Power supply device and injection molding machine system equipped with the same, and method for supplying driving power to injection molding machine

Abstract

To provide a battery-mounted power supply device used for an injection molding machine, in which loss of energy is suppressed while protecting a battery in performing a regenerative operation from an injection molding machine.SOLUTION: A power supply device 200 for an injection molding machine 100 comprises an AC / DC converter 210, a battery 230, and a controller 300. The AC / DC converter converts AC power from a system power supply 20 into DC power, and supplies the power to a DC bus 260. The battery is rechargeable by using DC power of the DC bus. The injection molding machine includes servo motors 151 to 154 and a servo amplifier 140 that drives the servo motors by using the power of the DC bus 260. The servo amplifier supplies regenerative power to the DC bus in performing a regenerative operation of the servo motors. The controller controls the AC / DC converter in the case where the power of the DC bus exceeds allowable charging power of the battery in performing a regenerative operation of the servo motors, and outputs power exceeding the allowable charging power to the system power supply.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a power supply device and an injection molding machine system including the same, and a method for supplying driving power to an injection molding machine, and more particularly to power control in a power supply device for an injection molding machine having a battery. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2018-008397 (Patent Document 1) and Japanese Patent Laid-Open Publication No. 2017-217836 (Patent Document 2) disclose a configuration in which a power storage device (battery) is provided in a power supply line to a servo amplifier of an injection molding machine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-008397 A [Patent Document 2] JP 2017-217836 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an injection molding machine equipped with a battery as described above, DC power obtained by converting AC power from an external power source (for example, a system power source) is used as driving power for driving the injection molding machine and as charging power for charging the battery.

[0005] On the other hand, when a motor is used to drive each device in an injection molding machine, when the motor performs a regenerative operation, the regenerative power generated by the motor is supplied to the DC bus of the power supply device. If the power supplied from the injection molding machine exceeds the allowable charging power of the battery, it may cause an overvoltage and lead to a failure of the battery. Furthermore, if such excess power is consumed by a heat dissipation resistor or the like, energy will be wasted.

[0006] The present disclosure has been made to solve such problems, and its purpose is to reduce energy loss while protecting the battery in a battery-equipped power supply device used in an injection molding machine during regenerative operation from the injection molding machine. [Means for solving the problem]

[0007] In the power supply device for an injection molding machine disclosed herein, when the power of the DC bus of the power supply device exceeds the allowable charging power of the battery during regenerative operation of the electric motor included in the injection molding machine, the power exceeding the allowable charging power is output to the system power supply. Effect of the Invention

[0008] According to the power supply device of the present disclosure, in a power supply device equipped with a battery for use in an injection molding machine, it is possible to reduce energy loss while protecting the battery during regenerative operation from the injection molding machine. [Brief description of the drawings]

[0009] [Figure 1] 1 is an overall schematic view of an injection molding machine system in which a power supply device according to a first embodiment is used. [Diagram 2] FIG. 2 is a diagram for explaining the configuration of the injection molding machine in FIG. [Diagram 3] FIG. 2 is a functional block diagram for explaining a power supply device. [Figure 4] FIG. 2 is a diagram for explaining a power supply circuit configuration of the injection molding machine system of the first embodiment. [Diagram 5] FIG. 1 is a first diagram for explaining a control circuit in a power supply device. [Figure 6] FIG. 2 is a second diagram for explaining a control circuit in the power supply device. [Figure 7] FIG. 3 is a third diagram for explaining a control circuit in the power supply device. [Figure 8] FIG. 8 is a diagram for explaining the phase shifter in FIG. 7. [Figure 9] 4 is a time chart for explaining the operation of the DAB converter. [Figure 10] 4 is a flowchart for illustrating details of regenerative power control in the first embodiment. [Figure 11] FIG. 1 is a first diagram for explaining a control circuit in a first control example when a battery is charged. [Figure 12] FIG. 2 is a second diagram for explaining a control circuit in the first control example when the battery is charged. [Figure 13] FIG. 11 is a diagram for explaining a control circuit in a second control example when the battery is charged. [Figure 14] FIG. 11 is a diagram for explaining a power supply circuit configuration of an injection molding machine system according to a second embodiment. [Figure 15] 11 is a diagram for explaining a control circuit in a power supply device according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and their description will not be repeated.

[0011] [Embodiment 1] <Injection molding machine system configuration> Fig. 1 is an overall schematic diagram of an injection molding machine system 10 using a power supply device 200 in embodiment 1. Referring to Fig. 1, the injection molding machine system 10 includes an injection molding machine 100 and a power supply device 200 for supplying power to the injection molding machine 100.

[0012] The power supply device 200 includes a battery 230. The battery 230 is charged by a portion of the power received from an external power source such as the power system 20. The power supply device 200 outputs the power received from the external power source and / or the power stored in the battery 230 to the injection molding machine 100. In the injection molding machine 100, devices such as a heater and a servo motor (see FIG. 2) are driven using the power supplied from the power supply device 200.

[0013] Also, a natural energy power generation device 30 may be used as an external power source instead of or in addition to the grid power supply 20. In the example of FIG. 1, the natural energy power generation device 30 includes a solar power generation device 31 and a DC / DC converter 35. The DC / DC converter 35 adjusts the DC power generated by the solar power generation device 31 to a predetermined voltage and supplies it to the power supply device 200. Note that the natural energy power generation device 30 may include other types of power generation devices instead of or in addition to the solar power generation device 31, as long as they are devices that generate power using natural energy. For example, the natural energy power generation device 30 may include a wind power generation device, a hydroelectric power generation device, a geothermal power generation device, a tidal power generation device, or the like.

[0014] <Injection molding machine configuration> 2 is a diagram for explaining the configuration of the injection molding machine 100 in FIG. 1. For convenience of explanation, the floor surface on which the injection molding machine 100 is placed is defined as an XY plane, and the direction perpendicular to the floor surface is defined as a Z-axis direction. The positive direction of the Z-axis may be referred to as the upper side or upward, and the negative direction as the lower side or downward. Although the injection molding machine 100 in the first embodiment is shown as a horizontal injection molding machine, it is not limited to the horizontal type and may be a vertical injection molding machine.

[0015] The injection molding machine 100 includes a clamping unit 110 for clamping a mold, an injection unit 120 for melting and injecting an injection material, an operation panel 130, and a control unit 140. In Fig. 2, the clamping unit 110 is disposed on the negative side of the X-axis with respect to the injection unit 120.

[0016] The mold clamping device 110 includes a bed 111, a fixed platen 112, a mold clamping housing 113, a movable platen 114, tie bars 115, a mold clamping mechanism 116, molds 117 and 118, and a ball screw 119. The bed 111 is placed on the floor surface, and devices such as the fixed platen 112, the mold clamping housing 113, and the movable platen 114 are mounted on the upper surface of the bed 111.

[0017] The fixed platen 112 is fixed to the end of the bed 111 closer to the injection unit 120 (i.e., in the positive direction of the X-axis). The mold clamping housing 113 is disposed at the end of the bed 111 in the negative direction of the X-axis. The fixed platen 112 and the mold clamping housing 113 are connected by a tie bar 115 including a plurality of bars. The mold clamping housing 113 is movable on the bed 111 in the X-axis direction.

[0018] The movable platen 114 is disposed on the bed 111 between the fixed platen 112 and the clamping housing 113. The movable platen 114 is configured to be movable in the X-axis direction. The clamping housing 113 and the movable platen 114 are connected by a clamping mechanism 116. The clamping mechanism 116 has a toggle mechanism. A ball screw 119 is connected to the toggle mechanism, and the movable platen 114 can be moved in the X-axis direction relative to the clamping housing 113 by driving a servo motor 151 disposed in the clamping housing 113 to rotate the ball screw 119. Note that a direct acting cylinder driven by hydraulic pressure may be used as the clamping mechanism 116.

[0019] Molds 117 and 118 are disposed on the movable platen 114 and the fixed platen 112, respectively. The molds 117 and 118 are disposed between the movable platen 114 and the fixed platen 112, facing each other. By moving the mold 117 in the X-axis direction using the mold clamping mechanism 116, the mold 117 and the mold 118 can be brought into close contact with each other, or the mold 117 can be separated from the mold 118. In the following description, the process of shifting the molds 117 and 118 from a separated state to a close contact state is referred to as "mold clamping". Also, the process of shifting the molds 117 and 118 from a close contact state to a separated state is referred to as "mold opening".

[0020] With the mold 117 and the mold 118 in close contact with each other in the mold clamping process, the inside of the mold is filled with molten material (resin), which is cooled and solidified, thereby molding a product of a desired shape. After the product is molded, with the mold 117 separated from the mold 118 in the mold opening process, the molded product can be removed from the mold 117 by operating an ejection mechanism (not shown) arranged on the movable platen 114. The ejection mechanism is driven by a servo motor 152 arranged on the movable platen 114. The process of removing the product using the ejection mechanism is referred to as the "ejection" process.

[0021] The injection device 120 includes a base 121, a heating cylinder 122, a driving device 124, a hopper 125, a nozzle touch device 127, and a temperature sensor 128. The base 121 is placed on the floor surface on the positive side of the X-axis of the bed 111, and the driving device 124 is mounted on the upper surface thereof. Servo motors 153 and 154 are arranged in the driving device 124.

[0022] The driving device 124 is provided with a heating cylinder 122 extending in the X-axis direction. The heating cylinder 122 includes a heater (not shown) for heating the inside, a screw 123, and an injection nozzle 126. The screw 123 is driven by a servo motor 153 in the driving device 124 and configured to be rotatable around the X-axis direction as a rotation axis. The screw 123 is also driven by a servo motor 154 and configured to be movable in the X-axis direction. The injection nozzle 126 is provided at the end of the heating cylinder 122 on the clamping device 110 side (i.e., the end in the negative direction of the X-axis). The heating cylinder 122 heats and melts the bead-shaped resin material fed from the hopper 125, and kneads it using the screw 123 to generate a molten material. The process of melting the resin material in this manner is called a "plasticization" process.

[0023] The nozzle touch device 127 is configured by, for example, a mechanism using a hydraulic cylinder or a mechanism using a ball screw, and connects the drive device 124 and the fixed platen 112 of the mold clamping device 110. When the nozzle touch device 127 is configured by a mechanism using a ball screw, the nozzle touch device 127 is driven by the drive device 124 to move the drive device 124 and the heating cylinder 122 in the X-axis direction. The nozzle touch device 127 brings the injection nozzle 126 into contact with the sprue bush of the mold 118 in the mold clamping device 110, and injects the molten material from the injection nozzle 126, thereby filling the cavity of the mold 117, 118 with the molten material. The servo motor 154 applies pressure to the molten material by moving the screw 123 in the heating cylinder 122 in the negative direction of the X-axis, and injects the molten material into the mold 117, 118 and keeps the pressure of the molten material constant after injection.

[0024] The configuration of the nozzle touch mechanism is not limited to the above-mentioned configuration in which the entire injection device is moved by a ball screw arranged between the fixed platen 112 and the driving device 124, and other configurations may be used. For example, a configuration in which a ball screw is used to connect the device frame and a fixed member at the rear of the heating cylinder, and the heating cylinder itself is moved toward the mold, may be used. Alternatively, a configuration in which a ball screw is used to connect a slide base on which the injection device is mounted and the device frame, and the injection device is moved together with the slide base to bring the injection nozzle into contact with the mold.

[0025] The process of injecting the molten material into the molds 117, 118 is referred to as an "injection" process. After the injection process, the process of cooling the molten material filled in the molds 117, 118 while maintaining a constant pressure is referred to as a "pressure holding" process.

[0026] The temperature sensor 128 is disposed near the injection nozzle 126 of the heating cylinder 122. The temperature sensor 128 detects the temperature of the molten material inside the heating cylinder 122 and outputs the temperature to the control device 140. The control device 140 controls the heater based on the detection value of the temperature sensor 128 to adjust the temperature of the molten material to a desired temperature.

[0027] Once the dwell step is completed, the mold opening and ejection steps are carried out to remove the molded product.

[0028] The injection molding machine 100 can continuously form products by cyclically repeating a mold clamping process, an injection process, a pressure holding process, a plasticizing process, a mold opening process, and an ejection process.

[0029] The control device 140 is stored inside the base 121. The control device 140 includes a CPU (Central Processing Unit) 141, a memory 142, and a servo amplifier 143 for driving the servo motors 151 to 154. The control device 140 acquires detection values ​​of various sensors arranged in the injection molding machine 100, and controls the injection molding machine 100 in an integrated manner.

[0030] The operation panel 130 is a device for an operator to operate the injection molding machine 100, and includes a display device such as a liquid crystal display and an input device such as a keyboard. The operation panel 130 is connected to the control device 140, and can acquire and display the status of the injection molding machine 100, and output a user operation signal from the input device to the control device 140. The operation panel 130 may be a touch panel in which the display device and the input device are integrated. The operation panel 130 may be attached to the bed 111 or base 121 of the injection molding machine 100, or may be disposed in a position independent of the injection molding machine 100.

[0031] <Power supply configuration> Next, details of power supply device 200 in Fig. 1 will be described with reference to Fig. 3. Referring to Fig. 3, power supply device 200 includes an AC / DC converter 210, a DC / DC converter 220, a battery 230, an inverter 240, a voltage sensor 270, and a control device 300. Control device 300 also includes a CPU 310 and a memory 320.

[0032] The AC / DC converter 210 converts AC power supplied from the system power supply 20, which is an external power supply, into DC power and supplies the DC power to a DC bus 260. The DC power converted by the AC / DC converter 210 is used as charging power for charging the battery 230 and / or driving power for driving the injection molding machine 100. In addition, power from the above-mentioned natural energy power generation device 30 is also supplied to the DC bus 260.

[0033] The DC / DC converter 220 converts the DC power of the DC bus 260 into a voltage suitable for charging the battery 230. The battery 230 is a secondary battery capable of being charged and discharged, such as a lithium ion battery or a lead storage battery. The battery 230 is charged using the DC power supplied from the DC / DC converter 220. The power stored in the battery 230 is used as driving power for the injection molding machine 100. In this case, the DC / DC converter 220 adjusts the voltage of the DC power from the battery 230 and supplies it to the DC bus 260. That is, the DC / DC converter 220 is a bidirectional DC / DC converter capable of converting power in both directions. As will be described later with reference to FIG. 4, the DC / DC converter 220 in the first embodiment is an insulating type DAB (Dual Active Bridge) converter.

[0034] The DC bus 260 is connected to the injection molding machine 100. Direct current (DC) power supplied from the DC bus 260 to the injection molding machine 100 is used, for example, as drive power for the servo motors 151-154 in the injection molding machine 100. The voltage sensor 270 detects the voltage of the DC bus 260 and outputs it to the control device 300.

[0035] The inverter 240 is a DC / AC converter and is connected to the DC bus 260. The inverter 240 converts the DC power of the DC bus 260 into AC power and supplies it to the injection molding machine 100. The AC power converted by the inverter 240 is used, for example, as driving power for a heater in the injection molding machine 100 and / or as a control power source.

[0036] The control device 300 comprehensively controls each device included in the power supply device 200. More specifically, the control device 300 controls the voltage V of the AC power supplied from the system power supply 20. S and current I LS from the AC / DC converter 210. The control device 300 also receives from the battery 230 the terminal voltage V bat , and the current flowing in / out of the battery 230 i p_bat Furthermore, the control device 300 acquires the DC voltage V of the DC bus 260 from the voltage sensor 270. DC Based on this information, control device 300 generates control signal CON1 for AC / DC converter 210, control signal CON2 for DC / DC converter 220, and control signal CON3 for inverter 240, and outputs them to the corresponding devices.

[0037] In the injection molding machine system 10 (see FIG. 1) configured as described above, the battery 230 is charged using AC power supplied from the power grid 20 and / or DC power generated by the natural energy power generation device 30, and the injection molding machine 100 is driven using power from the power grid 20, the natural energy power generation device 30, and the battery 230.

[0038] On the other hand, in the injection molding machine 100, as described in Fig. 2, servo motors 151-154 are used to drive the respective devices of the mold clamping unit 110 and the injection unit 120. As will be described later, a PWM type inverter is used in the servo amplifier 143 that drives the servo motors 151-154, and during regenerative operation such as deceleration, the servo motors 151-154 function as generators. The power generated by the servo motors is also used to drive other servo motors in the injection molding machine 100, but the power that is not consumed by the injection molding machine 100 is eventually supplied to a DC bus 260 (see Fig. 3) via an inverter.

[0039] In this case, as shown in Fig. 3, the power supplied to the DC bus 260 is used only for charging the battery 230. However, the battery 230 is usually set to a permissible charging power for device protection, and cannot be charged with power exceeding the permissible charging power. Therefore, if the power supplied to the DC bus 260 exceeds the permissible charging power of the battery 230 during regenerative operation of the injection molding machine 100, and the excess power cannot be processed, an overvoltage may occur, which may cause deterioration or failure of the device. In particular, if the power generation timing of the natural energy power generation device 30 (photovoltaic power generation device) and the regeneration timing of the servo motor overlap, the power supplied to the DC bus 260 is likely to exceed the permissible charging power of the battery 230.

[0040] Although it is conceivable to dissipate the surplus power as heat by a heat dissipation resistor, this is not recommended from the viewpoint of energy saving since it would result in unnecessary consumption of energy.

[0041] Therefore, in the first embodiment, as described above, when the power supplied to the DC bus 260 exceeds the charge allowable power of the battery 230, the AC / DC converter 210 is operated as an inverter to return the surplus power to the system power supply, thereby executing "battery protection control." This battery protection control suppresses energy loss while protecting the battery 230 during regenerative operation of the injection molding machine 100.

[0042] <Circuit configuration details> In the following, a circuit configuration for realizing the battery protection control in the first embodiment will be described in detail.

[0043] (Explanation of the electric circuit) Fig. 4 is a diagram showing details of the electric circuit configuration of the injection molding machine system 10 of the present embodiment 1. As described in Fig. 3, AC power from the system power supply 20 is converted to DC power by the AC / DC converter 210 and supplied to the DC bus 260. In addition, DC power generated by the solar power generation device 31 in the natural energy power generation device 30 is converted to a predetermined voltage by the DC / DC converter 35 and supplied to the DC bus 260. The power supplied to the DC bus 260 is supplied to the injection molding machine 100 as drive power, and is also used to charge the battery 230 via the DC / DC converter 220.

[0044] The AC / DC converter 210 includes a filter circuit 211 and a conversion circuit 212. The filter circuit 211 includes an inductor L f ,L s and inductor L f and inductor L s A capacitor C connected between each phase f The filter circuit 211 removes high-frequency noise components in the AC power supplied from the system power supply 20.

[0045] The conversion circuit 212 is a three-phase full-bridge type PWM rectifier, and includes switching elements Q1 to Q6 arranged between the power supply lines PL1 and NL1 of the DC bus 260. The a-phase of the filter circuit 211 is connected to a connection node of the switching elements Q1 and Q2 connected in series between the power supply lines PL1 and NL1. The b-phase of the filter circuit 211 is connected to a connection node of the switching elements Q3 and Q4 connected in series between the power supply lines PL1 and NL1. The c-phase of the filter circuit 211 is connected to a connection node of the switching elements Q5 and Q6 connected in series between the power supply lines PL1 and NL1. The conversion circuit 212 is controlled by a control signal CON1 from the control device 300, and rectifies the AC power that has passed through the filter circuit 211, and supplies the DC power to the DC bus 260. The conversion circuit 212 can also function as an inverter, and can convert the DC power of the DC bus 260 and supply the AC power to the system power supply 20.

[0046] 4, the filter circuit 211 is provided with a current sensor for detecting the current of each phase on the AC / DC converter 210 side and a voltage sensor for detecting each line voltage on the system power supply 20 side. LSa ,i LSb , and the voltage value V Sab ,V Sbc are output to the control device 300. Note that, since the phases of a three-phase AC power supply are shifted from each other by 120°, the above current values ​​and voltage values ​​can be obtained by detecting two phase currents and two line voltages.

[0047] In the DC bus 260, a smoothing capacitor C dc A capacitor C dc The terminal voltage V DC is detected by a voltage sensor 270 (FIG. 3) and output to the control device 300.

[0048] The DC / DC converter 35 of the natural energy power generation device 30 is a so-called boost chopper circuit. The DC / DC converter 35 is controlled by a control signal CON2 from the control device 300, and boosts the DC power generated by the solar power generation device 31 and supplies the boosted power to the DC bus 260.

[0049] As described in FIG. 2, a plurality of servo motors are arranged in the injection molding machine 100. Each servo motor is driven by a corresponding servo amplifier. FIG. 4 shows, as an example, a configuration in which servo amplifiers 1431 and 1432 are connected to servo motors 151 and 152, respectively. Each servo amplifier includes a three-phase full-bridge type inverter and is connected in parallel to a DC bus 260. Each servo amplifier is controlled by the CPU 141 of the injection molding machine 100, converts DC power from the DC bus 260 into AC power, and drives the corresponding servo motor.

[0050] The DC / DC converter 220 includes a conversion circuit 221 and a filter circuit 222 arranged between the conversion circuit 221 and the battery 230. The conversion circuit 221 is a bidirectional converter, and is configured to be able to convert the voltage of DC power from the DC bus 260 to charge the battery 230, and to convert the voltage of DC power stored in the battery 230 to output it to the DC bus 260.

[0051] As described above, the conversion circuit 221 is an isolated DAB converter. The conversion circuit 221 includes an isolation transformer TR having a winding ratio of N1:N2, and bridge circuits 2211 and 2212 arranged on the primary side and the secondary side of the isolation transformer TR, respectively. The bridge circuit 2211 includes a switching element Q 11 ~Q 14 The bridge circuit 2212 includes a switching element Q 21 ~Q 24 Includes.

[0052] In the bridge circuit 2211, the switching element Q 11 ,Q 12is connected in series between the power supply lines PL2 and NL2. Similarly, the switching element Q 13 ,Q 14 is connected in series between the power supply lines PL2 and NL2. 11 ,Q 12 The connection node of the switching element Q is connected to the positive terminal of the primary winding of the isolation transformer TR via the inductor L1. 13 ,Q 14 The connection node is connected to the negative terminal of the primary winding of the isolation transformer TR.

[0053] In the bridge circuit 2212, the switching element Q 21 ,Q 22 is connected in series between the power supply lines PL1 and NL1. Similarly, the switching element Q 23 ,Q 24 is connected in series between the power supply lines PL1 and NL1. 21 ,Q 22 The connection node of the switching element Q is connected to the positive terminal of the secondary winding of the isolation transformer TR via the inductor L2. 23 ,Q 24 The connection node of is connected to the negative terminal of the secondary winding of the isolation transformer TR.

[0054] The filter circuit 222 includes an inductor L connected between the positive terminal of the battery 230 and the power supply line PL2. b and a capacitor C connected between the power supply lines PL2 and NL2. b The filter circuit 222 is a low-pass filter including: a first filter circuit 222a and a second filter circuit 222b, and a second filter circuit 222c. The filter circuit 222 is configured to remove high-frequency noise that occurs in the power supply line due to switching of the conversion circuit 221 or the like.

[0055] The battery 230 has a terminal voltage V bat and a voltage sensor for detecting a current i input / output to / from the battery 230. p_bat A current sensor is provided for detecting the current.

[0056] In the DC / DC converter 220, the switching element Q 11 ~Q 14 and the control pulse of the switching element Q of the bridge circuit 2212. 21 ~Q 24 By adjusting the phase of the control pulse, charging to and discharging from the battery 230 can be controlled.

[0057] <Control circuit explanation> Next, a specific control method of the battery protection control executed in the control device 300 shown in FIG. 4 will be described. In the following description of the control circuit, FIG. 4 will also be referred to as appropriate. FIGS. 5 to 8 are functional block diagrams of the control circuit for explaining the battery protection control. FIG. 5 is a functional block diagram of a current control circuit 400 that calculates a current command value for controlling the DC bus 260 to a command voltage and a charging current command value of the battery 230. FIG. 6 is a functional block diagram of a drive control circuit 500 that generates a control signal for a switching element in the AC / DC converter 210. FIG. 7 is a functional block diagram of a drive control circuit 600 that generates a control signal for a switching element in the DC / DC converter 220 based on a current command value. FIG. 8 is a functional block diagram of a detailed circuit of the phase shifter 630 in FIG. 7.

[0058] (Current control circuit) First, a description will be given of the current control circuit 400 in Fig. 5. With reference to Fig. 5, the current control circuit 400 includes subtraction units 410 and 460, a PI control unit 420, a limiter circuit 430, a multiplication unit 440, and a division unit 450.

[0059] In the subtraction unit 410, a predetermined voltage command value V DC * , the voltage V of the DC bus 260 detected by the voltage sensor 270 DC The PI control unit 420 performs PI (proportional integral) control on the differential voltage calculated by the subtraction unit 410 to obtain the current command value i p Calculate.

[0060] Then, in the limiter circuit 430, the current command value i p The allowable charging current i of the battery 230 p_lim The allowable charging current is limited by i p_lim is defined by the following equation (1).

[0061] i p_lim =i bat_rating ×V bat / V eff (1) where i bat_rating indicates the rated current value of the battery, and V bat indicates the battery voltage, and V eff indicates the effective voltage of the AC power. The current command value i p is the allowable charging current i p_lim If it is within, the command value i p_sub * =i p On the other hand, the current command value i p is the allowable charging current i p_lim If it exceeds the command value i p_sub * =i p_lim It becomes.

[0062] The command value i after passing through the limiter circuit 430 p_sub * is multiplied by the effective value of the three-phase AC voltage from the system power supply 20 in the multiplication unit 440 to obtain the charging power command value P bat * Then, the charge power command value P bat * the battery voltage V bat The target charging current command value i bat * This target charging current command value i bat *Using this, a control signal CON2 (see FIG. 3) for the DC / DC converter 220 for charging the battery 230 is generated by a drive control circuit 600, which will be described later with reference to FIG.

[0063] In addition, in the subtraction unit 460, the current command value i p From the command value i after passing through the limiter circuit 430, p_sub * By subtracting, the current command value i p_dif * The current command value i p_dif * is used by a drive control circuit 500, described later in FIG. 6, to generate a control signal CON1 (see FIG. 3) for the AC / DC converter 210.

[0064] (AC / DC converter drive control circuit) Next, a description will be given of the drive control circuit 500 in Fig. 6. Referring to Fig. 6, the drive control circuit 500 includes three-phase-to-two-phase conversion units 510 and 540, subtraction units 520 and 530, PI control units 525 and 535, a two-phase modulator 550, a PLL (Phase Locked Loop) circuit 560, an oscillator 570, a comparator 580, and an inverter 590.

[0065] The PLL circuit 560 is a circuit for regulating the line voltage V Sab ,V Sbc ,V Sca The phase difference of each phase is used to generate a synchronous signal θ R Generate.

[0066] The three-phase to two-phase conversion unit 510 converts the phase current i LSa ,i LSb ,i LSc The three-phase to two-phase converter 510 receives a synchronization signal θ R According to the above, the three-phase current i LSa ,i LSb ,i LSc By dq transformation, the active power component current i dand the reactive current component current i q Calculate the two-phase currents.

[0067] Then, subtractors 520 and 530 calculate the differences between the d-axis and q-axis current command values, respectively. Here, the d-axis command value is the current command value i p_dif * The command value i of the q-axis of the reactive current component is q * is zero. Then, the PI control units 525 and 535 perform PI control on the differences with the command values ​​for the d-axis and q-axis, respectively, and the three-phase to two-phase conversion unit 540 converts the synchronization signal θ R A three-phase conversion is performed according to the above formula to generate a three-phase voltage command value.

[0068] Then, in order to reduce switching loss and improve the voltage utilization rate, the calculated three-phase voltage command value is two-phase modulated by two-phase modulator 550, and compared with a triangular wave from oscillator 570 by comparator 580 to generate PWM control signals for upper arm switching elements Q1, Q3, Q5 of each phase. Moreover, by inverting these signals by inverter 590, PWM control signals for lower arm switching elements Q2, Q4, Q6 are generated. AC / DC converter 210 is controlled according to the generated PWM control signal CON1 (see FIG. 3).

[0069] As explained in Fig. 5, the current command value i p is the allowable charging current i p_lim If it does not exceed i p =i p_sub * Therefore, the current command value i p_dif * becomes zero. In this case, the AC / DC converter 210 does not perform power conversion. On the other hand, the current command value i p is the allowable charging current i p_lim Exceeding the current command value i p_dif * When is no longer zero, the current command value i p_dif* Thus, the AC / DC converter 210 outputs the surplus power of the DC bus 260 to the system power supply 20.

[0070] (DC / DC converter drive control circuit) Next, the drive control circuit 600 will be described with reference to Fig. 7 and Fig. 8. With reference to Fig. 7, the drive control circuit 600 includes a subtraction unit 610, a PI control unit 620, and a phase shifter 630. With reference to Fig. 8, the phase shifter 630 includes an oscillator 631, comparators 632 and 634, and flip-flop circuits 633 and 635.

[0071] In the subtraction unit 610, the target charging current command value i bat * From the current value i detected by the current sensor of the battery 230, bat The difference calculated by the subtraction unit 610 is subjected to PI control by the PI control unit 620 to obtain the charging voltage command value V CON is generated.

[0072] In the phase shifter 630, the charging voltage command value V CON and the triangle wave V from oscillator 631 tri By comparing with the switching element Q 21 ~Q 24 A PWM control signal is generated to drive the f and triangular wave V tri By comparing with the switching element Q of the bridge circuit 2211 of the DAB converter, 11 ~Q 14 A PWM control signal is generated to drive the

[0073] More specifically, the charging voltage command value V CON and triangular wave V triA PWM signal (PWM2) is generated by comparing the PWM signal with the PWM signal by a comparator 634, and the PWM signal is input to a flip-flop circuit 635 to generate a switching element Q 21 ,Q 24 The control signal and the inverted switching element Q 22 ,Q 23 A control signal V f and triangular wave V tri A PWM signal (PWM1) is generated by comparing the PWM signal with the switching element Q 11 ,Q 14 The control signal and the inverted switching element Q 12 ,Q 13 and a control signal are generated.

[0074] 9 is a time chart for explaining the operation of the DAB converter (conversion circuit 221). In FIG. 9, the horizontal axis indicates time, and the vertical axis indicates the triangular wave V tri (LN10), charging voltage command value V CON (LN11), reference signal V f (LN12), the PWM signals PWM1 (LN20), PWM2 (LN30) in the bridge circuits 2211 and 2212, and the switching element Q 11 ,Q 14 The driving signal OutA (LN40) and the switching element Q 12 ,Q 13 The driving signal OutB (LN50) and the switching element Q 21 ,Q 24 The driving signal OutC (LN60) and the switching element Q 22 ,Q 23 3, the drive signal OutD (LN70) is shown.

[0075] Referring to FIG. 9, in the top graph, a triangular wave V tri is indicated by a solid line LN10, and the charging voltage command value V CON is shown by the dashed line LN11, and the reference voltage V fis shown by the dashed line LN12. The reference voltage V f is set to a fixed value of zero amplitude, and the triangular wave V tri and the reference voltage V f By comparing with the switching element Q of the bridge circuit 2211 of the DAB converter, 11 ~Q 14 A control signal PWM1 is generated to drive the LN20. The control signal PWM1 is a square wave pulse with a duty of 50% (LN20).

[0076] In addition, the charging voltage command value V CON and triangular wave V tri By comparing with the switching element Q of the bridge circuit 2212 of the DAB converter, 21 ~Q 24 A control signal PWM2 is generated to drive the charging voltage command value V CON varies depending on the power of the DC bus 260. In the example of FIG. 9, the charging voltage command value V CON increases over time. Therefore, as time passes, the triangular wave V tri and the charging voltage command value V CON The overlapping portion changes, and the pulse width and rise / fall timing of each pulse of the control signal PWM2 change (LN30).

[0077] 8, the drive signals OutA, OutB (LN40, LN50) whose amplitudes are inverted at each rising edge of the pulse are generated. The drive signal OutB is an inverted version of the drive signal OutA. The drive signal OutA drives the switching element Q 11 ,Q 14 is driven, and switching element Q 12 ,Q 13 is driven.

[0078] Similarly, the control signal PWM2 is input to the flip-flop circuit 635 in FIG. 8, whereby the drive signals OutC, OutD (LN60, LN70) whose amplitudes are inverted at each rising edge of the pulse are generated. The drive signal OutD is an inverted version of the drive signal OutC. The drive signal OutC drives the switching element Q 21 ,Q 24 is driven, and the switching element Q 22 ,Q 23 is driven.

[0079] As shown in FIG. 9, the charging voltage command value V CON When increases, the timing of the rising edge of the control signal PWM2 lags behind the timing of the rising edge of the control signal PWM1. That is, the phase (φ1 to φ4) of the control signal PWM2 relative to the control signal PWM1 becomes larger. In the DAB converter, when the switching phase of the bridge circuit on the primary side and the switching phase of the bridge circuit on the secondary side are in phase (that is, when the phase difference φ=0°), the transmitted power is zero, and as the phase difference increases, the transmitted power increases, reaching a maximum when the phase difference φ=90°.

[0080] If the transmitted power is P and the switching frequency is f, the power P can be expressed as the following equation (2), where ω=2πf.

[0081]

number

[0082] In this way, the target charging current command value i bat * By adjusting the phase difference between the switching of the two bridge circuits 2211 and 2212 of the conversion circuit 221 in response to the change in the voltage Vcc, the battery 230 can be charged with a desired power.

[0083] In the above example, the control signal PWM1 of the bridge circuit 2211 on the primary side (i.e., the battery 230 side) is constant, and the phase of the control signal PWM2 of the bridge circuit 2212 on the secondary side (i.e., the DC bus 260 side) is changed. However, the primary side control signal PWM1 may also be controlled to change its phase in accordance with, for example, the state of charge (SOC) of the battery 230.

[0084] By performing control using the above-described control circuit, when the power supplied to the DC bus 260 exceeds the allowable charging power of the battery 230, the AC / DC converter 210 is operated as an inverter to return the surplus power to the system power supply, thereby making it possible to suppress energy loss while protecting the battery 230 during regenerative operation of the injection molding machine 100.

[0085] Note that "AC / DC converter 210" in this disclosure corresponds to "first power conversion device" in this disclosure. Each of "servo amplifiers 143, 1431, 1432" in this disclosure corresponds to "drive device" in this disclosure. "Drive control circuit 500" and "drive control circuit 600" in this disclosure correspond to "first drive control circuit" and "second drive control circuit" in this disclosure, respectively. "Bridge circuit 2211" and "bridge circuit 2212" in this disclosure correspond to "first bridge circuit" and "second bridge circuit" in this disclosure, respectively.

[0086] <Control flow explanation> Fig. 10 is a flowchart for explaining the process of battery protection control in the first embodiment. In the following explanation of the control flow, Fig. 4 will also be referred to as appropriate. The process shown in Fig. 10 is executed by the current control circuit 400 (see Fig. 5) and the drive control circuits 500 (see Fig. 6) and 600 (see Fig. 7) in the control device 300 described above.

[0087] The control device 300 determines whether or not the injection molding machine 100 is in a regenerative operation in step (hereinafter, step will be abbreviated as "S") 100. The determination of whether or not the injection molding machine 100 is in a regenerative operation can be made based on, for example, a signal from the control device 300 of the injection molding machine 100, or the direction of the current supplied from the DC bus 260 to the injection molding machine 100.

[0088] If the injection molding machine 100 is in a regenerative operation (YES in S100), the process proceeds to S110, and the control device 300 controls the power P DC and the allowable charging power P of the battery 230 _lim The power P supplied to the DC bus 260 is obtained. DC is the voltage V of the DC bus 260 as described in the current control circuit 400 of FIG. DC and the target voltage V of the DC bus 260 DC * The current command value i p The allowable charging power P _lim Regarding the voltage V of the battery 230, bat , and rated current i bat_rating The allowable charging current i is calculated from p_lim Then, in S120, the control device 300 calculates the power P DC The allowable charging power P _lim It is determined whether or not the value exceeds the threshold.

[0089] Power P of DC bus 260 DC is the allowable charging power P _lim If it exceeds (P DC >P _lim If the answer is YES in S120, the process proceeds to S130, and the control device 300 determines the allowable charging power P _lim 6. Furthermore, the control device 300 generates a control signal for the DC / DC converter 220 so as to charge the battery 230 using power corresponding to the allowable charging power P _limThe control signal for the AC / DC converter 210 is generated so as to output to the system power supply 20 power exceeding the power P DC is the allowable charging power P _lim In the following cases (P DC ≦P _lim If NO at S120, the process proceeds to S140, which will be described later.

[0090] On the other hand, if the injection molding machine 100 is not in regenerative operation (NO at S100), processing proceeds to S140, and the control device 300 charges the battery 230 and drives the injection molding machine 100 using external power from the system power supply 20 and / or the natural energy power generation device 30 in a charge control mode described below.

[0091] <Charge control mode explanation> Next, an example of the control circuit in the charge control mode will be described. In the following description of the charge control mode, FIG. 4 will also be referred to as appropriate.

[0092] (First control example) The first control example of the charge control mode is a control applied when the battery 230 is charged using an external power source (the power grid 20 and the natural energy power generation device 30) while the injection molding machine 100 is stopped, such as when the factory is down. In the first control example, the power from the natural energy power generation device 30 is used to the maximum extent as charging power for the battery 230, while the generated power that may vary due to weather, etc. is compensated for by the power from the power grid 20. This makes it possible to charge the battery 230 with the maximum power (i.e., the allowable charging power) while suppressing the use of power from the power grid 20 and reducing electricity charges and carbon dioxide emissions.

[0093] In the first control example, the voltage control of the DC bus 260 is executed by the DC / DC converter 35 of the natural energy power generation device 30.

[0094] Fig. 11 is a diagram showing a current control circuit 700 in the first control example, and Fig. 12 is a diagram showing a drive control circuit 800 that drives DC / DC converter 220 used to charge battery 230. The drive control circuit for AC / DC converter 210 has a similar configuration to drive control circuit 500 shown in Fig. 6.

[0095] 11, a current control circuit 700 includes a subtraction unit 710, multiplication units 720 and 740, and division units 730 and 750.

[0096] The multiplication unit 740 multiplies the generated voltage V of the solar power generation device 31 obtained from a voltage sensor and a current sensor (neither of which are shown) provided in the natural energy power generation device 30 by pv and the supply current i pv Multiplying this gives the generated power P pv The division unit 750 calculates the power generation P pv The battery voltage V of the battery 230 bat By dividing by , the charging current i corresponding to the power generated by the solar power generation device 31 is obtained. bat_pv Calculate.

[0097] The subtraction unit 710 subtracts the rated current value i bat_rating The charging current i calculated by the division unit 750 is bat_pv Then, in the multiplication unit 720, the difference i calculated in the subtraction unit 710 is subtracted. bat_diff to battery voltage V bat By multiplying this, the charging power p to be supplied from the system power supply 20 is obtained. bat_diff Then, the charging power p bat_diff is divided by the effective value of the three-phase AC voltage from the system power supply 20, the current command value i d_ref * The current command value i d_ref *By inputting this to the subtraction unit 520 of the d-axis after three-phase to two-phase conversion in the drive control circuit 500, when the generated power of the natural energy power generation device 30 is insufficient relative to the allowable charging power of the battery 230, the shortage of power can be supplied from the system power supply 20.

[0098] Next, the drive control circuit 800 will be described with reference to Fig. 12. The drive control circuit 800 includes subtraction units 810 and 830, PI control units 820 and 840, and a phase shifter 850. In Fig. 12, the subtraction unit 810 and the PI control unit 820 correspond to the subtraction unit 410 and the PI control unit 420 in the current control circuit 400 in Fig. 5, respectively, and the subtraction unit 830, the PI control unit 840, and the phase shifter 850 correspond to the subtraction unit 610, the PI control unit 620, and the phase shifter 630 in the drive control circuit 600 in Fig. 7, respectively. Therefore, detailed description of each element of the drive control circuit 800 will not be repeated.

[0099] In the drive control circuit 800, the target charging current command value i bat * and the battery current i bat Based on the difference between these, a control signal CON2 (see FIG. 3) for the DC / DC converter 220 is generated.

[0100] In the first control example of the charge control mode, basically, power that matches the allowable charging power of the battery 230 is supplied from the system power supply 20 and / or the natural energy power generation device 30. Therefore, if regenerative power is supplied from the injection molding machine 100, the power supplied to the DC bus 260 may exceed the allowable charging power of the battery 230, and the DC bus 260 may become overvoltage. Therefore, it is desirable to apply the configuration of the first control example basically when the injection molding machine 100 is stopped.

[0101] (Second control example) In the above-described first control example, the battery 230 is basically configured to be always charged with the maximum power. In the second control example of the charge control mode, a configuration in which the battery 230 is charged with an arbitrary charging power will be described.

[0102] Fig. 13 is a diagram for explaining the control circuit in the second control example. Fig. 13 shows a drive control circuit for driving AC / DC converter 210 and a current control unit 900 for generating a command value for the drive control circuit. Note that the configuration of the drive control circuit in the second control example is basically the same as the configuration of drive control circuit 500 shown in Fig. 6, and therefore detailed description thereof will not be repeated.

[0103] In the second control example, the subtraction unit 520 of the drive control circuit 500 receives the current command value i d * The current control unit 900 includes a subtraction unit 910 and a PI control unit 920. The voltage command value V DC * and the voltage V of the DC bus 260 detected by the voltage sensor 270 DC The difference between the current command value i d * is generated.

[0104] The drive control circuit for driving the DC / DC converter 220 is basically the same as the drive control circuit 600 described in Fig. 7. In the second control example, the target charging current command value i bat * can be set arbitrarily with the rated current of the battery 230 as the upper limit. The natural energy power generation device 30 can be regarded as a current source. In the second control example, the power balance of the DC bus 260 (i.e., the voltage V DC The power supplied from the system power supply 20 is determined according to the above.

[0105] The configuration of the second control example can handle the regenerative power from the injection molding machine 100 to some extent, but cannot handle the case where the total of the power supplied to the DC bus 260 from the natural energy power generation device 30 and the injection molding machine 100 exceeds the allowable charging power of the battery 230. Therefore, the configuration of the second control example can be applied, for example, to the case where the allowable charging power of the battery 230 is sufficiently greater than the regenerative capacity of the injection molding machine 100.

[0106] [Embodiment 2] In the first embodiment, the configuration in which the natural energy power generation device 30 is connected to the DC bus 260 of the power supply device 200 as shown in FIG.

[0107] In the second embodiment, battery protection control in a configuration in which the natural energy power generation device 30 is directly connected to the battery 230 will be described.

[0108] 14 is a diagram for explaining the configuration of a power supply circuit of the injection molding machine system according to the second embodiment. b_2 The natural energy power generation device 30 is connected to the battery 230 via an inductor L b_2 That is, the charging current i supplied from the natural energy power generation device 30 p_bat2 A current sensor is provided to detect current. Since other circuit configurations are similar to those in the first embodiment shown in FIG. 4, description of overlapping elements will not be repeated.

[0109] 15 is a functional block diagram showing a current control circuit 400A according to the second embodiment. The elements included in the current control circuit 400A are substantially the same as those of the current control circuit 400 in FIG. 5, but the charging allowable current i p_lim 5. The drive control circuits of AC / DC converter 210 and DC / DC converter 220 are similar to those in FIGS.

[0110] In the current control circuit 400A, since the natural energy power generation device 30 is connected to the battery 230, the charging power that the battery 230 can receive from the DC bus 260 is the power obtained by subtracting the power supplied from the natural energy power generation device 30 from the charging allowable power of the battery 230. Therefore, the charging allowable current i p_lim is the charging current i from the natural energy power generation device 30 p_bat2 Using this, it is determined by the following equation (3).

[0111] i p_lim =(i bat_rating -i p_bat2 )×V bat / V eff (3) With this configuration, it becomes possible to charge the battery 230 while taking into consideration the power generation state of the natural energy power generation device 30 that directly charges the battery 230. When the power supplied to the DC bus 260 exceeds the allowable charging power of the battery 230, the AC / DC converter 210 is operated as an inverter to return the surplus power to the power grid, thereby making it possible to protect the battery 230 and suppress energy loss during the regenerative operation of the injection molding machine 100.

[0112] [Aspects] (Item 1) A power supply device according to one aspect is a power supply device used to supply drive power to an injection molding machine using power from a system power supply. The power supply device includes a first power conversion device, a battery, and a control device for controlling the first power conversion device. The first power conversion device is configured to convert AC power from the system power supply into DC power and supply the DC power to a DC bus. The battery is configured to be capable of being charged using the DC power of the DC bus. The injection molding machine includes an electric motor and a drive device for driving the electric motor using power from the DC bus. The drive device is configured to supply regenerated power generated during a regenerative operation of the electric motor to the DC bus. When the power of the DC bus exceeds the allowable charging power of the battery during a regenerative operation of the electric motor, the control device controls the first power conversion device to output power exceeding the allowable charging power to the system power supply.

[0113] (2) In the power supply device according to the 1st paragraph, the first power conversion device is a full-bridge type AC / DC converter including a plurality of switching elements. The control device includes a current control circuit configured to control a current flowing through the DC bus so that the voltage of the DC bus becomes a predetermined target voltage, and a first drive control circuit configured to generate a drive signal for the switching element included in the first power conversion device. The current control circuit includes a limiter circuit having an upper limit value determined based on a rated current of the battery. The current control circuit calculates a target current value from the voltage of the DC bus and the target voltage, sets the target current value after passing through the limiter circuit as a charging current command value for the battery, and sets a difference between the target current value and the charging current command value as a command value for the first drive control circuit. The first drive control circuit generates a drive signal for the first power conversion device using the command value.

[0114] (Item 3) The power supply device described in item 1 or 2 further includes a second power conversion device configured to charge the battery using DC power from the DC bus and to convert the power stored in the battery and supply it to the DC bus.

[0115] (4) In the power supply device according to the third aspect, the second power conversion device includes an isolated DAB converter.

[0116] (Item 5) In the power supply device described in item 3, the second power conversion device includes a first conversion circuit and a second conversion circuit, each of which includes a plurality of switching elements, and an isolation transformer connected to the first conversion circuit and the second conversion circuit. The control device includes a second drive control circuit that controls the exchange of power between the battery and the DC bus by controlling a phase difference between a drive signal for a switching element in the first conversion circuit and a drive signal for a switching element in the second conversion circuit.

[0117] (Item 6) In the power supply device according to item 1, the power supply device is configured to be able to receive DC power from a power generation device that uses natural energy.

[0118] (Item 7) The power supply device according to item 6, wherein the generator is connected to the DC bus. (Item 8) In the power supply device according to item 6, the power generation device is connected to a battery.

[0119] (Item 9) In the power supply device according to item 8, the first power conversion device is a full-bridge type AC / DC converter including a plurality of switching elements. The control device includes a current control circuit configured to control a current flowing through the DC bus so that the voltage of the DC bus becomes a predetermined target voltage, and a first drive control circuit configured to generate a drive signal for the switching element included in the first power conversion device. The current control circuit includes a limiter circuit having an upper limit value determined based on the rated current of the battery and the generated current supplied from the power generation device. The current control circuit calculates a target current value from the voltage of the DC bus and the target voltage, sets the target current value after passing through the limiter circuit as a charging current command value for the battery, and sets the difference between the target current value and the charging current command value as a command value for the first drive control circuit. The first drive control circuit generates the drive signal for the first power conversion device using the command value.

[0120] (Item 10) An injection molding machine system according to another aspect includes an injection molding machine and a power supply device for supplying drive power to the injection molding machine using power from a system power supply. The power supply device includes a first power conversion device, a battery, and a control device for controlling the first power conversion device. The first power conversion device is configured to convert AC power from the system power supply into DC power and supply the DC power to a DC bus. The battery is configured to be capable of being charged using the DC power of the DC bus. The injection molding machine includes an electric motor and a drive device for driving the electric motor using power from the DC bus. The drive device is configured to supply regenerated power generated during a regenerative operation of the electric motor to the DC bus. When the power of the DC bus exceeds the allowable charging power of the battery during a regenerative operation of the electric motor, the control device controls the first power conversion device to output power exceeding the allowable charging power to the system power supply.

[0121] (Item 11) A method according to another aspect relates to a method for supplying drive power from a power supply device to an injection molding machine using power from a system power supply. The power supply device includes a first power conversion device and a battery. The first power conversion device is configured to convert AC power from the system power supply into DC power and supply the DC power to a DC bus. The battery is configured to be chargeable using the DC power of the DC bus. The injection molding machine includes an electric motor and a drive device for driving the electric motor using the power of the DC bus. The drive device is configured to supply the regenerated power generated during a regenerative operation of the electric motor to the DC bus. The method includes the steps of (a) determining whether the electric motor is in a regenerative operation, (b) acquiring information on the power of the DC bus and the chargeable power of the battery, (c) determining whether the power of the DC bus exceeds the chargeable power during the regenerative operation of the electric motor, and (d) controlling the first power conversion device to output power exceeding the chargeable power to the system power supply when the power of the DC bus exceeds the chargeable power.

[0122] The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. [Explanation of symbols]

[0123] 10 injection molding machine system, 20 power supply system, 30 natural energy power generation device, 31 solar power generation device, 35,220 DC / DC converter, 260 DC bus, 100 injection molding machine, 110 mold clamping device, 111 bed, 112 fixed platen, 113 mold clamping housing, 114 movable platen, 115 tie bar, 116 mold clamping mechanism, 117,118 mold, 119 ball screw, 120 injection device, 121 base, 122 heating cylinder, 123 screw, 124 drive device, 125 hopper, 126 injection nozzle, 127 nozzle touch device, 128 temperature sensor, 130 operation panel, 140,300 control device, 142,320 memory, 143,1431,1432 servo amplifier, 151~154 Servo motor, 200 Power supply, 210 AC / DC converter, 211, 222 Filter circuit, 212, 221 Conversion circuit, 230 Battery, 240 Inverter, 270 Voltage sensor, 361, 570, 631 Oscillator, 400, 400A, 700 Current control circuit, 410, 460, 520, 530, 610, 710, 810, 830, 910 Subtraction unit, 420, 525, 535, 620, 820, 840, 920 PI control unit, 430 Limiter circuit, 440, 720, 740 Multiplication unit, 450, 730, 750 Division unit, 500, 600, 800 Drive control circuit, 510, 540 Three-phase to two-phase conversion unit, 550 Two-phase modulator, 560 PLL circuit, 580, 632, 634 Comparator, 590 Inverter, 630, 850 Phase shifter, 633, 635 Flip-flop circuit, 900 Current control section, 2211, 2212 Bridge circuit, C b ,C dc ,C f Capacitor, L1, L2, L b ,L f ,L s Inductor, NL1, NL2, PL1, PL2 Power lines, Q1~Q6, Q 11 ~Q 14 ,Q 21 ~Q 24 Switching element, TR isolation transformer.

Claims

1. A power supply device for supplying drive power to an injection molding machine using power from a system power supply, a first power conversion device configured to convert AC power from the system power supply into DC power and supply the DC power to a DC bus; a battery configured to be chargeable using DC power from the DC bus; a control device for controlling the first power conversion device, the injection molding machine includes an electric motor and a drive for driving the electric motor using power from the DC bus; The drive device is configured to supply generated regenerative power to the DC bus during a regenerative operation of the electric motor, The control device controls the first power conversion device to output power that exceeds the charging allowable power to the system power supply when the power of the DC bus exceeds the charging allowable power of the battery during regenerative operation of the motor.

2. the first power conversion device is a full-bridge type AC / DC converter including a plurality of switching elements, The control device includes: a current control circuit configured to control a current through the DC bus such that the voltage of the DC bus is a predetermined target voltage; a first drive control circuit configured to generate a drive signal for a switching element included in the first power conversion device; the current control circuit includes a limiter circuit having an upper limit value determined based on a rated current of the battery, The current control circuit includes: A target current value is calculated from the voltage of the DC bus and the target voltage; The target current value after passing through the limiter circuit is set as a charging current command value for the battery; A difference between the target current value and the charging current command value is set as a command value for the first drive control circuit; The power supply device according to claim 1 , wherein the first drive control circuit generates a drive signal for the first power conversion device using the command value.

3. 3. The power supply device according to claim 1, further comprising a second power conversion device configured to charge the battery using DC power from the DC bus and to convert power stored in the battery and supply the power to the DC bus.

4. The power supply device according to claim 3 , wherein the second power conversion device includes an isolated dual active bridge (DAB) converter.

5. The second power conversion device is a first conversion circuit and a second conversion circuit each including a plurality of switching elements; an isolation transformer connected to the first conversion circuit and the second conversion circuit; 4. The power supply device according to claim 3, wherein the control device includes a second drive control circuit that controls the exchange of power between the battery and the DC bus by controlling a phase difference between a drive signal of a switching element in the first conversion circuit and a drive signal of a switching element in the second conversion circuit.

6. The power supply device according to claim 1 , wherein the power supply device is configured to be capable of receiving DC power from a power generation device that uses natural energy.

7. The power supply of claim 6 , wherein the generator is connected to the DC bus.

8. The power supply device of claim 6 , wherein the power generator is connected to the battery.

9. the first power conversion device is a full-bridge type AC / DC converter including a plurality of switching elements, The control device includes: a current control circuit configured to control a current through the DC bus such that the voltage of the DC bus is a predetermined target voltage; a first drive control circuit configured to generate a drive signal for a switching element included in the first power conversion device; the current control circuit includes a limiter circuit having an upper limit determined based on a rated current of the battery and a generated current supplied from the power generation device, The current control circuit includes: A target current value is calculated from the voltage of the DC bus and the target voltage; The target current value after passing through the limiter circuit is set as a charging current command value for the battery; A difference between the target current value and the charging current command value is set as a command value for the first drive control circuit; The power supply device according to claim 8 , wherein the first drive control circuit generates a drive signal for the first power conversion device using the command value.

10. An injection molding machine; a power supply device for supplying driving power to the injection molding machine using power from a system power supply, The power supply device is a first power conversion device configured to convert AC power from the system power supply into DC power and supply the DC power to a DC bus; a battery configured to be chargeable using DC power from the DC bus; a control device for controlling the first power conversion device, the injection molding machine includes an electric motor and a drive for driving the electric motor using power from the DC bus; The drive device is configured to supply generated regenerative power to the DC bus during a regenerative operation of the electric motor, The control device, when the power of the DC bus exceeds the charging allowable power of the battery during regenerative operation of the motor, controls the first power conversion device to output the power that exceeds the charging allowable power to the system power supply.

11. A method for supplying driving power to an injection molding machine from a power supply device using power from a power grid, the method comprising the steps of: The power supply device is a first power conversion device configured to convert AC power from the system power supply into DC power and supply the DC power to a DC bus; a battery configured to be chargeable using DC power from the DC bus; the injection molding machine includes an electric motor and a drive for driving the electric motor using power from the DC bus; The drive device is configured to supply generated regenerative power to the DC bus during a regenerative operation of the electric motor, (a) determining whether the electric motor is in a regenerative operation; (b) acquiring information on the power of the DC bus and the charging allowable power of the battery; (c) determining whether the power of the DC bus exceeds the charging allowable power during a regenerative operation of the electric motor; (d) When the power of the DC bus exceeds the permissible charging power, controlling the first power conversion device to output the power exceeding the permissible charging power to the system power supply.

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