US1995277A - Rectifying system - Google Patents

Description

March 19, 1935. E. KERN RECTIFYING SYSTEM 2 Sheets-Sheet 1 Filed Nov. 28, 1932 MAO/M E. KERN RECTIFYING SYSTEM March 19, 1935.

Filed Nov. 28, 1932 2 Sheets-Sheet 2 Patented Mar. 19, 1935 UNITED STATES PATENT OFFICE RECTIFYING SYSTEM Switzerland Application November 28, 1932, Serial No. 644,598 In Germany December 28, 1931 14 Claims.

This invention relates to improvements in regulating systems and more particularly to means for regulating the output of a rectifying system employing an electron discharge device in which the flow of current is controlled by energization of suitable control electrodes.

In rectifying systems employing an electron discharge device, the voltage of the direct current output circuit is primarily a function of the voltage of the alternating current supply line but also varies in dependence on the current delivered by the system to the current consuming devices therein in the usual rectifying systems, the voltage of the direct current output circuit decreases when the current within such circuit increases. It is however frequently desired to obtain constant output voltages at all loads or to obtain variations of the output voltage which are different from the variations inherently produced by a rectifying system. Any desired relation between the values of voltage and of current in the output circuit may be automatically obtained by controlling the energization of the control electrodes of the discharge device by means of a distributor operable at the frequency of the supply line voltage and by adjusting such distributor depending upon conditions within the system.

It is, therefore, among the objects of the present invention to provide a regulating system for a rectifying system employing an electron discharge device whereby the output voltage of the rectifying system is automatically regulated in dependence upon conditions within the circuits comprising such system.

Another object of the present invention is to provide a regulating system for a rectifying system employing an electron discharge device whereby the control electrodes of the device is energized through a distributor which is automatically adjusted in dependence upon conditions within the rectifying system.

Another object of the present invention is to provide a regulating system for a rectifying system employing an electron discharge device in which the magnetic axis of an auxiliary synchronous motor is automatically shifted in dependence upon conditions within the rectifying system to adjust the energization of the control electrodes of the device and to regulate the output voltage of the system.

Objects and advantages, other than those above set forth, will be apparent from the following description when read in connection with accompanying drawings, in which:

Fig. 1 diagrammatically illustrates one embodiment of the present invention in which the output voltage of an electron discharge device operable as an alternating current rectifier is regulated by energizing the control electrodes of the device through a distributor having driving means automatically adjusted by means of a regulator responsive to the magnitudes of the voltage and of the current in the output circuit,

Fig. 2 diagrammatically illustrates a portion of a modified embodiment of the present invert-- tion differing from the embodiment illustrated in Fig. 1 in that the distributor is directly adjusted depending upon the value of only the current in the output circuit;

Fig. 3 diagrammatically illustrates another modified embodiment of the present invention differing from the embodiment illustrated in Fig. 2 in that the distributor is adjusted depending upon the value of the current in the input circuit; and

Fig. 4 diagrammatically illustrates a further modified embodiment of the present invention differing from the embodiment illustrated in Fig. 3 in the means for adjusting the distributor driving means.

Referring more particularly to the drawings by characters of reference, reference numeral 6 designates an alternating current supplyline of any desired number of phases and at any desired frequency, being herein shown as a three-phase line for the-reason that such type of line is most frequently utilized in practice. Line 6 energizes the delta connected primary winding 7 of a supply transformer having a secondary winding 8 comprising a plurality of winding portions connected in star to form a neutral point. The different portions of winding 8 are severally connected with the anodes 9 of an electron discharge device 11 herein shown as being operable as an alternating current rectifier. Rectifier 11 is herein illustrated as being of the vapor type having a vaporizable cathode 12 and is assumed to be provided with the usual ignition and excitation means (not shown in Figs. 1, 2 or 3). Cathode 12 is connected with the positive conductor 13 of the output circuit having the negative conductor 14 thereof connected with the neutral point of winding 8.

Rectifier 11 is provided with control electrodes 16 which may have a negative potential with respect to the potential of cathode 12 impressed thereon by means of a direct current generator 19 through resistances 17 and 18. A resistance 21 having a mid-tap connected with conductor 13 is connected across the terminals of the generator 19 to permit generator 19 to deliver current at voltages both positive and negative with respect to cathode l2. Generator 19 is preferably driven by means of a synchronous motor 22 having an armature 23 energized from line 6 and a plurality of field windings 24, 25 and 26 spatially distributed over the field of the motor. Motor 22 also drives the brush of a distributor 2'7 through which the control electrodes may be sequentially energized at a positive potential with respect to the potential of cathode 12 from generator 19 over resistance 17. Winding 26 of motor 22 is connected in series with a circuit comprising windings 24 and 25 connected in parallel and interconnected through resistances 28 of a. regulator 29. Such circuit maybe energized from any suitable direct current source and is preferably energized from generator 19. Regulator 29 may be of any type known in the art and is preferably operated by means of a voltage coil 31 connected across direct current line 13, 14 through a rheostat 34 and by means of a current coil 32 connected across a shunt 33 and energized from point of connection of resistance 28 with generperiphery of the field of the motor.

ator 19 to regulate the distribution of current between windings 24 and 25. It will be understood that, with suitable modifications, the control elements described may be utilized for controlling a discharge device operable for any operation known in the art such as direct current inversion, frequency conversion, etc.

In operation, assuming the system to be connected as shown in Fig. l and line 6 to be energized, winding 7 receives current from line 6 with the result that winding 8 impresses sixphase alternating current voltages in sequence on the anodes 9 of rectifier 11. The control electrodes 16 of rectifier 11 are generally maintained at a negative potential with respect to cathode 12 from. generator 19 over resistances 1'7 and 18 to prevent the operation of the anodes associated therewith. When an anode 9 is at a positive potential with respect to cathode 12, the associated control electrode 16 receives a positive potential from generator 19 over one of the segments of distributor 2'7 and resistance 17. Upon such positive energization of control electrode 16, anode 9 carries current, the flow of such current continuing until anode 9 is no longer positive.

with respect to cathode 12. Such cycle of operation is sequentially repeated for each anode of rectifier 11 during each cycle of the voltage of line 6, with the result that the system supplies a substantially uniform direct current to the output circuit 13, 14. As is well known, the voltageof the output circuit may be regulated by adjusting the moment in the voltage cycle of line 6 at which each control electrode is positively energized through distributor 2'7.

When the load" connected with circuit 13, 14 changes, the current drawn from the system also changes thereby causing a change in the current flowing in coil32. Due to the inherent characteristics of the rectifying system, the voltage of the output circuit also changes thereby causing a change in the potential in coil 31. Regulator- 29 therefore changes its position to shift the connection of generator 19 with resistance 28. The relative amounts of current flowing through windings 2.4 and 25 are therefore changed thus causing a spatial shift of the magnetic flux along the The magnetic axis of the field being thus shifted, the rotor of motor 22; will continue to rotate at synchronous s eed but, at any instant, will be in a position, with respect to the voltage wave of line 6, which is difierent from the position of such rotor at the previous load value. The brush of distributor 2'? therefore comes'into contact with each segment of the distributor at a time, considered with respect to the voltage wave of line 6, which is different from the time at which such contact occurred previously. Each control electrode therefore permits the associated anode to operate during a different period of the voltage wave of line 6 thus causing the voltage of line 13, 14 toreach a value differing from the value which such voltage would have in the absence of regulator 29. By suitably choosing the characteristics of regulator 29, the regulation between the current and the voltage in line 13, 14 may be predetermined in any desired manner; in particular, such voltage may be maintained constant at all loads or may be made to increase at increasing values of current. Such relation may be modified by changing the adjustment of rheostat 34. v

In the embodiment illustrated in Fig. 2, regulator 29 is omitted and windings 24 and 25 are connected in series across shunt 33. Windings 24 and 26 are then connected in series and are supplied from generator 19 through a rheostat 36. The negative terminal of generator 19 is connected with conductor 13 on the cathode side. of shunt 33 so that the positive terminal of the generator may be utilized for positively energizing the brush of distributor 2'7 with respect to the potential of the cathode 12. The control electrodes may be negatively energized with respect to cathode 12 by means of a suitable sourceof direct current and are preferably energized through a voltage divider 38 connected across line 13, 14.

The operation of the rectifying system to which the present embodiment is applied, is similar to that of the rectifying system illustrated in Fig. 1.

When the current in line 13, 14 changes, the voltage drop across shunt 33 changes thereby changing the amount of current flowing through windings 25 and 24. As in the'embodiment illustrated in Fig. 1, such change in the currents of such windings causes a shift of the magnetic axis of the field of motor 22 resulting in a change in the position of the brush of distributor 27, relative to the position of the segments thereof, such as to regulate the output voltage of the rectifying system. In the present embodiment the relation between the voltage and the current in the output circuit may be modified by adjustment of rheostat 36 controlling the how of current in windings 24 and 26.

In the embodiment illustrated in Fig. 3', the current flowing through windings 24 and 25 is obtained from a current transformer 39 energized by the input current of one terminal of transformer '7, 8. The secondary winding of transformer 39 supplies windings 24 and 25 through a rheostat 41 and through a current rectifier 42 of any desired type. The terminals of the secondary winding of transformer 39 may be bridged by two reactors 43 and 44 having the windings thereof connected in series. The cores of reactors 43' and 44 may be or" different cross sections so that, upon energization of the windings of the reactors, the core of reactor 43 will become saturated for a value of current at which the core of reactor 44 is still magnetized below the saturation point.

The operation of the rectifying system of the present embodiment is similar to that of the system illustrated in Fig. 1. When the current in line 13, 14 increases, the current drawn from line 6 by transformer "I, 8 increases correspondingly thus causing an increasing current to flow in the secondary winding of current transformer 39. A portion of such current ficwsover rheostat 41 and rectifier 42 into windings 24' and 25 thereby causing a shift of the magnetic axis of motor 22 in a manner similar to that previously described. The amount of current flowing through the windings of reactors 43 and 44 increases substantially proportionately to the current drawn by winding 7 until the core of reactor 43 becomes saturated. The relation between the current in transformer 39 and the current drawn by the reactors 43 and 44 changes so that, at currents increasing above the previous value, the effect of the current of transformer 39 on the position of the field of motor 22 will be different from that obtained at lower currents. The voltage of line 13, 14 may thus be regulated to present variations which are no longer continuous, but which may present any desired irregularities. It will be understood that the voltage of line 13, 14 may be made to follow a number of separate relations for different ranges of values of the output current by employing a larger number of reactors having cores saturable at different values of current. The value of the output voltage may also be varied by adjustment of rheostat 41.

In the embodiment illustrated in Fig. 4, motor 22 is shown as being provided with a six-phase armature 46 and with a single field winding 4'7. Winding 47 is energized from the excitation circuit of rectifier 11, such circuit comprising a transformer 48 energized from line 6 and supplying two excitation anodes 49 and 51 through resistances 52 and 53, the resistance 54 and a reactor 56. The excitation current flowing through resistance 54 is av substantially uniform direct current due to the presence of reactor 56 and energizes the field winding of motor 22 similarly to the energization thereof by generator 19 in the previously described embodiments. Three of the windings of armature 46 are energized from line 6 as in the previously described embodiments and the other three windings are energized from current transformers 57, 58 and 59 connected in the circuit of winding 7. The currents in the last mentioned armature windings may be regulated by means of rheostats 61, 62 and 63 connected across the terminals of the secondary windings of transformers 57, 58 and 59. The common point of resistance 54 and of reactor 56 is maintained at a substantially uniform direct current negative potential with respect to the potential of the cathode 12 due to the flow of excitation current in resistance 54 and such point is therefore connected with the control electrodes of rectifier 11 to energize such control electrodes at a negative potential. Such control electrodes are then energized at a positive potential through the brush of distributor 2'7 from any suitable source of direct current such as a battery 64.

The operation of the rectifying system shown in the present embodiment is similar to that of the system illustrated in Fig. 1. When the current in the output circuit increases, the current drawn by winding 7 from line 6 increases correspondingly and transformers '7, 58 and 59 will cause a shift of the position of the rotating magnetic field in armature 46 with respect to the voltage cycle in supply line 6. The shift of the magnetic axis of armature 46 thus obtained causes the rotor of motor 22 to continue rotating at synchronous speed but such rotor will, at every instant, have a position, with respect to the voltage cycle of line 6, which is different from the position it had previously. Adjustment of the position of the brush of distributor 2'7 with respect to the voltage cycle of line 6 is thus obtained as in the previously described embodiments to regulate the voltage of line 13,

14. In the present embodiment, the voltage applied to motor 22 may be adjusted by adjustment of the rheostats 61, 62 and 63 whereby any desired fraction of the currents supplied by transformers 5'7, 58 and 59 may be supplied to the windings of armature 46.

Although but a few embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing rom the spirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, a direct current generator for continuously applying a negative potential relative to the potential of the cathode on the control electrodes of said device, means for connecting said generator intermittently with the control electrodes to apply a potential thereto positive relative to the potential of the cathode of said device, and means operable responsive to variations in conditions of said system for varying the operation of the first said means.

2. In an electric current rectifying system, an I alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the 1 conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, means for continuously impressing a negative potential relative to the potential of the cathode on the control electrodes of said device, means for sequentially impressing a potential impulse positive relative to the cathode on the control electrodes of said device, a motor operable at synchronous speed relative to the voltage cycle of said supply line for operating both said means, and means for shifting the magnetic axis of said motor in response to conditions in said direct current line.

3. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, a direct current generator for continuously applying a negative potential relative to the potential of the cathode on the control electrodes of said device, means connecting said generator intermittently with the control electrodes to apply a potential thereto positive relative to the potential of the cathode of said de vice, a motor operable at synchronous speed relative to the voltage cycle of said supply line for operating said generator and said means, and

means for shifting the magnetic axis of said motor in response to conditions in said rent line.

i. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, means for continuously impressing a negative potential relative to the potential of the cathode on the control electrodes of said device, means for sequentially impressing a potential impulse positive relative to the potential of the cathode on the control electrodes of said device, a motor operable at synchronous speed relative to the voltage frequency of said supply line connected to operate both said means and having a plurality of field excitation windings, and means responsive to current and voltage conditions in said direct current line to control energization of the field windings of said motor.

5. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, means for continuously impressing a negative potential relative to the potential of the cathode on the control electrodes of said device, means for sequentially impressing a potential impulse positive relative to the potential of the cathode on the control electrodes of said device, a motor operable at synchronous speed relative to the voltage frequency of said supply line connected to operate both said means and having a plurality of field excitation windings, a resistance connected with the field windings of said motor, and a regulator having a current coil anda potential coil connected with said direct current'line and varying the amount of said redirect cursistance connected in circuit with the field windings of said motor to control energization thereof. 6. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof. being connected with said transformer, a direct current generator, a resistance connected with the terminals of said gen erator, a point of said resistance being connected with one of the conductors of said direct current line, one of the terminals of said resistance being connected with the control electrodes to continuously impress thereon a potential negative relative to the potential of the cathode of said device, means for sequentially connecting the other terminal of said resistance with the control electrodes to impress thereon a potential impulse positive relative to the potential of the cathode of said device, and means operable responsive to variations in conditions in the system for varying the operation of the first said means.

7. In an electric current rectifying system, an alternating current supply line, an electron dis-- charge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with theanodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and. the other conductor thereof being connected with said transformer, a direct current generator, a resistance connected with the terminals of said generator, a point of said resistance being connected with one of the conductors of said direct current line, one of the terminals of said resistance being connected with the control electrodes to continuously impress thereon a potential negative relative to the potential of the cathode of said device, means for sequentially connecting the other terminal of said resistance with the control electrodes to impress thereon a potential impulse positive relative to the potential of the cathode of said device, a motor operable at synchronous speed relative to the voltage frequency of said supply line for operating said generator and said means, and means operable in response to changes in conditions in said direct current line for shifting the magnetic axis of said motor.

8. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated con- 'rol electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the com ductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, a' direct current generator, a resistance connected with the terminals of said generator, a point of said resistance being connected with one of the conductors of said direct current line, one of the terminals of said resistance being connected with the control electrodes to continuously impress thereon a potential negative relative to the po tential of the cathode of said device, means for sequentially connecting the otherterrninal of said resistance with the control electrodes to impress thereon a potential impulse positive relative to the potential of the cathode of said device, a motor operable at synchronous speed relative to the voltage frequency of said supply line connected to operate both said generator and said means and having a plurality of field excitation windings, a resistance connected with the field windings of said motor, and a regulator having a current coil and a potential coil connected with said direct current line operable to vary the amount of said resistance connected in circuit with the field windings of said motor to control energization thereof.

9. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, a resistance connecting the conductors of said output line, a point of said resistance being connected with the control electrodes to continuously impress thereon a negative potential relative to the potential of the cathode of said device, means for sequentially impressing a potential impulse positive relative to the potential of the cathode on the control electrodes of said device, a motor operable at synchronous speed relative to the voltage frequency of said supply line for up crating said means, and means operable responsive to changes in said direct current line for shifting the magnetic axis of said motor.

10. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, a resistance connecting the conductors of said output line, a point of said resistance being connected with the control electrodes to continuously impress thereon a negative potential relative to the potential of the cathode of said device, a direct current generator arranged to be connected with the control electrodes to impress thereon a potential impulse positive reative to the potential of the cathode of said device, means for sequentially connecting said generator with the control electrodes of said device, and a motor operable at synchronous speed relative to the voltage frequency of said supply line for operating said generator and said means, said motor having a plurality of field windings connected with and energized from one conductor of said direct current line responsive to current flow therein to shift the magnetic axis of said motor to vary operation of said generator and said means.

11. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, a direct current generator, a resistance connected with the terminals of said generator, a point of said resistance being connected with one of the conductors of said direct current line, one of the terminals of said resistance being connected with the control elect es to continuously impress thereon a potei negative relative to the potential of the cathode of said device, means for sequentially connecting the other terminal of said resistance with the control electrodes to impress thereon a potential impulse positive relative to the potential of the cathode of said device, a motor operable at synchronous speed relative to the voltage frequency of said supply line and arranged to operate said generator and said means and having a plurality of field excitation windings, and means associated with said transformer and responsive to conditions therein for varying the current distribution in the field windings of said motor to control energization of the control electrodes of said device.

12. In an electric current rectifying system, an alternating current supply line, an electron discharge device having anodes with associated control electrodes and a cathode, a transformer connecting said supply line with the anodes of said device, a direct current output line, one of the conductors of said output line being connected with the cathode of said device and the other conductor thereof being connected with said transformer, a direct current generator, a resistance connected with the terminals of said generator, a point of said resistance being connected with one of the conductors of said direct current line, one of the terminals of said resistance being connected with the control electrodes to continuously impress thereon a potential negative relative to the potential of the cathode of said device, means for sequentially connecting the other terminal of said resistance with the con-- trol electrodes to impress thereon a potential impulse positive relative to the potential of the cathode of said device, a motor operable at synchronous speed relative to the voltage frequency of said supply line arranged to operate said generator and said means and having a plurality of field excitation windings, a current transformer associated with the first said transformer, reactors connected with said current transformer, and an electric current rectifier connecting said reactors with the field windings of said motor operable responsive to changes in conditions in the first said transformer for shifting the magnetic axis of said motor.

13. The combination of direct and alternating current circuits, an electron discharge device having electrodes connected with and forming asymmetric conductors for the fiow of current through said device from one to the other of said circiuts, a control electrode for controlling initiation of said flow of current between said circuits by way of said conductors, means having connection with said control electrode for impressing potential thereon of such sign and magnitude as to prevent initiation of flow of current between said conductors, means having connections for intermittently impressing potential on said control electrodes of such sign and magnitude as to perinitiation of fiow of current between said circuits by way of said conductors, motor means operable at synchronous speed relative to the voltage frequency of said alternating current circuit and comprising a plurality of field excitation windings for operating the second said means, a source of current for energizing said windings, and means operable responsive to and in dependence upon changes in conditions in one of said circuits for varying the flow of current through the respective said windings to thereby shift the magnetic axis of said motor to vary th operation of the second said means.

14. The combination of direct and alternating current circuits, an electric current converting device having a cathode and a plurality of anodes interconnecting said circuits, a plurality of control electrodes severally associated with said anodes, means having connections for continuously impressing potential on said control electrodes of such sign and magnitude as to prevent initiation of flow of current between said circuits by way of said anodes and cathode, means having connections for intermittently and sequentially impressing potential on said control electrodes of such sign and magnitude and during such recurring periods as to permit flow of current between said circuits by way of the associated anodes, motor means operable at synchronous speed relative to the voltage cycle of said alternating current circuit and comprising a plurality of windings foropcrating the second said means, a source of current for energizing said windings, and means operable responsive to and in dependence upon changes in conditions in one of said circuits for varying the fiow of current through the respective said windings to thereby shift the magnetic axis of said motor to vary the operation of the second said means.

ERWIN KERN.

Images