JP5106484B2 - Variable power supply device, motor drive control device, and protection circuit operating method thereof - Google Patents

Description

  The present invention relates to a variable power supply device, a motor drive control device, and a protection circuit operating method thereof.

  Conventionally, a variable power source that can arbitrarily change the power supplied to the motor driving device according to the type of motor to be mounted, and a motor driving device driven by an arbitrary voltage or current are known. Such a variable power supply and motor drive device can cope with a wide range of voltages from several tens of volts to several hundreds of volts, for example.

  FIG. 10 is a block diagram illustrating the configuration of a conventional variable power supply 1000. In FIG. 10, the voltage supplied from the DC power supply 1001 is converted into a desired voltage value by a DC / DC converter 1040 formed of an insulating transformer or the like, and the converted desired voltage value is supplied to a load 1160.

  The output voltage detector 1070 that monitors the output voltage of the variable power supply 1000 feeds back the detected output voltage to the PWM controller 1080. Further, the output voltage detection unit 1070 outputs the detected output voltage to the protection circuit 1090 that performs overvoltage protection or undervoltage protection.

  The variable power supply 1000 includes a reference voltage generation unit 1110, and inputs the reference voltage generated by the reference voltage generation unit 1110 to the PWM control unit 1080 and the protection circuit 1090. That is, the variable power supply 1000 uses the voltage generated by the same reference voltage generation unit 1110 in the PWM control unit 1080 and the protection circuit 1090 as a reference.

  FIG. 11 is a block diagram for explaining the configuration of another conventional variable power supply 1100. In FIG. 11, the same parts as those in FIG. 10 are denoted by the same reference numerals. The variable power source 1100 uses a voltage generated by the microcomputer 1112 and the D / A converter 1111 as a reference voltage for the PWM control unit 1080 and the protection circuit 1090 as a reference voltage.

  The variable power supply 1000 is a common reference voltage generated by the reference voltage generation unit 1110, the variable power supply 1100 is a common reference voltage generated by the microcomputer 1112 and the D / A converter 1111, the PWM control unit 1080 and the protection circuit 1090. Used for. For this reason, in any case, if a failure occurs in the generation of the reference voltage, the power supply function is impaired and the protection circuit 1090 also does not function.

  If a circuit for generating the reference voltage for the protection circuit 1090 is provided separately from the circuit for generating the reference voltage for the PWM control unit 1080, not only the circuit configuration but also the interface and the like increase. As a result, the power supply as a whole becomes complicated and large.

  FIG. 12 is a conceptual diagram illustrating a conventional overvoltage protection circuit 1204. In FIG. 12, the overvoltage protection circuit 1204 includes a thyristor 1205, a Zener diode 1206, resistors 1207, 1208, 1209 and a capacitor 1204. The Zener diode 1206 becomes conductive when the output voltage rises above a predetermined voltage, and raises the gate voltage of the thyristor 1205 above the ON voltage.

  For this reason, the high voltage line and the ground are short-circuited via the thyristor 1205. When the secondary side is short-circuited, the drive pulse output from the output terminal of the PWM control IC (not shown) to the gate of the switching element is stopped, so that the primary side is blocked and protected. Such an overvoltage protection circuit 1204 is disclosed, for example, in Patent Document 1 below.

  Since the power supply device described above is based on the premise that a single fixed voltage is output, the gate-on voltage of a single Zener diode can be used as a reference voltage for operating the protection circuit.

JP 10-323038 A

  In the variable power supply apparatus in which the output voltage is changed depending on the connected load and application, it is necessary to reset the reference voltage for operating the protection circuit every time the output voltage is changed. In order to reset, it becomes necessary to perform a new adjustment work such as exchanging the Zener diode, which is a complicated work. Further, in order to store the reference voltages corresponding to a plurality of output voltages in advance, the amount of program storage to the microcomputer increases.

  The present invention has been made in view of such problems, and even when the output voltage of the variable power supply apparatus is changed, the circuit configuration is complicated and increased, and additional adjustment work is required in accordance with the output voltage change. An object of the present invention is to provide a variable power supply device or the like that can automatically acquire the reference voltage of the protection circuit without any problems.

  The variable power supply device of the present invention is a variable power supply device capable of outputting the first voltage and the second voltage to loads having different operating voltages. When the first reference voltage is acquired from the output, and the output is outside the predetermined range with respect to the acquired first reference voltage, the output of the first voltage is limited and the second voltage is output. A protection circuit unit that obtains the second reference voltage from the output of the variable power supply device and limits the output of the second voltage if the output is out of a predetermined range with respect to the obtained second reference voltage. It is characterized by that.

  In the variable power supply device of the present invention, it is preferable that the protection circuit unit obtains the first reference voltage after a predetermined time has elapsed from the start of the output of the first voltage, and the predetermined time from the start of the output of the second voltage. The second reference voltage is acquired after elapse of time.

  In the variable power supply device of the present invention, preferably, when the protection circuit section starts the output of the first voltage and the first voltage becomes the first target voltage corresponding to the load, the variable power supply device After obtaining the first reference voltage from the output and starting the output of the second voltage, if the second voltage becomes the second target voltage corresponding to the load, the second reference is obtained from the output of the variable power supply device. A voltage is acquired.

  In the variable power supply device of the present invention, it is preferable that the protection circuit unit obtains the first reference voltage or the second reference voltage when the load outputs a ready signal.

  In the variable power supply device of the present invention, it is preferable that the protection circuit unit obtains the first reference voltage or the second reference voltage when the load starts to operate.

  The motor drive control device according to the present invention is a motor drive control device that can operate at a first voltage and a second voltage with respect to different motors. The first reference voltage is acquired from the input to the device, and if the input is outside the predetermined range with respect to the acquired first reference voltage, the input of the first voltage is limited and the second voltage is operated. In this case, the second reference voltage is acquired from the input to the motor drive control device, and the input of the second voltage is limited if the input is out of the predetermined range with respect to the acquired second reference voltage. A protection circuit portion is provided.

  In the motor drive control device of the present invention, the protection circuit unit preferably acquires the first reference voltage or the second reference voltage when the motor drive control device is ready to indicate that the motor drive control device is ready. It is characterized by doing.

  The motor drive control device according to the present invention is preferably characterized in that the protection circuit unit acquires the first reference voltage or the second reference voltage when the motor drive control device starts a motor drive operation.

  A protection circuit operating method for a variable power supply apparatus according to the present invention is a protection circuit operating method for a variable power supply apparatus that can output different voltages to loads having different operating voltages. The voltage output is outside the predetermined range in the acquisition step, the protection circuit operation availability determination step for determining whether the voltage output is outside the predetermined range with respect to the acquired reference voltage, and the protection circuit operation availability determination step If so, it has a voltage output limiting step of limiting the output of the voltage.

  The protection circuit operating method of the motor drive control device according to the present invention is the protection circuit operating method of the motor drive control device capable of operating at different first and second voltages for different motors. When the first reference voltage is acquired from the input to the motor drive control device and the input is outside the predetermined range with respect to the acquired first reference voltage, the first voltage input is The second reference voltage is acquired from the input to the motor drive control device when operating at the step of limiting and the second voltage, and the input is outside a predetermined range with respect to the acquired second reference voltage. A step of restricting the input of the second voltage.

  Even if the output voltage of the variable power supply is changed, the variable power supply can automatically acquire the reference voltage of the protection circuit without complicating or increasing the circuit configuration or requiring adjustment work associated with the output voltage change. Etc. can be provided.

It is a block diagram which illustrates notionally the structure of the variable power supply device concerning 1st embodiment. It is a figure explaining the variation of a reference voltage production | generation part. It is a conceptual block diagram for demonstrating the function of a protection circuit part. It is a block diagram which illustrates notionally the protection circuit part concerning 2nd embodiment. It is a block diagram which illustrates notionally the protection circuit part concerning 3rd embodiment. It is a block diagram which illustrates notionally the protection circuit part concerning 4th embodiment. It is a block diagram which illustrates notionally the motor drive control apparatus connected to the variable power supply device concerning 5th embodiment. FIG. 8A is a diagram for explaining the rated input of the load connected to the maximum output of the variable power supply device, and FIG. 8B is a diagram after a predetermined time T ₁ after the variable power supply device starts output. a drawing reference voltage acquisition unit is conceptually explaining a state of obtaining a reference voltage, FIG. 8 (c) are diagrams for explaining the timing T ₂ for outputting a trigger reference voltage acquisition unit comparison unit, FIG. 8 (d) is triggered by a reference voltage acquisition unit is ready signal is a diagram for explaining the timing T ₃ to obtain the output voltage of the variable power supply as the reference voltage from the output terminal or the like. It is a block diagram which illustrates notionally the circuit structure of a variable power supply device. It is a block diagram explaining the structure of the conventional variable power supply. It is a block diagram explaining the structure of the other conventional variable power supply. It is a conceptual diagram explaining the conventional overvoltage protection circuit. It is a figure which illustrates the motor drive which can be connected as load.

  The variable power supply apparatus described in the embodiment is a power supply apparatus that can change an output voltage from, for example, 100 volts to 800 volts in accordance with a load that supplies a voltage. In addition, the variable power supply device includes a protection circuit that detects at least one of overvoltage, low voltage, overcurrent, and low current and restricts power supply and the like.

  If the actual output voltage differs by, for example, 20% or more from the target voltage (corresponding to the set voltage to PWM) that the variable power supply device should output, the protection circuit determines that it is abnormal and shuts off the power supply. Let That is, when the variable power supply device outputs 100 volts as the target voltage, if the actual voltage output exceeds 120 volts, the protection circuit determines that the overvoltage is abnormal and cuts off the power supply. When the actual voltage output is less than 80 volts, the protection circuit determines that the low voltage is abnormal and cuts off the power supply.

  Further, when the variable power supply device outputs 600 volts as the target voltage, if the actual voltage output exceeds 720 volts, the protection circuit determines that the overvoltage is abnormal and cuts off the power supply. When the actual voltage output is lower than 480 volts, the protection circuit determines that the low voltage is abnormal and interrupts the power supply.

  As described above, the protection circuit monitors the output voltage with the allowable voltage ranges of 80 volts to 120 volts and 480 volts to 720 volts corresponding to the target output voltages of 100 volts and 600 volts of the variable power supply as normal ranges.

  The protection circuit described in the embodiment acquires the reference voltage (for example, target output voltage 100 volts, 600 volts) when calculating the allowable voltage range from the output of the variable power supply device, so the output of the variable power supply device has been changed. Even in this case, it is not necessary to change the reference voltage. Further, since the protection circuit does not use the reference voltage generation unit that supplies the reference voltage to the PWM included in the variable power supply device, the circuit configuration of the variable power supply device is not complicated or increased.

  In addition, since the protection circuit automatically takes in the new reference voltage that has been changed due to the change in the output voltage from the output of the variable power supply device, for example, replacement of a Zener diode that determines the operating voltage of the protection circuit for the protection circuit, etc. Do not need. Further, since the protection circuit automatically takes in a new reference voltage, it does not require additional writing processing such as programming (for example, correspondence storage of the protection circuit operation range for each output voltage, arithmetic processing program, etc.).

(First embodiment)
FIG. 1 is a block diagram conceptually illustrating the configuration of the variable power supply apparatus 100 according to the first embodiment. As shown in FIG. 1, the variable power supply apparatus 100 includes an input terminal 110 to which a commercial AC power supply is connected, rectifier diodes 121, 122, 123, and 124, and a smoothing capacitor 130.

  The variable power supply apparatus 100 includes a DC / DC converter 140 configured with an insulation transformer or the like. The variable power supply apparatus 100 includes a first voltage detection unit 160 and a second voltage detection unit 170 that detect an output voltage between the output terminals 150 that output the instructed target voltage. For convenience of explanation, the variable power supply device 100 includes the first voltage detection unit 160 and the second voltage detection unit 170 separately, but the first voltage detection unit 160 and the second voltage detection unit 170 are provided separately. A single voltage detection unit may be used, and any one of the outputs may be shared.

  In addition, the variable power supply apparatus 100 includes a reference voltage generation unit 1a0. The reference voltage generated by the reference voltage generation unit 1a0 is input to the PWM 180 as a voltage instruction value indicating the target voltage of the variable power supply device 100.

  The output voltage detected by the first voltage detector 160 is fed back to the PWM 180 that controls to change the output voltage. The PWM 180 appropriately adjusts the pulse width so that the output voltage becomes the target voltage instructed from the reference voltage generation unit 1a0.

  In addition, the protection circuit unit 190 monitors the output voltage of the variable power supply device 100 detected by the second voltage detection unit 170 and detects at least one of overvoltage, low voltage, overcurrent, and low current. Then, the operation of the PWM 180 is stopped or the like, and the power output of the variable power supply device 100 is cut or restricted.

  In addition, the protection circuit unit 190 acquires a reference voltage for determining whether the voltage is an overvoltage or the like at a predetermined timing from the output voltage of the variable power supply device 100 detected by the second voltage detection unit 170. Therefore, in the variable power supply device 100, it is not necessary to use the reference voltage generation unit 1a0 as the reference voltage of the protection circuit unit 190, and the output voltage from the variable power supply device 100 is automatically used as the reference voltage of the protection circuit unit 190. Available.

  For example, if the target output of the variable power supply apparatus 100 is 100 volts, the protection circuit unit 190 can use 100 volts as a reference voltage. For example, if the upper and lower sides of the reference voltage are 20%, that is, if the output voltage of the variable power supply device 100 is between 80 volts and 120 volts, it is determined that the output voltage range is normal. Moreover, if the target output of the variable power supply apparatus 100 is 600 volts, the protection circuit unit 190 can set 600 volts as the reference voltage, for example. For example, if the upper and lower 20% of the reference voltage, that is, if the output voltage of the variable power supply device 100 is between 480 volts and 720 volts, it is determined that the output voltage range is normal.

  FIG. 2 is a diagram for explaining a variation of the reference voltage generator 1a0 shown in FIG. As shown in FIG. 2A, the reference voltage generator 1a0 can generate a reference voltage by D / A converting the output of the microcomputer. Further, as shown in FIG. 2B, the reference voltage generator 1a0 may D / A convert the output of the controller and generate a reference voltage by external digital control.

  The reference voltage generator 1a0 may generate a reference voltage by external analog control as shown in FIG. 2 (c), and a reference voltage variable resistor may be used as shown in FIG. 2 (d). A voltage may be generated.

  FIG. 3 is a conceptual block diagram for explaining the function of the protection circuit unit 190. In FIG. 3, the protection circuit unit 190 acquires a reference voltage at a predetermined timing from the output voltage of the variable power supply device 100 acquired directly from the output terminal 150 or via the second voltage detection unit 170. Is provided.

Here, the predetermined timing at which the reference voltage acquisition unit 340 acquires the reference voltage from the output voltage may be, for example, a predetermined time after the variable power supply device 100 starts outputting the output voltage. 8 (b) is a diagram variable power supply 100 after a predetermined time T ₁ from the start of the output voltage, conceptually illustrating a state where the reference voltage acquisition unit 340 acquires a reference voltage.

8 (b), the predetermined time T _1, the voltage starts to output it is preferable that a time enough to end the transient state, typically several hundred milliseconds than 1 second. When the reference voltage acquisition unit 340 acquires the reference voltage after a predetermined time T ₁ after the variable power supply device 100 starts outputting the voltage, the output restriction enable / disable determination unit 330 causes the reference voltage acquisition unit 340 to acquire the reference voltage ( Typically, for example, 120% voltage is set to OVA voltage (overvoltage protection voltage) and 80% voltage is set to UVA voltage (low voltage protection voltage). ) To determine whether or not the protection operation is possible, that is, whether there is an abnormality.

FIG. 8A is a diagram for explaining operation inputs 820 and 830 of a connected load with respect to the maximum output 810 of the variable power supply apparatus 100. As shown in FIG. 8 (a), the variable power supply device 100 does not always output the maximum output 810, but supplies necessary operating power (the operation input 820 or the operation input 830) corresponding to the connected load to the load. To do. In the case of a load that operates with the operation input 820, the variable power supply device 100 sets the target output to the voltage V ₂ , so that a voltage instruction value corresponding to the voltage V ₂ is instructed to the PWM 180.

In this case, the protection circuit unit 190, the variable power supply apparatus 100 starts to output the voltage after a predetermined time T _1, acquires the output voltage as the reference voltage, the reference voltage (typically to a voltage V ₂ is) For example, when an output voltage exceeding a range of 20% above and below is detected, the protection circuit unit 190 determines that the output is abnormal.

In the case of a load that operates with the operation input 830, the variable power supply device 100 sets the target output to the voltage V ₁ , so that a voltage instruction value corresponding to the voltage V ₁ is instructed to the PWM 180.

In this case, the protection circuit unit 190 acquires the output voltage as a reference voltage after a predetermined time T ₁ after the variable power supply device 100 starts output, and uses the reference voltage (typically, the voltage V ₁ ). For example, when an output voltage exceeding the upper and lower 20% ranges is detected as a reference, the protection circuit unit 190 determines that the output is abnormal. Thereby, the protection circuit unit 190 can stably acquire the reference voltage corresponding to the actual output voltage without being affected by the transient state.

  The predetermined timing at which the reference voltage acquisition unit 340 acquires the reference voltage is, for example, after the variable power supply device 100 starts outputting the voltage, the output voltage becomes the target output (corresponding to the voltage setting value or the voltage instruction value). It is also possible to reach it.

  The predetermined timing at which the reference voltage acquisition unit 340 acquires the reference voltage may be, for example, when the startup process of the motor drive control device connected to the variable power supply device 100 is completed. Further, the predetermined timing at which the reference voltage acquisition unit 340 acquires the reference voltage may be, for example, when the motor drive control device connected to the variable power supply device 100 starts driving the motor.

  In addition, the protection circuit unit 190 outputs an output restriction from the output voltage of the variable power supply device 100 acquired directly from the output terminal 150 or via the second voltage detection unit 170 and the reference voltage acquired by the reference voltage acquisition unit 340. An output restriction enable / disable determining unit 330 that determines whether or not to start the protection operation is provided.

  As described above, the output restriction availability determination unit 330 starts the protection operation when a voltage output of the variable power supply apparatus 100 that exceeds, for example, a range of 20% above and below the reference voltage acquired by the reference voltage acquisition unit 340 is detected. I can do it. When the abnormality of the voltage output is detected, the output restriction availability determination unit 330 notifies the output restriction unit 310 that the protection operation is started. Further, the output limiting unit 310 outputs an instruction (or trigger) to stop pulse driving to the PWM 180.

  Receiving the instruction to stop the pulse drive, the PWM 180 stops the pulse drive so that the variable power supply apparatus 100 outputs the voltage instruction value (target output). In this case, the PWM 180 is not limited to stopping the pulse drive, and the pulse is driven so that the variable power supply apparatus 100 outputs a relatively safe voltage (for example, 10% of the voltage instruction value) smaller than the voltage instruction value. Also good.

(Second embodiment)
In the second embodiment, the variable power supply device 100 including the protection circuit unit 190 (2) that acquires the reference voltage at the timing when the voltage output of the variable power supply device 100 becomes the voltage instruction value to the PWM 180, that is, the target output. explain.

  FIG. 4 is a block diagram conceptually illustrating the protection circuit unit 190 (2) according to the second embodiment.

  In FIG. 4, portions corresponding to those in FIG. 3 are denoted by corresponding reference numerals, and description thereof is omitted here in order to avoid duplication of description. The protection circuit unit 190 (2) includes a comparison unit 410 that compares the voltage instruction value to the PWM 180 with the output voltage of the variable power supply device 100 acquired from the output terminal 150 or the like.

  When the output voltage reaches the voltage instruction value (that is, the target output), the comparison unit 410 outputs a trigger to the reference voltage acquisition unit 340 (2). When a trigger is input from the comparison unit 410, the reference voltage acquisition unit 340 (2) acquires an actual output voltage as a reference voltage from the output terminal 150 or the like.

Figure 8 (c) is a diagram comparing unit 410 will be described timing _{T 2} for outputting a trigger reference voltage acquisition unit 340 (2). As shown in FIG. 8 (c), the timing _{T 2} which outputs a trigger to the comparison unit 410 is the reference voltage acquisition unit 340 (2), the rising output voltage of the variable power supply 100, configured set voltage to PWM180 ( Vset) is reached.

If, when the rise of the output voltage of the variable power supply 100 is unstable by transients and the like, it is preferable to when it reaches the stable set voltage (Vset) and the acquisition timing T ₂ of the reference voltage. Note that the set voltage (Vset) to the PWM 180 is a voltage instruction value for instructing a target output to be precise, but will be described as being the same as the target output in the following description.

(Third embodiment)
In the third embodiment, the variable power supply device 100 including the protection circuit unit 190 (3) that acquires the reference voltage at a timing when a load connected to the variable power supply device 100 outputs a ready signal will be described.

  FIG. 5 is a block diagram conceptually illustrating the protection circuit unit 190 (3) according to the third embodiment. A load (not shown) connected to the variable power supply apparatus 100 can be, for example, a motor drive circuit. A load such as a motor driving circuit outputs a ready signal when voltage is supplied from the variable power supply device 100 and the motor is ready to be driven.

  In FIG. 5, portions corresponding to those in FIG. 3 are denoted by corresponding reference numerals, and description thereof is omitted here in order to avoid duplication of description.

  When a ready signal is input from a load (not shown), the reference voltage acquisition unit 340 (3) acquires the output voltage of the variable power supply device 100 as a reference voltage from the output terminal 150 or the like using the ready signal as a trigger.

FIG. 8 (d) is the reference voltage acquisition unit 340 (3), is a diagram for explaining a trigger ready signal, the timing T ₃ to obtain the output voltage of the variable power supply 100 as a reference voltage from the output terminal 150, etc. . As shown in FIG. 8 (d), the timing T ₃ by the reference voltage acquisition unit 340 (3) to obtain an output voltage of the variable power supply 100 as a reference voltage, after the output voltage of the variable power supply 100 rises, the load It is when the device itself is ready for operation. As a result, the protection circuit unit 190 (3) can use the output voltage applied to the load in the standby state as the reference voltage.

(Fourth embodiment)
In the fourth embodiment, a variable power supply device 100 including a protection circuit unit 190 (4) that acquires a reference voltage at a timing when a load connected to the variable power supply device 100 starts operating will be described.

  FIG. 6 is a block diagram conceptually illustrating the protection circuit unit 190 (4) according to the fourth embodiment. The load 660 connected to the variable power supply apparatus 100 can be a motor drive circuit, for example. The load 660 such as a motor drive circuit notifies the reference voltage acquisition unit 340 (4) that the operation is started when the operation is started after being ready. When the load 660 operates based on an external on signal instructing the start of operation, the reference voltage acquisition unit 340 (4) may directly receive an external on signal instructing the start of operation. Good.

  In FIG. 6, portions corresponding to those in FIG. 3 are denoted by corresponding reference numerals, and description thereof is omitted here in order to avoid duplication of description.

  When an ON signal is input from the load 660, the reference voltage acquisition unit 340 (4) acquires the output voltage of the variable power supply apparatus 100 from the output terminal 150 or the like as a reference voltage using the ON signal as a trigger.

FIG. 8 (d) is the reference voltage acquisition unit 340 (4) is triggered by the ON signal, describes a timing T ₄ be obtained as the reference voltage the output voltage of the variable power supply 100 from the output terminal 150 and the like. As shown in FIG. 8 (d), the timing T ₄ by the reference voltage acquisition unit 340 (4) obtains an output voltage of the variable power supply 100 as a reference voltage, after the operation preparation of the load itself has been completed, operation of the load It is time to start. As a result, the protection circuit unit 190 (4) captures the actual output voltage as the reference voltage almost simultaneously with the start of the operation of the load 660. Therefore, whether or not the output voltage has become abnormal thereafter is determined based on the captured reference voltage. It becomes possible to judge accurately.

(Fifth embodiment)
FIG. 7 is a block diagram conceptually illustrating a motor drive control device 700 connected to the variable power supply device 7100 according to the fifth embodiment. In FIG. 7, parts corresponding to those of the variable power supply device 100 shown in FIG. 1 are denoted by the corresponding reference numerals, and description thereof is omitted here to avoid duplication of explanation.

  The motor drive control device 700 connected to the variable power supply device 7100 is driven at a desired voltage corresponding to the characteristics of the motor to be driven, for example, from a wide range of voltages of 100 to 800 volts. In addition, the variable power supply device 7100 supplies a desired voltage corresponding to the characteristics of the motor to be driven to the motor drive control device 700 from a wide range of voltages, for example, 100 volts to 800 volts.

  The motor drive control device 700 includes a protection circuit unit 790 that blocks or reduces the voltage input if there is an abnormality in the voltage input from the variable power supply device 7100. In FIG. 7, the protection circuit unit 790 is illustrated as a configuration that blocks voltage output with respect to the PWM 180 of the variable power supply device 7100. However, the present invention is not limited to this, and the protection circuit unit 790 may be configured to block the voltage input to the motor drive circuit 710 by, for example, a disconnect switch or the like. Further, when there is an abnormality, it is possible to send an alarm signal to the outside.

The motor drive control device 700 includes a second voltage detection unit 770 that detects an input voltage, and the protection circuit unit 790 monitors the detected input voltage. The protection circuit unit 790, a motor drive circuit 710 obtains a reference voltage at the drive-on, i.e. the timing for starting the motor drive (corresponding to the timing T ₄ described above).

The protection circuit unit 790, the motor driving circuit 710 is ready, i.e. may obtain the reference voltage at the ready timing of starting a motor drive (corresponding to the timing T ₃ described above). The motor drive control device 700 accurately determines an abnormality such as an input voltage and blocks the input. In other words, the motor drive control device 700 can block the input to the motor drive control device 700 itself with little influence on other loads even when other loads are connected in parallel to the power source. .

  Next, the configuration of the variable power supply device 9000 that can additionally include the protection circuit unit 190 and the like described in the above embodiments will be briefly described. FIG. 9 is a block diagram conceptually illustrating the circuit configuration of the variable power supply device 9000.

  As shown in FIG. 9, the variable power supply device 9000 includes a current detection resistor Ri, a transistor Tr91, a freewheeling diode D95, a choke coil L91, a load 960, an output voltage detection circuit 910, an output current detection circuit 920, A PWM control circuit 930, a selection circuit 940, and a control circuit 950 are provided.

  The commercial frequency power supply 111 connected to the power supply input terminal 110 is rectified by a rectifier bridge (rectifier diodes 121 to 124), smoothed by a smoothing capacitor 130, and supplied to the collector of the transistor Tr91.

  The AC output generated at the emitter due to the on / off of the transistor Tr91 is smoothed by a smoothing circuit composed of the choke coil L91 and the capacitor C92, and is supplied to the load 960 via the current detection resistor Ri. That is, on / off of power supply to the load is controlled by the control circuit 950.

  When the control signal for turning on or off the power supply to the load is output to the PWM control circuit 930 by the control circuit 950, the PWM control circuit 930 detects the detection signal (feedback detection) from the output current detection circuit 920 and the output voltage detection circuit 910. ), The transistor Tr91 is turned on only during the period indicated. When the transistor Tr91 is turned on, a current flows through the circuit, a potential difference is generated between both ends of the current detection resistor Ri, and the value is input to the output current detection circuit 920. The voltage V supplied to the load 960 is divided by resistors R91 and R92 and input to the output voltage detection circuit 910.

  When the current value and the voltage value are detected by the output current detection circuit 920 and the output voltage detection circuit 910, detection signals corresponding to the respective values are generated and output to the selection circuit 940. The selection circuit 940 determines the priority of detection signals output from the output current detection circuit 920 and the output voltage detection circuit 910 to be input to the PWM control circuit 930 depending on the level of the voltage level. Is done.

  For example, by setting the voltage level of the output current detection signal to be higher than the voltage level of the output voltage detection signal in advance, the detection signal from the output current detection circuit 920 is prioritized, and the variable power supply device 9000 has a constant current. Take control. Thereafter, when the resistance value of the load 960 becomes stable as the temperature rises, the current value becomes relatively low. Therefore, in the PWM control circuit 930, the duty is restricted and the output value is higher than the voltage value output from the output current detection circuit 920. The voltage value output from the voltage detection circuit 910 becomes larger, and the control may be a control for shifting to the constant voltage control.

  The above-described operation of the variable power supply device 9000 is performed every pulse, that is, every time the transistor Tr91 is turned on. As a result, the inrush current to the load 960 is limited by the constant current control, and thereafter, the control shifts to the constant voltage control in a short time, and the stable control of the power supplied to the load 960 becomes possible.

  Further, the output voltage detection circuit 910 and the output current detection circuit 920 are configured to be able to change the reference voltage value to be compared by the differential amplifier as shown in FIG. For this reason, the PWM control circuit 930 can appropriately adjust the pulse width and appropriately change the output voltage and output current of the variable power supply device 9000 corresponding to the load 960.

  FIG. 13 is a diagram illustrating a motor driver that can be connected as loads 660, 960, 1160 and a motor drive circuit 710. FIG. 13A illustrates a motor driver that performs single-layer bipolar driving, and FIG. 13B illustrates a motor driver that drives a three-phase brushless motor. The three-phase brushless motor driver shown in FIG. 13B can rotate the motor at a speed synchronized with the switching cycle of each transistor, similarly to the three-phase synchronous motor.

  The variable power supply device 9000 can apply the above-described first to fifth embodiments.

  In addition, the variable power supply device and the motor drive control device described in the embodiment save the trouble of resetting the reference voltage of the protection circuit every time the output voltage of the power supply is changed, and the reference corresponding to the changed output voltage. Get voltage automatically.

  For this reason, it is not necessary to separately provide a voltage generation unit for generating the reference voltage of the protection circuit, and a simple and lightweight circuit configuration can be provided, and an increase in interface can be suppressed. Further, adjustment maintenance and program change for changing the reference voltage of the protection circuit are not required, and it is not necessary to store or calculate the reference voltage corresponding to the load in advance. For this reason, it is possible to suppress an increase in the amount of program written to the microcomputer. The protection circuit of each embodiment only needs to temporarily store the acquired reference voltage only while power is supplied to the load (that is, only while the protection function is enabled for the load). .

  In addition, since each variable power supply device described in the embodiment separately obtains the reference voltage of the protection circuit separately from the PWM reference voltage, it can be used when a failure occurs in the reference voltage created inside the power supply device. Even when either the microcomputer to be generated or the D / A converter fails, it is possible to avoid losing the function of the protection circuit.

  In each of the above-described embodiments, the example in which the protection circuit monitors overvoltage has been described. However, the present invention is not limited to this, and any one or more of overvoltage, overcurrent, low voltage, and low current is monitored and there is an abnormality. In some cases, the protection circuit can exhibit a protection function.

  The present invention is not limited to the description in each of the above-described embodiments, and the configuration of each variable power supply device and motor drive control device may be appropriately changed within a self-evident range. The operation process can be changed as appropriate.

  The present invention can be widely used for an output variable power supply device including an overvoltage protection circuit, a low voltage protection circuit, and the like.

  100 ... Variable power supply device 110 ... Power input terminal 121-124 ... Rectifier diode 130 ... Power input terminal 140 ... DC / DC converter 150 ... Output terminal 160 ... First voltage detection 170, second voltage detection unit, 180, PWM, 190, protection circuit unit, 1a0, reference voltage generation unit.

Claims (10)

In a variable power supply device capable of outputting a first voltage and a second voltage to loads having different operating voltages,
When outputting the first voltage, the first reference voltage is acquired from the output of the variable power supply device, and if the output is out of a predetermined range with respect to the acquired first reference voltage, Limit the output of the first voltage,
When outputting the second voltage, the second reference voltage is acquired from the output of the variable power supply device, and if the output is out of a predetermined range with respect to the acquired second reference voltage, A variable power supply apparatus comprising: a protection circuit unit that limits output of the second voltage. The variable power supply device according to claim 1,
The protection circuit unit acquires the first reference voltage after a predetermined time has elapsed from the start of output of the first voltage, and the second reference after the elapse of the predetermined time from the start of output of the second voltage. A variable power supply device characterized by acquiring a voltage. The variable power supply device according to claim 1,
When the first voltage reaches a first target voltage corresponding to the load after the output of the first voltage is started, the protection circuit unit receives the first reference from the output of the variable power supply device. After obtaining the voltage and starting the output of the second voltage, when the second voltage becomes a second target voltage corresponding to the load, the second reference voltage is output from the output of the variable power supply device The variable power supply device characterized by acquiring. The variable power supply device according to claim 1,
The variable power supply device, wherein the protection circuit unit acquires the first reference voltage or the second reference voltage when the load outputs a ready signal. The variable power supply device according to claim 1,
The protection circuit unit acquires the first reference voltage or the second reference voltage when the load starts to operate. The variable power supply device, wherein: In a motor drive control device capable of operating with a first voltage and a second voltage for different motors,
When operating at the first voltage, if the first reference voltage is acquired from the input to the motor drive control device, and the input is outside a predetermined range with respect to the acquired first reference voltage Limit the input of the first voltage,
When operating at the second voltage, if the second reference voltage is acquired from the input to the motor drive control device, and the input is outside a predetermined range with respect to the acquired second reference voltage A motor drive control device comprising: a protection circuit unit that limits input of the second voltage. In the motor drive control device according to claim 6,
The protection circuit unit acquires the first reference voltage or the second reference voltage when the motor drive control device is in a ready state indicating that the motor drive preparation is ready. Motor drive control device. In the motor drive control device according to claim 6,
The motor drive control device, wherein the protection circuit unit acquires the first reference voltage or the second reference voltage when the motor drive control device starts a motor drive operation. In a protection circuit operating method of a variable power supply device capable of outputting different voltages to loads having different operating voltages,
A reference voltage acquisition step of acquiring a reference voltage from the output of the voltage;
A protection circuit operation availability determination step for determining whether the output of the voltage is outside a predetermined range with respect to the acquired reference voltage;
And a voltage output limiting step of limiting the output of the voltage if the output of the voltage is outside the predetermined range in the step of determining whether or not the protection circuit can be operated. . In the protection circuit operating method of the motor drive control device operable with the first voltage and the second voltage respectively for different motors,
When operating at the first voltage, the first reference voltage is acquired from the input to the motor drive control device, and if the input is outside a predetermined range with respect to the acquired first reference voltage Limiting the input of the first voltage;
When operating at the second voltage, a second reference voltage is acquired from an input to the motor drive control device, and the input is outside a predetermined range with respect to the acquired second reference voltage. And a step of restricting the input of the second voltage. A method for operating a protection circuit of a motor drive control device.

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