Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
  • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
  • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
  • H02J9/062—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for AC powered loads

Definitions

• the invention relates to a device for providing an uninterruptible power supply, which is connected between the network and the consumer.
• networks are understood to mean only AC networks.
• devices and systems are operated on the network, from which an error-free and reliable functioning in continuous operation is required, e.g. electronic monitoring systems, computers etc. A necessary requirement for this is the undisturbed and uninterrupted power supply from the network.
• Devices which guarantee an absolutely uninterruptible power supply are known and practically always have a battery-operated DC voltage intermediate circuit permanently switched on between the network and the consumer. Disadvantages of these devices are their permanently present poor overall efficiency and the clocked output circuit with transformer and / or filter circuit, which does not ensure that the consumer is supplied with low-bandwidth, low-voltage, rigid supply.
• the invention consists in that the network can be separated from the parallel connection of the consumers with the known low-impedance stabilization device via a super-fast electronic overcurrent protection. If the mains voltage breaks the pass band of the stabilization device in the event of network faults, compensation currents occur which practically do not influence the voltage at the low-impedance stabilization device and which trigger the overcurrent protection. After a predeterminable minimum time of autonomous operation of the stabilization device with the consumers, the network is automatically synchronized again as soon as the network conditions permit this. The response bandwidth of the stabilization device that can be selected in network operation is automatically reduced to a small remaining amount for the duration of the autonomy time.
• the invention is explained in more detail below on the basis of the description and an exemplary embodiment. 1 contains a circuit arrangement for the device according to the invention.
• Fig. 2 illustrates the principle of operation of the device.
• the device consists of a circuit arrangement according to FIG. 1 and is subdivided into the stabilization part 1 and the connection part 2 to the network G.
• the consumers to be protected are connected to the connection L.
• the stabilization part 1 consists of CH 01097/85, PCT / CH
• the connecting part 2 essentially connects the mains connection G to the stabilizing part 1 and the consumer connection L via the super-fast interruption element 18.
• compensating currents flow between the mains and the stabilizing part 1. These are determined practically exclusively by voltage deviation and mains impedance and can be a multiple of the normal consumer current. Thanks to the low-impedance and thus voltage-rigid behavior of the stabilizing part 1, the consumer voltage is only very weakly influenced by the compensating current.
• This compensating current is detected with a shunt 19 in the stabilizing part 1, detected as a momentary value in the connecting part 2 with a maximum current monitor 20, which in turn triggers the input of the monostable multivibrator 21.
• Their tilt signal reaches the OR gate 22, which triggers the super-fast interruption element 18 via an optocoupler 23.
• the core of the interruption element preferably consists of two n-channel cross-field transistors 18a, 18b connected in series opposition with grid connections connected in parallel.
• the response threshold of the maximum current monitor 20 is selected such that, on the one hand, the conventional mains fuse upstream of the mains connection G does not yet respond and, on the other hand, the permissible transient current via the transistors 10, 11 is used as far as possible, preferably between half to 20 times the nominal current value of the mains fuse.
• the minimum autonomy time of stabilization part 1 and consumer is determined by the flip-flop constant of the monostable flip-flop 21.
• the supply of the consumers is meanwhile maintained absolutely without interruption by the stabilization part 1.
• a limit value monitoring element 24 for the mains voltage controls via a delay tion member 25, the OR gate 22 with.
• the interruption element 18 is closed again only when the flip-flop circuit 21 is also released when the limit value monitoring element 24 is released.
• slow-running network voltage deviations ie those with time constants greater than that of the low-pass element 7, the disconnection from the network takes place via the limit monitor 24 alone.
• the time delay ⁇ t on of the delay element 25, which leads to the opening of the interruption element 18, must be smaller than the flip-flop time constant of the flip-flop 21, so that no accidental switching back to a faulty network can take place.
• the time delay ⁇ t on is preferably one to four mains voltage periods and the flip-flop time constant of the flip-flop 21 is two to ten mains voltage periods.
• the time delay .DELTA.t off, which leads to the closing of the interruption element 18, serves to cover the time required for the resynchronization of the stabilization part 1 with the network, namely in terms of amplitude and phase angle. It is between one and 100 mains voltage periods and is preferably regulated automatically so that it grows with increasing network interruption time.
• the switches 31 and 32 are actuated via the OR gates 27, 28 and the actuators 29 and 30, respectively.
• the switch 31 the amplitude-regulating low-pass element 7 is switched from automatic tracking of the voltage to the current mains voltage to approximation to the nominal mains voltage. This is represented by the voltage reference element 33, the control time constant of the low-pass filter 7 can be chosen much larger in this case than in the case of automatic tracking.
• the synchronizing element 3 is separated from the network synchronization, the synchronizing element is constructed in such a way that, in autonomous operation, the frequency of the generator 4 approaches the nominal frequency with a similarly large time constant as in the low pass 7.
• the minimum voltage monitor 26 responds only at the lowest mains voltage and enables one even if the voltage amplitude is insufficient Utilization of network synchronization.
• an influence is exerted on the DC voltage control element 9 via an actuator 34 during autonomous operation, the positive and negative response threshold of the stabilization part 1 being reduced to small residual amounts, so that a constant voltage curve is ensured at the load terminal L in the voltage zero crossings.
• the actuator 34 also controls the switchover from the capacitors 12, 13 of the short-term energy storage device to higher-charged capacitors 14, 15 of the long-term energy storage device using the switches 35, 36.
• a low-inductance choke coil 37 helps to limit the rate of rise of the equalizing current in the case of steep, impressed interference voltage edges, and the overvoltage arrester 38 protects against overvoltages when the interruption element 18 is opened.
• the entire electronics of the stabilizing part 1 and the connecting part 2 are themselves provided with an uninterrupted supply.
• the mode of operation of the device is illustrated in FIG. 2.
• a first time period up to t 1 operation with the mains voltage present is shown.
• the consumer voltage 39 is identical to the mains voltage due to the closed interruption element 18.
• the positive and negative response thresholds 40 and 41 of the stabilizing part 1 are also shown.
• a single voltage peak 42 is limited to the residual value 43 in the known manner.
• the maximum current monitor 20 can additionally cause a disconnection from the network, the disconnection time then being equal to the flip-flop constant of the flip-flop 21.
• both the frequency of the generator 4 and the amplitude of the voltage via the low-pass element 7 are set to nominal value with very large time constants until the mains voltage returns like.
• the mains voltage 46 returns.
• the time period between t 2 and t 3 is used to synchronize and adjust the amplitude of the consumer voltage 47 to the mains voltage 46.
• the network is switched on at time t 3 by closing the interruption element 18.
• the consumer voltage 39 a is again identical to the mains voltage.
• the response thresholds 40a, 41a of the stabilizing part 1 are restored.
• a sensitive mains current monitor can be connected between the mains connection G and the connecting part 2, the output of which is connected to the Input of the monostable multivibrator 21 is connected.
• the mains current monitor gives a signal when this minimum required internal current is undershot, which causes the interruption element 18 to open and thus the mains connection G to become free of voltage and the response bandwidth to be reduced.
• the device can be supplemented as follows:
• the consumer connection L is fed by a fossil emergency power generator after a power failure, which is switched on after synchronization and amplitude control. This also takes over the control of synchronization and amplitude regulation in the stabilization part 1 as well as the supply of the transformer 17 and all the electronics of the device. When the network returns, the unit is separated from the device.
• the device according to the invention combines all the advantages required in the introduction. It is preferably used as protection for consumers who are at risk of interruption and transients, such as computers, monitoring and process control systems or medical devices.

Landscapes

• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Stand-By Power Supply Arrangements (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4279555

Family Applications (1)

Country Status (3)

Citations (4)

• 1985
  • 1985-10-28 CH CH462285A patent/CH675798A5/de not_active IP Right Cessation
• 1986
  • 1986-10-27 EP EP19860906251 patent/EP0243414A1/de not_active Withdrawn
  • 1986-10-27 WO PCT/CH1986/000148 patent/WO1987002838A1/de not_active Application Discontinuation

Patent Citations (4)

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