JP6773450B2 - Power supply for inductive load - Google Patents

Description

The present invention relates to an inductive load power supply device that drives an inductive load such as an electromagnet.

Accelerators used in fields such as physics experiments and medical treatments are provided with an inductive load power supply device that drives an inductive load such as an electromagnet by applying a large pulsed current. As such a device, for example, the inductive load power supply device 100 shown in FIG. 4 is known (see Patent Document 1).

In the inductive load power supply device 100, the switch elements 102, 105, and 109 are turned on (closed state) and the switch element 106 is turned off (open state) in Phase II. As a result, the output voltage of the charging power supply 101 is applied to the inductive load L, and the load current I rises (see FIG. 5). On the other hand, in the inductive load power supply device 100, the switch elements 102, 105, 109 are turned off and the switch element 106 is turned on in Phase IV. As a result, the electric power remaining in the inductive load L is regenerated to the charging power supply 101 in the path of “diode 108 → switch element 106 → diode 104”, and the load current I drops (see FIG. 5).

Further, the inductive load power supply device 100 includes a control unit 110 that controls the opening and closing of the switch elements 102, 105, 106, 109. The control unit 110 generally uses a voltage of a commercial AC power supply (not shown) as a power supply voltage.

Japanese Patent No. 5614813

As described above, the inductive load power supply device 100 can regenerate the electric power remaining in the inductive load L by controlling the opening and closing of the switch elements 102, 105, 106, 109. However, in the inductive load power supply device 100, when the voltage of the commercial AC power supply drops due to a power failure or the like, especially during Phases II and III, the control unit 110 can control the opening and closing of the switch elements 102, 105, 106, 109. There is a problem that the power remaining in the inductive load L cannot be consumed.

The present invention has been made in view of the above circumstances, and is a power source for an inductive load capable of safely consuming the electric power remaining in the inductive load even when an abnormality occurs in the commercial AC power source. The subject is to provide the device.

In order to solve the above problems, the inductive load power supply device according to the present invention is an inductive load power supply device for driving an inductive load, and the power supplied from the commercial AC power supply is converted into DC. An output power conversion unit, a power storage unit provided on the output side of the power conversion unit to store at least a part of the power output from the power conversion unit, and a plurality of power storage units provided on the output side of the power conversion unit. A load drive unit including a switch element and a freewheeling diode provided in each of the switch elements, at least a control unit that controls opening and closing of the switch element, an auxiliary power supply unit connected to a power storage unit, and a voltage of a commercial AC power supply The control unit includes a first voltage detection unit that detects the voltage of the power storage unit and a second voltage detection unit that detects the voltage of the power storage unit . The control unit is (1) when the voltage detected by the first voltage detection unit is normal. , The voltage of the commercial AC power supply is used as the power supply voltage. (2) If the voltage detected by the first voltage detector is abnormal, the auxiliary power supply unit generates an auxiliary voltage based on the power stored in the power storage unit. The voltage is configured to be the power supply voltage, and in the control unit, (3) the voltage detected by the first voltage detection unit is abnormal, and the voltage detected by the second voltage detection unit is predetermined. If it is smaller than the threshold value, the load drive unit is regenerated by controlling the opening and closing of the switch element, the power remaining in the inductive load is regenerated in the power storage unit, and (4) detected by the first voltage detection unit. If the voltage is abnormal and the voltage detected by the second voltage detection unit is larger than the threshold value, the load drive unit is returned to the recirculation state by controlling the opening and closing of the switch element, and the power remaining in the inductive load. Is configured to be consumed in the load drive unit.

In this configuration, when an abnormality such as a power failure occurs in the commercial AC power supply, the voltage generated by the auxiliary power supply unit is used as the power supply voltage of the control unit instead of the voltage of the commercial AC power supply. Therefore, according to this configuration, even if an abnormality such as a power failure occurs in the commercial AC power supply, the control unit appropriately controls the opening and closing of the switch element so that the power remaining in the inductive load can be safely consumed. Can be done.

Further, in this configuration, when the voltage of the power storage unit detected by the second voltage detection unit is smaller than the preset threshold value, the load drive unit is put into the regenerative state and the power remaining in the inductive load (hereinafter referred to as “power”). , "Residual power") is regenerated into the power storage. Therefore, according to this configuration, in the above case, the residual power can be effectively utilized and the power can be safely consumed.

It is preferable that the control unit of the inductive load power supply unit sends a command signal to the auxiliary power supply unit to start the operation when the voltage detected by the first voltage detection unit changes from normal to abnormal .

According to this configuration, when the voltage detected by the first voltage detection unit is normal, it is possible to prevent the power stored in the power storage unit from being consumed by the auxiliary power supply unit.

According to the present invention, it is possible to provide an inductive load power supply device capable of safely consuming the electric power remaining in the inductive load even when an abnormality occurs in the commercial AC power supply.

It is a circuit diagram of the power supply device for an inductive load which concerns on embodiment of this invention. It is a block diagram which shows the structure of the control part provided in the power-source device for inductive load shown in FIG. It is a figure which shows three operation states (power running state, regenerative state, and reflux state) of the load drive part provided in the power source device for inductive load shown in FIG. It is a circuit diagram of the power supply device for a conventional inductive load. It is an operation waveform diagram of the power supply device for inductive load shown in FIG.

Hereinafter, the inductive load power supply device according to the embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an inductive load power supply device 1 according to an embodiment. The inductive load power supply device 1 drives the inductive load L (electromagnet in this embodiment) by applying a large pulsed current (load current I), and creates a strong magnetic field around the inductive load L. It is a device for generating.

As shown in the figure, the inductive load power supply device 1 is connected to the power conversion unit 2 that converts the power supplied from the commercial AC power supply G into direct current and outputs it from the lines 9H and 9L, and the lines 9H and 9L. It includes a load drive unit 3 and a power storage unit 4, an auxiliary power supply unit 5 connected to the power storage unit 4, and at least a control unit 10 that controls the load drive unit 3. The inductive load power supply device 1 also includes a first voltage detection unit 6, a second voltage detection unit 7, and a current detection unit 8.

The power conversion unit 2 includes an AC / DC conversion circuit that converts the power supplied from the commercial AC power supply G into a direct current. The power after direct current is output from the lines 9H and 9L. The steady-state potential of line 9H with reference to line 9L is, for example, 400 [V]. The line 9L may be grounded.

The load drive unit 3 includes four switch elements SW1, SW2, SW3, SW4 and a freewheeling diode D1, D2, D3, D4 provided for each of the four switch elements SW1, SW2, SW3, SW4. The switch elements SW1 and SW2 and the freewheeling diodes D1 and D2 form the first arm 3a, and the switch elements SW3 and SW4 and the freewheeling diodes D3 and D4 form the second arm 3b. The arms 3a and 3b are provided between the lines 9H and 9L. The two switch elements SW1 and SW2 constituting the first arm 3a are connected in series at the first connection point Pa. Similarly, the two switch elements SW3 and SW4 constituting the second arm 3b are connected in series at the second connection point Pb.

The load driving unit 3 is connected to the inductive load L to be driven at the first connection point Pa and the second connection point Pb. The load drive unit 3 may further include a noise filter provided on the output side of each of the arms 3a and 3b.

Each switch element SW1, SW2, SW3, SW4 is composed of the same insulated gate bipolar transistor (IGBT, Insulated-Gate Bipolar Transistor). The gates of the switch elements SW1, SW2, SW3, and SW4 are connected to the control unit 10.

The power storage unit 4 is composed of a capacitor having a capacitance on the order of mF. As such a capacitor, an electrolytic capacitor or a film capacitor can be used. The electric power storage unit 4 stores at least a part of the electric power output from the electric power conversion unit 2. The potential difference between the lines 9H and 9L corresponds to the amount of electric power stored in the electric power storage unit 4.

The auxiliary power supply unit 5 includes a DC / DC conversion circuit that generates a predetermined DC voltage (hereinafter, referred to as “auxiliary voltage”) based on the electric power stored in the power storage unit 4. The auxiliary voltage is, for example, 5 [V]. The auxiliary voltage is used as the power supply voltage of the control unit 10.

The first voltage detection unit 6 detects the voltage input to the power conversion unit 2, that is, the voltage of the commercial AC power supply G, and transmits the detection signal S1 corresponding to the detected voltage to the control unit 10.

The second voltage detection unit 7 detects the voltage output by the power storage unit 4, that is, the potential difference between the lines 9H and 9L, and sends out the detection signal S2 corresponding to the detected voltage (potential difference) to the control unit 10. ..

The current detection unit 8 detects the load current I between the second connection point Pb of the second arm 3b and the inductive load L, and directs the detection signal S3 corresponding to the detected load current I toward the control unit 10. Send out. The current detection unit 8 may detect the load current I between the first connection point Pa of the first arm 3a and the inductive load L.

As shown in FIG. 2, the control unit 10 includes an AC / DC conversion unit 11, a step-down DC / DC conversion unit 12 provided in a subsequent stage, and another step-down DC / DC conversion unit provided in a subsequent stage. It includes a 14 and an arithmetic processing unit 15 provided in the subsequent stage, and a capacitor 13 provided between the step-down DC / DC converters 12 and 14.

The AC / DC conversion unit 11 converts the voltage (AC200 [V]) of the commercial AC power supply G into AC / DC. The step-down DC / DC conversion unit 12 steps down the output voltage (282 [V]) of the AC / DC conversion unit 11 to 5 [V]. The step-down DC / DC converter 14 requires the arithmetic processing unit 15 for the terminal voltage (maximum 5 [V]) of the capacitor 13 charged by the output voltage or auxiliary voltage of the step-down DC / DC converter 12. 3.3 The voltage is lowered to [V] and 1.2 [V]. The arithmetic processing unit 15 uses each of the 3.3 [V] and 1.2 [V] voltages output by the step-down DC / DC conversion unit 14 as the power supply voltage. The arithmetic processing unit 15 sends out the control signals S4 and S5 generated based on the command signal S6 from the outside and the detection signals S1, S2 and S3.

The arithmetic processing unit 15 determines whether or not the voltage of the commercial AC power supply G is normal based on the detection signal S1, and if it is normal, the load drive unit 15 is based on the command signal S6 and the detection signals S2 and S3. The control signal S4 transmitted to 3 is changed, and the operating state of the load driving unit 3 is switched to any of a power running state, a regenerative state, a recirculation state, and a stopped state.

In the power running state, as shown in FIG. 3A, the switch elements SW1 and SW4 are set to the on state (closed state), and the other switch elements SW2 and SW3 are set to the off state (open state). As a result, the current path of "power conversion unit 2 (power storage unit 4)-> switch element SW1-> inductive load L-> switch element SW4-> power conversion unit 2 (power storage unit 4)" is constructed, and the inductive load L is constructed. Load current I flows through. It should be noted that in each figure of FIG. 3, the illustration of the element or the like that does not construct the current path is omitted.

In the regenerative state, as shown in FIG. 3B, all the switch elements SW1, SW2, SW3, and SW4 are turned off. As a result, a current path of “inductive load L → diode D3 → power storage unit 4 → diode D2 → inductive load L” is constructed, and the residual power of the inductive load L is regenerated in the power storage unit 4.

In the reflux state, as shown in FIG. 3C, the switch element SW1 is turned on, and the other switch elements SW2, SW3, and SW4 are turned off. As a result, a current path of “inductive load L → freewheeling diode D3 → switch element SW1 → inductive load L” is constructed, and the residual power of the inductive load L is consumed as heat in the freewheeling diode D3.

In the stopped state, all the switch elements SW1, SW2, SW3, and SW4 are turned off.

When the arithmetic processing unit 15 receives the command signal S6 for driving the inductive load L when the voltage of the commercial AC power supply G is normal, the arithmetic processing unit 15 changes the operating state of the load driving unit 3 from the stopped state to the power running state. As a result, the load current I is raised, and then the load current I is lowered by changing the operating state of the load drive unit 3 to the regenerative state. If the detection signal S2 indicates a voltage larger than a predetermined threshold value, the arithmetic processing unit 15 may damage the power storage unit 4 due to overvoltage when regeneration is performed. Therefore, the load drive unit 3 The load current I is lowered by changing the operating state of the above to a reflux state instead of a regenerative state. When the detection signal S2 indicates a voltage smaller than a predetermined threshold value, the arithmetic processing unit 15 lowers the load current I by changing the operating state of the load driving unit 3 to the regenerative state as described above. ..

Further, the arithmetic processing unit 15 continues to send the control signal S5 for stopping the auxiliary power supply unit 5 while the voltage of the commercial AC power supply G is normal. As a result, the auxiliary power supply unit 5 is maintained in a stopped state (a state in which 5 [V] is not output). At this time, the auxiliary power supply unit 5 does not consume the power stored in the power storage unit 4. At this time, the capacitor 13 is charged by the output voltage of the step-down DC / DC converter 12.

On the other hand, when the arithmetic processing unit 15 detects that an abnormality such as a power failure has occurred in the voltage of the commercial AC power supply G based on the detection signal S1, the operating state of the load driving unit 3 changes from the previous state to the regenerative state. By doing so, the residual power of the inductive load L is regenerated in the power storage unit 4, and the load current I is lowered. After that, when it is detected that the load current I has been reduced based on the detection signal S3, the arithmetic processing unit 15 changes the operating state of the load driving unit 3 to the stopped state.

Similar to the case where the voltage of the commercial AC power supply G is normal, the arithmetic processing unit 15 regenerates only when the detection signal S2 shows a voltage larger than a predetermined threshold value (when there is a risk of overvoltage). The residual power of the inductive load L is consumed as heat by the recirculation state instead of the state. Also in this case, when the arithmetic processing unit 15 detects that the fall of the load current I is completed based on the detection signal S3, the operation state of the load drive unit 3 is changed to the stopped state.

If there is a risk of overvoltage when an abnormality such as a power failure occurs in the voltage of the commercial AC power supply G, the arithmetic processing unit 15 consumes the residual power of the inductive load L due to the reflux state. Further, if there is a risk of overvoltage while the residual power of the inductive load L is being regenerated, the arithmetic processing unit 15 switches the operating state of the load driving unit 3 from the regenerative state to the reflux state and the residual power. Continue to be consumed.

Further, when the arithmetic processing unit 15 detects that an abnormality such as a power failure has occurred in the voltage of the commercial AC power supply G based on the detection signal S1, it transmits a control signal S5 for operating the auxiliary power supply unit 5. In response to this, the auxiliary power supply unit 5 starts to output an auxiliary voltage of 5 [V].

When an abnormality occurs in the voltage of the commercial AC power supply G, the step-down DC / DC converter 12 stops the output. Further, it takes a certain amount of time from the transmission of the control signal S5 from the arithmetic processing unit 15 to the auxiliary power supply unit 5 until the output of the auxiliary voltage starts. In consideration of these, in this embodiment, the capacitor 13 is provided between the step-down DC / DC converters 12 and 14. As a result, the input voltage of the step-down DC / DC converter 14 is maintained near 5 [V] until the output of the auxiliary voltage starts, and the power supply voltage is supplied from the step-down DC / DC converter 14 to the arithmetic processing unit 15. Continue to be done.

As described above, in the inductive load power supply device 1, when an abnormality such as a power failure occurs in the commercial AC power supply G, the auxiliary voltage generated by the auxiliary power supply unit 5 instead of the voltage of the commercial AC power supply G is the power supply of the control unit 10. It becomes a voltage. Therefore, according to the inductive load power supply device 1, even after an abnormality occurs, the residual power of the inductive load L is safely consumed by switching the operating state of the load driving unit 3 to the regenerative state or the reflux state. be able to.

Although the inductive load power supply device 1 according to the embodiment of the present invention has been described above, the configuration of the present invention is not limited to the configuration of the embodiment.

For example, the power storage unit 4 may be a secondary battery such as a lithium ion battery.

Further, the switch elements SW1, SW2, SW3, and SW4 may be other semiconductor switches such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistor).

Further, in order to drive a large current, each of the arms 3a and 3b of the load drive unit 3 may have a plurality of arms connected in parallel.

1 Inductive load power supply 2 Power conversion unit 3 Load drive unit 3a 1st arm 3b 2nd arm 4 Power storage unit 5 Auxiliary power supply unit 6 1st voltage detection unit 7 2nd voltage detection unit 8 Current detection unit 10 Control unit 11 AC / DC converter 12 Step-down DC / DC converter 13 Capacitor 14 Step-down DC / DC converter 15 Arithmetic processing unit G Commercial AC power supply L Inductive load SW1, SW2, SW3, SW4 Switch element D1, D2, D3, D4 Freewheeling diode

Claims (2)

A power supply device for inductive loads that drives inductive loads.
A power converter that converts the power supplied from a commercial AC power supply into direct current and outputs it,
A power storage unit provided on the output side of the power conversion unit and storing at least a part of the power output from the power conversion unit,
A load drive unit including a plurality of switch elements provided on the output side of the power conversion unit and a freewheeling diode provided in each of the switch elements, and a load drive unit.
At least a control unit that controls the opening and closing of the switch element,
Auxiliary power supply unit connected to the power storage unit and
The first voltage detection unit that detects the voltage of the commercial AC power supply and
A second voltage detection unit that detects the voltage of the power storage unit, and
With
When the voltage detected by the first voltage detection unit is normal, the control unit uses the voltage of the commercial AC power supply as the power supply voltage, and (2) detects it by the first voltage detection unit. When the voltage is abnormal, the auxiliary power supply unit is configured to use the auxiliary voltage generated based on the power stored in the power storage unit as the power supply voltage .
Further, in the control unit, (3) when the voltage detected by the first voltage detection unit is abnormal and the voltage detected by the second voltage detection unit is smaller than a predetermined threshold value, By controlling the opening and closing of the switch element, the load drive unit is brought into a regenerated state, the power remaining in the inductive load is regenerated in the power storage unit, and (4) the voltage detected by the first voltage detection unit. Is abnormal and the voltage detected by the second voltage detection unit is larger than the threshold value, the load drive unit is brought into a recirculation state by controlling the opening and closing of the switch element, and the inductive load is applied. An inductive load power supply device characterized in that the remaining power is consumed in the load drive unit. Before SL control section, when the voltage detected by the first voltage detecting unit is abnormally changes from normal to claim 1, characterized in that to start the operation by sending a command signal to the auxiliary power unit The power supply for the inductive load described.

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