 20 comprises: a motor drive part supplying a drive current to respective phase coils Lu, Lv, and Lw of the motor 20 on the basis of a drive control signal S5 to rotate a rotor; a voltage comparison part 5 generating phase signals S1, S2, and S3 on the basis of a comparison result between a cross-terminal voltage and a zero-cross reference voltage Vz; a position detection circuit 6 outputting a position detection signal S4 indicating a rotational position of the rotor on the basis of the phase signals S1, S2, and S3; a control part 4 generating a drive control signal S5 on the basis of a rotational speed command signal Sin and the position detection signal S4; and an advance angle adjustment circuit 7 measuring a spike voltage time period generated by energization switching in the cross-terminal voltage on the basis of the phase signals S1, S2, and S3, and generating a zero-cross reference voltage Vz for the advance angle adjustment according to a comparison result with a preset predetermined reference time.

Description

  The present invention relates to a motor drive control device that performs drive control without a position sensor without providing a position sensor that detects the rotational position of a rotor.

  Conventionally, there is a position sensorless type motor drive control device that detects the rotational position of a rotor by using an induced voltage of a motor instead of a position sensor. This position sensorless motor drive control device generates a phase signal (pulse signal) by comparing the induced voltage that appears at the motor terminal in the open section (non-energized phase) with a reference voltage (equivalent neutral point potential) by a comparator. Based on this phase signal, the rotational position of the rotor is detected.

In general, in order to extract the motor torque to the maximum, so-called advance control is performed in which the induced voltage in the armature coil and the phase of the motor current are matched. On the other hand, in the position sensorless drive control, since the reference voltage is fixed, the advance angle position is also fixed. Therefore, there is a problem that the advance angle control cannot be performed and the motor efficiency is reduced and noise is generated at a speed other than the rotation speed adapted to the fixed advance angle.
To solve this problem, for example, Patent Document 1 discloses an invention of a drive device that enables advance angle control in position sensorless drive control.

  The means for solving the summary of Patent Document 1 includes “an overcurrent detection circuit 30 for detecting the value of the load current flowing to the inverter circuit 16, and the value of the load current detected by the overcurrent detection circuit 30 becomes low. The lead angle reference potential is raised and outputted, and when the detected load current value becomes high, the lead angle reference potential is lowered and outputted, and the stator winding 14 of each phase of the brushless DC motor 10 is output. The lead angle control circuit 32 generates a phase signal based on the cross timing between the terminal voltage of the terminal and the lead angle reference potential, and the position detection circuit 34 generates a position detection signal based on the phase signal. Yes.

JP 2005-31217 A

The invention described in Patent Document 1 has the following problems.
When detecting the load current flowing to the inverter circuit, the drive device described in Patent Document 1 passes the load current through the detection resistance element and detects it as a voltage value. The voltage detected by the detection resistance element is a relatively low voltage, and the load current detection accuracy is low. As a result, the advance angle adjustment accuracy is also lowered, and it is difficult to finely adjust the advance angle. In order to finely adjust the advance angle with the driving device described in Patent Document 1, it is necessary to add circuit components such as an amplifier, resulting in an expensive circuit configuration.
Therefore, an object of the present invention is to provide a motor drive control device capable of performing advance angle control with high accuracy while having an inexpensive circuit configuration.

In order to solve the above-described problems, a motor drive control device according to the present invention includes a motor drive unit that receives power supply from a power source and supplies a drive current to each phase coil of the motor based on the drive control signal to rotate the rotor. A voltage comparison unit that generates a position adjustment signal based on a comparison result between a terminal voltage of each phase coil and a reference voltage, and a position detection signal that indicates the rotational position of the rotor based on the position adjustment signal. A position detection unit, a control unit that generates the drive control signal based on an externally input rotational speed command signal and the position detection signal, and a voltage between terminals of each phase coil based on the position adjustment signal. Measure the spike voltage period of either rising or falling caused by energization switching, and the ratio between the spike voltage period and a preset reference time And an advance angle adjustment unit to be output to the voltage comparison unit generates the reference voltage for the advance angle adjustment depending on the results.
Other means will be described in the embodiment for carrying out the invention.

  According to the present invention, it is possible to provide a motor drive control device capable of performing advance angle control with high accuracy while having an inexpensive circuit configuration.

It is a schematic block diagram which shows the motor drive control apparatus in this embodiment. It is a timing chart which shows the operation waveform of each part of a drive control device. It is a flowchart which shows the specific example of the adjustment procedure of a zero cross reference voltage. It is a timing chart which shows the phase voltage waveform for demonstrating advance angle adjustment. It is a timing chart which shows the specific example (it shows U phase) which adjusts an advance angle.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a circuit configuration of a drive control device 1 for a motor 20 in the present embodiment. In the present embodiment, the spike voltage period at the time of rising of the inter-terminal voltage or the phase voltage is used for the advance angle adjustment.
In FIG. 1, a motor 20 according to the present embodiment is a three-phase brushless DC motor, and includes coils Lu, Lv, Lw for each phase and a rotor (not shown). One ends of these coils Lu, Lv, and Lw are Y-connected. The other end of the coil Lu is connected to the U phase, the other end of the coil Lv is connected to the V phase, and the other end of the coil Lw is connected to the W phase. The brushless DC motor 20 is driven to rotate when three-phase alternating current is input from the inverter circuit 2 to the U phase, the V phase, and the W phase. Hereinafter, the brushless DC motor 20 may be simply referred to as the motor 20.

  The motor 20 drive control device 1 (an example of a motor drive control device) includes an inverter circuit 2 and a pre-drive circuit 3 (an example of a motor drive unit) that drive the motor 20, a voltage comparison unit 5, and a position detection circuit 6 ( An example of a position detection unit), a control unit 4, an advance angle adjustment circuit 7 (an example of an advance angle adjustment unit), and a start reference voltage generation circuit 8 are provided. The drive control device 1 is connected to a DC power source Vd, and is connected to the motor 20 through three phases of U-phase wiring, V-phase wiring, and W-phase wiring. The drive control device 1 outputs a drive voltage to the motor 20 and controls the rotation of the motor 20. The terminal voltage Vu is applied to the U phase. An inter-terminal voltage Vv is applied to the V phase. An inter-terminal voltage Vw is applied to the W phase.

The motor drive unit includes an inverter circuit 2 and a predrive circuit 3. The direct current power supply Vd supplies power by applying a power supply voltage Vcc to the motor drive unit. The motor drive unit receives power supply from the DC power supply Vd and supplies drive current to the U-phase, V-phase, and W-phase coils Lu, Lv, and Lw of the motor 20 based on the drive control signal S5 from the control unit 4. Then rotate the rotor. The motor driving unit drives the motor 20 by a sine wave driving method.
The inverter circuit 2 (a part of the motor drive unit) is connected to the DC power source Vd to receive power, and the pre-drive circuit 3 (a part of the motor drive unit) and the coils Lu and Lv of each phase included in the motor 20 are provided. , Lw. The inverter circuit 2 energizes the coils Lu, Lv, and Lw of each phase of the motor 20 by the drive signals Vuu to Vwl of the pre-drive circuit 3.
The inverter circuit 2 has, for example, a total of six switching elements Q1 to Q6, two for each phase. These switching elements Q1 to Q6 are, for example, FETs (Field Effect Transistors). The inverter circuit 2 includes a U-phase switching leg, a V-phase switching leg, and a W-phase switching leg. The inverter circuit 2 is connected to the DC power source Vd and further connected to the resistor R0.

  The U-phase switching leg includes a switching element Q1 on the upper arm side and a switching element Q2 on the lower arm side. The drain terminal of the switching element Q1 is connected to the positive electrode of the DC power supply Vd. The source terminal of the switching element Q1 outputs a U-phase AC signal and is connected to the drain terminal of the switching element Q2. The source terminal of the switching element Q2 is connected to the ground (the negative electrode of the DC power supply Vd) via the resistor R0. The gate terminal of the switching element Q1 and the gate terminal of the switching element Q2 are connected to the pre-drive circuit 3, respectively.

  The V-phase switching leg includes an upper arm side switching element Q3 and a lower arm side switching element Q4. The drain terminal of the switching element Q3 is connected to the positive electrode of the DC power supply Vd. The source terminal of the switching element Q3 outputs a V-phase AC signal and is connected to the drain terminal of the switching element Q4. The source terminal of the switching element Q4 is connected to the ground (the negative electrode of the DC power supply Vd) via the resistor R0. The gate terminal of switching element Q3 and the gate terminal of switching element Q4 are connected to pre-drive circuit 3, respectively.

  The W-phase switching leg includes an upper arm side switching element Q5 and a lower arm side switching element Q6. The drain terminal of the switching element Q5 is connected to the positive electrode of the DC power supply Vd. The source terminal of the switching element Q5 outputs a W-phase AC signal and is connected to the drain terminal of the switching element Q6. The source terminal of the switching element Q6 is connected to the ground (the negative electrode of the DC power supply Vd) via the resistor R0. The gate terminal of switching element Q5 and the gate terminal of switching element Q6 are connected to predrive circuit 3, respectively.

That is, the inverter circuit 2 includes upper arm side switching elements Q1, Q3, Q5 connected between the respective phases of the coils Lu, Lv, Lw of the motor 20 and one terminal (positive terminal) of the DC power supply Vd, and Each of the coils Lu, Lv, Lw has lower arm side switching elements Q2, Q4, Q6 connected via a resistor R0 between the respective phases of the coils Lu, Lv, Lw and the other terminal (negative electrode terminal) of the DC power supply Vd.
The inverter circuit 2 is supplied with power from the DC power supply Vd, and when the drive signals Vuu to Vwl are input from the pre-drive circuit 3, the three-phase AC is converted to the U-phase wiring, V-phase wiring, and W-phase wiring of the motor 20. Shed.
The pre-drive circuit 3 (a part of the motor drive unit) constitutes a motor drive unit in combination with the connected inverter circuit 2 and is connected to the control unit 4. The pre-drive circuit 3 includes, for example, six gate drive circuits, and generates drive signals Vuu to Vwl for driving the inverter circuit 2.

The voltage comparison unit 5 includes comparators 51, 52, and 53 for each phase. The U-phase node is divided by resistors R 1 and R 2 and connected to one input terminal of the comparator 51. The V-phase node is divided by resistors R 3 and R 4 and connected to one input terminal of the comparator 52. The W-phase node is divided by resistors R5 and R6 and connected to one input terminal of the comparator 53. The other input terminals of the comparators 51, 52, 53 are connected to the advance adjustment circuit 7.
The comparator 51 of the voltage comparison unit 5 receives the phase voltage V1 obtained by dividing the inter-terminal voltage Vu corresponding to the induced voltage of the coil Lu and the zero-cross reference voltage Vz. The comparator 51 compares the phase voltage V1 and the zero-cross reference voltage Vz to generate a phase signal S1 (an example of a position adjustment signal).

The comparator 52 receives the phase voltage V2 obtained by dividing the inter-terminal voltage Vv corresponding to the induced voltage of the coil Lv, and the zero-cross reference voltage Vz. The comparator 52 compares the phase voltage V2 and the zero-cross reference voltage Vz to generate a phase signal S2 (an example of a position adjustment signal).
The comparator 53 receives the phase voltage V3 obtained by dividing the inter-terminal voltage Vw corresponding to the induced voltage of the coil Lw and the zero cross reference voltage Vz. The comparator 53 compares the phase voltage V3 and the zero cross reference voltage Vz to generate a phase signal S3 (an example of a position adjustment signal).
By doing in this way, the comparators 51 to 53 of the voltage comparison unit 5 can compare the inter-terminal voltages Vu, Vv, and Vw corresponding to the phase voltages V1 to V3 with the reference voltage corresponding to the zero-cross reference voltage Vz. it can. The voltage comparison unit 5 outputs the generated phase signals S1 to S3 (an example of a position adjustment signal) to the position detection circuit 6 and the advance angle adjustment circuit 7.

  The position detection circuit 6 (an example of a position detection unit) generates a position detection signal S4 indicating the rotational position of the rotor based on the phase signals S1 to S3 (an example of a position adjustment signal) from the voltage comparison unit 5, and controls the position detection signal S4. Output to part 4.

  The control unit 4 is connected to an external device (not shown) and the position detection circuit 6. The control unit 4 generates the drive control signal S5 based on the rotational speed command signal Sin input from the outside and the position detection signal S4 from the position detection circuit 6.

The advance adjustment circuit 7 includes a spike voltage measurement unit 71, a spike voltage period determination unit 72, and a zero cross reference voltage generation unit 73. The advance angle adjustment circuit 7 generates a zero-cross reference voltage Vz based on the phase signals S <b> 1 to S <b> 3 from the voltage comparison unit 5 and outputs the zero-cross reference voltage Vz to the voltage comparison unit 5. The zero-cross reference voltage Vz includes a spike voltage period ts (see FIG. 4) at the rise of the phase voltages V1, V2, and V3 generated by energization switching in the inter-terminal voltages Vu, Vv, and Vw, and a predetermined reference time set in advance. This is a comparison result with tz (not shown), and is used for advance angle adjustment and retard angle adjustment.
The spike voltage measuring unit 71 measures the spike voltage period ts based on the phase signals S1 to S3. Here, the spike voltage period ts is a period in which the spike voltage in FIG. 4 described later is equal to or higher than the zero-cross reference voltage Vz. In other words, the spike voltage period ts is a time interval between the zero cross timing at the rise of the spike voltage and the zero cross timing at the fall.

Hereinafter, the reason why the advance angle control can be performed using the spike voltage period ts will be described.
In the motor 20, the phase current fluctuates due to the load fluctuation. When the load of the motor 20 increases and the advance angle is delayed, the phase current immediately before the phase energization is turned off increases. As a result, the spike voltage period ts becomes longer. In this case, the advance angle can be controlled by advancing the advance angle by lowering the zero cross reference voltage Vz.
Conversely, when the load of the motor 20 decreases and the advance angle advances, the phase current immediately before the phase energization is turned off decreases. As a result, the spike voltage period ts is shortened. In that case, the advance angle can be controlled by delaying the advance angle by increasing the zero-cross reference voltage Vz.

  The spike voltage period determination unit 72 generates setting information of the zero cross reference voltage Vz (reference voltage) based on the comparison result between the spike voltage period ts and the predetermined reference time tz. The spike voltage period determination unit 72 includes a storage unit 74 that stores a plurality of predetermined reference times tz corresponding to the rotational speed of the rotor as a comparison table. The spike voltage period determination unit 72 uses a predetermined reference corresponding to the rotation speed of the rotor of the reference table based on the actual rotation speed of the rotor obtained based on the phase signals S1, S2, S3 (an example of the position detection signal). Time tz is set. As a result, the spike voltage period determination unit 72 can perform advance angle control according to the actual rotational speed of the rotor. Since the spike voltage period determination unit 72 can freely set a plurality of reference voltages in the storage unit 74 in accordance with the spike voltage period ts, the advance angle adjustment can be performed with high accuracy.

The zero-cross reference voltage generator 73 generates a zero-cross reference voltage Vz from the setting information output from the spike voltage period determination unit 72. The zero cross reference voltage Vz is a reference voltage for advance angle adjustment.
The start reference voltage generation circuit 8 generates a start reference voltage V0 based on the power supply voltage Vcc and outputs it to the zero-cross reference voltage generation unit 73 when the motor 20 is started.
The drive control device 1 of the motor 20 can perform advance angle control with a simple and inexpensive circuit configuration, and can perform drive control with high efficiency of the motor 20.

FIG. 2 is a timing chart showing operation waveforms of each part of the drive control device 1. For the sake of explanation, FIG. 2 shows an operation when the zero-cross reference voltage Vzs is not adjusted for the advance angle.
Each graph in FIG. 2 shows waveforms of the drive signals Vuu to Vwl, the phase voltages V1 to V3, the phase signals S1 to S3, and the position detection signal S4 from the top.

The drive signal Vuu turns on the switching element Q1 at about 30 ° and turns off at about 150 °.
The drive signal Vul turns off the switching element Q2 at about −30 °, turns on at about 210 °, and turns off at about 330 °.
The U phase is released from the ground by turning off the drive signal Vul at about −30 °. A positive spike voltage is generated in the phase voltage V1. Thereafter, the phase voltage V1 becomes the zero cross reference voltage Vzs when the voltage rises to about 0 °.
When the drive signal Vuu is turned on at about 30 °, the power supply voltage Vcc of the DC power supply Vd is supplied to the U phase. The phase voltage V1 becomes the power supply voltage Vcc.
The U phase is released from the positive electrode of the DC power supply Vd by turning off the drive signal Vuu at about 150 °. The phase voltage V1 generates a spike voltage in the negative direction. Thereafter, the phase voltage V1 becomes the zero-cross reference voltage Vzs when the voltage drops to about 180 °.
When the drive signal Vul is turned on at about 210 °, the U phase is connected to the ground. The phase voltage V1 is 0 [V].

The phase signal S1 is generated by comparing the phase voltage V1 with the zero cross reference voltage Vzs.
The phase signal S1 generates an H level pulse indicating a spike voltage in the positive direction at about −30 °, and changes from the L level to the H level at about 0 °. Further, the phase signal S1 becomes L level during the period due to the spike voltage in the negative direction at about 150 °, and then changes from H level to L level at about 180 °.

The drive signal Vvu turns on the switching element Q3 at about 150 ° and turns off at about 270 °.
The drive signal Vvl turns off the switching element Q4 at about 90 ° and turns on at about 330 °.
The V phase is released from the ground by turning off the drive signal Vvl at about 90 °. A positive spike voltage is generated in the phase voltage V2. Thereafter, the phase voltage V2 becomes the zero-cross reference voltage Vzs when the voltage rises to about 120 °.
When the drive signal Vvu is turned on at about 150 °, the power supply voltage Vcc of the DC power supply Vd is supplied to the V phase. The phase voltage V2 becomes the power supply voltage Vcc.
By turning off the drive signal Vvu at about 270 °, the V phase is released from the positive electrode of the DC power supply Vd. As the phase voltage V2, a spike voltage in the negative direction is generated. Thereafter, the phase voltage V2 becomes the zero cross reference voltage Vzs when the voltage drops to about 300 °.
When the drive signal Vvl is turned on at about 330 °, the V phase becomes conductive with the ground. The phase voltage V2 is 0 [V].
The phase signal S2 is generated by comparing the phase voltage V2 with the zero-cross reference voltage Vzs.
The phase signal S2 generates an H level pulse indicating a spike voltage in the positive direction at about 90 °, and changes from the L level to the H level at about 120 °. Further, the phase signal S2 becomes L level during the period by a negative spike voltage at about 270 °, and then changes from H level to L level at about 300 °.

The drive signal Vwu turns off the switching element Q5 at about 30 ° and turns on at about 270 °.
The drive signal Vwl turns on the switching element Q5 at about 90 ° and turns off at about 210 °.
By turning off the drive signal Vwu at about 30 °, the W phase is released from the positive electrode of the DC power supply Vd. The phase voltage V3 generates a spike voltage in the negative direction. Thereafter, the phase voltage V3 becomes the zero-cross reference voltage Vzs when the voltage drops to about 60 °.
When the drive signal Vwl is turned on at about 90 °, the W phase becomes conductive with the ground. The phase voltage V3 is 0 [V].
The W phase is released from the ground by turning off the drive signal Vwl at about 210 °. A positive spike voltage is generated in the phase voltage V3. Thereafter, the phase voltage V3 becomes the zero-cross reference voltage Vzs when the voltage rises to about 240 °.
When the drive signal Vwu is turned on at about 270 °, the power supply voltage Vcc of the DC power supply Vd is supplied to the W phase. The phase voltage V3 becomes the power supply voltage Vcc.
The phase signal S3 is generated by comparing the phase voltage V3 with the zero-cross reference voltage Vzs.
The phase signal S3 generates an L level pulse indicating a spike voltage in the negative direction at about 30 °, and changes from the H level to the L level at about 60 °. Further, the phase signal S3 becomes H level during the period by the positive spike voltage at about 210 °, and then changes from L level to H level at about 240 °.

  As shown in FIG. 2, the position detection signal S4 generates a positive H level pulse at about 0 °, at about 120 °, at about 240 °, and at about 360 °. . After the positive spike voltage is generated in the phase voltages V1, V2, and V3, when the voltage rises and exceeds the zero-cross reference voltage Vzs, a positive high-level pulse is generated in the position detection signal S4.

FIG. 3 is a flowchart showing a specific example of a procedure for adjusting the zero-cross reference voltage Vz.
The adjustment procedure shown in FIG. 3 is executed by the drive control device 1 when the motor 20 (see FIG. 1) starts and rotates at a steady speed.
In step S <b> 1, the control unit 4 determines whether it is the energized phase switching timing. If it is the energized phase switching timing (YES), the control unit 4 performs the process of step S2. If it is not the switching timing of the energized phase (NO), the process of step S1 is repeated.

In step S2, the control unit 4 outputs a drive control signal S5 in order to switch the energized phase. The pre-drive circuit 3 performs an energized phase switching process. Thereafter, the drive control device 1 performs the process of step S3.
In step S3, the spike voltage measuring unit 71 measures the spike voltage period ts and performs the process of step S4.

In step S4, the spike voltage period determination unit 72 determines whether or not the spike voltage period ts is equal to or longer than a predetermined reference time tz. If the spike voltage period ts is equal to or longer than the predetermined reference time tz (YES), the spike voltage period determination unit 72 performs the process of step S5, and if the spike voltage period ts is less than the predetermined reference time tz (NO). Step S6 is performed.
In step S5, the zero-cross reference voltage generation unit 73 decreases the output zero-cross reference voltage Vz (lowers the reference voltage), and ends the process of FIG.
In step S6, the zero-cross reference voltage generator 73 increases the output zero-cross reference voltage Vz (increases the reference voltage), and ends the process of FIG.
By controlling in this way, the drive control device 1 of the motor 20 can perform advance angle control with high accuracy while having an inexpensive circuit configuration.

FIG. 4 is a timing chart showing the waveform of the phase voltage V1 for explaining the advance angle adjustment. The vertical axis in FIG. 4 indicates the phase voltage V1 (V). The horizontal axis in FIG. 4 indicates time.
Time t11 is the start timing of the opening period 60 ° (P0). A positive spike voltage is generated in the phase voltage V1.
Time t12 indicates the end timing of the spike voltage in the positive direction of the phase voltage V1. The spike voltage period ts is a time from time t11 to time t12. Thereafter, the phase voltage V1 increases.
Time t13 is timing when the phase voltage V1 first crosses the zero-cross reference voltage Vzs after the spike voltage period ts.
Time t14 is the end timing of the open period 60 ° (P0) and the start timing of the phase energization period P1.
The zero-cross reference voltage Vzs is obtained when the advance angle is adjusted, and the zero-cross reference voltage Vz1 is obtained when the advance angle is adjusted. The zero-cross reference voltage Vz2 is obtained when the retardation is adjusted.

FIGS. 5A and 5B are timing charts showing a specific example of the advance angle adjustment. As shown in FIG. 5, each graph is a waveform of a U-phase phase voltage V1, a phase signal S1, and a position detection signal S4.
In each graph of FIG. 5A, a solid line indicates a case where the advance angle is adjusted. A broken line indicates before advance angle adjustment.
Time t21 is the start timing of the opening period 60 ° (P0). A positive spike voltage is generated in the phase voltage V1.
Time t22 indicates the end timing of the spike voltage in the positive direction of the phase voltage V1. The spike voltage period ts is the time from time t21 to time t22. Thereafter, the phase voltage V1 increases.
Time t23a is a timing at which the phase voltage V1 first crosses the zero-cross reference voltage Vz1 after the spike voltage period ts after the advance angle adjustment. Thereby, a phase signal S1 and a position detection signal S4 indicated by a solid line are generated.
Time t23b is the timing at which the phase voltage V1 first crosses the zero-cross reference voltage Vzs after the spike voltage period ts after the advance angle adjustment. Thereby, a phase signal S1 and a position detection signal S4 indicated by a broken line are generated.
Time t24 is the end timing of the open period 60 ° (P0) and the start timing of the phase energization period P1.
By reducing the zero-cross reference voltage Vzs to be compared with the phase voltage V1 to the zero-cross reference voltage Vz1, the output timing of the position detection signal S4 advances from the time t23b indicated by the broken line to the time t23a indicated by the solid line.

In each graph of FIG.5 (b), the continuous line has shown the case where retardation adjustment is carried out. A broken line indicates before the delay angle adjustment.
Time t31 is the start timing of the opening period 60 ° (P0). A positive spike voltage is generated in the phase voltage V1.
Time t32 indicates the end timing of the spike voltage in the positive direction of the phase voltage V1. The spike voltage period ts is the time from time t31 to time t32. Thereafter, the phase voltage V1 increases.
Time t33a is the timing at which the phase voltage V1 first crosses the zero-cross reference voltage Vzs after the spike voltage period ts after the delay angle adjustment. Thereby, a phase signal S1 and a position detection signal S4 indicated by a broken line are generated.
Time t33b is a timing at which the phase voltage V1 first crosses the zero-cross reference voltage Vz2 after the spike voltage period ts after the delay angle adjustment. Thereby, a phase signal S1 and a position detection signal S4 indicated by a solid line are generated.
Time t34 is the end timing of the open period 60 ° (P0) and the start timing of the phase energization period P1.
By raising the zero cross reference voltage Vzs to be compared with the phase voltage V1 to the zero cross reference voltage Vz2, the output timing of the position detection signal S4 is delayed from the time t33a indicated by the broken line to the time t33b indicated by the solid line.
Thus, since the drive control device 1 adjusts the advance / retard angle according to the spike voltage period ts, it is possible to realize control with quick response.
In addition, since the drive control apparatus 1 of this embodiment performs advance angle control using the spike voltage period ts when the phase voltages V1 to V3 rise, the spike voltage period ts when the phase voltages V1 to V3 fall. Is not used for advance control and is ignored.

(Modification)
The present invention is not limited to the above-described embodiment, and can be modified without departing from the spirit of the present invention. For example, there are the following (a) to (h).

(A) The advance angle control in the above embodiment uses the spike voltage period ts when the phase voltages V1 to V3 rise, but uses the spike voltage period ts when the phase voltages V1 to V3 fall. You may do it. In that case, the relationship between the adjustment of the zero-cross reference voltage Vz and the advance angle adjustment is reversed.
(B) At least a part of each component of the drive control device 1 may be software processing instead of hardware processing.
(C) The motor 20 is not limited to a three-phase brushless motor, and may be another type of motor. Further, the number of phases of the motor 20 is not limited to three phases.
(D) The driving method of the motor 20 is not limited to the sine wave driving method, and may be, for example, a rectangular wave driving method.
(E) At least a part of the drive control device 1 may be an integrated circuit (IC).

(F) The circuit block configuration of the advance adjustment circuit 7 shown in FIG. 1 is a specific example, and is not limited to this. For example, the storage unit 74 may not necessarily be included in the spike voltage period determination unit 72 and may be independent as another circuit unit.
(G) The flowchart shown in FIG. 2 is a specific example, and is not limited to the processing of these steps. For example, other processing may be inserted between the steps.

(H) The predetermined reference time tz corresponding to each rotational speed of the motor 20 may be set to an appropriate value based on the theory and the actual measurement result and stored in the storage unit 74. Further, the upper limit value and the lower limit value of the reference time corresponding to each rotation speed of the motor 20 may be stored in the storage unit 74. The advance or retard limit value can be determined by the upper limit value / lower limit value of the reference time corresponding to each rotational speed of the motor 20.

1 Drive control device (an example of a motor drive control device)
2 Inverter circuit (part of motor drive)
3 Pre-drive circuit (part of motor drive)
4 Control Unit 5 Voltage Comparison Units 51 to 53 Comparator 6 Position Detection Circuit (Example of Position Detection Unit)
7 Advance adjustment circuit (an example of advance adjustment unit)
71 Spike Voltage Measurement Unit 72 Spike Voltage Period Determination Unit 73 Zero-Cross Reference Voltage Generation Unit 74 Storage Unit 8 Start Reference Voltage Generation Circuit 20 Motor (3-phase Brushless DC Motor)
Sin Rotational speed command signal S1, S2, S3 Phase signal (an example of position adjustment signal)
S4 Position detection signal S5 Drive control signal Lu, Lv, Lw Coils V1, V2, V3 Phase voltage Vcc Power supply voltage Vd DC power supply Vu, Vv, Vw Terminal voltage Vuu, Vul, Vvu, Vvl, Vwu, Vwl Drive signal Vz, Vzs, Vz1, Vz2 Zero cross reference voltage (an example of reference voltage)
ts spike voltage period tz predetermined reference time Q1-Q6 switching element

Claims (5)

A motor drive unit that receives power supply from a power source and rotates a rotor by supplying a drive current to each phase coil of the motor based on a drive control signal;
A voltage comparison unit that generates a position adjustment signal based on a comparison result between a terminal voltage of each phase coil and a reference voltage;
A position detection unit that outputs a position detection signal indicating the rotational position of the rotor based on the position adjustment signal;
A control unit that generates the drive control signal based on an externally input rotational speed command signal and the position detection signal;
Based on the position adjustment signal, the spike voltage period is measured at either the rising or falling time generated by energization switching in the inter-terminal voltage of each phase coil, and the spike voltage period is set to a predetermined predetermined value. An advance adjustment unit that generates the reference voltage for advance adjustment according to a comparison result with a reference time and outputs the reference voltage to the voltage comparison unit;
A motor drive control device comprising: The advance angle adjustment unit is
A spike voltage measurement unit that measures the spike voltage period based on the position adjustment signal;
Based on a comparison result between the spike voltage period and the predetermined reference time, a spike voltage period determination unit that generates setting information of the reference voltage;
A zero-cross reference voltage generation unit that generates the reference voltage based on the setting information;
The motor drive control device according to claim 1, comprising: The advance angle adjustment unit is
A storage unit for storing information on a period of spike voltage corresponding to a plurality of rotation speeds of the rotor as a comparison table;
Based on the comparison table, the predetermined reference time according to the rotational speed of the rotor is set.
The motor drive control device according to claim 1, wherein the motor drive control device is a motor drive control device. The advance angle adjustment unit is
The spike voltage period is compared with the predetermined reference time, and when the spike voltage period is larger than the predetermined reference time, an advance is made according to the magnitude, and the spike voltage period is the predetermined reference time. When the time is smaller than the time, the reference voltage is generated so as to delay according to the magnitude.
The motor drive control device according to claim 1, wherein the motor drive control device is a motor drive control device. The voltage comparison unit
For each phase, each is provided with a comparator that inputs a voltage between coil terminals and the reference voltage, and outputs the position adjustment signal based on the comparison result to the position detection unit and the advance angle adjustment unit.
The motor drive control device according to claim 1, wherein the motor drive control device is a motor drive control device.

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