AT510356A1 - EMERGENCY POWER SUPPLY SYSTEM FOR REMOTELY RESTORING THE OWN REQUIREMENTS VOLTAGE IN TERMINALS AFTER A POWER FAILURE - Google Patents

Description

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Wienstrom GmbH

The invention relates to a Notstromvcrsorgungssystem for remotely controlled restoration of intrinsic voltage in substations after a power failure, in which the internal reserve of the substation was exhausted.

Modern utility power grids can usually be divided into the four voltage levels, maximum voltage, high voltage, medium voltage and low voltage. The maximum voltage is the voltage level of large power plants and Uberland Femleitungen referred. The maximum voltage may be 380 kV, for example. As high voltage, the voltage level of medium-sized power plants, industrial power plants and industrial customers is usually referred to; Depending on the network, for example, it may be 110 kV. As medium voltage, the voltage level is referred to, operated with the example of city utilities, for example, 10 or 20 kV. At this level is usually also the feeding of small power plants, wind farms and solar power plants. As low voltage we mean the lowest voltage level of a supply network, such as the three-phase alternating current, which is used to supply end consumers with a voltage of 230 and 400 volts.

As substations between the high and the high voltage level very large plants are used, over which often whole cities or substantial parts of it are fed. At the substations, for example, via dome repeaters several 110 kV grid groups (hereinafter referred to simply as "network group") are charged with voltage. These substations between the two upper voltage levels are referred to below as "delta repeaters", this designation is purely the linguistic delimitation compared to the other substations and should not imply any restriction to certain Umspanntechniken.

For example, a network group can provide a metropolitan area or industrial complex with Storm. Each network group usually contains several "smaller" substations, which apply voltage to the medium-voltage networks. These substations are, in the case of a city network, distributed throughout the city, many of which are unoccupied, as they operate remotely and require on-site intervention only for maintenance purposes.

The last interface between the medium voltage and low voltage levels are transformer stations, several of which are end users, e.g. a block of flats, a settlement or a village are supplied with electricity.

Due to the prevailing safety precautions, power failures are relatively rare, at least in European electricity grids. However, in the event of storms and thunderstorms caused by lightning or falling trees, sometimes parts of the respective power grid fail. Even more rarely are entire network groups affected by failures, whereby such failures can still occur at peak loads, such as increased power requirements due to particularly hot or cold weather conditions, ln such cases, the affected substation can usually be switched back within a few minutes, in exceptional cases, this takes a bit longer, but rarely more than 3 hours.

The worst case, ie the failure of an entire network, such as a power outage throughout the European electricity grid, is highly unlikely and has never occurred in Europe, for example. In other regions, such as the northeastern United States, such major failures have already occurred several times , and even with the more modern European network, the possibility of total failure can not be excluded. There are therefore guidelines throughout Europe on how to proceed in the case of a complete grid reconstruction in individual regions, such as a national power grid. There are several network restoration concepts, depending on which voltage level or from which location the reconstruction is started.

In the case of a pan-European power outage, for example, network reconstruction would take place simultaneously in several separate networks. For this purpose, a subnetwork, for example a national network, is separated from the rest of the network so that it forms a self-contained island network. First, the maximum voltage level is restored by starting up, synchronizing and connecting individual power plants based on a specific power plant. The coverage area is thus expanded step by step, which takes several hours to complete.

Once the maximum voltage in a grid area is restored, the high voltage grid can be prepared for gradual reconstruction. Each individual 110 kV network group is prepared for reconnection in such a way that the inrush current for the dome transformer, which covers the network group in one go, is kept as small as possible.

Once the high voltage level is restored, the individual substations can be put back into operation, the commissioning is only possible if the substations still has a sufficient own reserve. A stringing of a remote-controlled substation without own reserve and thus without protective devices (Sammclschiencn-, transformer, - line protection) is inadmissible. The problem is not only that no switching operations can be made more, but above all that no protection is available without auxiliary voltage.

When an island grid is set up, it can take up to eight hours for voltage to reach the transfer points, that is, the maximum voltage lead-in areas of a specific grid operator or load distributor. Another two hours are to be provided for the network restoration on the part of the load distributor until each substation is powered again at least for its own use.

Due to the available battery capacities with average station current and total power failure, a maximum of five to six hours can be expected in the remote-controlled stations in the network. After this time, no auxiliary voltage is available in the remote-controlled substations.

Although there are emergency concepts for grid rebuilding at all grid levels, the connection of the individual substations only works within the first six hours in the event of a fault. After that, all individual plants would have to be put into operation by hand with the help of an aggregate. Occupying each individual substation in order to disconnect the batteries in good time from the consumer is unrealistic due to the traffic chaos to be expected in the event of a total power failure (total failure of the traffic control center).

The previous backup batteries take up a large space. Therefore, it is usually not possible to simply increase the capacity of the own reserve, apart from the high costs associated with it.

The aim of the invention is to simplify the connection of the substations for network reconstruction significantly and accelerate.

The new system will work independently of the old concept and require considerably less space than would be required for a corresponding expansion of the internal reserve.

These and other objects of the invention are achieved by the emergency power supply system mentioned above in that the emergency power supply system has a 4 - < «* • k« *

The control unit having a charging unit and a charged from the charging unit additional battery, the additional battery has a nominal voltage corresponding to the intrinsic demand voltage of the substation of the substation, wherein the control unit is controlled via a communication link, and wherein a power distributor of Eigenbedarfsanlagc to Wiederinbetriebnahmc the substation with the Voltage of the additional battery can be acted upon. As a result, the substation can be switched on remotely even after the exhaustion of its own energy requirement, ie even after a power failure of more than 6 hours, by rebuilding its own requirements with the additional battery. Although the capacity of the battery is only sufficient for a few minutes, this is sufficient for switching on the protective devices. After switching on the substation, the internal power is supplied via the normal power supply again.

Advantageously, the additional battery of the emergency power supply system according to the invention can have a LIPO battery with one or more cells. LI PO batteries are characterized by an extremely high energy density, so that the dimensions of the overall system can be minimized.

In this case, in an advantageous embodiment of the invention, the charging unit for the charge of the individual cells of the LIPO battery having a balancer, which can be provided to prevent over-discharge of the cells voltage monitoring relay. The balancer ensures a uniform charge of the cells of the LIPO battery and thus extends their life,

Advantageously, the individual cells of the auxiliary battery may be separated from each other by partitions, so that the cells are protected from damage to an adjacent cell.

For the power supply of the control unit can be provided advantageously a Steuerstromakku. As a result, the power supply of the control unit is separated from the stored power reserve in the additional battery.

In an advantageous embodiment of the invention may be provided for charging the additional batteries and optionally the Steuerstromakkus a wind- a solar or a combined wind-solar power plant. This makes the emergency power supply system self-sufficient. The charge of the cells can also be continued during a power failure. Advantageously, the communication link may be a wired connection or a radio link, preferably via a fiber optic cable. Preference is given to a fiber-optic cable connection, which allows a trouble-free signal transmission from the control center to the substation even if other communication connections are no longer functional due to the power failure.

In an advantageous embodiment of the invention, the output of the emergency power supply system for Eigenbedarfsanlagc be protected by a decoupling diode. This prevents damage to the control unit and the auxiliary battery.

To connect the additional battery can be provided in a preferred embodiment of the invention, a solid state relay. This has a smaller size than a comparable contactor and no coil current is required, which would reduce the capacity of the batteries.

The invention further relates to a method for providing an intrinsic demand voltage in substations after power outages, in which the intrinsic demand reserve of the substation was exhausted, by means of a preferably remotely controlled emergency power supply system, the method comprising the following steps on the emergency power supply system:

Maintaining the charge of a spare battery during normal operation of the substation; After a power failure in which the internal power reserve of the substation has been exhausted, receiving a turn-on signal via a communication link; and

Energizing an energy converter of a domestic power station of the substation with the auxiliary voltage of the additional battery, the energy distributor in particular supplies the Fcmwirkanlagen and the protective devices of the substation with energy.

The inventive method allows even after a very long power failure, especially after a power failure of over 6 hours, the remote-controlled switching on an unmanned substation. It is not necessary to start up the factory by local technicians and switch on the self-service system with a mobile unit.

In an advantageous manner, the switch-on signal can be transmitted remotely via an optical fiber line.

In a further advantageous embodiment of the invention, a balancer can be provided to maintain the charge of the additional battery.

Furthermore, the state of charge of the additional batteries can be monitored continuously in an advantageous manner, whereby error messages can be indicated when defective batteries are detected. This facilitates the maintenance of the emergency power supply system, which must be operational even in the absence of a power failure for years.

An exemplary embodiment of the invention will be described in detail below with reference to illustrative drawings. Show it

1 is a schematic representation of a part of a network structure,

2 shows the essential elements of the invention of a substation in a highly schematic representation,

3 is a schematic representation of the self-consumption system of a substation,

Fig. 4 is a block diagram of the individual components of an emergency power supply system according to the invention and

Fig. 5 shows a perspective view of the aluminum construction on which the cells of the additional battery are arranged.

To illustrate the terms used, FIG. 1 shows an example of a network diagram of a network operator 21, for example a local urban power provider. In the illustration, own power plants of the network operator, which may be provided at all voltage levels, are not shown for the sake of simplicity. The regional network of the network operator is connected to a high-voltage network 16 of a transmission system operator 22, wherein the connection to one or more transfer point 17, 17 'takes place. At the Übergabestellcn are about so-called

Dome repeaters 18a-18c several network groups 19a-19c connected. The Kuppelumspanner 18a-18c provide on the one hand for a voltage reduction, for example, 390 kV in the high voltage network to, for example, 110 kV in the grid group, on the other hand, they are switchable so that each network group can be disconnected at the Kuppelumspannem 18a-18c from the mains and connected to this again.

Each network group 19a, 19b, 19c supplies a plurality of substations 20a to 20m, at which the distribution networks are supplied, for example, with a voltage of 10 or 20 kV. In the network of Fig. 1 are substations for 10 kV distribution networks (these are the substations 20a, 20b, 20c, 20e, 20f, 20g, 20h, 20k, 201 and 20m) and for 20 kV distribution networks (substations 20d and 20i) represented by different circuit symbols, The individual substations 20a to 20m are each to individual w «•«

Substations 1A to IE summarized. These substations 1A to IE are spatially distributed throughout the network operator's area, with most of these substations being vacant and remotely controlled by a central office. In the example network of FIG. 1, for example, only the substations 1A and IE, which are located directly at the transfer points 17, 17 ', occupied substations (this is indicated by the framing of the reference numerals), the other substations are 1B to ID and 1F remote controlled.

The number of remote-controlled substations varies greatly from one operator network to the next. The network of the network operator of the city of Vienna, for example, contains only five occupied substations. In contrast, there are more than 50 other unoccupied substations in this network, the individual substations can only be switched from the Feme, if the self-power supply of each substation is upright.

The lowest voltage level of the supply network is supplied by known transformer stations, but they are unproblematic in the context of the invention, since they do not have to be turned on after a power failure at network group level, but automatically resume their function when a voltage on the distribution network. The mode of operation of a transformer stations is known to a person skilled in the art, and these stations are therefore not shown in the figures for reasons of clarity.

FIG. 2 shows a schematic overview of a substation 1 in which an intrinsic demand system 6 and an emergency power supply system 3 according to the invention are provided. As "own use" a substation is the Glcichstromversorgung the resources of the substation referred to, with their own needs of several electrical equipment is composed, which are supplied by domestic demand transformers via rectifier. The internal power plant 6 is required to maintain the operation of the electric drives for the circuit breakers, controls and the various protection devices. Lead acid batteries, which in the event of a power failure constitute an internal reserve 2, serve as buffers for the internal power supply. The self-supply of a substation can be maintained, for example, with two hundred and five-fold lead acid batteries with 75Ah capacity in case of power failure up to about 6 hours.

As described in the introduction, there is the danger, especially in the unoccupied substations 1B, IC, ID and 1F, that in the case of a large-scale power failure in which the transmission network of a country must be rebuilt as an island grid, the batteries of the self-consumption system are insufficient and the substation no longer '' '' * '' * * * * * * * * * * Α · · " »- * 8 ·" can be switched on remotely if the corresponding network group 19 is connected to the mains too late.

The domestic power installation 6 generally has a plurality of energy distributors 5, 5 ', which are also referred to as busbars, and which are connected to one another via switches and diodes. An exemplary circuit diagram of an internal demand system 6 is shown in FIG. 3. 3 has three power distributors, the busbars 5a, 5b and 5c. The first two busbars 5a and 5b are each connected to a lead-acid battery 2a, 2b which serve as buffers and internal reserve. This directly connected to a battery busbars 5a, 5b serve the power of not necessary for the connection of the substation systems, such as the emergency lighting, and are connected via a switch 23a. The systems required for the connection of the substation, such as the Femwirkanlagen, the inverter or the contactors are connected to a separate busbar 5c. This busbar 5c is also connected via switches 23b, 23c to the other two busbars 5a, 5b, wherein diodes 24a, 24b separate the separate busbar 5c from the first two busbars 5a, 5b on one side, so that in the event of a power failure on the first busbars 5a, 5b, it is possible to supply only the separate busbars 5c via the emergency power supply system 3 in order to reconnect the substation to the grid, without thereby supplying the areas of the auxiliary power supply (eg the emergency lighting) which are not required for this connection have to.

In Fig. 2, the domestic power plant 6 is shown in a more schematic, wherein the first bus bars dargestelll as a single busbar 5 ', which is connected via the diode 24 with the separate busbar 5 in connection. The Femwirkanlagen 7, the protective devices 8 and the inverter 9 of the substation 1 are connected to the separate busbar 5.

When the in-house reserve 2 is consumed, it is generally sufficient to power the separate bus bar 5 for a few minutes until the substation is reconnected to the grid and the voltage of the captive facility 6 can be maintained by the normal route. The emergency flow supply system 3 according to the invention serves precisely to this Zwreck and contains a control unit 11 which is controlled via a communication link 4 from a control center. To power the emergency power supply system 3 is a Steuerstromakku 15, which also acts as a backup battery. The control power battery 15, e.g. a 12V lead-acid battery or similar can be charged via the mains. Hs, however, can also be provided a mains-independent power supply, such as a combined wind-solar power plant 25, with which the Steuerstromakku will continue aufgcladen even during a prolonged power failure.

The energy needed to turn on the substation is stored in a spare battery 10, which is charged via a charging unit 12. In a preferred embodiment of the invention, the additional battery 10 consists of a very compact 230V lithium polymer (LIPO) accumulator, which in turn is constructed from twenty-one series-connected 11.1V battery packs (each with three cells). The total battery capacity of such additional battery is 0.56 kW / h with a total voltage of 230V / DC. The maximum output current is 25A.

The cells are individually charged and balanced individually via the separate charging connections of the battery packs. The balanced charging of LIPOs is of eminent importance for the life of the cells, since lithium-polymer cells are very sensitive to over-voltage when charging. If different cell voltages occur during charging, in extreme cases negative voltages can occur on the cells during discharge, which can result in the destruction of the cell and pose a considerable fire risk.

To avoid this, the loading of the packs is carried out sequentially via a LIPO automatic charger (charging unit 12) with an integrated balancer 14, the charging unit 12 receiving the power from the 12V control power battery 15. If it becomes necessary to recharge the system after use, or if insufficient charging is possible due to a failure of the solar module or windmill, there is a possibility of mains charging.

The emergency power supply system 3 is protected by a decoupling diode 13 with respect to the power distributor 5 of the auxiliary power unit 6, so that voltage fluctuations of the power-consumption unit 6 do not affect the electronic components of the emergency power supply system 3.

The structure described above can be made extremely compact and inexpensive, since the LIPO cells used combine a high energy density with the advantage of very small dimensions. Commercially available LIPO cells may be used, such as those used in model making, for example, for electrically powered model airplanes.

The control unit 11 may be a conventional programmable logic controller (PLC), which preferably has a display unit, via the status or

Error messages can be output. For example, error messages may indicate a defective LIPO cell that needs to be replaced.

In "normal operation" of the substation, the system ensures that all LI PO cells are always fully charged and ready for use.

After a power failure, the control unit 11 of the emergency power supply system 3 can be instructed via the communication link 4 to put the power distributor 5 under tension, whereby the telecontrol equipment 7, the protection devices 8 and the inverter 9 are ready for use even when used reserve reserve 2. Even if the energy only keeps the energy supply for 10 to 15 minutes, this is sufficient to remotely connect the substation to the grid.

4 shows a detailed block diagram of the individual components of an emergency power supply system 3 according to the invention, the individual elements being described below on the basis of an exemplary embodiment. Embodiment:

The following exemplary embodiment is illustrative of the invention and is not intended to be construed in any way limiting the scope of the claims set forth in the claims.

Technical details

The regulation and monitoring of all battery states are realized in the present case via a compact control unit from the company Siemens (LOGO), which is provided with a display. It can also be used another analog acting control unit. As a buffer for the note needs due to the high energy density and the small size lithium polymer batteries are used.

Due to the limited inputs and outputs of the control unit, a self-developed print is used. Lead-acid batteries and a combined wind-solar power plant should ensure the power supply of the control unit and the charge of the lithium polymer batteries. The hardware, except for the wind-powered solar power system and the lead-acid battery, are housed in a housing for 19-inch cabinets.

The output voltage is decoupled from its own requirements via diodes, so that no current flow from the battery of the own demand to the emergency power supply is possible. Due to diodes at the supply of the C-rail of the own use, an energy flow in the direction of the empty EB-batteries is not possible.

To ensure galvanic isolation during charging, the battery system is disconnected from the power supply via the contactor and a DC Solid State Relay. The monitoring of the charging process, the decoupling of the error message from the balancer and the absolute prevention of the simultaneous charging of several packs (short circuit over several to all packs) is taken over by a control unit. This control board is supplied by the buffer battery with 12V.

A 5V fixed voltage regulator generates the supply voltage for the electronics and the relays. The circuit consists of a stabilizer with decoupling film capacitors (MKP) to suppress the tendency of the component to oscillate at the input and output, as well as one electrolytic capacitor each as a buffer at the input or output.

From five contacts of the SPS logo, which generate a bit pattern, control signals for twenty-one charge relays, an output contactor and solid state relays are generated via a demultiplexer.

The voltage of the lead-acid battery is permanently monitored.

The status of the charge controller from the solar panel and wind generator is evaluated by the control and automatically converted to grid charge in case of failure.

The output voltage is permanently monitored.

The cell voltages of the "LIPO batteries " are monitored during the charging process.

If the specified values deviate, a fault message is issued.

Depending on the charging status of the "LIPO batteries", different charging programs are activated in the control unit.

Due to the modular design, the leaching of individual components after faults is possible at any time.

Bridging the measurement inputs allows the simulation of a discharge for battery state control. Through the Balancer output socket, a voltage measurement of the individual cells to control measurements during the annual discharge test is possible.

At the 12V lead-acid buffer, a discharge measurement is also carried out annually to ensure the continuous performance.

Lithium polymer battery (LIPO)

A major advantage is the use of lithium polymer accumulators. The high energy density of the batteries is an important aspect to the

To ensure self-supply. Twenty-one pieces of battery packs, each with three cells connected in series, give an approximate DC output voltage of 230 volts.

Lithium polymer batteries (also called LIPO) are one of the latest developments in energy storage. In contrast to the lithium ion battery, which consists of liquid electrolytes, the lithium polymer battery is generated from a gel-like to solid electrolyte foil. The negative electrode is the electrolyte. The positive electrodes are sheet films having a thickness of less than 0.1 millimeter.

Due to the better tone conductivity, mainly lithium-polymer batteries with a gel-like consistency are used. The batteries with solid electrolyte foil reach a high conductivity only from an operating temperature of 60 ° C. The innovative composition of the chemical properties of the LIPO battery is the reason why it has the highest energy density of all batteries marketed so far. The production costs fell sharply due to the high demand. Due to the individual design and the low weight, the batteries are often used in model making.

A disadvantage with respect to the life of lithium-polymer batteries is the thermal and electrical sensitivity. Overcharging or over-discharging the batteries can lead to the destruction of the cells. It is therefore absolutely necessary to charge the batteries via a charge controller, the balancer.

For LIPO batteries with a gel-like design, make sure that they are operated in a temperature range between zero and sixty degrees Celsius. Outside this range, the cell may become defective. The storage of discharged battery packs is to be avoided in any case.

In addition to the high energy density of the lithium-polymer battery, the individual design of the battery packs is an advantage. Also, charged batteries can be stored for months without capacity loss, which significantly increases the life. For storage, the battery should be charged to nominal voltage.

load

Proper charging and discharging of lithium-polymer batteries is of the utmost importance for the lifetime. The maximum voltage of 4.2 V must never be exceeded. In order to prevent the destruction of the battery, it is essential to use a special charge controller. This charges the batteries in two steps. In the first step, it is charged with a constant current until the cell has reached the rated voltage of approx. 3.7V. At the second step

the charge is carried out with a constant voltage until the cell reaches the end of charging voltage of max. Has reached 4.2V. Then the charger cgi turns off and the battery is fully charged.

Balancer

The balancer is a charge controller that was specially developed for lithium batteries. It provides optimal protection when charging the lithium cells. As determined during unloading tests, the individual cells of the battery packs discharge differently. In order to create the same conditions under the cells during charging, the balancer compensates for the different cell voltages.

Most of the rechargeable battery packs consist of several cells connected in series, with a nominal voltage of about 3.7 V. In order to be able to control each cell, one connection per cell is carried out. Thus, the charge controller can not only monitor the total voltage, but also each individual cell separately. The controller charges the batteries as already mentioned in two steps. When the maximum voltage of 4.2V per cell is reached, the charge shuts off.

The charging processes are indicated by LEDs on the device. When charging, the LED lights green, the charge is completed, lit another red. If an LED flashes, a cell defect has been detected and the balancer interrupts the charging process. These signals are transmitted to the controller using an optocoupler. Thus, the charge states are always readable on the display of the PLC.

Principle of the rule

Balancers use two methods to regulate the cell voltage. So it is possible on the one hand to charge cells with low state of charge with a higher current. The most commonly chosen method is to apply the highest voltage cell with a resistor that absorbs the excess energy.

optocoupler

With the help of an optocoupler, the signal diodes of the balancer can be evaluated and transmitted to the control unit. It is important that with a defective rechargeable battery an interference signal is immediately passed on to the PLC. It should then be displayed in the display of the respective broken battery. A simple exchange of the battery pack then ensures the additional functionality.

Optocouplers consist of a light emitting diode, which acts as a transmitter and a photodiode or a phototransistor as a receiver. Both are welded in an opaque housing. Depending on the design, an amplifier can be connected downstream in the optocoupler in order, for example, to control a relay directly. For the galvanic isolation of the input and output circuits, it is often used in other electronic components. The solid state relay of the emergency power supply system is also controlled by means of a built-in optocoupler.

Control unit PLC (Siemens LOGO)

The Siemens LOGO was for small control systems such as shutters. Lighting or home installations developed. Due to their large number of special functions, the LOGO can also be used to solve complicated automations. It is inexpensive, small, easily programmable, expandable at any time, complies with DIN standard 43880 and can be mounted on a DIN rail. The programming of the software of the control unit can be adapted to the respective application with little effort.

Up to fifty messages can be shown on the display. It can be seen at a glance whether the batteries are defective, charged or discharged, or the system is currently in standby mode or executing a command. An overview of the program flow is clearly visible.

Combined wind solar power plant

The 12V lead-acid battery should be charged via several sources. One of the most important things is the power supply of the control unit. A wind-solar power plant acquired in commercial trade enables a charge independent of the grid. If the system is out of operation due to a fault, a charge from the network is being considered.

A separate charge controller with LCD screen and user display functions takes over the charge control of the lead acid battery. Two independent battery banks can be connected and charged. The various measurement data are tapped on a digital LCD display.

Lead acid battery with 70Ah

The lead-acid battery is used to charge the individual lithium-polymer batteries and to supply power to the Siemens LOGO control unit. To avoid overcharging the battery, a special charge controller is used. The battery will not only turn off *** ·· ...

Cost reasons, but he is best suited for the execution of a combined wind-solar power plant. The lead battery used in the embodiment is a maintenance-free 70Ah gel battery. The individual cells are welded, only one pressure relief valve allows the escape of gases, which can occur, for example, in case of overcharging. The gel-like consistency of the battery is achieved by the addition of silica to sulfuric acid. One advantage is that Gclakkus emit much less oxygen than conventional lead-acid batteries. This eliminates a regular maintenance and filling of the battery. Disadvantages occur only in case of improper overcharging of the batteries, which has a dehydration of the battery.

Entkonneldiode

The decoupling diode has an input (anode) and an output (cathode). A current flow is only possible from the anode to the cathode. So only in one direction. The diode is located at the output in such a way that no unwanted current flow can destroy or impair the own electronics. The influence of external voltages can be avoided.

Spannunusüberwachungsrelais

The voltage monitoring relay is designed to protect against over-discharge of the twenty-one series-connected lithium polymer batteries. A deep discharge of the batteries can reduce the lifetime of the individual cells many times or even destroy them.

The relay is only ready for operation when the PLC switches to active mode. If there is a deep discharge and the relay drop, a signal is forwarded to the control unit. The active mode is canceled in this case and can only be put back into operation after the batteries have been charged. The relay must be manually set to the required voltage value via a controller on the component itself.

Solid State Relays (SSR)

The SSR is a solid state relay that enables the switching of very high DC voltages. One reason for selecting the device is the small size compared to a comparable contactor and the advantage that no coil current costs the battery capacity. For Solid State Relays, the switching is not realized as usual with a spring contact, but with 1GBT (Insulated Gate Bipolar Transistor). The galvanic separation of different voltage levels is carried out by an optocoupler, which is cinched in the housing. cooler

The electronic components are cooled by a cooler. When electrical equipment is driving or switching high currents, cs comes to a high temperature. If a heat sink alone is not sufficient, there is the possibility of additional cooling by means of fans. The decoupling diodes and the solid-state relay are mounted on the heat sink. The cooler is mounted on the rail of the rear wall of the housing.

The contactor

Special requirements are placed on the contactor. Since the coil voltage is twelve full and the coil current should be as low as possible in order not to unnecessarily limit the battery capacity, a special model of a contactor is selected, which accommodates no more than 230 mA coil current.

Terminal blocks Terminal blocks that are fixed to a DIN rail were used for clear and always traceable wiring. These can be numbered and arranged as desired. Thus, a wiring plan can be created at any time based on the number sequence.

Neozed fuse element

The fuse elements of the Neozed elements are designed to be used for both DC and AC (AC 500V / DC 250V). Due to their design, the fuse is a reliable protection against overcurrent and short circuit currents. Gluing the contacts, as may be the case with circuit breaker is excluded.

If the rated current is exceeded, the fusible wire in the fuse will burn depending on the current-time behavior. The characteristic diagram of the manufacturer can be traced very exactly as soon as the fuse triggers.

Board design object:

In order to keep the power consumption of the circuit as low as possible due to the battery operation, it is not possible to use any number of expansion modules for the PLC. To achieve the twenty-two necessary output states, 5 bits of digital data are sufficient. A daisy-chained 4-bit Demultiplexer (Demux) can convert up to 32 channels from the bit pattern of five LOGO relay outputs at the output of the Demux.

The states 0 and 16 (0 of the 2nd block) are not used because in the event of a PLC failure undefined states can arise. For example, with state 0 on all inputs, the zeroth output is already active.

By using the Demux, a hardware lock is achieved that reliably prevents the simultaneous switching on of two or more relays. The simultaneous switching on of several batteries would lead to impermissibly high short-circuit currents via the charging lines, which would destroy the relays, the batteries and the printed circuit board.

The cascading of two blocks is realized by means of an inverter and one of the enable inputs (active LOW). Accordingly, depending on the input signal at bit 5, only one block is active at a time.

The second enable line is used to switch off all outputs in general. The shutdown of all outputs is necessary for bit pattern changes due to runtime differences of the LOGO relay outputs. In Bercy mode and Sleep mode, the second enable line shuts off all outputs as a precaution and to reduce power consumption.

The voltage supply of the digital part of the circuit and the relay contacts of the LOGO is handled by a standard 1A / 5V voltage regulator. The wiring corresponds to the standard application according to the data sheet. No high currents are to be expected inside the circuit, nevertheless the voltage regulator is cooled with a finger heat sink. The 5V voltage is supplied through a fuse on the terminal block to allow the supply of any peripheral devices (protocol converter).

The output component is a four-pole power relay with 4A / 250V AC, and 3A / 30V DC contact switching capacity. This relay type is sufficient for normal operation with charging currents of maximum 1.5 Λ safely. With a coil resistance of 1.45 Ω, the very small coil current of 8 mA results. By choosing the relays, consideration is given to energy-saving battery operation.

As a display instrument on the print, low-power LEDs are provided at each relay and at the outputs. The Vorwiderständc are calculated so that at maximum operating voltage of 14.5V (charging voltage), the LEDs record a maximum of 2mA current. These components are designed for the lowest possible power consumption.

All electronic components are pluggable with precision sockets and easy to replace. The relays are also pluggable mounted on special relay sockets to allow easy replacement in the event of a defect.

casing

The housing has been selected to match existing equipment. The hardware parts were housed in a five-height housing, suitable for each 19-inch cabinet. The housing is designed to have enough space for all hardware parts, the control unit is externally operable and easy to see, there is sufficient ventilation and it is possible to expand any possible components at any time. On the rear wall of the housing several hardware parts are mounted by top hat rail, while on the front panel, the display of the control unit is arranged.

An exchange of individual battery packs should be possible with a few Hangriffen. The purpose of this is an aluminum construction, which is shown in Fig. 5 with the board arranged thereon and the compartments for twenty-one LIPO battery packs. The aluminum construction is designed so that an exchange of the batteries at any time with a few simple steps is possible. Should a battery pack become bloated or explode due to a defect, the individual braces are used to protect the other batteries. The board is mounted on the base plate by means of spacers. The central arrangement has been chosen so that the short connection lines of the batteries can be connected directly to the PCB module. ».1 * 9 * - .. ·

Substation (1) Reserve reserve (2) Emergency power Supply system (3) Communication connection (4) Power distribution board (5) Power station (6) Femwirkanlagen (7) Protection devices (8) Inverter (9)

Additional battery (10)

Control unit (11)

Charging unit (12) Decoupling diode (13)

Balancer (14)

Control battery (15) High-voltage network 16 Transfer points 17 Dome transformer 18 Mains group 19a-19c Substation 20 Network operators 21 Transmission system operators 22 Switches 23 Diode 24

Wind solar power plant 25

FOR D. APPLICATION) i | 3 1. AÖfi. 2010 L PAizM,

^ DIPL. INFO / PETER ITZE

Claims (13)

PATENT ATTORNEY • 1060 WIEN, AMERLINGSTRASSE 8 CHWALLAGASSE 4 • * «» «· *« * 4 »... Wienstrom GmbH NOOl I261 / Wp Claims 1. Emergency power supply system (3) for remotely controlled restoration of internal voltage in a substation (1) after a power failure in which the internal power reserve (2) of the substation (1) has been exhausted, characterized in that the emergency power supply system (3) comprises a control unit (11), a charging unit (12) and an additional battery (12) charged by the charging unit (12). 10), wherein the additional battery (10) has a nominal voltage which corresponds to the intrinsic demand voltage of the domestic power plant (6) of the substation (1), wherein the control unit (11) via a communication link (4) is controllable, and wherein a power distributor ( 5) of the domestic power plant (6) for restarting the substation (1) with the voltage of the additional battery (10) can be acted upon. 2. emergency power supply system (3) according to claim 1, characterized in that the additional battery (10) has a LIPO battery with one or more cells. 3. emergency power supply system (3) according to claim 2, characterized in that the charging unit (12) for charging the individual cells of the LIPO battery has a balancer (14), wherein voltage monitoring relay can be provided to prevent a total discharge of the cells. 4. emergency power supply system (3) according to any one of the preceding claims, characterized in that the individual cells of the auxiliary battery (10) are arranged separated by partitions. 5. emergency power supply system (3) according to any one of the preceding claims, characterized in that the power supply of the control unit (11) is provided a Steuerstromakku (15). 6. emergency power supply system (3) according to any one of the preceding claims, characterized in that the Audaden the additional batteries (10) and optionally the Steuerstromakkus (15) a wind, a solar or a combined wind-solar power plant is provided. 7. emergency power supply system (3) according to any one of the preceding claims, characterized in that the communication link (4) is a, preferably guided over a fiber optic cable, wired connection or a radio link. 8. emergency power supply system (3) according to any one of the preceding claims, characterized in that the output of Notstromversorgungssytems (3) for F.igenbedarfsanlage (6) is protected by a Entkoppeldiodc (13). 9. emergency power supply system (3) according to any one of the preceding claims, characterized in that for connecting the additional battery (10) is provided a solid state relay. 10. A method for providing a standby voltage in substations after Stromausfallcn, in which the intrinsic power reserve of the substation was exhausted, by means of a preferably remotely controlled emergency power system, the method comprising the following steps on the emergency power supply system: maintaining the charge of a spare battery during normal operation of the substation; after a power failure in which the internal reserve of the substation was exhausted. Receiving a turn-on signal via a communication link; and applying a power distribution of a Eigcnbedarfsanlage the substation with the intrinsic supply voltage of the auxiliary battery, the power distributor in particular the Femwirkanlagen and the protective devices of the substation supplied with energy. 11. The method according to claim 10, characterized in that the switch-on signal, preferably via a glass fiber line, is femübermittelt. 12. The method according to claim 10 or 11, characterized in that for Aufrechtcrhalten the charge of the additional battery, a balancer is provided. 13. The method according to any one of claims 10 to 12, characterized in that the state of charge of the additional batteries is monitored continuously and that error messages are indicated when detecting defective batteries.