Power supply device

Abstract

To provide a power supply that can reuse regenerated power generated in an inductive load and increase energy saving effects.SOLUTION: A power supply 1 includes: a DC-converted unit 10 that rectifies and smoothes an AC power supply AC; a power factor improvement unit 20 that inputs an applied voltage applied to a capacitor 15 as an input voltage Va and improves a power factor; and a control unit 40 that controls a power factor improvement operation by the power factor improvement unit 20 on the basis of a target output voltage Vt which is a target value of an output voltage of the power factor improvement unit 20 and the input voltage Va, wherein a regenerative voltage Vc from a motor drive device 100 is regenerated into the capacitor 15.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a power supply device.

Background Art

[0002] In recent years, industrial robots and the like that operate arms and the like by controlling the rotation and stop of motors have become widely popular. When control is performed to decelerate and stop a motor mounted on such an industrial robot, regenerative power is generated due to the inertial rotation of the motor and the generated power is returned to the motor drive power supply unit, and the voltage of the motor drive power supply unit may increase. When the voltage of the motor drive power supply unit rises above a certain value, the motor drive power supply unit may detect it as an abnormal voltage and stop operating to protect the circuit. Therefore, a technique has been proposed in which a regenerative power discharge resistor is provided in the motor drive power supply, and the generated regenerative power is discharged by the regenerative power discharge resistor and consumed as heat, thereby suppressing an increase in the voltage of the motor drive power supply unit (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the invention described in Patent Document 1, since the regenerative power generated in the motor is consumed as heat, the generated electric energy cannot be effectively utilized.

[0005] Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a power supply device that can reuse regenerative power generated in an inductive load and enhance an energy saving effect. [Means for solving the problem]

[0006] Embodiment 1; One or more embodiments of the present invention propose a power supply device that converts an AC voltage supplied from an AC power source into a DC voltage and uses the DC voltage to drive an inductive load, comprising: a DC conversion unit that rectifies the AC voltage with a rectifier diode and smooths it with a capacitor; a power factor correction unit that receives the applied voltage applied to the capacitor as an input voltage and improves the power factor; and a control unit that controls the power factor correction operation by the power factor correction unit based on a target output voltage which is a target value of the output voltage of the power factor correction unit and the input voltage, and regenerates the regenerative voltage from the inductive load to the capacitor. In this configuration, the power factor correction unit receives the output voltage of the DC conversion unit and the regenerative voltage from the inductive load as input. If the regenerative voltage is regenerated after the power factor correction unit (for example, at the output capacitor of the stage after the power factor correction unit), the regenerative power cannot be reused if the regenerative voltage is lower than the output voltage of the power factor correction unit. However, according to the present invention, since the regenerative voltage is input to the power factor correction unit, the regenerative power generated in the inductive load can be reused as a power supply source for the power supply device. Therefore, it is possible to reduce the amount of power supplied from the AC power source, thereby increasing energy-saving effects.

[0007] Embodiment 2; One or more embodiments of the present invention propose a power supply device in which, when the regenerative voltage is greater than the output voltage of the DC conversion unit, the control unit performs control to start the power factor correction operation if the regenerative voltage is less than the target output voltage, and performs control to stop the power factor correction operation if the regenerative voltage is equal to or greater than the target output voltage. This allows the regenerative power generated in an inductive load to be reused as a power source for the power supply unit. Therefore, it is possible to reduce the amount of power supplied from the AC power source, thereby increasing energy-saving effects. [Effects of the Invention]

[0008] According to the present invention, regenerative power generated in an inductive load can be reused, thereby enhancing energy-saving effects. [Brief explanation of the drawing]

[0009] [Figure 1] This is a configuration diagram of a power supply device according to an embodiment of the present invention. [Figure 2] This figure shows the circuit configuration of a power supply device according to an embodiment of the present invention. [Figure 3] This figure shows the input voltage to the power factor correction unit of the power supply device according to an embodiment of the present invention, and the operation of the control unit. [Figure 4] This diagram shows the flow of the control unit of the power supply device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0010] <Embodiment> The power supply device 1 according to this embodiment will be described with reference to Figures 1 to 4.

[0011] <Configuration of Power Supply Unit 1> As shown in Figure 1, the power supply device 1 according to this embodiment is configured to include a DC conversion unit 10, a power factor correction unit 20, a DC / DC converter unit 30, and a control unit 40. The output of power supply unit 1 is supplied to motor drive unit 100. Further details of the motor drive unit 100 will be described later.

[0012] (Configuration of the DC conversion unit 10) The DC conversion unit 10 rectifies the AC voltage using a rectifier diode and smooths it using a capacitor. Specifically, the AC voltage supplied from the AC power source is full-wave rectified, and the resulting voltage is smoothed to convert it into a DC voltage. As shown in Figure 2, the DC conversion unit 10 is composed of rectifier diodes 11 to 14 and a capacitor 15. One end of the AC power supply AC is connected to the anode electrode of the rectifying diode 11 and the cathode electrode of the rectifying diode 12, and the other end of the AC power supply AC is connected to the anode electrode of the rectifying diode 13 and the cathode electrode of the rectifying diode 14. The cathode electrode of the rectifying diode 11 and the cathode electrode of the rectifying diode 13 are connected. Also, the anode electrode of the rectifying diode 12 and the anode electrode of the rectifying diode 14 are connected to the ground. That is, the rectifying diodes 11 to 14 form a bridge circuit, and the AC voltage supplied from the AC power supply AC is full-wave rectified. Note that the DC conversion unit 10 is supplied with power of, for example, an AC voltage of 200V from the AC power supply AC. One end of the capacitor 15 is connected to the cathode electrode of the rectifying diode 11 and the cathode electrode of the rectifying diode 13, and the other end of the capacitor 15 is connected to the ground. That is, the voltage full-wave rectified in the above-mentioned bridge circuit is smoothed by being connected to the capacitor 15 and converted into a DC voltage. For example, a film capacitor is used for the capacitor 15. The output voltage of the DC conversion unit 10 converted into a DC voltage is input to the power factor improvement unit 20.

[0013] (Configuration of the power factor improvement unit 20) The power factor improvement unit 20 is connected to the output side of the DC conversion unit 10, takes the applied voltage applied to the capacitor 15 as an input voltage, and improves the power factor. The power factor improvement unit 20 is constituted by a boost switching power supply. The power factor improvement unit 20 boosts the input voltage Va applied to the capacitor 15 of the DC conversion unit 10 to the target output voltage Vt. As shown in FIG. 2, the power factor improvement unit 20 is configured to include at least a coil 21, a diode 22, a transistor 23, and a capacitor 24. One end of the coil 21 is connected to one end of the capacitor 15 of the DC conversion unit 10, and the other end of the coil 21 is connected to the anode electrode of the diode 22 and the drain electrode of the transistor 23. The source electrode of transistor 23 is connected to ground, and the gate electrode of transistor 23 is connected to the control unit 40, which will be described later. Here, a metal-oxide-semiconductor field-effect transistor (MOSFET) can be used as an example of transistor 23. The cathode electrode of diode 22 is connected to one end of capacitor 24. The other end of capacitor 24 is connected to ground. The output voltage Vb of the power factor correction unit 20 is input to the DC / DC converter unit 30.

[0014] (Configuration of DC / DC converter section 30) The DC / DC converter unit 30 is configured, for example, by an isolated DC / DC converter circuit, and converts the output voltage Vb supplied from the power factor correction unit 20 into DC / DC to supply stable power to the motor drive device 100.

[0015] (Configuration of the control unit 40) The control unit 40 is composed of, for example, a microcontroller or a dedicated IC, and controls the output voltage of the power factor correction unit 20 by controlling the on / off state of the transistor 23. Specifically, the control unit 40 controls the output voltage Vb at point B shown in Figure 2 and the target output voltage Vt of the power factor correction unit 20 to be the same value. More specifically, the control unit 40 acquires the value of the output voltage Vb and controls the timing of turning the transistor 23 of the power factor correction unit 20 on and off based on the voltage difference with the target output voltage Vt. Here, the target output voltage Vt of the power factor correction unit 20 described above is set to, for example, 300V. Details regarding the control of the control unit 40 will be described later.

[0016] (Configuration of the motor drive unit 100) The motor drive unit 100 is configured to include at least a regenerative voltage generation unit 110 and a motor 120. The motor drive device 100 is, for example, an industrial robot, and is a device that drives an inductive load, which is a motor 120, using power supplied from a power supply device 1, to operate the robot's arm or the like. Motor 120 is DC driven. The regenerative voltage generation unit 110 generates a regenerative voltage Vc from the regenerative power generated in the motor 120 and supplies this regenerative voltage to the power supply unit 1. Specifically, the regenerative voltage generation unit 110 generates a regenerative voltage Vc from the regenerative power generated when the motor 120 decelerates or stops, and supplies it to the power supply unit 1. The regenerative voltage Vc (point C in Figure 2) generated by the regenerative voltage generation unit 110 is connected to one end of the capacitor 15 (point A in Figure 2) via the diode 50.

[0017] (Regarding the value of the input voltage Va) Using Figure 3, the input voltage Va supplied to the power factor correction unit 20 will be explained. The input voltage Va of the power supply unit 1 to which the motor drive unit 100 is connected (the voltage value at point A in Figure 2) is determined by the output voltage value of the DC conversion unit 10 and the regenerative voltage Vc supplied from the regenerative voltage generation unit 110. If the regenerative voltage Vc is less than the output voltage of the DC conversion unit 10 (for example, 200V), the output voltage of the DC conversion unit 10 becomes the input voltage Va. In other words, if the regenerative voltage Vc is smaller than the output voltage of the DC conversion unit 10, the power supply unit 1 operates by receiving power from the AC power supply. On the other hand, if the regenerative voltage Vc is greater than the output voltage of the DC conversion unit 10, the regenerative voltage Vc becomes the input voltage Va. In other words, if the regenerative voltage Vc is greater than the output voltage of the DC conversion unit 10, the power supply unit 1 operates by receiving power from the regenerative power generated in the motor 120 of the motor drive unit 100. Furthermore, during the period when the regenerative voltage Vc is greater than the output voltage of the DC conversion unit 10, the bridge circuit (rectifier diodes 11-14) of the DC conversion unit 10 prevents current from flowing from the AC power supply, resulting in zero power supply from the AC power supply. Here, since the regenerative voltage Vc is connected to point A via diode 50, more specifically, when (output voltage of DC conversion unit 10 + forward voltage value Vf of diode 50) < regenerative voltage Vc, the input voltage Va will output Va = (regenerative voltage Vc - forward voltage value Vf of diode 50).

[0018] (Control of the control unit 40) The control unit 40 controls the power factor correction operation of the power factor correction unit 20 based on the target output voltage Vt, which is the target value of the output voltage of the power factor correction unit 20, and the input voltage Va. When the regenerative voltage Vc is greater than the output voltage of the DC conversion unit 10, the control unit 40 controls the operation to start power factor correction if the input voltage Va (= regenerative voltage Vc) is less than the target output voltage Vt, and controls the operation to stop power factor correction if the input voltage Va (= regenerative voltage Vc) is equal to or greater than the target output voltage Vt, and operates the DC / DC converter unit 30 using the regenerative power. Specifically, as shown in Figure 3, if the regenerative voltage Vc is greater than the output voltage of the DC conversion unit 10, and the regenerative voltage Vc is less than the target output voltage Vt, the control unit 40 performs control to start a power factor correction operation to boost the regenerative voltage Vc to the target output voltage Vt. Furthermore, if the regenerative voltage Vc is greater than the output voltage of the DC conversion unit 10, and the regenerative voltage Vc is equal to or greater than the target output voltage Vt, control is performed to stop the power factor correction operation that boosts the regenerative voltage Vc to the target output voltage Vt. In other words, the control unit 40 starts a power factor correction operation to boost the regenerative voltage Vc to the target output voltage Vt if the regenerative voltage Vc is less than the target output voltage Vt, but stops the power factor correction operation if the regenerative voltage Vc is equal to or greater than the target output voltage Vt because there is no need to boost the voltage. Furthermore, as shown in Figure 3, if the regenerative voltage Vc is smaller than the output voltage of the DC conversion unit 10, the output voltage of the DC conversion unit 10 becomes the input voltage Va. At this time, the control unit 40 starts a power factor correction operation to raise the output voltage of the DC conversion unit 10 to the target output voltage Vt because the output voltage of the DC conversion unit 10 is smaller than the target output voltage Vt. Furthermore, if the regenerative voltage Vc from the regenerative voltage generation unit 110 is in the form of a DC pulse, and the regenerative voltage Vc (peak value) is equal to or greater than the target output voltage Vt, the power factor correction unit 20 repeatedly stops and restarts its power factor correction operation, using the regenerated power and a portion of the AC power supply (output power of the DC conversion unit 10) to operate the DC / DC converter unit 30. As described above, the control unit 40 controls the start and stop of the power factor correction operation (boost operation) in the power factor correction unit 20 based on the target output voltage Vt of the output voltage of the power factor correction unit 20 and the input voltage Va input to the power factor correction unit 20.

[0019] (Processing by the control unit 40) The processing flow of the control unit 40 will be explained using Figure 4.

[0020] The control unit 40 determines whether or not the power supply unit 1 has been turned on (step S110). If the control unit 40 determines that the power supply unit 1 has been turned on (YES in step S110), it proceeds to step S120. On the other hand, if the control unit 40 determines that the power supply unit 1 is not turned on ("NO" in step S110), it returns to step S110 and transitions to the standby state.

[0021] If the control unit 40 determines that the power supply unit 1 has been turned on (YES in step S110), it obtains the voltage value of the input voltage Va (step S120) and proceeds to step S130.

[0022] The control unit 40 determines whether the input voltage Va is equal to or greater than the target output voltage Vt (step S130). Specifically, the control unit 40 compares the input voltage Va obtained in step S120 with the target output voltage Vt of the power factor correction unit 20 and determines whether the input voltage Va is equal to or greater than the target output voltage Vt. If the control unit 40 determines that the input voltage Va is equal to or greater than the target output voltage Vt (YES in step S130), it proceeds to step S140. On the other hand, if the control unit 40 determines that the input voltage Va is smaller than the target output voltage Vt (NO in step S130), it proceeds to step S150.

[0023] If the control unit 40 determines that the input voltage Va is equal to or greater than the target output voltage Vt (YES in step S130), it stops the power factor correction operation (step S140) and proceeds to step S160. Specifically, the control unit 40 turns off the transistor 23 of the power factor correction unit 20 using a control signal connected to the gate electrode of the transistor 23.

[0024] If the control unit 40 determines that the input voltage Va is smaller than the target output voltage Vt ("NO" in step S130), it starts power factor correction operation (boost control) (step S150) and proceeds to step S160.

[0025] The control unit 40 determines whether or not the power supply unit 1 has been turned off (step S160). If the control unit 40 determines that the power supply unit 1 is not turned off (NO in step S160), it returns to step S120 and continues processing. On the other hand, if the control unit 40 determines that the power supply unit 1 has been turned off (YES in step S160), it terminates the process.

[0026] <Effects and Effects> As described above, the power supply device 1 according to an embodiment of the present invention is a power supply device that converts an AC voltage supplied from an AC power source into a DC voltage and drives an inductive load using the DC voltage, and comprises a DC conversion unit 10 that rectifies and smooths the AC power source, a power factor correction unit 20 that receives the applied voltage applied to the capacitor 15 as an input voltage Va and improves the power factor, and a control unit 40 that controls the power factor correction operation by the power factor correction unit 20 based on a target output voltage Vt, which is a target value of the output voltage of the power factor correction unit 20, and the input voltage Va, and is a power supply device that regenerates the regenerative voltage Vc from the inductive load (motor 120) to the capacitor 15. According to the power supply device 1 of this embodiment, the regenerative power generated in the inductive load (motor 120) can be reused as a power supply source for the power supply device 1, thereby reducing the power supplied from the AC power source. This makes it possible to enhance the energy-saving effect of power supply unit 1.

[0027] Furthermore, the control unit 40 of the power supply device 1 according to the embodiment of the present invention controls the power factor correction operation to start when the regenerative voltage Vc is greater than the output voltage of the DC conversion unit 10 and the regenerative voltage Vc is less than the target output voltage Vt, and controls the power factor correction operation to stop when the regenerative voltage Vc is equal to or greater than the target output voltage Vt. As a result, when the regenerative voltage Vc is greater than the output voltage of the DC conversion unit 10, the regenerative power generated in the motor 120 can be reused as a power source for the power supply unit 1. Therefore, it is possible to reduce the amount of power supplied from the AC power source, thereby increasing energy-saving effects.

[0028] <Other examples> Figures 1 and 2 show an example in which the power supply unit 1 and the motor drive unit 100 are configured as separate components, but the power supply unit 1 may also be configured to include the motor drive unit 100.

[0029] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and includes designs and the like that do not depart from the spirit of this invention. [Explanation of symbols]

[0030] 1;Power supply 10;DC conversion section 20; Power Factor Improvement Section 30; DC / DC converter section 40; Control Unit 100; Motor drive device 110; Regenerative voltage generation unit 120; motor

Claims

[Claim 1] In a power supply device that converts an AC voltage supplied from an AC power source into a DC voltage and uses the DC voltage to drive an inductive load, A DC conversion unit that rectifies the AC voltage using a rectifier diode and smooths it with a capacitor, A power factor correction unit that takes the applied voltage applied to the capacitor as the input voltage and improves the power factor, The system includes a control unit that controls the power factor correction operation by the power factor correction unit based on a target output voltage, which is a target value of the output voltage of the power factor correction unit, and the input voltage. The regenerative voltage from the inductive load is regenerated to the capacitor. When the regenerative voltage is greater than the output voltage of the DC conversion unit, The control unit is a power supply device that performs control to start the power factor correction operation when the regenerative voltage is less than the target output voltage, and to stop the power factor correction operation when the regenerative voltage is equal to or greater than the target output voltage.

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