CH118813A - Electrical energy distribution installation. - Google Patents

Description

  

      Installation-distribution of electrical energy. This invention relates to an installation for distributing electrical energy, comprising means for transmitting energy between two electrical working circuits.



  In some electrical distribution systems comprising both AC and DC circuits. direct current, the alternating current circuit is the main source of energy and direct current energy is obtained by transfer devices which are controlled from the alternating current circuit. However, part of the direct current energy is usually supplied by an independent source, such as one or more generators to be controlled by steam or analog.

   In this way, a certain amount of direct current energy is available, even if the alternating current source should fail.



  In large industrial establishments and factories, such as for example steel mills and rolling mills, some important machines are powered by AC motors, and in this case it is exceedingly important that AC power is always available for powering. these machines, considering that the interruption of this service can often involve great losses and sometimes a danger for the personnel.



  In this order of ideas, the object installation of the invention comprises two sources of electrical energy arranged to respectively supply two separate working circuits of current of different predetermined characteristics and a rotary transfer device. for connecting said circuits so as to transfer, if necessary, energy from one of the circuits to the other, this rotary transfer device being automatically controlled to, so as to transfer energy from one circuit to the other. the other, in one or the other direction,

   dependent on the load demands relating to the respective circuits and the availability of energy at the respective energy sources and further being automatically adjusted so that the transferred current has the predetermined electrical characteristics required for said circuits .

        In this installation, it may be advantageous to ensure that when the rotary transfer device operates to transfer energy from one circuit to another, it is automatically controlled by a voltage fault. in the first circuit so that the rotary transfer device transfers energy from the second circuit to the first without disconnecting the transfer device from either of the circuits.



  Another means can also be advantageously provided so that the operation of the rotary transfer device is normally initiated automatically depending on a load request arising in one or the other circuit in order to provide it with power. energy from the other circuit.



  In an electrical installation, in which one of the circuits is an alternating current circuit and the other a direct current circuit, the rotary transfer device may comprise an alternating current dynamoelectric machine mechanically coupled with a dynamoelectric machine. direct current (motor-generator unit), the direct current machine possibly having a field rheostat controlled automatically so as to adjust the voltage of said machine in accordance with the voltage of the direct current circuit when the transfer device transfers energy from the fired circuit to.

   alternating current to the direct current circuit and to adjust the speed of said machine in accordance with the frequency of the circuit. alternating current when energy is transferred from the direct current circuit to the alternating current circuit.



  On the other hand, when the operation. of the rotary transfer device is. initiated to supply power to the DC circuit from the AC circuit, there may be means for the aforesaid rheostat to be automatically actuated so as to cause the voltage of the DC machine to match. to the voltage of the direct current circuit before connecting said machine to the latter and that, when the operation of the rotary transfer device is initiated to supply energy to the alternating current circuit from then the circuit to. current:

   continuous, said rheos tat is automatically actuated polish adjust. speed of the DC machine so that the frequency of the machine ( <B> to </B> alternating current matches the frequency of the circuit at. alternating current before connecting said alternating current machine to the alternating current circuit.



  In addition to that., Hi. current machine. alternative can be fitted with an automatically controlled field rheostat. so that. adjust the voltage of the machine. alternating current, when the rotary transfer device operates to transfer energy from the direct current circuit to the alternating current circuit.



  Means; can also be provided to control, by hand, the operation of the rotary transfer device to. by firing from any desired location, these means can be established so as to allow the transfer device to be started, stopped or disabled. A positive indicator can be provided to indicate these conditions to. the operator.



  In -drawing a.nnéxé, given by way of example, FIGS. 1, 2, 3 and 4, placed end to end one next to the other in the order of their numbering represent the whole of one embodiment of the object of the invention.



  To simplify the drawing, gleam them; that the installation comprises are represented only schematically by a zig zag line enclosed in a circle and the switches controlled by a relay are represented associated with the wax they control. Ires switches are shown:

   open or closed depending on their position when the relay which actuates them is de-energized, and they bear the same reference digits as the respective relay, but with an additional differentiation digit;

      thus for example, the three switches of the relay 36 are designated by 36-1, 3G-2 and 36-3. To facilitate the description of the circuits in fig. 3 and 4, these are marked with different letters of the alphabet.



  Referring to these figures, it can be seen that an alternating current circuit 1 and a direct current circuit comprising the conductors 2 and 3 are provided with an alternating current dynamoelectric machine 4 and a current dynamoelectric machine. continuous 5, respectively. The rotating parts of these machines are mechanically linked together by means of a shaft 6 so that each machine can operate the other.

    The alternating current machine 4 can be connected to the alternating current circuit 1 by a start switch 7 and an autotransformer 8 or directly by a run circuit switch 9.



  As seen in fig. 1, the dynamoelectric machine to. alternating current 4 comprises an armature winding 4A and a field winding 413, the latter being arranged to be short-circuited by a resistor 46 and an inductive relay 47 or to be supplied with direct current from the conductors 51 and 3, by means of a rheostat: for adjusting the field 52 which is commanded by a reversible rheos tat control motor 91.

   The machine is connected to the alternating current circuit 1 through the run circuit switch 9 during operation and through the starter switch 7 and the auto-transformer 8 during operation. -from starting. Potential transformers 55 and 89 are provided, that 55 to supply a voltage and transfer relay, in time, 53, and the other, 89, to supply the voltage coil of an inverter relay to. alternating current 48, the frequency regulator of the alternating current 61 (fig. 2) and the voltage regulator @ of the alternating current 90.

   Current transformers 77 in the conductors of the native alternating current circuit going to the machine 4 are linked to an alternating current underload relay 69, to an alternating current thermal relay 33, to a short circuit relay alternating current 74, to the alternating current inverter relay 48 and to a phase-balanced relay 71. Co: nductors 2 and 3, of the direct current circuit are provided, with an indicator and control device 23 connected thereto and also connected to a single additional control conductor 28.



  The part shown in FIG. 2 comprises in combination with the coupled machines 4, 5 a maximum speed device 31.

    In the machine 5 the field comprises, on board, a bypass winding 5A connected in series with a field adjustment rheostat 63 which is controlled by a reversible control motor 60, then a field rolling one. series <B> He </B> - arranged to be short-circuited, when the machine is running as a motor, by a switch 85, and a switching or interpolar winding in series 10, through which a direct current thermal relay 73 is connected.

   A direct current voltage regulator 58 comprises a voltage balancing element 58A, a voltage regulating element 58B and a current regulating element 580. The machine 5 is connected to the main conductor 2 by the line. Intermediate, a DC circuit breaker 21 in series with a branch 22 to which are connected a reverse current relay 82 and a reversing DC overload relay 97.

   A direct current starter switch 18, switches 19 and 20, resistors 12, 13 and 14 and load relays in series 15, 16 and 17 are provided for starting the machine 4 by means of current. of the main DC circuit.



  Figs. 3 and 4 show the relays. and control coils to initiate the required sequence of operations. The relays and control coils shown in fig. 3 are as follows: A main control controller relay 35, an auxiliary control controller relay 34, a time relay 30, an 80A time relay coupling coil, a.

       undervoltage 29, a shutdown relay 32, a stop relay 36, a control relay 39, an auxiliary relay 40, a start circuit switch control relay 42, a start relay interruption at time 44, of the closing, opening \ and zero voltage coils 7A, 7B and <B> 70, </B> respec tively ,, for the circuit breaker 7 (fig. 1), a current field winding contact device. alternative 45, a transfer relay 43 and. a control relay for the run circuit switch 56.



  Fig. 4 shows the following control relays and coils: A reversing control regulator relay 41, an auxiliary reversing control regulator relay 86, a start-up control relay. inversion 76, an auxiliary start control relay to, inversion 72, a time relay 64, a polarized relay 66, a relay to. voltage <B> 67, </B> a direct current circuit switch control relay 65, an interrupt relay at. time 68, an auxiliary relay 49, an auxiliary relay 84, a direct current starting switch control relay 81.

    closing, opening and zero voltage coils 9A, 9B and. 9C, respectively, for circuit switch 9 and closing and zero voltage coils 21A and. 210, respectively, for the circuit switch 21.



  To make the operation of the installation fully understood, it will be described in relation to the various services that it must be able to perform. From this point of view, the following description has been divided into various chapters which are as follows: Automatic start on the AC side depending on the. direct current control; 20 Automatic shutdown in the event of a drop in direct current demand; 30 Protective devices for stopping machines; 40 Machine shutdown following manual control; <B> 50 </B> Start-up, machines. following a manual command; <B> 60 </B> Conditions requiring the, reverse march; <B> 70 </B> Start on the DC side (reverse) to provide native alternating current;

    80 Passage of the. normal walking to. reverse gear for machines already in service.



  Under normal conditions, when the voltages of both AC circuit and DC circuit are about their normal values, AC 1.a ma, chiiw 4 is automatically turned on and made to run as a motor synchronous to operate the direct current machine 5 as a generator before supplying the direct current circuit.

    This operation is initiated automatically depending on the energy demand in the circuit. current; continuous and is automatically stopped, when this energy demand remains below a predetermined value for a predetermined time interval.

   In the case, however, the circuit voltage is at. alternating current] falls below a predetermined value, la. DC machine 5 is made to operate as a motor, being supplied with current by 1P direct current circuit, and operates the machine. - alternating current 4 to make it work as a generator supplying the alternating current circuit 1 until the. normal source of alternating current becomes available again to maintain the. voltage of circuit 1 at substantially its value. normal.



  If the voltage in circuit 1 fails, while the AC machine 4 is operating as a motor to drive the DC machine as a generator, the direction of energy flow through the machines 4 and 5 will simply be reversed to force machine 5 to run as a motor and machine 4 as a generator.

   If, however, the voltage fails when machines 4 and 5 are stopped, the equipment (the automatic control will immediately start to operate to start the machine with direct current 5 as a motor supplied by the circuit. The speed of machines 4 and 5 is automatically adjusted to a predetermined value and circuit switch 9 is then closed to allow machine 4 to supply circuit 1 until the normal source of alternating current is again available.



  In order to subordinate the manual remote control to the automatic control of the transfer device., We have. provided on the positive indicator and control 23 comprising push-button switches 24 and 25, a single-pole knife switch 26 and an indicating device 27. The electrical connections between the indicating and control device 23 and the various devices in the The installation are established by means of conductors 2 and 3 of the direct current circuit and the additional control conductor 28.

   If it is desired that automatic control and manual control of the transfer device be available at the same time, the knife switch 26 is closed to its right position as shown in the drawing. If you then want to turn on the transfer device, when there is no <U> of </U> demand of sufficient energy in the direct current circuit to effect the automatic starting of the device, push-button 25 is pressed. In the same way, when one wishes to immediately stop the operation of the device. the device at all times while it is running, push button 24.

   If it is desired to prevent the operation of the apparatus entirely, either because of the operation of the automatic equipment or because of the manual actuation of the push-button 25, the switch is closed. knife 26 in its left position.

   The indicating device 27 is arranged to indicate when the transfer device is operatively connected between the working circuits and, in the event that more than one transfer device is provided, this indicating device will indicate how many of these devices would be operatively connected between the working circuits.



  It will be understood that the conductors 2 and 3 of the direct current circuit are usually the conductors of a network extending over an entire industrial establishment and that they are, therefore, available for connections at any desired point. . From the factory. Therefore, the only additional conductor that must be installed to connect the remote indicating and control equipment with the local control equipment of the translational devices is the control conductor 28.

       <i> 10 </I> Automatic start <I> on the side to neck- </I> <I> alternative rant depending on demand </I> <I> in </I> current <I> continuous. </I>



  To explain the operation of the electrical installation described above, it will first be assumed that the -dynamo-electric machines 4 and 5 are at rest. and that their connection with their respective circuits is interrupted.

   When a demand for energy in the direct current circuit exceeds the capacity of the transfer devices which already supply it with energy, the voltage between conductors 2 and 3 drops to a value such that the sub relay -voltage or low load 29 (shown in circuit 4, fig. 3) allows its switch 29-1 (circuit B-2) to open, and its switch 29-2 (circuit B) to close .

   The control coil of the time relay 30 (circuit B) is then connected between the conductors 2 and 3 of the direct current circuit to be energized, this circuit being closed as a result of the fact that the switch 31-1 of the device to maximum speed 31, switch 32-1 of the shutdown relay 32, switch 33-1 of the AC thermal relay 33, switch 29-2 of the undervoltage relay 29 and the switch 34--1 of auxiliary control relay 34 are closed.

   The time relay 30 then begins to actuate its switch 30-1 (circuit B-5) to move it towards its closed position.



  If the low voltage condition in the DC circuit persists during the time interval in which relay 30 is set to close its switch 30-1, the control coil of control relay 35 (circuit B-5 ) is excited. The excitation circuit for the coil of relay 35 extends from conductor 2 through switches 31-1 and 32-1 (circuit B), switch 32-2 (circuit B-5) of relay -de Out of play 32, switch 36-1 of the stop relay 36, la, resistor 37, la, coil - (the control of relay 35, switch 30-1 and an auxiliary switch 9-1 of the driving circuit breaker 9 to the driver 3.

   The relay 35 then closes its switches 35-1. (circuit B-3), 35-2 (circuit B-51) and 35-3 (circuit D) and opens its switch 35--4 (circuit V-21). Thus, the switch 35-2 bypasses the switches 31-1 and 9-1 in order to maintain the excitation of the relay 35 after one or both switches 30-1 and 9-1 are open. The closing of the switch 35-3 connects the. auxiliary control relay control coil 34 (circuit D) between conductors 2 and 3 of the direct current circuit. through resistance 38. La.

         control coil of control relay 39 (circuit D-1), which will be described later, is connected directly between conductors 2 and 3 when switch 35-3 is closed. When the auxiliary control relay 34 is energized, it opens its switches 34-1 (circuit B) and 34-2 (circuit B-52) and closes switches 34-3 (circuit C) and 34-4 (circuit AA ).



  Closing switch 34-3 (circuit C) establishes a connection of an auxiliary conductor 2A, to which a number of control devices described below are connected, with conductor 2 of the direct current circuit. When the conductor 2A is supplied by the conductor 2, the auxiliary control relay, 40 (circuit E), is energized. The circuit of this relay 40 extends through the switch 41-1 of the relay 41 (circuit 1 ") which will be described below.

   When the relay control coil 4 () is. energized, switch 4 ((- 1 (circuit F) is closed to cause energization of the cone coil of the starting circuit switch control relay, 42.

   The excitation circuit of relay 42 is extended from conductor 2A through switch 43-1 of transfer relay 43 (circuit Ii), an auxiliary switch 7-1 of starting circuit switch 7, a switch 4--1 for the interruption release: t. time 44 (circuit G-11, and a switch 40-1 of relay 40 of conductor 3 of the direct current circuit.



  When the control coil of relay 12 is thus energized, two switches: 12-1 (circuit F_) and 42--2 (circuit G) are thereby closed. The switch 42-1 thus bypasses the auxiliary switch 7-1 of the starting circuit switch, 7 so as to. maintain the excitement of the. coil. of relay 42 after circuit breaker 7 a. been brought to its closed position.

   When switch 42-2 is closed, it connects the. closing coil 7A of the starting circuit switch 7 between conductors 2 and 3 of the direct current circuit to cause the closing of the switch 7. At the same time as the closing coil 7 A is energized , the. control coil of the interruption relay to. time 14 is also connected between conductors, 2 and 3.

   This circuit extends through switch 42- \? (circuit G) and an auxiliary switch 56-1 of the hopscotch circuit switch control relay 56 (circuit L), which will be described later. After a predetermined time interval, the relay at. time 44 opens its switches 44-1 (circuit F) and 4.1-2 (circuit L) and closes switch 44-3 (circuit .7). The operation of switches 44-2 and 44--3 -is currently ineffective and their function will be deerit later.



  When switch: 14-1 is open, the circuit of the control coil of relay 42 (circuit F) is opened to allow this relay to return to its de-energized position, in which its switches 42-1 and 42-2 are open. The opening of switch 42-1 (circuit F) cuts the restraint circuit for the control coil of relay 42 and opening of switch 42-2 cuts off the excitation circuits for the closing coil 7A of the starter circuit switch 7 and for the. control coil of the interrupt relay 44 (circuits G and G-1).



       The starter circuit switch 7 is now closed and remains engaged in its closed position until it is brought to. open up. When the circuit switch 7 is closed, alternating current is supplied to the armature winding 4A of the dynamoelectric machine 4 from the circuit 1 through the auto-transformer 8. The auto-transformer 8. transformer 8 serves to reduce the potential which is imparted to the machine 4 during the start-up period thereof.

         During this period, the field winding 4B of the. machine 4 is disconnected from its excitation circuit by a switch 45-1 of the winding contact device, field 45, the control coil of which is shown. In circuit T. The control coil of the contact device 45 is de-energized until later in the following operations.

   A second switch 45-2 of the contact device 45, which is closed when the control coil of the contact device is de-energized, closes a circuit. bypass for the field winding 4B, comprising the resistor 46 and the control coil of the inductive relay 47.



  Since the field winding of machine 4 is shunted by a resistor and is not energized by an external source when the start circuit switch 7 is closed, machine 4 starts up. to run as an induction motor and operates the DC machine 5 using the shaft 6. At this moment, however, there is no load on the. direct current machine and, therefore, the. The speed of the AC machine will increase until it approaches synchronous speed.

   Until the synchronous speed is approximately reached, the current induced in the field winding 4B from then the armature winding 4A, passes through the control coil of the relay 47 and hand holds the switch. 47-1 (circuit J) - of this relay in the open state to prevent an excitation of the control coil of the contact device 45.

   When, however ,. the speed @ of machine 4 is approaching <B> of </B> syn chronism, the current, which is induced, in its field winding, falls to a value which, is insufficient to keep open the switch 47-1 of the relay 47. This switch closes, therefore, to connect a terminal of the control coil of the contact device 45 to the control conductor 2A.



  Where energy is. supplied to the armature bearing 4A of the AC machine 4 as a result of the closing of the starter circuit switch 7, the AC changeover relay 48 (fig. 1) opens its switch 48-1 (circuit U) and close its switch 48-2 (circuit U). When switch 48-1 closes, it short circuits the control coil of auxiliary relay 49 (circuit U) to prevent energization.

   When. on the other hand, switch 48-1 is open, the closing of this circuit is suspended to allow the excitation of the control coil of relay 49. Switch 48-2 is connected in series with the cam coil. command of the relay 49 to establish an excitation circuit for the latter when this switch is closed.



  One terminal of the control coil of the relay 49 is connected by a resistor 50, and the conductor 51 to a terminal of the direct current machine 5. As the speed of the machine 5 increases, as a result of the operation of the machine. AC machine 4, the voltage between its terminals gradually rises to a value sufficient to actuate various control devices in the installation. Thus, when the switch 48-1 is open and the switch 48-2 is closed, the control coil of the relay 49 is energized by current from the direct current machine 5.

   The excitation circuit for this relay extends from conductor 51 through resistor 50, the relay coil -19, switch 48-2 and switch 39-1 (circuit r $ ') to conductor 3 of the relay. DC circuit, to which the other terminal of the DC machine 5 is connected, as described above. As already described, the switch 39-1 of the relay 39 was closed, when the control coil of this relay was energized simultaneously with the energization of the auxiliary control relay 34 (circuit D and D-1).



  When the control coil of the relay 49 'is energized as described above, this relay or a switch 49-1 (circuit V) and closes the switches 49-2 (circuit Ii) and .19-3 (circuit J-1). The function of switch 49-1 will be. -described later. Interrupt 49-2 is connected in parallel with switch 48-2 to maintain a hold circuit for the control coil of relay 49.

   By closing switch 49-3, the circuit for energizing the control coil of contact device 45 is closed (circuit J), to cause switch 45-2 to open and close. switches 45-1. and 45-3 which have been described above. Another switch, 45-4 (fig. 1), which will be described later, is also closed when the control box of the contact device 45 is energized.

   When switch 45-2 is open, the branch circuit of field coil 4B of AC machine 4 is open and when switch 45-1 is closed, winding 4B is connected. between the terminals of the. direct current machine 5. This circuit extends from the conductor 51 through the switch 45-1, the field coil 4B, the resistor 52 and the control coil of a field current relay 57 to conductor 3 of circuit at. direct current.

   The field winding 4B is then excited by the current of the machine. current. continuous 5 ef forces the machine to alternating current .1 ü come to synchronism and to. walk synchronous motor committee.



  The voltage and transfer relay, at. time. 53, is connected by a resistor 54 to. the secondary bearing of the potential transformer 55, of which. the primary winding is connected across a phase of the alternating current circuit 1. The relay 53 is provided with switches 53-1 and <B> 53-2 </B> (circuits b: and V = 21, respectively).

   The switches 53-1 and 53-2 are arranged to be kept open as long as the voltage imparted to the. control coil of relay 53 exceeds a predetermined value, such as a value corresponding to 70. # \ o of the normal voltage of the AC circuit 1. When the auxiliary switch 45-r of the contact device 45 is closed by the fact that it is brought to its closed position, the.

   control coil of relay 53 is short-circuited through switch 45-4 and an auxiliary switch 9-2 of on-circuit switch 9, which is closed when switch 9 is open. Since the circuit breaker 9 is open, when the switch 45-4 is closed, the switches 53-1 and 53-2 are liable to close. Closing of switch 53-2 (circuit V-21) has no effect at this time, because switch 35-4, which is connected in series with it, is open as a result of the relay being energized. control 35. Closing of switch 53-1 (circuit K) acts.

    however, to complete a driver circuit for: transfer relay control coil 43. This circuit. extends from the control conductor 2A through the coil of the relay 43, a switch 37-1 of the field current relay 57 (fi. 1) and the switch 53-1 to the conductor 3 of the current circuit continued. The field current relay 57 is arranged to close its switch 57-1 as soon as the field winding 4 $ is crossed by an excitation current of a predetermined value, such as, for example, three quarters of the current of. normal excitement.

   In this way, the relay 57 closes its switch 57-1 soon after the switch 45-1 of the aforementioned contact device is closed, to connect the field winding 4B to the terminals of the direct current machine 5.



  In this way, the coil <B> of The control of the transfer relay 43 (circuit K) is energized as soon as the AC machine 4 has started to operate as a synchronous motor and the current through its field winding has reached a predetermined value. When the transfer relay 43 control coil is. energized, this relay opens its switch 43-1 (circuit F), which has been described previously, and closes switches 43-2 (circuit I), 43-3 (circuit L) and 43-4 (circuit M-1 ).

    The switch 43-3 closes a circuit d2, held for the. control coil of relay 43 to maintain the excitation of: the coil of this relay as long as the control conductor 2A is supplied by the conductor 2. of the circuit. direct current.



  When switch 43-2 is closed, a circuit is completed to energize the control coil 713 (circuit I) of the starting circuit switch 7. This circuit extends from conductor 2 of the direct current circuit through l switch 43-2, the control coil 713 and an auxiliary switch 7-2 to conductor 3 of the circuit. at. direct current. As soon as the.

    coil 7B is energized, the starting circuit switch 7 is caused to open to disconnect the. native alter current machine 4 of the auto-transformer 8 and to disconnect the auto-transformer 8 from the alternating current circuit 1. When the circuit breaker 7 opens, its auxiliary switch 7-2 (circuit 1) is caused to open in order to de-energize coil 7B.



  When the circuit switch 7 is caused to open, an auxiliary switch 7-3 (circuit L) closes to complete a circuit for energizing the control coil of the control relay 56 of the switch-off switch. run circuit 9. This circuit extends from the control conductor _2A through switch 7-3, coil = of relay 56, an auxiliary switch 9-3 of run circuit breaker 9, the switch 44-2 of interrupt relay 44 which is now de-energized, and switch 43-3 of transfer relay 43 to conductor 3 of the direct current circuit.

   Relay 56 then opens its switch 56-1 (circuit G-1) and closes switch 56-2 (circuit <I> L) </I> -and 56-3 (lVl circuit). The switch 56-2 is connected in parallel with the auxiliary switch 9-3 of the operating circuit switch 9 and is used to maintain a retaining circuit for the control coil of the relay 56, after that circuit switch 9 has been closed.



  When switch 56-3 is closed, a circuit is closed to energize the closing coil 9A (circuit. M) of the run circuit switch 9. The armature windings 4A of the, AC machine 4 are then energized directly from the AC circuit 1. At the same time as the. closing coil 9A is energized, the time interrupt relay 44 is energized again.

   The excitation circuit of this relay now extends from conductor 2 of the direct current circuit through switch 56-3 (circuit <B> 31) </B> of the control relay 56 which has been described previously, the switch 43-4 (circuit M-1) of the transfer relay 43 which has also been described, a conductor 98 and the coil of the relay 44 (circuit cooked 9-1) to conductor 3 of the direct current circuit. Switch 58-1 (circuit G-1) of control relay 56 is now open and is at this time used to -cm- de-energize closing coil 7A of start circuit switch 7.



  After a predetermined time interval has elapsed after the control coil of the time interrupt relay 44 has been energized, this relay opens its switches 44 _-- 1 (circuit F) and 44-2 (circuit L) and closes its switch 44-3 (circuit J). The opening of the switch 44-1 (circuit. F) is now ineffective, since this circuit is already open, because the switch 43-1 of the transfer relay 43 is or green.

   Closing switch 4.1-3 is also ineffective at this time and its function will be. described later. The opening of switch 44-2 (circuit L) acts however to interrupt the excitation circuit of control relay 56. This relay then opens its switches 56-2 (circuit. L) and 56-3 (circuit. M) and close its switch 56-1 (circuit G-1).

   Opening the switch 56-2 interrupts the holding circuit. relay control coil 56 (circuit L) and the opening of switch 56-3 interrupts the excitation circuits for the closing coil 9A (circuit <B> 31) </B> of the on circuit switch 9 and for the. switch-off relay control coil 44 (circuit G-1). During the time required for the operation of the relay 44, the circuit switch 9 was closed and switched on in the closed position, so that the energization of its closing coil 9A is no longer necessary.

   As a result of the description given above, only one interrupting relay is used in time to cause the de-energization of the closing coils of two circuit switches operated individually in the appropriate time interval. after each coil has been energized.



  When the circuit switch 9 is closed to connect the armature winding 4A of the AC machine 4 directly to circuit 1, the machine 4 begins to operate normally as a synchronous motor and is ready to operate the machine. china direct current 5 as a generator to supply power to the direct current circuit. The way of connecting the machine 5 to its circuit in order to supply it will be described later.



  When circuit switch 9 closes, it opens auxiliary switches 9-1 (circuit B-5), 9-2 (fig. 1), 9-3 (circuit L), 9--4 (circuit B -54) and 9-5 (circuit X), and closes auxiliary switches 9-6 (circuit B-4), 9-ï (circuit B-54), 9-8 (circuit J), 9-9 ( circuit O) and 9-10 (circuit S). Opening switch 9-1 is ineffective because switch 35-2 (circuit B-54) maintains a hold circuit for the control coil of relay 35 (circuit B).

   On opening, switch 9-2 (fig. 1) interrupts the short circuit between the terminals of relay 53 and allows this relay to come into operation, as will be described later. The opening of switch 9-3 (circuit L) prevents the re-citatio.n of the control coil of the control relay 56, when the relay 44 returns to its de-energized position to close its switch 44. -2. The function of the other auxiliary switches of the circuit switch 9 will be apparent in the. continuation of the description of the operation of the installation.



  When the auxiliary control relay 40 (circuit K) was energized in dependence on the. closing of switch 3-1--1 (circuit. C) of the auxiliary control relay 34 6circuited D), as described previously, relay 40 closed, in response to switch .10-1 (circuit F), which has been described,

   two interfaces 40-2 and 40-3 which are shown in fig. 2 between the DC voltage regulator 58 and a reversible motor 60 for controlling a rheostat. The motor 60 is also arranged to be connected to the frequency regulator of the alternating current 61 by two switches 62-1 and <B> 62-2 </B> an auxiliary reversing control relay 62 (circuit I'-2) which will be described later.

   At this point of operation, the control box of relay 62 is de-energized to allow switches 69-1 and 62-2 to remain open. Motor 60 is, therefore, only controlled by DC voltage regulator 58 through switches 40-? and 40-3, and is. disconnected from the frequency regulator 61.

        The DC voltage regulator 58 comprises the three elements 58A, 58B and <B> 580, </B> each of which is provided with a rocker arm and a pair of contact members at each end thereof, which are arranged to be selectively engaged along the side to which the rocking arm is tilted.



  Element 58A is a tension balancing element comprising two coils in opposition to each other, which can act on cores connected to the respective ends of the rocking arm. The left coil is connected between conductors 2 and 3 of the main circuit to. direct current and the coil! on the right is connected between conductors 3 and 51, or in other words, between the terminals of the direct current machine 5.

    The two coils of element 58A have the same number of ampere-turns and are arranged so that when equal voltages are applied to them, they exert equal forces on their cores in order to maintain the toggle bias of this. element in equilibrium position.

   However, when the voltage between conductors 2 and 3 of the main DC circuit is greater than that of machine 5, the left coil of element 58A prevails over the right coil, causing the coil to switch. rocking arm so as to close the right contact members of this element, and vice versa. Element 58A is also provided with two auxiliary switches 58L and 58R, the mission of which will be explained later. These switches will be selectively closed depending on the side to which the rocker arm is tilted.



  Element 58B of voltage regulator 58 is a voltage regulating element comprising a single coil interposed between conductors 2 and 3 of the DC main circuit and acting on a core connected to the left end of the arm. toggle of this item.

   A tension spring urges the other end of this rocker arm and is dimensioned so that when the voltage printed on the coil of this element is less than the normal desired tension between conductors 2 and 3 of the main circuit to direct current, the spring exerts a greater force on the rocking arm than the coil, thus causing the rocking arm to swing so as to close the left contacts of this element.

       Similarly, when the tension between conductors 2 and 3 is greater than that desired, the force of the coil will be greater than that of the spring and the toggle arm will be tilted so as to close the contact members of the coil. right.



       Element 58C of voltage regulator 58 is a current adjusting element which is similar to voltage adjusting element 58B. The coil of this element is connected in parallel to the interpolar field winding 10 of the machine 5. As the winding 10 is connected in series to the armature winding of the machine 5, the voltage between. the terminals thereof is directly proportional to the quantity of current flowing through the armature bearing.

   It can thus be seen that when this current exceeds a predetermined value, the force exerted by the coil of the element 580 is greater than that due to the spring thereof and that, consequently, the rocker arm is tilted so as to close the right contact members. On the other hand, when the current is less than the predetermined value, the 1st rocker arm is tilted in the opposite direction to close the left contact members of this element.

   The coil and the spring are set so that this predetermined value of the current is the maximum value that can be allowed to pass through the armature winding of the machine 5.



       As soon as the relay 40 closes its switches 40-2 and 40-3, the DC voltage regulator 58 begins to control the operation of the motor 60 actuating a rheostat. The first operation of the voltage regulator 58 is to balance the voltage of the machine 5 against the voltage of the direct current circuit.

    This is accomplished by the voltage balancing element 58A which acts as a result of the DC circuit switch 21 not yet being closed and an auxiliary switch 21 thereof. Ci, which is closed when the circuit switch 1 is open, is connected in series with the circuit extending from the upper terminal of the machine 5 through the conductor 51 to the toggle arm of the element. 58A.

   The voltage adjusting element 58B and the adjusting element - the current <B> 580 </B> of the regulator 58 remain inoperative until the circuit switch 21 is closed, due to the fact that the circuit extending to the toggle arms of these elements contains an auxiliary switch 21-8 of the circuit switch 21 which is closed only when this circuit switch is closed.



  As it was read previously, the ele ment fl'équilibra.ge voltage 58A closes its right contact members when the flight between conductors 2 and 3 of the circuit. direct current is greater than that of machine 5 and closes its left contact members when the voltage of machine 5 is greater than that existing between conductors 2 and 3. Therefore, until the voltage of the , machine 5 is brought to a value equal to that of the direct current circuit, the right contact members of element 58A are closed to connect the armature and the right field winding of the reversible motor 60 rheostat control switch in series between the terminals of the. machine 5.

   This circuit extends from the upper terminal of the machine 5 through the conductor 51, the switch 21-7, the rocker arm and the right contact members of the element 58A, the switch 40-2, l The right field winding and the armature of the motor 60 and the conductor 3 to the lower terminal of the machine 5. The right field winding of the motor 60 is so arranged with respect to the armature that when the motor is energized in this way, it rotates in a suitable direction to decrease the efficiency of a resistor 63 which is connected in circuit with the bypass field winding 5A of the machine 5.

   The excitement of the. machine 5 is, therefore, increased to generate its voltage until this flight <B> t </B> -tit, level equal to that existing between conductors 2 and 3 of the current circuit. continued.



  If the voltage of machine 5 is set to a value greater than that of the direct current circuit, the arm < The flip-flop of element 58A is flipped in the opposite direction to open the right contact members and to close the left contact members of this element. Engine <B> 60 </B> is then excited by the current. of a circuit extending from the upper terminal of the machine 5 through the conductor 51., the switch? 1-7, the arm to. toggle and contact members. left of element 58A, switch 40-3, left field winding and armature of motor 60 and conductor 3 to. the lower limit of the machine 5.

   The left field winding of motor 60 is set in such a way with respect to the armature that when the motor is energized in this way, it rotates in a proper direction to increase the efficiency of resistor 63, thereby decreasing the voltage generated by the machine 5. In this way, it is seen that the voltage balancing element 58A controls the motor 60 to vary the efficiency of the. resistor 63 until the voltage of the. machine 5 is exactly equal to that of the direct current circuit.



  Until this equilibrium condition is reached, the two auxiliary switches 58R and 58L of the voltage balancing element 58A, the connections of which are shown to circuit P, are alternately closed to energize the coil. control of a time relay 64 (circuit P). This relay is. provided with a switch 64-1 (circuit rS \) which is. closed after the control coil of relay 64 has been de-energized for a predetermined time interval.

         In other words, this relay is arranged to bring its switch 64--1 instantly to its. fully open position whenever its control coil is exited for a moment, but allows. the switch 6.1-1 dc will close only when the control coil 64 has been continuously de-energized for a predetermined time interval.

   In this way, the auxiliary switches 58R and 58L prevent the closing of the switch 64-1, while the voltage balancing element 58A is operative to raise or lower the voltage of the machine 5, and allows the closing of this switch only after the voltage of the machine 5 has been reached. been balanced for a predetermined time interval with the voltage of the current circuit. continued.



  An auxiliary switch 7-4 - for the starting circuit breaker 7 which is closed when the switch 7 is on. closed, and a switch 57-2 of the field current relay 57, which is closed when the relay 57 is not energized to a predetermined degree, are each connected in parallel to the switches 58R and 58L (circuit P). These switches prevent de-energization of the control coil of relay -64 and, purely as a result, the closing of switch 64-1, while the starter circuit switch 7 is closed and while the current is running. traversing the field winding 4B of the machine 4 is less than a predetermined value, respectively.



  As a result, when the circuit switch 7 is open, the current flowing through the field bearing 4B is greater than a predetermined value, and the voltage of the machine 5 has been balanced against that of the machine. circuit to. direct current for a predetermined time interval, switch 64-1 (circuit S) is able to close. The switch 64--1 cooperates with certain other switches, which are yet to be described, to connect the. DC circuit switch control relay control coil 65 (S circuit) between machine terminals 5.



  The polarized relay 66 (circuit Q) is connected directly to the terminals of the. DC machine 5 and est. arranged to close a switch 66-1 (circuit R) when the voltage of the machine 5 rises with the correct polarity with respect to the polarity of the dc circuit. This relay provides protection against the possibility of connection of the machine 5 to the direct current circuit with reversed polarity. When switch 66-1 is closed, voltage relay 67 (circuit R) is connected to the machine terminals 5.

   The circuit of the control coil of the relay 67 extends through the switch 39-1 (circuit S) of the control relay 39 which has been described previously.



  If the voltage of the machine 5 is greater than a certain value, such as for example 85% of the normal voltage, the relay 67 produces the closing of its switch 67-1 (circuit S). The control coil of the relay 65 (circuit S) is then energized from then the machine 5 by means of the circuit extending from the conductor 51 by the auxiliary breaker 9-10 of the circuit switch. on 9, an auxiliary switch 21-1 of the dc circuit switch 21 (fig. 2),

   a switch 68-1 of the time interruption relay 68 (circuit T-1), the switch 64-1 of the time relay 64, the switch 67 = 1 of the voltage relay 67 and the switch 39-1 . of the relay. control 39 to the conductor 3 of the direct current circuit. Then relay 65 closes its two switches 65-1 and 65-2 (circuits <I> S </I> and <I> T, </I> respectively).

   Switch 65-1 thus bypasses auxiliary switch 21-1 (circuit S) of circuit switch 21 so as to maintain energization of the control coil of relay 65 after switch 21 is closed, the switch 65-2 completes a circuit to energize the closing coil 21A (circuit T) of the circuit switch 21 and to energize the control coil of the time switch relay 68 (circuit T- 1).



  The circuit switch 21 is closed as a result of the energization of its control coil 21A and is engaged in its closed position. The switch relay 68 opened its switch 68-1 (circuit S) after a predetermined time interval to de-energize the control coil of the control relay 65. The switches 65-1 and 65-2 can then open.

   Opening switch 65-1 interrupts the hold circuit for the. relay control coil 65 (circuit S ') and. opening the switch 65-9 interrupts the excitation current for the. closing coil 21A (cir- cuit T) of switch 21 and for the. switch relay control box 68 (circuit T-1). Switch 21 is. then engaged in its. closed position and all its control devices are de-energized.



  The operation of starting and connecting the machines .1 and 5 to their respective circuits to translate AC power into DC power under normal conditions is now complete. The machines continue. to operate in this manner as long as there is sufficient energy demand in the DC circuit. During this regime, the direct current voltage regulator 58 operates in the manner described for adjusting the. voltage and charge of the. machine. direct current 5.

    This operation consists in what it allows. machine 5 to bear a certain load, and as long as the machine load is less than a predetermined value, the tension adjustment key element 58B maintains the tension of the machine at its. goes their normal. When, however, the load exceeds this predetermined value, the current adjustment element <B> 580 </B> operates to maintain the current flow from the machine to the. maximum admissible value by varying its voltage correspondingly.



  When the circuit switch 21 was closed, its auxiliary switch 21-7 was open to disconnect the toggle arm of the voltage balancing element a8A from the lead 51 and the auxiliary switch 21-8 was closed to disconnect. connecting the toggle arm of the current adjusting element 58C to the conductor 51. The element 58A was thus rendered inoperative and the elements 58B and <B> 580 </B> were made operational <u following the closing of circuit switch 21.

    As said above, when the value of the current passing through the. machine 5 is less than. the, maximum admissible value, the members (the left contact (the current adjustment element 68C remain closed. These members: df # contact complete in the closed state a circuit extending: from the conductor 51 by switch 21-8, the toggle liras of the current adjustment element.

     <B> 580 </B> and said contact members to the base arm of the voltage adjustment element 58B, thus making this element operative to maintain the voltage between the conductors: 2 and 3 of the DC circuit at 1. desired predetermined value.



  The tension adjusting element 58B acts as the. as indicated by the fact that it closes its left contact members when the voltage between conductors 2 and 3 is below the desired value. thereby completing a circuit for energizing the control motor 60 <B> of </B> rheostat.

   This circuit extends from the upper terminal of the machine 5 through the conductor 51, the switch 21-8, the arm to. Toggle and left contact members of the current adjusting element <B> 580, </B> the left rocker arm and contact members of tension adjuster 58B, switch .10-2, right field winding and motor armature 60 and 1P conductor 3 to. the lower terminal of machine 5. Motor 60 therefore operates to decrease the key efficiency of resistor 63, thereby increasing the excitation of machine 5.

   The voltage generated by the. machine 5 is thus increased to raise the voltage printed on the conductors:? and 3, to. the desired value. If this voltage rises above the desired value, element 58B closes its right contact members to complete a circuit extending through switch .10-3 and the field coil. left and the armature of the motor 60. This operates, therefore, to increase the efficiency of the resistor 63, thereby reducing. the excitation, and hence the voltage, of machine 5 to the desired value.

   It can thus be seen that, while the machine 5 is connected to the direct current circuit by the circuit switch 21 and that the current flowing through the machine is below the maximum desired value , the voltage adjustment element $ 58 is operative to maintain the voltage between conductors 2 and 3 at the desired value pre-determined by suitably adjusting the excitation of the motor 60 to vary the excitation of the machine 5.



  If the current flowing through machine 5 exceeds the maximum desired value, the current adjustment element <B> 580 </B>. Opens its left contact members and closes its right contact members. The opening of these left contact members interrupts the circuit going to the rocking arm of the tension adjusting element 58B, discussed above, and thereby renders the element 58B inoperative from the point of view. of the control of the excitation of the motor 60. The closing of its contact members: on the right of the element <B> 580 </B> completes a circuit for energizing the motor 60 by means of its left field winding so as to. cause the. voltage reduction. of the. machine 5, as described above.

   This circuit extends from the upper key terminal of the machine 5 through conductor 51, switch 2I-8, arm to. Toggle and contact members: right of element 58C, switch 40-â, left field winding and armature of motor 60 - and lead 3 to lower terminal: of machine 5 The voltage of the latter is thus immediately reduced to. that the current which passes through it is reduced to the maximum desirable value, and the control element: of current <B> 580 </B> continue to adjust the voltage of machine 5 as long as the load imposed on it is so great that normal flight would cause current to flow. excessive.

   As soon as this condition ceases to exist, the voltage regulator 58B will again be made operative to maintain the voltage of the DC circuit at its normal value. <i> 20 </I> Automatic shutdown <I> in the case of a </I> studs <I> in </I> continuous coicrarit.



  When the load of machine 5 drops and remains below a predetermined value for a predetermined time interval, it is desirable to shut down machines 4 and 5. This is accomplished with the aid of an alternating current underload relay 69 (fig. 1) and time relay 30 (circuit B). In addition to its main control coil, the relay 30 includes the. Auxiliary coupling coil 30A allowing the relay to actuate a number of switches with different time settings. The operation of a relay of this type is described, for example, in Swiss Patent No. 112290.

   The references 30, 30A., 30-1, 30-2 and 30-3 correspond respectively. to reference numbers 35, 64, 42, 168 and 94 of fi-. 2 of said patent.



  The control coil: of the minimum load relay 69 is connected in series with one of the current transformers 77 (fig. 1) so that its excitation is proportional to the value of. current passing through the armature windings 4A of machine 4. When this current falls below a predetermined value, relay 69 closes its switch 69-1 (circuit B-4) to: energize the main control coil ( circuit B) and the auxiliary coil 30g (circuit B-3) of the time relay 30.

   The excitation circuit for the main control coil of relay 30 extends from conductor 2 of circuit to. direct current via switch 31-1 of the speeding device 31, switch 32-1 of the interrupting relay 32, the main control coil: of relay 30, switch 38-1 of relay AC thermal 33, conductor 70, switch 69-1 of the low load relay 69 and auxiliary switch 9-6 of the run circuit switch 9, which is closed when the switch 9 is closed, to conductor 3 of the direct current circuit.

   The excitation circuit of the auxiliary coil 30A extends from the controller 2 through the switches 31-1 and 32-1, the coil 30A, the switch 33-1 of the control relay 35, and interrupts them. teurs 69-1 and 9-6 to the driver 3.



  As the coupling coil 30A is then energized, switch 30-1 is not closed, but switches 30-2 (circuit B --- 52) and 30-3 (circuit C'-5) are . brought to them. respective closing positions. The time setting of the switch 30-3 is. considerably less than that of the switch 30-2, but its. closing is. at this time without effect, as will be described later.

   If the. load required of the machine 4 <B>, </B> -iu, -mente <B> to </B> a value greater than t, than the.



  value at which the relay to. minimum load 69 is adjusted to close its switch 69-1 before the time relay 30 has closed its switch 30-2, it will be possible for this switch to return immediately to its open position. In this way, the. minimum load condition shall persist continuously for the time interval for which switch 30-2 is adjusted to operate in order to cause the. automatic disconnection of machines 4 and 5 from their circuits.



  When switch 30-2 is closed as a result of this condition, it short circuits the control coil of the control relay. main 35 (circuit B-5), and switches 35-1 (circuit B-3), 35-2 (circuit B-54), and 35-3 (circuit D) can open and the switch 35-4 (circuit I'-21) may close. The function of switch 35-4 will be. described later. As a result of opening the switch 35-1, the auxiliary coupling coil 30A of the time relay 30 (circuit B-3) is de-energized and the switch 30-2 can return to its original position.

   The opening of the switch 35-2 interrupts the holding circuit of the control coil of the relay 35 and prevents an immediate re-energization of the latter, when the short circuit between its terminals is suspended as a result of the opening of the switch 30-2. The opening of the switch 35-3 interrupts the excitation circuit for the control coil of the auxiliary control relay 34 (circuit D) and allows this relay to open its switches 34-3 (circuit C ) and 34-4 (circuit 4A) and to close its switches 34-1 (circuit B) and 34-2 (circuit B-52).

   The actuating coil of the control relay 39 (circuit D-1) is also de-energized when the switch 35-3 Pst open, and this relay or then its switch 39-1 (circuit .S) and close its switch 39-2 (circuit 0).



  Control lead 2A is not immediately disconnected from lead 2 when switch 34-3 (circuit C) is open, as their switch is bypassed by an auxiliary switch 21-2 of the current circuit switch. continuous 21 which is closed when switch 21 is closed.

   So. the conductor 2A is supplied by the conductor 2, as long as the circuit switch 21. is. closed. The circuit switch 21 is opened as a result of the opening of the switch 39-1 (circuit S), because the actuating coil. at zero voltage 21C (circuit S-1) of the switch 21 is then de-energized.



  When switch 21 opens, auxiliary switch 221-9- (circuit C) also opens to disconnect the conductor \? A of conductor 2 Pt thereby de-energize all control devices connected to conductor 2A, including the zero voltage actuating coil 9C (circuit N) of the operating circuit switch 9 which causes opening of switch 9 To disconnect machine 4 from the circuit.

   The supply of the driver 2A by the auxiliary switch 21-2 until due the switch 21 opens, ensures the. disconnection of machine 5 from the direct current circuit before disconnection of the. machine 4 of the alternating current circuit so as to prevent reversal of the. current direction between the circuits.



  As the machines gradually come to rest, the tension generated by the. machine 5 gradually decreases to zero and the control devices which were excited by it return to their de-energized positions. All the equipment in the station is now in the. same condition which it originally occupied and it is again ready to operate under the same conditions as described above.



   <B> <I> 30 </I> </B> <I> Protective devices for stopping </I> <I> machines. </I> The running of the machines can be stopped automatically depending on predetermined conditions other than the minimum load condition as described above. Different protection devices, such as AC thermal relay 33 (fig. 1) and phase balanced current relay 71 (fig. 1) can be provided with switches such as 33-2 (circuit B-51 ) and 71-1 (circuit B-54), respectively, to short circuit the coil - the drive of relay 35 (circuit B-5)

    a in order to stop the running of the machines in the same way that they are stopped following the closing of the switch 30-2 (circuit B-52) during a maintained minimum load. Switch 71-1 -is connected in series with an auxiliary switch 9-7 (circuit B --- 54) between the terminals of relay 35 so that unbalanced currents in the different phases of the induct 4A windings of the machine 4 cause the coil of the relay 35 to be short-circuited only when the on-circuit switch 9 is closed.



  If such an imbalance condition occurs during start-up of machine 4, this indicates internal disturbances of the machine, and it is then desirable to take the machine out of service until an inspection of the machine. this has been done. This result is obtained using the switch-off relay 32 (circuit C).

   If the phase-balanced relay 71 closes its switch while starting the machine, the short-circuiting of the control coil of relay 35 (circuit B-5) is prevented because the auxiliary switch - 9-7 (circuit B-54) is open, but as another auxiliary switch 9-4 (circuit C-2) of the run circuit switch 9. is closed, the relay control coil. switch-off 32 (circuit C) is energized.



  The excitation circuit of relay 32 extends from conductor 2 of the direct current circuit through switch- 34-3 (circuit C) of auxiliary control relay 34, the closed breaker 72-1 of relay 72 (circuit V-22) which will be described later, the coil of relay 32, switch 9-4 (circuit C-2) and switches 71-1 and 35-2 (circuit B-54) to conductor 3.

   Relay 32 then opens its switches 32-1 (circuit B) and 32-3 (circuit B-5) which snap into their open position and remain in it until 'they are carried out by hand by the supervisor. Switches 32-1 and 32-2 open the circuits of time relay 30 (circuit B) and relay 35 (circuit B-5) and thus completely prevent any further operation of the machines, until the relay 32 is returned to the starting position.



  Other relays such as a direct current thermal relay 73 (fig. 2), and an alternating current short-circuit relay 74 (fig. 1) are provided with switches 73-1 (circuit C -3) and 74-1 (circuit C-4) which are also arranged to cause the activation of the deactivation relay 32, if they are closed as a result of predetermined abnormal conditions.

   Switch 30 -.- 3 (circuit C-5) of time relay 30 is connected in series with an auxiliary switch 7-5 of start circuit switch 7 so that when switch 30 -3 is closed while switch 7 is closed, disabling relay 32 is energized. This provides protection to prevent the machine 4 from running for an unusually long time on the start connections in the station.



  This protection is obtained by providing an auxiliary switch <B> 7-8 </B> (circuit B-3) in switch 7, which energizes the main control coil and auxiliary coil 30A of time relay 30 as soon as switch 7 is closed.



  If the change from start connections to run connections is. carried out within a normal period of time, switch 7 will be opened before switch â0-3 is closed. The coils of relay 30 will then be de-energized following the opening of auxiliary switch 7-6 (circuit B-3) and this relay returns to its original position. If, however, switch 7 remains closed for an abnormal period of time, such as for example two minutes, switch 30-3 (circuit C-5) will be closed and will cause the installation to be taken out of service as described. upper.

   When the installation is taken out of service during the start-up period of the machine 4, the start-up circuit switch 7 is released by a zero-voltage coil 7-C (circuit H) which is de-energized when the conductor 2A is disconnected from conductor 2 by opening switch 34-3 (circuit C) of auxiliary relay 34.



  It emerges from the. description above that the machines can be stopped and disconnected from the electric circuits in two ways, namely as a result of the minimum load maintained or as a result of the operation of any of the different positive protection devices. Protective devices can be divided into two classes, namely those which react to temporary abnormal conditions and those which react to permanent faults.

   If temporary abnormal conditions occur, they will cause the machines to stop, but will allow them to be put back into operation when conditions return to normal. If, however, permanent faults occur, they will cause the machines to stop immediately and prevent them from being restarted until. that a supervisor examined the installation, fixed the decommissioning delay and repaired the fault which had caused the. disturbance.

       <i> 40 </I> Stop <I> (the </I> wachines <I> at the </I> site of iiiiie coiri- waede iiwiwelle.



  The machines can also be stopped at. the. main from the 23 lfib control post. 1l. If it is desired to stop this equipment immediately at any time, but to allow it to restart automatically, push-button? 4 is pressed.

   In this way, the control conductor 28 will be directly connected to the conductor 2 of the direct current circuit, which causes the energization of the control coil of the stop relay 36 (circuit A _1). The excitation circuit for this relay passes from the conductor? of the direct current circuit, by switch 21 in the control station, conductor 28, coil (read relay 36 and switch 3-1-.1r of auxiliary relay 34 to reach conductor 3.



  When the coil of relay 36 is energized, this relay opens its switches 36-1 (circuit B-5) and 36-2 (circuit @ 1 A-3) and closes its switch 36-3 (circuit A A). The last switch bypasses switch 34-4 (circuit A _1) so as to maintain the excitation of the control coil of relay 36 after relay 34 opens its switch 31-4, as long as the pusher 24 is kept lowered. Switch 36-1 (circuit B-5) opens the so-called relay circuit. 35 and thereby causes the stopping of running machines, as described above.

   Opening the switch 36-2 (circuit A A-3) prevents the establishment of a short circuit between conductors 2 and 3 of the direct current circuit which might otherwise occur under certain conditions.



  Immediately. when switch 24 is activated, the circuit. of the coil of relay 36 (circuit AA) is interrupted so that this relay opens its switch 36-3 (circuit AA) again and closes its switches 36-1 (circuit B-5) and 36-2 ( circuit <I> A </I> A-3). Automatic or manual starting of the device can then be carried out at any time. desired. If it is desired to prevent the switching on of the apparatus, the knife switch 26 at the control station 23 is. snapped into its upper position.

   If the switchgear is functioning normally to draw energy from the alternating current circuit and to supply energy to the direct current circuit, the normal auxiliary control relay 34 (circuit D ') will be energized and its switch 34 --9: (circuit <I> A A) </I> will be closed. The control coil of the stop relay 36 (circuit <I> A A) </I> will then be energized as previously described and its switch 3'6-3 main will hold a retention circuit for it as long as switch 26 is closed in its upper position, and the operation of the apparatus will be prevented due to the fact that switch 36-1 (circuit B-5) will be kept open.



  Likewise, if the switchgear works in the opposite way, that is to say to take energy from the direct current circuit and to supply energy to the alternating current circuit, a switch 72-2 (circuit <I> A A) </I> of the auxiliary changeover relay 72 (circuit V-22), which will be described later, will be closed. Switch 72-2 will bypass switches 39-4 and 36-3 (circuit <I> A A) </I> and the stop relay control coil 36 will be energized in the same way as if switch 34-4 were closed.



  If switch 26 is closed in its left position, while machines 4 and 5 are not running, switches 34-4, 36-3 and 72-2 (circuit AA) will all be open, and the coil stop relay 36 will not be energized until the apparatus tends to activate, either in the normal direction or in the reverse direction.

   When this attempt to start occurs, one or the other of the two switches 39 ---- 4, 72-2 will be closed, and the stop relay 36 will then operate as before to prevent the operation of the device. the switchgear until the switch 26 has been returned from its left position and an automatic or manual start indication has been given.



   <B> <i> 50 </I> </B> <I> Starting machines following a </I> command <I> manual. </I> The apparatus can be put into operation by hand from the control station 23 by closing the push-button switch 25, provided that the switch 26 is closed in its right-hand position and that the start is not not prevented by the presence of abnormal conditions in the central station. The circuit for manual starting starts from the conduc-. Their 3 of the DC circuit and passes through the push button switch 25 and the knife switch 26

  in the right position at the station, control 23, by the control conductor 28, by a resistor 75 and a switch 36-2 (circuit <I> A A-3), </I> by a switch 76-1 (circuit B-52) of the reverse start control relay 76:

    (circuit V-21), which will be. described later, by a switch 34-2 (circuit B-52) of the normal auxiliary control relay 34 (circuit D), by the control coil of the normal control relay 35 (circuit B-5), and then by resistor 37 and switches 36-1, 32-2, 32-1 and 31-1 (circuit B-5 and B), as described above ± for automatic start, to reach conductor 2 of the circuit to continuous current.

   The actuating coil of the normal control relay 35 is thus energized by firing the direct current circuit and the rest of the automatic control means functions as described above to start up machines 4 and 5 and to connect them to their respective control circuits. The control conductor 28 has yet another function, namely that of activating the indicating device 27 in the control station 25 to indicate whether the machines of the installation are working or not.

   When the circuit switch 21 is closed to connect the machine 5 to the direct current circuit, an auxiliary switch 21-3 (circuit A A-1) is closed to connect a resistor 78 in series with the indi vidual device. cateur 27 across the direct current circuit. This circuit is expanding. of the conductor 2 of the direct current circuit by a resistor 99, the indicating device 27 (fig. 1), the control conductor 28 and the resistor 78 and the switch 21-â (circuit <B> A </B> A-1) to conductor 3 of the direct current circuit.

    Device 27 can. be an ammeter or a voltmeter, appropriately graduated, and when it is crossed by a current of a predetermined value, according to the predetermined resistance of the above-described circuit, its needle will take a predetermined position which will correspond to. a mark on the graduation indicating that a motor unit is connected between the working circuits of the installation.



  For more than one drive unit in the installation, additional circuits <I> A A-2 </I> are provided in parallel with the -4 A-1 circuit. Each such additional circuit comprises a resistor 178 and the auxiliary switch 121-3 of the main DC switch of the corresponding unit. Of this sort, to. As each additional unit is turned on, another resistor will automatically be connected in parallel with resistor 78, thus reducing the total resistance of the indicating device 27 circuit.

   In other words, the resistance of this circuit will vary according to the number of units in operation, and as the deflection of the needle of the indicating device 27 will vary according to the current flowing through it, and, therefore, also the resistance of its circuit. , this device will indicate exactly how many running units will be connected to the DC circuit. <B> <i> 60 </I> </B> <I> Conditions </I> demanding <I> the </I> walk <I> reversed. </I> The above description deals in detail with the different phases of operation of the installation, assuming that energy is available at all times in the alternating current circuit 1.

   As mentioned above, however, if the voltage of circuit 1 were to fail, it is desirable that the. My direct current machine 5 must work as a motor to power the, alternating current machine 4 as a generator to power the circuit. 1.

   There is, therefore at. consider four possible service conditions, viz. failure of both AC and DC voltages while machines are operating normally; 20 a fault of the voltages of the alternating current and the direct current, the machines not working. not; A lack of alternating current voltage only while the machines are running; and I a lack of AC voltage only while the machines are not running.



  For condition 1, the machines will stop, which is the same as in condition 2. If the. DC voltage is reestablished before the AC voltage, which corresponds to the. condition 4-, the machines will start and run "in reverse", that is, transmitting energy from the direct current circuit to the alternating current circuit, which is the reverse of the normal walking. Under condition 3, the machines will continue to. walk and there. direction of their energy transmission will be reversed without stopping and restarting the machines.

   It is therefore necessary to consider the starting and reverse running of the machines starting from their stop and a work reversal while the machines are running. These conditions will now be described in the order listed.



   <B> <I> 70 </I> </B> Starting srtr <I> the side to </I> direct current (inverted) to provide <I> said, </I> current <I> alternative. </I> Suppose any one of the above conditions 1, \? and 4, when direct current is available at the central station and alternating current is not available, the machines will not work. When the alternating current voltage is missing, relay 53 (fig. 1)

       closes switches 53-1 (circuit Ii) and 53- \? (circuit V-21). When switch 58-2 is closed, it completes a circuit to energize the actuating coil of the reverse start control relay 76 (circuit V-21), and of the auxiliary reverse start control relay 72 (circuit V-22).

   This circuit extends from conductor 2 of the direct current circuit through switches 81-1, 32-1, 82-2 and 36-1 (circuits B and B-5), which have already been described, on the conductor 79, by a switch 40-4 (circuit V-2) of the normal auxiliary control relay 40 (circuit B) which is now de-energized, then by two parallel paths, one of which comprises a resistor 80 and the coil. control of relay 76 (circuit V-21), and the other of which includes the control coil of relay 72 (circuit V-22),

      and then by switch 85 = 4 of normal control relay 35 and switch 53-2 of voltage relay 53 to conductor 3 of the direct current circuit.



  When relay 76 is de-energized, it turns on switch 76-1 (circuit B-52) and closes switches 76-2 (circuit L-1), 76-3 (circuit V-21) and 76-4 ( circuit X). Relay 72 opens switch 72-1 (circuit C) and simultaneously closes switches 72-2, 72-3 and 72-4 (circuit B-53), 72-5 (circuit C-1), and 72-6 and 72-7 (circuit D). The switches 76-1 and 72-2 have already been described. The function of the other switches listed above will be described as they come into operation.



  When switch 76-4 closes, it completes a circuit to energize the aotation coil of control relay 81 of the direct current starting contact device (circuit X). This circuit extends from conductor 2 of the direct current circuit through an auxiliary switch 9-5 of the alternating current circuit breaker 9, the coil of relay 81 and switch 76-4 to conductor 3 of the direct current circuit.

   The relay 81 then closes its switch 81-1 (circuit Y) to connect the closing coil 18A of the direct current starting contact device 18 (FIG. 2) across the direct current circuit. The contact device 18 is then closed to connect the upper terminal of the machine 5 to the conductor 2 of the direct current circuit by the resistors 12, 13 and 14 and the current relays in series 15, 16 and 17 .



  The DC machine 5 now receives energy from the DC circuit through the circuit just described and begins. walk as a motor. The current flowing through the relays 15, 16 and 17 is first of all high enough to force these relays to open their respective switches 15-1 (circuit Z), 16-1 (circuit Z Z) and 17-1 (circuit S). Like speed and, therefore;

    the back-electromotive force of the machine 5 increases however, this current decreases to a value such that the relay 15 can close its switch 15-1 to cause the closing coil 19A (circuit Z) of the contact device 19 serving to shunt resistor 12 (fig. 2) is energized from the direct current circuit. The contact device 19 will then close to short-circuit the resistor 12 (fig. 2).



  The speed of the machine 5 then increases further until the current through the relay 16 drops to a value such that the switch 16-1 is closed to cause the energization of the closing coil 20 A (circuit ZZ ) of the -contact device 20 (fig. 2). The contact device 20 then closes to short-circuit the control coil of the relay 15 and the. resistor 13 (fig. 2).

   As the current flowing through relay 17 decreases to a value which allows this relay to close its switch 17-1 (circuit S), the actuating coil of the main continuous circuit switch control relay 65 (circuit S) will be ex cited. The circuit for energizing relay 65 can be traced as described above for normal machine operation, except that it goes through switch 17-1, instead of through switch 9-10.

   Circuit switch 21 is now closed and connected and its. closing coil is energized in the same manner as described above. Switch 39-1 (circuit S) of control relay 39 (circuit D-1) is then closed due to the fact that the control coil of this relay was connected to the DC circuit by the: closing of the switch 72-7 (circuit D) of relay 72 (circuit V-22) previously mentioned.

         Switch 72-6 (circuit D) of the same relay closed simultaneously to bypass the normal control relay actuator coil 34 to prevent its energization and operation. Switch 34--3 (circuit C) therefore did not close to connect conductor 2a to conductor 2, and the connection between conductors is not made until the current circuit breaker. continuous 21 is closed to close its auxiliary switch 21-2. (circuit C).



  When the machine 5 started to take energy from the DC circuit through the switch. circuit 21, the current passed through the shunt 22 (fig. 2) in the opposite direction of the. direction normal to force the reverse current relay 82 (fib. 2) to open a switch 82-1 (circuit V) and to close a switch 8 \ i-2 (circuit V).

    As the energy reversal relay at. AC current 48 (fig. 1) is de-energized due to the fact that the circuit. windings :, armature 4A of machine 4 is or green, switch 48-1 (circuit U) of this relay is closed and switch 48-2 (circuit U) is open. The control coil of relay 49 (circuit U) is therefore de-energized and its switch 49-1 (circuit V) is closed.

   In this way, when the switch 82-9 is closed, the circuit of the actuating coil of the reversing control relay 41 is completed starting from the conductor 79 by the resistor 83, the coil of the relay 41 and them. switches 82-2 and 49-1 to reach conductor 3. Next, relay 41. opens its switch 41-1 (circuit E) and closes its switch 41-2 (circuit V).

      Opening rc- switch 11-1 pre-energizes the actuation coil of the normal auxiliary control relay 40 (circuit E) and, consequently, its switch -10-4 (circuit V- 2) remains closed and its switches, 40-1 (circuit F) and 40-2 and 40-3 (fig.?) Remain open.

    As the switch 40-1 is. open the coil. control of relay 42 (circuit F) cannot be ex @@ itée, switch 12-2 (circuit G) remains open, P # t, therefore, the closing coil 7A of the circuit switch to AC current 7 cannot be energized. However, the run circuit switch 9 is closed as will be described below.



  The switch 41-? of the output relay 41 is connected in parallel with the switch 82-2 (circuit T ') and maintains a retaining circuit for the relay 41 after the switch 82-2 opens. This switch also completes the excitation circuit of the auxiliary relay 84 (circuit I'-1) and of the auxiliary reversing control relay 62 (circuit T'-2). The circuit of relay 8-1 extends from conductor 79 through the,

    coil of relay 84 and by switches 47.-2 and 49-1 to conductor 3. When relay 84 is energized, it closes a switch 84-1 (circuit Tl ') to connect the closing coil 85A of the contact device bypass 85 (fi, -. 2) has circuit to. current; continued. Cc, contact device is then closed to bypass the series field winding 11 of the machine 5 while it is running as a motor.



  The auxiliary reversing control relay circuit 62 extends from conductor 79 through switch 40-4 (circuit V-2), auxiliary switch 21-4 (circuit V-2) of the circuit switch. 21 (wire-. 2), the coil of relay 62 and switches 41-2 and 49-1 to conductor 3. Relay 62 closes switches 62-1 and 62-2 (fig. 2), previously mentioned, and 62-3 and 62-4 (fi--. 1) and opens the switches 62-5 and 62-6 (fi. 1).

   The function of the switches will still be described more fully.



  The switch 76-2 (circuit L-1) of the reverse start control relay 76 is in series with an auxiliary switch 21-5 (circuit L-1) of the circuit switch 21 to cause the excitation of the transfer relay control coil 43 (circuit K) as soon as the switch 21 is closed.

       The alternating current circuit switch 9 (fig. 1) is now closed, engaged in this position and its closing coil is de-energized in the same way as it has. been described for the normal start-up of the apparatus.



       When switch 9 is. closed, its auxiliary switch 9-8 (circuit J) coo father with switch 44 --- 3 (circuit J) of the time interrupt relay. 44 (circuit G-1) which remains closed for a moment after switch 9 is closed, to effect the excitation of the closing coil of the key contact device 45 (circuit J).

   This device (the contact immediately opens its switch 45-2 (fig. 1) @and closes its switches 45-1 (fig. 1) and 45-3 (circuit- J).

         The switch 45-2 opens the circuit of -discovery of the field winding 4B of the machine 4 and the switch 45-1 connects the bearing -4B to the terminals of the machine 5 to make it excited by the direct current circuit. The switch 45 = 3 thus puts in bypass the switch 44-3 (circuit J) of the interruption relay 44 so as to keep the excitation of the closing coil of the contact device 45 after the switch. breaker 44-3 a. been open.



  Auxiliary switch 9-9 (circuit 0) of switch 9 connects the actuating coil (read auxiliary reversing control relay 86 (circuit 0-1) to the direct current circuit when the switch 9 is closed Relay 86 then opens its switch 86-1 (circuit B-53) and closes its switch 86-2 (circuit B-63).

   Until switch 9 was closed, switch 86-1 cooperated with switch 72-3 (circuit B-53) - of the auxiliary start control relay @ reverse. 72 to short-circuit the actuating coil of the normal control relay 35 (circuit B-5), but this short-circuit is then broken and the switch 86-2 cooperates with the breaker 72-4 (circuit B -53). Of the relay.

   72 to connect the actuating coil of relay 35 to the circuit. current. The relay 35 is thus energized and its switch 35-2 (circuit B-54) establishes a restraint circuit to maintain the energization of its control coil after the switch 72 -4 is open.



  Relay 35 then operates its switches in the same manner as described above. Switch 35 = 4: (circuit V-21) is open to allow relays 76 and 72 to return to their de-energized state. Thus the short-circuit of the actuating coil of the normal auxiliary control relay 34 (circuit D) is broken by the opening of the switch 72-6 and the Tiles 34 and 39.

   are energized by switch 35-3 (circuit) of the norma control relay, lej 35.



  The machines 4 and .5 are now operating in inverted conditions, that is to say by absorbing energy from the direct current circuit and supplying power. the alternating current circuit. During. this operation in reverse conditions, the alternating current frequency regulator 61 (fig. 2) controls the rheostat control motor 60 by the switches 62-1 and 62 = 2, this motor being disconnected from the current voltage regulator continued:

      58 due to the fact that the switches 40-2 and 40-3 are open. Frequency regulator 61 includes a rocker arm and a pair of contact members at each end thereof which are arranged to be selectively engaged depending on the side to which that rocker arm is tilted. Two control coils are provided so as to act on cores re linked to the respective ends of the rocker arm. The left control coil circuit includes a reactance in series with it and the right control coil circuit includes a similarly connected resistor.

   These two circuits are connected in parallel one with the other and are supplied with current by the conductors 87 and 88 from the secondary winding of a potential transformer 89 (fig. 1), of which the primary winding is connected to a phase of the circuit of the armature windings 4A- of the. AC machine 4.



  The potential transformer 89 is also connected to. voltage regulator control coil to. alternating current 9f% (fig. 1) and to a potential coil of the alternating current flow reversal relay 48 (fig. 1), of which. current coil is supplied by one of the current transformers 77. These current transformers also cite the coils with. current in thermal relay 33, relay to. flow reversal 48, the underload relay 69, the phase balancing relay 71 and the at relay. short circuit 74, as shown.

    The functions of all these relays have been de- fined previously.



  The frequency regulator 61 is constructed in such a way that when equal currents flow through its two control coils, its toggle arm is in the equilibrium position, but when the current travels the left coil exceeds the one crossing the, reel on the right, the rocker arm knows tilted to close the contact members on the right and vice versa. The reactance ft the resistor which are connected in series with the respective control coils are chosen so that the impedances of the two coil circuits are equal to the desired frequency of the ac circuit 1. Therefore, when the. machine 4 generates a voltage at. the. desired frequency.

    equal currents will flow through the: two control coils of the frequency regulator 61, since the circuits of these coils are supplied with current in parallel with each other from the terminals of machine 4 by the intermediate transformer 89 and conductors 87 and 88. If machine 4 is operated at too high a speed, the frequency of the voltage generated by it will also be too high and the frequency regulator 61 will have to operate to reduce the speed of the machine. . machine 4.

    This is accomplished due to the fact that the circuit impedance of the left coil of the frequency regulator is greater than at the normal frequency, as a result of the reactance included in the circuit, while the impedance of the circuit of the: right coil is substantially unchanged. The, right coil will be. consequently more strongly excited than the. spool left and arm at. toggle will be toggled so. perform the. closure of its left contact members.

   A circuit will be there. completed from the upper bound of the <B>, </B> machine 5 by driver 51, rocker arm and left contact members of governor 61, switch 62-1, right field winding and motor armature 60 and the. driver 3 to. the lower terminal of the machine 5.



  As noted above, when the '60 engine is energized in this way, it operates to decrease the efficiency of the. resistance 63, thereby increasing the excitation of the machine 5. As the machine 5 then works as a direct current shunt motor, this increase in its excitation causes a reduction in its speed and it follows that the frequency of the voltage generated by the machine 4 is correspondingly reduced.

   Similarly, when the frequency is too low, the excitation of the. left coil of regulator 61 is larger than that of. right coil and the right contact members of this regulator are alois closed to cause the excitation of the motor 60 by the intermediary of its winding. left field. The excitation of the machine 5 is thus reduced and its. speed is correspondingly increased to cause a suitable increase in the frequency of the voltage generated by the machine 4.

   It is thus seen that while the. machine 5 functions as a motor to activate machine 4 as a generator, regulator 61 controls the speed of machine 5 by means of motor 60 and resistor 63 so as to maintain it. frequency of the voltage generated by the machine 4 at the desired predetermined value.



  During the reverse operation of the machines 4 and 5, it is necessary to keep the amplitude of the voltage generated by the machine 4 constant at a predetermined value, likewise. than the frequency of this flight.

   This is achieved by the AC voltage regulator 90 (Fig. 1), which is similar in all respects to the voltage regulating element 58B of the DC voltage regulator 58 (Fig. 2), except that it is provided with an AC control coil instead of a DC coil. This control coil is energized directly from the secondary winding -du transformer 89 (FIG. 1), the primary winding of which is connected to the terminals of the machine 4, as mentioned above.

    Regulator 90 operates, therefore, to close its left contact members when the voltage generated by machine 4 is below the predetermined desired value and to close its right contact members when this voltage is over. above the desired value, in a manner exactly similar to operation (the tension adjuster 58B, described above in detail.



  The left and right contact members of regulator 90 are connected to the left and right field bearings 91A and 91B of the reversible rheostat control motor 91 (fig. 1) through the switches. 62-4 and 62-3 (fig. 1), respectively, from the auxiliary control relay to. inversion 62 (circuit V-2), which are closed due to the activation of this relay during inverted operation of the machines.

   The rocker arm of the regulator 90 is connected to the upper terminal of the machine 5 through the conductor 51, and the lower terminal of the armature of the motor 91 is connected to the lower terminal of the machine 5 through the conductor 3. the same way as the arm. toggle item. voltage setting 58B and the lower terminal of the motor armature 60.



  In this way, in a manner similar to the operation of element 58B, when the voltage generated by machine 4 is below. predetermined value, the ma ter 91 will be excited by its left field winding 91A and this motor will then operate in such a way as to reduce the efficiency of the resistor 52 which is connected in series with the field winding 4B of the machine 4 The excitation of the machine 4 and the voltage generated by it are then correspondingly increased.

   Likewise, when the voltage of machine 4 is above the desired value, motor 91 is energized by its right field winding 91B to increase the efficiency of resistor 52 and thereby decrease the voltage of line. machine 4. Therefore, the voltage regulator 90 is operative during the reverse operation of machines 4 and 5 to keep the voltage generated by machine 4 constant at the desired predetermined value.



  When the. machine 4 operates as a synchronous motor, it is desirable that its field excitation and hence the efficiency of resistor 52 be kept at a constant predetermined value corresponding to the position of the rheostat drive motor 91 shown in the drawing . This is achieved using switches 62-5 and 62-6 of the auxiliary control relay in version 62 and contact members 92, 93, 94 and 95, which are associated with the motor 91.



  The stationary contact member 92 is connected to the lead 2 of the direct current circuit through a lead 96. The contact member 93 is operated by the motor 91 and is always in engagement with the contact member 92. The member 93 is also in engagement. taken with contact member 94 or contact member 95, depending on whether a larger or smaller portion of resistor 52 is inserted into the circuit of field winding 4B than is desirable when the. my china 4 works as a motor.

   If the. Exact proportion of resistor 52 is switched on with winding 4B, contact member 93 is in the position shown in FIG. 1, in which it is not in contact with Him of the contact members 94 and 95.



  When the machine 4 ceases to operate as a generator, the auxiliary reversing control relay 62 is de-energized to allow its switches 62-5 and 62-6 to close. If more than the desired portion of resistor 52 is then connected in circuit with winding 4B, contact member 93 will engage contact members 92 and 94 to close a circuit for energizing motor 91 through. 'through its field winding 91A. The motor 91 then operates so as to reduce the efficiency of the resistor 52.



  If there is. not a sufficient part of the. resistor 52 connected to the circuit of the rolling 4B, the contact member 93 will engage with the contact members 92 and 95 to complete a circuit for. eg motor 91 through its field winding <B> 9113. </B> Motor 91 then operates in the opposite direction in order to increase the efficiency of the resistance <B> 52. </B> As soon as contact member 93 reaches the. position shown in the drawing, the motor 91 is de-energized and its operation stopped. The above description shows the effectiveness of the. resistance 52 is always automatically adjusted to a predetermined value, when the machine stops in its reverse operation.



  While the. direct current machine 5 starts as a motor supplied by the direct current circuit as previously described, the. main or driving coil and the. auxiliary coil 30A of the time relay 30 are energized to put the devices out of service in the same manner as described. for the. normal start-up, if the two machines are not connected to their respective circuits within a predetermined time interval.

   The driving coil and the auxiliary coil 30A of the time relay 30 are then energized by the intermediary of the switches., Auxiliaries 18-1 (circuit B-1) and 18-2 (circuit B-2) of the contact device DC starting switch 18 (fig. 2). If relay 30 closes under switch 30-3 (circuit C-5) before.

    that the AC circuit switch 9 is closed, the deactivation relay 32 is energized by the switch 30-3 and another auxiliary switch 18-3 (circuit C- 51.) of the contact device 18 in order to put the machines out of service in the same way as previously described.



  * If, however, the circuit switch is closed within a normal period of time after contact 18 has been closed, the. actuating coil of control relay 81 (circuit X) will be de-energized by opening of auxiliary switch 9-5 (circuit Y) of switch 9. Switch 81-1 (circuit Y) then opens to de-energize the control coil 18A of the contact device 18, thus allowing the latter to open, together with. its auxiliary switches 18-1, 18-2 and 18-3.

   Time relay 30 is then de-energized following the opening of switches 18-1 and 18-2 and switch 30-3 returns to its de-energized position.



  8th <I> Passage of the </I> wrarehe normal <I> at the </I> reverse warche for <I> the </I> îrzaclzirres <I> already. </I> in. <I> service. </I> In the event that the AC voltage should run out, while machines 4 and 5 are operating normally, machines will continue to operate, but will be immediately reversed to power the circuit. alternating current.

   A fault in the AC voltage while the machines are running normally will be immediately recognized by the AC flow reversal relay .18 (fig. 1) and by the reverse current relay 82 (fig. 2) ).



  Relay 48 then opens its switch 48-2 (circuit L ') and closes its switch 48-1 (circuit L'), thus de-energizing relay 49 and forcing switch 49-1 (circuit V) to close. Relay 82 opens its switch 82-1 (circuit V) and closes its switch 82-2 (circuit V), thus causing the energization of relays 41 (circuit V), 84 (circuit V-1) and 82 ( circuit V-2), just as described above.

   The bypass contact device 85 is closed to bypass the series field winding 11 of the machine 5 as a result of the closing of the switch 84--1 of the relay 84. The actuating coil of the relay. Normal auxiliary control 40 (circuit E) is de-energized by opening the switch 41-1 of the reversing control relay 41 (circuit V) and the switches of the relay 40 are activated as described above.



  The DC voltage regulator 58 is then rendered ineffective and the operation of the machines 4 and 5 is controlled by the frequency regulator 61 and the voltage regulator 90 which have already been fully described.



  Any desired protection device can be provided to control the reverse operation of machines 4 and 5, such as a DC overload relay in version 97 (fig. 2). The control coil of relay 97 is connected to shunt 32 (fig. 2) so that its excitation is proportional to the value of the current passing through the armature windings of the DC machine 5.

   When the intensity of this current exceeds a predetermined value, the relay 97 closes its switch 97-1 (circuit C) to energize the deactivation relay 32 in order to prevent a continuation of the operation of the machines. 4 and 5 until the station has been examined by a supervisor as previously described.



  The AC thermal relay 33 (fig. 1) is provided with switches 33-3 (circuit V) and 33-.4 (circuit V-21) which are arranged to short-circuit the actuating coils of the relay. control switch 41 (circuit V) and the reverse start control relay 76 (circuit V-21) respectively, when a persistent excessive current value passes through the armature windings of the AC machine 4.

    Thus, if this condition occurs, while the machines are running in reverse condition or while they are starting in reverse, all subsequent operation of the machines will be. prevented until the thermal release returns to its original position.

   It goes without saying that protective devices could be provided to prevent the operation of the machine either temporarily or until the installation has been examined by a supervisor, in dependence, of any pre-conditions. @ determined occurring while the machines are working either normally or vice versa.

      If alternating current becomes available in the circuit from the normal source, while the machines are operating in reverse, the machines will be immediately returned or restored to normal operation and are again subjected,

   to the control devices corresponding to normal operation. This reestablishment is caused by the AC flow reversal relay 48 and the DC current reversal relay 82 which operate in exactly the opposite direction as described above for the AC voltage failure. while the machines are operating normally.

   All control units return to their normal operating conditions and control of machine operation is transferred from frequency regulator 61 and voltage regulator 90 to DC regulator 58. This operating condition has been fully described previously. previously.



       It follows -from this description that ends-. tall.ation normally transmits energy in one direction between two circuits, but will also be able to transmit energy in the opposite direction depending on predetermined conditions. The operation of the installation is. in all conditions completely automatic and the switchgear is fully protected by automatic devices.

 

Claims (1)

CLAIM Installation -distribution of electrical energy comprising two energy sources, normally arranged to supply respectively two main, separate working circuits with current with different predetermined electrical characteristics, characterized in that these circuits are arranged to be connected to each other by a rotary transfer device in order to transfer energy from one of the circuits to the other when necessary, this transfer device being automatically controlled so as to transfer transfer energy from one circuit to another, in each direction, depending on the load demands relating to the respective circuits and the availability of energy at their respective sources and being, moreover, automatically adjusted so that the transferred current has the predetermined electrical characteristics required for said circuits. SUB-CLAIMS 1 Installation according to claim, characterized in that the rotary transfer device is combined with means such that when it operates to transfer energy from one circuit to another, it is automatically controlled by a voltage fault in the first-mentioned circuit so that the rotary transfer device transfers energy from the second-mentioned circuit to the first-mentioned circuit without disconnecting the transfer device from the one or the other of the circuits .. 2 Installation according to claim and sub-revëndicat.ion 1, characterized in that the rotary transfer device is combined with automatic means to initiate, normally, its operation depending on a demand for energy arising in the one or the other circuit and then supplying the latter with energy from the other circuit. 3 Installation according to claim, wherein one of the working circuits is an alternating current circuit and the other a current circuit. continuous and in which the transfer device. rotary comprises a dynamoelectric machine. alternating current mechanically coupled to a direct current dynamoelectric machine (motor-generator unit), this direct current machine comprising an automatically controlled field rheostat established so as to adjust the voltage of said machine in accordance with the voltage of the machine. direct current circuit where the rotary transfer device transfers energy from the circuit to, native alternating current to the circuit: at. direct current and adjust it. speed, (, of said machine in concorance with the frequency of the alternating current circuit when energy is transferred from the direct current circuit to the alternating current circuit. .1 Installation according to claim and sub-claim 3, characterized in that the aforesaid field rheostat control is further set in such a way that when the operation of the rotary transfer device is caused to supply power at the circuit at. direct current from then the alternating current circuit, the rheostat is automatically activated to bring the voltage to the. direct current machine to correspond with the vol tage of the direct current circuit before connecting this machine to the direct current circuit and that, moreover, when the operation of the rotary transfer device, is caused to supply power. energy to the alternating current circuit from the direct current circuit, the rheostat is automatically actuated to adjust the speed of the. direct current machine so that the. frequency of the, AC machine coImespolt <le with. frequency tlü alternating current circuit before connecting the alternating current machine to the alternating current circuit. 5 Installation according to claim and sub-claim 3, characterized in that the AC machine also comprises an automatically controlled field rheostat established so as to adjust the voltage of the. AC machine when the rotary transfer device operates to transfer energy from the DC circuit to the AC circuit.