JP5160108B2 - Lifting magnet control system - Google Patents

Description

  The present invention relates to a lifting magnet control system.

  Lifting magnets are used to lift and carry suspended loads such as iron pieces in construction work and the like, and are installed at the tip of a vehicle arm such as a hydraulic excavator. When using a lifting magnet, current is passed in a certain direction to excite the lifting magnet, and the suspended load is attracted and lifted. Then, when releasing the suspended load, the lifting magnet is demagnetized by passing a current in the opposite direction.

  FIG. 8 shows a conventional system configuration for supplying such excitation current and release current to the lifting magnet. The lifting magnet control system 100 shown in FIG. 1 includes an induction AC generator 102, a DC conversion unit 104 that converts AC power output from the induction AC generator 102 into DC power, and a DC output that is output from the DC conversion unit 104. An H bridge circuit 108 that supplies power to the magnet 106 while controlling the direction of electric power, and a capacitor 116 for regenerating energy stored in the magnet 106 are provided. The lifting magnet control system 100 drives an automatic voltage regulator (AVR) 110 that boosts the AC voltage when the AC voltage output from the induction AC generator 102 is low, and an H-bridge circuit 108. And a power supply module 114 that generates a DC power supply voltage supplied to the bridge driver 112 from the AC voltage from the induction AC generator 102. When the control system 100 is mounted on a vehicle, the vehicle includes a hydraulic pump driven by an engine and a hydraulic motor driven by the hydraulic pump, and the induction AC generator 102 is driven by the hydraulic motor. Is done.

Patent Document 1 discloses a self-propelled working machine equipped with a lifting magnet. In this self-propelled working machine, when the AC voltage output from the generator is low, the AC voltage is boosted by a boost chopper circuit.
JP 2004-299818 A

  As described above, a conventional lifting magnet control system mounted on a vehicle includes an induction AC generator as a generator. However, when the rotational speed of the vehicle engine falls below a certain fixed value, the output voltage from the induction AC generator tends to drop sharply. Therefore, it is difficult to keep the suspended load adsorbed when the engine speed decreases, and the power supply voltage of the bridge driver is generated using the AC power from the induction AC generator. If the voltage drops, the bridge driver cannot operate, and the suction operation becomes impossible. Therefore, there is a demand for a lifting magnet control system that cannot lower the engine speed in order to carry suspended loads even during nighttime work, and that can carry suspended loads even when the engine speed is low.

  The present invention has been made in view of the above-described problems, and provides a lifting magnet control system that is mounted on a vehicle equipped with a lifting magnet and can adsorb a suspended load to the lifting magnet even when the engine speed is low. For the purpose.

In order to solve the above-mentioned problems, a lifting magnet control system according to the present invention is a lifting magnet control system mounted on a vehicle equipped with a lifting magnet, and is supplied from a synchronous AC generator and a synchronous AC generator. A DC converter that converts AC power into DC power and a plurality of transistors, an H bridge circuit that controls the direction of DC power and supplies the DC power to the lifting magnet, and drives the transistors a bridge driver for a storage battery for supplying a DC supply voltage to the bridge driver, a DC conversion unit, H-bridge circuit portion, and a magnet control board for mounting the bridge driver, the magnet control panel, induction synchronous alternator Adjusts the output voltage of the induction alternator when converted to an alternator Characterized in that it has a space for mounting the automatic voltage regulator that.

  In this lifting magnet control system, a synchronous AC generator is provided as a generator. The output voltage of the synchronous alternator tends to decrease in proportion to the decrease in the engine speed of the vehicle. Therefore, the output voltage does not drop rapidly as in the induction AC generator, and the adsorption force can be maintained even if the engine speed is somewhat reduced. Further, since the power supply voltage from the storage battery is supplied to the bridge driver, even if the engine speed decreases, the operation of the bridge driver is not affected. That is, according to this lifting magnet control system, even if the engine speed is low, the lifting magnet can be adsorbed to the lifting magnet, so that the suspended load is prevented from dropping due to a decrease in the engine speed, and the engine rotation is performed at night. It is also possible to work quietly by reducing the number.

The lifting magnet control system also includes a magnet control panel on which a DC conversion unit, an H-bridge circuit unit, and a bridge driver are mounted. When the synchronous AC generator is replaced with an induction AC generator, the magnet control panel more and this with a space for mounting the automatic voltage regulator for regulating the output voltage of the induction alternator, even when the synchronous alternator is retrofit to the induction alternator divert the lifting magnet control system Can increase versatility.

  ADVANTAGE OF THE INVENTION According to this invention, the lifting magnet control system which can be mounted in the vehicle equipped with the lifting magnet and can make a lifting magnet adsorb | suck to a lifting magnet even when an engine speed is low can be provided.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a lifting magnet control system according to the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In the following description, a transistor includes both a bipolar transistor and a field effect transistor (FET). When the transistor is an FET, the base is read as the gate, the collector as the drain, and the emitter as the source.

  FIG. 1 is a perspective view illustrating a configuration of a lifting magnet vehicle that is a work machine on which the lifting magnet control system according to the present embodiment is mounted. As shown in FIG. 1, a lifting magnet vehicle (hereinafter referred to as a magnet vehicle) 1 is a lifting magnet (hereinafter referred to as a lifting magnet) that attracts and captures a suspended load 90 such as a steel material by a magnetic force at the tip of an arm 12 of a hydraulic excavator (base machine). , Magnet) 10 is mounted. Further, the magnet vehicle 1 includes a cab 14 for accommodating an operator who operates the position of the magnet 10, the excitation operation, and the release operation.

  A lifting magnet control system (hereinafter referred to as a magnet control system) 2 mounted on the magnet vehicle 1 includes a magnet control panel 3 that supplies power to the magnet 10 and a synchronous AC generator that supplies three-phase AC power to the magnet control panel 3. 4 and a battery (storage battery) 5 for supplying a DC power supply voltage to the magnet control panel 3. The magnet vehicle 1 is equipped with a hydraulic pump driven by the engine of the vehicle 1 and a hydraulic motor driven by the hydraulic pressure from the hydraulic pump, and the synchronous AC generator 4 is driven by the hydraulic motor. The The synchronous alternator 4 is a so-called permanent magnet (PM) synchronous generator having a permanent magnet as a field.

FIG. 2 is a block diagram showing the configuration of the magnet control system 2 according to the present embodiment. As described above, the magnet control system 2 includes the magnet control panel 3, the synchronous AC generator 4, and the battery 5. The magnet control panel 3 has a magnet drive circuit 31 and a bridge driver 32. The magnet drive circuit 31 receives the three-phase AC power supply voltages V _{AC1 to} V _AC3 from the synchronous AC generator 4, and the bridge driver 32 is a battery. 5 receives DC power supply voltage _VBAT . The magnet drive circuit 31 is a circuit that supplies power (excitation current I ₁ , release current I ₂ ) to the magnet 10, and includes an H bridge circuit unit that controls the direction of the current flowing through the magnet 10. The bridge driver 32 is a circuit that drives the H-bridge circuit unit, and the DC power supply voltage V _BAT is constant (for example, DC 24V).

  FIG. 3 is a circuit diagram showing a configuration of the magnet drive circuit 31. Referring to the figure, the magnet drive circuit 31 includes a DC conversion unit 33, an H bridge circuit unit 34, an energy absorption unit 35, a control unit 36, a current measurement unit 37, and a potential difference measurement unit 38.

The DC converter 33 is a circuit part for converting the AC power supply voltages V _{AC1 to} V _AC3 supplied from the synchronous AC generator 4 into the DC power supply voltage V _DC . The DC converter 33 of the present embodiment is configured by a bridge circuit including six diodes 33a to 33f, and performs three-phase full-wave rectification. The generated DC power supply voltage V _DC is provided to the positive power supply line 33g and the negative power supply line 33h. In addition, the DC conversion unit may be configured by, for example, a pure bridge circuit using a thyristor or a mixed bridge circuit using a diode and a thyristor. In the case where the DC conversion unit is configured by a pure bridge circuit or a mixed bridge circuit, the thyristor is phase-controlled at a predetermined control angle by a phase control circuit (not shown).

  The H bridge circuit unit 34 is a circuit part for controlling the direction of the current supplied to the magnet 10. The H bridge circuit section 34 includes four transistors 34a to 34d and four diodes (rectifiers) electrically connected between current terminals (between the collector and the emitter or between the source and drain) of the four transistors 34a to 34d. (Elements) 34e to 34h and terminals 34i and 34j to which wires 18a and 18b for supplying current to the magnet 10 are connected.

  Specifically, one current terminal of the transistor 34a is electrically connected to the positive power supply line 33g, and the other current terminal of the transistor 34a is electrically connected to the terminal 34i. One current terminal of the transistor 34b is electrically connected to the terminal 34i, and the other current terminal of the transistor 34b is electrically connected to the negative power supply line 33h. One current terminal of the transistor 34c is electrically connected to the positive power supply line 33g, and the other current terminal of the transistor 34c is electrically connected to the terminal 34j. One current terminal of the transistor 34d is electrically connected to the terminal 34j, and the other current terminal of the transistor 34d is electrically connected to the negative power supply line 33h. The anodes of the diodes 34e to 34h are electrically connected to the other current terminals of the transistors 34a to 34d, respectively, and the cathodes of the diodes 34e to 34h are electrically connected to one of the current terminals of the transistors 34a to 34d, respectively. It is connected to the.

The bases of the transistors 34a to 34d are electrically connected to the bridge driver 32 (see FIG. 2). The conduction state between the collector and the emitter in each of the transistors 34a to 34d is a control current Sa provided from the bridge driver 32. Controlled by ~ Sd. For example, when the control current Sa to the base terminal of the transistor 34a and 34d, Sd are provided, the exciting current _{I 1} in the positive direction, the transistor 34a, the terminal 34i, the magnet 10, through the terminal 34j, and the order of the transistor 34d. The control current Sb to the base terminal of the transistor 34b and 34c, the Sc is provided, opposite the direction of release current (demagnetizing current) _{I 2} is, transistor 34c, the terminal 34j, magnet 10, the terminal 34i, and the transistor 34b sequentially flows (i.e., in the opposite direction to the exciting current I _1).

The energy absorption part 35 is a circuit part for absorbing the energy accumulated in the magnet 10 when the excitation current I ₁ to the magnet 10 is switched to the release current I ₂ . The energy absorption unit 35 includes an npn transistor 35a, a diode (rectifier element) 35b, a resistance element 35c, and a capacitor (capacitance element) 35d. The diode 35b is arranged as necessary and can be omitted.

  The transistor 35a and the resistance element 35c are electrically connected between the positive power supply line 33g and the negative power supply line 33h, and are connected in series with each other. Specifically, the collector terminal of the transistor 35a is electrically connected to the positive power supply line 33g, and the emitter terminal of the transistor 35a is electrically connected to one end of the resistance element 35c. The other end of the resistance element 35c is electrically connected to the negative power supply line 33h. The cathode and anode of the diode 35b are electrically connected to the collector terminal and the emitter terminal of the transistor 35a, respectively. The capacitor 35d is connected in parallel to the transistor 35a and the resistance element 35c. Note that a control current Se is provided to the base terminal of the transistor 35a from the control unit 36 described later, and the conduction state of the transistor 35a is controlled by the control current Se.

  The current measuring unit 37 measures the direction and magnitude of the current flowing toward the energy absorbing unit 35 through the positive power supply line 33g between the H bridge circuit unit 34 and the energy absorbing unit 35. The current measuring unit 37 provides the control unit 36 with a current signal Si indicating the direction and magnitude of the current as a measurement result. The potential difference measuring unit 38 is a circuit portion for measuring a potential difference between the positive power supply line 33g and the negative power supply line 33h. The potential difference measuring unit 38 provides the control unit 36 with a potential difference signal Sv indicating a potential difference as a measurement result. The magnet drive circuit 31 of the present embodiment includes both the current measurement unit 37 and the potential difference measurement unit 38, but the magnet drive circuit 31 includes only one of the current measurement unit 37 and the potential difference measurement unit 38. Also good.

  The control unit 36 controls the conduction state in the transistor 35a of the energy absorbing unit 35 based on the current signal Si and the potential difference signal Sv. The control unit 36 outputs a control current Se when a current from the H-bridge circuit unit 34 to the energy absorption unit 35 is generated, or when the potential difference signal Sv is equal to or greater than a predetermined value. Conduction between emitters. In addition, the control unit 36 stops the output of the control current Se when the current signal Si becomes equal to or lower than a predetermined value or when the potential difference signal Sv becomes equal to or lower than the predetermined value in a state where the transistor 35a is conductive. Thus, the collector-emitter of the transistor 35a is disconnected.

Here, the arrangement of components inside the magnet control panel 3 will be described. FIG. 4 is a side view showing the inside of the magnet control panel 3. The magnet control panel 3 has a metal case 39, and the magnet drive circuit 31 and the bridge driver 32 described above are built in the case 39. In the figure, A is a cooling fan, B is diode module (diode 33a~33f DC converter 33 in this is contained), C is the transistor 35a of the energy absorbing portion _{35, D 1,} D ₂ are IGBT Module (in which the transistors 34a to 34d of the H-bridge circuit unit 34 are housed), E is a CPU board including the bridge driver 32, F is a resistance element 35c of the energy absorption unit 35, and G includes a control unit 36 A wiring board, H and I are detection circuits for detecting current and voltage to the magnet 10, and J is a terminal block. K is a space for mounting the automatic voltage regulator, and nothing is installed in this embodiment. The automatic voltage regulator is installed to adjust the output voltage of the induction alternator when the synchronous alternator 4 is replaced with an induction alternator.

  Next, the operation of the magnet drive circuit 31 will be described. 5 shows (a) a voltage applied to both ends of the magnet 10, (b) an amount of current in the positive power supply line 33g between the H bridge circuit section 34 and the energy absorbing section 35, and (c) a positive power supply. It is a graph which shows a time waveform of the potential difference between the line 33g and the negative side power supply line 33h, respectively. 5B, the direction of the current from the H bridge circuit unit 34 to the energy absorption unit 35 is positive.

First, at a certain time t ₀ , the synchronous AC generator 4 is driven to generate three-phase AC power supply voltages V _{AC1 to} V _AC3 . These AC power supply voltages V _{AC1 to} V _AC3 are converted into the DC power supply voltage V _DC by the DC conversion unit 33 and provided to the H bridge circuit unit 34 (see FIG. 5C). Then, at time _{t 1,} to excite the magnet 10. That is, the bridge driver 32 makes the transistors 34a and 34d of the H bridge circuit section 34 conductive. Accordingly, the transistor 34a, the magnet 10, the exciting current _{I 1} flows in the order of the transistor 34d (see Figure 5 (b)). That is, the excitation voltage V is output between the terminal 34i and the terminal 34j of the H bridge circuit unit 34 (see FIG. 5A). Thereby, the magnet 10 is excited and can attract and lift an iron piece or the like.

Subsequently, the operation moves to release iron pieces from the magnet 10. First, at time _{t 2,} to release the excitation of the magnet 10. That is, the bridge driver 32 disables the transistors 34a and 34d of the H bridge circuit unit 34. At this time, due to the energy accumulated in the magnet 10, a voltage due to the back electromotive force is generated at both ends of the magnet 10 (that is, between the terminals 34i and 34j) (Q portion in FIG. 5A). At the same time, a current (R portion in FIG. 5B) resulting from the back electromotive force flows through the diode 34f, the magnet 10, and the diode 34g.

  At this time, the current due to the accumulated energy flows to the capacitor 35d of the energy absorption unit 35 for a very short time until the control unit 36 conducts the transistor 35a of the energy absorption unit 35. As the voltage across the capacitor 35d increases, the potential difference between the positive power line 33g and the negative power line 33h increases (S portion in FIG. 5C).

When the current due to the stored energy flows through the positive power supply line 33g, the current flows from the H bridge circuit section 34 to the energy absorption section 35, so that the direction of the current in the positive power supply line 33g is reversed. The control unit 36 recognizes that the current from the H bridge circuit unit 34 to the energy absorption unit 35 is generated by the current signal Si, thereby recognizing that the current due to the stored energy flows through the positive power supply line 33g. (Point P _{1 in} FIG. 5B). Then, the control unit 36 outputs a control current Se to conduct between the collector and emitter of the transistor 35a. As a result, the current due to the stored energy flows to the resistance element 35c via the transistor 35a, and is gradually attenuated while being consumed in the resistance element 35c.

Alternatively, since the voltage between both ends of the capacitor 35d increases due to the current due to the stored energy flowing to the capacitor 35d, the control unit 36 determines that the potential difference between the positive power line 33g and the negative power line 33h is a predetermined value V _th1. Also by the above, it can be recognized that the current due to the stored energy is flowing through the positive power supply line 33g (that is, even if the potential difference signal Sv from the potential difference measuring unit 38 becomes a predetermined value or more) (FIG. 5). (C) point P ₂ ). In such a case, the control unit 36 may output a control current Se to make the collector-emitter of the transistor 35a conductive.

Subsequently, when the magnitude of the current (current signal Si) from the H-bridge circuit unit 34 toward the energy absorption unit 35 becomes equal to or less than the predetermined value _Ith2 (point P _{3 in} FIG. 5B), the control unit 36 stores data. Recognize that the current due to energy is sufficiently attenuated. Then, the control unit 36 stops the output of the control current Se and disconnects between the collector and the emitter of the transistor 35a. The predetermined value I _th2 is preferably a value as close as possible to 0 [A].

Alternatively, also by the potential difference between the positive power supply line 33g and the negative side power line 33h is equal to or less than a predetermined value V _th3, (i.e., by the potential difference signal Sv from the potentiometric unit 38 is equal to or less than the predetermined value )) It can be recognized that the current due to the stored energy is sufficiently attenuated (point P _{4 in} FIG. 5C). In such a case, the control unit 36 may stop the output of the control current Se and disconnect between the collector and the emitter of the transistor 35a.

Then, at time _{t 3,} to demagnetize the magnet 10. That is, the bridge driver 32 makes the transistors 34b and 34c of the H bridge circuit section 34 conductive. Thus, the transistor 34c, the magnet 10, and the order of the transistor 34b release current _{I 2} flows (see Figure 5 (b)). That is, the release (demagnetization) voltage −V is output between the terminal 34 i and the terminal 34 j of the H-bridge circuit unit 34 (see FIG. 5A). Thereby, the magnet 10 is demagnetized and the iron piece etc. which were adsorbed can be released.

After demagnetization is complete, the non-delivery of the transistors 34b and 34c of the H-bridge circuit portion 34 at time _{t 4.} At this time, due to the energy accumulated in the magnet 10, a voltage due to the back electromotive force is generated at both ends of the magnet 10 (that is, between the terminals 34i and 34j) (T portion in FIG. 5A). At the same time, a current (the U portion in FIG. 5B) resulting from the counter electromotive force flows through the diode 34h, the magnet 10, and the diode 34e. The current due to the stored energy is absorbed by the energy absorbing unit 35 in the same manner as the above-described operation.

  The effect which the magnet control system 2 concerning this embodiment shows is explained. The magnet control system 2 includes a synchronous AC generator 4 as a generator. Here, FIG. 6A is a graph showing an example of a general output voltage characteristic of the synchronous AC generator, and FIG. 6B uses the synchronous AC generator as a generator of the magnet control system. It is a graph which shows an example of the characteristic of the magnet applied voltage in a case. 6A and 6B, the horizontal axis represents the number of revolutions [rpm] of the generator. As shown in FIG. 6A, the output voltage of the synchronous alternator is proportional to the rotational speed. Therefore, the magnet applied voltage is proportional to the rotational speed in a low rotational speed region below a certain rotational speed (about 1400 rpm in the figure) as shown in FIG. 6B. Note that, in a high rotational speed range equal to or higher than the rotational speed, the effective value of the magnet applied voltage is controlled to be constant (200 [V] in the figure) by PWM control by the bridge driver 32 (see FIG. 1).

  On the other hand, in the case of an induction alternator, as shown in FIG. 7A, when the rotational speed falls below a certain value (about 1200 rpm in the figure), the output voltage tends to rapidly decrease. Therefore, it becomes difficult to keep the suspended load adsorbed when the engine speed decreases. Further, in the conventional control system, as shown in FIG. 8, the DC power supply voltage for the bridge driver 112 is generated using the power from the generator 102, so that the output voltage of the generator 102 has a certain value. The DC power supply voltage cannot be generated when For this reason, when the output voltage of the generator 102 falls below a certain value, the bridge driver 112 cannot operate, and the magnet applied voltage decreases to near 0 [V] as shown in FIG. Is impossible. Also, in the method of boosting the magnet applied voltage using an automatic voltage regulator when the engine speed is low, excessive field current continues to flow through the generator if it continues to operate at a low speed, so the life of the generator Will be shorter.

  According to the magnet control system 2 according to the present embodiment, since the synchronous alternator 4 is provided, the output voltage of the generator rapidly increases as shown in FIGS. 7A and 7B even if the engine speed decreases. In addition, since the DC power supply voltage to the bridge driver 32 is also supplied from the battery 5, the magnet applied voltage is maintained at a significant level up to a somewhat low engine rotation range, and the attractive force is reduced. Can be maintained. That is, according to the magnet control system 2, the suspended load 90 can be attracted to the magnet 10 even when the engine speed is low, so that the suspended load 90 is prevented from dropping due to a decrease in the engine speed, and at night. It is also possible to work quietly at a low engine speed. In addition to eliminating the need for an automatic voltage regulator, a drive mechanism such as a hydraulic motor can be operated at a low speed, so that wear of parts can be suppressed and the life of the system can be extended.

  Further, the ability to perform the adsorption operation at a low engine speed is also preferable in the following points. In a vehicle such as a hydraulic excavator, the hydraulic pressure decreases as the engine speed decreases. Accordingly, the operation of the arm 12 shown in FIG. 1 becomes gentle, and even an unfamiliar operator can easily operate the arm 12. Furthermore, since the operation can be continued with the engine speed kept low, fuel consumption can be reduced.

  Moreover, as shown in FIG. 4, the magnet control panel 3 preferably has a space K for mounting an automatic voltage regulator. Thereby, even when the synchronous alternator 4 is replaced with an induction alternator, the magnet control system 2 can be used and versatility can be improved.

  In the present embodiment, the resistance element 35c is used for the energy absorbing portion 35 (see FIG. 3). Conventionally, the energy stored in the magnet is generally regenerated using the capacitor 116 shown in FIG. A capacitor having a relatively large capacity is used as the capacitor 116. However, if the withstand voltage of the large capacity capacitor is increased, the cost is increased and the size is increased. On the other hand, the synchronous alternator outputs a voltage proportional to the engine speed as shown in FIG. 6A, so that when the engine speed increases, the regeneration capacitor is required to have a pressure resistance. Therefore, the conventional magnet control system generally employs an induction alternator that can suppress the output voltage even when the engine speed increases as shown in FIG.

  On the other hand, in the present embodiment, the resistance element 35c (see FIG. 3) is used instead of such a large-capacitance capacitor, so that it can withstand a higher output voltage from the generator. That is, according to the magnet control system 2 of the present embodiment, the synchronous AC generator 4 whose output voltage increases in proportion to the engine speed can be suitably employed as the generator.

  The lifting magnet control system according to the present invention is not limited to the above-described embodiment, and various other modifications are possible. For example, in the above embodiment, a three-phase AC generator is exemplified as the generator, but as the generator of the present invention, various generators can be applied regardless of the number of phases as long as it is a synchronous AC type.

It is a perspective view which shows the structure of a lifting magnet vehicle. It is a block diagram which shows the structure of a magnet control system. It is a circuit diagram which shows the structure of a magnet drive circuit. It is a side view which shows the inside of a magnet control board. (A) the voltage applied to both ends of the magnet, (b) the amount of current in the positive power supply line between the H bridge circuit section and the energy absorption section, and (c) the positive power supply line and the negative power supply line It is a graph which shows each time waveform of the potential difference between. (A) It is a graph which shows an example of the general output voltage characteristic of a synchronous alternator. (B) It is a graph which shows an example of the characteristic of a magnet applied voltage at the time of using a synchronous alternating current generator as a generator of a magnet control system. (A) It is a graph which shows an example of the general output voltage characteristic of an induction AC generator. (B) It is a graph which shows an example of the characteristic of a magnet applied voltage at the time of using an induction AC generator as a generator of a magnet control system. It is a figure which shows the conventional system structure for supplying an exciting current and a release current to a lifting magnet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lifting magnet vehicle, 2 ... Lifting magnet control system, 3 ... Magnet control board, 4 ... Synchronous alternating current generator, 5 ... Battery, 10 ... Lifting magnet, 12 ... Arm, 14 ... Driver's cab, 31 ... Magnet drive circuit, 32 ... Bridge driver, 33 ... DC conversion unit, 34 ... Bridge circuit unit, 35 ... Energy absorption unit, 36 ... Control unit, 37 ... Current measurement unit, 38 ... Potential difference measurement unit, 39 ... Housing, 90 ... Suspended load, I ₁ ... excitation current, I ₂ ... release current, V _{AC1 to} V _AC3 ... three-phase AC power supply voltage, V _BAT ... DC power supply voltage.

Claims (1)

A lifting magnet control system mounted on a vehicle equipped with a lifting magnet,
A synchronous alternator,
A DC converter that converts AC power supplied from the synchronous AC generator into DC power;
An H-bridge circuit unit configured to include a plurality of transistors and control the direction of the DC power to supply the DC power to the lifting magnet;
A bridge driver for driving the plurality of transistors;
A storage battery for supplying a DC power supply voltage to the bridge driver ;
A magnet control board on which the DC converter, the H-bridge circuit, and the bridge driver are mounted ;
The magnet control panel has a space for mounting an automatic voltage regulator for adjusting an output voltage of the induction AC generator when the synchronous AC generator is replaced with an induction AC generator. , Lifting magnet control system.

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