CS259503B2 - Voltage regulator for electric heating resistors grouping - Google Patents

Abstract

Electronic switching elements having a tripping behaviour which are connected to the proportional voltage of a voltage divider which carries the operating voltage control grouping devices on the output side. The proportional voltage occurring on the voltage divider (1/2) is split into different connected selection stages (4, 5, 6) on the basis of frequencies which can be expected, including zero frequency, that is to say DC voltage, and the grouping devices are controlled via the frequency determined. In the case of the multi-voltage selection device, tuned-frequency tuned circuits are provided as selection stages (4,5) for AC voltages, an RC element being used as the selection stage (6) for zero frequency. Each selection stage (4, 5, 6) is connected to a number (corresponding to the number of voltages which can be expected in the frequency band) of triggering stages (7-10) which respond in a voltage-stepped manner. It is thus possible to differentiate in a simple manner and irrespective of voltage tolerances precisely between the railway frequencies, including zero frequency, and to make correct groupings for inductive loads. <IMAGE>

Description

A voltage selector for railway carriages on international lines detects DC and AC voltages on the main heating line and rearranges the heating resistors using staggered responsive flip-type electronic switching members connected to the proportional voltage of the voltage divider leading the voltage operation. At least three frequency discriminators are connected to a reliable resistor grouping independent of mains voltage fluctuations and tolerances, at least three frequency discriminators connected to the resistor of the ohmic voltage divider to distinguish between the expected line frequencies of 16 2/3 Hz and 50 Hz AC and zero frequency DC systems. resonant circuits tuned to 50 Hz and 16 2/3 Hz and for DC voltage as RC-element, and to determine the value of the corresponding line voltage of 1000 V _AC , 1 500 V _AC , 1 500 V _DC or 3 000 V _DC discriminators connected at least one electronic trigger circuit, responding in the frequency range to possible voltage values.

BACKGROUND OF THE INVENTION The present invention relates to a voltage selector for grouping electrical heating resistors in a railway carriage of international traffic, which detects DC or AC voltage on a main heating line, using staggered electronic toggle type switchgear connected to a proportional voltage divider. the operating voltage and controls the grouping device.

The voltage selectors measure the voltage on the main heating line or the contact wire and, in conjunction with the grouping switching device and the high-voltage contactors, group the following electrical devices that correspond to the prevailing heating voltage.

In a known device of this kind according to German Pat. No. 1,438,759, proportional DC voltages for rising and falling voltages are taken from two parallel set-off potentiometers with multiple taps and fed in stepwise to memory elements that control regrouping contactors via logic and timers. The cost of construction elements including measurement transducers and special adjustment potentiometers is considerable.

In another known device, the converter is already omitted and the proportional voltages are taken from the simple voltage divider connected to the heating line according to the applied DC or AC voltage. The voltages obtained are fed to the trigger circuits (threshold switches) assigned to the individual grouping ranges via the time and smoothing function RC members.

Diodes and resistors cause a change in the tripping and tripping values of the AC tripping circuits compared to DC voltages in special artificial circuits, where the AC voltage distorts one half wave. Tuning the threshold switches themselves and among themselves is not easy. In addition, the smoothing capacitors of the RC members simultaneously serve to delay the switch-off time of the threshold switches, so that the adjustment is difficult. A delayed switch-off is necessary in order to prevent the threshold switches from being subjected to short-term current interruptions, eg caused by irregular movement of the pantographs. Due to the necessary compromise, shutdown times cannot be arbitrarily set.

In the known devices, the choice is generally made according to the prevailing voltage. Individual voltages, eg 1 kV of 16 2/3 Hz networks with 1.5 kV of 50 Hz networks or with 1.5 kV networks, may overlap due to the often undervoltage or overvoltage in different railway networks. kV dc network. The trigger circuits assigned to the individual voltages cannot then reliably distinguish the correct ranges. However, for inductive appliances, which are used more and more frequently, it is important whether the grouping is carried out with a frequency of 16 2/3 Hz or at a DC voltage.

The purpose of the invention is to provide by simple means a multi-voltage switch so that it operates independently of mains voltage fluctuations and tolerances and can perform grouping reliably at both rising and falling mains voltage.

The principle of the invention is that at least three frequency discriminators are connected to the partial resistor of the ohmic voltage divider to differentiate the expected line frequencies of 16 2/3 Hz and 50 Hz AC and zero frequency DC systems designed for alternating voltage as tuned resonant circuits tuned to frequency 50 Hz and 16 2/3 Hz and for DC voltage as RC-element, and to determine the value of the relevant line voltage:

000 in _st ,

500 _VAC ,

500 V _DC or

000 V _DC is connected at least one electronic trigger circuit behind individual discriminators, reacting in the frequency range to possible voltage values.

In the switch according to the invention, overlapping voltages cannot cause a false switching.

The invention will be explained on the basis of the circuit diagram of the voltage selector k grouping the heating resistors in the railroad coaches. It should be noted, however, that the invention can also be used for other applications.

According to the drawing, the voltage divider У2 is connected with its partial resistor 1 to the heating line of the train and the partial resistor 2 is earthed. The voltage that can be taken at point 3 of the resistive divider V2 against ground is proportional to the heating line voltage. Depending on the type of rail network, this voltage may be 1000 V at 16 2/3 Hz, 1500 V at 50 Hz, 1500 V or 3000 V DC.

These values are nominal and actual operating conditions allow for considerable tolerances, especially for DC networks very often up to + 30%. Proportional DC or AC voltages from point 3 of divider 1/2 are fed to selector stages 4, 5, 6. Selector stage 4 consists of a resonant or oscillating circuit tuned to 16 2/3 Hz and is a criterion for 1000 V AC, that works with this frequency. The selection stage 5 consists of an oscillating circuit tuned to a frequency of 50 Hz and can recognize an AC voltage of 1500 V from a DC voltage of the same magnitude. The selection stage В is made up of an RC-element that responds only to DC voltage.

The selection stages 4 and 5 have a zero reaction at direct voltage, i.e. at zero frequency. Behind the electoral stages

4, 5, 6 the trigger circuits 7 are connected,

8, 9, 10. When the selector stage 4 responds, the trigger circuit 7 is energized, when the selector stage 5 is triggered, the trigger circuit 8 is energized. The DC selector stage 6 is shorted at the AC voltage by a capacitor in the RC member; Trigger circuits 9 and 10 have different response values, that is, when the selection stage 6 detects a DC voltage, either the trigger circuit 9 for a DC voltage of 1,500V responds, or both the trigger circuits 9 and 10 for a DC voltage Separate timers 11, 12, 13, 14 are connected to the outputs of the trigger circuits 7, 8, 9, 10. These: timers 11 to 14 serve to delay the drop-out, i.e., maintain the following transistors 15, 16, 17, 18 for a period of time in the conductive state, even if the voltage of the heating line is interrupted for a short time, for example, by sudden movements of the vehicle pantograph or wagon. The time elements 11-14 are adjustable separately and independently of one another and are preferably formed as integrated units.

Output relays 19, 20, 21, 22 are connected to a line 23 supplying power via transistors 15, 16, 17, 18 with a grounded emitter. The coils of the output relays 19 to 22 are connected to the collectors of the respective transistor 15 to 18 and on the other hand, via the normally open contacts 20a, 21a, 22a of the higher voltage stages to the supply voltage of the line 23. The emitters of the transistors 15 to 18 are grounded together. Through the additional trigger circuit 24, which is connected to the selection stage 6 and set to the maximum bias value, the additional transistor 25 connected in the line 23, which disconnects the entire device when the maximum value, for example 3,900 V DC, is reached. The device is reconnected when the voltage drops, for example to 3,700 V. The supply voltage from line 23 to the output relays 19 to 22 is additionally provided via the normally open contact 26a of the safety relay 26, which is controlled by the safety release circuit 27. when the voltage at a defined measuring point 28 of the voltage divider connected to terminal 29 (1000 V terminal) in the grouped heating resistor switching circuit exceeds, for example, 1,300V. so for AC voltage. If the voltage at the measuring point 28 exceeds 3,000 V, this indicates a misalignment of the heating resistors. The safety trigger circuit 27 starts to react and energizes the safety relay 26 via transistor 30. The idle contact 26a interrupts the supply voltage from line 23, so that the output relays 19 to 22 drop off. The normally open contacts 20a, 21a, 22a of these relays switch to the standby position for 3000 V. The safety relay 26 remains closed via the work contact 26b. The selector can only be brought back to standby by briefly disconnecting the battery.

The output relays 19 to 22, which are connected to a high voltage, are powered by a battery 31 and a converter consisting of an inverter 32, an isolation transformer 33 and a rectifier 34 connected to the line 23. Thus, the battery 31 is voltage separated from the voltage selector. that carries high voltage. On the other hand, the voltage supply for the own grouping device with the switching device motor 35 takes place directly from the battery 31 at a low voltage level. The grouping contacts of the output relays 19 to 22 belonging to the grouping device indicated are indicated by 19b, 19c, 20b, 20c, 21b, 21c and 22b. The switching device connects the battery voltage to the heating contactors via its contacts via the line 36. The relay 41 is connected via the timing element 40 to the heating contactors. The work contact 41b connects the voltage to line 36 to the contactor of the monitored circuit (1000 V stage). Each time the line 36 is switched from a voltage to a conductive state when switching from a voltage-free state, the timing element 40 energizes again and the heating circuit of the controlled circuit (1000 V stage) is energized for a short time regardless of whether the corresponding partial heater thermostat is connected. The stress is examined, as already mentioned, at measuring point 28.

Optoelectric coupler 37, which is part of the disconnecting automatics for the supply voltage battery 31, is connected in parallel to the partial resistor 2 of the voltage divider 1/2. Only when there is a voltage on the heating line and thus on the partial resistor 2, is the output of the optoelectric coupler 37 output, as a result of which the disconnecting trip circuit 38 reacts and activates the relay 39. Via a working contact 39a In the event of a heating line voltage failure, there is no need to group the heating resistors, which means that the inverter 32 does not need the supply voltage for output relays 19 to 22 and is therefore disconnected by opening the operating contact 39a.

It should also be noted that the optoelectric coupler is connected to the inverter 32 of the inverter via contact 39a of the battery 31 as soon as the optoelectric coupler detects voltage. Thus, the switching device corresponds to a 3000 V stage. If, for example, 50 Hz AC voltage is present on the voltage divider 1/2, the selection stage 5 reacts and the contact 20a opens via the output relay 20. The 50 Hz frequency can only be applied to the voltage range of 1500 V, as a result of which the working contact b closes and the normally closed contact 20c opens. The switchgear motor 35 goes from 3000 V DC to 1500 V AC, and as soon as the motor 35 reaches the selected stage, voltage 36 passes to the heating contactors. At the same time, the timing element 40 of the relay 41 is energized so that the contactor of the monitored heating circuit can first be closed. The safety trigger circuit 27 detects the voltage at the measuring point 28 and disconnects the entire heating device if necessary. After the delay of the timing element 40, other contactors can be connected if the safety release circuit 27 has not tripped.

The invention makes it possible to create a multi-voltage selector, which can also easily and reliably group inductive consumers.

Claims (5)

SUBJECT 1. A voltage selector for the grouping of electric heating resistors in an international service passenger rail, which detects DC or AC voltage on the main heating line, using staggered electronic flip-flop type switchgear connected to a proportional voltage divider operating voltage; and controls a grouping device, characterized in that at least three frequency discriminators (4, 5, 6) are connected to the partial resistor (1) of the ohmic voltage divider (1, 2) to differentiate the expected line frequencies of 16 2/3 Hz and 50 Hz AC systems and zero frequencies of DC systems, created for AC voltage tuned resonant circuits tuned to 50 Hz and 16 2/3 Hz and for DC voltage as RC-element, and to determine the value of the corresponding line voltage of 1000 V _AC , 1 500 V _AC , 1500 _Vdc is at least one electronic trigger circuit (7 to 10) is connected downstream of the individual discriminators (4, 5, 6) and responds in the frequency range to possible voltage values. Voltage selector according to claim 1, characterized in that the trigger circuits (7 to 10) are connected via four timers (11 to 14) and transistor stages (15 to 18) to four output relays (19 to 22) whose coils BACKGROUND OF THE INVENTION, each of them is connected to the respective transistor stage (15 to 18) and together via the normally open contacts (22a, 21a, 20a) of the switching stages with a higher voltage to the supply voltage. 3. A selector according to claim 1 or 2, characterized in that an additional trigger circuit (24), set to a maximum voltage value, is connected to the RC member for overvoltage protection, the output of which is connected to the control electrode of the transistor (25). the output is connected to coils of output relays. (19 to 22) connected in parallel via the normally open contacts (22a, 21a, 20a). The selector according to any one of claims 1 to 3, characterized in that a normally open contact (26a) of the safety relay (26) connected to the output of the safety release circuit (27) is connected in the common supply circuit of the output relay coils (19 to 22). ) connected by its input to another voltage divider (28, 29) connected to the groups of appliances. Selector according to one of Claims 1 to 4, characterized in that an optoelectronic element (37) is connected to the partial resistor (2) of the ohmic voltage divider (1, 2), the output of which is connected to the switching circuit via an additional trigger circuit (38). a battery relay (39) (39) for supplying the grouping switching device.