JP2014116408A - Power source device for electromagnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power source device for an electromagnet, which can obtain a desired pulse-like current stably for a long time.SOLUTION: The power source device for an electromagnet comprises: a first current source configured to rise up/down the pulse-like current by means of discharge/regenerative current of a first capacitor; a second current source configured to maintain the pulse-like current at the top by means of discharge currents of second and third capacitors; a charging power source control part 7 configured to control charging powers 20, 30, and 32 of the corresponding capacitors so that a charging voltage reaches a predetermined set value; and current value determination means 73a configured to perform first to third determinations right after rise-up or right before rise-down in order to judge whether the current value at the top is included in a predetermined range or not. The current value determination means 73a performs the fist determination each time one pulse-like current is created, performs the second determination when it is judged in the determination that correction is unnecessary, and performs the third determination when it is judged in the determination that correction is unnecessary. The charging power source control part 7 corrects the set value judged to need correction.

Description

  The present invention relates to an electromagnet power supply device for applying a pulsed large current to an electromagnet used in an accelerator or the like.

  Accelerators used in fields such as physical chemistry experiments and medicine are equipped with an electromagnet power supply device for applying a pulsed large current to an electromagnet. As a conventional electromagnet power supply device, for example, a device using a power crowbar circuit described in Non-Patent Document 1 is known.

  As shown in FIG. 11A, this type of electromagnet power supply device 100 includes a first capacitor 101 and a second capacitor 102 having a capacitance value larger than that of the first capacitor 101. When the second switch 104 is turned ON / OFF, the discharge current (= electromagnet current I) of the first capacitor 101 and / or the second capacitor 102 is applied to the electromagnet 105.

More specifically, in the electromagnet power supply device 100, the first capacitor 101 is charged in advance with a high voltage of several thousand volts and the second capacitor 102 is charged with a voltage of several hundred volts in advance. As shown in FIG. 11B, when the first switch 103 is turned on at time t ₀ , the discharge current of the first capacitor 101 is supplied to the electromagnet 105 and the electromagnet current I is at the top (for example, several tens of kA). Stand up at a stretch. When the first switch 103 at time t ₁ and the second switch 104 is OFF is turned ON, the discharge current of the second capacitor 102 is supplied to the electromagnet 105, the current value of the electromagnet current I is maintained near the top. Thereafter, as the discharge current of the second capacitor 102 decreases, the current value of the electromagnet current I decreases.

  FIG. 12 shows another conventional electromagnet power supply device 200 whose concept is very similar to that of the electromagnet power supply device 100. As shown in the figure, the electromagnet power supply device 200 includes a first current source 201, a second current source 202, and a control unit 206.

The first current source 201 supplies the electromagnet current I to the top at a stroke by supplying the electromagnet 205 with the discharge current of the first capacitor 211 that has been precharged with a voltage of several thousand volts output from the first charging power supply 210. increased (Fig. 13 (B) of the time t ₀ ~ time t _1), and by regenerating the regenerative current by the back electromotive force of the electromagnet 205 in the first capacitor 211, once falling lower the electromagnet current I from the top (Fig. 13 (B) time t ₂ to time t ₃ ).

The second current source 202 supplies the electromagnet 205 with the discharge current of the second capacitor 221 precharged with a voltage of several hundred volts output from the second charging power source 220 after the electromagnet current I is raised. The current value at the top is maintained until the electromagnet current I falls (time t ₁ to time t _{2 in} FIG. 13B).

In this electromagnet power supply device 200, a period during which the electromagnet current I is raised (time t ₀ -time t ₁ ), a period during which the electromagnet current I is maintained (time t ₁ -time t ₂ ), and a period during which the electromagnet current I is lowered. At (time t ₂ to time t ₃ ), the conduction states of the two switching elements 215 a and 215 d of the first current source 201 and the two switching elements 225 a and 225 d of the second current source 202 are switched. The conduction states of these switching elements 215a, 215d, 225a, 225d are switched by the control unit 206 connected via appropriate drive circuits 216, 226.

Tami, “Pulse Power Technology Using Capacitors”, Journal of the Electrostatic Society, 1994, Vol. 18, No. 4, p. 355-363

  By the way, in the conventional electromagnet power supply device 200, in order to obtain a desired (ideal pulse-like) electromagnet current I, the operator determines and determines the charging voltages of the first capacitor 211 and the second capacitor 221. The operator sets the output voltages of the first charging power source 210 and the second charging power source 220 according to the charging voltage.

  Since the setting of the output voltages of the first charging power supply 210 and the second charging power supply 220 requires skill, it is practically impossible to change the setting of the output voltage while operating the electromagnet power supply apparatus 200. For this reason, in the conventional electromagnet power supply device 200, if the resistance value inside the electromagnet 205 or the first and second current sources 201 and 202 increases due to long-term use, as shown in FIG. There was a problem that the current value at the top of I was reduced by several percent from the start of use.

  Further, in the electromagnet power supply apparatus 200, when changing the setting of the output voltage of the first charging power supply 210 and the second charging power supply 220, the operation of the electromagnet power supply apparatus 200 is temporarily stopped, so that a desired electromagnet current I is set. There was also a problem that it took a lot of time and labor to obtain.

  This invention is made | formed in view of the said situation, The place made into the subject is to obtain a desired pulse-like electric current (electromagnet electric current) stably for a long time, without taking a lot of time and an effort. An object of the present invention is to provide a power supply device for an electromagnet.

  In order to solve the above-described problems, an electromagnet power supply device according to the present invention is (1) an electromagnet power supply device that continuously applies a pulsed current to an electromagnet, and is a first capacitor charged with a first voltage. By supplying the first discharge current to the electromagnet, the pulsed current is raised to the top, and the regenerative current due to the back electromotive force of the electromagnet is regenerated to the first capacitor, so that the pulsed current is lowered from the top. After the rise of the one current source and the pulsed current, the second discharge current of the second capacitor charged with the second voltage lower than the first voltage is supplied to the electromagnet, and then the second current lower than the second voltage is supplied. By supplying the third discharge current of the third capacitor charged with three voltages to the electromagnet together with the second discharge current, the second current is maintained at the top until the pulse current falls. A current source, a charging power source for charging the first capacitor, the second capacitor, and the third capacitor, and a first current value at least immediately after the rising of the pulsed current; Current value measuring means for measuring the second current value immediately before the lowering, the third current value at the top different from that immediately after the starting and immediately before the lowering, and the set values of the first voltage, the second voltage, and the third voltage are determined. A charging power source control unit that controls an output voltage of the charging power source so that the first voltage, the second voltage, and the third voltage are set to respective set values. A first determination as to whether or not the second current value is included in the predetermined range, a second determination as to whether or not the second current value is included in the predetermined range, and a first determination as to whether or not the third current value is included in the predetermined range. 3 determinations, and based on the results of the first determination, the second determination, and the third determination. Each having current value determining means for determining whether or not correction of the set value of the first voltage, the set value of the second voltage, and the set value of the third voltage is necessary. The first determination is always performed every time the current is generated. If it is determined that the correction of the set value of the first voltage is unnecessary in the first determination, the second determination is performed, and the second voltage is determined in the second determination. When it is determined that the correction of the set value is unnecessary, a series of determination steps for performing the third determination is repeatedly performed, and the charging power supply control unit corrects the set value determined to be corrected, the first voltage, The output voltage of the charging power supply is controlled so that the second voltage and the third voltage become the set values after correction.

  According to this configuration, when the current value of the pulsed current decreases due to long-term use, the set values of the charging voltages (first voltage, second voltage, and third voltage) of the first to third capacitors Is corrected, and the output voltage of the charging power supply is controlled so that each charging voltage becomes a set value after correction. Therefore, a desired pulsed current can be obtained stably for a long time without much time and effort.

  In the electromagnet power supply device according to (1) above, (2) the charging power supply control unit determines that the first voltage is determined when it is determined in the determination step that correction of the set value of the first voltage is necessary as a result of the first determination. Is corrected, the output voltage of the charging power supply is controlled so as to be the corrected first voltage setting value, the first determination is performed again, and then it is determined that the correction of the first voltage setting value is unnecessary. If it is determined that the setting value of the first voltage is not corrected, the process proceeds to the second determination. As a result of the second determination, if it is determined that the setting value of the second voltage needs to be corrected, The set value is corrected, the output voltage of the charging power supply is controlled so as to be the set value of the corrected second voltage, the first determination and the second determination are performed again, and then the set value of the second voltage is corrected. Is determined to be unnecessary, the process proceeds to the third determination without correcting the set value of the second voltage, and the result of the third determination When it is determined that correction of the set value of the third voltage is necessary, the set value of the third voltage is corrected, and the output voltage of the charging power supply is controlled to be the set value of the corrected third voltage, After performing the first determination, the second determination, and the third determination again in order, if it is determined that correction of the set value of the third voltage is unnecessary, the first determination is performed without correcting the set value of the third voltage. Can be configured to migrate.

  In the electromagnet power supply device of the above (1) or (2), (3) the charging power supply control unit includes a plurality of ranges used in the first determination, and 1 in the range so that the smaller the range is, the smaller the range is. A plurality of correction amounts used for correction of the first voltage and a plurality of ranges used in the second determination, which are associated with each other, are associated with the ranges on a one-to-one basis so that the smaller the range is, the smaller the range is. In addition, a plurality of correction amounts used for the correction of the second voltage, a plurality of ranges used in the third determination, and a plurality of ranges associated with the plurality of ranges in a one-to-one relationship so as to be smaller as the range is narrower. 3 further includes a storage unit storing a plurality of correction amounts used for correcting the voltage, and the first determination, the second determination, and the third determination are used in descending order of the plurality of ranges, respectively, and the charging power source control unit Is compensated by either determination in the current value determination means. If it is judged that the required, by referring to the storage unit, it is preferable to correct the set value by adding or subtracting the correction amount associated with the range used in the determination.

  According to this configuration, in the first to third determinations, a plurality of ranges are used in order from the largest, the determination is performed a plurality of times, and the smaller the range, the smaller the correction amount is used and the set value is corrected. The time required to obtain a desired pulse current can be further shortened.

  In the electromagnet power supply device according to (1) to (3) above, (4) as the third current value, an average value of two or more current values at the apex that is different from immediately after startup and immediately before shutdown may be used. .

  In the electromagnet power supply device according to (1) to (4) above, (5) the set values of the first voltage, the second voltage, and the third voltage at the start of use are preset initial values or the previous use start A setting value at the time may be used.

  In the electromagnet power supply device of (1) to (5) above, for example, (6) the charging power supply includes a first charging power supply that outputs a first voltage, a second charging power supply that outputs a second voltage, and a third voltage. And a third charging power source that outputs

  In the electromagnet power supply device of (1) to (5) above, (7) the charging power supply includes a first charging power supply that outputs the first voltage, a third charging power supply that outputs the third voltage, and a fourth voltage. And a second voltage may be a sum voltage of the third voltage and the fourth voltage.

  ADVANTAGE OF THE INVENTION According to this invention, the power supply apparatus for electromagnets which can obtain a desired pulse-shaped electric current stably for a long time can be provided, without taking much time and an effort.

It is a circuit diagram of the power supply device for electromagnets concerning the present invention. It is a block diagram of the charging power supply control part in this invention. It is a wave form diagram of the power supply device for electromagnets concerning the present invention, (A) is a whole wave form figure of electromagnet voltage, (B) is an enlarged wave form figure of (A), (C) is a whole wave form figure of electromagnet current, (D) is an enlarged waveform diagram of (C). It is a wave form diagram of the power supply device for electromagnets concerning the present invention, and (A) is an enlarged waveform figure in dashed-dotted line circle A in Drawing 3 (A), and (B) is in dashed-dotted line circle B in Drawing 3 (C). FIG. It is a flowchart of feedback control (START-step S12) in this invention. It is an example of the range-correction amount table stored in the memory | storage part in this invention. 6 is a flowchart of feedback control (steps S12 to S23) performed following step S12 of FIG. It is a flowchart of the feedback control (steps S23 to S34) performed following step S23 of FIG. It is a figure which shows the time change of the electromagnet current in this invention. It is a circuit diagram of the power supply apparatus for electromagnets which concerns on the modification of this invention. (A) is a circuit diagram of a conventional electromagnet power supply device, and (B) is a waveform diagram of an electromagnet current. It is a circuit diagram of the conventional electromagnet power supply device. It is a wave form diagram of the conventional power supply device for electromagnets, (A) is a wave form figure of electromagnet voltage, (B) is a wave form figure of electromagnet current. It is a figure which shows the time change of the electromagnet electric current in the conventional power supply apparatus for electromagnets.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an electromagnet power supply device according to the present invention will be described with reference to the accompanying drawings.

[Configuration of power supply for electromagnet]
FIG. 1 shows an electromagnet power supply device 1A according to an embodiment of the present invention. The electromagnet power supply device 1A is for applying an electromagnet current I which is a pulsed large current to the electromagnet 5, and as shown in the figure, the first current source 2, the second current source 3, and the control Unit 6, charging power source control unit 7, and current sensor 8 (corresponding to “current value measuring means” of the present invention) 8.

  The first current source 2 includes a first charging power supply 20 that outputs a first voltage (for example, several thousand volts), a first capacitor 21 that is charged with the first voltage, and four switching elements 25a that are H-bridge connected. ˜25d. One surge absorbing capacitor (not shown) is connected in parallel to each of the four switching elements 25a to 25d.

  The switching elements 25a to 25d of the first current source 2 constitute a bridge circuit unit, and the connection point of the first switching element 25a and the second switching element 25b is the first output terminal, the third switching element 25c and the fourth switching element 25d. Is the second output terminal. The first capacitor 21 is connected in parallel to the bridge circuit unit.

  The first switching element 25a and the fourth switching element 25d of the first current source 2 are power semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) and are control terminals of the first switching element 25a and the fourth switching element 25d. The gate is connected to the control unit 6 through a suitable drive circuit 26.

  The second current source 3 includes a second charging power source 30 that outputs a second voltage (for example, hundreds of tens of volts) lower than the first voltage, a second capacitor 31 that is charged with the second voltage, and a second voltage. A third charging power source 32 that outputs a lower third voltage (for example, 100 V), a third capacitor 33 having a larger capacitance value than the second capacitor 31 charged with the third voltage, and a third capacitor 33. Are connected in series, four switching elements 35 a to 35 d connected in H-bridge, and a fifth switching element 35 e connected in parallel to the rectifying element 34. Each of the four switching elements 35a to 35d and the fifth switching element 35e is connected in parallel with one surge absorbing capacitor (not shown).

  The switching elements 35a to 35d of the second current source 3 constitute a bridge circuit unit, and the connection point of the first switching element 35a and the second switching element 35b is the third output terminal, the third switching element 35c and the fourth switching element 35d. Is the fourth output terminal. The second capacitor 31 and the series circuit of the third capacitor 33 and the rectifying element 34 are connected in parallel to this bridge circuit unit.

  The first switching element 35a, the fourth switching element 35d, and the fifth switching element 35e of the second current source 3 are power semiconductor elements such as IGBTs, and the first switching element 35a, the fourth switching element 35d, and the fifth switching element. A gate which is a control terminal of 35e is connected to the control unit 6 through an appropriate drive circuit 36.

  The first output terminal of the first current source 2 and the fourth output terminal of the second current source 3 are connected to the electromagnet 5. The second output terminal of the first current source 2 and the third output terminal of the second current source 3 are directly connected.

  In FIG. 1, the first switching element 25a and the fourth switching element 25d of the first current source 2 and the first switching element 35a, the fourth switching element 35d and the fifth switching element 35e of the second current source 3 are controlled. Since the switching elements 25a, 25d, 35a, 35d, and 35e are turned on (conductive) / off (non-conductive), the drive circuits 26 and 36 are required because they are controlled by the unit 6.

  On the other hand, the second switching element 25b and the third switching element 25c of the first current source 2 and the second switching element 35b and the third switching element 35c of the second current source 3 do not switch ON / OFF, and the control unit Therefore, it is not necessary to perform control by 6, so that only the diode can be used, and the drive circuits 26 and 36 are unnecessary. This is why the switching elements 25b, 25c, 35b, and 35c are represented by diodes in FIG.

  As shown in FIG. 2, the charging power supply control unit 7 includes a difference calculation unit 71, an FPGA (Field Programmable Gate Array) 72, a PLC (Programmable Logic Controller) 73, and a storage unit 74. The PLC 73 has current value determination means 73a.

  The charging power supply controller 7 determines the set values of the charging voltages (first voltage, second voltage, third voltage) of the first capacitor 21, the second capacitor 31, and the third capacitor 33, and sets the capacitors 21, 31, 33. The output voltages of the first charging power source 20, the second charging power source 30 and the third charging power source 32 are controlled so that the charging voltage becomes the respective set values.

  As the set value of each charging voltage, the initial value set in advance or the set value at the start of the previous use is used at the start of use. When the current value at the top decreases, it is corrected. A specific method for correcting the set value will be described later. Instead of the initial value and the setting value at the start of previous use, the setting value at the end of use or the setting value used on the day when environmental conditions such as temperature are relatively similar may be used.

[Operation of electromagnet power supply]
As shown in FIG. 3, the operation of the electromagnet power supply device 1 </ b> A is divided into five phases I to V. In each phase, the first switching element 25a and the fourth switching element 25d of the first current source 2, and the first switching element 35a, the fourth switching element 35d and the fifth switching element 35e of the second current source 3 are controlled by the control unit. Under the control of 6, ON / OFF is switched as shown in the table below. Hereinafter, the operation of the electromagnet power supply device 1A in each phase will be described in order.

(Phase I)
Phase I is a preparation phase in which the first capacitor 21, the second capacitor 31, and the third capacitor 33 are charged.

  More specifically, the first capacitor 21 is charged by the first voltage output from the first charging power supply 20 until the voltage at both ends reaches several thousand volts, and the second capacitor 31 is output from the second charging power supply 30. The second voltage is charged until the voltage at both ends reaches several hundreds of volts, and the third capacitor 33 is charged by the third voltage output from the third charging power supply 32 until the voltage at both ends reaches approximately 100V. The

(Phase II)
Phase II is a current rising phase. In Phase II, the first current source 2 supplies the first discharge current of the first capacitor 21 to the electromagnet 5, whereby the electromagnet current I is raised to the top.

  More specifically, in Phase II, the first switching element 25a of the first current source 2 → the first output end of the first current source 2 → the electromagnet 5 → the fourth output end of the second current source 3 → the second current source 3 The fourth switching element 35d → the second switching element 35b (diode) of the second current source 3 → the third output terminal of the second current source 3 → the second output terminal of the first current source 2 → the first current source 2 The first discharge current of the first capacitor 21 flows through the path of the fourth switching element 25d. As a result, the electromagnet voltage rises to the charging voltage (= first voltage, several thousand volts) of the first capacitor 21, and the electromagnet current I rises to several tens of kA.

  In Phase II, the first switching element 35a of the second current source 3 may be set to ON, and the fourth switching element 35d of the second current source 3 may be set to OFF. In this case, the first discharge current of the first capacitor 21 is as follows: → the fourth output terminal of the second current source 3 → the third switching element 35 c (diode) of the second current source 3 → the second current source 3 It flows through the path of the first switching element 35a → the third output end of the second current source 3 →.

(Phase III)
Phase III is a current maintenance phase. In Phase III, the second current source 3 supplies the second discharge current of the second capacitor 31 and the third discharge current of the third capacitor 33 to the electromagnet 5, so that the current value of the electromagnet current I at the top is kept constant. Is done.

  More specifically, at the beginning of the transition to Phase III, the first switching element 35a of the second current source 3 → the third output end of the second current source 3 → the second output end of the first current source 2 → the first current source 2nd switching element 25d → second switching element 25b (diode) of the first current source 2 → first output terminal of the first current source 2 → electromagnet 5 → fourth output terminal of the second current source 3 → second The second discharge current of the second capacitor 31 flows through the path of the fourth switching element 35d of the current source 3. At this time, the voltage across the second capacitor 31 decreases from the second voltage (hundreds of tens of volts) with a relatively steep slope (hereinafter referred to as “first slope”) as the second discharge current is released. . Therefore, as shown in FIG. 3B, the electromagnet voltage also decreases with the same slope.

  When the voltage across the second capacitor 31 falls below the third voltage, the rectifying element 34 becomes conductive, and the third discharge current of the third capacitor 33 is also electromagnet through the same path as the second discharge current of the second capacitor 31. 5 begins to be fed. The voltage at both ends of the second capacitor 31 and the voltage at both ends of the third capacitor 33 decrease at a gentler slope than the first slope (hereinafter referred to as “second slope”) as the second and third discharge currents are released. I will do it.

  The first inclination can be adjusted by the capacitance value of the second capacitor 31, and the second inclination can be adjusted by the capacitance values of the second capacitor 31 and the third capacitor 33. In the electromagnet power supply device 1A according to the present embodiment, the capacitance value of the third capacitor 33 is set to be twice that of the second capacitor 31, the second gradient is set to about 1/3 of the first gradient, and further By appropriately adjusting the voltage difference between the second voltage and the third voltage, the electromagnet voltage waveform is approximated to an ideal electromagnet voltage waveform.

  In Phase III, the first switching element 25a of the first current source 2 may be set to ON and the fourth switching element 25d of the first current source 2 may be set to OFF. In this case, the second and third discharge currents are:-> second output terminal of the first current source 2-> third switching element 25 c (diode) of the first current source 2-> first of the first current source 2 It flows through the path of the switching element 25a → the first output end of the first current source 2 →.

(Phase IV)
Phase IV is a current falling phase. In Phase IV, the electromagnet current I is lowered from the top by causing the first capacitor 21 to regenerate a regenerative current caused by the back electromotive force V ₁ (−thousands of volts) of the electromagnet 5.

  More specifically, in Phase IV, the fourth output terminal of the second current source 3 → the fourth switching element 35d of the second current source 3 → the second switching element 35b (diode) of the second current source 3 → the second current source. 3 third output terminal → second output terminal of the first current source 2 → third switching element 25c (diode) of the first current source 2 → first capacitor 21 → second switching element 25b of the first current source 2 ( Diode) → A regenerative current flows through the path of the first output terminal of the first current source 2. As a result, the regenerative current is regenerated in the first capacitor 21 and the electromagnet current I is rapidly reduced from the top with a steep gradient (hereinafter referred to as “third gradient”).

  In Phase IV, the first switching element 35a of the second current source 3 may be set to ON, and the fourth switching element 35d of the second current source 3 may be set to OFF. In this case, the regenerative current is the fourth output terminal of the second current source 3 → the third switching element 35 c (diode) of the second current source 3 → the first switching element 35 a of the second current source 3 → the second current source 3. It flows in the path of the third output end →.

(Phase V)
Phase V is a slow-down phase. In the phase V, the regeneration to the first capacitor 21 is stopped, and the regenerative current caused by the back electromotive voltage V ₂ (V ₂ <V ₁ ) of the electromagnet 5 is regenerated in the second capacitor 31 and the third capacitor 33 to thereby regenerate the electromagnet. The current I is gently lowered.

  More specifically, in phase V, the fourth output terminal of the second current source 3 → the third switching element 35c (diode) of the second current source 3 → the second capacitor 31 → the second switching element 35b of the second current source 3 (Diode) → third output terminal of the second current source 3 → second output terminal of the first current source 2 → fourth switching element 25d of the first current source 2 → second switching element 25b of the first current source 2 ( Diode) → path of the first output terminal of the first current source 2 and... → third switching element 35c (diode) of the second current source 3 → fifth switching element 35e of the second current source 3 → third A regenerative current flows through a path from the capacitor 33 to the second switching element 35b (diode) of the second current source 3.

  As a result, the regenerative current is regenerated in the second capacitor 31 and the third capacitor 33, and the electromagnet current I decreases at a gentler slope (hereinafter referred to as “fourth slope”) than the third slope. When the gradient of the electromagnet current I becomes gentle, the energy of resonance generated between the electromagnet 5 and the second current source 3 becomes small. Therefore, as shown in FIG. Is suppressed (for example, suppressed to 0.1% or less of the current value at the top).

  In phase V, the first switching element 25a of the first current source 2 may be set to ON and the fourth switching element 25d of the first current source 2 may be set to OFF. In this case, the regenerative current is:-> second output terminal of the first current source 2-> third switching element 25 c (diode) of the first current source 2-> first switching element 25 a of the first current source 2-> second 1 Current source 2 flows through the first output end of the current source 2.

[Operation of charging power supply controller]
First, an outline of the operation of the charging power supply control unit 7 will be described with reference to FIG.

In the charging power source control unit 7, in phase II to phase IV, the electromagnet current I ₁ immediately after the start-up (time t ₁ in FIG. 3C) measured by the current sensor 8 immediately before the start-up (FIG. 3C). electromagnet current I ₂ at time t _2), the current value of the electromagnet current I ₃ at different apex immediately after rising and falling immediately before time t ₅ in (FIG. 3 (C)) is input to the difference calculation section 71 The

  The difference calculation unit 71 calculates the difference between these current values (actually measured values) and the set value (target value) of the electromagnet current I output from the PLC 73 and D / A converted by the FPGA 72, and inverts the calculated difference. Amplified and output to the FPGA 72. The FPGA 72 A / D converts the inverted and amplified difference and outputs it to the PLC 73. The set value (target value) of the electromagnet current I is set in advance by the operator.

  The PLC 73 performs feedback control, which will be described later, based on the difference output from the FPGA 72 while referring to the storage unit 74, and charges the first to third capacitors 21, 31, 33 (first voltage, second voltage, A set value of (third voltage) is determined, and an output voltage command value corresponding to the set value is output to each of the charging power supplies 20, 30, 32.

[Feedback control]
Next, feedback control performed by the PLC 73 will be specifically described with reference to FIGS. In PLC73, as triggered by the difference I _diff1, I _diff2, I _diff3 output from FPGA72, feedback control is started.

As shown in FIG. 5, the PLC 73 first determines whether or not there is a difference input (S1). PLC73, if the electromagnet current I ₁ output from FPGA72, I _2, each difference between the _{I 3 I diff1, I diff2,} I diff3 is not input, it is determined that no differential input (No in S1), the difference I _diff1, I _diff2, I _diff3 is repeated determination (S1) of the differential input to the input.

On the other hand, when the difference I _diff1, I _diff2, I _diff3 is input, PLC73, it is determined that there is differential input (in S1 Yes), the current value determination means 73a, the electromagnet current I ₁ within a predetermined range First, it is determined whether or not the set value of the charging voltage (first voltage) of the first capacitor 21 needs to be corrected (S2, S5, S8). In the present embodiment, the absolute value of the difference I _diff1 electromagnet current I ₁ by whether or not included in the scope R _1, R ₂ or R ₃ to be described later, the electromagnet current I ₁ is included in a predetermined range Determine whether or not.

As shown in FIG. 6, the storage unit 74 includes a plurality of ranges R ₁ , R ₂ ,... R ₉ and first to third voltages used in the first determination and second and third determinations described later. correction plurality of correction amount K _1, K ₂ used in the, and · · · K ₉ is stored. The boundary values I _set1 , I _set2 , and I _set3 of the ranges R ₁ , R ₂ ,... R ₉ in the present embodiment are the set value (target value) × 10% of the electromagnet current I at the top, respectively. X1% and the set value x0.1%. Further, the correction amounts K ₁ , K ₂ , and K ₃ used for correcting the first voltage are associated with the ranges R ₁ , R ₂ , and R ₃ on a one-to-one basis so as to decrease as the range becomes narrower. The correction amounts K ₄ , K ₅ , K ₆ used for correcting the second voltage and the correction amounts K ₇ , K ₈ , K ₉ used for correcting the third voltage are similarly set in the respective ranges R ₄ , R ₅ ,. .. 1 to 1 associated with R ₉

In step S2, whether or not the absolute value of the difference I _diff1 of the electromagnet current I ₁ is included in the range R ₁ by the current value determination means 73a, that is, whether or not the difference I _diff1 exceeds 10% of the set value. The first determination is performed for the first time. When it is determined that the absolute value of the difference I _diff1 is included in the range R ₁ (exceeds 10% of the set value), the current value determining unit 73a determines that correction of the set value of the first voltage is necessary ( If it is determined that the absolute value of the difference I _diff1 is not included in the range R ₁ (10% or less of the set value), it is determined that correction is unnecessary (No in S2).

If it is determined in step S2 that correction is necessary (Yes in S2), the PLC 73 refers to the storage unit 74 and adds or subtracts the correction amount K ₁ associated with the range R ₁ to the set value of the first voltage. As a result, the set value of the first voltage is corrected, and the corrected set value is determined as a new set value (S3). Whether the correction amount K ₁ is added or subtracted depends on the polarity of the difference I _diff1 of the electromagnet current I ₁ .

  When the new setting value of the first voltage is determined, the PLC 73 determines the output voltage command value of the first charging power supply 20 so that the charging voltage (first voltage) of the first capacitor 21 becomes the new setting value. Then, the output voltage command value is output to the first charging power source 20 (S4). In the present embodiment, the new set value of the first voltage becomes the output voltage command value of the first charging power supply 20.

When the output voltage command value of the first charging power supply 20 is outputted, PLC73 until the next electromagnet currents I _1, I _2, each of the I ₃ difference I _diff1, I _diff2, I _diff3 is input again the difference The determination of presence / absence of input is repeated (S1). That is, in the electromagnet power supply device 1 </ b> A according to the present embodiment, a maximum of one correction is performed for one pulse.

On the other hand, if it is determined in step S2 that no correction is necessary (No in S2), the current value determination unit 73a determines whether or not the absolute value of the difference I _diff1 of the electromagnet current I ₁ is included in the range R ₂ , that is, A second first determination is made as to whether or not the difference I _diff1 falls within the range of 10% to 1% of the set value, and it is determined whether or not the set value of the first voltage needs to be corrected ( S5).

If it is determined in step S5 that correction is necessary (Yes in S5), the PLC 73 sets the first voltage by adding or subtracting the correction amount K ₂ associated with the range R ₂ to the set value of the first voltage. The value is corrected (S6), the output voltage command value of the first charging power source 20 according to the new set value after correction is output (S7), and the presence / absence of differential input is again determined (S1).

On the other hand, if it is determined in step S5 that no correction is necessary (No in S5), the current value determination unit 73a determines whether or not the absolute value of the difference I _diff1 of the electromagnet current I ₁ is included in the range R ₃ , that is, the difference. A third first determination is made as to whether I _diff1 is included in the range of 1% to 0.1% of the set value, and it is determined whether correction of the set value of the first voltage is necessary. (S8).

If it is determined in step S8 that correction is necessary (Yes in S8), the PLC 73 sets the first voltage by adding or subtracting the correction amount K ₃ associated with the range R ₃ to the set value of the first voltage. The value is corrected (S9), the output voltage command value of the first charging power supply 20 corresponding to the new set value after correction is output (S10), and the presence / absence of differential input is again determined (S1).

  On the other hand, if it is determined in step S8 that no correction is necessary (No in S8), the PLC 73 sets the immediately previous set value as a new set value without correcting the set value of the first voltage (S11). Output voltage command value of 1 charging power supply 20 is output (S12).

Next, as shown in FIG. 7, the current value determining means ₇₃ a _performs the second determination as to whether or not the absolute value of the difference I _diff2 of the electromagnet current I ₂ is included in a predetermined range R ₄ , R ₅ or R _6. To determine whether or not it is necessary to correct the set value of the charging voltage (second voltage) of the second capacitor 31 (S13, S16, S19). Similar to the first determination, the second determination is performed a maximum of three times using the ranges R ₄ , R ₅ , and R ₆ that are narrowed in stages.

If it is determined in steps S13, S16, and S19 that correction is necessary (Yes in S13, S16, and S19), the PLC 73 sets the correction amounts K ₄ , K ₅ , and K associated with the ranges R ₄ , R ₅ , and R _6. The set value of the second voltage is corrected by adding or subtracting ₆ to the set value of the second voltage (S14, S17, S20), and the output voltage of the second charging power source 30 according to the new set value after the correction The command value is output (S15, S18, S21), and the presence / absence of a difference input is determined again (S1).

  On the other hand, if it is determined that correction is not necessary in all of steps S13, S16, and S19 (No in S19), the PLC 73 does not correct the set value of the second voltage (S22), and the output of the second charging power source 30. A voltage command value is output (S23).

Next, as shown in FIG. 8, the current value determining means 73 a performs the third determination as to whether or not the absolute value of the difference I _diff3 of the electromagnet current I ₃ is included in a predetermined range R ₇ , R ₈ or R _9. To determine whether or not it is necessary to correct the set value of the charging voltage (third voltage) of the third capacitor 33 (S24, S27, S30). Similar to the first determination and the second determination, the third determination is performed up to three times using the ranges R ₇ , R ₈ , and R ₉ that are narrowed in stages.

If it is determined that correction is necessary in steps S24, S27, and S30 (Yes in S24, S27, and S30), the PLC 73 corrects the correction amounts K ₇ , K ₈ , and K associated with the ranges R ₇ , R ₈ , and R _9. The set value of the third voltage is corrected by adding or subtracting ₉ to the set value of the third voltage (S25, S28, S31), and the output voltage of the third charging power source 32 according to the new set value after correction The command value is output (S26, S29, S32), and the presence / absence of a difference input is again determined (S1).

  On the other hand, if it is determined that correction is unnecessary in all of steps S24, S27, and S30 (No in S30), the PLC 73 does not correct the set value of the third voltage (S33), and outputs the third charging power source 32. A voltage command value is output (S34), and the presence / absence of a difference input is determined again (S1).

After all, according to the feedback control performed by the PLC 73, the set value of the first voltage is first determined (S11), and the current value of the electromagnet current I ₁ is determined. Then, the set value of the second voltage is determined (S14, S17, S20, S22 ), the current value of the electromagnet current I ₂ is determined. When it is necessary to correct the first voltage setting value by setting the second voltage setting value, the first voltage setting value is corrected according to the flow shown in FIG. 5 (S3, S6, S9). When the set value of the first voltage is determined (S11) and the set value of the second voltage is also determined (S22), finally, the set value of the third voltage is determined (S25, S28, S31, S33). When it is necessary to correct the set value of the second voltage because the set value of the third voltage is determined, the set value of the first voltage is determined according to the flow shown in FIG. 5 and then the flow shown in FIG. Accordingly, the set value of the second voltage is corrected (S14, S17, S20).

  That is, according to the electromagnet power supply device 1A according to the present embodiment, when the current value of the electromagnet current I is reduced due to long-term use, the maximum value of 1 per pulse is obtained by feedback control performed by the PLC 73. Each charging power source 20 so that a new set value is determined in the order of the first voltage, the second voltage, and the third voltage, and the first to third voltages become the new set values after correction. , 30, 32 are controlled. Therefore, according to the electromagnet power supply device 1A according to the present embodiment, as shown in FIG. 9, a desired electromagnet current (pulsed current) I can be obtained stably for a long time.

[Modification]
As mentioned above, although preferable embodiment of the power supply device for electromagnets which concerns on this invention was described, this invention is not limited to the said structure.

  FIG. 10 shows an electromagnet power supply device 1B according to a modification of the present invention. The electromagnet power supply device 1B is different from the electromagnet power supply device 1A according to the above-described embodiment in that the electromagnet power supply device 1B includes the second current source 4 instead of the second current source 3.

  The second current source 4 outputs a third charging power source 42 that outputs a third voltage (for example, 100 V), a third capacitor 43 that is charged with the third voltage, and a fourth voltage (for example, several tens of volts). A fourth charging power source 40, a second capacitor 41 charged with a second voltage that is the sum of the third voltage and the fourth voltage (for example, hundreds of volts), and a third capacitor 43 connected in series. A rectifying element 44, four switching elements 45a to 45d connected in an H-bridge, and a fifth switching element 45e connected in parallel to the rectifying element 44 are provided. However, as in the above embodiment, the second switching element 45b and the third switching element 45c of the second current source 4 need not be switched ON (conductive) / OFF (non-conductive) and must be controlled by the control unit 6. Therefore, it can be covered with a diode, and the drive circuit 46 is unnecessary.

  In the electromagnet power supply device 1B, since the second capacitor 41 is charged with the second voltage that is the sum of the third voltage and the fourth voltage, the charging power supply controller 7 performs steps S15, S18, S21, In S23, the output voltage commands of the third charging power source 42 and the fourth charging power source 40 are set so that the charging voltage (second voltage) of the second capacitor 41 becomes the set value determined in steps S14, S17, S20, and S22. The value is determined, and the output voltage command value is output to the third charging power source 42 and the fourth charging power source 40. Thereby, in the electromagnet power supply device 1B according to the present modification, a desired electromagnet current I can be obtained stably for a long time as in the above embodiment.

In the above embodiment, as the current value of the electromagnet current I _{3 at} the top, the current value at the time when the transitional change immediately after start-up is almost settled (time t ₅ in FIG. 3C) is used. You may use the average value of the current value of 2 or more points | pieces in the top part different from immediately before starting and immediately before falling.

  In the above embodiment, the first to third determinations are all performed three times, but the number of determinations may be reduced or increased. When the number of determinations is increased, it is necessary to complete all determinations after the generation of one electromagnet current I and before the generation of the next electromagnet current I (before shifting to Phase II). .

The ranges R ₁ , R ₂ , R ₃ used in the first determination in the above embodiment can be arbitrarily changed as long as they are narrowed in steps, and the correction amounts K ₁ , K ₂ , K ₃ are also small in steps. If it becomes, it can be changed arbitrarily. The ranges R ₄ , R ₅ ,... R ₉ and the correction amounts K ₄ , K ₅ ,... K ₉ used in the second and third determinations can be changed in the same manner.

In the above embodiment, in the first to third determination, electromagnet currents I _1, I _2, whether I ₃ is included in a predetermined range, the electromagnet currents I _1, I _2, each of the I ₃ difference I _The determination is based on whether or not the absolute values of _diff1 , I _diff2 and I _diff3 are included in the predetermined ranges R _{1 to} R ₉ , but may be determined by other methods.

  In the above embodiment, the second current source 3 is provided with the fifth switching element 35e, and the regenerative current is regenerated in the second capacitor 31 and the third capacitor 33 in the phase V, but the fifth switching element 35e is not provided. The regenerative current may be regenerated only by the second capacitor 31.

  In the above embodiment, the current value at the top of the electromagnet current I is kept constant by the discharge currents of the two capacitors (second capacitor 31 and third capacitor 33) precharged with different voltages, but the electromagnet voltage waveform is ideal. More preferably, the number of capacitors is three or more, and the gradient of the electromagnet voltage is switched twice or more from the viewpoint of approximating by the electromagnet voltage waveform. When the number of capacitors is three or more, the charging power supply control unit 7 has the highest charging voltage among the capacitors included in the second current source 3 in steps S14, S17, S20, and S22 of FIG. The setting value of the charging voltage of the capacitor may be determined, and the setting value of the charging voltage of the remaining capacitor in the second current source 3 may be determined in steps S25, S28, S31, and S33 of FIG.

  In the electromagnet power supply device 1A according to the above-described embodiment, a switch is provided that allows the charging power supply control unit 7 to select whether or not to perform the control in steps S2 to S34, and the switch is turned ON / OFF between step S1 and step S2. You may add the step which determines. If it is determined that the switch is ON in this step, the control in steps S2 to S34 is performed as described above. If it is determined that the switch is OFF, the set values of the first to third voltages are not corrected. The output voltage command value of each charging power source 20, 30, 32 can be output and the presence / absence of differential input can be determined again (S1).

  The switching elements 25a to 25d of the first current source 2 and the switching elements 35a to 35e of the second current source 3 in the above embodiment can each be configured by a parallel circuit of an IGBT and a diode.

1A, 1B Electromagnet power supply device 2 First current source 3, 4 Second current source 5 Electromagnet 6 Control unit 7 Charging power source control unit 8 Current sensor (current value measuring means)
20 1st charge power supply 21 1st capacitor | condenser 25a-25d 1st-4th switching element 26,36,46 of 1st current source Drive circuit 30 2nd charge power supply 31,41 2nd capacitor | condenser 32,42 3rd charge power supply 33 , 43 3rd capacitors 34, 44 Rectifier elements 35a-35d, 45a-45d, 1st-4th switching elements 35e, 45e of the 2nd current source, 5th switching element 40 of the 2nd current source 4th charge power supply 71 Difference Calculation unit 72 FPGA
73 PLC
73a Current value determination means 74 storage section

Claims (7)

An electromagnet power supply device that continuously applies a pulsed current to an electromagnet,
By supplying a first discharge current of a first capacitor charged with a first voltage to the electromagnet, the pulsed current is raised to the top, and a regenerative current due to a back electromotive voltage of the electromagnet is supplied to the first capacitor. A first current source that causes the pulsed current to fall from the top by regenerating,
After the rise of the pulsed current, a second discharge current of a second capacitor charged with a second voltage lower than the first voltage is supplied to the electromagnet, and then a third lower than the second voltage. Supplying a third discharge current of a third capacitor charged with a voltage together with the second discharge current to the electromagnet, thereby maintaining the pulsed current at the top until the pulsed current falls. The source,
A charging power source provided in the first current source and the second current source, for charging the first capacitor, the second capacitor, and the third capacitor;
At least a first current value immediately after the rise of the pulsed current, a second current value immediately before the fall, and a current value that measures a third current value of the top that is different from the just after the rise and immediately before the fall Measuring means;
The set values of the first voltage, the second voltage, and the third voltage are determined, and the output voltage of the charging power supply is set so that the first voltage, the second voltage, and the third voltage become the set values. A charging power control unit for controlling
With
The charging power supply controller includes a first determination as to whether or not the first current value is included in a predetermined range, a second determination as to whether or not the second current value is included in a predetermined range, A third determination is made as to whether or not the third current value is included in a predetermined range, and the set values of the first voltage are determined based on the results of the first determination, the second determination, and the third determination, respectively. And a current value determining means for determining whether or not correction of the set value of the second voltage and the set value of the third voltage is necessary,
The current value determination means always performs the first determination every time one pulsed current is generated. If it is determined in the first determination that correction of the set value of the first voltage is unnecessary, the current value determination means 2, and when it is determined that the correction of the set value of the second voltage is unnecessary in the second determination, a series of determination steps for performing the third determination is repeatedly performed, and the charging power supply controller The set value determined to be necessary is corrected, and the output voltage of the charging power source is controlled so that the first voltage, the second voltage, and the third voltage become the set values after correction. Electromagnet power supply. In the determination step, the charging power supply controller
As a result of the first determination, when it is determined that the set value of the first voltage needs to be corrected, the set value of the first voltage is corrected so as to be the set value of the first voltage after correction. After controlling the output voltage of the charging power source and performing the first determination again, if it is determined that correction of the set value of the first voltage is unnecessary, the set value of the first voltage is not corrected. Transition to the second determination,
As a result of the second determination, when it is determined that the set value of the second voltage needs to be corrected, the set value of the second voltage is corrected so as to be the set value of the second voltage after correction. When the output voltage of the charging power source is controlled and the first determination and the second determination are performed again in order, and it is determined that correction of the set value of the second voltage is unnecessary, the setting of the second voltage is performed. The process proceeds to the third determination without correcting the value,
As a result of the third determination, when it is determined that the setting value of the third voltage needs to be corrected, the setting value of the third voltage is corrected so that the corrected setting value of the third voltage is obtained. When the output voltage of the charging power source is controlled and the first determination, the second determination, and the third determination are sequentially performed again, and it is determined that correction of the set value of the third voltage is unnecessary, The electromagnet power supply device according to claim 1, wherein the first determination is made without correcting a set value of the third voltage. The charging power supply control unit is configured to correct a plurality of ranges used in the first determination, and a plurality of ranges used in the correction of the first voltage, which are associated with the ranges in a one-to-one relationship so as to be smaller as the range is smaller. A correction amount, a plurality of ranges used in the second determination, and a plurality of correction amounts used for correcting the second voltage, which are related to the range in a one-to-one relationship so that the range is smaller as the range is smaller. A plurality of ranges used in the third determination, and a plurality of correction amounts used for correcting the third voltage, which are related to the plurality of ranges on a one-to-one basis so as to decrease as the range becomes narrower. A storage unit further stored;
The first determination, the second determination, and the third determination are used in order of increasing the plurality of ranges,
If the current value determination means determines that correction is necessary in the current value determination unit, the charging power supply control unit refers to the storage unit and calculates a correction amount associated with the range used for the determination. 3. The electromagnet power supply device according to claim 1, wherein the set value is corrected by addition or subtraction.   The electromagnet according to any one of claims 1 to 3, wherein the third current value is an average value of current values at two or more points at the top, which is different from immediately after the start-up and immediately before the start-up. Power supply.   The set value of the first voltage, the second voltage, and the third voltage at the start of use is a preset initial value or a set value at the start of previous use. The power supply apparatus for electromagnets in any one of -4. The charging power source is
A first charging power supply for outputting the first voltage;
A second charging power source for outputting the second voltage;
A third charging power source for outputting the third voltage;
The electromagnet power supply device according to claim 1, comprising: The charging power source is
A first charging power supply for outputting the first voltage;
A third charging power source for outputting the third voltage;
A fourth charging power source for outputting a fourth voltage;
Have
6. The electromagnet power supply device according to claim 1, wherein the second voltage is a sum voltage of the third voltage and the fourth voltage.

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