JP4519471B2 - Power converter - Google Patents

Description

  The present invention relates to a power conversion device having a three-phase power conversion function using a semiconductor switching element including an IGBT (Insulated Gate Bipolar Transistor).

  In a conventional elevator system, a large DC motor is used for driving an elevator. However, a DC motor is not newly used at present, and a three-phase AC induction motor or a permanent magnet motor is often used. . However, on the other hand, there are still many elevator systems that use the past DC motors as they are, and some of them have already been operated for more than 20 years, and are aging considerably.

  Therefore, although the aging elevator system is being renewed as described above, the renewal of the control system that replaces only the control device while leaving the DC motor in place from the viewpoint of budget, construction period, removal space, etc. Construction method is taken.

  At present, PWM control by a converter device-inverter device of an AC electric motor is mainly used as a control device that is generally used. However, the control renewal method has a three-phase power conversion function in a portion corresponding to the inverter device. A power converter using a DC chopper circuit is configured and used to drive a DC motor.

FIG. 7 is a diagram showing a configuration of a conventional power converter.
In the figure, reference numeral 51 denotes a DC power supply that includes a three-phase AC power supply and a converter device and generates a required DC voltage. The DC voltage generated from the DC power supply 51 is between the P-side bus 52p and the N-side bus 52n. To be applied. 53 is similarly connected between the P-side bus 52p and the N-side bus 52n, and includes a plurality of switching elements 53p1, 53n1, 53p2, and 53n2 having a two-phase power conversion function. This is a smoothing capacitor that suppresses a surge voltage generated when a switching device such as a converter device (not shown) or an armature chopper device 53 is operated.

  Reference numeral 55 denotes a DC motor, which is connected to power lines 56 a and 56 b output from the armature chopper device 53. 57 is a field coil of the DC motor 55, and 58 is a field control unit that controls the field magnetic flux by energizing the field coil 57. Reference numeral 59 denotes an armature current sensor.

Next, the operation of the above apparatus will be described.
A required DC voltage is applied between the P-side bus 52p and the N-side bus 52n from a DC power source 51 such as a converter device. Further, the switching elements 53p1 to 53n2 constituting the armature chopper device 53 are gate-controlled based on a gate control signal output from a control unit (not shown), and a direct current applied between the P-side bus 52p and the N-side bus 52n. By choppering the voltage, the voltage applied between the armatures of the DC motor 55 is controlled to drive the DC motor 55. Further, since the DC motor 55 is not driven unless there is a field magnetic flux, it is possible to drive the DC motor 55 by generating a field magnetic flux by causing a field current to flow from the field control unit 58 which is a separate unit to the field coil 57. To do.

Further, as another conventional power conversion device, one having a configuration as shown in FIG. 8 has been proposed. In this power converter, among the three-phase inverter devices, switching elements 53p1 to 53n2 having a two-phase power conversion function constitute an armature chopper device 53a, and the remaining one-phase switching elements 53p3 and 53n3 are for field use. A power line 56d derived from a common connection portion of the switching elements 53p3 and 53n3 constituting the chopper device 53b and the power line outputted from the N-side bus 52n side of the power converter itself while constituting the chopper device 53b. This is a technique in which the field coil 57 of the DC motor 55 is connected to 56c, and the field control unit 58 shown in FIG. 7 is not required (Patent Document 1).
Japanese Patent Application Laid-Open No. 08-256497

By the way, the following problems are pointed out in the above power converters.
First, in the former power converter, the field control unit 58 is provided, but since this unit 58 is a separate unit, a new installation space is required. By the way, in renewal properties such as elevators, the size of the machine room has already been determined, and necessary equipment has been provided in accordance with the size, so there is a possibility that the installation space cannot be secured again.

  Further, when the field control unit 58 is a separate unit, a signal line (not shown) of a gate control signal for controlling the field control unit 58 becomes long, which may cause a malfunction due to noise or the like. Although it can be stored in other panels, it is necessary to modify the panel and take measures against noise.

  Further, in the power conversion device, a three-phase converter device or a three-phase inverter device is usually used. Of these, the armature chopper device 53 uses only a two-phase power conversion function. There is a problem that remains.

  Next, in the power conversion device that does not require the latter field control unit, the induced voltage of the motor 55 increases and the DC power supply voltage increases as the speed and capacity of the DC motor 55 increase. The rated voltage of the coil 57 becomes smaller than the DC power supply voltage, and a large voltage load is applied to the field coil 57, which may cause insulation deterioration of the coil 57 and breakage.

  The present invention has been made in view of the above circumstances, and does not require a field control unit, and even when the rated voltage of the field coil of the DC motor is lower than the voltage between the PN buses, the voltage applied to the field coil is kept low. It aims at providing the power converter device which avoids damage.

  Another object of the present invention is to provide a power converter that connects an output line inside the power converter and a regenerative resistor, not a field coil, and suppresses a voltage increase between PN buses during regeneration. It is in.

(1) In order to solve the above problems, the present invention provides a plurality of semiconductor switching elements having a three-phase power conversion function between PN buses to which a required DC voltage is applied, and operations of the plurality of semiconductor switching elements. In a three-phase power converter that drives a DC motor having a field coil, each of which is connected in series with a plurality of smoothing capacitors that suppress the surge voltage that sometimes occurs,
The armature of the DC motor is connected to the output side of the plurality of semiconductor switching elements having the power conversion function for two phases among the plurality of semiconductor switching elements having the three-phase power conversion function, and supplied from the outside A plurality of armature chopper devices that perform a chopper operation based on a first gate control signal and a plurality of semiconductor switching elements having the three-phase power conversion function and having a power conversion function for the remaining one phase. A field chopper device configured to perform chopper operation based on a second gate control signal supplied from the outside and a plurality of semiconductor switching elements constituting the field chopper device A feedback circuit element is connected together with the field coil between the smoothing capacitor and a middle point of the plurality of smoothing capacitors, The chopper operation by the use chopper device supplying an electric current to the field coil, and a configuration in which the field voltage reduction circuit to return the power energy stored in the field coil to the midpoint of the smoothing capacitor.

  With this configuration, the second control signal is sent from the external control unit to the field chopper device, and the chopper operation is performed here, so that the field coil of the DC motor can be controlled. Even when the rated voltage is lower than the voltage between PN buses, the midpoint voltage of the smoothing capacitor is chopper-operated with the field chopper device to energize the field coil, and the energy stored in the field coil is used for feedback. By feeding back to the middle point of the smoothing capacitor through the circuit element, as a result, the load voltage of the field coil can be suppressed, and therefore the field coil can be prevented from being damaged in advance, and the DC motor can be surely provided without providing a field control unit. Can be controlled.

  In the power conversion device having the configuration (1), when three or more smoothing capacitors are connected in series, the field voltage reduction circuit includes a plurality of semiconductors constituting the field chopper device. By connecting a feedback circuit element together with the field coil between a connection portion of the switching element and a connection point of the adjacent smoothing capacitor closest to the N-side bus of the three or more smoothing capacitors, Even when the rated voltage of the field coil is lower than half of the voltage between the PN buses, the voltage generated at the connection point of the adjacent smoothing capacitor closest to the N-side bus is chopper operated to energize the field coil to the field coil Since the energy stored in the field coil is returned to the connection point of the smoothing capacitor through the feedback circuit element, the load voltage applied to the field coil is small. Ri, it is possible to eliminate the damage caused by insulation deterioration and the like.

(3) Further, the present invention provides a plurality of semiconductor switching elements having a three-phase power conversion function and a surge voltage generated during operation of the plurality of semiconductor switching elements between PN buses to which a required DC voltage is applied. In the three-phase power converter for driving a DC motor having a field coil in which a plurality of smoothing capacitors to be suppressed are connected in series and the field current is controlled to flow from the field control unit,
The armature of the DC motor is connected to the output side of the plurality of semiconductor switching elements having the power conversion function for two phases among the plurality of semiconductor switching elements having the three-phase power conversion function, and supplied from the outside A plurality of armature chopper devices that perform a chopper operation based on a first gate control signal and a plurality of semiconductor switching elements having the three-phase power conversion function and having a power conversion function for the remaining one phase. A resistance connection device configured to perform a switching operation based on a switching control signal supplied from the outside, a connection point of a plurality of semiconductor switching elements constituting the resistance connection device, and the N-side bus The voltage that appears between the PN buses due to the switching operation by the resistance connection device during the regeneration mode of the DC motor It is a structure in which a regenerative current consumption resistor to consume the regenerative current to reduce.

  With the above configuration, the present invention increases the voltage between the PN buses in the regenerative mode of the DC motor and adversely affects the field coil side, but has a power conversion function for the remaining one phase. A resistance connection device is configured with a plurality of semiconductor switching elements, and a regenerative current consuming resistor is connected from the connection point of the plurality of semiconductor switching elements to the N-side bus, and the operation of the switching elements constituting the resistance connection device causes the PN Since the regenerative current is passed through the regenerative current consumption resistor so as to reduce the increasing voltage between the buses, the field coil can be prevented from being damaged.

  In addition, any power conversion device can be realized by using a DC motor having a field coil at the time of elevator renewal and having a three-phase power conversion function that is generally used at present.

(3) Furthermore, the present invention provides the power converter according to (1) or (2),
When applying to an AC motor instead of a DC motor, a plurality of semiconductor switching elements having the three-phase power conversion function are used as a three-phase inverter device, and a plurality of semiconductor switching devices for each phase constituting the inverter device If an output line connected to the armature and field coil or regenerative current consumption resistance of the DC motor from the connection point of the element is connected to the AC motor as it is, the power converter can be applied to the AC motor as it is.

  The present invention effectively uses the remaining one-phase power conversion function in addition to the chopper device for armature having a two-phase power conversion function, among a plurality of semiconductor switching elements having a three-phase power conversion function, By controlling so that the voltage applied to the field coil is kept low, it is possible to provide a power conversion device that eliminates the need for the field control unit and reduces the voltage load applied to the field coil to avoid breakage.

  Moreover, this invention can provide the power converter device which can suppress the voltage rise between the PN bus | baths at the time of regeneration by utilizing effectively the remaining one-phase power conversion function, and connecting with the resistor for regeneration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a configuration diagram showing an embodiment of a power converter according to the present invention.
In FIG. 1, for example, 1 converts AC power output from a three-phase AC power source 2 into DC power, supplies a required DC voltage to the armatures 3 a and 3 b of the DC motor 3, and drives the DC motor 3. It is the power converter device used as the principal part of this invention. 4 is a field coil of the DC motor 3, and 5 is an armature current sensor for detecting an armature current flowing from the power converter 1 to the power lines 6 a and 6 b connected to the armatures 3 a and 3 b of the DC motor 3. is there. Reference numeral 7 denotes a control unit that sends and controls a gate control signal to a semiconductor switching element having a three-phase power conversion function and the like constituting the power conversion device 1.

  Specifically, the power conversion device 1 is configured such that an AC power output from the three-phase AC power source 2 is a plurality of IGBTs and the like that are gate-controlled based on a gate control signal output from an external control unit 7. The converter device 11 that performs chopper operation by the converter switching elements 11a,... And converts it into a DC voltage of the required power, and the DC voltage that is connected between the P-side bus 12p and the N-side bus 12n and converted by the converter device 11 Is driven by a plurality of switching elements 13p1-13n1, 13p2-13n2, such as IGBTs, which are gate-controlled based on a gate control signal output from an external control unit 7, and a DC motor is supplied through power lines 6a and 6b. 3 of armature chopper device 13a to be supplied to 3 armatures 3a and 3b, and switching of the two phases of the three-phase power conversion function The elements 13p1 to 13n2 are used as the armature chopper device 13a. In order to obtain a voltage for applying the remaining one phase to the field coil 4, the P-side bus 12p and the N-side bus 12n A field chopper device 13b composed of switching elements 13p3 and 13n3 for field choppers such as IGBTs connected in series between them and gate-controlled in accordance with a gate control signal from the external control unit 7 as described above; A field midpoint voltage acquisition circuit 14 as a field voltage reduction circuit and a field current current sensor 15 are configured.

  The armature detection current detected by the armature current current sensor 5 and the field detection current detected by the field current current sensor 15 are introduced into the control unit 7.

  This field midpoint voltage acquisition circuit 14 includes a plurality of smoothing capacitors 14a1 and 14a2 connected in series between the P-side bus 12p and the N-side bus 12n, and between the P-side bus 12p and the N-side bus 12n. Are connected in series and individually connected in parallel so that the voltages applied to the smoothing capacitors 14a1 and 14a2 are evenly distributed, and a switching element 13p3 constituting the field chopper device 13b, 13n3 and a midpoint 14c of the smoothing capacitors 14a1 and 14a2, and when the switching element 13n3 is turned on, the midpoint voltage of the smoothing capacitors 14a1 and 14a2 is the field coil 4-power line 6c-switching. When field current flows through the path of element 13n3-N side bus 12n and switching element 13n3 is off A feedback semiconductor element 14d to lower the voltage between the field coil 4 by returning the power energy stored in the field coil 4 at the midpoint 11c of the smoothing capacitor 14a1,14a2 are provided.

  One end side of the field coil 4 is connected to the power line 6d derived from the middle point 14c of the smoothing capacitors 14a1 and 14a2, and derived from the connection point between the switching elements 13p3 and 13n3 constituting the field chopper device 13b. The other end of the field coil 4 is connected to the power line 6c via the field current current sensor 15.

Next, the operation of the power conversion apparatus as described above will be described with reference to FIG.
First, a gate control signal is transmitted from the control unit 7 to the converter device 11 to control switching of the plurality of switching elements 11a,... Constituting the converter device 11, and the three-phase AC power output from the AC power supply 2 is required power. (ST1). Thereafter, the control unit 7 determines whether or not the field magnetic flux is established from the current detected by the current sensor 15 or the like (ST2). If not established, the control unit 7 applies the switching element 13n3 of the field chopper device 13b. A gate control signal is sent, the midpoint voltage of the midpoint 14c divided by the smoothing capacitors 14a1 and 14a2 is applied, a chopper operation is performed by the switching element 13n3, and the field coil 4 is energized (ST3).

  At this time, when the field switching element 13n3 is in the ON state, based on the voltage appearing at the midpoint 14c, which is the connection point of the smoothing capacitors 14a1 and 14a2, the midpoint 14c—the field coil 4—the current sensor 15 for the field current. The current flows into the N-side bus 12n through the path of the switching element 13n3-N-side bus 12n. At this time, the current, that is, the field current is detected by the field current sensor 15 and sent to the control unit 7. (ST4). On the other hand, when the field switching element 13n3 is in the OFF state, the energy stored in the field coil 4 is fed back to the midpoint 14c of the smoothing capacitors 14c1 and 14c2 through the feedback semiconductor element 14d. Reduce the voltage.

  The control unit 7 compares the detected current of the field current current sensor 15 with a preset current, and sends a gate control signal if the detected current does not reach the preset current. The switching elements 13p3 and 13n3 of the field chopper device 13b perform a chopper operation according to the gate control signal, energize a required field current, and establish a field magnetic flux (ST5).

  Then, after performing the series of processing operations as described above, when it is determined that the field magnetic flux has been established by returning to step ST2, the control unit 7 determines whether or not to continue the DC motor 3. (ST6). At this time, when a start command for the DC motor 3 is generated, the control unit 7 transmits a gate control signal to the chopper switching elements 13p1 to 13n2 of the armature chopper device 13a. The armature chopper device 13a performs a chopper operation according to the gate control signal, applies a required drive voltage between the armatures 3a and 3b of the DC motor 3, and operates the DC motor 3 (ST7). While the DC motor 3 is in operation, the current flowing into the armatures 3a and 3b of the DC motor 3 is detected by the armature current sensor 5 and transmitted to the control unit 7 (ST8). The control unit 7 transmits a gate control signal to the chopper switching elements 13p1 to 13n2 of the armature chopper device 13a while comparing the detection current of the armature current current sensor 5 with a preset set current. . The armature chopper device 13a performs a chopper operation of a voltage between the P and N side buses 12p and 12n in accordance with a gate control signal from the control unit 7, and causes an armature current to flow through the armatures 3a and 3b. 3 is controlled (ST9).

  Further, it is determined whether or not a motor stop command is input at predetermined intervals during the operation of the DC motor 3 (ST10). If no stop command is input, the process returns to step ST7 and the same processing is repeatedly executed. To do.

  According to the embodiment as described above, the smoothing capacitors 14a1 and 14a2 are connected in series between the N and P buses 12p and 12n to which the required DC voltage converted by the converter device or the like is applied, and a plurality of field magnets are also connected. A field chopper device 13b having chopper switching elements 13p3 and 13n3 is connected, and a feedback semiconductor element 14d is connected between the common connection point of the field chopper switching elements 13p3 and 13n3 and the midpoint of the smoothing capacitors 14a1 and 14a2. And the middle voltage of the capacitor is applied to the field coil 4 of the DC motor 3 while performing chopper operation, so that the rated voltage of the field coil 4 of the DC motor 3 is between the N and P buses 12p and 12n. Even when the applied voltage is lower than the applied voltage, the field coil 4 while the midpoint voltage is operated by the field chopper device 13b. On the other hand, when the switching element 13n3 is turned off, the energy stored in the field coil 4 is fed back to the midpoint 14c of the smoothing capacitors 14a1 and 14a2 through the feedback semiconductor element 14d. As a result, the field coil 4 Load voltage applied to the magnetic field coil 4 can be reduced, so that the insulation deterioration of the field coil 4 can be eliminated and damage can be avoided, and the DC motor 3 can be controlled without providing a field control unit.

(Second Embodiment)
FIG. 3 is a block diagram showing another embodiment of the power converter according to the present invention. In the figure, the same or equivalent parts as in FIG. 1 are denoted by the same reference numerals and will be described in detail with reference to FIG. 1, and different parts will be described below compared with FIG.

  This power converter is the same as that shown in FIG. 1 except for a circuit for generating a field magnetic flux, that is, a field chopper device 13b and a field voltage reduction circuit.

  In the field chopper device 13b, a series circuit of a positive switching element 13p3 and a negative switching element 13n3 is connected between a P-side bus 12p and an N-side bus 12n, as in FIG.

  As the field voltage reduction circuit, three or more smoothing capacitors 14a1, 14a2,..., 14an are connected in series between the P-side bus 12p and the N-side bus 12n, and an equal voltage is applied to each of the smoothing capacitors. Balance resistors 14b1, 14b2,..., 14bn are individually connected so as to be applied. Further, the common connection point of the positive side switching element 13p3 and the negative side switching element 13n3, and the smoothing capacitor 14a (n−1) closest to the N side bus 12n side among the plurality of smoothing capacitors 14a1, 14a2,. (Not shown) and a common connection point 14e of 14an are connected to the feedback semiconductor element 14d.

  One end of the field coil 4 is connected to the power line 6d derived from the common connection point 14e, and the field is connected to the power line 6c derived from the common connection point of the positive side switching element 13p3 and the negative side switching element 13n3. The other end of the field coil 4 is connected via a magnetic current sensor 15.

  This embodiment is an example in which three or more smoothing capacitors 14a1, 14a2,..., 14an are connected between the P-side bus 12p and the N-side bus 12n, and the operation is the same as in FIG. Therefore, it is omitted here.

  According to this embodiment, even when the rated voltage of the field coil 4 of the DC motor 3 is lower than half of the voltage between the P-side bus 12p and the N-side bus 12n, it is connected in series between the P and N-side buses 12p and 12n. By operating the voltage divided by the smoothing capacitor 14an closest to the connected N-side bus 12n by the field chopper device 13b, the energy stored in the field coil 4 when the switching element 13n3 is in the OFF state By returning to the common connection point 11e of the smoothing capacitor 14a (n-1) (not shown) and 14an close to the N side bus 11b through the feedback semiconductor element 14d, the load voltage applied to the field coil 4 can be reduced. As a result, the field coil 4 can be prevented from being damaged, and the DC motor 3 can be controlled without providing a field control unit.

(Third embodiment)
FIG. 4 is a block diagram showing another embodiment of the power conversion device according to the present invention.
In FIG. 1, for example, 1 converts AC power output from a three-phase AC power source 2 into DC power, supplies a required DC voltage to the armatures 3 a and 3 b of the DC motor 3, and drives the DC motor 3. It is the power converter device used as the principal part of this invention. 4 is a field coil of the DC motor 3, 5 is an armature current sensor for detecting an armature current flowing from the power converter 1 to the power lines 6 a and 6 b connected to the armatures 3 a and 3 b of the DC motor 3, A field control unit 8 controls the field magnetic flux by controlling the current flowing into the field coil 4.

  The power converter 1 includes a diode rectifier 21 that rectifies AC power output from the three-phase AC power supply 2 to a required DC voltage, a smoothing capacitor 22 that suppresses a surge voltage generated during operation of the switching element, Gate control from an external control unit 7 is applied between the P-side bus 12p-N side bus 12n to which the DC power source converted by the diode rectifier 21 is applied, and the DC voltage applied between the buses 12p-12n is applied. An armature chopper device 13a chopped by a plurality of armature chopper switching elements 13p1 to 13n2 such as an IGBT gate-controlled under a signal and supplied to the armatures 3a and 3b of the DC motor 3; Of the phase power conversion function, the two phases are used as the armature chopper device 13a, but the remaining one phase is consumed by the regenerative current. Therefore, the switching elements 13p4 and 13n4 for regeneration are connected in series between the P-side bus 12p and the N-side bus 12n, and are gate-controlled based on the gate control signal from the external control unit 7 as described above. A regenerative current consumption device 13c, and a regenerative current consumption resistor 23 that is connected between a common connection point of the regenerative switching elements 13p4 and 13n4 of the regenerative current consumption device 13c and the N-side bus 12n, and consumes the regenerative current; , And a voltage detector 24 for detecting a DC voltage applied between the buses 12p-12n.

  Next, the operation of the power conversion apparatus as described above will be described with reference to FIG.

  The three-phase AC power output from the three-phase AC power source 2 is rectified by the diode rectifier 21, the DC voltage of the required power is taken out and applied between the P-side bus 12p and the N-side bus 12n (ST21). At this time, the control unit 7 determines whether or not the field magnetic flux is established by the field coil 4 (ST22). If the field magnetic flux is not established, the field current is supplied from the field control unit 8 to the field coil 4. (ST23) and the field magnetic flux is established (ST22).

  When it is determined in step ST22 that the field magnetic flux has been established, the control unit 7 determines whether or not to start the DC motor 3 (ST24). At this time, when a start command for the DC motor 3 is generated, a gate control signal is transmitted to the chopper switching element 13a1 of the armature chopper device 13a. The armature chopper device 13a performs a chopper operation according to the gate control signal, applies the obtained drive voltage between the armatures 3a and 3b, and operates the DC motor 3 (ST25).

  When the DC motor 3 is in operation, the control unit 7 takes in the armature current flowing into the armatures 3a and 3b of the DC motor 3 from the armature current sensor 5 (ST26), and from the voltage detector 24 to the bus 12p- The DC voltage applied between 12n is taken in (ST30), and the following processing is executed.

  That is, the control unit 7 takes in the armature current detected by the armature current current sensor 5, compares the armature current with a preset current, and sends the gate control signal to the armature chopper device. It transmits to the switching elements 13p1 to 13n2 for chopper 13a. The chopper device 13a for armature performs a chopper operation on the voltage between the P and N side buses 12p and 12n in accordance with the gate control signal from the control unit 7, and causes the armature current to flow through the armatures 3a and 3b. The operation control is performed (ST27). Further, it is determined whether or not a motor stop command is input at predetermined intervals during the operation of the DC motor 3 (ST28). If no stop command is input, the process returns to step ST26 and the same process is repeated. To do.

  In addition, after taking in the voltage between the buses 12p-12n detected by the voltage detector 24 (ST30), the control unit 7 compares the voltage between the buses with a preset voltage, and the DC motor 3 is regenerated. It is determined whether or not the mode is set (ST31). Normally, when the DC motor 3 is in the regenerative mode, the voltage between the buses 12p-12n rises. Therefore, when the voltage between the buses from the voltage detector 24 exceeds the set voltage, the regenerative mode is determined. Here, when the regeneration mode is determined, a gate control signal is transmitted to the regeneration switching elements 13p4 and 13n4 of the regeneration current consuming device 13c (ST32), and the regeneration switching element 13p4 is turned on, whereby the bus 12p− The regenerative current consumption resistor 23 is connected between 12n (ST33). That is, by turning on the regenerative switching element 13p4, the P-side bus 12p and the regenerative current consumption resistor 23 are connected, and by passing a current through the regenerative current consumption resistor 23, the voltage between the buses 12p-12n is increased. Lower.

  Thereafter, the control unit 7 compares the detection voltage between the buses detected by the voltage detector 24 with a predetermined set voltage, and if the detection voltage between the buses has dropped to the set voltage (ST34), the control unit 7 sends the regenerative current consumption device 13c to The gate control signal being transmitted is stopped (ST35).

  Therefore, according to the embodiment as described above, even when a three-phase power conversion device of a switching element having no power regeneration function such as a converter and having a three-phase power conversion function is applied to the DC motor 3, The remaining one-phase switching element is configured as the regenerative current consuming device 13c, and the regenerative current consuming resistance is between the connection point of the regenerative switching elements 13p4 and 13n4 constituting the regenerative current consuming device 13 and the N-side bus 12n. 23, the switching elements 13p4 and 13n4 are controlled to be turned on and off in the regeneration mode, and the increasing voltage between the buses 12p-12n is consumed by the regenerative current consumption resistor 23. It is possible to stop the rise, thereby contributing to a reduction in the voltage load on the field coil 4 and avoiding damage to the field coil 4 in advance. It can be.

(Fourth embodiment)
FIG. 6 is a block diagram showing still another embodiment of the power converter according to the present invention.
This embodiment is an example of changing from a DC motor 3 to a three-phase AC motor such as a three-phase induction motor or a three-phase permanent magnet synchronous motor in consideration of the existing elevator equipment state and user requirements when the elevator is renewed. It is.

  In the figure, reference numeral 21 denotes a diode rectifier that rectifies AC power output from the three-phase AC power source 2 into a DC voltage of required power, and 13d denotes a P-side bus 12p to which the DC voltage rectified by the diode rectifier 21 is applied. A plurality of chopper switching elements 13p1-13n1, such as an IGBT having a three-phase converter function that is connected between the N-side bus 12n and gate-controlled under a gate control signal from a control unit 7 (not shown); A chopper device 22 including 13p2-13n2 and 13p5-13n5 is a smoothing capacitor 22 that suppresses a surge voltage generated when the switching elements 13p1-13n1, 13p2-13n2, and 13p5-13n5 are operated. Power lines 6 a to 6 c connected to the DC motor 3 and the field coil 4 or the regenerative current consumption resistor 23 are led out from the chopper device 13 d.

  Assuming that there are, for example, three types of motor facilities 31, 32, and 33, the motor facility 31 or 32 is used when the user intends to make use of the DC motor 3. The motor facilities 31 and 32 are as described in the above-described embodiment.

  However, the DC motor 3 that has already been installed may be changed to a three-phase AC motor due to a request from a user or the like. When such a request is made, the semiconductor switching element having the three-phase power conversion function can be applied to the motor equipment 33 by using it as the chopper device 13d having the three-phase converter function. The electric motor equipment 33 has a configuration including a three-phase AC motor 34 such as a three-phase induction motor or a three-phase permanent magnet synchronous motor.

  When the motor equipment 31 is employed when the elevator is renewed, the armatures 3a and 3b of the DC motor 3 are connected to the external power lines 6a and 6b, and one end of the field coil 4 is connected to the external power line 6c. At the same time, the other end side of the field coil 4 is guided to the smoothing capacitor 22 and connected to, for example, the midpoints 14b of the plurality of smoothing capacitors (see FIG. 1).

  When the motor equipment 32 is employed during the renewal of the elevator, the armatures 3a and 3b of the DC motor 3 are similarly connected to the external power lines 6a and 6b, and the regenerative current consumption resistor 23 is connected to the external power line 6c. At the same time, the regenerative current consumption resistor 23 is connected to the N-side bus 11b side of the power converter.

  Further, when the motor equipment 33 having the three-phase AC motor 34 is used instead of the DC motor 3 at the time of renewal of the elevator, the power terminals of the respective phases (not shown) of the three-phase AC motor 34 are connected to the external power lines 6a to 6c. It is possible to control the operation of the three-phase AC motor 34 by connecting to the base and operating the chopper device 13d as an inverter device by a control unit (not shown).

  According to this embodiment, when the elevator is renewed or failed, not only can it cope with any motor equipment, but for example, when an existing DC motor as a load is replaced with a three-phase AC motor, the power conversion device itself is replaced. The AC motor can be operated and controlled with little modification without replacement.

  In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the configuration of FIG. 6, the diode rectifier 21 is used to convert the AC power output from the AC power source 2 into the DC voltage of the required power, but the converter device 11 shown in FIG. Good.

  Further, the embodiments can be implemented in combination as much as possible, and in that case, the effect of the combination can be obtained. Further, each of the above embodiments includes various higher-level and lower-level inventions, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, when an invention is extracted because some constituent elements can be omitted from all the constituent elements described in the means for solving the problem, the omitted part is used when the extracted invention is implemented. Is appropriately supplemented by well-known conventional techniques.

The block diagram which shows one Embodiment of the power converter device which concerns on this invention. The operation | movement flowchart explaining operation | movement of the power converter device shown in FIG. The block diagram which improved a part of power converter shown in FIG. The block diagram which shows other embodiment of the power converter device which concerns on this invention. The operation | movement flowchart explaining operation | movement of the power converter device shown in FIG. The block diagram which shows other embodiment of the power converter device which concerns on this invention. The block diagram which shows the conventional power converter device. The block diagram which shows another conventional power converter device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Power converter device, 2 ... Three-phase alternating current power supply, 3 ... DC motor, 3a, 3b ... Armature, 4 ... Field coil, 5 ... Current sensor for armature current, 6a-6c ... Power line, 7 ... Control , 8 ... Field control unit, 11 ... Converter device, 12p ... P side bus, 12n ... N side bus, 13a ... Chopper device for armature, 13b ... Chopper device for field, 13c ... Regenerative current consumption device, 14 ... Field 14a1, 14a2, ..., 14an ... smoothing capacitors, 14b1, 14b2, ..., 14bn ... balance resistors, 14d ... feedback semiconductor elements, 15 ... current sensors for field current, 21 ... diode rectifiers , 22 ... smoothing capacitor, 23 ... regenerative current consumption resistance, 24 ... voltage detector, 34 ... three-phase AC motor.

Claims (4)

A plurality of semiconductor switching elements having a three-phase power conversion function and a plurality of smoothing capacitors for suppressing a surge voltage generated during operation of each of these semiconductor switching elements are connected in series between PN buses to which a required DC voltage is applied. In a three-phase power converter that drives a DC motor that is connected and has a field coil,
The armature of the DC motor is connected to the output side of the plurality of semiconductor switching elements having the power conversion function for two phases among the plurality of semiconductor switching elements having the three-phase power conversion function, and supplied from the outside An armature chopper device that performs chopper operation under the first gate control signal;
Of the plurality of semiconductor switching elements having the three-phase power conversion function, the second gate control signal is configured by a plurality of semiconductor switching elements having a power conversion function for the remaining one phase, and is supplied from the outside. And a field chopper device that performs chopper operation;
A feedback circuit element is connected together with the field coil between a connection portion of a plurality of semiconductor switching elements constituting the field chopper device and a midpoint of the plurality of smoothing capacitors, and a midpoint voltage of the smoothing capacitor And a field voltage reduction circuit for energizing the field coil by the chopper operation by the field chopper device and returning the power energy stored in the field coil to the midpoint of the smoothing capacitor. A power conversion device. The power conversion device according to claim 1,
When three or more smoothing capacitors are connected in series,
The field voltage reduction circuit includes a connection portion between a plurality of semiconductor switching elements constituting the field chopper device and a connection point between adjacent smoothing capacitors closest to the N-side bus of the three or more smoothing capacitors. A power conversion device comprising a feedback circuit element connected together with the field coil. A plurality of semiconductor switching elements having a three-phase power conversion function and a plurality of smoothing capacitors for suppressing a surge voltage generated during operation of each of these semiconductor switching elements are connected in series between PN buses to which a required DC voltage is applied. In a three-phase power converter that drives a DC motor that is connected and has a field coil that is controlled to receive a field current from a field control unit,
The armature of the DC motor is connected to the output side of the plurality of semiconductor switching elements having the power conversion function for two phases among the plurality of semiconductor switching elements having the three-phase power conversion function, and supplied from the outside An armature chopper device that performs chopper operation under the first gate control signal;
Among the semiconductor switching elements having the three-phase power conversion function, the semiconductor switching elements are composed of a plurality of semiconductor switching elements having the power conversion function for the remaining one phase, and are switched based on a switching control signal supplied from the outside. A regenerative current consuming device that performs the operation;
The regenerative current consuming device is connected between a connection point of a plurality of semiconductor switching elements and the N-side bus. When the DC motor is in a regenerative mode, the regenerative current consuming device switches between the PN buses by a switching operation. A power conversion device comprising: a regenerative current consumption resistor that consumes a regenerative current so as to reduce a voltage that appears. In the power converter according to any one of claims 1 to 3,
When trying to apply to an AC motor instead of the DC motor as a load,
A plurality of semiconductor switching elements having a three-phase power conversion function are used as a three-phase inverter device, and the armature and field of the DC motor are connected from the connection points of the plurality of semiconductor switching elements of each phase constituting the inverter device. A power conversion device characterized in that an output line connected to a coil or a regenerative current consumption resistor is connected to the AC motor as it is.

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